JP3364852B2 - Mold structure for insert molding of electronic parts - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold used for insert molding of an electronic (electric) component such as a connector. 2. Description of the Related Art For example, when a pin-piercing type connector 1 as shown in FIG. 1 is insert-molded, a pin protrusion dimension 1a of the connector 1 is a total length of a lower die 2, a lower die piece 3, and a pin 1p. L. For this reason, the dimensional tolerance of the protruding dimension 1a becomes an accumulated numerical value, and the pin holding dimension 4a of the upper die 4 must be loose in consideration of the tolerance. This is a design problem when high-precision contact is required or when height restriction is required. As a countermeasure to this problem, a method of FIG. 2 in which the mold for insert molding is turned upside down has been considered. However, as shown in FIG. 1 (b), a connector 1 shown in FIG. Dimension D of one end such as a cone, triangular pyramid
When 1 has a shape smaller than the dimension D2 of the other end,
Since the mold cannot be opened or ejected after molding, it is structurally impossible. [0004] In order to solve such a problem of dimensional accuracy, as shown in FIG. 3, the pin holding dimension 4 a of the upper die 4 is fixed, while A mold structure in which a spring 3a and a spring fixed piece 3b are provided below the lower mold piece 3 of the lower mold 2 in order to absorb the dimensional tolerance, and the lower mold piece 3 is an elastic system has been considered. [0005] However, in the case of this spring type structure, a space for accommodating the spring is absolutely necessary. However, in a small connector mold, the space for accommodating the spring cannot be obtained due to length and diameter restrictions, and the structure is employed. May not be possible. Further, in the spring type structure, since the surface for receiving the pin is composed of two or more parts, a dimensional difference between the parts and a variation in the spring pressure of the spring inevitably occur, and the number of poles ( The balance when the number of pins is large is poor. Therefore, when the mold is opened and the pin is kept pressed, a tilting force is applied, and the eject from the mold after molding becomes hard, or the mold outer periphery is scratched. . Furthermore, since the parts are composed of a plurality of parts and each part is small, it is difficult to disassemble and reassemble the mold by cleaning or the like. SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the spring type in a mold structure for insert molding of electronic parts. According to the present invention, there is provided insert molding of an electronic component having through pins protruding up and down, wherein the pin holding dimensions of the upper die are fixed and the lower die is fixed. In a mold structure in which a lower mold piece provided in a mold is an elastic type, the lower mold piece is formed as a single part that is partially curved to obtain elasticity. With this structure, only a curved space for generating elasticity is required, so that the space for installing the lower mold piece is considerably smaller than that of the spring type. In addition, since it is a single part, there is no dimensional difference between the parts, quality can be kept uniform, and there is no variation in spring pressure. In addition, because it was made into one part,
The removal work is very easy, the disassembling and assembling work of the mold is easy, the time required for the work is shortened, and the number of parts is reduced, which is advantageous in cost. FIG. 4 is an enlarged sectional view of a main part of an embodiment of the present invention. The insert molded electronic component in this example is also the connector 1 in FIG. The upper die 4 has a pin holding dimension 4a fixed as in the conventional example of FIG. Therefore, pin 1p
Is determined by the gripping dimension 4a, and the accuracy is high. On the other hand, in the lower die 2, a lower die piece 5, which is a part of an integrally molded plastic product, is installed as an elastic pin receiver to absorb dimensional tolerances. As shown in FIG. 4 (b), the lower die piece 5 has one end bent in a U-shape to obtain elasticity. The same operation as the pattern piece 3 is performed. As a result, as long as there is only a space 1s for accommodating the curved shape, the lower mold piece 5 can be installed, and the installation volume can be suppressed smaller than that of the spring type. Therefore, it can be moved in a smaller space, and can function sufficiently even if the connector becomes smaller. Further, the number of components is only one, and there is no trouble of disassembling and assembling unlike the lower die piece 3 having three components in FIG. Therefore, the workability of attaching / detaching to / from the mold is improved, and problems such as running out of parts are eliminated. And since it is a single part, homogenization is achieved, dimensions and spring pressure are stabilized, contributing to stable quality of molded products.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 (a) is a sectional view of a main part showing a conventional mold structure,
(B) is a plan, cross-sectional, and bottom view of the connector formed by the mold. FIG. 2 is a cross-sectional view corresponding to FIG. 1, illustrating a problem with a conventional solution to the problem. FIG. 3 is a sectional view of a main part showing a conventional elastic mold structure. FIG. 4 is a sectional view of an essential part showing an elastic mold structure according to the present invention. [Description of Signs] 1 connector 1p pin 2 lower mold 4 upper mold 4a pin holding dimensions 5 lower mold piece

Claims (1)

(57) [Claim 1] For insert molding of an electronic component having a penetrating pin projecting up and down, the upper die has a fixed pin holding dimension and is provided on a lower die. A mold structure in which the lower mold piece is an elastic type, wherein the lower mold piece is partly curved to obtain elasticity.