JPH018455Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a steering system for an automobile, specifically, a steering system that absorbs collision energy when the driver makes a secondary collision with the steering wheel during an accident.
The present invention relates to an energy absorbing steering device that can reduce the impact on a driver.

A number of energy absorbing methods have been devised for energy absorbing steering devices using members that have energy absorbing ability, such as steering shafts, column tubes, column brackets, etc., but the steering device targeted by this invention This adopts an energy absorption method in which the column bracket that supports the column tube on the vehicle body side has energy absorption ability.

Conventionally, this type of steering device was
There is one disclosed in Publication No. 55-22309. This is designed to absorb collision energy by bending and deforming the column support part integrally formed with the main part of the column bracket. According to this device, the main part of the column bracket is firmly fixed to the vehicle body so as not to be deformed by collision energy, so energy absorption is imposed only on the column support part. However, the amount of energy absorbed by this column support (deformation stroke and deformation load) is naturally limited by the shape of the support, so it has been unreasonable to hope for a larger amount of energy absorption than a certain level. In addition, in order to increase the deformation stroke, it is possible to increase the distance between the bending deformation part and the column tube, but if this is done, the support rigidity for the column tube will decrease, and the deformation load will also decrease, resulting in a loss of energy. In addition, the absorption capacity cannot be satisfied, and the column tube is likely to vibrate due to a decrease in support rigidity for the column tube, making it impractical. Furthermore, since the deformation portion of the device is limited to one location, the stability of the deformation load during energy absorption is lacking.

Therefore, in view of the above-mentioned conventional drawbacks, the purpose of this invention is to increase as much as possible the amount of energy absorption of the column bracket that supports the column tube on the vehicle body side, and to increase the deformed parts to reduce the amount of energy absorbed. An object of the present invention is to provide an energy absorbing steering device capable of stabilizing deformation load during absorption.

This invention to achieve the above-mentioned purpose supports a column tube on the vehicle body side with a column bracket, and a steering shaft for transmitting the rotation of the steering wheel to the steering gear is rotatably installed inside the column tube. A steering device comprising: a first deformable bracket which is formed into a substantially U-shape and whose left and right ends are fixed to the vehicle body; and an opening in the center into which a column tube can be inserted. A fixing part connected to the lower part of the column support part formed in a substantially S-shape is fixed to the lower surface of the first deformable bracket, and a column mounting part connected to the upper part of the column support part is attached to the column tube. and a second deformable bracket fixed to the upper side, the left and right attachment parts of the first deformable bracket to the vehicle body are set as deformable parts, and the connection between the column support part and the fixed part in the second deformable bracket is set as the deformable part. A lower deformable part is set in the installation part, and an upper deformable part is set in the continuous part between the column support part and the column attachment part.

An embodiment of this invention will be described below with reference to the drawings. In FIG. 1, which shows the energy absorbing steering device from the side, an auxiliary bracket 2 is fixed to the lower part of a support bracket 1 attached to the vehicle body. A clamp piece 3 is fastened to the auxiliary bracket 2 with a bolt (not shown) while holding the lower part of the column tube 4. Inside the column tube 4, a steering shaft 5 has a bearing 6 and a bush 7.
It is rotatably supported through. The steering shaft 5 is divided into a top shaft 8 and a lower shaft 9 in the column tube 4, and the mutual ends of both shafts 8 and 9 are connected to each other by a coupling means such as serrations to enable rotation torque to be transmitted and to be shortened. It consists of being done. Tip of the shaft 8 of the steering shaft 5 (upper end)
protrudes upward from the column tube 4, and a steering wheel 10 is attached to the tip thereof. Further, the tip (lower end) of the lower shaft 9 projects downward from the column tube 4, and is connected to the steering gear via a universal joint, intermediate shaft, etc. (not shown). Thereby, the rotation of the steering wheel 10 is transmitted to the steering gear via the steering shaft 5. Therefore, the column tube 4 is connected to the auxiliary bracket 2 and the clamp piece 3.
The steering wheel 10 is held between the steering wheel 10 and the steering wheel 10 so that it can slide coaxially when an impact force (load) of a predetermined value or more is applied in the axial direction from the steering wheel 10 side. During this sliding, the steering shaft 5 is shortened by the upper shaft 8 fitting into the lower shaft 9 in response to the above-mentioned impact force.

