JPH0687383B2 - Method of manufacturing fixed contact for elastic push button switch - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method of manufacturing a fixed contact of an elastic push button switch.

<< Summary of the Invention >> According to the present invention, a pair of contact pieces whose one ends are connected to each other is formed by punching a tape material having conductivity, and only the connecting portions of the contact pieces are gold-plated. When the connecting portion of the contact pieces is cut at the center, the intermediate portions of both contact pieces are bent to form a gap between the cut surfaces.

<< Background of the Invention >> In an elastic push button switch in which a fixed contact is composed of a pair of contact pieces, the contact pieces are insert-molded in a switch case.

Then, one ends of the contact pieces are opposed to each other on the bottom surface of the switch case, and they form a fixed contact body.

The movable contact that short-circuits the ends of these contact pieces is made of conductive rubber, and is provided at the bottom of the bowl-shaped rubber member that is in a prone posture on the bottom surface of the switch case.

Here, in the prior art, a wire is laterally fitted into a hole formed in one end side of both contact pieces to be cut, and the wires protruding to both sides of the contact piece are caulked to thereby fix the fixed contact. A body is formed.

One end of the fixed contact body forming side is opposed on the bottom surface of the switch case during the insert molding, and the movable contacts are pressed against the caulked portions through the bowl-shaped rubber member so that both contact pieces are brought into conduction to perform switching. Be done.

However, in this type of elastic push button switch in the related art, since the caulking portion is projected from the bottom surface of the switch case, the movable contact made of conductive rubber pressed against these locally plastically deforms, and therefore the switch contact is made. There is a problem that the contact pressure is lowered, a problem that the contact reliability of the contact is lowered due to the transfer of metal on the fixed contact side to the movable contact side, and a caulking margin is required, which is inconvenient for downsizing the contact. There was a problem that it would occur.

Therefore, before insert molding into the switch case,
It has been proposed to locally plate only one end of each contact piece on the side where the fixed contact body is formed, thereby solving the conventional problem.

In the proposal, the conductive hoop material 10 of FIG. 8 is gold-plated 12 in the longitudinal direction at the center in the width direction as shown in FIG. 8, and then the hoop material is gold-plated as shown in FIG. The die is punched.

As a result, the terminal piece holding frames 16 having the pilot holes 14 are formed on both sides of the hoop material 10, and the pair of terminal pieces 20-each extending from the terminal piece holding frames 16 on both sides toward the center of the hoop material 10- 1,20-2 are formed.

Half-moon shaped fixed contact body portions 20-1 and 20-2 each having a gold-plated 12 are formed at their forming tips, and they are opposed to each other with a predetermined gap.

The fixed contact body portions 20-1 and 20-2 of the contact pieces 20-1 and 20-2 are exposed on the bottom surface of the switch case during insert molding of the switch case, and therefore the movable contact made of conductive rubber is pressed during switching. The surface is flat with gold plating.

As a result, local plastic deformation of the movable contact is prevented, stable contact contact pressure is maintained, caulking margins are not required, the contact part is miniaturized, and gold plating has excellent environmental resistance, so contact reliability of the contact is improved. Is increased.

However, in the fixed contact manufacturing method according to this proposal, since the material loss of the hoop material 10 is large, the manufacturing cost of the switch increases, which is an improvement compared with the case where the gold plating 12 is applied over the entire surface of the hoop material 10. However, since the loss of gold-plated material is still large, the manufacturing cost of the switch also rises at that point, and since the contact pieces 10-1 and 10-2 are cantilevered with respect to the contact piece holding frame 16, the dimensional accuracy is improved. And the gap is formed between the fixed contact body portions 20-1 and 20-2, the life of the die used for punching in FIG. 9 is short, and the diver portion 21 in FIG. 9 is molded. When cut later, there is a problem that the cut surface is exposed and a short circuit may occur between the contact pieces.

<Purpose of the Invention> The present invention has been made in view of the problems of the above proposal,
The purpose of this is to secure elastic push button switches with low material loss, low cost, high dimensional accuracy, longer life of die used for punching, and effective prevention of short circuit between terminal pieces. It is to provide a manufacturing method of a contact.

<< Structure and Effect of the Invention >> In order to achieve the above object, the present invention comprises a pair of contact pieces insert-molded in a switch case, and a fixed contact body is formed by one end of both contact pieces facing each other on the bottom surface of the switch case. In the method of manufacturing a fixed contact for an elastic push button switch, by punching a conductive tape material,
A pair of contact pieces whose ends are connected to each other on the side where the fixed contact body is formed and a contact piece holding frame that holds both contact pieces are integrally formed, and gold plating is applied only to the connecting portion of both contact pieces. It is characterized in that the connecting portion of the piece is cut at the center, and the middle portion of both contact pieces is bent to form a gap between the cut surfaces.

