JPH0617654Y2 - Telescopic steering device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an improvement of a telescopic steering device having a shock absorbing mechanism in an automobile.

[Prior art]

The steering device of an automobile mainly has a steering function,
A collapsible structure has been conventionally used to reduce an impact load caused by a collision of an occupant with a steering wheel during a vehicle collision. In the conventional telescopic steering device, a tube portion is formed at the lower end of the upper shaft to which the steering wheel is attached, and a column tube is attached to the outside to form a telescopic structure, and inside the sliding shaft connected to the main shaft. The head is attached and the structure is collapsible. Further, the upper shaft tube is fastened to the column tube by a fastening member so that the contracting operation does not occur at normal times, and the column tube is attached to the body via a capsule having a shear pin. Further, the sliding shaft and the main shaft are integrated via a shear pin.

By the way, the shock absorbing mechanism of this type of telescopic steering device is as follows. First, when the occupant collides with the steering wheel, the steering wheel is deformed, and an axial load is applied to the upper shaft. This load causes slippage between the column tube and the column tube, and the upper shaft is pushed in. Since the attachment plate facing the end face of the column tube is attached to the upper shaft, this plate hits the cushioning material provided on the end face of the column tube to transfer the load to the column tube. When the transmission force to the column tube is strong, the capsule breaks, the connection with the body is released, and the column tube makes a stroke movement. afterwards,
The upper shaft tube is bottomed on the sliding shaft head, and the shear pin of the main shaft is cut by the axial movement of the shaft, and the contraction operation is further performed. During this time, the impact force is absorbed and relaxed by the frictional force due to the tightening member, the contact between the attachment plate and the column tube cushioning material, and the capsule rupture.

[Problems to be solved by the invention]

However, in the conventional telescopic steering device, since the upper shaft tube bottoms on the sliding shaft immediately after the capsule that is connecting the column tube and the body is cut, a bottoming load occurs, There was a problem that a large load was concentrated in a short time.

An object of the present invention is to provide a telescopic steering device capable of reducing a large load generated in a short time and stabilizing the generated load.

[Means and Actions for Solving Problems]

In order to achieve the above object, in the telescopic steering device according to the present invention, in particular, the tightening force of the tightening member is
It is smaller than both the shearing force of the shear pin that connects the column tube and the body and the shearing force of the shear pin that connects the sliding shaft and the main shaft, and while attaching the cushioning material to the tube bottom part of the upper shaft where the sliding shaft head is inserted, The bottom dimension of the upper shaft tube on the sliding shaft head is smaller than the bottom dimension of the attachment plate on the column tube.

With such a configuration, it is possible to relieve the bottoming load of the upper shaft tube by the buffer material inside the tube, accelerate the bottoming of the upper shaft tube, and quickly cut the shear pin between the sliding shaft and the main shaft. Therefore, it is possible to obtain a telescopic steering device having a stable cushioning function by preventing the load from being concentrated.

〔Example〕

Hereinafter, a telescopic steering device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of the telescopic steering device of the embodiment. The steering wheel 10 is attached to the upper shaft 12, and a tube 12A having an open end surface is formed at the lower end of the upper shaft 12. Inside the tube 12A, a head portion 14A of a sliding shaft 14 is inserted by serration connection, and both have a telescopic structure in which only movement along the axial direction is allowed. The lower end of the sliding shaft 14 is fixedly connected through a shear pin 18 while being telescopically connected to a main shaft 16 that transmits a steering force to a gear box. Further, the outer peripheries of these steering shaft portions are surrounded by the column tube 20. The column tube 20 is composed of an upper column tube 20A and a lower column tube 20B. The upper column tube 20A is connected to a body 24 by a capsule 22 having a shear pin 22A, and the lower column tube 20B.
Is fixed to the body 24 by a support member. Further, both the upper and lower column tubes 20A and 20B are connected to each other in a collapsible structure so that they can expand and contract in the axial direction. Further, the upper column tube 20A attached to the body 24 via the capsule 22 has the upper shaft tube 12A inserted therein, and both of them are telescopically coupled. Further, the upper column tube 20A is provided with a tightening member 26 which is attached to the inner wall surface of the upper column tube 20A and can be pressed against the outer peripheral surface of the upper shaft tube 12A. Therefore, the upper shaft 12 is structured to move in the axial direction and enter the upper column tube 20A by being pushed by the pushing force that overcomes the frictional force of the tightening member 26. Further, in order to transmit the axial load of the upper shaft 12 to the upper column tube 20A, a flange-shaped attachment plate 28 is attached to the outer peripheral portion of the upper shaft 12, and the attachment plate 28 is attached to the upper column tube 20A. It faces the upper end surface. On the other hand, a cushioning material 30 is attached to the upper end surface of the upper column tube 20A so as to reduce the collision load of the attachment plate 28.

