JPS6116577Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a switch, more specifically a rotary operation type switch that is used in combination with a variable resistor, and its purpose is to improve the contact reliability of the contact portion. It is in.

The details of the present invention will be explained below with reference to an embodiment shown in FIGS. 1 to 9.

FIG. 1 shows a rotary variable resistor in which a switch according to the embodiment is integrally incorporated, and is used, for example, as a volume control volume with a power switch. In the figure, reference numeral 1 denotes a known rotary variable resistor, including an insulating substrate 2 on which a resistor is formed, a terminal 3, a rotating body with a printing plate that slides on the resistor, a rotating shaft 4 that drives the rotating body, It includes a bearing 5, a metal cover 6, etc.

Reference numeral 7 denotes a case of a switch fixed to the rear stage of the variable resistor 1 by a mounting leg 6a of a metal cover 6. A drive body 28, which will be described later, is pivotally supported in the case 7. 28, the variable resistor 1
A protrusion (not shown) provided on the rotating body is engageable. Then, in the middle of rotation of the rotating body (usually at the rotation end position of the rotating shaft 4 of the variable resistor 1), the protrusion of the rotating body engages with the driving body 28 to rotate the driving body 28. There is.

The case 7 is made of insulating synthetic resin, and has a cylindrical body with only one side having a bottom and the bottom surface having a substantially circular shape from the front to the rear, as shown in the first and second figures. The round bottom of the case 7 is divided into three depths, with the inner bottom 8 being the reference, the inner bottom 10 being lower than this, and the inner bottom 9 being higher than the inner bottom. ing. Reference numeral 11 denotes a circular recess for rotatably holding a protrusion 30 of a drive body 28, which will be described later.

Reference numerals 12 and 13 denote a first fixed contact piece and a second fixed contact piece made of a highly conductive metal plate fixed to the case 7, and both the fixed contact pieces 12 and 13 are attached to the contact portion 1 of the case 7.
4 and 15 are located on the inner bottom surface portion 8, and their terminal portions 16 and 17 are led out from the inner bottom surface portion 8. The first fixed contact piece 12 has a flat plate part 18 bent at right angles to the terminal part 16 and has a contact part 14 formed by embossing, and the back surface of the flat plate part 18 is brought into close contact with the inner bottom surface part 8. be. Reference numeral 19 denotes a recess provided on the terminal portion 16, and by snapping the shoulder of the recess 19, the first fixed contact piece 12 is fixed to the bottom surface of the case 7. Also, the second fixed contact piece 1
A contact portion 15 is similarly provided on the flat plate portion 20 of No. 3 by embossing, and the contact portion 15 is in a vertical positional relationship with the inner bottom surface portion 8.

Reference numeral 21 denotes a wing portion for preventing the second fixed contact piece 13 from coming off, and 22 a fitting portion, and the second fixed contact piece 13 is also attached to the case 7 by means of an engagement similar to the first fixed contact piece 12.
is fixed to the bottom of the

23 is a movable contact piece made of a highly conductive metal plate;
A substantially fan-shaped cam hole 25 is bored at one end of the flat plate portion 24, and a vertically erected bent portion 25 is formed at the other end of the flat plate portion 24. Contact portion 26 formed by embossing on
is formed. The contact portion 26 of the movable contact piece 23 is connected to the contact portion 15 of the second fixed contact piece 13.
The back surface of the flat plate portion 24 of the movable contact piece 23 is always in contact with and slides on the contact portion 14 of the first fixed contact piece 12 . 7
is a protrusion provided on the back surface of the flat plate portion 24, which contacts and slides on the inner bottom surface portion 10.

28 is a drive body made of an insulator, and on its upper surface,
A protrusion 29 is provided that can freely engage with a protrusion of the rotating body of the variable resistor 1 described above. Further, a cylindrical protrusion 30 that is pivotally supported in the recess 11 of the inner bottom surface 8 and a cam portion 31 having a substantially wing-shaped cross section are integrally provided on the lower surface of the driving body 28.

The drive body 28 is rotatably held around a protrusion 30 that is pivotally supported in the recess 11, and a cam portion 31 is positioned within the cam hole 25 of the movable contact piece 23.

