JPS6056631A - Power transmission apparatus for shaft driving type car - Google Patents

Abstract

PURPOSE:To obtain a compact apparatus by selectively connecting bevel gears with a driving shaft by a shift mechanism and suppressing the increase of the width of a crankcase. CONSTITUTION:On the outer periphery between a bevel gear 35 for advance and a bevel gear 37 for retreat on a front shaft 21, a shift member 39 which constitutes a shift mechanism 42 is installed through straight spline engagement so as to be shiftable in the direction of axis line with respect to the front shaft 21 and not to be revolved around the axis. When the shift member 39 is transferred forward, the dog teeth 40 at the front edge engage with the bevel gear 35 for advance and connects said bevel gear 35 with the front shaft 21. When the shift member is transferred rearward, other dog teeth 41 at the rear edge engage with the gear 37 for retreat and connects the bevel gear 37 with the front shaft 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle whose rear wheels are driven by a shaft, and more particularly to the structure of a power transmission device that transmits engine power to the rear wheels.

For example, a shaft-driven four-wheeled motor vehicle can be driven in reverse by incorporating a pack gear into its power transmission system.

In this case, if the pack gear is installed on the transmission side of the engine, a new gear train will be required, so it is proposed to install the pack gear at the connection between the engine power output shaft and the drive shaft for driving the rear wheels. ing.

However, in the past, the output shaft that outputs engine power was extended and a pack gear was installed on this extended part, which caused the problem that the width of the crankcase increased by the length of the shaft. There was room for thought.

The present invention was made based on these circumstances, and
To provide a power transmission device for a shaft-driven vehicle that is simple in structure and compact in its entirety in making it possible to move backwards without significantly modifying an existing engine.

That is, in order to achieve the above object, the present invention provides a pair of bevel gears facing each other at the front end of a rear wheel drive drive shaft extending in the longitudinal direction of the vehicle body, and these bevel gears are connected to the output shaft of the engine. The present invention is characterized in that a shift mechanism is provided between the pair of bevel gears and selectively connects the bevel gears to the drive shaft while meshing with other bevel gears provided in the bevel gears.

An embodiment of the present invention will be described below based on drawings in which the present invention is applied to a four-wheeled motor vehicle.

In the figure, reference numeral 1 denotes a frame constituting the vehicle body. At the front of this frame 1, left and right front wheels 3, 3, which are steered by a steering wheel 2, are supported. Approximately in the center along the longitudinal direction of the frame 1 is a 4-cycle single-cylinder ennon 4
A fuel tank (not shown) is installed above the engine 4 and is covered by a force/reflector 5, and a seat 6 is connected to the rear of the engine 4. It is set up.

A crankshaft 9 driven by a piston 8 is accommodated in the crankcase 7 of the engine 4, as schematically shown in FIG. The signal is transmitted to the shaft 10 and is also transmitted to the output shaft 1 through a gear transmission 13 of a constant mesh type. One end of this output shaft 11 is connected to the crankcase 7
The bevel gear 34 on the output side is fixed to this lead-out portion.

A hollow cylindrical rear arm 15 extending rearward is connected to the rear end opening of the case cover 14, and this rear arm 15 is located on one side of the vehicle body. A gear case 16 is connected to the rear end opening of the rear arm 15, and a rear wheel shaft 18 is pivotally supported by the gear case 16 via a bearing 17. Left and right rear wheels 19 and 19 are attached to both ends of the rear wheel shaft 18.

A drive shaft 20 for driving rear wheels 19 and 19 is inserted through the rear arm 15. The drive shaft 20 of this embodiment is divided into two parts, a front shaft 21 and a rear shaft 22, and these two shafts 21 and 22 have an externally toothed gear 23 on the front shaft 21 side and an internally toothed gear 23 on the rear shaft 22 side. They are interlocked by meshing with the gear 24. The rear end of the rear shaft 22 is introduced into the gear case 16, and a reducing bevel gear 25 provided at this introduced end meshes with a reducing bevel gear 27 that is pivotally supported in the gear case 16 via a 41tt receiver 26. ing.

A sleeve 7'2B is welded to the center of the reducing bevel gear 27, and this sleeve 28 is engaged with the outer periphery of the rear wheel shaft 18 in a straight line so that it rotates together with the rear wheel shaft 18. There is.

Further, the opening of the gear case 16 is closed by a cover 29 which also serves to support the bearing 26, and this cover 29 is also supported on the frame 1 side. cover 29
is integrally formed with a hollow hub 30 that covers the rear wheel shaft 1B,
This hollow knob 30 is provided with three drum brakes for driving the rear wheels facing the gear case 16. The rear shaft 22 is provided with a buffer mechanism 32 that absorbs and alleviates power transmission to the front shaft 21 when an excessive reverse load is applied from the rear shaft 22 side.

