JP2978788B2 - Automotive steering column - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering column for a motor vehicle, and more particularly, to reducing the number of parts and the number of assembling steps and the cost based thereon.

[0002]

2. Description of the Related Art A steering column for an automobile is a device for steering a steered wheel of an automobile. Generally, a jacket tube for rotatably supporting a steering shaft having a steering wheel mounted on an upper end portion around the axis is generally used. A substantially middle portion is fixed to the vehicle body with an upper bracket and a lower end is fixed to a vehicle body with a lower bracket. The lower end of the steering shaft is connected to the intermediate shaft, and the intermediate shaft is connected to the steering gear box.

[0003] By the way, in the event of an automobile collision, the front part of the vehicle body retreats, so that the steering wheel protrudes toward the driver through the intermediate shaft and the steering column (rear projection of the steering wheel due to a primary collision), or In order to prevent the driver occupant from moving forward and colliding with the steering wheel (secondary collision) due to the reaction due to the collision of the vehicle body, the steering column absorbs the movement stroke due to the primary collision, and the steering column is a shaft. A structure that contracts in the direction is employed.

[0004] As is well known, in order to absorb the movement stroke in the primary collision, the stroke is absorbed by contracting the intermediate shaft in the axial direction. Further, a stopper is provided on the steering column so that the steering wheel does not protrude toward the driver. The contraction of the steering column in a secondary collision
In addition to providing an energy absorbing member, the jacket tube and the steering shaft are divided into an upper part and a lower part, and their one ends are coaxially and axially contractible. Furthermore, when a driver collides with the steering wheel, the upper bracket is disengaged from the vehicle body because the steering column contracts in the axial direction.

[0005]

However, the conventional steering column has a contraction function at a predetermined load or more, so that the number of components is large and the number of assembly steps is increased, and the stroke load is required to be stabilized. Since high accuracy is required in the joint, the cost has been increased.

A mounting member for the steering column on the vehicle body side, a stopper for preventing the steering wheel from protruding to the driver's side during a primary collision, and an energy absorbing member for a secondary collision are separately formed. Therefore, the number of parts is large and the cost is high.

Accordingly, the present invention provides a steering column capable of reducing the number of parts and reducing the cost.

[0008]

In a steering column for an automobile according to the present invention, a lower bracket and an upper bracket fixed to a vehicle body are attached to a lower end portion and a substantially intermediate portion of a jacket tube as described in claim 1, In an automobile steering column in which a steering shaft capable of axially contracting is penetrated and is rotatably supported around a center of the shaft through a bearing, the upper bracket includes a vehicle body mounting portion, and a vehicle body front side of the vehicle body mounting portion. A front wall portion hanging vertically from both sides, and a column mounting portion extending substantially perpendicularly from the front wall portion to the rear side of the vehicle body and reaching the side surface of the jacket tube, are integrally formed, The bent part between the vehicle body mounting part and the front wall part is
Formed by the inclined slope portion and two bent portions Te, and is characterized by forming a predetermined gap between the upper and the vehicle body mounting portion of the column mounting portion. Also, according to claim 2
As described above, the lower bracket is a plate body having a vehicle body mounting portion.
A window hole is formed in the jacket tube.
Through the window hole and
At the lower left and right sides of the jacket tube
Bends that project forward or rearward
The steering column for an automobile according to claim 1, wherein:

Therefore, at the time of a primary collision, the column mounting portion abuts against the vehicle body mounting portion to prevent rearward projection, and at the time of a secondary collision, the bent portion of the upper bracket is deformed to absorb energy.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
It will be described based on. The steering column 1 has an upper bracket 4 connected to a substantially middle portion of a single jacket tube 3 having a lower bracket 2 connected to a lower bracket 2, and a steering shaft 5 penetrates through the inside of the jacket tube 3. A steering wheel (not shown) is connected to the upper end, and an intermediate shaft 6 is connected to the lower end.

In the jacket tube 3, a bearing 7 is fixed to the inner peripheral surface at the upper end, and the lower end is enlarged in diameter, and the bearing 8 is fixed to the inner peripheral surface in front of the lower end. The steering shaft 5 is supported on these bearings 7 and 8. The steering shaft 5 comprises an upper shaft 9 having a partially oval cross section projecting from the upper end of the jacket tube 3 at the upper end, and a lower shaft 10 having a similar cross section is provided at the lower end of the shaft 9.
Are fitted with a predetermined length. The fitting portion is configured such that a resin or the like is interposed between the upper shaft 9 and the lower shaft 10 so that the lower shaft 10 can be contracted into the upper shaft 9 with a predetermined load or more.

