JPH0133419Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention consists of a hydraulic pressure guarantee circuit unit connected to a hydraulic pump, a feedback type controller unit linked to a steering wheel, and a check valve installed between them to prevent kickback to the steering wheel. The present invention relates to a hydraulic power steering device in which a hydraulic cylinder for wheel steering is connected to the controller unit.

The above-mentioned device is configured to provide a feedback system that still applies rotational operating force to the handle when the hydraulic cylinder has reached its stroke end or when a steering member connected to the cylinder has reached its end of operation. In the open state of the controller, the reaction force applied to the steering wheel when another object comes into contact with the steering wheel, that is, the kickback, is prevented by the check valve. Since the check valve was interposed in the conduit connecting the two units, a large amount of space was required for the entire steering device.

The object of the present invention is to make the entire steering device compact and easy to manufacture and process through extremely simple modification.

Next, embodiments of the present invention will be described in detail based on the drawings.

At the rear of the traveling body 3, which is equipped with driving front wheels 1, 1 and driving rear wheels 2, 2 for left and right steering, there is a power take-off shaft 4 for driving a working device such as a rotary, and a power take-off shaft 4 for driving a working device such as a rotary, and for raising and lowering the working device from the ground. Lift arm 5 for
A passenger seat 6 is provided between the left and right driving rear wheels 2, 2, and a steering handle 7 is disposed at the front of the seat 6, thereby forming an agricultural tractor.

The hydraulic power steering device 8 for the front wheels 1, 1 is configured as shown in FIG.
An arm 11 is integrally connected to axle cases 10b, 10b which are rotatable around the vertical axis with respect to the fuselage side axle case part 10a, and a trunnion type steering hydraulic cylinder 12 which is freely swingable around the vertical axis is formed. A pivotally connected steering member 13 is attached to the fuselage 3 so as to be swingable around the vertical axis, and the steering member 13 and the arms 11, 11 are connected to rods 14,
It is pivotally connected at 14.

A feedback type controller unit 15 is interlocked and connected to the handle 7, and a hydraulic guarantee circuit unit 16 having a built-in flow rate adjustment valve _V1 and a relief valve _V2 and the controller unit 15 are connected to the pump flow path a, The unit cases A and B are connected face-to-face in a state where they communicate with each other, and the hydraulic pump P is connected to the pump passage a of the hydraulic guarantee circuit unit 16, and the hydraulic pump P is connected to the controller unit 15. The steering hydraulic cylinder 12 is connected thereto.

Furthermore, a check valve V for preventing kickback against the handle 7 when the controller unit 15 is in the open state is fitted inside the unit cases A and B across the connecting portions of the pump channels a and b. I have let you.

That is, as shown in FIG. 3, the check valve main body is internally fitted and screwed into the threaded hole for pipe connection formed in the pump flow path a of the hydraulic pressure guarantee circuit unit 16, and the check valve V The downstream protruding portion of the controller unit 16 is fitted into the pump passage b formed in the case B of the controller unit 16.

Note that the check valve V may be fitted inside the pump passages a and b of either of the unit cases A and B, and the present invention may also be applied to the steering device 8.
It can be installed on various agricultural and construction work vehicles and passenger cars.

In summary, the present invention provides the above-mentioned hydraulic power steering device in which the pump passages of the hydraulic guarantee circuit unit and the controller unit are connected by connecting the unit cases, and the check valve is connected to the hydraulic guarantee circuit unit and the controller unit. The check valve main body is internally fitted into a threaded hole for pipe connection formed in the pump passage of one of the circuit unit and the controller unit, and the protruding portion of the check valve is inserted into the threaded hole for connecting the pipe formed in the pump passage of one of the circuit unit and the controller unit. It is characterized by being fitted into the pump channel formed in the case of the unit in an unconnected state.

That is, by fitting the check valve V into the unit cases A and B, the pump channels a and b can be connected to each other by directly connecting the cases A and B, which is extremely simple as a whole. Through extensive modifications, it has become possible to construct a compact steering device with a function to prevent backlash.

Moreover, since the check valve is built-in and the pump flow path is used as the space for the built-in, there is no need to prepare a separate hole to incorporate the check valve into the unit case, simplifying the process and reducing costs. This has the advantage of reducing the Furthermore, since the check valve is screwed into the pump flow path of one unit case, and is simply inserted into the pump flow path of the other unit case without being connected, the check valve is not connected to the pump flow path of the other unit case. There is an advantage that the unit cases can be easily connected with each other with the valve installed in the pump flow path.

[Brief explanation of the drawing]

The drawings show an embodiment of the hydraulic power steering device according to the present invention, and FIG. 1 is a side view of a tractor;
Figure 2 is a system diagram of the power steering system, Figure 3
The figure is a sectional view of the main part. 7...Steering handle, 12...Hydraulic cylinder, 15...Controller unit, 16...Hydraulic pressure guarantee circuit unit, A, B...Unit case,
a, b...Pump flow path, P...Hydraulic pump, V...
...Check valve.

Claims (1)

[Scope of utility model registration request] Hydraulic guarantee circuit unit 1 connected to hydraulic pump P
A feedback system controller unit 15 interlocked with the steering wheel 6 and the steering handle 7 is connected therebetween via a check valve V for preventing kickback to the steering handle 7. This is a hydraulic power steering device in which a hydraulic cylinder 12 is connected, and the pump passages a and b of the hydraulic guarantee circuit unit 16 and the controller unit 15 are connected by connecting unit cases A and B, and the check Valve V
The main body of the check valve V is internally fitted into a threaded hole for connecting a pipe formed in the pump passage a of one of the hydraulic pressure guarantee circuit unit 16 and the controller unit 15. A hydraulic power steering device characterized in that a protruding portion of the check valve V is fitted into a pump passage b formed in a case B of the other unit 16 in a disconnected state.