JPS6349658B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an impact energy absorbing structure for a steering wheel, in which a horn switch body is disposed between a cover body and an energy absorbing body made of brittle plastic.

Conventionally, this type of impact energy absorbing structure was as shown in FIG. After the cover body 1 and the energy absorber 2 are molded separately, the horn switch body 3 is usually attached to the energy absorber side, and the cover body 1 and the energy absorber 2 are then attached to the boss plate 5. It was hot. Therefore, separate molding molds are required for molding the cover body 1 and the energy absorber 2, a horn switch body is attached to the energy absorber, and the energy absorber and the cover body are each attached to a boss plate 5. This posed the problem of increasing assembly man-hours and manufacturing costs.

Therefore, the inventor of the present invention proposed that the energy absorber be integrally molded by injecting a brittle plastic material into the cover body in which the horn switch is set. In order to prevent material from flowing into the horn switch, it is necessary to cover the horn switch with a cover etc. in advance to keep it in a sealed state, which poses the problem of requiring extra material costs and man-hours. .

This invention was made to solve the above problems, and it is possible to significantly reduce mold costs and assembly man-hours, as well as eliminate the need for materials and work man-hours to cover the horn switch in advance. The purpose is to provide an impact energy absorbing structure.

In the impact energy absorbing structure of the present invention, a rib is formed on the inner surface of the cover body on which the horn switch is set, and the entire circumference of the contact plate of the horn switch comes into contact with the inner surface of the cover body. The above object is achieved by integrally molding the energy absorber by injection molding a brittle plastic material into the body.

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows a cross-sectional view of the impact energy absorbing structure during molding.
The cover body 11 is molded by injection molding using soft plastic materials such as PUR, PVC, or their soft foams, and after the cover body 11 is molded, only the male mold is released, and the cover body 11 is held by the female mold 12. The state will be as follows. In this state, the horn switch 13 is inserted into the cover body 11.
A rib 14 is provided on the inner surface of the tip of the cover body on which the horn switch 13 is set, and a rib 14 is provided so as to make contact with the entire circumference of the contact plate 13a of the horn switch 13.
It is set in a fixed position abutting the periphery of 3a. 1
3b is a contact point of the horn switch 13, 13c is an elastic insulator, and a lead wire 13d is drawn out from the center of the contact plate 13a.

With the horn switch 13 set in the cover body 11, press the male mold 1 with the presser tube 15a in the center.
5 on top of the female die 12, and the presser tube 1
5'a presses the horn switch 13 onto the rib 14 to close the mold. At this time, the lead wire 13d of the horn switch 13 is inserted into the presser tube 15a. Then, a hard foamed plastic material such as hard foamed PUR/PS is injected as a brittle plastic through an injection port 15b provided in a part of the male mold 15, and is filled into the internal space of the cover body 11 and foamed and hardened. At this time, the injected plastic material is prevented from penetrating into the horn switch 13 by the ribs 14, and its function will not be impaired even if the horn switch 13 itself is not coated in advance.

As described above, a brittle plastic material is injected inside the cover body 11 to form the energy absorber 1.
As shown in FIG. It is led out through a vertical hole formed by the cylinder.

FIG. 4 shows another embodiment in which the horn switch 13 is set inside the cover body. As shown in this figure, an undercut-shaped protrusion 18a is provided on the inner surface of the cover body 18, and this protrusion 18a and ribs are provided. The contact plate 13a of the horn switch 13 can be sandwiched between the contact plate 18b and the energy absorber 18b to prevent the energy absorber from flowing in during injection molding.

As explained above, according to the impact energy absorbing structure of the present invention, the energy absorber is integrated by injection molding a plastic material into the cover body, and the female mold can be shared with the cover body during molding. Furthermore, since the cover body, horn switch, and energy absorber are attached to the boss plate in an integrated state, assembly is easy and the number of man-hours can be reduced. Furthermore, when molding the energy absorber, it is possible to prevent material from flowing into the horn switch set inside the cover body.
There is no need to seal the horn switch with a cover or the like in advance, and the cost of materials and man-hours for this can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional impact energy absorbing structure, FIG. 2 is a sectional view of an embodiment of the present invention during molding, FIG. 3 is a sectional view of the completed impact energy absorbing structure, and FIG. The figure is a schematic sectional view of another embodiment. 11, 18... Cover body, 13... Horn switch, 13a... Contact plate, 14... Rib,
15a...presser tube, 16...energy absorber, 18
a...Protrusion.

Claims (1)

[Claims] 1. In an impact energy absorbing structure for a steering wheel in which a horn switch is disposed between a brittle plastic energy absorber and a cover body, the entire contact plate of the horn switch is attached to the inner surface of the cover body where the horn switch is set. The energy absorber is integrated by injection molding a brittle plastic material into the cover body, which forms a rib whose periphery is in contact with the cover body, and the horn switch is pressed and set onto the rib. Steering wheel impact energy absorption structure.