JPH0740847A - Front wheel auxiliary steering device - Google Patents

Abstract

(57) [Abstract] [Purpose] To increase the strength of a bracket that receives mutually opposite internal forces among the brackets for mounting the actuator and the gear box on the vehicle body while the steering gear box is stroked by the actuator to assist the front wheels. [Structure] When the pinion 5 is driven by a steering operation, the rack 6 is stroked and the left and right front wheels are mainly steered. When the actuator 7 is operated, the steering gear box 2 is displaced by the deformation of the elastic body 9,
Auxiliary steering of the front wheels is possible. The cantilever bracket 10 for the steering gear box 2 and the actuator 7 which receive mutually opposite forces during the front wheel assist steering are reinforced by a bridge member 12 that restrains relative displacement between these brackets, and they are repeatedly mutually reciprocated. Even if a reverse internal force is applied,
It does not cause deformation or relative displacement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front wheel auxiliary steering device for auxiliary steering, in addition to main steering of front wheels by a steering gear box.

[0002]

2. Description of the Related Art Normally, a vehicle steers front wheels by a steering wheel through a steering gear box.
There is a vehicle in which the front wheels are increased or reduced by auxiliary steering.

As a front wheel steering mechanism therefor, for example, a mechanism as disclosed in Japanese Patent Laid-Open No. 58-214457 is known. This front wheel steering mechanism is as shown in FIGS. 2 and 3, and in FIG. 2, 1 is the left and right front wheels, 2 is the steering gear box, and 3 is the steering wheel.

The steering wheel 3 is connected to a pinion 5 of a steering gear box 2 via a steering shaft 5, and a rack 6 of the steering gear box 2 meshing with the pinion is connected to the left and right front wheels 1 at both ends thereof through a steering linkage. . Then, when the steering wheel 3 is rotationally operated, the pinion 5 driven by the shaft 4 thereby causes the rack 6 to stroke the rack 6 in the lateral direction of the vehicle body, so that the left and right front wheels 1 can be mainly steered. it can.

The front wheel assist steering actuator 7 is arranged in the vehicle width direction, and one end of the actuator 7 is attached to the steering gear box 2.
The other ends are connected to the vehicle body (specifically, front wheel suspension member) 8. The steering gear box 2 is displaceable in the vehicle width direction via a pair of elastic bodies 9 so that the vehicle body 8
Attach to. Here, when the actuator 7 is expanded / contracted, the steering gear box 2 is displaced in the vehicle width direction through the deformation of the elastic body 9, and the front wheel 1 is further increased or decreased relative to the main steering, so-called auxiliary steering. can do.

The structure for mounting the steering gear box 2 and the actuator 7 on the vehicle body 8 is as shown in FIG. First, when mounting the steering gear box 2, a pair of cantilever brackets 10 are provided on the vehicle body 8, and the steering gear box 2 can be displaced in the vehicle width direction via the elastic body 9 at the ends of the brackets 10. Install. When mounting the actuator 7, the cantilever bracket 1 is attached to the vehicle body 8.
1 is provided, and the cylinder 7a of the actuator 7 is provided at the tip thereof.
And the piston 7b of the actuator 7 is connected to the steering gear box 2.

[0007]

However, in such a conventional front wheel auxiliary steering system, the internal forces of the steering gear box side bracket 10 and the actuator side bracket 11 which are opposite to each other are applied to each other during the front wheel auxiliary steering by the operation of the actuator 7. Is unavoidable.

When the actuator side bracket is also used as one of the steering gear box side brackets for the sake of simplification of the structure, the combination of the actuator side bracket and the other steering gear box side bracket is not necessary. A reverse internal force is applied to.

As described above, the brackets to which the mutually opposite internal forces are applied cause deformation or relative displacement due to repeated front wheel assist steering, and displace the mounting position of the actuator 7 to the steering gear box 2. In this case, even if the stroke of the actuator 7 is the same, the front wheel auxiliary steering angle is different, and the conventional front wheel auxiliary steering device has a problem that it is difficult to achieve accurate steering angle control.

It is an object of the present invention to eliminate the above-mentioned problem by bridging and reinforcing the brackets to which mutually opposite internal forces are applied.

[0011]

To this end, the present invention provides a plurality of cantilevered brackets for the steering gear box so that the front wheels are mainly steered by a steering gear box and can be assisted by an actuator. In the front wheel auxiliary steering device, one end of the actuator is connected to the vehicle body by a cantilever bracket, and the other end is connected to the steering gear box. A bridging member for restraining relative displacement of the pair of brackets is provided between brackets that receive mutually opposite forces during front wheel assist steering by the actuator.

[0012]

The front wheel is mainly steered by the steering gear box and assisted by the actuator. In this auxiliary steering, the steering gear box attached to the vehicle body by the plurality of cantilever brackets via the elastic body is deformed by the operation of an actuator whose one end is also connected to the vehicle body by the cantilever bracket. It is generated by displacing through.

By the way, among all the above-mentioned cantilever type brackets, a bridging member for restraining relative displacement of the pair of brackets is installed between brackets which receive mutually opposite forces during front wheel assist steering by the actuator. Therefore, these brackets are reinforced by the bridging member, and even if the front wheels assist steering repeatedly apply mutually opposite internal forces, they do not cause deformation or relative displacement, and the actuator of the steering gear box does not move. It can prevent the mounting position from being changed. Therefore, the steering angle control by the front wheel assist steering can be accurately maintained.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows an embodiment of a front wheel assist steering device according to the present invention, in which the same parts as those in FIGS. 2 and 3 are designated by the same reference numerals.

In this embodiment, the steering gear box 2 arranged in the width direction of the vehicle is mounted on both ends of the steering gear box 2 by a pair of cantilever brackets 10 via an elastic body 9 made of rubber or the like.
It is attached to the vehicle body 8 so that it can be displaced in the vehicle width direction. Although the actuator 7 is also arranged in the vehicle width direction, it is attached to the vehicle body 8 while also using one of the steering gear box mounting brackets 10 (the right bracket 10 in the drawing).

Therefore, the cylinder 7a of the actuator 7 is fitted to the bracket 10 and the cylinder 7a
Then, the steering gear box 2 is liquid-tightly sealed and slidably inserted. And the piston 7b of the actuator 7
Is slidably fitted in the cylinder 7a and fitted and fixed on the steering gear box 2. Thus, chambers 7c and 7d are defined on both sides of the piston 7b, and ports 7e and 7f for these chambers are formed in the cylinder 7a.

When the pinion 5 is driven by rotating the steering wheel, the rack 6 is stroked in the lateral direction of the vehicle body, whereby the left and right front wheels are mainly steered. Here, during operation of the actuator 7 that strokes the piston 7b by supplying and discharging operating pressure to and from the chambers 7c and 7d via the ports 7e and 7f, the steering gear box 2
Is displaced in the vehicle width direction through the deformation of the elastic body 9, so that the front wheel can be increased or reduced to the main steering and assisted steering.

During such front wheel assist steering by the actuator 7, the cantilever type bracket 10 receives mutually opposite forces due to the elastic reaction force caused by the deformation of the elastic body 9, causing the deformation and relative displacement as described above. , The position where the actuator 7 is attached to the steering gear box 2 is deviated, and it is difficult to achieve accurate front wheel assist steering. However, in order to solve this situation, in this example, these pairs are formed between the cantilever brackets 10. A bridging member 12 is installed to restrain the relative displacement of the bracket.

According to this structure, the cantilever type bracket 10 reinforces each other by the bridging member 12, so that the front wheel assist steering causes deformation and relative displacement even when internal forces in opposite directions are repeatedly applied. Therefore, the mounting position of the actuator 7 with respect to the steering gear box 2 can be prevented from being changed, and the steering angle control by the front wheel assist steering can be accurately maintained.

It is needless to say that the bridge member 12 should be arranged on the side opposite to the bracket 10 with respect to the central axis of the steering gear box 2 in order to maximize the effect.

[0021]

As described above, the front wheel assist steering apparatus according to the present invention, among all the cantilever brackets for mounting the steering gear box and the actuator on the vehicle body, mutually operates during front wheel assist steering by the actuator. Since a bridging member that constrains the relative displacement of the pair of brackets is installed between the brackets that receive the opposite force, the brackets that form the pair reinforce each other by the bridging member, and the front wheel assist steering repeatedly Even if internal forces in opposite directions are applied, deformation and relative displacement are not caused, and it is possible to prevent the mounting position of the actuator with respect to the steering gear box from being deviated, and the rudder angle control by front wheel assist steering can be performed accurately. Can be kept.

[Brief description of drawings]

FIG. 1 is a detailed sectional view of a vehicle body mounting portion of a steering gear box and an actuator showing an embodiment of a front wheel auxiliary steering device according to the present invention.

FIG. 2 is a schematic view of a front wheel steering system illustrating a conventional front wheel auxiliary steering device.

FIG. 3 is a detailed sectional view of a vehicle body mounting portion of a steering gear box and an actuator in the front wheel steering system.

[Explanation of symbols]

 2 Steering gear box 5 Pinion 6 Rack 7 Actuator 7a Actuator cylinder 7b Actuator piston 7c Actuator working chamber 7d Actuator working chamber 8 Body 9 Elastic body 10 Cantilever bracket 12 Bridge member

Claims (1)

[Claims] 1. The steering gear box is attached to a vehicle body through an elastic body by a plurality of cantilever brackets so that the front wheels can be mainly steered by a steering gear box and can be assisted by an actuator. A front wheel assist steering device in which one end of the cantilever bracket is connected to the vehicle body and the other end is connected to the steering gear box. A front wheel assist steering system characterized in that a bridging member for restraining relative displacement of the pair of brackets is installed between the brackets receiving the force of.