JP2013187053A - Opening and closing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an opening and closing device by which a circuit breaker can be miniaturized by reducing a component constant.SOLUTION: The opening and closing device comprises: an alternating-current power source 11; a latching relay 3 having a relay drive coil 31 and a relay contact point 32, applying opening signals to the relay drive coil to open the relay contact point, and applying closing signals to the relay drive coil to close the relay contact point; an alternating-current half-wave drive circuit 11 connected to both ends of a serial circuit connected to the alternating-current power source and the relay drive coil, and driving the relay drive coil by alternating-current half-wave signals based on alternating-current signals of the alternating-current power source to open the relay contact point; and a magnetic field application section 9 for applying an electromagnetic force in one direction to arc generated on the relay contact points by applying a magnetic field to the relay contact point so as to move the arc.

Description

  The present invention relates to a switchgear suitable for a switch used in a watt-hour meter.

  A switch mounted on a smart meter (electronic watt hour meter) must open and close a current of several tens to several hundreds of times. When a large current is opened and closed many times, a larger driving force and contact diameter are required to prevent the contacts of the switch from being damaged and welded. For this reason, a switch will enlarge.

  Therefore, a method is known in which magnetic flux is applied between the contacts of the switchgear and the arc is stretched by Lorentz force (electromagnetic force) to improve the current interrupting performance and downsize the switch. For example, in the switchgear described in Patent Document 1 shown in FIG. 10, a permanent magnet 77 is disposed in the vicinity of the fixed contact terminal 76 of the switchgear so that the magnetic pole surface is perpendicular to the axis of the movable contact. And downsizing.

  Further, in the electromagnetic relay described in Patent Document 2 shown in FIG. 11, magnetic flux is applied to the arc-extinguishing coil 42 disposed in the vicinity of the contact using the back electromotive force generated when the drive coil 92 is de-energized. It is generated and the arc is stretched to improve the breaking performance.

JP 2004-71512 A JP 2009-9950 A

  However, when interrupting the alternating current, the direction of the electromagnetic force depends on the direction of the current and becomes two directions, and the arc is stretched in two directions by the electromagnetic force. For this reason, it is necessary to take measures to prevent damage caused by the arc in the two directions in which the arc is stretched.

  In order to prevent arc damage, measures such as increasing the distance between the switch container and the container's internal members and contacts, increasing the container's thickness, or setting a member that can withstand arc contact, etc. Has been taken. For this reason, the number of parts increases and the switch becomes large.

  The subject of this invention provides the switchgear which can reduce a switch by reducing a component constant.

  In order to solve the above problems, the switchgear according to the present invention has an AC power source, a relay drive coil and a relay contact, applies an open signal to the relay drive coil to open the relay contact, A latching relay that applies a closing signal to the relay driving coil to close the relay contact, and is connected to both ends of a series circuit in which the AC power source and the relay driving coil are connected. An AC half-wave drive circuit for opening the relay contact by driving the relay drive coil with an AC half-wave signal based thereon, and an arc generated at the relay contact by applying a magnetic field to the relay contact in one direction. And a magnetic field applying unit that moves the arc by applying an electromagnetic force.

  According to the present invention, the AC half-wave drive circuit opens the relay contact by driving the relay drive coil with the AC half-wave signal, so that the direction of the current when the relay contact is cut off is one direction. That is, the countermeasure for damage to the relay contact due to the arc can be completed in one direction. Therefore, it is possible to provide a switchgear that can reduce the size of the switch by reducing the component constant.

It is a circuit diagram which shows the switchgear which concerns on Example 1 of this invention. It is a figure which shows the direction of the electric current of the switchgear which concerns on Example 1 of this invention, magnetic flux, and Lorentz force. It is a structural diagram which shows the switchgear which concerns on Example 2 of this invention. It is a circuit diagram which shows the switchgear which concerns on Example 2 of this invention. It is a structural diagram which shows the switchgear which concerns on Example 3 of this invention. It is structural drawing which shows the switchgear which concerns on Example 4 of this invention. It is a structural diagram which shows the switchgear which concerns on Example 5 of this invention. It is structural drawing which shows the switchgear which concerns on Example 6 of this invention. It is structural drawing which shows the switchgear which concerns on Example 7 of this invention. It is a figure which shows an example of the conventional switchgear. It is a figure which shows another example of the conventional switchgear.

