JP7359093B2 - changeover switch - Google Patents

Description

The present invention makes it possible to open the welded contact with a simple configuration even when the normally closed fixed contact and the movable contact in a C contact structure in which the movable contact is snap-actioned using a tension spring are welded together. Regarding the changeover switch.

As shown in FIG. 6, the conventional changeover switch includes a normally closed first fixed terminal board 1, a normally open second fixed terminal board 2, and a common fixed terminal board 3 as fixed members. The normally closed first fixed terminal board 1 has a first fixed contact 1a attached to its distal end, and a first external connection terminal 1b integrally formed at its base end. Also, a second fixed contact 2a is attached to the tip of the normally open second fixed terminal plate 2, and is opposed to the first fixed contact 1a of the normally closed first fixed terminal plate 1 at a predetermined interval below. It is located. A second external connection terminal 2b is integrally formed at the base end. Further, the common fixed terminal plate 3 has a U-shaped support frame 3a formed at its distal end for supporting movable members such as the movable contact 6 and the operating lever 7, and a common external connection terminal 3b at its base end. are integrally formed. The first fixed terminal board 1, the second fixed terminal board 2, and the common fixed terminal board 3 are embedded in an insulating base 4 formed of a common insulating resin at their intermediate portions, and are fixedly supported by penetrating this. Ru.

The movable contact 6, which is a movable member, has double-headed movable contacts 6a and 6b attached to its tip, and a contact fulcrum that abuts the support frame 3a and serves as a rotation fulcrum for the movable contact 6 at its base end. A portion 106c is formed. The operation lever 7, which is another movable member, has an operation fulcrum portion 107a formed at its tip portion, which serves as a rotation fulcrum by coming into contact with a support 5 that supports the operation lever 7 provided on the insulating base 4. An operating piece 7b that is operated from the outside is provided at the base end. This operating lever 7 is supported by a support frame 3a formed on the common fixed terminal plate 3, and the upper limit position is thereby limited.

The movable contact 6 and the operating lever 7 are connected by a tension spring 8 that connects the distal end of the movable contact 6 and the proximal end of the operating lever 7.

The changeover switch 110 configured in this manner is configured such that when the operating piece 7b of the operating lever 7 is in the upper position, the tension spring 8 pulls the tip end of the movable contact 6 and the base end of the operating lever 7 upward. The movable contact 6 is rotated toward the first fixed contact 1a, and the movable contact 6a comes into contact with the first fixed contact 1a. This closes the circuit between the common fixed terminal board 3 and the first fixed terminal board 1.

When the operating piece 7b is pushed down and the operating lever 7 is rotated clockwise about the operating fulcrum part 107a, the center line of the tension spring 8 moves below the contact fulcrum part 106c, and this tension spring 8 The direction of the acting force is reversed, the movable contact 6 is suddenly pulled downward, the movable contact 6b is closed to the second fixed contact 2a of the second fixed terminal plate 2, and the common fixed terminal plate 3 is closed to the second fixed terminal plate 2. Switch and connect to the fixed terminal board 2. Note that the above changeover switch is disclosed in Patent Document 1, for example.

Japanese Patent Application Publication No. 2008-66082

By the way, in the C contact structure in which the movable contacts 6a and 6b are snap-actioned using the tension spring 8, when attempting to disconnect the normally closed first fixed contact and the movable contact 6a to break the circuit, the contacts may be welded together. If so, even if the operating lever 7 is moved clockwise, the tension spring 8 only stretches, the movable contact 6 does not move, and the first fixed contact and the movable contact 6a cannot be separated. That is, when the first fixed contact and the movable contact 6a are welded together, there is a problem that the normally closed contact cannot be opened.

The present invention has been made in view of the above, and even when the normally closed fixed contact and the movable contact in a C contact structure in which the movable contact is snap-actioned using a tension spring are welded, It is an object of the present invention to provide a changeover switch that enables opening of welded contacts with a simple configuration.

In order to solve the above-mentioned problems and achieve the objects, the present invention provides a first fixed terminal board having a first fixed contact attached to the distal end and a normally closed first external connection terminal formed at the proximal end. and a second fixed terminal board having a second fixed contact attached to its tip and a normally open second external connection terminal formed at its base end, and a support frame having a U-shaped upper part attached to its tip. , a common fixed terminal board in which a common external connection terminal is formed at the base end, the first fixed contact and the second fixed contact are vertically arranged to face each other at a predetermined interval, the first fixed terminal board, an insulating base to which the second fixed terminal board and the common fixed terminal board are attached; a movable contact capable of contacting the first fixed contact and the second fixed contact is formed at the distal end; and the movable contact is formed at the base end. A movable contact is formed with a contact fulcrum part that comes into contact with a support frame and becomes a pivot point, and an operation fulcrum part that comes into contact with a support body provided on the insulating base with its tip end formed therein and becomes a pivot point. an operating lever having a base end provided with an operating piece that is operated from the outside, the operating lever being rotatably supported within the support frame between the distal end and the proximal end; and the distal end of the movable contact. and a tension spring connecting the side and the base end side of the operating lever, and by rotating the operating piece of the operating lever in the up and down direction, the movable contactor uses the contactor fulcrum part as a fulcrum. The operation lever is driven in reverse and alternately switches between contact between the movable contact and the first fixed contact and contact between the movable contact and the second fixed contact by a snap action mechanism using the tension spring. It is characterized in that a protrusion is provided that assists the movable contactor to descend as the operating lever descends.

Further, in the above invention, the present invention provides that the contact fulcrum portion is rotatably coupled to the support frame, and the operation fulcrum portion is rotatably coupled to the support body. It is characterized by

According to the present invention, even if a normally closed fixed contact and a movable contact in a C contact structure in which the movable contact is snap-actioned using a tension spring are welded, the welded contact can be opened with a simple configuration. enable.

FIG. 1 is a perspective view showing the external configuration of a changeover switch according to an embodiment of the present invention. FIG. 2 is a right side view showing the configuration of the changeover switch shown in FIG. 1. FIG. 3 is a diagram showing the state of the changeover switch before pushing the operating piece of the operating lever downward. FIG. 4 is a diagram showing the state of the movable contact when it is reversed. FIG. 5 is a diagram showing the state of the movable contact after being reversed. FIG. 6 is a perspective view showing the external configuration of a conventional changeover switch. FIG. 7 is a partially cutaway view showing a schematic configuration of an operation switch incorporating a changeover switch.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

<Overall configuration>
FIG. 1 is a perspective view showing the external configuration of a changeover switch 10 according to an embodiment of the present invention. Further, FIG. 2 is a right side view showing the configuration of the changeover switch 10 shown in FIG. 1. As shown in FIG.

As shown in FIGS. 1 and 2, the changeover switch 10 includes a first fixed terminal board 1, a second fixed terminal board 2, and a common fixed terminal board 3. The first fixed terminal plate 1 has a first fixed contact 1a attached to its distal end, and a normally closed first external connection terminal 1b formed at its base end. Further, the second fixed terminal plate 2 has a second fixed contact 2a attached to its distal end, and a normally open second external connection terminal 2b formed at its proximal end. Further, the common fixed terminal plate 3 has a support frame 3a having a U-shaped upper portion attached to its distal end, and a common external connection terminal 3b formed at its base end.

Each intermediate portion of the first fixed terminal board 1, the second fixed terminal board 2, and the common fixed terminal board 3 is supported by an insulating base 4 made of insulating resin. That is, the insulating base 4 exposes the first fixed contact 1a, the second fixed contact 2a, and the support frame 3a at the top (+Z direction), and exposes the first external connection terminal 1b, the second external connection terminal 2b, and the common external connection. The terminal 3b is exposed and supported at the bottom (-Z direction). The insulating base 4 has the first fixed contact 1a and the second fixed contact 2a facing each other at a predetermined interval d in the vertical direction (Z direction), and the first fixed terminal board 1 and the second fixed terminal board 2 and the common fixed terminal plate 3 are attached and supported.

The changeover switch 10 also includes a movable contact 6, an operating lever 7, and a tension spring 8. The movable contact 6 has movable contacts 6a and 6b formed at its distal end that can abut the first fixed contact 1a and the second fixed contact 2a, respectively, and its base end abutted against the support frame 3a and serves as a rotation fulcrum. A contact fulcrum portion 6c is formed.

