JPS6291377A - Wheel steering device - Google Patents

Abstract

PURPOSE:To provide sufficient small sharp turn performance, by a method wherein two support arms are positioned eccentrically from the axis of a wheel support member, the one is so coupled to a car body as to allow slewing of the support arm, and the other is laterally moved by means of an actuator. CONSTITUTION:A suspension 20 causes two support arms 21 and 22 to be positioned eccentrically from an axis L1 of a wheel support member 22, and the rear support arm 22 is so coupled to a car body 10 that it can be slewed and laterally moved. When pressure oil is fed to a right chamber R1 or a left chamber R2 of a hydraulic cylinder 40 in linkage with operation of a front wheel steering device, a piston 42 or a rod 43 is moved, a rear support arm 22 and a wheel support member 23 are moved rightward or leftward, and a right rear wheel RW is steered in linkage with steering of a front wheel. In this case, a left rear wheel is also steered in a similar manner described above. This enables provision of sufficient small sharp turn performance.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a wheel steering device for a vehicle, and particularly to a wheel support that extends substantially in the left-right direction of a vehicle body and rotatably supports wheels at each outer end. A simple wheel constructed by effectively utilizing a suspension (for example, MacPherson type suspension, double wishbone type suspension, etc.) that includes a pair of front and rear support arms J1 that are swingably connected to a member as a suspension lower arm. It relates to a steering device.

[Prior art]

This type of wheel steering device can be used as a rear wheel steering device of an automobile, and one of them is, for example, the Utility Model Application No. 58-1.
This method is proposed in Japanese Patent No. 92773. In this device, the inner end of each support arm is connected to the vehicle body via a rubber bushing, and the rear support arm is directly moved in the left-right direction by an actuator. Only a small amount of deformation allowed by the rubber bushing can be used to move the actuator in the left-right direction. In addition, in this device, the support axis of the wheel support member (rotation center line of the wheel) and the front support arm are substantially aligned when viewed from above the vehicle, and the rear support arm is moved left and right by the actuator. However, the wheel support portion of the wheel support member hardly moves in the left-right direction.

[Problem that the invention seeks to solve]

For this reason, with the conventional device described above, not only is it not possible to give a large steering angle to the wheels, but also the camber of the outer wheel during cornering and the length from the center of the vehicle body to the ground contact surface can hardly be changed. , it may not be possible to obtain the desired cornering performance.

[Means for solving problems]

The present invention has been made to solve the above-mentioned problems, and consists of a pair of front and rear wheel support members that extend substantially in the left-right direction of the vehicle body and are swingably connected to a wheel support member that rotatably supports a wheel at each outer end. In the suspension provided as a suspension lower arm as a support arm, both of the support arms are offset forward and rearward, respectively, with respect to the support axis of the wheel support member, and the inner end of either one of the support arms is is swingably connected to the vehicle body, the inner end of the other support arm is swingably connected to the vehicle body and movable in the left/right direction, and the other support arm is assembled to the vehicle body by an actuator. The wheel steering device was configured to move left and right.

[Action/effect of the invention]

In the wheel steering device according to the present invention, since the rear support arm can be moved significantly in the left-right direction by the actuator, the wheel support member can be tilted greatly in the left-right direction, and a large steering angle can be given to the wheel. It is possible to obtain sufficient turning performance.

In addition, in the wheel steering device according to the present invention, by moving the rear support arm largely in the left-right direction, the wheel support portion of the wheel support member can also be largely moved in the left-right direction. can be moved significantly outward. Therefore, the length of the wheel from the center of the vehicle body to the ground contact surface can be made sufficiently long, and the camber angle of the wheel can be greatly changed to the negative side, making it possible to put the wheel in a state where it is effective to pedal. This makes it possible to significantly improve driving stability during cornering.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

Figures 1 and 2 show an example in which the wheel steering system according to the present invention is implemented as a rear wheel steering system for a front-wheel drive vehicle (however, only approximately the right half is shown because it is symmetrical).
The steering system is constructed by effectively utilizing a McPherson type suspension 20, which includes a pair of front and rear support arms 21 and 22 as suspension lower arms, which extend in the left-right direction of the vehicle body.

