CN107020951B - Splitter - Google Patents

Abstract

The present invention provides a transfer case that can shorten the distance between the output shaft and the second shaft to miniaturize the transfer case compared to the prior art. When the nut member (92) is rotationally driven by the motor (84), the nut member (92) moves in the direction of the first axis C1 of the rear wheel side output shaft (44), and the nut member (92) moves in the direction of the first axis C1 of the output shaft (44) on the rear wheel side. The linear motion is transmitted to the front-wheel drive clutch (50) via the first transmission mechanism (88a). Therefore, since the linear motion of the nut member (92) of the screw mechanism (86) provided on the rear wheel side output shaft (44) is transmitted to the front wheel drive clutch (50) via the first transmission mechanism (88a), Therefore, it is not necessary to provide a ball cam and a lead screw for adjusting the transmission torque of the clutch as in the prior art, so that the distance between the rear wheel side output shaft (44) and the fork shaft (102) can be appropriately shortened.

Description

Splitter

technical field

The present invention relates to a technique for reducing the size of a transfer case compared to the prior art in a transfer case equipped with a high-low-speed switching mechanism that shifts the rotation of an input shaft and transmits it to an output shaft , and a clutch that transmits or cuts off part of the power of the output shaft to the output member, or adjusts the transmission torque transmitted to the output member.

Background technique

For example, there is known a transfer case including an input shaft; an output shaft; a high-low speed switching mechanism that shifts the rotation of the input shaft and transmits it to the output shaft; and an output member that outputs power The target is distinguished from the output shaft; the clutch, which transmits or cuts off part of the power of the output shaft to the output member, or adjusts the transmission torque to the output member. The transfer case described in Patent Document 1 is such a transfer case. In the transfer case for a four-wheel drive vehicle described in Patent Document 1, the switching operation of the high-low-speed switching mechanism and the adjustment of the transmission torque of the clutch are performed by a single motor (actuator). In the transfer case of the above-mentioned Patent Document 1, as a conversion mechanism for converting the rotation of the motor into linear motion, a drum cam is used for the switching operation of the high-low speed switching mechanism, and a ball cam and a lead screw are used for the switching operation. For the adjustment of the transmission torque of the clutch.

prior art literature

Patent Literature

Patent Document 1: Specification of US Patent Application Publication No. 2007/0251345

SUMMARY OF THE INVENTION

The problem to be solved by the invention

However, in the transfer case of the above-mentioned Patent Document 1, the drum cam and the lead screw are actuated by rotationally driving the second shaft arranged in parallel with the output shaft by a motor, but in order to To obtain a predetermined transmission torque in the clutch, it is necessary to set the length of the lead screw provided between the output shaft and the second shaft to a predetermined value or more. The distance between them will become longer and the transfer case will become larger.

The present invention has been made on the background of the above-mentioned facts, and an object thereof is to provide a transfer case which can be made smaller in size by reducing the distance between the output shaft and the second shaft as compared with the conventional transfer case. Shifter.

methods for solving problems

The gist of the first invention is to include: (a) an input shaft; an output shaft; a high-low speed switching mechanism that shifts the rotation of the input shaft and transmits it to the output shaft; and an output member that sets the output target of the power Different from the output shaft; a clutch, which transmits or cuts off part of the power of the output shaft to the output member, or adjusts the transmission torque transmitted to the output member, the characteristics of the transfer case (b) an actuator, and (c) a screw mechanism that surrounds the output shaft with a screw member of either one of a screw shaft member and a nut member that are screwed to each other by using the actuator. The nut member moves in the direction of the axis of the output shaft by rotating and driving the shaft center; (d) a first transmission mechanism, which transfers the linear motion of the nut member in the screw mechanism to the direction of the axis of the output shaft. The clutch transmits; (e) a cam engagement member connected to the second shaft and the one of the second shafts arranged in parallel with the output shaft and supported so as to be movable in the axial direction. On one side of the screw member; (f) a drum cam, which is connected to the second shaft and the other side of the one screw member, and has a cam groove that engages with the cam engaging member, And by rotating around the axis of the output shaft of the one threaded member, relative to the cam engagement member, it moves relative to the axis of the second shaft; (g) second transmission Mechanism having the second shaft for switching the movement of the cam engaging member or the drum cam in the axial direction of the second shaft to the high and low speed via the second shaft The mechanism performs transmission, and the high-low-speed switching mechanism is switched between the high-speed side gear stage and the low-speed side gear stage.

In addition, the gist of the second invention is that (a) the cam groove formed in the drum cam is provided with an inclined cam groove portion and a switching cam groove portion, the inclined cam groove portion having a direction opposite to the output shaft The axis of the output shaft or the axis of the second shaft extends in a direction inclined, and the switching cam groove portion extends in a direction perpendicular to the axis of the output shaft or the axis of the second shaft, and is used to adjust the transmission torque transmitted to the output member, (b) by the switching cam groove portion, no matter how the one threaded member rotates around the axis of the output shaft, the The relative movement of the cam engaging member and the drum cam in the axial center direction of the second shaft.

Furthermore, the gist of the third invention is that a first switching cam groove portion serving as the switching cam groove portion is provided at one end portion of the inclined cam groove portion, and the other end of the inclined cam groove portion is provided with a first switching cam groove portion as the switching cam groove portion. The portion is provided with a second switching cam groove portion as the switching cam groove portion.

In addition, the gist of the fourth invention is that (a) the cam groove formed in the drum cam is provided with an inclined cam groove portion, the inclined cam groove portion extending toward the axis of the output shaft or (b) when the one threaded member is rotated around the axis of the output shaft by the actuator, passing through the inclined cam groove part, the drum cam is moved relative to the cam engagement member on the second shaft by a movement amount larger than the movement amount of the nut member in the axial center direction of the output shaft relative movement in the direction of the axis.

Moreover, the gist of the fifth invention is that (a) the cam engaging member is connected to the second shaft, and (b) the drum cam is connected to the one screw member.

In addition, the gist of the sixth invention is that, when the one screw member is the nut member, the nut member is supported so as to be rotatable around the axis of the output shaft, and the screw shaft is rotatably supported. A member is supported so that it cannot move in the axial center direction of the said output shaft, and cannot rotate about the axial center of the said output shaft.

Furthermore, the gist of the seventh invention is that, when the one screw member is the screw shaft member, the nut member is supported so as not to be rotatable around the axis of the output shaft, and the screw The shaft member is supported so as to be immovable in the axial center direction of the output shaft and to be rotatable around the axial center of the output shaft.

Further, the gist of the eighth invention is that the output shaft support bearing which rotatably supports the end portion on the drum cam side among the both end portions of the output shaft, is provided in the drum cam. The length of the output shaft in the axial direction of the output shaft is arranged on the inner side of the drum cam.

Further, the gist of the ninth invention is that (a) the actuator is connected to the nut member of the screw mechanism via a worm gear mechanism, and (b) the cam engagement member is connected to the In the worm wheel of the worm gear mechanism, (c) the drum cam is coupled to the second shaft, and (d) the drum cam is formed in a partial cylindrical shape along the outer circumference of the worm wheel.

Furthermore, the tenth aspect of the present invention resides in that the second transmission mechanism includes a waiting mechanism for moving the cam engagement member in the axial center direction of the second shaft via a spring member or the The movement of the drum cam in the axial center direction of the second shaft is transmitted to the second shaft.

Moreover, the gist of the eleventh invention is that the nut member is screwed to the threaded shaft member via a plurality of balls.

Furthermore, the gist of the twelfth invention is that (a) the clutch adjusts the transmission torque transmitted to the output member, and (b) the clutch is a single-plate clutch or a multi-plate clutch.

Invention effect

According to the first aspect of the invention, there is provided: an actuator; and a screw mechanism that surrounds the shaft of the output shaft with the screw member of either one of the screw shaft member and the nut member that are screwed to each other by the actuator. The nut member is moved in the direction of the axis of the output shaft, and the nut member is rotationally driven; and a first transmission mechanism transmits the linear motion of the nut member in the screw mechanism to the clutch. transmission; a cam engagement member connected to one of the second shaft and the one screw member, which are arranged in parallel with the output shaft and are supported so as to be movable in the axial direction; a drum A cam is connected to the other of the second shaft and the one threaded member, has a cam groove that engages with the cam engaging member, and passes around the one threaded member The axis of the output shaft rotates to move relative to the cam engaging member in the direction of the axis of the second shaft; the second transmission mechanism has the second shaft and transfers the The movement in the axial center direction of the second shaft of the cam engaging member or the drum cam is transmitted to the high-low-speed switching mechanism via the second shaft, and the high-low speed switching mechanism is switched. The mechanism is switched between the high-speed side gear stage and the low-speed side gear stage. Therefore, when the one threaded member is driven to rotate around the axis of the output shaft by the actuator, the nut member moves in the direction of the axis of the output shaft, and the nut moves in the direction of the axis of the output shaft. Linear motion of the components is transmitted to the clutch via the first transmission mechanism. Further, when the one screw member is driven to rotate around the axis of the output shaft by the actuator, the drum cam is positioned on the shaft of the second shaft with respect to the cam engagement member. relative movement in the center direction, so that the movement of the cam engaging member on the second shaft or the movement of the drum cam on the second shaft is transmitted to the second shaft via the second transmission mechanism. The high and low speed switching mechanism. Accordingly, since the linear motion of the nut member of the screw mechanism provided on the output shaft is transmitted to the clutch via the first transmission mechanism, it is not necessary to provide a ball cam as in the related art The lead screw is used, for example, to adjust the transmission torque of the clutch, so that the distance between the output shaft and the second shaft can be appropriately shortened, and the transfer case can be miniaturized.

Further, according to the second aspect of the invention, the cam groove formed in the drum cam is provided with an inclined cam groove portion and a switching cam groove portion, the inclined cam groove portion being directed toward a shaft relative to the output shaft The switching cam groove portion extends in a direction perpendicular to the axis of the output shaft or the axis of the second shaft, and is used for The transmission torque transmitted to the output member is adjusted, and the switching cam groove portion prevents the cam engagement member from interacting with the cam engagement member regardless of how the one screw member rotates around the axis of the output shaft. The relative movement of the drum cam in the axial direction of the second shaft. Therefore, when the cam engaging member is engaged with the inclined cam groove portion of the cam groove formed on the drum cam, when the one screw member is caused to surround the output shaft, When the shaft center is driven to rotate, the drum cam moves relative to the cam engagement member in the direction of the shaft center of the second shaft, whereby the gear stage of the high-low-speed switching mechanism is switched. In addition, when the cam engaging member is engaged with the switching cam groove portion of the cam groove, the cam is prevented regardless of how the one screw member rotates around the axis of the output shaft. The relative movement of the engaging member and the drum cam in the axial center direction of the second shaft allows the nut member to move toward any position while maintaining the state of the gear stage of the high-low-speed switching mechanism. The axis direction of the output shaft is moved so that the linear motion of the nut member is transmitted to the clutch via the first transmission mechanism. Thereby, the transmission torque transmitted to the output member can be adjusted by the clutch while maintaining the state of the gear stage of the high-low-speed switching mechanism.

Further, according to the third aspect of the invention, a first switching cam groove portion as the switching cam groove portion is provided at one end of the inclined cam groove portion, and the other end of the inclined cam groove portion is provided with a first switching cam groove portion as the switching cam groove portion. The portion is provided with a second switching cam groove portion as the switching cam groove portion. Therefore, when the cam engagement member is engaged with the first switching cam groove portion or the second switching cam groove portion by rotating the one screw member around the axis of the output shaft , the high-low-speed switching mechanism can be switched to the high-speed side gear stage or the low-speed side gear stage. Furthermore, even if the one screw member surrounds the axis of the output shaft in a state where the cam engaging member is engaged with the first switching cam groove portion or the second switching cam groove portion However, no matter how the one threaded member rotates around the axis of the output shaft, the cam engaging member and the drum cam are prevented from being in contact with each other in the direction of the axis of the second shaft. Because of relative movement, the high-low-speed switching mechanism can be switched to the high-speed side gear stage or the low-speed side gear stage state, and the transmission torque transmitted to the output member through the clutch can be adjusted. adjust.

Further, according to the fourth aspect of the invention, the cam groove formed in the drum cam is provided with an inclined cam groove portion, the inclined cam groove portion extending toward the axis of the output shaft or the first The shaft centers of the two shafts extend in an inclined direction, and when the one screw member is rotated about the shaft center of the output shaft by the actuator, the inclined cam groove portion causes the drum to rotate. The cam engages with the cam engaging member in the axial direction of the second shaft by a larger movement amount than the movement amount of the nut member in the axial center direction of the output shaft. relative movement. Therefore, the responsiveness of switching between the high-speed-side gear stage and the low-speed-side gear stage of the high-low-speed switching mechanism is the same as, for example, in the axial direction of the output shaft by the nut member in the screw mechanism. The movement of the high-speed side gear stage and the low-speed side gear stage are greatly improved.

Further, according to the fifth invention, the cam engagement member is coupled to the second shaft, and the drum cam is coupled to the one screw member. Therefore, in order to perform the switching operation of the high-low-speed switching mechanism, the drum cam is coupled to the one screw member of the screw mechanism provided on the output shaft. Accordingly, since it is not necessary to provide the drum cam on the second shaft, it is not necessary to provide the drum cam on the second shaft as in the conventional transfer case in which the drum cam is provided on the second shaft. The drum cam on the second shaft does not interfere with the high-low speed switching mechanism and the clutch provided on the output shaft, so that the gap between the output shaft and the second shaft can be shortened appropriately the distance.

Further, according to the sixth invention, when the one screw member is the nut member, the nut member is rotatably supported around the axis of the output shaft, and the screw shaft is A member is supported so that it cannot move in the axial center direction of the said output shaft, and cannot rotate about the axial center of the said output shaft. In this way, when the one screw member is the nut member, when the nut member is rotationally driven by the actuator, the nut member is directed toward the axis of the output shaft. direction so that the linear motion of the nut member is transmitted to the clutch via the first transmission mechanism. When the nut member is driven to rotate by the actuator, the drum cam connected to the nut member rotates, and the cam engaging member that engages with the cam groove rotates By moving in the axial direction of the second shaft, the linear motion of the cam engagement member is transmitted to the high-low-speed switching mechanism via the second transmission mechanism.

Further, according to the seventh invention, when the one screw member is the screw shaft member, the nut member is supported so as not to be rotatable around the axis of the output shaft, and the screw The shaft member is supported so as to be immovable in the axial center direction of the output shaft and to be rotatable around the axial center of the output shaft. In this way, when the one threaded member is the threaded shaft member, when the threaded shaft member is rotationally driven by the actuator, the nut member is placed in the position of the output shaft. By moving in the axial direction, the linear motion of the nut member is transmitted to the clutch via the first transmission mechanism. Further, when the screw shaft member is rotationally driven by the actuator, the drum cam connected to the screw shaft member is rotated, and the cam engaged with the cam groove is rotated. The engaging member moves in the axial direction of the second shaft, so that the linear motion of the cam engaging member is transmitted to the high-low-speed switching mechanism via the second transmission mechanism.

