JPH0288368A - Rear-wheel steering device for vehicle - Google Patents

Abstract

PURPOSE:To stably support a rear wheel steering mechanism by supporting the steering mechanism on a car body by plural supporting members so that these plural supporting members have difficult mounting angles when viewed from the side surface of the car body, and thereby obtaining supporting strength withstanding forces from various directions. CONSTITUTION:On both end parts of a casing 22 housing a steering shaft of a rear wheel steering mechanism 21 one end sides of brackets 30, 31 are attached, the other end sides of the brackets 30, 31 are fixed to a cress-member 18 of a car body, and the steering mechanism 21 is supported by the cross member. The bracket 30 is horizontally projected from the cross-member 18 to the rear side when viewed from the side surface of the car, and the bracket 31 is projected upward from the cross-member 18 at an angle of about 45 degrees. As a result, the brackets 30, 31 have supporting strength withstanding forces acting from various directions due to vibration of a vehicle and the like, and thereby the rear wheel steering mechanism 21 can be stably supported on the car body.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rear wheel steering device for a vehicle that steers the rear wheels in order to improve the running characteristics of a vehicle whose front wheels are steered. .

(Prior Art) Vehicles whose front wheels are steered are sometimes equipped with a rear wheel steering device that steers the rear wheels in order to improve driving characteristics. Such a rear wheel steering device includes -i, a knuckle arm attached to the rear wheel, a tie rod connected to the knuckle arm, and a rear wheel steering mechanism section that steers the rear wheel via the knuckle arm and the tie rod. It is assumed that the

As one such rear wheel steering device, for example, Japanese Utility Model Application Publication No. 62-25277 uses a motor as a driving means for steering, and the rotation of the motor is reduced by a speed reducer. , which is configured so that the rear wheels are steered by transmitting the signal to a steering shaft connected to the rear wheels via a knuckle arm and a tie rod.

(Problem to be Solved by the Invention) In a vehicle equipped with a rear wheel steering device as described above, the rear wheel steering mechanism section is usually mounted on the lower surface of the vehicle body floor via a plurality of support members. It is attached.

Each of the plurality of support members has one attachment portion connected to the vehicle floor, and the other attachment portion connected to the rear wheel steering mechanism, and the rear wheel steering mechanism is viewed from the side of the vehicle. The mounting angles are usually the same. However, when a plurality of support members are connected to the rear wheel steering mechanism in this way, the support strength of these support members for the rear wheel steering mechanism may be affected by vibrations and rolling of the vehicle body acting on each support member. Among the forces from various directions associated with this, even if it is sufficient for the force from one direction, it is insufficient for the force from a different direction, and the rear wheel steering mechanism There is a risk that the parts may be left in an unstable state.

In view of the above, the present invention provides a rear wheel steering mechanism that steers the rear wheels via a knuckle arm and a tie rod, and is configured such that a rear wheel steering mechanism section that steers the rear wheels is supported by a vehicle body by a plurality of support members, and the plurality of support members are An object of the present invention is to provide a rear wheel steering device for a vehicle, which has support strength capable of withstanding forces acting from various directions, and is capable of supporting a rear wheel steering mechanism in a stable state. shall be.

(Means for Solving the Problem) In order to achieve the above-mentioned object, a rear wheel steering device for a vehicle according to the present invention includes a knuckle arm attached to a rear wheel of a vehicle,
A tie rod connected to the knuckle arm, a rear wheel steering mechanism section that steers the rear wheels via the knuckle arm and the tie rod, and first and second support members. However, one of the attachment parts is connected to the vehicle body of the vehicle, and the other attachment part is connected to the rear wheel steering mechanism, and the rear wheel steering mechanism of each of the first and second support members is connected to the rear wheel steering mechanism of the first and second support members. The mounting angles seen from the side of the vehicle body with respect to the parts are different from each other.

(Function) In the rear wheel steering device for a vehicle according to the present invention configured as described above, each of the first and second support members has a mounting angle with respect to the rear wheel steering mechanism section when viewed from the side of the vehicle body. are different from each other, so that among the forces that act on the first and second support members from various directions due to vehicle vibration, rolling, etc., not only the force from one direction but also the force from the other Since it has support strength that can withstand force from any direction, the rear wheel steering mechanism section is supported by the vehicle body in a stable state.

(Embodiment) FIGS. 1 and 2 show an example of a rear wheel steering device for a vehicle according to the present invention together with a rear part of a vehicle to which the device is applied.

In FIGS. 1 and 2, left and right rear wheels 12 of a vehicle 10
are each provided with a coil spring 13. A strut type suspension consisting of an oil damper 14, a lower arm 16, etc. is provided. Each lower arm 16 is connected to the vehicle body floor 1
5 (Fig. 3, Fig. 4).
The suspension is swingably connected to a cross member 18 attached to the lower surface of the vehicle by bolts or the like, so that each suspension is supported by the cross member 18 to the vehicle body.

