JPH0140333Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a steering device for an automobile having a dampable steering torque transmission device for transmitting steering torque of a steering wheel to a steering gear.

[Prior art]

In a steering device with a rack and pinion type steering gear, the tie rod is a short straight line that connects the steering gear and the steering knuckle arm, but if excessive torque is applied to the steering wheel, the threaded part of the tie rod The teeth of the steering gear may become deformed and the wheel alignment may become misaligned.

[The problem that the idea aims to solve]

The problem with this invention is that even if excessive torque is applied to the steering wheel, it can avoid deformation of the tie rod threads and the teeth of the steering gear, and prevent steering system failures caused by excessive torque. To provide a device that can notify the driver of the

[Means to solve the problem]

In order to solve this problem, according to the present invention, a dampable steering torque transmission device includes a hollow female member having a non-circular inner peripheral contour and a hollow male member rotatably engageable with the female member. The male member is integrally formed with a torque transmitting portion having a non-circular outer peripheral contour that fits into the female member without any play, and is integrally formed following this torque transmitting portion in the axial direction, and is plastically deformed when the torque exceeds a certain torque. a reduced cross-sectional portion which is formed integrally with the reduced cross-sectional portion in the axial direction, and which is similar to the non-circular inner circumferential contour of the female member and has a major axis smaller than this but larger than the minor axis of the non-circular inner circumferential contour. and a relative rotation angle limiting portion having a non-circular outer peripheral contour.

[Effect of idea]

According to the present invention, with normal steering torque, steering is performed reliably through the tight fit between the torque transmitting parts of the female and male members, but when a vehicle crashes, etc., excessive torque is generated. When applied to the steering wheel, the reduced cross-section portion plastically deforms, and this plastic deformation absorbs the impact energy, thereby preventing the threaded portion of the tie rod and the teeth of the steering gear from deforming due to this excessive torque. In this case, even if plastic deformation occurs in the reduced cross-section portion, the relative rotation angle limiting portion of the male member engages with the female member while being twisted by a small rotation angle relative to the torque transmission portion, making steering impossible. It will never become. Moreover, in this case, since play occurs in the rotational direction between the female member and the relative rotation angle limiting portion, the driver can be aware of this abnormality in the steering system, that is, the plastic deformation of the reduced cross-section portion.

〔Example〕

The present invention will be described with reference to the embodiments shown in the drawings.

In FIG. 1, the steering torque of the steering wheel 10 is determined by the steering main shaft 12,
Universal joint 14, intermediate shaft 1 configured to be expandable and retractable
6, the left and right tie rods 2 are connected via the universal joint 18 and the rack-and-pinion steering gear 20.
2 and 24.

A dampable steering torque transmission device is provided at the intermediate shaft 16, as shown in FIG.
This steering torque transmission device includes a solid male member 26 having a torque transmission portion 32 having a non-circular circumferential contour in which both ends of two mutually parallel line segments are connected by a circular arc, and an axial direction formed on the outer periphery of the male member 26. and a hollow female member 28 having a similar non-circular inner circumferential contour. Following the torque transmitting portion 32 of the male member 26 in the axial direction, there is a reduced cross-section portion 30 that plastically deforms when a torque exceeds a certain value, and a short diameter of the non-circular inner peripheral contour of the female member 28, which is similar to but smaller than this contour. A relative rotation angle limiting portion 34 having a non-circular outer circumferential contour with a longer diameter (diameter of a circular arc) larger than (interval between line segments) continues integrally.

[Effect]

During normal operation, the steering torque of the steering wheel 10 is transmitted to the torque transmission portion 32 of the hollow male member 26 and the hollow female member 2 via the reduced cross-section portion 30.
8, the steering gear 20
transmitted to.

Steering wheel 10 due to vehicle collision, etc.
When excessive impact torque is applied to the reduced cross-section portion 30, the reduced cross-section portion 30 is plastically deformed and absorbs the impact energy.
Therefore, deformation of the threaded portions of the tie rods 22, 24 or the teeth of the steering gear 20 is avoided, and misalignment of the wheels is also avoided.

After plastic deformation of the reduced cross-section portion 30, as shown in FIG. This is done through the engagement of the Therefore, even after the cross-section reduced portion 30 is plastically deformed, steering will not become impossible. Note that the rotational play in this case allows the driver to immediately know that there is an abnormality in the steering system.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the entire steering device, Figure 2 is a perspective view of the entire steering device.
The figure is a cross-sectional view along the axis of the dampable steering torque transmission device, Figure 3 is a cross-sectional view along the - line in Figure 2, and Figure 4 corresponds to Figure 3 after the cross-sectional reduced part has been plastically deformed. FIG. ...Bufferable steering torque transmission device, 26...
...Male member, 28...Female member, 30...Reduced cross section portion, 32...Torque transmission portion, 34...Relative rotation angle limiting portion.

Claims (1)

[Claims for Utility Model Registration] 1. A bufferable steering torque transmission device for transmitting steering torque of the steering wheel 10 to the steering gear 20 includes a hollow female member 28 having a non-circular inner peripheral contour, and the female member 28. and a hollow male member 26 that can be rotationally engaged with the
This male member 26 is integrally formed with a torque transmitting member 32 which fits into the female member 28 without any play and also has a non-circular outer circumferential contour, and is integrally formed following this torque transmitting portion in the axial direction. A deformable cross-section reduced portion 30 is formed integrally with the deformable cross-section reduced portion in the axial direction, and is similar to the non-circular inner circumferential contour of the female member 28, but smaller than the minor axis of the non-circular inner circumferential contour. and a relative rotation angle limiting portion 34 having a non-circular outer peripheral contour with a large major diameter.
Automotive steering device. 2. The device according to claim 1, wherein the buffer operation torque transmission device is provided on the intermediate shaft 16 between the steering main shaft 12 and the steering gear 20.