JPS587504B2 - Steering angle limiting device for power steering device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering angle limiting device that reduces the hydraulic assisting action of a power steering device when the steering wheel of a vehicle rotates to its rotational angle limit and locks.

In the case of a normal power steering device (puff steering), it is often experienced that the driver applies excessive force to the steering wheel without realizing that the rotation of the wheels is locked, or the wheels lock due to an impact. .

As a result, the assisting force of the power steering and the steering wheel applied by the driver generate extremely excessive force and impact on the steering output system, which may damage or deform the steering output ring or damage the link joint. There was a possibility that an accident would occur.

To solve this problem, puff steering has been proposed in which the power assisting action of the power steering is disabled when the steering wheel reaches near its rotational position limit.

However, with this conventional power steering, the rotational position of the gear is detected inside the steering gear and the power assisting force is stopped. The lock position and the power assist stop position of the gear did not match, which often resulted in a reduction in the rotation angle of the steering wheel.

It is also possible to make the power assisted stop + position of the stop gear adjustable to avoid this problem, and adjust it to match the lock position of the tires after installation on the vehicle, but this adjustment is not only troublesome, but also affects the steering system. There were disadvantages such as the need for parts replacement and readjustment at each service.

The present invention has been proposed in order to eliminate the above-mentioned drawbacks of the prior art, and by sensing the locking of wheels or links and thereby stopping the operation of the power steering, the present invention provides a power steering system that does not require any adjustment. It is an object of the present invention to provide a steering angle limiting device.

The present invention will be described below with reference to the embodiments shown in the drawings. Fig. 1 is a plan view showing the hydraulic and electric circuits of a power steering system according to an embodiment of the present invention, and 1 is a power steering gear which is connected via a normal output link. It is connected to two steering wheels.

Further, the power steering gear 1 is hydraulically connected to a hydraulic pump 2 and a pipe 3, and is further connected to a tank 4 and a pipe 5.

Naturally, piping is also provided between the pump 2 and the tank 4.

The above structure is a normal power steering, but in the embodiment shown in FIG. 1, a solenoid valve 6 is provided between the piping 3 and the piping 5.

This solenoid valve 6 cuts off communication between the pipes 3 and 5 when no current flows, and connects the pipes 3 and 5 when current flows.

Also, one end of the nolenoid wiring of the nolenoid valve 6 is connected to one terminal of the switch J7, and the other end is connected to two switches 8 in parallel.
and 8' to the other terminal of the battery 7.

These two switches 8, 8' are energized when they are touched by nuts 9, 9', which are parts of the steering link, respectively, and are fixed to the vehicle frame, suspension arm, or the like.

FIG. 2 shows one embodiment of the switches 8, 8'.
It is a reed switch that is energized when the magnet 11 approaches, and is integrally joined to the base 12.

Also, a magnet holder 1 made of an insulating material is molded integrally with the magnet 11.
3, the base 1 is inserted into the switch case 14 via the spring 15.
It is pushed in by 2.

On the other hand, one end of the magnet holder 13 protrudes outward from the switch case 14, and the base 12 is connected to the switch case 14.
It is caulked and fixed.

The switch case 14 is screwed to a frame of the vehicle or a part 16 of a suspension arm, which normally serves as a stopper part of a knuckle of the vehicle, and is locked with a nut 17.

Reference numeral 18 denotes a portion of the knuckle arm 9 or 9', which gradually approaches the switch as the steering angle becomes sharper and eventually comes into contact with the magnet holder 13.

Note that the switch case 14 is one part 1 of the knuckle arm.
It also serves as a stopper to limit the movement of 8.

Further, 19 in FIG. 1 is a king pin. FIG. 3 shows one embodiment of the solenoid valve 6, in which a hole provided in a part 20 of the steering gear or pump has a groove 21 communicating with the discharge side of the hydraulic pump and a groove 22 communicating with the tank. It is formed in a circumferential shape, and a piston 23 is inserted into this hole.

A groove 24 is provided in a part of the outer circumference of the piston 23,
The groove 24 normally communicates only with the groove 21 and is cut off from the groove 22.

The lower end of the piston 23 communicates with the groove 22 through a passage 25, and a spring 27, the other end of which is held by a cover 26, is compressed and installed in a hole provided at the upper end of the piston 23.

