Electromagnetic operating mechanism

Abstract

To provide an electromagnetic operation mechanism to which a technique for suppressing a magnetic flux from a permanent magnet to a yoke without going through an armature and increasing a magnetic flux from the permanent magnet to the yoke through the armature is applied.SOLUTION: An electromagnetic operation mechanism 3 separates an armature 15 from a yoke 14, thereby separating a pair of electrodes 5a, 5b. The electromagnetic operation mechanism 3 includes a magnet that generates a magnetic flux forming a first magnetic path 17a leading to the yoke via the armature and a magnetic flux forming a second magnetic path 17b leading to the yoke without going through the armature and a flux suppression mechanism 19 that suppresses the magnetic flux from the magnet to the yoke without going through the armature.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of this invention relate to electromagnetic operating mechanisms.

Background Art

[0002] As a switching device for power reception and distribution provided in buildings and large facilities, for example, a switchgear including a switch such as a circuit breaker or a disconnector is known. In the switchgear, a vacuum valve is applied as a component of the switch, and by interrupting an accidental current and opening and closing a load current with the vacuum valve, power is stably supplied.

[0003] The vacuum valve has a pair of separable electrodes, and these electrodes are separated and connected (opened and closed) by an electromagnetic operating mechanism. The electromagnetic operating mechanism is configured to include, for example, an open coil, a closed coil, a permanent magnet, an armature, etc. inside a yoke. The yoke and the armature are made of a material (for example, iron, electromagnetic steel sheet) having a higher magnetic permeability than air. According to this configuration, an electric current is passed through the coil to generate a magnetic flux, and the pair of electrodes are separated and connected (opened and closed) by the magnetic force obtained at that time.

[0004] For example, when closing the opened electrodes, an electric current is passed through the closed coil to generate a magnetic flux in the same direction as the permanent magnet, and the armature is displaced in a direction to bring the electrodes into contact with each other. Then, when the armature and the yoke come into contact with each other, the energization of the closed coil is stopped. At this time, the magnetic flux of the permanent magnet forms a closed loop through the armature and the yoke. As a result, a magnetic force in a direction to attract the armature to the yoke is generated between the armature and the yoke. As a result, the armature and the yoke are maintained in a state of being in close contact with each other. Thus, the pair of electrodes are held in a closed state in which they are in contact with each other.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] Incidentally, when closing the open electrode, the magnetic flux generated from the permanent magnet forms two distinct loop-shaped magnetic paths (for example, a first magnetic path and a second magnetic path) inside the yoke until the armature contacts the yoke. The magnetic flux forming the first magnetic path travels from the permanent magnet through the armature to the yoke. The magnetic flux forming the second magnetic path travels from the permanent magnet to the yoke without passing through the armature.

[0007] In this case, the magnetic flux forming the second magnetic path does not contribute to the generation of a magnetic force that attracts the armature to the yoke. Therefore, it is necessary to increase the magnetic flux (i.e., magnetomotive force) of the closing coil by the amount of the magnetic flux of the second magnetic path. Thus, a technique is needed to reduce the magnetic flux due to the closing coil by suppressing the magnetic flux of the second magnetic path and increasing the magnetic flux of the first magnetic path, but currently no such technique is known.

[0008] The object of the present invention is to provide an electromagnetic operating mechanism to which a technique is applied that suppresses the magnetic flux from the permanent magnet to the yoke without passing through the armature, and increases the magnetic flux from the permanent magnet to the yoke via the armature. [Means for solving the problem]

[0009] According to the embodiment, an electromagnetic operating mechanism moves a pair of electrodes apart by moving an armature apart from a yoke, comprising a magnet that generates a magnetic flux forming a first magnetic path to the yoke via the armature and a magnetic flux forming a second magnetic path to the yoke without passing through the armature, and a magnetic flux suppression mechanism that suppresses the magnetic flux from the magnet to the yoke without passing through the armature, wherein the yoke is composed of an inner yoke and an outer yoke arranged to cover the outside of the inner yoke, and the outer yoke is provided with a support portion that protrudes toward the inner yoke, and the magnetic flux suppression mechanism is housed in a space enclosed by the support portion, the outer yoke and the inner yoke, and the magnetic flux suppression mechanism is larger than the inner yoke and arranged adjacent to the support portion when viewed in the direction of moving the armature apart from the yoke. doing . [Brief explanation of the drawing]

