JPH0121532Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a variable resistor with a switch used in electronic equipment.

Conventional configurations and their problems Generally, electronic devices such as tape recorders sometimes use variable resistors with switches for the purpose of miniaturization, and there is a demand for small and highly reliable resistors.

A conventional variable resistor with a switch will be explained below. Figures 1 and 2 are a top view and a sectional view of a conventional variable resistor with a switch, in which 1 is the main body of the single-shaft double variable resistor, 2 is the rotation axis of the variable resistor main body 1, and 3 is the rotating shaft of the variable resistor main body 1. A switching piece 4, which is press-fitted into the rotary shaft 2 and rotates with the rotation of the rotary shaft 2, is a metal frame for reinforcing the variable resistor main body 1, and also serves as a fixed contact of the switch. Reference numeral 5 denotes a resin case for fixing each component of the variable resistor main body 1, and a mounting base 14 for a movable contact is integrally provided on the outer periphery of the reinforcing metal frame 4.

Reference numeral 6 denotes a movable contact that is press-fitted into the mounting base 14 parallel to the rotating shaft 2, and has an arcuate protrusion 6a projecting from the upper end of the movable contact toward the reinforcing metal frame 4 serving as the fixed contact. , this protrusion 6a is adapted to come into contact with and separate from the upper edge portion 4a of the reinforcing metal frame 4. Here, the movable contact 6 is a plate portion 6b between parallel notches provided in the spring plate.
An arc-shaped protrusion 6a is provided at the tip of the protrusion 6a.
It is attached to the mounting base 14 by press-fitting the plate portions 6c on both sides of the plate portion 6b having the above-mentioned plate portions 6c into the mounting holes 14a of the mounting base 14. The mounting base 14 has a groove 14b for allowing the plate portion 6b having the protrusion 6a to move in the front-rear direction.

7 is a soldering terminal of the variable resistor main body 1 to the printed wiring board, 8 is a soldering terminal of the movable contact 6 to the printed wiring board, and 9 is a printed wiring board of the reinforcing metal frame 4 as the fixed contact. 10 is a protrusion of the switching piece 3 that moves the movable contact 6. 11 is a resistor printed board of the variable resistor main body 1, and 12 is its resistor. Reference numeral 13 denotes a sliding terminal that rotates with the rotation of the rotating shaft 2 and contacts the resistor 12 to change the resistance value.

The operation of the conventional single-shaft dual variable resistor with switch constructed as described above will be described below.

As shown in FIGS. 1 and 2, the movable contact 6 is pushed away by the projection 10 of the switching piece 3, which is attached to the variable resistor main body 1 so as to rotate in accordance with the rotation of the rotating shaft 2. The switch is opened by pulling the contact 6 away from the fixed contact 4 made of a reinforcing metal frame.

Next, as shown in FIGS. 3 and 4, when the rotating shaft 2 of the variable resistor main body 1 is rotated, the switching piece 3 rotates in accordance with the rotation, and the protrusion 10 separates from the movable contact 6. The movable contact 6 returns to its original position by its own repulsive force, contacts the fixed contact 4 made of a reinforcing metal frame, and closes the switch.

However, in the above conventional configuration, the operating direction of the movable contact 6 is perpendicular to the contact surface of the upper edge portion 4a of the movable contact 4 made of the reinforcing metal frame, as shown in FIGS. 5a and 5b. Therefore, if foreign matter such as dust or flux due to soldering etc. adheres to the contact area between the fixed contact 4 and the movable contact 6 made of the reinforcing metal frame, the foreign matter cannot be removed only by the contact/separation action of the contact. This was causing poor contact. Further, conventional solutions to the above problem have been to increase the size of the variable resistor main body 1, such as by changing the shape of the resin case 5 so as to completely cover the contact portion.

Purpose of the invention The purpose of the present invention is to solve the above-mentioned conventional problems and to provide a variable resistor with a switch that allows a highly reliable switch mechanism to be constructed in a very small space.

Structure of the invention The variable resistor with a switch of the invention has a concave groove opened in the radial axis direction of the rotating shaft of the variable resistor main body on the outer periphery of a reinforcing metal frame that also serves as a fixed contact. A movable contact is mounted on a mounting base protruding from the outer periphery of the main body in an inclined state with respect to the radiation axis passing through the groove, facing the groove serving as the fixed contact, and mounted on the rotating shaft. The present invention is characterized in that the movable contact is moved toward and away from the groove by a protruding portion of the switching piece.

