JPH0924842A - Shock absorbing-type steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a shock absorbing structure of a steering column, and to achieve protection of a driver. SOLUTION: A steering shaft 2 is rotatably supported inside a cylindrical steering column 1. An intermediate part outer peripheral surface of the steering column 1 is supported by supporting brackets 3a, 3a. Supporting cylinders 23 are fixed on the lower ends of respective supporting brackets 3a, 3a. A plurality of projecting parts 24, 24 formed on the inner peripheral surfaces of respective supporting cylinders 23, 23 are brought in elastic contact with the outer peripheral surface of the steering column 1, and the contact parts are frictionalengaged with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The shock absorbing steering system according to the present invention is used for rotatably supporting a steering shaft which constitutes a steering system of an automobile. Further, at the time of a collision, the shock column is displaced in the axial direction while absorbing the impact energy, thereby alleviating the impact applied to the body of the driver who collides with the steering wheel.

[0002]

2. Description of the Related Art A steering apparatus for an automobile transmits the movement of a steering wheel to a steering gear via a steering shaft. Also, the steering shaft is
It is supported by a part of the vehicle body (under the dashboard) via the steering column.

9 to 11 show a first example of a conventional steering device. The steering shaft 2 is rotatably supported inside a cylindrical steering column 1. A steering wheel (not shown) is fixed to the rear end of the steering shaft 2 (the right end in FIGS. 9 to 10) and the front end (see FIGS. 9 to 10).
The left end portion of is connected to the input shaft of the steering gear via the universal joint and the transmission shaft. A pair of support brackets 3, 3 are fixed to the outer peripheral surface of the intermediate portion of the steering column 1 by welding or the like.

Each of the support brackets 3 and 3 is made by press working a metal plate such as a steel plate having sufficient rigidity.
It has a pair of support plate portions 4 and 4 and mounting plate portions 5 and 5 which are bent in opposite directions from the upper ends of the support plate portions 4 and 4, respectively. Further, the lower end edges of the support plate portions 4 and 4 are connected by a semi-cylindrical connecting portion 6, and the inner peripheral surface of the connecting portion 6 abuts against the outer peripheral surface of the steering column 1. The contact surface 7 is used. The curvature of the inner peripheral surface of the abutting surface 7 substantially matches the curvature of the outer peripheral surface of the steering column 1. In the steering column 1, the outer surface of the intermediate portion is welded and fixed to the pair of support brackets 3 and 3, and the mounting plate portions 5 and 5 of the support brackets 3 and 3 are further fixed to the vehicle body by screws (not shown).

In the case of the steering device constructed as described above, the steering column 1 remains fixed to the vehicle body. Reference numeral 8 is a cylinder bracket in which a key cylinder of a steering lock device which is a kind of anti-theft device is mounted.

FIG. 12 shows, as a second example of the conventional steering device, an impact absorption type steering device for alleviating the impact applied to the body of the driver at the time of a secondary collision. In this shock absorbing type steering device, as the steering shaft 2 and the steering column 1, what has a so-called collapsible structure in which the entire length is divided is used. That is, the steering column 1 includes an outer column 9 and an inner column 10 each made of a steel plate in a cylindrical shape.
Combining and in a telescopic manner. The inner peripheral surface of the front end portion of the outer column 9 and the outer peripheral surface of the rear end portion of the inner column 10 are fitted to each other with a predetermined strength. Therefore, the steering column 1 has a sufficiently large bending rigidity, but when a large compressive load (impact load) is applied in the axial direction, the fitting portion slides to reduce its overall length.

Further, the steering shaft 2 can be expanded and contracted over its entire length by fitting the inner peripheral surface of the front end portion of the cylindrical outer shaft 13 and the outer peripheral surface of the rear end portion of the circular rod-shaped inner shaft 14 to each other. I am trying. Further, through holes 15, 1 formed in the front end portion of the outer shaft 13
5 and the recesses 16, 16 formed on the outer peripheral surface of the rear end portion of the inner shaft 14 are filled with synthetic resin 17, 17. When a strong compressive load (impact load) is applied in the axial direction (left and right direction in FIG. 12), the synthetic resin 1
7 and 17 are torn at the boundary between the through holes 15 and 15 and the recesses 16 and 16, and the entire length of the steering shaft 2 is allowed to shrink.