  Hereinafter, an opening and closing device according to an embodiment of the present invention will be described in detail with reference to the drawings.

  The present invention is configured to supply power for driving a latching relay from an AC power source, and to open the relay contact by one polarity of the AC signal of the AC power source, and to set the direction of the current when the relay contact current is interrupted. It was made to become one direction. In addition, by applying a magnetic field between the relay contacts by a permanent magnet or a permanent magnet and an iron core (yoke), and applying a specific one-way electromagnetic force to the arc, it is applied to the arc between the relay contacts when the current is interrupted. The electromagnetic force is unidirectional, and the countermeasure against damage due to arc is unidirectional.

  1 is a circuit diagram illustrating a switchgear according to a first embodiment of the present invention. The switchgear shown in FIG. 1 includes diodes 1a and 1b, switches 2a and 2b, a latching relay 3, a load 4 including a resistor, and an AC power supply 5.

  A diode 1a, a switch 2a, and a relay drive coil 31 are connected in series at both ends of the AC power supply 5. A diode 1b, a switch 2b, and a relay drive coil 31 are connected in series at both ends of the AC power supply 5. One end of the AC power supply 5 is connected to the anode of the diode 1a and the cathode of the diode 1b. A relay contact 32 and a load 4 are connected in series at both ends of the AC power supply 5.

  The series circuit of the diode 1a and the switch 2a and the series circuit of the diode 1b and the switch 2b are connected in parallel to constitute the AC half-wave drive circuit 11. The AC half-wave drive circuit 11 generates an AC half-wave signal based on the AC signal from the AC power supply 5 and drives the latching relay 3 with the generated AC half-wave signal to open the relay contact 32.

  The latching relay 3 has a relay drive coil 31 and a relay contact 32, applies an open signal to the relay drive coil 31, opens the relay contact 32, and applies a close signal to the relay drive coil 31 to open the relay contact. 32 is a relay that is energized only when the open / close state changes, and the open / close state is determined by the direction in which the relay drive coil 31 is energized.

  According to the switchgear according to the first embodiment configured as described above, the switch 2a is turned on by the open signal, and the current flows through the path of the AC power source 5 → the diode 1a → the switch 2a → the relay drive coil 31 → the AC power source 5. Then, the AC power supply 5 is applied to the relay drive coil 31, and the relay contact 32 is opened.

  On the other hand, the switch 2b is turned on by the closing signal, current flows through the path of the AC power source 5 → the relay drive coil 31 → the switch 2b → the diode 1b → the AC power source 5, and the AC power source 5 is applied to the relay drive coil 31. The relay contact 32 is closed. By alternately applying the open signal and the close signal, the relay contact 32 is repeatedly opened and closed.

  In this case, when only the open signal or the closed signal is viewed over a plurality of periods, the signal applied to the relay drive coil 31 is an AC half-wave signal. When the relay contact 31 is opened by applying the generated AC half-wave signal to the relay drive coil 31 to drive the relay drive coil 31, the current at the time of relay contact cutoff is the same as the DC cutoff in the AC cutoff. The direction is one direction.

  That is, countermeasures against damage to the relay contact 31 due to arc can be completed in one direction. Therefore, it is possible to provide a switchgear that can reduce the size of the switch by reducing the component constant.

  FIG. 2 shows directions of current, magnetic flux, and Lorentz force of the switchgear according to the first embodiment of the present invention. As shown in FIG. 2A, when the magnetic flux B by the permanent magnet 9 is applied to the arc 10 (current I) generated at the relay contact 32, the Lorentz force F is applied to the arc as shown in FIG. 10, the arc 10 is stretched only in one direction of the Lorentz force F. Further, by providing the insulator 6 in the moving direction of the arc 10, it is possible to take measures against damage to the switchgear due to the arc 10.

  FIG. 3 is a structural diagram illustrating the switchgear according to the second embodiment of the present invention. The switchgear according to the second embodiment shown in FIG. 3 is characterized in that an arc extinguishing coil 8 is arranged in place of the permanent magnet 9 of the first embodiment.