Further, according to the eighth invention, due to the output shaft support bearing rotatably supporting the end portion on the drum cam side among the both end portions of the output shaft, the drum cam Since the output shaft is arranged inside the drum cam within the range of the length in the axial center direction, the length of the dimension in the axial center direction of the output shaft of the transfer case can be appropriately shortened.

Further, according to the ninth invention, the actuator is connected to the nut member of the screw mechanism via the worm gear mechanism, and the cam engagement member is connected to the worm wheel of the worm gear mechanism, so The drum cam is connected to the second shaft, and the drum cam is formed in a partial cylindrical shape along the outer circumference of the worm wheel. Therefore, since the drum cam and the worm wheel can be disposed adjacent to each other, the distance between the output shaft and the second shaft can be appropriately shortened.

Further, according to the tenth invention, the second transmission mechanism includes a waiting mechanism for moving the cam engagement member in the axial center direction of the second shaft via a spring member or the The movement of the drum cam in the axial center direction of the second shaft is transmitted to the second shaft. Therefore, at the time of switching between the high-speed side gear stage and the low-speed side gear stage of the high-low-speed switching mechanism, the shock generated by the switching of the high-low-speed switching mechanism passes through the spring member of the waiting mechanism and absorbed.

Further, according to the eleventh invention, the nut member is screwed to the threaded shaft member via a plurality of balls. Therefore, since the relative rotation between the nut member and the threaded shaft member becomes smooth, the required electric power of the actuator during operation is stably reduced.

According to the twelfth invention, the clutch adjusts the transmission torque transmitted to the output member, and the clutch is a single-plate clutch or a multi-plate clutch. Therefore, the continuously variable control of the transmission torque of the clutch can be implemented, and the driving force distribution control between the front wheels and the rear wheels can be further implemented according to the driving conditions.

Description of drawings

FIG. 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is a diagram illustrating a main part of a control system for implementing various controls in the vehicle.

FIG. 2 is a cross-sectional view illustrating a schematic configuration of a transfer case, and is a view showing a mode for setting a 4WD running state in a high-speed side gear stage.

FIG. 3 is a frame diagram illustrating a schematic configuration of a transfer case.

4 is a cross-sectional view illustrating a schematic configuration of a transfer case, and is a view showing a mode for a 4WD running state with a low-speed side gear stage set to a 4WD lock state.

FIG. 5 is an enlarged view of FIG. 2 for explaining a drum cam provided in the transfer case.

6 is a cross-sectional view taken along line VI-VI of FIG. 5 , FIG. 6( a ) is a view showing the position of a cam engagement member connected to the fork shaft when the fork shaft is at the high gear position, and FIG. 6 ( c) is a diagram showing the position of the cam engagement member connected to the fork shaft when the fork shaft is at the low gear position, and FIG. 6(b) is a diagram showing the switching of the fork shaft from the high gear position to the low gear position A diagram showing the position of the cam engagement member connected to the fork shaft.

7 is a cross-sectional view illustrating a schematic configuration of a transfer case according to another embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7 .

FIG. 9 is an enlarged view in which a part of the transfer case of FIG. 7 is enlarged.

10 is a cross-sectional view taken along line X-X of FIG. 9 , FIG. 10( a ) is a diagram showing the position of a drum cam connected to the fork shaft when the fork shaft is at a high gear position, and FIG. 10( c ) is a diagram showing the fork shaft Figure 10(b) is a diagram showing the position of the drum cam connected to the fork shaft when the shaft is in the low gear position, and Fig. 10(b) is a diagram showing the fork shaft being connected to the fork shaft while the fork shaft is being switched from the high gear position to the low gear position Diagram of the position of the drum cam.

11 is a diagram illustrating a schematic configuration of a transfer case according to another embodiment of the present invention, and is an enlarged view showing a part of the transfer case.

12 is a cross-sectional view taken along line XII-XII of FIG. 11 , and is a diagram showing the position of the drum cam connected to the fork shaft when the fork shaft is at the high gear position.

13 is a cross-sectional view taken along line XII-XII of FIG. 11 , FIG. 13( a ) is a diagram showing the position of the drum cam connected to the fork shaft when the fork shaft is at the high gear position, and FIG. 13( c ) is A diagram showing the position of the drum cam connected to the fork shaft when the fork shaft is at the low gear position, and FIG. 13(b) is a diagram showing the position of the drum cam connected to the fork when the fork shaft is being switched from the high gear position to the low gear position. Diagram of the position of the drum cam on the shaft.

14 is a cross-sectional view taken along line XII-XII of FIG. 11 , and is a diagram showing the position of the drum cam connected to the fork shaft when the fork shaft is at the low gear position.

15 is a cross-sectional view taken along line XII-XII of FIG. 11 , and FIGS. 15( a ) and 15 ( c ) are diagrams showing the position of the drum cam connected to the fork shaft when the fork shaft is at the low gear position, Fig. 15(b) shows that the spring member of the waiting mechanism included in the transfer case is compressed and the urging force of the spring member is compressed during the movement of the drum cam from Fig. 15(a) to Fig. 15(c). Diagram of the state applied to the drum cam.

16 is a cross-sectional view taken along line XII-XII of FIG. 11 , FIG. 16( a ) is a view showing the position of the drum cam connected to the fork shaft when the fork shaft is at the low gear position, and FIG. 16( c ) is a Figure 16(b) is a diagram showing the position of the drum cam connected to the fork shaft when the fork shaft is at the high gear position, and FIG. 16(b) shows that the fork shaft is being switched from the low gear position to the high gear position. Diagram of the position of the drum cam on the fork shaft.

17 is a cross-sectional view taken along line XII-XII of FIG. 11 , FIGS. 17( a ) and 17 ( c ) are views showing the position of the drum cam when the fork shaft is at the high gear position, and FIG. 17( b ) is In the movement of the drum cam from FIG. 17( a ) to FIG. 17( c ), the spring member of the waiting mechanism included in the transfer case is compressed and the urging force of the spring member is applied to the drum cam. state diagram.

18 is a frame diagram illustrating a schematic configuration of a transfer case according to another embodiment of the present invention.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in the following Examples, the drawings are simplified or modified as appropriate, and the dimensional ratios, shapes, and the like of each part are not necessarily drawn accurately.

Example 1

FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and is a diagram illustrating a main part of a control system for implementing various controls of the vehicle 10 . In FIG. 1 , a vehicle 10 includes an engine 12 as a driving force source, left and right front wheels 14L, 14R (referred to as front wheels 14 unless otherwise distinguished), and left and right rear wheels 16L, 16R (in the Unless otherwise distinguished, it is referred to as a rear wheel 16), a power transmission device 18 that transmits the power of the engine 12 to the front wheel 14 and the rear wheel 16, respectively. The rear wheel 16 is a main drive wheel as a drive wheel both during two-wheel drive (2WD) running and during four-wheel drive (4WD) running. The front wheels 14 are driven wheels when running in 2WD, and are auxiliary driving wheels which are driving wheels when running in 4WD. Vehicle 10 is a front-engine rear-wheel drive (FR) based four-wheel drive vehicle.

The power transmission device 18 includes a transmission 20 connected to the engine 12 , a transfer case 22 for a four-wheel drive vehicle that is a power distribution device for front and rear wheels connected to the transmission 20 , and a transfer case 22 connected to the transmission 20 , respectively. The front vehicle transmission shaft 24 and the rear vehicle transmission shaft 26 on the gear 22, the differential gear device 28 for the front wheels connected to the front vehicle transmission shaft 24, and the rear wheel differential gear connected to the rear vehicle transmission shaft 26 Gear unit 30, left and right front wheel axles 32L, 32R (referred to as front wheel axles 32 unless otherwise distinguished) connected to front wheel differential gear unit 28, connected to rear wheel axles 32L and 32R Left and right rear wheel axles 34L and 34R (referred to as rear wheel axles 34 unless otherwise distinguished) and the like on the differential gear device 30 are provided. In the power transmission device 18 configured in this way, the power of the engine 12 transmitted to the transfer case 22 via the transmission 20 is transmitted from the transfer case 22 to the rear vehicle propeller shaft 26 and the differential gear for rear wheels in this order. The power transmission path on the rear wheel side of the device 30 , the rear wheel axle 34 and the like is transmitted to the rear wheel 16 . In addition, a part of the power of the engine 12 transmitted to the rear wheel 16 is distributed to the front wheel 14 via the transfer case 22 , and passes through the front vehicle propeller shaft 24 , the differential gear unit 28 for front wheels, and the front wheel axle 32 in this order. It is transmitted to the front wheel 14 through the same power transmission path on the front wheel side.

The differential gear device 28 for front wheels includes a front clutch 36 on the side of the front wheel axle 32R (that is, between the differential gear device 28 for front wheels and the front wheel 14R). The front clutch 36 is an electrically (electromagnetically) controlled meshing clutch that selectively connects or disconnects the power transmission path between the front wheel differential gear device 28 and the front wheel 14R. In addition, the front clutch 36 may be provided with a synchronizing mechanism (synchronizing mechanism).

2 to 4 are diagrams illustrating a schematic configuration of the transfer case 22 . FIGS. 2 and 4 are cross-sectional views of the transfer case 22 , and FIG. 3 is a frame diagram of the transfer case 22 . In FIGS. 2 to 4 , the transfer case 22 includes a transfer case 40 as a non-rotating member. The transfer case 22 includes an input shaft 42 rotatably supported by the transfer case 40 around a common first axis (axial center) C1 , and output power to the rear wheels 16 serving as first left and right drive wheels output shaft (output shaft) 44 on the rear wheel side; output power to the front wheels 14 as the second left and right drive wheels, that is, the output target of the power is differentiated from the geared reel-shaped drive gear of the output shaft 44 on the rear wheel side (output member) 46; a high-low speed switching mechanism 48 serving as a sub-transmission that shifts the rotation of the input shaft 42 and transmits it to the rear wheel side output shaft 44; The front wheel drive clutch (clutch) 50 is a multi-plate friction clutch (multi-plate clutch) that adjusts the torque, that is, transmits a part of the power of the rear wheel side output shaft 44 to the drive gear 46 . The input shaft 42 and the rear wheel side output shaft 44 are each supported by the transfer case 40 via a pair of first support bearings 71 and second support bearings (output shaft support bearings) 73 so as to be rotatable concentrically with each other, The drive gear 46 is concentrically supported via the third support bearing 75 so as to be rotatable relative to the rear wheel side output shaft 44 . That is, the input shaft 42 , the rear-wheel-side output shaft 44 , and the drive gear 46 are respectively supported by the transfer case 40 so as to be rotatable around the first axis C1 . In addition, in the rear wheel side output shaft 44 , the rear wheel side output shaft 44 is connected to the rear wheel side output shaft 44 by the bearing 77 arranged between the rear end portion of the input shaft 42 and the front side end portion of the rear wheel side output shaft 44 . The front end portion of the rear wheel side output shaft 44 is rotatably supported, and the rear side end portion of the rear wheel side output shaft 44 , that is, the two end portions of the rear wheel side output shaft 44 , is supported by the second support bearing 73 . The end portion on the side of the drum cam 100 described later is rotatably supported.

As shown in FIGS. 2 to 4 , the transfer case 22 includes a front wheel side output shaft 52 , a front wheel side output shaft 52 and a front wheel side output shaft around a common second axis line C2 parallel to the first axis line C1 in the transfer case 40 . 52 is a toothed reel-shaped driven gear 54 provided integrally. Further, the transfer case 22 includes a front wheel drive chain 56 wound between the drive gear 46 and the driven gear 54 , and a 4WD lock as a dog clutch integrally connected to the rear wheel side output shaft 44 and the drive gear 46 . stop mechanism 58.

The input shaft 42 is connected to an output shaft (not shown) of the transmission 20 via a joint, and is rotationally driven by a driving force (torque) input from the engine 12 via the transmission 20 . The rear wheel side output shaft 44 is a main drive shaft connected to the rear vehicle propeller shaft 26 . The drive gear 46 is provided so as to be relatively rotatable around the rear wheel side output shaft 44 . The front wheel side output shaft 52 is an auxiliary drive shaft connected to the front vehicle propeller shaft 24 via a joint (not shown).

The transfer case 22 configured in this way adjusts the transmission torque to the drive gear 46 via the front-wheel drive clutch 50, and transmits the power transmitted from the transmission 20 only to the rear wheels 16, or also forwards. Wheel 14 makes the assignment. In addition, the transfer case 22 is locked by the 4WD lock mechanism 58 to a 4WD locked state that does not cause a difference in rotation between the rear vehicle propeller shaft 26 and the front vehicle propeller shaft 24, and a 4WD lock state that allows a rotational difference between the two. Any state switching in the locked state. Further, the transfer case 22 establishes any one of the high-speed gear stage (high-speed-side gear stage) H and the low-speed side gear stage (low-speed-side gear stage) L, and shifts the rotation from the transmission 20 and transmits it to the rear. That is, the transfer case 22 transmits the rotation of the input shaft 42 to the output shaft 44 on the rear wheel side via the high-low speed switching mechanism 48 , and sets the transmission torque via the front-wheel drive clutch 50 to zero and the 4WD lock mechanism When the 58 is released, the power transmission from the rear-wheel-side output shaft 44 to the front-wheel-side output shaft 52 is not performed, and on the other hand, torque or 4WD lock is transmitted via the front-wheel drive clutch 50 In a state where the stopper mechanism 58 is engaged, power is transmitted from the rear-wheel-side output shaft 44 to the front-wheel-side output shaft 52 via the drive gear 46 , the front-wheel drive chain 56 , and the driven gear 54 .

