JPS6122528A - Electric contact device - 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 [Technical Field] The present invention relates to an electrical contact device used in relays, contactors, switches, etc.

[Background Art] In this type of electrical contact device used at a rated current of around 1 to 30 amperes, welding of the contacts due to inrush current when the contacts are turned on is more problematic than wear of the contacts.

That is, the main loads in the rated current range are small motors, solenoids, various lamps, etc., and in most of these, an inrush current of 5 to 100 times flows when the contact is closed. Contact welding in electrical contact devices is caused by mechanical vibrations caused by collisions between contacts during the closing operation, arc heat generated by bounce caused by electromagnetic repulsion caused by conducting current, or Joule heat caused by current concentration at the contact area. Therefore, as the inrush current increases, it becomes more likely to occur. Therefore, for electrical contact devices used for loads with large inrush currents, it is common to deal with this by increasing the contact pressure, contact pulling force, or contact shape, or by installing a current limiting reactor outside the electrical contact device. It is.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to provide an electrical contact device that can improve the welding resistance of the contact against rush current.

[Disclosure of the Invention] The electrical contact device according to the present invention is such that the contact fixing portion of the fixed/movable contact is formed into a shape with substantially equal spacing between opposing pieces, and arranged so that the opposing pieces are inserted alternately. , both the fixed and movable contacts are formed separately into a energizing contact and an arcing contact and are fixed to the corresponding opposing pieces, and when both of the contacts are closed, the arcing contact is closed first, and when both of the contacts are opened, the current is energized. This feature is characterized in that the contacts are opened first.

I'll explain later.

Reference numeral 1 designates a hinge-type relay to which the electrical contact device of the present invention is applied, and a housing is constituted by a base 2 and a cover 3, and a fixed contact terminal 4, a movable contact terminal 5, and a coil terminal 6 are arranged outside the housing. It is placed on a stand 2, and the housing is equipped with an electromagnet device consisting of an amachia 11 to which a yoke 7, a fixed core 8, a coil 9, and a movable contact 10 are attached, and a fixed contact 12 connected to the fixed contact terminal 4. has been done. Reference numeral 13 denotes a return spring tensioned and suspended between the yoke 7 and the amatia 11.

The fixed contact 12 is made of a rigid plate, and the tip of the base 12a -
By connecting L-shaped bent pieces from the side, the base 1
One facing piece 12b which is the tip of 2H, the other facing piece 12C facing this at a predetermined interval, and both facing pieces 12b, 12c.
It has a contact fixing part F formed in an opening shape with a connecting piece 12d that connects the two.

The movable contactor 10 is made of an elastic plate, and by connecting an L-shaped bent piece from the tip to the side of the base 10a, one opposing piece 10b, which is the tip of the base 10a, is connected at a predetermined interval (fixed). A contact fixing portion M formed in a mouth shape with a connecting piece 10d that connects the other opposing piece 10C and both opposing pieces 10b and 10c at a distance (approximately equal to the predetermined interval of the contacts 12).
has.

Therefore, both contact fixing parts F and M are connected to each other in the opposing pieces 12b and 12.
c, 10b, 10c is 12C → 10c → 12b → 10b
They are arranged so that they enter alternately in this order.

The fixed contacts 14 and the movable contacts 15 fixed to the contact fixing parts F and M of each contactor 12.10 are made of current-carrying contacts 14a and 15a made of a low-resistance material (for example, silver or silver alloy) and high-melting-point material (for example, made of copper). or copper alloy) arc contacts 14b, 15b
Separated and formed.

These arc contacts 14b and 15b are the energizing contact 14a.
, the height of the contact point is slightly higher than that of 15a. Therefore, the energizing contact 14a of the fixed contact 14 is connected to one opposing piece 12b.
The arc contact 14b is on the inner surface of the other opposing piece 12c, the energizing contact 15a of the movable contact 15 is on the inner surface of one opposing piece 10b, and the arcing contact 15b is on the outer surface of the other opposing piece 10G. They are each fixed to a corresponding opposing piece. Therefore, when the contacts are in an open state, the gap Gb between the arcing contacts 14b and 15b is the same as the gap Gb between the current-carrying contacts 14a and 15b.
It is smaller than the gap Ga between the arc contacts 14b and 15a, which means that when both contacts 14 and 15 are closed, the arc contacts 14b and 15
The contacts b are turned on first, and when both contacts 14 and 15 are opened, the energizing contacts 14815a are opened first.

