JP7499684B2 - Electromagnetic Actuators and Circuit Breakers - Google Patents

Description

This disclosure relates to an electromagnetic actuator used to close a circuit breaker and a circuit breaker.

Conventionally, in electromagnetically operated circuit breakers, an electromagnetic actuator is used in the closing operation to close the circuit. For example, Patent Document 1 discloses an electromagnetic actuator having an excitation coil that generates magnetic flux, an armature that is arranged in the internal space of the excitation coil and is movable in the axial direction of the excitation coil, and a core that is arranged outside the excitation coil and forms a magnetic path through which the magnetic flux passes together with the armature. The armature has a base portion, one end of which is moved toward and away from the core when driven in the driving direction by the magnetic flux of the excitation coil, and an extension portion that is continuous with the other end of the base and has a smaller diameter than the base.

In the electromagnetic actuator described in Patent Document 1, a step portion that forms a step between the base portion and the extension portion of the armature, and an extension portion provided on the core form a magnetic latch portion that temporarily restricts the movement of the armature in the driving direction when power supply to the excitation coil begins. In such an electromagnetic actuator, when power supply to the excitation coil begins, the magnetic latch portion attracts the armature in the direction opposite to the driving direction of the armature, restricting the movement of the armature in the driving direction, but when the current flowing through the excitation coil gradually increases and reaches a certain specified value, the magnetic flux from the extension portion of the core to the step portion of the armature becomes saturated, suppressing the attraction force generated between the extension portion of the core and the step portion of the armature.

When the current flowing through the excitation coil increases further, the magnetic flux from the extension of the core to the extension of the armature increases, and the attractive force in the driving direction of the armature exceeds the load on the armature. As a result, the armature begins to move in the driving direction, and the magnetic gap between the step of the armature and the extension of the core expands.

As a result, the attractive force generated in the direction opposite to the drive direction disappears. The attractive force in the drive direction then increases by the amount of the lost attractive force in the direction opposite to the drive direction. In addition, the magnetic gap between the armature and the core in the drive direction shrinks, so the attractive force in the drive direction increases suddenly and the drive speed increases. By utilizing this characteristic, the armature can be moved in the drive direction at a nearly constant speed regardless of the voltage applied to the excitation coil, and as the armature moves, the opening and closing mechanism is driven, completing the closing operation of the circuit breaker.

Japanese Utility Model Application Publication No. 3-61311

In the electromagnetic actuator described in Patent Document 1, the step of the armature and the extension of the core are in contact before the closing operation, and the magnetic gap between the step of the armature and the extension of the core is small. However, variations in the flatness of the contact surfaces of these steps and extensions increase the variation in the magnetic gap between the step and the extension. When the variation in the magnetic gap is large, the variation in the attractive force in the opposite direction to the driving direction generated by the magnetic latch portion including the step of the armature and the extension of the core increases, and the variation in the attractive force in the driving direction when the armature starts to move in the driving direction increases.

The present disclosure has been made in consideration of the above, and aims to obtain an electromagnetic actuator that can reduce the variation in the attractive force in the driving direction when the armature starts to move in the driving direction.

In order to solve the above-mentioned problems and achieve the object, an electromagnetic actuator of the present disclosure is an electromagnetic actuator used for closing a circuit breaker, and includes an excitation coil, an armature, a core, and a conductor. The excitation coil generates a magnetic flux. The armature is disposed in an internal space of the excitation coil so as to be movable in a driving direction by the magnetic flux generated by the excitation coil. The core is disposed outside the excitation coil, and forms a magnetic path through which the magnetic flux passes together with the armature . The armature has a base portion extending in the driving direction, and an extension portion extending in the opposite direction to the driving direction from an end of the base in the opposite direction to the driving direction with an outer diameter smaller than that of the base, and a circumferential extension portion protruding radially from the outer periphery of the extension portion is formed at the end of the base in the opposite direction to the driving direction. The core has a pair of core body parts extending in the drive direction, a core lid part connecting the pair of core body parts at the end sides in the drive direction of the core body parts, and a pair of extension parts extending from the end parts of the pair of core body parts in the opposite direction to the drive direction so as to form an opening through which the extension parts of the armature are inserted, and the pair of extension parts have a pair of protrusions that face the circumferential expansion parts of the armature and protrude from the extension parts in the drive direction. The conductor has a pair of first conductor parts arranged between the pair of circumferential expansion parts of the armature and the pair of protrusions of the core, a pair of second conductor parts arranged between the extension parts of the armature and the pair of extension parts of the core, and a third conductor part connecting the pair of second conductor parts, and is fixed to the extension parts of the armature.

The present disclosure has the effect of reducing the variation in the suction force in the driving direction when the armature starts to move in the driving direction.

FIG. 1 is a side view of the inside of a circuit breaker according to a first embodiment when the circuit breaker is opened; FIG. 1 is a side view of the inside of a circuit breaker according to a first embodiment when the circuit breaker is closed; FIG. 13 is a diagram showing a change in the converted mass obtained by converting the mass of the mechanism during the closing operation into the mass at the position of the electromagnetic actuator in the circuit breaker according to the first embodiment from the open position to the closed position. FIG. 13 is a diagram showing a change in the converted mass obtained by converting the mass of the mechanism unit into the mass at the position of the electromagnetic actuator during the closing operation in the case where the restoring force of the flexible conductor is generated in the closing direction in the circuit breaker according to the first embodiment, from the opening position to the closing position. FIG. 1 is a front view of an electromagnetic actuator according to a first embodiment; FIG. 1 is a side view of an electromagnetic actuator according to a first embodiment; FIG. 1 is a front view of an armature according to a first embodiment. FIG. 1 is a perspective view of an armature according to a first embodiment; FIG. 1 is a front view of a core according to a first embodiment; FIG. 1 is a perspective view of a core according to a first embodiment; FIG. 1 is a perspective view of a conductor according to a first embodiment; FIG. 1 is a front view of the electromagnetic actuator according to the first embodiment when the armature is in an initial position; An enlarged view of region A shown in FIG. FIG. 2 is a front view of the electromagnetic actuator according to the first embodiment when the armature starts to move in the driving direction; An enlarged view of region B shown in FIG. FIG. 1 is a diagram showing an example of a current flowing through an excitation coil of an electromagnetic actuator according to a first embodiment; FIG. 1 is a perspective view of an electromagnetic actuator according to a first embodiment, excluding an excitation coil and a bobbin; An enlarged view of region C shown in FIG. FIG. 1 is a diagram for explaining another shape of the conductor according to the first embodiment; FIG. 1 is a front view showing an example of a region of a housing to which an electromagnetic actuator according to a first embodiment is fixed; FIG. 1 is a side view showing an example of a region of a housing to which an electromagnetic actuator according to a first embodiment is fixed; FIG. 1 is a front view showing an example of an area of a housing in a state in which an electromagnetic actuator according to a first embodiment is fixed; FIG. 1 is a side view showing an example of an area of a housing in a state in which an electromagnetic actuator according to a first embodiment is fixed; FIG. 23 is a cross-sectional view taken along line XXIII-XXIII shown in FIG. FIG. 23 is a cross-sectional view taken along line XXIV-XXIV shown in FIG.