The front end of the front shaft 21 is introduced into the case cover 14 and is located within the case cover 14 perpendicularly to one end of the output shaft 11. A forward bevel gear 35 and a reverse bevel gear 37 are attached to the front end of the front shaft 21 so as to face each other. The forward bevel gear 35 is rotatably attached to the front shaft 2 via a sleeve 33, and a bearing 3 is mounted on the inner surface of the case cover 14.
6, and is always engaged with the output bevel gear 34 from the front side of the vehicle body. Further, the reverse bevel gear 37 is pivotally supported within the front end opening of the rear arm 15 via a bearing 38, and is always engaged with the output side bevel gear 34 from the rear side of the vehicle body. therefore,
The forward bevel gear 35 and the reverse bevel gear 37 are rotated in opposite directions due to their meshing directions with respect to the output bevel gear 34. On the outer periphery between the forward bevel gear 35 and the reverse bevel gear 37 on the front shaft 21, a shift member 39 constituting the shift mechanism 42 is connected to the front shaft 2 by straight spline engagement. Although it is movable in the axial direction, it is mounted so that it cannot rotate in the axial direction. When the shift member 39 is moved forward, the dog teeth 40 at the front end thereof mesh with the forward bevel gear 35 to connect the forward bevel gear 35 to the front shaft 2, and when the shift member 39 is moved backward, the rear Another dog tooth 41 at the end meshes with the reverse bevel gear 37 to connect the bevel gear 37 to the front shaft 2.

On the other hand, such a shift member 39 is reciprocated on the front part @21 by a shift mechanism 42 that is interlocked with forward and reverse switching operations. This shift mechanism 42 will be explained with reference to FIGS. 4 to 6. A guide rod 43 is housed inside the case cover 14 outside the front shaft 21 and parallel to the front shaft 2. A goss portion 45 of a shift hawk 44 is attached to the guide rod 43 so as to be slidable in the axial direction. A fork-shaped claw portion 46 at the tip of the syntohawk 44 fits into a groove portion 47 on the outer periphery of the shift member 39, and by reciprocating the shift fork 44 in the axial direction of the guide rod 43, the shift member 39 is front axis 2
1 toward the forward bevel gear 35 side or the reverse bevel gear 37 side. When the dogs 40 and 41 of the clutch member 39 mesh with the forward bevel gear 35 and the backward bevel gear 37, the ball 48 housed in the boss portion 45 is inserted into the groove 48 on the outer peripheral surface of the guide rod 43.゜49
The shift fork 44 is configured to be elastically fitted therein to position the shift fork 44.

Furthermore, a bracket 51 is fixed to the upper surface of the front end of the crankcase 7 and is located on one side of the cylinder 50 of the engine 4. An operating lever 53 and a lever 54 are mounted on a pivot shaft 52 that is pivoted to the bracket 5. Fixed. The operating lever 53 is manually operated by the driver, and is reciprocated between a forward traveling position in which it is pushed forward and a reverse traveling position in which it is pulled backward. It is designed to be held in position.

Further, on the upper surface of one side of the case cover 14, a rotation shaft 56 extending in the vertical direction is pivotally supported.

The upper end of the rotating shaft 56 passes through the case cover 14 and is led out, and a rotating lever 57 is fixed to this leading end. The tip of this rotating lever 57 and the tip of the lever 54 are connected by the blade 5 and the rod 58. Therefore, when the operating lever 53 is rotated back and forth, the rod 58 is reciprocated in the front and back direction, and this rod The reciprocating motion of 58 is again converted into a rotary motion by the rotary lever 57 and transmitted to the rotary shaft 56. A shift lever 59 is fixed to the lower end of the rotation shaft 56 which is rotated in conjunction with the operation lever 53, and the tip of the shift lever 59 is connected to the projection on the upper surface of the above-mentioned part 45. 60, and this engagement moves the entire shift hawk 44 to the guide rod 4.
It is designed to move back and forth in the axial direction of 3.

When the operating lever 53 is set to the forward traveling position as shown in FIG. It meshes with the bevel gear 35. Therefore, the rotation of the output shaft 11 is transmitted to the drive shaft 2o via the output side bevel gear 34, the forward bevel gear 35, and the shift member 39. Since the rotation of the drive shaft 2θ rotates the sleeper IJ-f 28 via the reducing bevel gear 25 and the reducing bevel gear 27, the rear wheel shaft 18 engaged with the sleeper 28
is rotated in the direction of the arrow, thereby driving the rear wheels 19, 19 in the forward direction.

