JP2017027710A - Electromagnetic pull-out device and circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic pull-out device that can suppress a magnetic flux leaking from the gap between a pole head and an armature, and a circuit breaker using the same.SOLUTION: A plunger 2 and a damping spring 3 are arranged inside a cylinder 1 which is formed in a cylindrical shape to be bottomed. A pole head 4 closes the opening of the cylinder 1. An electromagnetic coil 5 is wound around the cylinder 1. A yoke 6 has a first piece 6a and a second piece 6b which are arranged along the axial direction of the cylinder 1. An armature 7 is supported by the yoke 6 so as to be rotatable between a first position where the armature 7 is in contact with the pole head 4 and a second position where the armature 7 is away from the pole head 4. A magnetic shielding piece 9 is provided to the pole head 4 and arranged at a side of the armature 7. The armature 7 is rotatable within a range where the armature 7 does not protrude from the magnetic shielding piece 9 in the axial direction of the cylinder 1 in side view.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electromagnetic trip device and a circuit breaker, and more particularly to an electromagnetic trip device and a circuit breaker using an electromagnetic coil.

  2. Description of the Related Art Conventionally, there has been known a circuit breaker that includes a plurality of electromagnetic devices each having an electromagnetic coil and covers the outer periphery of the electromagnetic coil in the electromagnetic device with a case formed of a magnetic shielding member (for example, see Patent Document 1).

  The electromagnetic device of patent document 1 has a yoke (yoke), an oil dashpot, an electromagnetic coil, a case, and a movable iron piece (amateur). An electromagnetic coil is wound around the outer periphery of the oil dash pot, and the outer periphery of the electromagnetic coil is covered with a case. The movable iron piece is provided near the upper end of the side plate of the yoke. The movable iron piece can be tilted up and down in a horizontal posture in contact with a fixed iron piece (pole head) provided at the upper end of the oil dash pot and an inclined posture away from the fixed iron piece. The electromagnetic coil is connected to the main circuit. When an overcurrent occurs in the main circuit, a current flows through the electromagnetic coil and is excited, and the fixed iron piece attracts the movable iron piece to the horizontal posture side. When the movable iron piece is attracted to the fixed iron piece, the movable iron piece operates the trip bar, and the main circuit is shut off by an opening / closing mechanism linked to the trip bar.

  The case shields the magnetic field of the electromagnetic coil of the adjacent pole when an overcurrent occurs in the main circuit. In the circuit breaker of Patent Document 1, the mutual influence due to the magnetic field generated from the adjacent electromagnetic coils is reduced by interposing the case between the adjacent electromagnetic coils.

JP 2002-251949 A

  The case in Patent Document 1 reduces the mutual influence of a magnetic field generated from an adjacent electromagnetic coil when a current flows through the electromagnetic coil, but leakage between a fixed iron piece (pole head) and a movable iron piece (amateur). There was a possibility that the magnetic flux could not be suppressed.

  The present invention has been made in view of the above reasons, and an object thereof is to provide an electromagnetic trip device capable of suppressing magnetic flux leaking between a pole head and an amateur and a circuit breaker using the same.

  The electromagnetic trip device of the present invention comprises a cylinder made of a non-magnetic material having a bottomed cylindrical shape, a magnetic body, a plunger provided inside the cylinder, provided inside the cylinder, and A brake spring that pushes toward the bottom of the cylinder, a magnetic body, a pole head that closes the opening of the cylinder, an electromagnetic coil wound around the cylinder, and a magnetic body, provided outside the electromagnetic coil. A yoke having a first piece disposed along the axial direction of the cylinder, and a second piece disposed along a direction intersecting the axial direction of the cylinder from the first piece; An arm supported by the yoke so as to be rotatable between a first position in contact with the pole head and a second position away from the pole head; and the pole head A magnetic shielding piece provided on a side of the armature, and the armature is rotatable in a range not protruding from the magnetic shielding piece in the axial direction of the cylinder in a side view. To do.

  A circuit breaker according to the present invention includes the above-described electromagnetic trip device.

  The electromagnetic trip device of the present invention can suppress magnetic flux leaking from between the pole head and the amateur.

  The circuit breaker of the present invention can suppress magnetic flux leaking from between the pole head and the amateur.

