JPS5946828B2 - Shock absorbing steering device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shock absorbing steering device that protects a motor vehicle driver from injury during a collision.

Conventional shock-absorbing steering devices use a steering shaft or
The main method is to install a special energy absorption device in the steering column to absorb energy during a collision, which has the drawback of requiring a large amount of manufacturing cost.

In order to solve these drawbacks, it is known that a plate-shaped energy absorption device is installed with both ends fixed to the steering column, which moves forward and downward in the event of a collision, and to a fixed body part, but the The disadvantage is that it requires additional man-hours to prepare grooves.

An object of the present invention is to provide a low-mounted shock-absorbing steering device in which the man-hours required for the energy absorbing device are extremely reduced. Bend the column twice in the axial direction and attach both overlapping ends to the vehicle body with mounting bolts, and one movable end is detached from the mounting bolt via the locking metal fitting that is locked to the mounting bolt. The other fixed end is permanently engaged with the mounting bolt, and the bent part between the movable end and the fixed end prevents the steering column from moving forward and downward in the event of a collision. Accordingly, the movable end portion moves together with the steering column, forming a new bent portion in the middle, and generates a ff1f'l deformation in which the bending position of the mounting portion is sequentially shifted, and becomes an energy absorbing portion that absorbs energy. That is.

To explain this with reference to the embodiment shown in the figure, in FIG. 1, a steering shaft 1 has a bundle 4 attached to its upper part, and is rotatably supported on a steering column 3 via a lower bearing 6 and an L portion bearing (not shown). The lower part is connected to the upper joint 10 and the lower joint 1 through 11 to the steering gear 1.
It is connected to 2.

The steering column 3 is attached to the vehicle body part 9 by a column bracket 2 fixed to the steering column 3 at the upper part and by a lower bracket 8 having a column support member 7 that slidably supports the steering column 3 at the lower part. .

The steering column 3 is only allowed to move forward and downward as in the conventional case, but it does not have an energy absorption device.

The steering shaft 1 is shown as a single shaft, but due to the presence of two joins 1-10.11, it is displaced to the position shown by the chain line in the event of a collision. This is because there is no influence from whiskers, and when the steering shaft 1 is directly connected to the steering gear 12, or when the steering shaft 1 is connected directly to the steering gear 12,
When connecting through two joints, the steering shaft 1 should be connected vertically to
It is common and safe to divide it into shafts, with one shaft inserted inside the other shaft.

As shown in FIGS. 2 to 5, the column bracket 2 is a U that is fixed to the steering column 3 by means such as welding.
It comprises a body part 21 having a letter-shaped cross section and attachment parts 22, 22 located on both sides of the body part 21.

The mounting part 22, which attaches the steering column 3 to the vehicle body part 9 with the mounting bolt 13, is double bent in the axial direction of the steering column 3, and has an elongated and crushed U-shape with a bending position 27 at the lower front. , one end on the steering column 3 side becomes a movable end 24, into which a locking fitting 5 (having a rectangular cross section) is fitted.

The end of the mounting portion 22 on the vehicle body portion 9 side is a fixed end portion 23, and is provided with a slot system such as a long hole 28 that cannot be opened.

In the present invention, a bolt hole that does not open refers to a bolt hole in which the bolt does not come out of the bolt hole even if the bolt is inserted and the bolt is moved in the diametrical direction of the bolt, such as a round hole or a long hole. A hole with no chipped parts around the hole, such as a square hole, corresponds to this type of hole.On the other hand, a U-shaped hole or the like that allows a bolt to be removed from the bolt hole is called a bolt hole with one end open.

The movable end portion 24 has a U with one end open on the bundle 4 side.
A letter-shaped bolt hole 29 is provided, and the movable end 24 and the fixed end 23Gj are overlapped, and the bolt hole of the locking fitting 5, the U-shaped bolt hole 29 of the movable end, and the elongated hole 28 of the fixed end. The mounting bolt 13 is inserted through the mounting portion 22 to attach the mounting portion 22 to the vehicle body.

Between the movable end portion 24 and the fixed end portion 23, there is a portion having a wide width B and serving as the energy absorbing portion 25 on the movable end portion 24 side;
There is a part that becomes the energy absorbing part 26 on the side of the fixed end part 23 with a narrower width B2, and the energy absorbing part 2 with a narrower width.
A first bending position 27 is provided near the boundary with the wide energy absorbing portion 25 within the bending portion 6 .