Specifically, the high and low speed switching mechanism 48 includes a single pinion type planetary gear device 60 and a high and low speed sleeve 62 . The planetary gear device 60 includes a sun gear S connected to the input shaft 42 so as not to rotate about the first axis line C1 with respect to the input shaft 42 , and the sun gear S is arranged substantially concentrically with respect to the sun gear S. The ring gear R, which is connected to the transfer case 40 in a non-rotatable manner about the first axis C1 , and the plurality of pinions P meshed with the sun gear S and the ring gear R are rotatable and can surround the sun. The carrier CA is supported so that the gear S revolves. Therefore, the rotational speed of the sun gear S is constant with respect to the input shaft 42 , and the rotational speed of the carrier CA is decelerated with respect to the input shaft 42 . In addition, the high-speed side gear teeth 64 are fixedly provided on the inner peripheral surface of the sun gear S, and the low-speed side gear teeth 66 having the same diameter as the high-speed side gear teeth 64 are fixedly provided on the carrier CA. The high-speed side gear teeth 64 are spline teeth related to the establishment of the high-speed side gear stage H that output the rotation of the input shaft 42 at the same speed. The low-speed-side gear teeth 66 are spline teeth related to the establishment of the low-speed-side gear stage L that output rotation on the low-speed side relative to the high-speed side gear teeth 64 . The high-low-speed sleeve 62 is splined to the rear-wheel-side output shaft 44 so as to be capable of relative movement in a direction parallel to the first axis line C1, and has a fork connecting portion 62a and outer peripheral teeth 62b, which are The outer peripheral teeth 62b are adjacent to and integrally provided with the fork coupling portion 62a, and the outer peripheral teeth 62b are respectively connected to the high speed side gear teeth 64 and the low speed side by moving in a direction parallel to the first axis C1 of the rear wheel side output shaft 44 Gear teeth 66 mesh. The rotation of the input shaft 42 at the same speed as the rotation of the input shaft 42 is transmitted to the rear wheel side output shaft 44 by meshing the high-speed side gear teeth 64 with the outer peripheral teeth 62b, and by meshing the low-speed side gear teeth 66 with the outer peripheral teeth 62b, the input The decelerated rotation of the shaft 42 is transmitted to the rear wheel side output shaft 44 . The high-speed side gear teeth 64 and the high-low speed sleeve 62 function as a clutch for the high-speed side gear stage forming the high-speed side gear stage H, and the low-speed side gear teeth 66 and the high-low speed sleeve 62 function as a low-speed side forming the low-speed side gear stage L. The gear stage functions as a clutch.

The 4WD lock mechanism 58 has lock teeth 68 fixedly provided on the inner peripheral surface of the drive gear 46 and a lock sleeve 70 capable of performing a first operation with respect to the output shaft 44 on the rear wheel side. The rear wheel side output shaft 44 is splined to the rear wheel side output shaft 44 so as to move in the direction of the axis C1 without relative rotation. The outer peripheral teeth 70 a mesh with the locking teeth 68 formed on the drive gear 46 by movement in the direction of the axis C1 . The transfer case 22 is formed by the engagement of the 4WD lock mechanism 58 in which the outer peripheral teeth 70a of the lock sleeve 70 mesh with the lock teeth 68, and the rear wheel side output shaft 44 and the drive gear 46 rotate integrally. 4WD locked state.

The high-low-speed sleeve 62 is provided in the space on the side of the drive gear 46 with respect to the first support bearing 71 provided on the input shaft 42 (more specifically, with respect to the planetary gear device 60 ). The lock sleeve 70 is independently provided in the space between the high-low-speed switching mechanism 48 and the drive gear 46 so as to be adjacent to the high-low-speed sleeve 62 . The transfer case 22 has between the high and low speed sleeves 62 and the locking sleeves 70 , respectively contacting the high and low speed sleeves 62 and the locking sleeves 70 , and connecting the high and low speed sleeves 62 and the locking sleeves to each other. The first spring 72 in a preloaded state is urged by the side separated from each other. The transfer case 22 is provided with the protrusions 44 a of the rear wheel side output shaft 44 between the drive gear 46 and the lock sleeve 70 , respectively, in contact with the lock sleeve 70 . 68 The second spring 74 in a preloaded state which is energized by the separation side. The biasing force of the first spring 72 is set to be larger than that of the second spring 74 . The convex portion 44 a is a convex portion of the rear-wheel-side output shaft 44 that is provided in a radially inner space of the drive gear 46 to protrude toward the lock tooth 68 . The high-speed side gear teeth 64 are provided at positions farther from the lock sleeve 70 than the low-speed side gear teeth 66 when viewed from a direction parallel to the first axis C1 . The outer peripheral teeth 62b of the high-low-speed sleeve 62 are engaged with the high-speed side gear teeth 64 on the side of the high-low-speed sleeve 62 away from the locking sleeve 70 (the left side in Figs. The side close to the locking sleeve 70 (the right side in FIGS. 2 and 3 ) meshes with the low-speed side gear teeth 66 . The outer peripheral teeth 70 a of the lock sleeve 70 are engaged with the lock teeth 68 on the side (right side in FIGS. 2 and 3 ) of the lock sleeve 70 close to the drive gear 46 . Therefore, the outer peripheral teeth 70 a of the lock sleeve 70 mesh with the lock teeth 68 at the positions where the high and low speed sleeves 62 mesh with the low speed side gear teeth 66 .

The front-wheel drive clutch 50 is a multi-plate friction clutch including a clutch hub 76 connected to the rear-wheel-side output shaft 44 in a relative-rotatable manner and connected in a relative-rotatable manner The clutch drum 78 on the drive gear 46, the frictional engagement element 80 interposed between the clutch driven disc hub 76 and the clutch drum 78 and selectively disconnecting or connecting the two, the frictional engagement element 80 Depressed piston 82. The front-wheel drive clutch 50 is disposed opposite to the high-low speed switching mechanism 48 with respect to the drive gear 46 around the first axis C1 of the rear-wheel-side output shaft 44 in the direction of the first axis C1 of the rear-wheel-side output shaft 44 . On one side, the friction engagement element 80 is pressed by the piston 82 that moves toward the drive gear 46 side. The front-wheel drive clutch 50 is in a released state in a state where it moves to the non-pressing side (right side in FIGS. 2 and 3 ) so as not to come into contact with the frictional engagement element 80 . The side away from the drive gear 46 in the direction parallel to the first axis C1. On the other hand, in a state where the front-wheel drive clutch 50 moves to the pressing side (left side in FIGS. 2 and 3 ) and is in contact with the frictional engagement element 80 , the torque is transmitted to the frictional engagement element 80 by the movement amount of the piston 82 . (torque capacity) is adjusted so as to be in a released state, a slipping state, or a fully engaged state, and the pressing side is the side where the piston 82 approaches the drive gear 46 in a direction parallel to the first axis C1.

The transfer case 22 connects the rear wheel side output shaft 44 to the 4WD lock mechanism 58 in the released state of the front wheel drive clutch 50 and in the released state of the 4WD lock mechanism 58 in which the outer peripheral teeth 70a of the lock sleeve 70 and the lock teeth 68 are not engaged. The power transmission path between the drive gears 46 is interrupted, and the power transmitted from the transmission 20 is transmitted only to the rear wheels 16 . The transfer case 22 distributes the power transmitted from the transmission 20 to the front wheels 14 and the rear wheels 16 in the slip state or the fully engaged state of the front-wheel drive clutch 50 , respectively. In the slip state of the front-wheel drive clutch 50, the transfer case 22 allows the rotational differential between the rear-wheel-side output shaft 44 and the drive gear 46 to be in a differential state (4WD unlocked state). The transfer case 22 is brought into a 4WD locked state by integrally rotating the rear wheel side output shaft 44 and the drive gear 46 in the fully engaged state of the front wheel drive clutch 50 . The front-wheel drive clutch 50 can continuously change the torque distribution between the front wheels 14 and the rear wheels 16 between, for example, 0:100 to 50:50 by controlling the transmission torque.

The transfer case 22 is further provided with an electric motor (actuator) 84 (see FIG. 3 ), which operates the high-low speed switching mechanism 48 , the front-wheel drive clutch 50 , and the 4WD locking mechanism 58 , which The screw mechanism 86 for converting rotational motion into linear motion, and the transmission mechanism 88 for transmitting the linear power of the screw mechanism 86 to the high-low speed switching mechanism 48 , the front wheel drive clutch 50 and the 4WD lock mechanism 58 respectively.

The screw mechanism 86 is disposed on the opposite side of the drive gear 46 with respect to the front-wheel drive clutch 50 around the same first axis C1 as the rear-wheel-side output shaft 44 , and includes a worm gear via the transfer case 22 . The worm mechanism 90 is indirectly connected to the motor 84 by a nut member (one screw member) 92 as a rotating member, and a threaded shaft member (the other screw member) 94 screwed with the nut member 92. The member 94 is arranged on the rear wheel side output shaft 44 so as to be immovable in the direction of the first axis C1 of the rear wheel side output shaft 44 and not rotatable around the first axis C1 so that the rear of the threaded shaft member 94 is provided. A connecting member 95 that connects the end portion of the side to the transfer case 40 which is a non-rotating member. The nut member 92 is screwed to the threaded shaft member 94 via the plurality of balls 96 , and the screw mechanism 86 is a ball screw in which the nut member 92 and the threaded shaft member 94 operate via the plurality of balls 96 . In addition, the threaded shaft member 94 is relatively rotatably supported by the rear wheel side output shaft 44 via a needle bearing 97 . In the screw mechanism 86 configured in this way, the motor 84 is used to make a nut supported by the rear wheel side output shaft 44 and serving as a screw member of either the screw shaft member 94 and the nut member 92 that are screwed with each other. The member 92 is driven to rotate around the first axis C1 of the rear wheel side output shaft 44 , so that the nut member 92 moves in the direction of the first axis line C1 of the rear wheel side output shaft 44 . In addition, among the nut member 92 and the screw shaft member 94 supported by the rear wheel side output shaft 44 , by screwing the nut member 92 with the screw shaft member 94 , the nut member 92 can surround the rear wheel side output shaft 44 The threaded shaft member 94 is supported by the rear wheel side output shaft 44 so as to rotate on the first axis C1 of the rear wheel side, and the threaded shaft member 94 is prevented from moving in the direction of the first axis C1 of the rear wheel side output shaft 44 through the connecting member 95 Moreover, it is supported by the rear-wheel-side output shaft 44 so as not to rotate around the first axis C1 of the rear-wheel-side output shaft 44 . In addition, in the present embodiment, as shown in FIGS. 2 and 5 , when the nut member 92 is rotated in the direction of the arrow F1 around the first axis C1 by the motor 84, the nut member 92 is connected to the threaded shaft through the motor 84. The thread between the members 94 moves in the direction away from the front-wheel drive clutch 50 in the first axis direction C1, that is, in the direction indicated by the arrow F2.

The worm gear mechanism 90 is a gear pair including a worm 98 formed integrally with the motor shaft of the electric motor 84 and a worm wheel 100 a formed on a drum cam 100 fixedly provided at the rear of the nut member 92 . On the lip portion 92a at the end of the side. For example, the rotation of the electric motor 84 , which is a brushless motor, is transmitted to the nut member 92 at reduced speed via the worm gear mechanism 90 . The screw mechanism 86 converts the rotation of the motor 84 transmitted to the nut member 92 into linear motion of the nut member 92 . Further, by rotationally driving the motor 84, the worm wheel 100a formed on the drum cam 100 that is connected, that is, is fixed to the nut member 92, is positioned in the direction of the first axis C1 of the output shaft 44 on the rear wheel side. Although the worm wheel 100a moves, the width in the direction of the first axis C1 of the worm wheel 100a is larger than the width in the direction of the first axis C1 of the worm 98 formed on the motor shaft. Therefore, even if the worm wheel 100a moves, the worm wheel The worm 98 formed on the motor shaft of the electric motor 84 fixed to the transfer case 40 also always meshes with the worm 100a, and the outer peripheral teeth of the worm wheel 100a are formed as spur teeth.

The transmission mechanism 88 includes a first transmission mechanism (first transmission mechanism) 88a that transmits the linear motion of the nut member 92 in the screw mechanism 86 to the front wheel drive clutch 50, and a cam to be described later is coupled to The movement of the fork shaft (second shaft) 102 of the engaging member 103 in the direction of the third axis (axial center) C3 is transmitted to the second transmission mechanism (second transmission mechanism) 88b for transmitting the high-low speed switching mechanism 48, wherein the The cam engaging member 103 is engaged with the cam groove 100 c formed in the drum cam 100 . In addition, as shown in FIGS. 2 to 4 , the cam engaging member 103 is connected to the fork shaft 102 , and the drum cam 100 is connected to the nut member 92 . As shown in FIGS. 2 and 5 , the drum cam 100 includes an annular worm wheel 100 a that meshes with the worm 98 formed on the motor shaft of the electric motor 84 , and the 100a has a protrusion 100b protruding in a direction approaching the rear vehicle propeller shaft 26, and a cam groove 100c formed on the outer periphery of the protrusion 100b. In addition, the said protrusion 100b is the shape which shows the part of a cylindrical shape which protrudes in the direction approaching the rear vehicle propeller shaft 26 in the circumferential direction of the worm wheel 100a. The second support bearing 73 which rotatably supports the end on the drum cam 100 side among the both ends of the rear wheel side output shaft 44 is on the second side of the rear wheel side output shaft 44 of the drum cam 100 . It is arranged on the inner side of the drum cam 100 within a length range in the direction of the one axis C1. In addition, the radial dimension R1 of the rear wheel side output shaft 44 of the drum cam 100 becomes the radial dimension R2 of the rear wheel side output shaft 44 of the high-low speed switching mechanism 48 and the rear wheel side output shaft of the front wheel drive clutch 50 The drum cam 100 is formed so that the radial dimension R3 or less of 44 may be used. The above-mentioned dimension R2 is the outer diameter dimension of the ring gear R or the carrier CA of the high-low-speed switching mechanism 48 . The above-mentioned dimension R3 is the outer diameter dimension of the clutch drum 78 of the front-wheel drive clutch 50 .

