JPH07125523A - Suspension device of working vehicle - Google Patents

Abstract

PURPOSE:To provide a suspension device of a working vehicle, capable of absorb ing and damping vibration in traveling without affecting work performance. CONSTITUTION:Vibration generated by irregularity of a road surface is transmitted to wheels 4 and an axle 3 in traveling of a working vehicle 1A, so as to vertically contract and extend a piston of a hydraulic cylinder 6 attached between a car body 2 and the axle 3. This contraction and extension are performed by deformation of a triangular link mechanism composed of the hydraulic cylinder 6, the link 7 and a part of the car body 2. Pressure oil is moved between the cylinder and a pressure accumulator 11 through a throttle 12 according to the contraction and extension. Since the relationship between the change of pressure of the hydraulic cylinder 6 and the stroke is determined by compressive elasticity of gas accumulated in the pressure accumulator 11, this compressive elasticity serves as a spring function, so as to absorb vibration. Pressure oil passes the throttle 12, thereby vibration having a short period is damped. Since the link mechanism is connected to the center part of the axle 3, the ground contact performance of the right and left wheels 4 is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension system for a work vehicle used in a work vehicle that moves by wheels with tires.

[0002]

2. Description of the Related Art In a work vehicle that moves by wheels with tires, for example, a wheel shovel or a wheel loader, an axle for driving the wheels and a vehicle body are directly fixed to each other or are connected by a pin joint. An example of such a work vehicle will be described with reference to the drawings. FIG. 5 is a front view of a schematic configuration of a main part of the work vehicle, and FIG. 6 is a side view thereof. In each drawing, 1 is a work vehicle, 2 is a vehicle body, 3 is an axle mounted on the vehicle body 2, and 4 is left and right wheels driven by the axle 3. The front or rear axle 3 is connected to the vehicle body 2 by a pin 5, and the other axle 3 is directly connected to the vehicle body 2.

One axle 3 is connected to the vehicle body 2 via a pin 5.
It is possible to maintain the rolling rigidity of the vehicle body 2 when the work vehicle bends and travels by increasing the grounding property of the four wheels by directly connecting it to the vehicle body 2 by directly connecting the other axle 3 to the vehicle body 2. .

[0004]

Generally, the wheels 4 in the conventional work vehicle 1 are for moving at a work site, and are assumed to move at low speed even when moving on a road. I was trying. However, in recent years
Work vehicle 1 often travels on a general road, which hinders the travel of other vehicles at low speeds, causing road congestion.

For this reason, the work vehicle 1 is provided with a high-speed traveling performance so that the work vehicle 1 travels at a high speed on an ordinary road. However, the work vehicle 1 having the above-mentioned structure is connected to the axle 3 at a high speed. When the vehicle is run, the vertical movement of the wheels 4 due to the unevenness of the road surface is directly transmitted to the vehicle body 2, the ride comfort of the operator is extremely deteriorated, and further, the resonance vibration of the vehicle body 2 is generated due to the elasticity of the tires of the wheels 4. The whole body 2 bounces and the ground contact with the road surface becomes poor. From these things,
There is a problem that the stability of the operation of the work vehicle 1 is adversely affected.

In order to eliminate such a problem, it is conceivable to interpose an appropriate suspension between the vehicle body 2 and the axle 3 as in the case of a normal vehicle. However, the suspension intervenes the work performance of the work vehicle 1. Obviously, it's going to make it worse and you can't use suspension.

An object of the present invention is to solve the above problems in the prior art and to provide a suspension system for a work vehicle capable of absorbing and damping vibrations during traveling without affecting work performance.

[0008]

In order to achieve the above object, the present invention provides a vehicle body equipped with a working mechanism, an axle mounted on the front and rear of the vehicle body, and a tire mounted and driven by each of the axles. In a work vehicle including left and right wheels, one hydraulic cylinder pin-connected between the vehicle body and the substantial center of at least one of the axles, and the one axle and the vehicle body. A link that shares a pin connection on the axle side of the hydraulic cylinder and that is pin-connected to the vehicle body, a pressure accumulator connected to the hydraulic cylinder by a pipe, and a throttle interposed in the pipe. It is characterized by being provided.

The present invention is also characterized in that the axle is provided with a stabilizer in the above-mentioned configuration, or the spring is provided in parallel with the hydraulic cylinder by removing the pressure accumulator, the pipe and the throttle in the above-mentioned configuration. .

[0010]

When the work vehicle is running, the hydraulic cylinder expands and contracts according to the unevenness of the road surface, and the pressure oil is taken in and out from the pressure accumulator each time, whereby the vibration of the vehicle body is absorbed. Further, although the pressure oil is taken in and out through the throttle, the throttle restricts the movement of the pressure oil, and eventually functions to damp vibration having a short cycle. Further, a triangular link mechanism is configured by the hydraulic cylinders, the links, and the vehicle body structure between them, and the hydraulic cylinders are expanded and contracted by the deformation of the triangular link mechanism. There is no need to install it on both the left and right sides. Further, even if a spring is provided in parallel with the hydraulic cylinder instead of the pressure accumulator, the pipe and the throttle, the spring absorbs and damps the vibration in the same manner as described above. Further, when the stabilizer is provided, the stabilizer suppresses rolling of the vehicle body.

[0011]

The present invention will be described below with reference to the illustrated embodiments. 1 is a front view showing a schematic configuration of a suspension system for a work vehicle according to an embodiment of the present invention, and FIG. 2 is a side view of the work vehicle shown in FIG. In each of these figures, the same or equivalent parts as those shown in FIG. 3 are designated by the same reference numerals. 1A shows a work vehicle to which the suspension system of this embodiment is attached. Reference numeral 6 denotes a hydraulic cylinder mounted between the vehicle body 2 and substantially the center of the axle 3 on one axle 3 of the work vehicle 1A, and is pin-connected to the vehicle body 2 and the axle 3 by pins 8 and 9. . Reference numeral 7 denotes a link mounted between the axle 3 and the vehicle body 2, which is pin-coupled to the axle 3 by a pin 8 common to the hydraulic cylinder 6 and pinned to the vehicle body 2 by a pin 10. The hydraulic cylinder 6, the link 7, and the vehicle body structure between the pin 9 and the pin 10 constitute a triangular link mechanism. The other axle 3 and the vehicle body 2 are fixed to each other, thereby increasing the rigidity of the vehicle body against rolling.

Reference numeral 11 denotes a pressure accumulator connected to the hydraulic cylinder by piping, and 12 denotes a throttle provided between the pressure accumulator 11 and the hydraulic cylinder 6. The link 7, the hydraulic cylinder 6, the pipe, the throttle 12, and the pressure accumulator 11 constitute the suspension device of this embodiment.

Since the hydraulic cylinder 6 and the pressure accumulator 11 are in communication with each other when the vehicle body 2 is stationary, their pressures are the same. Next, when the work vehicle 1A travels, the wheels 4 move up and down due to the unevenness of the road surface, and accordingly, the piston of the hydraulic cylinder 6 expands and contracts via the axle 3 while deforming the triangular link mechanism. The pressure of the hydraulic cylinder 6 decreases when the pressure increases, and the pressure of the hydraulic cylinder 6 increases when the pressure decreases.

When the pressure of the hydraulic cylinder 6 decreases, pressure oil is supplied from the pressure accumulator 11 to the hydraulic cylinder 6, and when the pressure of the hydraulic cylinder 6 increases, the pressure oil from the hydraulic cylinder 6 is accumulated in the pressure accumulator 11. When the hydraulic cylinder 6 receives an external force due to the unevenness of the road surface due to the supply and accumulation of the pressure oil between the hydraulic cylinder 6 and the pressure accumulator 11, the piston strokes to absorb the external force and the vehicle body 2 Absorbs the transmission of vibrations to.

Here, the relationship between the change in the pressure of the hydraulic cylinder 6 and the stroke of the piston is determined by the compression elasticity of the gas accumulated in the pressure accumulator 11, and the compression elasticity of this gas absorbs the vibration. Acts as a spring function. Further, when the stroke of the piston of the hydraulic cylinder 6 changes rapidly (the cycle of vibration is short), the movement of the pressure oil between the hydraulic cylinder 6 and the pressure accumulator 11 is limited by the throttle 12 interposed in the pipe, and as a result, , Short cycle vibrations are dampened. Further, since the axle 3 is rotatable around the pin 8, even if the road surface has irregularities, the ground pressure of each wheel 4 can be kept equal, and the grounding property of the work vehicle can be improved to improve the work performance. Adverse effects can be eliminated.

As described above, in this embodiment, the hydraulic cylinder 6 and the link 7 are provided between the vehicle body 2 and substantially the center of the axle 3.
Also, since a triangular link mechanism constituted by a part of the vehicle body 2 is attached by pin connection, the hydraulic cylinder 6 and the pressure accumulator 11 are connected by piping, and the throttle 12 is interposed in the piping, there is no influence on work performance. It is possible to absorb and damp vibrations of the work vehicle while it is running. Furthermore, with the above link mechanism, it is not necessary to provide hydraulic cylinders 6 on each of the left and right wheels 4, and only one hydraulic cylinder 6 is required. .

Further, as described above, since the other axle 3 and the vehicle body 2 are fixed, rolling of the vehicle body 2 can be suppressed. That is, a work vehicle is usually heavier and has a higher center of gravity than a general passenger vehicle. Therefore, when the work vehicle travels in a bend, the work vehicle is greatly affected by rolling and lacks stability. However, in this embodiment, the other axle 3 is the vehicle body 2
Since it is fixed, it is obvious that the effect of the rolling can be reduced, and the stability of the work vehicle traveling can be increased.

FIG. 3 is a side view of a schematic structure of a suspension system for a work vehicle according to another embodiment of the present invention. In the figure, the same or equivalent parts as those shown in FIG. 1 are designated by the same reference numerals. 1B shows the work vehicle of the present embodiment. In the working vehicle 1B according to the present embodiment, the work vehicle 1B shown in FIG.
The suspension device shown in is attached. Then, in order to suppress rolling of the vehicle body 2, the illustrated stabilizer 13 is attached to at least one axle. With this configuration, it is possible to suppress rolling of the vehicle body 2 and to obtain better vibration absorption and damping as compared with the configuration of the previous embodiment.

FIG. 4 is a side view of a schematic configuration of a suspension system for a work vehicle according to still another embodiment of the present invention. In the figure, the same or equivalent parts as those shown in FIG. 1 are designated by the same reference numerals. 1C shows the work vehicle of this embodiment. In the working vehicle 1C of the present embodiment, the pressure accumulator 11, the throttle 12 and the pipe shown in FIG. 1 are removed, and a spring 14 is provided in parallel with the hydraulic cylinder 6 instead of them. With such a configuration, similarly to the configuration shown in FIG. 1, it is possible to absorb and damp vibrations, and further, it is possible to omit the pressure accumulator 11, the throttle 12 and the piping, thus simplifying the structure. be able to. It is apparent that the stabilizer shown in FIG. 3 can also be mounted in the configuration of this embodiment to suppress rolling.

[0020]

As described above, according to the present invention, a pin-connected hydraulic cylinder, a link, and a link mechanism composed of a part of the vehicle body are provided between the vehicle body and the axle, and the hydraulic cylinder and the pressure accumulator are provided. Connect with a pipe, provide a throttle on the pipe,
Alternatively, since a spring is provided in parallel with the hydraulic cylinder instead of the pressure accumulator, the pipe, and the throttle, it is possible to absorb and damp the vibration generated when the work vehicle travels without affecting the work performance. Further, the link mechanism can eliminate the need for providing hydraulic cylinders on the left and right wheels.
Furthermore, by providing a stabilizer on the axle,
Rolling of the vehicle body can be suppressed.

[Brief description of drawings]

FIG. 1 is a front view of a schematic configuration of a suspension device for a work vehicle according to an embodiment of the present invention.

2 is a side view of the work vehicle shown in FIG. 1. FIG.

FIG. 3 is a side view of a schematic configuration of a suspension device for a work vehicle according to another embodiment of the present invention.

FIG. 4 is a side view of a schematic configuration of a suspension device for a work vehicle according to still another embodiment of the present invention.

FIG. 5 is a front view of a schematic configuration of a conventional work vehicle.

FIG. 6 is a side view of the work vehicle shown in FIG. 1.

[Explanation of symbols]

 2 vehicle body 3 axle 4 wheel 6 hydraulic cylinder 7 link 8, 9, 10 pin 11 pressure accumulator 12 throttle

Claims (3)

[Claims] 1. A work vehicle comprising a vehicle body provided with a work mechanism, axles attached to the front and rear of the vehicle body, and left and right wheels to which tires are attached and driven by the respective axles. One hydraulic cylinder pin-coupled between the substantial center of at least one of the axles and the vehicle body, and a pin joint on the axle side of the hydraulic cylinder shared between the one axle and the vehicle body. A suspension system for a working vehicle, further comprising a link pin-connected to the vehicle body, a pressure accumulator connected to the hydraulic cylinder by a pipe, and a throttle interposed in the pipe. 2. A work vehicle comprising a vehicle body provided with a work mechanism, axles attached to the front and rear of the vehicle body, and left and right wheels to which tires are attached and driven by the respective axles. One hydraulic cylinder pin-coupled between the substantial center of at least one of the axles and the vehicle body, and a pin joint on the axle side of the hydraulic cylinder shared between the one axle and the vehicle body. A suspension system for a work vehicle, further comprising a link that is pin-connected to the vehicle body and a spring that is connected in parallel to the hydraulic cylinder. 3. The suspension system for a work vehicle according to claim 1 or 2, wherein a stabilizer is provided on one of the axles.