JP2007103243A - Electromagnetic actuator and switch gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic actuator capable of improving the efficiency at closing of circuit. <P>SOLUTION: The electromagnetic actuator is provided with a yoke 30 for forming a flux path, formed so as to protrude its middle part in the axial direction toward the inside; an armature 13, formed so as to move inside the yoke 30; a circuit closing coil 15 and a circuit opening coil 16 for generating magnetic flux, arranged at one side of the yoke 30 with the middle part of the yoke 30 as a boundary; a permanent magnet 14 for moving or holding the armature 13, arranged at the other side of the yoke 30 with the middle part of the yoke 30 as a boundary; and an operation rod 17, penetrating through the yoke 30 and fixed to the armature 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electromagnetic actuator used in an operation mechanism for opening and closing a vacuum valve and the like, and a switch such as a vacuum circuit breaker and a vacuum switch provided with the electromagnetic actuator.

  Conventional switch operating mechanisms such as vacuum circuit breakers and vacuum switches are known that use electromagnetic actuators that generate the required operating force to perform open and close operations (for example, patents). Reference 1).

  As shown in FIG. 7, this type of switch is configured to open / close the interrupting portion 1a that interrupts current from the upper part of the figure, the wipe spring part 1b that applies contact load when the interrupting part 1a is closed, and the interrupting part 1a at the lowermost part of the figure. An operating mechanism 1c is arranged and configured. In FIG. 7, the closed state is shown on the right side of the figure, and the open state is shown on the left side of the figure.

  A three-phase vacuum valve 5 having a pair of contact points 3 and 4 that can be brought into contact with and separated from each other in the vacuum insulating container 2 is provided in the blocking part 1a. The fixed side of the vacuum valve 5 for three phases is fixed to the upper fixing member 6, respectively. Further, an insulating operation rod 7 that is movable in the axial direction is connected to the movable side of the vacuum valve 5.

  The wipe spring portion 1 b is provided with a wipe spring folder 9 that houses a wipe spring 8 connected to the insulating operation rod 7. The wipe spring 8 applies a contact load when the pair of contacts 3 and 4 are in contact with each other. Further, the three-phase wipe spring folders 9 are respectively connected to the connecting member 10.

  The operation mechanism unit 1c is provided with an electromagnetic actuator 11 that generates an operation force during an opening / closing operation. The electromagnetic actuator 11 includes a yoke 12 for forming a magnetic path, a magnetic armature 13 provided to move in the yoke 12, a permanent magnet 14 for moving or holding the closed circuit of the armature 13, and an outer periphery of the permanent magnet 14 A non-magnetic operating rod 17 that is fixed to the armature 13, penetrates the yoke 12, and is connected to the connecting member 10, and the yoke 12. It is comprised from the stopper plate 18 of the nonmagnetic material which plugs up the opening part of the lower part of illustration.

  Here, a projecting annular projecting portion 12 a is provided at an intermediate portion of the inner surface of the yoke 12, and a closed coil 15 and an open coil 16 are disposed between the projecting portion 12 a and the permanent magnet 14. In addition, an end portion of the armature 13 facing the stopper plate 18 is provided with a flange portion 13a protruding in a hook shape, and the flange portion 13a moves between the protrusion portion 12a and the stopper plate 18. Such an electromagnetic actuator 11 is fixed to the lower fixing member 19. An opening spring 20 that biases the operating rod 17 to move in the opening direction is provided at the end of the operating rod 17 in the lower fixing member 19.

  In the closed state, the closed coil 15 is excited to generate a magnetic flux in the yoke 12. Then, as shown by the solid line in the figure, a magnetic circuit is formed that passes through the permanent magnet 14 → the yoke 12 → the protruding portion 12 a → the armature 13 so as to surround the closed coil 15 and the open coil 16. In addition, a similar magnetic circuit is formed by the permanent magnet 14 as indicated by a dotted line. The magnetic force in these magnetic circuits overcomes the spring force of the open spring 20 and the armature 13 moves in the closed direction above the figure. At the same time, the operating rod 17 moves upward in the figure, and the contacts 3 and 4 are in contact with each other. When the contacts 3 and 4 are in contact with each other, a contact load is applied by the wipe spring 8, the closed coil 15 is de-energized, and the closed state is maintained by the attractive force of the permanent magnet 14.

