JP2011129268A - Electromagnetic contactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To review components of a magnetic contactor, such as an operation power supply, an exciting coil, and a control system, to reduce power consumption, facilitate miniaturization and cost cut, increase reliability, and achieve the same effect even for control operations using a PLC, etc. <P>SOLUTION: A single operation power supply is provided for power supply to a plurality of magnetic contactor contact units. Each contact unit includes one exciting coil by which an exciting power is switched depending on closing or holding of contact. The magnetic contactor has a magnetic contactor control unit which controls the magnetic contactor contact units to switch the exciting power based on a closing completion signal and has a control unit that carries out control for switching on and off. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electromagnetic contactor, and more particularly to an electromagnetic contactor with reduced power consumption.

The electromagnetic contactor is for opening and closing an electric circuit by operating a contact by exciting an electromagnet provided in a housing, and is used when starting and stopping an electric motor, for example.
In addition, electromagnets for electromagnetic contactors are generally excited by alternating current, but in large models, they are excited by converting alternating current to direct current to prevent a roaring sound when maintaining the ON state. There is also.

  For example, in Patent Document 1, an electronic circuit is configured between an AC operating power supply and an exciting coil, and the AC state is converted into DC by the electronic circuit and supplied to an operating coil for exciting an electromagnet, thereby turning the ON state. A method of reducing power consumption by preventing the generation of a roaring sound during holding and adopting a double-coil system with a closing coil and a holding coil as the operating coil is disclosed.

Japanese Patent Laid-Open No. 3-101028

However, in Patent Document 1, it is necessary to provide an AC → DC conversion circuit for each electromagnetic contactor, and a coil space for winding two types of coils on one bobbin, and an insulation space between the two coils. It is necessary to secure.
Further, in order to control the electromagnetic contactor, it is necessary to switch the electric power itself for exciting the coil. That is, it is necessary to switch a large power of about 100 to 400 volts AC and several amperes of AC when expressed by the AC power before the DC conversion. Currently, PLC (Programmable Logic Controller) is often used as an electronic control method for performing switching control of an electromagnetic contactor, but it is difficult to open and close such a large power directly from the PLC. It was necessary to control via another relay.

These are factors that make the magnetic contactor expensive and large, and have been an obstacle to reducing power consumption.
In view of the above problems, an object of the present invention is to provide an electromagnetic contactor with reduced power consumption.

  To achieve the above object, the present invention provides an electromagnetic contactor having an electromagnetic contactor contact unit and an electromagnetic contactor control unit, the electromagnetic contactor contact unit having a main contact for supplying or releasing electric power. An electromagnetic changeover switch and an excitation coil for turning on the changeover switch, and the electromagnetic contactor control unit supplies excitation power for turning on the changeover switch to the excitation coil. A plurality of supply voltage adjustment units in which the supplied excitation power has a plurality of set values, a voltage adjustment control unit for controlling the excitation power supplied to the excitation coil by the plurality of supply voltage adjustment units, and the changeover switch. A control unit having a control signal input unit for receiving a command for turning on or off from an external device, and the control unit and the plurality of supply voltage adjusting units. It is characterized by having an operating power generating unit for supplying operating power.

  Further, the present invention is the above-described electromagnetic contactor unit, wherein the switch of the electromagnetic contactor contact unit has an auxiliary contact that operates in synchronization with the main contact, and whether or not the auxiliary contact is in the on state. A closing completion signal indicating the above is generated and supplied to the control unit of the electromagnetic contactor control unit, and the voltage adjustment control unit of the control unit of the electromagnetic contactor control unit is turned on by the control signal input unit. The first excitation power required for turning on is supplied to the exciting coil when receiving a command to perform the first excitation, and the first excitation required for holding the turned on state is supplied when the closing completion signal is supplied. The supply voltage adjusting unit is controlled to supply the second exciting power, which is smaller than the power, to the exciting coil.