As described above, the shock absorbing steering column constituted by the steering column 1 and the steering shaft 2 supports the intermediate portion of the outer column 9 and the front end portion of the inner column 10 on the vehicle body. For this reason, the rear support bracket 11 is fixed to the middle portion of the outer column 9 by welding, and the inner column 10 is fixed.
The front support bracket 12 is also fixed to the front end of the by welding.

In the shock absorbing type steering device constructed as described above, when a secondary collision occurs in which the driver's body hits the steering wheel in the event of a collision accident, the rear support bracket 11 falls off from the vehicle body, and the outer casing. Allow the column 9 to move forward. Then, the steering column 1 and the steering shaft 2 contract.
At this time, the energy of collision is absorbed. Then, the steering wheel is allowed to be displaced forward (to the left in FIG. 12) to reduce the impact on the body of the driver.

Next, FIGS. 13 to 14 show a steering device having a tilt mechanism for adjusting the height position of a steering wheel as a third example of the conventional steering device. An elevating bracket 19 is welded and fixed to the lower surface of the middle portion of the steering column 1, and a rear supporting bracket 11a is arranged so as to sandwich the elevating bracket 19. The elevating bracket 19 constitutes a tilt mechanism and moves up and down together with the steering column 1 when adjusting the height position of the steering wheel. That is, the elevating bracket 19 is sandwiched from both sides by the rear support bracket 11a fixed to the vehicle body side.
On the other hand, the front end portion (the left end portion in FIG. 13) of the steering column 1 is pivotally supported on the vehicle body by a front support bracket 12a that spans the horizontal shafts 18, 18.

When adjusting the height position of the steering wheel, the lifting bracket 19 is moved in the left-right direction (see FIG. 13).
The tilt bolt 21 that penetrates through the front and back directions, and the left and right direction in FIG. 14) and engages with the elongated hole formed in the rear support bracket 11a is loosened by operating the tilt lever 20. The structure and operation of such a tilt mechanism is well known in the art, and therefore detailed illustration and description thereof will be omitted.

[0012]

Among the steering devices constructed and operated as described above, the steering devices of the first and third examples have a structure in which the steering column 1 does not reduce the total length, and therefore, in the event of a collision accident. The impact energy may not be sufficiently absorbed, which may result in insufficient protection of the driver. In addition, as in the second example, if the collapsible structure in which the entire length of the steering column and the steering shaft is divided in order to sufficiently absorb the impact energy, parts manufacturing, parts management, and assembly work are troublesome. Therefore, the production cost increases. Therefore, it is desired to realize a structure that can sufficiently absorb the impact energy at the time of a collision and sufficiently protect the driver even if the steering column and the steering shaft are not divided. The shock absorbing steering device of the present invention has been invented in view of such circumstances.

[0013]

SUMMARY OF THE INVENTION A shock absorbing steering system according to the present invention comprises a steering column which is formed in a cylindrical shape and which does not shorten the entire length, and a steering column which is rotatably supported inside the steering column. A steering shaft for fixing a steering wheel to a rear end portion protruding from a rear end opening of the column, and a support bracket fixed to the vehicle body while supporting the steering column. Then, by displacing the steering column in the axial direction at the time of a collision, the impact energy applied to the steering wheel is absorbed.

Particularly, in the shock absorbing type steering device of the present invention, the support bracket has a cylindrical portion at the lower end thereof, and the inner peripheral surface of the cylindrical portion is opposed to the inner peripheral surface. A protrusion is formed on at least one of the outer peripheral surface of the portion that moves together with the steering column. The intermediate portion of the steering column is supported by the lower end portion of the support bracket by elastically abutting the protrusion on the opposite peripheral surface.