The electromagnetic actuator and circuit breaker according to the embodiment are described in detail below with reference to the drawings.

Embodiment 1.
The circuit breaker according to the first embodiment is an air circuit breaker that opens and closes an electric circuit such as a low-voltage distribution line, and detects at least one of an overcurrent and an earth leakage current to break the electric circuit. Note that the circuit breaker according to the first embodiment may be a circuit breaker other than an air circuit breaker. In the following, for convenience of explanation, the positive direction of the Z axis is defined as the upward direction, and the negative direction of the Z axis is defined as the downward direction.

Figure 1 is a side view of the inside of the circuit breaker according to the first embodiment when the contacts are open. Figure 2 is a side view of the inside of the circuit breaker according to the first embodiment when the contacts are closed. As shown in Figure 1, the circuit breaker 1 according to the first embodiment includes a housing 2 made of an insulating material, a power supply side terminal 3 and a load side terminal 4 each attached to the housing 2, and a flexible conductor 5 having one end 5a connected to the load side terminal 4 inside the housing 2.

The circuit breaker 1 also includes a mover 6 having one end 6a connected to the other end 5b of the flexible conductor 5, a mover holder 7 having one end 7a rotatably attached to the housing 2 inside the housing 2, and a pressure spring 8 having one end and the other end attached to the other end 7b of the mover holder 7 and the other end 6b of the mover 6.

The power supply side terminal 3 is connected to a power supply side conductor (not shown) outside the housing 2, and the load side terminal 4 is connected to a load side conductor (not shown) outside the housing 2. A fixed contact 10 is attached to the power supply side terminal 3 inside the housing 2, and a movable contact 11 is attached to the other end 6b of the mover 6.

The flexible conductor 5 is a flexible conductor, and as described above, one end 5a is connected to the load side terminal 4 and the other end 5b is connected to the movable element 6. The load side terminal 4 and the movable element 6 are electrically connected by the flexible conductor 5. When the movable contact 11 comes into contact with the fixed contact 10, the circuit breaker 1 is in a closed state in which the power supply side terminal 3 and the load side terminal 4 are electrically connected and current flows. When the movable contact 11 is separated from the fixed contact 10, the circuit breaker 1 is in an open state in which the power supply side terminal 3 and the load side terminal 4 are electrically disconnected.

One end 7a of the mover holder 7 is attached to the housing 2 so as to be rotatable around the holder shaft 12. In addition, the middle part 7c of the mover holder 7 is rotatably attached to one end 6a of the mover 6 by the mover pin 13. The mover holder 7 is provided with a mover stopper 9.

The mover stopper 9 limits the angle at which the mover 6 rotates around the mover pin 13 relative to the mover holder 7. In the state shown in FIG. 1, one end 6a of the mover 6 abuts against the mover stopper 9. Therefore, the mover stopper 9 restricts the other end 6b of the mover 6 from rotating in a direction away from the other end 7b of the mover holder 7, but the other end 6b of the mover 6 can rotate in a direction approaching the other end 7b of the mover holder 7.

The contact pressure spring 8 is a spring for pressing the movable contact 11 against the fixed contact 10. In the state shown in FIG. 1, the contact pressure spring 8 is in a charged state shorter than its natural length and has a certain initial contact pressure. Therefore, when the other end 6b of the mover 6 rotates in a direction approaching the other end 7b of the mover holder 7, the distance between the other end 6b of the mover 6 and the other end 7b of the mover holder 7 becomes smaller, and the contact pressure spring 8 is further charged.

The circuit breaker 1 also includes an electromagnetic actuator 20 disposed inside the housing 2 as a closing actuator for the circuit breaker 1, and a transmission mechanism 30 that transmits the driving force of the electromagnetic actuator 20 to the movable element 6 to bring the movable contact 11 into contact with and separate from the fixed contact 10. The circuit breaker 1 also includes an opening spring 39, one end and the other end of which are attached to the transmission mechanism 30 and the housing 2, a tripping mechanism 40 that maintains the closed state and releases the closed state, and a drive circuit 45 that drives the electromagnetic actuator 20.

When the excitation coil 21 wound around the bobbin 22 of the electromagnetic actuator 20 is energized by the drive circuit 45, the armature 23 (described later) moves upward, which is the drive direction, and the shaft 25 fixed to the armature 23 moves upward.

The transmission mechanism 30 includes a connecting link 31, one end 31a of which is rotatably connected to the shaft 25 of the electromagnetic actuator 20 by a connecting pin 34, a main shaft 32, which is rotatably connected to the other end 31b of the connecting link 31 by a connecting pin 35, and a link 33, which is rotatably connected to one end 32a of the main shaft 32.

The main shaft 32 is attached to the rotating shaft 36 so as to be rotatable around the rotating shaft 36, whose absolute position is fixed relative to the housing 2. The main shaft 32 is connected to the other end 31b of the connecting link 31 by a connecting pin 35 at an area closer to the tripping mechanism 40 than the rotating shaft 36. In addition, the transmission mechanism 30 of the circuit breaker 1 includes an engagement pin 41, which is fixed to the other end 32b of the main shaft 32.

One end 33a of the link 33 is rotatably connected to one end 32a of the main shaft 32 by a connecting pin 38, and the other end 33b is rotatably attached to one end 6a of the mover 6 and the middle part 7c of the mover holder 7 by a mover pin 13.

The main shaft 32, the link 33, and the movable member holder 7 form a toggle mechanism in a four-joint link with the rotating shaft 36 and the holder shaft 12 as fixed rotation centers. Therefore, the closer to the dead point where the rotating shaft 36, the connecting pin 38, and the movable member pin 13 are arranged in a straight line, the smaller the force required to drive the transmission mechanism 30.

As described above, the opening spring 39 has one end and the other end attached to the main shaft 32 and the housing 2, and the elastic restoring force of the opening spring 39 urges the main shaft 32 in a direction that displaces the transmission mechanism 30 to the opening position.

When the circuit breaker 1 is in an open state and current is applied to the electromagnetic actuator 20, the shaft 25 of the electromagnetic actuator 20 moves upward, which is the drive direction. The upward movement of the shaft 25 causes the main shaft 32 to rotate clockwise in FIG. 1 around the rotation axis 36, and the connection angle between the main shaft 32 and the link 33 becomes smaller. The connection angle is the angle between the extension direction of the main shaft 32 and the extension direction of the link 33.

As the connection angle becomes smaller, the movable member 6 moves forward, and as shown in FIG. 2, the fixed contact 10 and the movable contact 11 come into contact with each other, and the circuit breaker 1 enters a closed state. In addition, the engagement pin 41 engages with the latch 42. The latch 42 is restricted from rotating counterclockwise in FIG. 2 by the latch 43, thereby maintaining the closed state of the circuit breaker 1. Hereinafter, the part of the circuit breaker 1 that changes the circuit breaker 1 from an open state to a closed state by the movement of the shaft 25 will be referred to as the mechanism. Such a mechanism includes the transmission mechanism 30, the movable member holder 7, the movable member 6, and the flexible conductor 5.