It is sectional drawing of the electromagnetic trip apparatus 100 which concerns on one Embodiment of this invention. It is sectional drawing for demonstrating operation | movement of the electromagnetic trip apparatus 100 which concerns on the same embodiment in the case of a low overcurrent area | region. It is another sectional view for explaining the operation of the electromagnetic trip device according to the same embodiment in the case of the low overcurrent region. It is sectional drawing for demonstrating operation | movement of the electromagnetic trip apparatus 100 which concerns on the same embodiment in the case of a starting electric current area | region. It is sectional drawing for demonstrating operation | movement of the electromagnetic trip apparatus 100 which concerns on the same embodiment in the case of a short circuit current area | region. It is a perspective view of the electromagnetic trip device 100 concerning the embodiment. It is a principal part enlarged view of the circuit breaker 10 provided with the electromagnetic trip device 100 concerning the embodiment. It is a sectional view of circuit breaker 10 provided with electromagnetic trip device 100 concerning the embodiment.

  Hereinafter, an electromagnetic trip device 100 according to an embodiment of the present invention will be described with reference to FIGS.

<Configuration>
FIG. 1 is a basic configuration diagram of an electromagnetic tripping device 100 according to the present embodiment. The electromagnetic trip device 100 includes a cylinder 1, a plunger 2, a braking spring 3, a pole head 4, an electromagnetic coil 5, a yoke 6, an armature 7, and a magnetic shielding piece 9.

  The cylinder 1 is made of a nonmagnetic material (for example, brass) and is formed in a bottomed cylindrical shape. A plunger 2 and a braking spring 3 are arranged inside the cylinder 1. The opening of the cylinder 1 is closed with a pole head 4. The brake spring 3 is a coil spring. In the following description, the opening side of the cylinder 1 is called a front end side, and the bottom side of the cylinder 1 is called a rear end side.

  The plunger 2 is made of a magnetic material and is provided inside the cylinder 1. The plunger 2 has a substantially axisymmetric shape with a substantially circular cross section. The plunger 2 includes a columnar protrusion 2 a having a diameter smaller than the inner diameter of the brake spring 3 and a columnar large diameter portion 2 b with which one end of the brake spring 3 contacts. The diameter of the large diameter portion 2 b is larger than the inner diameter of the brake spring 3. The protruding portion 2 a is configured to enter the inside of the braking spring 3. The brake spring 3 is provided inside the cylinder 1 and pushes the plunger 2 toward the bottom of the cylinder 1.

  The pole head 4 is made of a magnetic material and closes the opening of the cylinder 1. The plunger 2 and the brake spring 3 are accommodated in a space surrounded by the cylinder 1 and the pole head 4. The space surrounded by the cylinder 1 and the pole head 4 is in a sealed state and is filled with a liquid such as silicone oil, but may be configured not to be filled with a liquid. 2 to 5, the illustration of the braking spring 3 is omitted for easy understanding of the configuration.

  The yoke 6 is made of a substantially L-shaped magnetic material. The yoke 6 is provided outside the electromagnetic coil 5, and is disposed along a direction intersecting the axial direction of the cylinder 1 from the first piece 6 a and the first piece 6 a disposed along the axial direction of the cylinder 1. And a second piece 6b. The second piece 6 b extends from the rear end of the first piece 6 a toward the plunger 2 side, and is fixed to the cylinder 1. The first piece 6a is preferably disposed in parallel to the axis of the cylinder 1. The second piece 6b preferably extends in a direction perpendicular to the axis of the cylinder 1 from the rear end of the second piece 6b. The yoke 6 only needs to be arranged so as to form a magnetic path with the plunger 2 as will be described later, and is not necessarily fixed to the cylinder 1.

  The electromagnetic coil 5 is wound around the cylinder 1. The electromagnetic coil 5 is disposed at a position sandwiched between the plunger 2 and the yoke 6.

  The electromagnetic coil 5 is electrically connected to the main electric circuit 11 of the circuit breaker 10 (see FIG. 8). In the present embodiment, the electromagnetic coil 5 and the main electric circuit 11 are separate members and are electrically connected. However, the present invention is not limited to this, and the electromagnetic coil 5 and the main electric circuit 11 are integrally formed of the same member. Also good.