[0010] [Figure 1] A cross-sectional view showing the internal configuration of an electromagnetic operating mechanism according to one embodiment. [Figure 2] Figure 1 is a cross-sectional view showing the closed circuit state of the electromagnetic operating mechanism. [Figure 3] A cross-sectional view showing the internal configuration of the electromagnetic operating mechanism according to the first modified example. [Figure 4] A cross-sectional view showing the internal configuration of the electromagnetic operating mechanism according to the second modified example. [Figure 5] A cross-sectional view showing the internal configuration of the electromagnetic operating mechanism according to the third modified example. [Modes for carrying out the invention]

[0011] "One embodiment" Figures 1 and 2 show an electromagnetic operating mechanism 3 that operates a vacuum valve 2 on a switchgear switch 1 (e.g., a circuit breaker or disconnector), with Figure 1 being the open state diagram and Figure 2 being the closed state diagram. In the example shown in Figures 1 and 2, the switch 1 includes a vacuum valve 2, a coupling mechanism 4, and an electromagnetic operating mechanism 3. The vacuum valve 2 and the electromagnetic operating mechanism 3 are interconnected by the coupling mechanism 4.

[0012] As shown in Figures 1 and 2, the vacuum valve 2 has a pair of electrodes that can be moved apart (a fixed electrode 5a and a movable electrode 5b) and an insulating container 6 that houses these electrodes 5a and 5b. The pair of electrodes 5a and 5b are made of a conductive material such as copper, aluminum, or chromium. The insulating container 6 is made of an insulating material (for example, ceramic) and is cylindrical in shape.

[0013] The fixed electrode 5a is connected to a fixed current-carrying shaft 7a fixed to the switch 1. The movable electrode 5b is connected to the movable current-carrying shaft 7b so as to face the fixed electrode 5a. The fixed current-carrying shaft 7a and the movable current-carrying shaft 7b are made of a conductive material such as copper, aluminum, or chromium. The movable current-carrying shaft 7b is connected to a coupling mechanism 4 (a support shaft 11, which will be described later).

[0014] The coupling mechanism 4 includes a folder 8, a wipe spring 9, a support 10, a support shaft 11, an opening spring 12, and a coupling shaft 13.

[0015] A storage section 8p is provided inside the folder 8, and the wipe spring 9 and the support 10 are housed in this storage section 8p. The wipe spring 9 is made of, for example, a compression coil spring, with one end fixed to the storage section 8p and the other end fixed to the support 10.

[0016] The support body 10 is constantly subjected to the biasing force of the wipe spring 9 and is maintained in an elastic contact state with the flange portion 8f of the folder 8. A support shaft 11 extending along the biasing direction of the wipe spring 9 is connected to the support body 10, and the movable energizing shaft 7b described above is connected to the extended end of the support shaft 11.

[0017] In the folder 8, a connecting shaft 13 is provided on the opposite side of the flange portion 8f, and the connecting shaft 13 is connected to an electromagnetic operating mechanism 3 (operating shaft 16 described later). A pedestal portion 13p for supporting an opening spring 12 (for example, a compression coil spring) is provided on the connecting shaft 13. Thereby, when opening a closed electrode, for example, the biasing force of the opening spring 12 can be made to act on the electromagnetic operating mechanism 3 (operating shaft 16 described later) from the pedestal portion 13p through the connecting shaft 13.

[0018] The electromagnetic operating mechanism 3 includes a yoke 14, an armature 15, an operating shaft 16, a permanent magnet 17, a coil 18 (closed-circuit coil 18a, open-circuit coil 18b), and a magnetic flux suppression mechanism 19. The yoke 14 and the armature 15 are made of a material having a higher magnetic permeability than air (for example, iron, electromagnetic steel sheet).

[0019] In the examples of FIGS. 1 and 2, the yoke 14 is composed of an inner yoke 14a fixed to the switch 1 and an outer yoke 14b, and the outer yoke 14b is arranged to cover the outside of the inner yoke 14a. The permanent magnet 17, the coil 18 (closed-circuit coil 18a, open-circuit coil 18b), and the magnetic flux suppression mechanism 19 are arranged in a region surrounded by the inner yoke 14a and the outer yoke 14b (that is, inside the yoke 14).