Figure 3 is a diagram showing the change in the converted mass, obtained by converting the mass of the mechanical part during the closing operation into the mass at the position of the electromagnetic actuator, from the open position to the closed position in the circuit breaker according to the first embodiment. In Figure 3, the vertical axis is the converted mass of the mechanical part at the position of the electromagnetic actuator 20, and the horizontal axis is the stroke of the electromagnetic actuator 20. The stroke of the electromagnetic actuator 20 is the distance traveled in the driving direction of the shaft 25 of the electromagnetic actuator 20.

As shown in FIG. 3, when the shaft 25 of the electromagnetic actuator 20 of the circuit breaker 1 is in the open position, the converted mass at the position of the electromagnetic actuator 20 is large, and as the shaft 25 moves from the open position toward the closed state, the converted mass of the mechanism at the position of the electromagnetic actuator 20 becomes smaller.

The characteristics shown in FIG. 3 mean that the movement of the electromagnetic actuator 20 slows down at the initial position of the closing operation, and the back electromotive force of the excitation coil 21 caused by the increase in the speed of the shaft 25 can be reduced. Since the back electromotive force of the excitation coil 21 can be reduced, the current flowing through the excitation coil 21 does not decrease, and the electromagnetic actuator 20 can maintain a high output. Furthermore, in the circuit breaker 1, the more the state of the mechanism moves in the closing direction, the higher the speed increases due to the change in mass, so that sufficient inertia can be stored and a stable closing operation can be achieved.

Also, as shown in FIG. 3, when the link 33 is made of resin, the converted mass of the mechanism at the position of the electromagnetic actuator 20 is smaller than the converted mass of the mechanism at the position of the electromagnetic actuator 20 when the link 33 is made of metal. Therefore, by forming the link 33 from a resin material, the mass change from the open state to the closed state can be increased, and the effect of the increase in speed due to the mass change can be enhanced. The same effect can be achieved by forming the moving member holder 7 from a resin material instead of the link 33. Furthermore, the above-mentioned effect can be further enhanced by forming both the link 33 and the moving member holder 7 from a resin material.

In addition, in the open state of the circuit breaker 1 shown in FIG. 1, the flexible conductor 5 is bent, so the restoring force of the flexible conductor 5, which tries to extend in a straight line to its original shape, acts in the closing direction, moving the movable contact 11 closer to the fixed contact 10 through the end of the connected movable member 6. Therefore, the rattle caused by the fit tolerance between the movable member 6 and the movable member pin 13, and the rattle caused by the fit tolerance between the movable member pin 13 and the link 33 are each reduced in the closing direction. On the other hand, the rattle caused by the fit tolerance between the shaft 25 and the connecting link 31, the fit tolerance between the connecting link 31 and the main shaft 32, and the fit tolerance between the main shaft 32 and the link 33 are each reduced in the opening direction by the opening spring 39 attached to the main shaft 32.

Figure 4 is a diagram showing the change in the converted mass, obtained by converting the mass of the mechanism part during the closing operation into the mass at the position of the electromagnetic actuator, from the open position to the closed position when the restoring force of the flexible conductor is generated in the closing direction in the circuit breaker according to the first embodiment. As shown in Figure 4, when the restoring force of the flexible conductor 5 is generated in the closing direction, if the electromagnetic actuator 20 does not move slightly due to the influence of the above-mentioned fitting tolerance, the backlash that has been trapped in the opening direction of the mechanism part is not filled, and furthermore, the backlash that has been trapped in the closing direction of the movable member 6 is not filled, so that the movable member 6 and the flexible conductor 5, which are heavy current-carrying conductors, do not move.

Therefore, the mass of the mover 6 and the flexible conductor 5 does not affect the initial operation of the electromagnetic actuator 20, and even if the arrangement of parts in the mechanism varies, the mass of the mechanism converted into the position of the electromagnetic actuator 20 does not vary. Therefore, in the circuit breaker 1, the effect of variations in the arrangement of parts is reduced, enabling stable operation of the electromagnetic actuator 20.

In addition, in the circuit breaker 1, by making the core 24 of the electromagnetic actuator 20 a laminated iron core, it is possible to reduce eddy current heat generated in the electromagnetic actuator 20 by the main circuit current flowing through the power supply side terminal 3, the fixed contact 10, the movable contact 11, the movable member 6, the flexible conductor 5, and the load side terminal 4.

Next, the configuration of the electromagnetic actuator 20 will be specifically described. FIG. 5 is a front view of the electromagnetic actuator according to the first embodiment. FIG. 6 is a side view of the electromagnetic actuator according to the first embodiment.

As shown in Figures 5 and 6, the electromagnetic actuator 20 includes an excitation coil 21 that is formed in a cylindrical shape and generates a magnetic flux when current is passed through the drive circuit 45, a bobbin 22 around which the excitation coil 21 is wound, and an armature 23 that is disposed in the internal space of the excitation coil 21 and is movable in the vertical direction, which is the axial direction of the excitation coil 21.

The electromagnetic actuator 20 also includes a core 24 that is disposed outside the excitation coil 21 and that, together with the armature 23, forms a magnetic path through which magnetic flux passes, a shaft 25 that is fixed to the armature 23, and a conductor 26 that is disposed between the latch formation region of the armature 23 and the latch formation region of the core 24, forming a magnetic latch portion 75 described below.

The electromagnetic actuator 20 is provided with a guide 27 for guiding the movement direction of the armature 23 in the vertical direction. The guide 27 allows the shaft 25 to be displaced in the vertical direction, but restricts displacement in directions other than the vertical direction. The electromagnetic actuator 20 will be described in detail later.

Figure 7 is a front view of the armature according to the first embodiment, and Figure 8 is a perspective view of the armature according to the first embodiment. As shown in Figures 7 and 8, the armature 23 includes two outside armatures 23A and one middle armature 23B, and is configured by stacking the outside armature 23A, the middle armature 23B, and the outside armature 23A in a direction perpendicular to the driving direction. Each of the outside armature 23A and the middle armature 23B is formed by stacking magnetic plates, such as electromagnetic steel plates.

The armature 23 has a base 50 that extends in the drive direction, and an extension 56 that extends in the opposite direction to the drive direction from an end 52 of the base 50 that is opposite to the drive direction and has a smaller outer diameter than the base 50. In the example shown in Figures 7 and 8, each of the base 50 and the extension 56 is formed in a rectangular parallelepiped shape, but it may also be cylindrical, etc.

The end 51 of the base 50 in the driving direction is provided with a recess 511, and the shaft 25 shown in Figures 5 and 6 is attached to the recess 511. The upper surface of the end 51 of the base 50 in the driving direction includes the recess 511, a flat surface 512, and a pair of tapered surfaces 513 that are inclined downward with the flat surface 512 in between.

At the end 52 of the base 50 opposite the driving direction, a circumferential extension 53 is formed as an armature side latch formation region that constitutes part of the magnetic latch section 75 described below. The circumferential extension 53 is formed in a region that extends circumferentially from the outer periphery of the extension section 56 to the base 50.

Figure 9 is a front view of the core according to the first embodiment, and Figure 10 is a perspective view of the core according to the first embodiment. As shown in Figures 9 and 10, the core 24 has two outside cores 24A and one middle core 24B, and is configured by stacking the outside cores 24A, the middle cores 24B, and the outside cores 24A in a direction perpendicular to the driving direction. Each of the outside cores 24A and the middle cores 24B is formed by stacking magnetic plates, such as electromagnetic steel plates.

The middle core 24B has a larger outer shape than the outside core 24A when viewed in a direction perpendicular to the driving direction, which is the stacking direction of the core 24, and includes fixed portions 67, 68 exposed from the outside core 24A in the direction perpendicular to the driving direction. The fixed portions 67, 68 are formed with through holes 67a, 68a that penetrate in the direction perpendicular to the driving direction and through which fastening members are inserted. Note that the through holes 67a, 68a are non-threaded holes, but may be threaded holes.

The core 24 has a core opening end 60 that forms an opening 62 through which the extension 56 of the armature 23 can be inserted, a core lid 63 that faces the core opening end 60 at a position away from the core opening end 60 in the driving direction, and a pair of core body portions 64 that connect the core lid 63 and the core opening end 60.

The core opening end 60 has a pair of opposing extensions 61, and an opening 62 is formed between the pair of extensions 61 through which the extension 56 of the armature 23 is inserted. The inner surface 611 of each extension 61 has a protrusion 66 that faces the circumferential extension 53 of the armature 23 and is a core-side latch formation area that constitutes part of the magnetic latch section 75 described below, and an opposing portion 612 that faces the extension 56 of the armature 23.

The inner surface of the core lid 63 includes a flat surface 631 and a pair of tapered surfaces 632 that are inclined downward on either side of the flat surface 631. The tapered surfaces 632 of the core lid 63 are parallel to the tapered surface 513 of the base 50 of the armature 23.

The core lid 63 has a through hole 634 formed therein, and the shaft 25 is arranged to be movable in the vertical direction through the through hole 634. The through hole 634 of the core lid 63 is formed so that its central axis coincides with the coil axis of the excitation coil 21, and the above-mentioned guide 27 is attached thereto. The central axis of the shaft 25 coincides with the central axis of the armature 23. By inserting the shaft 25 into the guide 27 attached to the through hole 634 of the core lid 63, the armature 23 is arranged inside the excitation coil 21 and the core 24 so that the central axes of the shaft 25 and armature 23 coincide with the coil axis. This allows the driving direction of the armature 23 to be parallel to the coil axis direction of the excitation coil 21.

Figure 11 is a perspective view of the conductor according to the first embodiment. The conductor 26 shown in Figure 11 has a pair of first conductor parts 70 arranged between the circumferential expansion part 53 of the armature 23 and the protrusion part 66 of the core 24, a pair of second conductor parts 71 arranged between the pair of extension parts 56 of the armature 23 and the facing part 612 of the core 24, and a third conductor part 72 connecting the pair of second conductor parts 71. The conductor 26 is formed, for example, by subjecting a plate-shaped conductor to punching and bending processes. Each of the pair of first conductor parts 70 and the pair of second conductor parts 71 is formed in a flat plate shape.

The operation of the electromagnetic actuator 20 will now be described in detail. Fig. 12 is a front view of the electromagnetic actuator according to embodiment 1 when the armature is in the initial position, and Fig. 13 is an enlarged view of area A shown in Fig. 12. Fig. 14 is a front view of the electromagnetic actuator according to embodiment 1 when the armature starts to move in the drive direction, and Fig. 15 is an enlarged view of area B shown in Fig. 14. For ease of explanation, Figs. 12 to 15 show the excitation coil 21 in cross section, and the bobbin 22 is omitted.

The initial position of the electromagnetic actuator 20 is the position of the shaft 25 of the electromagnetic actuator 20 when the drive circuit 45 is not energizing the excitation coil 21, and is the position of the shaft 25 in the circuit breaker 1 in the open state shown in FIG. 1. The closing position of the electromagnetic actuator 20 is the position of the shaft 25 of the electromagnetic actuator 20 when the drive circuit 45 has completed energizing the excitation coil 21, and is the position of the shaft 25 in the circuit breaker 1 in the closed state shown in FIG. 2.

As shown in FIG. 13, the first conductor portion 70 of the conductor 26 is disposed between the circumferential extension portion 53 of the armature 23, the core 24, and the protrusion portion 66. The magnetic latch portion 75 is configured including the circumferential extension portion 53 of the armature 23, the core 24, the protrusion portion 66, and the first conductor portion 70 of the conductor 26. In addition, the second conductor portion 71 of the conductor 26 is disposed between the extension portion 56 of the armature 23 and the facing portion 612 of the core 24.

As shown in FIG. 13, when the electromagnetic actuator 20 is in the initial position, a first magnetic path M1 and a second magnetic path M2 are formed. The first magnetic path M1 is a magnetic path in which magnetic flux passes through the protrusion 66 of the core 24, the first conductor portion 70 of the conductor 26, and the circumferential extension portion 53 of the armature 23. The second magnetic path M2 is a magnetic path in which magnetic flux passes through the opposing portion 612 of the core 24, the second conductor portion 71 of the conductor 26, and the extension portion 56 of the armature 23.

When the electromagnetic actuator 20 is in the initial position and the drive circuit 45 starts supplying power to the excitation coil 21, the magnetic latch section 75 temporarily restricts the movement of the armature 23 in the drive direction. However, due to the inductance of the excitation coil 21, when the current gradually increases and reaches a certain specified value, the magnetic flux flowing from the protrusion 66 of the core 24 through the first conductor section 70 of the conductor 26 to the circumferential extension section 53 of the armature 23 becomes saturated, and the adhesive force generated between the protrusion 66 of the core 24 and the circumferential extension section 53 of the armature 23 is suppressed.

When the current flowing through the excitation coil 21 further increases, the magnetic flux flowing from the opposing portion 612 of the core 24 through the second conductor portion 71 of the conductor 26 to the extension portion 56 of the armature 23 increases, so that the attractive force in the driving direction of the armature 23 exceeds the load applied to the armature 23 by the attraction force generated by the magnetic latch portion 75. Therefore, as shown in FIG. 15, the armature 23 starts to move in the driving direction, and the magnetic gap between the protrusion portion 66 of the core 24 and the circumferential extension portion 53 of the armature 23 expands.

