JP2004074932A - Shock absorbing type steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive shock absorbing type steering device capable of surely absorbing a shock when a vehicle collides and bottoms. <P>SOLUTION: A suspension spring bracket 10 is fixed to an outer circumference of an outer cylinder 8 of a lower column tube 7 by, for example, welding. The suspension spring bracket 10 is provided with a pair of arms 11 projecting toward both sides of the lower column tube 7. Each arm 11 has a projection 20 projecting toward the lower fixed bracket 12. When the vehicle collides and bottoms, the projections 20 and the end wall 14 of the lower fixed bracket 12 abut each other and the arms 11 deform to absorb the shock energy. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a shock absorbing device applied to a steering device of a vehicle.
[0002]
[Prior art]
2. Description of the Related Art Some vehicle steering devices include a steering column including a lower column tube fixed to a vehicle body and an upper column tube swingably fixed to the vehicle body. A steering shaft is rotatably supported inside the steering column, and the steering shaft housed on the lower column tube side and the steering shaft housed on the upper column tube side are connected via a universal joint. ing.
[0003]
Thus, the upper column tube and the steering shaft housed on the upper column tube side can be swung with respect to the vehicle body, and the tilt of the steering wheel can be adjusted.
Further, the above-mentioned steering device is capable of reducing as much as possible impact force applied to the driver when the driver collides with the steering wheel due to a vehicle collision or the like, thereby reducing damage to the driver. A possible shock absorber is provided. For example, the lower column tube is configured to include an inner cylinder fixed to the vehicle body via a lower fixing bracket, and an outer cylinder fitted to the inner cylinder. The impact energy is absorbed by the force, and the impact force applied to the driver is reduced.
[0004]
However, for example, when the distance over which the outer cylinder can slide with respect to the inner cylinder (shock absorption stroke) is short, the outer cylinder may reach the lower fixing bracket (bottom out).
[0005]
[Problems to be solved by the invention]
Therefore, an annular bottom bumping member formed by welding a rubber spacer to a metal plate is fitted to the lower column tube so as to be in contact with the lower fixing bracket, and at the time of bottom bumping, the bottom bumping member is brought into contact with the outer cylinder, It is conceivable to buffer the impact at the time of bottom strike.
However, according to the shock absorbing device having the above-described configuration, since the bottom bumping member made of the composite component is provided, there is a concern that the manufacturing cost is increased due to an increase in component cost and assembly cost.
[0006]
In order to increase the energy absorbed by the inner and outer cylinders when they slide, it is conceivable to expand a part of the inner cylinder of the lower column tube. However, even in the case of the expansion, the manufacturing cost is increased.
The present invention has been made under such a background, and an object of the present invention is to provide an inexpensive shock-absorbing steering device capable of reliably cushioning an impact at the time of bottom collision.
[0007]
Means for Solving the Problems and Effects of the Invention
According to a first aspect of the present invention, there is provided a steering column including a lower column tube and an upper column tube which are flexibly connected to each other, and an adjustable steering column including a lower column tube fixed to a vehicle body. A lower fixing bracket, a suspension spring bracket fixed to the lower column tube and moving relative to the lower fixing bracket at the time of a vehicle collision, and a suspension spring for supporting a part of the load of the steering column, One end of the suspension spring is engaged with the engagement portion of the suspension spring bracket, and the other end is engaged with the upper column tube or a member fixed to the upper column tube. This shock absorbing part abuts against the lower fixing bracket during a vehicle collision and undergoes plastic deformation. A shock absorbing steering apparatus characterized by absorbing the impact energy by.
[0008]
ADVANTAGE OF THE INVENTION According to this invention, at the time of a vehicle collision, it is possible to absorb a shock energy by the shock absorption part of the bracket for suspension springs, and to reduce bottoming. For this reason, the conventional bottom bumping member provided exclusively can be abolished, and the manufacturing cost can be remarkably reduced through reduction of component cost and assembly cost.
The invention according to claim 2 is the shock absorbing steering device according to claim 1, wherein the shock absorbing portion includes a cantilevered arm projecting to both sides of the lower column tube.
