JPH0839603A - Molding of insert part - Google Patents

Abstract

PURPOSE:To preliminarily apply bending processing to a brush and to dispense with a cover plate to reduce cost by positioning a metal plate under a contact part to perform insert molding. CONSTITUTION:Inner' clip washers 17 are inserted in the bar rings 16 provided to a terminal 12 under pressure to be integrated therewith and fitted in a mold for a housing 13, A brush 11 and the terminal 12 are integrated and the brush 11 is covered with a terminal pressing mold 22 provided with the root pressing part 24 of the brush a terminal pressing part 25 and an escape hole 23 provided so as to be prevented from the contact with the brush 11. A resin is injected into the mold in this state to form the housing 13. At this time, the housing 13 becomes a bottomed housing and the brush 11 subjected to normal bending processing as a matter of course is subjected to insert molding along with the terminal 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding an insert-molded part having an electric contact and an output take-out part, which is mainly used for a variable resistor, an encoder, a switch and the like.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG.

Reference numeral 2 is a terminal, and a brush 1 is formed at the other end of at least one of the terminals 2.

When insert molding this terminal 2,
The brush 1 was inserted into the molding die of the housing 3 without being bent, the housing 3 was formed by insert molding, and then the brush 1 was bent to form the contacts. Therefore, the housing 3 has through holes 9 both above and below the insert portion of the brush 1, and after molding the housing 3, one side is covered with another cover plate 8 to form the housing.

[0005]

However, in the conventional molding method described above, in order to form the brush 1 inside the housing 3, the through hole 9 is required in the housing 3, and this through hole 9 is required.
It is necessary to cover one side of the above in order to prevent invasion of dust or the like into the contact portion, and the cover plate 8 is used separately from the housing 3 to cover the through hole 9.

For this reason, the housing portion includes the housing 3 and the cover plate 8.
There is a problem that the cost is increased because it is composed of two parts and the number of steps for combining them is also required. Further, since the terminal 2 has an integral structure with the brush 1, if the material thickness is reduced in consideration of the spring property of the brush 1, the terminal 2 is also weakened and is easily deformed.

[0007]

In order to solve the above-mentioned problems, the present invention arranges a metal plate such as a terminal below a contact part such as a brush subjected to bending, covers the contact part, and Insert molding is performed by insert molding with a molding die that abuts against a metal plate.

[0008]

As described above, since the metal plate is positioned below the contact parts and the insert molding is performed, the brush can be preliminarily bent, and the cover plate is not necessary, and the cost can be reduced. is there.

Further, since the metal plate and the contact part can be formed of different materials and materials, when the metal plate is used as the terminal, the strength of the terminal and the brush can be sufficiently secured.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. As shown in the figure, 11 is a brush having a plurality of spring properties, 12 is a terminal arranged below each brush 11 and electrically connected, and 13 is the brush 11 and the terminal 12 described above. It is an insert-molded housing.

Next, a method of manufacturing the casing will be described together with the details of the above configuration. Reference numeral 17 is a chrysanthemum seat provided on the brush 11 that has been bent in advance, and is press-fitted into and integrated with the burring 16 provided on the terminal 12, and is inserted into a molding die (not shown) for the housing 13. It The brush 11 and the terminal 12 which are integrated with each other, the root pressing portion 24 of the brush 11,
The brush 11 is covered with a terminal pressing die 22 (combined with the molding die) provided with escape holes 23 provided so that the terminal pressing portion 25 and the brush 11 do not come into contact with each other, and the terminal pressing die 22 is also provided. Is in contact with the terminal 12.

In this state, resin is injected into the mold to form the housing 13. At this time, the housing 13 has a bottomed shape, and the brush 11 is naturally bent and insert-molded together with the terminal 12.

The terminal 12 does not need to cover the entire bottom of the housing 13, and it is sufficient that the terminal 12 is at least only under the brush. Even if the terminal 12 is not a terminal 12 but a metal plate, the escape hole 23 from the bottom is provided. Any material can be used as long as it can prevent the inflow of resin with the terminal pressing die 22.

The integration of the brush 11 and the terminal 12 is
In the above-mentioned embodiment, press-fitting is used, but it is also possible to use other known methods such as eyelet crimping and welding.

FIG. 3 shows another embodiment of the present invention. Explaining only the points different from the embodiment of FIG. 1, the above embodiment shows a method of molding an insert part into a bottomed casing. On the other hand, it shows a method of molding the insert part into the flat plate-shaped molded product 24.

FIG. 4 also shows another embodiment of the present invention, in which the brush 32 and the terminal 33 are made of the same material, and the folded portion 30 is pre-bent and insert-molded to form a flat plate. The product 25 is formed. At this time, since the bending process is performed in advance, it is possible to provide the molded product 25 more efficiently and more accurately than a product that is bent after molding.

[0017]

According to the present invention, a metal plate is arranged below a contact part such as a brush which is bent as described above, and the metal plate and the contact part such as the bent brush are arranged in an escape hole. Since the mold resin prevents the molding resin from flowing into this escape hole, it is possible to insert-mold the contact parts that have already been bent, and reduce the number of parts by eliminating the cover plate that was required in the past. At the same time, the production efficiency is improved. Further, it is possible to appropriately combine a material having a spring property and a metal plate.

Even when a metal plate is used as a terminal and made of the same material as the contact part, the contact part can be bent at the time when the metal material is used, so that the insert molded part can be formed efficiently and accurately. .

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a housing according to an embodiment of a method for molding an insert part of the present invention.

FIG. 2 (a) is a side sectional view taken along line AA ′ of FIG. 1 (FIG. 1). FIG. 2 (b) is a plan view of line AA ′ of FIG. 2 (FIG. 1).

FIG. 3 is a perspective view of the other embodiment.

FIG. 4 is a perspective view of the other embodiment.

FIG. 5 is a perspective view of a conventional housing.

[Explanation of symbols]

 11 Brush 12 Terminal 13 Housing 22 Terminal Holding Mold 23 Relief Hole

Claims (2)

[Claims] 1. The above-mentioned other molding die which is combined with the above-mentioned molding die in which at least a contact part and a metal plate are disposed below the contact part, and a clearance hole is provided in the contact part. A method for molding an insert part, which is located in the escape hole, and in which the other molding die is brought into contact with the metal plate to prevent the molding resin from flowing into the escape hole to form the insert part. 2. The contact part and the metal plate are made of the same material,
The method for forming an insert part according to claim 1, wherein the insert part is formed after bending the contact part.