According to this configuration, since the movable contact faces the groove of the fixed contact in an inclined state, the switching piece rotates in response to the rotation axis of the variable resistor main body,
In an operation in which the movable contact is brought into contact with the concave groove serving as the fixed contact by the protrusion of the switching piece, after the contact, the movable contact moves a certain distance along the edge of the concave groove while in contact; In an operation in which the movable contact is separated from the fixed contact, the movable contact moves a predetermined distance along the edge of the groove while in contact with the movable contact. Therefore, foreign substances such as dust and flux adhering to the contact area between the fixed contact and the movable contact are removed by moving the movable contact a certain distance while in contact with the fixed contact. Reliability can be greatly improved and miniaturization can be achieved.

DESCRIPTION OF EMBODIMENTS FIGS. 6 and 7 show an embodiment of the present invention. 2
1 is the main body of the single-shaft dual variable resistor, 22 is the rotating shaft of the variable resistor main body 21, and 23 is the rotating shaft 22.
A switching piece 24 that is press-fitted into the switch and rotates in conjunction with the rotation of the rotating shaft 22 is a metal frame for reinforcing the variable resistor main body 21, and this reinforcing metal frame is designed to hold variable resistor components to be described later. , and a part of it is used as a fixed contact for the switch. Reference numeral 25 designates a resin case for fixing each component of the variable resistor main body 21, and the rotary shaft 22 is rotatably held in the center of the resin case, and the resistor printed circuit board 3 is mounted on the upper and lower surfaces.
1 is arranged, and the reinforcing metal frame 24
holds the resistor printed board 31 together with the resin case 25. Further, the resin case 25 is attached to the reinforcing metal frame 2.
A mounting base 34 for the movable contact 26 is provided protrudingly located on the outer periphery of the movable contact 26 .

Reference numeral 26 denotes a movable contact which is press-fitted into the resin case 25 at an angle such that it operates in an oblique direction with respect to the contact surface 26c of the fixed contact 24 on the mounting base 34, and a movable contact 26 is attached to the upper end of the movable contact for reinforcement as the fixed contact. An arcuate protrusion 26a is protruded from the metal frame 24 side, and this protrusion 26a is adapted to come into contact with and separate from the contact edge portion 24b of the groove 24a of the fixed contact 24 made of the reinforcing metal frame. In other words,
Since the concave groove 24a is opened in the direction of the radial axis of the rotation shaft 22, the movable contact 26 is disposed in a relationship that is inclined with respect to the radial axis. Further, the movable contact 26 is provided with an arc-shaped protrusion 26a at the tip of a plate portion 26b between parallel notches provided in the spring plate, and the plate portion 26a having this protrusion 26a is
The plate portion 26c of 6b is inserted into the mounting hole 34 of the mounting base 34.
It is attached to the mounting base 34 by being press-fitted into the section a. The mounting base 34 has a groove 34b for allowing the plate portion 26b having the protrusion 26a to move in the front-rear direction.

27 is a soldering terminal of the variable resistor main body 21 to the printed wiring board, 28 is a soldering terminal of the movable contact 26 to the printed wiring board, and 29 is a printed wiring board of the reinforcing metal frame 24 as the fixed contact. 30 is a protrusion of the switching piece 23 that moves the movable contact 26.

31 is a resistor printed board of the variable resistor main body 21, and 32 is its resistor. Reference numeral 33 denotes a sliding terminal that rotates in accordance with the rotation of the rotating shaft 22 and contacts the resistor 32 to change the resistance value.

1 with a switch of this embodiment configured as described above
The operation of the dual shaft variable resistor will be explained below.

As shown in FIGS. 6 and 7, the movable contact 26 is pushed away by the projection 30 of the switching piece 23, which is attached to the variable resistor main body 21 so as to rotate in accordance with the rotation of the rotating shaft 22. The switch is opened by pulling the contact 26 away from the fixed contact 24 made of a reinforcing metal frame.