Next, when the operating lever 53 is pulled rearward and switched to the reverse travel position, the rod 58 is pushed rearward, so that the shift lever 59 is moved to the third position via the rotary lever 57 and the rotary shaft 56.
As shown by the imaginary line in the figure, it is rotated at a constant angle toward the rear.

Shift member 3 via shift hawk 44 due to rotation with
9 is moved to the reverse bevel gear 37 side, the meshing between the dog tooth 40 and the forward bevel gear 35 is released, and conversely, the other dog tooth 4) at the ridge end of the clutch member 39 is disengaged.
meshes with the reverse bevel gear 37 by 9 degrees. Therefore, the output shaft 110
Since the rotation is transmitted to the drive shaft 20 through the output side bevel gear 34, the general purpose bevel gear 37, and the shift member 39, the drive shaft 20 is rotationally driven in the opposite direction. Then, the drive shaft rotates 200 times, following the same path as in the case of forward movement.
Since the signal is traced and transmitted to the temporary ring 18, the rear wheels 19 and 19 are driven in the opposite direction, making it possible to move to the left.

This type of power transmission device is caused by a bevel gear 35 for RIJ forward movement and a bevel gear 37 for reverse movement on the 111J shaft 2 for rear SRM movement extending in the longitudinal direction on one side of the vehicle body.
Since these are provided facing each other, there is no need to significantly change the structure of the engine 4 or its shifting gear 13 side when installing the reverse gear. Moreover, in this case, even if the reverse bevel gear 37 is provided at the connection between the output shaft 1 and the drive shaft 20, it is also necessary to extend the output shaft 11 as in the conventional case, which increases the width of the crankcase 7 side. can be suppressed.

Furthermore, the shift member 39 that selectively connects the forward bevel gear 36 and the reverse bevel gear 37 directly to the front shaft 21 is installed at a position exactly facing the output side bevel gear 34.
A part of the gap on the front shaft 2 can be effectively used. At the same time, the output side bevel gear 34 and the forward bevel gear 35
Since the reduction ratio between the reduction bevel gear 25 and the reduction bevel gear 27 is much smaller than that between the reduction bevel gear 25 and the reduction bevel gear 27, the reverse bevel gear 37 is provided on the side of the output side bevel gear 34. For example, the bevel gear 37 does not become large in size, which also contributes to downsizing of the entire device.

Furthermore, the reverse bevel gear 37 can be installed on the front portion 41127 at a position opposite to the forward bevel gear 35, and at a position where the direction of engagement with the rear output bevel tooth base 34 is opposite. The structure can be simplified without increasing the number of gears.The vehicle according to the present invention is not limited to a four-wheeled motor vehicle, and the same applies even if the vehicle is a three-wheeled motor vehicle with one front wheel. It can be implemented.

According to the present invention described in detail above, a pair of bevel gears facing each other is provided at the front end of the drive shaft extending in the front-rear direction of the JJL body, and these bevel gears are meshed with another bevel gear of the output shaft. Since the shift mechanism is selectively connected to the drive shaft, even if a bevel gear for reversing is provided at the connection between the output shaft and the drive shaft, in order to enable reverse travel, it is possible to There is no need to extend the output shaft as described above, and the increase in the width of the crankcase can be suppressed, making it possible to make the entire device more compact. In addition, since the reverse bevel gear only needs to be opposed to the forward bevel gear, the number of shafts and gears does not increase significantly, which has the advantage of simplifying the power transmission mechanism for the reverse drive.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a side view of a four-wheeled motor vehicle, Fig. 2 is a rear view, Fig. 3 is a sectional view of the power transmission system, and Fig. 4 is a cross-sectional view of the four-wheeled motor vehicle. Figure 5 is a partially sectional side view of the operating mechanism, Figure 6 is a side view taken along line -■, Figure 6 is Vl-
It is an arrow view along the Vl storehouse. 1...AL body (frame), 4...engine, 11
...output shaft, 18...rear wheel shaft, 2o...drive shaft,
34... Output side bevel gear, 35... Forward bevel gear, 3
7... Reverse bevel gear, 39... Shift member, 42...
...Shift mechanism. Applicant's agent Patent attorney Takehiko Suzue Cause 1 Figure 2

Claims (1)

[Claims] In a chassis 71-driven vehicle in which the output shaft of the engine and the rear wheel shaft are connected by a drive shaft extending along the front-rear direction of the vehicle body, a pair of bevel gears facing each other is provided at the front end of the drive shaft, and these A shaft-driven vehicle characterized in that a gear is meshed with another bevel gear provided on the output shaft, and a shift mechanism is provided between the pair of bevel gears to selectively connect these bevel gears to the drive shaft. power transmission device.