JP2000229577A - Energy absorption structure of steering column - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the initial load of a steering column of a type that uses a bending deformation of a clamp to absorb energy at the time of a secondary collision. SOLUTION: In a steering column of a type for absorbing energy at the time of a secondary collision by utilizing bending deformation of a lower clamp 7, a bent portion 17 of the lower clamp 7 is provided.
In addition, a jacket tube attaching portion A is provided on the steering wheel side, and a weak portion B, that is, an elongated hole 16 formed in the rib 15 is provided between the bent portion 17 and the jacket tube attaching portion A. The position of the long hole 16 is freely changed according to the set load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy absorbing structure for a steering column, and more particularly to an improvement in a steering column of a type utilizing a bending deformation of a clamp for energy absorption in a secondary collision.

[0002]

2. Description of the Related Art As a type in which the bending deformation of a lower clamp is used for energy absorption at the time of a secondary collision in a steering column, the invention described in Japanese Utility Model Laid-Open No. 5-29185 and Japanese Utility Model Laid-Open No. 61-29971 is known. is there.

As a type utilizing the bending deformation of the upper clamp, there is a device described in Japanese Utility Model Laid-Open Publication No. Sho 62-16897 and Japanese Patent Laid-Open Publication No. Hei 9-169279.

[0004] In these energy absorbing structures,
By providing ribs and flanges at the deformed part between the clamp body mounting part and the jacket tube mounting part, the position of the bent part that performs bending deformation is always constant, thereby stabilizing the energy absorption load. ing.

[0005]

However, in such a steering column utilizing the bending deformation of the lower or upper clamp, the jacket tube mounting portion is arranged on the steering wheel side with respect to the bent portion of the clamp. This has the advantage that a large stroke can be taken and the clamp can be miniaturized, but there is a problem that the initial load at the time of a secondary collision increases because the load acting in the direction of pushing up the deformed portion increases.

Accordingly, an object of the present invention is to reduce the initial load of a steering column of the type that absorbs energy during a secondary collision by utilizing bending deformation of a clamp.

[0007]

In order to achieve the above object, according to the present invention, as described in claim 1, energy absorption at the time of a secondary collision utilizing bending deformation of a clamp for supporting a steering column on a vehicle body. In the steering column, a jacket tube mounting portion is provided on the steering wheel side with respect to a bent portion set in the clamp, and a fragile portion deformable by an initial load between the bent portion and the jacket tube mounting portion. The present invention provides an energy absorbing structure for a steering column, comprising:

According to a second aspect of the present invention, the line connecting the fragile portion and the jacket tube mounting portion is substantially perpendicular to the axis of the jacket tube than the line connecting the bent portion and the jacket tube mounting portion. An energy absorbing structure for a steering column configured to be close.

Further, as described in claim 3, the fragile portion is formed on a rib formed in a vertical direction on a deformed portion of the clamp.
Provided is an energy absorbing structure for a steering column, characterized in that an elongated hole is formed in a lateral direction.

Therefore, since the fragile portion is deformed before the bent portion is deformed, an increase in the initial load can be suppressed.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a lower clamp according to an embodiment of the present invention; 1 to 3, reference numeral 1 denotes a jacket tube for rotatably supporting a steering shaft 2, and reference numeral 3 denotes a distance bracket 4 coupled to the jacket tube 1 slidably in a vertical direction and fixed detachably to a vehicle body 5. The upper and lower clamps are integrally connected by a connecting member 3a. Reference numeral 6 denotes a tilt lever for fastening the distance bracket 4 held by the upper clamp 3 with a fastening nut 6a and a fastening bolt 6b. Reference numeral 7 denotes a lower clamp for rotatably supporting the lower end of the jacket tube 1 and fixing it to the vehicle body 5. Is a spring connecting the distance bracket 4 and the upper bracket 3.

