Electromagnetic contactor

Abstract

To more effectively suppress separation of a contact portion in an electromagnetic contactor during a short circuit.SOLUTION: A capsule case 12 is made of resin. A fixed yoke 51 is disposed between a pair of fixed contacts 14, and at least a portion of the fixed yoke is held within a body 61 that constitutes the capsule case 12. A movable yoke 52 is provided on a movable contact 15, and faces the fixed yoke 51. The fixed yoke 51 and the movable yoke 52 attract each other by forming a magnetic path around an axis in the direction of current flow through the movable contact 15 when the contact portion 23 is closed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electromagnetic contactor. [Background technology]

[0002] Patent Document 1 discloses the provision of a fixed yoke and a movable yoke to suppress the separation (floating) of the contacts due to electromagnetic repulsion when a short-circuit current flows. The fixed yoke and the movable yoke form a magnetic path around an axis in the direction of current flow through the movable contactor and are configured to attract each other, with the fixed yoke fixed to a holder linked to the movable core, and the movable yoke fixed to the movable contactor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-506868 Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which the fixed yoke is fixed to a holder that moves with the movable core, the fixed yoke moves together with the movable core, and as a result, when the fixed yoke and the movable yoke attract each other, the force of the electromagnet in the closing direction is reduced, and it may not be possible to effectively prevent the contacts from separating due to the electromagnetic repulsive force. An object of the present invention is to more effectively prevent separation of contact portions in an electromagnetic contactor when a short circuit occurs. [Means for solving the problem]

[0005] An electromagnetic contactor according to an aspect of the present invention includes a container, a pair of fixed contacts, a movable contact, a fixed yoke, and a movable yoke. The container is made of resin. The pair of fixed contacts are fixed through the container, and fixed contacts are formed on one end side inside the container. The movable contact has movable contacts facing the fixed contacts on both ends, and opens and closes a contact section consisting of the movable contact and the fixed contact when displaced along the depth direction inside the container. The fixed yoke is disposed between the pair of fixed contacts, and at least a portion of the fixed yoke is held within a body constituting the container. The movable yoke is provided on the movable contact and faces the fixed yoke. The fixed yoke and the movable yoke attract each other by forming a magnetic path around an axis in the direction of current flow through the movable contact when the contact section is closed. Effect of the Invention

[0006] According to the present invention, since the fixed yoke is held within the body constituting the resin container, even if the fixed yoke and the movable yoke attract each other, the force of the electromagnet in the inserting direction is not reduced, and therefore separation of the contacts during a short circuit can be more effectively suppressed. [Brief description of the drawings]

[0007] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 2 is a diagram showing a fixed yoke and a movable yoke. [Diagram 5] FIG. [Figure 6] FIG. 2 is a diagram showing a fixed yoke held by a capsule case. [Figure 7] FIG. 2 is a diagram showing a fixed yoke held by a capsule case. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that each drawing is a schematic view and may differ from the actual one. In addition, the following embodiment illustrates an apparatus and method for embodying the technical idea of ​​the present invention, and does not specify the configuration as described below. In other words, the technical idea of ​​the present invention can be modified in various ways within the technical scope described in the claims.

[0009] <<Embodiment>> "composition" In the following description, the three mutually orthogonal directions will be referred to as a vertical direction, a width direction, and a depth direction for the sake of convenience. FIG. 1 is a diagram showing an electromagnetic contactor 11. As shown in FIG. Here, the electromagnetic contactor 11 is shown as viewed from one side in the vertical direction, one side in the width direction, and from the front side in the depth direction. The electromagnetic contactor 11 includes a capsule case 12 (container) and a capsule cover 13. The capsule case 12 is made of insulating resin, and is formed into a deep container shape with both sides in the vertical direction, both sides in the width direction, and the front side in the depth direction closed, and the back side in the depth direction open. The capsule cover 13 is made of insulating resin, and is formed into a shallow container shape with both sides in the vertical direction, both sides in the width direction, and the back side in the depth direction closed, and the front side in the depth direction open, and is fitted into the back side in the depth direction of the capsule case 12 and sealed.

