JPS5926363A - Steering apparatus for car - Google Patents

Abstract

PURPOSE:To improve operation performance by freely fitting a joint member having a rear wheel tie-rod connected, onto an oscillating member connected to an operating shaft and allowing the steering direction of rear wheels to be varied according to car speed, in an apparatus for steering rear wheels in interlock with steering of front wheels. CONSTITUTION:At the same time when front wheels are steered by operating a steering wheel, rear wheels 2 are steered through an operating shaft 9. In said steering apparatus, an oscillating shaft 14 is connected to the rear edge of the operating shaft 9 through a universal-joint 11, input shaft 12, and a universal joint 15. A joint member 16 connected onto the chassis side through a link 18 and a bracket 19 is freely installed in the intermediate part of the oscillating shaft 14, and the inner edge part of a rear wheel steering tie-rod 20 is connected onto the both sides of the member 16. An arm member 17 which extends in the rectangular direction is fixed at the rear edge of the oscillating member 14, and a sliding member 29 which is retreated by a ball-screw mechanism 28 installed onto the output shaft of a motor 26 is connected onto the other edge side of this arm member 17 through a link 30.

Description

[Detailed description of the invention] The present invention relates to a steering system for a vehicle, particularly a four-wheeled vehicle.

More specifically, in conjunction with steering the front wheels, the rear wheels are also steered, and at the same time, the steering angle ratio between the front wheels and the rear wheels is controlled according to the vehicle speed, thereby facilitating the steering of the four-wheeled vehicle. The present invention relates to a vehicle steering system that significantly reduces the minimum turning radius of the vehicle.

The present applicant has provided a medium-sized steering device in which the front wheels and rear wheels can be simultaneously steered by first steering the steering wheels.

The present invention further improves such a steering system so that the steering angle ratio between one front wheel and one rear wheel can be controlled in accordance with the ilj speed. That is, the object of the present invention is to steer the rear wheels in the same direction as the front wheels when the vehicle is running at high speed, and to steer the rear wheels in the opposite direction to the front wheels when the vehicle is running at low speed. To provide a steering device for a vehicle, which provides good maneuverability during driving and improves maneuverability of steering wheels during low-speed running.

In order to achieve such an object, the present invention includes a swing shaft that is swingably connected to the rear end of an input shaft that rotates in conjunction with a steering wheel, and a drive shaft for the rear wheels located between the swing shaft and on the left and right sides of the swing shaft. A joint section formed by connecting tie rods is loosely fitted, an arm member is fixed at right angles to the axis at the lower end, and a motor whose rotation is controlled according to the vehicle speed is arranged behind the swing shaft. , a sliding member that slides the i11+-L: by rotation of the motor is screwed onto the output shaft of the motor, and the sliding member and the arm gap are pivotally connected by a link member. A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the basic structure of a four-wheeled vehicle equipped with a steering system according to the present invention, FIG. 2 is an enlarged perspective view of the main parts of FIG. , (cl.
is a cutaway side view showing the operating principle of this steering device, No. 4-South a
It is a liver view of vb-Vc-se.

Reference numeral 1 in FIG. 1 is a steering wheel operated by the driver, and its steering wheel 2 is connected to a direction change means built into a gearbox 3, and the steering rotation of the steering wheel 1 is controlled by a rack ant vinyl. By means of the on-type direction changing means, the movement is converted into a movement of the right front wheel steering tie rods 5, 5 in the vehicle width direction via the connecting rod 4. And both tie rods 5
．． The outer end of the front wheel 6.6'f is connected to a knuckle arm 7.7 which supports the front wheel 6.6'f and is rotatable in the left direction i, so that the front wheel 6. 6
is steered in the direction of the steering force of the steered wheels 1.

The configuration of the front wheel steering means described above is the same as the known one,
By attaching a power steering device to the gearbox 6,
Steering operation of the steering wheel 1 is assisted by the power steering device.

The internal mechanism of the gearbox 6 includes a rack and pinion,
A connecting shaft 8 is connected via an operating force transmission means suitable for the mechanism, such as a bevel gear or a worm gear, and the front end of an operating shaft 9 extending in the longitudinal direction of the heavy body is connected to the connecting shaft 8 by a universal joint 10.

The front end of an input shaft 12 is connected to the rear end of the operating shaft 9 by a universal joint 11, and the input shaft 12 is rotatably supported by a bearing bracket 13 attached to the vehicle body. Furthermore, the front end of a swing shaft 14 shown in detail in FIG. 2 is swingably connected to the rear end of the input shaft 12 by a universal joint 15, and a joint is provided in the middle of the swing shaft 14 as shown in the figure. The side 16 is loosely fitted, and one end of an arm member 17 is fixed to the rear end thereof at right angles to the axis.

The above joint part 16 is the link part +-J1Q-1°1
8-2 and the link bracket 19, and are rotatably connected to the vehicle body side, and the inner ends of rear wheel steering tie rods 20 and 20 are pole joined on both sides of the tie rods 20 and 20.
1.21, one-way tie rod 20.
The outer ends of 20 are connected to left and right knuckle arms 23.23 that support rear wheels 22.22, as shown in FIG. Each knuckle arm 2 is suspended by a shock absorber 24 whose upper end is connected to the vehicle body, and a lower arm 25, 25 whose inner end is connected to the vehicle body in a vertically swinging manner.

