JPH0524982Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a parking brake structure for a working vehicle equipped with a pair of left and right steering brakes.

[Conventional technology]

In the parking brake structure of this type of work vehicle,
Conventionally, when operating the parking brake, a pair of left and right steering brake operating tools and a left and right operating arm that independently turn on and off the left and right steering brakes were connected by a connecting rod. In this system, the left and right steering brake operating tools were pressed together to the brake operating position, and a locking device was used to maintain both operating tools in the depressed state (for example, in 1983-
Publication No. 37078).

[The problem that the idea aims to solve]

In this case, the parking brake cannot be operated without depressing the left and right steering control tools one by one, which makes the operation complicated, and the parking brake cannot be operated by depressing only one of the left and right steering devices. If this were to be done, it would be necessary to take steps such as integrating the left and right steering controls in advance with a latch.
In any case, the complexity of operability could not be resolved.

An object of the present invention is to provide a device that improves operability by adding a twist to the linkage between the left and right operating arms and the artificial brake operating tool.

[Means to solve the problem]

The characteristic configuration of the present invention is that a single artificial brake operating tool and left and right operating arms that independently turn on and off the left and right steering brakes are linked by a release wire, and the artificial brake operating device in the release wire is The point where the outer end or one end of the brake operating tool side is connected to the artificial brake operating tool, and the other of the outer end or the inner end is fixedly supported to a mounting support frame for supporting the artificial brake operating tool. and, the outer end and inner end of the operating arm side are separately attached to the left and right operating arms, respectively.

[Effect]

As shown in FIGS. 1 and 2, for example, the inner end 15d of the release wire 15 is connected to the brake pedal as the artificial brake operation tool 17, and the outer end 15c is attached to the support frame 18.
When the outer end 15a and the inner end 15d are separately attached to the left and right operating arms 7A and 7B, when the brake pedal 17 is depressed, the right operating arm 7B is pulled to the inner end 15b and the brake is activated. At the same time, the corresponding outer end 15a moves toward the inner end 15b, the left operating arm 7A moves toward the right operating arm 7B, and both the left and right steering brakes 4A and 4B are activated.

[Effect of idea]

Therefore, when operating the parking brake, only a single brake operating tool is operated, which simplifies the operation. Moreover, since both the left and right operating arms are connected to the inner end of the release wire and the corresponding outer end, the amount of movement during brake operation is the same, and the braking force is different between the left and right steering brakes. This can be easily achieved by simply attaching the outer end and the inner end to the left and right operating arms separately, without using any other means.

〔Example〕

A parking brake structure used in a combine harvester as an example of a work vehicle will be described.

As shown in FIG. 3, a transmission case 3 supporting drive cases 2, 2 for a pair of left and right crawler traveling devices 1, 1 is provided with a pair of left and right steering clutches and brakes 4A, 4B. The clutches and brakes 4A and 4B are composed of a pawl clutch type steering clutch and a multi-disc type steering brake which is engaged and operated by a clutch sleeve of the steering clutch. A shift fork 5 that acts on the clutch sleeve to turn on and off the steering clutches and brakes 4A and 4B is attached to the operating shaft 6 while being engaged with the clutch sleeve. Operating arms 7A and 7B are fixed to the outwardly projecting ends of the transmission case 3 of the operating shaft 6 for the left and right steering clutches and brakes 4A and 4B so as to be able to rotate together,
It is powered and operated by left and right operation cylinders 8A and 8B, which will be described later. In other words, the operating arm 7
A left and right operation cylinder 8 whose piston rod contacts the operation arms 7A and 7B from above.
A, 8B, and an electromagnetic control valve 9 that selectively supplies hydraulic oil to the left and right operating cylinders 8A, 8B, and the left and right operating cylinders 8A, 8B.
A variable relief valve 10 is provided in the drain oil confluence path from the middle of the stroke, so that the steering clutches and brakes 4a and 4B can be operated with power.

A single manual operating lever 11 is provided for the steering clutches and brakes 4A and 4B, and an electromagnetic control lever is operated based on the detection result of the operating lever swing of the potentiometer 12 at the swing axis X position of the operating lever 11. The control valve 9 is switched to supply oil to the operating cylinder 8A or 8B on the swinging direction side of the operating lever 11. Then, the piston rod is extended, the operating arm 7A or 7B on the steering direction side is rotated, and the steering clutch is disengaged. When the operating lever 11 is further swung from the clutch disengaged position, the throttling effect of the variable relief valve 10 becomes effective, and the exhaust pressure can be varied.The higher the exhaust pressure is, the further the piston rod is extended, increasing the steering braking force. If the variable relief valve 10 is completely closed, the braking force can be maximized. The swing operating arm 13 and the operating lever 11 for the variable relief valve 10 are interlocked and connected by a release wire 14, so that the operating force for the manual operating lever 11 is used as the squeezing force of the variable relief valve 10.

As shown in FIG. 1, an outer end 15a of a release wire 15 having a Bowden cable structure consisting of an inner wire 15I and an outer wire 15U is attached to one end of the left operating arm 7A, which is rotatably fitted to the operating shaft 6, on the horizontal axis. It is attached via a piece member 16 that is relatively rotatable around the center Y, and the inner end 15b of the inner wire 15I extending from the outer end 15a is connected to one end of the right operating arm 7B with a pin via an elongated hole. . On the other hand, the other outer end 15c of the release wire 15 is fixed to a mounting support frame 18 to which a parking pedal 17 as a single human operating tool is attached, and the inner wire 15I extending from the outer end 15c The inner end 15d is fixedly attached to a swing arm 19 that rotates together with the parking pedal 17. Therefore,
When the parking pedal 17 is depressed and locked and fixed by the lock member 20, the inner wire 15I is pulled and the outer wire 15U changes its posture, causing the operating arms 7A and 7B to swing toward each other as shown in the figure. . Therefore, the left and right steering brakes are applied and the parking brake is activated.

As shown in FIG. 1, the release wire 15
is detoured in a curved line between the operating lever 11 and the operating arm 7A, so a guide rod 21 that supports the outer wire 15U in a substantially horizontal state is provided near the left operating arm 7A to prevent movement of the inner wire 15I relative to the outer wire 15U. The structure can be configured to prevent water from entering the outer wire 15U while reducing wear caused by the outer wire 15U.

[Another embodiment] Parking brake 17 of the release wire 15
The objects to which the side outer end 15c and the inner end 15d are attached may be exchanged, and the objects to be attached to the outer end 15a and the inner end 15b of the operating arms 7A and 7B may be exchanged.

The manual brake operation tool 17 may be of an operation lever type.

The above embodiment may be used for other working vehicles such as agricultural tractors.

Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings show an embodiment of the parking brake structure for a working vehicle according to the present invention, in which FIG. 1 is a front view showing the parking brake structure, FIG. 2 is a side view showing the operation structure of the parking brake and steering brake, and FIG. FIG. 3 is a hydraulic configuration diagram showing the operating structure of the steering clutch and brake. 4a, 4B...Steering brake, 7A, 7B...
Operation arm, 15... Release wire, 15a,
15c...Outer end, 15b, 15d...Inner end, 17...Artificial brake operation tool, 18...Mounting support frame.

Claims (1)

[Scope of utility model registration request] A single artificial brake operating tool 17 and left and right operating arms 7A and 7B that independently turn on and off the left and right steering brakes 4A and 4B are linked by a release wire 15, and the Outer end 15 on the side of the artificial brake operating tool 17
c or the inner end 15d is connected to the artificial brake operating tool 17, and the outer end 1
5c or the other of the inner ends 15d to a mounting support frame 1 for mounting the artificial brake operating tool 17.
8, and an outer end 15a and an inner end 15b of the operating arm side are separately attached to the left and right operating arms 7A, 7B, respectively.