JPS623335Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shock absorbing steering device that protects an automobile driver from injury during a collision.

Conventional shock-absorbing steering devices have the disadvantage that they require a large amount of manufacturing cost because they absorb energy during a collision by specially providing an energy-absorbing device on the steering shaft or steering column.

In order to solve this drawback, the present applicant has proposed
Although the device described in Publication No. 68471 was proposed, the present invention aims to provide a shock-absorbing steering device with a simpler structure and good performance at low cost. , a shock-absorbing steering device comprising a steering column rotatably supporting the steering shaft, and a column bracket for mounting the steering column on a vehicle body, the column bracket having a U-shape fixed to the steering column. and a mounting portion projecting outward in a perpendicular direction from each end of the U-shape of the central portion, the mounting portion being formed in the axial direction of the steering column and extending beyond the length of the shock absorption stroke. A U-shaped thin plate locking fitting is inserted into the mounting portion so as to sandwich the upper and lower surfaces of the mounting portion from a direction perpendicular to the axial direction of the steering column. and the column bracket is tightened and fixed to the vehicle body part together with the locking metal fitting by a mounting bolt inserted through a bolt hole provided in the locking metal fitting and a mounting bolt passage of the mounting portion. The mounting part is pressed by the U-shaped opposing surface of the stopper and is supported by the vehicle body part so as to be movable in a shock absorbing stroke, and at least one of the contact surfaces of the mounting part and the stopper is The column bracket is provided with a coating made of a material with a low sliding friction coefficient, so that the column bracket does not disengage early under the tightening force of the mounting bolt in the event of a collision, and the locking metal fitting remains in contact with the locking fitting throughout the entire shock absorption stroke. The collision energy is absorbed while sliding on the contact surface with the locking fitting while keeping the contact area constant.

To explain this with respect to an embodiment of the present invention, in FIG. 1, a steering shaft 1 has a handle 4 attached to its upper part, and is rotatably supported by a steering column 3 via a lower bearing 6 and an upper bearing (not shown). , is connected to a steering gear 12 via an upper joint 10 and a lower joint 11 at its lower part.

The steering column 3 is attached to a vehicle body part 9 by a column bracket 2 fixed to the steering column 3 at the upper part and by a lower bracket 8 which slidably supports the steering column 3 at the lower part. The steering column 3 is only allowed to move forward and downward as in the conventional case, but it does not have an energy absorption device.
The steering shaft 1 is shown as a single shaft, but due to the existence of two joints 10 and 11, the steering shaft 1 is displaced to the position shown by the chain line in the event of a collision.
This is due to the fact that the thrust does not affect the steering shaft 1 directly to the steering gear 12.
or when connecting via a single joint, the steering shaft 1 is divided into two shafts, an upper and a lower shaft, as in a known structure, taking into consideration the effect of upthrust, and one shaft is connected to the other shaft. It is common and safe to insert the device inside the device.

As shown in FIGS. 2 and 3, the column bracket 2 includes a central portion 21 having a U-shaped cross section that is fixed to the steering column 3 by means such as welding.
and mounting portions 22, 22 projecting outward in the right angle direction from the respective ends of the U-shape of the central portion 21.

The attachment portion 22 is a portion for attaching the steering column 3 to the vehicle body portion 9 with the attachment bolt 7, and a portion thereof extends longer toward the handlebar 4 than the length of the central portion 21 in the axial direction of the steering column 3.

Each mounting portion 22 has a mounting bolt passage 23 having a length slightly longer than the shock absorption stroke length in the axial direction of the steering column 3, and the mounting bolt passage 23 has a width dimension slightly larger than the shaft diameter of the mounting bolt 7. It is enlarged, and the upper end on the handle 4 side is open.

The locking fitting 5 is made of a thin plate and has a U-shaped bent shape, and is provided with an oblong bolt hole 13. The locking fittings 5 are attached to the respective attachment portions 22 of the column brackets in a direction perpendicular to the axial direction of the steering column 3 so as to sandwich both upper and lower surfaces of the attachment portions 22. The mounting bolt 7 is screwed into the vehicle body part 9 through the bolt hole 13 of the locking metal fitting and the mounting bolt passage 23 of the column bracket, and the column bracket 3 is allowed to move with a shock absorbing stroke and is tightened to the car body part 9 together with the locking metal fitting 5. Fixed.

The upper and lower surfaces of the mounting surface 22 of the column bracket and the U-shaped opposing inner surfaces of the locking fitting 5 are pressed against each other and are in contact with each other, and at least one of these contact surfaces is coated with a material having a low sliding friction coefficient, for example, 4 A coating of fluorinated ethylene resin, nylon, synthetic resin containing a solid lubricant such as molybdenum disulfide, or metal soap having resin properties is provided. Note that the reference numeral 14 in FIG. 2 is a washer.

Figure 4 is a static load diagram showing an example of the experimental results of the embodiment of the present invention, with the horizontal axis representing the shock absorption stroke and the vertical axis representing the load. The effective stroke S is shown in Fig. 3 as follows.
This is the distance from the end surface of the locking fitting 5 on the handle 4 side to the open end of the mounting bolt passage 23.