[0009]
According to the present invention, the same effect as that of the first aspect can be obtained. Furthermore, if the arm is cantilevered, the deformation load at the time of absorbing the impact can be easily set as desired. According to a third aspect of the present invention, in the shock absorbing steering device according to the second aspect, the arm has a protruding portion that protrudes to a lower side from a fixing portion of the suspension spring bracket to the lower column tube. is there.
According to the present invention, the same effects as those of the invention described in claim 2 can be obtained. Further, at the time of a vehicle collision, the arm can be deformed with a desired deformation load by bringing the protruding portion into contact with the lower fixing bracket.
[0010]
According to a fourth aspect of the present invention, in the first to third aspects, the distance between the lower fixing bracket and the impact absorbing portion in the axial direction of the lower column tube substantially corresponds to an impact energy absorbing stroke at the time of a vehicle collision. It is a shock-absorbing steering device characterized by the following.
According to the present invention, the effects of the inventions of claims 1 to 3 can be made effective by setting the distance between the lower fixing bracket and the shock absorbing portion in the axial direction of the lower column tube.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings. FIG. 1 is a schematic plan view showing a schematic configuration of a shock absorbing steering device 1 according to an embodiment of the present invention, and FIG. 2 is a front view showing a part of the shock absorbing steering device 1 of FIG. .
Referring to FIG. 1, an impact-absorbing steering device 1 includes a steering column 3 rotatably supporting a steering shaft 2 to which a steering wheel (not shown) is fixed at one end. The other end 4 of the steering shaft 2 is connected to an intermediate shaft (not shown) that is connected to the steering shaft 2 so as to be integrally rotatable. As a result, the turning force of the turning operation of the steering wheel is transmitted to a steering mechanism (not shown) including a pinion, a rack shaft, and the like via the steering shaft 2 and the intermediate shaft to steer the wheels. Is possible.
[0012]
In the shock absorbing steering device 1 according to the present embodiment, when a vehicle collides, the impact disengages the holding piece 5 and the holding piece 6 having a so-called capsule structure, and as shown in FIG. The outer tube 8 of the lower column tube 7 provided on the lower column tube 7 slides relative to the inner tube 9 of the lower column tube 7 on the lower side (in the direction of the white arrow in FIG. 3), and the frictional force of this sliding causes the impact energy It is designed to absorb.
[0013]
Further, when the impact due to the collision of the vehicle is large and the sliding of the outer tube 8 of the lower column tube 7 does not stop, as shown in FIG. 4, a pair of impact absorbing portions provided on the suspension spring bracket 10 is provided. Arm 11 is in contact with the lower fixing bracket 12 and is plastically deformed to absorb the remaining impact energy.
For details of the above-described holding pieces 5 and 6, the lower column tube 7, the outer cylinder 8 of the lower column tube 7, the inner cylinder 9 of the lower column tube 7, the suspension spring bracket 10, the arm 11, and the lower fixing bracket 12, It will be described later.
[0014]
With reference to FIG. 1, the steering column 3 includes the above-described lower column tube 7 arranged on the front side of the vehicle, and an upper column tube 13 arranged behind the lower column tube 7. The tubes 7 and 13 are concentric and are arranged in the axial direction of the tubes 7 and 13.
The lower column tube 7 includes the inner cylinder 9 and the outer cylinder 8 as described above, and the inner cylinder 9 is press-fitted into the outer cylinder 8 with a predetermined press-fit load.
[0015]
Referring to FIG. 2, an outer peripheral surface of the inner cylinder 9 of the lower column tube 7 is formed in an angle shape having an end wall 14 and a top plate 15 near the other end 4 of the steering shaft 2. The above-mentioned lower fixing bracket 12 (a cross section of the lower fixing bracket 12 is shown in FIG. 2) is fixed by, for example, welding. Referring to FIG. 1, a pair of mounting holes 16 are formed through the top plate portion 15 of the lower fixing bracket 12, respectively. Is fixed to the vehicle body 17 (a part is shown by a dashed line in FIG. 2).
