JPH0810545Y2 - Vehicle transaxle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a transaxle suitable for a relatively small work vehicle, particularly a transaxle mounted on an axle case and attached to and supported by a vehicle body frame so that rear axles for left and right wheels can be mounted. The present invention relates to a vehicle transaxle in which the left and right rear wheels are steerably supported by the outer ends of the left and right axle housings that are supported.

[Conventional technology and its problems]

Brake devices for braking a vehicle in such a vehicle transaxle have conventionally been generally installed in an axle case.

In this case, if a brake is provided on the drive side of the differential in the axle case, when the brake is applied, the differential operates due to the torque difference applied to the left and right rear wheels when the road surface is in poor condition. When the vehicle is turning and braked, danger can occur. Therefore, there is also a structure in which left and right brakes are installed on the driven side of the differential device in order to achieve safe vehicle braking, but with this structure, the lateral width of the axle case is expanded and the gap between the left and right body frames is reduced. It is not suitable for small vehicles that are going to be as small as possible.

In a transaxle equipped with a differential with a defrost clutch, the defrost clutch is activated at the same time as the brake is applied in order to obtain a safe vehicle braking while providing a brake on the driving side of the differential. In many cases, a structure that interlocks the brake with the defroster clutch is adopted. However, since the defrost clutch must be able to operate even while the vehicle is running, the interlocking mechanism between the brake and the defrost clutch becomes complicated in structure, and reliability for reliably performing the intended function is ensured. It is not always expensive.

There is a conventional example in which left and right brakes that directly brake the left and right rear wheels are provided at the ends of the left and right axle housings, but if this structure is adopted in a vehicle that steers the left and right rear wheels, the brake case part of each brake It is necessary to widen the interval (tred) between the left and right rear wheels so that the brake arm or the like does not regulate the turning angle of the rear wheels, and this is not suitable for small vehicles.

[Invention task]

Therefore, this invention intends to provide a brake for directly braking the rear wheel axle in the vehicle transaxle having the structure described above without increasing the distance between the left and right body frames and the distance between the left and right rear wheels. It is a thing.

(Problem solving means)

Therefore, as illustrated in the accompanying drawings, the present invention includes left and right axle housings 4 mounted on an axle case 1 and attached to and supported by a vehicle body frame 2 to support left and right rear wheel axles 3. The following measures were taken in a vehicle transaxle in which the rear wheels 5 are supported so that they can be steered and turned.

That is, the present invention is designed so that each axle housing 4 is arranged in the longitudinal direction in the inner housing portion 4A and the outer housing portion 4B.
Split the body frame 2 on the outer surface of the inner housing part 4A.
Mounting support part 6 to the inner housing part 4A
The brake case 7 whose side is open is integrally formed with the inner end of the outer housing portion 4B, and the case lid 8 for the brake case 7 is integrally formed with the outer end of the inner housing portion 4A.

Then, a brake 9 for braking each rear wheel axle 3 is installed in the brake case 7, and the brake case 7 and the case lid 8 are fastened with each other by a bolt 10 having a head 10a facing the mounting support portion 6 side. At the same time, the brake arm 11 of the brake 9 is arranged between the body frame 2 and the case lid 8.

[Function and effect of device]

According to this invention, by simultaneously operating the left and right brakes 9 for braking the left and right rear wheel axles 3, it is possible to obtain a safe vehicle braking in a straight traveling state.

A brake 9 is built into each axle housing 4 at a position midway in the length direction of each of the left and right axle housings 4, and mounting support for the vehicle body frame 2 is provided on the outer surface of the inner housing portion 4A. Since the distance between the left and right body frames 2 can be kept small, the inner and outer housing parts 4A and 4B can be fixed by fixing the case lid 8 to the brake case 7 which is located midway in the length direction of the axle housing. Since the head portion 10a of the bolt 10 and the brake arm 11 for the brake 9 that connect the two are connected to the vehicle body frame 2 side, a member protruding from the brake case 7 midway in the length direction of the axle housing to the rear wheel 5 side is provided. Since it does not exist, the turning of the rear wheels 5 is not hindered, and it is not necessary to increase the distance between the left and right rear wheels.

〔Example〕

The illustrated embodiment relates to an example in which the present invention is implemented in a tractor as shown in FIG.

