JPH06298113A - Steering device for vehicle - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a steering device for a vehicle, which has a high degree of freedom of arrangement and which does not significantly change the steer characteristics during bounding and rebounding. A pair of left and right carriers 11 that rotatably support the left and right wheels A, and a pair of left and right front lower arms 12 that connect a lower end front of each carrier 11 and a vehicle body (bracket B) to the vehicle steering system. , A pair of left and right rods 16 that are assembled to the vehicle body behind each carrier 11 so as to be movable in the front-rear direction, and a pair of left and right rear lower arms 13 that connect the rear ends of the lower ends of the carriers 11, and the rear lower arms 13 and A pair of left and right links 14 that connect the front lower arms 12 and a transmission mechanism 20 that moves the rods 16 in opposite directions to each other by rotation of the steering shaft S are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device used in an automobile.

[0002]

2. Description of the Related Art A conventional vehicle steering system is, for example, as disclosed in Japanese Unexamined Patent Publication No. 2-204131, a rack bar which is mounted so as to be movable in the left-right direction and is moved left and right by the rotation of a steering shaft. (Relay rod)
And a pair of left and right tie rods that extend in the lateral direction of the vehicle and are respectively connected at the left and right ends to the respective end portions of the rack bar and the swing ends of the left and right knuckle arms.

[0003]

In the conventional vehicle steering system described above, since the pair of left and right tie rods extend in the lateral direction of the vehicle, the rack bar cannot be sufficiently separated from the axle, and the engine and the steering wheel cannot be separated from each other. There is a problem that the degree of freedom of system arrangement is small. Further, since it is configured separately from the suspension mechanism, there is a problem that the tie rod changes the steer characteristic during bound and rebound. The present invention has been made to solve the above problems, and an object of the present invention is to provide a vehicle steering system that has a high degree of freedom in arrangement and that does not significantly change steer characteristics during bounding and rebounding.

[0004]

In order to achieve the above-mentioned object, in the present invention, the vehicle steering system includes a pair of left and right carriers that rotatably support left and right wheels.
A pair of left and right front lower arms that connect the front lower end of each carrier and the vehicle body, a pair of left and right rods that are movably assembled in the vehicle body in the front and rear direction at the rear of each carrier, and connect the rear lower end of each carrier. A pair of left and right rear lower arms, a pair of left and right links that connect each of the rear lower arms to each of the front lower arms, and a transmission mechanism that moves the rods in opposite directions to each other by rotating the steering shaft.

[0005]

In the vehicle steering system according to the present invention, when the steering shaft rotates, the left and right rods are moved in opposite directions by the transmission mechanism, and this movement is transmitted to the respective carriers via the left and right rear lower arms. Both left and right carriers are steered in the same direction. In addition, during bounding and rebounding, each front lower arm moves up and down with the connecting part with the vehicle body as a fulcrum, and each rear lower arm moves up and down with the connecting part with each rod as a fulcrum, but each rod does not move and steer. It is possible to reduce the change in the characteristic and positively adjust the steer characteristic by arranging the connecting points of the respective members.

[0006]

1 and 2 show an embodiment of a vehicle steering system according to the present invention. The vehicle steering system is shown by omitting each member on the left side.
And a pair of left and right front lower arms 12, a pair of left and right rear lower arms 13, a pair of left and right links 14, and a transmission mechanism 20.
Is equipped with. The carrier 11 rotatably supports the wheel A, and is suspended by a front lower arm 12, a rear lower arm 13, and a strut 15.

The front lower arm 12 has a rubber bush joint 31 having three degrees of freedom in the direction of rotation at one end (other joints having three degrees of freedom in the direction of rotation can also be used).
Is connected to a bracket B that is fixed to a vehicle body (not shown) via a ball joint 32 having three degrees of freedom in the rotational direction at the other end, and is connected to the front of the lower end of the carrier 11. The rear lower arm 13 has a universal joint 33 having two degrees of freedom in the rotation direction at one end.
The lower end of the carrier 11 is connected to the rod 16 via a ball joint 34 having 3 degrees of freedom in the rotation direction at the other end while being connected to the rod 16 via another (other joints having 2 degrees of freedom in the rotation direction are also possible). Are linked to. In addition,
The universal joint 33 is attached to the rod 16 so as to be rotatable and immovable in the axial direction.

The link 14 has a front lower arm 1 through a joint 35 having one degree of freedom in the rotational direction at one end.
The second end is connected to the middle part of the rear lower arm 13 via a ball joint 36 having three degrees of freedom in the rotation direction at the other end. Strut 15
Is known per se and is connected at its lower end to the upper part of the carrier and at its upper end to the vehicle body. As shown in FIGS. 1 to 3, the rod 16 is a gear housing 21 fixed to the bracket B behind the carrier 11.
It is assembled in such a manner as to be movable in the front-rear direction and non-rotatable, and is configured to be moved in the axial direction by the transmission mechanism 20.