[0016]
Referring to FIG. 1 again, the above-mentioned suspension spring bracket 10 is fixed to the outer cylinder 8 of the lower column tube 7 on the outer peripheral surface of one end 18 on the side where the inner cylinder 9 is press-fitted, for example, by welding. . The suspension spring bracket 10 includes a fixing portion 19 that is welded to the outer cylinder 8 of the lower column tube 7, and the above-described pair of arms 11 that project from the fixing portion 19 to both sides of the lower column tube 7. I have.
Each arm 11 is provided with a protruding portion 20 that protrudes from the one end 18 of the outer cylinder 8 of the lower column tube 7 to the lower side (the lower fixing bracket 12 side). Each arm 11 is formed with a recessed engaging portion 21 adjacent to the outer side of each projecting portion 20, and a part of the load of the steering column 3 is applied to each engaging portion 21. One end 23 of the suspension spring 22 for receiving the spring is engaged.
[0017]
On the other hand, an upper bracket 25 is fixed to the other end 24 of the outer cylinder 8 of the lower column tube 7 by, for example, welding. The upper bracket 25 is mounted on the vehicle body via a pair of right and left mounting bodies 26.
Each attachment body 26 is called a so-called capsule, and has the above-described holding pieces 5 and 6. The holding piece 6 is formed with a pair of mounting holes 27 penetrating therethrough, and the screws 40 inserted into the mounting holes 27 are screwed into the screw holes of the vehicle body, so that the holding piece 6 is attached to the vehicle body (not shown). )).
[0018]
On the other hand, the upper column tube 13 includes a cylindrical portion 28 and an engaging portion 29 for engaging the suspension spring 22.
The cylindrical portion 28 is connected to the outer tube 8 of the lower column tube 7 via a support shaft (not shown) penetrating the cylindrical portion 28 and the outer tube 8 of the lower column tube 7. Swing (bending with respect to the lower column tube 7) around the support shaft is possible. Further, the shock absorbing steering device 1 is provided with an operation lever 30 for performing a tilt lock and a release of the tilt lock. By rotating the operation lever 30 to release the tilt lock, The tilt adjustment can be performed by swinging the cylindrical portion 28.
[0019]
The engagement portion 29 is provided at the lower end of the cylindrical portion 28 and has a pair of engagement holes 31 formed therein. The other end 32 of the suspension spring 22 described above is engaged with the pair of engagement holes 31.
The above is the configuration of the shock absorbing steering device 1 according to the present embodiment. Next, a case where impact energy is applied to the impact absorbing steering device 1 due to a vehicle collision will be described. When the vehicle collides, an impact load resulting from a collision of the driver with the steering wheel or the like is applied to a mounting portion between the upper bracket 25 and a vehicle body (not shown). If the impact load is equal to or more than a certain value, the engaging member 50 connecting the holding piece 5 and the holding piece 6 is sheared, and a part of the impact energy is absorbed. At the same time, the upper bracket 25 comes off the vehicle body, and the outer cylinder 8 of the lower column tube 7 slides relative to the inner cylinder 9 as shown in FIG. 3, and the shock energy is further absorbed by the friction caused by the relative sliding. Is done.
[0020]
On the other hand, referring to FIG. 1, the distance A until the protruding portion 20 of the suspension spring bracket 10 fixed to the outer cylinder 8 of the lower column tube 7 and the end wall 14 of the lower fixing bracket 12 abuts on each other, Since the length of the outer cylinder 8 of the lower column tube 7 is substantially slidable, the distance A substantially corresponds to the impact energy absorbing stroke.
Referring to FIG. 3, when the impact energy at the time of a vehicle collision is large and the outer cylinder 8 of the lower column tube 7 slides with respect to the inner cylinder 9 by a distance A cannot absorb the impact energy. The projection 20 of the arm 11 of the suspension spring bracket 10 abuts on the end wall 14 of the lower fixing bracket 12. Next, referring to FIG. 4, arm 11 is plastically deformed by contact with end wall 14 of lower fixing bracket 12, and the remaining impact energy is absorbed.
[0021]
According to the present embodiment, at the time of a vehicle collision, it is possible to absorb the impact energy by the pair of arms 11 which are the impact absorbing portions of the suspension spring bracket 10 and reduce the bottom butt. For this reason, the conventional bottom bumping member provided exclusively can be abolished, and the manufacturing cost can be remarkably reduced through reduction of component cost and assembly cost.
Further, since each arm 11 is formed in a cantilever shape, it is easy to set a desired deformation load when absorbing an impact. Furthermore, since the projections 20 are provided on each of the arms 11, the projections 20 can be brought into contact with the end walls 14 of the lower fixing bracket 12 at the time of a collision of the vehicle, so that the arms can be deformed with a desired deformation load. It is.
[0022]
Further, by setting the distance A in the axial direction of the lower column tube 7 between the end wall 14 of the lower fixing bracket 12 and the projecting portion 20 of the arm 11 as an impact absorbing portion, the effect of the impact absorbing portion buffering impact energy can be obtained. It can be effective.
Note that the present invention is not limited to the above embodiment.
For example, in the present embodiment, the lower column tube 7 has been described as a configuration including two cylinders of the outer cylinder 8 and the inner cylinder 9, but the invention is not limited thereto, and the lower column tube 7 may be configured of a single cylinder. . In this case, the outer cylinder 8 slides relatively to the inner cylinder 9 by providing a cutout or the like in the cylinder and setting the lower column tube 7 to be compressed in the axial direction at the time of a vehicle collision. It is possible to achieve the same effect as described above. Furthermore, since only one cylinder is required to form the lower column tube 7, the present invention can be implemented at lower cost.
[0023]
Further, the configuration in which the projecting portion 20 is provided on the arm 11 of the suspension spring bracket 10 has been described. However, the present invention is not limited to this, and the arm 11 may be bent to the lower side without providing the projecting portion 20. In this case, there is no need to provide the projecting portion 20 on the arm 11, and the present invention can be implemented at lower cost.
In addition, the present invention can be variously modified within the scope of the claims.
[Brief description of the drawings]
FIG. 1 is a schematic plan view illustrating a schematic configuration of a shock absorbing steering device according to an embodiment of the present invention.
FIG. 2 is a front view showing a part of the shock absorbing steering device of FIG.
FIG. 3 is a schematic plan view showing a state where an outer cylinder of a lower column tube slides due to an impact due to a vehicle collision.
FIG. 4 is a schematic plan view showing a state in which the projection of the arm of the suspension spring bracket and the lower fixing bracket are in contact with each other and the arm is deformed.
[Explanation of symbols]
3 Steering Column 7 Lower Column Tube 10 Bracket for Suspension Spring 11 Arm 12 Lower Fixing Bracket 14 End Wall 20 Projection A Distance

Claims (4)

A tilt-adjustable steering column including a lower column tube and an upper column tube flexibly connected to each other;
A lower fixing bracket fixed to the vehicle body for mounting the lower column tube,
A suspension spring bracket fixed to the lower column tube and relatively moved with respect to the lower fixing bracket at the time of a vehicle collision,
With a suspension spring to support part of the load on the steering column,
One end of the suspension spring is engaged with an engagement portion of the suspension spring bracket, and the other end is engaged with an upper column tube or a member fixed to the upper column tube,
The suspension spring bracket is provided with a shock absorbing portion,
The shock absorbing steering device is characterized in that the shock absorbing portion absorbs shock energy by abutting against a lower fixing bracket and being plastically deformed during a vehicle collision. 2. The shock absorbing steering device according to claim 1, wherein the shock absorbing portion includes a cantilevered arm projecting to both sides of the lower column tube. 3. The shock absorbing steering device according to claim 2, wherein the arm has a protruding portion that protrudes to a lower side from a fixing portion of the suspension spring bracket to the lower column tube. 4. The shock absorbing steering apparatus according to claim 1, wherein an axial distance between the lower fixing bracket and the shock absorbing portion in the axial direction of the lower column tube substantially corresponds to a shock energy absorbing stroke at the time of a vehicle collision. .

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