The locking metal fitting 5 (described in Japanese Utility Model Application Publication No. 52-141737) is one in which the inner surface of a plate bent in the shape of an opening is coated with a film made of a synthetic resin having a low coefficient of friction and bolt holes are provided. As shown in Figure 8,
The two washers 5A and 5A coated with a synthetic resin film described in Publication No. 2 may be used, or the metal fitting commonly called a capsule described in Japanese Patent Publication No. 45-27248, which is widely used. It may be.

When a car collides, the steering column 3 is pushed forward and downward due to a secondary collision.

At this time, the movable end 24 of the mounting part of the column bracket is fitted with the mounting bolt 13 through the bolt hole 29 with one end open on the bundle 4 side, so the load is applied to the front and lower side on the opposite side of the bundle. The bolt 13 and the locking fitting 5 are released from locking.

However, since the fixed end portion 23 of the attachment portion is fitted into the attachment bolt 13 through the elongated hole 28, it can only move forward and downward by the gap a of the attachment bolt 13 on the bundle side within the elongated hole 28.

Therefore, as the movable end 24 moves, the initial bending position 27 provided in the narrow-width energy absorbing portion 26 gradually shifts toward the wide-width energy absorbing portion 25 on the movable end 24 side. As the plastic deformation progresses, the final bending position 27A finally reaches the boundary between the movable end 24 and the wide energy absorbing portion 25, as shown in FIG.

This position is indicated by a dotted line in FIG. 3, and if the distance from the first bending position 27 is S, then the moving distance of the movable end 24 is 2 S + a, and this distance is the plasticity due to the bending position misalignment. The deformation results in a collapse stroke that absorbs impact energy.

The energy that can be absorbed is determined by adjusting this collapse stroke, the material, plate thickness, and width of the attachment part, especially the energy absorbing part, and the bending radius R of the bending part (see FIG. 3).

The energy absorbing part 26 on the fixed end part 23 side is at the first bending position 27 here, and when the bending position 27 starts plastic deformation, the movable end part 24 is still between the locking fitting 5 and the friction. Since a detachment load is generated due to resistance, in order to prevent a large load from occurring at the beginning of the collapse stroke, in order to reduce the load that causes plastic deformation at the bending position 27, the fixed end portion including the first bending position 27 is The width dimension of the energy absorbing portion 26 on the 23 side is set to a small value B2 so as to have lower rigidity than the energy absorbing portion 25 on the other side.

Figures 6 to 8 show that the fixed end 23 of the column bracket mounting part and the energy absorbing part 25, 26 are formed separately from a material with a thinner thickness than the body 21 and the movable end of the mounting part. Another embodiment of the column bracket is shown in FIG. 6, in which a part of the wide energy absorbing part 25 is overlapped and welded to the movable end part 24A, and the movable end part 24
A has two plane parts, and one plane view shows a locking fitting 5.
are fitted and attached to the vehicle body part, and the other flat part is overlapped with the energy absorbing part 25.

By overlapping and integrating them in this manner, the flat surface of the thick movable end portion 24A has the advantage of restricting buckling of the thin energy absorbing portion.

In the embodiment shown in FIG. 7, the movable end portion 24B is connected to the energy absorption portion 2.
5. Fold it twice in the opposite direction to the bending direction of 26, and attach one end of the thin energy absorbing part 25 to the movable end part 24.
It is clamped at the bending part B so that it can move as a unit, and has the same effect as the embodiment shown in FIG.

In this case, the U-shaped hole 29B is provided in common at the bent portion of the movable end portion 24B and the end portion of the energy absorbing portion 25.

The embodiment of FIG. 8 has a fixed end portion 23 and an energy absorbing portion 25.
．． 26 is bent in a direction opposite to that of the first to third embodiments, and is integrally fixed to the movable end portion 24C by welding.

In this case, since the mounting bolts do not prevent forward and downward movement, the energy absorbing portion is also provided with a recess 30.

In this embodiment, as described above, two washers 5A coated all over with a synthetic resin film having a low coefficient of friction are used as the locking fittings.