  In the switchgear according to the second embodiment shown in FIG. 3, two latching relays 3a and 3b having relay drive coils 31a and 31b and relay contacts 32a and 32b are provided. An arc extinguishing coil 8 is provided between the two latching relays 3a and 3b and between the relay contact 32a and the relay contact 32b.

  A U-shaped first yoke 12 made of a magnetic material is provided outside the two latching relays 3a and 3b and covers the two latching relays 3a and 3b. A magnetic field generated by the current flowing in the arc extinguishing coil 8 passes through the relay contacts 32a and 32b and the first yoke 12, and constitutes a closed magnetic circuit.

  The AC half-wave drive circuit 11a applies an AC half-wave signal to the relay drive coils 31a and 31b and the arc extinguishing coil 8. FIG. 4 is a circuit diagram showing a switchgear according to Embodiment 2 of the present invention. As shown in FIG. 4, the arc extinguishing coil 8 is connected in parallel with the relay drive coils 31a and 31b.

  As described above, according to the switchgear according to the second embodiment, each of the relay drive coils 3a and 3b is opened / closed by the AC half-wave signal from the AC half-wave drive circuit 11a, and the direction of the current when the current is interrupted is one direction. It is. Therefore, the same effect as that of the switchgear according to the first embodiment can be obtained.

  Further, when the arc extinguishing coil 8 is energized with an AC half-wave signal only at the time of opening, the magnetic field is applied to the arc extinguishing coil 8 → the relay contact 32a → the first yoke 12 → the relay contact 32b → the arc extinguishing. A closed magnetic path is formed by the path of the coil 8 for use. For this reason, the arc is stretched only in one direction of the Lorentz force.

  Therefore, by using the AC half-wave drive circuit 11a as a power source, it is not necessary to use an extra switch or power source, and therefore the configuration of the switchgear can be simplified.

  FIG. 5 is a structural diagram illustrating the switchgear according to the third embodiment of the present invention. In the third embodiment shown in FIG. 5, the relay contact 32 shown in FIG. 1 includes an energized contact material (first contact material) 13 and an arc-proof contact (second arc) arranged in the arc movement direction with respect to the energized contact 13. A contact material 14). That is, different contact materials are used for the arc movement direction.

  The energizing contact 13 is made of a material suitable for energization, and is, for example, a silver alloy. A material suitable for energization is a contact having high electrical conductivity and hardly causing deterioration due to environmental influences.

  The arc resistant contact 14 is made of a material excellent in arc resistance, and is, for example, tungsten. A material excellent in arc resistance is a contact with little evaporation and melting of the contact material even when exposed to an arc.

  As described above, according to the switchgear according to the third embodiment, the arc generated at the energizing contact 13 can be moved to the arc-proof contact 14 by the Lorentz force. Further, by using the energization material 13 suitable for energization and the arc-proof contact 14 having excellent arc resistance, the switchgear can be downsized.

  FIG. 6 is a structural diagram illustrating the switchgear according to the fourth embodiment of the present invention. The fourth embodiment shown in FIG. 6 is characterized in that a permanent magnet 9 is arranged between the relay drive coils 3a and 3b instead of the arc extinguishing coil 8 of the switchgear according to the second embodiment shown in FIG. .

  By disposing the permanent magnet 9, magnetic flux can be applied to the two relay contacts 32 a and 32 b by one permanent magnet 9. Thereby, the number of permanent magnets 9 can be reduced, and the size of the switchgear can be reduced.

  Further, by arranging the first yoke 12 covering the two relay contacts 32a and 32b, the magnetic flux applied to the two relay contacts 32a and 32b can be increased, and the leakage magnetic flux to the surroundings can be reduced.

  In the switchgear according to the fourth embodiment shown in FIG. 6, the permanent magnet 9 is disposed between the latching relay 3a and the latching relay 3b, but the permanent magnet 9 can be positioned at any position on the magnetic path passing through the relay contacts 32a and 32b. Even if it arrange | positions, the effect similar to the switchgear which concerns on Example 4 shown in FIG. 6 is acquired.

  FIG. 7 is a structural diagram illustrating the switchgear according to the fifth embodiment of the present invention. The switchgear according to Embodiment 5 shown in FIG. 7 is characterized in that the permanent magnet 9 is disposed in a part of the second yoke 12a covering the latching relay 3a and the latching relay 3b. A third yoke 12b made of a magnetic material is disposed between the latching relay 3a and the latching relay 3b.