As shown in FIG. 6 , the cam groove 100c formed on the outer periphery of the drum cam 100 has an inclined cam groove portion 100d extending in a direction inclined with respect to the first axis C1 of the rear wheel side output shaft 44, A first cam groove portion 100e serving as a switching cam groove portion extending in a direction (vertical direction) perpendicular to the first axis C1 at the end portion on the screw mechanism 86 side of the cam groove portion 100d is formed in the inclined cam groove A second cam groove portion 100f extending in the vertical direction with respect to the first axis line C1 at the end portion of the portion 100c on the opposite side to the screw mechanism 86 side. According to the drum cam 100 constructed in this way, for example, as shown in FIG. From the state of the distal end portion 103a, when the motor 84 rotates the nut member 92 around the first axis C1 in the direction of the arrow F1, and the drum cam 100 is rotated around the first axis C1 in the direction of the arrow F1, the cam The distal end portion 103a of the engaging member 103 moves along the inclined cam groove portion 100d of the drum cam 100 by a movement amount D in the direction of the arrow F2, that is, in the direction of the third axis C3 of the fork shaft 102. The amount of movement of the nut member 92 in the direction indicated by the arrow F2, that is, the amount of movement of the nut member 92 in the direction indicated by the arrow F2 by the action of the thread between the threaded shaft members 94 is larger than that. That is, when the nut member 92 is rotated in the direction of the arrow F1 around the first axis C1 by the motor 84 from the state shown in FIG. 6( a ), the cam groove portion 100d is inclined so that the drum cam 100 is Relative movement in the direction of the third axis C3 of the fork shaft 102 with respect to the cam engaging member 103 is performed by a movement amount D that is greater than the amount of the movement D which is greater than the amount by which the nut member 92 passes through the thread between the threaded shaft member 94 . The amount of movement amount to be moved in the direction of the arrow mark F2 due to the action. Further, for example, as shown in FIG. 6( c ), from the state where the distal end portion 103 a of the cam engaging member 103 is arranged in the second cam groove portion 100 f of the cam groove 100 c of the drum cam 100 , the motor 84 is used to When the nut member 92 is rotated about the first axis C1 in the direction opposite to the direction indicated by the arrow F1, and the drum cam 100 is rotated in the opposite direction of the direction indicated by the arrow F1 about the first axis C1, the cam engaging member 103 The distal end portion 103a of the drum cam 100 will move along the inclined cam groove portion 100d of the drum cam 100 in a direction opposite to the direction indicated by the arrow F2 by a movement amount D that is opposite to the direction indicated by the arrow F2 of the nut member 92 The amount of movement of the upper portion, that is, the amount of movement of the nut member 92 in the direction opposite to the direction indicated by the arrow F2 by the action of the thread between the threaded shaft members 94 is larger. That is, when the electric motor 84 is rotationally driven to rotate the drum cam 100 around the first axis C1 of the rear-wheel-side output shaft 44 via the nut member 92, the cam groove 100c formed in the drum cam 100 is connected to the cam groove 100c. The cam engaging member 103 engaged with the cam groove 100 c moves in the direction of the first axis C1 , that is, in the direction of the third axis C3 of the fork shaft 102 . That is, when the electric motor 84 is rotationally driven to rotate the drum cam 100 about the first axis C1 of the rear-wheel-side output shaft 44 via the nut member 92 , the drum cam 100 is positioned relative to the cam engaging member 103 . Relative movement is performed in the direction of the third axis C3 of the fork shaft 102 . In addition, the one-dot chain line circle shown in FIG.6(b) and (c) shows the position of the front-end|tip part 103a of the cam engaging member 103 of FIG.6(a). The first axis C1 of the rear wheel side output shaft 44 , the second axis line C2 of the front wheel side output shaft 52 and the third axis line C3 of the fork shaft 102 are respectively parallel. Further, from the state shown in FIG. 6( a ), for example, the motor 84 rotates the nut member 92 around the first axis C1 in a direction opposite to the direction indicated by the arrow F1 , and the drum cam 100 rotates around the first axis C1 . When the cam engaging member 103 rotates in the direction opposite to the direction indicated by the arrow F1 on the axis C1, the cam engaging member 103 does not move in the direction of the first axis C1 of the output shaft 44 on the rear wheel side, that is, in the direction of the third axis C3 of the fork shaft 102, and the cam The engaging member 103 moves along the first cam groove portion 100e. That is, in a state where the cam engaging member 103 is engaged with the first cam groove portion 100e, the first cam groove portion 100e causes the nut member 92 to move in the opposite direction to the direction indicated by the arrow F1 regardless of how the nut member 92 surrounds the first axis C1. During rotation, the movement of the cam engaging member 103 in the direction of the third axis C3 of the fork shaft 102 is prevented, that is, the relative movement of the cam engaging member 103 and the drum cam 100 in the direction of the third axis C3 of the fork shaft 102 is prevented .

As shown in FIGS. 2 to 5 , the first transmission mechanism 88 a includes a thrust bearing 105 interposed between the piston 82 and the flange portion 92 a of the nut member 92 to prevent the piston 82 from rubbing against the nut member 92 . The relative movement stop member 107 on the side of the engaging element 80 . The piston 82 is connected to the nut member 92 via the thrust bearing 105 and the stopper member 107 so as not to move relative to the nut member 92 in the direction of the first axis C1 and to be relatively rotatable about the first axis C1 . Thereby, the linear motion of the nut member 92 in the screw mechanism 86 is transmitted to the piston 82 of the clutch 50 for front-wheel drive via the 1st transmission mechanism 88a.

In addition, as shown in FIGS. 2 to 5 , the second transmission mechanism 88 b is provided with the second transmission mechanism 88 b arranged in parallel with the first axis C1 of the rear wheel side output shaft 44 in the transfer case 40 so as to be able to communicate with the third axis C3 The fork shaft 102 supported so as to move in the direction, the fork 104 fixed to the fork shaft 102 and connected to the high-low speed sleeve 62, the direction of the first axis C1 of the cam engaging member 103, that is, the direction of the third axis C3 The waiting mechanism 106 transmits the movement of the fork shaft 102 to the fork shaft 102 via the spring member 112 . In addition, the above-mentioned waiting mechanism 106 is provided in the cam engaging member 103 . Therefore, in the second transmission mechanism 88b, the movement of the cam engaging member 103 in the direction of the first axis C1, that is, in the direction of the third axis C3, is directed to the high-speed switching mechanism 48 via the waiting mechanism 106, the fork shaft 102, and the fork 104. The low speed sleeve 62 transmits. Accordingly, when the cam engaging member 103 is moved in the direction of the arrow F2 from the state shown in, for example, FIGS. 2 and 6( a ), the high-low-speed sleeve 62 moves to the drive gear 46 side, that is, The outer peripheral teeth 62b of the high-low-speed sleeve 62 are moved to the positions where they mesh with the low-speed side gear teeth 66 . In addition, when the cam engaging member 103 is moved in the opposite direction to the direction indicated by the arrow F2 from the state shown in FIG. 4 and FIG. side movement, that is, the outer peripheral teeth 62 b of the high and low speed sleeves 62 are moved to the positions where they mesh with the high speed side gear teeth 64 .

In addition, the transmission mechanism 88 includes a third transmission mechanism 88 c that transmits the linear motion of the nut member 92 in the screw mechanism 86 to the 4WD lock mechanism 58 . The third transmission mechanism 88c includes a fork shaft 102, a fork 104, a waiting mechanism 106, and a high-low-speed sleeve 62 connected to the fork 104 as in the second transmission mechanism 88b. The first spring 72 is arranged in a compressed state between the lock sleeves 70 , and the second spring 74 is arranged in a compressed state between the lock sleeve 70 and the convex portion 44 a of the rear wheel side output shaft 44 .

Therefore, in the third transmission mechanism 88c, when the cam engaging member 103 is moved in the direction indicated by the arrow F2 as described above, the outer peripheral teeth 62b of the high-low-speed sleeve 62 are moved to the position where they mesh with the low-speed side gear teeth 66 , the locking sleeve 70 acts via the first spring 72 with a thrust in the locking direction toward the drive gear 46 side. As a result, the outer peripheral teeth 70 a of the lock sleeve 70 move toward the drive gear 46 against the biasing force of the second spring 74 which is set to be weaker than the first spring 72 , and interact with the drive gear 46 . The locking teeth 68 are engaged. In addition, when the cam engaging member 103 is moved in the opposite direction of the arrow mark F2 from the state in which the outer peripheral teeth 62b of the high and low speed sleeve 62 mesh with the low speed side gear teeth 66, the outer peripheral teeth 62b of the high and low speed sleeve 62 are moved When the lock sleeve 70 moves to the position where it meshes with the high-speed gear teeth 64 , the second spring 74 acts on the lock sleeve 70 with an urging force in the 4WD lock release direction away from the drive gear 46 . Accordingly, the locking sleeve 70 is moved to the side away from the driving gear 46 by the biasing force of the second spring 74 so that the outer peripheral teeth 70 a of the locking sleeve 70 are separated from the locking teeth 68 of the driving gear 46 .

As shown in FIG. 5, the waiting mechanism 106 is provided with two cylindrical members 108a and 108b with flanges that surround the fork shaft 102 so as to be slidable in the direction parallel to the third axis C3. The three axes C3 are arranged, and the flanges provided on one end thereof are opposite to each other; the partition plate 110 is cylindrical and interposed between the two flanged cylindrical parts 108a, 108b; the spring part 112 , which is arranged at the outer peripheral side of the partition plate 110 in a pre-pressed state; and a gripping member 114 , which is slidable in a direction parallel to the third axis C3 for the two cylindrical members 108a, 108b with flanges to hold. The grip member 114 slides the flanged cylindrical members 108a and 108b on the fork shaft 102 by contacting the flanges of the flanged cylindrical members 108a and 108b. The lengths between the ridges in the state where the ridges of the ridged cylindrical members 108 a and 108 b are in contact with the gripping member 114 are longer than the length of the separator 110 . Therefore, the state where all the flanges are in contact with the grip member 114 is formed by the biasing force of the spring member 112 . In addition, in the waiting mechanism 106, the outer peripheral surface of the fork shaft 102 is provided with stoppers 118a, 118b which prevent the flanged cylindrical members 108a, 108b from being separated in the direction parallel to the third axis C3, respectively. By making the flanged cylindrical members 108a and 108b inseparable by the stoppers 118a and 118b, in the second transmission mechanism 88b, the linear power of the nut member 92 can be raised via the fork shaft 102 and the fork 104. The low-speed switching mechanism 48 transmits.

The outer peripheral teeth 70a of the lock sleeve 70 mesh with the lock teeth 68 at the positions where the fork shaft 102 meshes the outer peripheral teeth 62b of the high and low speed sleeve 62 with the low speed side gear teeth 66 (hereinafter referred to as low speed gear positions). The friction engagement element 80 of the front-wheel drive clutch 50 does not pass the piston 82 at the position where the fork shaft 102 meshes the outer peripheral teeth 62b of the high-low-speed sleeve 62 with the high-speed side gear teeth 64 (hereinafter referred to as the high-speed gear position). While being pressed, it is not pressed by the piston 82 at the low gear position of the fork shaft 102 . In addition, in FIG. 6 , FIG. 6( a ) is a diagram showing the position of the cam engaging member 103 when the fork shaft 102 is at the high gear position, and FIG. 6( c ) is a diagram showing when the fork shaft 102 is at the low gear position 6(b) is a diagram showing the position of the cam engaging member 103 during switching of the fork shaft 102 from the high gear position to the low gear position. Further, when the nut member 92, that is, the drum cam 100, is rotated in the opposite direction to the direction indicated by the arrow F1 by the motor 84 from the state shown in FIG. 6(a), the first cam groove portion 100e passes through the Therefore, the cam engaging member 103 does not move in the direction of the third axis C3 of the fork shaft 102, but prevents the piston 82 of the front-wheel drive clutch 50 from being pressed against the fork shaft 102 in the high-speed gear position. The position on the frictional engagement element 80 moves from the position pressed against the frictional engagement element 80 .

At the high-speed gear position of the fork shaft 102, the length between the flanges of the flanged cylindrical members 108a, 108b can be set between the length in a state in which the flanges are both in contact with the grip member 114 and the length of the partition plate 110 Variety. Therefore, the waiting mechanism 106 allows the nut between the position where the friction engagement element 80 of the front-wheel drive clutch 50 is pressed by the piston 82 and the position where it is not pressed while the fork shaft 102 is in the high gear position. Movement of the member 92 in a direction parallel to the first axis C1.

The transfer case 22 includes a gear position holding mechanism 120 (see FIG. 2 ) that holds the high-speed gear position of the fork shaft 102 and also holds the low-speed gear position of the fork shaft 102 . The gear position maintaining mechanism 120 includes a receiving hole 122 formed on the inner peripheral surface of the transfer case 40 on which the fork shaft 102 slides, a lock ball 124 received in the receiving hole 122 , and a lock ball 124 received in the receiving hole 122 . A lock spring 126 that urges the lock ball 124 to the fork shaft 102 side, is formed on the outer peripheral surface of the fork shaft 102 and receives a part of the lock ball 124 at the position of the high-speed gear of the fork shaft 102. The concave portion 128h, and the concave portion 128l into which a part of the lock ball 124 is received at the low gear position of the fork shaft 102. By the gear position maintaining mechanism 120, even if the output from the electric motor 84 stops at the respective gear positions, the respective gear positions of the fork shaft 102 are maintained.

The transfer case 22 includes a low gear position detection switch 130 that detects the low gear position of the fork shaft 102 . The low gear position detection switch 130 is, for example, a ball-type contact switch. The low gear position detection switch 130 is fixedly provided in a through hole 132 formed in the transfer case 40 at a position in contact with the fork shaft 102 moved to the low gear position. When the low gear position is detected by the low gear position detection switch 130, for example, an indicator for notifying the driver that the low gear stage L is in the 4WD locked state is turned on.

Returning to FIG. 1 , the vehicle 10 includes an electronic control unit (ECU) 200 including, for example, a control unit of the vehicle 10 that switches between a 2WD state and a 4WD state. The electronic control device 200 is configured to include, for example, a so-called central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), an input/output interface, and the like. In the microcomputer, the CPU executes various controls of the vehicle 10 by performing signal processing according to a program pre-stored in the ROM using the temporary storage function of the RAM. For example, the electronic control device 200 executes output control of the engine 12, switching control of the driving state of the vehicle 10, and the like, and is configured as needed for engine control, driving state control, or the like. As shown in FIG. 1 , the electronic control device 200 is supplied with various sensors provided in the vehicle 10 and the like (for example, the engine rotational speed sensor 202 , the motor rotation angle sensor 204 , the wheel speed sensors 206 , the accelerator opening degree sensor 208, H range selector switch 210 for selecting the high-speed side gear stage H by the driver's operation, 4WD selector switch 212 for selecting the 4WD state by the driver's operation, for selecting the 4WD state by the driver's operation Various actual values (eg, engine speed Ne, motor rotation angle θm, front wheels 14L, 14R, and rear wheels 16L, 16R) obtained from detection signals detected by 4WD lock selector switch 214, etc. to select the 4WD lock state Each of the wheel speeds Nwfl, Nwfr, Nwrl, Nwrr, the accelerator opening θacc, the H range line request Hon indicating that the H range selector switch 210 was operated, and the 4WD signal indicating that the 4WD selector switch 212 was operated 4WDon is required, LOCKon of a signal indicating that the 4WD lock selector switch 214 has been operated, etc.). As shown in FIG. 1 , the electronic control device 200 is output to the output control device of the engine 12 , the actuator of the front clutch 36 , the electric motor 84 , the transfer case 22 , and the like, for example, for performing output control of the engine 12 . The engine outputs a control command signal Se, an operation command signal Sd for switching the state of the front clutch 36, a motor drive command signal Sm for controlling the amount of rotation of the electric motor 84, and the like.

In the vehicle 10 configured as described above, the amount of movement (stroke) of the nut member 92 is controlled by controlling the amount of rotation of the electric motor 84 . At the high gear position of the fork shaft 102 , the position where the piston 82 does not come into contact with the friction engagement element 80 , that is, the position of the piston 82 that is about to put the front-wheel drive clutch 50 in the disengaged state, is used to set the vehicle 10 A position in a 2WD traveling state in which only the rear wheels 16 are driven at the high-speed side gear stage H (hereinafter referred to as the H2 position). When the front clutch 36 is set to the disengaged state at the H2 position of the piston 82, during 2WD running, each rotating element constituting the power transmission path from the drive gear 46 to the front wheel differential gear device 28 (The drive gear 46, the front wheel drive chain 56, the driven gear 54, the front wheel side output shaft 52, the front vehicle transmission shaft 24, the front wheel differential gear device 28, etc.), the rotation is not transmitted from the engine 12 side , and the rotation is not transmitted from the front wheel 14 side. Therefore, in 2WD running, the rotation of the respective rotating elements is stopped, thereby preventing the rotating elements being driven to rotate, thereby reducing the running resistance.

