JP4378794B2 - Power transmission device for moving vehicles - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a power transmission device in a mobile vehicle such as an agricultural tractor or a riding management machine, and intends to simplify the configuration of a power transmission unit in a mission case.
[0002]
[Prior Art and Problems to be Solved by the Invention]
2. Description of the Related Art A mobile vehicle such as an agricultural tractor has a known structure in which various shift modes such as a key shift type and a gear slide type are different or the number of shift stages is different even if the gear transmission mode is also used.
By the way, as described above, when the speed change mode, the number of steps, and the like are different, it is common to prepare another mission case to correspond to a model having a different specification.
[0003]
However, preparing a new transmission case for each transmission mode and the like in this manner tends to increase costs.
[0004]
[Means for Solving the Problems]
The present invention is proposed in view of the above-mentioned problems, and the following technical means have been taken.
That is, a key shift type transmission mechanism and a slide gear type transmission mechanism in which the transmission operation direction is a linear direction in a transmission case (12) that includes a transmission mechanism that appropriately changes the rotational power from the engine (7) side. And a clutch (18) is provided on the bottom surface of the front end in the transmission case (12), and a speed change operation part for various transmissions is provided in an excess space above the clutch (18).
The clutch (18) includes a clutch drum (18a) integrally fixed to a clutch side gear (17) meshed with a gear (16) fixed to a rear end portion of the input shaft (14) and a clutch support shaft (19). And a large number of friction plates (22) between the boss portion (20) rotating integrally therewith,
A hydraulic pump (28) is detachably provided at the front portion of the transmission case (12) driven by a clutch side gear (17) integral with the clutch drum (18a),
In the key shift type transmission mechanism, when the engine speed is low, the shift shaft (48) is directly moved back and forth without disengaging the clutch (18) to change the speed.
Further, a driven shift member for shifting the key shift transmission mechanism and the slide gear transmission mechanism is provided in the transmission case (12), and a shift operation member (77) for artificially shifting the driven shift member is provided. Both the key shift transmission mechanism and the slide gear transmission mechanism are configured to be shared by the same member,
Furthermore, a power transmission device for a mobile vehicle, characterized in that a mission case (12) is shared by providing a support metal (75) for the key shift transmission mechanism and a support metal (110) for the slide gear transmission mechanism. The configuration is as follows.
[ 0005 ]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on the embodiments shown in the drawings.
Reference numeral 1 denotes a small tractor, which has front wheels 2, 2 and rear wheels 3, 3 on the front and rear portions of the fuselage. An engine 7 is mounted in the bonnet 4, and this engine 7 has a flywheel 5 on the front side and a radiator 6 It is attached to the fuselage with the mounting direction opposite to normal so that is on the rear side.
[0006]
An output shaft 10 that protrudes rearward from the engine 7 and an input shaft 14 that is mounted on the front wall of the transmission case 12 are interlocked and connected via a universal joint 15 to transmit the rotational power on the engine 7 side to the transmission case. It is configured to transmit to the 12 side.
The configuration of the power transmission system will be described with reference to FIG.
The rear end of the input shaft 14 is secured a gear 16, the clutch-side formic ya 17 with the gear 16 meshes constantly. A clutch drum 18a of the clutch 18 is integrally fixed to the clutch side gear 17, and a large number of friction plates 22 are provided between the clutch drum 18a and the boss portion 20 rotating integrally with the clutch support shaft 19. It is intervened. A ring body 24 is provided on the clutch support shaft 19 in a non-rotatable state. When the ring body 24 is moved forward by stepping on a clutch pedal (not shown), the interval between the friction plates 22 is increased and the clutch 18 is disengaged. Further, when the clutch pedal is stepped on, the lining 25 fixed to the front portion of the ring body 24 is pressed against the end surface of the boss portion 20 so as to brake it and stop the rotation of the clutch support shaft 19. In the figure, reference numeral 26 denotes a spring member. Reference numeral 28 denotes a hydraulic pump, which is detachably attached to the front portion of the transmission case 12 and is rotationally driven by obtaining rotational power from the front portion of the clutch side gear 17. The hydraulic pump 28 serves as a drive source for driving the working machine 92 such as a rotary tiller connected to the rear part of the machine body up and down by hydraulic pressure. Although different from this embodiment, the power steering device may be operated using the hydraulic pump 28.
