JPH0452574B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field The present invention relates to a switch body such as a push button switch, and more particularly to a method for manufacturing a switch body.

(2) Prior art In recent years, radios, cassette tape recorders,
Electronic devices such as VCRs and TVs have fixed contacts embedded in the casing, and a movable contact is housed in the switch body, and a stem is attached to the switch body to push the movable contact and connect it to the fixed contact. Push button switches are widely used.

Conventionally, a method for manufacturing the switch body of this push button switch is known, for example, as described in Japanese Patent Application Laid-Open No. 121226/1983.

This manufacturing method involves attaching a fixed contact to a mold consisting of an upper mold and a lower mold for molding the housing, and filling the cavity formed in the mold with synthetic resin to integrate the housing and the fixed contact. It is something to be molded.

This manufacturing method is characterized by the following two points. First, the first feature is that the upper surface of the contact part of the fixed contact is brought into close contact with the lower mold of the upper mold, and a pin is inserted through a narrow gap at the position corresponding to the lower surface of the contact of the lower mold. This is what was established.

Next, the second feature is that during molding, due to the increased pressure of the synthetic resin flowing through the narrow gap, the contact portion is pressed upward, increasing the degree of adhesion between its upper surface and the lower surface of the upper mold. Therefore, since the synthetic resin flows only to the lower surface, resin fogging on the upper surface is prevented, and a covering portion that becomes the bottom of the casing is formed on the lower surface. This prevents flux from entering the housing during soldering.

However, when an ultra-small switch body or a contact portion of a fixed contact is formed by complicated bending so as to have a hat-shaped cross section, strict dimensional accuracy is required. If the plate thickness of the fixed contact becomes thinner, for example, by 0.1 to 0.2 m/m from the conventional approximately 0.3 m/m, the contact portion of the fixed contact becomes unstable in terms of strength. As a result of further analysis of these points, it was found that the dimensional accuracy achieved by conventional methods is limited to approximately 5/100 mm. However, it has been found that, for example, when a dimensional accuracy of approximately 2/100 mm is required, it is impossible to maintain the shape of the contact portion within the dimensional accuracy using resin pressure alone. Therefore, the required method cannot be realized, and a problem arises in which it is impossible to prevent resin fogging on the upper surface of the contact portion.

(3) Purpose This invention was made in view of the above-mentioned problems, and aims to provide a method for manufacturing a switch body that prevents resin from forming on the contact portion of a fixed contact and prevents flux from entering the housing. There is.

(4) Configuration In order to achieve the above object, the present invention manufactures a switch body as described below.

That is, in a method for manufacturing a switch main body, the method includes mounting a fixed contact having a contact portion on a mold for molding a housing, filling the mold with synthetic resin, and integrally molding the housing and the fixed contact. is divided into a primary mold and a secondary mold, and the fixed contact is placed in a first cavity located near the contact portion of the primary mold, and the fixed contact is placed on the entire upper surface thereof and the contact point on the lower surface thereof. At the same time, the first cavity is filled with resin and integrated with the lower surface of the contact portion and the lower surface of the fixed contact in the vicinity thereof. After molding the primary switch body with the resin part made of
The next switch body is installed in a second cavity shaped like a casing of the second mold, and the entire upper surface of the contact part and a part of the lower surface of the resin part are held between an upper mold and a lower mold, respectively. The fixed contact and the housing are manufactured integrally by mounting the fixed contact in the second mold and filling the second cavity with resin.

By using this manufacturing method, it is possible to provide a switch body that prevents the upper surface of the contact portion from being covered with resin and prevents flux from entering the housing.

(5) Examples The present invention will be explained below based on the drawings.

1 to 5 are drawings showing one embodiment of the present invention. In the figure, the reference numeral 1 indicates a push button switch, and the switch body 2 is made by integrally molding a housing 3 made of synthetic resin and fixed contacts 4 and 5.
A spherical protrusion 8 houses a movable contact 6 having a contact 6a that can freely come into contact with and separate from the fixed contacts 4 and 5, and presses the movable contact 6 to connect it to the fixed contacts 4 and 5.
The stem 7 and the lid 9 are attached to the stem 7 and the lid 9 so as to be vertically movable through the hole 9a, and the lid 9 is attached to the housing 3. The switch body 2 is constructed as described below.

That is, as shown in FIGS. 1 and 2, the housing 3 is formed as a rectangular box that is open at the top and has a mounting portion 3a to which the lid 9 is mounted. And housing 3
Here, an L-shaped leg portion 4a of the fixed contact 4 is disposed on the left outer side. An embedding part 4b that is bifurcated into a U-shape and is embedded in the housing 3 is connected to the upper end of the leg 4a. Each of the buried portions 4b is provided with a contact portion 4c which is formed into a hat-like cross section and whose upper surface is exposed for contacting and separating from the contact portion 6a of the movable contact 6.

Further, like the fixed contact 4, the fixed contact 5 is also formed by providing a leg portion 5a, a buried portion 5b, and a contact portion 5c, respectively. Then, as shown in FIG. 2, the leg portion 5a is placed on the right outer side of the housing 3, and the contact portion 5c is placed between the two contact portions 4c.
b is buried in the housing 3.

The switch body 2 having the above structure is manufactured by first forming the primary switch body 20 shown in FIG. 3 and based on this, so a method for manufacturing the primary switch body 20 will be described.

The reference numeral 10 shown in FIG. 4 is a primary mold, which is composed of an upper mold 11 and a lower mold 12 combined therewith. The upper die 11 is provided with a groove 11a into which the upper surface of the contact portion 4c of the fixed contact 4 is fitted.

The lower mold 12 has an insertion hole 12a into which the leg 4a of the fixed contact 4 is inserted, and a groove 11a of the upper mold 11.
A void portion 12b is provided at a position corresponding to .

Therefore, when the fixed contact 4 is attached to the primary mold 10, its upper surface, that is, the upper surface of the buried portion 4b and the contact portion 4c, and the lower surface of the buried portion 4b excluding the lower surface of the contact portion 4c and the vicinity thereof, respectively. It is held between the upper mold 11 and the lower mold 12, and the leg portion 4a is inserted into the insertion hole 12a.
Since the fixed contact 4 is inserted into the primary mold 10
It is installed while maintaining dimensional accuracy. Then, when the upper mold 11 and the lower mold 12 are combined and clamped, the primary mold 10 has a groove 11a and a cavity 12b.
The first cavity 13 is configured by the above. After filling the first cavity 13 with synthetic resin and cooling it, the mold is opened to form the primary switch body 20.

The primary switch body 20 includes a fixed contact 4 and a buried portion 4 on the lower surface of the contact portion 4c of the fixed contact 4 and in the vicinity thereof.
b, and a resin 21 integrally molded with the lower surface thereof.

Note that the resin portion 21 is similarly molded on the fixed contact 5, so a description thereof will be omitted.

Next, the primary switch body 20 is attached to the secondary mold 14 as shown in FIG. Secondary mold 1
4 is composed of an upper mold 15 and a lower mold 16, and the upper mold 15
A groove portion 15a is provided in which the upper surface of the contact portion 4c of the fixed contact 4 is brought into close contact to prevent resin fogging, and a gap portion 15b forming a second cavity 18 in the shape of a housing.

The lower mold 16 also has an insertion hole 16a into which the leg 4a of the fixed contact 4 is inserted, and a housing-shaped cavity 1.
A cavity 16b constituting 8 is provided.

17 is a projection provided on the upper surface of the lower mold 16, and a primary switch main body 20 is mounted on the upper surface.
A support member 17a that supports the lower surface of the resin portion 21,
17a are provided respectively. In addition, support member 1
Since 7a is formed as a small protrusion to support the resin portion 21, no void is created in the housing 3 that may cause flux to enter.

The primary switch body 20 mounted on the secondary mold 14 having the above-mentioned configuration is the contact portion 4 of the fixed contact 4.
c is fitted into the groove 15a of the upper mold 15 so that the entire upper surface thereof is in close contact with the groove 15a. Then, the resin part 21 is attached to the lower mold 1
The leg portion 4a of the fixed contact 4 is inserted into the insertion hole 16a.

Therefore, the primary switch main body 20 is sandwiched and mounted between the upper and lower molds of the secondary mold 14. Therefore, dimensional accuracy can be maintained due to the pressure applied during molding of the synthetic resin. Moreover, when the upper mold 15 and the lower mold 16 are combined and clamped, the cavity 15b
A second mold 14 is configured with a second cavity 18 in the shape of a casing, which forms the casing 3 by the space 16b and the casing 16b. Moreover, since the primary switch main body 20 is installed inside the second cavity 13 shaped like a housing, when the mold is opened after filling and cooling the synthetic resin, the buried portion 4b of the fixed contact 4 will be buried in the housing 3. , the switch body 2 (see FIG. 2) can be formed in which the upper surface of the contact portion 4c is exposed from the housing 3.

Next, the effect will be explained. Primary mold 10
In this case, the entire upper surface of the fixed contact 4 and the buried portion 4b excluding the area near the lower surface of the contact portion on the lower surface are held between an upper mold 11 and a lower mold 12. Then, the upper surface of the contact portion 4c is tightly fitted into the groove portion 11a of the upper die 11,
The leg portion 4a is inserted into the insertion hole 12 of the lower mold 12. Therefore, the contact portion 4c is thin and has a complicated shape.
Even if the resin part 21 is integrally molded with the fixed contact 4, it is possible to mold the primary switch main body 20 with an extremely simple shape, without causing strength problems or deformation during molding and maintaining dimensional accuracy. can.

Moreover, the primary switch main body 20 has a fixed contact 4
and the buried portion 4 in the vicinity of the lower surface of the contact portion 4c.
Only the resin portion 21 is provided on the lower surface of the portion b, and no protrusion of any kind is provided on the upper surface. The resin portion 21 reinforces the lower surface and the periphery of the contact portion 4c of the fixed contact 4 in the primary switch main body 20, thereby preventing deformation. Therefore, the contact part 4
The dimensional accuracy of c is maintained.

In addition, in the secondary mold 14, the contact portion 4c of the primary switch body 20 is held between the upper mold and a portion of the lower surface of the resin portion 21 between the upper mold and the lower mold.
The dimensional accuracy of the fixed contact 4 can be maintained even when pressure is applied during resin molding. Therefore, the buried portion 4b of the fixed contact 4 is buried in the housing 3 without any voids that may cause flux intrusion, and the buried portion 4b of the fixed contact 4 is
c can be exposed from the casing 3 while preventing the resin from covering the top surface.

On the other hand, in order to achieve the same purpose as the present invention, that is, to prevent the contact portion of the fixed contact from being covered with resin and to prevent flux from entering the housing, the fixed contact is placed in a housing that is molded using a primary mold, for example. A primary switch body is known that is formed by being buried with only the exposed portion exposed. However, such a primary switch body is provided with a protruding attachment portion for attaching a lid or the like to its housing. Therefore, when this primary switch body was mounted on the secondary mold, there was a problem in that the mounting portion collided with the secondary mold and was scraped. However, since the primary switch body according to the present invention does not have a protruding mounting portion, such a problem does not occur.

(6) Effects As explained above, according to the present invention, the mold is divided into a primary mold and a secondary mold, and the contact portion of the fixed contact is formed in the primary mold. A primary switch body is formed by integrally molding a reinforcing resin part on the lower surface and the lower surface of the buried part in the vicinity, and the second
Since the switch body is formed by embedding the fixed contacts of the primary switch body in the housing using a secondary mold, various effects as described below can be obtained.

(1) Even in the case of an ultra-compact switch body where the fixed contact plate is thin and the shape of the contact part is complex and requires strict dimensional accuracy, the fixed contact is made in the primary mold, and the contact part is It is possible to obtain an ultra-small primary switch main body with an extremely simple shape, in which a resin part is integrally provided as a reinforcing member on the lower surface of the switch and the buried lower surface in the vicinity thereof.

(2) Therefore, since the shape of the primary mold is simplified, costs can be reduced.

(3) Also, since the primary switch body does not have any parts that will be scraped by hitting the secondary mold when it is installed on the secondary mold, it is extremely difficult to install it on the secondary mold. It becomes easier.

(4) Furthermore, even when pressure is applied during molding of the synthetic resin in the secondary mold, the primary switch body can be fixed while maintaining the dimensional accuracy of the fixed contact. This prevents resin fogging, and
A switch body is obtained in which a fixed contact is embedded in a casing that prevents flux from entering.

(5) Furthermore, by attaching the movable contact portion, etc. to the switch body, the push button switch can be extremely easily configured in an ultra-compact size.

[Brief explanation of drawings]

1 to 5 show one embodiment of the present invention, FIG. 1 is a sectional view of a push button switch with a switch body manufactured according to the present invention attached, FIG. 2 is a plan view of the switch body, and FIG. The figure shows the main body of the primary switch as shown in the cross-sectional view taken along the - line in Figure 2.
Figure 4 is a cross-sectional view of the main parts of the primary mold, and Figure 5 is the sectional view of the second mold.
It is a sectional view of the main part of the next mold. 1...Push button switch, 2...Switch body, 3
...Housing, 4, 5...Fixed contacts, 4c, 5c...
Contact part, 10... Primary mold, 11, 15... Upper mold, 11a, 12b... Gap part, 13... First cavity, 12, 16... Lower mold, 14... Secondary mold Mold, 15b, 16b...Gap, 18...Second
Cavity, 20... Primary switch body, 21
...Resin department.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a switch body, which comprises: attaching a fixed contact having a contact portion to a mold for molding a housing, filling it with synthetic resin, and integrally molding the housing and the fixed contact. In this step, the mold is divided into a primary mold and a secondary mold, and the fixed contact is placed on the entire upper surface of the first cavity located near the contact portion of the primary mold. The lower surface of the contact portion, excluding the vicinity of the lower surface, is sandwiched and mounted between an upper mold and a lower mold, and the first cavity is filled with resin to fix the lower surface of the contact portion and its vicinity. After molding a primary switch body having a resin part integrated with the lower surface of the contact, the primary switch body is installed in the second cavity of the casing shape of the secondary mold, and the contact is The entire upper surface of the part and a part of the lower surface of the resin part are held between an upper mold and a lower mold, respectively, and mounted in the secondary mold, and the second cavity is filled with resin to form the fixed contact. A method of manufacturing a switch main body, characterized in that the switch main body is manufactured integrally with the casing.