JP2001114113A - Energy absorbing member for shock-absorbing type steering wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy absorbing member which can optionally change the shock absorbing function without changing the dimensions and shapes of a fold-back part thereof, including a thickness, a widths and a curvature so that a holding member for holding the fold-back part can be commonly used for various kinds of energy absorbing members. SOLUTION: That part which is adapted to be plastically deformed upon secondary collision, and in which a fold-back part 13a is formed is formed therein at its widthwise central part with a through-hole 25 having dimensions and a shape which are limited so as to adjust the shock-absorbing function of the shock-absorbing member 12a, whereby it is possible to enable various kinds of energy absorbing members to fit a common holding part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy absorbing member for a shock absorbing steering device, which absorbs impact energy and plastically deforms in the event of a collision, thereby preventing an impact applied to the driver's body which hits a steering wheel. ease.

[0002]

2. Description of the Related Art In a collision accident, a secondary collision occurs in which a driver's body collides with a steering wheel, following a primary collision in which an automobile collides with another automobile or the like. In order to reduce the impact applied to the driver's body in the event of this secondary collision, and to prevent serious damage to the driver's body, a driver protection device called a shock absorbing steering device is provided. Various types have been conventionally considered. Also, various members for absorbing impact energy at the time of a secondary collision have been conventionally known. Of these, the energy absorbing member formed by folding a part of a plastically deformable metal plate such as a mild steel plate into a U-shape is relatively simple in structure, and a small and inexpensive shock absorbing steering device can be obtained. It has been commonly used for some time.

FIGS. 5 to 8 show an example of a conventional shock-absorbing steering apparatus incorporating such an energy absorbing member described in Japanese Utility Model Publication No. 6-45415. A steering shaft 2 having a steering wheel 1 fixed to a rear end (right end in FIGS. 5 to 7) is rotatably supported inside a steering column 3.
Such a steering column 3 is supported on a vehicle body 5 via a support bracket 4 welded and fixed to an intermediate portion. The support bracket 4, which is formed by press-forming a steel plate or the like having sufficient rigidity, has a pair of mounting plate portions 6, 6 protruding on both left and right sides of the steering column 3.
Having.

A pair of notches 7, 7 are formed at the rear end of each of the mounting plate portions 6, 6 so as to open to the rear edge side of each of the mounting plate portions 6, 6. Further, sliding brackets 8 are externally fitted to portions corresponding to the notches 7 at the rear ends of the mounting plate portions 6, 6, respectively. These sliding brackets 8 are formed in a U-shape as a whole by bending a metal plate or by injection molding a synthetic resin. The rear end of each of the mounting plate portions 6 is sandwiched by a pair of sliding plate portions 9 constituting such a sliding bracket 8. Then, insertion holes 10 formed in portions of the respective sliding plate portions 9, 9 which are aligned with each other,
A bolt 11 is inserted into the notch 10 and the notches 7, 7, and a male screw portion of the bolt 11 is screwed into a screw hole formed in the vehicle body 5, and further tightened, so that the support bracket 4 is attached. It is supported by the vehicle body 5.

[0005] An energy absorbing member 12 for absorbing impact energy at the time of a secondary collision is mounted between the support bracket 4 and the vehicle body 5. The entire energy absorbing member 12 is formed in a J-shape by bending a plastically deformable band-shaped metal plate such as a mild steel plate. That is, in order to constitute such an energy absorbing member 12, the intermediate portion of the strip-shaped metal plate as shown by the solid line in FIG. A folded portion 13 is formed at the left end of each of the fifth to seventh parts. In addition, the base end of the strip-shaped metal plate (see FIGS.
At the right end of the hole).

Such an energy absorbing member 12 is attached to the bolt 11 screwed and tightened to the vehicle body 5 as described above, and to the front ends (the left ends in FIGS. 5 to 7) of the mounting plates 6, 6. It is mounted in a state of being hung over the handling member 15 fitted and fixed. That is, the base end of the energy absorbing member 12 sandwiches the base end between the lower surface of the vehicle body 5 and the upper surface of the sliding bracket 8 and inserts the bolt 11 into the insertion hole 14.
Is inserted and fixed to the vehicle body 5.
On the other hand, the tip of the energy absorbing member 12 where the folded portion 13 is formed is engaged with the outer peripheral surface of the handling member 15.

[0008] As shown in detail in FIG.
Are formed into a substantially J-shape by injection molding a synthetic resin, and a pair of flat plate portions 16a, 1
6b and a continuous portion 17 having a semicircular cross section for connecting the front edges of the flat plate portions 16a and 16b to each other. or,
A pair of parallel flange portions 18, 18, each of which extends toward the outer peripheral side, are provided on both ends in the width direction of the continuous portion 17 and one flat plate portion 16 a. The distance between the inner surfaces of the flanges 18, 18 facing each other is slightly larger than the width of the energy absorbing member 12.

[0008] Guide projections 19, 19 are provided on the inner diameter side of the flanges 18, 18 on the outer diameter side of the continuous portion 17, respectively. A gap slightly larger than the plate thickness of the energy absorbing member 12 is provided between the leading edge (the edge on the continuous portion 17 side) of each of the guide projections 19 and 19 and the outer peripheral surface of the continuous portion 17. Exists. Also, both ends of the one flat plate portion 16a facing the outer surface {lower surface of FIG.
8 is provided with a guide plate 20 connected to the inner surface. Between the guide plate 20 and the one flat plate portion 16a,
There is a gap through which the one end of the band-shaped metal plate constituting the energy absorbing member 12 can be inserted without large play. Further, an engaging portion 21 is protruded from the inner surface of the distal end portion of the other flat plate portion 16b.

The handling member 15 as described above is a fitting portion 2 formed by folding the front end of each of the mounting plate portions 6 into a U-shape.
The outer fitting is supported on 2, 22. That is, each of the fitted portions 22, 2 is located between the pair of flat plate portions 16a, 16b.
2 is inserted from the side opposite to the continuous portion 17. Then, in a state where the outer peripheral surfaces of the fitted portions 22, 22 are brought into contact with the inner peripheral surface of the continuous portion 17, the other flat plate portion 1 is formed.
The engaging portion 21 formed on the inner surface of the distal end portion 6b is engaged with the notched engaged portions 23, 23 formed on the edges of the engaged portions 22, 22, respectively. Also, in this state, the outer surface of the guide plate 20 (the lower surface in FIG. 8B) is formed by the holding plate portions 24, 24 formed near the front ends of the mounting plate portions 6, 6.
Supported by

Then, in order to lock the tip of the energy absorbing member 12 to the above-described handling member 15, the tip of the energy absorbing member 12 is connected to the continuous portion 17 and the pair of flat plate portions 16a, 16b. Are fitted along the outer peripheral surface of the outer case. That is, the tip of the band-shaped metal plate constituting the energy absorbing member 12 is inserted into the portion between the one flat plate portion 16a and the guide plate 20, and the folded portion 13 is connected to the outer periphery of the connecting portion 17. Surface and each of the above-mentioned guide projections 1
9 and 19 are arranged between them. In this state, the tip of the energy absorbing member 12 is moved between a pair of flange portions 18 provided on the handling member 15.
It is held without rattling over the width direction.

The energy absorbing member 12 constructed as described above
The shock-absorbing steering column device incorporating the following functions in the event of a collision to reduce the shock applied to the driver's body that hits the steering wheel 1 in the following manner.
Due to the secondary collision accompanying the collision accident, the steering column 3
When a strong impact directed forward (to the left in FIGS. 5 to 7) is applied to the support bracket 4 via the bracket, an action is exerted between the rear ends of the mounting plates 6, 6 and the sliding plates 9, 9. The rear end of each of the mounting plates 6, 6 comes out of the space between the sliding plates 9, 9 against the frictional force generated. Thereby, the support bracket 4 is displaced forward together with the steering column 3.

As a result of the support bracket 4 being displaced forward as described above, the folded portion 13 of the energy absorbing member 12 is being handled by the outer peripheral surface of the continuous portion 17 of the handling member 15, while the chain line is shown in FIG. It is displaced forward as shown by. In other words, the formation position of the folded portion 13 is
It moves to the tip side of the band-shaped metal plate constituting the energy absorbing member 12. At this time, a part of the energy absorbing member 12 is continuously plastically deformed in the longitudinal direction.
As a result, the impact energy applied to the steering column 3 is absorbed, and the impact applied to the driver's body hitting the steering wheel 1 is reduced.