On the other hand, a motor 26 fixed to the shaft is disposed behind the swing shaft 14, and an output shaft 27 of the motor 26 is provided.
is coaxial with the operating shaft 9 and the input shaft 12 and extends forward, and a °C sliding member 29 is screwed onto the output shaft 27 via a ball screw mechanism 28 shown in FIG.
The sliding member 29t1 moves back and forth on the output shaft 27 by forward and reverse rotation of the output shaft 27.

The lower part of the sliding member 29 and the lower part of the front 112 arm member 17 are pivotally connected by a link member 30 as shown.

By the way, a computer 31 is installed in the vehicle, and the computer 61 receives signals from a vehicle speed sensor 32 that detects the vehicle speed and a position sensor 66 that detects the position of the sliding member 29, and generates an appropriate control signal according to the vehicle speed. to the motor 26.

When the sliding member 29 is in the position shown in FIG. It rotates concentrically with the shaft 14, so the joint part side 16 does not swing left and right at this time, and the tie rod 20, 20 whose inner end is connected to this joint part side 16 remains immovable. At this time, only the front wheels 6.6 are steered, and the rear wheels 22,22 are not steered at all as in the conventional vehicle.

By the way, when the vehicle is running at a low speed where the vehicle speed is less than the W period setting value, the computer 61 receives a signal from the vehicle speed sensor 62 and controls the rotation of the motor 26 according to the vehicle speed at that time. The sliding part phase 29 is moved forward as shown in K. Due to this advancement of the sliding part 4at 29, the swing shaft 14 is moved forward.
(As shown in Figure 3 (b), it tilts downward, and as a result, the pivot point p is moved downward by CI below the center of the input shaft.In this way, the pivot point p is in the center of the input shaft) For example, if the input shaft 12 is rotated by a predetermined angle in the counterclockwise direction, the tie rod 20.20 moves in the opposite direction to the front wheel tie rods 5, 5, and the rear wheel 22.2
2 is the steering angle 11 in the opposite direction to that of the front wheels 6.6, and at this time the steering angle ratio of the two is continuously changed according to the speed.
．． I am forced to do it.

Next, if the heavy speed increases beyond the initial set value, the computer 31 causes the motor 26 to reverse in accordance with the current heavy speed, and as a result, the sliding member 29 moves as shown in FIG. 3 (CI). It retreats on the output shaft 27. Due to this retreat of the sliding part 29, the swing shaft 14 tilts to one side in the opposite direction as shown in FIG. If the pivot point p is located above the center of the input shaft, the input l
By turning 111112 at a predetermined angle, the rear wheel tie rod 2
0.20 moves the front wheel tie rod 5.5 in the same direction,
As a result, the rear wheels 22.22 are also steered in the same direction as the front wheels 6.6, contrary to the above, and the front and rear wheel steering angle ratios at this time are continuously changed in accordance with the vehicle speed.

As mentioned above, since the rear wheels are steered in the opposite direction to the front wheels when driving at low speeds, the rotational raw diameter of the vehicle can be significantly reduced, thereby improving the steering wheel stability. It is possible to make the direction "2".

Also, when driving at high speeds, the rear wheels are steered in the same direction as the front wheels, so even immediately after starting steering, the rear wheels generate cornering force at the same time as the front wheels, causing the vehicle's lateral acceleration to reach the intended value for a short period of time. It is possible to improve steering stability by improving steering response.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view showing the general basic structure of a four-wheeled vehicle equipped with a steering device according to the present invention, and FIG. The enlarged perspective view and FIGS. 3(a) and 3(bl, fc) are cutaway side views showing the operating principle of the present steering system. In the drawing, 1 is a steering wheel, 5 is a front rotary Ichikawa tie rod, 6 is a front wheel, 9 is an operating shaft, 12&;l: human power i1'll+, 1
4 is a swing shaft, 16 is a joint member, 17 is an arm part, 20 is a tie rod for rear wheel steering, 22 is a rear wheel, 26 is a motor, 28 is a wheel screen t-1 size (!ν1.29
is the sliding part, 31 is the computer, 32 is the vehicle speed sensor,
36 is a position sensor. Special W [Applicant: Honda Motor Co., Ltd., Agent, Patent Attorney, Part 1, Patent Attorney: Kunihiko Ohashi

Claims (1)

[Claims] In a medium-sized steering device in which the rear wheels are steered together with the front wheels by the steering operation of the steering wheels, a swinging wheel 11 is mounted on the rear end of the input shaft that rotates in conjunction with the steering wheels. At the same time, a joint part formed by connecting tie rods for the rear wheels is loosely fitted on the left and right sides of the swing shaft, and an arm part is connected to the joint part 1 (4) at right angles to the axis. A motor 4, which is fixedly fixed and whose rotation is controlled according to the vehicle speed, is disposed on the swing shaft 71h, and a sliding shaft is mounted on the output shaft of the motor, which slides the shaft 1- by the rotation of the motor. A steering device for a vehicle, characterized in that the members are screwed together, and the sliding part and the arm member are pivotally connected by a link part.