Further, a reversing spring 32 is interposed between the movable contact piece 23 and the driving body 28, and the reversing spring 32 has both ends 32a and 32b inserted into the small hole 33 of the movable contact piece 23 and the small hole of the driving body 28. 34, and both 2
3 and 28 are connected. Therefore, the reversing spring 32
Due to the elastic force in the direction of the arrow in FIG. 5, the lower end of the cam portion 31 of the drive body 28 is always in elastic contact with the fold line side 25a of the cam hole 25 of the movable contact piece 23. As a result, the movable contact piece 23 is held swingably about the cam portion 31 as a fulcrum.

The operation of the switch with the above configuration will be explained with reference to FIG. 9. As shown in FIG. When the drive body 28 rotates clockwise from this state, the cam portion 31 of the drive body 28 first presses the edge of the cam hole 25 (the right half side of the folded line side 25a), and the movable contact piece 23 moves to the position b in the same figure. As shown in FIG. 2, the contact portion 26 is caused to slide on the contact portion 15 of the second fixed contact piece 13 by slightly rocking it in the clockwise direction. After that, when the driving body 28 continues to rotate in the same direction against the elastic force of the reversing spring 32 and passes the dead center, the movable contact piece 23 is suddenly rotated counterclockwise due to the accumulated spring force. The contact portion 26 is separated from the second fixed contact piece 13, and becomes the state shown in FIG.

It goes without saying that when the movable contact piece 23 rotates, the first fixed contact piece 12 and the movable contact piece 23 are always in contact and conduction, as described above. Then, if the driving body 28 is rotated counterclockwise from the state shown in FIG.
2, the movable contact piece 23 rotates clockwise and returns to the state shown in FIG.

As described above, according to the present invention, the contact part of the movable contact piece slides on the contact part of the second fixed contact piece, so that a constantly cleaned contact surface can be maintained, and arcing can be avoided. This has the effect of removing metal powder, dust, etc. that has adhered to the contact area, and has the advantage of increasing contact reliability and extending the life of the switch. Furthermore, since the movable contact piece slides on the contact portion of the first fixed contact piece, a clean contact surface can be maintained at all times in the same way as between the movable contact piece and the second fixed contact piece. Since the movable contact piece is supported by the contact portion of the first contact piece, it is possible to maintain a stable positional relationship between the movable contact piece and the second fixed contact piece.

[Brief explanation of the drawing]

The drawings all relate to one embodiment of the present invention; Fig. 1 is a side view of a variable resistor with a switch, Fig. 2 is a plan view showing the inner bottom surface of the switch case, and Figs. 3 and 4 are of a fixed type variable resistor. A perspective view showing the contact piece, Fig. 5 is a plan view showing the inner bottom surface of the case with the movable contact piece and the drive body attached, and Figs. 6 a and b are a plan view and a side view of the movable contact piece, respectively. , FIG. 7 is a side view of the reversing spring, FIGS. 8a and 8b are side and bottom views of the driving body, respectively, and FIGS. 9a, b, and c are operation explanatory diagrams. 7... Case, 12... First fixed contact piece, 13
...Second fixed contact piece, 14, 15...Contact part, 2
3...Movable contact piece, 25...Cam hole, 26...Contact part, 28...Driver body, 31...Cam part, 32...
Reversing spring.

Claims (1)

[Scope of utility model registration request] A first fixed contact piece and a second fixed contact piece are attached to the inner bottom surface of the case, a driving body is rotatably supported on the inner bottom surface of the case, and the driving body and the movable contact piece are connected to each other. are connected by a reversing spring, and the movable contact piece and the first fixed contact piece are always in contact with each other, and the movable contact piece and the second fixed contact piece are detachable, and as the driving body rotates, In the configuration in which the movable contact piece is reversely driven by the spring force of the reversing spring that is accumulated, the first
The fixed contact piece is formed with a convex contact portion that supports and slides on the movable contact piece within the rotation range of the movable contact piece and is long in the rotation direction of the movable contact piece, so that At this time, the contact portion supports and is capable of sliding contact with the movable contact piece, and the cam portion of the driving body is brought into elastic contact with the cam hole edge of the movable contact piece by the spring force of the reversing spring, and the cam portion of the driving body is brought into elastic contact with the cam hole edge of the movable contact piece. A switch characterized in that, during rotation, the movable contact piece is directly slightly oscillated by a cam portion of the drive body, so that the movable contact piece slides on the second fixed contact piece.