  Thus, according to the switchgear according to the fifth embodiment, since the permanent magnet 9 and the third yoke 12b are arranged on the magnetic path of the second yoke 12a, a stronger magnetic flux passes through the relay contacts 32a and 32b. Therefore, the shutoff performance of the switchgear can be improved.

  FIG. 8 is a structural diagram illustrating a switchgear according to Embodiment 6 of the present invention. The switchgear according to Example 6 shown in FIG. 8 is provided with three latching relays 3a to 3c, a permanent magnet 9a is disposed between the relay contact 32a and the relay contact 32b, and the relay contact 32b and the relay contact 32c. A permanent magnet 9b is disposed between the first yokes 12 so as to cover the three relay contacts 32a to 32c, thereby forming a closed magnetic circuit.

  In the switchgear according to the sixth embodiment, the same effect as the switchgear according to the fifth embodiment can be obtained. Further, when four or more latching relays 3a to 3c are provided, the same effect as that of the switchgear according to the fifth embodiment can be obtained.

  FIG. 9 is a structural diagram illustrating a switchgear according to Embodiment 7 of the present invention. The switchgear according to Example 7 shown in FIG. 9 forms recesses 7a and 7b in the lateral direction of the relay contacts 32a and 32b in the containers for storing the relay contacts 32a and 32b, that is, the latching relay containers 30a and 30b. One end of the permanent magnet 9 is fitted into the recess 7a of the relay contacts 32a, 32b, and one end of the first yoke 12 is fitted into the recess 7b of the relay contacts 32a, 32b.

  Thus, according to the switchgear according to the seventh embodiment, one end of the permanent magnet 9 is fitted into the recess 7a of the relay contacts 32a and 32b, and one end of the first yoke 12 is fitted into the recess 7b of the relay contacts 32a and 32b. Thus, since the permanent magnet 9 and the first yoke 12 can be disposed closer to the relay contacts 32a and 32b, a stronger magnetic flux can be applied to the relay contacts 32a and 32b, and the interruption performance is further improved. be able to.

1a, 1b Diode 2a, 2b Switch 3, 3a, 3b Latching relay 4 Load 5 AC power supply 6 Insulator 7, 7a, 7b Recess 8 Arc arc extinguishing coil 9, 9a, 9b Permanent magnet
10, 33 Arc 11, 11a, 11b AC half wave drive circuit 12 1st yoke 12a 2nd yoke 12b 3rd yoke 13 Current contact 14 Arc resistant contact 16 Drive device 30a, 30b Latching relay container 31, 31a, 31b Relay drive coil 32, 32a, 32b Relay contact

Claims (6)

AC power supply,
A latching relay having a relay drive coil and a relay contact, applying an open signal to the relay drive coil to open the relay contact, and applying a close signal to the relay drive coil to close the relay contact When,
The relay contact is opened by driving the relay drive coil with an AC half-wave signal based on an AC signal of the AC power supply, connected to both ends of a series circuit in which the AC power supply and the relay drive coil are connected. AC half-wave drive circuit,
A magnetic field application unit that applies an electromagnetic force in one direction to the arc generated at the relay contact by applying a magnetic field to the relay contact, and moves the arc;
An opening / closing device comprising:   The switchgear according to claim 1, wherein the magnetic field application unit is made of a permanent magnet or an electromagnet.   The switchgear according to claim 1 or 2, wherein an insulator is provided in the arc moving direction by the magnetic field application unit.   The said relay contact consists of the 1st contact material suitable for electricity supply, and the 2nd contact material provided adjacent to this 1st material and excellent in arc resistance, The 1 thru | or Claim characterized by the above-mentioned. 4. The switchgear according to any one of items 3.   2. The closed magnetic circuit according to claim 1, wherein a plurality of the latching relays are arranged adjacent to each other, and a permanent magnet and a yoke made of a magnetic material are arranged on a magnetic path passing through the plurality of relay contacts. Item 5. The switchgear according to any one of items 4.   6. The switchgear according to claim 5, wherein a concave portion into which one end of the permanent magnet and one end of the yoke are fitted is provided at a position facing the relay contact in a container accommodating the latching relay.

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