JPH0510152U - Steering wheel pad with planar switch - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a steering wheel pad equipped with a membrane switch capable of preventing deformation of the membrane switch as a planar switch and maintaining performance such as withstand voltage and insulation of the membrane switch. It is in. [Structure] An insert 7 made of a hard material, a resin cover 9 made of a soft material provided on the insert 7, and a membrane switch 10 embedded in the resin cover 9, and the membrane switch 10 and the resin cover. 9, a deformation preventing layer 17 formed of a liquid release agent, a lubricant or the like for preventing the deformation of the membrane switch 10 is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a steering wheel pad that is mounted on a steering wheel of an automobile and includes a planar switch.

[0002]

[Prior Art]

 Conventionally, the following are known as steering wheel pads equipped with an airbag. That is, as shown in FIG. 7, the holder 1 made of a metal plate, which constitutes the frame of the pad P, is mounted on the boss portion 2 of the steering shaft S. An inflator 3 is attached and fixed to the holder 1 at a central portion of the pad P via a flange portion 4 by a plurality of rivets 5.

The inflator 3 is provided with an ignition device, and the gas generating agent is decomposed by the operation of the ignition device to generate nitrogen gas. An airbag 6 made of polyamide fiber is folded and stored around the outer periphery of the upper portion of the inflator 3. The airbag 6 is inflated by the nitrogen gas generated by the inflator 3.

An insert 7 is attached and fixed to the holder 1 by a rivet 8. This insert 7 is made of a hard material such as polyethylene terephthalate (PET), a high hardness thermoplastic polyurethane (TPU), or a metal such as aluminum in order to maintain a certain shape and protect the inflator 3 and the airbag 6. Has been formed.

A polyamide resin net 11 is attached and fixed to the upper part of the insert 7, and a planar switch (hereinafter referred to as a membrane switch) 10 which is operated by a pressing force from above is arranged on the net 11. There is. The net 11 and the membrane switch 10 are formed inside the resin cover 9 by insert molding together with the insert 7. That is, it is molded by setting the insert 7 in a cavity of a mold (not shown) and then injecting a molten resin material forming a resin cover 9 into the cavity. The resin cover 9 is made of a soft material such as soft vinyl chloride resin and the TPU.

As shown in FIG. 6, the membrane switch 10 is arranged below the line when the airbag 6 is inflated and the pad P is expanded, that is, below the inflation line L in FIG. There is. As shown in FIG. 5, the membrane switch 10 has a flat trapezoidal shape, and lead wires 18a and 18b are taken out from both sides of the lower part thereof and connected to a horn device (not shown). As shown in FIG. 4, in this membrane switch 10, a phosphor bronze thin plate 13 is sandwiched between two stainless steel thin plates 12 and further covered with a resin thin film 14. It is formed by.

As shown in FIGS. 4 and 5, the two stainless steel thin plates 12 are provided with strip-shaped insulating layers 15 as band-like spacing members on the outer periphery thereof, respectively. A large number of spacers 16 as spacing members are formed so as to project. The insulating layer 15 and the spacer 16 serve to insulate the thin plate 12 made of stainless steel from the thin plate 13 made of phosphor bronze. By pressing this membrane switch 10, one of the stainless steel thin plates 12 comes into contact with the phosphor bronze thin plate 13 to conduct electricity, and the horn can be sounded via the lead wires 18a and 18b. You can do it.

[0008]

[Problems to be solved by the device]

 However, as described above, the thin film membrane switch 10 is molded together with the insert 7 and the net 11 by the insert molding method, and after molding, is embedded in the resin cover 9 in a state of being in close contact therewith. On the other hand, the coefficient of thermal expansion of stainless steel or phosphor bronze forming the thin plates 12 and 13 of the membrane switch 10 is smaller than that of urethane resin forming the resin cover 9.

Therefore, when the atmospheric temperature of the pad P rises or falls during use, the membrane switch 10 expands and contracts less than the resin cover 9. As a result, if the membrane switch 10 and the resin cover 9 are in close contact with each other, the membrane switch 10 may be deformed.

In that case, there has been a problem that performance such as withstand voltage and insulation of the membrane switch 10 is deteriorated. The present invention has been made in view of the above problems, and an object thereof is to provide a planar switch capable of preventing deformation of the planar switch and maintaining performance such as withstand voltage and insulation of the planar switch. To provide steering wheel pads.

[0011]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, an insert made of a hard material for reinforcing the pad disposed in the pad, a cover layer made of a soft material provided on the insert, and the cover layer A steering wheel pad comprising a sheet-like switch embedded in the sheet-like switch, the sheet-like switch having a deformation preventing layer provided between the sheet-like switch and the cover layer to prevent deformation of the sheet-like switch. It is a summary.

[0012]

[Action]

 A deformation prevention layer is provided between the planar switch and the cover layer. Therefore, even if the ambient temperature of the pad rises or falls and the planar switch and the resin cover expand or contract differently, the planar switch moves relative to the resin cover. As a result, the planar switch does not deform, and the performance such as withstand voltage and insulation is maintained.