  In the case of the open circuit state, the open coil 16 is excited to overcome the magnetic force of the permanent magnet 14 and move the armature 13 downward in the figure to separate the contacts 3 and 4 from each other. After the open circuit, the open coil 16 is de-energized and the open circuit state is maintained by the spring force of the open spring 20.

  Here, in the closed state, the magnetic flux in the yoke 12 is formed by the closed coil 15 and the permanent magnet 14 in the same direction. For this reason, when the closed coil 15 is excited, magnetic saturation occurs in the yoke 12, and it becomes difficult to move the armature 13 with sufficient magnetic force. That is, there is a problem that the magnetic flux generated by the closed coil 15 is not easily transmitted into the armature 13 and the efficiency of the electromagnetic actuator 11 is lowered.

On the other hand, there is known an electromagnetic actuator in which a permanent magnet is disposed at an intermediate portion in a yoke and a closed coil and an open coil are disposed on both sides of the permanent magnet. Even in such an electromagnetic actuator, since the magnetic fluxes of the permanent magnet and the closed coil are formed in the same direction, magnetic saturation is likely to occur in the yoke when the closed coil is excited, and the efficiency of the electromagnetic actuator is reduced. (For example, refer to Patent Document 2).
JP 2002-270423 A (4th page, FIG. 1) JP 2004-146336 A (Page 6, FIG. 1)

  In the conventional electromagnetic actuator 11 described above, there is a problem that magnetic saturation occurs in the yoke 12 when the circuit is closed, making it difficult to move the armature 13 with a sufficient magnetic force, and the efficiency at the time of closing is lowered.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an electromagnetic actuator capable of improving the efficiency at the time of closing and a switch equipped with the electromagnetic actuator.

  In order to achieve the above object, an electromagnetic actuator of the present invention includes a yoke for forming a magnetic path with an axial intermediate portion protruding inward, an armature provided to move in the yoke, A closed coil and an open coil that generate a magnetic flux arranged on one side of the yoke at the middle part, and a permanent magnet that moves or holds the armature arranged on the other side of the middle part of the yoke; And an operating rod which penetrates the yoke and is fixed to the armature.

  According to the present invention, when a closed coil is arranged on one side and a permanent magnet is arranged on the other side to excite the closed coil with the axial intermediate portion of the yoke forming the magnetic path as a boundary, the closed coil having a small magnetic resistance is surrounded. The magnetic circuit and the magnetic circuit passing through the permanent magnet are formed so that a sufficient magnetic force can be generated in each magnetic circuit, and the efficiency when the electromagnetic actuator is closed can be improved. it can.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, an electromagnetic actuator according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view illustrating a configuration of an electromagnetic actuator according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating a magnetic circuit formed by a closed coil when the electromagnetic actuator according to the first embodiment of the present invention is closed. FIG. 3 is a diagram for explaining a magnetic circuit formed by permanent magnets when the electromagnetic actuator according to the first embodiment of the present invention is closed, and FIG. 4 is formed by permanent magnets during armature movement according to the first embodiment of the present invention. FIG. 5 is a diagram for explaining details of the magnetic circuit, and FIG. 5 is a diagram for explaining the magnetic force when the electromagnetic actuator is closed according to the first embodiment of the present invention. In addition, in each figure, the same code | symbol was attached | subjected about the component similar to the past. Moreover, since the structure of the switch using an electromagnetic actuator is the same as that of the past, the detailed description is abbreviate | omitted.