In addition, as shown in FIG. 2 , at the high gear position of the fork shaft 102 , the position of the piston 82 that puts the front wheel drive clutch 50 in the slip state is used to set the vehicle 10 to the high gear. A position in a 4WD running state in which power is transmitted to both the front wheels 14 and the rear wheels 16 at stage H (hereinafter referred to as the H4 position), wherein the above-mentioned position of the piston 82 that puts the front-wheel drive clutch 50 in the slip state The position is that by driving the motor 84 by a predetermined amount of rotation from the position where the piston 82 is not in contact with the frictional engagement element 80 to move the nut member 92 to the pressing side by a predetermined stroke accordingly, the piston 82 and the frictional engagement element 80 are moved. The position where the friction engagement element 80 abuts. At the H4 position of the piston 82 , by controlling the transmission torque of the front-wheel drive clutch 50 according to the pressing force of the piston 82 , the torque distribution between the front wheels 14 and the rear wheels 16 is adjusted as required. .

Further, at the low gear position of the fork shaft 102, as shown in FIG. 4, since the front-wheel drive clutch 50 is set to the released state and the 4WD lock mechanism 58 is set to the engaged state, it is set to be used for The low-speed side gear stage L sets the vehicle 10 to a position in the 4WD running state in the 4WD locked state (referred to as the L4 position).

As described above, according to the transfer case 22 of the present embodiment, when the nut member 92 is driven to rotate about the first axis C1 of the rear wheel side output shaft 44 by the electric motor 84 , the nut member 92 rotates on the rear wheel side output shaft 44 . The linear motion of the nut member 92 is transmitted to the front-wheel drive clutch 50 via the first transmission mechanism 88a. In addition, when the nut member 92 is driven to rotate about the first axis C1 of the rear-wheel-side output shaft 44 by the motor 84, the drum cam 100 connected to the nut member 92 rotates and engages with the cam groove 100c. The engaged cam engaging member 103 moves in the direction of the third axis C3 of the fork shaft 102 , that is, the drum cam 100 connected to the nut member 92 rotates, and the drum cam 100 rotates relative to the cam engaging member 103 . The relative movement in the direction of the third axis C3 of the fork shaft 102 causes the movement of the fork shaft 102 in the cam engagement member 103 to be transmitted to the high-low speed switching mechanism 48 via the second transmission mechanism 88b. As a result, since the linear motion of the nut member 92 of the screw mechanism 86 provided on the rear wheel side output shaft 44 is transmitted to the front wheel drive clutch 50 via the first transmission mechanism 88a, it is no longer necessary as in the prior art. For example, by providing a ball cam and a lead screw for adjusting the transmission torque of the front-wheel drive clutch 50, the distance between the rear-wheel-side output shaft 44 and the fork shaft 102 can be appropriately shortened, and the transfer case 22 can be reduced in size. change.

Further, according to the transfer case 22 of the present embodiment, the cam engaging member 103 is coupled to the fork shaft 102 , and the drum cam 100 is coupled to the nut member 92 . Therefore, the drum cam 100 is coupled to the nut member 92 of the screw mechanism 86 provided on the rear wheel side output shaft 44 in order to perform the switching operation of the high and low speed switching mechanism 48 . Therefore, since it is no longer necessary to provide the drum cam on the second shaft as in the prior art, it is no longer necessary to install the drum cam on the second shaft as in the conventional transfer case in which the drum cam is provided on the second shaft. The drum cam on the second shaft does not interfere with the high-low-speed switching mechanism and the clutch provided on the output shaft, so that the distance between the output shaft 44 on the rear wheel side and the fork shaft 102 can be shortened appropriately. distance between.

Further, according to the transfer case 22 of the present embodiment, the nut member 92 is rotatably supported around the first axis C1 of the rear wheel side output shaft 44 , and the threaded shaft member 94 is rotatable on the rear wheel side output shaft 44 . It is supported so as to move in the direction of the first axis C1 and not to rotate about the first axis C1 of the rear wheel side output shaft 44 . In this way, when the nut member 92 is rotationally driven by the motor 84, the nut member 92 is moved in the direction of the first axis C1 of the rear wheel side output shaft 44, and the linear motion of the nut member 92 is transmitted through the first transmission mechanism 88a. It is transmitted to the clutch 50 for front-wheel drive. Then, when the nut member 92 is driven to rotate by the motor 84, the drum cam 100 connected to the nut member 92 is rotated, and the cam engaging member 103 engaged with the cam groove 100c is placed on the fork shaft 102. It moves in the direction of the third axis C3, and the linear motion of the cam engaging member 103 is transmitted to the high-low speed switching mechanism 48 via the second transmission mechanism 88b.

Further, according to the transfer case 22 of the present embodiment, the second support bearing 73 rotatably supports the end portion on the drum cam 100 side among the both end portions of the rear wheel side output shaft 44, Since the drum cam 100 is arranged inside the drum cam 100 within the length of the rear wheel side output shaft 44 in the direction of the first axis C1, the rear wheel side output shaft 44 in the transfer case 22 is appropriately shortened in The length of the dimension in the direction of the first axis C1.

Further, according to the transfer case 22 of the present embodiment, in the cam groove 100 c formed in the drum cam 100 , the inclined cam groove extending in the direction inclined with respect to the first axis C1 of the rear wheel side output shaft 44 is provided In the portion 100d, when the nut member 92 is rotated about the first axis C1 of the rear wheel side output shaft 44 by the electric motor 84 and the drum cam 100 is rotated about the first axis C1 of the rear wheel side output shaft 44, the cam engaging member 103 moves along the inclined cam groove portion 100d of the drum cam 100 by a movement amount D that is larger than the movement amount D of the rear wheel side output shaft 44 of the nut member 92 in the direction of the first axis C1, while the fork The shaft 102 moves in the direction of the third axis C3. Therefore, the responsiveness of the high-low-speed switching mechanism 48 for switching the high-speed side gear stage H and the low-speed side gear stage L is related to the direction of the first axis C1 of the rear wheel side output shaft 44 via, for example, the nut member 92 in the screw mechanism 86 . Compared with the switching of the high-speed side gear stage H and the low-speed side gear stage L, it is greatly improved.

Further, according to the transfer case 22 of the present embodiment, in the cam groove 100 c formed in the drum cam 100 , the first axis extending in the direction orthogonal to the first axis C1 of the rear wheel side output shaft 44 is provided with the first The cam groove portion 100e rotates the nut member 92 around the first axis C1 in the opposite direction to the direction indicated by the arrow F1 by the motor 84, and causes the drum cam 100 to rotate in the opposite direction to the direction indicated by the arrow F1 around the first axis C1. When the cam engaging member 103 is rotated in the direction of the fork shaft 102, the cam engaging member 103 does not move in the direction of the third axis C3 of the fork shaft 102, and the cam engaging member 103 moves along the first cam groove portion 100e. That is, by using the first cam groove portion 100e to move the cam engaging member 103 along the first cam groove portion 100e, the nut member 92 can move in the direction of the first axis C1 of the rear wheel side output shaft 44 , the linear motion of the nut member 92 is transmitted to the front-wheel drive clutch 50 via the first transmission mechanism 88a. Therefore, the transmission torque to the drive gear 46 can be adjusted by the front-wheel drive clutch 50 in a state where the high-low-speed switching mechanism 48 is switched to the high-speed side gear stage H.

Further, according to the transfer case 22 of the present embodiment, the nut member 92 is screwed to the threaded shaft member 94 via the plurality of balls 96 . Therefore, since the relative rotation between the nut member 92 and the threaded shaft member 94 becomes smooth, the required electric power of the electric motor 84 during operation is stably reduced.

Further, according to the transfer case 22 of the present embodiment, the front-wheel drive clutch 50 is a clutch that adjusts the transmission torque transmitted to the drive gear 46 , and the front-wheel drive clutch 50 is a multi-plate clutch. Therefore, the continuously variable control of the transmission torque of the front-wheel drive clutch 50 can be performed, and the driving force distribution control of the front wheels 14 and the rear wheels 16 can be further performed according to the driving situation.

Further, according to the transfer case 22 of the present embodiment, the second transmission mechanism 88 b is provided with a stand-by for transmitting the movement of the cam engaging member 103 in the direction of the third axis C3 of the fork shaft 102 to the fork shaft 102 via the spring member 112 Institution 106. Therefore, at the time of switching between the high-speed side gear stage H and the low-speed side gear stage L in the high-low speed switching mechanism 48 , the shock generated by the switching of the high-low speed switching mechanism 48 is absorbed by the spring member 112 of the waiting mechanism 106 . .

Next, other embodiments of the present invention will be described. In addition, the same code|symbol is attached|subjected to the part common to the said Example 1, and the description is abbreviate|omitted.

Example 2

7 to 10 are diagrams illustrating the transfer case 134 according to other embodiments of the present invention. The transfer case 134 of the present embodiment differs from the transfer case 22 of the first embodiment in that the cam engaging member 136 is connected to the nut member 140 of the screw mechanism 138, and the drum cam 142 is connected to the fork shaft 102 via the waiting mechanism 144, and the shape of the thrust bearing 154 and the stopper member 156 provided in the first transmission mechanism (first transmission mechanism) 88d are different, and provided in the second transmission mechanism ( The shape of the waiting mechanism 144 on the second transmission mechanism 88e is different, and other aspects are substantially the same as the transfer case 22 of the first embodiment.

As shown in FIGS. 7 and 9 , the screw mechanism 138 is arranged around the same first axis C1 as the rear-wheel-side output shaft 44 on the side opposite to the drive gear 46 with respect to the front-wheel drive clutch 50 , and said The screw mechanism 138 includes a nut member 140 as a rotating member indirectly connected to the electric motor 84 via a worm gear mechanism 146 included in the transfer case 134 , a screw shaft member 148 screwed to the nut member 140 , 148 is arranged on the rear-wheel-side output shaft 44 so as not to move in the direction of the first axis C1 of the rear-wheel-side output shaft 44 nor to rotate around the first axis C1, and the rear end portion of the threaded shaft member 148 is connected to the rear end of the threaded shaft member 148. The connecting member 150 that connects the transfer case 40 as a non-rotating member. The nut member 140 is screwed to the threaded shaft member 148 via the plurality of balls 152 , and the screw mechanism 138 is a ball screw in which the nut member 140 and the threaded shaft member 148 operate via the plurality of balls 152 . Further, the threaded shaft member 148 is supported on the rear wheel side output shaft 44 so as to be relatively rotatable via the needle bearing 153 . In the screw mechanism 138 configured in this way, the screw shaft member 148 and the nut member 140 supported by the rear wheel side output shaft 44 and screwed to each other are rotationally driven by the electric motor 84, so that the nut member 140 is rotated in the The output shaft 44 on the rear wheel side moves in the direction of the first axis C1. That is, the screw mechanism 138 converts the rotation of the motor 84 transmitted to the nut member 140 into linear motion of the nut member 140 . In addition, among the nut member 140 and the threaded shaft member 148 supported by the rear wheel side output shaft 44 , the nut member 140 can surround the rear wheel side output shaft 44 by screwing the nut member 140 and the threaded shaft member 148 together. The threaded shaft member 148 is supported by the rear wheel side output shaft 44 so as to rotate in the first axis C1 of the rear wheel side, and the threaded shaft member 148 cannot move in the direction of the first axis C1 of the rear wheel side output shaft 44 and cannot surround the threaded shaft member 148 through the connecting member 150 The rear-wheel-side output shaft 44 is supported by the rear-wheel-side output shaft 44 so as to rotate on the first axis C1 . In addition, in the present embodiment, as shown in FIGS. 7 and 9 , when the nut member 140 is rotated in the direction of the arrow F1 around the first axis C1 by the motor 84 , the nut member 140 passes through the space between the nut member 140 and the threaded shaft member 148 . The screw moves in the direction indicated by the arrow F2, which is a direction away from the front-wheel drive clutch 50 in the first axis direction C1.

The first transmission mechanism 88d that transmits the linear motion of the nut member 140 of the screw mechanism 138 to the front wheel drive clutch 50 is provided with a space between the piston 82 and the flange portion 140a of the nut member 140 as shown in FIG. 9 . The thrust bearing 154 in between, and the annular stopper member 156 for preventing the relative movement of the piston 82 with respect to the nut member 140 to the friction engagement element 80 side. The piston 82 is coupled to the nut member 140 via the thrust bearing 154 and the stopper member 156 so as to be immovable relative to the nut member 140 in the direction of the first axis C1 and relatively rotatable about the first axis C1 . Thereby, the linear motion of the nut member 140 in the screw mechanism 138 is transmitted to the piston 82 of the clutch 50 for front-wheel drive via the 1st transmission mechanism 88d.

As shown in FIGS. 7 to 9 , the cam engaging member 136 is connected (joined) to the annular worm wheel 146a in the worm gear mechanism 146, and the worm wheel 146b is output around the rear wheel side by the motor 84 via the worm 146b When the first axis C1 of the shaft 44 rotates, the cam engaging member 136 rotates together with the nut member 140 around the first axis C1 of the rear wheel side output shaft 44 . In addition, the worm wheel 146a moves in the direction of the first axis C1 of the rear wheel side output shaft 44 by driving the motor 84 to rotate, but the outer peripheral teeth 146c of the worm wheel 146a are formed as spur teeth, so that even if the worm wheel 146a is in the first axis C1 direction Moving in the direction of the axis C1 also always engages with the worm 146 b formed on the motor shaft of the motor 84 . In addition, the worm gear mechanism 146 is a gear pair including a worm wheel 146a and a worm screw 146b.

