JPH0128602Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a terminal board for a switch, and in particular, a terminal board for a switch that is made by insert-molding a fixed contact piece consisting of a contact part and a terminal part into an insulating plate made of a thermoplastic synthetic resin material, etc. Regarding.

Conventionally, in a switch terminal board in which a fixed contact piece is insert-molded into an insulating plate, the contact part of the insulating board is deformed due to the heat of soldering the terminal part, and this causes the contact part of the terminal board and the movable contact part to deform. This has the disadvantage that poor contact occurs at the contact portion.

Therefore, the present invention aims to improve the reliability of a switch terminal board in which a fixed contact piece consisting of a contact part and a terminal part is insert-molded on such an insulating board, and that contact failures caused by deformation of the insulating board due to the heat of soldering the terminal part will not be induced. The purpose of the present invention is to provide a terminal board for a switch that provides high contact.

Next, one embodiment of the terminal board for a switch according to the present invention will be described in detail with reference to the drawings in comparison with a conventional terminal board.

Conventionally, the terminal board of a switch is made by inserting a fixed contact piece consisting of a contact part and a terminal part into an insulating plate made of synthetic resin, etc. As shown in FIG. terminal insertion hole 1
1a..., and implant the fixed contact piece 12... into the terminal insertion hole 11a..., and attach the base 12c of the terminal part 12b on the opposite side to the contact part 12a using a jig with wedge-shaped teeth ( The fixed contact piece 12 is fixed to the insulating substrate 11 by bending the fixed contact piece 12 to the outside using a screw (not shown) and crimping it. As shown in FIG. 2, on such a switch terminal board, a contact portion 20a of a movable contact piece 20 is bent into an Ω-shape on both sides of the contact portion 12a.
were in sliding contact with each other to form switching contacts. On the other hand, in recent years, electronic devices such as radio cassettes have become smaller in size, and the switches used in these devices are also required to be smaller. In order to reduce the size, it is necessary to use a fixed contact piece with a thin plate thickness. In this case, if the plate thickness of the fixed contact piece becomes thin, it becomes extremely difficult to drill a narrow hole that matches the plate thickness to be drilled in the insulating board, which limits miniaturization. This has the disadvantage that the fixing strength of the terminal is weakened, and the terminal is prone to looseness, making it impossible to obtain stable contact. For this reason, as shown in FIG. 3, a switch terminal board in which a fixed contact piece 32 is formed by insert molding on an insulating substrate 31 made of a synthetic resin material has come to be used. It is preferable to use a thermosetting resin as the material for the insulating substrate 31 because of its high heat resistance, but since it has poor workability, thermoplastic resin is generally widely used. However, in the case of this thermoplastic resin insulating board 31, when the terminal part 32b is soldered, the insulating board surface is deformed at the peripheral part 33 of the contact part 32a due to heat, as shown in FIG. Excitement,
When the movable contact piece 20 slides on the surface of the contact part 32a,
The lower end contact 20a of the movable contact piece 20 collides with the raised part 31a, causing chattering, or if the raised part 31a is large, the contact part 20a of the movable contact piece 20 rides on the raised part 31a. There was a drawback that poor contact with the contact portion 32a of the fixed contact piece 32 occurred, resulting in unstable contact.

The present invention aims to solve the above-mentioned drawbacks, and FIGS. 5 and 6 are diagrams showing a switch terminal board according to the present invention. In FIG. 5, reference numeral 41 denotes an insulating substrate made of a thermoplastic synthetic resin material, and a fixed contact piece 42 is vertically insert-molded into this insulating substrate 41. On the upper surface of the insulating substrate 41, a concave narrow groove 41a is formed around the contact portion 42a of the fixed contact piece 42, as clearly shown in FIG.
When a switch made of the switch terminal board configured as described above is assembled into a radio set or the like and is attached by soldering, the contact portion 42a of the insulating board 41 and the terminal portion are heated by the heat applied to the terminal portion 42b. The area around the contact surface with the contact portion 42b is deformed due to heat, but especially on the upper surface of the insulating substrate 41 that comes into contact with the contact portion 42a, since the concave narrow groove 41a is provided around the contact portion 42a, there is no deformation from the contact portion 42a. The heat is not directly transferred to the upper surface of the insulating substrate 41, and the upper surface of the insulating substrate 41 in contact with the contact portion 42a is kept flat without being bulged due to thermal deformation. Further, since the concave narrow groove 41a is formed around the contact portion 42a, the deformed and raised portion of the insulating substrate is filled in the concave narrow groove 41 appropriately.
Even though a is provided, there is no play in the terminal. Furthermore, in the case of insert molding, the molding material leaks into a small gap between the mold mating surface or the pressure contact surface between the insert part and the mold, causing burrs in this area. On the contact portion 42a side, since the pressure contact surface with the mold is located inside the surface of the insulating substrate 41, it hardly protrudes to the top surface of the substrate, and even if it does, it melts due to heat during soldering. The portion does not accumulate in the recess and deform as in the conventional case, which further promotes the swelling.

As explained above in detail, the terminal board of the switch according to the present invention has a fixed contact piece inserted into an insulating substrate made of a thermoplastic material, and a fixed contact piece 42 on the contact part side of the fixed contact piece 42. Since a concave narrow groove is formed in the terminal, when soldering is performed on the terminal part of the fixed contact piece, the insulating substrate around the contact part does not become thermally deformed and swell up due to heat, unlike in the conventional case. Although a thermoplastic resin material is used as the material of the insulating substrate, the switch terminal board can prevent deformation of the insulating substrate surface and has highly reliable contact performance without causing play in the terminals.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the structure of a conventional slide switch terminal plate, Figure 2 is a cross-sectional view showing the structure of a conventional slide switch switching contact, and Figure 3 is a cross-sectional view showing the structure of a conventional slide switch switching contact. 4 is a sectional view of the terminal board showing a state in which the terminals are soldered and the board surface is deformed; FIG. 5 is a sectional view showing the structure of the slide switch terminal board according to the present invention; FIG. 6 is a cross-sectional view of the terminal board after the terminals have been soldered. 11...Insulating board, 11a...Terminal insertion hole, 1
2... Fixed contact piece, 12a... Contact part, 12b...
Terminal part, 12c...Base, 20...Movable contact piece, 2
0a... Contact portion, 31... Insulating substrate, 31a...
Raised portion, 32a...Contact portion, 32b...Terminal portion, 41...Insulating substrate, 41a...Concave narrow groove, 4
2...Fixed contact piece, 42a...Contact part, 42b...
Terminal section.

Claims (1)

[Scope of utility model registration request] In a terminal board for a switch, a fixed contact piece consisting of a contact portion and a terminal portion is insert-molded on an insulating substrate made of an insulating material having thermoplasticity so that the contact portion and the terminal portion each protrude outward. 1. A terminal board for a switch, characterized in that a concave narrow groove is provided on the surface of the insulating substrate in the vicinity of the contact portion where the substrate and the contact portion come into contact with each other to absorb a bulging portion due to heat of an insulating material constituting the insulating substrate.