JPH02304831A - Manufacture of plastic seal switch - Google Patents

Abstract

PURPOSE:To eliminate incorrect sealing without using a dedicated sealing agent to simplify manufacturing process by a method wherein a plastic member and a plastic base are integrated by heat welding as well as this base and a plastic case are integrated by heat welding. CONSTITUTION:An approximately center part of a terminal 4 is integrally fixed to a plastic mold 1 by insert molding. Then this mold is engaged with and fixed to a mounting part of a base 5 in press-fitted state, and a lead part 2 is positioned so that a contact 3 aligns with a specific position. With the upper surface 6a of a case 6 leveled with a protrusion 1a of the plastic mold 1 and the upper surface of a protrusion 5a of the base 5, a joint of the protrusion 1a of the plastic mold 1 and the protrusion 5a of the base 5 is integrated by heat welding, and then a joint of the protrusion 5a of the base 5 and the upper end of the case 6 is integrated by heat-welding. Thus sealing stability can be improved without sealing agent while manufacturing process can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a method of manufacturing a plastic seal switch used in a relay switch or the like.

(Summary of the Invention) This invention is a method of sealing between a terminal with a contact, a plastic base, and a plastic case in the above switch, by fixing a plastic member to the terminal, and positioning and fixing the plastic member and the base, and the base and the case. At the same time, they are integrated by thermal welding to obtain a seal, thereby improving the seal stability without using a sealant, and making it possible to omit the sealant application process and curing/drying process.

(Prior art and its problems) Conventionally, as shown in Fig. 3, a switch used for a relay switch, etc. is a plastic base 5 on which terminals 4゜4' having contacts and a return spring 21 are fixed. There is one in which an electromagnet 24 consisting of a movable iron piece 22, a coil 23, etc. is mounted and fixed, and then a box-shaped plastic case 6 is externally fixed to the base 5.

By the way, in this type of switch, the joint surface between the plastic base 5° case 6 and the terminals 4, 4- is sealed using a sealant to prevent flux from entering. That is, sealing is achieved by applying a liquid or semi-solid sealant to each joint surface and curing it by heating at a predetermined temperature.

However, this sealing method requires a special sealant in a liquid or semi-solid state, resulting in problems such as the sealant adhering to the terminals 4 and 4' near the sealing part. .

In addition, the manufacturing process has become complicated because a sealing agent application process and a curing and drying process must be performed. Furthermore, when the sealant hardens and dries, its volatile components generate reactive harmful gases, which enter the switch and cause sealing failure.

(Object of the Invention) This invention was made in view of the above-mentioned problems, and its purpose is to create a plastic seal switch that can eliminate seal defects without using a special sealant and simplify the manufacturing process. The purpose of this invention is to provide a method for manufacturing the same.

(Structure and Effects of the Invention) In order to achieve the above-mentioned objects, the present invention fixes a plastic member to a terminal having contacts, and then integrates the plastic member and a plastic base by heat welding. The base and the plastic case are integrated by heat welding.

According to this invention, the plastic member to which the terminal is fixed, the plastic base, and the base and the plastic case are integrated by heat welding, so that the sealing between these members is complete and the flux Intrusion can be reliably prevented. At the same time, since the use of a sealant is eliminated, the process of applying and curing and drying the sealant becomes unnecessary, which improves productivity and prevents sealing defects caused by organic gas.

(Example) An example of the main part of this invention will be described below based on the drawings.

FIGS. 1 and 2 are a sectional view and a perspective view, respectively, showing the seal structure of this embodiment. In both figures, reference numeral 4 denotes a terminal extending to the outside of the switch, and the inside portion thereof is a lead portion 2 having a contact 3. This terminal 4 is fixed to a plastic base 5 via a plastic molded product 1.

The entire base 5 is housed and fixed within a plastic case 6. Further, the upper surface 6a of the case 6 is on the same level as the projections 1a and 5a for heat welding formed at the joint between the plastic molded product 1 and the base 5. Here, the material of the case 6 is the same as that of the plastic molded product 1 and the base 5;
For example, PC or PBT are used. “Next, we will explain the manufacturing method of this plastic seal switch. First, the approximately center portion of the terminal 4 is fixed integrally to the plastic molded product 1 by insert molding. Next, this molded product 1 is press-fitted into the mounting location of the base 5. , and position the lead part 2 so that the contact point 3 matches a predetermined position.

After that, the case 6 is placed on the base 5 and fixed by engagement. Then, while holding the case 6 so that the upper surface 6a is almost flush with the upper surfaces of the protrusion 1a of the plastic molded product 1 and the protrusion 5a of the base 5, first, the protrusion 1a of the plastic molded product 1 and the protrusion 5a of the base 5 are held. The joints between the protrusions 5a of the base 5 and the upper end of the case 6 are then integrated by heat welding.

In this case, the order of heat welding may be such that the base 5 and the case 6 are first integrated, and then the base 5 and the plastic molded product 1 are integrated, or these two joints may be integrated by heat welding at the same time. It may be changed into

Also, the plastic molded product 1 and the base 5 to which the terminal 4 is fixed
They may be integrated in advance by heat welding, the case 6 may be placed over this assembly, and the joints may be integrated by heat welding. This improves the sealing performance at each joint between the plastic molded product 1 and the base 5 and between the base 5 and the case 6 without using a special sealant.

Since this manufacturing method does not require a sealant, the seal coating process and curing/drying process are eliminated, and the conventional problem of sealant adhering to the terminals 4 is also solved. In addition, since the joint can be sealed simply by heating, the workability and automation of the sealing process are made easier.
A reduction in manufacturing costs and an increase in productivity are achieved.

In the embodiment, after the terminal 4 was fixed to the plastic molded product 1, this block body was used as a single item and attached to the base 5, but as shown by the two-dot chain line 1-1 in FIG. They may be connected and this connection block body may be mounted on the base 5.

In addition, in the example, the material of the plastic molded product 1 is base 5.
Although the same materials as those for case 6 and case 6 are used, these materials are not necessarily the same, and similar plastic materials may be used as long as good thermal weldability can be maintained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the main part of the method of this invention, Fig. 2 is a perspective view of an insert molded product to which the terminal of Fig. 1 is fixed, and Fig. 3
The figure is an exploded perspective view showing a conventional switch. 1...Plastic molded product (plastic member) 2.
...Terminal 4...Plastic base 6...Plastic case

Claims (1)

[Claims] 1. After fixing a plastic member to a terminal having contacts, the plastic member and the plastic base are integrated by heat welding, and the base and the plastic case are integrated by heat welding. A method for manufacturing a plastic seal switch.