[ 0007 ]
A small-diameter gear 27 is fixed to the rear end portion of the clutch support shaft 19, and a large-diameter gear 30a of the two-stage gear 30 is always meshed with the gear 27. The two-stage gear 30 is loosely fitted on a transmission shaft 32 to be described later.
Four gears 34, 35, 36, and 37 are integrally fixed by spline fitting to a shift counter shaft 33 that is provided behind the clutch support shaft 19 and has the same axial center. The gear 34 always meshes with the small-diameter gear 30b of the two-stage gear 30, and transmits the rotational power on the clutch support shaft 19 side to the counter shaft 33 side.
[ 0008 ]
The gear 35 meshes with the first-speed gear 39 on the transmission shaft 32, the gear 36 meshes with the second-speed gear 40, and the gear 37 always meshes with the third-speed gear 41 on the transmission shaft 32. ing.
A plurality of locking grooves 44 that are recessed in the radial direction are provided on the inner peripheral surfaces of the gears 39, 40, and 41, and the tips of keys 47 and 47, which will be described later, enter the locking grooves 44. The corresponding gear and the transmission shaft 32 are configured to rotate together.
[ 0009 ]
The keys 47 and 47 are attached to one shifter shaft 48 made of a solid bar. Specifically, the rear end portion (right side) of the shifter shaft 48 is cut into a slit shape, and two pieces are provided in this slit portion. The keys 47 and 47 are pivotally attached. One spring 49 is interposed between the pair of keys 47, 47. The claws 47a, 47a of the keys 47, 47 expand outward, and the protrusions of the claws 47a, 47a are locked. It enters into the groove 44.
[ 0010 ]
A neutral collar 50 is provided immediately before the first-speed gear 39, and a reverse gear 51 is loosely fitted on the transmission shaft 32 in front of the collar.
Reference numeral 52 denotes a back counter gear attached to the reverse counter shaft 46. The back counter gear is always engaged with the gear 35. When the keys 47 and 47 enter the groove 44 of the reverse gear 51, the transmission shaft 32 rotates in the reverse direction. It is like that. 53 is a circumferential locking groove provided at the front end portion of the shifter shaft 48. When a shifter described later is fitted into the groove 53 portion and an operation lever (not shown) is reciprocated in the front-rear direction, the shifter shaft 48 is moved back and forth. Moving in the direction, one of reverse, forward 1st speed, forward 2nd speed, and forward 3rd speed is selected.
[ 0011 ]
Two sets of two-stage gears 54 and 55 are loosely fitted on the transmission countershaft 33 so as not to move back and forth, but to rotate only, and the front two-stage gear 54 has a large diameter on the front side. The gear 54a always meshes with the gear 57 at the rear end of the transmission shaft 32. The small-diameter gear 54b of the two-stage gear 54 meshes with the large-diameter gear portion 59a of the auxiliary transmission gear 59 that is on the drive pinion 58 and is spline-fitted so as to be movable back and forth. An internal gear 59b is provided on the front inner peripheral portion of the auxiliary transmission gear 59. When the auxiliary transmission gear 59 is moved forward and meshed with the gear 57 at the rear end of the transmission shaft 32, the auxiliary transmission gear 59b is engaged. “High speed” is obtained, and when the large-diameter gear 59 a of the sub-transmission gear 59 is engaged with the small-diameter gear 54 b of the two-stage gear 54, the “low-speed” of sub-transmission is obtained. A gear 60 that rotates integrally with the drive pinion 58 is provided behind the auxiliary transmission gear 59. The gear 60, a small-diameter gear 55a of the two-stage gear 55, a large-diameter gear 55b of the two-stage gear 55, and a front wheel drive shaft 61 are provided. It is configured to transmit power to the front wheels 2 through the upper gear 62 sequentially.
