JPH0231347Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a valve device in power steering for automobiles and the like.

Power steering, which uses hydraulic pressure to power-assist the movement of the steering linkage, is widely known in order to reduce the burden of steering wheel operation.A control valve selectively sends this hydraulic pressure to the power cylinder in response to steering wheel operation. The apparatus is generally constructed as shown in FIGS. 1 to 3, for example (see Japanese Patent Laid-Open No. 130864/1986).

This is a rack-and-pinion power steering system, with a rack 1 interlocked with a steering link (not shown), and a pinion 2 meshing with the rack 1 formed integrally with a pinion shaft (input shaft) 5.

Reference numeral 4 denotes a housing containing these, and a control valve 3 is disposed on the upper part.

The pinion shaft 5 is rotatably supported by the housing 4 via bearings 6 and 7.

Bearings 6 and 7 are mounted on rack 1, as shown in FIG.
An elliptical long hole 8 whose long axis is parallel to
An outer race 9 is inserted into the pinion shaft 5 so that the pinion shaft 5 can be displaced by a predetermined distance left and right.

However, the pinion shaft 5 is connected to a steering shaft on the handlebar side (not shown);
A mechanism (not shown) for absorbing this left and right displacement is interposed in the middle.

In the control valve 3, a valve spool 11 that slides in a direction parallel to the rack 1 is housed in a sleeve portion 10 formed in the housing 4.

There are two annular grooves 1 on the outer periphery of the valve spool 11.
2A, 12B are formed, and an annular pump port 15 and tank ports 13A, 13B are formed on the inner periphery of the sleeve portion 10, and are further located between them and communicate with left and right cylinder chambers of a power cylinder (not shown). control ports 14A, 14B
is provided, and as the valve spool 11 moves left and right, pressure oil from the pump port 15 is sent to either one of the control ports 14A or 14B, and the other control port 14B or 14A is sent to the tank port 13A or 13B. communication, thereby performing power assist.

A pin hole 16 is formed in the valve spool 11 and is perpendicular to the pinion shaft 5.
When the drive pin 21 of the drive lever 17 is connected to the housing 4
It is inserted through the opening 18 provided in the.

This drive lever 17 has a support pin 20 and a drive pin 21 protruding from the center of a ring portion 19 that is rotatably fitted to the pinion shaft 5 via a bearing 23. The end part fits into the support hole 24 formed in the housing 4,
By swinging the drive lever 17 left and right around this support pin 20, the valve spool 11 is displaced left and right via the drive pin 21.

In such a configuration, when the pinion shaft 5 is rotated to the left or right by operating a handle (not shown), the pinion shaft 5 is initially rotated because the resistance of the rack 1 connected to the steering link is large.
It is easy 1 by the amount allowed by the long hole 8 due to the rotation of
The pinion shaft 5 is displaced along.

At this time, since the ring portion 19 of the drive lever 17 is displaced together with the pinion shaft 5, the drive lever 17 is tilted around its support pin 20, and the drive pin 21 at the tip is tilted.
can swing greatly.

This causes the valve spool 11 to switch,
Pressure oil is supplied to a power cylinder (not shown), which drives the rack 1 in the rotational direction of the pinion shaft 5.

On the other hand, when the rotation of the handle stops, at that moment the control valve 3 remains switched and drives the rack 1 in the same direction, but since the pinion 2 has already stopped rotating, the pinion shaft 5 is displaced together with the rack 1 and returned to its initial position, returning the valve spool 11 to its neutral state.

In this way, the steering operation is powered assisted, but since the rotation of the steering wheel is sensed and the control valve 3 is switched via the drive lever 17, it needs to be installed near the pinion shaft 5. When switching control valves via links, etc.,
It becomes necessary to make the relationship between the direction of displacement of the steering shaft and the displacement direction of the control valve symmetrical or equal between the left and right sides, which imposes considerable restrictions on the installation of the control valve, and at the same time, it is necessary to make the relationship between the direction of displacement of the steering shaft and the displacement direction of the control valve symmetrical or equal. Due to this, there was a tendency to make the design and layout quite difficult.

The present invention aims to solve such problems, that is, to greatly improve the degree of freedom in installing control valves.

In order to achieve the above object, the present invention provides a power supply system equipped with a member that is displaced based on the steering reaction force accompanying the steering operation, and a control valve that selectively switches the hydraulic fluid sent to the power cylinder in response to the member. In the steering, the above-mentioned member and the control valve are interconnected via a push-pull cable provided to move forward and backward in the direction of displacement of the member, and the displacement of the above-mentioned member is transmitted to the control valve via the push-pull cable. I decided to do so.

Hereinafter, embodiments of the present invention will be described based on the drawings.