The suspension 20 includes a front support arm 21 whose inner end 21a is swingably connected to the vehicle body 10 via a rubber bush B1, and whose inner end 22a is swingably connected to the vehicle body 10 via a rubber bush B2 and a bolt 30 in a swingable and horizontal direction. The rear support arm 22 is connected movably to
3. A wheel support member 23 that is swingably connected via B4 and rotatably supports the rear wheel RW;
comb bush B on the lower end of the vehicle body 10 and the front of the vehicle body 10 respectively.
5. It consists of a radius rod 24 which is swingably connected via B6, a shock absorber 25 and a spring 26, and whose lower end is integrally connected to the upper end of the wheel support member 23, and whose upper end is strut mounted to the vehicle body 10 located above. It is composed of struts 28 and the like that are swingably connected via a strut 27.

Therefore, this suspension 20 has a wheel support member 2
Both support arms 21 and 22 are offset forward and rearward, respectively, with respect to the axis Ll (rotation center line of the rear wheel RW) of No. 3 (see Fig. 1), and the inner end of the rear support arm 22 is 22a is of a known type except that it is connected to the vehicle body 10 via a rubber bush B2 and a bolt 30 so as to be swingable and movable in the left and right direction, and the bolt 30 is shown in FIGS. 1 and 3. As described above, a hydraulic cylinder 40 serving as an actuator is slidably fitted into a long hole 11a in the left and right direction of a bracket 11 fixed to the vehicle body 10.
It is designed to be moved left and right.

The hydraulic cylinder 40 includes a cylinder body 41 that is arranged horizontally, extends in the left-right direction, and is fixed to the vehicle body 10, a piston 42 that is fitted into the cylinder body 41 so as to be slidable in the axial direction, and A pressure oil supply/discharge device (not shown) that is integrally provided and configured by a rod 43 that liquid-tightly penetrates the cylinder body 41 from side to side and is connected to the bolt 30, and operates in conjunction with a front wheel steering device (not shown). When pressure oil is supplied to the right chamber R1, the piston 42 and rod 43 move to the left, and when pressure oil is supplied to the left chamber R2, the piston 42 and rod 43 move to the right. There is. In this embodiment, when the vehicle is running at low speed, the rear wheel steering device is in opposite phase to the front wheel steering device (for example, when the front wheels are steered to the left, the rear wheels are steered to the right). ), and the rear wheel steering device is in phase with the front wheel steering device when the vehicle is running at medium or high speeds (
For example, the hydraulic cylinder 40 is operated so that when the front wheels are steered to the left, the rear wheels are steered to the left.

In this embodiment configured as described above, when the driver rotates the steering wheel, the front wheel steering device operates, and in conjunction with this, the pressure oil supply and discharge device operates the right chamber R1 or the left side of the hydraulic cylinder 40. Pressure oil is supplied to the chamber R2, and the piston 42 and rod 43 move leftward or rightward. Therefore, the bolt 30 moves to the left or right, and the support arm 22 and the wheel support member 23 at the rear of the suspension 20 move.
etc. move leftward or rightward, the wheel support member 23 tilts rightward or leftward, and the right rear wheel RW is steered in accordance with the steering of the front wheel. At this time, the bolt and suspension on the left side (not shown) operate in the same manner as the bolt 30 and suspension 20 described above due to the left or right movement of the piston 42 and rod 43, so the left rear wheel also operates in the same manner as the right rear wheel RW. is steered by.

Furthermore, in this embodiment, when the vehicle is running at medium or high speeds, the rear wheel steering is controlled in the same phase as the front wheel steering device, and for example, when the front wheels are steered to the left, the right rear wheel RW is also steered to the left. Be steered. To steer the right rear wheel RW to the left, the piston 42 and rod 43 of the hydraulic cylinder 40 move to the right, the bolt 30 moves to the right, and the rear support arm 2
2, the wheel support member 23, etc. move to the right, and the wheel support member 23 tilts to the left.

At this time, the wheel support member 23 of the right rear wheel RW, which is the outer side during cornering, moves to the right (that is, moves outward), so that the right rear wheel RW moves from the vehicle body center CL to the right rear wheel RW.
As the length to the ground contact surface of W becomes longer, the right rear wheel R
W, the wheel support portion 23° When the strut 28 and other components tilt counterclockwise in Fig. 2 around the strut mount 27, the camber angle of the right rear wheel RW changes to the negative side, so the right rear wheel RW is stepped on. The burr becomes effective, improving driving stability during cornering.

Note that when the vehicle is running at low speed, the rear wheel steering is controlled in the opposite phase to the front wheel steering device, so for example, when the front wheels are steered to the left, the right rear wheel RW operates in the opposite manner to the above. However, since the centrifugal force is small at this time, it has little effect on driving stability during cornering.

By the way, in this embodiment, as described above, since the rear support arm 22 can be moved largely in the left-right direction by the hydraulic cylinder 40, the wheel support member 2
3 can be largely tilted in the left-right direction, a large steering angle can be given to the right wheel RW, and sufficient turning performance can be obtained.

In addition, by largely moving the rear support arm 22 in the left and right direction, the wheel support member 230 and the wheel support portion 23a
Since the wheel can also be moved largely in the left-right direction, when the vehicle is running at medium to high speeds, it is possible to move the outer wheel when cornering, for example, the right rear wheel RW when turning left, to the outer side. Therefore, the wheel RW
The length from the vehicle body center CL to the ground contact surface can be made sufficiently long, and the camber angle of the wheel RW can be greatly changed to the negative side.
It is possible to put the W in a state where the pedal effort is effective, and driving stability during cornering can be significantly improved.

[Modified example]

In the above embodiment, the bolt 30 is directly supported by the bracket 11, but instead of being directly supported by the bracket 11, for example, as shown in FIG.
Bolt 30 with shackle 12 swingably connected to 1
It is also possible to implement it in such a way as to support. In this case, the bolt 30 also moves in the vertical direction due to the swinging of the shackle 12 (this amount is small);
A rubber bushing must be interposed at the joint between the bolt 30 and the tip of the rod 43 of the hydraulic cylinder 400.

Further, in the above embodiment, the left and right rear wheels are moved by a single horizontally arranged hydraulic cylinder 40, but it is also possible to move the left and right rear wheels by a pair of left and right hydraulic cylinders. It is. In this case,
As shown in FIG. 5, each hydraulic cylinder 40R, 40
If L is arranged so that each rod extends diagonally downward, or as shown by the imaginary line, each hydraulic cylinder 40R240
Since the rear support arm 22 can be moved not only in the horizontal direction but also in the vertical direction by the L, in addition to the functions and effects of the above-mentioned embodiment, the roll center can also be changed. It is possible to improve vehicle handling and ride comfort. In addition, in the vehicle configured as shown in FIG. 5, both the left and right hydraulic cylinders 40
By similarly moving the R940L rod forward or backward, toe-in, camber, tread, roll center, etc. can be changed as appropriate without generating turning force in the rear wheel steering device.

[Brief explanation of drawings]

Fig. 1 is a plan view showing one embodiment of the present invention, Fig. 2 is a rear view of the same, Fig. 3 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 4 is a bolt support structure ( 3), and FIG. 5 is a partial rear view showing a modification of the present invention. Explanation of symbols 10...Vehicle body, 20...Φ suspension, 21.2
2... Support arm, 23... Wheel support member, 30.
...Bolt, 40...Hydraulic cylinder (actuator), RW...Rear wheel.

Claims (1)

[Claims] In a suspension comprising, as a suspension lower arm, a pair of front and rear support arms swingably connected to a wheel support member extending substantially in the left-right direction of the vehicle body and rotatably supporting a wheel at each outer end, Both the support arms are deviated forward and backward, respectively, with respect to the support axis, and the inner end of one of the support arms is swingably connected to the vehicle body, and the other support arm is pivotably connected to the vehicle body. A wheel steering device in which the inner end of the arm is connected to the vehicle body so as to be swingable and movable in the left and right directions, and the other support arm is moved left and right by an actuator attached to the vehicle body.