JPH03182804A - Vehicle tread adjusting device - Google Patents

Abstract

PURPOSE:To make tread adjustment by means of easy switch operation, connecting a solenoid change-over valve between a hydraulic cylinder for expanding and contracting an axle case and a hydraulic source to expand and contract the hydraulic cylinder by the solenoid change-over valve. CONSTITUTION:In a hydraulic circuit provided with a hydraulic cylinder 64 which expands and contracts an axle case to adjust tread, there are provided respective main and auxiliary hydraulic pumps 76, 77 which are driven by an engine 78 installed on an automobile, whereas solenoid change-over valves 80 for tread adjustment are connected respectively between the hydraulic cylinder 64 and an auxiliary hydraulic pump (hydraulic source) 77. In the case of increasing the tread, for example, a solenoid 81 on one side is energized and the solenoid change-over valve 80 is changed over from neutral position to expanding side. The pressurized oil form the auxiliary hydraulic pump 77 is introduced into an oil chamber 72 on one side of the hydraulic cylinder 64 through the solenoid change-over valve 80, a circuit on the other side and a check valve 86 on one side, thus expanding the hydraulic cylinder 64.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a wheel width adjustment device for a vehicle.

(Prior art) As a rear wheel distance adjustment device for a vehicle such as a tractor,
The rear axle case is made up of a fixed case on the vehicle body side and a movable case that is slidably fitted into the fixed case, and the rear axle case is expanded and contracted by hydraulic cylinders arranged in parallel or on the same axis. There is one that allows it to expand and contract.

This type of wheel width adjustment device uses an auxiliary control control valve to control the work equipment mounted externally, and has a switch on the output side of the auxiliary control valve that switches between the external work equipment side and the wheelbase adjustment side. A valve is provided, and after switching the switching valve to the wheelbase adjustment side, the auxiliary control valve is operated to cause the hydraulic cylinder to extend and contract.

(Problems to be Solved by the Invention) Conventionally, when adjusting the wheelbase, it is necessary to operate the control lever of the auxiliary control and the switching lever of the switching valve, which makes the operation complicated. In addition, since the auxiliary control valve and the like are located on the tractor body side, it is difficult to employ the control valve in a tractor equipped with an independent suspension type cabin.

SUMMARY OF THE INVENTION In view of these conventional problems, it is an object of the present invention to provide a vehicle wheel distance adjustment device that can be easily remotely controlled using an electromagnetic switching valve.

(Means for Solving the Problems) The present invention includes a telescoping axle case 5, a hydraulic cylinder 64 for telescoping the axle case 51, and a switching valve for controlling the telescoping of the hydraulic cylinder 64. In the wheel distance adjustment device for a vehicle equipped with this system, an electromagnetic switching valve 80 is connected between a hydraulic power source 77 and a hydraulic cylinder 64.

(Function) When adjusting the wheelbase distance, the electromagnetic switching valve 804; Z is energized to switch to the extension or contraction direction. Then, pressure oil from the hydraulic source 77 is supplied to the hydraulic cylinder 64 via the electromagnetic switching valve 80, and the hydraulic cylinder 64 operates in the extending or contracting direction. This causes the axle case 51 to expand or contract,
The wheelbase distance between the left and right wheels changes.

In this case, since the electromagnetic switching valve 80 is used, the wheelbase distance can be adjusted with a simple switch operation, and the operation is easy and remote control is also possible.

(Example) The invention will now be described in detail with reference to the illustrated embodiments.

In FIGS. 2 to 4, reference numeral 1 denotes a tractor body, which has front wheels 2 and rear wheels 3. The rear wheel 3 is the Mi7 of the tractor body 1.
Brake case 50 on both rear sides of case 49,
It is attached via a rear axle case 51 and a rear center axle 52. Rear axle case 51i! , a fixed case 53 and a movable case 54 slidably fitted into the fixed case 53.
It has this structure and is attached to the minition case 49 via the fixed case 53↓ and the brake case 50. T4 in plate case 50, mission case 49
A brake (not shown) is provided for braking a differential yoke shaft 55 protruding from a rear wheel differential device, and the differential yoke shaft 55 is interlocked and connected to a rear axle 524 via a planetary reduction gear 56. The rear axle 52 includes a first shaft 57 connected to a planetary reduction gear 56 and a spline cylindrical shaft 58.
It is configured to be expandable and contractible with a second shaft 59 connected via. The first shaft 57 is supported by the fixed case 53 via bearings 60, and the second shaft 59 is supported by bearings 61, 62.
This second shaft 5 is supported by a movable gear 54 via U2.
The disk 64a of the rear wheel 3 is cut into the flange portion 63 at the outer end of the wheel 9.

A hydraulic cylinder 64 for extending and contracting the rear axle case 51 is disposed horizontally on the rear side of the rear axle case 51, and is housed in a holding case 65 formed integrally with the fixed case 53. The hydraulic cylinder 64 has a piston rod 6 whose inner end is fixed to the fixed case 53, a piston 67 fixed to the outer end of the piston rod 66, and is slidably fitted onto the piston 67 and the piston rod 6. It consists of a cylinder body 68. The piston rondro 8 is cylindrical,
An inner cylinder 71 is inserted into the piston rod 8 so as to form oil passages 69 and 70 inside and outside, and the oil passages 69 and
70 is a cylinder body 68 partitioned by a piston 67
The oil chambers 72 and 73 are connected to each other. An interlocking body 74 is fixed to the outer end of the cylinder body 68, and the interlocking body 74
is fixed to the outer end of the movable case 54. Note that a cylindrical stopper 75 is loosely fitted into the oil chamber 72 of the cylinder body 68.

FIG. 1 shows a hydraulic circuit including left and right hydraulic cylinders 64. In FIG. 1, 76 is a main hydraulic pump 1, and 77 is an auxiliary hydraulic pump (hydraulic pressure #i), which are driven by an engine 78 at the front of the tractor body 1.

The main hydraulic pump 76 is for supplying pressure oil to a hydraulic system for raising and lowering the working machine, and is of high pressure. The auxiliary hydraulic pump 77 is for supplying pressure oil to a clutch 79 such as a PTO clutch, dual speed clutch, double speed swing clutch, etc., and has a lower pressure (approximately 20 kg/crfi) than the main hydraulic pump 76. It is used. 80 is an electromagnetic switching valve for adjusting the wheelbase distance, and is connected between the hydraulic cylinder 64 and the hydraulic pump 77.

This electromagnetic switching valve 80 is a three-position direct switching type equipped with solenoids 8L82, each of which is connected to a switch on the control panel side provided near the driver's seat.

Double pilot type check valves 85, 86 are interposed in circuits 83, 84 connecting each outlet port of the electromagnetic switching valve 80 and each oil chamber 72, 73 of the hydraulic cylinder 64.

Each of the check valves 85 and 86 allows pressure oil to flow from the electromagnetic switching valve 80 to the hydraulic cylinder 64 side, and also allows pressure oil to flow in the opposite direction when pressure is generated on the electromagnetic switching valve 80 side in circuits 83 and 84 on opposite sides. Constructed to allow oil flow.

Next, the operation will be explained. The wheelbase of rear wheel 3 is gIllllffff
When doing so, first remove either the left or right rear axle case 51.
is expanded and contracted, and then the other rear axle case 51 is expanded and contracted. For example, if the wheelbase is to be increased, the extension switch is operated and the solenoid 81 of the electromagnetic switching valve 80 is energized. Then, the electromagnetic switching valve 80 switches from neutral to the extension side, so the pressure oil from the hydraulic pump 77 is sent to the circuit 83 side via the electromagnetic switching valve 80, the check valve 85 opens, and the pressure oil is transferred to the hydraulic cylinder 64. into the oil chamber 72. On the other hand, since pressure oil comes to the circuit 83, the check valve 86 on the opposite side opens due to the pilot pressure, and the oil chamber 73 of the hydraulic cylinder 64 opens.
of oil is returned via check valve 86. This causes the hydraulic cylinder 64 to operate in the extension direction. That is, the cylinder body 68 of the hydraulic cylinder 64 slides outward, and the movable case 54 of the rear axle case 51 and the second
The shaft 59 slides outward via the interlocking body 74. When the rear wheel 3 moves to an appropriate position, the solenoid 8
1 is demagnetized, the electromagnetic switching valve 80 is returned to neutral, and the hydraulic cylinder 64 is stopped. Then, the pressure in circuit 83 decreases, so check valve 86 closes, and both check valves 85.
86 are both closed.

By using the electromagnetic switching valve 80 in this way, the wheelbase distance can be adjusted with a simple switch operation, and therefore,
It is easy to operate and can be controlled remotely.

When the wheelbase distance is adjusted, the check valves 85 and 86 of the circuits 83 and 84 are both closed, and each oil chamber 7 of the hydraulic cylinder 64 is closed.
Even if the internal pressure of 2 and 73 rises, the flow of the pressure oil is blocked. Therefore, the hydraulic cylinder 64 and the rear axle case 51 are completely locked so that they cannot extend or contract, and even if a large axial force acts on the rear axle case 51 when driving on a slope, etc.
This does not change the wheelbase.

In the embodiment shown in FIG. 1, check valves 85 and 86 are provided for safety after adjusting the wheelbase, but as shown in FIG. 8
0 and the hydraulic cylinder 64 may be directly connected.

It goes without saying that the wheelbase distance of the front wheels 2 can also be adjusted in the same manner.

(Effects of the Invention) According to the present invention, since the hydraulic cylinder 64 is expanded and contracted using the electromagnetic switching valve 80, the wheelbase distance can be adjusted by a simple switch operation.

Therefore, it is easier to operate than before, and remote control is also easier.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a hydraulic circuit diagram, FIG. 2 is a side view of the tractor, and FIG. 3 is a plan cross-sectional view of the rear wheel wheelbase adjustment section. Figure 4 is IV-I of Figure 3.
It is a V arrow view. FIG. 5 is a circuit diagram showing another embodiment of the present invention. l... Tractor body, 3... Rear wheel, 51... Rear axle case, 52... Rear axle, 53... Fixed case,
54... Movable case, 64... Hydraulic cylinder, 72
．． 73...Oil chamber, 77...Auxiliary hydraulic pump (hydraulic #
), 80...Solenoid switching valve. Patent applicant To Kubota Iron Works Co., Ltd. -31-

Claims (1)

[Claims] (1) A vehicle equipped with a telescoping axle case (51), a hydraulic cylinder (64) for telescoping the axle case (51), and a switching valve for controlling the telescoping of the hydraulic cylinder (64). In the wheel distance adjustment device, the hydraulic power source (7
7) and the hydraulic cylinder (64).
) is connected to a wheel distance adjustment device for a vehicle.