[0013]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. In this embodiment, parts different from the conventional example will be mainly described, and the same reference numerals will be used for the same members as the conventional example.

As shown in FIG. 1, an insert 7 and a net 11 whose end is fixed to the insert 7 are embedded in a resin cover 9 made of urethane resin. The membrane switch 10 as a planar switch is arranged on the net 11. A deformation prevention layer 17 for preventing deformation of the membrane switch 10 is provided on the outer surface of the membrane switch 10.

The deformation prevention layer 17 is formed of a liquid or paste-like substance such as a silicone-based release agent, a lubricant, other oils and greases. The deformation preventing layer 17 may be formed by a dipping method or a coating method by brushing or spraying. The thickness of the deformation preventing layer 17 depends mainly on the viscosity of the liquid or pasty substance. The higher the viscosity is, the thicker the thickness is. However, even if the thickness is a little thin, the membrane switch 10 can be moved relative to the resin cover 9. You can

The operation and effect of assembling and using the membrane switch 10 in the steering wheel configured as described above will be described. First, the deformation prevention layer 17 is formed on the outer surface of the membrane switch 10 by immersing the membrane switch 10 in the liquid substance in advance. Next, the insert 7, the net 11, and the membrane switch 10 covered with the deformation preventing layer 17 are fixed at a predetermined position in the cavity of the mold, and in that state, the melted urethane resin material is injected into the cavity. As a result, as shown in FIGS. 1 and 2, a pad P in which the membrane switch 10 is embedded in the resin cover 9 is formed.

The pad P thus formed is exposed to a high temperature atmosphere in summer or a low temperature atmosphere in winter during use. At that time, since the thin plates 12 and 13 of the membrane switch 10 formed of stainless steel or phosphor bronze have a smaller coefficient of thermal expansion or contraction than the resin cover 9 formed of urethane resin, the thin plates 12 and 13 expand more than the resin cover 9. , Small shrinkage. Therefore, the membrane switch 10 tends to move relative to the resin cover 9.

At this time, since the membrane switch 10 is covered with the deformation preventing layer 17 made of a liquid substance as shown in an enlarged view in FIG. 2, the membrane switch 10 is against the resin cover 9 during its expansion and contraction. Relative movement is possible. For example, as shown in FIG. 3, when the atmospheric temperature becomes high, the membrane switch 10 shrinks less than the resin cover 9, so the membrane switch 10 moves relatively to the left side in the figure with respect to the resin cover 9. ..

Therefore, it is possible to avoid the situation where the membrane switch 10 is deformed because the membrane switch 10 is in close contact with the resin cover 9 as in the conventional case. As a result, the initial performance such as withstand voltage and insulation of the membrane switch 10 is continuously maintained. Therefore, the operation of the membrane switch 10 is normally maintained.

The present invention is not limited to the above embodiment, but may be configured as follows. (1) In the above embodiment, the pad P is applied to the pad P having the structure in which the airbag 6 is housed, but the pad P without the airbag 6 may be applied. (2) The resin cover 9 in the above embodiment may be covered with a leather or cloth as a sheet-like skin. (3) The deformation prevention layer 17 may be a member other than the liquid substance shown in the embodiment, such as a sponge, which is easily deformable and allows the resin cover 9 and the membrane switch 10 to move relative to each other. (4) The membrane switch 10 may be used as a switch for an auto drive or the like other than the horn switch.

[0021]

[Effect of the device]

 As described above in detail, according to the present invention, it is possible to prevent the planar switch from being deformed and to continuously maintain the withstand voltage and the insulating property of the planar switch.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a pad of a steering wheel according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an essential part showing an enlarged membrane switch in a pad.

FIG. 3 is an enlarged sectional view of an essential part showing the operation of the present embodiment.

FIG. 4 is a partial cross-sectional view showing a membrane switch.

FIG. 5 is a plan view showing a membrane switch.

FIG. 6 is a schematic plan view showing a steering wheel.

FIG. 7 is a schematic cross-sectional view showing a pad of a steering wheel.

[Explanation of symbols]

7 ... Insert, 9 ... Resin cover as cover layer, 1
0 ... Membrane switch as planar switch, 17 ...
Deformation prevention layer, P ... Pad.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tohru Hikari, 1 Ochiai, Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi Prefecture Toyota Gosei Co., Ltd. Address inside Toyota Gosei Co., Ltd.

Claims (1)

[Claims for utility model registration] 1. An insert (7) made of a hard material for reinforcing the pad (P) arranged in the pad (P), and provided on the insert (7). A cover layer (9) made of a soft material, and a planar switch (1) embedded in the cover layer (9).
0) and a deformation prevention layer (17) for preventing deformation of the planar switch (10) is provided between the planar switch (10) and the cover layer (9). Steering wheel pad with a switch.