JPS6346972A - Energy absorbing type steering device - Google Patents

Abstract

PURPOSE:To absorb the energy at a collision, by installing a W-shape curling wire at a steering column, and installing an energy absorbing box to a car body to absorb the energy corporated with the curling wire. CONSTITUTION:At a part of the peripheral surface of a steering column 12, a projection 22 with a constricted part at the intermediate position is furnished projecting in the radius direction, and at a part of the car body 20, a recess is formed in which an energy absorbing box 30 is installed. Between the projection 22 and the energy absorbing box 30, a W-shape curling wire 40 is installed. The curling wire 40 is composed of a single and even-sized wire, and fixed to the projection 22. When the steering column 12 and a column bracket 14 are moved downward owing to a secondary collision, the projection 22 is also moved integrally, the curling wire 40 is stretched to produce a plastic deformation, and the energy is absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an energy absorbing steering device. Here, the energy absorption type steering gear is a steering column that is attached to the vehicle body so that the steering wheel is attached to the upper end and the steering shaft is connected to the steering gear via the joint -St at the lower end, so that the steering shaft can only be moved forward and downward. An energy absorption device made of a curved plate or the like is interposed between the steering column and the vehicle body, and as the steering device moves forward and downward, the plate of the energy absorption device changes its shape. It absorbs the energy of a collision by deforming.

[Prior art and its drawbacks]

An example of a conventionally known energy absorbing steering device of this type is the one disclosed in Japanese Utility Model Application Publication No. 53-157230. This is an energy absorbing plate having a bent portion, with one end fixed to a part of the vehicle body and the other end fixed to a steering column.

However, since this conventional example does not have a means for regulating the state of plastic deformation of the bent portion, there is a drawback that the plastic deformation resistance of the energy absorbing plate is not constant with respect to the movement stroke of the steering column.

The present invention aims to eliminate the drawbacks of the conventional examples described above, namely, to reduce the initial peak load at the time of a collision and to reduce the collision energy at a constant rate in an energy absorbing device using an energy absorbing member having a bent portion. An energy-absorbing steering device that reliably absorbs energy? It was made for the purpose of providing.

[Means and operations for solving the problems] In order to achieve the above object, in the present invention, a W-shaped curling wire is attached to the steering column, and an energy absorption box is attached to the vehicle body. Specifically, the curling wire is locked to the steering column at a central locking portion, and a pair of plastically deformed portions extend diagonally above the steering column. On the other hand, the energy absorption box works with the above-mentioned curling wire to absorb energy at the time of a collision, and has a part that supports the plastically deformed part and a part that prevents floating, and the shape of the plastically deformed part when it deforms remains constant. It includes a part that defines the movement of the plastically deformed part and a part that prevents the plastically deformed part from moving.

When a collision occurs, the locking parts of the steering column and curling wire move diagonally downward, the end face of the plastically deformed part comes into contact with the movement prevention part of the energy absorption box, and the plastically deformed part then plastically deforms and absorbs energy. It will be absorbed. The floating of the plastic deformed part during plastic deformation is prevented by the floating prevention part, and the shape of the plastic deformed part is regulated to be constant by the deformation regulating part (plastic deformation is made to progress at a constant rate). .

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2, a steering wheel (not shown) is fixed to the upper end of the steering shaft 10, and the lower end is connected to a steering gear (not shown) directly or via a joint.The steering shaft 10 is rotatably supported by a steering column 12, and the steering column 12 has a column bracket 1 having a U-shaped cross section.
4 and bolts 16 to the vehicle body portion 2G. The mounting portion 17 of the column bracket 14 is formed with a long hole 19 (see FIG. 4) that opens in one direction. The steering shaft 10 and the steering column 12 extend obliquely downward toward the steering gear.

As shown in FIGS. 1 and 3, the steering column 1
A protrusion 22 with a constricted middle portion is provided on a part of the outer peripheral surface (the side facing the vehicle body portion 20) of the protrusion 22 protruding in the radial direction.
On the other hand, as shown in FIG. 2, a recess 24 is formed in the vehicle body portion 20, and an energy absorption box 30 is mounted therein.

As is clear from FIGS. 2 and 3, the energy absorption box 30 includes a flat plate portion 32 having approximately the same width and length as the column bracket 14, and a pair of flat plate portions 32 formed at a widthwise intermediate portion of the flat plate portion 32. A parallel side platform portion 34, a ceiling portion 36 that is continuous with the side wall portion 34 and interconnects the side wall portion 34, and a side wall portion 34.
and a pair of end walls 3 continuous to both sides of the ceiling section 36 in the width direction.
It consists of 8. A long hole 33 is formed in the side of the flat plate portion 32, and the front gd bolt 16 passes through the long hole 19 and this long hole 33. The surface of the mounting portion 1T of the bracket 14 that contacts the flat plate portion 32 and the surface that contacts the head of the bolt 160 are coated with Teflon or the like to reduce friction.