  Amateur 7 is made of a magnetic material. The amateur 7 is connected to the first piece 6a of the yoke 6 so as to be able to rotate toward the pole head 4 side. In other words, the armature 7 is supported by the yoke 6 so as to be rotatable between a first position in contact with the pole head 4 and a second position away from the pole head 4. As shown in FIG. 1, the second position of the amateur 7 is a position in which the tip portion of the amateur 7 opposite to the portion supported by the yoke 6 is separated from the pole head 4. A tip portion of the amateur 7 opposite to the portion supported by the yoke 6 receives a spring force in a direction away from the pole head 4 by a coil spring 71 (see FIG. 8). As shown in FIGS. 3 to 5, the first position of the amateur 7 is a position in a state where the tip portion of the amateur 7 opposite to the portion supported by the yoke 6 is in contact with the pole head 4. The armature 7 in the first position is attracted to the pole head 4 with a suction force that exceeds the spring force received from the coil spring.

  The amateur 7 can rotate within a range that does not protrude from the magnetic shielding piece 9 in the axial direction of the cylinder 1 in a side view.

  The magnetic shielding piece 9 is formed in a rectangular plate shape. The magnetic shielding piece 9 is provided on the pole head 4 and is disposed on the side of the armature 7. The magnetic shielding piece 9 is arranged so that the plane portion is orthogonal to a plane parallel to the front surface of the pole head 4. The magnetic shielding piece 9 is fixed to the pole head 4 by a support portion 91. The support portion 91 is provided at an edge portion of the magnetic shielding piece 9 close to the pole head 4. The support portion 91 is provided to increase the distance from the edge portion of the pole head 4 to the planar portion of the magnetic shielding piece 9. The support portion 91 prevents the magnetic shielding piece 9 from coming into contact with the armature 7 when the armature 7 moves to the first position. The pole head 4, the support portion 91, and the magnetic shielding piece 9 are integrally formed of the same member. The magnetic shielding piece 9 is formed in such a size that the armature 7 does not protrude in the axial direction of the cylinder 1 in a side view, regardless of whether the armature 7 is in the first position or the second position. “Side view” means viewed from a direction perpendicular to the axial direction of the cylinder 1 and along the thickness direction of the magnetic shielding piece 9.

  As shown in FIG. 7, the circuit breaker 10 includes three electromagnetic trip devices 100. In this embodiment, when distinguishing and explaining each electromagnetic trip apparatus 100, it calls the electromagnetic trip apparatuses 101-103. When the electromagnetic trip devices 101 to 103 are not distinguished from each other, the electromagnetic trip devices 101 to 103 are referred to as an electromagnetic trip device 100.

  As shown in FIG. 8, the circuit breaker 10 of this embodiment includes a latch 50, a trip mechanism 51, a handle 52, and a contact 53. The three electromagnetic trip devices 100 in the circuit breaker 10 are arranged side by side in a direction in which the axial directions of the cylinders 1 are parallel to each other and perpendicular to the axial direction of the cylinders 1. When the handle 52 is operated or when the latch 50 is pushed by the amateur 7, the trip mechanism 51 operates to open the contact 53, and the circuit breaker 10 opens the electric circuit electrically connected to the contact 53. Open electrically. As an example, each of the electromagnetic trip devices 101 to 103 of the circuit breaker 10 of the present embodiment is electrically connected to a three-phase three-wire distribution system electric circuit.

<Operation>
Hereinafter, the operation of the electromagnetic trip device 100 according to the present embodiment when the current flowing through the electromagnetic coil 5 is in the low overcurrent region will be described with reference to FIGS. The current in the low overcurrent region is, for example, a current that is about 1.25 to 2 times the rated current of the electromagnetic trip device 100.

  When a current flows through the electromagnetic coil 5, a magnetic flux is formed. The magnetic flux passes through a magnetic path formed by the pole head 4, the armature 7, the yoke 6 and the plunger 2. As shown in FIG. 1, since a gap is formed between the pole head 4 and the protruding portion 2 a of the plunger 2, a magnetic attractive force acts between the pole head 4 and the plunger 2. That is, a force in the direction of moving toward the pole head 4 acts on the plunger 2.

  When the magnetic attractive force acting on the plunger 2 becomes larger than the force by which the braking spring 3 pushes the plunger 2, the plunger 2 starts to move toward the pole head 4 side. As the plunger 2 moves, the gap length between the pole head 4 and the plunger 2 (projecting portion 2a) becomes smaller. If the gap length is reduced, the resistance of the magnetic circuit formed by the pole head 4, the armature 7, the yoke 6, and the plunger 2 is reduced, so that the magnetic flux is increased.