As described above, the distal end of the energy absorbing member 12 having the folded portion 13 is disposed between the pair of flanges 18 provided on the handling member 15 in the width direction. It is held without rattling over. For this reason, even when a part of the energy absorbing member 12 is plastically deformed continuously in the length direction as described above, the tip of the energy absorbing member 12 can be prevented from being displaced in the width direction. . For this reason, it is possible to stably absorb the impact energy as described above.

Another example of a shock-absorbing steering device incorporating a plate-like energy absorbing member is disclosed in Japanese Patent Application Laid-Open No.
Japanese Patent Publication No. 329796 describes a structure in which an energy absorbing member is arranged on the upper surface side of a steering column.
In the case of the structure described in this publication, when the steering column is displaced forward due to the impact of the secondary collision, the bent portion of the energy absorbing member fixed to the vehicle body is handled by the handle pin fixed to the steering column. By handling, the position where the bent portion is formed is moved to the tip side of the energy absorbing member. At this time, based on the fact that a part of the energy absorbing member is continuously plastically deformed in the length direction,
Absorbs impact energy at the time of secondary collision.

[0015]

The shock absorbing performance required of the shock absorbing steering device incorporating the energy absorbing member as described above differs depending on the type of vehicle on which the shock absorbing steering device is mounted. Therefore, it is necessary to adjust the shock absorbing performance according to the type of vehicle on which the shock absorbing steering device is mounted. Conventionally, in order to adjust such shock absorbing performance, for example, the width or thickness of the portion where the folded portion 13 is formed in the energy absorbing member 12 is changed or the folded portion is formed. 13
By changing the curvature of the metal plate, the position at which the folded portion 13 is formed is moved along the length of the metal plate to adjust the impact load to be absorbed. However, when changing the width dimension, thickness dimension, or curvature of the portion where the folded portion 13 is formed as described above, the portion where the folded portion 13 is formed is rattled accordingly. It is necessary to change the size and shape of the handling member 15, which is a member for holding the handle. For this reason, it is not possible to reduce the cost based on sharing the handling members between different vehicle types.

On the other hand, in the case of the shock-absorbing steering device described in the above-mentioned Japanese Patent Application Laid-Open No. 7-329796, the energy absorbing member is disposed on the upper surface side of the steering column where there is no space in the space. Therefore, implementation may be difficult depending on the vehicle type. Also, the work of assembling the handle pins fixed to the steering column side is troublesome. The energy absorbing member for a shock absorbing steering device of the present invention has been invented in view of the above-mentioned circumstances.

[0017]

An energy absorbing member for a shock absorbing steering device according to the present invention is made of a plastically deformable band-shaped metal plate, and has a longitudinal direction existing between a base end and a tip end. The intermediate portion was folded back into a U-shape to form a folded portion, and the base end was connected to one of the steering column and the fixed portion, and was supported by the other of the steering column and the fixed portion. A handling member is arranged on the inner peripheral side of the folded portion, and when the steering column is displaced forward due to an impact in a collision accident, the folded member is handled by the handling member and the folded portion is moved to the distal end side. Used in a state where In particular, in the energy absorbing member for a shock absorbing steering device of the present invention, a through hole is formed in a widthwise middle portion of a portion where the folded portion is moved by being handled by the handling member in a collision accident. To change the cross-sectional area of the part,
The performance of absorbing the impact energy obtained by moving the folded portion is adjusted.

[0018]

As described above, in the case of the energy absorbing member for a shock absorbing steering device of the present invention, a through-hole is formed at a widthwise intermediate portion of a portion where the folded portion moves, thereby reducing the cross-sectional area of the portion. By changing, the impact energy absorption performance is adjusted. Therefore, even when the shock absorbing performance of the energy absorbing member is changed according to the type of vehicle on which the shock absorbing steering device is mounted, the shape and size of the energy absorbing member are changed except for the shape and size of the through hole. Nothing to do. For this reason, the handling members and the like can be shared between vehicle types having different required shock absorbing performance.

[0019]

FIG. 1 shows a first embodiment of the present invention. The feature of the present invention lies in the shape of the energy absorbing member 12a. In particular, in the case of this example, the structure and operation of the shock absorbing steering device incorporating the energy absorbing member 12a are the same as those of the conventional structure shown in FIGS. For this reason, the illustration and description of the shock absorbing steering device incorporating the energy absorbing member 12a of the present embodiment are omitted or simplified, and the structure and operation of the energy absorbing member 12a of the present embodiment will be mainly described below.