  According to the present invention, an electromagnetic contactor with reduced power consumption can be provided, and there is an effect that it can contribute to effective utilization of energy resources.

It is a system block diagram of the electromagnetic contactor which shows one Example of this invention.

In one embodiment of the present invention, a case where a plurality of electromagnetic contactors are provided is targeted, and a power supply circuit for exciting a plurality of coils for opening and closing the contactors, that is, an AC → DC converter is integrated. The coil is unified without making it a double coil of a making coil and a holding coil, and the exciting current is switched between making and holding. In addition, an electromagnetic contactor control unit that performs opening / closing control of a plurality of electromagnetic contactors is provided.
Thereby, the power consumption of the magnetic contactor including the controller is reduced. Furthermore, it can be expected to reduce costs and improve reliability by reducing the number of components.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a system configuration diagram of an electromagnetic contactor showing an embodiment of the present invention. The whole includes an electromagnetic contactor control unit 1, electromagnetic contactor contact units 101 to 103, a PLC 201 and a personal computer 301.

In general, when the electromagnetic contactor indicates the whole including the components shown in FIG. 1, when referring to the electromagnetic contactor control unit 1 and the electromagnetic contactor contact units 101 to 103, only the electromagnetic contactor contact units 101 to 103 are used. May point. In the description of this embodiment, terms may be used in common within a range that does not cause misunderstanding.
Moreover, although the example which has three electromagnetic contactor contact units 101-103 and the component concerning this was shown here, of course, this is not a limiting condition of this invention. Any number may be present as long as there are a plurality. In addition, even if there are a plurality of contactor contact units that actually operate, for example, only one contactor unit is in operation, it is within the scope of the present invention.

The electromagnetic contactor control unit 1 drives power for supplying excitation power to the magnetic contactor contact units 101 to 103 controlled by the magnetic contactor control unit 1 and the electromagnetic contactor control unit 1 itself. Is supplied from the external AC power source 2.
The externally supplied power supplied from the external AC power source 2 is converted into DC by the AC → DC converter 11 to generate a DC power source. The generated DC power supply includes a supply voltage adjustment unit 12 to 14 for supplying excitation power to the magnetic contactor contact units 101 to 103, a control unit 15 including a CPU (Central Processing Unit) 154, and an RS-232C transmission unit. 17 is supplied as an operating power source.

The control unit 15 includes an ON / OFF control unit 151 that controls whether the electromagnetic contactor contact units 101 to 103 connected to the electromagnetic contactor control unit 1 are turned on or released.
Moreover, it has the voltage adjustment control part 152 which adjusts the power supply for exciting the exciting coils 101A-103A of the magnetic contactor contact units 101-103.
Further, a signal (contact state signal, which will be described later in detail) indicating the state of the main contact generated by the auxiliary contact included in the changeover switches 101B to 103B of the magnetic contactor contact units 101 to 103 is supplied from the changeover switches 101B to 103B. Based on this, for example, a changeover switch state input unit 153 for controlling the voltage adjustment control unit 152 is provided.

Furthermore, the control part 15 has the control signal input part 154 which supplies the control signal for injection | throwing in and release of the electromagnetic contactor contact units 101-103 from the outside, for example, PLC201.
In addition, for example, it has a program signal input unit 155 that receives a command of a control method (described later in detail) from an external device such as the personal computer 301. Accordingly, the magnetic contactor control unit 1 has an RS-232C transmission unit 17 for connecting to an external device such as the personal computer 301 for communication.

Further, the control unit 15 stores information on the electromagnetic contactor contact units 101 to 103 connected to the electromagnetic contactor control unit 1, for example, a value of input current and holding current described later, or a command from the personal computer 301 or the PLC 201. A memory unit 16 for storing program information and the like for performing control in accordance with is attached. Of course, the memory unit 16 may be built in the control unit 15.
In addition, the control unit 15 includes relays 18 to 20, and the operation thereof will be described later. The diodes 21 to 26 are components for preventing a reverse current generated when the exciting currents of the exciting coils 101A to 103A rapidly decrease.

