JPS6160349A - Energy absorbing device for steering wheel - Google Patents

Abstract

PURPOSE:To effectively absorb an impact energy in vertical, lateral, longitudinal and oblique directions, by mounting an energy absorbing device to a steering shaft. CONSTITUTION:An energy absorbing device 26 is located in a space defined between a core cover 24 and a core portion 12, and is fixed to a steering shaft 16 by means of a bolt 30. The energy absorbing device 26 is provided with a reinforcing member 44 extending from an angular portion between a top plate 36 and one side plate 38 to an angular portion between the other side plate 38 and a bottom plate 40 in a substantially diagonal direction of a plate structure member 42 in section. The reinforcing member 44 is fixed to an inner surface of the top plate 36 at one end, and is also fixed to an inner surface of the bottom plate 40 at the other end. The side plates 38 are provided with bent portions 38a to which the top plate 36 is fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an energy absorption device for a steering wheel, which is attached to a boss at the tip of a steering shaft and absorbs energy to reduce impact on an occupant.

(Prior Art) A steering wheel is attached to the tip of a steering shaft, and the attachment portion has a structure in which a boss portion including a mounting bolt protrudes upward. However, in the event of a collision, the occupant's body is likely to hit the boss, and when it does hit, there is a problem in that a shock is applied to the occupant's body. For this reason, in order to protect the safety of the occupants, energy absorbing members have traditionally been placed around the boss to cover it, to prevent the occupant's body from directly hitting the boss in the event of a collision, and to absorb the energy of the collision. It is known that the collision shock can be alleviated by absorbing it. For example, Japanese Patent Application Laid-Open No. 58-152660 discloses a cross-sectional shape having a top plate so as to cover the boss portion, and two side plates extending downward in parallel to each other at right angles from the end of the top plate. A structure equipped with an energy absorbing member is disclosed.

(Problems to be Solved) The structure disclosed in JP-A-58-152660 has the following characteristics: the vertical direction, that is, the axial direction of the steering shaft; It has appropriate rigidity against forces in three directions, and can exhibit the desired energy absorption function, but it has insufficient rigidity against forces applied from diagonal directions at the corners of the top plate and side plates. The problem is that they are too weak and deform without absorbing enough energy and therefore cannot absorb impact forces. To solve this problem, increasing the thickness of the energy absorbing member or creating a box-shaped structure with a top plate and four side plates reduces the rigidity in the vertical direction, the longitudinal direction of the absorbing member, and the lateral direction of the absorbing member. If it becomes too much, there is a problem that the buffering function actually deteriorates.

Therefore, the object of the present invention is to not only deal with forces in the vertical, longitudinal, and lateral directions of the absorbing plate (but also with respect to forces acting diagonally from the corners of the top plate and the side plates). Another object of the present invention is to provide an energy absorbing device for a steering wheel that has appropriate rigidity and can sufficiently exhibit a buffering function.

(Structure and operation of the invention) In order to achieve the above object, the present invention is structured as follows. That is, the steering wheel energy absorption device of the present invention is attached to the tip of the steering shaft, and includes at least a substantially rectangular top plate and two opposing and substantially perpendicularly extending from the edge of the top plate. The present invention includes a plate structure having a side plate, and a reinforcing member attached to the plate structure so as to extend diagonally across a cross section of a space defined by the top plate and the two side plates. The plate structure may be a cylindrical structure with a rectangular cross section having a top plate, two side plates and a bottom plate,
A structure without a bottom plate may also be used.

A pair of reinforcing members are preferably attached with the boss portion interposed therebetween. Further, the reinforcing member is not limited to a plate member, but may be a bar member or the like, and any fixing means such as welding or bolting can be used for attachment to the plate structure. In this structure, when a force is applied from the diagonal direction of the corner of the top plate and the side plate, the reinforcing member counteracts the diagonal crushing of the plate structure and mainly absorbs the impact energy by bending and deforming the reinforcing member. absorb.