According to the present invention, the loss of the tape material (the hoop material 10) and the plating material is significantly reduced, which makes it possible to significantly reduce the manufacturing cost of the elastic push button switch.

Further, since the tape material is punched so that the fixed contact body forming ends of both contact pieces are connected to each other, the dimensional accuracy can be remarkably improved.

Furthermore, since the center of the connecting part is cut, and then the gap between the cut surfaces is formed by bending the middle part of both contact pieces,
It is possible to significantly improve the life of the mold.

Since the contact piece eventually double-supports with respect to the contact piece holding frame, the diver section is not required, which enables effective material removal and short-circuit between contact pieces without spoiling the aesthetic appearance of the switch. Can be prevented in advance.

<< Description of Embodiments >> Preferred embodiments of a manufacturing method according to the present invention will be described below with reference to the drawings.

In this embodiment, the hoop material 10 is punched as shown in FIG.

At that time, the contact pieces 18-1, 1 are arranged parallel to the longitudinal direction of the hoop material 10.
8-2 is punched out and their fixed contact bodies 20-1 and 20-2 are connected.

Two pairs of the contact pieces 18-1 and 18-2 are punched at the same time in the width direction of the hoop material 10, and the fixed contact body portions 20-1 and 20-2.
-2, the other ends of the contact pieces 18-1 and 18-2 opposite to the -2 side are drawn out from the frame side of the contact piece holding frame 16.

When the above punching process is performed on the hoop material 10,
Gold plated only on the connecting part of both contact pieces 18-1, 18-2 12
Is applied.

In this embodiment, the gold plating 12 is applied by a so-called partial plating method, and the partial plating method can be an intermittent method, a jet method or the like.

In this embodiment, gold plating 12 is applied in a circular shape as shown in FIG. 2 around the boundary between the fixed contact body portions 20-1 and 20-2 which are the connecting portions of both contact pieces 18-1 and 18-2. In plating, other unnecessary parts are masked.

A plating material can be used as the hoop material 10, but a phosphor bronze or brass material plated with Ni can also be used.

Further, the plating thickness of the gold plating 12 is set to about 0.8 to 1.0 μm, which ensures sufficient contact reliability of the contacts.

In this way, when the gold plating treatment is applied only to the connecting portions of the contact pieces 18-1, 18-2 in FIG. 1, as shown in FIG. 3, the contact pieces 18-1, 18-2 in FIG. The connecting portion of 18-2 is cut at the center.

Further, as shown in FIG. 4, a bending process is performed in which a step is provided at an intermediate portion of both contact pieces 18-1, 18-2, whereby a fixed contact body of both contact pieces 18-1, 18-2 is formed. Section 18-1,18-
A gap G of about 0.3 mm is formed between the two.

As a result, as shown in FIG. 5, two pairs of contacts in which the fixed contact body portions 20-1 and 20-2 having the gold plating 12 are opposed to each other through the gap G and cantilevered on the contact piece holding frame 16 Piece 18-
1, 18-2 are formed on the hoop material 10.

These contact pieces 18-1 and 18-2 are switch cases 22 shown in FIG.
As shown in FIG. 7, insert molding is performed, and the fixed contact body portions 20-1 and 20-2 are arranged at the center of the bottom of the switch case 22.

The other ends of the contact pieces 18-1 and 18-2, which are opposite to those, are pulled out from the lower side portion of the switch case 22 toward the lower side of the figure.

Further, the bottom of the switch case 22 has an opening above the fixed contact bodies 20-1 and 20-2, which exposes the fixed contact bodies 20-1 and 20-2 on the bottom surface of the switch case 22. ing.

In FIG. 6, a bowl-shaped rubber member 24 is inserted into the switch case 22 in a lying posture, and is placed on the bottom surface of the switch case 22 in that posture as shown in FIG.

As shown in the figure, a movable contact 26 is provided on the bottom of the rubber member 24, and the movable contact 26 is formed integrally with the rubber member 24 having conductivity.

The head portion of the rubber member 24 in FIG. 7 is pushed by an operator 27 fitted in the switch case 22, and the movable contact 26 is lowered by the pushing operation and the fixed contact body portions 20-1 and 20 By contacting -2, both are conducted and switching is performed.

In the switch shown in FIG. 6, both legs of the light emitting diode 28 are fitted into both sides of the switch case 22 through slits formed on the side of the operator 27, and the main body is housed in the head of the operator 27. To be done.

And the reflected plate 30 is fitted on the head of the operator 27,
Then, the button 32 to be pushed is externally fitted.

Further, the reflection plate 30 and the button 32 are provided with a light transmission window and a light hole, respectively, through which the lighting light of the light emitting diode 28 is radiated to the outside.

Further, in FIG. 7, the terminal pieces 18-1 and 18-2 and the rubber member 24 are
The movable contact 26 is insulated from the movable contact 26 by the bottom of the switch case 22.

Furthermore, the gap G of the fixed contact body 20-1, 20-2 is 0.3 mm.
However, in this type of switch, contact pieces 18-1,18
Since the voltage between -2 is low, no inconvenience occurs in the switch operation.

As described above, according to this embodiment, as can be understood from the comparison between FIG. 1 and FIG. 9, the hoop material 10 can be effectively used for forming a fixed contact, and the material loss is extremely small. It becomes possible to do.

Further, according to this embodiment, the center of the connecting portion of the contact pieces 18-1 and 18-2 is cut as shown in FIG. 3, and then the intermediate portion thereof is bent as shown in FIG. Since the gap G is formed by doing so, the gold plating 12 portion other than the fixed contact body portions 20-1 and 20-2 does not cause material loss as shown in FIG. It can be used for.

As described above, according to the present embodiment, the material loss can be significantly reduced, so that the manufacturing cost of the switch can be significantly reduced.

Further, according to this embodiment, the gap G is not punched out to form the gap G, and the cutting and bending processes are performed as shown in FIGS. 3 and 4, so that the life of the die is reduced. The cost of manufacturing the switch can be further reduced.

Further, as shown in FIG. 1, the fixed contact body 20-1, 20-
As a result, 2 is double-supported with respect to the contact piece holding frame 16,
Since no diver part is provided, the material loss can be further reduced. In addition, the diver section is not cut after molding, and therefore the cut surface is not exposed so that the appearance of the switch is not spoiled and the short-circuit between the contact pieces 18-1 and 18-2 is surely prevented. Will also be possible.

According to this embodiment, a constant and accurate gap G is formed by the cutting process shown in FIG. 3 and the bending process shown in FIG. 4, which makes it possible to manufacture a fixed contact with high dimensional accuracy.

[Brief description of drawings]

FIG. 1 is an explanatory drawing of punching processing for a hoop material, FIG. 2 is an explanatory drawing of gold plating processing for a contact piece connecting portion, FIG. 3 is an explanatory view showing center cutting processing of the contact piece connecting portion, and FIG. 4 is an intermediate contact piece. Fig. 5 is an explanatory view of the bending process of the part, Fig. 5 is a hoop material product explanatory diagram in which the punching process of Fig. 1, the gold plating process of Fig. 2, the cutting process of Fig. 3 and the bending process of Fig. 4 have been performed. FIG. 6 is an exploded perspective view of the elastic push button switch, FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6, and FIG.
FIG. 9 is a drawing for explaining the gold plating process in the proposed method, and FIG. 9 is a drawing for explaining the punching process of the hoop material in the proposed method. 10 …… Hoop material 12 …… Gold plated 14 …… Pilot hole 16 …… Contact piece holding frame 18-1,18-2 …… Contact piece 20-1,20-2 …… Fixed contact body 22 …… Switch case 24 …… Rubber member 26 …… Movable contact 27 …… Operator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-53-42362 (JP, A) JP-A-54-50973 (JP, A) JP-A-54-63279 (JP, A) JP-A-54- 149872 (JP, A) JP 57-128421 (JP, A) JP 59-198618 (JP, A) Actual development 54-57373 (JP, U))

Claims (1)

[Claims] 1. A method of manufacturing a fixed contact for an elastic push button switch, comprising a pair of contact pieces insert-molded in a switch case, the fixed contact body being formed by one end of both contact pieces facing each other on the bottom surface of the switch case. In, by punching the conductive tape material,
A pair of contact pieces whose ends are connected to each other on the side where the fixed contact body is formed and a contact piece holding frame that holds both contact pieces are integrally formed, and gold plating is applied only to the connecting portion of both contact pieces. A method for manufacturing a fixed contact for an elastic push button switch, characterized in that the connecting portion of the piece is cut at the center, and the middle portion of both contact pieces is bent to form a gap between the cut surfaces.