JPS6085069A - Steering device for front and rear wheels of vehicle - Google Patents

Abstract

PURPOSE:To facilitate the parking of a vehicle between others in tandem or the traverse displacement of the vehicle, at a low speed, by altering the ratio of steered angle of rear wheels to front wheels depending on the speed of the vehicle, and using a manual switch means to select an optional ratio of steered angle. CONSTITUTION:An ordinary operation of automatically altering the ratio of steered angle depending on the speed of a vehicle is chosen by pressing the first push button 35a of a selector switch 34. Necessary information b1 for modifying the ratio of steered angle is calculated from steered angle ratio data obtained from a vehicle speed sensor 32 and corresponding to the vehicle speed, and actual steered angle ratio data obtained from a position sensor 33, and is sent out, as is, from a computer 31. When an optional push button other than said one 35a in the selector switch 34 is pressed, prescribed steered angle ratio data stored in the computer 31 are read out therefrom and compared with the steered angle ratio data obtained from the position sensor 33, so that modifying information b2 is provided. At that time, the computer 31 stops sending out the modifying information b1, and sends out the other modifying information b2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a front and rear wheel edge 1i'ii device for a vehicle that can variably control the steering angle of the rear wheels relative to the front wheels.

The present applicant has already proposed a vehicle steering device (Japanese Patent Application No. 577134888, etc.) that steers the rear wheels in conjunction with the steering of the front wheels and varies the steering angle ratio of the rear wheels to the front wheels according to the vehicle speed. . An overview of this device will be explained. At low speeds, the rear wheels are steered in the opposite phase to the front wheels, or almost to zero, while at high speeds, on the contrary, the rear wheels are steered in the same phase as the front wheels. This steering angle ratio is a continuous function of the vehicle speed, as shown by D in FIG. When the vehicle speed becomes lower than this, the steering angle ratio becomes negative, that is, the phase is reversed, and the steering angle ratio is continuously controlled according to this function curve to achieve both the functions of the steering system at low and high speeds. As a result, both the minimum turning radius and the difference between the inner wheels of the vehicle are significantly reduced at low speeds, and the maneuverability of the vehicle is dramatically improved when entering a garage, driving on narrow curved roads, knee turns, etc. On the other hand, at high speeds, maneuvering responsiveness can be dramatically improved.

By the way, when parallel parking at low speeds or when performing side-by-side maneuvering in a narrow space, it is often easier to steer the vehicle if the front and rear wheels are steered in the same phase rather than in opposite phases.

Therefore, an object of the present invention is to make it possible to arbitrarily change the steering angle ratio (or steering angle) of the rear wheels to the front wheels, regardless of the vehicle speed or the amount of front wheel steering angle, thereby improving maneuverability of the vehicle, especially at low speeds. To provide a front and rear wheel steering device for a vehicle that can significantly improve the performance of vehicles.

In order to achieve the above object, the present invention is applied to a front and rear wheel steering system for a vehicle that variably controls the steering angle of the rear wheels according to certain conditions. or a manual switching means consisting of two or more pieces of steering angle ratio (or rear wheel turning angle) information and an external selection switch for selecting this arbitrary steering angle ratio (or rear wheel turning angle) information; It is characterized in that the steering angle ratio (or rear wheel turning angle) can be arbitrarily changed by.

Below, preferred embodiments that further embody the present invention will be described in detail with reference to the drawings.

In the drawings, Fig. 1 is a perspective view showing the general basic structure of a vehicle equipped with a front and rear wheel steering system, Fig. 2 is an enlarged perspective view of the rear wheel steering system, and Figs. 3 (a), (b) and (C) is a cutaway side view showing the principle of operation.

First, in order to clarify the present invention, the configuration and operation of the front and rear wheel steering device will be explained with reference to FIGS. 1 to 3. The handle shaft 2 of the handle 1 is built into a rack and pinion type gear box 3, and tie rods 5.5 are connected to the left and right ends of the rack shaft 4, and a front wheel 7.7 is connected to the outer ends of both tie rods 5, 5. A supported knuckle arm 6.6 is connected, and the front wheels 7, 7 are steered in the steering direction of the steering wheel 1 in a known manner.

On the other hand, a rear serpentine shaft 8 is led out from the gear box 3, and a long linkage shaft 10 is connected to the rear end of this shaft 8 via a universal joint 9.