Next, the column bracket 20 supporting the upper part of the column tube 4 mentioned above on the support bracket 1 will be described in detail. Column bracket 20
Figure 2 shows the side view of the same, Figure 3 shows the back side of the same,
Figure 4 shows the same longitudinal section, and Figure 5 shows the same cross section.
In the figure, the column bracket 20 is composed of a first deformed bracket 21 and a second deformed bracket 22. The first deformed bracket 21 is
A plastically deformable band-shaped metal plate is bent into a substantially U-shape, and mounting flanges 23, 23 having bolt holes 24 are provided at the left and right ends thereof, and
Reinforcing flanges 25, 25 are bent outward at its front and rear edges. In addition, the first deformed bracket 21
is curved in the center in the vertical direction so that the lower part is shifted forward with respect to the upper part. A developed view of the first modified bracket 21 described above is shown in FIG. The dashed-dotted lines in FIG. 6 indicate the main bending lines. The above-mentioned first deformed bracket 21 is attached to the support bracket 1 on the vehicle body side through the left and right bolt holes 24, 24 with fixing bolts 26,
26, and the attachment portion thereof is set at the deformable portion 27. A second deformation bracket 22 supported within this first deformation bracket 21
, a metal plate that can be plastically deformed is bent, and has a column support part 29 in the center, a fixing part 28 in the lower part,
It is formed into a substantially S-shape consisting of a column support part 29 and a column attachment part 30 at the upper part. Fixed part 28
is in the form of a band, with both ends thereof bent upward, and is shaped to follow the lower surface of the first deformable bracket 21. Both ends and the center part of the fixed part 28 are welded 31 to the first deformed bracket 21.
32, and the second deformable bracket 22 is supported by the first deformable bracket 21. A column support part 29 connected to the rear edge of the fixing part 28 is raised rearward and upward in an oblique manner, and an opening 33 through which the column tube 4 is inserted is formed in the center of the column support part 29. . Left and right lips 34, 34 and a lower lip 35 protrude rearward from the edges of the opening 33, respectively. The column tube 4 is inserted through the opening 33, and the tube 4 is supported by surface contact between the lips 34 and 35, and the upper surface of the tube 4 and the opening 33
A gap CL is formed between the upper edge and the upper edge. Reinforcement ribs 3 are provided in the vertical direction on the left and right sides of the column support portion 29.
6,36 are formed. A column attachment part 30 connected to the upper edge of the column support part 29 is bent obliquely rearward and downward, and its tip 37 is formed in a shape along the upper surface of the column tube 4. A tip 37 of this column attachment portion 30 is fixed to the upper surface of the column tube 4 by welding 38. The developed view of the second deformed bracket 22 described above is shown in the seventh figure.
Shown in the figure. The dashed-dotted lines in FIG. 7 indicate the main bending lines. Thus, in the second deformed bracket 22, the part where the fixed part 28 and the column support part 29 are connected is set to the lower deformed part 39, and the part where the column support part 29 and the column attachment part 30 are connected is set to the upper part. It is set in the deformation section 40.

In the energy absorbing steering device described above, when the driver has a secondary collision with the steering wheel 10 due to an accident such as a head-on collision or a rear-end collision, the steering shaft 5 is shortened due to the collision load, and the steering wheel 10 is is pushed forward and downward (lower left in Figure 1). Along with this movement of the wheel 10, the column tube 4 also moves in the axial direction between the auxiliary bracket 2 and the clamp piece 3 while deforming the column bracket 20, and by deforming the column bracket 20, the collision energy is reduced. absorption is achieved, thus reducing the impact on the driver.

Next, the collision energy absorption effect of the column bracket 20 will be explained in detail by citing an example of its deformation model.

The impact load from the column tube 4 first causes deformation in the lower deformed portion 39 of the second deformed bracket 22, that is, the column support portion 29 moves forward (counterclockwise in FIG. 4) based on the lower deformed portion 39. ), resulting in deformation. As the deformation of the lower deformed portion 39 progresses, the column tube 4 and the opening 33 of the second deformed bracket 22
The deformation stops when the upper part abuts with the gap CL between them disappearing. Then,
Next, the upper deformed portion 4 of the second deformed bracket 22
0, i.e. the column attachment part 30
is rotated rearward (clockwise in FIG. 4) based on the upper deformation portion 40, resulting in deformation. Along with the deformation of both the deformation parts 39 and 40 of the second deformation bracket 22, the first deformation bracket 21 also deforms at its deformation part 27, and the lower part of the deformation bracket 21 moves forward based on the deformation part 27. Deformation occurs due to rotation (clockwise in FIG. 4).

The deformed portion 27 of the first bracket 21 described above,
The collision energy is absorbed by the cooperative deformation of the upper and lower deformable portions 39 and 40 of the second deformable bracket 22.

