JPS62143321A - Manufacture of resin mold bushing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention includes a center conductor and a grounding shield electrode concentric with the center conductor in a synthetic resin molded layer integrally having a mounting flange. The present invention relates to a method of manufacturing an embedded resin molded bushing.

[Technical Background of the Invention and Points Therebetween] Conventionally, as shown in FIG. 5, a resin molded bushing has a central conductor 3 and a central conductor in a synthetic resin molded layer 2 integrally having a mounting flange 1. A grounding shield electrode 4 formed in a cylindrical shape with a wire mesh is embedded concentrically with the grounding shield electrode 4, and a connecting wire 5 is brazed to the outer periphery of the grounding shield electrode 4. A ring-shaped grounding terminal 6 that doubles as a hole is attached by brazing.
is embedded in the mounting flange 2. and,
As a method for manufacturing this molded bushing, the sixth method is
As shown in the figure, the molding die 7 is composed of an upper mold 7a and a lower mold 7b, and first, a center conductor 3 is placed in the center of the lower mold 7b before molding.
At the same time, the grounding shield electrode 4 is supported concentrically with the center conductor 3 via the connecting wire 5 by fitting the grounding terminal 6.6 into guide pins 7c, 7c set upright on the lower mold 7b. Next, the upper mold 7a is set on the upper part of the lower mold 7b, and the ground terminal 6,
6 and the upper end of the center conductor 3 is held concentrically with the holding fitting 7e, and a synthetic resin is injected into the space formed by the upper mold 7a and the lower mold 7b to form the mold layer 2. The resin molded bushing is then molded.

However, since the grounding shield electrode 4 is made entirely of braided wire and has low strength, it is easily deformed or moved by the resin injected during molding of the mold layer 2. There is a problem that the concentric state with the center conductor 3 cannot be maintained. In order to solve this problem, as shown in FIG. 7, a plurality of ring-shaped metal reinforcing wires 8, for example four, are brazed to the outer circumference of the grounding shield electrode 4 to reinforce the grounding shield electrode 4. A version with increased rigidity is provided, but in this case, the stiffness of the reinforcing wire 8 is large and the shrinkage amount is greater than that of the mold layer 2 in the process of cooling the molded special synthetic resin of the mold layer 2 after hardening. Because of the difference, this acts to prevent the shrinkage of the mold layer 2, increasing the residual stress generated within the mold layer 2, and causing stress during subsequent overcurrent strength tests and heat cycle tests, or during use. A new problem arises in that cracks and the like occur due to repeated heating and cooling.

[Object of the Invention] The present invention has been made in view of the following two circumstances, and the object thereof is to prevent the grounding shield electrode from moving or deforming during molding of the mold layer, and to prevent the grounding shield electrode from moving or deforming so that it is concentric with the center conductor. It is an object of the present invention to provide a method for manufacturing a resin molded bushing that can maintain its condition and minimize the stress generated in the mold layer due to expansion and contraction, thereby preventing the occurrence of cracks and the like.

[Summary of the Invention] The present invention provides a method in which a grounding shield electrode is integrally molded into a synthetic resin cylindrical body having a holding protrusion protruding from the outer periphery, and a cylindrical body integral with the grounding shield electrode is placed in the mold. The body and the center conductor are arranged concentrically, and the holding protrusion of the cylindrical body is held in the flange molding recess of the mold, and then a synthetic resin is injected into the mold to form a mold layer. The cylindrical body reinforces the grounding shield electrode, the holding protrusion holds the grounding shield electrode concentrically with the center conductor, and the amount of shrinkage between the mold layer and the cylindrical body is reduced. The feature is that the difference can be made small and the stress in the mold layer can be reduced.

[Embodiment of the Invention] - Hereinafter, an embodiment of the present invention will be described with reference to Varnish No. 4 to FIG.

First, in FIG. 2, 11 is a center conductor, and 12 is a grounding shield electrode arranged concentrically at intervals around the outer periphery of the center conductor 11, which is formed into a cylindrical shape by a wire mesh made of braided fine wires. Both ends 12a are curved into an arc shape. 13 is a cylindrical body formed integrally with the grounding shield electrode 12 by so-called insert molding using a flexible synthetic resin so as to cover the outer periphery of the grounding shield electrode 12, as shown in FIG. Both ends of this are formed as a ring part 13a concentric with the grounding shield electrode 12, and m number of recessed parts 13b, for example four, are formed around the outer periphery of this ring part 13a. Reference numeral 14 designates m number of, for example, four, holding protrusions which are protruded from approximately the center of the outer circumference of the cylindrical body 13 and have spherical tips. Reference numeral 15 denotes a connecting wire embedded in the holding protrusion 14, one end of which is soldered to the grounding shield electrode 12 as shown in FIG. It is connected to the ground terminal 16 of the shape. 1
7 is the center conductor 11. Grounding shield electrode 12, cylindrical body 1
3. A molded layer made of synthetic resin such as epoxy resin so as to embed the holding protrusion 14 and the grounding terminal 16, and a mounting flange is provided approximately in the center of the outer circumferential portion of this lead layer 17, that is, on the outside of the grounding shield electrode 12. 18 is integrally formed, and a ground terminal 16 is disposed within this mounting flange 18, thereby forming a resin molded bushing 19.

Next, 1 regarding the manufacturing method of the resin molded bushing 19.
Be happy. In FIG. 1, 20 is a lower mold 21 and an upper mold 22.
This is a mold for molding the mold layer 17, and in an open state with the upper mold 22 moved upward,
First, insert the center conductor 1 into the fitting hole 21a at the center of the inner bottom of the lower mold 21.
Insert and support the lower end of 1. Next, the cylindrical body 13, which has been integrally molded with the grounding shield electrode 12 by insert molding in advance, is brought into contact with the inner surface 21b of the lower mold 21 so that the ring portion 13a at the lower end of the cylindrical body 13 is brought into contact with the inner surface 21b of the lower mold 21, and the tip of the holding protrusion 14 is attached to the lower mold. 21, and the ground terminal 16 is placed on the upper end surface of the lower mold 2.
The grounding shield electrode 12 is set concentrically with the center conductor 11 by inserting the grounding shield electrode 12 into the guide pin 23 erected on the upper end surface of the electrode 1 . Next 1-! ! ! 22 is molded to the second part of the lower mold 21 so that the ring part 13a at one end of the cylindrical body 13 is brought into contact with the inner surface 22a, and the holding protrusion 14 is attached to the second end surface of the four flange forming parts 22b. and the upper end of the ground terminal 16. Further, a rectangular holding fitting 24 is attached to the upper part of the upper mold 22, and the upper end portion of the center conductor 11 is inserted and supported into the hole 24a of this holding fitting 24. As a result, the center conductor 11 and the grounding shield electrode 12 are connected to the mold 2.
It is held concentrically within 0.

After that, resin is injected into the mold 20 through the opening between the inner surface 22a of the upper mold 22 and the holding fitting 24 to form a mold layer 17 that integrally has the mounting flange 18. A resin molded flange 19 is manufactured. In this case, the resin injected into the mold 2o enters the outside of the cylindrical body 3 through the recessed part 13b formed in the ring part 13a of the cylindrical body 13, and is molded as the mounting flange 18. .

In the method for manufacturing the resin molded bushing 19 described above, the holding protrusion 14 of the cylindrical body 13 is fitted and held within the four flange forming parts 22b in the mold 20, so that the grounding shield electrode 12 is connected to the center conductor 11. Since the grounding shield electrode 12 is held concentrically with the grounding shield electrode 12, the grounding shield electrode 12 is not moved by the resin injected when molding the mold layer 17 and the mounting flange 18. Furthermore, since the grounding shield electrode 12 is reinforced by being integrated into the cylindrical body 13 in advance, it will not deform even when pressed by the injected resin, and the center conductor 11 and the grounding shield electrode The concentric state with 12 can be maintained normally. In addition, since the cylindrical body 13 is made of synthetic resin and has relatively good flexibility,
The mold layer 17 can expand and contract according to the contraction of the synthetic resin during molding and the expansion and contraction of the mold layer 17 due to heating and cooling during use. The stress generated in the mold layer 17 can be minimized, and cracks etc. will not occur in the mold layer 17 even when overcurrent tests and heat cycle tests are performed, or when heating and cooling are repeated during use. It can be prevented.

[Effects of the Invention] As is clear from the above description, the present invention is such that a grounding shield electrode is integrally molded into a synthetic resin cylindrical body with a holding protrusion protruding from the outer periphery, and this is placed in a mold. A cylindrical body integral with a grounding shield electrode and a center conductor are disposed concentrically, and the holding protrusion of the cylindrical body is held in a flange forming recess of a mold, and then the cylindrical body is placed in the mold. Since the mold layer is formed by injecting resin, is it a grounding shield? f
It is possible to prevent the movement and deformation of S and I4 and maintain a concentric state with the center conductor, and to reduce the difference in the amount of expansion and contraction between the mold layer and the cylindrical body, reducing stress generated in the mold layer and preventing cracks, etc. This has the effect of preventing this from occurring.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of the present invention. Figure 1 is a longitudinal cross-sectional view of the manufacturing process, Figure 2 is a longitudinal cross-sectional view of a resin molded bushing, and Figure 3 is a cross-sectional view of the resin molded bushing. Fig. 4 is a perspective view of the cylindrical body, Fig. 5 is a view corresponding to Fig. 2 showing a conventional example, and Fig. 6 is a view corresponding to Fig. 1 of the conventional example.
FIG. 7 is a diagram equivalent to FIG. 1 showing another conventional example. In the figure, 11 is the center conductor, 12 is the grounding shield electrode, 1
3 is a cylindrical body, 14 is a holding protrusion, 17 is a mold layer, 18
is a mounting flange, 19 is a resin molded bushing, 2
0 indicates a mold, and 22b indicates four parts for flange forming. 8 Garyu Figure 3 Figure 4 Figure 5 Figure 7 Emperor Figure 6.

Claims (1)

[Claims] 1. A method for manufacturing a resin molded bushing in which a center conductor and a grounding shield electrode concentric with the center conductor are embedded in a synthetic resin mold layer that integrally has a mounting flange on the outer periphery, The grounding shield electrode is integrally molded into a cylindrical body made of synthetic resin with a holding protrusion protruding from the outer periphery, and the cylindrical body integral with the grounding shield electrode and the center conductor are arranged concentrically within the mold. At the same time, the holding protrusion of the cylindrical body is held in the flange forming recess of the mold, and then a synthetic resin is injected into the mold to mold the mold layer. Method for manufacturing resin molded bushings.