JPH1129050A - Impact absorbing steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate rotation of a handle part and absorb impact energy in a more stable state by constituting an intermediate shaft so as to absorb impact also after impact by a primary collision is received. SOLUTION: An intermediate shaft 19 has an inner shaft 120 connected to a second yoke 18 of a universal coupling at one end and an outer shaft 121 having a serration coupling part fitting into the inner shaft 120. The outer shaft 121 is connected to a first yoke 24 of a second universal coupling 23. The serration coupling part between the inner shaft 120 and the outer shaft 121 is made longer as a whole. The serration coupling part is radially crushed, a plastic deformation part which is axially and integrally fixed is made longer, the whole of the intermediate shaft 19 is not destroyed by impact from the lower side of a vehicle due to a primary collision and load which gradually deforms also impact energy from the side of a steering shaft at the time of a secondary collision can be supported.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorbing type steering device for a motor vehicle.

[0002]

2. Description of the Related Art Various shock absorbing steering systems for automobiles have been proposed. Among them, for example,
As disclosed in Japanese Patent No. 19057, the steering column is supported by the vehicle body at two front and rear positions. In the case of a secondary collision, the steering column leaves the supporting position and moves relative to the vehicle body together with the steering shaft. In this case, for example, the plastic deformation member is deformed to absorb the impact due to the secondary collision.

In such a shock absorbing type steering device, a steering shaft is connected to an intermediate shaft via a first universal joint at an end opposite to the steering wheel side, and the intermediate shaft is connected to the opposite end at the opposite end. , Second
Is connected to the steering gear on the steering wheel side via the universal joint.

For example, as disclosed in Japanese Patent Application Laid-Open No. Hei 8-91230, this intermediate shaft comprises an inner shaft connected to a first universal joint and a cylindrical outer shaft connected to a second universal joint. One end of the inner shaft is inserted into the outer shaft, and a male serration portion and a female serration portion engaged with the male serration portion are formed on both ends, and rotation is transmitted by these serration connections.

[0005] The serration joint is partially crushed in the diameter direction to form an oval section, so that there is no play between the two members.

As another example of such an intermediate shaft,
For example, in the case of Japanese Utility Model Laid-Open No. 6-72779, a part of the shaft on the inner side is made thinner, and a sleeve divided in the axial direction is fitted and fixed to the outer periphery thereof, and is fixed in the axial direction.
In the case of a primary collision, the fitting and fixing portion is first sheared in response to a displacement input due to an impact from the front portion of the vehicle, and when a larger displacement input is input, the shaft is bent from a narrow portion. This portion is bent at the time of the secondary collision, even if it is not bent by the impact of the primary collision.

As described above, the intermediate shaft according to the prior art is
When the portion fixed in the axial direction between the inner and outer shafts is cut or broken, the supported load drops sharply. There is also a structure in which a load supported at the time of cutting or breaking is intentionally reduced.

[0008]

SUMMARY OF THE INVENTION
In the steering device of the type in which the steering column structure is supported on the vehicle body at two places in front and rear as described at the beginning with regard to 19057, if the above-mentioned intermediate shaft system is used, the intermediate shaft is broken at the time of a primary collision and the load is reduced. As a result, the steering column structure separates from the two mounting positions on the vehicle body due to the secondary collision, and during the absorption of the impact (FIG. 3), the instrument panel portion on the vehicle body side is used as a fulcrum in FIG. As shown in (1), the handle portion is easily turned upward. Such rotation of the handle portion shifts the position of the airbag between the handle portion and the occupant from a predetermined position, which may be a safety problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a shock absorbing steering apparatus which solves such problems in the prior art and which can absorb shock energy in a more stable state without rotation of a handle portion. I do.

[0010]

According to the present invention, a steering shaft connected to a steering wheel, a steering column for rotatably and integrally holding the steering shaft in an axial direction, and So that in the event of a secondary collision, the steering column separates from the support position and moves relative to the vehicle body with the steering shaft to absorb the impact of the secondary collision. And a middle shaft connected at one end to the steering shaft via a first universal joint and connected at the other end to a wheel via a second universal joint. In the absorption steering apparatus, the intermediate shaft is configured to be able to absorb shock even after receiving an impact due to a primary collision. .

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;

FIG. 1 shows an example of a conventional shock absorbing type steering apparatus for a vehicle. A steering wheel (not shown), that is, a steering shaft 1 integrally having a steering wheel at a right end is rotatable by a steering column 2. And they are integrally supported in the axial direction.

The steering column 2 is supported on the vehicle body 3 at first and second positions, for example, as disclosed in Japanese Utility Model Laid-Open No. 7-19057.

That is, at the first support position, the steering column 2 is integrally held by a lifting bracket 4, and the lifting bracket 4 is held by a pair of left and right mounting plates 5 so as to be vertically movable. The left and right mounting plates 5 are fixed to the vehicle body 3 via the capsule 7 by bolts (not shown).

The relationship between the left and right mounting plates 5, the capsule 7 and the mounting bolts is such that the mounting position is fixed by these three members in a normal state, but a load exceeding a predetermined value due to a secondary collision is applied via the steering column. When hanging on the mounting plate 5,
The connection between the capsule 7 and the mounting plate 5 is cut and broken, so that the steering column can move in the lower left direction in FIG. 1 together with the mounting plate 5 and the like.