  As shown in FIG. 1, a yoke 30 for forming a magnetic path in the electromagnetic actuator 11 includes a first yoke 30a on the blocking section 1a side in the upper part of the figure, a second yoke 30b in the middle part, and a lower part in the figure. A third yoke 30c on the stopper plate 18 side (anti-blocking portion side) is configured to be connected in the axial direction. A closed coil 15 and an open coil 16 are disposed inside the first yoke 30a. In addition, a permanent magnet 14 and a fourth yoke 30d connected to the third yoke 30c are disposed inside the third yoke 30c. Note that all of the fourth yoke 30d portion may be the permanent magnet 14.

  The second yoke 30 b protrudes inward from the first yoke 30 a and the third yoke 30 c, and the protruded surface faces the side surface of the armature 13 provided so as to move in the yoke 30. Thereby, with the second yoke 30b as a boundary, the closed coil 15 and the open coil 16 are arranged on one side in the axial direction, and the permanent magnet 14 is arranged on the other side.

  A non-magnetic operating rod 17 fixed to the armature 13 is provided through the yoke 30. An end portion of the armature 13 facing the stopper plate 18 is provided with a flange portion 13a protruding in a hook shape, and the flange portion 13a can move between the fourth yoke 30d and the stopper plate 18.

  Here, when the sectional area of the first yoke 30a perpendicular to the axial direction of the operating rod 17 is s1, and the sectional area of the second yoke 30b parallel to the axial direction of the operating rod 17 is s2, s2> s1. Yes. The cross-sectional area of the third yoke 30c may be the same as that of the first yoke 30a. When the gap length between the second yoke 30b and the armature 13 is g3, and the gap length between the permanent magnet 14 and the armature 13 is g4, g3 <g4.

  Further, assuming that the gap length between the flange 13a and the third yoke 30c is g5, g3 <g5. Further, assuming that the gap length at the time of opening between the fourth yoke 30d and the flange portion 13a is g2, g3 <g2. This gap length g2 is the same as the gap length g1 when the armature 13 and the first yoke 30a are opened (g1 = g2). Furthermore, if the gap length between the permanent magnet 14 and the third yoke 30c is g6, then g4 <g6.

  Next, a magnetic circuit formed in the closed state will be described with reference to FIGS.

  When the closing coil 15 is excited, three magnetic circuits are formed so as to surround the closing coil 15 and the opening coil 16 as indicated by a solid line in FIG. The first magnetic circuit m1 passing through the first yoke 30a → the second yoke 30b → the armature 13 and the first yoke 30a → the second yoke 30b → the permanent magnet 14 → the fourth yoke 30d → the flange 13a → A second magnetic circuit m2 passing through the armature 13 and a first magnetic circuit m3 passing through the first yoke 30a → the second yoke 30b → the third yoke 30c → the flange 13a → the armature 13 are formed.

  Also on the permanent magnet 14 side, three magnetic circuits are formed as shown by dotted lines in FIG. The permanent magnet 14 → the fourth yoke 30d → the flange 13a → the armature 13 → the fourth magnetic open circuit m4 passing through the second yoke 30b, and the permanent magnet 14 → the fourth yoke 30d → the flange 13a → the armature 13 → the first A fifth magnetic circuit passing through one yoke 30a → the second yoke 30b, and a sixth magnet passing through the permanent magnet 14 → the fourth yoke 30d → the flange 13a → the third yoke 30c → the second yoke 30b. A circuit m6 is formed.

  In such magnetic circuits m1, m2, m3, m4, m5, and m6, a strong magnetic force is generated by the magnetic circuit m1 on the closed coil 15 side, and the armature 13 can be moved upward in the drawing. This is because the magnetic circuit m2 has a larger magnetic resistance due to the addition of the gap length g2, and the magnetic circuit m3 has the magnetic circuit m6 formed by the permanent magnet 14 and the direction of the magnetic flux in the third yoke 30c. This is because the direction is opposite and a strong magnetic force cannot be generated.

  On the permanent magnet 14 side, a strong magnetic force is generated by the magnetic circuit m4, and the armature 13 can be moved upward in the drawing similarly to the magnetic circuit m1. In the magnetic circuit m5, the gap length g1 is added to increase the magnetic resistance. In the magnetic circuit m6, the gap length g3 <g5 is set, so that the magnetic resistance increases and a strong magnetic force cannot be generated. Because.

