JPS61216406A - Variable resistor - 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 The present invention relates to a variable resistor, and more specifically, the present invention relates to a variable resistor. When a curable synthetic resin is used, it prevents unnecessary flow of the synthetic resin, protects the resistor and electrode from being contaminated, and allows pin terminals, etc. to be arranged as intended. Provide configuration for.

(Prior art) Conventionally, the pin terminals of rotary variable resistors, etc. 1. When insert molding is performed with housing, due to the fluidity of the low-pressure molding thermosetting resin used for insert molding, the resin flows into the vertical red electrode body provided on the ceramic substrate, etc. This was a hindrance to producing clear resistors and electrode bodies.

(Problems to be Solved by the Invention) In recent years, as there has been a demand for smaller variable resistors, thinner and smaller ones have to be manufactured. However, due to the fluidity of the synthetic resin used in insert molding, it is often difficult to provide resistors and electrodes on the substrate that are not contaminated by these, leading to problems such as the occurrence of defective products. I scored very few points.

(Means for solving the problem) Therefore, when a thermosetting resin for low pressure molding is used for insert molding of pin terminals and housings, unnecessary flow,
In order to prevent inflow, a filling member such as a glass body is interposed as an intrusion prevention member in the gap between a pair of electrode bodies surrounding a fan-shaped resistor provided on a ceramic substrate, and a filling member such as a glass body is interposed between the pair of electrode bodies and a ceramic body. Similarly, a filling member such as a glass body is inserted as an intrusion prevention member between another pair of electrode bodies having contacts at the center of the substrate.

(Function) Filling members such as glass bodies, which are intrusion prevention members, are used for insert molding housings, pin terminals, etc. using thermosetting resin for low pressure molding on the outer periphery of resistors and electrode bodies provided on ceramic substrates. When applying it, it prevents the fluid resin from penetrating unnecessary parts of the substrate such as ceramic.

(Example) An example of the present invention will be described below with reference to the accompanying drawings. Incidentally, the state before insert molding is first explained. In FIG. 1, a pair of substantially U-shaped electrode bodies 4b and 4c are formed on a substrate made of ceramic or the like so as to embrace an inverted T-shaped electrode body 4a and a sector-shaped resistor 6, which will be described later.
and the fan-shaped resistor 6 are printed and fired. Further, the U-shaped electrode body 4b.

A filling member 8 is also placed between the body 4 and the ~-shaped electrode body 4a as well as between the electrode bodies 4b and 4a.

The filling members 10 and 12i are interposed therebetween and printed and fired on the substrate 2 made of ceramic or the like. In this embodiment, a glass body is used as the filling member. Figure i2 shows a single band-shaped metal piece 14.
A plan view is shown in which a single pin terminal 16 and a pair of pin terminals 18 and 20 are formed by punching out the pin terminal 16. The bin terminals 16, 18, and 20 are arranged to form the apexes of a substantially triangular shape, and correspond to the electrode bodies 4a and 4b of FIG. 1, respectively.

It is dimensioned to be welded onto 4c. The top surfaces of the tip welding parts 22, 24, and 26 of the bin terminals 16, 18, and 20 are not plated, and the bin terminal groups are arranged on 4a @ 4b+4C, respectively, as shown in FIG.
Welding is performed using an R-rarel gap electrode rod (not shown). Note that the pin terminal group 16, 18° 20 is a band-shaped metal piece 14.
It has already been mentioned that the metal pieces 28 and 30 extend from the metal pieces 28 and 30 facing each other and are arranged in a substantially triangular shape so as to face each other. code 3
Reference numeral 2 denotes a positioning hole provided in the band-shaped metal piece 14. Therefore, a plurality of groups of these pin terminals are fabricated on the strip-shaped metal piece 14 in parallel in series.

