CN116547769A

CN116547769A - Electromagnetic contactor

Info

Publication number: CN116547769A
Application number: CN202180078025.1A
Authority: CN
Inventors: 五十岚胜俊; 曾田昇吾
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2023-08-04
Anticipated expiration: 2041-03-19
Also published as: WO2022195835A1; JPWO2022195835A1; CN116547769B; JP7008888B1; KR20230077755A; KR102633487B1

Abstract

An object of the present invention is to provide an electromagnetic contactor capable of preventing a movable core from being separated poorly without using a nonmagnetic spacer. For this purpose, in the electromagnetic contactor of the present invention, a plurality of slits are formed in the fixed core or the movable core so as to define a path of magnetic flux generated when a current is applied to the coil and extend the path. The magnetic resistance can be increased without using a nonmagnetic spacer to reduce the magnetic flux, prevent poor separation, and reduce the number of components to reduce the cost.

Description

Electromagnetic contactor

Technical Field

The present invention relates to an electromagnetic contactor having a coil, a fixed core, and a movable core.

Background

The electromagnet portion of the electromagnetic contactor applies a voltage to the coil, thereby forming a magnetic circuit between the movable core and the fixed core, and the movable core is attracted to the fixed core to be in a closed state. On the other hand, when the attraction of the cores is released, the application of voltage to the coils is stopped, so that the magnetic flux in the cores is reduced, the holding force between the cores is weakened, and the movable cores are separated from the fixed cores, and the movable cores are brought into an open state.

In order to prevent the electromagnetic contactor from becoming a separation failure when the electromagnetic contactor is in an open state, it is necessary to reduce the holding force for the movable core to be attracted to the fixed core. For example, in patent document 1, a nonmagnetic spacer is provided between a fixed core and a movable core, which are paths of magnetic fluxes, in order to prevent separation failure.

Patent document 1: japanese laid-open patent publication No. 51-147263

Disclosure of Invention

However, in the technique described in patent document 1, since the nonmagnetic spacer is provided, the number of components increases, and thus there is a problem that the manufacturing cost is increased. Further, by providing the nonmagnetic spacer, the magnetic resistance increases, and in the closed state, it is necessary to increase the holding current for attracting the movable core.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electromagnetic contactor capable of preventing a separation failure of a movable core without providing a nonmagnetic spacer.

An electromagnetic contactor of the present invention includes: a fixed iron core which winds a coil and generates a magnetic field by applying a current to the coil; and a movable core that moves to a closest position to the fixed core when a magnetic field generated in the fixed core is generated, and that contacts the fixed core, wherein a plurality of slits are formed in the fixed core or the movable core so as to define and extend a path of a magnetic flux generated when a current is applied to the coil.

ADVANTAGEOUS EFFECTS OF INVENTION

The electromagnetic contactor of the present invention can prevent poor separation without using a nonmagnetic spacer by providing a slit in the fixed core or the movable core, and therefore can reduce the number of components and reduce the cost.

Drawings

Fig. 1 is an external oblique view of an electromagnetic contactor according to embodiment 1.

Fig. 2 is an internal perspective view of the electromagnetic contactor according to embodiment 1.

Fig. 3 is an internal cross-sectional view of the electromagnetic contactor of embodiment 1.

Fig. 4 is an internal cross-sectional view of the electromagnetic contactor of embodiment 2.

Fig. 5 is an internal cross-sectional view of the electromagnetic contactor of embodiment 3.

Fig. 6 is an internal cross-sectional view of the electromagnetic contactor of embodiment 4.

Detailed Description

Embodiment 1.

Fig. 1 is an external oblique view of an electromagnetic contactor 1 according to embodiment 1. As shown in fig. 1, the electromagnetic contactor 1 includes a top case 2, a bottom case 3, and coil terminals 4A and 4B.

The top case 2 accommodates a contact portion not shown. The contact portion forms a part of a circuit for opening and closing a current flowing through a load such as a motor, and is energized in a closed state and is not energized in an open state.

The bottom case 3 is fixed to the top case 2, and accommodates the movable core 5 and the fixed core 61.

Coil terminals 4A, 4B are fixed to bottom case 3. The coil terminals 4A and 4B are terminals for applying a voltage to a coil 8 described later of the electromagnetic contactor 1, and are made of, for example, ferrous metal capable of being energized.

Next, the internal structure of the electromagnetic contactor 1 will be described. Fig. 2 is an internal perspective view of the electromagnetic contactor 1. As shown in fig. 2, the electromagnetic contactor 1 includes a movable core 5, a fixed core 61, a coil bobbin 7, and a coil 8 inside a bottom case 3.

In the following description, the direction in which the movable core 5 moves is defined as the up-down direction when the movable core 5 and the fixed core 61 are in contact and not in contact. The direction that crosses the vertical direction and extends along the longitudinal direction of the movable core 5 is defined as the left-right direction. The direction transverse to the vertical direction and along the width direction of the movable core is defined as the depth direction.

The movable core 5 has an I-shape and may be formed of either a laminated core or a block core. The movable core 5 is provided on the upper portion of the fixed core 61 so as to be movable up and down, and is moved to the closest position to the fixed core 61 by the magnetic field generated in the fixed core 61 being moved downward, and is moved upward when no magnetic field is generated. The closest position of the movable iron core 5 with respect to the fixed iron core 61 is the position of the movable iron core 5 in which the movable iron core is in the closed state. The movable core 5 and the movable-side contacts are linked, and the movable core 5 moves downward, whereby the movable-side contacts and the fixed-side contacts are closed, and the movable core 5 moves upward, whereby the contacts are opened. The movable core 5 and the fixed core 61 have the same height of contact surfaces, and the movable core 5 and the fixed core 61 are in contact with each other through the contact surfaces. The movable core 5 of fig. 2 is provided with a hole for fixing a driving member that is linked to the movable core 5. The hole is used to allow a rivet for connecting the laminated cores to pass when the movable core 5 is constituted of the laminated cores.

The fixed core 61 has an E-shape and may be formed of either a laminated core or a block core. Hereinafter, the left side as viewed from the front of the fixed core 61 is referred to as a left pole, the center is referred to as a center pole, and the right side is referred to as a right pole. The portion connecting the center pole and the right pole of the fixed core 61 and the center pole and the left pole is referred to as a connecting side. No gap is generated between the fixed core 61 and the movable core 5 of the present invention.

Conventionally, in order to prevent separation failure, a method of shortening the left and right poles of the fixed core 61 from the center pole is known instead of using a nonmagnetic spacer. By shortening the center pole of the fixed core 61 from the right pole to the left pole, a gap can be provided between the center pole of the fixed core 61 and the movable core 5 in the closed state of the electromagnetic contactor 1. In the method of forming the gap as described above, only the center pole of the fixed core 61 and the movable core 5 are repeatedly contacted, and thus the center pole of the fixed core 61 is extremely easily worn. Due to wear, the distance between the center pole of the fixed core 61 and the movable core 5, which is set in advance, varies. Since the magnetic resistance is proportional to the distance between the center pole and the movable core 5, if the magnetic resistance changes due to abrasion of the center pole, there is a problem that the stabilization of the opening/closing characteristics is also affected. However, the present invention has an effect that since a gap is not formed between the fixed core 61 and the movable core 5, the present invention is not affected by abrasion and impact of the left and right poles caused by repeated opening and closing, and therefore has stable opening and closing characteristics, and the risk of quality failure can be eliminated.

The fixed core 61 of fig. 2 is provided with holes through which rivets for connecting the laminated cores pass. The center pole of the fixed core 61 penetrates the coil bobbin 7 fixed to the bottom case 3, and the fixed core 61 is fixed to the bottom case 3 via the coil bobbin 7. The fixed core 61 is made of ferrous metal.

The fixed core 61 is magnetized by a magnetic field generated by applying a current to the coil 8 through the coil terminals 4A and 4B.

4 slits 91A, 91B, 91C, and 91D are provided below the fixed core 61. In embodiment 1, the slits 91A and 91B are arranged on the connection side connecting the center pole and the left pole of the fixed core 61, and the slits 91C and 91D are arranged on the connection side connecting the center pole and the right pole of the fixed core. The slits 91A and 91C extend in the vertical direction, which is the direction in which the movable core 5 moves from the upper end surface of the connecting side. The slits 91B and 91D extend in the up-down direction from the lower end surface of the connecting side. The slits 91A and 91B, and the slits 91C and 91D are each arranged in mirror symmetry. In fig. 2, the slit 91A on the lower side of the connecting side is near the left pole, and the slit 91D is near the right pole. The slits 91B and 91C are provided in a position very close to the center of the upper side of the connecting side.

Next, the operation and effects of the electromagnetic contactor 1 will be described with reference to fig. 3. Fig. 3 is a cross-sectional view of the electromagnetic contactor 1 according to embodiment 1. By applying voltages to the coil terminals 4A and 4B, currents flow through the coil 8, and magnetic circuits 10A and 10B are generated in the coil 8 and the coil bobbin 7. The generated magnetic circuits 10A, 10B flow from the center pole of the fixed core 61 to the left pole and the right pole via the connecting sides, whereby the fixed core 61 is magnetized. Next, the magnetic circuits 10A and 10B reach the movable core 5 from the left and right poles of the fixed core 61, and return to the center pole of the fixed core 61. As described above, by providing the slits 91A, 91B, 91C, 91D in the generation path of the magnetic field around the fixed core 61, the paths of the magnetic circuits 10A, 10B flowing back in the fixed core 61 are limited as shown in fig. 3, and the sectional area becomes smaller, and the magnetic resistance becomes larger. In addition, the paths of the magnetic circuits 10A, 10B are lengthened, and the magnetic resistance is thereby also increased.

Therefore, the cross-sectional area through which the magnetic flux passes is reduced, and the magnetic paths 10A and 10B are lengthened, so that the magnetic resistance can be increased without providing a nonmagnetic spacer, the magnetic flux can be reduced, and the poor separation of the movable core 5 can be prevented.

If the slits 91A, 91B, 91C, 91D are formed in the fixed core 51 so as to reduce the cross-sectional area and extend the magnetic circuits 10A, 10B, the slits 91A, 91B, 91C, 91D may be formed in the left pole, the right pole, or the like other than the connecting side. However, even if the movable core 5 repeatedly collides with the fixed core 61, the fixed core 61 is not easily damaged by providing the connecting sides 91A, 91B, 91C, and 91D.

The fixed core 61 is magnetized, and thereby the movable core 5 is attracted to the fixed core 61, and the closed state is achieved. Since the attraction force is generated between the movable core 5 and the fixed core 61 in the closed state, the holding current can be reduced because the holding current can be maintained even by a small magnetic flux. By reducing the holding current, the power consumption of the electromagnetic contactor 1 can be reduced. Specifically, the amount of movement of the movable core 5 can be detected using a current control board not shown in the bottom case 3, and the current applied when the movable core contacts the fixed core 61 can be reduced.

As described above, according to embodiment 1, by providing the fixed core 61 with the slit, the magnetic resistance can be increased and the magnetic flux can be reduced without using the nonmagnetic spacer between the movable core 5 and the fixed core 61, and therefore, the separation failure can be prevented, and the number of components can be reduced, thereby reducing the cost. In addition, the cost of assembly can be reduced by eliminating the nonmagnetic spacer, and the quality can be stabilized without being affected by repeated opening and closing.

Embodiment 2.

Next, embodiment 2 will be described. Fig. 4 is an internal cross-sectional view of the electromagnetic contactor 1 of embodiment 2. In the following description, the same reference numerals are given to the components overlapping with those of embodiment 1, and the description thereof is omitted.

In embodiment 2, slits 91B and 91C are formed in the movable core 5, not in the fixed core 61. In embodiment 2, the slits 91B and 91C extend upward from the lower end surface of the movable core 5. The slits 91B and 91C are provided near the center pole of the lower side of the movable core 5. The positions of 91B and 91C are not limited to the above-described positions if the magnetic circuits 10A and 10B are formed to be long.

Therefore, in the electromagnetic contactor 1 according to embodiment 2, the magnetic paths 10A and 10B are lengthened by the slits 91B and 91C of the movable core 5 in the same manner as in fig. 3 of embodiment 1, and therefore, the magnetic resistance can be increased without providing a nonmagnetic spacer, the magnetic flux can be reduced, and the poor separation of the movable core 5 can be prevented, so that the number of components can be reduced and the cost can be reduced.

Embodiment 3.

Next, embodiment 3 will be described. Fig. 5 is an internal cross-sectional view of the electromagnetic contactor 1 of embodiment 3. Unlike the slits 91A, 91B, 91C, and 91D extending in the vertical direction, which is the direction in which the movable core 5 moves from the upper and lower end surfaces of the connecting side of the fixed core 61 in embodiment 3, the fixed core 62 is formed with slits 92A, 92B, 92C, and 92D inclined in the vertical direction toward the center pole. The slits 92A, 92B, 92C, 92D are preferably formed to extend the magnetic circuits 10A, 10B.

Therefore, the electromagnetic contactor 1 of embodiment 3 is provided with the inclined slits 92A, 92B, 92C, 92D, whereby the magnetic circuits 10A, 10B can be lengthened compared to the electromagnetic contactor 1 of embodiment 1, and the magnetic resistance can be increased, so that separation failure can be prevented more reliably.

Embodiment 4.

Next, embodiment 3 will be described with reference to fig. 6. Fig. 6 is an internal cross-sectional view of the electromagnetic contactor 1 of embodiment 4. In embodiment 1, slits 91A, 91B, 91C, and 91D are formed in fixed core 61, but in embodiment 4, hole 11A is formed in fixed core 63 instead of slit 91, and hole 11B is formed instead of slit 91D. The holes 11A and 11B may be provided with fixing pins, not shown, for connecting the fixed core 63 and the bottom case 3. As shown in fig. 6, by combining the slits 91B and 91C on the connecting side with the holes 11A and 11B and forming them at different positions in the lateral direction, the magnetic circuits 10A and 10B can be lengthened as in embodiment 1.

Therefore, according to embodiment 4, when the electromagnetic contactor 1 using the fixing pin or the fixed core 63 is small in the lateral direction and the slit cannot be formed below the connecting side, the non-magnetic spacer is not used, and the separation failure of the movable core 5 can be prevented, so that the number of components can be reduced and the cost can be reduced.

As described above, according to the electromagnetic contactor 1 of the present invention, since the slits are formed in the fixed core or the movable core 5, the magnetic resistance can be increased and the magnetic flux can be reduced without using the nonmagnetic spacer, and therefore, the separation failure can be prevented, and the number of components can be reduced and the cost can be reduced.

Description of the reference numerals

1. Electromagnetic contactor

2. Top shell

3. Bottom shell

4A, 4B coil terminal

5 Movable iron core

61. 62, 63 fixed iron core

7. Coil bobbin

8. Coil

91A, B, C, D, 92A, B, C, D slit

10A, 10B magnetic circuit

11A, 11B wells.

Claims

1. An electromagnetic contactor, comprising:

a fixed iron core around which a coil is wound, the fixed iron core generating a magnetic field by applying a current to the coil; and

a movable core that moves to a closest position with respect to the fixed core when the magnetic field generated in the fixed core is generated, and contacts the fixed core,

a plurality of slits are formed in the fixed core or the movable core so as to define a path of magnetic flux generated when a current is applied to the coil and extend the path.

2. The electromagnetic contactor according to claim 1, wherein,

the fixed iron core is E-shaped and is provided with a left pole, a central pole, a right pole and a connecting edge which extend in the moving direction of the movable iron core, the connecting edge connects the central pole with the right pole and the central pole with the left pole,

the slits are arranged in mirror symmetry with respect to the fixed core.

3. An electromagnetic contactor according to claim 1 or 2, wherein,

the slit extends in a moving direction of the movable core.

4. An electromagnetic contactor according to claim 1 or 2, wherein,

the slit is inclined with respect to a moving direction of the movable core.

5. The electromagnetic contactor according to claim 1, wherein,

instead of the slit, a hole is provided.