JPH08119117A - Mounting structure for energy absorption pad - Google Patents

Abstract

PURPOSE: To provide an energy absorption pad mounting structure capable of increasing the number of reinforcement ribs for adding prescribed strength to a boss, or reducing the size of the ribs without any increase in boss diameter, and almost free from a restriction on the degree of freedom for the design of an energy absorption pad. CONSTITUTION: An energy absorption pad 11 is formed out of a soft resin cover section 13, and a hard resin insert 15 to be broken under the preset load value for energy absorbing action. Also, the whole or a part of a mounting means is formed into the insert 15, and a tapping screw 43 is screwed into a tapping boss 39 strengthened with a reinforcement rib 18. Regarding the status of inserting the screw 43 into the boss 39, effective screwing length L is kept equal to three times or more of a nominal diameter, and a gap equal to or above 1mm is formed on the bottom section of the prepared hole of the boss 39.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting an energy absorbing pad which is composed of a soft resin coating portion and a hard resin insert which is damaged by a set load value and has an energy absorbing action. Relates to a mounting structure for an energy absorbing pad in which a tapping screw is screwed into a tapping boss formed in a hard resin insert.

Here, as an energy absorbing pad,
The horn pad will be described as an example, but the present invention is not limited to this.

[0003]

2. Description of the Related Art Recently, in order to improve energy absorption characteristics of a steering wheel, a hard resin insert is damaged (cracked) at a set load value in the design of a horn pad, etc. The need to design to have a curve has arisen.

On the other hand, a horn pad or the like is generally held by a contact plate or the like by screwing a tapping screw through a holding spacer into a tapping boss formed in a hard resin insert as a part of mounting means. To adopt.

[0005] The tapping boss usually has reinforcing ribs arranged around it to secure its strength.

[0006]

However, since it is necessary to form a slit and a guide V groove for breaking in order to give the hard resin insert energy absorbing characteristics, it is possible to dispose a reinforcing rib that interferes with these. Disappears, that is,
It is necessary to reduce the number and size of the reinforcing ribs. Therefore, it becomes difficult to dispose reinforcing ribs of the number or size necessary for imparting a predetermined strength to the boss, and as a result, the energy absorbing pad, particularly,
The degree of freedom in designing hard resin inserts is greatly limited.

Although it is possible to deal with the problem by increasing the diameter of the boss, it is not desirable because a large shrinkage which appears on the surface of the resin insert through the resin coating portion is likely to occur.

In view of the above, the present invention makes it possible to reduce the number or size of the reinforcing ribs for imparting a predetermined strength to the boss without increasing the diameter of the boss, and the energy absorbing pad can be designed freely. It is an object of the present invention to provide an attachment structure for an energy absorbing pad which is almost unlimited in degree.

[0009]

The energy absorbing pad mounting structure of the present invention solves the above problems by the following constitution.

A structure for mounting an energy absorbing pad consisting of a soft resin coating portion and a hard resin insert which is damaged by a set load value and has an energy absorbing action, wherein all or part of the mounting means is the hard resin insert. In the configuration in which the tapping screw is screwed into the tapping boss reinforced by the boss reinforcing rib,
The tapping screw is screwed into the tapping boss in such a manner that the effective screwing length is 3 times or more of the nominal diameter, and there is a clearance of 1 mm or more at the bottom of the pilot hole of the tapping boss. Is characterized in that.

[0011]

EXAMPLES The present invention will now be described in detail based on examples (see FIGS. 1 to 4).

(1) Basically, the energy absorption pad 1
Reference numeral 1 denotes a structure including a soft resin coating portion 13 and a hard resin insert 15 that is damaged by a set load value and has an energy absorbing action (see an energy absorption curve in FIG. 5).
All or part of the attaching means is formed in the hard resin insert 15 and the tapping screw 43 is screwed into the tapping boss 39 reinforced by the boss reinforcing ribs 18.

Specifically, the hard resin insert 15 is
A main body reinforcing rib 17 for ensuring rigidity is formed, and a central slit 19 is formed at a longitudinal center line position and side slits 20 are formed on both sides thereof in order to break at a set load value. A guide V groove 21 is formed.

In the illustrated example, the energy absorbing pad also serves as a horn pad, and therefore is incorporated in a horn switch mechanism as described below.

