JPH03101028A - Electromagnetic contactor - Google Patents

Abstract

PURPOSE:To prevent defective insertion or pumping by providing a means detecting the positions of a moving core and a fixed core and contacts opened or closed by this detecting means, and opening the contacts later after the moving core and the fixed core are brought into contact with each other interlockingly with the moving core. CONSTITUTION:When an electromagnetic contactor is turned on and cores 2 and 3 are completely brought into contact with each other, the magnetic flux passing a magnetic lever 4 is sharply decreased, and the suction force between the moving core 2 and the magnetic lever 4 is reduced, thus a moving insulator 5a excited by springs 5f and 5e in a contact unit pushes back the action point 4a of the magnetic lever 4 downward. If the wipe of the contact setting the time delay from the time when the moving insulator 5a starts to be moved to the time when contacts 5c and 5d are separated is made deep, the timing to switch the coil current can be delayed after cores are brought into contact. Contacts of a selector switch can be switched to 'OFF' later after the moving core 2 and the fixed core 3 are brought into contact, and defective insertion or pumping is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electromagnetic contactor, and more particularly to an electromagnetic contactor having coil switching means for a double-coil electromagnetic contactor using direct current excitation.

(Prior Art) A conventional electromagnetic contactor is disclosed in Japanese Utility Model Application Laid-Open No. 61-8930. As shown in FIG. 7, the knob 3a attached to the case or coil unit of the electromagnetic contactor is operated by the movable insulating base 1, which is the supporting part of the movable core 2, or by the switching switch pressing part that engages with the movable insulating base 1. The switch was pressed down to open and close the switching contact.

(Problems to be Solved by the Invention) In the above-mentioned conventional technology, the excitation force when the movable core and the fixed core collide is the excitation force during holding, so there is a risk of causing a charging failure or pumping.

To solve this problem, the electromagnetic force is designed to be large, and the operating timing of the selector switch is maintained with high accuracy. There was a need.

The present invention has been made to improve the above-mentioned problems, and by switching from the closing coil to the holding coil after the cores come into contact with each other, it eliminates closing failures and pumping, and uses a small electromagnet. The object of the present invention is to provide an electromagnetic contactor that can switch the excitation current by using a changeover switch.

(Means for Solving the Problem) The above object is a movable double-coil electromagnetic contactor that has a movable core, a fixed core, a closing coil that is energized only when closing, and a holding coil that is always energized. means for detecting the positions of the movable core and the fixed core in conjunction with the core;
This is achieved by configuring the contact to be opened and closed by the detection means, and the contact to be opened and separated later than when the movable core and the fixed core come into contact with each other.

(Function) With the above configuration, the switch is opened and opened after the movable core and the fixed core are brought into contact with each other, and the timing of switching the excitation current can be delayed, and problems such as poor closing and pumping can be eliminated.

(Example) An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the internal structure of the electromagnetic contactor according to the present invention, and shows the state before the electromagnetic contactor is turned on.

Since the coil 7 is not excited before being turned on, one end 4b of the magnetic lever 4 is in close contact with the side surface of the movable core 2 due to the restraint of the movable insulating table 1. Therefore, the point of action 4a of the magnetic lever 4 pushes the movable insulator 5a upward, and the contact 5c15d of the contact unit 5 is in the ON state. FIG. 6 is a detailed sectional view showing the internal structure of the contact unit 5. FIG. Note that 5e is a contact spring for buffering when the contacts 5c and 5d are turned on.

Next, when the coil 7 is excited, as shown in FIG.
The movable core 2 and the movable insulating stand 1 engaged with the movable core 2 are attracted toward the fixed core 3. As a result, the magnetic lever 4 restrained by the movable insulating table 1 is released, and becomes movable in the direction away from the side surface of the movable core I due to the biasing force of the return spring 5f within the contact unit 5. However, since the rotation fulcrum of the magnetic lever 4 is in contact with the fixed core 3, the leakage magnetic flux remaining between the movable core 2 and the fixed lower 3 causes the magnetic lever 4 to be attracted to the movable core 2. It will be retained for a while. When the movable core 2 and the fixed core 3 are completely in close contact with each other, the leakage magnetic flux disappears, so the switching contact 5C15d is turned OF by the biasing force of the return spring 5f.
It becomes F state.

As a result, it is possible to obtain a contact changeover switch that turns off with a delay from the time when the movable core 2 and the fixed core 3 come into contact with each other.

When the electromagnetic contactor is released, the movable core 2 and the fixed core 3 are separated, and the movable insulating base 1 is moved away from the fixed core 3. As the magnetic contactor 4 is released, the tapered part of the one end 4b of the magnetic lever 4 and the movable insulating base 1 are moved away from each other. By contacting and sliding with the outer beam, the magnetic lever 4 is restored to the position shown in FIG. At this time, the point of action 4a of the magnetic lever 4 pushes up the movable insulator 5a, and the contacts 5c and 5d are in the ON state.

FIG. 3 is a wiring diagram of the electromagnetic contactor of the present invention, in which 11 is a holding coil, 12 is a closing coil 13 is a switching contact,
When the switching contact 13 is turned off, the circuit of the closing coil 12 is opened and the circuit of the holding coil 11 is closed.

An embodiment in which a permanent magnet is installed inside the movable insulating table 1 is shown in FIGS. 4 and 5. FIG. 4 shows the state of the electromagnetic contactor before it is turned on. 12 is the above-mentioned permanent magnet, and since one end 4b of the magnetic lever 4 is attracted to the permanent magnet 12, the point of action 4
The movable insulator 5a connected to the movable insulator 5a is pulled upward against the biasing force of the return spring 5f, and the contacts 5c and 5d are in the ON state.

When the coil 7 is excited, the movable core 2 and the movable insulating stand 1 are attracted toward the fixed core 3, as shown in FIG. Therefore, the permanent magnet 12 also moves downward, and the magnetic lever 4
One end 4b is released from the attractive force, and the movable insulator 5a moves downward in the figure due to the biasing force of the return spring 5f, and the contact point 5c
, 5d are in the OFF state. When the electromagnetic contactor is released, the contact 5C1 is restored by the restoring mechanism of the movable insulator 5a (not shown).
5d is turned on.

In each of the above embodiments, when the magnetic contactor is turned on, when the core is completely polarized, the magnetic flux passing through the magnetic lever 4 is drastically reduced, and the movable core 2
Since the attractive force between the magnetic lever 4 and the magnetic lever 4 decreases, the movable insulator 5a is biased by the springs 5f and 5e in the contact unit.
pushes back the point of action 4a of the magnetic lever 4 downward, but at this time, from the beginning of the movement of the movable insulator 5a, the contact point 5C1
By setting a time delay until 5d opens, that is, by wiping the contact deeply, the timing of switching the coil current can be delayed after the core polarization.

Fig. 8(a) is a characteristic diagram showing the relationship between the time from the start of suction to the contact electrode and the distance between the cores, and Fig. 8(b) and (C) are (
a) In connection with the figure, the making current and the holding current;
FIG. 2 is a comparative characteristic diagram of the prior art and the present invention in relation to elapsed time. In conventional changeover switches, the coil current is switched at time T1 before the core becomes polarized, and the current is polarized with a weak holding current, resulting in weak attraction force and causing problems due to core jump. , T, 10T, that is, after the core is polarized, the excitation current is switched, indicating that the above-mentioned problem is resolved.

(Effects of the Invention) By carrying out the present invention, it is possible to turn off the contact point of the changeover switch with a delay after the movable core and the fixed core are connected, and it is possible to provide an electromagnetic contactor that does not have closing failures or pumping. .

[Brief explanation of drawings]

Fig. 1 shows the internal structure of the electromagnetic contactor according to the present invention before the electromagnetic contactor is turned on, Fig. 2 shows the state in which the coil is excited, and Fig. 3 shows the internal structure of the electromagnetic contactor according to the present invention. Wiring diagram of the contactor, FIG. 4 is a state before turning on another embodiment of the present invention, FIG. 5 is a diagram showing a state in which the coil is excited, and FIG. 6 is a detailed sectional view of the contact unit. FIG. 7 is a configuration diagram of a conventional magnetic contactor, and FIG. 8 is a characteristic diagram (a) showing the relationship between time and core distance, and the relationship between the prior art and the present invention between making current, holding current, and elapsed time. They are comparative characteristic diagrams (b) and (c). l...Movable insulating stand 3...Fixed core 5...Contact hill knit 5a...Movable insulator 5c15d...Contact 5f...Return spring 11...Holding coil 13...Switching contact 2... Movable core 4... Magnetic lever 5b... Unit case 5e... Contact spring 7... Coil 12... Closing coil 8-

Claims (1)

[Claims] 1. A double-coil electromagnetic contactor having a movable core, a fixed core, a closing coil that is energized only when closing, and a holding coil that is always energized, which operates in conjunction with the movable core. , a contact unit having means for detecting a relative movement position of the movable core with respect to the fixed core, and a contact that is opened and closed by the detection means, the contact being opened later than when the movable core and the fixed core come into contact. An electromagnetic contactor characterized by comprising a means for separating the contactor. 2. The means by which the contact opens later than when the movable core and the fixed core come into contact is such that the magnetic lever constituting the detection means is caused by an attractive force due to leakage magnetic flux remaining between the fixed core and the movable core. The electromagnetic contactor according to claim 1, wherein the electromagnetic contactor is restrained. 3. The means by which the contact opens later than when the movable core and the fixed core come into contact is restrained by the attractive force of a permanent magnet provided on the movable core side by a magnetic lever constituting the detection means. The electromagnetic contactor according to claim 1, characterized in that: