JPS63274521A - Method and apparatus for molding hermetically closed housing having terminal - Google Patents

Abstract

PURPOSE:To mold a housing excellent in a hermetically close property, by providing a press pin equipped with a spring in a mold and filling the mold with a resin against the energizing force of the spring. CONSTITUTION:A press pin 14 is pushed up by the energizing force of a spring 15 to determine the position of a terminal 13. A resin is injected from a gate to fill a cavity 12. When the cavity 12 is filled with the resin and the internal pressure thereof reaches injection pressure, the filling of the resin advances while the press pin 14 overcomes the energizing force of the spring 15 to be pushed back. When the protruding part 19 of the press pin 14 is brought into contact with the step part of a groove 18, the filling of the resin is stopped. Since the resin is allowed to fill against the energizing force of the spring 15 of the press pin 14 to be solidified, a housing excellent in a hermetically close property can be molded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for molding a housing for an electronic component having a resin-sealed structure, particularly a closed-type housing that can be molded integrally with a terminal. The present invention relates to the molding device.

Many electronic components, such as SAW (surface acoustic wave) filters, chip potentiometers, chip polyurethane, chip trimmers, and ladder filters, have one end of the terminal used as an electrode inside to improve the sealing of the housing. Closed housings are often used which have terminals that are embedded in the housing in an exposed state and have the other end extended outside the housing. Since it is important to position the electrode portions exposed inside the closed housing, it is necessary to fix the portions of the terminals that will become the electrode portions with pins or the like when molding the housing. Therefore, the following two methods have been conventionally adopted as methods for molding closed housings having terminals.

The first method, as shown in FIG. 6(a), is to fix the electrode parts of the terminals 3 and 4 assembled in the mold 1゜2 with a protruding part 5 equipped with a gate, and to fill the resin into the cavity. 6 and molded, the void 7 created by the protrusion 5 was again filled with resin to form a closed housing, as shown in FIG. 6(b).

As shown in FIG. 7, the second method is to press the electrode parts of the terminals 3 and 4 assembled into the mold 1.
8 and inject the resin into the cavity 6,
During the injection, the presser pin 8.8 was extracted by a hydraulic mechanism, and the area where the presser pin 8.8 was removed was also filled with resin to form a closed housing.

Ming tries to decide. However, the first two-step molding method not only requires two types of molds, which increases mold costs, but also requires twice the cycle time, resulting in poor productivity and increased molding costs. there were.

In addition, the method of using the second hydraulic mechanism has the problem that the equipment such as the hydraulic mechanism and the mechanism that controls the amount of resin to be injected and the timing for removing the presser pin 8.8 becomes complicated, and the equipment cost increases. was there.

In this way, both methods increase the product cost.

Therefore, in the molding method according to the first invention, a terminal is assembled into a mold constituting a cavity in which a housing can be molded, and one end of the terminal is attached to a presser pin biased by a biasing means. Injecting and filling the cavity with resin while positioning the terminal by sandwiching it between the mold and the inner surface of the mold,
It is characterized in that the injection pressure of the resin overcomes the urging force of the urging means to push back the presser pin and fill the pushed back portion with the resin.

The molding device according to the second invention includes a plurality of molds forming a cavity in which the housing is molded and a cavity in which the terminal is assembled, and a mold that is slidably attached to the mold and assembled in the cavity. a holding pin that holds down the terminal and determines the position of the terminal, and functions as a mold to form a part of the housing with the cavity when pushed back; and a holding pin that urges the holding pin in the terminal positioning direction. At the same time, it is characterized by comprising a biasing means set to be compressed by the injection pressure of the resin injected into the mold.

Therefore, when resin is injected and filled into the cavity while holding and positioning the terminal with a presser pin, after the cavity is filled with resin, the presser pin becomes biased by the urging force of the urging means due to the injection pressure of the resin. The resin is filled into that area while being pushed back against the resistance. At this time, there is no need for a mechanism for pushing back the presser pin, and there is no need to replace the mold.

Kyouka 1 Next, embodiments of the present invention will be described based on the accompanying drawings.

FIG. 1 is a cross-sectional view schematically showing the main parts of an apparatus for molding a closed housing having terminals, and an upper mold 10 and a lower mold 11 are attached to a main body of the apparatus (not shown). Upper mold 1
0 and the lower mold 11 have a recess forming a cavity 12 in which the housing can be completely molded and a terminal 1 in opposing parts.
A recess into which 3 is assembled is formed.

In the lower mold 11, a hollow space 18.17 with a large diameter for attaching the holding pin 14 and the spring 15 is formed, and the hollow space 1
6 has grooves 18 cut in a plurality of places.

The holding pin 14 is mounted in the cavity 16 of the lower mold 11 so as to be slidable in the axial direction. A protruding portion 19 is provided at the lower end of the presser pin 14 , and this protruding portion 19 engages with the groove 18 to prevent rotation of the presser pin 14 .
The holding pin 14 is cut so as not to come into contact with the end of the groove 18 and fall out of the space 16. Further, a protrusion 20 is formed on the upper end surface of the holding pin 14, and the terminal 13 assembled in the mold 10. The pressure receiving surface 21 receives the injection pressure of the injected resin, and transmits the resin injection pressure in the axial direction of the holding pin 14.

The spring 15 is arranged so as to protrude from the space 17 to the space 16, and urges the lower end surface of the holding pin 14 upward in the figure. The biasing force of the spring 15 is the biasing force (spring force) W (kg
), the injection pressure of the resin is P (kg/cm2), and the area (projected area in the axial direction) of the pressure receiving surface 21 of the holding pin 14 is A (
cm”), it is set to satisfy the condition expressed as PXA>W.

Note that the injection pressure P is a gauge pressure, and the cavities 16 and 17 are open to the atmosphere.

Next, the molding method will be explained.

In FIG. 1, terminals 13.13 are assembled to the lower mold 11 with the upper mold 10 and the lower mold 11 opened. At this time, the terminal 13 is slightly raised by the presser pin 14. Next, when the upper mold 10 and the lower mold 11 are closed, the terminal 13.
0, it is allowed to come into close contact with the inner surface of the upper die 10 and can be completely positioned. Note that the surface of the terminal 13 that is brought into close contact with the inner surface of the upper mold 10 is exposed after the mold is released and serves as an electrode portion.

In this state, the resin is completely injected from the gate (not shown) and the cavity 12 is completely filled. When the stmt fills the cavity 12 and the pressure inside the cavity 12 reaches the injection pressure P, the holding pin 14 overcomes the biasing force W of the spring 15 and is pushed back, filling that area with resin, as shown in FIG. Similarly, the convex portion 19 of the holding pin 14 comes into contact with the stepped portion of the groove 18 and is allowed to stop. At this time, resin injection is also stopped, the resin in the cavity 12 is solidified, and the terminal 13.
A closed housing having 13 is molded.

In this way, since the presser pin 14 is pushed down by the injection pressure of the resin, a housing with excellent airtightness can be molded at low cost without the need for any complicated equipment such as a hydraulic mechanism or control mechanism. .

Although one embodiment of the present invention has been described in detail above, the present invention can be configured in other forms.

For example, the biasing means is not limited to the spring 15, but may be made of an elastic material such as rubber, or may be a bag-like elastic body sealed with gas. A plurality of pins 14 may be provided.

On the other hand, a convex portion 19 protruding from the lower end of the holding pin 14
The groove 18 formed in the lower die 11 is not necessarily necessary, and it is sufficient if the presser pin is configured so that it does not fall off from the lower die.

Next, a variable resistor equipped with a closed housing obtained according to the present invention will be described with reference to FIGS. 3 to 5.

As shown in the exploded perspective view of FIG. 3, this variable resistor includes a resin case 24 with an opening formed on the top surface, a pair of fixed side lead terminals 25 and 26, and a cylindrical collector electrode terminal 27.
a variable side lead terminal 28 integrally formed with a resistor board 31 having an arc-shaped resistor 30 formed on the surface of an insulating board 29, a slider 33 having contacts 32 formed thereon, and a driver groove 34. It consists of a driver plate 35 on which is formed, and a cover sheet 36 made of a transparent material.

As shown in FIGS. 4 and 5, the fixed side lead terminal 25.
26 and the variable side lead terminal 28, the electrode portion 25a,
26b and the current collecting electrode terminal 27 are exposed through the opening of the resin case 24 and molded into the resin case 24 by the molding method and apparatus according to the present invention.

The resistance board 31 has a through hole 29 formed approximately in the center thereof.
a, and insert the current collecting electrode terminal 27 through the resistor 30.
The electrode portions 25g, 26b of the fixed side lead terminals 25, 26 are electrically connected to the arc-shaped electrodes 30g, 30b provided at both ends of the terminal, and are fixed to the resin case 24. The slider 33 is integrated with the driver plate 35 by inserting a cylindrical portion 35g formed in the driver plate 35 into a through hole 33g formed in the center thereof, and caulking the tip of the cylindrical portion 35a. . Integrated slider 3
3 and the driver plate 35 are attached to the resistor board 31 by inserting the collector electrode terminal 27 into the cylindrical part 35a and rotatably caulking the tip thereof, so that the two contact points 32 are connected to the resistor 30. It is designed to slide. Additionally, a cover sheet 36 is adhered to the periphery of the opening of the resin case 24, thereby sealing the opening.

Electronic components having such a sealed structure can be flux-cleaned using a solvent after being soldered to a printed circuit board, and devices with excellent performance can be provided.

As detailed above, according to the first invention and the second invention, the terminal assembled in the mold is fixed and positioned with the presser pin, and the terminal is injected into the cavity. Since the presser pin is pushed back by resin injection pressure and the resin is filled in that area, there is no need for complicated mold changes or complex equipment such as hydraulic mechanisms, making it simple and inexpensive, and with high sealing performance. Excellent effects such as the ability to obtain a closed housing having terminals are produced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of a molding apparatus according to the present invention, and FIG. 2 is a sectional view of a main part for explaining the operation of the molding apparatus of FIG. 3 is an exploded perspective view showing a variable resistor having a housing obtained by the present invention, FIG. 4 is a plan view of the variable resistor shown in FIG. 3, and FIG. 5 is a plan view of the variable resistor shown in FIG. 3. FIG. FIGS. 6(a) and 6(b) are sectional views of main parts for explaining a conventional molding method, and FIG. 7 is a sectional view of main parts for explaining another conventional molding method. 10... Upper mold, 11... Lower mold, 12... Cavity, 13... Terminal, 14... Holder pin, 15...
- Spring (biasing means), 20... protrusion, 21... pressure receiving surface.

Claims (2)

[Claims] (1) A method of molding a closed housing having a terminal embedded in a housing with one end surface of the terminal exposed inside the housing, and the other end of the terminal extending outside the housing. In this step, a terminal is assembled into a mold constituting a cavity in which the housing is molded, and one end of the terminal is held between the inner surface of the mold and the inner surface of the mold by a presser pin biased by a biasing means. With the terminal positioned, resin is injected and filled into the cavity, and the injection pressure of the resin overcomes the biasing force of the biasing means to push back the holding pin while filling that part with the resin. A method for molding a sealed housing having a terminal, characterized by: (2) An apparatus for molding a closed housing having a terminal embedded in a housing with one end surface of the terminal exposed inside the housing, and the other end of the terminal extending outside the housing. , a plurality of molds forming a cavity in which the housing is molded and a cavity in which the terminal is assembled; a holding pin that determines the position of the terminal and functions as a mold for forming a part of the housing with the cavity when pushed back; 1. A molding device for a closed housing having a terminal, comprising: a biasing means configured to be compressed by the injection pressure of resin injected into the housing.