By pressing the horn pad 11 against the spring force, the movable contact 23 that interlocks with the horn pad 11 has a fixed contact 2 arranged below the horn pad 11.
It is equipped with a mechanism that comes into contact with 5 and becomes conductive. And
The fixed contact 25 is formed on a contact plate 27 made of sheet metal, and the spacer shaft insertion hole 2 formed on the plate 27
The holding spacer 33 that is inserted into the connector 9 and is locked by the flange portion 31 is attached, and the contact stroke is adjusted. This holding spacer 33 is provided with a temporary fixing rib 3.
4 together with 4 form the attachment means of the energy absorbing pad.

Specifically, the spring force is carried by a pair of inverted chevron-shaped leaf springs 37, 37 which are attached to the upper surfaces of both sides of the contact plate 27 having a central opening through the insulating piece 35. In addition, the movable contact 23 is the inverted chevron leaf spring 3
Pressing ribs 1 formed under both ends of 7, 37 and also as reinforcing ribs formed in the insert 15 of the horn pad 11.
7A contacts the upper surfaces of both ends of the inverted chevron-shaped leaf springs 37, 37 to press the movable contact 23.

In addition, the holding spacer 33 is inserted into the spacer shaft insertion hole 29 from below from the boss 39 formed in the insert 15 of the horn pad 11, and the tip of the spacer shaft 24 is brought into contact with the boss 39. , From the bottom of the spacer 33 to the boss 3
A tapping screw 43 is screwed and fixed in the prepared hole 41 formed in 9. In the figure, reference numeral 45 is a clip for temporarily fixing the contact plate 27 to the spoke portion of the steering wheel or the like.

(2) In the above structure, as shown in FIG.
The tapping screw 43 is screwed into the tapping boss 39 in such a manner that the effective screwing length L is three times or more the nominal diameter, and a gap S of 1 mm or more is formed at the bottom of the prepared hole 41 of the tapping boss 39. I have.

The effective screw-in length L is set as in this embodiment.
By making it 3 times or more, the screw-in length becomes longer,
The strength of the boss portion can be increased as compared with the conventional case where the strength is twice as strong as the nominal diameter.

When the effective screw-in length L is set to be slightly stronger than twice the nominal diameter, the boss reinforcing rib 18 exceeds the damage-inducing V-groove 21 as shown by the chain double-dashed line and the side wall of the main body of the hard resin insert. It was necessary to reinforce the tapping boss 39 by extending it up to 15a, or extending over the slit portion 20 to the next reinforcing rib 17, but in the present embodiment, as shown in the drawing, the slit 20 is provided. It can be reduced to a right-angled triangle having a size that ends before the damage-inducing V groove 21.

[0021]

As described above, in the mounting structure of the energy absorbing pad of the present invention, the mode of screwing the tapping screw into the tapping boss is an effective screwing length of 3 times or more of the nominal diameter, and Since there is a gap of 1 mm or more at the bottom of the prepared hole of the tapping boss, the apparent strength of the tapping boss when the pad is attached increases. Even if the diameter of the boss is not increased, the number of reinforcing ribs for imparting a predetermined strength to the boss can be reduced or the size thereof can be reduced, and the degree of freedom in designing the energy absorbing pad is hardly limited.

[Brief description of drawings]

FIG. 1 is a back view of an energy absorption pad in which a horn switch is assembled according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a sectional view taken along line CC of FIG.

FIG. 5 is a model diagram of an absorption characteristic curve of an energy absorption pad

[Explanation of symbols]

 11 Energy Absorbing Pad 13 Soft Resin Cover 15 Hard Resin Insert 17 Main Body Reinforcing Rib 18 Boss Reinforcing Rib 21 Damage Induction V Groove 39 Tapping Boss 41 Taping Boss 43 Tapping Screw

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akio Hosoi No. 1 Nagahata, Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi Toyota Gosei Co., Ltd. Address within Toyoda Gosei Co., Ltd.

Claims (1)

[Claims] 1. A structure for mounting an energy absorbing pad comprising a soft resin coating portion and a hard resin insert which is damaged by a set load value and has an energy absorbing function, wherein all or part of the mounting means is made of the hard resin. In the configuration in which the tapping screw is screwed into the tapping boss formed on the resin insert and reinforced with the boss reinforcing ribs, the tapping screw is screwed into the tapping boss in such a manner that the effective screwing length is equal to the nominal diameter. An attachment structure for an energy absorbing pad, which is three times or more in size and has a clearance of 1 mm or more at the bottom of the prepared hole of the tapping boss.