Deformation stroke S of this column bracket 20
The relationship between F and deformation load F will be described. The relationship in the deformed portion 27 of the first deformed bracket 21 is represented by the diagram shown in FIG. 8, and the relationship in both deformed portions 39 and 40 of the second deformed bracket 22 is shown in FIG. It is represented by the diagram shown.
Therefore, the relationship between the two deformation brackets 21 and 22 in cooperation is represented by a diagram as shown in FIG.
Composite deformation from point O of 1, 22 to each point a1, a2, second deformation bracket 22 from point A to point B
The deformation from point a2 to point b2, and the deformation at point B and above is more than a1 of the first deformed bracket 21. In this way, the deformation stroke S is increased by the combined stroke of both deformation brackets 21 and 22, and the deformation load F is increased due to the increase in the deformation portion.
can be set to a substantially constant state (see the part between point A and point B in the middle of FIG. 10).

Furthermore, when a torsional load is applied to the column tube 4 around its axis, the second deformable bracket 22 is placed inside the first deformable bracket 21.
Since their outer edges abut due to their torsional deformation, rigidity against the torsional load can also be obtained.

Also, the lip 34 of the second deformed bracket 22
.about.35 prevents the column tube 4 from being twisted relative to the opening 33. Furthermore, by providing a gap CL between the column tube 4 and the opening 33 of the second deformable bracket 22, interference between the column tube 4 and the second deformable bracket 22 during energy absorption is prevented as much as possible. This can contribute to increasing the deformation stroke of the second deformation bracket 22 related to energy absorption and to stabilizing the deformation load.

Note that each deformed portion 27, 39, 40 of the first deformed bracket 21 and the second deformed bracket 22
Settings regarding the deformation order, the magnitude of the deformation load, etc. in are selected as appropriate from a design standpoint.

That is, according to this invention, a column bracket for supporting a column tube on the vehicle body side,
A first deformable bracket formed in a substantially U-shape with its left and right ends fixed to the vehicle body side, and a lower part of a column support part formed in a substantially S-shape with an opening in the center into which a column tube can be inserted. A second fixed part is fixed to the lower surface of the first deformable bracket, and a column mounting part is fixed to the upper side of the column tube.
The left and right attachment parts of the first deformable bracket to the vehicle body side are set as deformable parts, and the lower deformable part is set in the part of the second deformable bracket where the column support part and the fixing part are connected. At the same time, by setting the upper deformation part in the continuous part between the column support part and the column mounting part, the deformation part can be changed to both the left and right deformation parts of the first deformation bracket and the top and bottom deformation parts of the second deformation bracket. Since the number of deformation strokes for absorbing collision energy is longer and the deformation load is larger than that of conventional ones,
The amount of energy absorbed can be increased, and the left and right deformed portions of the first deformed bracket and the second
By setting both the upper and lower deformation parts of the deformation bracket at specific positions, it is possible to stabilize the deformation load, and by changing the deformation load of each deformation part of both brackets, the energy absorption characteristics can be varied. This has the effect of increasing the degree of freedom in design.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a right side view of the energy absorbing steering device. Figure 2 is an enlarged view of the column bracket in Figure 1, Figure 3 is an enlarged view of the column bracket seen from the steering wheel side, and Figure 4 is an enlarged view of the column bracket in Figure 3.
A line sectional view, FIG. 5 is a -V line sectional view of FIG. 2,
Fig. 6 is a developed view of the first deformed bracket, Fig. 7 is a developed view of the second deformed bracket, and Figs.
0 is a diagram showing the relationship between deformation stroke and deformation load, FIG. 8 is a diagram related to the first deformation bracket, FIG. 9 is a diagram related to the second deformation bracket,
FIG. 10 is a diagram relating to the column bracket. 1...Vehicle side support bracket, 4...Column tube, 5...Steering shaft, 10
... Steering wheel, 20 ... Column bracket, 21 ... First deformed bracket, 22 ...
...Second deformation bracket, 27...Deformation part, 33
...opening, 39...lower deformed part, 40...upper deformed part.

Claims (1)

[Scope of utility model registration request] A steering device in which a column tube is supported on the vehicle body side by a column bracket, and a steering shaft for transmitting rotation of a steering wheel to a steering gear is rotatably installed inside the column tube, and the column tube is connected to the column bracket. A first deformable bracket formed in a substantially U-shape with its left and right ends fixed to the vehicle body side, and a column support portion formed in a substantially S-shape with an opening in the center into which a column tube can be inserted. A second deformable bracket has a fixing part connected to the lower part fixed to the lower surface of the first deformed bracket, and a column mounting part connected to the upper part of the column support part is fixed to the upper side of the column tube. configure,
The left and right attachment parts of the first deformable bracket to the vehicle body are set as deformable parts, and the lower deformable part is set in the part of the second deformable bracket where the column support part and the fixing part are connected, and the column support part and the fixed part are connected to each other. An energy-absorbing steering device characterized in that an upper deformable portion is set in a portion connected to a column attachment portion.