(Example) An example of the present invention will be described in detail below with reference to the drawings. As shown in FIG. 2, the steering wheel 10 has a core portion 12 in the center.
The steering wheel 10 is fixed to the steering shaft 16 by fitting the through hole 14 provided therein with the boss portion 18 formed at the tip of the steering shaft 16 . In this case, the teeth provided on the inside of the through hole 14 and the teeth formed on the outer periphery of the boss portion 18 are spline-engaged to prevent relative rotation between the steering wheel 10 and the steering shaft 16. It looks like this. This central core portion 12 is connected to a donut-shaped grip portion 22 by spoke portions 20 extending radially from the core portion 12. A core cover 24 is attached to the core part 12 so as to cover the upper part of the core part 12. In the space formed between the core cover 24 and the core portion 12, an energy absorbing device 26 having a substantially rectangular cross section is arranged along the inner surface of the space. This energy absorbing device is fixed to the steering shaft 16 together with the core portion 12 of the steering wheel 10 by bolts 30 via washers 28. In addition, the core cover 24
The outside is covered by Camp 32. As shown in FIG. 1, the energy absorbing device 26 includes a substantially rectangular top plate 36 having an opening 34 in the center for bolt attachment work, and two opposing edges of the top plate 36 extending downward and parallel to each other in a substantially perpendicular direction. two side plates 38 that extend as shown in FIG.
The energy absorbing device 26 also includes a plate structure 42 that is integrated with the top plate 36 and a bottom plate 40 that is parallel to the top plate 36 and the bottom plate 40. A reinforcing member 4 extending substantially diagonally across the cross section of the plate structure 42 over the corner with the plate structure 40.
The reinforcing member 44 has one end welded and fixed to the inside of the top plate 36 and the other end to the inside of the bottom plate 40. A pair of reinforcing members 44 are provided so as to sandwich the boss portion 18 therebetween. The side plate 38 is provided with a bent portion 38a bent inward at the upper end, and this bent portion 38a
A top plate 36 is welded and fixed to. A through hole 40a is provided in the center of the bottom plate 40, and the boss portion 18 is inserted through this hole 40a. Further, the side plate 38 is provided with a rectangular opening 38b.
Thereby, the rigidity of the side plate 38 is adjusted to an appropriate level. The top plate 36 has a plurality of screw holes 36a.
are provided, and the cap 32, core cover 24, and plate structure 42 are fixed together with screws (not shown). Further, the bottom plate 40 has a projecting portion 40b on the side thereof, and this projecting portion 40b is also provided with a screw hole 40c. Therefore, the bottom plate 40 is more firmly fixed to the spoke portion 20 of the steering wheel 10 with screws (not shown).

When an impact force is applied to the energy absorbing device 26 having the above-described structure, if the impact force is in the vertical direction, that is, in the axial direction of the steering shaft 16, the energy absorbing device 26 has the side plate 38 in the vertical direction. It absorbs energy by transforming into Further, in response to a force in the longitudinal direction in which the side plate 38 extends, which is perpendicular to the direction in which the steering shaft 16 extends, the side plate 38 mainly deforms within its plane and absorbs the energy. In this case, side plate 3
Since the opening 38b is formed in 8, the rigidity is adjusted to an appropriate level, and deformation occurs at an appropriate level. Further, when the impact force is a lateral force in the same plane as the longitudinal force and perpendicular to the longitudinal force, energy is mainly absorbed by bending and deforming the side plate. Furthermore, the reinforcing member 44
absorbs energy by deforming.

(Effects of the Invention) According to the present invention, energy can be sufficiently absorbed even when impact force is applied to the energy absorption device from any direction, and the device of the present invention has a high buffering function. have In particular, even when an oblique force is applied to the energy absorbing device, the energy absorbing device does not buckle easily and can obtain the desired energy absorbing effect.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an energy absorbing device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing how the energy absorbing device of the present invention is used. 10., Steering wheel, 16. ,. Steering shaft, 18...Boss part, 20...
Spoke part, 22... Grip part, 24... Core cover, 26... Energy absorption device, 28... Washer, 30... Bolt, 36... Top plate, 40... Bottom plate procedure correction Book Date 1, Month, Day 1, Showa Showa 1984 Patent Application No. 184172
Item 3. Relationship with the case of the person making the amendment Name of applicant (313) Mazda Motor Corporation 4, Agent 5. Date of amendment order Voluntary (1) The scope of the claims is amended as shown in the attached sheet. t2J Specification, page 3, line 19, “weakly” is changed to “strongly”
I am corrected. W7 In the same book, page 4, line 6, ``It is to provide.'' is corrected to ``It is to provide.'' (4) Insert the following sentence between the 4th and 5th lines of page 8 of the same book. "In the above embodiment, the other end of the reinforcing member 44 is fixed to the bottom plate 40 of the plate structure 42, but if this bottom plate 40 is not provided, for example, it may be fixed to the side plate 38 or directly fixed to the core part 12. Claims

Claims (1)

[Claims] an energy absorbing device attached to a tip end of a steering shaft, the plate structure having at least a substantially rectangular top plate and two side plates facing each other and extending downward in a substantially perpendicular direction from an edge of the top plate; An energy absorption device for a steering wheel, comprising a reinforcing member extending diagonally across a cross section of a space defined by a top plate and two side plates, and having both ends attached to the plate structure.