The energy absorbing member 12a of this embodiment is formed by bending a plastically deformable belt-like metal plate such as a mild steel plate, as in the case of the above-described conventional energy absorbing member 12 (FIGS. 5 to 7). The whole is formed in a J-shape. That is, in order to constitute such an energy absorbing member 12a, the middle part of a strip-shaped metal plate as shown by a solid line in FIG. 1 (left end) is formed with a folded portion 13a. Also, the base end of the strip-shaped metal plate (right end in FIG. 1)
Further, an insertion hole 14 for inserting the bolt 11 (FIG. 7) is formed.

In particular, in the case of the energy absorbing member 12a of the present embodiment, the center of the band-shaped metal plate in the width direction at the portion where the folded portion 13a moves at the time of absorbing the impact energy due to the secondary collision, A long through hole 25 is formed along the length direction of the strip-shaped metal plate. That is, when absorbing the impact energy based on the secondary collision, the folded back portion 13a provided at the tip of the energy absorbing member 12a is handled by the outer peripheral surface of the continuous portion 17 (FIGS. 5 to 8) of the handling member 15. As a result, it is displaced forward as indicated by the chain line in FIG. In other words, the formation position of the folded portion 13a moves toward the tip end (the left end in FIG. 1) of the band-shaped metal plate constituting the energy absorbing member 12a. The through-hole 25 is formed in a range from the central portion in the length direction of the strip-shaped metal plate to a portion closer to the front end, where the folded portion 13a moves. Further, in the case of this example, this through hole 25 is used.
Have the same width over the entire length.

By the way, the impact energy at the time of the secondary collision as described above is such that when the folded portion 13a moves toward the tip end of the strip-shaped metal plate, a part of the strip-shaped metal plate becomes longer. It is absorbed based on the continuous plastic deformation in the direction. The magnitude of the impact energy that can be absorbed by the plastic deformation of a part of the metal plate is determined by the cross-sectional area (thickness × width) of the part of the metal plate plastically deformed in this way.
Is proportional to the size of For this reason, in the case of the present example, by forming the above-described through-hole 25, the cross-sectional area of the portion where the folded portion 13a is formed in the strip-shaped metal plate is described as follows. Of the energy absorbing member 12a.

As described above, the energy absorbing member 12a of this embodiment
In the case of (1), in order to adjust the shock absorbing performance of the energy absorbing member 12a, a part of the band-shaped metal plate constituting the energy absorbing member 12a, in which the folded portion 13a moves when absorbing the impact energy, is used. At the center in the width direction,
A long through hole 25 is formed along the length direction of the strip-shaped metal plate. Therefore, even when the shock absorbing performance of the energy absorbing member 12a is changed depending on the type of vehicle on which the shock absorbing steering device incorporating the energy absorbing member 12a is mounted, the shape and dimensions of the through hole 25 are changed. The shape and dimensions of the energy absorbing member 12a do not change. For this reason, the energy absorbing member 12a needs to be
15 for holding the robot without rattling (FIGS. 5 to 8)
Can be shared.

FIG. 2 shows a second embodiment of the present invention.
An example is shown. In the case of this example, the energy absorbing member 12b
The width dimension of the through-hole 25a formed in the through hole 25a is changed in the longitudinal direction of the through-hole 25a. That is, in the case of this example,
The width of the through hole 25a is determined by the energy absorbing member 12
The width becomes gradually narrower toward the tip (left end in FIG. 2) of the band-shaped metal plate constituting b. In the case of the present example having such a configuration, in the range where the through holes 25a are formed in the strip-shaped metal plate, the cross-sectional area (thickness dimension × width dimension of the solid portion) of the strip-shaped metal plate is on the front end side. It gets bigger as you go. For this reason, the impact energy absorbed while moving the turn-back portion 13b to the distal end side during the secondary collision can be increased as the amount of forward displacement of the steering column 3 (FIGS. 5 to 7) increases, thereby providing a driver protection aspect. Therefore, more effective shock absorption can be performed. That is, in the case of this example, the above-described through hole 2
By increasing the width of the base end side of 5a (the right end side in FIG. 2),
The impact load applied to the driver's body immediately after the secondary collision can be sufficiently reduced. Therefore, protection of the driver can be more effectively achieved. Other configurations and operations are the same as those of the above-described first example.