  Here, the magnetic flux of the first magnetic circuit m1 and the fourth magnetic circuit m4 passes through the second yoke 30b, but the cross-sectional area of the second yoke 30b is larger than the cross-sectional area s1 of the first yoke 30a. Since s2 is increased, it is difficult to achieve magnetic saturation in the second yoke 30b. When the cross-sectional area s1 = 1, the cross-sectional area s2 = 1.2 to 1.5. If s2 = 1.2 or less, there is a possibility of magnetic saturation when the maximum magnetic force of the permanent magnet 14 is used. If s2 = 1.5 or more, magnetic saturation can be prevented, but the second yoke 30b. Is unfavorable due to the increase in size. Accordingly, the first magnetic circuit m1 and the fourth magnetic circuit m4 having a small magnetic resistance are formed at the time of closing, so that the magnetic force generated by the closing coil 15 and the permanent magnet 14 can be sufficiently generated. it can.

  Next, details of the magnetic circuit formed by the permanent magnet 14 when the armature 13 is moved will be described with reference to FIG. The state immediately before the movement is shown on the left side of FIG. 4, and the state at the time of movement is shown on the right side of the figure.

  Immediately before the movement, the magnetic circuit m4 is formed as described above, and further, the seventh magnetic circuit m7 passing through the permanent magnet 14 → the fourth yoke 30d → the armature 13 → the second yoke 30b, and the permanent magnet 14 → fourth. The eighth magnetic circuit m8 passing through the yoke 30d → the third yoke 30c → the second yoke 30b is formed.

  However, in the magnetic circuit m4, the gap length g2 is added to increase the magnetic resistance, so that the magnetic force generated by the magnetic circuits m7 and m8 increases immediately before the movement. For this reason, the magnetic force acting on the armature 13 is such that the horizontal force fh orthogonal to the axial direction is larger than the vertical force fv parallel to the axial direction. Since the gap length g4 <g6 is satisfied, the horizontal force fh by the magnetic circuit m7 is larger than that of the magnetic circuit m8.

  When the armature 13 moves, the gap length g2 is shortened, the magnetic resistance of the magnetic circuit m4 is lowered, and the vertical force fv is larger than the horizontal force fh. The perpendicular force fv increases as the gap length g2 decreases.

  The magnetic force generated by these magnetic circuits m4, m7, and m8 increases as the distance from the open circuit position approaches the closed circuit position, as shown by the load characteristics in FIG. On the other hand, as a required characteristic of the switch, as shown by a dotted line, it gradually rises from the open circuit position to the time of contact of the contacts 3 and 4 and immediately rises immediately after the contact to apply a contact load, and then gently A magnetic force that rises and compresses the wipe spring 8 is required. In contrast to such required characteristics, the load characteristics by the magnetic circuits m4, m7, and m8 satisfy the conditions from the open position to the closed position.

  Therefore, the magnetic force for moving the armature 13 is sufficiently generated in the first magnetic circuit m1 having a small magnetic resistance surrounding the closed coil 15 and the fourth magnetic circuit m4 having a small magnetic resistance passing through the permanent magnet 14. The efficiency of the electromagnetic actuator 11 can be improved. And the switch using this electromagnetic actuator 11 can perform reliable making operation.

  According to the electromagnetic actuator 11 of the first embodiment, when the closed coil is disposed in the first yoke 30a, the permanent magnet 14 is disposed in the third yoke 30c, and the closed coil 15 is excited, Since the first magnetic circuit m1 surrounding the small closed coil 15 and the fourth magnetic circuit m4 passing through the permanent magnet 14 are formed, it is difficult for each of the magnetic circuits m1 and m4 to be magnetically saturated. Sufficient magnetic force can be generated, and the efficiency at the time of closing can be improved.

