JPH08295251A - Shock absorption type steering column device - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a structure that reduces the impact of a secondary collision and effectively protects the driver at low cost. [Structure] During a secondary collision, the outer column 17 is displaced forward, and the fixed end portion 34 of the energy absorbing member 31 is pulled forward. The stud 26 is not displaced while being supported by the support bracket 3. Therefore, the extension portion 33 of the energy absorbing member 31 is accompanied by the forward displacement of the fixed end portion 34.
However, it is squeezed by the stud 26 and plastically deforms. The energy required for this plastic deformation reduces the impact on the driver's body that collides with the steering wheel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The shock absorbing steering column device according to the present invention is designed to protect the life of an occupant during a collision by constructing the steering column so as to absorb the shock during a collision.

[0002]

2. Description of the Related Art When a vehicle collides, a so-called secondary collision occurs in which the vehicle collides with another vehicle or the like, which is a so-called primary collision, and then the driver collides with the steering wheel. In order to reduce the impact on the driver during this secondary collision and protect the driver's life, the steering shaft that fixes the steering wheel at one end shortens the total length when a strong impact is applied, In general, a so-called collapsible steering shaft is used and a steering column having the steering shaft inserted therein is of a shock absorbing type.

As a shock absorbing type steering column device used for such a purpose, for example, an actual flat type 5
The one disclosed in Japanese Laid-Open Patent Publication No. 75057 is known.
This conventionally known shock absorption type steering column device is configured as shown in FIGS. The steering column 1 is configured by combining an outer column and an inner column in a telescopic shape, and the total length thereof is shortened when a strong axial force is applied. A steering shaft 2 is rotatably supported inside the steering column 1. A steering wheel (not shown) is fixed to a portion of the rear end portion of the steering shaft 2 protruding from the rear end opening of the steering column 1.

A support bracket 3 for supporting the steering column 1 on the vehicle body is composed of a pair of left and right support plate portions 4, 4.
Further, the displacement side bracket 5 welded and fixed to the lower surface of the intermediate portion of the steering column 1 is sandwiched between the support plate portions 4 and 4. Notches 6, 6 are formed on the left and right side walls of the displacement side bracket 5 so that the rear edge (the right edge in FIG. 12) side is open. Further, elongated holes 7 and 7 which are long in the vertical direction are formed in portions of the support plates 4 and 4 which are aligned with the notches 6 and 6, respectively. Then, an adjusting nut 9 is screwed to the other end of an adjusting bolt 8 which is a coupling member, which is inserted through the respective long holes 7, 7 and the notches 6, 6 from one side to the other side (from right to left in FIG. 13). I am letting you. The adjusting bolt 8 may move up and down along each of the elongated holes 7 by the engagement of the head portion 10 and the side edge of the one elongated hole 7, but does not rotate.

The distance between the adjusting nut 9 and the head portion 10 is determined by adjusting the adjusting nut 9 to the tilt lever 11.
(Refer to FIGS. 1, 2, 4, and 5 showing the embodiment of the present invention) to change by rotating. Then, by changing this distance, the steering column 1 to which the displacement side bracket 5 is fixed can be fixed to the support bracket 3,
Alternatively, the fixed position can be released and the vertical position of the steering wheel can be adjusted.

Further, a rear end portion of the energy absorbing member 12 (a front part and a rear part are represented in a traveling direction of the vehicle, as shown in FIGS. 12 and 14) is located at an intermediate portion of the adjusting bolt 8 and inside the displacement side bracket 5. The right end portion of) is fitted and supported. The front end portion (the left end portion in FIGS. 12 and 14) of the energy absorbing member 12 is welded and fixed to the lower surface of the intermediate portion of the steering column 1. Therefore, the rear end portion of the energy absorbing member 12 is supported by the vehicle body, which is not displaced even in a collision, through the adjusting bolt 8 and the support bracket 3, and the front end portion is displaced in the front direction in a collision. Supported by.

The energy absorbing member 12 is formed by punching out a single metal plate having plasticity.
It has a corrugated shape as shown in. In addition, the support portion 13 provided at the rear end of the energy absorbing member 12 has a left and right
Forming a pair of bent portions 14, 14, each bent portion 1
Circular holes 15 and 15 for inserting the adjusting bolt 8 are formed in 4 and 14, respectively. Further, a tongue piece 16 is formed at the front end portion of the energy absorbing member 12, and the tongue piece 16 is formed.
Is fixed to the lower surface of the steering column 3 by welding.

In the case of the conventional shock absorbing type steering column apparatus in which the energy absorbing member 12 having the above-mentioned shape is incorporated between the adjusting bolt 8 and the steering column 1 as shown in FIGS. When an impact force that pushes the steering column 1 forward is applied due to a secondary collision resulting from a collision accident, the steering column 1 is displaced forward while plastically deforming so that the energy absorbing member 12 extends in the front-rear direction. Tolerate. In the case of the conventional structure shown in FIGS. 12 to 13, the force required to start the displacement (extension) of the energy absorbing member 12 does not become particularly large as compared with the structure known before that. Therefore, the displacement of the steering column 1 to the front is smoothly started, and the impact force applied to the driver's body at the moment of the secondary collision can be reduced.

[0009]

In the case of the conventional structure shown in FIGS. 12 to 14, there is no particular problem in terms of protecting the driver at the time of a secondary collision, but the energy absorbing member 12 of the energy absorbing member 12 has the following reasons. Not only the manufacturing cost is high, but also the assembling work of the energy absorbing member 12 is troublesome for the following reasons. Since the shape of the energy absorbing member 12 is complicated, the manufacturing cost of the press die increases. Moreover, this energy absorbing member 1
When 2 is stamped and formed from a steel plate, a large amount of waste material is generated, and thus the material yield is poor. Adjusting bolt 8 which is a connecting member when assembled
And the notches 6 and 6 and the long holes 7 provided in pairs, respectively.
7 and the circular holes 15, 15. However, the work of aligning the circular holes 15, 15 provided in the energy absorbing member 12 with the notches 6, 6 and the long holes 7, 7 is troublesome.

The energy absorbing member 12 for the above reason.
Due to the increase in cost and the decrease in the efficiency of the assembling work due to the above reasons, the cost of the shock absorbing steering column device shown in FIGS. The shock absorption type steering column device of the present invention was invented in view of such circumstances.

[0011]

The impact absorption type steering column device of the present invention is, like the conventional impact absorption type steering column device described above, a steering column in which a steering shaft for fixing a steering wheel to a rear end thereof can be inserted. And a pair of support plate portions for sandwiching the steering column from the left and right sides, a support bracket that is supported and fixed to the vehicle body, through holes formed in each of the support plate portions, and the through holes. In this state, a coupling member for coupling and supporting the intermediate portion of the steering column to the support bracket, and an energy absorbing member made of a plastically deformable metal plate and provided between the support bracket and the steering column. Composed.

Particularly, in the shock absorbing type steering column device of the present invention, the energy absorbing member is continuous with the folded-back portion arranged on the rear side of the coupling member and from the upper end side of the folded-back portion. An extending portion that extends forward from a gap between the upper surface of the coupling member and the lower surface of the steering column, and a fixed end portion that is fixed to the steering column continuously from the lower end side of the folded portion are provided.

[0013]

The operation of the shock absorbing steering system of the present invention constructed as described above is as follows. At the time of a secondary collision, a forward load is shocked from the steering wheel to the steering column via the steering shaft. Then, due to this load, all or part of the steering column is displaced forward. On the other hand, the support bracket and the coupling member are not displaced while being supported by the vehicle body. Therefore, the coupling member is displaced rearward with respect to the steering column with the start of displacement of the steering column (actually, the steering column is displaced forward without the coupling member moving). At the same time, the fixed end of the energy absorbing member is pulled forward by the steering column.

When the fixed end portion of the energy absorbing member is pulled forward in this way, the folded portion of the energy absorbing member is squeezed by the coupling member, so that the energy absorbing member is plastically deformed. That is, as the steering column is displaced forward, the folded-back portion moves from the originally formed portion toward the tip of the extending portion. In this way, by plastically deforming the energy absorbing member so as to move the folded-back portion toward the tip of the extension portion, the impact energy applied to the steering wheel from the driver's body in association with the secondary collision is generated. Is absorbed. As a result, the impact applied to the driver's body is alleviated and the driver is protected.

[0015]

1 to 8 show a first embodiment of the present invention. The steering column 1 is the second half (right half of FIG. 1).
The outer column 17 constituting the front end portion (the left end portion in FIG. 1) and the rear end portion (the right end portion in the FIG. 1) of the inner column 18 constituting the front half portion (the left half portion in FIG. 1) are telescopically formed. Composed in combination. The front end of the steering column 1 is supported by the swing support bracket 19 so as to be slightly swingable with respect to the vehicle body. In the illustrated embodiment,
As the swing support bracket 19, a structure for swinging and supporting the front end portion of the steering column 1 based on elastic deformation of a metal plate is shown. Of course, as is well known,
It is also possible to adopt a structure in which the front end of the steering column 1 is swingably supported by the horizontal axis.