  The magnetic contactor contact units 101 to 103 each have exciting coils 101A to 103A and changeover switches 101B to 103B. Each of the exciting coils 101A to 103A has one coil, and is different from the double coil type provided with different coils for turning on and holding as described above. The changeover switches 101B to 103B, in addition to a main contact for supplying power to or disconnecting the target device, as described later, a signal indicating completion of turning on the main contact by moving in synchronization with the main contact. It has an auxiliary contact to generate.

Next, the operation of the electromagnetic contactor of FIG. 1 will be described.
The case where the magnetic contactor contact units 101 to 103 are turned on and the changeover switches 101B to 103B are turned on will be described. Of course, the three changeover switches are not simultaneously turned on, and a plurality of switches can be controlled individually.

It is assumed that a closing command signal for switching on the electromagnetic contactor contact unit 101 is input from an external device, for example, the PLC 201, to the control signal input unit 154 of the control unit 15.
Upon receiving the input command signal, the control unit 15 generates a control signal from the ON / OFF control unit 151 and inputs the relay 18 included in the electromagnetic contactor control unit 1 in order to turn on the electromagnetic contactor contact unit 101. Of course, if the input command from the PLC 201 is for the electromagnetic contactor contact unit 102, the relay 19 is input. If the input command is for the electromagnetic contactor contact unit 103, the relay 20 is input. The relays 18 to 20 are not limited to relay switches that are turned ON / OFF by electromagnetic force, but may be any switches as long as necessary power can be switched.

When the relay 18 is turned on, the electric power converted into direct current by the alternating current → direct current conversion unit 11 is supplied to the electromagnetic contactor contact unit 101 via the diode 21, the supply voltage adjustment unit 12, and the relay 18.
In the magnetic contactor contact unit 101, the exciting coil 101A of the magnetic contactor contact unit 101 is excited by the supplied DC power. Thereby, in the changeover switch 101B of the magnetic contactor contact unit 101, the main circuit movable contact connected to the movable iron core moves and contacts in the direction of the other main circuit fixed contact connected to the fixed iron core. As a result, the magnetic contactor contact unit 101 can supply, for example, power supplied to the main circuit fixed contact (for example, power supplied to an operator or each household by the power company) to the main circuit movable contact, for example. It functions to supply electric power to a device (for example, a motor not shown).

Here, the changeover switches 101B to 103B of the magnetic contactor contact units 101 to 103 are, for example, main contacts separately from the main contact (having the main circuit fixed contact and the main circuit movable contact) for supplying power as described above. It has an auxiliary contact that switches in synchronization with the operation. When the insertion of the main contact of the electromagnetic contactor contact unit 101 is completed, the auxiliary contact outputs a closing completion signal accordingly.
The closing completion signal generated by the auxiliary contact is input to the changeover switch state input unit 153 included in the control unit 15 of the electromagnetic contactor control unit 1 and is supplied to the CPU 154 through this. Based on this, the CPU 154 recognizes that the electromagnetic contactor contact unit 101 to be turned on has been turned on.

On the other hand, the electromagnetic contactor generally requires the most coil excitation power when moving the contact from the released state to the closed state. As an example, in the case of an electromagnetic contactor with a rated current of 10 A, the required power at the time of charging is about 45 VA, whereas the required power at the time of holding after charging is about 9 VA. When the rated current is 100 A, the required power at the time of turning on is about 490 VA, whereas the required power at the time of holding after the turning on is about 50 VA.
In response to the above matters, the control unit 15 of the electromagnetic contactor control unit 1 outputs a control signal from the voltage adjustment control unit 152 of the control unit 15 in response to the completion of the insertion of the electromagnetic contactor 101 to be input. For example, the supply voltage adjusting unit 12 configured by a transistor or an FET (Field Effect Transistor) is controlled to reduce the supply power to the electromagnetic contactor contact unit 101 to a necessary value.

