JPS58140941A - Switch - 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 This invention provides a single AC load 'g! The present invention relates to a switch that opens and closes a contact connected to a terminal of a power source by opening and closing a movable iron piece.

In this type of switch, the switching operation signal for the movable iron piece is generally provided by direct current. That is, when the above operation signal is input to the yoke and it is excited, the movable iron piece is attracted to this yoke and the contact is closed, causing an AC load current to flow.If the application of the above operation signal is interrupted, the yoke will be turned off. When the excitation state is released, the movable iron piece separates from the yoke and the contact opens.

In such conventional switches, the timing of cutting off the operating signal is done randomly in relation to the phase of the AC load current, so the contacts are opened at the zero phase (zero cross) of the AC load current. There weren't many things. Therefore, when the contacts open, arcing occurs between the contacts,
The resulting wear and tear on the contacts has been a problem.

This invention has been made in view of the above circumstances, and in addition to applying attraction between the yoke and the movable iron piece using AC load current, the contact pressing force is applied at or near the zero cross of the AC load current. The object of the present invention is to provide a switch which can be released so that less arcing occurs when the contacts are separated.

Next, embodiments of the invention will be described with reference to the drawings.

In FIGS. 1 and 2, 1 indicates an electromagnetic coil, and a yoke 2 around which the electromagnetic coil 1 is wound has one end that serves as an adsorption portion 2a for a movable iron piece 5, which will be described later.
The suction portion 2a and the coil winding portion 2b are connected to each other via an upright stepped portion 20 to form a main yoke 6. Further, a U-shaped auxiliary yoke 4 is integrally formed at the other end of the main yoke 6 in an extending manner. The movable iron piece 5 has one end 5a connected to the main yoke 6.
is arranged on the back side of the suction part 2a, while the other end part 5
b is arranged on the surface side of the extending end portion 4a of the auxiliary yoke 4. The movable iron piece 5 is swingably supported by a hinge 6 on the auxiliary yoke 4 at its intermediate portion. In this case, the hinge 6 is such that the movable iron piece 5 is balanced on one end side and the other end side, and the movable iron piece 5 is moved with a minute force.
It is desirable to install it in a position where it can be swayed.

Next, 7 indicates a fixed contact piece, and 8 indicates a movable contact piece. The fixed contact piece 7 is attached to an insulator 9 that fully supports the yoke 2, and has a fixed contact 7& at its tip, and its base end is folded so as to pass under the movable iron piece 5. It is bent to form the AC load terminal 7b. On the other hand, the movable contact piece 8
is fixed to the insulator 9 with its base end 8 & disposed so as to straddle the upper part of the other end of the movable iron piece 5, and
One end of this base end portion 8a is extended in a folded manner, and this folded portion 8b is disposed below the other end of the movable iron piece 5 to form an AC load terminal 80. Roughly speaking, the movable portion 8d of the movable contact piece 8 is slightly bent downward with respect to its base end 8a, and the elasticity of the movable portion 8d causes the movable iron piece 5 to be connected to the main yoke via the insulating plate 10. 6 in the opening direction at all times. Note that 8θ indicates a movable contact provided at the tip of the movable portion 8d, which faces the fixed contact 7&.

Here, as shown in FIG. 6b, the suction part 21L of the yoke 2 is such that the movable iron piece 5 is attracted to this suction part 2IL and pushes up the movable part 8d of the movable contact piece 8, so that the movable contact 8e The movable iron piece 5 is provided at such a level that a gap A is formed between the movable iron piece 5 and the movable iron piece 5 even when the metal contactor 81L comes into contact with the fixed contactor 81L.

Next, 10 is a terminal 19 of the electromagnetic coil 1.

A DC operating power supply connected to 1b, 11 indicates its switch, 12 indicates an AC load current connected to the AC load terminal 7bt8C, and 16 indicates its load.

In the above, when an input signal is applied to the terminals 1a and 1b of the electromagnetic coil 1 from the state shown in FIG. It is sucked by the suction part 21,
As a result, the movable iron piece 5 closes against the bias of the movable portion 8d of the movable contact piece 8. In this case, as shown in FIG. 6b, the movable contact 8e contacts the fixed contact 7a and the contact is closed. At this time, the load current flows through a coiled electrical path formed by the fixed contact piece 7 and the movable contact piece 8, as shown by the arrow in FIG. A force is generated that causes the iron piece 5 to swing in the same direction as the force due to the input signal.

Here, the closing movement limit of the movable iron piece 5 is regulated by the movable contact 8e contacting the fixed contact 7a, so the suction part 2& of the yoke 2 and the movable iron piece 5 do not come into contact with each other, and there is a gap between them. A gap A will be formed. Therefore, even if the movable iron piece 5 is excited, residual magnetism is prevented from remaining in the yoke 2.

Next, when the input signal is cut off, the excited state of the yoke 2 due to the input signal disappears. However, in a phase where the load current is relatively large, the urging force Fr by the movable contact piece 8 and the attraction force of the movable iron piece 5 due to the load current become large, and the closed state of the contact is maintained as it is. Next, as the load current decreases, the above-mentioned attractive force becomes smaller than the above-mentioned urging cuff r, and the movable iron piece 5 is moved to open by this urging force 11'r, and the contact point is opened. As described above, since the load current becomes smaller than the force Fr when the load current is near or at the zero cross, the occurrence of arcing can be suppressed. Therefore, if the arc current of the contact is made larger than the load current value that generates a force equivalent to the above-mentioned biasing force, the contact can be opened and closed without generating any arc.

As is clear from the above explanation, according to the present invention, one load current can be cut off near or at the zero cross, so arcing at the contact part can be suppressed as much as possible, and its life can be extended. It becomes possible.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the invention, FIG. 2 is an explanatory diagram of a magnetic circuit, and FIGS. 6a and 6b are sectional views for explaining the operation. 1... Electromagnetic coil, 2... Yoke, 6... Main yoke, 4... Auxiliary yoke, 5... OT moving iron piece,
6... Hinge, 7... Fixed contact piece, 8... Movable contact piece, 10... DC operating power supply, 12... AC load power supply, 16... Load. ! 1m'i, 1';-, :, '=', ;σ Fig. 1 Fig. 2 Ki 2r Stable Mouse Miro Theory - Isao et al. Mini 1 Fig. 3a Fig. 3b

Claims (1)

[Claims] (1) A movable iron piece is supported so as to be able to swing open and close relative to a main yoke around which an electromagnetic coil is wound, and this movable iron piece is always urged in the opening direction.One end of this movable iron piece is held by the main yoke. In a switch that performs the switching operation of one AC load source through the switching operation of attracting and separating,
The other end of the movable iron piece extends backward to assist 11T!
0 iron piece, and an auxiliary yoke opposite to this auxiliary movable iron piece is formed integrally with the main yoke, and the movable iron piece is arranged so as to span between the back side of the main yoke and the front side of the auxiliary yoke. A switch characterized in that an electric path formed by a fixed contact piece and a movable contact piece connected to a load terminal forms a coil around the movable iron piece.