JPH0323417Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a steering rack device used in a rack-and-pinion type steering device for axle vehicles such as automobiles, and in particular to a steering rack device equipped with a steering vibration reduction mechanism. Pertains to.

BACKGROUND TECHNOLOGY It is known that the rack-and-pinion type steering used in automobiles and other vehicles has greater vibration due to shimmy and flutter than other types of steering. It has already been proposed to incorporate a damper device in the middle of the tie rod, as shown in, for example, Japanese Utility Model Application No. 76472/1983.

Problems to be Solved by the Invention A damper device is installed in the middle of the tie rod to reduce vibrations of the steering wheel due to shimmy and flutter, but the length of the tie rod changes due to the damping action of the damper device.
This results in a disadvantage that the amount of toe of the steered wheels changes. Furthermore, if the damper device is installed in the middle of the tie rod, the direct feeling of the steering will be impaired.

In view of the above-mentioned problems, the present invention has been developed with a steering vibration reduction mechanism that reduces the steering vibration transmitted to the steering wheel without changing the length of the tie rod, and is configured so as not to significantly impair the direct feeling of the steering wheel. The object is to provide a steering rack device.

Means for Solving the Problems According to the present invention, a rack member having a series of rack teeth, a rack member extending movably through the rack member in an axial direction and extending from both ends thereof linking rods each connected to a tie rod;
a movable stopper member for controlling the axial movement of the linking rod relative to the rack member; an elastic member for elastically coupling the rack member and the linking rod in the thrust direction; This is achieved by a steering rack device with a steering vibration reduction mechanism, which includes a control device for controlling the arrangement position of the movable stopper member so as to increase the allowable axial movement amount with respect to the rack member.

Functions and Effects of the Invention According to the above-described configuration, a damping action is performed by the elastic deformation of the elastic member in the thrust direction, and at this time, the relative positional relationship between the rack member and the linking rod in the axial direction is changed. However, the length of the tie rod does not change, and as a result, the toe amount of the steered wheels does not change, and steering vibration transmitted to the steering wheel is reduced. Moreover, the permissible axial movement of the linking rod relative to the rack member is adjusted according to the level of steering vibration, and when the steering vibration is already large, the permissible axial movement is increased to reduce steering vibration. On the other hand, when the steering vibration is small, the permissible axial movement amount is reduced in order to improve the steering direct feeling, thereby achieving both reduction in steering vibration and improvement in the steering direct feeling.

Embodiments Hereinafter, the present invention will be described in detail with reference to embodiments with reference to the accompanying drawings.

FIG. 1 shows one embodiment of a steering rack assembly according to the present invention. In FIG. 1, reference numeral 10 designates a rack member, which is strip-shaped and has a series of rack teeth 12 in its longitudinal direction, axially. The rack member 10 is provided with an engagement hole 14 extending therethrough in its longitudinal direction. A linking rod 16 is fitted into the engagement hole 14 so as to be movable in its axial direction. An interlocking rod 16 extends through the engagement hole 14 and projects outwardly from ends 18 and 20 of the rack member 10 at each end thereof, each end of which includes a universal joint. Rack end members 22 and 24 forming sockets are fixedly attached by screws 26 and 28. Shoulders 30 and 32 of rack end members 22 and 24 each correspond to the ends 18 of rack member 10.
and 20, and the distance between the shoulders 30 and 32 is set to be longer than the length of the distance between the ends 18 and 20 of the rack member 10 by a predetermined amount.

Left and right tie rods 34 and 36, respectively, are universally connected to the rack end members 22 and 24 by balls 38 and 40 provided at their ends.

Between one end 18 of the rack member 10 and the shoulder 30 of the rack end member 22 and the rack member 10
Compression spring members 42 and 44 are mounted between the other end 20 of the rack end member 24 and the shoulder 32 of the rack end member 24, respectively. Compression spring members 42 and 44 are
Each of them elastically connects the rack member 10 and the linking rod 16 in the thrust direction, and normally, the rack member 1
0 is located at a central position between shoulders 30 and 32.

At the ends 18 and 20 of the rack member 10 are ring-shaped movable stop members 46 and 48, respectively, which are fitted with screws 46.
a and 48a so as to be movable in the axial direction of the rack member 10. Movable stopper member 4
6 opposes the shoulder 30 of one rack end member 22 and limits the amount of rightward movement of the linking rod 16 relative to the rack member 10 in the figure;
The amount of movement of the connecting rod 16 to the left with respect to the rack member 10 is limited in the view. Movable stop members 46 and 48 each rotate to change their axial position with respect to rack member 10 by the action of screws 46a and 48a, so that shoulders 30, 32
By changing the interval for the linked rod 1
The permissible axial movement amount for the rack member 10 of No. 6 is variably set.