[0015]

The operation of the shock absorbing steering system of the present invention constructed as described above to rotatably support the steering shaft is similar to that of the conventional steering system described above. Particularly, in the case of the shock absorbing steering device of the present invention, a cylindrical portion is provided at the lower end of the support bracket,
Since the inner peripheral surface of the cylindrical portion and the outer peripheral surface facing the inner peripheral surface are elastically abutted by the plurality of protrusions, it is not necessary to form a collapsible structure in which the steering column and the steering shaft are divided. Also, the steering column can be displaced forward in the case of a secondary collision. During the forward displacement, frictional engagement between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the steering column can sufficiently absorb the impact energy associated with the secondary collision. Therefore, the driver can be sufficiently protected in the case of a secondary collision. Further, the manufacturing cost can be reduced by simplifying the parts manufacturing, the parts management, and the assembly work.

[0016]

1 and 2 show a first embodiment of the present invention. A feature of the present embodiment is that an impact absorption type steering device integrated with a steering column is configured which can sufficiently absorb impact energy at the time of a collision without forming a steering column and a steering shaft as a separate structure. Since the configuration and operation of the other parts are the same as those of the first example of the conventional structure described above, the description of the equivalent parts will be omitted or simplified, and the characteristic part of the present embodiment will be mainly described below.

At a lower end portion of a pair of front and rear support brackets 3a, 3a for supporting the steering column 1 at two front and rear positions, a support cylinder 2 corresponding to a cylindrical portion in the claims is provided.
3 and 23 are fixed by welding. The steering column 1 is press-fitted inside the support cylinders 23, 23. That is, each of the support brackets 3a, 3
The lower end edges of the pair of left and right support plate portions 4 and 4 forming a are connected to each other by a semi-cylindrical connecting portion 6 protruding downward. And each support bracket 3a, 3a
The abutting surface 7 which is the inner peripheral surface of the connecting portion 6 at the lower end of the
Further, the outer peripheral surfaces of the lower half portions of the support cylinders 23, 23 are fixed by welding. Each of the support cylinders 23, 23 is formed into a short cylindrical shape as a whole by, for example, rolling a steel pipe and then cutting it into a predetermined length. On the inner peripheral surface of the support cylinders 23, 23 thus manufactured, a plurality of protrusions 24, 24 each long in the axial direction (the left-right direction in FIG. 1, the front and back directions in FIG. 2) are provided inward in the diametrical direction. Is formed so as to project toward.
The diameter of the inscribed circle of the tip edges of the plurality of protrusions 24, 24 in the free state is smaller than the diameter of the steering column 1. Therefore, when the steering column 1 is press-fitted into the support cylinders 23, 23, the outer peripheral surface of the intermediate portion of the steering column 1 has the plurality of protrusions 24,
24 is elastically abutted, and the abutting portion frictionally engages. In this state, the steering column 1 is supported by the lower ends of the pair of support brackets 3a, 3a.

In the shock absorbing steering system of the present invention constructed as described above, a strong compressive (shock) load is applied to the steering shaft 2 in the axial direction due to the secondary collision of the driver hitting the steering wheel. When the steering column 1 is added, the outer peripheral surface of the steering column 1 and the support cylinders 23, 2
The contact portion 3 with the inner peripheral surface moves forward while moving away the impact energy at the time of collision (to the left in FIG. 1). As a result, the driver who hits the steering wheel is protected. That is, as described above, the plurality of protrusions 24, 24 formed on the inner peripheral surface of each of the support cylinders 23, 23 elastically contact the outer peripheral surface of the steering column 1 facing each other, so that the contact portion is rubbed. Engaged. Therefore, the compression load allows the abutment portion to slip in the axial direction and allows the steering column 1 to be displaced forward. Then, the sliding friction absorbs the impact energy applied to the steering column 1. Therefore, the impact applied to the body of the driver hit by the steering wheel fixed to the rear end of the steering shaft 2 rotatably supported by the steering column 1 is alleviated. In the illustrated embodiment, the projections 24, 24 are formed at four locations in the circumferential direction, but the locations where the projections 24, 24 are formed are increased or the projections 24, 24 are widened. As a result, the area of contact (contact) with the outer peripheral surface of the steering column 1 can be increased, and even greater impact energy can be absorbed.