Further, the cross member 18 is attached with the stabilizer 17 and a rear wheel steering mechanism 21 having a two-axis structure and forming the main part of the rear wheel steering device 20. The rear wheel steering device 20 includes such a rear wheel steering mechanism 21, two brackets 30 and 31, and both ends of a rear wheel steering shaft that is disposed inside a casing 22 and extends in the vehicle width direction. It includes a pair of tie rods 23 whose one ends are connected to each other, and a pair of knuckle arms 24 whose one end is connected to the other end of the tie rod 23 and whose other ends are respectively attached to the rear wheel 12. Ru.

The rear wheel steering mechanism 21 in the rear wheel steering device 20 includes a rear wheel steering shaft disposed within the above-mentioned casing 22, and a reduction gear portion 25 disposed in series in the vehicle width direction on the front side of the casing 22. Ship maintenance brake section 26. Clutch section 27. Servo motor unit 28 and servo motor unit 28 arranged so that the output shaft is substantially parallel to the rear wheel steering axis
It is made up of a steering drive section which is attached to a rotor encoder section 29 that detects the rotation angle of the output shaft of the servo motor section 28, a steering brake section 26, a clutch section 27, and a steering drive section. The operation of the servo motor section 28 is controlled by a control unit (not shown) according to a predetermined control mode.

Then, with the clutch section 27 in the rear wheel steering mechanism 21 in the engaged state and the steering brake section 26 in the non-operating state, the servo motor section 28 is operated, and the servo motor section 28 is activated. Rotation is reduced by gear part 25
As a result, the rear wheel steering shaft is moved in the vehicle width direction, and the rear wheels 12 are steered.

The two brackets 30 and 31 have a U-shaped cross-sectional outline, and one end thereof is attached to flanges 22a and 22b, respectively, provided near both ends of the casing 22 in which the rear wheel steering shaft is built. The rear wheel steering mechanism 21 is attached to the cross member 1 by bolts, and is fixed to the other end of the cross member 18 by welding or the like.
8.

The bracket 30 projects horizontally from the cross member 18 toward the rear side when viewed from the side of the vehicle body as shown in FIG. As seen from the side of the vehicle body, the cross member 18 protrudes upward from the cross member 18 toward the rear side at an angle of approximately 45 degrees with respect to the horizontal direction.

The entire rear wheel steering mechanism 21 supported by the brackets 30 and 31 is tilted toward the front side, and the steering drive section of the rear wheel steering mechanism 21 is connected to the cross member 1.
8.

Note that a tire storage section 34 for storing a spare tire 33 is provided in the vehicle floor section 15 on the rear side of the cross member 18 and the rear wheel steering mechanism 21 so as to protrude downward. A fuel tank 35 is disposed on the lower surface side of the vehicle body floor portion 15 on the front side of the fuel tank 21 . Furthermore, between the reduction gear part 25 and the right rear wheel 12, an exhaust pipe 39 is attached to the lower surface of the vehicle body floor part 15 by support members 36 and 37 and extends from the front side to the rear side. It is arranged in such a way that
A silencer 40 is attached and numbered at the rearmost end of the exhaust pipe 39.

In the rear wheel steering device 20 having the configuration as described above, each of the brackets 30 and 31 is connected to the rear wheel steering mechanism 21.
By making the mounting angles as seen from the side of the vehicle body different from each other, it has support strength capable of withstanding forces acting from vertical or diagonal directions. Therefore, the rear wheel steering mechanism 21 is supported by the cross member 18 in a stable state by the brackets 30 and 31.

In the above example, two brackets 30 and 31 are used, but the vehicle rear wheel steering device according to the present invention does not necessarily have to be configured in this way, and three or more brackets may be used. The attachment angle of at least one of the brackets to the rear wheel steering mechanism section as viewed from the side of the vehicle body and the attachment angle of the other brackets to the rear wheel steering mechanism section may be different from each other.

(Effects of the Invention) As is clear from the above description, according to the vehicle rear wheel steering device according to the present invention, the first and second support members are arranged in a manner that the rear wheel steering mechanism of each rear wheel steering mechanism is viewed from the side of the vehicle body. Since the mounting angles are different from each other and the support strength is strong enough to withstand forces acting from various directions due to vibrations and rolling of the vehicle body, each of the first and second support members has different mounting angles. , the rear wheel steering mechanism can be supported on the vehicle body in a stable state.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing an example of a rear wheel steering device for a vehicle according to the present invention together with the rear part of a vehicle to which the device is applied; FIG. 2 is a rear view of the example shown in FIG. 1; FIG. and FIG. 4 are side views of the main parts shown in FIG. 1. In the figure, 12 is a rear wheel, 15 is a vehicle floor, 18 is a cross member, 20 is a rear wheel steering device, 21 is a rear wheel steering mechanism, 23
is the tie rod, 24 is the knuckle arm, 25 is the reduction gear part, 28 is the servo motor part, 30 and 31 are the platen

Claims (1)

[Scope of Claims] A knuckle arm attached to a rear wheel of a vehicle, a tie rod connected to the knuckle arm, and a rear wheel steering mechanism section that steers the rear wheel via the knuckle arm and tie rod. first and second support members, each of which has one attachment portion connected to the vehicle body of the vehicle, and the other attachment portion of which is connected to the rear wheel steering mechanism; A rear wheel steering device for a vehicle, wherein the mounting angles of the second support members relative to the rear wheel steering mechanism portion are different from each other when viewed from a side surface of the vehicle body.