JPH03182805A - Vehicle tread adjusting device - Google Patents

Abstract

PURPOSE:To made easy tread adjustment by forming a change-over valve disposed between right and left hydraulic cylinders which expand an axle case and its hydraulic source out of a control valve which supplies and shuts down pressurized oil and a solenoid change-over valve which changes over expansion and contraction of the hydraulic cylinder. CONSTITUTION:For adjusting right and left rear wheels one by one by expansion, for example, an auxiliary control valve 91 is manually operated by an operation lever 92 to supply pressurized oil to a circuit 90 and energize the solenoid 81 of a solenoid change-over valve 80. After the pressurized oil from a main hydraulic pump 76 is fed to a circuit 83 side through the auxiliary control valve 91 and the solenoid valve 80 on one side, a check valve 85 is opened for introduction into the oil chamber 72 of a hydraulic cylinder 64. On the other hand, a check valve 86 on opposite side is opened to return the oil gathering in an oil chamber 73 in the hydraulic cylinder 64 through the check valve 86. By this, the hydraulic cylinder 64 is expanded to increase tread. Then the solenoid 81 is energized to return the solenoid change-over valve 80 to its neutral position and stop 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 left and right rear axle cases are configured to be expandable and retractable by a fixed case on the vehicle body side and a movable case that is slidably fitted into the fixed case. There is one that allows it to expand and contract.

In this type of wheel distance adjustment device, a manual switching valve is provided between each left and right hydraulic cylinder and a hydraulic power source, and the left and right rear wheels are operated to expand and contract by operating the left and right operating levers, and the left and right rear wheels are moved to one side. The wheelbase distance is adjusted step by step.

(Problems to be Solved by the Invention) In the above-mentioned conventional technology, the left and right hydraulic cylinders are controlled by respective manual switching valves, so it is difficult to take up space for the operation lever, and the lever operation is complicated. It is difficult to adopt this method for tractors with attached wheels, and it is difficult to control both the left and right sides simultaneously.

By the way, a 1-actor is usually equipped with a hydraulic system for lifting and lowering the work equipment at the rear, and an auxiliary control valve for operating an auxiliary actuator is installed near this hydraulic system. It is manually operated.

The present invention provides an electromagnetic switching valve for controlling the left and right hydraulic cylinders that extend and retract the left and right axle cases, and connects the left and right electromagnetic switching valve to a hydraulic power source via a manually operated control valve. It is an object of the present invention to provide a wheel distance adjustment device for a vehicle that can solve technical problems and make effective use of an auxiliary control valve.

(Means for Solving the Problem) The specific configuration for solving the problem in the present invention includes a telescopic left and right axle case 51, a left and right hydraulic cylinder 64 for expanding and contracting the left and right axle case 51, and a left and right hydraulic cylinder 64 for expanding and contracting the left and right axle case 51. In a wheel distance adjustment device for a vehicle that includes a switching valve provided between a hydraulic power source 76 and a hydraulic pressure source 76 to control expansion and contraction of the cylinder 64, the switching valve includes a control valve 91 that manually switches the pressure oil supply on and off. This control is provided with an electromagnetic switching valve 80 which is provided between the first valve 91 and the left and right hydraulic cylinders 64 to switch the expansion and contraction of each hydraulic cylinder 64.

(Function) After turning on and operating the manually operated control valve 91, when the left and right electromagnetic switching valves 80 and 80 are energized, the hydraulic cylinder 64 operates in the extension or contraction direction to adjust the wheelbase.

The control valve 91 simultaneously connects and disconnects the hydraulic pressure supplied to the left and right electromagnetic switching valves 80 and 80, and the left and right electromagnetic switching valves 80 and 80 separately and remotely control the hydraulic pressure supplied to the left and right hydraulic cylinders 64, and switch the direction. do.

(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 wheels 3 are attached to both sides of the rear of four transmission cases of the tractor body by means of a brake case 50, a rear axle case 51, and a rear axle 52 via the intermediary 7.

The rear axle case 51 is telescopically constructed of a fixed case 53 and a movable case 54 slidably fitted into the fixed case 53, and the fixed case 53 is attached to the transmission case 49 via the brake case 50. ing.

A brake (not shown) is provided in the brake case 50 for braking the differential yoke shaft 55 that protrudes from the rear wheel differential device in the solution case 49.
5 is operatively connected to the rear axle 52 via a planetary reduction gear 56.

The rear axle 52 is a first shaft 5 connected to an idle X reduction gear 56.
7 and a second shaft 59 connected thereto via a spline cylindrical shaft 58, making it expandable and retractable.

The first shaft 57 is supported by the fixed case 53 via a bearing 60, and the second shaft 59 is supported by the movable case 54 via a bearing 6L62. 3 disks 64a are attached.

A hydraulic cylinder 64 for extending and contracting the rear axle case 51 is arranged in parallel 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 consists of a piston throat 66 whose inner end is fixed to the fixed case 53, a piston 67 fixed to the outer end of the piston rod 66, and a main body 68 of the piston 67 and the piston rod 66. The piston rotor 8 is cylindrical, and the piston rotor 8 has an oil passage 69 inside and outside.

Inner cylinder 71 is inserted so as to form 70, and its ?
169 and 70 communicate with respective oil chambers 72 and 73 within the cylinder body 68 which is partitioned from the piston 67.

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 the main hydraulic pump (hydraulic source);
Reference numeral 7 designates an auxiliary hydraulic pump, which is driven by an engine 78 located at the front of the tractor body l.

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 clutches 79 such as PT○ri launch, dual speed clutch, double speed swing clutch, etc., and has a lower pressure (approximately 20 kg/ctA) than the main hydraulic pump 76. something is being used.

A pair of left and right electromagnetic switching valves 80 are connected between the left and right hydraulic cylinders 64 and the main hydraulic pump 76 for adjusting the wheelbase. This electromagnetic switching valve 80 is a three-way switching type equipped with solenoids 8182, each of which has a solenoid 8L8.
2 is connected to a switch on the control panel provided near the driver's seat.

Double pilot type check valves 85, 86 are interposed in circuits 83, 84 that connect the outlet bows 1 to 1 of the electromagnetic switching valve 80 and the oil chambers 72, 73 of the hydraulic cylinder 64. Each check valve 85, 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, 84 on opposite sides. The bottom of the tank is designed to allow oil to flow.

Further, a manually operated double-acting auxiliary control valve 91 with butene 1 is interposed in the circuits 89 and 90 connecting each inlet port of the left and right electromagnetic switching valve 80 and the main hydraulic pump 76.

The spool of this auxiliary control valve 91 is operated by a control lever 92, switched to three positions including a neutral position by a detent member 93, and biased toward the neutral position by a spring.

This auxiliary control valve 91 is originally provided in the hydraulic system for lifting and lowering the work machine, and is connected in parallel with the hydraulic circuit 94 of the hydraulic system, but the main hydraulic pump 76 and the hydraulic circuit 94 are connected in parallel. It may be connected in series between. Since the auxiliary control valve 91 can switch the pressure oil supply direction using the electromagnetic switching valve 80, it may be a three-position conversion type that only connects and disconnects the pressure oil, but as described above, it is possible to use the existing one. Since it uses , it shows the third-place purchase switching type.

The auxiliary control valve 91 is located near the hydraulic system and below the tractor driver's seat, and the operating lever 92 is protruded from below to above on the side of the driver's seat.

Next, the wheelbase distance adjustment operation of the rear wheel 3 will be explained.

First, to adjust the extension of the left and right rear wheels 3 one by one, for example,
Manually operate the auxiliary control valve 91 with the operating lever 92 to open the circuit 9.
Pressure oil is supplied to 0, and one extension switch is operated to energize solenoid 1 and 81 of electromagnetic switching valve 80. Then,
Pressure oil from the main hydraulic pump 76 is sent to the circuit 83 side via the auxiliary control valve 9I and one electromagnetic switching valve 80, the check valve 85 is opened, and the pressure oil is transferred to the oil chamber 7 of the hydraulic cylinder 64.
Enter 2.

On the other hand, since pressure oil comes to the circuit 83, the check valve 86 on the opposite side is opened by the pilot pressure, and the oil in the oil chamber 73 of the hydraulic cylinder 64 is returned via the 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 rear axle 5
The second shaft 59 of No. 2 slides outward via the interlocking body 74.

When the rear wheel 3 moves to an appropriate position, the solenoid 81 is demagnetized, the electromagnetic switching valve 80 is returned to neutral, and the hydraulic cylinder 64 is stopped. Then, since the pressure in the circuit 83 decreases, the check valve 86 closes, and both the check valves 85 and 86 become 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. Contraction regulation is carried out in a similar manner.

If the wheelbase is adjusted, check valve 858 of circuit 83.84
6 are both in the closed state, and each oil chamber 72 of the hydraulic cylinder 64
．． Even if the internal pressure of 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 expand or contract, and even if a large axial force is applied to the rear axle case 51 when driving on a slope, the wheelbase will change accordingly. Never.

Moreover, if the auxiliary control valve 91 is operated in the tangential direction via the operation lever 92 after operating the extension or contraction switches of both the left and right electromagnetic switching valves 80, the left and right hydraulic cylinders 64 are simultaneously extended or contracted. It will cause a contraction operation,
If the loads applied to the left and right rear wheels 3 are approximately the same, the wheelbase distance can be adjusted by the same amount.

FIG. 5 shows another embodiment, which differs from the embodiment shown in FIG. 1 in the type of auxiliary control valve 91'. This auxiliary control valve 9
1 is a single-acting type, and the return oil from the left and right electromagnetic switching valves 80 does not pass through, but is returned to the transmission case.

In this way, the control valve 9J provided between the main hydraulic pump 76 and the left/right electromagnetic switching valve 80 only needs to connect/disconnect the supplied hydraulic pressure, and is similar to the auxiliary control valve conventionally provided in hydraulic systems for lifting and lowering work equipment. can be substituted as is or by using some of its functions.

In each embodiment, check valves 85 and 86 are provided for safety after adjusting the wheel distance.
, 86 may be omitted and the electromagnetic switching valve 80 and the hydraulic cylinder 64 may be directly connected.

It goes without saying that the adjustment of the distance between the front wheels 2 can also be carried out in the same manner.

FIG. 6 shows an example of the structure in which the suction pipe 97 is attached to the filter head 96.

A filter cartridge 98 is attached to a filter head 96 attached to the hydraulic pump, and one end of a suction vibe 97 for connection to a transmission case is attached.

One end of the suction vibrator 97 is inserted into the filter head 96 via an O-ring 99, but conventionally, the end of the suction vibrator 97 is
'', weld a fixing fitting 100 to the Zakujo pipe 97, and attach this fitting 100 to the filter head with a screw 101.
However, welding of the metal fitting 100 is complicated and alignment with the screw hole of the filter head 96 is difficult.

Therefore, in the example shown in FIG.
A circumferential groove 102 is formed at the end of the circumferential groove 102, and the fixing metal fitting 100 is engaged with this circumferential groove 102.Welding is not required, and the circumferential groove 102 can be easily processed at the same time as the groove for the O-ring 99. This eliminates the need for alignment between the screw 101 and the screw hole, making it possible to reduce costs and facilitate assembly.

(Effects of the Invention) According to the present invention, the left and right extraction pressure cylinders 64 are expanded and contracted by using the left and right electromagnetic switching valves 80, so that wheel spacing can be adjusted with a simple switch operation. Therefore, the operation is easier than in the past, and remote control is also easier. In addition, since the manually operated control valve 91 is provided between the electromagnetic switching valve 80 and the hydraulic pressure source 7G, the hydraulic pressure supply to the left and right electromagnetic switching valves 80 can be simultaneously connected and disconnected, and this control valve The auxiliary control valve 91 that is originally provided in the hydraulic system can be used.

[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, FIG. Figure 4 is the TV-IV in Figure 3.
31...Truck body, 3... ·Rear wheel,
51...Rear axle case, 64...Hydraulic cylinder, 7
6... Main hydraulic pump (hydraulic source), 80... Solenoid switching valve for wheelbase adjustment, 91... Auxiliary controllability Applicant Kubota Iron Works Co., Ltd. JP-A-3 182805 (5) -Q-

Claims (1)

[Claims] (1) A telescoping left and right axle case (51), a left and right hydraulic cylinder (64) for expanding and contracting the left and right axle case (51), and a hydraulic power source (64) for controlling the expansion and contraction of the left and right hydraulic cylinder (64). 76), in which the switching valve includes a control valve (91) that manually switches pressurized oil supply on and off; and the left and right hydraulic cylinders (64).
4) A wheel length adjustment device for a vehicle, comprising an electromagnetic switching valve (80) for switching expansion and contraction of each of the above.