JPH0115970B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in an electric switching device such as a remote control relay that opens and closes contacts by driving an electromagnetic device.

[Prior art]

Conventionally, this type of device, such as a remote control relay, has been constructed as shown in FIG. That is, in the figure, 1 is a housing made of an insulating material, and 2 is a DC-operated electromagnetic device attached to this housing 1, which includes a winding frame 2a, an electromagnetic coil 2b, a pair of yokes 2c, a fixed iron core 2d, and a movable iron core 2e.
3 is a permanent magnet interposed between both yokes 2c of this electromagnetic device 2, 4 is a mover made of an insulating material fixed to the end of the movable iron core 2e of the electromagnetic device 2, and 5 is this mover 4. A compression spring interposed between the movable iron core 2e and the yoke 2c constantly biases the movable iron core 2e in a direction away from the fixed iron core 2d. A movable conductor 6 is supported by the movable element 4 and has a movable contact 6a. 7 is a fixed contact 7 facing this movable contact 6a.
a, and a fixed conductor 8 having a terminal 7b with a terminal screw screwed into the end thereof, 8 is electrically connected to the movable conductor 6 via a flexible copper stranded wire 9, and the terminal screw is screwed into the fixed conductor 8. This terminal is screwed together and serves as a main circuit terminal together with the terminal 7b. 10 is the electromagnetic coil 2
This control section controls the direction of the excitation current 10b, and is composed of a microswitch 10a having a C contact that functions as a changeover switch, and a rectifier stack 10b. Reference numeral 11 denotes a leaf spring consisting of an elastic piece whose one end is fixed to the casing 1, the middle part of which is interlocked with the movable element 4, and the tip of which is connected to the micro switch 10.
This is a switching operation for a. Reference numeral 12 denotes a pair of terminals of a control circuit electrically connected to the electromagnetic coil 2b via the control section 10.

Next, the operation of the conventional remote control relay will be explained. That is, in FIG. 1, when the OFF button of the remote control switch (not shown) is operated,
The electromagnetic coil 2b is excited via the terminal 12 of the control circuit and the control unit 10, and the movable iron core 2e is attracted to the fixed iron core 2d against the compression spring 5, and the movable contact 6a of the movable conductor 6 is attracted via the movable element 4. is separated from the fixed contact 7a of the fixed conductor 7. At this time, the micro switch 1 is
0a is switched, energization is blocked by the rectifier stack 10b, the electromagnetic coil 2b is de-energized, the movable iron core 2e is constantly attracted by the permanent magnet 3, and the movable contact 6a is separated from the fixed contact 7a. maintain the same condition. Next, when the ON button of the remote control switch is operated from the contact open state shown in FIG.
The magnetic flux is canceled and the movable iron core 2e separates from the fixed iron core 2d due to the bias of the compression spring 5, and the movable contact 6a of the movable conductor 6 applies a predetermined contact pressure to the fixed contact 7a of the fixed conductor 7 via the movable element 4. be contacted by At this time, the micro switch 10a is switched via the leaf spring 11 that interlocks with the movable element 4, and the control unit 10 becomes ready for the next OFF operation, and until the OFF button of the next remote control switch is operated,
Contact state is maintained. A remote control relay with this type of operation is housed in a standard distribution board, and is operated remotely and centrally to open and close the remote control relay using a remote control switch located at any location away from the location of the standard distribution board. It is. It is especially suitable for remote and centralized control of lighting equipment in buildings, schools, stores, hospitals, gathering places, etc. However,
When an overcurrent such as an overload or short circuit current flows through the remote control relay, an electromagnetic repulsion force (concentrated contact current repulsion force) is generated between the movable contact 6a and the fixed contact 7a.
The disadvantage is that the movable contact 6a temporarily floats above the fixed contact 7a, and the arc generated between the contacts 6a and 7a causes abnormal wear and welding of the contacts 6a and 7a, making them impossible to reuse.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and includes providing a pair of magnetic members on a movable conductor and a fixed conductor, which are arranged opposite to each other and generate an electromagnetic attraction force by an electric current. The purpose of this invention is to provide a reliable electrical switching device that can prevent abnormal wear and welding of contacts.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 2 and 3 each show an embodiment of the present invention, with FIG. 2 being a side view thereof and FIG. 3 being an enlarged perspective view showing the main parts thereof. In the figure, reference numeral 13 denotes first and second magnetic parts 13a and 13b fixed to the movable conductor 6 and bent into a substantially U-shape.
A movable magnetic member 14 having a movable magnetic member 14 is fixed to the fixed conductor 7 so as to face the movable magnetic member 13,
First and second magnetic parts 14 bent into a substantially U-shape
It is a fixed magnetic member having a and 14b.