An input shaft 12 is connected to the rear end of the linkage shaft 10 via a universal joint 11, and this manpower shaft 12 is arranged on the left-right center line of the rear of the vehicle body, and is rotatably supported by a bearing bracket 13. There is.

Furthermore, a second
A swing shaft 15 shown in detail in the figure is connected to the swing shaft 15.
A joint member 16 is loosely fitted in the middle. Tie rods 18°18 are connected to the left and right ends of the joint member 16 via ball joints 17, 17, and the joint member 16 is swingably supported on the vehicle body side by links 21, 22 and brackets 23. . Further, a knuckle arm 19.19 supporting a rear wheel 20.20 is connected to the outer ends of both tie rods 18.18.

- An arm 25 is fixed to the rear end of the swing shaft 15 at right angles to the axis, a link 26 is pivotally attached to the lower end of the arm 25, and a slider 27 is pivotally attached to the rear end of the link 26. ing. As shown in FIG. 3, this slider 27 is connected to the output of a motor 29 by +111
30 are screwed together, and the output shaft 30 is coaxial with the input shaft 12 and extends rearward to fix the motor 29 to the vehicle body.

On the other hand, the vehicle is equipped with an on-vehicle computer 31, which receives signals from the vehicle speed-hinge 32 that detects the vehicle speed and the position/seat 33 that detects the position of the slider 27, and calculates an appropriate value according to the vehicle speed. Control signal to motor 2
Supply to 9.

Therefore, the slider 27 is at the position shown in FIG.
input shaft 12 and swing shaft 15.
Since the joint member 16 rotates concentrically with the joint member 16, the joint member 16 does not swing from side to side, and the tie rods 18 and 18 also remain stationary. Therefore, only the front wheels 7 and 7 are steered, and the rear wheels 20 and 20 are all (
Not steered.

On the other hand, when the vehicle speed is low (less than the set value), the computer 31
receives the signal from the vehicle speed sensor 32 and makes a judgment, and the motor 2
The rotation of 9 is controlled according to the vehicle speed at that time, and the rotation shown in FIG.
Move the slider 27 forward as shown in FIG. As the slider 27 moves forward, the swing shaft 15 tilts downward, and the pivot point P is offset (eccentrically) by an amount e below the axis of the human-powered shaft 12, so the joint member 16 swings left and right. The tie rods 18.18 are moved in the opposite direction to the front wheel tie rods 5, 5, so the rear wheels 20.20 are moved to the front wheels 7, 5.
7 is steered in the opposite phase. At this time, the steering angle ratio of the front and rear wheels changes continuously in accordance with the vehicle speed.

Also, when the vehicle speed exceeds the set value, the computer 3
1 rotates the motor 29 in the reverse direction according to the vehicle speed at that time, and moves the slider 27 backward as shown in FIG. 3(C). This retreat of the slider 27 causes the swing shaft 15 to tilt in three directions.
The pivot point P is offset from the axis of the input shaft 12 by e2 in three directions, and the rear wheel tie rods 18 and 18 are moved in the same direction as the front wheel tie rods 5, 5, so that the rear wheel 20
．． 20 is steered in the same phase as the front wheels 7, 7. At this time, the steering angle ratio of the front and rear wheels also changes continuously in accordance with the vehicle speed.

Next, the main structure of the present invention will be explained with reference to FIGS. 4 to 6. FIG. 4 is a configuration diagram of main parts, FIG. 5 is a functional block diagram of FIG. 4, and FIG. 6 is a steering angle ratio output characteristic diagram in FIG. In addition, in FIGS. 4 and 5, the same parts as in FIGS. 1 to 3 are designated by the same reference numerals to clarify the structure. First, in FIG. 4, the reference numeral 34 indicates a steering angle ratio (for example, a plurality of push buttons 35a, 35b, etc. arranged side by side).
This is a manual selection switch for the steering angle of the rear wheels (the same applies hereinafter), and is located on the instrument panel 36 in the vehicle interior so that it can be operated manually by the driver. The selection switch 34 is connected to the computer 31 and inputs the selection result of the steering angle ratio selected by the selection switch 34 to the computer 31.

Next, the manual selection function of the steering angle ratio in the computer 31 will be explained with reference to FIG.