As shown in FIG. 9 , the waiting mechanism 144 is disposed so as to be slidable with the fork shaft 102, and one end portion of the waiting mechanism 144 is provided with a pair of beaded circles in which the beaded portions 158a and 160a are formed. The cylindrical members 158 and 160, the spring member 162 arranged in a preloaded state between the flanged portions 158a and 160a in the pair of flanged cylindrical members 158 and 160, and a ring-shaped stop member 164 are provided. A gripping member 166 for gripping the pair of flanged cylindrical members 158 and 160 so as to be slidable in a direction parallel to the third axis C3, and a pair of flanged cylindrical members 158 in the fork shaft 102 to prevent , 160 are separated from the ring-shaped first stopper 168 and the second stopper 170 by a predetermined distance or more in the direction parallel to the third axis C3, preventing the pair of flanged cylindrical members 158 and 160 from opposing the fork A spherical rotation preventing ball 172 that rotates around the third axis C3 by the shaft 102 . In the waiting mechanism 144 configured as described above, for example, when the drum cam 142 moves in the direction of the arrow F2, the gripping member 166 is brought into contact with the flange portion 158a of the flanged cylindrical member 158, and the The flange part 160a of the flanged cylindrical member 160 comes into contact with the second stopper 170 via the spring member 162, and the fork shaft 102 moves in the direction indicated by the arrow F2. In addition, for example, when the drum cam 142 moves in the direction opposite to the direction indicated by the arrow F2, that is, in the direction indicated by the arrow F4, the stopper member 164 provided on the holding member 166 will collide with the convex portion of the flanged cylindrical member 160. The side part 160a abuts, and the flange part 158a of the flanged cylindrical member 158 abuts the first stopper 168 via the spring member 162, and the fork shaft 102 moves in the direction indicated by the arrow F4. In addition, when the fork shaft 102 is at the high-speed gear position, for example, when the drum cam 142 is about to move in the direction of the arrow mark F4, the spring member 162 is compressed and the flanged cylindrical member 160 moves toward the flanged cylinder. The member 158 moves in the approaching direction, allowing the drum cam 142 to move in the direction indicated by the arrow F4. In addition, when the fork shaft 102 is at the low gear position and, for example, the drum cam 142 is about to move in the direction of the arrow mark F2, since the spring member 162 is compressed and the flanged cylinder member 158 will move towards the flanged cylinder The movement of the member 160 in the approaching direction allows the drum cam 142 to move in the direction indicated by the arrow F2. In addition, the transfer case 40 is formed with a support portion 40 a that supports the end portion of the fork shaft 102 on the rear wheel 16 side, and the fork shaft 102 is integrally provided with the fork shaft 102 at the low-speed gear position. The support portion 40a of the transfer case 40 abuts against an annular stopper member 174 that prevents the movement of the fork shaft 102 from the low gear position in the direction indicated by the arrow F2. In addition, although not shown, the transfer case 134 is provided with a stopper member that prevents the movement of the fork shaft 102 from the high gear position in the direction indicated by the arrow F4. Further, the drum cam 142 is integrally connected to the holding member 166 of the waiting mechanism 144, and as shown in FIG. A pair of reinforcing members 176 to improve the strength of the connection.

As shown in FIG. 8, the drum cam 142 is formed in a partial cylindrical shape along the outer circumference of the worm wheel 146a, and the drum cam 142 is arranged adjacent to the worm wheel 146a so that the cam engaging member 136 is formed on the drum cam The cam groove 142a on the inner circumference of 142 is engaged, that is, the cam engaging member 136 is arranged in the cam groove 142a.

As shown in FIG. 10 , the cam groove 142a formed on the inner periphery of the drum cam 142 includes: an inclined cam groove portion 142b extending in a direction inclined with respect to the third axis C3 of the fork shaft 102; A first cam groove portion 142c serving as a switching cam groove portion extending in a direction orthogonal to the third axis C3 at an end portion of the portion 142b opposite to the side of the waiting mechanism 144 is formed in the inclined cam groove portion 142b A second cam groove portion 142d extending in a direction orthogonal to the third axis C3 at the end portion on the side of the waiting mechanism 144. According to the drum cam 142 configured in this way, as shown in FIG. 10( a ), for example, when the cam is arranged from the end portion on the inclined cam groove portion 142b side of the first cam groove portion 142c of the cam groove 142a From the state of the engaging member 136, when the motor 84 rotates the nut member 140 around the first axis C1 in the direction of the arrow F1 and the cam engaging member 136 rotates around the first axis C1 in the direction of the arrow F1, The drum cam 142 moves along the inclined cam groove portion 142b in the direction indicated by the arrow F2, that is, in the direction of the third axis C3 of the fork shaft 102, by a movement amount larger than that in the direction indicated by the arrow F2 of the nut member 140. , that is, the amount of movement by which the nut member 140 moves in the direction indicated by the arrow F2 by the action of the thread between the nut member 140 and the threaded shaft member 148 . Further, for example, as shown in FIG. 10( c ), from the state where the cam engaging member 136 is arranged in the second cam groove portion 142d of the cam groove 142a, the nut member 140 is caused to surround the first axis by the motor 84 When the cam engaging member 136 is rotated in the direction opposite to the direction indicated by the arrow F1 and the cam engaging member 136 is rotated in the direction opposite to the direction indicated by the arrow F1 around the first axis C1, the drum cam 142 is rotated along the inclined cam groove portion 142b. It moves in the direction opposite to the direction indicated by the arrow F2 (the direction indicated by the arrow F4), that is, in the direction of the third axis C3 of the fork shaft 102, by a movement amount larger than that of the nut member 140 in the direction opposite to the direction indicated by the arrow F2. The amount of movement in the direction, that is, the amount of movement by which the nut member 140 moves in the direction opposite to the direction indicated by the arrow F2 by the action of the thread between the nut member 140 and the threaded shaft member 148 . That is, when the motor 84 is driven to rotate and the cam engaging member 136 is rotated about the first axis C1 of the rear-wheel-side output shaft 44 via the nut member 140 , the cam engaging member 136 is formed in the drum cam 142 by making the cam engaging member 136 rotate. The upper cam groove 142 a is engaged to move the drum cam 142 in the direction of the third axis C3 of the fork shaft 102 . That is, when the electric motor 84 is driven to rotate and the cam engaging member 136 is rotated about the first axis C1 of the rear-wheel-side output shaft 44 via the nut member 140 , the drum cam 142 is rotated relative to the cam engaging member 136 Relative movement is performed in the direction of the third axis C3 of the fork shaft 102 . In addition, the one-dot chain line circle shown in FIG.10(b) and (c) shows the position of the cam engaging member 136 of FIG.10(a).

As shown in FIG. 7 , in the second transmission mechanism 88e that transmits the movement in the direction of the third axis C3 of the fork shaft 102 to which the drum cam 142 is connected to the high-low speed switching mechanism 48, the fork shaft 102 and the fork 104 are provided. and a waiting mechanism 144 that transmits the movement of the drum cam 142 in the direction of the third axis C3 to the fork shaft 102 via the spring member 162 . Therefore, in the second transmission mechanism 88e, for example, when the drum cam 142 is moved in the direction of the arrow F2 from the state shown in FIG. That is, the outer peripheral teeth 62b of the high-low-speed sleeve 62 move to the position where they mesh with the low-speed side gear teeth 66 . Further, for example, when the drum cam 142 is moved in the direction opposite to the direction indicated by the arrow F2 (the direction indicated by the arrow F4) from the state shown in (c) of FIG. Moving away from one side, that is, the outer peripheral teeth 62 b of the high-low-speed sleeve 62 is moved to the position where it meshes with the high-speed side gear teeth 64 . In addition, in FIG. 10 , (a) of FIG. 10 is a diagram showing the position of the drum cam 142 when the fork shaft 102 is at the high gear position, and (c) of FIG. 10 is a diagram showing the position of the fork shaft 102 when the fork shaft 102 is at the low gear position. The position of the drum cam 142 is a diagram, and FIG. 10( b ) is a diagram showing the position of the drum cam 142 during switching of the fork shaft 102 from the high gear position to the low gear position. In addition, from the state shown in FIG. 10( a ), for example, the cam engaging member 136 engaged with the first cam groove portion 142 c is caused by the motor 84 to move in the direction opposite to the direction indicated by the arrow F1 , that is, the direction indicated by the arrow F3 When turning in the direction of rotation, the drum cam 142 will not move in the direction of the third axis C3 of the fork shaft 102, but the piston 82 of the front wheel drive clutch 50 will never be pressed in the state where the fork shaft 102 is in the high gear position The position on the frictional engagement element 80 moves to the position pressed against the frictional engagement element 80 . That is, in a state where the cam engaging member 136 is engaged in the first cam groove portion 142c, the cam engaging member 136 connected to the nut member 140 passes through the first cam groove portion 142c regardless of how the cam engaging member 136 coupled to the nut member 140 is about the first axis C1. Rotating in the direction opposite to the direction of the arrow mark F1 prevents the movement of the drum cam 142 in the direction of the third axis C3 of the fork shaft 102 , that is, the cam engaging member 136 and the drum cam 142 are in the third axis of the fork shaft 102 . Relative movement in the C3 direction is blocked. In the high-low-speed switching mechanism 48, the high-speed side gear stage H is established when the fork shaft 102 is at the high-speed gear position, and the low-speed side gear stage L is established when the fork shaft 102 is at the low-speed gear position.

As described above, according to the transfer case 134 of the present embodiment, when the nut member 140 is rotationally driven by the motor 84, the nut member 140 moves in the direction of the first axis C1 of the rear wheel side output shaft 44, and the nut member The linear motion of 140 is transmitted to the clutch 50 for front-wheel drive via the 1st transmission mechanism 88d. Further, when the nut member 140 is rotationally driven by the motor 84, the cam engaging member 136 connected to the nut member 140 is rotated and the drum cam 142 is moved in the direction of the third axis C3 of the fork shaft 102. That is, the cam engaging member 136 connected to the nut member 140 rotates so that the drum cam 142 relatively moves relative to the cam engaging member 136 in the direction of the third axis C3 of the fork shaft 102, and the drum cam The movement of the fork shaft 102 in 142 is transmitted to the high-low speed switching mechanism 48 via the second transmission mechanism 88e. Thereby, since the linear motion of the nut member 140 of the screw mechanism 138 provided on the rear wheel side output shaft 44 is transmitted to the front wheel drive clutch 50 via the first transmission mechanism 88d, it is not necessary to, for example, as in the prior art By providing a ball cam and a lead screw for adjusting the transmission torque of the front-wheel drive clutch 50, the distance between the rear-wheel-side output shaft 44 and the fork shaft 102 can be appropriately shortened, and the transfer case 22 can be reduced in size. .

Further, according to the transfer case 134 of the present embodiment, the electric motor 84 is connected to the nut member 140 of the screw mechanism 136 via the worm gear mechanism 146, the cam engaging member 136 is connected to the worm wheel 146a of the worm gear mechanism 146, and the drum The cam 142 is connected to the fork shaft 102, and the drum cam 142 is formed in a partial cylindrical shape along the outer periphery of the worm wheel 146a. Therefore, since the drum cam 142 and the worm gear 146a can be arranged adjacent to each other, the distance between the rear wheel side output shaft 44 and the fork shaft 102 can be appropriately shortened.

Further, according to the transfer case 134 of the present embodiment, in the cam groove 142a formed on the drum cam 142, the inclined cam groove portion 142b extending in the direction inclined with respect to the third axis C3 of the fork shaft 102 is provided, When the nut member 140 is rotated about the first axis C1 of the rear wheel side output shaft 44 by the electric motor 84, the drum cam 142 tilts the cam groove portion 142b so as to be larger than the nut member 140 at the rear wheel side output shaft 44. It moves in the direction of the third axis C3 of the fork shaft 102 by the amount of movement in the direction of the first axis C1. Therefore, the responsiveness of switching between the high-speed-side gear stage H and the low-speed-side gear stage L of the high-low-speed switching mechanism 48 is the same as, for example, the nut member 140 in the screw mechanism 138 in the direction of the first axis C1 of the rear-wheel-side output shaft 44 . Compared with the case where the high-speed side gear stage H and the low-speed side gear stage L are switched by moving, it is greatly improved.

In addition, according to the transfer case 134 of the present embodiment, the second transmission mechanism 88 e is provided with the standby for transmitting the movement in the direction of the third axis C3 of the fork shaft 102 of the drum cam 142 to the fork shaft 102 via the spring member 162 . Institution 144. Therefore, when the high-low speed switching mechanism 48 switches the high-speed side gear stage H and the low-speed side gear stage L, the shock generated by the switching of the high-low speed switching mechanism 48 is absorbed by the spring member 162 of the waiting mechanism 144 .

Next, other embodiments of the present invention will be described. In addition, the same code|symbol is attached|subjected to the part common to the Example 2 mentioned above, and description is abbreviate|omitted.

Example 3

11 to 17 are diagrams illustrating a transfer case 178 according to another embodiment of the present invention. The transfer case 178 of the present embodiment is different from the transfer case 134 of the second embodiment in that the shapes of the cam engaging member 180 and the drum cam 182 are different, and the fork When the shaft 102 is in the low gear position, the outer peripheral teeth 70a of the lock sleeve 70 do not mesh with the lock teeth 68, and otherwise are substantially the same as the transfer case 134 of the second embodiment.

As shown in FIG. 11 , the cam engaging member 180 is connected (joined) to the annular worm wheel 146a of the worm gear mechanism 146, and when the motor 84 causes the worm wheel 146b to surround the second output shaft 44 on the rear wheel side via the worm 146b When the first axis C1 is rotated, the cam engaging member 180 is rotated around the first axis C1 of the rear wheel side output shaft 44 together with the nut member 140 .

The drum cam 182 is integrally connected to the holding member 166 of the waiting mechanism 144. Although not shown, between the drum cam 182 and the holding member 166, for example, a pair of reinforcements shown in FIG. 8 is connected. Part 176 is the same pair of reinforcing parts. Further, the drum cam 182 is formed in a partial cylindrical shape along the outer circumference of the worm wheel 146a, and the cam engaging member 180 is engaged with the cam groove 182a formed on the inner circumference of the drum cam 182, that is, The drum cam 182 is arranged adjacent to the worm wheel 146a so that the cam engaging member 180 is arranged in the cam groove 182a.

As shown in FIGS. 12 and 14 , the cam groove 182 a formed on the inner periphery of the drum cam 182 has a first inclined cam groove portion (inclined) extending in a direction inclined with respect to the third axis C3 of the fork shaft 102 A cam groove portion) 182b as a switching cam groove portion formed on an end portion of the first inclined cam groove portion 182b on the rear wheel 16 side and extending in a direction orthogonal to the third axis C3 of the fork shaft 102 The first switching cam groove portion 182c is formed on the end portion of the first inclined cam groove portion 182b on the opposite side to the rear wheel 16 and extends in a direction orthogonal to the third axis C3 of the fork shaft 102. A second switching cam groove portion 182d serving as a switching cam groove portion, a second inclined cam groove portion (inclined cam groove portion) 182e extending in a direction inclined with respect to the third axis C3 of the fork shaft 102, The first connecting groove portion 182f connecting the end portion of the groove portion 182b opposite to the rear wheel 16 side and the end portion of the second inclined cam groove portion 182e opposite to the rear wheel 16 side is connected to the first inclined cam A second connection groove portion 182g for connecting an end portion of the groove portion 182b on the rear wheel 16 side and an end portion of the second inclined cam groove portion 182e on the rear wheel 16 side. Moreover, the 1st inclined cam groove part 182b and the 2nd inclined cam groove part 182e are arrange|positioned so that it may mutually oppose. 12 is a diagram showing the position of the drum cam 182 when the fork shaft 102 is in the high gear position, and FIG. 14 is a diagram showing the position of the drum cam 182 when the fork shaft 102 is in the low gear position.