The tractor includes a body frame 2 which is formed by a plate material and has a long rectangular shape in a front and rear view in a plan view, and an engine 13 is mounted on a front portion of the vehicle body. The axle case 1 is arranged between the left and right rear wheels 5, and the rear output shaft 13a of the engine 13 and the front input shaft 14 of the axle case 1 are connected by a transmission shaft 15 along the front-rear direction. I am doing it. Axle case 1
A passenger seat 16 is provided above the vehicle, and a steering handle 18 for steering the left and right front wheels 17 and the left and right rear wheels 5 at the same time is exposed in front of the passenger seat 16.

The axle case 1 of the present embodiment is a differential device 26 (first
(Fig.) And a transmission case (not shown) also serve as a transmission case, but the present invention can be implemented even if only a differential device is accommodated.

As shown in FIGS. 1 and 3 and 4, the inner housing portion 4A of each axle housing 4 has a mounting flange 20 at the base end, and the mounting flange 20 is attached to the outer surface of the axle case 1 by a bolt 21. It is attached to the axle case 1. The outer housing portion 4B has a holding portion 23 of a ball bearing 22 for supporting the rear wheel axle 3 on its inner surface, and a fork-shaped support arm 24 for supporting the rear wheel 5 so that it can be steered and turned. As shown in FIG. 1, each rear wheel 5 has a fork-shaped supporting metal 5b integral with its wheel disc 5a, and the supporting arm 24 is clamped from above and below to a pair of upper and lower pins 25 by this supporting metal 5b. The rear wheel 5 can be connected to the axle housing 4 by connecting to the support arm 24.
The outer housing portion 4B is supported so as to be steerable and turnable. The left and right rear wheel axles 3 are the left and right output shafts of the differential device 26 installed in the axle case 1, and the wheel axles 4c around the wheel discs 4a of the rear wheels 5 are located at the ends of the rear wheel axles 3, respectively. It is connected by a universal joint 27.

As shown in FIGS. 1 and 3, the mounting support portion 6 is integrally formed on the upper surface of the inner housing 4A adjacent to the case lid 8 in the form of a pedestal portion that is long in the front-rear direction. At the lower end of the body frame 2, a mounting plate portion 2a along the upper surface of the mounting support portion 6
Are integrally formed, and the bolts 29 screwed from the side of the mounting plate 2a support the mounting of the vehicle body frame 2 by the mounting support portion 6. In the illustrated case, in addition to the bolts 10 so as to further strengthen the connection and fixation between the housings 4A and 4B, as shown in FIG. 3, a portion of the mounting support portion 6 protruding from the inner housing portion 4A is brake case 7. Also provided is a bolt 30 for connecting to.

As shown in FIG. 1, the brake 9 includes a plurality of friction elements 3 for the rear wheel axle 3 and the brake case 7.
It is configured as a friction multi-plate type in which 2, 33 are supported so that they can slide only. The case lid 8 is inside the brake case 7.
A compression plate 34 is installed on the opposite side to the compression plate 34, and a ball 35 housed in a cam groove is disposed between the compression plate 34 and the inner surface of the brake case 7. A horizontal operating shaft 36 that is inserted from the case lid 8 side is provided in the brake case 7, and a pressing plate 34 that is biased to move to the opposite side of the friction elements 32, 33 group by a return spring 37 is installed on the operating shaft 36. Further, the displacement plate 34 is engaged so as to be rotationally displaced by the rotational displacement of the operating shaft 36. Due to the rotational displacement of the pressing plate 34, the ball 35 moves to the shallow portion of the cam groove and presses the plate 34, whereby the friction elements 32 and 33 are frictionally engaged between the inner surface of the case lid 8 and the pressing plate 34. The operation of the brake 9 is obtained by the adjustment. Brake arm 11
Is attached to the outer end portion of the operation shaft 36 by welding above the attachment support portion 6.

As shown in FIGS. 1 and 3, an operating rod 39 is connected to the free end of the brake arm 11, and the brake arms 11 of the left and right brakes 9 have a single brake pedal 40 as shown in FIG.
Is connected to. That is, the brake pedal 40, which is operated by a driver sitting on the seat 16 (FIG. 1), is attached to a pipe 41 that is arranged along the left-right direction and is rotatably supported around the axis. The arms 42 attached to both ends of the pipe 41 and the brake arms 11 of the left and right brakes 9 are connected by the left and right operation rods 39. A torque limiting spring portion 39a and a brake operation timing adjusting turnback portion 39b are inserted into each operating rod 39. As described above, the left and right brakes 9 are simultaneously operated by depressing the brake pedal 40.

