JPS6353827A - Contact switch for ac - Google Patents

Abstract

(57) [Abstract] 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 is equipped with an electromagnetic device for opening and closing contacts such as relays and contactors, and particularly relates to an AC contact switching device for controlling switching of an AC load. .

[Background Art] The contacts of this type of contact opening/closing device generally use silver thread contacts. Welding occurs in such contacts due to changes in the state of the contact surfaces when a lamp load or a motor load is opened and closed due to inrush current, or even when a resistive load is opened and closed many times. However, such welds are usually not very strong, and most of them are so-called light welds that can be removed by applying a slight external force or vibration.

[Purpose of the Invention] The present invention has been made in view of the above-mentioned reasons, and its purpose is to provide an alternating current contact that can detach both lightly welded contacts, thereby prolonging the life of the contacts. The purpose is to provide a contact opening/closing device.

[Disclosure of the Invention] The AC contact switching device of the present invention has a fixed contact provided with a fixed contact and a movable contact provided with a movable contact, and the movable contact controls an excitation coil of an electromagnet device. A contact opening/closing device that opens and closes both contacts in response to an armature displaced by It is something.

According to the present invention, when light welding occurs between both contacts, an alternating current continues to flow through the electric circuit section interlinking with the magnetic circuit of the electromagnet device, so a pulsating attractive force is generated in the 1f & stone device.
Therefore, this suction force is transmitted to both contacts via the armature and the movable contact, and light welds can be removed.

(Example) Below, the first example of the present invention when applied to a relay is as follows.
This will be explained based on FIGS. 1 to 4.

Reference numeral 1 denotes a table made of an insulating material, which forms a housing together with a case (not shown). The main components are fixedly mounted in this housing, and the contact terminals 2.3 and excitation coil terminals 4, 5 of the electromagnet device are elevated from the device stand 1.

A fixed contact 6 has a fixed contact 7 provided at its tip, and its base end is fixed to the instrument stand 1. Reference numeral 8 denotes a movable contact made of a conductive plate spring material, which has a movable contact 9 at its tip that contacts and separates from the fixed contact 7, and its base end is held and fixed to an electromagnet device to be described later.

The electromagnet device 10 includes a U-shaped yoke 11. Iron core 12 fixed to yoke 11. An excitation coil 14 is wound around the outer periphery of the iron core 12 via a coil frame 13, and an armature 15 is positioned such that its tip is attracted to the end surface of the iron core 12 and its base end is swingably supported by the tip of the yoke 11. The return spring 16 is tension-suspended between the base end of the armature and the yoke 11 to bias the armature 15 from the suction state to the release state, and the base end of the yoke 11 is fixed to the instrument stand 1. The movable contactor 8 is held and fixed to a holder 17 made of an insulator provided at the intermediate portion of the armature 15. Therefore, the movable contact 8 is
By controlling the excitation coil 14 of the electromagnet W10, both contacts 7.9 are opened and closed in response to the displacing armature 15.

A coil 18 is connected in series to both contacts 7.9, and is wound at a position where it can act in the same manner as the excitation coil 14 in the electromagnet device 10, for example, around the outer periphery of the excitation coil 14. For this coil, the wire diameter is made thicker and the number of turns is made smaller than that of the excitation coil 14. In its design, the voltage drop with respect to the AC power supply on the load side is made as small as possible, and in addition, a suction force that is smaller than the suction force of the excitation coil 14 is applied to generate a pulsating suction force that can remove light welds. Make it. In other words, the coil 18 is part of an electrical circuit connected in series to both the contacts 7 and 9 and the AC power source, and is arranged so as to interlink with the magnetic circuit of the electromagnet device. Note that the coil 18 is not limited to being wound around the outer periphery of the excitation coil 14, but may be wound around the yoke 11.

21.22 is a lead wire connecting the exciting coil 14 and the exciting coil terminal 4.5, 23 is a lead wire connecting the movable contact 8 and the contact terminal 2, 24 is a lead wire connecting the contact terminal 3 and the coil 18, 25 is a lead wire connecting the coil 18 and the fixed contact 6; 26 is a DC power source for the excitation coil 14;
7 is a control switch for the excitation coil 14. However,
Both contacts 7.9 and coil 18, i.e. both contact terminals 2
．． An AC power supply 28 and a load 29 are connected in series between 3 and 3.