Further, a solenoid 28 is installed on the outer periphery of the piston 23 and inside the cover 26.

Note that the cover 26 is caulked and fixed to a portion of the steering gear or a portion 20 of the pump.

29 is a solenoid 2 provided on the outer periphery of the piston 23
The OJ ring is a reservoir to prevent oil leakage to part 8, and 30 in Fig. 1 is a handle.

The above is an example of a configuration for integral type power steering, but a linkage type power steering in which the valve and actuator parts are separate parts is configured in exactly the same way.

Further, the solenoid valve can be arranged not only between the discharge circuit of the hydraulic pump and the return circuit to the tank, but also so as to connect both cylinder chambers of the actuator.

Also, depending on the space of the vehicle, it can be configured integrally with the hydraulic pump, steering gear, actuator, valve of the power steering device, etc., or it can be connected with hydraulic piping and installed separately from the power steering device. It can also be mounted in any position.

Next, to explain the operation, in the normal state (switches 8 and 8' are off), no current flows through the solenoid 28, so the piston 23 is held in the position shown in FIG. 3 by the spring 27, and the groove 21 and 22 are cut off (to explain this state with reference to FIG. 1, pipes 3 and 5 are cut off).

). Therefore, the function of power steering is guaranteed without being completely different from the operation of conventional power steering.

Next, turn the handle 30 in the direction of the arrow in Figure 1.
The wheel rotates in the direction of the arrow around the kingpin 19, and the knuckle arm 9 approaches the switch 8 (knuckle arm 9
' moves away from the switch 8'), one part 18 of the knuckle arm hits the magnet holder 13, and when the holder 13 is further pushed in against the spring 15, the reed switch 10 is turned on by the movement of the magnet 11, and the nozzle is turned on. The noid valve 6 is energized.

Next, when current flows through the solenoid 28, the piston 23 moves upward against the spring 21, so the grooves 21 and 22 communicate with each other via the groove 24 (as shown in FIG. 1, the pipes 3 and 5 communicate with each other). ), the oil pressure of pump 2 will not increase.

That is, the assisting force is eliminated (or reduced), and no excessive force is applied to the link system.

When you return the nondle 30 from this state, the knuckle arm 1
The reed switch 10 is turned off when the portion 18 is returned and the magnet 11 is returned to its original set position by the spring 15, so the piston 23 of the solenoid valve 6 is also returned to its original position by the spring 27, and the pipes 3 and 5 are cut off. It becomes normal power steering.

Also, when the handle 30 is rotated in one direction opposite to that described above, the same operation as described above is performed.

Since the present invention is configured as explained in detail above,
By installing the device of the present invention at the link or wheel stopper position of a normal steering link system, it is possible to detect the locking of a wheel or knuckle arm using a small unitized switch. There is no need for any troublesome adjustments after installation or during maintenance.

Furthermore, since the power steering circuit can be controlled by a small solenoid valve, the device of the present invention can be installed integrally with the power steering gear and pump, or installed separately depending on the space available.

[Brief explanation of the drawing]

FIG. 1 shows the hydraulic pressure of a steering angle limiting device showing an embodiment of the present invention.
FIGS. 2 and 3 are system diagrams showing a state in which the electric circuit is installed in the steering wheel portion, and are detailed cross-sectional views of the main parts in FIG. 1, respectively. Explanation of main parts of the diagram 1...Power steering gear,
2... Hydraulic pump, 3, 5... Piping, 4... Tank, 6... Solenoid valve, 8, 8'... Switch, 9, 9'... Knuckle arm, 10...
・Reed switch, 11...Magnet, 21, 22, 24
... groove, 23 ... screw}/, 27 ... spring, 28
···solenoid.

Claims (1)

[Claims] 1. In a power steering device of a vehicle, wiring is provided to a stopper portion of a steering wheel or a link connected to the wheel to a solenoid valve provided between a discharge circuit of a pump of said steering device and a return circuit to a tank. a switch is provided, and when the wheel or link approaches or contacts the switch, the solenoid valve opens, and the discharge circuit of the pump and the return circuit to the tank are connected to provide a hydraulic assisting effect of the power steering device. A steering angle limiting device for a power steering device, characterized in that the steering angle is reduced.