Inside such a steering column 1, the front and rear ends of the steering shaft 2 are provided with roller bearings 20.
And a ball bearing 21. As the ball bearing 21, a deep groove type is used. Therefore, the steering shaft 2 is the steering column 1
It is rotatably supported inside (incapable of displacement in the axial direction). A steering wheel (not shown) is fixed to the rear end portion of the steering shaft 2 protruding from the rear end opening of the steering column 1.

A displacement side bracket 22 having a shape as shown in FIG. 6 is welded and fixed to the lower surface of the intermediate portion of the outer column 17 constituting the steering column 1. This displacement side bracket 22 formed by bending a steel plate
Is a curved plate portion 23 that is in close contact with the lower surface of the outer column 17 and the width direction of the curved plate portion 23 (see FIGS. 1, 2, 3, 5).
(Front-back direction, left-right direction in FIG. 4) and a pair of left and right folding plate portions 24, 24 bent downward from both edge portions. Then, the bent plate portions 24, 24 are formed with notches 6, 6 having an opening on the rear end edge (right end edge in FIGS. 1, 2, and 5) side.

The support bracket 3 supported and fixed to the vehicle body at the lower portion of the dashboard or the like is the displacement bracket 2 described above.
It has a pair of support plate portions 4 and 4 for sandwiching 2 from both left and right sides. Then, the mounting plate portions 25, 25 bent from the upper end edges of the respective support plate portions 4, 4 in the left and right opposite directions are supported and fixed to the vehicle body by bolts or the like not shown. The support plate portions 4 and 4 constituting the support bracket 3 are
Arc-shaped elongated holes 7, 7 having the center of swing by the swing support bracket 19 as the center are formed. Each of these long holes 7, 7 corresponds to the through hole described in the claims.

These long holes 7, 7 and the respective notches 6,
A stud 26, which is a coupling member, is inserted into the connector 6. A pair of flat portions 27 which are parallel to each other are formed at one end portion (right end portion in FIG. 4) of the stud 26, and are formed on the flat portion 27 and one (right side in FIG. 4) support plate portion 4. The stud 26 is prevented from rotating by engaging with the side edge of the long hole 7. A nut 28 is screwed into a portion of one end of the stud 26 protruding from the outer surface of the one support plate portion 4. A part of the tubular portion 29 formed on the nut 28 in the state where the assembly adjustment work is completed is
It crimps toward the said flat part 27. Therefore, after the assembly adjustment work is completed, the nut 28 is attached to the stud 26.
It never rotates against. On the other hand, the tilt lever 1 is provided at a portion of the other end portion (left end portion in FIG. 4) of the stud 26 that protrudes from the outer surface of the other support plate portion 4 (left side in FIG. 4).
The screw hole 30 formed in the base end portion of 1 is screwed. The distance between the inner side surface of the nut 28 (left side surface in FIG. 4) and the inner side surface of the base end portion of the tilt lever 11 (right side surface in FIG. 4) is
It can be expanded and contracted by operating the tilt lever 11. Therefore, the height position of the steering wheel can be adjusted by swinging the steering column 1 around its front end portion by the same operation as the above-described conventional structure.

Further, between the support bracket 3 and the displacement side bracket 22 fixed to the steering column 1, a plastically deformable metal plate such as a mild steel plate is formed in a shape as shown in FIG. An energy absorbing member 31 is provided. The energy absorbing member 31 includes a U-shaped folded-back portion 32, an extending portion 33 continuous from the upper end side of the folded-back portion 32, and a fixed end portion 34 continuous from the lower end side of the folded-back portion 32. The fixed end portion 34 is formed in an L-shaped cross section, and both end portions of the fixed end portion 34 project outward in the width direction from both left and right side edges of the main body of the energy absorbing member 31.

The energy absorbing member 31 thus configured
The displacement side bracket 22 and the displacement side bracket 22 are combined as shown in FIG. That is, the left and right edges of the fixed end portion 34 are
Bending plate portions 24 and 2 that constitute the displacement side bracket 22.
On the inner side surface of 4, the butts are abutted on the front side of the notches 6, 6 slightly forward of the back end, and the abutted portions are welded. In this state, the folded-back portion 32 is located slightly rearward of the deep ends of the notches 6 and 6. Then, between the inner side surface of these folded-back portions 32 and the rear ends of the notches 6 and 6,
A space 35 is formed in which the stud 26 can be inserted.

