JPH0696652A - Operation circuit for electromagnetic contactor or the like - Google Patents

Abstract

PURPOSE:To properly check the operation of a relay by ensuring the interruption of operation output upon pressing a stop pushbutton switch, even fusing occurs on the auxiliary contact of the relay. CONSTITUTION:Control voltage applied to control power supply terminals U and V, is transmitted to the operating coil 12 of the first relay 1 via a stop pushbutton switch 5b, the first auxiliary (b) contact 21-b of the second relay 2 and the first auxiliary (b) contact 31b-1 of the third relay 3. The auxiliary (a) contact 11a-1 of the relay 1 is thereby turned on and kept in a self-holding state. A start pushbutton switch 5a is pressed and control voltage is applied to the operating coil 22 of the relay 2 via the auxiliary (a) contact 11a-2 of the relay 1. The relay 2 is thereby actuated and the auxiliary (a) contact 21a-1 of the relay 2 is thereby turned on and kept in the self-holding state. At the same time, the relay 3 is operated via the application of the control voltage to the operating coil 32 thereof. The contact 31b-1 is turned off on the operation of the relays 2 and 3, and the relay 1 is turned to inoperative state. In addition, the contact 11a-2 is turned off, while the contact 11b-1 is turned on, and control voltage is applied to the coils 22 and 32 via the contact 11b-1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation circuit such as an electromagnetic contactor.

[0002]

2. Description of the Related Art FIG. 2 shows an operation circuit of a conventional electromagnetic contactor or the like.
It is a circuit diagram which shows an example. In Figure 2, the operating circuit is
Power source, normally open contact type push button switch 5a for starting,
It consists of a closed contact type stop button switch 5b and a relay 4.
This relay 4 has the first and second auxiliary a contacts 41
_a-1, 41_a-2And a control voltage is applied to its operating coil 42.
It operates by applying voltage. And the control power supply terminal U,
Push button switch 5b for stopping and push button switch for starting
5a and the operation coil 42 of the relay 4 are connected in series.
The relay 4 is connected in parallel with the start pushbutton switch 5a.
1 auxiliary a contact 41 _a-1Is connected to the control power supply terminal U
The second auxiliary a contact 4 of the relay 4 between the operation output terminal R
1_a-2Is connected, and the operation output terminal S is connected to the control power supply terminal V.
It is connected. Between these operation output terminals R and S
Operation load, for example, the operation coil 62 of the electromagnetic switch 6 is connected
To be done.

A control voltage is applied to the control power supply terminals U and V,
When the start push button switch 5a is pressed, a control voltage is applied to the operation coil 42 of the relay 4 through the stop push button switch 5b, and the relay 4 operates. When the relay 4 operates, the first auxiliary a contact 41 _a-1 is switched on, so that the relay 4 is held by itself. At the same time, the second auxiliary a contact 4
1 _{a-2 is} also switched on and the operation coil 6 of the electromagnetic switch 6
A control voltage is applied to 2 and its main contact 61 is closed. When the stop button switch 5b is pressed, the energization of the operation coil 42 of the relay 4 is stopped, the relay 4 is switched off, and the second auxiliary a contact 41a _-2 is switched off. Then, the energization of the operation coil 62 of the electromagnetic switch 6 is stopped, and the main contact 61 thereof is opened. At the same time, the first auxiliary a contact 41 _a-1 is turned off, the self-holding circuit is released, and the initial state is restored.

[0004]

Generally, the auxiliary contact of a relay may cause welding due to chattering or the like when switching from OFF to ON in a charged state. When the auxiliary contact is welded, the welded auxiliary contact does not separate even if the stop button switch is pressed to stop energizing the operation coil.
Sometimes the relay does not switch to inactive.

When the auxiliary contact of the relay is welded in the above-mentioned operation circuit, for example, when the first auxiliary contact is welded, the stop button switch is pressed to stop energizing the operation coil of the relay. Also, since the operation coil is re-energized and the relay operates when the pressing is stopped, the second auxiliary contact is turned on, and the operation load, for example, the operation coil of the electromagnetic contactor is continuously energized through this auxiliary contact. When the second auxiliary contact is welded, even if the stop button switch is pressed to stop the energization of the operation coil, the operation load, regardless of this operation,
For example, the operation coil of the electromagnetic contactor is continuously energized through this auxiliary contact which is welded and not opened. For this reason, the electromagnetic contactor is not opened and causes a serious accident.