  The power supplied when the electromagnetic contactor contact units 101 to 103 connected to the electromagnetic contactor control unit 1 are turned on and held is determined as follows. First, the memory unit 16 stores in advance a data table of specifications relating to input power and holding power according to the type and model of the magnetic contactor contact unit. The type of the electromagnetic contactor contact units 101 to 103 connected to the electromagnetic contactor control unit 1 through the RS-232C transmission unit 17 and the program signal input unit 155 by operating the personal computer 301 connected to the outside by the user, for example. And the model are designated to the CPU 154. In response to this, data relating to the input power and holding power in the type and model of the corresponding magnetic contactor contact unit is read from the memory unit 16 and supplied to the CPU 154. The CPU 154 supplies this data to the voltage adjustment control unit 152. The voltage adjustment control unit 152 controls the supply voltage control units 12 to 14 based on the supplied data to supply power to the excitation coils 101A to 103A at the time of turning on and holding according to the specifications.

  For example, when the rated current of the changeover switch 101B of the magnetic contactor contact unit 101 is 10 A, in the above-described example, for example, 45 VA power is supplied to the exciting coil 101A when turned on. An auxiliary contact that operates in synchronization with the signal indicating that the main contact of the changeover switch 101B has been turned on is generated. After the changeover switch state input unit 153 receives the generated input completion signal, the CPU 156 refers to the data stored in the memory unit 16, and the voltage adjustment control unit 152 controls the supply voltage control unit 12 based on this data. Adjust the power supply. For example, by setting the supply voltage when holding the exciting coil 101A of the magnetic contactor contact unit 101 to a value of about 20% of the on-time voltage, the supply power is reduced to 9 VA, for example.

  Similarly to the above, the magnetic contactor contact units 102 and 103 connected to the magnetic contactor control unit 1 are held based on the input completion signals output from the changeover switches 102B and 103B of the respective magnetic contactor contact units 102 and 103. In some cases, the supply voltage is changed by the supply voltage adjusting units 13 and 14 from the time of turning on to reduce the supply power to the exciting coils 102A and 102B.

Next, an applied method of using the magnetic contactor control unit 1 will be described.
This unit 1 has an RS-232C transmission unit 17 and can communicate with, for example, a personal computer 301. Thereby, programming or the like in the personal computer 301 can be stored in, for example, the memory unit 16 of the unit 1.

For example, when it is desired to sequentially turn on the magnetic contactor contact units 101 to 103 connected to the unit 1, the magnetic contactor contact unit 101 is turned on by issuing a turn command to the magnetic contactor contact unit 101. The unit 1 that has received the closing completion signal reduces the power supplied to the magnetic contactor contact unit 101 to the value at the time of holding, and drives the relay 19, for example, from the ON / OFF control unit 151 of the control unit 15. The contactor contact unit 102 is turned on. Upon receiving power supply from the unit 1, the magnetic contactor contact unit 102 is turned on. Upon receipt of the input completion signal, the unit 1 reduces the power supplied to the magnetic contactor contact unit 102 to the value at the time of holding. For example, the relay 20 is driven from the ON / OFF control unit 151 of the control unit 15, and the electromagnetic contactor contact unit 103 is turned on. A similar closing operation is also performed on the magnetic contactor contact unit 103 and further held.
Conventionally, it has become possible to internally handle sequences that have been externally assembled or, for example, PLC 201 has been programmed.