(Operation) FIGS. 1 and 2 show a state in which the excitation coil 14 is not excited and both contacts 7.9 are in an open state. When the exciting coil 14 is excited in this state, the armature 15 is attracted to the end surface of the iron core 12 against the spring force of the return spring 16. Therefore, the movable contact 8 responds to the armature 15, and the movable contact 9 contacts the fixed contact 7 to be in the closed state. In this closed state, both the excitation coil 14 and the coil 18 are excited, but since the attraction force due to the coil is small, the attraction force that affects the armature 15 has an extremely small amount of pulsation, as shown in FIG. 15 hardly vibrates.

Next, to explain the case where light welding occurs between both contacts 7 and 9, even if the control switch 27 is opened and the exciting coil 14 is no longer excited, the coil 18 remains excited by the AC power source 28. Therefore, the suction force that affects the armature 15 pulsates as shown in FIG. Therefore, the armature 15 vibrates in response to this pulsating attraction force and the spring force of the return spring 16, and the vibration is transmitted to both contacts 7.9 via the movable contact 8 and yoke 11, and removes the light welding between them. It is.

5 and 6 show a second embodiment of the present invention, which is substantially different from the first embodiment only in the coil 18, that is, both contacts and the electrical circuit connected in series to the AC power source. Therefore, members having substantially the same functions other than the electric circuit portion are given the same reference numerals as in the first embodiment, and their explanations will be omitted. Further, members not directly related to the essential parts of the present invention, such as lead wires, are also omitted.

The electric path portion of this embodiment does not include a coil, but includes a conductor 38 having a conductive portion 38a passing between the yoke 11 and the iron core 12. The conductor 38 is the conductive part 3
8a has a shape in which both ends are bent at substantially right angles in opposite directions, one end is connected to the contact terminal 2 or 3, and the other end is connected to the contact terminal 39.
are respectively connected to the movable contactor 8 via. In other words, this conductor 38 is also part of the electrical circuit connected in series to both contacts 7.9 and the AC power supply 28, and is arranged to interlink with the magnetic circuit of the electromagnet device. Of course conductor 3
8 and the contact terminal 2 or 3 may be integrally formed using a conductive plate material, or the conductor 38 may be plastically worked using a hard copper wire or the like.

This device also has the same effects as the first embodiment, and the structure of the electric circuit portion is simple, making it cheaper than the device including a coil.

Although the first and second embodiments have been described as being applicable to relays, they can also be applied to contactors and the like. The four coils 18 are not limited to being wound only around the outer periphery of the excitation coil 14, but may be wound around the yoke 11.

[Effects of the Invention] The AC contact switching device of the present invention has a fixed contact provided with a fixed contact and a movable contact provided with a movable contact, and the movable contact controls the excitation coil of the electromagnet device. A contact opening/closing device that opens and closes both contacts in response to an armature displaced by Therefore, if light welding occurs between both contacts, alternating current continues to flow through the electrical circuit, creating a pulsating attraction force in the electromagnetic device. It is transmitted to both contacts, and light welds can be removed, thereby extending the life of the contacts.

[Brief Description of the Drawings] Fig. 1 is a side view showing the first embodiment of the present invention applicable to a relay, Fig. 2 is its connection diagram, and Fig. 3 is the attraction of the electromagnet device in its normal state. Figure 4 shows the attraction force characteristics of the electromagnetic device when light welding occurs. FIG. 5 is a side view of the second embodiment of the present invention, and FIG. 6 is a plan view of the fu 11 in a direction different by 90 degrees. 1--Device stand, 6--Fixed contact, 7-Fixed contact, 8-
-・Movable contact, 9-movable contact, io-electromagnetic device, 1
1--yoke, 12-iron core, 14--excitation coil, 1
5 - armature, 16 - return spring, 18 - coil (electrical circuit section), 28 - AC power supply, 29 - load, 38 - conductor (electrical circuit section).

Claims (2)

[Claims] (1) It has a fixed contact with a fixed contact and a movable contact with a movable contact, and the movable contact operates both contacts in response to the displacing armature by controlling the excitation coil of the electromagnet device. What is claimed is: 1. A contact switching device for opening/closing operation, wherein both the contacts and an electric circuit section connected in series to an AC power source are arranged so as to interlink with a magnetic circuit of the electromagnet device. (2) The AC contact switching device according to claim 1, wherein the electric circuit section includes a coil wound around a magnetic circuit of the electromagnet device.