As shown in FIG. 2, the lower bracket 2 is formed such that the upper edge of a plate having a window hole 12 into which the jacket tube 3 is loosely fitted is inclined obliquely rearward and both right and left ends thereof are bent in the orthogonal direction. A body mounting portion 14 having a reinforcing flange 13 is formed, and the jacket tube 3 is fixed at a welded portion 15 perpendicularly to the lower inner peripheral edge of the window hole 12 and the lower edge is bent in an orthogonal direction. It has a reinforcing flange 16. The jacket tube 3 can cope with a tilt operation of the steering column 1 by bending and deforming the central portion 11 of the plate body. Since the tilt angle of the steering column is small, the lower bracket 2 does not break due to elastic deformation.

As shown in FIG. 3, the upper bracket 4 includes a vehicle body mounting portion 17 and a vehicle front portion of the vehicle body mounting portion 17.
Front wall portions 18, 18 hanging vertically from both sides of the side ,
The column mounting portion 1 extends substantially perpendicularly from the inside of the front wall portion 18 to the rear side of the vehicle body and reaches the side surface of the jacket tube 3.
9 are integrally formed, and a bent portion 20 is formed by bending a portion between the vehicle body mounting portion 17 and the front wall portion 18 at a predetermined curvature, and the bent portion 20 is bent and deformed by a load of a predetermined load or more. It is possible. A predetermined gap α is formed between the upper part of the column mounting portion 19 and the vehicle body mounting portion 17.

A square hole 21 is formed in the column mounting portion 19 in a vertical direction, and a tightening bolt 22 is inserted through the square holes 21 and 21. The tightening bolt 22 has a head 22a fixed to a detent member 23 fitted into the square hole 21, and a nut 24 is screwed into the screw portion 22b. The nut 24 is fixed to a tilt lever 25, and a fastening member 26 which is engaged with the square hole 21 and is prevented from rotating is interposed between the nut 24 and the column mounting portion 19. A distance bracket 27 through which the tightening bolt 22 penetrates is fixed to the lower surface of the jacket tube 3 by welding, and the distance bracket 27 is configured to be vertically movable between the column mounting portions 19 to form a tilt mechanism. .

Therefore, when the nut 24 is rotated by rotating the tilt lever 25 downward, the column mounting portions 19, 19, which press the distance bracket 27 between the nut 24 and the head 22a of the tightening bolt 22, are formed. By loosening and releasing the tightening of the distance bracket 27,
The distance bracket 27 can be moved up and down. Therefore, when the jacket tube 3 is brought into a desired inclined state via the steering wheel, the jacket tube 3 can be turned up and down around the joint with the lower bracket 2. Since the maximum tilt angle is small, the lower bracket 2 does not elastically deform and break.

When the tilt lever 25 is returned to the original state, the set tilt is locked. In other words, the distance bracket 27 is clamped between the head 22a of the tightening bolt 22 and the nut 24 and tightened, whereby the distance bracket 27 is attached to the column mounting portions 19,19.
It is fixed by friction between them.

Next, the steering column 1 having the above-described structure will be described.
In the case of a primary collision, when the front part of the vehicle body retreats and thereby the jacket tube 3 moves rearward in the vehicle body, the front wall parts 18 and 1 of the upper bracket 4
8 is pushed rearward, the upper end of the column mounting portion 19 moves through the gap α and abuts against the lower surface of the vehicle body mounting portion 17 to stop the rearward movement of the jacket tube 3.

Further, at the time of a secondary collision, when a load of the driver is applied to the steering wheel, the jacket tube 3 moves forward of the vehicle body, and the bent portions 20, 20 of the upper bracket 4 are deformed in the opening direction. In addition to absorbing energy, the lower bracket 2 is deformed to absorb the stroke of the jacket tube 3 in the axial direction.

In addition, the vehicle body mounting portion 1 of the lower bracket 2
If the distance from the welding tube 4 to the welded portion 15 of the jacket tube 3 cannot be sufficiently secured and is short, the necessary stroke at the time of the secondary collision cannot be secured, and therefore, as shown in FIG. It is also possible to separate them into two and form folded portions 30, 30 with a radius in the vicinity thereof. Further, the shape of the folded portions 30, 30 is not limited to a radius, and it is sufficient that the iron plate is folded.

Further, as a modified example of the upper bracket 4, as shown in FIG.
May be replaced by forming the inclined portion 40 inclined with respect to the column axis and the two bent portions 20A and 20B. The slope portion 40 has a predetermined width by being inclined forward from the plane of the vehicle body attachment portion 41 through the bent portion 20A,
A front wall portion 42 is formed integrally with a lower portion of the slope portion 40 via a bent portion 20B. Adjusting holes 43 are formed on the bent portion 20A of the bent portion 20 on the left and right along the bending, and the bent portion 20B of the bent portion 20 has a front wall portion 42 on the inner surface side.
And a rib 44 is formed between them. The other configuration is the same as that of the upper clamp 4, and the same portions are denoted by the same reference numerals and the description thereof will not be repeated.

Therefore, the bent portion 20 is formed with two bent portions 20A and 20B.
In the case of a secondary collision, as shown in FIG. 6, when an impact load is input to the position of the square hole 21 via the jacket tube 3 at the time of the secondary collision, the front wall portion 42 is pushed to the front side of the vehicle body. First, the bent portion 20A is bent so as to open,
Then, a two-stage energy absorption effect is obtained in which the bent portion 20B comes into contact with the vehicle body mounting surface 45 and opens. That is, since the steering column 1 is mounted to be inclined with respect to the vehicle body, a load in the axial direction of the column axis and a load in the vertical direction act on the upper bracket 4 at the time of a secondary collision. Since the slope portion 40 is deformed upward with the fulcrum 20A as a fulcrum, a vertical component acting when an impact load is input obliquely to the axis of the jacket tube can be absorbed, so that the initial load is reduced. be able to. In addition, the adjustment hole 43 of the bent portion 20A
Is to weaken the bending strength of the bent portion 20A to adjust the initial load in the initial stage of the collision.
The ribs 44 are for adjusting the load at the time of the collision progress, and can be adjusted appropriately, so that the energy absorption characteristics at the time of the secondary collision can be improved.

Thus, the upper bracket 4 supporting one jacket tube to the vehicle body has the function of preventing the steering wheel from projecting rearward due to the primary collision, and having the function of absorbing stroke and energy due to the secondary collision. The simplification was extremely simplified, the number of assembly steps was reduced, and the cost was reduced.

[0023]

According to the present invention described above, the three functions necessary for the steering column, namely, the holding of the steering wheel, the prevention of rearward protrusion in the case of a primary collision, and the energy absorption structure in the case of a secondary collision are integrated into one component. Therefore, the number of parts, the number of assembly steps, and the cost can be reduced.

Further, since the bent portion between the vehicle body mounting portion and the front wall portion is formed by a slope portion inclined with respect to the column axis and two bent portions, a load acting in a direction perpendicular to the axis is applied. Because it can be absorbed, the initial load acting at the time of the secondary collision can be reduced.

Furthermore, since the upper and lower brackets are deformed in the axial direction of the column, there is no need to divide and fit the jacket, resulting in low cost. Further, since the load required for deformation is determined by the shape of the bent portion of the upper bracket, it is easy to stabilize.

[Brief description of the drawings]

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

FIG. 2 is a view of arrow A of the lower bracket.

FIG. 3 is a sectional view of the upper bracket taken along line BB.

FIG. 4 is a view similar to FIG. 2 showing another example of a lower bracket.
Arrow view

FIG. 5 is a front view (A), a side view (B), and a plan view (C) showing another example of an upper bracket.

FIG. 6 is an operation explanatory view of the upper bracket shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Steering column 2 ... Lower bracket 3 ... Jacket tube 4 ... Upper bracket 5 ... Steering shaft 6 ... Intermediate shaft 7, 8 ... Bearing 9 ... Upper shaft 10 ... Lower shaft 12 ... Window hole 13, 16 ... Reinforcement flange 14, 17 41, body attaching part 15 ... welded part 18, 42 ... front wall part 19 ... column attaching part 20 ... bent part 20A, 20B ... bent part 40 ... slope part

Claims (2)

(57) [Claims] 1. A lower bracket and an upper bracket fixed to a vehicle body are attached to a lower end portion and a substantially intermediate portion of a jacket tube, and a steering shaft capable of being axially contracted through the inside thereof is rotatable around a shaft through a bearing. In the steering column for an automobile, the upper bracket is a vehicle body mounting portion, and a front wall portion vertically hanging from both sides of the vehicle body mounting portion on the front side of the vehicle body,
A column mounting portion extending substantially perpendicularly from the front wall portion to the rear of the vehicle body and extending to the side surface of the jacket tube is integrally formed, and a bent portion between the vehicle body mounting portion and the front wall portion is formed.
With a slope part inclined with respect to the column axis and two bent parts
A steering column for an automobile, wherein a predetermined gap is formed between an upper portion of the column mounting portion and a vehicle body mounting portion. 2. The lower bracket has a window hole formed in a plate body having a vehicle body mounting portion, and the jacket tube passes through the window hole and is connected to an inner peripheral edge of a lower portion thereof .
Left and right sides sandwiching the jacket tube below the window hole
Bends projecting to the front or rear of the vehicle
Automotive steering column according to claim 1, characterized in that it is formed.