[0020] Inside the inner yoke 14a, a single operating shaft 16 extending straight is provided so as to be reciprocally movable. The connecting shaft 13 of the connecting mechanism 4 described above is connected to one end side of the operating shaft 16, and the armature 15 is connected to the other end side of the operating shaft 16. The armature 15 includes a shaft support portion 15p and a flange portion 15f. The shaft support portion 15p firmly supports the operating shaft 16. The flange portion 15f protrudes, for example, radially along a direction orthogonal to the operating shaft 16 from the shaft support portion 15p. The armature 15 to which the operating shaft 16 is connected has its movement range restricted by a stopper (not shown) to prevent it from falling off from the yoke 14.

[0021] The inner yoke 14a has both end faces (the first yoke contact surface S1 and the first yoke fixing surface F1) arranged parallel to each other when viewed in the reciprocating direction of the operating shaft 16. The first yoke contact surface S1 is configured to face the shaft support portion 15p of the armature 15. On the shaft support portion 15p of the armature 15, a first armature contact surface T1 facing the first yoke contact surface S1 is configured. According to this configuration, by advancing (approaching) the armature 15 toward the yoke 14, the first armature contact surface T1 can be brought into planar contact with the first yoke contact surface S1.

[0022] The outer yoke 14b extends from the outside of the flange portion 15f of the armature 15 through the outside of the inner yoke 14a to a position where it faces the first yoke fixing surface F1 and is non-contact with the above-described operating shaft 16. In the examples of FIGS. 1 and 2, the permanent magnet 17 is provided adjacent to the first yoke fixing surface F1, and in this state, it is sandwiched between the inner upper surface M1 of the outer yoke 14b and the first yoke fixing surface F1.

[0023] Furthermore, a support portion 14p protrudes from the inner side surface M2 of the outer yoke 14b toward the inner yoke 14a (specifically, the shaft support portion 15p that supports the operating shaft 16). The coil 18 (closed-circuit coil 18a, open-circuit coil 18b) and the magnetic flux suppression mechanism 19 are accommodated in the space surrounded by the support portion 14p, the outer yoke 14b, and the inner yoke 14a.

[0024] That is, a support surface M3 facing the inner upper surface M1 of the outer yoke 14b is provided on the support portion 14p. An outer side surface M4 facing the inner side surface M2 of the outer yoke 14b is provided on the inner yoke 14a. The coil 18 (closed-circuit coil 18a, open-circuit coil 18b) and the magnetic flux suppression mechanism 19 are accommodated in the region surrounded by the inner upper surface M1, the inner side surface M2, the support surface M3, and the outer side surface M4.

[0025] In the examples shown in Figures 1 and 2, the closing coil 18a and the opening coil 18b are arranged in alignment with each other along the reciprocating direction of the operating shaft 16. The closing coil 18a is positioned adjacent to the inner upper surface M1 of the outer yoke 14b and the outer surface M4 of the inner yoke 14b. The opening coil 18b is positioned adjacent to the support surface M3 of the support portion 14p and the closing coil 18a. In other words, the opening coil 18b is sandwiched between the support surface M3 of the support portion 14p and the closing coil 18a.

[0026] Furthermore, in the examples shown in Figures 1 and 2, the support portion 14p has a second yoke contact surface S2 on the opposite side of the support surface M3. The second yoke contact surface S2 is configured to face the flange portion 15f of the armature 15. The flange portion 15f of the armature 15 has a second armature contact surface T2 that faces the second yoke contact surface S2. With this configuration, by advancing (approaching) the armature 15 toward the yoke 14, the second armature contact surface T2 can be brought into planar contact with the second yoke contact surface S2.

[0027] According to the above configuration, when the armature 15 is moved back and forth, this reciprocating motion is transmitted from the operating shaft 16 to the connecting mechanism 4 via the connecting shaft 13, causing the connecting mechanism 4 to reciprocate. This operates the movable energizing shaft 7b connected to the support body 10 (support shaft 11). As a result, the movable electrode 5b can be moved toward and away from (opened and closed) the fixed electrode 5a.

[0028] In this case, in the open circuit state where the pair of electrodes 5a and 5b are separated (see Figure 1), the gap between the first armature contact surface T1 and the first yoke contact surface S1, and the gap between the second armature contact surface T2 and the second yoke contact surface S2 are set to the same dimension when viewed in the reciprocating direction of the operating shaft 16.

[0029] As a result, when transitioning to a closed state (see Figure 2) where the open pair of electrodes 5a and 5b are in contact with each other, the armature 15 is advanced (approached) toward the yoke 14, thereby allowing the first and second armature contact surfaces T1 and T2 to simultaneously come into planar contact with the first and second yoke contact surfaces S1 and S2.

[0030] Incidentally, with the configuration described above, within the electromagnetic operating mechanism 3, regardless of whether or not current is supplied to the closed coil 18a and the open coil 18b, the magnetic flux generated from the permanent magnet 17 forms two loop-shaped magnetic paths (for example, the first magnetic path 17a and the second magnetic path 17b). The magnetic flux forming the first magnetic path 17a goes from the permanent magnet 17 through the armature 15 to the yoke 14. The magnetic flux forming the second magnetic path 17b goes from the permanent magnet 17 to the yoke 14 without going through the armature 15.

[0031] The magnetic flux suppression mechanism 19 is configured to suppress the magnetic flux that forms the second magnetic path 17b, that is, the magnetic flux that reaches the yoke 14 without passing through the permanent magnet 17 and the armature 15. In the example shown in Figures 1 and 2, the magnetic flux suppression mechanism 19 is positioned adjacent to the closed coil 18a and the open coil 18b, which are aligned with each other. In this state, the magnetic flux suppression mechanism 19 is positioned adjacent to the inner upper surface M1 and inner side surface M2 of the outer yoke 14b and the support surface M3 of the support portion 14p.

[0032] The magnetic flux suppression mechanism 19 has a magnetoresistive portion 19p that extends in a direction traversing the second magnetic path 17b. The magnetoresistive portion 19p is positioned adjacent to the outside of the coil 18 (closed coil 18a, open coil 18b) in the direction in which the magnetic flux forming the second magnetic path 17b passes through the coil 18. The magnetoresistive value of the magnetoresistive portion 19p is set higher than the magnetoresistive value of the first magnetic path 17a.

[0033] Here, if the transmittance of the magnetoresistive part 19p is μ, its area is S, and its thickness is d, then the magnetoresistive resistance R of the magnetoresistive part 19p can be set based on the relationship R = μ × d / S. The area S refers to the area of ​​the surface of the magnetoresistive part 19p perpendicular to the magnetic flux forming the second magnetic path 17b (for example, the surface of the magnetoresistive part 19p that contacts the inner surface M2 of the outer yoke 14b, or the surface of the magnetoresistive part 19p that contacts the coil 18, specifically the surface of the magnetoresistive part 19p facing the outer surface M4 of the inner yoke 14a). The thickness d refers to the thickness (wall thickness, distance) of the magnetoresistive part 19p in the direction through which the magnetic flux forming the second magnetic path 17b passes (specifically, the direction perpendicular to both the outer surface M4 of the inner yoke 14a and the inner surface M2 of the outer yoke 14b that are facing each other).

[0034] Furthermore, the magnetoresistive portion 19p can be made of a conductive, non-magnetic material such as stainless steel or resin. When the magnetoresistive portion 19p is made of a non-magnetic material, it is preferable to divide the magnetoresistive portion 19p into multiple parts and cover each divided magnetoresistive portion 19p with an insulator (e.g., rubber or vinyl). This electrically insulates each magnetoresistive portion 19p, thereby preventing the conduction of induced current.

[0035] The pair of electrodes 5a and 5b described above are moved apart (opened and closed) by such an electromagnetic operating mechanism 3. For example, when opening electrodes 5a and 5b from a closed circuit (see Figure 2) where a magnetic force is generated in the direction that attracts the armature 15 to the yoke 14 (see dotted arrow L in Figure 2), current is supplied to the opening coil 18b to generate a magnetic flux (not shown) in the opposite direction to that of the permanent magnet 17. As a result, a magnetic flux in the opposite direction to that of the permanent magnet 17 is applied from the opening coil 18b through the yoke 14 and armature 15.

[0036] This reduces the magnetic force of the permanent magnet 17 in the direction L that attracts the armature 15 to the yoke 14. When this magnetic force falls below the biasing force of the opening spring 12, the biasing force of the opening spring 12 acts on the electromagnetic operating mechanism 3 (i.e., the operating shaft 16) from the base portion 13p via the connecting shaft 13. As a result, the armature 15 retracts (separates) from the yoke 14. Thus, electrodes 5a and 5b are separated from each other, resulting in an open circuit state (see Figure 1).

[0037] On the other hand, when closing the open electrodes 5a and 5b, current is passed through the closing coil 18a to generate a magnetic flux in the same direction as the permanent magnet 17. In this case, until the armature 15 contacts the yoke 14, the magnetic flux generated from the permanent magnet 17 forms two loop-shaped magnetic paths (first magnetic path 17a and second magnetic path 17b) inside the yoke 14.

[0038] The magnetic flux forming the first magnetic path 17a travels from the permanent magnet 17 through the armature 15 to the yoke 14. The magnetic flux forming the second magnetic path 17b travels from the permanent magnet 17 to the yoke 14 without passing through the armature 15. In the examples in Figures 1 and 2, the magnetic flux forming the second magnetic path 17b travels from the permanent magnet 17 through the inner yoke 14 and the closing coil 18a towards the outer yoke 14b.

[0039] At this time, the magnetic flux forming the second magnetic path 17b is suppressed by the magnetic flux suppression mechanism 19 (i.e., the magnetoresistive part 19p) described above, and does not reach the outer yoke 14b. In other words, the magnetic flux forming the second magnetic path 17b, which does not contribute to the generation of a magnetic force in the direction that attracts the armature 15 to the yoke 14, is suppressed.

[0040] This increases the magnetic flux in the first magnetic path 17a. As a result, until the armature 15 contacts the yoke 14, only the magnetic flux forming the first magnetic path 17a from the permanent magnet 17 through the armature 15 to the yoke 14 is generated. Thus, the armature 15 can be displaced in the direction that brings electrodes 5a and 5b into contact with each other.

[0041] As described above, according to this embodiment, by providing a magnetoresistive portion 19p that extends in a direction transverse to the second magnetic path 17b, when closing the open electrodes 5a and 5b, it is possible to suppress magnetic flux that does not contribute to the generation of a magnetic force in the direction that attracts the armature 15 to the yoke 14 (i.e., the magnetic flux that forms the second magnetic path 17b). As a result, it is possible to increase the magnetic flux from the permanent magnet 17 through the armature 15 to the yoke 14 (i.e., the magnetic flux that forms the first magnetic path 17a). As a result, without increasing the magnetic flux (i.e., magnetomotive force) of the closing coil 18a, the armature 15 can be advanced (approached) to the yoke 14, and a closed state in which electrodes 5a and 5b are in contact with each other can be achieved.

[0042] "First Variation" In the embodiment described above, it was assumed that the magnetoresistive section 19p was arranged adjacent to the outside of the coil 18 (closed coil 18a, open coil 18b). However, in this modified example, as shown in Figure 3, the magnetoresistive section 19p is arranged adjacent to the inside of the coil 18 in the direction in which the magnetic flux forming the second magnetic path 17b (see Figure 1) passes through the coil 18.

[0043] This modified version can achieve the same effects as the embodiment described above. Note that the other configurations are the same as those in the embodiment described above, and therefore their description will be omitted.

[0044] "Second variation" In the embodiments and modifications described above, it was assumed that the magnetoresistive section 19p was made of a non-magnetic material. However, in this modification, as shown in Figure 4, the magnetoresistive section 19p is made up of a three-dimensional space where no objects exist. The magnetoresistive section 19p may be arranged adjacent to the outside of the coil 18 (closed coil 18a, open coil 18b), as in the embodiments described above, or adjacent to the inside of the coil 18, as in the first modification described above. In this case, the space is filled with a gas such as air, which has a relative permeability of 1.

[0045] According to this modified example, the magnetic resistance of the empty magnetic resistance section 19p can be increased. This makes it possible to realize a magnetic resistance section 19p in which no induced current flows. As a result, the same effects as those of the embodiment described above can be achieved. Note that the other configurations are the same as those of the embodiment described above, so their description will be omitted.

[0046] "Third Variation" In the embodiments and modifications described above, it was assumed that the magnetoresistive section 19p was configured separately from the coil 18. However, in this modification, as shown in Figure 5, the magnetoresistive section 19p is configured by covering the coil 18 (closed coil 18a, open coil 18b) with an insulating material (for example, rubber or vinyl) not shown.