FIG. 4 shows that the board 2 having the configuration shown in FIG. 3 and the pin terminal groups 16, 18, 20 are insert-molded using a thermosetting material whose main raw material is a low-pressure thermosetting synthetic resin. , is a plan view of the housing 34. FIG. Of course, a splittable mold is used to carry out the insert molding, but in this case, unnecessary fluid synthetic resin may flow out of the mold before heat curing is completed, and the resistor may be damaged. 6, electrode body 4
a.

A filling member 8, which is a blocking member interposed between the electrode bodies 4a and 4b, plays the role of preventing adhesion to the electrode bodies 4b and 4c and contaminating them; a filling member 12 between the electrode bodies 4b and 4a;
This is a filling member 10 between the electrode bodies 4a and 4c.

In FIG. 4, the housing 34 is constructed by insert molding, and at the same time, the housing step 36, the raised part 42 having stopping walls 38, 40 on both sides, etc. are made of the synthetic resin. After the insert molding is completed and the rotor, case, etc. are assembled, the band-shaped metal pieces 28, 3 (l) are cut off and the lengths of the pin terminals 16° 18.20 are adjusted.

The rotor 44 shown in FIG. 7 is fitted into the housing 34 constructed by insert molding as shown in FIG. 4.

A diagonal groove 50 is bored in the rotor 44 to accommodate a brush wire nog 48 made of a wire rod attached to the support piece 46 in parallel,
A chain part 52 is provided around this groove, a part of the chain part is used as a fan-shaped stopper 54, and end faces 56 are formed on both sides of the fan-shaped stopper 54. After the rotor 44 is fitted and combined with the housing 34, an O-ring 5 is attached to the outer periphery of the rotor 44.
By assembling case 58 via 9, the manufacture of the variable resistor is completed. FIG. 5 is a plan view thereof. The case 58 has a hole 60 that allows the case 58 to connect to the protrusion 62 of the housing 34.
The case 58,) and the housing 34 are fitted together to prevent them from falling off.

When a screwdriver or the like is applied to the slit 62 bored in the upper end of the rotor 44 and the rotor is rotated by a predetermined angle clockwise or counterclockwise, the wiper 48 slides on the base plate 2 together with the rotor. , resistor 6, electrode bodies 4a, 4b, 4c
etc., respectively, thereby obtaining the desired resistance value.

(Effects of the Invention) In the variable resistor of the present invention, since the intrusion prevention member is disposed in the gap between the electrode bodies provided on the substrate, the housing can be constructed by insert molding the substrate and pin terminals. Even if molding is performed using a fluid thermosetting resin for low-pressure molding, the unnecessary synthetic resin will be prevented from entering the interior by the intrusion prevention member, and will not be able to resist the resistor or electrode body. It will not cause any contamination phenomenon due to the wear and tear, and will not lead to deterioration of the performance of the variable resistor.

[Brief explanation of the drawing]

Figure WJ1 is a plan view of related parts printed and fired on the substrate of the present invention, Figure 2 is a plane view of a pin terminal punched from a band-shaped metal piece, and Figure 3 is a plan view of the pin terminal of Figure 2 bonded to Figure 1. Fig. 4 is a plan view of the insert-molded housing, Fig. 5 is a plan view of the completed variable resistor with the case attached,
6 is a cross-sectional view taken along the line ■--M in FIG. 5, FIG. 7 is a bottom view of the rotor, and FIG. 8 is a cross-sectional view taken along the line ■--■ in FIG. 5. 2...Substrate 4a...Italic electrode body 4b
, 4c... Single-shaped electrode body 6... Resistor element 8...
Filling member 10...Filling member 12...Filling member 34...Using 58...Case

Claims (1)

[Claims] 1. In a rotary variable resistor, a filling member is interposed in the gaps between a plurality of electrode bodies provided on a substrate to prevent unnecessary synthetic resin from entering the interior when forming a housing by insert molding. A variable resistor that prevents 2. The variable resistor according to claim 1, wherein the synthetic resin is preferably a thermosetting synthetic resin for low-pressure molding. 3. The variable resistor according to claim 1, wherein the filling member is a glass body.