An object of the present invention is to reliably check the operation of the relay, and therefore to confirm beforehand the welding of the auxiliary contact of the relay, and even if the auxiliary contact of the relay is welded, it will stop. It is an object of the present invention to provide an operation circuit such as an electromagnetic contactor that surely stops the operation output when the power push button switch is pressed.

[0007]

In order to achieve the above-mentioned object, an operating circuit of the present invention comprises a normally closed contact type switch and an operating coil of a first relay between control power terminals to which a control voltage is applied. Is connected in series, the normally open contact type switch and the operation coil of the second relay are connected in series to the operation coil of the first relay, and the operation coil of the second relay is connected to the third operation coil of the second relay. When the operation coil of the relay is connected in parallel, the first relay operates under the condition that the second and third relays do not operate and self-holds, and then when the normally open contact type switch is operated, the second relay operates. The relay operates on the condition of the operation of the first relay and self-holds, the third relay operates and self-holds by the operation of the second relay, and the first relay operates by the operation of the second and third relays. The relay is switched to inactive, and the first relay is inactive. What the second and third of the relay is the first
The self-holding is performed under the condition that the relay is inoperative, and the operation output is output from the operation output terminal under the condition that the first relay is inoperative and the second and third relays are operating. In such a configuration, the first relay has the first and second relays.
Of auxiliary a contacts of the first and second auxiliary b contacts of
The second relay has first and second auxiliary a contacts and a first auxiliary b contact, and the third relay has first and second auxiliary a contacts and a first auxiliary b contact. A first auxiliary b contact of the second relay is connected in series between the normally closed contact type switch and the operation coil of the first relay, and further connected to the first auxiliary b contact of the second relay. The first auxiliary a contact of the first relay is connected in parallel, and the second auxiliary a contact of the first relay is further provided between the normally open contact type switch and the operation coil of the second relay. The second auxiliary a contact of the second relay is connected between the second auxiliary a contact of the first relay and the operation coil of the third relay, and the normally closed contact type switch and the third auxiliary The first auxiliary b contact of the first relay and the first auxiliary a contact of the third relay are connected in series with the operation coil of the relay of By connecting the second auxiliary b contact of the first relay, the second auxiliary a contact of the second relay and the second auxiliary a contact of the third relay in series to the operation output terminal. Will be realized. It should be noted that both the normally closed contact type switch and the normally open contact type switch are preferably push button switches.

[0008]

As described above, the welding of the auxiliary contact of the relay is usually caused by chattering or the like when switching from ON to OFF in the charged state, so the auxiliary a contact is mainly targeted. The operation circuit of the present invention outputs an operation output on the condition that the first relay operates once and then switches to become inoperative, and the operations of the second and third relays. Therefore, as shown in FIG. 1, when operating power is applied to the control power supply terminal and the first relay operates, if the first or second auxiliary a contact is welded, then the second
And even if the third relay operates and the first auxiliary b-contacts thereof are turned off to stop the energization of the operation coil of the first relay, the first relay does not switch to the non-operation state and remains in the operation state. Maintained. Therefore, the second auxiliary b of the first relay b
The contact is not switched on and the operation output is not output. That is, since the conditions of the non-operation of the first relay and the operation of the second and third relays are not satisfied and the operation output is not output, welding is found in advance.

When the first or second auxiliary a contact is welded when the second relay operates, the operation output is output without any trouble, but the stop push button switch is pressed to operate the operation coil. Even if the energization is stopped, the second relay does not switch to the inoperative state. However, since the operation coil of the third relay is also deenergized at the same time by the pressing of the stop push button switch, the second relay does not operate. The second auxiliary contact a is switched off and the operation output is stopped. Since the first auxiliary b contact of the second relay remains off due to the non-operation of the second relay, the operation coil of the first relay is not energized and the first relay does not operate. The next start is stopped.

Furthermore, when the third relay operates,
If the first or second auxiliary a contact is welded, this case is similar to the case of welding the second relay, but when the stop push button switch is pressed, the operation output is output by the second relay. Be stopped. If the second relay and the third relay are simultaneously welded, the operation output will not be stopped even if the stop push button switch is pressed,
Such a probability is extremely low, and the operation output can be almost certainly stopped.

[0011]

1 is a circuit diagram showing an embodiment of an operation circuit for an electromagnetic contactor or the like according to the present invention. In FIG. 1, the operation circuit includes a control power source having terminals U and V, operation output terminals R and S, a normally open contact type start push button switch 5a, a normally closed contact type stop push button switch 5b, first and second. Auxiliary a contact 11
_a-1 , _11a-2 and first and second auxiliary b contact 1
1 _{b- 1} and 11 _b-2 , which operate by applying a control voltage to the operating coil 12 thereof,
And _a second relay having second auxiliary a-contacts, 21 _a-1 , 21 _a-2 and first auxiliary b-contact 21 _b-1 , which operates by applying a control voltage to the operating coil 22 thereof. 2, first and second auxiliary contact a 31 _a-1, 31 _{a- 2} and the first
And the third relay 3 which has an auxiliary b contact 31 _b-1 and is operated by applying a control voltage to the operation coil 32. The stop push button switch 5b, the first auxiliary b contact _{21b- 1 of} the second relay 2 and the first auxiliary b contact 31 of the third relay 3 are provided between the control power supply terminals U and V.
_b-1 , the operation coil 12 of the first relay 1 are connected in series, respectively, and the first auxiliary b contact 21 of the second relay 2
First auxiliary a contact 11 of the first relay ₁ in parallel with _b-1
a-1 is connected. Further, between the control power supply terminals U and V, a start push button switch 5a, a second auxiliary a contact _{11a-2 of} the first relay 1 are provided via a stop push button switch 5b.
The operation coils 22 of the second relay 2 are connected in series, and the first auxiliary a contact 21 _a-1 of the second relay 2 and the third relay 3 are connected in parallel to the operation coil 22 of the second relay 2.
Operation coils 32 are connected in series, and the connection point of the stop push button switch 5b and the start push button switch 5a, the first auxiliary a contact _{21a-1 of} the second relay 2 and the operation of the third relay 3 are operated. The first coil 1 is connected to the connection point of the coil 32.
The first auxiliary b contact 11 _b-1 and the first auxiliary a contact 31 _{a-1 of} the third relay 3 are connected in series.
The second auxiliary b contact 11 _b-2 of the first relay 1 and the second relay 2 of the second relay 2 are provided between the control power supply terminal U and the operation output terminal R.
Auxiliary a contact 21 _a-2 of the second relay a of the third relay 3
The contacts 31 _a-2 are connected in series, and the control output terminal S is connected to the operation output terminal S.

The operation of this operating circuit is as follows.
First, when a control voltage is applied to the control power supply terminals U and V, the control voltage is applied to the stop push button switch 5b, the first auxiliary contact _{b 21b-1 of} the second relay 2 and the first auxiliary b contact _21b-1 of the third relay 3. It is applied to the operation coil 12 of the first relay ₁ through the auxiliary b contact 31 _b-1 , and the first relay 1 operates and the first relay 1 operates.
The first auxiliary a-contact 11 _a-1 of the relay 1 is turned on and self-held. That is, the first relay 1 operates on the condition that the second and third relays 2 and 3 do not operate.

Next, when the start push button switch 5a is pressed, a control voltage is applied to the operation coil 22 of the second relay 2 through the second auxiliary a contact _{11a-2 of} the first relay 1 and the second relay 2 Operates, the first auxiliary a contact 21 _{a-1 of} the second relay 2 is turned on and self-held, and a control voltage is applied to the operation coil 32 of the third relay 3 to cause the third relay 3 to operate. Operate. By the operation of the second relay, both the first auxiliary b-contact 21 _b-1 and the operation of the third relay turn off the first auxiliary b-contact 31 _b-1 and the first relay 1 does not operate. Switch to. First
This second auxiliary a contact 11 due to the non-operation of the relay 1 of
_a-2 is off, the first auxiliary b contact 11 _b-1 is on,
Operation coil 22 of second relay 2 and third relay 3
A control voltage is applied to the operation coil 32 through the first auxiliary b contact 11 _b- 1 of the first relay 1, and the second relay 2 and the third relay 3 are each self-held. That is, the second and third relays 2 and 3 are the first relay 1
It operates on the condition of the inactivity of.

No operation of the first relay 1, second and third
The second auxiliary b of the first relay 1 by the operation of the relay of
Contact 11 _b-2 , second auxiliary a contact 21 of the second relay 2
_a-2, a third of the second auxiliary contact a 31 _a-2 operation output terminal R both turned on, the control voltage S of the relay 3, that the operation output is outputted, the operation load, for example, an electromagnetic contactor 6 Is input to the operation coil 62 and its main contact 61 is closed.