Next, FIG. 3 shows another example of a shock absorbing type steering device incorporating the energy absorbing members 12a (12b) of the first and second examples described above. In the case of the shock absorbing type steering device shown in FIG. 3, the base end of the energy absorbing member 12a (12b) is connected to the steering column 3
A gripping member 15a, which is fixed to the lower surface and supported by a portion fixed to the vehicle body, is disposed on the inner peripheral side of the folded portion 13a (13b). Therefore, the handling member 15a is provided behind the base end of the energy absorbing member 12a (12b). That is, the energy absorbing member 12a (12
The arrangement of b) is opposite to the above case. The configuration and operation of the energy absorbing member 12a (12b) itself are as follows.
This is the same as in the first and second examples described above.

FIG. 4 shows the respective shock absorbing performances of the structure of the present invention described above and the conventional structure described above. In FIG. 4, a solid line α indicates the shock absorbing performance of the conventional energy absorbing member shown in FIGS. Energy absorbing member 12 of the first embodiment of the present invention shown in FIG.
a indicates the shock absorbing performance, and the broken line γ indicates the shock absorbing performance of the energy absorbing member 12b of the second example of the embodiment of the present invention shown in FIG. The positions of the change points a, b, and c appearing on the chain line β and the broken line γ are changed by changing the width, the length, the shape, and the like of the through holes 25, 25a.
It is freely adjustable. That is, in the case of the energy absorbing member of the present invention, the shape of the through hole formed in the widthwise intermediate portion of the energy absorbing member (the shape may be other than the shape shown in FIGS. By appropriately selecting the width, the length, and the like, the shock absorbing performance required for various automobiles can be easily realized.

[0027]

The energy absorbing member for a shock-absorbing steering system according to the present invention is constructed and operates as described above.
A member for holding the energy absorbing member of the present invention without rattling can be shared between vehicle types having different required shock absorbing performance. As a result, manufacturing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of an energy absorbing member showing a first example of an embodiment of the present invention.

FIG. 2 is a perspective view showing the second example.

FIG. 3 is a partial side view showing another example of the shock absorbing steering device incorporating the energy absorbing members of the first and second examples of the embodiment of the present invention.

FIG. 4 is a diagram showing the shock absorbing performance of the energy absorbing member in comparison between the present invention and a conventional structure.

FIG. 5 is a schematic side view of a conventional shock absorbing steering device incorporating a conventional energy absorbing member.

FIG. 6 is an exploded perspective view corresponding to a part X in FIG. 5;

FIG. 7 is a schematic side view corresponding to a portion X in FIG. 5 and showing states before and after a secondary collision.

8A and 8B show a handling member, wherein FIG. 8A is a view as viewed from the left of FIG. 8B, FIG. 8B is a sectional view taken along the line Y-Y of FIG. Sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steering wheel 2 Steering shaft 3 Steering column 4 Support bracket 5 Body 6 Mounting plate part 7 Notch 8 Sliding bracket 9 Sliding plate part 10 Insertion hole 11 Bolt 12, 12a, 12b Energy absorption member 13, 13a, 13b Folding part 14 Insertion hole 15, 15a Handle member 16a, 16b Flat plate portion 17 Continuous portion 18 Flange portion 19 Guide protrusion 20 Guide plate 21 Engaging portion 22 Fitted portion 23 Engaged portion 24 Suppressing plate portion 25, 25a Through hole

Claims (1)

[Claims] 1. A lengthwise intermediate portion between a base end and a front end formed of a plastically deformable strip-shaped metal plate is folded back into a U-shape to form a folded portion. Attaching the base end to one of the fixed parts and disposing the handle member supported by the other of the steering column and the part fixed to the vehicle body on the inner peripheral side of the folded part, When the steering column is displaced forward due to an impact at the time of a collision, the handle member handles the folded portion and moves the folded portion toward the distal end. In the member, the cross-sectional area of the portion is changed by forming a through hole in the widthwise intermediate portion of the portion where the folded portion is moved by being handled by the handling member in the event of a collision accident. In addition, an energy absorbing member for an impact-absorbing steering device is characterized in that the impact energy absorbing performance obtained by moving the folded portion is adjusted.