The energy absorbing member 31 and the displacement side bracket 22 combined as shown in FIG. 8 are the lower surface of the outer column 17 constituting the steering column 1 as shown in FIGS. Then, the displacement side bracket 22 is joined to the lower surface of the outer column 17 by welding. Then, the stud 26 is inserted into the space 35 to form a shock absorbing steering column device. In the state where the shock absorption type steering column device is configured as described above, the folded-back portion 32 is arranged on the rear side of the stud 26 (right side in FIGS. 1 and 2). Also, the extension 33
Is the upper surface of the stud 26 and the displacement side bracket 2
2 extends forward from a gap 36 between the lower surface of the curved plate 23 and the lower surface of the curved plate 23. Further, the fixed end portion 34 is fixed to the displacement side bracket 22 at a portion in front of the stud 26 (on the left side in FIGS. 1 and 2) continuously from the lower end side of the folded portion 32.

The operation of the shock absorbing steering system of the present invention constructed as described above is as follows. At the time of a secondary collision, the forward load transmitted from the steering wheel (not shown) to the steering shaft 2 is impacted on the outer column 17 constituting the steering column 1 via the deep groove type ball bearing 21. Due to this load, the inner peripheral surface of the front end portion of the outer column 17 slides against the outer peripheral surface of the inner column 18, and the entire length of the steering column 1 is shortened. When the total length of the steering column 1 is shortened in this way, the outer column 17 which is a part of the steering column 1 is displaced forward. On the other hand, the support bracket 3 and the stud 26 are not displaced while being supported by the vehicle body. Therefore, when the displacement of the outer column 17 is started, the stud 26 comes out rearward from the notches 6 formed in the displacement side bracket 22 (actually, the stud 26 does not move and the displacement side bracket 22 does not move). Is displaced forward). At the same time, the fixed end portion 34 of the energy absorbing member 31 is pulled forward by the displacement side bracket 22 fixed to the outer column 17.

When the fixed end portion 34 of the energy absorbing member 31 is pulled forward in this manner, the energy absorbing member 3
The folded portion 32 of No. 1 is squeezed by the outer peripheral surface of the intermediate portion of the stud 26, so that the energy absorbing member 31 is plastically deformed. That is, as the displacement side bracket 22 is displaced forward, the folded-back portion 32 is formed from the portion originally formed as shown in FIG. 2 to the tip of the extended portion 33 as shown in FIG. Move towards. In this way, the energy absorbing member 31 is plastically deformed in order to move the folded-back portion 32 toward the tip of the extension portion 33, so that the energy absorption member 31 is applied to the steering wheel from the driver's body in association with the secondary collision. Impact energy is absorbed. As a result, the impact applied to the driver's body is alleviated and the driver is protected.

Particularly, in the case of the shock absorbing type steering column apparatus of the present invention, since the shape of the energy absorbing member 31 is simple, not only the cost of manufacturing the die for punching and forming is low, but also the step of the material is reduced. The stay will be higher. As a result, the cost of the energy absorbing member 31 is reduced. Also, in order to assemble the shock absorbing steering column device, the notch 6,
At the same time as inserting the stud 26 into the 6 and the long holes 7 and 7,
The energy absorbing member 31 can be attached at a predetermined position. Therefore, the assembly work of the shock absorption type steering column device is facilitated, and the cost can be reduced from this aspect.

Next, FIGS. 9 to 10 show second to third embodiments of the present invention. In the first embodiment described above, the width dimension of the extending portion 33 forming the energy absorbing member 31 is not changed over the entire length, whereas in the second to third embodiments, the extending portion is formed. The width dimensions of 33a and 33b are changed in the respective length directions. In this way, each extension 3
By changing the width dimension of 3a, 33b, the energy absorbed by each energy absorbing member 31a, 31b can be changed in accordance with the displacement of the outer column 17 (see FIGS. 1, 2, and 4). That is, as in the case of the first embodiment, the energy absorbing member 31 in which the width dimension of the extending portion 33 does not change is
It absorbs almost constant energy regardless of the displacement of the outer column 17.