[ 0012 ]
A PTO gear 65 having a small-diameter gear portion 65a, a medium-diameter gear portion 65b, and a large-diameter gear portion 65c is provided concentrically at the rear shaft end of the transmission countershaft 33. A counter shaft 68 is mounted on the shaft. A PTO transmission gear 69 composed of a two-stage gear is provided on the PTO shaft 67. When the large-diameter gear 69a of the PTO transmission gear 69 is engaged with the small-diameter gear 65a of the PTO gear 65, the PTO shaft 67 has a first forward speed. When the rotation is transmitted and the small-diameter gear 69b meshes with the medium-diameter gear 65b, the PTO shaft 67 is configured to transmit the rotation at the second forward speed.
[ 0013 ]
The PTO counter shaft 68 is loosely fitted with a two-stage gear 70 that cannot move in the front-rear direction and can only rotate. The large-diameter gear 70a of the two-stage gear 70 is always meshed with the large-diameter gear 65c of the PTO gear 65. It is configured as follows.
The two-stage gear 69 on the PTO shaft 67 can change not only the speed of the PTO shaft 67 but also the rotational direction of the shaft 67. That is, when the two-stage gear 69 is slid rearward and the small-diameter gear 69b is engaged with the small-diameter gear 70b of the two-stage gear 70, the PTO shaft 67 rotates in the reverse direction. That is, the first reverse speed is obtained. In FIG. 1, 71 is a hydraulic cylinder, 72 is a lift arm, 73 is a lift rod, and 74 is a rotary input shaft.
[ 0014 ]
The transmission case 12 includes a main case portion 12a that accommodates a transmission gear group and a sub case portion 12b that accommodates a clutch 18 portion, which are detachably joined. Further, a support metal 75 for supporting the clutch support shaft 19, the transmission shaft 32 and the reverse counter shaft 46 is detachably attached to the case portion 12a. In the front space portion of the support metal 75, a shift member 76 is configured above the clutch 18. An operation support shaft 77 that is a speed change operation member is provided above the front end side of the shifter shaft 48, and a shifter 78 is fixed to the center portion thereof. The tip of the shifter 78 is configured to engage with the locking groove 53 of the shifter shaft 48 and to operate the shifter shaft 48 back and forth as the operation support shaft 77 rotates back and forth. Reference numeral 79 denotes a steel ball which is suitably projected from the inner surface of the case so as to be engaged with the operation positioning locking grooves 80, 80... Provided on the shifter 78 side to hold each shift position (see FIG. 3).
[ 0015 ]
Next, FIG. 4 will be described. FIG. 4 shows a slide gear type transmission mechanism, and different points from the key shift type transmission mechanism of FIG. 2 will be described below. In addition, the same code | symbol shows the same structural member. The large-diameter gear 92a of the two-stage gear 92 is always meshed with the small-diameter gear 91 on the rear end side of the clutch support shaft 90 constituting the clutch 18. The small diameter gear 92b is always meshed with the largest diameter gear 94 among the gears 94, 95, 96, 97 which are loosely fitted to the transmission countershaft 93. On the other hand, the transmission shaft 98 that rotatably supports the two-stage gear 92 slides the transmission slide gear 101 including the two-stage gear portions 99a and 99b and the two-stage internal clutch portions 100a and 100b in the axial direction. Provide freely. The two-stage gear 92 is integrally formed with a clutch portion 92c that meshes with the internal gear clutch portion 100a, while the reverse gear 103 that meshes with the gear 97 via the reverse counter gear 102 meshes with the internal gear clutch portion 100b. The clutch portion 103a is integrally molded. Accordingly, the variable speed slide gear 101 slides in the axial direction, and the internal gear clutch portion 100a and the clutch portion 92c, the gear 99a and the gear 95, the gear 99b and the gear 96, and the internal gear clutch portion 100b and the clutch portion 103a in this order. The first gear, the second gear, the third gear and the reverse gear can be obtained.
[ 0016 ]
Next, the shift mechanism 104 of the speed change mechanism will be described. The shifter stay 105 is slidable in the axial direction in parallel with the speed change shaft 98 and supported by the main case portion 12a. A shifter 106 that engages with the speed change slide gear 101 is fixed to the shifter stay 105, and an engagement pin 107 protrudes from the front end side. The pin 107 is fixed to the operation support shaft 77 and is fixed to the lower end side. A predetermined shift can be achieved by engaging the engagement groove of the arm 108 having the character-shaped engagement groove and moving the shift shifter 106 back and forth based on the turning operation of the operation support shaft 77. .. Are suitably formed on the rear end side of the shifter stay 105, and locking recesses 109, 109... For positioning balls (not shown) are formed.