The upper clamp 3 has a U-shaped groove 3b opened to the rear side of the vehicle body. The upper clamp 3 is fixed to the vehicle body 5 by inserting a bolt into a bolt insertion hole 9a formed in a slider 9 which covers the U-shaped groove 3b with upper and lower surfaces. You. The slider 9 has a substantially U-shaped cross section, and a lower portion of the upper clamp 3 has an extension 9b extending to a rear side of the vehicle body by a predetermined length. The extension 9b is inserted into a long hole 3d provided in a front wall 3c of the upper clamp 3 which is inclined forward of the vehicle body. When the upper clamp 3 separates from the vehicle body 5, the extension 9 b supports the upper clamp 3 so that it does not immediately fall downward.

As shown in FIGS. 4 and 5, the lower clamp 7 is formed by bending a sheet metal having a predetermined thickness and a substantially U-shape in a plan view into a substantially F-shape in a side view.
0 is a U-shaped base which is a flat plate-shaped vehicle body mounting portion 1
Deformed portions 13, 13 are formed on the left and right end portions of the right and left sides of the opening 12 through which the jacket tube 1 penetrates, and are bent downward and obliquely hang down. And supporting parts 14 and 14 bent at substantially right angles.

A substantially elliptical rib 15 is formed in the deformed portion 13 so as to protrude toward the front side of the vehicle body in a vertically long shape, and the rib 15 is provided with a horizontally long slot 16. The elongated holes 16, 16 are located on the same horizontal line, and are located below the bent portion 17 which is a bent portion, and serve as fragile portions which are initially deformed by an initial load. The long hole 16 is for weakening the rib 15, and this weakening is not limited to the long hole 16, and
The setting position and the number are not limited. Support part 14
Shafts 21 and 21 (FIG. 1) projecting from vertical surfaces 20 and 20 formed on both side surfaces of the lower end portion of the jacket tube 1.
(See FIG. 1), and a shaft hole 18 is formed to rotatably support the lower end of the jacket tube 1.

The corner at the lower end of the deformed portion 13 is bent substantially at right angles to the front of the vehicle body to reinforce the deformed portion 13 as shown by an imaginary line a. As shown in FIG. 2B, a stamped and formed sheet metal is bent substantially at a right angle from the deformed portion 13, and a shaft hole 18 is formed in a base portion.
Below it, square nuts 19 are fixed so as to face each other. Opposing pair of nuts 19,1
A bolt is inserted through 9 to support a column cover or the like (not shown).

The operation of the steering column according to the above configuration at the time of a vehicle collision will be described. When a driver's load is applied to the steering shaft 2 via the steering wheel by the secondary collision, the jacket tube 1
Moves toward the front of the vehicle body, the upper clamp 3 is disengaged from the vehicle body via the U-shaped grooves 3b, 3b, and moves toward the front of the vehicle body.
Slide on the extension 9b. On the other hand, when the jacket tube 1 moves to the front side of the vehicle body, as shown in FIG. 6, the lower clamp 7 bends and deforms to the front side of the vehicle body to absorb the impact load.

That is, in FIG. 6, a line y connecting the jacket tube mounting portion A where the shaft hole 18 is located and the weakened portion B where the elongated hole 16 is located is the jacket tube mounting portion A.
Jacket tube 1 than line z connecting
Is made to be nearly orthogonal to the axis c of
When an impact load (arrow A) is input, the fragile portion B is first bent and deformed toward the front of the vehicle body. When the deformation of the fragile portion B proceeds to some extent, the load for bending the bent portion 17 becomes larger than the load for bending the fragile portion B, so that the deformation of the bent portion 17 starts and the fragile portion B The deformation stops. This prevents the deformation portion 13 from being deformed in two stages, thereby preventing the initial load from increasing.