The operation lever 7 has an operation fulcrum part 7a that is a rotation fulcrum by contacting the support 5 provided on the insulating base 4 at its tip end, and an operation piece 7b that is operated from the outside at its base end. The distal end portion and the proximal end portion are rotatably supported within the support frame 3a. The tension spring 8 connects the distal end side of the movable contact 6 and the proximal end side of the operating lever 7 .

The changeover switch 10 has a C contact structure in which a tension spring 8 is used to cause the movable contacts 6a, 6b to snap action. The terminal of the C contact is a common fixed terminal plate 3 which is a common (COM) terminal connected to a movable contact 6 having movable contacts 6a and 6b. A normally closed (NC: normally closed) terminal is a first fixed terminal board 1 having a first fixed contact 1a, and a normally open (NO: normally open) terminal is a second fixed terminal board having a second fixed contact 2a. It is 2.

<Snap action mechanism>
FIG. 3 is a diagram showing the state of the changeover switch 10 before the operation piece 7b of the operation lever 7 is pushed downward. Moreover, FIG. 4 is a diagram showing the state of the movable contactor 6 when it is reversed. Furthermore, FIG. 5 is a diagram showing the state of the movable contactor 6 after being reversed.

As shown in FIG. 3, before the operating piece 7b of the operating lever 7 is pushed downward (-Z direction: direction A), the movable contact 6a at the tip of the movable contact 6 is in contact with the center line C of the tension spring 8. It is located above the rotational fulcrum (+Z direction) of the child fulcrum portion 6c. In this case, the movable contact 6a is in a normally closed state in which contact with the first fixed contact 1a is maintained due to the tension of the tension spring 8.

As shown in FIG. 4, when the operating piece 7b is pushed further downward and the center line C of the tension spring 8 passes through the rotation fulcrum of the contact fulcrum 6c, the direction of the acting force of the tension spring 8 is reversed. , a snap action occurs in which the movable contactor 6 is suddenly pulled downward (-Z direction: direction B).

Then, as shown in FIG. 5, the movable contact 6b remains in contact with the second fixed contact 2a. In this state, the center line C of the tension spring 8 is located below the rotation fulcrum of the contact fulcrum 6c (in the -Z direction).

Note that when the operating piece 7b is returned upward (in the +Z direction) in the state shown in FIG. 5, a snap action occurs that returns to the state shown in FIG. 3. The operation lever 7 is restricted from upward movement by a stopper 3d protruding inward at the upper end of the support frame 3a, and from downward movement by a stopper 4a formed on the insulating base 4. . Note that the downward restriction of the operating lever 7 may be formed in the support frame 3a similarly to the stopper 4a.

<Circuit-opening assist structure>
Here, the operating lever 7 is provided with a protrusion 7c that assists the movable contact 6 to descend as the operating lever 7 descends. As shown in FIG. 4, when the movable contact 6 is reversed, the protrusion 7c engages with the protrusion 6d of the movable contact 6, pushes the movable contact 6 downward, and moves the movable contact 6 downward. Assist movement.

As a result, when the normally closed first fixed contact 1a and the movable contact 6a are welded together, the first fixed contact 1a and the movable contact 6a may not be separated by the tensile force of the tension spring 8 alone, and the circuit cannot be opened. However, even in this case, the protrusion 7c forcibly pulls down the movable contact 6 and acts in a direction to peel off the welded contact, so that the circuit can be reliably opened.

<Contact fulcrum part and operation fulcrum part>
Further, the contact fulcrum portion 6c is rotatably coupled to the support frame 3a, and the operation fulcrum portion 7a is rotatably coupled to the support body 5. That is, the contact fulcrum part 6c is rotatably coupled to the fulcrum receiving part 3c of the rotation fulcrum formed in the support frame 3a, and prevents the movable contact 6 from coming off from the fulcrum receiving part 3c. . Further, the rotation shaft serving as the operating fulcrum portion 7a is rotatably coupled to the fulcrum receiving portion 5a of the support body 5 to prevent the operating fulcrum portion 7a from coming off the fulcrum receiving portion 5a.

As a result, when the normally closed first fixed contact 1a and the movable contact 6a are welded together, the first fixed contact 1a and the movable contact 6a are not separated by the tensile force of the tension spring 8 alone, and the tension spring 8 Although it may break, even in this case, the movable contact 6 and the operating lever 7 do not come off their respective pivot points, so the protrusion 7c provided on the operating lever 7 will force the movable contact 6 to pull down and peel off the welded contacts, so the circuit can be reliably opened.

