JPS621788Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mounting device for an energy absorbing steering device.

As a conventional mounting device, the applicant first proposed the
Although the device described in Publication No. 25981 has been proposed and is achieving the desired effect, it is useful when the weight of the steering column increases significantly due to the addition of a tilt device, or to further increase the support rigidity of the steering column. When the number of mounting bolts is increased from two to four, the peak crash load when the steering column mounting part starts to separate from the support part of the vehicle body increases in a crash test, and energy absorption steering It has been found that there is a drawback that the performance of the device is reduced.In order to eliminate this drawback, the purpose of the present invention is to provide a mounting device that reduces the peak load at the start of disengagement. A steering shaft whose directional length can be reduced, a steering column that rotatably supports the steering shaft, and energy that absorbs collision energy as the steering column and the steering shaft move downward in the axial direction. A mounting device for an energy absorbing steering device comprising an absorbing means and a column bracket fixed to the steering column and fixed to a vehicle body part by a bolt, wherein the column bracket is connected to a U-shaped part fixed to the steering column. and a mounting portion protruding outward in a right angle direction from each end of the U-shaped portion, the mounting portion having a notch parallel to the axial direction of the steering column and opening toward the handlebar for bolt insertion. a notch and an elongated hole longer than the width in the width direction of the notch on the side opposite to the handle side, the notch being a slit with a bottom continuous to the notch surface on the side closer to the center of the steering column; A narrow deformed portion is formed by the elongated hole at the end of the mounting portion on the side opposite to the steering wheel, and the deformed portion is connected to the elongated hole on the side closer to the center of the steering column. The mounting portion is deformed when it slides together with the steering column during a collision, and the sliding movement of the mounting portion on the side far from the center of the steering column is delayed.

An embodiment of the present invention will be explained with reference to FIGS. 1 to 3. A modified shaft part of a known structure is provided at the lower part of an upper shaft 2 to which a handle 1 is fixed at the upper end. It fits inside the irregularly shaped tube part of a known structure provided on the upper part of the connected lower shaft 5, and 2
It is fixed in the axial direction by a shear pin 6 provided at a certain location, and transmits the rotation of the handle 1 to the steering gear 3. If an axial impact of more than a predetermined value is applied, the shear pin 6 is cut, and the irregularly shaped shaft part is It is a steering shaft that fits into the inside of the irregularly shaped tube part and reduces the axial length.

The steering column consists of an upper column 7 and a lower column 8. The upper column 7 rotatably supports the upper shaft 2 of the steering shaft, and the lower column 8 rotatably supports the lower shaft 5 of the steering shaft. The upper column 7 is fitted onto the upper part of the lower column 8.

The steering shaft or the steering column is provided with a known energy absorbing means that absorbs the energy of the collision as the steering shaft and the steering column move downward in the axial direction at the time of a collision, but this is not shown.

The column bracket 9 is fixed to the upper column 7 by suitable means such as welding, and is attached to the vehicle body part 10 to allow the steering column to move downward in the axial direction.
installed on. That is, the column bracket 9 has a U-shaped portion 18 fixed along the outer peripheral surface of the upper column 7, and mounting portions 19 projecting outward in a right angle direction from both ends of the U-shaped portion 18. The portion 19 is provided with a notch 11 for inserting a bottle in the form of an elongated hole, which is cut parallel to the axial direction of the steering column and has an open handle side, and is longer than the width in the width direction of the notch 11 on the side opposite to the handle side. A long hole 15 is formed. The notch 11 is communicated with the elongated hole 15 by a slit formed so that the bottom remains continuously on the notch surface near the center of the steering column. As a result, a narrow deformed part 14 is formed by the elongated hole 15 at the end of the attachment part 19 on the side opposite to the handle. The rectangular part indicated by the chain line in the figure is the washer 12, and the circular part indicates the mounting bolt 13.

The washer 12 is a thin plate member bent into a U-shape, and this washer 12 is inserted into the notch 1 of the column bracket 9.
The column bracket 9 is inserted into the column bracket 9 so as to close the opening of the column 1 from above. A mounting bolt 13 inserted through a bolt hole provided in the washer 12 and a notch 11 in the mounting portion 19 is screwed into the vehicle body portion 10, and the column bracket 9 is tightened and fixed to the vehicle body portion 10.

If the steering shaft is hit from the side of the handlebar 1 during a car collision, the notch 1 will open as shown in Figure 3.
1, the portion of the mounting portion 19 closer to the center of the steering column begins to slide first, and the deformable portion 14 is deformed.