When the stop push button switch 5b is pressed, the second
And the energization of the operation coils 22 and 23 of the third relay is stopped.
Stopped, the second and third relays switch to inactive
These second auxiliary a contacts 21_a-2, 31_a-2Is which
Is also turned off and the operation output is stopped. For example, the electromagnetic contactor 6
Is opened. At the same time, these first auxiliary b contacts 21
_b-1, 31_b-1Turns on and returns to the initial state.

[0016]

According to the operation circuit of the electromagnetic contactor or the like of the present invention, the operation of the auxiliary contact of the relay, and thus whether the auxiliary contact is welded or not, can be confirmed in advance. Even if welding occurs at the contacts, the operation output is reliably stopped when the stop push button switch is pressed.For example, even if the stop push button switch is pressed, the electromagnetic contactor does not open. It prevents the occurrence of serious accidents.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of an operation circuit for an electromagnetic contactor or the like according to the present invention.

FIG. 2 is a circuit diagram showing an example of an operation circuit of a conventional electromagnetic contactor or the like.

[Explanation of symbols]

1 1st relay 11 _a-1 1st auxiliary a contact of 1st relay 11 _a-2 2nd auxiliary a contact of 1st relay 11 _b-1 1st auxiliary b contact of 1st relay 11 _b-2 2nd auxiliary b contact of 1st relay 12 Operating coil of 1st relay 2 2nd relay 21 _a-1 1st auxiliary a contact of 2nd relay 21 _a-2 2nd relay Second auxiliary a contact of 21 _b-1 first auxiliary b contact of second relay 22 operation coil of second relay 3 third relay 31 _a-1 first auxiliary a contact of third relay 31 _a-2 2nd auxiliary a contact of 3rd relay 31 _b-1 1st auxiliary b contact of 3rd relay 32 Operation coil of 3rd relay 5a Push button switch for start 5b Push button switch for stop 6 Electromagnetic Contactor 62 Operation coil of electromagnetic contactor U Control power supply terminal on one side V Control power supply terminal on the other side R Operation output terminal on one side S Other side Production output terminal

Claims (3)

[Claims] 1. A normally closed contact type switch and an operating coil of a first relay are connected in series between control power supply terminals to which a control voltage is applied, and the operating coil of the first relay is normally opened in parallel. The contact type switch and the operation coil of the second relay are connected in series, the operation coil of the third relay is connected in parallel to the operation coil of the second relay, and the first relay is the second
And when the normally open contact type switch is operated next, the second relay operates on the condition that the third relay does not operate, and the second relay operates on the condition of the operation of the first relay and self maintains. , The third relay operates and self-holds by the operation of the second relay, the first relay switches to the non-operation by the operation of the second and third relays, and the first relay operates by the non-operation of the first relay. The second and third relays self-hold on condition that the first relay is inoperative, and the operation output is output from the operation output terminal on condition that the first relay is inoperative and the second and third relays are in operation. An operation circuit for electromagnetic contactors, etc. 2. The device according to claim 1, wherein the first relay has first and second auxiliary a-contacts and first and second auxiliary b-contacts, and the second relay has first and second auxiliary-a contacts. A second auxiliary a-contact and a first auxiliary b-contact, and a third relay having first and second auxiliary a-contacts and a first auxiliary b-contact, and a normally-closed contact type switch. A first auxiliary b-contact of the second relay is connected in series between the operating coil of the first relay and a first auxiliary b-contact of the second relay in parallel with the first auxiliary b-contact of the second relay. The first auxiliary a contact is connected, and the second auxiliary a contact of the first relay is provided between the normally open contact type switch and the operating coil of the second relay, and the second auxiliary a contact of the first relay is further provided. The second auxiliary a contact of the second relay is connected between the auxiliary a contact and the operation coil of the third relay, and the normally closed contact type The first auxiliary b contact of the first relay and the first auxiliary a contact of the third relay are connected in series between the switch and the operation coil of the third relay, and the first auxiliary a contact of the third relay is connected to the operation output terminal. A second auxiliary b contact of the relay, a second auxiliary a contact of the second relay, and a second auxiliary a contact of the third relay are connected in series, and an operation circuit for an electromagnetic contactor or the like. . 3. The device according to claim 1 or 2,
The normally closed contact type switch is a push button switch, and the normally open contact type switch is a push button switch. An operation circuit for an electromagnetic contactor or the like.