The connection between the contact fulcrum part 6c and the fulcrum receiving part 3c is such that the contact fulcrum part 6c does not come off from the fulcrum receiving part 3c, and the connection between the operation fulcrum part 7a and the fulcrum receiving part 5a is It is sufficient that the fulcrum part 7a does not come off from the fulcrum receiving part 5a, and they may be connected to each other by, for example, a hinge structure.

Here, the conventional changeover switch 110 shown in FIG. 6 is not provided with the protrusion 7c. Further, in the conventional changeover switch 110, the contact fulcrum portion 106c is in protruding contact with the fulcrum receiving portion 103c of the support frame 3a, and the operation fulcrum portion 107a is in contact with the fulcrum receiving portion 105a of the support body 5. It's making a sharp abutment. Therefore, if the tension spring 8 breaks when the normally closed first fixed contact 1a and the movable contact 6a open, the movable contact 6 will come off the support frame 3a and the operating lever 7 will also come off the support 5. , it was not possible to open the circuit by peeling off the welded contacts.

Note that FIG. 7 is a partially cutaway view showing a schematic configuration of an operation switch 11 incorporating the above-mentioned changeover switch 10. As shown in FIG. 7, the changeover switch 10 is provided within an operation switch 11 that performs an operation such as pressing to switch a circuit. The operating switch 11 engages with the operating lever 7 to operate the operating lever 7, thereby causing the changeover switch 10 to perform circuit switching such as opening.

In addition, each configuration illustrated in the above embodiments is a functional schematic, and does not necessarily need to be physically configured as illustrated. In other words, the form of dispersion/integration of each device and component is not limited to the one shown in the diagram, but all or part of it may be functionally or physically dispersed/integrated in arbitrary units depending on various usage conditions. It can be configured as follows.

1 First fixed terminal board 1a First fixed contact 1b First external connection terminal 2 Second fixed terminal board 2a Second fixed contact 2b Second external connection terminal 3 Common fixed terminal board 3a Support frame 3b Common external connection terminal 3c, 5a , 103c, 105a fulcrum receiving part 3d, 4a stopper 4 insulating base 5 support 6 movable contact 6a, 6b movable contact 6c, 106c contact fulcrum 6d convex part 7 operating lever 7a, 107a operating fulcrum 7b operating piece 7c Projection 8 Tension spring 10, 110 Changeover switch 11 Operation switch C Center line d Predetermined interval

Claims (2)

a first fixed terminal board having a first fixed contact attached to its distal end and a normally closed first external connection terminal formed at its proximal end;
a second fixed terminal board having a second fixed contact attached to the distal end and a normally open second external connection terminal formed at the proximal end;
a common fixed terminal board having a U-shaped upper support frame attached to the distal end and a common external connection terminal formed at the proximal end;
an insulating base on which the first fixed contact and the second fixed contact are vertically arranged facing each other at a predetermined interval, and the first fixed terminal board, the second fixed terminal board, and the common fixed terminal board are attached; ,
A movable contact member having a movable contact that can come into contact with the first fixed contact and the second fixed contact at the distal end, and a contact fulcrum part that comes into contact with the support frame and serves as a rotational fulcrum at the base end. with a contactor,
An operation fulcrum part that is a rotation fulcrum is formed by having the distal end abut against a support provided on the insulating base, and an operating piece that is operated from the outside is provided at the proximal end, and the distal end and the proximal end an operating lever rotatably supported within the support frame;
a tension spring connecting the distal end side of the movable contact and the proximal end side of the operating lever;
Equipped with
By rotating the operation piece of the operation lever in the vertical direction, the movable contact is reversely driven about the contact fulcrum part, and the snap action mechanism by the tension spring causes the movable contact and the first fixed Alternating between contact with the contact and contact between the movable contact and the second fixed contact,
The changeover switch is characterized in that the operating lever is provided with a protrusion that assists the movable contact in descending as the operating lever is lowered. The contact fulcrum part is rotatably coupled to the support frame,
The changeover switch according to claim 1, wherein the operation fulcrum is rotatably coupled to the support.

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