A plastic deformation member 8 for absorbing shock, which will be described later, is also fixed to the bolt (not shown).

The above-mentioned lifting bracket 4 is mounted on the mounting plate 5 via a tilt bolt 9. The elevating bracket 4 is provided with a tilt lever 10. If the tilt bolt 9 is loosened by rotating the tilt lever 10, the elevating bracket 4 can move up and down with respect to the mounting plate 5 together with the steering column 2. Can be adjusted.

In the second support position, a suspension bracket 12 is provided integrally with the steering column 2. The suspension bracket 12 is fixed to a bracket 15 fixed to the vehicle body 3 via a bolt 13 and a nut 14.

The above-described plastic deformation member 8 for absorbing shock, one end of which is fixed to the first position, extends to the second support position, is wound around a bolt 13, and is folded upward.

The portion of the bracket 15 to which the bolt 13 is attached is a slot extending in the axial direction. When the steering column 2 moves to the lower left due to the impact at the time of the secondary collision, the bolt 13 causes the plastic deformation member 8 to move. Shock is absorbed by plastically deforming to extend.

The steering shaft 1 is connected at a lower left end thereof to a first yoke 17 of a first universal joint 16. The second yoke 18 of the first universal joint is connected to the inner shaft 20 of the intermediate shaft 19.

The outer shaft 21 of the intermediate shaft 19 is fitted to the inner shaft 20, and is serrated for transmitting rotation at that portion. In this serration coupling portion, the outer shaft 21 and the inner shaft 20 are partially crushed in the radial direction and fixed to each other so as to prevent rattling therebetween.

The outer shaft 21 is the second universal joint 2
3 is connected to the first yoke 24. The second yoke 25 of the second universal joint 23 is connected to a steering gear (not shown) connected to a steered wheel (not shown).

In the conventional example having such a structure, immediately after the primary collision of the wheels, the impact from the vehicle body is applied to the intermediate shaft 19 from below.

The intermediate shaft 19 is normally broken by this impact (the state shown in FIG. 2). Next, in a secondary collision stage, when an impact is applied to a handle (not shown), the steering column 2 separates from the first and second support positions described above, and moves while extending the plastic deformation member 8 to the lower left in the figure. To absorb the secondary collision energy.

As described above, the steering column 2 sometimes rotates counterclockwise in the drawing around a part of the instrument panel of the vehicle body as a fulcrum, so that the steering column 2 expands on the steering wheel. It can happen that the position of the airbag becomes unstable.

FIG. 5 shows an intermediate shaft in which the above problem has been solved. One embodiment of the present invention is a shock absorbing steering apparatus employing the intermediate shaft shown in FIG. 5 instead of the intermediate shaft shown in FIG. is there.

The intermediate shaft 19 shown in FIG. 5 has an inner shaft 120 whose one end is connected to the second yoke 18 of the universal joint 16, and an outer shaft 121 having a serration coupling portion fitted therein. The outer shaft 121 is connected to the first yoke 24 of the second universal joint 23.

In the present embodiment, the serration connection between the inner shaft 20 and the outer shaft 121 is made longer as compared with the intermediate shaft of the conventional example described above. The plastically deformed portion, which is crushed in the radial direction and is integrally fixed in the axial direction, is made longer, and the intermediate shaft is not completely destroyed even in the event of an impact from below the vehicle due to a primary collision. At the time of the next collision, it is a plastically deformed portion sufficient to support a constant load or a load that is gradually deformed even with impact energy from the steering shaft side.

[0030]

According to such a structure, since the intermediate shaft also supports the load caused by the secondary collision, there is an effect that the upward rotation of the steering column at the time of the secondary collision can be prevented. This also has a significant effect on the occupant's body safety, as it stabilizes the position of the airbag.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a steering system according to one of conventional examples, wherein (a) is a partial cross-sectional side view, and (b) is (a).
(C) is a CC view of (a).

FIG. 2 is a view showing a state in which an intermediate shaft is broken by a primary collision of the steering system shown in FIG.

FIG. 3 is a diagram showing a state in which two support positions for a vehicle body have been separated immediately after a secondary collision of the steering system shown in FIG. 1;

FIG. 4 is a view showing a state in which the steering system shown in FIG. 1 has separated from a supporting position on the vehicle body after the secondary collision and the column is rotating.

FIG. 5 is an enlarged view showing only an intermediate shaft portion according to the embodiment of the present invention.

[Explanation of symbols]

 1. Steering shaft 2. Steering column 3. Body 19. Intermediate shaft 20. Inner shaft 21. Outer shaft

Claims (1)

[Claims] A steering shaft connected to a steering wheel; a steering column rotatably and integrally holding the steering shaft in an axial direction; and supporting the steering column on a vehicle body at two front and rear positions. In the event of a secondary collision, the steering column separates from the support position, and moves relative to the vehicle body together with the steering shaft, thereby absorbing a shock due to the secondary collision, An intermediate shaft connected at one end to the steering shaft via a first universal joint and connected at the other end to a wheel via a second universal joint. The intermediate shaft is configured to be able to absorb shock even after receiving a shock due to a primary collision. The impact absorbing steering apparatus.