Next, FIG. 3 shows a second embodiment of the present invention. In the case of the present embodiment, the cylindrical sleeve 27 is fitted onto the outer peripheral surface of the intermediate portion of the steering column 1, and
The sleeve 27 is fixed to the steering column 1 by welding. Further, a plurality of protrusions 2 are formed on the outer peripheral surface of the sleeve 27.
4a and 24a are formed to project outward in the diametrical direction. On the other hand, a cylindrical portion 22 is provided at the lower end of the support bracket 3b.
As shown in FIG. 3, the support plates 4 and 4 are formed by bending the intermediate part inward. The inner diameter of the cylindrical portion 22 in the free state is smaller than the diameter of the circumscribed circle of the plurality of protrusions 24a, 24a formed on the outer peripheral surface of the sleeve 27. In the assembled state of the shock absorbing steering device, the cylindrical portion 22 holds down the outer peripheral surface of the sleeve 27 welded and fixed to the intermediate portion of the steering column 1.
Therefore, the steering column 1 includes the tip ends of the protrusions 24a, 24a formed on the outer peripheral surface of the sleeve 27 fitted on the steering column 1 and the inner periphery of the cylindrical portion 22 formed on the lower end of each support bracket 3a. The support brackets 3b are supported in a state where the surfaces are elastically brought into contact with each other and the contact portions are frictionally engaged with each other. The axial length of the sleeve 27 is set to be sufficiently larger than the length of the support bracket 3b so that the steering column 1 is displaced forward.
The protrusions 24a, 24a and the cylindrical portion 22 are frictionally engaged with each other. Other configurations and operations are similar to those of the above-described first embodiment.

Next, FIG. 4 shows a third embodiment of the present invention. In the case of the present embodiment, the sleeve 27 (FIG. 3) is omitted, and a plurality of protrusions 24a, 24a are directly formed on the outer peripheral surface of the steering column 1 in the axial direction. The plurality of protrusions 24a, 24a formed on the outer peripheral surface of the steering column 1 and the inner peripheral surface of the cylindrical portion 22 formed on the lower end of the support bracket 3b are elastically brought into contact with each other. Other configurations and operations are the same as in the above-described second embodiment.

Next, FIG. 5 shows a fourth embodiment of the present invention. In the case of this embodiment, the steering column 1 in which the projections 24a, 24a are directly formed on the outer peripheral surface is used as in the third embodiment described above. Also, the support bracket 3
A support cylinder 23a corresponding to a cylindrical portion is welded and fixed to the lower end of c. The tip edges of the protrusions 24a, 24a are elastically brought into contact with the inner peripheral surface of the support cylinder portion 23a. This support cylinder 23a is provided with a support bracket 3c.
Is welded and fixed to the lower surface of the connecting portion 6a that is curved in an arc shape and that connects the support plate portions 4 and 4 forming the above. Other configurations and operations are similar to those of the third embodiment described above.

Next, FIGS. 6 to 7 show a fifth embodiment of the present invention. In the case of the present embodiment, the support bracket 3a has the same structure as that of the first embodiment described above, and the one support bracket 3d has the conventionally known structure to support the steering column 1, respectively. That is, the front end side (the left end side in FIGS. 6 to 7) of the steering column 1 is supported by the support bracket 3a to which the support cylinder 23 corresponding to the cylindrical portion is fixed by welding. Also, steering column 1
The mounting plate portions 5 and 5 that form the support bracket 3d that supports the rear end side (the right end side in FIGS. 6 to 7) are provided with notches 25 and 25 that open to the rear end edges, respectively. The sliding plates 26, 2 are formed on the portions where the notches 25, 25 are formed.
6 is locked. The rear end of the steering column 1
By bolting bolts (not shown) through which the sliding plates 26, 26 are inserted into screw holes provided in the vehicle body and further tightening,
It is supported by the car body.

At the time of a secondary collision resulting from a collision accident, the driver bumps into the steering wheel and the steering shaft 2
When a compressive load is applied in the axial direction (FIGS. 6 to 7), the engagement between the notches 25, 25 formed in the support bracket 3d at the rear end of the steering column 1 and the sliding plates 26, 26 is released, The steering column 1 moves axially left. The front outer peripheral surface of the steering column 1 and the projections 24, 24 formed on the inner peripheral surface of the support cylinder 23 corresponding to the cylindrical portion are frictionally engaged with each other, so that the compression acting on the steering column 1 in the axial direction is performed. While absorbing the impact energy of the load,
This steering column 1 is allowed to move forward. As a result, the driver can be protected.

Next, FIG. 8 shows a sixth embodiment of the present invention. In the case of the present embodiment, the present invention is applied to a steering device incorporating a tilt mechanism for adjusting the height position of the steering wheel. In this embodiment, the support cylinder 23 having the structure shown in the first embodiment is welded and fixed to the front support bracket 12a pivotally supported by the horizontal shafts 18, 18. That is, the support cylinder 23 corresponding to the cylindrical portion is welded and fixed to the front support bracket 12a,
The outer peripheral surface of the steering column 1 and the protrusions 24 formed on the inner peripheral surface of the support cylinder 23 are elastically brought into contact with each other.
The rear support bracket 11a (FIG. 13) that supports the rear portion of the steering column 1 so as to be able to move up and down is supported by the vehicle body in the same structure as in the fifth embodiment. Alternatively, the rear support bracket 11a may be fixed to the vehicle body, and the lift bracket 19 may be supported to the rear support bracket 11a such that it can be displaced forward. Other configurations and operations are similar to those of the first embodiment described above.

[0025]

Since the shock absorbing steering column of the present invention is constructed and operates as described above, it has a simple structure and a small number of parts. It is possible to effectively protect the driver by preventing a large impact on the driver's body.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a view similar to FIG. 2, showing a second embodiment of the present invention.

FIG. 4 is a view similar to FIG. 2, showing a third embodiment of the present invention.

FIG. 5 is a view similar to FIG. 2, showing a fourth embodiment of the present invention.

FIG. 6 is a plan view showing a fifth embodiment of the present invention in a normal state.

FIG. 7 is a plan view similarly showing a state after a collision.

FIG. 8 is a view similar to FIG. 14, showing a sixth embodiment of the present invention.

FIG. 9 is a plan view showing a first example of a conventional structure.

FIG. 10 is a side view of the same FIG. 9.

FIG. 11 is a sectional view taken along line BB of FIG. 10;

FIG. 12 is a partial cross-sectional view showing a second example of the conventional structure.

FIG. 13 is a partial cross-sectional view showing a third example of the conventional structure.

14 is a cross-sectional view taken along line CC of FIG.

[Explanation of symbols]

 1 Steering column 2 Steering shaft 3, 3a, 3b, 3c, 3d Support bracket 4 Support plate part 5 Mounting plate part 6, 6a Connecting part 7 Abutment surface 8 Cylinder bracket 9 Outer column 10 Inner column 11, 11a Rear support bracket 12 , 12a Front support bracket 13 Outer shaft 14 Inner shaft 15 Through hole 16 Recess 17 Synthetic resin 18 Horizontal shaft 19 Lifting bracket 20 Tilt lever 21 Tilt bolt 22 Cylindrical part 23, 23a Support cylinder 24, 24a Projection 25 Cutout 26 Sliding plate 27 Sleeve

Claims (1)

[Claims] 1. A steering column, which is formed in a cylindrical shape and does not reduce its overall length, and a steering wheel, which is rotatably supported only inside the steering column and projects from a rear end opening of the steering column. And a support bracket fixed to the vehicle body while supporting the steering column, and absorbing the impact energy applied to the steering wheel by axially displacing the steering column at the time of a collision. In the shock absorbing steering device, the support bracket has a cylindrical portion at the lower end thereof, and an inner peripheral surface of the cylindrical portion and an outer peripheral surface of a portion which faces the inner peripheral surface and moves with the steering column. A projection is formed on at least one of the peripheral surfaces of the A shock absorbing steering device characterized in that an intermediate portion of the steering column is supported by a lower end portion of the support bracket by elastically contacting the steering column.