In addition, when all the interlocks of the magnetic contactor contact units 101 to 103 connected to the unit 1 are to be unlocked, even one closing completion signal output from the magnetic contactor contact units 101 to 103 is in an ON state. At this time, it is possible to perform a process such that the input process to the magnetic contactor contact unit is not performed even if the input signal to the other magnetic contactor contact unit is input.
In addition, when the electromagnetic contactor is frequently introduced and the release process is performed, the holding time is short, and the effect of reducing the power supplied to the electromagnetic contactor contact unit may be small. In such a case, the CPU 154 can ignore the closing completion signal output by each electromagnetic contactor contact unit, and can prevent the supply power reduction process at the time of holding to each electromagnetic contactor contact unit from being performed.

  As described above, the embodiment of the present invention includes an electromagnetic contactor control unit including a control unit in which the control functions of a plurality of electromagnetic contactor contact units are assembled. In addition, the AC-to-DC converter that was previously provided for each of the plurality of magnetic contactors is separated from the magnetic contactor, and excitation power for a plurality of electromagnetic contactor contact units and operating power to the control unit are supplied. An AC → DC converter is provided in the electromagnetic contactor control unit. Power consumption can be reduced by unifying the AC to DC converter.

Moreover, the power consumption especially at the time of holding | maintenance can be reduced by detecting the contact state of an electromagnetic contactor contact unit with an auxiliary contact, and switching the electric power supplied to the exciting coil of an electromagnetic contactor contact unit. In addition, in the exciting coil, it is possible to promote downsizing and cost reduction by sharing the input coil and the holding coil without sharing them. Moreover, since it is not necessary to consider the insulation between both coils, reliability can be improved.
Furthermore, an input from a control signal input unit for switching the coil excitation power is supplied to the electromagnetic contactor control unit, and the control unit performs supply control of the excitation power, thereby eliminating, for example, a control relay. In addition, direct control from the PLC can be performed. As a result, it is possible to promote the reduction of the price and the reduction of power consumption.

  The embodiment described above is an example, and many modifications based on the gist of the present invention can be considered. Both are within the scope of the present invention.

  1: Magnetic contactor control unit, 2: AC power supply, 11: AC → DC conversion unit, 12-14: Supply voltage adjustment unit, 15: Control unit, 16: Memory unit, 17: RS-232C transmission unit, 18- 20: Relay, 101-103: Electromagnetic contactor contact unit, 201: PLC, 301: PC.

Claims (4)

An electromagnetic contactor having an electromagnetic contactor contact unit and an electromagnetic contactor control unit,
The electromagnetic contactor contact unit is:
An electromagnetic changeover switch having a main contact for turning on or off power;
Having an exciting coil for turning the changeover switch on;
The electromagnetic contactor control unit is
A plurality of supply voltage adjustment units for supplying excitation power for turning on the changeover switch to the excitation coil, and the excitation power to be supplied has a plurality of set values;
A voltage adjustment control unit for controlling excitation power supplied to the excitation coil by the plurality of supply voltage adjustment units; and a control signal input unit for receiving a command for turning on or off the changeover switch from an external device. A control unit;
An electromagnetic contactor comprising: an operating power supply generating unit that supplies operating power to the control unit and the plurality of supply voltage adjusting units. The electromagnetic contactor according to claim 1,
The changeover switch of the contactor contact unit has an auxiliary contact that operates in synchronization with the main contact, generates a closing completion signal indicating whether or not the auxiliary contact is in a closing state, and the electromagnetic contactor To the control unit of the control unit,
When the control signal input unit receives a command to turn on the changeover switch, the voltage adjustment control unit of the control unit of the electromagnetic contactor control unit supplies a first excitation power necessary for turning on the excitation coil. When the application completion signal is supplied, the supply voltage is supplied so as to supply the excitation coil with a second excitation power that is lower than the first excitation power necessary for maintaining the application state. An electromagnetic contactor that controls an adjustment unit. The electromagnetic contactor according to claim 1,
An electromagnetic contactor characterized in that a command for turning on or releasing the changeover switch is based on PLC. The electromagnetic contactor according to claim 1,
The electromagnetic contactor characterized in that the power source generated by the operating power source generator is a DC power source.

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