With such an apparatus, in the present embodiment, the cushioning material 32 made of polyurethane is formed on the inner bottom portion of the upper shaft tube 12A into which the sliding shaft head portion 14A is inserted.
Is attached to alleviate the bottoming load on the sliding shaft head 14A of the tube 12A. Further, the bottomed dimension A of the upper shaft tube 12A determined by the distance between the cushioning material 32 and the sliding shaft head 14A is determined by the distance between the attachment plate 28 and the column tube side cushioning material 30. It is set smaller than the bottom dimension B of the attachment plate 28. By making a difference between the bottomed dimensions A and B and setting A <B, the pushing load generated in the upper shaft 12 is transmitted to the sliding shaft 14 first, and later to the upper column shaft tube 20A. It was made to let.

With this configuration, the occupant can operate the steering wheel 1
When it collides with 0, the steering wheel 10 is first deformed and a pushing force is generated on the upper shaft 12. Since the tightening force of the tightening member 26 is smaller than the shearing force of the shear pins 18 and 22A, this load causes the telescopic tightening member 26 to slip, and the cushioning material 32 in the upper shaft tube 12A causes the sliding shaft head to move. 14A contacts and deforms. Since the dimension with bottom is A <B due to this axial load, the load is transmitted to the shear pin 18 between the main shaft 16 and the sliding shaft 14, and the pin 18 is sheared. After that, the sliding shaft 14 axially moves in the main shaft 16, whereby the attachment plate 28 attached to the upper shaft 12 comes into contact with the column tube side cushioning material 30 to be deformed, and the upper column tube 20A is connected to the body 24. Capsule 2
Shear pin 22A of 2 is sheared, and column tube 20A
This causes the stroke movement of.

As described above, according to the present embodiment, since the shear pin 18 on the main shaft 16 side is cut earlier than the shear pin 22A on the column tube 20 side, the generated load is the deformation force of the cushioning material 32 in the upper shaft tube 12A. , The shear pin shear force of the capsule 22 and the stroke force of the column tube 20 are the sum of the forces of the three, and the bottom load between the upper shaft tube 12A and the sliding shaft head 14A and the shear pin 18 of the main shaft 16 are sheared. Loads will not be generated at the same time. Therefore, load generation is not concentrated, and stable impact mitigation can be achieved.

[Effect of consideration]

As described above, according to the telescopic steering device of the present invention, the timing of transmitting the load from the upper shaft to the sliding shaft is made earlier than the timing of transmitting the load to the column tube, and the bottomed load of the upper shaft tube is cushioned. I tried to ease it, so
The impact load is effectively dispersed and a stable cushioning effect can be produced.

[Brief description of drawings]

FIG. 1 is a sectional view of the telescopic steering device of the embodiment. 10 ... Steering wheel, 12 ... Upper shaft, 12A ... Upper shaft tube, 14 ... Sliding shaft, 16 ... Main shaft, 18 ... Share pin, 20 ... Column tube, 22 ... Capsule, 24 ... Body, 26 ... Tightening member, 28 ... Attachment plate, 30, 32 ... Cushioning material.

Claims (1)

[Scope of utility model registration request] 1. A tube is formed at an end of an upper shaft to which a steering wheel is attached, and a head portion of a sliding shaft connected to a main shaft through a share pin is inserted into the tube, and the tube is provided outside the tube. Has a telescopic structure by externally inserting a column tube attached to the body via a shear pin.A fastening member for fastening the tube of the upper shaft to the column tube is attached and the column shaft is pushed into the column shaft. In a telescopic steering device equipped with an attachment plate that comes into contact with the end surface of the column tube during movement, the tightening force of the tightening member is due to the shearing force of the shear pin connecting the column tube and the body and the sliding shaft and the main shaft. The shearing force of the shear pin connecting the shafts is smaller than any of the shearing force, and a cushioning material is attached to the bottom of the tube of the upper shaft, and the bottomed dimension of the tube of the upper shaft to the sliding shaft head is determined by the attachment plate. Telescopic steering device characterized in that it is smaller than the size of the bottom of the column tube.