  By increasing the magnetic flux, the magnetic attractive force acting on the plunger 2 is further increased, and the gap length between the pole head 4 and the plunger 2 is further decreased. By repeating the above, the gap length gradually decreases and the magnetic flux gradually increases. In the case of the low overcurrent region, as shown in FIG. 2, when the protrusion 2 a of the plunger 2 approaches the pole head 4 or reaches a position in contact with the pole head 4, the arm 7 moves toward the pole head 4 side. A large suction force heads. The amateur 7 rotates toward the pole head 4 with the portion supported by the yoke 6 as an axis, and moves to a first position in contact with the pole head 4 as shown in FIG. Then, when the armature 7 moves to the first position, the latch 50 (see FIG. 8) of the mechanism part of the circuit breaker 10 is pushed. When the latch 50 is pushed by the amateur 7, the trip mechanism 51 operates to open the contact 53. That is, the circuit breaker 10 electrically opens the energized circuit.

  Since the magnetic shield piece 9 is provided on the pole head 4, an attractive force directed toward the magnetic shield piece 9 also acts on the armature 7. However, this suction force works in a direction perpendicular to the direction in which the armature 7 moves from the second position to the first position, and thus has a great influence when the armature 7 moves closer to the pole head 4. Absent.

  Next, the operation of the electromagnetic tripping device 100 according to this embodiment when the current flowing through the electromagnetic coil 5 is in the starting current region will be described with reference to FIG. The current in the starting current region is, for example, about 6 to 8 times the rated current of the electromagnetic trip device 100.

  When a current flows through the electromagnetic coil 5, a magnetic flux is formed. The magnetic flux passes through a magnetic path formed by the pole head 4, the armature 7, the yoke 6 and the plunger 2. Gaps are formed between the pole head 4 and the plunger 2 and between the armature 7 and the pole head 4, respectively. Therefore, when a current flows through the electromagnetic coil 5, a force in the direction of moving toward the pole head 4 acts on the plunger 2 and the armature 7 due to the magnetic attractive force.

  Compared to the low overcurrent region, in the starting current region, the current flowing through the electromagnetic coil 5 is large, so that a larger magnetic flux can be obtained. Therefore, when the gap length between the pole head 4 and the plunger 2 is reduced to some extent, the armature 7 starts to move toward the pole head 4 side. In the case of the starting current region, when the gap length between the pole head 4 and the plunger 2 becomes about 70% of the gap length in the case of no energization (see FIG. 4), the armature 7 rotates from the first position. And move to the second position. And the amateur 7 pushes the latch 50 of the mechanism part of the circuit breaker 10.

  Next, the operation of the electromagnetic tripping device 100 according to this embodiment when the current flowing through the electromagnetic coil 5 is in the short-circuit current region will be described with reference to FIG. The current in the short-circuit current region is, for example, a current that is greater than 8 times the rated current.

  When the current flowing through the electromagnetic coil 5 is in the short-circuit current region, the current is larger than eight times the rated current, so that a large magnetic flux can be obtained even if the gap length between the pole head 4 and the plunger 2 is not reduced. Therefore, even when the plunger 2 is not substantially moved, the armature 7 rotates from the first position and moves to the second position. That is, the armature 7 rotates from the first position and moves to the second position in a relatively short time after a sufficiently large current with respect to the rated current starts to flow through the electromagnetic coil 5. Therefore, when the current flowing through the electromagnetic coil 5 is in the short-circuit current region, the armature 7 is moved to the second position even when the plunger 2 is not substantially moved from the bottom side of the cylinder 1 as shown in FIG. It has become.

  When the current flowing through the electromagnetic coil 5 is in the short-circuit current region, a large magnetic flux can be obtained even if the gap length between the pole head 4 and the plunger 2 is not reduced, and the armature 7 can rotate in a relatively short time from the start of energization. It moves and is attracted to the pole head 4 side. On the other hand, the plunger 2 cannot operate in a time as short as the amateur 7 due to the influence of the viscosity of the fluid existing inside the cylinder 1. Therefore, when the armature 7 rotates and is attracted to the pole head 4 side, the plunger 2 is still at the bottom of the cylinder 1 as shown in FIG.

<Action>
Hereinafter, the operation of the magnetic shielding piece 9 of the present embodiment will be described with reference to FIG.