On the other hand, as shown in FIG. 9 (A), in the case of a shock absorbing steering column device incorporating an energy absorbing member 31a having an extending portion 33a whose width dimension increases toward the tip, , As shown in FIG.
The energy absorbed increases as the displacement of the outer column 17 increases. On the other hand, as shown in FIG. 10 (A), in the case of an impact absorption type steering column device incorporating an energy absorbing member 31b having an extending portion 33b whose width dimension becomes smaller toward the tip end portion, FIG. As shown in, as the displacement of the outer column 17 increases,
The energy absorbed is small. As described above, in the case of the shock absorbing steering column device of the present invention, the relationship between the progress of displacement and the amount of energy absorbed can be set arbitrarily. On the other hand, in the case of the conventional structure shown in FIGS. 12 to 14, it is only possible to set the amount of energy absorbed to be substantially constant or to gradually increase it as shown in FIG. 9 (B). Is. In other words, in the case of the conventional structure,
As shown in FIG. 10B, it is impossible to set the absorbed energy to be gradually smaller.

Next, FIG. 11 shows a fourth embodiment of the present invention. In the case of the present embodiment, the fixed end portion 34 constituting the energy absorbing member 31c is formed in the middle portion of the outer column 17.
a is directly welded and the displacement side bracket 22 (see FIG. 2) is omitted. A coupling member such as a stud is inserted into a space 35a between the folded-back portion 32 and the fixed end portion 34a that form the energy absorbing member 31c. Other configurations and operations are similar to those of the first to third embodiments described above.

[0029]

Since the shock absorbing steering column device of the present invention is constructed and operates as described above, it is possible to inexpensively obtain a structure capable of alleviating the shock at the time of a secondary collision and effectively protecting the driver. To be

[Brief description of drawings]

FIG. 1 is a side view showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of the right half of FIG.

3 is an enlarged view of the left half of FIG.

4 is a sectional view taken along line AA of FIG.

FIG. 5 is a view similar to FIG. 2 showing a state at the time of a secondary collision.

FIG. 6 is a perspective view of a displacement side bracket.

FIG. 7 is a perspective view of an energy absorbing member.

FIG. 8 is a perspective view showing a state in which a displacement side bracket and an energy absorbing member are connected to each other.

FIG. 9 is a perspective view showing a second embodiment of the energy absorbing member and a diagram showing an energy absorbing characteristic obtained by the energy absorbing member of the second embodiment.

FIG. 10 is a perspective view showing a third embodiment of the energy absorbing member and a diagram showing an energy absorbing characteristic obtained by the energy absorbing member of the third embodiment.

FIG. 11 is a partial side view of a steering column with an energy absorbing member fixed, showing a fourth embodiment of the present invention.

FIG. 12 is a vertical cross-sectional side view of essential parts showing a conventional shock absorption type steering column device.

13 is a sectional view taken along line BB of FIG.

FIG. 14 is a plan view of an energy absorbing member.

[Explanation of symbols]

 1 Steering Column 2 Steering Shaft 3 Support Bracket 4 Support Plate 5 Displacement Side Bracket 6 Notch 7 Long Hole 8 Adjust Bolt 9 Adjust Nut 10 Head 11 Tilt Lever 12 Energy Absorbing Member 13 Support 14 Bent 15 Circular Hole 16 Tongue One piece 17 Outer column 18 Inner column 19 Swing support bracket 20 Roller bearing 21 Ball bearing 22 Displacement side bracket 23 Curved plate part 24 Bending plate part 25 Mounting plate part 26 Stud 27 Flat part 28 Nut 29 Tube part 30 Screw hole 31, 31a , 31b, 31c Energy absorbing member 32 Folding part 33, 33a, 33b Extending part 34, 34a Fixed end part 35, 35a Space 36 Gap

Claims (1)

[Claims] 1. A steering column in which a steering shaft for fixing a steering wheel at a rear end thereof can be inserted, and a steering column which holds the steering column from both left and right sides.
A support bracket having a pair of support plate parts, which is supported and fixed to the vehicle body, through holes formed in each of the support plate parts, and an intermediate part of the steering column is supported by the through holes through the through holes. In a shock absorbing steering column comprising a coupling member coupled to and supported by a bracket, and an energy absorbing member made of a plastically deformable metal plate and provided between the supporting bracket and the steering column. The absorbing member is continuous from the folded-back portion arranged on the rear side of the coupling member and from the upper end side of the folded-back portion, and extends forward from the gap between the upper surface of the coupling member and the lower surface of the steering column. A shock absorbing type steering having an extending portion and a fixed end portion fixed to the steering column continuously from a lower end side of the folding portion. Lamb apparatus.