The transmission mechanism 20 is for moving the left and right rods 16 whose left side is not shown in the drawing in the opposite directions by the rotation of the steering shaft S, and is provided with a pair of left and right shafts 22 and 23. Each shaft 22, 2
3 is rotatably assembled to the gear housing 21, and pinions 24 that mesh with rack teeth 16a integrally formed on the rod 16 are integrally assembled to each outer end as shown in the drawing only on the right side. Bevel gears 25 and 26 are integrally attached to the inner ends of the respective gears. The bevel gears 25 and 26 are rotated in opposite directions by a bevel gear 27 that is integrally rotated by a steering wheel C via a steering shaft S. With such a configuration, the shafts 22 and 23 are rotated.
Rotate in mutually opposite directions, and the left and right rods 16 are moved in mutually opposite directions.

In this embodiment constructed as described above, when the steering wheel C is rotated to rotate the steering shaft S, the shafts 22,
23 rotate in mutually opposite directions, the left and right rods 16 move in opposite longitudinal directions, and this movement is transmitted to each carrier 11 via each left and right rear lower arm 13, and both left and right carriers 11 steer in the same direction. To be done. When bound and rebounded, each front lower arm 12
Move up and down with a connecting portion with the bracket B as a fulcrum, and each rear lower arm 13 moves up and down with a connecting portion with each rod 16 as a fulcrum.
Since the joints 32, 33, 34, and 35 are located on the axis line of and are on the same plane as the axis line, the rods 16 do not move in the front-rear direction, and the steer characteristics do not change significantly.

In the above embodiment, one end of the front lower arm 12 is connected to the bracket B through the rubber bush joint 31 having three degrees of freedom in the rotational direction, but as shown in FIG. Lower arm 1
It is also possible to implement by connecting one end of 2 to the bracket B via a universal joint 37 having two degrees of freedom in the rotation direction. In this case, it is necessary to employ a ball joint 38 having three degrees of freedom in the rotational direction at the connecting portion between the front lower arm 12 and the link 14.
In the above embodiment, one end of the rear lower arm 13 is connected to the rod 16 via the universal joint 33, but the joints (34, 36, 33) related to the rear lower arm 13 are on the same axis. Or if either of the joints (34, 36) is a joint with two degrees of freedom in the direction of rotation, FIG.
Alternatively, one end of the rear lower arm 13 may be connected to the rod 16 via a ball joint 39 having three degrees of freedom in the rotation direction.

[0012]

In summary, in the vehicle steering system according to the present invention, the left and right carriers are steered via the left and right rear lower arms by moving the left and right rods arranged behind the left and right carriers in the front-rear direction. Therefore, the transmission mechanism that moves the left and right rods in opposite directions to each other by the rotation of the steering shaft can be sufficiently separated from the axle, and the degree of freedom in arranging the steering system is increased. Also, during bounding and rebounding, each front lower arm moves up and down with the connecting part with the vehicle body as a fulcrum, and each rear lower arm moves up and down with the connecting part with each rod as a fulcrum, but each rod moves in the front-back direction. Without changing the steering characteristics, it is possible to positively adjust the steering characteristics by arranging the connecting points of the respective members, so that the steering stability is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a vehicle steering system according to the present invention.

FIG. 2 is an enlarged perspective view of a main part of the vehicle steering system shown in FIG.

FIG. 3 is a perspective view showing a configuration of a transmission mechanism shown in FIG.

FIG. 4 is a perspective view of an essential part showing a modified example of the front lower arm connection configuration.

FIG. 5 is a main part perspective view showing a modified example of the rear lower arm connection configuration.

[Explanation of symbols]

11 ... Carrier, 12 ... Front lower arm, 13 ... Rear lower arm, 14 ... Link, 16 ... Rod, 16a ...
Rack, 20 ... Transmission mechanism, 21 ... Gear housing, 2
2, 23 ... Shaft, 24 ... Pinion, 25, 26, 2
7 ... Bevel gear, A ... Wheel, B ... Bracket, C ... Steering wheel, S ... Steering shaft.

Claims (1)

[Claims] 1. A pair of left and right carriers that rotatably support the left and right wheels, a pair of left and right front lower arms that connect between the front lower end of each carrier and the vehicle body, and a front and rear direction of the vehicle body behind the respective carriers. A pair of left and right movably mounted rods, a pair of left and right rear lower arms that connect the rear ends of the lower ends of the carriers, a pair of left and right links that connect the rear lower arms and the front lower arms, and the rods. A vehicle steering system having a transmission mechanism that moves the steering shaft in opposite directions by rotation of the steering shaft.