[0047] The configuration of the magnetoresistive section 19p is not shown in the diagram, but for example, a wire made of non-magnetic copper or aluminum and an insulating material are prepared. In the first configuration method, the wire is wound a predetermined number of times to form a coil 18 (closed coil 18a, open coil 18b), and then the entire surface of the coil 18 is covered with the insulating material. In the second method, the entire surface of the wire is covered with the insulating material, and then the wire covered with the insulating material is wound a predetermined number of times to form a coil 18.

[0048] Regardless of the configuration method used, the magnetic resistance R of the magnetoresistive section 19p can be set based on the relationship R = μ × d / S, similar to the embodiment described above. Furthermore, since the relative permeability of the magnetoresistive section 19p is approximately 1, high magnetic resistance can be achieved.

[0049] This modified version can achieve the same effects as the embodiment described above. Note that the other configurations are the same as those in the embodiment described above, and therefore their description will be omitted.

[0050] Although one embodiment of the present invention and several variations have been described above, these embodiments and variations are presented as examples and are not intended to limit the scope of the invention. These embodiments and variations can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0051] 1... Switch, 2... Vacuum valve, 3... Electromagnetic operating mechanism, 4... Coupling mechanism, 5... Electrode, 5a... Fixed electrode, 5b... Movable electrode, 6... Insulating container, 7a... Fixed energizing shaft, 7b... Movable energizing shaft, 8... Folder, 8p... Housing section, 8f... Flange section, 9... Wipe spring, 10... Support, 11... Support shaft, 12... Opening spring, 13... Coupling shaft, 13p... Base section, 14... Yoke, 14a... Inner yoke, 14b... Outer yoke, 14p... Support section, 15... Armature, 15 p...Axis support, 15f...Flange, 16...Operating shaft, 17...Permanent magnet, 17a...First magnetic circuit, 17b...Second magnetic circuit, 18...Coil, 18a...Closing coil, 18b...Open coil, 19...Magnetic flux suppression mechanism, 19p...Magnetic resistance part, F1...First yoke fixing surface, S1...First yoke contact surface, S2...Second yoke contact surface, T1...First armature contact surface, T2...Second armature contact surface, M1...Inner upper surface, M2...Inner side surface, M3...Support surface, M4...Outer side surface.

Claims

1. An electromagnetic operating mechanism that moves a pair of electrodes apart by moving the armature apart from the yoke, A magnet that generates a magnetic flux forming a first magnetic path that goes through the armature to the yoke, and a magnetic flux forming a second magnetic path that goes through the armature to the yoke without passing through the armature, It has a magnetic flux suppression mechanism that suppresses the magnetic flux from the magnet to the yoke without passing through the armature, The yoke is composed of an inner yoke and an outer yoke arranged to cover the outside of the inner yoke, The outer yoke is provided with a support portion that protrudes toward the inner yoke. The magnetic flux suppression mechanism is housed in the space enclosed by the support portion, the outer yoke, and the inner yoke, The magnetic flux suppression mechanism is an electromagnetic operating mechanism that is larger than the inner yoke and positioned adjacent to the support portion when viewed in the direction of moving the armature away from the yoke.

2. The magnetic flux suppression mechanism has a magnetoresistive portion extending in a direction traversing the second magnetic path, The electromagnetic operating mechanism according to claim 1, wherein the magnetic resistance of the magnetic resistance section is set higher than the magnetic resistance of the first magnetic path.

3. The yoke contains a coil that is energized when the pair of electrodes are brought into contact or separated. The electromagnetic operating mechanism according to claim 2, wherein the magnetoresistive portion is arranged adjacent to the outside of the coil in the direction in which the magnetic flux forming the second magnetic path passes through the coil.

4. The yoke contains a coil that is energized when the pair of electrodes are brought into contact or separated. The electromagnetic operating mechanism according to claim 2, wherein the magnetoresistive portion is arranged adjacent to the inside of the coil in the direction in which the magnetic flux forming the second magnetic path passes through the coil.

5. The electromagnetic operating mechanism according to claim 2, wherein the magnetoresistive portion is made of a non-magnetic material.

6. The electromagnetic operating mechanism according to claim 2, wherein the magnetic resistance portion is composed of space.

7. The yoke contains a coil that is energized when the pair of electrodes are brought into or out of contact. The electromagnetic operating mechanism according to claim 2, wherein the magnetic resistance portion is configured by covering the coil with an insulating material.

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