  When a current flows through each of the electromagnetic coils 5 of the electromagnetic trip devices 101 to 103, a magnetic flux is generated. Since the electromagnetic trip devices 101 to 103 have the magnetic shielding pieces 9, the respective magnetic fluxes generated by the electromagnetic trip devices 101 to 103 are mainly the pole head 4, the armature 7, the magnetic shielding pieces 9, and the yoke 6. And pass through magnetic paths L1 to L3 formed by the plunger 2. A part of each magnetic flux generated in the electromagnetic trip devices 101 to 103 passes through a magnetic path formed by the pole head 4, the magnetic shielding piece 9, the yoke 6, and the plunger 2. Since the magnetic shielding piece 9 is disposed between the pole head 4 and the amateur 7, the leakage magnetic flux between the pole head 4 and the amateur 7 is suppressed.

<Effect>
Hereinafter, the effect of the electromagnetic trip device 100 of the present embodiment will be described in comparison with a comparative example. The circuit breaker of the comparative example is an electromagnetic trip device that does not have the magnetic shielding piece 9.

  When currents having different polarities flow through the three electromagnetic tripping devices of the comparative examples, the magnetic fluxes generated by the adjacent electromagnetic tripping devices are opposite to each other. Therefore, there is a possibility that the magnetic fluxes generated by the adjacent electromagnetic trip devices weaken each other.

  On the other hand, the electromagnetic trip devices 101 to 103 of the present embodiment have a magnetic shielding piece 9. The magnetic shielding piece 9 is provided on the pole head 4 and is disposed on the side of the armature 7. Respective magnetic fluxes generated by the electromagnetic trip devices 101 to 103 mainly pass through magnetic paths L1 to L3 formed by the pole head 4, the armature 7, the magnetic shielding piece 9, the yoke 6, and the plunger 2. . Since the magnetic shielding piece 9 forms a magnetic path between the armature 7 and the pole head 4, the magnetic flux leakage between the pole head 4 and the armature 7 is suppressed. Therefore, the electromagnetic trip devices 101 to 103 arranged side by side in the direction orthogonal to the axial direction of the plunger 2 are difficult to weaken each other's magnetic flux. Since the amount of magnetic flux generated in the electromagnetic coil 5 is easily stabilized according to the magnitude of the current flowing through the electromagnetic coil 5, the operating characteristics of the amateur 7 with respect to the magnitude of the current flowing through the electromagnetic coil 5 can be stabilized. For example, it is possible to suppress a delay in the timing of the arm 7 rotating and moving with respect to the magnitude of the current flowing through the electromagnetic coil 5.

  Further, by suppressing the magnetic flux leaking between the armature 7 and the pole head 4, the decrease in the amount of magnetic flux passing through the magnetic path formed by the pole head 4, the armature 7, the yoke 6 and the plunger 2 is suppressed. . Therefore, even when the number of electromagnetic trip devices 100 is one, the amount of magnetic flux generated when a current flows through the electromagnetic coil 5 is easily stabilized, and the operation of the armature 7 with respect to the magnitude of the current flowing through the electromagnetic coil 5 The characteristics can be stabilized.

  As described above, the electromagnetic trip device 100 of the present embodiment includes the cylinder 1, the plunger 2, the brake spring 3, the pole head 4, the electromagnetic coil 5, the yoke 6, the armature 7, and the magnetic shield. And a piece 9. The cylinder 1 is made of a bottomed cylindrical nonmagnetic material. The plunger 2 is made of a magnetic material and is provided inside the cylinder 1. The brake spring 3 is provided inside the cylinder 1 and pushes the plunger 2 toward the bottom of the cylinder 1. The pole head 4 is made of a magnetic material and closes the opening of the cylinder 1. The electromagnetic coil 5 is wound around the cylinder 1. The yoke 6 is made of a magnetic material, is provided outside the electromagnetic coil 5, and is arranged in a direction intersecting the axial direction of the cylinder 1 from the first piece 6 a disposed along the axial direction of the cylinder 1 and the first piece 6 a. It has the 2nd piece 6b arrange | positioned along. The amateur 7 is made of a magnetic material, and is supported by the yoke 6 so as to be rotatable between a first position in contact with the pole head 4 and a second position away from the pole head 4. The magnetic shielding piece 9 is provided on the pole head 4 and is disposed on the side of the armature 7. The amateur 7 has the axis of the cylinder 1 from the magnetic shielding piece 9 in a side view (when viewed from a direction perpendicular to the axial direction of the cylinder 1 and a direction parallel to the plane portion of the first piece 6a of the yoke 6). It can be rotated in the range that does not come out in the direction.