In order to steer the left and right rear wheels 5, as shown in FIGS. 1 and 3, a support plate attached to the lower surface of the attachment flange 20 of the left and right axle housings 4 with bolts 43 at both ends.
44 is provided on the lower surface side of the axle case 1, and the support plate 44
A vertical support shaft 45 is welded and fixed to the central portion of the. On this vertical support shaft 45, a bifurcated steering arm 46 on the lower surface side of the support plate 44,
A boss portion 46a at the center of the arm 46 is rotatably supported by being fitted through a bearing. A knuckle arm 47 is attached to the fork-shaped support hardware 5b of each rear wheel 5 by a bolt 48 on the lower surface side thereof, and the left and right knuckle arms 47 are connected to the steering arm 46 by the left and right tie rods 49 and held. By turning the steering arm 46, the left and right rear wheels 5 are steered and turned. As shown in FIG. 3, a stopper portion 50 is provided on the upper surface of the outer housing portion 4A of the axle housing 4 so as to project.
On the other hand, a stopper bolt 51 that abuts against the rear wheel 5 and restricts the turning movement of the rear wheel 5 is provided on the support metal 5b so as to be adjustable in forward and backward directions.

As shown in FIG. 2, a center arm 54 is rotatably operated by the steering handle 18 via a steering gear box 53.
However, it is installed at a relatively low level. As shown in FIGS. 2 and 5, the center arm 54 has a drag rod 55 extending forward and a drag rod 56 extending backward.
And are connected. The former drag rod 55 is one side front wheel
17 is connected to one end of a bell crank-shaped knuckle arm 57, and the other end of the knuckle arm 57 is connected to a knuckle arm 59 of the other front wheel 17 by a tie rod 58. The rearward-facing drag rod 56 is a rear wheel and is connected to one end of a rear wheel steering arm 46. As described above, the left and right front wheels 17 and the left and right rear wheels 5 are simultaneously steered and turned by operating the steering handle 18.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional rear view showing a main part of a tractor equipped with an embodiment of the present invention, FIG. 2 is a schematic vertical side view of a part of the tractor, and FIG. 3 is a partial cross-section of the main part of the tractor. A plan view, FIG. 4 is a schematic perspective view of the embodiment, and FIG. 5 is a schematic plan view showing a steering mechanism of the tractor. 1 ... Axle case, 2 ... Body frame, 3 ... Rear wheel axle, 4 ... Axle housing, 4A ... Inner housing part, 4B ... Outer housing part, 5 ... Rear wheel, 6
…… Mounting support, 7 …… Brake case, 8 …… Case lid, 9 …… Brake, 10 …… Bolt, 10a …… Head, 1
1 …… Brake arm, 20 …… Mounting flange, 24 ……
Support arm, 25 …… pin, 29 …… bolt, 36 …… operation axis, 40 …… brake pedal, 46 …… steering arm, 47 ……
Natsukuru Arm, 49 ... Tyrod.

Claims (1)

[Scope of utility model registration request] 1. Left and right rear wheels 5 can be steered and turned to the outer ends of left and right axle housings 4 mounted on an axle case 1 and mounted and supported on a vehicle body frame 2 to support left and right rear wheel axles 3. In a vehicle transaxle that is supported by, each axle housing 4 is divided into an inner housing portion 4A and an outer housing portion 4B in the longitudinal direction, and the axle housing 4 is attached to the vehicle body frame 2 on the outer surface of the inner housing portion 4A. While the support portion 6 is provided, a brake case 7 having an opening on the inner housing portion 4A side is integrally formed with the inner end of the outer housing portion 4B, and a case lid 8 for this brake case 7 is integrally formed with the outer end of the inner housing portion 4A. A brake 9 for braking each rear wheel axle 3 is installed in the brake case 7, and a head portion is provided between the brake case 7 and the case lid 8 on the side of the mounting support portion 6 described above.
A transaxle for a vehicle, characterized in that it is fastened with a bolt (10) facing a bolt (10a), and a brake arm (11) of the brake (9) is arranged between the body frame (2) and the case lid (8).