FIG. 9 is an example showing the results of a crash test conducted on the shock-absorbing steering device of the present invention shown in FIG. 1 using MYSS, A203.
The maximum value for the following was 750k19, which was a good result.

The shock-absorbing steering device of the present invention constructed as described above can achieve good results by absorbing energy in a part of the mounting part of the column bracket, and its structure is only that the mounting part is bent double. It is a simple product that does not require cutting or grooves in the energy absorption part, and eliminates any troublesome processing.In particular, the material cost is low when the fixed end part and energy absorption part are separated from the movable end part. Therefore, it is possible to provide a shock-absorbing steering device that is inexpensive and has good performance.

Also, since it is double-folded, it has the effect of allowing a large collapse stroke despite the small axial dimensions of the steering column.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a longitudinal cross-sectional view of a shock absorbing steering device showing how it is installed in an automobile, and FIG.
The figure is a cross-sectional view taken along the ■-■ line in Figure 1, and Figure 3 is a cross-sectional view of the
An enlarged sectional view taken along the line I-I in the figure, Figure 4 is the same as in Figure 3.
5 is a view corresponding to FIG. 3 showing the state after the movement is completed, and FIGS. 6 to 8 are a plan view of the column bracket mounting part shown in FIG. 9
The figure is a graph showing the results of a collision test. Explanation of symbols, 1: Steering shaft, 2: Column bracket, 3 Steering column, 4 Steering wheel, 5: Locking metal fitting, 9
: Vehicle body part, 13: Mounting bolt, 21: Body part, 22: Mounting part, 23: Fixed end part, 24: Movable end part, 25, 26:
Energy absorption part, 28: Long hole, 29: U half hole.

Claims (1)

[Scope of Claims] 1. A steering shaft equipped with a bundle, a steering column rotatably supporting the steering shaft, and a column bracket for mounting the steering rig column to the vehicle body, the column bracket being made of plastic material. It is formed of a deformable plate-like material and includes a body fixed to the steering column and attachment parts located on both sides of the body, each attachment part being folded twice in the axial direction of the steering column, Both overlapping ends are attached to the vehicle body part by mounting bolts, and one end is removably engaged with the mounting bolt via a locking fitting that is locked to the mounting bolt, thereby forming a movable end. and the other end irremovably engages with the mounting bolt to become a fixed end, and a bent part is provided between the movable end and the fixed end to extend in the axial direction in the event of a collision. It has an energy absorption part that absorbs energy by forming a new bent part, and as the steering column moves forward and downward in the event of a collision of the automobile, the movable end part moves together with the steering column, and the energy absorption part 1. An impact-absorbing steering device characterized by absorbing impact energy by causing plastic deformation in which the bending position of the mounting portion is sequentially shifted by forming a new bending portion of the mounting portion. 2. The movable end of the mounting part has a bolt hole with one end on the bundle side open, and the fixed end has a bolt hole that is not opened, and each bolt hole is overlapped and fitted with the mounting bolt. The shock absorbing steering device according to claim 1, characterized in that: 3. A patent claim characterized in that the energy absorbing portion has portions with different width dimensions, and the width dimension on the fixed end side including the first bending position is smaller than the width dimension on the movable end side. The shock absorbing steering device according to item 1. 4. The shock absorbing steering device according to claim 1, wherein the rigidity of the fixed end portion of the energy absorbing portion including the first bending position is smaller than the rigidity of the movable end portion. 5. A patent claim characterized in that the attachment part has a movable end part, an energy absorbing part and a fixed end part formed separately, and a part of the energy absorbing part is overlapped with the movable end part and fixed to the movable end part. The shock absorbing steering device according to item 1. 6. The movable end of the mounting portion, the energy absorbing portion and the fixed end are formed separately with different plate thicknesses, a part of the energy absorbing portion is overlapped with the movable end and fixed together, and the plate is fixed. 2. The shock absorbing steering device according to claim 1, wherein the thick movable end portion restricts buckling of the thin energy absorbing portion. 7. The movable end of the attachment part, the energy absorption part and the fixed end are formed as separate bodies with different plate thicknesses, and the thick movable end part is bent in the direction opposite to the bending direction of the energy absorption part.
2. The shock-absorbing steering device according to claim 1, wherein the energy-absorbing portion is folded heavily and a part of the thin energy-absorbing portion is held between the bent portions of the movable end portions so as to be movable as a unit.