  Next, an electromagnetic actuator according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view illustrating the configuration of the electromagnetic actuator according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in that a fifth yoke is provided in the opening of the third yoke. In FIG. 6, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, a fifth yoke 30e is provided in the opening of the third yoke 30c, and the armature 13 is surrounded by the first, second, third, and fifth yokes 30a, 30b, 30c, and 30e. Yes. For this reason, the magnetic circuit by the permanent magnet 14 is a permanent magnetic circuit m9 passing through the permanent magnet 14, the fourth yoke 30d, the flange 13a, the fifth yoke 30e, the third yoke 30c, and the second yoke 30b. A magnetic circuit m10 passing through the magnet 14, the fourth yoke 30d, the flange 13a, the fifth yoke 30e, the armature 13, and the second yoke 30b is formed.

  Thereby, the magnetic flux by the permanent magnet 14 is formed in the fifth yoke 30e, and works in the opposite direction to that for moving the armature 13 in the closing direction. For this reason, the movement start of the armature 13 is suppressed. As a result, the armature 13 starts moving after the magnetic flux generated by the closed coil 15 is sufficiently formed, so that the armature 13 can be moved with a strong magnetic force, and the efficiency during closing can be improved.

  According to the electromagnetic actuator 11 of the second embodiment, the efficiency during closing can be further improved.

Sectional drawing which shows the structure of the electromagnetic actuator which concerns on Example 1 of this invention. The figure explaining the magnetic circuit formed with a closed coil at the time of electromagnetic actuator closing concerning Example 1 of the present invention. The figure explaining the magnetic circuit formed with a permanent magnet at the time of the electromagnetic actuator circuit closing based on Example 1 of this invention. The figure explaining the detail of the magnetic circuit formed with a permanent magnet at the time of the armature movement which concerns on Example 1 of this invention. The figure explaining the magnetic force at the time of the electromagnetic actuator circuit closing based on Example 1 of this invention. Sectional drawing which shows the structure of the electromagnetic actuator which concerns on Example 2 of this invention. Sectional drawing which shows the structure of a switch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Blocking part 1b Wipe spring part 1c Operation mechanism part 2 Vacuum insulation container 3, 4 Contact 5 Vacuum valve 6 Upper fixing member 7 Insulation operation rod 8 Wipe spring 9 Wipe spring folder 10 Connecting member 11 Electromagnetic actuator 12, 30 York 12a Protrusion part 13 Armature 13a collar 14 permanent magnet 15 closing coil 16 opening coil 17 operating rod 18 stopper plate 19 lower fixing member 20 opening spring 30a first yoke 30b second yoke 30c third yoke 30d fourth yoke 30e fifth yoke

Claims (5)

A yoke for forming a magnetic path in which an intermediate portion in the axial direction protrudes inward;
An armature provided to move in the yoke;
A closed coil and an open coil for generating a magnetic flux arranged on one side of the middle of the yoke;
A permanent magnet that moves or holds the armature disposed on the other side of the middle of the yoke;
An electromagnetic actuator comprising: an operating rod penetrating the yoke and fixed to the armature.   2. The electromagnetic actuator according to claim 1, wherein the yoke has a cross-sectional area in which an intermediate portion of the yoke is parallel to the axial direction of the operating rod, larger than a cross-sectional area orthogonal to the axial direction of the operating rod. .   The electromagnetic actuator according to claim 1, wherein a gap length between the permanent magnet and the armature is shorter than a gap length between the permanent magnet and the yoke.   The electromagnetic actuator according to any one of claims 1 to 3, wherein the yoke is formed so as to surround the armature. A blocking portion having a pair of contactable contacts;
A wipe spring for applying a contact load when the contact is closed;
An operation mechanism unit comprising an electromagnetic actuator coupled to the blocking unit;
The electromagnetic actuator includes a yoke for forming a magnetic path in which an axial intermediate portion projects inward,
An armature provided to move in the yoke;
A closed coil that is disposed on one side of the yoke as a boundary, generates a magnetic flux in the yoke, and moves the armature in the closed direction; and an open coil that moves the armature in the open direction;
A permanent magnet that is arranged on the other side of the middle part of the yoke and keeps the armature moved or closed;
A switch comprising an operation rod fixed to the armature and connected to the blocking portion.

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