As a result, the attractive force generated in the direction opposite to the drive direction disappears. The attractive force in the drive direction increases by the amount of the disappeared attractive force in the direction opposite to the drive direction. In addition, the magnetic gap between the armature 23 and the core 24 in the drive direction shrinks, so the attractive force in the drive direction increases suddenly and the drive speed increases. By utilizing this characteristic, the armature 23 can be moved in the drive direction at an almost constant speed, regardless of the magnitude of the current voltage from the drive circuit 45. As the armature 23 moves in this way, the transmission mechanism 30 is driven, and the closing operation of the circuit breaker 1 is completed.

As shown in FIG. 13, the magnetic latch portion 75 has the first conductor portion 70 of the conductor 26 disposed between the protrusion 66 of the core 24 and the circumferential extension portion 53 of the armature 23, and the protrusion 66 of the core 24 and the circumferential extension portion 53 of the armature 23 are not in contact with each other. Therefore, compared to a case where the first conductor portion 70 is not provided, the magnetic gap variation can be suppressed in response to the variation or tolerance variation during assembly of the electromagnetic actuator 20. Therefore, in the electromagnetic actuator 20, the variation in the attractive force in the driving direction when the armature 23 starts to move in the driving direction, i.e., the variation in the initial load force due to the magnetic latch portion 75, can be suppressed, enabling stable operation.

In addition, since the first conductor portion 70 of the conductor 26 is disposed between the protrusion portion 66 of the core 24 and the circumferential expansion portion 53 of the armature 23, the electromagnetic actuator 20 can stabilize its operation even when a rectified alternating current is supplied from the drive circuit 45 to the excitation coil 21.

Figure 16 is a diagram showing an example of a current flowing through an excitation coil of an electromagnetic actuator according to embodiment 1. In Figure 16, the vertical axis represents the coil current, which is the current flowing through excitation coil 21, and the horizontal axis represents time.

As shown in FIG. 16, when a rectified alternating current is supplied from the drive circuit 45 to the excitation coil 21, a ripple current of the power supply frequency flows as a coil current in the excitation coil 21, but the change in the attractive force caused by such a ripple current can be suppressed by the eddy current generated in the first conductor portion 70 of the conductor 26.

Therefore, in the electromagnetic actuator 20, the armature 23 can be prevented from starting to move too quickly in response to the peak of the ripple current, and operation can be stabilized regardless of whether the current supplied from the drive circuit 45 is a direct current or an alternating current. In the above example, the first conductor portion 70 through which the magnetic flux of the first magnetic path M1 passes and the second conductor portion 71 through which the magnetic flux of the second magnetic path M2 passes are integrated, but the same effect can be obtained even if the first conductor portion 70 and the second conductor portion 71 are configured separately. In addition, the conductor 26 may be configured without the third conductor portion 72.

The first conductor portion 70 is disposed between a portion of the projection 66 of the core 24 and a portion of the circumferential extension 53 of the armature 23, and is not disposed between the remaining portion of the projection 66 of the core 24 and the remaining portion of the circumferential extension 53 of the armature 23. This allows the electromagnetic actuator 20 to suppress variation in the gap between the projection 66 of the core 24 and the circumferential extension 53 of the armature 23.

Figure 17 is a perspective view of the electromagnetic actuator according to the first embodiment excluding the excitation coil and bobbin, and Figure 18 is an enlarged view of region C shown in Figure 17. As shown in Figures 17 and 18, the first conductor portion 70 of the conductor 26 of the conductor is disposed between the protrusion 66 of the core 24 and the circumferential expansion portion 53 of the armature 23, between a portion of the outside core 24A and a portion of the outside armature 23A, and the first conductor portion 70 is not disposed between the region straddling the outside armature 23A and the middle armature 23B and the region straddling the outside core 24A and the middle core 24B.

Because the outside armature 23A and the middle armature 23B have different shapes, when the outside armature 23A and the middle armature 23B are stacked, misalignment is likely to occur between the outside armature 23A and the middle armature 23B. Similarly, because the outside core 24A and the middle core 24B have different shapes, when the outside core 24A and the middle core 24B are stacked, misalignment is likely to occur between the outside core 24A and the middle core 24B.

Therefore, when the first conductor portion 70 is disposed between the area spanning the outside armature 23A and the middle armature 23B and the area spanning the outside core 24A and the middle core 24B, the gap between the protrusion portion 66 of the core 24 and the circumferential expansion portion 53 of the armature 23 varies greatly due to individual differences, and the suction force in the driving direction varies greatly when the armature 23 starts to move in the driving direction.

On the other hand, in the electromagnetic actuator 20, the first conductor portion 70 is not disposed between the area spanning the outside armature 23A and the middle armature 23B and the area spanning the outside core 24A and the middle core 24B. This makes it possible to prevent the gap between the protrusion 66 of the core 24 and the circumferential expansion portion 53 of the armature 23 from varying significantly due to individual differences, and the operation of the electromagnetic actuator 20 can be stabilized.

The shape of the conductor 26 is not limited to the above-mentioned example. FIG. 19 is a diagram for explaining another shape of the conductor according to the first embodiment. As shown in FIG. 19, the conductor 26 has a first conductor portion 70 disposed between the region spanning the outside armature 23A and the middle armature 23B and the region spanning the outside core 24A and the middle core 24B.

When the positional misalignment between the outside armature 23A and the middle armature 23B and between the outside core 24A and the middle core 24B are small, the first conductive portion 70 may be disposed between the area straddling the outside armature 23A and the middle armature 23B and the area straddling the outside core 24A and the middle core 24B, as shown in FIG. 19.

In addition, since the electromagnetic actuator 20 has the second conductor portion 71 of the conductor 26 disposed between the opposing portion 612 of the core 24 and the extension portion 56 of the armature 23, even if a rectified alternating current is supplied from the drive circuit 45 to the excitation coil 21, the change in the attractive force due to the ripple current can be suppressed by the eddy current generated in the second conductor portion 71 of the conductor 26.

In addition, as shown in FIG. 6, the magnetic latch portion 75 is covered by a bobbin 22, and the electromagnetic actuator 20 is configured so that the magnetic latch portion 75 cannot be inadvertently contacted from the outside. This makes it possible to prevent misalignment of the members that make up the magnetic latch portion 75, and to stabilize operation.

Next, the suction surface of the armature 23 will be described. As shown in FIG. 12, the end 51 of the base 50 of the armature 23 is formed with a tapered surface 513 that is inclined in a direction perpendicular to the driving direction, and the tapered surface 513 functions as an suction surface that suctions with the core 24.

The tapered surface 513 of the armature 23 faces the tapered surface 632 of the core 24 across a gap in the driving direction, and the tapered surfaces 513 and 632 that face each other in the driving direction are parallel to each other. The tapered surface 513 is attracted to the tapered surface 632 of the core 24 by the attractive force generated by the magnetic flux of the second magnetic path M2, moves in the driving direction, and is attached to the tapered surface 632 of the core 24.

When the armature 23 is driven, the gap between the protrusion 66 of the core 24 and the circumferential extension 53 of the armature 23 increases, the magnetic flux passing through the first magnetic path M1 including the magnetic latch portion 75 is greatly reduced, and the initial load force becomes almost entirely an attractive force in the driving direction. As a result, the attractive force in the driving direction of the electromagnetic actuator 20 of the circuit breaker 1 is significantly increased, allowing the movable contact 11 to move to the fixed contact 10, and the closing operation is performed reliably.

The reason why the magnetic latch portion 75 and the attraction surface having a tapered surface such as the tapered surfaces 513 and 632 can significantly increase the attraction force in the drive direction will be described.
When comparing the coil currents that generate a predetermined attractive force when the armature 23 starts to be driven, the coil current is smaller when the attractive surface is a tapered surface than when the attractive surface is flat instead of tapered. In other words, for the same coil current, the attractive force at the initial position of the armature 23 is larger when the attractive surface is a tapered surface. For this reason, for an electromagnetic actuator that can pass a coil current of the same rated value, the attractive force in the opposite direction to the driving direction generated in the magnetic latch unit 75 can be set larger when the attractive surface is a tapered surface. In other words, by making the attractive surface tapered, the attractive force in the driving direction after the armature 23 starts to be driven increases by the attractive force in the opposite direction to the driving direction generated in the magnetic latch unit 75 compared to when the attractive surface is flat, so that the attractive force in the driving direction can be significantly increased.

Therefore, when comparing the attractive force in the driving direction generated in the armature 23 after the armature 23 begins to drive with the presence or absence of a tapered surface and the presence or absence of the magnetic latch portion 75, the attractive force is greatest when both the tapered surface and the magnetic latch portion 75 are present, the second greatest is when there is no tapered surface but the magnetic latch portion 75 is present, and the attractive force is smallest when the magnetic latch portion 75 is absent regardless of the presence or absence of a tapered surface.
In other words, in the electromagnetic actuator 20 in which the effect of the magnetic latch portion 75 is superimposed on an attraction surface having a tapered surface such as the tapered surfaces 513 and 632, the attractive force generated by the magnetic latch portion 75 in the direction opposite to the driving direction can be set to be large, so that when the armature 23 is driven, the attractive force of the armature 23 can be greatly increased.

Next, a method for fixing the electromagnetic actuator 20 to the housing 2 will be described. FIG. 20 is a front view showing an example of an area of the housing to which the electromagnetic actuator according to the first embodiment is fixed, and FIG. 21 is a side view showing an example of an area of the housing to which the electromagnetic actuator according to the first embodiment is fixed.

20 and 21, the housing 2 includes multiple support parts 81, 82, and 83, and the multiple support parts 81, 82, and 83 protrude in the same direction from the wall part 80 of the housing 2. In the example shown in FIG. 20, the housing 2 includes two support parts 81, two support parts 82, and one support part 83.

Each support portion 81 has an abutment surface 81a that abuts against the fixed portion 67 of the middle core 24B of the electromagnetic actuator 20, and a mounting hole 81b to which a fastener is attached. Each support portion 82 has an abutment surface 82a that abuts against the fixed portion 68 of the middle core 24B of the electromagnetic actuator 20, an abutment surface 82b that abuts against the bottom surface of the outside core 24A of the electromagnetic actuator 20, and a mounting hole 82c to which a fastener is attached. The mounting holes 81b and 82c are, for example, screw holes. The support portion 83 has an abutment surface 83a.

The support parts 81 and 82 are both used to fix the electromagnetic actuator 20 to the housing 2. The support part 81 is used to fix the core lid part 63 side of the core 24 to the housing 2, and the support part 82 is used to fix the core opening end part 60 side of the core 24 to the housing 2. Of the support parts 81 and 82, the support part 82 is further used to position the electromagnetic actuator 20 relative to the housing 2. The contact surface 83a of the support part 83 is used as the axis alignment surface for the electromagnetic actuator 20.

Fig. 22 is a front view showing an example of a region of a housing in a state where an electromagnetic actuator according to embodiment 1 is fixed, and Fig. 23 is a side view showing an example of a region of a housing in a state where an electromagnetic actuator according to embodiment 1 is fixed. Fig. 24 is a cross-sectional view taken along line XXIII-XXIII shown in Fig. 22, and Fig. 25 is a cross-sectional view taken along line XXIV-XXIV shown in Fig. 22.

As shown in FIG. 24, when the electromagnetic actuator 20 is fixed to the housing 2, the fixed portion 67 of the middle core 24B of the electromagnetic actuator 20 is fixed to the fixed portion 67 in abutment against the abutment surface 81a of the support portion 81, and the fixed portion 68 of the middle core 24B of the electromagnetic actuator 20 is fixed to the fixed portion 68 in abutment against the abutment surface 82a of the support portion 82. The fixed portion 67 is fixed to the support portion 81 and the fixed portion 68 is fixed to the support portion 82 by fasteners (not shown).

The core 24 of the electromagnetic actuator 20 is formed by laminating magnetic plates such as electromagnetic steel plates, so there is variation in the thickness of each magnetic plate depending on the number of laminated magnetic plates. In the circuit breaker 1 according to the first embodiment, the middle core 24B of the electromagnetic actuator 20 is fixed to the supports 81 and 82, so the variation in the relative position between the shaft 25 and the housing 2 can be reduced to half the number of laminated middle cores 24B. Therefore, in the circuit breaker 1, the variation in the relative position between the shaft 25 and the housing 2 in the left-right direction shown in FIG. 24 can be significantly reduced compared to when the outside core 24A is fixed to the supports 81 and 82.

Also, as shown in FIG. 24, when the electromagnetic actuator 20 is fixed to the housing 2, the bottom surface 65 of the outside core 24A of the electromagnetic actuator 20 abuts against the abutment surface 82b of the support portion 82. This reduces the variation in the relative position between the shaft 25 and the housing 2 in the vertical direction in FIG. 24.

One method of fixing the electromagnetic actuator to the housing is to press the electromagnetic actuator into the housing to position it, but with this method, the input impact is applied directly to the housing, which may damage the housing. On the other hand, with the above-mentioned method of fixing the electromagnetic actuator 20 to the housing 2, a gap is provided between the electromagnetic actuator 20 and the lower surface 81c of the support part 81 that faces the abutment surface 82b of the support part 82. Therefore, the input impact is applied to the support part 81 via a member that fixes the middle core 24B to the housing 2, such as a bolt, and is not directly applied to the support part 81, which prevents damage to the support part 81.

As shown in FIG. 25, the contact surface 83a of the support portion 83 is contacted with the outside armature 23A via the conductor 26. Since the circuit breaker 1 has the configuration shown in FIG. 1, the stored forces of the opening spring 39 and the contact pressure spring 8 act as a reaction force on the shaft 25 of the electromagnetic actuator 20 along the inclination of the connecting link 31. This reaction force is applied in the direction of the arrow shown in FIG. 25, and acts to rotate the shaft 25 and the armature 23 connected thereto counterclockwise in FIG. 25 with the guide 27 as a fulcrum, but the rotation is suppressed by the contact surface 83a of the support portion 83.