In FIG. 4, the drive lever 17, which is a member that is displaced based on the steering reaction force accompanying the steering operation, has a drive pin removed, and drive arms 30 and 31 are protruded from left and right symmetrical positions, respectively. One end of the push-pull cables 32 and 33 is tied to the arms 30 and 31, and the other end is connected to both ends of the valve spool 11 through guide sheaves 34 and 3.
5, and the valve spool 11 is configured to be displaced in the same direction via push-pull cables 32 and 33 as the drive lever 17 is tilted.

Although the outline of the control valve 3 is only shown, the specific configuration is the same as that shown in Fig. 2.
Since the other parts are the same as those in FIGS. 1 to 3, the same reference numerals are given and the explanation will be omitted.

In the illustrated state, if the pinion shaft 5 is displaced, for example, to the right as the handle is operated, the drive lever 17 will tilt to the right about the support pin 20, and the left drive arm 30 will move the push-pull cable 32. By pulling, the right drive arm 31 compresses the push-pull cable 33.

Therefore, the valve spool 11 of the control valve 3 is displaced to the left, and the control valve 3 is switched.

This also applies when the drive lever 17 is tilted in the opposite direction, and the valve spool 11 is switched left and right depending on the direction of rotation of the handle.

Note that the push-pull cables 32 and 33 transmit motion not only in tension but also in compression, but cables that only perform tension may be connected to both ends of the valve spool 11.

The embodiment shown in FIG. 5 is an example in which the left and right push-pull cables 32, 33 are not arranged symmetrically, and the control valve 3 is located at the drive lever 1.
Even if it is not directly above 7 but shifted to the right,
Displacements caused by steering operations can be transmitted without any hindrance.

Note that the push-pull cables 32 and 33 are directly connected to the outer periphery of the bearing portion 19 of the drive lever 17.

In the embodiment shown in FIG. 6, the control valve 3 is arranged on the side of the support pin 20 of the drive lever 17, and the push-pull cables 32, 33 are connected directly to the outer periphery of the ring part of the drive lever 17, as in FIG. It is connected in a specific way.

Furthermore, in the embodiment shown in FIG. 7, when the pinion shaft 5 is displaced parallel to the rack 1 at the initial stage of steering, other parts than the drive lever 17 are used, such as the bearings 6 and 7.
Since both are displaced in the same manner, switching of the control valve 3 is controlled by connecting the push-pull cables 32, 33 to the outer race 9 of the bearing 6 or 7.

Note that 36 and 37 are guide sheaves attached to the housing 4 side.

As can be understood from the above, in the present invention, if the push-pull cables 32 and 33 are connected by a member that causes displacement in two directions such as left and right or front and rear based on the steering reaction force accompanying steering operation, The present invention is not limited to the drive lever 17 and the bearings 6, 7, and can also be applied to a power steering system other than the rack-and-pinion type, such as a semi-integral type or a separate type. For example, in recirculating ball type steering, the rotation of the steering shaft is transmitted to the sector shaft via a ball screw mechanism, so the steering reaction force causes the steering shaft to be displaced by the amount of clearance provided in the axial direction. do. Even in the rack and pinion type, the rack usually has a diagonal tooth configuration, so the steering shaft is also displaced in the axial direction by the steering reaction force. Therefore, it is possible to adopt a configuration in which this axial displacement is transmitted to the control valve using a push-pull cable.

As described above, the present invention transmits the movement of a member that slides or rotates in two directions such as left and right, front and back, etc. in response to steering operation to the control valve via the push-pull cable. If a link is used as in the past to transmit the displacement associated with the control valve to the control valve, it is necessary to make the relationship between the direction of displacement and the direction of valve movement symmetrical or equal. The design and layout were difficult because the relationship with the vehicle suspension etc. had to be considered, but these problems can be solved at once. In particular, with this invention, by extending the push-pull cable, the control valve can be placed as far away as necessary from the components that respond to steering operation, allowing for an extremely high degree of freedom in in-vehicle layout and manufacturing. This has the advantage of improving flexibility and assemblability.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view of the main part of a conventional power steering system, and Figures 2 and 3 are its -,
- line sectional view. FIG. 4 is a schematic configuration diagram of the first embodiment of the present invention, and FIGS.
It is a schematic block diagram of 4th Example. 1... Rack, 2... Pinion, 3... Control valve, 5... Pinion shaft, 6, 7... Bearing, 8... Oval shaped long hole, 11... Valve spool, 17... Drive lever, 20 ...Support pin, 2
4... Support hole, 30, 31... Drive arm, 3
2, 33... Push-pull cable, 34, 3
5, 36, 37... Guide sheave.

Claims (1)

[Scope of utility model registration request] In a power steering system that includes a member that is displaced based on a steering reaction force accompanying a steering operation, and a control valve that selectively switches hydraulic oil sent to the power cylinder in response to the member, the above member is separated from the member. and a control valve provided at a position where the member is moved forward and backward in the direction of displacement of the member, and the displacement of the member is transmitted to the control valve via the push-pull cable. A power steering valve device characterized by: