JP2025137306A - Manufacturing method for composite of metal terminal and resin - Google Patents

Abstract

[Problem] To provide a manufacturing method for a metal terminal/resin composite that improves airtightness by tightly adhering the metal terminal to the resin in an insert-molded metal terminal/resin composite. [Solution] The present invention uses a molding device A equipped with pushable compression bars 4 on both the upper and lower halves 10A and 10B of a molding die 10 into which a metal terminal 2 is placed and resin 3 is injected. The compression bars 4 are pushed out before the resin 3 injected into the molding die 10 solidifies, compressing the resin 3 at the outer periphery 6 of the metal terminal 2. After the compression bars 4 are retracted to release the pressure, the resin 3 solidifies within the molding die 10, forming the metal terminal 2 by insert molding. [Selected Figure] Figure 1

Description

The present invention relates to a method for producing an insert-molded metal-resin composite.

In a composite of insert-molded metal terminals and resin, the difference in thermal expansion between the metal terminal and the resin leads to a larger expansion coefficient of the resin, which creates gaps between the metal terminal and the resin due to thermal cycling, resulting in reduced airtightness. Therefore, paragraph 0024 of the detailed description of the invention in Patent Document 1 states that resin injected into a mold at high temperature and pressure initially fills the metal terminal 1 without any gaps. As the resin subsequently cools and solidifies in the mold, the resin surrounding the metal terminal 1 shrinks and changes volume, creating gaps 8 at the interface between the metal terminal 1 and the housing resin portion 2. However, in the resin enclosed and filled within the groove 9 forming the acute-angled shape 11 in the metal terminal 1, in both cases, the shrinkage behavior of the resin acts on at least one surface of the acute-angled shape 11 in a direction that generates compressive stress perpendicular to the surface of the acute-angled shape 11, forming a seal portion 13 that partially blocks the interfacial gap 8. This eliminates air leakage from both sides of the metal terminal 1 in the plate width direction, improving airtightness.

However, in Patent Document 1, it is necessary to process grooves in the metal terminals.

JP 2012-1011394 A

An object of the present invention is to provide a method for manufacturing a composite of a metal terminal and a resin, which is insert-molded to form a composite of a metal terminal and a resin, and which improves airtightness by tightly adhering the metal terminal and the resin.

The present invention provides a method for manufacturing a composite of a metal terminal and resin using a molding device having an upper mold and a lower mold in which a metal terminal is placed and resin is injected, the molding device including a compression bar that can be freely pushed out, and the compression bar is pushed out before the resin injected into the molding die solidifies, compressing the resin around the outer periphery of the metal terminal, and then the compression bar is retracted to release the pressure, and the resin solidifies within the molding die, thereby insert-molding the metal terminal. The present invention also provides a method for manufacturing a composite of a metal terminal and resin using the method for manufacturing a composite of a metal terminal and resin described in claim 1, the method including the method for manufacturing a composite of a metal terminal and resin using a molding device having an upper mold and a lower mold in which a metal terminal is placed and resin is injected, the molding device including a compression bar that can be freely pushed out, and the compression bar is pushed out before the resin injected into the molding die solidifies, compressing the resin around the outer periphery of the metal terminal, and then the compression bar is retracted to release the pressure, and the resin solidifies within the molding die, thereby insert-molding the metal terminal.

The method for manufacturing a composite of metal terminal and resin of the present invention is a method for manufacturing a composite of metal terminal and resin, in which the metal terminal is insert-molded using a molding device having extrudable compression bars on each of the upper and lower halves of a molding die into which the metal terminal is placed and resin is injected.The compression bars are extruded before the resin injected into the molding die solidifies, compressing the resin around the outer periphery of the metal terminal, and then the compression bars are retracted to release the pressure.The resin solidifies within the molding die and the metal terminal is insert-molded, thereby providing a composite of metal terminal and resin in which the metal terminal and resin are closely adhered to each other, thereby improving airtightness.

1A and 1B are cross-sectional views of a molding device used in a method for producing a composite of a metal terminal and a resin according to the present invention, in which FIG. 1A shows a state before a compression bar is extruded, and FIG. 1B shows a state after the compression bar has been extruded. 10A and 10B are explanatory diagrams showing the action of compressing resin at the outer peripheral portion of the metal terminal of the present invention. 2. A cross-sectional view taken along line AA in FIG. 5A and 5B are cross-sectional views taken along the line BB in FIG. 1 is a plan view showing a composite of a metal terminal and a resin according to the present invention;

(The resin is compressed around the outer periphery of the metal terminal.)
2 and 3 are explanatory diagrams showing how the injected resin 3 in the lower die 10B of the molding die 10 is compressed at the outer peripheral portion 6 of the metal terminal 2. Before the molten resin 3 injected into the lower die 10B of the molding die 10 solidifies, the compression bar 4 is extruded and protrudes from the lower die bottom 10B1, so that the wall surface of the lower die bottom 10B1 holds the molten resin 3, compressing the resin 3 at the outer peripheral portion 6 of the metal terminal 2. This compression firmly adheres the resin 3 at the outer peripheral portion 6 of the metal terminal 2, and the compression bar 4 is retracted from the lower die bottom 10B1 to release the pressure. The compression bar 4 shown in FIGS. 2 and 3 is formed in a cylindrical shape and surrounds the metal terminal 2.

(Embodiment of manufacturing method of composite of metal terminal and resin)
1(a) and 1(b) show the operation of compressing resin 3 on the outer peripheral portions 6 of two metal terminals 2 using a molding device A that insert-moldes two metal terminals 2. This molding device A comprises a molding die 10, a nozzle 11, and a compression bar 4. The molding die 10 has an upper die 10A and a lower die 10B that can be opened and closed. Two metal terminals 2 are placed within the molding die 10, and the upper die 10A is provided with a nozzle 11 that injects molten resin 3 using a cylinder (not shown) to fill the interior of the molding die 10. The compression bar 4 is retracted into each of the upper die 10A and the lower die 10B and can be pushed outward. The pushing operation is performed in conjunction with the upper die 10A and the lower die 10B as the molten resin 3 injected into the molding die 10 cools and solidifies. Furthermore, every time the compression bar 4 is insert-molded so that it can be freely extruded between the upper mold 10A and the lower mold 10B, the resin 3 adhering thereto is removed, and the removed resin 3 is reused.

The metal terminal 2 is made of aluminum, copper or copper alloy, or nickel or nickel alloy, has a circular or rectangular cross-sectional shape, and can have one or more terminals. Figures 1(a) and 1(b) show an example of two metal terminals 2 with a circular cross-section.

The resin 3 may be a thermoplastic resin such as PPS resin, PBT resin, PPE resin, PEEK resin, or PA resin, as long as it can be melted and injection molded.

In Fig. 1(a), upper mold 10A and lower mold 10B of molding die 10 are closed, and molten resin 3 is injected to fill the closed molding die 10. Next, in Fig. 1(b), before the molten resin 3 solidifies, compression bar 4 is pushed out in the direction of the arrow and then retracted to release the pressure, the molding die 10 is cooled, and although not shown, upper mold 10A and lower mold 10B of molding die 10 are opened to remove the insert-molded composite 1 of the metal terminal and resin.

(composite of metal terminal and resin)
4 and 5 show a composite 1 of metal terminals and resin obtained by the method of manufacturing a composite of metal terminals and resin of the present invention. In Fig. 4 and Fig. 5, during insert molding of two metal terminals 2 and resin 3, the resin 3 is compressed at the outer peripheral portion 6 of each metal terminal 2, firmly adhering the metal terminals 2 and resin 3. This makes the composite 1 of metal terminals and resin sufficiently airtight, as it is less likely to develop gaps between the metal terminals 2 and resin 3 due to thermal cycling. In Fig. 4, 5 indicates a circular mark left in the resin 3 by the extrusion operation of the cylindrical compression bar 4.

The method of manufacturing a composite of a metal terminal and a resin according to the present invention can be used in fields where adhesion between the metal and the resin is required in composites formed by insert molding of the metal and the resin.

A Molding device 1 Composite of metal terminal and resin 2 Metal terminal 3 Resin 4 Compression bar 5 Trace 6 Outer periphery 10 Molding mold 10A Upper mold 10B Lower mold 11 Nozzle

Claims (2)

A method for manufacturing a composite of a metal terminal and resin, in which the metal terminal is insert-molded using a molding device having a pushable compression bar on each of the upper and lower halves of a molding die into which the metal terminal is placed and resin is injected, characterized in that the compression bar is pushed out before the resin injected into the molding die solidifies, compressing the resin at the outer periphery of the metal terminal, and then the compression bar is retracted to release the pressure, and the resin solidifies within the molding die, thereby insert-molding the metal terminal. 2. The method for manufacturing a composite of a metal terminal and a resin according to claim 1, wherein the metal terminals to be insert-molded are plural, and a cylindrical compression bar surrounding each of the metal terminals is extruded.