External teeth 50 and 52 are provided on the outer periphery of each of the movable stopper members 46 and 48, and these external teeth 50 and 52 are attached to shafts 54 and 56, respectively, and are rotationally driven by a servo motor 58. Drive pinions 60 and 62 are in mesh with each other.

The operation of the servo motor 58 is performed by a control device 70, and the control device 70 is given information about the steering vibration level due to shimmy and flutter from an acceleration sensor 72 attached to the steering wheel 66. When this vibration level is large, for example, When the value is greater than a predetermined value, the servo motor 58 is driven to rotate in order to increase the permissible axial movement of the link rod 16 relative to the rack member 10;
On the other hand, when the vibration level is small, for example below a predetermined value, the servo motor 58 is driven to rotate in order to reduce the permissible axial movement amount. The servo motor 58 may be controlled with a hysteresis characteristic in order to avoid a hunting phenomenon in controlling the permissible axial movement amount with respect to the vibration level. For example, a control hysteresis of about 0.05G in vibration level may be provided. Therefore, if the target value is e.g.
If it is 0.3G, the vibration level (acceleration) is
When the vibration level increases beyond 0.3G, the servo motor 58 is driven to increase the permissible axial movement amount, and when the vibration level decreases beyond 0.25G, the servo motor 58 is driven to decrease the permissible axial movement amount. It's fine as long as it's driven.

Furthermore, if the vibration level does not fall below a predetermined value even if the permissible axial movement amount of the linkage rod 16 relative to the rack member 10 is set to the maximum value, the control device 70 lights up a warning light 74 to remind the driver to adjust the wheel balance. It may also be designed to prompt adjustment work.

According to the above-described structure, when vibration in the axial direction is transmitted from the steering wheel to the link rod 16 via the tie rods 34 and 36 due to shimmy or the like while the vehicle is running, the link rod 16 is moved to the compression spring member 42. Alternatively, while elastically deforming the rack member 1
Move in the axial direction with respect to 0. This prevents the axial vibrations of the linkage rod 16 from being transmitted to the rack member 10, thereby reducing the vibrations of the steering wheel 66.

Under the above-mentioned action, even if the tie rod 16 moves axially relative to the rack member 10, the length of the tie rod does not change, so the amount of toe of the steered wheel does not change.

The operation of the servo motor 58 is controlled according to the steering vibration level detected by the acceleration sensor 72, and thereby the movable stopper members 46, 4
The axial position of the rack member 8 changes. This allows the rack member 1 of the linkage rod 16 to
The permissible axial movement amount relative to 0 is the acceleration sensor 7.
The steering vibration level is set to the minimum limit necessary to keep the steering vibration level below a predetermined value in accordance with the steering vibration level detected by No. 2, thereby improving the direct feeling of the steering.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited thereto, and various embodiments are possible within the scope of the present invention. It will be clear to those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of a steering rack assembly according to the present invention. 10...Rack member, 12...Rack tooth, 14
...Engaging hole, 16...Linking rod, 18, 20...
...End part, 22, 24...Rack end member, 2
6, 28... Screw, 30, 32... Shoulder, 34,
36...Tie rod, 38,40...Ball, 4
2, 44... Compression spring member, 46, 48... Movable stopper member, 46a, 48a... Screw, 50,
52... External tooth, 54, 56... Shaft, 58... Servo motor, 60, 62... Drive pinion, 6
6... Steering wheel, 70... Control device, 72... Acceleration sensor, 74... Warning light.

Claims (1)

[Scope of utility model registration request] a rack member having a series of rack teeth; a linking rod extending axially movably through the rack member and connected to a tie rod at each end; and an axis of the linking rod relative to the rack member. a movable stopper member for controlling directional movement; an elastic member for elastically coupling the rack member and the linking rod in the thrust direction; and a permissible axial movement amount of the linking rod relative to the rack member in response to an increase in steering vibration. A steering rack device with a steering vibration reduction mechanism, comprising: a control device for controlling the arrangement position of the movable stopper member so as to increase the vibration of the movable stopper member.