As a result, the shaft 25 does not tilt, and the increase in friction and stroke loss that would occur if the shaft 25 tilts can be prevented, allowing the circuit breaker 1 to perform a stable closing operation. Furthermore, due to the effect of the contact surface 83a of the support portion 83, the electromagnetic actuator 20 can be configured with a single guide 27, without the need to provide multiple guides 27 that guide the shaft 25 in the up and down direction in the electromagnetic actuator 20.

In the example shown in FIG. 25, the armature 23 is applied to the contact surface 83a of the support portion 83 through the conductor 26, but the same effect can be obtained even if the armature 23 is applied directly to the contact surface 83a of the support portion 83.

As described above, the electromagnetic actuator 20 according to the first embodiment is an electromagnetic actuator used for closing the circuit breaker 1, and includes the excitation coil 21, the armature 23, the core 24, and the conductor 26. The excitation coil 21 generates a magnetic flux. The armature 23 is arranged in the internal space of the excitation coil 21 so as to be movable in the driving direction by the magnetic flux generated by the excitation coil 21. The core 24 is arranged outside the excitation coil 21, and forms a magnetic path through which the magnetic flux passes together with the armature 23. The conductor 26 is arranged between the circumferential extension portion 53, which is the latch formation region of the armature 23 that forms the magnetic latch portion 75 that temporarily limits the movement of the armature 23 in the driving direction when power supply to the excitation coil 21 begins, and the protrusion portion 66, which is the latch formation region of the core 24. This allows the electromagnetic actuator 20 to reduce the variation in the attractive force in the driving direction when the armature 23 begins to move in the driving direction.

The end 51 of the armature 23 in the driving direction has a tapered surface 513 that is inclined with respect to the driving direction. The core 24 faces the tapered surface 513 of the end 51 of the armature 23 in a direction parallel to the driving direction, and has a tapered surface 632 that is an attraction surface parallel to the tapered surface 513.

The conductor 26 is also disposed between a portion of the circumferential extension 53, which is the latch formation region of the armature 23, and a portion of the protrusion 66, which is the latch formation region of the core 24. This allows the electromagnetic actuator 20 to suppress variation in the gap between the protrusion 66 of the core 24 and the circumferential extension 53 of the armature 23.

The electromagnetic actuator 20 also includes a bobbin 22 around which the excitation coil 21 is wound. The magnetic latch section 75 is covered by the bobbin 22. This makes it possible for the electromagnetic actuator 20 to suppress misalignment of the members that make up the magnetic latch section 75, thereby stabilizing operation.

The armature 23 has a base 50 extending in the driving direction, and an extension 56 extending in the opposite direction to the driving direction from an end 52 of the base 50 in the opposite direction to the driving direction with an outer diameter smaller than that of the base 50. A circumferential extension 53, which is a latch formation region of the armature 23, is formed at the end 52 of the base 50. The core 24 has a pair of extensions 61 that face the extension 56 in opposite directions to each other in a direction perpendicular to the driving direction. Each of the pair of extensions 61 has an opposing portion 612 that is a first conductor portion that faces the extension 56 in a direction perpendicular to the driving direction, and a protrusion 66 that is a second conductor portion that faces the circumferential extension 53 that is the latch formation region of the armature 23 in the driving direction and functions as the latch formation region of the core 24. This allows the electromagnetic actuator 20 to reduce the variation in the attractive force in the driving direction when the armature 23 starts to move in the driving direction. The configuration of the magnetic latch portion 75 is not limited to the above-mentioned configuration.

The circuit breaker 1 according to the first embodiment includes an electromagnetic actuator 20, a transmission mechanism 30 that causes the movable contact 11 to contact the fixed contact 10 by the driving force of the electromagnetic actuator 20 when the armature 23 of the electromagnetic actuator 20 moves in the driving direction, and a housing 2 that accommodates the electromagnetic actuator 20 and the transmission mechanism 30. The core 24 includes an outside core 24A, a middle core 24B, and an outside core 24A that are stacked in order from the housing 2 side in a direction perpendicular to the driving direction. The outside core 24A is an example of a first divided core or a third divided core, and the middle core 24B is an example of a second divided core. Each of the outside core 24A and the middle core 24B is formed by stacking magnetic plates in a direction perpendicular to the driving direction. The middle core 24B has a plurality of fixed portions 67, 68 that are exposed from the outside core 24A in a direction perpendicular to the driving direction and are fixed to the housing 2. Therefore, in the circuit breaker 1, the variation in the relative position between the shaft 25 and the housing 2 in the left-right direction shown in FIG. 24 can be significantly reduced compared to when the outside core 24A is fixed to the supports 81 and 82.

The housing 2 also includes a plurality of support parts 81, 82 that protrude toward the plurality of fixed parts 67, 68 and fix the plurality of fixed parts 67, 68 to the housing 2. Some of the support parts 81, 82, the support parts 81, fix the fixed part 67 at the end of the core 24 in the driving direction to the housing 2. The remaining support parts 82 of the support parts 81, 82 fix the fixed part 68 at the end of the core 24 in the opposite direction to the driving direction to the housing 2, and further have an abutment surface 82b that abuts against the bottom surface 65 of the armature 23 before it moves in the driving direction. This allows the circuit breaker 1 to reduce variation in the relative position between the shaft 25 and the housing 2 in the vertical direction in FIG. 24 as well.

The housing 2 also includes a support portion 83 having a contact surface 83a that contacts the armature 23 in an area opposite the drive direction, either directly or via the conductor 26. This makes it possible to prevent increased friction and stroke loss caused by tilting of the shaft 25 in the circuit breaker 1, and ensures stable closing operation. Furthermore, in the circuit breaker 1, the effect of the contact surface 83a of the support portion 83 makes it possible to configure the electromagnetic actuator 20 with a single guide 27, without providing multiple guides 27 that guide the shaft 25 in the vertical direction in the electromagnetic actuator 20.

The transmission mechanism 30 also includes a main shaft 32, a link 33, and a moving piece holder 7. The link 33 is an example of a first link, and the moving piece holder 7 is an example of a second link. The main shaft 32 rotates around the rotating shaft 36 as the armature 23 moves in the driving direction. The rotating shaft 36 is an example of a first rotating shaft. The link 33 has one end 33a rotatably connected to the main shaft 32. The moving piece holder 7 has one end 7a rotatably supported by the holder shaft 12 on the housing 2, and the other end 7b rotatably connected to the other end 33b of the link 33. The holder shaft 12 is an example of a second rotating shaft. At least one of the link 33 and the moving piece holder 7 is formed of a resin member. As a result, in the circuit breaker 1, the mass change from the open state to the closed state can be increased, and the effect of the speed increase associated with the mass change can be enhanced.

The circuit breaker 1 also includes a mover 6 having a movable contact 11, and a flexible conductor 5 having one end 5a fixed to the load side terminal 4 and the other end 5b connected to the mover 6. The flexible conductor 5 generates a restoring force in the closing direction that moves the movable contact 11 closer to the fixed contact 10 before power is supplied to the excitation coil 21. This reduces the effect of variations in the arrangement of parts in the circuit breaker 1, enabling stable operation of the electromagnetic actuator 20.