(Operation) In FIGS. 1 and 3(a), both contacts 14 and 15 are in an open state.

When the coil 9 of the electromagnet device is excited in this state, the amachia 11 is attracted to the fixed iron core 8, so the movable contact 1
0 rotates counterclockwise. As a result of this rotation, the arc contacts 14b and 15b first become closed as shown in FIG. 3(b). As the movable contact 10 further rotates, the other opposing piece 10'c of the movable contact 10 is bent, and the energizing contacts 14a and 15a are also in the closed state as shown in FIG. When the coil 9 of the electromagnet device is demagnetized in this state, the amachia 11 receives the spring force of the return spring 13, and the movable contact 1
0 is a clockwise return rotation. With this return rotation, the energizing contacts 14a and 15a first become open as shown in FIG. 3(b), then the arcing contacts 14b and 15b also become open, and as shown in As shown in Figure (a) (both contacts 14 and 15 return to the open state).

As is clear from this operation, the electrical contact device of the present invention is capable of preventing arcs made of high melting point materials under conditions where phenomena that have an extremely large effect on contact welding, such as arcs due to inrush current or bounce during closing operations, occur. The service contacts 14b and 15b bear these burdens and improve the welding resistance, and in the official steady state, the current-carrying contacts 14a and 15a made of a low-resistance material suppress the rise in temperature of the contacts. Further, the arcing when the contacts are opened is borne by the arcing contacts 14b and 15b, so that welding resistance can be further improved. Moreover, both contacts 10.
Since the 12 contact fixing parts F and M are formed in a U-shape, the energizing contacts 14a and 15a and the arcing contacts 14b and 1
5b is isolated, and the arc contact 14b
, 15b is less likely to adhere to the energizing contacts 14a, 15a, and the contact reliability of the contacts is also improved.

Note that although the embodiment has been described as being applied to a hinge type relay, the present invention is not limited to this and can be applied to contactors, switches, etc.

[Effects of the Invention] As described above, in the electrical contact device according to the present invention, the contact fixing portions of both the fixed and movable contacts are formed in a U-shape in which the spacing between the opposing pieces is approximately equal, and the opposing pieces are inserted alternately. Arranged like this,
Both the fixed and movable contacts are formed separately into a current-carrying contact and an arcing contact, and are fixed to the corresponding opposing pieces.When both of the contacts are closed, the arcing contact is closed first, and when both of the contacts are opened, the current-carrying contact is connected. Because it is configured so that the contacts are opened first,
It is possible to improve the welding resistance of the contacts against inrush current.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a hinge type relay to which the electrical contact device of the present invention is applied, Fig. 2 is a perspective view of the main part showing an embodiment of the present invention, and Fig. 3 (a), (b), and (c). 1 is a side view of a main part explaining the operation, (a) is an open state, (b) is a state immediately after being turned on, and (C) is an official steady state. 1- hinge type relay, 2- device stand, 3- cover, 7-
- Yoke, 8 - Fixed iron core, 9 - Coil, 1° - Movable contact, 11 - Amathia, 12 - Fixed contact, 14 - Fixed contact, 14a - Contact for current, 14b - Contact for arc, 15 - Movable contact, 15a - Current-carrying contact, 15b - Arc contact, F - Contact fixing part of fixed contact, M - Contact fixing part of movable contact. Patent applicant Matsushita Electric Works Co., Ltd. Patent attorney Toshimaru Takemitsu (and 2 others) Figure 1 Figure 2 Figure 3 (a)

Claims (1)

[Claims] (1) An electrical contact device having a fixed contact fixed to a fixed contact and a movable contact fixed to a movable contact and brought into contact with and separated from the fixed contact, wherein the contact fixing portions of both the contacts are connected to their opposing parts. They are formed in a U-shape with substantially equal spacing, and arranged so that the opposing pieces are inserted alternately, and both of the contacts are formed separately into a current-carrying contact and an arcing contact, which are fixed to the corresponding opposing pieces, and both of the contacts 1. An electrical contact device characterized in that the arc contacts are closed first when the contacts are closed, and the energizing contacts are opened first when the contacts are opened.