[ 0017 ]
A support metal 110 is detachably attached to the main case portion 12a so as to support the clutch support shaft 90, the transmission shaft 98, and the reverse counter shaft 111.
One end of the operation support shaft 77 protrudes from the main case portion 12a, and is configured to cooperate with an operation lever (not shown) as appropriate with a wire or the like.
Next, the operation of the above example will be described. First, in the key shift type transmission mechanism, the rotational power of the engine 7 is transmitted to the clutch 18 in the transmission case 12 via the universal joint 15 and the input shaft 14. In a state where the clutch 18 is engaged, the rotational power is transmitted to the shift counter shaft 33 side through the small-diameter gear 27 and the second gear 30 of the clutch support shaft 19 in order.
[ 0018 ]
Then, a combination of a plurality of constantly meshing gears interposed between the transmission countershaft 33 and the transmission shaft 32 is selected by sliding the keys 47 and 47 back and forth to advance from the first forward speed. A shift is made within the range of the third speed, or the first reverse speed is selected. Further, if the auxiliary transmission gear 59 provided behind the key type main transmission unit is moved back and forth, a two-step shift can be achieved.
[ 0019 ]
In this embodiment, the clutch 18 is turned on and off to change the speed. However, when the rotational speed of the engine 7 is relatively low, for example, about 1500 rpm, the shift shaft 48 is directly moved back and forth without disengaging the clutch 18. It can be moved and shifted.
On the other hand, in the slide gear type speed change mechanism, when the shifter 106 is moved, the speed change slide gear 101 slides on the speed change shaft 98, and only the slide operation of the speed change slide gear 101 allows the forward three steps and the reverse one step. A shift state can be obtained.
[ 0020 ]
Next, the operation of the PTO system will be explained. When the PTO speed change lever (not shown) is appropriately operated to move the PTO speed change gear 69 in the front-rear direction, the first forward speed, the second forward speed, and the first reverse speed are obtained. That is, when the large-diameter gear 69a of the PTO transmission gear 69 meshes with the small-diameter gear 65a of the PTO gear 65, the first forward speed is achieved. When the second rotational speed is obtained and the small-diameter gear 69b of the PTO transmission gear 69 is engaged with the large-diameter gear 65c of the PTO gear 65, the first reverse speed is obtained.
[ 0021 ]
As described above, according to this embodiment, the main case portion 12a of the transmission case 12 and the operation support shaft 77 provided on the main case portion 12a can be shared, and in a transmission mechanism with different specifications such as a key shift transmission mechanism and a slide gear transmission mechanism. By sharing the operation interlocking system, it can contribute to low cost.
In this embodiment, the clutch 18 is provided on the bottom surface of the front end of the transmission case 12, and the shifting operation part of various transmissions is provided in the surplus space above the clutch 18 so that the operation part can be easily mounted. Assembly and disassembly can be easily performed.
[ 0022 ]
As for the entire transmission case 12, the support metal 75 of the key shift type transmission mechanism (first transmission mechanism) and the support metal 110 of the slide gear type transmission mechanism (second transmission mechanism) are provided exclusively for the transmission. Without changing the length of the case 12 itself, it is possible to configure a transmission mechanism having different specifications while sharing the mission case 12 with some changes.
[ 0023 ]
【The invention's effect】
The transmission case 12 in which interior a transmission mechanism for appropriately shifting the rotational power from the engine 7 side, thereby constituting a key shift transmission mechanism and sliding gear type transmission mechanism, the front end bottom portion within the transmission case (12) A clutch 18 is provided, and a shift operation portion for various transmissions is provided in an excess space above the clutch (18). Further, a driven shift member for shifting the key shift transmission mechanism and the slide gear transmission mechanism is provided in the transmission case (12), and a shift operation member (77) for artificially shifting the driven shift member is provided. Both the key shift transmission mechanism and the slide gear transmission mechanism are configured to be shared by the same member,
Furthermore, since the support metal (75) of the key shift type transmission mechanism and the support metal (110) of the slide gear type transmission mechanism are provided for exclusive use and the transmission case (12) is shared, it can contribute to cost reduction .