Therefore, the load acting as resistance at the initial stage of movement is the load caused by tightening the mounting bolt 13, which is caused by the notch 1.
This is the sum of the sliding friction resistance due to a load that is approximately half of the tightening load generated in the portion near the steering column 1 and the load due to elastic deformation or plastic deformation of the deformable portion 14. The deformation load on the deformation portion 14 is slight;
The force applied to the part of the mounting part 19 far from the center of the steering column is weakened, and the force applied to the part of the mounting part 19 far from the center of the steering column is
The part does not slide out at the same time as the part on the closer side. Subsequently, the deformed portion 14 undergoes further plastic deformation, and the force applied to the portion of the mounting portion 19 far from the center of the steering column increases, and then the entire mounting portion 19 slides, and the mounting portion 19 separates from the tightening of the mounting bolt 13. . If the width of the deformed portion 14 is made narrower and the length thereof longer, the initial resistance can be reduced.

FIG. 6 is a graph showing the relationship between the detachment load and the displacement of the upper column 7, in which the chain line represents the prior art shown in FIG. 7, the solid line represents the embodiment shown in FIG. 2, and the conventional load It is slightly larger than half.

Fig. 4 shows another embodiment in which four mounting bolts 13 are used to improve the mounting support rigidity of the column bracket 9, and the notch 11 through which the bolt is inserted is elongated in the axial direction and intersects with the axis of the steering column. Since the length of the deformed portion 14 in the direction cannot be large enough to correspond to the length of the notch 11, the tightening force of the mounting bolt 13 on the side opposite to the handle remains even after the deformation, but the initial resistance of the collision is due to the notch 11. It is small because only the inside slides first.

FIG. 5 shows another embodiment of the hole 15 connected to the notch 11, in which the elongated hole 15 is a U-shaped elongated hole and has a slit connecting this hole and the notch 11.
A narrow and long deformed part 16 is formed by providing a groove 17 inserted from the side surface in the part of the attachment part 19 sandwiched between the letter-shaped elongated holes.

The mounting device of the present invention constructed as described above has a notch for inserting a bolt that opens toward the handlebar side and is cut parallel to the axial direction of the steering column in the mounting portion of the column bracket, and has a length wider than the width of this notch. A hole is provided on the side opposite to the handle side, and the notch is communicated with a slit leaving a continuous bottom on the notch surface on the side near the center of the steering column, and the above-mentioned cutout is provided at the end of the mounting portion on the side opposite to the handle side. Since a narrow deformed part is formed by the elongated hole, when the mounting part near the center of the steering column slides together with the steering column, the deformed part deforms, and the mounting part far from the center of the steering column slides. The movement is delayed, and the attachment part separates from the mounting bolt in two stages, which significantly reduces the peak load at the beginning of detachment, making it possible to prevent collisions even when the weight of the steering column increases or the support rigidity is improved. It has the effect of maintaining performance. Since this mounting device has a bottom portion that is continuous with the cutout surface on the side near the center of the steering column, the steering column is prevented from protruding upward.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention,
Figure 1 is a partially cutaway side view showing how the energy absorbing steering device is attached to the vehicle body.
Fig. 2 is a plan view of the main part of the mounting device, Fig. 3 is a plan view in the middle of deformation, Figs. 4 and 5 are plan views showing a part of the mounting part showing other embodiments, and Fig. 6 7 is a graph showing the relationship between the displacement of the steering column and the detachment load, and FIG. 7 is a plan view showing a part of the mounting portion of the prior art. Explanation of symbols, 1...Handle, 2...Upper shaft,
3... Steering gear, 4... Universal joint, 5...
... lower shaft, 6 ... shear pin, 7 ... upper column,
8...Lower column, 9...Column bracket, 1
0... Vehicle body part, 11... Bolt hole, 12... Washer, 13... Mounting bolt, 14, 16... Deformed part, 15... Elongated hole, 17... Groove, 18... U-shaped part, 19...Mounting part.

Claims (1)

[Scope of utility model registration request] A steering shaft with a handle attached to its upper end and whose axial length can be reduced; a steering column rotatably supporting the steering shaft;
An energy absorbing steering wheel comprising: energy absorbing means for absorbing collision energy as the steering column and the steering shaft move downward in the axial direction; and a column bracket fixed to the steering column and fixed to a vehicle body part with bolts. In the device mounting device, the column bracket has a U-shaped portion fixed to the steering column and a mounting portion projecting outward at a right angle from each end of the U-shaped portion;
The mounting portion has a notch for inserting a bolt that is cut out parallel to the axial direction of the steering column and opens toward the handle, and has an elongated hole longer than the width in the width direction of the notch on the side opposite to the handle. have in
The notch is communicated with the elongated hole by a slit leaving a continuous bottom on the notch surface on the side near the center of the steering column, and the elongated hole is formed at the end of the mounting portion on the side opposite to the steering wheel. A narrow deformed part is formed, and the deformed part is deformed when the mounting part on the side closer to the center of the steering column slides together with the steering column during a collision, and the deformed part deforms when the mounting part on the side far from the center of the steering column deforms. A mounting device for an energy absorbing steering device, characterized in that the peak load at the time of a collision is reduced by delaying the sliding movement of the parts.