  According to the above configuration, the armature 7 has a magnetic shielding piece in a side view (when viewed from a direction orthogonal to the axial direction of the cylinder 1 and a direction parallel to the plane portion of the first piece 6a of the yoke 6). 9 is rotated in a range not coming out in the axial direction of the cylinder 1. The magnetic shielding piece 9 is disposed on the side of the armature 7 and forms a magnetic path between the armature 7 and the pole head 4 at the second position (position not in contact with the pole head 4). Therefore, the magnetic shielding piece 9 suppresses leakage magnetic flux between the armature 7 and the pole head 4. In other words, the electromagnetic tripping device 100 can suppress the leakage magnetic flux between the pole head 4 and the amateur 7.

  In the electromagnetic trip device 100 of this embodiment, it is preferable that the pole head 4 and the magnetic shielding piece 9 are the same member and are integrally formed.

  According to the above configuration, since the magnetic shielding piece 9 is provided on the pole head 4, an increase in the number of parts of the electromagnetic trip device 100 can be suppressed. By providing the magnetic shielding piece 9 on the pole head 4, the number of assembling steps of the electromagnetic trip device 100 can be reduced.

  The circuit breaker 10 according to the present embodiment includes the electromagnetic trip device 100 described above.

  According to the above configuration, the circuit breaker 10 can suppress the leakage magnetic flux between the pole head 4 and the amateur 7.

  Since the magnetic shielding piece 9 of the present embodiment is provided on the pole head 4, an increase in the number of parts of the circuit breaker 10 can be suppressed. By providing the magnetic shielding piece 9 on the pole head 4, the assembly man-hour of the circuit breaker 10 can be reduced.

  It does not matter whether the material of the magnetic shielding piece 9 is the same as that of the pole head 4 or not. Further, the magnetic shielding piece 9 and the pole head 4 do not need to be integrally formed, and the magnetic shielding piece 9 and the pole head 4 may be connected by welding or the like.

  The magnetic shielding piece 9 of this embodiment overlaps with a part of the pole head 4 including the front surface of the pole head 4 when viewed from the side, but does not have to overlap with a part of the pole head 4. The magnetic shielding piece 9 overlaps the armature 7 protruding from the yoke 6 when viewed from the side, but the armature 7 protrudes from the magnetic shielding piece 9 in the thickness direction of the first piece 6a when viewed from the side. May be. Even in that case, the magnetic shielding piece 9 can suppress the leakage magnetic flux between the pole head 4 and the armature 7.

  Although the circuit breaker 10 of this embodiment is provided with the three electromagnetic trip apparatuses 100, it should just be provided with the at least 1 electromagnetic trip apparatus 100. FIG. For example, in the case of the circuit breaker 10 that electrically disconnects the three electric paths, three electromagnetic trip devices are required, but two electromagnetic trip devices 100 of the present embodiment are provided, and a magnetic shielding piece is further provided. One electromagnetic tripping device not provided with 9 may be provided. By disposing an electromagnetic tripping device that does not include the magnetic shielding piece 9 next to the magnetic shielding piece 9, the electromagnetic tripping device 100 of the present embodiment, and an electromagnetic tripping device that does not include the magnetic shielding piece 9 It is possible to suppress the mutual interference of the magnetic flux by the magnetic shielding piece 9.

  The magnitude of the current in the low overcurrent area, the magnitude of the current in the starting current area, and the magnitude of the current in the short-circuit current area with respect to the rated current of the electromagnetic trip device 100 are examples, and are limited to the above-described magnitudes of current. Not intended. The current in the low overcurrent region, the current in the starting current region, and the current in the short circuit current region are such that the current increases in the order of the current in the low overcurrent region, the current in the starting current region, and the current in the short circuit current region. Any current may be used.

  By the way, the magnetic shielding piece 9 may be formed of a member different from the pole head 4. Hereinafter, an electromagnetic trip device 100 in which the magnetic shielding piece 9 is formed of a member different from the pole head 4 and formed of a member having a higher magnetic permeability than the pole head 4 will be described as a modification of the present embodiment. .

  In the electromagnetic trip device 100 of this modification, the pole head 4 and the magnetic shielding piece 9 are formed of different members. The magnetic shielding piece 9 is fixed to the pole head 4 by welding or caulking. Since the pole head 4 and the magnetic shielding piece 9 can be formed of different members, the pole head 4 and the magnetic shielding piece 9 can be individually formed. Therefore, compared with the case where the pole head 4 and the magnetic shielding piece 9 are integrally formed, each of the pole head 4 and the magnetic shielding piece 9 is easily formed in an arbitrary shape. Further, since the fixing position of the magnetic shielding piece 9 with respect to the pole head 4 can be determined after the pole head 4 and the magnetic shielding piece 9 are formed, the degree of freedom of the fixing position of the magnetic shielding piece 9 with respect to the pole head 4 is increased. be able to.

  The magnetic shielding piece 9 of this modification is formed of a material having a higher magnetic permeability than the pole head 4. By making the permeability of the magnetic shielding piece 9 higher than the permeability of the pole head 4, the effect of magnetically shielding the magnetic flux leaking between the pole head 4 and the armature 7 can be enhanced.

  As described above, in the electromagnetic trip device 100 of the present modification, the pole head 4 and the magnetic shielding piece 9 are different members.

  According to the above configuration, since the pole head 4 and the magnetic shielding piece 9 are different members, the pole head 4 and the magnetic shielding piece 9 are compared with the case where the pole head 4 and the magnetic shielding piece 9 are integrally formed. Each can be easily formed into an arbitrary shape.

  In the present embodiment, since the fixing position of the magnetic shielding piece 9 with respect to the pole head 4 can be determined after the pole head 4 and the magnetic shielding piece 9 are formed, the degree of freedom of the fixing position of the magnetic shielding piece 9 with respect to the pole head 4 is determined. Can be raised.

  In the electromagnetic trip device 100 of the present modification, it is preferable that the magnetic shielding piece 9 has a higher magnetic permeability than the pole head 4.

  According to the above configuration, the effect of magnetically shielding the magnetic flux leaking from between the pole head 4 and the armature 7 can be enhanced by making the magnetic shielding piece 9 have a higher magnetic permeability than the magnetic permeability of the pole head 4. it can.

(Conclusion)
As described above, the embodiments have been described as examples of the technology in the present invention. For this purpose, the accompanying drawings and detailed description are provided.

  Accordingly, among the components described in the attached drawings and detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to exemplify the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  Moreover, since the above-mentioned embodiment is an illustration of the technique in the present invention, various modifications, replacements, additions, omissions, and the like can be made within the scope of the claims or an equivalent scope thereof.

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Plunger 3 Braking spring 4 Pole head 5 Electromagnetic coil 6 Yoke 6a 1st piece 6b 2nd piece 7 Amateur 9 Magnetic shielding piece 10 Circuit breaker 100 Electromagnetic trip device

Claims (5)

A cylinder made of a non-magnetic material having a cylindrical shape with a bottom;
A plunger made of a magnetic material and provided inside the cylinder;
A braking spring provided inside the cylinder and pushing the plunger toward the bottom of the cylinder;
A pole head made of a magnetic material and blocking the opening of the cylinder;
An electromagnetic coil wound around the cylinder;
A first piece made of a magnetic material, provided outside the electromagnetic coil and disposed along the axial direction of the cylinder, and disposed along a direction intersecting the axial direction of the cylinder from the first piece. A yoke having a second piece;
An armature made of a magnetic material and supported by the yoke so as to be rotatable between a first position in contact with the pole head and a second position away from the pole head;
A magnetic shielding piece provided on the pole head and disposed on the side of the amateur,
The electromagnetic trip device according to claim 1, wherein the armature is rotatable in a range that does not protrude from the magnetic shielding piece in the axial direction of the cylinder in a side view. The electromagnetic trip device according to claim 1, wherein the pole head and the magnetic shielding piece are the same member and are integrally formed. The electromagnetic trip device according to claim 1, wherein the pole head and the magnetic shielding piece are different members. The electromagnetic trip device according to claim 3, wherein a magnetic permeability of the magnetic shielding piece is higher than a magnetic permeability of the pole head. A circuit breaker comprising the electromagnetic trip device according to any one of claims 1 to 4.

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