[0024]
In addition, since the shift operation directions of the key shift transmission mechanism and the slide gear transmission mechanism are both linear, they can be efficiently accommodated in a narrow space, which is effective for small specification vehicles.
Further , the clutch (18) is provided on the bottom surface of the front end in the transmission case (12), and the speed change operation part of various transmissions is provided in the surplus space above the clutch (18), so that the operation part can be easily attached. It can be easily assembled and disassembled .
The clutch (18) includes a clutch drum (18a) integrally fixed to a clutch side gear (17) meshed with a gear (16) fixed to a rear end portion of the input shaft (14) and a clutch support shaft (19). ) And a boss portion (20) rotating integrally therewith , so that a large number of friction plates (22) are provided. Therefore , in the key shift type transmission mechanism, when the engine speed is low, the clutch (18 ), The shift shaft (48) can be moved directly back and forth for shifting.
[Brief description of the drawings]
FIG. 1 is an overall side view of a tractor.
FIG. 2 is a cross-sectional view of a transmission of a first transmission mechanism.
FIG. 3 is an explanatory diagram of a shift member of the first speed change mechanism.
FIG. 4 is a sectional view of a mission of a second speed change mechanism.
FIG. 5 is an explanatory diagram of a shift member of a second speed change mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Tractor, 2 ... Front wheel, 3 ... Rear wheel, 4 ... Bonnet, 7 ... Engine, 12 ... Transmission case, 14 ... Input shaft, 15 ... Universal joint, 18 ... Clutch, 19 ... Clutch spindle, 28 ... Hydraulic pump , 30 ... Two-stage gear, 32 ... Transmission shaft, 33 ... Transmission countershaft, 34, 35, 36, 38 ... Gear, 44 ... Locking groove, 47, 47 ... Key, 48 ... Shifter shaft, 52 ... Back counter Gear 53, locking groove 58, drive pinion, 61 front wheel drive shaft, 65 PTO gear, 67 PTO shaft, 68 PTO counter shaft, 69 PTO transmission gear, 75 support metal, 76 shift member , 77 ... operation support shaft, 78 ... shifter, 79 ... steel ball, 80, 80 ... locking groove, 90 ... clutch support shaft, 93 ... speed change counter shaft, 94, 95, 96, 97 ... gear, 98 ... speed change shaft 99a, 99b ... gear part, 100a, 100b ... internal clutch part, 101 ... speed-change slide gear, 102 ... reverse counter gear, 103 ... reverse gear, 103a ... clutch part, 104 ... shift mechanism, 105 ... shifter stay, 106 ... Shifter, 107 ... engaging pin, 108 ... arm, 109, 109 ... locking recess 109, 109 ..., 110 ... support metal

Claims (1)

In the transmission case (12) having a speed change mechanism for appropriately changing the rotational power from the engine (7) side, both a key shift speed change mechanism and a slide gear speed change mechanism in which the speed change operation direction is a linear direction are configured. As well as
A clutch (18) is provided on the bottom surface of the front end in the transmission case (12), and a speed change operation part for various transmissions is provided in an excess space above the clutch (18).
The clutch (18) includes a clutch drum (18a) integrally fixed to a clutch side gear (17) meshed with a gear (16) fixed to a rear end portion of the input shaft (14) and a clutch support shaft (19). And a large number of friction plates (22) between the boss portion (20) rotating integrally therewith,
A hydraulic pump (28) is detachably provided at the front portion of the transmission case (12) driven by a clutch side gear (17) integral with the clutch drum (18a),
In the key shift type transmission mechanism, when the engine speed is low, the shift shaft (48) is directly moved back and forth without disengaging the clutch (18) to change the speed.
Further, a driven shift member for shifting the key shift transmission mechanism and the slide gear transmission mechanism is provided in the transmission case (12), and a shift operation member (77) for artificially shifting the driven shift member is provided. Both the key shift transmission mechanism and the slide gear transmission mechanism are configured to be shared by the same member,
Furthermore, a power transmission device for a mobile vehicle, characterized in that a mission case (12) is shared by providing a support metal (75) for the key shift transmission mechanism and a support metal (110) for the slide gear transmission mechanism. .

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