The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies. Parts of the configurations may be omitted or modified without departing from the spirit of the invention.

1 Circuit breaker, 2 Housing, 3 Power supply terminal, 4 Load terminal, 5 Flexible conductor, 5a, 6a, 7a, 31a, 32a, 33a One end, 5b, 6b, 7b, 31b, 32b, 33b Other end, 6 Movable piece, 7 Movable piece holder, 7c Mid-way part, 8 Pressure spring, 9 Movable piece stopper, 10 Fixed contact, 11 Movable contact, 12 Holder shaft, 13 Movable piece pin, 20 Electromagnetic actuator, 21 Excitation coil, 22 Bobbin, 23 Armature, 23A Outside armature, 23B Middle armature, 24 Core, 24A Outside core, 24B Middle core, 25 Shaft, 26 Conductor, 27 Guide, 30 Transmission mechanism, 31 Connecting link, 32 Main shaft, 33 Link, 34, 35, 38 Connecting pin, 36 Rotating shaft, 39 opening spring, 40 tripping mechanism, 41 engagement pin, 42, 43 latch, 45 drive circuit, 50 base, 51, 52 end, 53 circumferential extension, 56 extension, 60 core opening end, 61 extension, 62 opening, 63 core cover, 64 core body, 65 bottom surface, 66 protrusion, 67, 68 fixed portion, 67a, 68a, 634 through hole, 70 first conductor, 71 second conductor, 72 third conductor, 75 magnetic latch portion, 80 wall, 81, 82, 83 support, 81a, 82a, 82b abutment surface, 81b, 82c mounting hole, 81c lower surface, 83a abutment surface, 511 recess, 512, 631 Flat surface, 513, 632 tapered surface, 611 inner surface, 612 opposing portion, M1 first magnetic path, M2 second magnetic path.

Claims (8)

An electromagnetic actuator used for closing a circuit breaker,
An excitation coil that generates a magnetic flux;
an armature disposed in an internal space of the excitation coil so as to be movable in a drive direction by a magnetic flux generated by the excitation coil;
a core that is disposed outside the excitation coil and that, together with the armature, forms a magnetic path through which the magnetic flux passes;
A conductor ;
the armature has a base portion extending in the drive direction, and an extension portion extending in the opposite direction to the drive direction from an end of the base portion in the opposite direction to the drive direction with an outer diameter smaller than that of the base portion, and a circumferential extension portion protruding in a radial direction from an outer periphery of the extension portion is formed at the end of the base portion in the opposite direction to the drive direction,
the core has a pair of core body portions extending in the drive direction, a core lid portion connecting the pair of core body portions at end sides in the drive direction of the core body portions, and a pair of extension portions extending from ends of the pair of core body portions in a direction opposite to the drive direction so as to form an opening through which the extension portion of the armature is inserted, the pair of extension portions are formed with a pair of protrusions that face the circumferential expansion portion of the armature and protrude from the extension portions in the drive direction,
The conductor has a pair of first conductor parts arranged between the pair of circumferential expansion parts of the armature and the pair of protrusion parts of the core, a pair of second conductor parts arranged between the extension part of the armature and the pair of extension parts of the core, and a third conductor part connecting the pair of second conductor parts, and is fixed to the extension parts of the armature.
Electromagnetic actuator. A magnetic latch portion is formed by the circumferential expansion portion of the armature, the pair of protrusions of the core, and the pair of first conductor portions of the conductor.
2. The electromagnetic actuator according to claim 1. The end of the base of the armature in the driving direction is
a tapered surface inclined with respect to the driving direction;
The core lid portion of the core is
3. The electromagnetic actuator according to claim 1, further comprising an attraction surface that faces the tapered surface of the end of the armature in a direction parallel to the driving direction and is parallel to the tapered surface. A bobbin is provided around which the excitation coil is wound,
The circumferential extension portion of the armature, the pair of protrusions of the core, and the pair of first conductor portions of the conductor are
The electromagnetic actuator according to claim 1 , wherein the electromagnetic actuator is covered by the bobbin. An electromagnetic actuator according to any one of claims 1 to 4 ;
a transmission mechanism that causes a movable contact to come into contact with a fixed contact by a driving force of the electromagnetic actuator when the armature of the electromagnetic actuator moves in the driving direction;
a housing that houses the electromagnetic actuator and the transmission mechanism,
The core is
a first divided core, a second divided core, and a third divided core stacked in this order from the housing side in a direction perpendicular to the drive direction,
Each of the first divided core, the second divided core, and the third divided core has
The magnetic plate is formed by stacking magnetic plates in a direction perpendicular to the driving direction,
The second divided core is
a plurality of fixed portions exposed from the first split core and the third split core in a direction perpendicular to the drive direction and fixed to the housing; an electromagnetic actuator used for closing a circuit breaker, the actuator comprising: an excitation coil which generates a magnetic flux; an armature which is disposed in an internal space of the excitation coil and is movable in a drive direction by the magnetic flux generated by the excitation coil; a core which is disposed outside the excitation coil and which, together with the armature, forms a magnetic path through which the magnetic flux passes; and a conductor which is disposed between a latch forming region of the armature and a latch forming region of the core, the latch forming region forming a magnetic latch portion which temporarily limits the movement of the armature in the drive direction when power supply to the excitation coil is started;
a transmission mechanism that causes a movable contact to come into contact with a fixed contact by a driving force of the electromagnetic actuator when the armature of the electromagnetic actuator moves in the driving direction;
a housing that houses the electromagnetic actuator and the transmission mechanism,
the core has a plurality of fixed portions fixed to the housing,
the housing includes a plurality of support portions that protrude toward the plurality of fixed portions and fix the plurality of fixed portions to the housing,
Some of the support parts among the plurality of support parts are
An end portion of the core in the driving direction is fixed to the housing,
The remaining support portions of the plurality of support portions are
an end portion of the core opposite to the driving direction is fixed to the housing, and the end portion further includes an abutment surface that abuts against a bottom surface of the core before the core moves in the driving direction;
The housing includes:
a support portion having a contact surface that is contacted directly or via the conductor in a region of the armature opposite to the driving direction. The transmission mechanism includes:
a main shaft that rotates about a first rotation axis in accordance with movement of the armature in the driving direction;
a first link having one end rotatably connected to the main shaft;
a second link having one end side rotatably supported on a second rotating shaft of the housing and another end side rotatably connected to the other end side of the first link,
7. The circuit breaker according to claim 5 , wherein at least one of the first link and the second link is formed of a resin member. a movable element having the movable contact;
a flexible conductor having one end fixed to a load side terminal and the other end connected to the movable element,
The flexible conductor includes:
8. The circuit breaker according to claim 5, wherein a restoring force is generated in a closing direction that moves the movable contact toward the fixed contact before power is supplied to the exciting coil.

Images