JPS6398405A - Preparation of switch case - Google Patents

Abstract

PURPOSE:To make a hole-filling operation unnecessary and to reduce the total cost of a switch, by bending a terminal in such a way that a convex face is formed in the opposite direction against the press-cut direction, clamping the terminal between a top force and a bottom force and contacting the concave face of the terminal to the receiving face of a cavity under pressure. CONSTITUTION:A terminal 9 of a base plate 6 is press-cut from the convex face side to the concave face side. The base plate 6 is transferred and positioned along the guide of a bottom force 13 in such a way that the convex face of the terminal 9 faces upward, and a top force 12 and the bottom force 13 are clamped. The curved terminal 9 is clamped between flat facing faces of the top and the bottom forces 12 and 13, and the free end 2a of the terminal 9 is contacted under pressure on a receiving face B due to a counterforce. After clamping the mold, a resin 15 is injected and poured in a cavity 11 from a gate 12a, and the resin is applied in the cavity 11 without penetrating between a fixed contact 2a and the receiving face B. The terminal 9 is cut off and bent and a switch case in which a case 1 and a terminal 2 are integrally combined can be thereby obtained. Since no hole communicating to the fixed contact 2a exists on the rear face of the case 1, there is no possibility of contact obstruction due to the penetration of flux.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a switch case in which a part of a terminal serving as a switch contact is embedded in a synthetic resin case and these are integrated.

[Conventional technology]

A conventional example of this type of switch case will be explained based on a dip switch shown in FIG.

In the figure, 1 is a case made of thermoplastic synthetic resin with an open top surface, and 2 is a metal terminal that is partially embedded in the case 1 by integral molding. No, a plurality of pairs of terminals 2 are installed at equal intervals in a direction perpendicular to the plane of the paper. 2a is a fixed contact portion provided on each terminal 2, and a predetermined gap A is formed between the pair of opposing fixed contact portions 2a. 3 is a synthetic resin slider, and 4 is a metal slider, a part of which is attached to the lower surface of the slider 3. Although not shown, the slider 3 is made to be able to slide only in the left and right directions in FIG. By sliding, the slider 4 alternatively comes into contact with the paired fixed contact portion 2a.
Conduction is possible. The sliders 3 are provided in a number corresponding to the number of paired terminals 2. 5
is a cover made of thermoplastic synthetic resin that covers the open surface of the case 1, and is provided with a plurality of guide grooves 5a from which the knob 3a of the slider 3 protrudes and slides. It is fixed to case 1.

In a DIP switch configured in this manner, the case 1 and each terminal 2 are usually integrally molded using a molding machine (hereinafter, this integral height will be referred to as a switch case), increasing mass productivity. The process of manufacturing such a switch case will be explained with reference to FIGS. 7 and 8. First, hoop-shaped metal plates prepared in advance are sequentially fed and a base plate 6 of a predetermined shape is pressed. As shown in FIG. 7, this base plate 6 has a plurality of terminal parts 9 protruding from a pair of frame parts 8 having a large number of feed holes 7 at equal intervals, and a frame part 8 facing each other.
After this is sent into a mold device (not shown), molten resin is injected into a cavity 11 shown by a two-dot chain line in the figure.

Next, the molten resin is cooled and solidified in a mold apparatus, and as shown in FIG. 8, a synthetic resin case 1 having a plurality of terminal portions 9 on both sides is molded.

Finally, each terminal part 9 is separated from the frame part 8 at the position shown by the broken line in FIG. 8, and by bending the separated terminal part 9, the case 1 and the terminal 2
Get the Zunawaji switch case, which is an integrated product.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned mold device, the mold structure shown in FIG. 9 is adopted in the area where the pair of terminals 2 face each other (near the fixed contact portion 2a).
2a is an upper mold, 13 is a lower mold having a protrusion 13a, 1
4 is a presser pin provided integrally with the upper die 12a; 15 is a resin; the base plate 6, which has been pressed into a predetermined shape, is held between the opposing terminal portions 9 (refixed contact portions 2a) of the lower die; After conveying to the mold apparatus so that the protrusion 13a of I3 is positioned, the upper mold 12 and lower mold 13 are clamped, and molten resin 15 is injected into the cavity 11 through the gate 12a. Here, the vicinity of the free end of the re-fixed contact part 2a is pressed against the receiving surface B of the lower mold 13 by the presser bottle 14 during mold clamping, so that the molten resin 15 is transferred between the fixed contact part 2a and the lower mold 13.
There is almost no possibility that it will get between it and the receiving surface B.

However, in such a mold structure, the fixed contact portion 2a is pressed and fixed to the receiving surface B by the presser pin 14 that reaches into the cavity 11, so the molten resin 15 is cooled and solidified, and the switch case is attached to the mold device. When taken out, the fifth
As shown in the figure, a hole 1a is formed on the lower surface of the case 1 by the presser pin 14, and flux, etc.
There is a problem in that the contact reaches the fixed contact portion 2a through the contact point, inducing contact failure such as short circuit or corrosion of the switch contact. For this reason, conventional dip switches require a step of closing the hole 1a after molding the switch case, such as filling the hole 1a with another resin or pasting adhesive tape for sealing on the bottom surface of the case 1. Manufacturing costs were forced to rise.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing a switch case, which eliminates the problems of the prior art described above, eliminates the need for a step of filling holes in the case, and reduces the total cost of the switch.

[Means for solving problems]

In order to achieve the above object, the present invention involves sandwiching a terminal press-cut into a predetermined shape between an upper mold and a lower mold so that its free end comes into contact with the receiving surface of the cavity, and then inserting the terminal into the cavity. In a method for manufacturing a switch case, in which a synthetic resin case and the terminal are integrally molded by filling a molten resin with the molten resin and cooling and solidifying the molten resin, The terminal is characterized in that after being bent so that the opposite direction becomes a convex surface, the terminal is held between the upper mold and the lower mold, and the concave surface is pressed into contact with the receiving surface of the cavity.

[Effect]

When pressing a terminal of a predetermined shape from a hoop-shaped metal plate, the terminal is bent so that the opposite direction to the pressing direction becomes a convex surface, and then this terminal is inserted between an upper mold and a lower mold. When placed and clamped, the terminal receives a pressing force in a direction opposite to the bending direction, and the free end of the terminal is pressed against the receiving surface by the reaction force. At this time, the contact between the terminal and the receiving surface is a line contact through the fine burrs that are generated on the terminal during press punching, so in combination with the elastic force of the terminal itself, the free end of the terminal It comes into close contact with the receiving surface. Therefore, even if the holding bottle for pressing the terminal to the receiving surface is omitted, the molten resin can be filled into the cavity without entering between the terminal and the receiving surface, and the holding bottle can be used to switch the hole-free switch. Cases can be molded.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a mold opening state of a molding die according to an embodiment of the present invention, FIG. 2 is a sectional view showing an injection process using the molding die, and FIG. 3 is a sectional view showing a fixed contact portion and An explanatory diagram showing the state of contact with the receiving surface, and FIG. 4 is a cross-sectional view of a switch case molded using the molding die, and the same reference numerals are given to parts and parts that are equivalent to the conventional structure described above. However, the explanation will be omitted to avoid duplication.

This embodiment differs from the conventional example in the shape of the terminal portion 9 supplied to the molding die, and the basic structure of the molding die is the same as the conventional example. That is, the base plate 6, which is press-worked from a hoop-shaped metal plate, has a frame portion, a terminal portion, etc. formed thereon as in the conventional example (see FIG. 7), and among these, the terminal portion 9 is formed as shown in FIG. As shown in Figure 1, it is curved so that the upper side is convex, and although it is not clear from Figure 1,
The terminal portion 9 is pressed from the convex side to the concave side.

When molding the switch case, after press-working the base plate 6 having the terminal portions 9 and the like having the shape described above from a hoop-shaped metal plate, the base plate 6 is pressed so that the convex surface of the terminal portion 9 faces upward. The lower mold 13 is transported and positioned along the guide portion, and the upper mold 12 and the lower mold] 3 are clamped. During such mold clamping, the terminal portion 9, which had been curved so that the upper surface was convex, is held between the flat opposing surfaces of the upper mold 12 and the lower mold 13 and becomes flat, so that the terminal portion 9 is bent due to the reaction force. The free end (fixed contact portion 2a) of is pressed against the receiving surface B. Moreover, since the terminal portion 9 is conveyed so that the end of the punching is opposed to the receiving surface B during press punching, as shown in FIG. 3, the peripheral edge of the terminal portion 9 is The resulting fine burrs C (so-called burrs) come into contact with the receiving surface B, and the elastic force of the terminal portion 9 itself in the direction of the receiving surface B causes stress to concentrate on the burrs C, causing the fixed contact portion 2a and the receiving surface to Adhesion with B is ensured.

After the mold is clamped in this way, as shown in FIG. The cavity 11 is evenly filled without entering the mold, the mold is opened after being cooled and assimilated, and the terminal part 9 is separated and bent, so that the case 1 and the terminal 2 are integrated as shown in Fig. 4. A switch case is obtained.

The switch case molded in this way is Case 1
Since there is no hole on the bottom surface leading to the fixed contact part 2a, there is no risk of contact failure due to infiltration of flux, etc. Also, since resin does not protrude onto the top surface of the fixed contact part 2a, there is no risk of contact failure due to the insulating coating. There is no risk of injury.

FIG. 5 is a sectional view of a molding die showing another embodiment of the present invention, and parts corresponding to those in FIG. 1 are given the same reference numerals.

In the case of this embodiment, an inclined surface 12b that slopes downward toward the cavity recess is formed on the lower surface of the upper mold 12, and an inclined surface 12b that slopes downward toward the receiving surface B in correspondence with the inclined surface 12b is formed on the upper surface of the lower mold 13. An inclined surface 13b that descends diagonally is formed. On the other hand, the terminal portion 9 is bent in a dogleg shape so that the upper surface thereof is convex, and is pressed from the convex side to the concave side.

Therefore, when the upper mold 12 and the lower mold 13 are clamped from the open state shown in FIG.
, 13b and the receiving surface B in a dogleg shape in the opposite direction to that during press working, and the fixed contact portion 2a is pressed against the receiving surface B by the reaction force. In this way, in this embodiment, the fixed contact portion 2a can be brought into close contact with the receiving surface B with a larger force than in the first embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, the free end of the terminal can be brought into close contact with the receiving surface of the cavity by utilizing the elasticity of the terminal itself and the spacing during press-pull, which is not necessary in the past. The process of filling holes in the case is omitted, and the cost of the switch can be reduced.

[Brief explanation of the drawing]

Figures 1 to 4 relate to one embodiment of the present invention, in which Figure 1 is a sectional view showing the mold opening state of the mold, and Figure 2 is a sectional view of the main part of the mold during the injection process. 3 is an explanatory view showing the contact state between the fixed contact part and the receiving surface, FIG. 4 is a sectional view of a molded switch case, and FIG. 5 is a molding metal plate according to another embodiment of the present invention. FIGS. 6 to 9 are sectional views showing the open state of the mold, FIGS. 6 to 9 are related to conventional examples, FIG. 6 is a sectional view of the dip switch, and FIGS. 7 and 8 are explanations showing the manufacturing process of the terminal and case. 9 are cross-sectional views of a mold device used in the manufacturing process. DESCRIPTION OF SYMBOLS 1... Case, 2... Terminal, 2a... Fixed contact part, 6... Base plate, 9... Terminal part, 11... Cavity, 12... Upper mold, 12b...・Slope surface, 13・
...Lower mold, +-3b...Slanted surface, 15...Resin, B
...Ukemen, C...Paris. Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] A terminal that has been pressed into a predetermined shape is held between an upper mold and a lower mold so that its free end contacts the receiving surface of the cavity.
Thereafter, in the method for manufacturing a switch case, the cavity is filled with molten resin, the molten resin is cooled and solidified, and the synthetic resin case and the terminal are integrally molded. After the terminal is bent so that it has a convex surface in a direction opposite to the direction in which it is removed, the terminal is held between the upper mold and the lower mold so that its concave surface is pressed into contact with the receiving surface of the cavity. How to manufacture the case.