JPS61113567A - Steering device for front and rear wheels - Google Patents

Abstract

PURPOSE:To allow an increase in front wheels and the maximum steering angle at inverse phase by forcibly moving the radial slot of a rear suspension forward and backward based on the handle steering angle information. CONSTITUTION:When a computer 29 determines from the sensing signal of a sensor 28 that the steering state of a handle 1 approaches to a critical angle, the computer 29 outputs an output signal that drives a motor 27. This motor 27 rotates a crank rod 26 by + or -90 deg.. By this rotation, crank pins 26a and 26a on both ends are crank-rotated so as to face the forward and backward direction. As a result, one of the radial slots 19 and 19 for left and right rear wheels is pulled and moved in front and the other is pressed in rear and moved.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a steering device for front and rear wheels of a vehicle.

(Prior art) The present applicant filed Japanese Patent Application No. 57-93394 (Japanese Unexamined Patent Publication No. 58-2
No. 09657), an eccentric shaft provided on the input shaft of the rear wheel steering system that rotates in conjunction with the steering wheel and a joint member that connects and supports the left and right rear wheel tie rods are fitted so as to be relatively rotatable. We proposed a front and rear wheel steering system consisting of: According to this, the rear wheels are steered in the same direction as the front wheels by a small steering angle operation of the steering wheel, and the rear wheels are steered in the opposite direction by a large steering angle operation, which improves maneuverability during high-speed driving. To improve maneuverability of a vehicle by obtaining a small turning radius. Note that this steering system is a type of so-called symmetric function type in which the maximum steering angle of the rear wheels when the front wheels are in the same phase as the front wheels is equal to that when the front wheels are in the opposite phase.

Various structures have been proposed for such symmetric function type steering systems.

(Problem to be Solved by the Invention) By the way, if the maximum steering angle of the rear wheels when the phase is opposite to that of the front wheels can be increased, a smaller turning radius can be obtained, which further improves the maneuverability of the vehicle. becomes possible.

Therefore, an object of the present invention is to make it possible to increase the maximum steering angle of the rear wheels when the phase is opposite to that of the front wheels in a basically symmetric function type steering system by devising the rear wheel suspension system. It is an object of the present invention to provide a novel steering device for front and rear wheels in which desired asymmetric function-type output characteristics can be obtained.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a sensor (2B ) and a control means (
28) and the drive device (2B) that moves one of the radius rods (1111) and (19) of the left and right rear wheel suspension systems forward and the other rearward, respectively. ).

Specifically, when the sensor (28) detects that the noddle steering angle is close to the limit, the rear wheel radius rods (19), (19) are controlled by the drive devices (2B), (27) via the control means (28). ) forcibly move back and forth to move the front wheels (
ill), rear wheel (1B) when the phase is opposite to (8),
(1B) The maximum steering angle is increased.

(Example) Examples will be described below based on the accompanying drawings.

Figure 1 is a schematic perspective view of the entire steering device, with the nozzle (1
) is connected to the rack and pinion gearbox (3).
), and tie rods (
5) and (5) are connected to form a tie loft (5).

Knuckle arms (7), (7) supporting the front wheels (6), (8) are connected to (5), and as is known, the front wheels (13)
), (8) are steered in the steering direction of the steering wheel (1).

A long linkage shaft (11) is connected to the pinio shaft (8) led out rearward from the gear box (3) via a universal joint (9), and the rear end of the shaft (11) An input shaft (21) of a rear wheel steering system is connected via a joint (12). This input shaft (21) is arranged so as to be aligned with the left-right center line of the vehicle body, and is supported on the vehicle body side via a bearing holder (20).

An eccentric shaft (22) whose axis is eccentric is integrally provided at the rear end of the input shaft (21).

On the other hand, tie lofts (15) are connected to knuckle arms (17), (17) that support rear wheels (111), (18).
) and (15') are connected and supported via ball joints (14) and (14), respectively, to a joint member (23), and this joint member (23) can be freely rotated relative to the eccentric shaft (22). Fits in.

Further, an arm (20) is fixed to the joint member (23), and the arm (20) is pivotally connected to a link (25) that is pivotally supported under the vehicle body.

In addition, lower arms (18), (18) are connected to the lower part of the rear wheel knuckle arms (17), (17), and a radius rod extending forward is connected to the outer end of the lower arms (1B), (18). (1θ) and (19) are connected.

Thus, the front wheels (11), (
Regarding the steering characteristic of 8), a front and rear wheel steering device of a symmetrical function type is configured, which has a steering characteristic of the rear wheels (1B) and (1B) represented by a sinusoidal curve indicated by characteristic (R). be done.