First, a normal operation (auto operation) in which the steering angle ratio is automatically varied by 1 in accordance with the vehicle speed will be explained.

In this case, the selection switch 34 is the first pushbutton 35
Selected by pressing a. As described above, the vehicle speed signal detected from the vehicle speed sensor 32 is input to the computer 31, and converted into steering angle ratio data Ka corresponding to the vehicle speed by the conversion process A.On the other hand, the actual steering angle ratio is input from the position sensor 33. Data Kb is obtained, and each steering angle ratio data Ka and Kb are subjected to comparison calculation processing.
I-ro. On the other hand, since the above-mentioned automatic operation A1 is selected in the selection switch 34, the selection process ``2'' outputs the repair IF information + the computer 31 as it is, and the vehicle speed is outputted via the output device 37. A correction control signal S1 is supplied to the motor 29 to change the steering angle ratio to a required value according to the steering angle ratio.

On the other hand, predetermined steering angle ratio information 2 is set and stored in the storage device of the computer 31. This information 2 is, for example, a plurality of steering angle ratio data having an arbitrary size, K2. K
, ,...Kn. Then, in the selection switch 34, if you press any push button other than the push button 35a, for example, the push button 35b, 1 is read out from the steering angle ratio information 2 to the steering angle ratio take, which is read from the position sensor 33. The steering angle ratio data Kb is compared with the steering angle ratio data Kb to obtain repair information b2. On the other hand, in the selection process c, if a pushbutton other than the automatic activation AT on the selection switch 34 is pressed, this is received, and the output of the modification information b1 is stopped and the modification information b2 is selected to be output. As a result, the output device 3
From step 7, a correction control signal S2 is supplied to the motor 29, and the steering angle ratio of the rear wheels is set to . This is the other pushbutton 3
5b, 35c, etc., and the driver selects any steering angle ratio shown in FIG. 6 by using the selection switch 34. to 2
．． Kl...K11 can be selected and set manually. The various processes in the computer 31 described above are executed by a predetermined control program (software) stored in the computer 31, for example, in a storage device.

In the above embodiment, the on-vehicle computer 31 is used, but an electrical circuit or mechanical configuration having the ground-to-ground function may be used.

Moreover, although the steering angle ratio of one front and rear wheel can be manually selected using the position sensor 33, the rear wheel steering angle may be similarly selected.

Furthermore, the present invention is not limited to the embodiments, but includes a front and rear wheel steering device that hydraulically controls the front and rear wheels and transmits front wheel steering angle information using hydraulic pressure, or transmits the front wheel steering angle to the computer 31 as an electrical signal. The present invention can be similarly applied to a front and rear wheel steering device, etc.

As described above, the front and rear wheel steering device for a vehicle according to the present invention can vary the steering angle ratio of the rear wheels to the front wheels depending on the vehicle speed, etc., and can also arbitrarily select any steering angle ratio by the manual switching means. This allows for easy parallel parking and side-to-side parking, especially at low speeds, and greatly improves maneuverability of the vehicle.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the general basic structure of a vehicle equipped with a front and rear wheel steering system, Figure 2 is an enlarged perspective view of the rear wheel steering system, and Figures 3 (al, (1)l, and (C) are rear A cutaway side view showing the operating principle of the wheel steering system, Figure 4 is a diagram showing the main parts, and Figure 5 is a diagram showing the main parts of the wheel steering system.
The functional block diagram shown in FIG. 6 is a steering angle ratio output characteristic diagram in FIG. 5. Also in the drawing? 31 is an in-vehicle computer, 32 is a vehicle speed sensor, 33 is a position sensor, 34 is a manual selection switch,
35a, 35b, 35C are push buttons '1), 10-9 are selection processing, 2 is steering angle ratio information, and E is comparison calculation processing. Patent applicant Honda Motor Co., Ltd. agent Patent attorney 2 1) Production department Patent attorney Kuni Ohashi Production volume Patent attorney Yu Koyama Figure 3 Figure 4 Figure 5 Figure 31 Figure 6

Claims (1)

[Claims] In a front and rear wheel steering system of a vehicle that variably controls the steering angle of the rear wheels according to certain conditions, the steering angle ratio (or 1. A front and rear wheel steering device for a vehicle, comprising a manual switching means for selecting rear wheel steering/steering angle information and changing it to an arbitrary steering angle ratio (or rear wheel steering angle).