Next, the operation of this invention will be explained. That is, the second
From the contact open state shown in the figure, the remote control switch
When the ON button is operated, terminal 12 of the control circuit
The electromagnetic coil 2b is reverse excited via the control unit 10, the magnetic flux of the permanent magnet 3 is canceled, and the compression spring 5
The movable core 2e separates from the fixed core 2d due to the bias, and the movable contact 6a moves to the fixed contact 7 via the mover 4.
touched by a. In this contact state, the third
As shown in the figure, the current A flowing through the movable conductor 6 generates an electromagnetic attractive force between the first magnetic parts 13a and 14a of the movable magnetic member 13 and the fixed magnetic member 14, and the current A flows through the fixed conductor 7. The current B generates an electromagnetic attractive force between the second magnetic parts 13b and 14b of the movable magnetic member 13 and the fixed magnetic member 14. Therefore, when an overcurrent such as an overload or short-circuit current flows through the remote control relay, the movable conductor 6 acts to attract the fixed conductor 7, and the contact pressure becomes larger than the contact current concentration repulsion force. , the movable contact 6a does not float above the fixed contact 7a, and both contacts 6a, 7a
shall not cause abnormal wear or welding. Eventually, a separately installed circuit or breaker will cut off the overcurrent.

In addition, in the above embodiment, the movable magnetic member 13 and the fixed magnetic member 14 are provided with the first and second magnetic parts 13a, 13b, 14a, and 14b, respectively, but the first and second magnetic parts It is also possible to provide only one of the magnetic parts of the part and apply the electromagnetic attractive force by the current flowing through one of the movable conductor 6 and the fixed conductor 7, and the same effect as in the above embodiment can be obtained. It is something that plays.

Furthermore, in the above embodiment, the first and second magnetic parts 13a and 13b of the movable magnetic member 13 and the first and second magnetic parts 14a and 14b of the fixed magnetic member 14 are bent into a substantially U-shape, respectively. Although shown as being integrally formed, it may have a shape other than a substantially U-shape, and each of the first and second magnetic parts 13a, 13b, 14a, 14b may be formed separately. However, the same effect as in the above embodiment can be obtained.

Further, in the above embodiment, a remote control relay has been described, but an electric switching device such as an electromagnetic contactor may be used, and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, a pair of magnetic members are provided, which are attached to the movable conductor and the fixed conductor so as to face each other, and which generate electromagnetic attraction force toward each other due to the current flowing through at least one of both conductors. As a result, the movable conductor acts to attract the fixed conductor, and the movable contact does not float away from the fixed contact due to overcurrent, which prevents abnormal contact wear and contact welding, and improves reliability. It is possible to obtain a high-quality electric switchgear.

[Brief explanation of drawings]

Fig. 1 is a side view showing a conventional remote control relay, Figs. 2 and 3 each show an embodiment of the present invention, Fig. 2 is a side view thereof, and Fig. 3 is a main part thereof. FIG. In the figure, 2 is an electromagnetic device, 6 is a movable conductor, 6a is a movable contact, 7 is a fixed conductor, 7a is a fixed contact, 13 is a movable magnetic member, 13a is a first magnetic part, 13b is a second magnetic part, 14 is a fixed magnetic member, 14a is a first magnetic part, and 14b is a second magnetic part. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. An electromagnetic device, a fixed conductor having a fixed contact, a movable conductor having a movable contact that can be moved into and out of contact with the fixed contact by driving the electromagnetic device, and this movable conductor and the fixed conductor. An electric switchgear comprising a pair of magnetic members that are mounted to face each other and generate an electromagnetic attraction force with each other due to a current flowing through at least one of the two conductors. 2. The magnetic members each consist of a pair of first and second magnetic members, and an electromagnetic attractive force acts on the first magnetic member due to the current flowing through the fixed conductor, and an electromagnetic attractive force acts on the first magnetic member due to the current flowing through the movable conductor. The electric switching device according to claim 1, wherein an electromagnetic attractive force acts on the second magnetic member. 3. The electric switchgear according to claim 2, wherein the first and second magnetic members are each bent into a substantially U-shape and formed integrally.