As shown in FIG. 12 , in the first switching cam groove portion 182c, in a state where the cam engaging member 180 is engaged with the first switching cam groove portion 182c, even if the nut member 140, that is, the cam engaging member, is caused to be caused by the motor 84 180 rotates around the first axis C1 of the rear wheel side output shaft 44, but since the first switching cam groove portion 182c extends in a direction orthogonal to the third axis C3, the drum cam 182 also does not move toward the fork. The shaft 102 moves in the direction of the third axis C3. That is, in a state where the cam engaging member 180 is engaged with the first switching cam groove portion 182c, no matter how the nut member 140 rotates around the first axis C1 of the rear wheel side output shaft 44, the cam engaging member 180 is blocked. Relative movement of the drum cam 182 in the direction of the third axis C3 of the fork shaft 102 . Therefore, when the cam engaging member 180 is rotated in the direction of the arrow F3 around the first axis C1 by the motor 84 from the state in which the cam engaging member 180 is engaged with the first switching cam groove portion 182c, the When the fork shaft 102 is in the high gear position, the piston 82 of the front-wheel drive clutch 50 is moved from a position not pressed against the frictional engagement element 80 to a position of pressed against the frictional engagement element 80 . In addition, in FIG. 12 , within the range where the cam engaging member 180 engaged with the first switching cam groove portion 182c is rotated in the direction of the arrow F3 by the motor 84, the fork shaft 102 is at the high gear position and the front wheel The rotational range of the cam engagement member 180 in which the piston 82 of the drive clutch 50 is not pressed against the friction engagement element 80 , that is, the cam engagement member 180 released by the front wheel drive clutch 50 when the fork shaft 102 is in the high gear position The rotation range of is denoted as the first range H2. In addition, in FIG. 12, the fork shaft 102 is at the high gear position and the front wheel is in the range where the cam engaging member 180 engaged with the first switching cam groove portion 182c is rotated in the direction of the arrow F3 by the motor 84. The rotational range of the cam engagement member 180 in which the piston 82 of the driving clutch 50 is pressed against the friction engagement element 80 , that is, the cam engagement member 180 which is engaged with the front wheel drive clutch 50 when the fork shaft 102 is in the high gear position The rotation range of is represented as the second range H4.

13 is a diagram illustrating the position of the drum cam 182 relative to the cam engagement member 180 when the fork shaft 102 is switched from the high gear position to the low gear position. As shown in FIG. 13( a ), from the state in which the cam engaging member 180 is engaged with the end portion on the rear wheel 16 side of the first inclined cam groove portion 182 b , the nut member 140 is caused to surround the first axis by the motor 84 . When the cam engaging member 180 is rotated in the direction of the arrow mark F1 around the first axis C1 and the cam engaging member 180 is rotated in the direction of the arrow mark F1, the drum cam 182 moves along the first inclined cam groove portion 182b by the following amount Move in the direction of arrow F2, that is, in the direction of the third axis C3 of the fork shaft 102, the movement amount is greater than the amount of movement of the nut member 140 in the direction of the arrow F2, that is, greater than the distance between the nut member 140 and the threaded shaft member 148. The amount of movement that moves in the direction of the arrow mark F2 by the action of the screw. 13( a ) is a diagram showing the position of the drum cam 182 when the fork shaft 102 is at the high gear position, and FIG. 13( c ) is a diagram showing the position of the drum cam 182 when the fork shaft 102 is at the low gear position The position diagram, FIG. 13( b ) is a diagram showing the position of the drum cam 182 during the switching of the fork shaft 102 from the high-speed gear position to the low-speed gear position. In addition, the one-dot chain line circle shown in FIG.13(b) and (c) shows the position of the cam engaging member 180 of FIG.13(a).

The position of the drum cam 182 relative to the cam engaging member 180 is the same as that of FIG. 13( c ), as shown in FIG. 14 , in the second switching cam groove portion 182d, the cam engaging member 180 and the second switching cam groove are In a state where the end of the first inclined cam groove portion 182b side of the portion 182d is engaged, even if the cam engaging member 180, which is the nut member 140, is caused to move toward the arrow around the first axis C1 of the rear wheel side output shaft 44 by the motor 84 Although the second switching cam groove portion 182d extends in a direction orthogonal to the third axis C3, the drum cam 182 does not move in the direction of the third axis C3 of the fork shaft 102, either. That is, in a state where the cam engaging member 180 is engaged with the second switching cam groove portion 182d, the cam engaging member 180 is prevented regardless of how the nut member 140 rotates around the first axis C1 of the rear wheel side output shaft 44. Relative movement of the drum cam 182 in the direction of the third axis C3 of the fork shaft 102 . Therefore, from the state where the cam engaging member 180 is engaged with the end of the second switching cam groove portion 182d on the first inclined cam groove portion 182b side, the cam engaging member 180 is caused to surround the first axis C1 by the motor 84 . On the other hand, when turning in the direction of the arrow F3, the piston 82 of the front-wheel drive clutch 50 is moved from the position where the piston 82 of the front-wheel drive clutch 50 is not pressed against the friction engagement element 80 to the position where the fork shaft 102 is in the low gear position. The position on the engaging element 80 moves. 14, the fork shaft 102 is positioned at the low gear position and forward The rotational range of the cam engagement member 180 in which the piston 82 of the wheel drive clutch 50 is not pressed against the friction engagement element 80 , that is, the cam engagement member released by the front wheel drive clutch 50 when the fork shaft 102 is in the low gear position The rotation range of 180 is represented as the first range L2. In addition, in FIG. 14 , within the range where the cam engaging member 180 engaged with the second switching cam groove portion 182d is rotated in the direction of the arrow F3 by the electric motor 84, the fork shaft 102 is at the low gear position and the front wheel The rotational range of the cam engagement member 180 in which the piston 82 of the drive clutch 50 is pressed against the friction engagement element 80 , that is, the cam engagement member 180 engaged with the front wheel drive clutch 50 when the fork shaft 102 is in the low gear position The rotation range of , expressed as the second range L4.

The position of the drum cam 182 relative to the cam engaging member 180 is as shown in FIG. 13( c ) and FIG. 15( a ), which is the same as FIG. 14 , when the cam engaging member 180 and the second switching cam groove portion 182d The end portion on the side of the first inclined cam groove portion 182b, that is, the end portion of the first inclined cam groove portion 182b on the opposite side from the rear wheel 16 side is engaged, and the nut member 140 is surrounded by the motor 84. When the first axis C1 is rotated in the direction of the arrow mark F1 and the cam engaging member 180 is rotated in the direction of the arrow mark F1 around the first axis C1, the drum cam 142 is rotated along the first connecting groove portion 182f as shown in the figure. As shown in (b) of 15, it moves in the direction of the arrow mark F2. 15( a ) is a diagram showing the position of the drum cam 182 when the fork shaft 102 is at the low gear position, and FIG. 15( b ) is a diagram showing that the fork shaft 102 is moved further from the low gear position to the arrow The figure which marked the position of the drum cam 182 which moved in the F2 direction. As shown in (b) of FIG. 15 , when the drum cam 182 moves the fork shaft 102 further from the low gear position in the direction of the arrow F2, that is, from the stopper 174 (see FIG. 11 ) provided on the fork shaft 102 ) When the drum cam 182 is further moved in the direction indicated by the arrow F2 from the state in contact with the support portion 40a of the transfer case 40, since the spring member 162 of the waiting mechanism 144 is compressed, the drum cam 182 will pass through the The urging force Fa in the opposite direction to the direction indicated by the arrow F2 is applied to the elastic restoring force of the spring member 162 . Therefore, as shown in FIG. 15( b ), from the state in which the cam engaging member 180 is engaged with the first connection groove portion 182f, the cam engaging member 180 is caused to move toward the arrow around the first axis C1 by the motor 84 . When the drum cam 182 is rotated in the direction of the mark F1, the drum cam 182 is moved in the opposite direction to the direction of the arrow mark F2 by the above-mentioned urging force Fa, and as shown in FIG. 15( c ), the cam engaging member 180 and the second An end portion of the inclined cam groove portion 182e on the opposite side to the rear wheel 16 side is engaged. In addition, the one-dot chain line circle shown in FIG.15(b) and (c) shows the position of the cam engaging member 180 of FIG.15(a).

16 is a diagram illustrating the position of the drum cam 182 relative to the cam engaging member 180 when the fork shaft 102 is switched from the low gear position to the high gear position. The position of the drum cam 182 relative to the cam engaging member 180 is as shown in FIG. 16( a ), which is the same as FIG. 15( c ). The nut member 140 is rotated in the direction of the arrow F3 around the first axis C1 by the motor 84, and the cam engagement member 180 is rotated around the first axis C1 from the state where the opposite end of the wheel 16 is engaged. When the drum cam 182 is rotated in the direction indicated by the arrow F3, the drum cam 182 moves in the direction indicated by the arrow F4 along the second inclined cam groove portion 182e by a movement amount greater than that of the nut member 140 in the direction indicated by the arrow. The amount of movement in the direction opposite to the F2 direction (the direction indicated by the arrow F4 ), that is, is greater than the amount of movement of the nut member 140 in the direction indicated by the arrow F4 by the action of the thread between the nut member 140 and the threaded shaft member 148 . 16( a ) is a diagram showing the position of the drum cam 182 when the fork shaft 102 is at the low gear position, and FIG. 16( c ) is a diagram showing the position of the drum cam 182 when the fork shaft 102 is at the high gear position The position diagram, FIG. 16( b ) is a diagram showing the position of the drum cam 182 during the switching of the fork shaft 102 from the low gear position to the high gear position. In addition, the one-dot chain line circle shown in FIG.16(b) and (c) shows the position of the cam engaging member 180 of FIG.16(a).

The position of the drum cam 182 relative to the cam engaging member 180 is the same as that shown in FIG. 16( c ), as shown in FIG. 17( a ), when the rear wheel from the cam engaging member 180 and the second inclined cam groove portion 182e From the state where the ends on the 16 side are engaged, the nut member 140 is rotated in the direction of arrow F3 around the first axis C1 by the motor 84, and the cam engaging member 180 is rotated in the direction of arrow F3 around the first axis C1. During the rotation, the drum cam 182 moves in the direction indicated by the arrow F4 as shown in FIG. 17( b ) along the second connecting groove portion 182g. 17( a ) is a diagram showing the position of the drum cam 182 when the fork shaft 102 is at the high gear position, and FIG. 17( b ) is a diagram showing that the fork shaft 102 is further moved to the arrow mark F4 from the high gear position A diagram showing the position of the drum cam 182 whose direction has moved. As shown in FIG. 17(b), when the drum cam 182 further moves the fork shaft 102 in the direction of the arrow mark F4 from the high gear position, that is, the movement of the fork shaft 102 in the direction of the arrow mark F4 is not allowed. When the drum cam 182 is further moved in the direction of the arrow F4 from the state, since the spring member 162 of the waiting mechanism 144 is compressed, as shown in FIG. 17(b), the spring member 162 passes over the drum cam 182 as shown in FIG. The elastic restoring force is applied to the urging force Fb in the opposite direction to the direction of the arrow mark F4. Therefore, as shown in FIG. 17( b ), when the cam engaging member 180 is rotated in the direction of the arrow mark F3 by the motor 84 from the state in which the cam engaging member 180 is engaged with the second connecting groove portion 182g , the drum cam 182 moves in the opposite direction to the direction indicated by the arrow F4 by the above-mentioned biasing force Fb, and as shown in FIG. 17( c ), the cam engaging member 180 is engaged with the first switching cam groove portion 182c combine. In addition, the one-dot chain line circle shown in FIG.17(b) and (c) shows the position of the cam engaging member 180 of FIG.17(a).

In the transfer case 178 configured as described above, when the cam engaging member 180 is rotated about the first axis C1 by the motor 84 , the fork shaft 102 is driven by the cam groove 182 a formed in the drum cam 182 . From the high gear position to the low gear position or from the low gear position to the high gear position, the transmission torque of the front wheel drive clutch 50 can be adjusted while the fork shaft 102 is in the high gear position or the low gear position .

As described above, according to the transfer case 178 of the present embodiment, in the cam groove 182 a formed in the drum cam 182 , the cam groove 182 a extends in a direction inclined with respect to the third axis C3 of the fork shaft 102 and is engaged with the cam The first inclined cam groove portion 182b to which the member 180 is engaged and the second switching cam groove portion 182d extending in the direction orthogonal to the third axis C3 of the fork shaft 102 pass through the second switching cam groove portion 182d, thereby Regardless of how the nut member 140 rotates in the direction of the arrow F3 around the first axis C1 of the rear-wheel-side output shaft 44, the cam engagement member 180 and the drum cam 182 are prevented from being connected in the direction of the third axis C3 of the fork shaft 102. relative movement. Therefore, when the cam engaging member 180 is engaged with the first inclined cam groove portion 182b formed in the cam groove 182a of the drum cam 182, the nut member 140 is caused to rotate around the first axis C1 of the rear wheel side output shaft 44. When rotated in the direction of the arrow F1, the drum cam 182 moves relative to the cam engaging member 180 in the direction of the third axis C3 of the fork shaft 102, and for example, the high-low-speed switching mechanism 48 is switched to the low-speed side gear. Grade L. In addition, when the cam engaging member 180 engages with the second switching cam groove portion 182d of the cam groove 182a in a state where the high-low-speed switching mechanism 48 is switched to the low-speed side gear stage L, no matter how the nut member 14 surrounds the rear The rotation of the first axis C1 of the wheel-side output shaft 44 in the direction of the arrow F3 prevents the relative movement of the cam engaging member 180 and the drum cam 182 in the direction of the third axis C3 of the fork shaft 102. Therefore, at high and low speeds When the switching mechanism 48 is switched to the low-speed side gear stage L, the nut member 140 moves in the direction of the first axis C1 of the rear wheel side output shaft 44, and the linear motion of the nut member 140 is transmitted via the first transmission mechanism 88d. to the clutch 50 for front wheel drive. Thereby, in the state where the high-low-speed switching mechanism 48 is switched to the low-speed side gear stage L, the transmission torque transmitted to the drive gear 46 can be adjusted by the front-wheel drive clutch 50 .