The length in the axial direction of the mounting bolt passage 23 is set longer than the effective stroke S, but it does not necessarily have to match the shock absorption stroke until the load becomes zero in Fig. 4, and even if it is slightly shorter than that. , most of the energy is absorbed within the effective stroke S, so the effective stroke S
Since only a peak load that is lower than the load inside is generated and there is no practical problem, lengths and shortenings of that degree are permissible.

FIG. 5 shows another embodiment in which the steering column 3 is attached to the vehicle body part 9 with three mounting bolts,
This is a drawing corresponding to FIG. 3.

The left and right mounting parts 24 and 25 of the column bracket are asymmetrical, and the left mounting part 24 is attached to the vehicle body part 9 with one mounting bolt, and the right mounting part 25 is attached to the vehicle body part 9 with two mounting bolts. Ru. The mounting bolt passage 26 provided in the left mounting part 24 is provided with a length close to the above-mentioned shock absorption stroke, but the mounting bolt passage 27 provided in the right mounting part 25 is longer than this, and has a length similar to that of the shock absorption stroke. A length close to the shock absorbing stroke can be secured for the mounting bolt on the inner handle side. That is,
It is sufficient to take the effective stroke S from the handle-side end surface of the locking fitting 5' on the handle side of the right mounting part 25 to the handle-side end of the mounting part 25, and the length is sufficient for the mounting bolt on the side opposite to the handle. Of course, it is possible to secure a travel distance of .

In this embodiment, unlike the first embodiment, the ends of the mounting bolt passages 26 and 27 on the handle side are not open, and the mounting bolt passages 26 and 27 are elongated holes with both ends closed. ing.

In the shock-absorbing steering device of the present invention configured as described above, when a car collides, the steering column is pushed forward and downward due to a secondary collision in which the driver collides with the steering wheel after the primary collision. At this time,
In conventional shock-absorbing steering devices, the mounting portion of the column bracket separates from the locking bolts and locking fittings, but in the device of the present invention, the mounting bolt passage provided in the mounting portion has a length close to the shock-absorbing stroke. Since the locking bracket is mounted perpendicular to the axial direction of the steering column, the contact area of the locking bracket with the column bracket remains constant under the tightening force of the mounting bolt. It does not come off from the mounting part until the end of the shock absorbing stroke, and because of the coating of a material with a low sliding friction coefficient provided on the contact surface of at least one of the mounting part and the U-shaped inner surface of the locking fitting, it Just by tightening the mounting bolts with a normal torque, the device slides without creating a large load and absorbs the energy caused by a collision.

In this way, the steering column is guided by the mounting bolts and moves forward and downward without prematurely separating from the vehicle body, so the direction of movement of the steering column can be kept constant without shifting left or right. , the energy absorption performance does not deteriorate due to a change in the direction of movement of the steering column, and the energy absorption performance is good. In addition, the mounting portion of the column bracket is simply extended to provide a mounting bolt passage, and no energy absorbing member is particularly provided on the steering shaft or steering column, so the structure is simple and can be provided at low cost.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal cross-sectional view of a shock absorbing steering device showing how it is installed in an automobile; FIG. 2 is a cross-sectional view taken along the - line in FIG. 1; and FIG. 2 is a partially omitted plan view viewed from the direction of the arrow; FIG. 4 is a static load diagram showing an example of experimental results; and FIG.
FIG. Explanation of symbols, 1... Steering shaft, 2... Column bracket, 3... Steering column, 4... Handle, 5, 5'... Locking metal fittings, 7... Mounting bolt, 9... Vehicle body part, 13...Bolt hole, 21...
...Central part of column bracket, 22, 24, 2
5...Column bracket mounting part, 23, 26,
27...Mounting bolt passage.

Claims (1)

[Scope of utility model registration request] The vehicle includes a steering shaft into which a handle is inserted, a steering column which rotatably supports the steering shaft, and a column bracket which attaches the steering column to the vehicle body, and the column bracket is attached to the steering column. It has a fixed U-shaped central portion and a mounting portion projecting outward at right angles from each end of the U-shape of the central portion, the mounting portion being formed in the axial direction of the steering column and having a shock absorbing stroke. A U-shaped thin plate locking fitting is attached to the mounting portion from the upper and lower surfaces of the mounting portion in a direction perpendicular to the axial direction of the steering column. The column bracket is tightened and fixed to the vehicle body portion together with the locking metal fitting by a mounting bolt inserted through a bolt hole provided in the locking metal fitting and a mounting bolt passage of the mounting portion. The column bracket is pressed against the mounting portion by the U-shaped facing surface of the locking metal fitting and is supported by the vehicle body portion so as to be movable in a shock absorbing stroke, and the contact surface of the mounting portion and the locking metal fitting is At least one surface is provided with a coating made of a material with a low coefficient of sliding friction, and in the event of a collision, the column bracket engages with the locking fitting throughout the entire shock absorption stroke under the tightening force of the mounting bolt. A shock-absorbing steering device characterized in that the contact area of the steering device is kept constant and the energy of a collision is absorbed while sliding on the contact surface with the locking metal fitting.