A W-shaped curling wire 40 is interposed between the protrusion 22 and the energy absorption box 30. This curling wire 40 is made of a single wire of uniform thickness, and in its initial state, as shown in FIG.
A pair of parallel and adjacent long straight portions 44 that are integrated by a C-shaped locking portion 42 that is locked to 2, and a semicircular bent portion (radius of curvature &) 46 continuous to the free end thereof, Bending part 4
It includes an upper part d that is continuous with G and a pair of short straight parts 48 (length t) that are parallel to the straight part 44 and mutually parallel. The pair of straight portions 44 extend through the space 39fc between the end walls 38. The outer peripheral surface of the straight portion 48 is in contact with the side wall 34, and the end surface of the straight portion 48 is separated from the end wall 38 to some extent (gap S). The heights of the side walls 34 and the end walls 38 are slightly larger (higher) than the eight diameters of the curling wire 30.

Next, the functions and effects of this embodiment will be explained.

When the vehicle collides, the mounting portion 17 of the column bracket 14 is pushed away from the bolt 16 due to the secondary collision, and the steering column 12 and column bracket 14 are moved diagonally downward. This movement is performed smoothly because the mounting portion 1T is coated with Teflon.

Therefore, the protrusion 22 also moves integrally with the protrusion 22 in the same direction, and the locking portion 42 of the curling wire 40 is strongly pulled in one direction. As a result, the end surface of the straight portion 48 first comes into contact with the end wall 38, and thereafter the bent portion 46 and the straight portion 48 are plastically deformed (the bent portion 46 gradually moves toward the tip side). ). This curling wire 40
Plastic deformation (total deformation is 2 C1-1'): t
' is the length of the straight part of the curling wire after plastic deformation. ), the energy of the collision is absorbed, and according to this curling wire 40, the energy is absorbed at a constant rate and reliably. (Note that for the plastic deformation 2 (t-1') of the curling wire 40,
The steering column will move by ``S+2 (t-t') the length of the long hole 33'').

The reason for this is that the plastically deformed portions (folded portions 46 and straight portions 48) of the curling wire 40 are shaped so that there is almost no gap between the flat plate portion 32 and the ceiling portion 36 in the height or thickness direction. The bent portion 46 is inserted and is in contact with the outer side wall 34 in the width direction, thereby preventing the bent portion 46 from floating during plastic deformation and keeping the shape (curvature) constant. It is from.

In addition, since the curling wire 40 is manufactured by simply bending a single wire, the cost is low and it does not take up much space. Nor.

Note that the present invention is not limited to the above embodiments,
It goes without saying that changes and improvements can be made as appropriate without impairing the spirit of the invention. For example, the detailed structure of the energy absorption box 30 (side walls 34, end walls 38 and ceiling walls 36)
Of course, the length, height, width, etc.) and the specific shape of the curling wire 40 (length of the straight portion 44, 48, curvature of the bent portion 4B, etc.) can be arbitrarily selected.

〔Effect of the invention〕

As described above, according to the present invention, a W-shaped curling wire is attached to the steering column, and an energy absorption box that cooperates with the curling wire to regulate or control its plastic deformation is attached to the vehicle body. Therefore, the energy of the collision is reliably absorbed at a constant rate, and the safety of the driver is ensured. Further, since curling wire is a mass-produced product obtained by bending a single wire, the cost is low, and since it can be placed in a narrow space, the steering device does not need to be bulky.

[Brief explanation of the drawing]

FIG. 1 is a front view showing one embodiment of the present invention, and FIG. 2 is a front view showing one embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along the line ■-■ in the figure, FIG. 3 is a view taken along the arrow ■ (partially broken) in FIG. 1, and FIG. 4 is an explanatory view of the operation of FIG. [Explanation of symbols of main parts] 12...Steering column 20...Vehicle body part 30...Energy absorption box 40...W-shaped curling wire Fig. 1 Fig. 2

Claims (1)

[Scope of Claims] A steering column rotatably supporting a steering shaft having a steering wheel attached to an upper end thereof is fixed to a vehicle body part by a column bracket, and the steering column is movable axially downward,
An energy absorbing steering device, wherein a curling wire fixed to the steering column is engaged with an energy absorbing box fixed to the vehicle body part, wherein the curling wire has a W-shape. and a locking portion formed at the center is locked to a protrusion protruding from the steering column, and a pair of plastically deformed portions extend obliquely upward from the steering column, and the energy absorption box is connected to the curling ring. A support part that contacts and supports the lower surface of the plastically deformed part of the wire; a floating prevention part that can contact the upper surface of the plastically deformed part and prevents it from floating; A deformation regulating part that contacts and regulates the shape of the quantitatively deformed part to be constant during plastic deformation, and a movement prevention part that can come into contact with the end face of the plastically deformed part and prevents its movement after making contact. An energy absorbing steering device comprising: