JPS606824B2 - 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 for a power steering device.

In conventional power steering systems, when the steering wheel of the vehicle is turned in one direction, the hydraulic assisting force is released just before the steering locks, thereby preventing excessive force or impact on the steering output system due to unnecessary assisting force. Various attempts have been proposed to eliminate the damage caused by this.

This conventional device for releasing the hydraulic auxiliary force has a complicated mechanism, is inaccurate in adjusting the release timing, and has poor workability. The present invention was proposed in order to solve the above-mentioned conventional drawbacks, and by providing a magnetic switch and a solenoid valve, the present invention provides a power source that ensures the release of the hydraulic auxiliary force and facilitates adjustment of the release timing. It is an object of the present invention to provide a steering angle limiting device for a steering device.

Embodiments of the drawings will be described below. FIG. 1 shows a sectional view of a power steering gear A showing an embodiment of the present invention, 1 is a housing, 2 is a valve housing connected to the housing 1, and 3 is a valve housing 2. It is a steering shaft supported by the worm shaft 4 and connected to the worm shaft 4 inside the housing 1.

A piston 5 is connected to the worm shaft 4 via a plurality of balls 6, and the piston 5 is also connected to a sector shaft 7 supported by the housing 1 via a rack 5' and a sector gear 7'. .

Further, 8 is a side cover, and the above mechanism has the same structure as a conventional power steering device. FIG. 2 is a detailed sectional view of a steering angle limiting device showing an embodiment of the present invention, in which 9 is fixed to the sector gear 7' of the sector shaft 7 with a magnet.

Reference numeral 10 is an adjustment bolt fixed to the side cover 8 by a seal lock nut 11. An insulator 12 with a built-in reed switch 13 is fixed to the tip of the bolt 10, and a reed wire 14 is connected to the reed switch 13. is wired through the insulator 12 and the adjustment bolt 10.

Also, the sensitive part of the reed switch 13 is the adjustment bolt 10.
It is eccentric from the center D, and the degree of proximity to the magnet 9 can be adjusted by the rotational position of the bolts 1 and 0. That is, when the sector shaft 7 is at the operating angle limit position, the adjustment bolt 10 can be rotated to operate the reed switch 13, and the adjustment port 10 can be fixed by tightening the seal lock nut 11 at that position. It is now possible to seal it. Figure 3 shows the power steering hydraulic and electrical circuits, and the power steering gear A shown in detail in Figure 1.
and pump B are connected by a hydraulic pipe 17a, the gear A and reservoir C are connected by a pipe 17b, and the reservoir C and pump B are connected by a pipe 17c. 16 is hydraulic piping 1
A solenoid valve installed between 7a and 17b,
One wiring 18a of the solenoid of the valve 16 is connected to one terminal of the battery 15, and the other wiring 18b is connected to two terminals in parallel.
Lead wires 14, 1 from the lead switches 13, 13
4 to the other terminal of the battery 15.

FIG. 4 shows the detailed structure of the solenoid valve 16, in which a hole provided in a part 19 of the power steering gear A or pump B has a groove 20 communicating with the discharge side of the pump B and a groove 21 communicating with the IJ server C. are formed on the circumference, respectively, and a piston 22 is inserted into the hole. A groove 23 is provided in a part of the outer periphery of the piston 22.
0 is suitable, and the lotus communication with the groove 21 is blocked. 24 is a passage provided in the piston 22, through which the lower end of the piston and the groove 21 are connected.

A spring 26, one end of which is held by a cover 25, is compressed and incorporated into a hole provided at the upper end of the piston 22. A solenoid 27 is provided on the inner surface of the cover 25 and on the outer periphery of the piston 22. It is being The cover 25 is also caulked to a portion 19 of the gear A or the pump B.
28 is the ○ ring on the outer circumference of the piston 22, and the solenoid 2
This prevents oil from leaking to the 7th part.

Next, the effect will be explained. When a handle (not shown) is turned, the steering shaft 3 and the worm shaft 4 rotate, and the piston 5 slides inside the housing via the ball 6.
Therefore, at the same time as the sector shaft 7 rotates due to the engagement between the rack 5' and the sector gear 7', the oil pressure corresponding to the rotational resistance of the sector shaft 7 is controlled by the valve control section.
It acts on the end face of the piston 5 to assist. Rotation of the sector shaft 7 deflects the steered wheels via a Bittman arm (not shown) fixed to one end of the sector shaft 7 and a steering linkage mechanism (not shown). In this case, the reed switch 13 is activated at the sector shaft rotational angle position just before the steering wheel locks (
The rotational position of the adjustment bolt io is adjusted so that it turns on (→off). Within the operating angle limit of the sector shaft 7, the reed switch 13 is in the OFF state and the solenoid 2
7, no current flows through the piston 22, and the piston 22
6 is in the position shown in FIG. 4, grooves 20 and 21 are blocked (pipes 17a and 17b do not pass).
Hydraulic assisting force due to the hydraulic pressure supplied by pump B acts on the end surface of piston 5. Next, when the steered wheels are about to lock, the reed switch 13 is activated (off→on) to energize the solenoid 27. When the solenoid 27 is energized, the piston 22 moves upward against the spring 26 and closes the groove 23.
The grooves 20 and 21 fit through the pipe 17a.
and 17b are suitable for lotus. That is, the hydraulic pressure supplied from pump B is short-circuited to reservoir C, and the hydraulic pressure supplied to power steering gear A is decreased. Although the reed switch 13 in the above embodiment was a biased reed switch, a straight curved switch was used instead, so that the sensitive part of the switch could move toward or away from the magnet. As explained in detail above, the present invention is equipped with a magnetic switch and a solenoid valve to release the hydraulic assisting force just before the steering wheel locks. In addition, the release timing can be easily adjusted.

Further, in the present invention, a magnet switch is attached to the adjustment bolt, and when the rotation angle of the sector shaft reaches a predetermined angle, the rotation angle is detected by the magnet switch and the solenoid valve is opened and closed. The degree of proximity between the sensitive part and the magnet can be easily adjusted by the rotational position of the adjustment bolt. That is, when the sector shaft is at the operating angle limit position, the reed switch can be easily adjusted by rotating the adjust port.
By tightening the lock nut at that position, the adjustment bolt can be fixed and sealed. If the magnetic switch is a non-contact type magnetic lead switch, troubles caused by wear and damage to the contact parts can be avoided.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view of a power steering gear showing an embodiment of the present invention, Fig. 2 is a side sectional view of the main part, Fig. 3 is a system diagram showing the hydraulic piping and electric circuit, and Fig. 3 is a system diagram showing the hydraulic piping and electric circuit. FIG. 4 is a sectional view of the solenoid valve in FIG. 3. Explanation of the main parts of the diagram, 4... Steering axis, 5...
... Piston, 7 ... Sector shaft, 9 ... Magnet, 13 ... Reed switch, A ... Power steering gear, B ... Pump, C ... Reservoir, 17a, 17b , 17c...hydraulic piping, 16...
・Solenoid valve, 20, 21, 23...Groove, 22...
...Piston 26...Spring, 27...Solenoid.Figure 2Figure 3Figure 4

Claims (1)

[Claims] 1. A power steering system for a vehicle is equipped with a magnetic switch including a reed switch attached to an adjustment bolt that is threadedly engaged with the power steering gear housing and prevented from rotating by a lock nut, and that controls the rotation angle of the sector shaft. When the rotation angle reaches a predetermined angle, the magnetic switch detects the rotation angle and opens and closes the solenoid valve, thereby short-circuiting the hydraulic pressure supplied to the power steering device to a reservoir and reducing the hydraulic assisting force. A steering angle limiting device for a power steering device, characterized in that: