JPH04301330A - Switch housing and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent resin from being covered on contacts due to the movement of the contacts when a housing is molded. CONSTITUTION:In the manufacture of a switch housing 21 exposed with multiple fixed contacts 22a, 22b, 22c on the inner bottom face of the housing 21, projections 25, 26, 27 are formed on the peripheries of the fixed contacts 22a, 22b, 22c, and layer-down sections 38 are formed between the fixed contacts 22a, 22c and between the fixed contacts 22b, 22c.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a switch housing used in a push button switch and a method for manufacturing the same.
In particular, the present invention relates to a switch housing for preventing fixed contacts from being covered with resin and a method for manufacturing the same.

0002

2. Description of the Related Art A conventional switch housing of this type will be explained with reference to FIGS. 5 to 11. FIG. 5 is a cross-sectional view showing the overall structure of the push button switch, FIG. 6 is a cross-sectional view of main parts showing the relationship between the terminal and the housing after resin molding, and FIG.
8 is a sectional view of the main part showing the relationship between the hoop material and the housing after resin molding, FIG. 8 is a sectional view of the main part showing the second conventional manufacturing method, and FIG. 9 shows the state of injection molding of molten resin. A sectional view of the main part, FIG. 10 is a perspective view of the main part showing a hoop-shaped fixed contact, FIG.
1 is a cross-sectional view of main parts showing a third conventional manufacturing method. The push-button switch is made of synthetic resin and includes a housing 1 having an opening, fixed contacts exposed on the inner bottom surface of the housing 1 facing the opening, for example, fixed contacts 2a and 2b on both sides, a central fixed contact 2c, and fixed contacts 2a on both sides. , 2b and facing the central fixed contact 2c; a stem 5 provided on the movable contact 3 to press the movable contact 3 toward the fixed contact 2c; The frame 6 movably supports the stem 5 and is attached to the upper end of the housing 1 by means such as staking to suppress upward movement of the stem 5. As shown in FIGS. 7 and 10, the hoop material 7 used in this housing 1 includes support parts 8 and 9 extending in the longitudinal direction, central fixed contacts 2a and 2b connected to the support part 8, and one Support part 9
It has a central fixed contact 2c extending from, and between the fixed contacts 2a, 2b on both sides and the central contact 2c and each support part,
Connection pieces 8a and 8b are provided. Although omitted in FIG. 7, other similarly configured parts also include supporting parts 8 and
are arranged sequentially at equal intervals along the When manufacturing such a housing 1, first, the hoop material 7 is supplied to the mold device 12 shown in FIG.
Molten resin 16 is injected into a cavity formed between movable molds 14 through a gate 15. Along with this, the molten resin 16 flows from the side of the support part 9 of the central fixed contact 2c to the side of the support parts 8 of the fixed contacts 2a and 2b on both sides, filling the cavity with this molten resin 16, and then melting the resin 16. After the resin 16 is cured, it is released from the mold device 18 to obtain the housing 1 in the state shown in FIG. 7, and then the supporting parts 8 and 9 protruding from both ends of the housing 1 are cut, respectively.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned prior art, the molten resin 16 injected from the gate 15
When passing near the support part 9 of the central contact point 2c, a force acts on the support part 9 and the bent part 9b in the direction shown by the arrow 17 in FIG. The central fixed contact 2c deforms from the state shown by the two-dot chain line to the state shown by the solid line, and as a result, the resin flow path between the support part 9 and the movable mold 14 becomes wider, and the flow in this part becomes faster. There was a problem in that a portion of the molten resin 16 covered the contact surfaces of the fixed contacts 2a, 2b, and 2c. When the contact surfaces 2a, 2b, and 2c are covered with resin in this manner, there is a fear that contact failure of the contacts may occur.

Therefore, as shown in FIG.
A, 2b, and 2c are brought into contact with the bottom surface 14a of the movable mold 14, and in this state, the molten resin 16 is filled into the cavity through the gate 15. However, in this case, resin injection pressure is applied directly to the side surfaces of the fixed contacts 2a, 2b, 2c, so each contact part 2a, 2b, 2c moves due to this pressure, causing resin to cover the contacts. As a result, there was a problem in that the contacts were molded in an inclined state. As an improvement measure, for example, as shown in FIG. 8, protrusions 2d are provided on the upper surfaces of the fixed contacts 2a, 2b, 2c, and a recess 19 is provided on the movable mold side so as to face the protrusions 2d. By positioning the protrusion 2d in this recess 19 and bringing the base portions 2e of the fixed contacts 2a, 2b, and 2c into contact with the movable mold, each contact protrusion 2
The structure is such that the resin does not enter onto the surface of d.

However, in the above conventional manufacturing method, in order to prevent the fixed contacts from being covered with resin, the movable mold 1 is
The base portion 2e of the fixed contacts 2a, 2b, 2c is mounted on the bottom surface 14a of 4.
and the protrusions 2 of the fixed contacts 2a, 2b, 2c
d is brought into contact with the inner surface 19a of the recess of the mold 14, and this protrusion 2
A slight gap is provided between d and the recess side surface 19b, but in this case, the height of the protrusion 2d of each fixed contact 2a, 2b, 2c and the depth of the recess 19 must be the same, and the metal There was a problem in that high dimensional accuracy was required during mold production, resulting in an increase in the cost of the switch. Furthermore, in the above manufacturing method, when filling the cavity with molten resin 16, the resin pressure from the gate is applied directly to the side surfaces of each fixed contact 2a, 2b, 2c, and the resin injection pressure causes each Contact portions 2a, 2b, 2c
moves, which causes a problem of resin covering. In this case, although resin does not cover the protrusion 2d, the contact becomes tilted due to the resin covering, making it difficult to use as a contact. There was a problem that the function of the device was impaired. Therefore, the present invention has been made in view of the actual state of the prior art, and an object thereof is to provide a method for manufacturing a switch housing that can prevent fixed contacts from being covered with resin.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned technical problems, the present invention provides a switch housing having a housing having an opening and a plurality of fixed contacts exposed at the inner bottom surface of the opening of the housing. Projections formed on the housing are provided around the sides of the plurality of fixed contacts, and a stepped portion is provided on the inner bottom surface of the case located between the fixed contacts.

Further, in the method for manufacturing a switch housing of the present invention, the upper surface of the fixed contact is structured to be in contact with a mold, and a mold and a recess are provided around the side of the fixed contact, and each A mold is used to project a protrusion between the contacts, and a cavity in the mold is filled with molten resin to mold the housing.

[0008]

[Operation] Since the sides of the fixed contact are surrounded by a mold, the fixed contact part is not directly subjected to resin pressure when filled with molten resin. Therefore, movement of the fixed contact can be prevented.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for manufacturing a switch housing according to the present invention will be described below with reference to the drawings. Figures 1 to 4
1 is a perspective view showing the switch housing, FIG. 2 is a cross-sectional view of the main part of FIG. 1, and FIG. Main part sectional view showing the state of filling with molten resin, FIG. 4
FIG. 2 is a cross-sectional view of main parts showing the mold structure. Also in the present invention, fixed contacts 22a, 22b, 22c are provided in the housing 21.
is exposed, and a pair of support members 23 and 24 are extended from the side of the housing 21, and these extensions are used as terminals, which is the same as the conventional method, but the present invention is characterized by the following configuration. It is in. That is, each fixed contact 22a
, 22b, 22c are formed with protruding parts 25, 26, 27, and a stepped part 40 is provided on the inner bottom surface of the case located between the protruding parts 25, 26, 27. . As shown in FIG. 3, a mold device 20 for molding such a housing 21 includes a cavity 31 formed at the joint surface of a fixed mold 28 and a nest 30 located on the movable mold 29 side, and a runner. 32 and a gate 34 for injecting molten resin 33 into the cavity 31. In the initial state when the hoop material 35 is supplied to the mold device 20, each fixed contact 22a, 22b, 2
2c is located so as to be in contact with the inner bottom surface 30a of the recess of the nest 30 provided on the movable mold side 29, and the fixed contact 22a
, 22b, 22c and the inner surface 30b of the recess, a slight gap is provided to form the recess 30c. Furthermore, protrusions 30d formed by molds are protruded between the fixed contacts 22a and 22c and between the fixed contacts 22b and 22c (not shown), respectively.

In this embodiment, as shown in FIG. 1, since the fixed contacts 22a and 22b are formed into approximately rectangular shapes, the shapes of the protrusions 25 and 27 are also necessarily rectangular. Since the fixed contact 22c is formed in a substantially annular shape, the recess 30c around the fixed contact 22c is similarly formed in an annular shape. In this embodiment, when manufacturing the housing 21, first the hoop material 35 is supplied to the mold device 20 and the hoop material 35 is
After inserting the pilot pin 37 into the hole 36 of the connecting part and positioning it, the hoop material 35 is sandwiched between the fixed mold 28 and the movable mold 29. In this state, the molten material fed through the runner 32 Resin 33 is injected into cavity 31 through gate 34. After the molten resin 33 has hardened, the movable mold 29 is lowered, and the movable mold 29
By pushing up the housing 21 to which it is attached using the ejecting pin 38, the housing 21 is released from the mold device 20, and then the supporting parts 23 and 24 protruding from both ends of the housing 21 are cut at predetermined positions. Fixed contact 2
Since the sides of the contacts 2a, 22b, and 22c are surrounded by the mold, the molten resin flows directly from the gate to the fixed contacts 22a, 22.
Since the resin does not wrap around between the upper surfaces of b and 22c and the nest 30, the problem of resin covering the contact portions can be solved. Furthermore, in the structure of the present invention, since the upper surface of the fixed contact is formed flat, the height dimension from the bottom surface of the case to the upper surface of the contact can be reduced. In the above embodiment, the protrusions 25, 26, 27 formed around the fixed contact portions 22a, 22b, 22c are formed on the same surface as each contact, but this is just an example; It is also possible to provide a taper around the portions 25, 26, 27. Further, in this embodiment, a structure is described in which the center fixed contact 22c is formed at a lower position than both side fixed contacts 22a and 22b, but this is just an example, and the position of the stepped portion 40 and the center fixed contact 22c is explained. It is also possible to increase the

[0011]

As the present invention is constructed as described above, the upper surface of the fixed contact is not covered with resin, and it is possible to prevent the contact portion from being covered with resin. Therefore, a highly reliable contact structure can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a switch housing of the present invention.

FIG. 2 is a sectional view of a main part of the switch housing of the present invention.

FIG. 3 is a sectional view of a main part showing a state in which the cavity of the mold apparatus of the present invention is filled with molten resin.

FIG. 4 is a sectional view of essential parts showing the mold structure of the present invention.

FIG. 5 is a sectional view showing the overall structure of a conventional push button switch.

FIG. 6 is a sectional view of a main part showing the relationship between a conventional terminal and a housing.

FIG. 7 is a sectional view of a main part showing the relationship between a conventional hoop material and a housing.

FIG. 8 is a sectional view of a main part showing a second conventional manufacturing method.

FIG. 9 is a sectional view of a main part showing a state of conventional injection molding of molten resin.

FIG. 10 is a perspective view of a main part of a conventional hoop-shaped fixed contact.

FIG. 11 is a sectional view of a main part showing a third conventional injection molding state of molten resin.

[Explanation of symbols]

Claims (2)

[Claims] 1. A switch housing comprising a housing having an opening and a plurality of fixed contacts exposed at the inner bottom surface of the opening of the housing, wherein a protrusion is formed on the housing around the side of the plurality of fixed contacts. What is claimed is: 1. A housing for a switch, characterized in that a stepped portion is provided on the inner bottom surface of the case located between the fixed contacts. 2. A method for manufacturing a switch housing, which comprises supplying a hoop material having a plurality of fixed contacts to a mold device, and filling a cavity of the mold device with molten resin to mold the switch housing. The upper surface of the fixed contact is in contact with the mold, a recess is provided around the side of the fixed contact, and a protrusion is protruded between each contact by the mold, and the cavity in the mold is A method for manufacturing a switch housing, characterized in that the housing is filled with molten resin and then molded.