Further, according to the transfer case 178 of the present embodiment, the first switching cam groove portion 182c is provided at the end portion of the first inclined cam groove portion 182b on the rear wheel 16 side, and the first inclined cam groove portion 182b is connected to the rear wheel. A second switching cam groove portion 182d is provided at the end portion on the opposite side to the 16 side. Therefore, when the cam engaging member 180 is engaged with the first switching cam groove portion 182c or the second switching cam groove portion 182d by rotating the nut member 140 around the first axis C1 of the rear wheel side output shaft 44 , the high-low-speed switching mechanism 48 can be switched to the high-speed side gear stage H or the low-speed side gear stage L. In the state where the cam engaging member 180 is engaged with the first switching cam groove portion 182c or the second switching cam groove portion 182d, even if the nut member 140 rotates around the first axis C1 of the rear wheel side output shaft 44 However, no matter how the nut member 140 rotates around the first axis C1 of the output shaft 44 on the rear wheel side, the movement of the drum cam 182 in the direction of the third axis C3 of the fork shaft 102 is prevented, so that the high and low speed can be switched between The transmission torque transmitted to the drive gear 46 is adjusted by the clutch 50 for front wheel drive while the mechanism 48 is switched to the state of the high speed side gear stage H or the low speed side gear stage L.

Example 4

FIG. 18 is a diagram illustrating a transfer case 184 according to another embodiment of the present invention. The transfer case 184 of the present embodiment is different from the transfer case 22 of the first embodiment in that the structure of the screw mechanism 190 is changed as follows, and is different from the transfer case of the first embodiment in other points. The nut member 188 is moved in the direction of the first axis C1 of the rear wheel side output shaft 44 by driving the screw shaft member (one screw member) 186 to rotate by the motor 84 in substantially the same manner as the actuator 22 .

As shown in FIG. 18 , the clutch hub 76 is formed with a protrusion 76 a protruding in a direction approaching the end of the threaded shaft member 186 on the front wheel 14 side. The first thrust bearing 192 is arranged between the wheel-side ends. Further, the transfer case 40 is formed with a protrusion 40b protruding in a direction approaching the end of the screw shaft member 186 on the rear wheel 16 side, and the protrusion 40b and the end of the screw shaft member 186 on the rear wheel 16 side are formed with the protrusion 40b. A second thrust bearing 194 is arranged between the parts. In addition, the threaded shaft member 186 is supported by the rear wheel side output shaft 44 so as to be relatively rotatable via the needle bearing 97 . That is, by the protrusion 76a of the clutch hub 76 and the protrusion 40b of the transfer case 40, the threaded shaft member 186 cannot move in the direction of the first axis C1 of the rear wheel side output shaft 44 and can pass through The needle bearing 97 is supported by the rear wheel side output shaft 44 so as to rotate around the first axis C1 of the rear wheel side output shaft 44 . In addition, the threaded shaft member 186 is formed with a worm wheel 186 a that meshes with the worm 98 formed on the motor shaft of the electric motor 84 , and the threaded shaft member 186 is connected to the drum cam 100 .

Further, as shown in FIG. 18 , the transfer case 40 is formed with inner peripheral spline teeth 40c, and the nut member 188 is formed with outer peripheral spline teeth 188a which are spline-fitted with the inner peripheral spline teeth 40c. The nut member 188 is screwed to the threaded shaft member 186 via the plurality of balls 196 , and the screw mechanism 190 is a ball screw in which the nut member 188 and the threaded shaft member 186 operate via the plurality of balls 196 . That is, the nut member 188 is supported so as to be movable in the direction of the first axis C1 of the rear wheel side output shaft 44 but not rotatable about the first axis C1 by the inner peripheral spline teeth 40c of the transfer case 40 . on the transfer case 40.

Accordingly, when the threaded shaft member 186 is rotationally driven by the electric motor 84, the nut member 188 moves in the direction of the first axis C1 of the rear wheel side output shaft 44, and the linear motion of the nut member 188 passes through the first transmission mechanism 88a is transmitted to the front-wheel drive clutch 50 . Further, when the screw shaft member 186 is driven to rotate by the motor 84, the drum cam 100 connected to the screw shaft member 186 is rotated, and the cam engaging member 103 engaged with the cam groove 100c is positioned on the fork shaft. 102 moves in the direction of the third axis C3, and the linear motion of the cam engaging member 103 is transmitted to the high-low speed switching mechanism 48 via the second transmission mechanism 88b.

As described above, according to the transfer case 184 of the present embodiment, the nut member 188 is supported so as not to be rotatable around the first axis C1 of the output shaft 44 on the rear wheel side, and the threaded shaft member 186 cannot be output on the rear wheel side. The shaft 44 is supported so as to be movable in the direction of the first axis C1 and rotatable around the first axis C1 of the output shaft 44 on the rear wheel side. In this way, when the threaded shaft member 186 is rotationally driven by the electric motor 84, the nut member 188 moves in the direction of the first axis C1 of the rear wheel side output shaft 44, and the linear motion of the nut member 188 passes through the first transmission mechanism 88a is transmitted to the front-wheel drive clutch 50 . Then, when the screw shaft member 186 is rotationally driven by the motor 84, the drum cam 100 connected to the screw shaft member 186 is rotated, and the cam engaging member 103 engaged with the cam groove 100c is moved toward the fork. The shaft 102 moves in the direction of the third axis C3, and the linear motion of the cam engaging member 103 is transmitted to the high-low-speed switching mechanism 48 via the second transmission mechanism 88e.

Although the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention can be applied to other forms.

For example, in the above-described embodiment, the transfer case 22 , 134 , 178 , 184 is provided with the front wheel drive clutch 50 that adjusts the transmission torque transmitted to the drive gear 46 , but the front wheel drive clutch 50 may be substituted for the front wheel drive. The wheel drive clutch 50 is provided with a dog clutch (engaging clutch) that transmits or blocks a part of the power of the rear wheel side output shaft 44 to the drive gear 46 .

In addition, in the above-mentioned embodiment, although the ball screw was exemplified as the screw mechanism 86, it is not limited to this form. For example, the screw mechanism 86 only needs to be a conversion mechanism that converts the rotational motion of the motor 84 into linear motion, and it may be a simple combination of the screw shaft member 94 and the nut member 92 that are directly screwed to each other. . Specifically, the screw mechanism 86 may be a slide screw or the like. In the case of the sliding screw, the mechanical efficiency of converting the rotary motion into the linear motion is set to be lower than that of the ball screw, but a certain effect is obtained, that is, the clutch for driving the front wheel can be obtained. 50 exerts a higher thrust, or the stroke required for the operation of the high-low-speed switching mechanism 48 can be obtained.

In addition, in the above-mentioned embodiment, although the screw mechanism 86 is indirectly connected to the electric motor 84 via the worm gear mechanism 90, it is not limited to this form. For example, the nut member 92 of the screw mechanism 86 and the electric motor 84 may be directly connected without the worm gear mechanism 90 . Specifically, the nut member 92 and the electric motor 84 may be directly connected so that the pinion provided on the motor shaft of the electric motor 84 meshes with the gear teeth formed in the nut member 92 .

In addition, in the above-described embodiment, the FR-based four-wheel drive vehicle is exemplified as the vehicle 10 to which the transfer case 22 , 134 , 178 , 184 is applied, but it is not limited to this. For example, the vehicle 10 to which the transfer case 22, 134, 178, 184 is applied may also be a front-engine front-wheel drive (FF) based four-wheel drive vehicle. In addition, although the clutch 50 for front-wheel drive is a multi-plate clutch, this invention can be applied even if it is a single-plate clutch. Further, the transfer case 22 may include a gear position holding mechanism 120 or a low-speed gear position detection switch 130 .

Further, in the aforementioned embodiments, the engine 12 exemplified as the driving force source uses an internal combustion engine such as a gasoline engine or a diesel engine. In addition, as a driving force source, another power machine such as an electric motor can be used alone or in combination with the engine 12 . In addition, the transmission 20 is various automatic transmissions, such as a planetary gear type multi-speed transmission, a continuously variable transmission, a synchromesh type parallel two-shaft transmission (including a well-known DCT), or a well-known manual transmission. In addition, although the front clutch 36 is an electromagnetic dog clutch, it is not limited to this. For example, the front clutch 36 may be a dog tooth of a form including a shift fork that moves the sleeve in the axial direction, and the shift fork is driven by an actuator that can be electrically or hydraulically controlled clutch or friction clutch.

In addition, the above-mentioned content is only one embodiment, and this invention can be implemented with the form which added various changes and improvement based on the knowledge of those skilled in the art. For example, in the first embodiment described above, as shown in the third embodiment, when the fork shaft 102 is at the low gear position, the outer peripheral teeth 70a of the lock sleeve 70 can be prevented from meshing with the lock teeth 68, and the The cam groove 100c of the drum cam 100 is a cam groove 182a having a shape like the drum cam 182. As shown in FIG.

Symbol Description

22, 134, 178, 184: Transfer case; 42: Input shaft; 44: Rear wheel side output shaft (output shaft); 46: Drive gear (output part); 48: High and low speed switching mechanism; 50: Front wheel drive For clutch (clutch); 73: Second support bearing (output shaft support bearing); 84: Electric motor (actuator); 94, 148: Screw shaft member; 92, 140: Nut member (one screw member); 86 , 138, 190: screw mechanism; 88a, 88d: first transmission mechanism (first transmission mechanism); 88b, 88e: second transmission mechanism (second transmission mechanism); 96, 152: balls; 100, 142, 182: Drum cam; 100c, 142a, 182a: cam groove; 100d, 142b: inclined cam groove part; 100e, 142c: first cam groove part (switching cam groove part); 102: fork shaft (second shaft); 103, 136, 180: cam engagement member; 106: waiting mechanism; 112: spring member; 146: worm gear mechanism; 146a: worm gear; 182b: first inclined cam groove portion (inclined cam groove portion); 182c: first switching cam groove portion (switching cam groove portion); 182d: second switching cam groove portion (switching cam groove portion); 182e: second inclined cam groove portion (inclined cam groove portion); 186: screw shaft member (one screw member) ;188: Nut part; C1: First axis (shaft center); C3: Third axis (shaft center); D: Movement amount; H: High-speed side gear stage; L: Low-speed side gear stage.

Claims (12)

1. a kind of transfer gear, comprising:

Input shaft；

Output shaft；

Output block is configured to, to the output target output power different from the output shaft；

High low speed switching mechanism, is configured to, and transmits the rotation speed change of the input shaft and to the output shaft, and The high low speed switching mechanism includes high-speed side gear stage and low speed side gear stage；

Clutch is configured to, and a part of the power of the output shaft is passed from the axial output block of the output It passs or is truncated or the transmitting torque transmitted from the axial output block of the output is adjusted；

Actuator；

Thread mechanism comprising as the thread spindle component and nut part of a pair of of screwed part, the thread spindle component with And the nut part mutually screws up, the thread mechanism is configured to, and makes the thread spindle component by the actuator And the screwed part of the either side in nut part rotates driving around the axle center of the output shaft, to make described Nut part is moved on the axis direction of the output shaft；

First transmission mechanism, is configured to, by movement of the nut part on the axis direction of the output shaft to institute Clutch is stated to be transmitted；

Second transmission mechanism comprising the second axis configured in parallel with the output shaft, second axis is configured to, in institute It states and is moved on the axis direction of the second axis；

Cam engaging part, the either side being attached in the screwed part and second axis of the party On；

Drum cam is attached on another party in the screwed part and second axis of the party, and is wrapped The cam path engaged with the cam engaging part is included, the drum cam is configured to, and passes through the screwed part of the party The axle center around the output shaft rotation on the axis direction of second axis relative to the cam holding section Part makes a relative move,

Second transmission mechanism will be concatenated the cam engaging part and the drum cam on second axis In movement of the side on the axis direction of second axis via second axis and to the high low speed switching mechanism into Row transmitting, so that the high low speed switching mechanism is switched to high-speed side gear stage and low speed side gear stage.

2. transfer gear as described in claim 1, wherein

The cam path of the drum cam include tilting cam groove portion and switching cam groove portion,

The tilting cam groove portion to the axle center in axle center or second axis relative to the output shaft and inclined direction Extend,

The switching cam groove portion direction orthogonal to the axle center in axle center or second axis relative to the output shaft Extend,

The switching cam groove portion is configured to, no matter the screwed part of the party how to surround the axle center of the output shaft into Row rotation prevents the cam engaging part and the drum cam described opposite on the axis direction of second axis It is mobile.

3. transfer gear as claimed in claim 2, wherein

The switching cam groove portion includes that the first switching cam groove portion and second switch cam groove portion,

On the end for the side that the first switching cam groove portion is arranged on the tilting cam groove portion,

On the end for another party that the second switching cam groove portion is arranged on the tilting cam groove portion.

4. the transfer gear as described in any one in claims 1 to 3, wherein

The cam path of the drum cam include tilting cam groove portion and switching cam groove portion,

The tilting cam groove portion to the axle center in axle center or second axis relative to the output shaft and inclined direction Extend,

The tilting cam groove portion is configured to, in the screwed part for making the party by the actuator around described defeated When the axle center of shaft is rotated, make the drum cam with the nut part on the axis direction of the output shaft Amount of movement compare and biggish amount of movement and carried out on the axis direction of second axis relative to the cam engaging part Relative movement.

5. the transfer gear as described in any one in claims 1 to 3, wherein

The cam engaging part is concatenated on second axis,

The drum cam is attached on the screwed part of the party.

6. transfer gear as claimed in claim 5, wherein

The drum cam is attached on the nut part,

The nut part is supported in such a way that the axle center that can surround the output shaft is rotated,

The thread spindle component on the axis direction of the output shaft can not carry out mobile and can not surround described defeated The mode that the axle center of shaft is rotated is supported.

7. transfer gear as claimed in claim 5, wherein

The drum cam is attached on the thread spindle component,

The nut part is supported in such a way that the axle center that can not surround the output shaft is rotated,

The thread spindle component on the axis direction of the output shaft can not carry out mobile and can surround the output The mode that the axle center of axis is rotated is supported.

8. transfer gear as claimed in claim 5, wherein

The end of the drum cam side in the both ends of the output shaft is supported in a manner of it can rotate defeated Shaft support bearing out is configured in the drum in the length range on the axis direction of the output shaft of the drum cam The inside of shape cam.

9. the transfer gear as described in any one in claims 1 to 3,6 to 8, wherein

The actuator is attached on the nut part of the thread mechanism via worm gear mechanism,

The cam engaging part is attached on the worm gear of the worm gear mechanism,

The drum cam is concatenated on second axis,

The drum cam is the part-cylindrical shape along the periphery of the worm gear.

10. the transfer gear as described in any one in claims 1 to 3,6 to 8, wherein

Second transmission mechanism includes waiting mechanism, and the waiting mechanism is via spring members and by the cam engaging part In the movement of movement or the drum cam on the axis direction of the output shaft on the axis direction of the output shaft It is transmitted to second axis.

11. the transfer gear as described in any one in claims 1 to 3,6 to 8, wherein

The nut part is screwed up via multiple balls with the thread spindle component.

12. the transfer gear as described in any one in claims 1 to 3,6 to 8, wherein

The clutch is the either side in veneer clutch and multi-plate clutch,

The clutch is configured to, and the transmitting torque of the opposite output block transmitting is adjusted.