JPS6121335Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a steering device that absorbs impact energy during a collision of an automobile.

Heretofore, as an example of this type of impact energy absorbing steering device, there is one disclosed in Japanese Utility Model Publication No. 49-9855. The device shown in the same publication has a plurality of conical friction rings interposed between a relatively movable inner cylinder and an outer cylinder, but the structure is complicated due to the large number of parts. In addition to being complicated, it is not possible to reduce the size of at least the outer cylinder.

The present invention aims to provide a steering device that can efficiently absorb impact energy with an extremely simple structure.A stopper ring having an inclined surface is provided on the end face of the lower shaft, while a stopper ring is provided on the outer periphery of the upper shaft. A coil spring having a smaller diameter than the outer diameter of the upper shaft is attached with a constant tightening force so as to face the inclined surface of the stopper ring, so that the upper shaft and the coil are substantially connected. It is designed to absorb impact energy through the frictional force between it and the spring.

Hereinafter, embodiments of this invention will be described in detail using the drawings.

FIG. 1 shows an embodiment of the steering device according to this invention, which includes a jacket tube 1 and a steering shaft that is slidably and rotatably supported through the jacket tube 1. It is mainly composed of 2.

The jacket tube 1 is attached to the vehicle body 4 by a bracket 3, while the steering shaft 2 is attached to an upper shaft 2a and a lower shaft 2b.
The upper shaft 2a and the lower shaft 2b are connected in a serration portion 5 so as to be relatively slidable. A steering wheel (not shown) is attached to the shaft end (right end in FIG. 1) of the upper shaft 2a. In the figure, 6 is a universal joint for connecting the steering shaft 2 to a steering gear (not shown), and 7 is a bush.

The bracket 3 has a substantially U-shape as shown in FIG. It is integrally fixed to the bracket 3 by mounting. By inserting the mounting bolt 12 into the long hole 11 of the slide block 9, the jacket tube 1 including the steering shaft 2 is movably mounted on the vehicle body 4. That is,
When the impact force A due to the secondary collision is applied from the steering wheel side, and a load exceeding the set value is applied to the molded resin, the resin is sheared, and the bracket 3 is detached from the jacket while leaving the slide block 9 on the vehicle body side. It moves downward in the axial direction together with the tube 1, thereby absorbing impact energy.

Further, an inclined surface 13 is provided at the end of the lower shaft 2b.
A coil spring 14 is fixed on the outer periphery of the upper shaft 2a adjacent to the stopper ring 13.
is attached so as to face the stopper ring 13. Before this coil spring 14 is attached to the upper shaft 2a, its inner diameter is set smaller than the outer diameter of the upper shaft 2a, and therefore, as shown in the figure, the coil spring 14 is attached to the upper shaft 2a. In this state, it is fixed with a constant tightening force.

As a result of this configuration, when an impact force from the direction A is applied to the steering shaft 2 due to a collision, the steering shaft 2 exerts a contraction force. That is, when the upper shaft 2a and the lower shaft 2b make a relative sliding movement in the serration section 5, the end of the coil spring 14 comes into contact with the inclined surface 13a of the stopper ring 13. Then, since the opposite side of the coil spring 14 is an inclined surface, it contracts diagonally at a certain angle with respect to the axis of the upper shaft 2a, causing a so-called falling phenomenon, and the outer peripheral surface of the upper shaft 2a and An extremely large frictional force will be generated between the two. The frictional force generated between the coil spring 14 and the upper shaft 2a absorbs the impact energy at the time of a collision in addition to the impact absorption by the slide block 9 described above.

It should be noted that the stopper ring 13 does not necessarily have to be completely integrated with the lower shaft 2b, but may have a function of compressing the coil spring 14 in some way.

Here, in the above embodiment, a cylindrical coil spring was used as the coil spring, but a conical coil spring is used to change the pressing force with the upper shaft around which the coil spring is wound. The shock load absorption characteristics can also be controlled by selecting the number of turns of the coil spring.

As is clear from the above explanation, according to the present invention, by combining the stopper ring disposed on the lower shaft side and the coil spring attached to the upper shaft side, a simple structure with a small number of parts is achieved. In addition to efficiently absorbing impact energy despite the structure, it is possible to create a steering device with an energy absorption mechanism without major design changes to conventional steering devices, so there is less increase in the weight and price of the device. I'll try it.

Furthermore, by changing the number of turns, thickness, and diameter of the coil spring, the shock load absorption characteristics can be easily controlled.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram showing an embodiment of the impact energy absorbing steering device according to this invention;
FIG. 2 is an exploded view showing details of the bracket of FIG. 1. 1... Jacket tube, 2... Steering shaft, 2a... Upper shaft, 2...
Lower shaft, 13...Stopper ring, 13
a... Inclined surface, 14... Coil spring.

Claims (1)

[Scope of utility model registration request] A jacket tube mounted to the vehicle body so as to be movable axially downward via a bracket; an upper shaft rotatably supported within the jacket tube and connected to each other so as to be slidable in the axial direction; In an impact energy absorbing steering device comprising a steering shaft having a lower shaft, a stopper ring having an inclined surface is disposed on the end face of the lower shaft, and a stopper ring having an inclined surface is disposed on the outer periphery of the upper shaft. An impact energy absorbing steering device characterized in that a coil spring set to a small diameter is mounted so as to face the inclined surface of the stopper ring with a constant tightening force.