In the above, rear wheel tie loft (19), (19)
A pipe (lea) with the axis line in the left and right direction at the front end of the (1
9a), and crank pins (2B) formed at both ends of the crank rod (2B) are provided in both pipes (19a) and (19a).
213a).

(28a) are fitted so as to be relatively rotatable. These crank rods (28a) and (28a) are connected to the crank rod (26
), and are initially set so that the right crank pin (28a) is directed downward, and the left crank pin (28a) is directed downward, for example.

The crank rod (2B) is supported by an electric motor (27) fixed under the vehicle body, and rotated by the drive of the motor (27).

A steering angle sensor (28) is provided on the support shaft (2) of the handle (1) to detect the steering angle state of the /X steering wheel.
27) is equipped with an on-vehicle computer (2θ) that outputs output signals and controls the drive.

Next, the effect will be explained.

When the computer (28) determines from the detection signal of the sensor (2nd day) that the steering condition of the steering wheel (1) approaches the limit angle, the computer (29) outputs an output signal to drive the motor (27). This motor (27) rotates the crank rod (2B) by ±80 degrees, and by this rotation, the crank bins (28a), (28a) at both ends are rotated so as to face in the front-rear direction, respectively.

This creates a radius rod (tS) for the left and right rear wheels.

One of (18) is pulled forward and moved, and the other is pushed backward and moved.

FIG. 2 shows, with imaginary lines, the change in suspension angle when the radius rod (1B) is moved forward.

Also, Fig. 3 shows the relationship between the crank pin (28a) and the radius rod (l$), Fig. 3 (a) shows the forward movement state of the radius rod (19), Fig. 3 (b) shows the neutral state, FIG. 3(C) shows the backward movement state.

Winter ゞ°'Peter (29) 1st front wheel (°)・(°) and rear wheel (1B) that moves when the phase is opposite to that of
The motor (27) is driven to increase the turning angle of (1B), and the radius rods (19), (19) are moved back and forth by crank rotation of the crank rod (2B).

Therefore, as shown by characteristic (E) in Fig. 4, the rear wheel (IEI)
, (to) when the front wheels (8), (8) are in opposite phase, a characteristic is obtained in which the steering angle is forcibly increased from near the limit of the steering wheel steering angle. As a result, only the turning radius can be significantly reduced, which greatly improves the maneuverability of the vehicle.

By the way, in the embodiment, the radius rod was moved back and forth by the crank rod, but it is also possible to form a rack on the radius rod, mesh a pinion with the rack, and drive this pinion to rotate with a motor. 2
Equipped with several motors. Further, the symmetric function type steering system is not limited to the one in the embodiment, and any other arbitrary system may be adopted.

(Effects of the Invention) As described above, according to the present invention, the 5'7
Z ef・ゝ／゛7 F ) Lp steering angle information 9 groups 6
°゛tte.

Because it is forced to move forward and backward, although it is basically a symmetric function type steering system, it is possible to obtain an asymmetric function type rear wheel steering characteristic, especially when the rear wheels are in the opposite phase to the front wheels. It becomes possible to increase the

[Brief explanation of drawings]

Figure 1 is a schematic perspective view of the entire steering system, Figure 2 is a schematic plan view of the main parts of the rear wheel suspension system, and Figures 3 (a), (b) and (C
) are side views showing the changing states of the radius rod,
FIG. 4 is a steering characteristic diagram. In one drawing, (1) is the handle, (B)' is the front wheel, (11
) is the linkage shaft, (15) is the rear wheel tie rod, (
1B) is the rear wheel, (18) is the lower arm, (19) is the radius rod, (21) is the input shaft, (22) is the eccentric shaft, (
23) is a joint member, (2B) and (27) are drive devices, (28) is a sensor, and (29) is a control means. Patent applicant Honda Motor Co., Ltd. Agent Patent attorney 2 1) □Yobetsu Patent attorney Kunihiko Ohashi Patent attorney
Yu Koyama-45'

Claims (2)

[Claims] (1) A small steering angle operation of the steering wheel steers the rear wheels in the same direction as the front wheels, a large steering angle operation steers them in the opposite direction, and the maximum rotation of the rear wheels is achieved when the front wheels are in phase and in opposite phase. In a vehicle equipped with a steering device for front and rear wheels of a symmetrical function type with equal steering angles, a sensor detects a steering angle state of a steering wheel, a control means for receiving a detection signal from the sensor and outputting an output signal, and the control A steering device for front and rear wheels, comprising a drive device that is actuated by an output signal of the means to move one of the radius rods of the left and right rear wheel suspension devices forward and the other to the rear. (2) In claim 1, when the sensor detects that the steering angle state of the steering wheel is near the limit, the drive device is operated by the control means to move the front wheels in the opposite phase to the front wheels. A front and rear wheel steering device that increases the maximum steering angle of the wheels.