JPH081995Y2 - Braking device for self-propelled vehicles - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a brake device mounted on a self-propelled vehicle such as an agricultural chemical spraying vehicle. More specifically, the operation feeling is improved and the braking advantage is adjusted. The present invention relates to a brake device for a self-propelled vehicle that can be used.

[Conventional technology]

In a braking system for a self-propelled vehicle in which the braking force of the brake body reaches the maximum with a short stroke of the brake pedal, in order to avoid applying excessive force to the brake body when the brake pedal is strongly depressed, the brake pedal A cushioning material such as a spring is interposed between the brake body and the brake body.

FIG. 4, FIG. 5 and FIG. 6 are perspective views of a conventional brake device with a cushioning material mounted on a self-propelled vehicle such as a speed sprayer. The same parts as those of the embodiment of the present invention to be described later are designated by the same reference numerals, the description thereof will be omitted, and the main points will be described.

In FIG. 4, the tension coil spring 40 is used for the brake pedal 10.
Is interposed between the rod 32 and the rod 32, and the operating force of the brake pedal 10 is transmitted to the rod 32 while being pulled when the brake pedal 10 is depressed.

In FIG. 5, the compression coil spring 42 is fitted between the bracket 28 and the spring seat 44 at the end of the rod 32 on the brake pedal 10 side, and the nut 46 is screwed onto the rod 32 so that The spring seat 44 is prevented from coming off. Then, as the brake pedal 10 is depressed, the compression coil spring 42
Is compressed, and the operating force of the brake pedal 10 is transmitted to the rod 32 via the compression coil spring 42, the spring seat 44 and the nut 46.

In FIG. 6, the wire material 48 has an outer tube 50 fixed to a portion of the vehicle body near the brake pedal 10 and the wheel brake 14 at both ends, and a bracket 2 penetrating through the outer tube 50 at each end.
And inner wires 52 locked to 8, 36. The operating force of the brake pedal 10 is transmitted to the wheel brake 14 via the inner wire 52 of the wire material 48.

Furthermore, in FIG. 4 and FIG. 5, a tension coil spring is provided.
In some cases, the wire material 48 is used instead of the rod 32 while leaving the compression coil spring 40 and the compression coil spring 42.

[Problems to be solved by the device]

As shown in FIG. 4, the problems of the brake device for transmitting the operating force of the brake pedal 10 to the wheel brake 14 via the tension coil spring 40 are as follows.

(A) Since the tension coil spring 40 expands as the amount of depression of the brake pedal 10 increases, it is difficult to determine the stroke of the brake pedal 10, and the feeling of depression of the brake pedal 10 becomes fluffy, resulting in lack of stability. To do.

(B) Since the tension coil spring 40 hangs by its own weight in the free state, it is necessary to hold the tension coil spring 40 so that it does not hang down.

As shown in FIG. 5, in the brake device in which the operating force of the brake pedal 10 is transmitted to the wheel brake 14 via the compression coil spring 42, the compression coil spring 42 is
Although it exhibits a certain elasticity, it loses its function as a cushioning material between the brake pedal 10 and the wheel brake 14 after the lines are in close contact with each other, and the excessive displacement of the brake pedal 10 is not absorbed to the wheel brake 14. It may be transmitted and an excessive force may be applied to the wheel brake 14.

As shown in FIG. 6, the problems of the brake device for transmitting the operating force of the brake pedal 10 to the wheel brake 14 via the inner wire 52 are as follows.

(A) The inner wire 52 has a small elastic limit in the expansion / contraction direction, and when the brake pedal 10 is excessively displaced, an excessive force is applied to the wheel brake 14 or the inner wire 52 is expanded by plastic deformation.

(B) The amount of expansion and contraction of the inner wire 52 varies, and the pedal force of the brake pedal 10 and the wheel brake 14 vary depending on the product.
It is easy for the control force to vary.

The brake device using the wire material 48 in place of the rod 32 of FIGS. 4 and 5 has both the problem of the tension coil spring 40 or the compression coil spring 42 and the problem of the wire material 48.

An object of the present invention is to provide a brake device for a self-propelled vehicle that can eliminate the above-mentioned problems of the prior art.

[Means for solving the problem]

Here, the present invention relates to a brake device for a self-propelled vehicle comprising a brake pedal (10), a brake body (14) for braking a wheel, and an elastic cushioning body interposed therebetween, wherein the elastic cushioning body is provided. A torch bar (18) and a first arm (22) fixed to one end of the torch bar (18) and transmitting the displacement of the brake pedal (10).
And a second arm (24) fixed to the other end of the torch bar (18) for giving a displacement for operating the brake body (14).

[Action]

The torsion bar (18) for buffering the first arm (22) elastically twists the first arm (22) in response to the operation of the brake pedal (10) while transmitting torque, and the displacement in the rotational direction transmitted along with this torque transmission is second. It is transmitted to the brake body (14) via the arm (24), and the brake pedal (10) brakes the wheels. When the brake body (14) reaches the maximum displacement, the displacement of the brake pedal (10) is absorbed by the elastic torsion of the torsion bar (18).

〔Example〕

The invention will be described below with reference to the embodiments shown in FIGS.

FIG. 1 is a perspective view of a brake device. This brake device is installed in a self-propelled vehicle such as a speed sprayer. The brake pedal 10 is disposed below the driver's seat so that the driver's foot can step on it downward, the lower end of the brake pedal 10 is rotatably supported by the support shaft 12, and the return coil spring 13 is provided.
Is pulled in the upward swing direction. In the speed sprayer, one brake pedal 10 is provided for each rear wheel (not shown) in order to use a one-sided brake for reducing the minimum turning radius. Only one brake pedal 10 is shown. The wheel brake 14 is arranged on each rear wheel, and brakes the rear wheel according to the swing of the brake lever 16. Torsion bar 18
Extends horizontally in the left-right direction and is rotatably supported by a frame (not shown) via a bearing 20. Each length l
The first arm 22 and the second arm 24 of ₁ and l ₂ are fixed to both ends of the torsion bar 18 and rotate integrally with both ends of the torsion bar 18. The rod 26 extends in the front-back direction,
The front and rear ends are rotatably coupled to the intermediate part of the brake pedal 10 and the upper end of the first arm 22 via brackets 28 and 30, respectively. The rod 32 extends in the front-back direction,
The front and rear ends are rotatably coupled to the upper ends of the second arm 24 and the brake lever 16 via brackets 34 and 36, respectively.

 The operation of the embodiment will be described.

To brake a speed sprayer equipped with a braking device, or to apply a single brake,
When the brake pedal 10 is depressed, the brake pedal 10 swings downward around the support shaft 12 against the return coil spring 13. When the brake pedal 10 swings downward, the rod 2
6, first arm 22, torsion bar 18, second arm 2
Transmitted to the brake lever 16 via 4 and the rod 32,
The wheel brake 14 brakes the rear wheels. The wheel brake 14 receives a reaction force from the rear wheels at the time of braking, and this reaction force is transmitted to the second arm 24 via the brake lever 16 and the rod 32. As a result, the torsion bar 18 moves to the first arm 2
2, It receives a torque in the opposite direction from the second arm 24 and is elastically twisted. The rocking caused by the further depression of the brake pedal 10 after the brake lever 16 reaches the maximum displacement is absorbed by the elastic torsion of the torsion bar 18.

Figure 2 shows the pedal force of the brake pedal 10 and the wheel brake.
The relationship with the braking force of 14 is shown. When the cushioning material is not interposed between the brake pedal 10 and the brake lever 16 of the wheel brake 14 (broken line), the displacement of the brake pedal 10 is transmitted to the brake lever 16 without being absorbed by the cushioning material. The brake lever 16 swings beyond the maximum displacement, and an excessive force is applied to the wheel brake 14. When a coil spring such as a tension coil spring is interposed (dashed line), the displacement of the brake pedal 10 is absorbed by the elastic deformation of the tension coil spring, so that an excessive braking force is applied to the wheel brake 14. This is prevented,
Due to the extension of the tension coil spring, a fluffy feel occurs in the operation of the brake pedal 10. On the other hand, in the embodiment (solid line), as a result of the torsion bar 18 being interposed between the brake pedal 10 and the wheel brake 14, the brake pedal
The displacement of 10 is absorbed by the torsion of the torsion bar 18,
Even if the brake pedal 10 is unnecessarily deeply depressed,
It is possible to prevent the brake lever 16 of the wheel brake 14 from being excessively displaced, prevent an excessive braking force from being generated, and avoid changing the distance between the brake pedal 10 and the brake lever 16, It provides a stable operation feeling.

Further in this invention, by setting the relationship, such as by connexion following to changing the arm ratio between the length l ₁ of the first arm 22 and the length l ₂ of the second arm 24 You can That is, (1) In the case of l ₁ > l ₂ , the time until the braking force reaches the maximum with respect to the pedal effort of the brake pedal 10 can be made faster than in the case of l ₁ = l ₂ .

(2) When l ₁ <l _{2 With} respect to the pedaling force of the brake pedal 10, the time until the braking force becomes maximum can be made slower than when l ₁ = l ₂ .

 The above relationship is graphically represented as shown in FIG.

In the illustrated embodiment, the torsion bar 18 and the brake lever 16 of the wheel brake 14 are connected by a rod 32, but instead of transmitting the displacement by the rod 32, the displacement of the second arm 24 is hydraulically changed. It is also possible to transmit to the wheel brake 14.

[Effect of device]

In this invention, the torsion bar is interposed between the brake pedal and the brake main body via the first arm and the second arm, respectively, and the elastic twist of the torsion bar is used to change the displacement of the brake pedal. It has the following effects.

(A) The torsion bar functions as a cushioning material between the brake pedal and the brake main body, and the displacement of the brake pedal is absorbed by the torsion bar as a cushioning material against excessive displacement of the brake main body, resulting in an excessive amount in the brake body. It is possible to prevent excessive force from being applied.

(B) The first arm can freely change the relationship of the control force (brake input) with respect to the pedal effort of the brake pedal by changing the arm ratio of the second arm, that is, the ratio of the respective lengths. You can

(C) Like a tension coil spring, it does not expand as the pedaling force of the brake pedal increases and the distance between the brake pedal and the brake main body does not increase, so a fluffy feeling when operating the brake pedal. Is eliminated, and the operational stability of the brake pedal is increased.

(D) Since the elasticity is not lost due to the close contact between the wires unlike the compression coil spring, the function as a cushioning material can be maintained over a wide range of depression of the brake pedal.

(E) In the torsion bar, the variation in the relationship between the twisting force and the twist amount is small, and the variation in the pedaling force of the brake pedal and the braking force of the brake main body for each product is reduced.

(F) Change the relationship between the torsional force and the amount of twist of the torsion bar by changing the material, length and quenching of the torsion bar, and freely change the setting relationship between the pedal effort of the brake pedal and the braking force of the brake body. You can

[Brief description of drawings]

FIGS. 1 and 2 relate to an embodiment of the present invention. FIG. 1 is a perspective view of a brake device, FIG. 2 is a graph showing a relationship between a pedaling force of a brake pedal and a braking force of a wheel brake, and FIG. Graphs showing the results of changing the arm ratio, FIGS. 4, 5, and 6 are perspective views of a conventional brake device with a cushioning material mounted on a self-propelled vehicle such as a speed sprayer. 10 …… Brake pedal, 14 …… Wheel brake (brake body), 18 …… Torsion bar, 22 …… First arm, 24 …… Second arm.

Claims (1)

[Scope of utility model registration request] 1. A brake device for a self-propelled vehicle, comprising: a brake pedal (10); a brake body (14) for braking a wheel; and an elastic cushioning body interposed therebetween. , The torch bar (18) and the brake pedal (1) fixed to one end of the torch bar (18).
0) a first arm (22) to which the displacement is transmitted, and a second arm (24) fixed to the other end of the torsion bar (18) to give a displacement for operating the brake body (14). Braking device for running vehicles.