As described above, by setting the weak portion B having a low rigidity in the middle of the deformable portion 13, the load acting in the direction of pushing up the deformable portion 13 against the impact load can be reduced, so that the initial load is reduced. That is, as shown in FIG. 7, the position of the fragile portion B is brought closer to the jacket tube 1 as shown in FIG.
To reduce the amount of deformation of the bent portion 17 and reduce the amount of deformation of the bent portion 17 or to reduce the amount of deformation of the bent portion 17 by increasing the amount of deformation of the weak portion B by bringing the position of the weak portion B closer to the bent portion. Thereby, the energy absorption characteristics can be tuned.

FIGS. 8 and 9 show a third embodiment of the lower clamp according to the present invention. The third embodiment is different from the above-mentioned embodiment in that, instead of providing the long hole 16 as the fragile portion B, FIG. This is because the ribless portion 30 is provided, and the other configuration and its operation and effect are the same as those in the previous example.
The overlapping description is omitted.

FIGS. 10 and 11 show a lower clamp according to a fourth embodiment of the present invention. The difference from the above embodiment is that a rib 15 for reinforcing the deformed portion 13 is provided. The notch 31 is provided on both the left and right sides of the deformed portion 13 as the fragile portion B, whereby the deformation load of the deformed portion 13 can be reduced.
The initial load can be reduced by deforming the deforming portion 13 in two stages.

In the above embodiment, the lower clamp 7 has been described as an example. However, since the energy absorbing structure by the bending deformation of the set bent portion 17 can be applied to the upper clamp 3, it is not necessary to provide the fragile portion B. It is not limited only to the lower clamp 7.

[0022]

According to the present invention described above, even if the jacket tube mounting portion is provided on the steering wheel side with respect to the bent portion of the clamp, the initial load can be reduced, so that the energy absorbing function can be improved and The stroke of the clamp can be increased and the size of the clamp can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view of a steering column showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a sectional view taken along line XX of FIG. 1;

FIG. 4 is a front view of the lower clamp.

FIG. 5 is a plan view of a lower clamp.

FIG. 6 is an explanatory diagram of an operation at the time of a secondary collision of the lower clamp.

FIG. 7 is an explanatory diagram of an operation of a lower clamp shown in another example at the time of a secondary collision.

FIG. 8 is a front view of a main part showing another example of the lower clamp.

FIG. 9 is a side view of the lower clamp of FIG. 8;

FIG. 10 is a front view of a main part showing still another example of the lower clamp.

FIG. 11 is a side view of the lower clamp of FIG. 10;

[Explanation of symbols]

c: axis line of the jacket tube 1 y: line connecting the jacket tube mounting portion A and the fragile portion B z: line connecting the jacket tube mounting portion A and the bent portion 17 1 ... jacket tube 2 ... steering shaft 3 ... upper clamp 4 ... Distance bracket 5 ... Car body 6 ... Tilt lever 7 ... Lower clamp 9 ... Slider 11 ... Car body mounting part 12 ... Opening part 13 ... Deformation part 14 ... Support part 15 ... Rib 16 ... Elongated hole 17 ... Bending part 18 ... Shaft hole 30 ... Rib-less part 31 ... Notch

Claims (3)

[Claims] 1. A steering column for absorbing energy at the time of a secondary collision by utilizing bending deformation of a clamp supporting a steering column to a vehicle body, wherein a jacket tube mounting portion is steered with respect to a bent portion set in the clamp. An energy absorbing structure for a steering column, wherein the energy absorbing structure is provided on the wheel side, and a fragile portion that can be deformed by an initial load is provided between the bent portion and the jacket tube mounting portion. 2. The apparatus according to claim 1, wherein a line connecting the fragile portion and the jacket tube mounting portion is substantially perpendicular to an axis of the jacket tube than a line connecting the bent portion and the jacket tube mounting portion. The energy absorbing structure of the described steering column. 3. The energy absorbing structure for a steering column according to claim 1, wherein the weak portion is formed by forming a horizontally long hole in a rib formed in a vertical direction in a deformed portion of the clamp. .