Next, as shown in FIGS. 8 and 9, when the rotating shaft 22 of the variable resistor main body 21 is rotated, the switching piece 23 rotates in accordance with the rotation, and the protrusion 30 separates from the movable contact 26. The movable contact 26 returns to its original position due to its own repulsive force, contacts the fixed contact 24 made of a reinforcing metal frame, and closes the switch.

In addition, in such an operation, the arc-shaped protrusion 26a of the movable contact 26 comes into contact with the contact edge 24b of the groove 24a of the fixed contact 24 made of a reinforcing metal frame, as shown in FIGS. 10a, b, and c. The contact edge portion 2 of the concave groove 24a of the fixed contact 24 made of the reinforcing metal frame of the variable resistor main body 21, whether the switch is closed by moving the switch or the switch is opened by moving away.
Move a certain distance while remaining in contact with 4b.

In this way, when the switch is opened or closed, the movable contact 26
moves a certain distance in contact with the contact edge 24b of the concave groove 24a of the fixed contact 24 made of a reinforcing metal frame, so that the protrusion 26a of the movable contact 26 and the fixed contact are moved by the contact/separation movement when opening/closing the switch. It is possible to eliminate dust and flux due to soldering etc. that have adhered between the concave groove 24a of No. 24 and the contact edge portion 24b.

Therefore, according to this embodiment, the movable contact 26 of the single-shaft dual variable resistor main body 21 with a switch is arranged so as to be operated in an oblique direction with respect to the contact surface 24c of the fixed contact 24 made of a reinforcing metal frame. , a movable contact 2 of a fixed contact 24 made of a reinforcing metal frame.
6 is made into a concave groove 24a to form a contact edge and brought into contact with the movable contact 26.
This makes it possible to realize a highly reliable and compact switch function.

Effects of the invention In the variable resistor with a switch of the invention, the operating direction of the movable contact is inclined with respect to the concave groove as a fixed contact made of a reinforcing metal frame, so that the movable contact is in contact with the fixed contact. Since the variable resistor can be moved a certain distance by its own action, the reliability of the switch mechanism is extremely high, and it is possible to realize a variable resistor with a switch that is extremely small and inexpensive. . Furthermore, a concave groove is provided in the part of the fixed contact that contacts the movable contact,
Since the movable contact and the fixed contact are brought into contact at two points, an excellent switch function with higher reliability can be realized.

[Brief explanation of drawings]

Figure 1 is a plan view of a conventional single-shaft dual variable resistor with a switch, Figure 2 is its A-A' sectional view, and Figure 3 is a cross-sectional view of the same.
4 is an explanatory diagram of its operation, FIG. 5 is a simplified diagram of the switch mechanism, FIG. 6 is a plan view of a single-shaft dual variable resistor with a switch in an embodiment of the present invention, and FIG. 7 is a diagram illustrating its operation. 8 and 9 are explanatory diagrams of its operation, FIG. 10 is a simplified diagram of the switch mechanism of the above embodiment, and FIG. 11 is a perspective view with the movable contact removed. FIG. 12 is a perspective view of the switch with the switching piece removed. 21... Variable resistor body, 21... Rotating shaft, 2
3... Switching piece, 24... Metal frame for reinforcement and fixed contact, 25... Resin case, 26... Movable contact, 27, 28, 29... Soldered terminal, 30...
Projection of switching piece, 31...Resistance printed circuit board of variable resistor main body, 32...Resistor, 33...Sliding terminal, 34...Mounting base.

Claims (1)

[Scope of utility model registration request] A switching piece made of an insulator attached to the rotating shaft of the variable resistor body and a switching piece integrally protruding from the resin case of the variable resistor body so as to be located outside the outer periphery of the reinforcing metal frame of the variable resistor body. a fixed contact formed with a groove opened in the radial axis direction passing through the rotation axis on the outer circumferential position of the reinforcing metal frame facing the mounting base; and the groove. a movable contact mounted on the mounting base in an inclined state with respect to the radiation axis passing through the mount and disposed opposite to the groove serving as the fixed contact;
a protrusion provided on the outer periphery of the switching piece that responds to the rotational shaft to move the movable contact toward and away from the fixed contact, the movable contact being rotated by the rotation of the protrusion provided on the switching piece; A variable resistor with a switch, characterized in that, after contacting the edge portion of the groove, the variable resistor moves a certain distance while maintaining the contact state.