[0010] The capsule case 12 and the capsule cover 13 are filled with pressurized barrier gas such as hydrogen or nitrogen. Therefore, the capsule case 12 and the capsule cover 13 are fixed with an epoxy resin adhesive, and the entire outer peripheral surface including the boundary is gas-barrier coated with a laminated film of clay crystals. Specifically, the interlayer ions of the refined smectite are replaced and bound with an organic binder such as PVA (polyvinyl alcohol) or water-soluble nylon to create a maze effect and prevent the permeation of gas molecules such as hydrogen and nitrogen. The laminated film is laminated in the thickness direction, and has a thickness of, for example, 2 μm. The gas barrier coating is completed by, for example, spraying the coating liquid into a mist and applying it to the capsule case 12 and the capsule cover 13, and baking at a temperature of, for example, 150° C. or higher at which the interlayer ions are incorporated into the clay crystals. In this way, since the entire outer peripheral surface is gas-barrier coated, it is preferable that the outer peripheral shape of the capsule case 12 and the capsule cover 13 is a polygonal shape composed of linear planes with as few irregularities as possible.

[0011] FIG. 2 is a cross-sectional view of the electromagnetic contactor 11. As shown in FIG. Here, a cross section of the electromagnetic contactor 11 passing through the center in the width direction and along the vertical and depth directions is shown as viewed from one side in the width direction. FIG. 3 is a cross-sectional view of the electromagnetic contactor 11. As shown in FIG. Here, a cross section of the electromagnetic contactor 11 passing through the center in the vertical direction and extending in the width and depth directions is shown as viewed from one vertical direction. First, a description will be given of the basic structure of the electromagnetic contactor 11. The electromagnetic contactor 11 includes a pair of fixed contacts 14, a movable contactor 15, a contact support 16, and an electromagnet portion 17. The pair of fixed contacts 14 is made of a conductive metal and is formed into a generally cylindrical shape extending in the depth direction. The pair of fixed contacts 14 are arranged vertically at a distance from each other, protrude from the inside to the outside of the capsule case 12, and are integrated with the capsule case 12 by insert molding. The vertical inner end of the end face of the fixed contact 14 facing the back in the depth direction becomes the fixed contact 21.

[0012] The movable contactor 15 is made of a conductive metal, extends vertically, is formed in a flat plate shape aligned in the vertical and width directions, and is disposed deeper in the depth direction than the pair of fixed contactors 14. Both outer ends in the vertical direction of the end face of the movable contactor 15 facing the front in the depth direction become movable contacts 22 opposing the fixed contacts 21. The fixed contacts 21 and the movable contacts 22 form a contact section 23, and the contact section 23 opens and closes when the movable contactor 15 is displaced in the depth direction. The contact support 16 is formed in a frame shape with both sides in the width direction and both sides in the depth direction closed, and the movable contactor 15 and the contact spring 26 are held inside the contact support 16. The contact spring 26 is a compression coil spring that expands and contracts in the depth direction, and urges the movable contactor 15 toward the front in the depth direction. A permanent magnet 27 and a yoke 28 that induce an arc of the contact portion 23 are held inside the capsule case 12. The permanent magnet 27 is flat and arranged on both sides in the vertical direction, sandwiching the movable contactor 15 therebetween. The yoke 28 is a U-shaped yoke that closes both the outside in the vertical direction and both sides in the width direction and opens toward the inside in the vertical direction, and is arranged on the outside in the vertical direction of the permanent magnet 27.

[0013] The electromagnet portion 17 is disposed at the back in the depth direction, and includes a spool 31, a plunger 32, an outer yoke 33, a bottom yoke 34, a permanent magnet 35, an auxiliary yoke 36, and a back spring 37. The spool 31 is made of insulating resin, and has a coil 42 wound around a cylindrical winding shaft 41 that extends in the depth direction. A cylindrical plunger ring 43 is fitted inside the winding shaft 41 at the front in the depth direction, and a cylindrical sliding collar 44 is fitted at the back in the depth direction. A rib 45 is formed at the back in the depth direction of the spool 31, surrounding all four sides perpendicular to the depth direction, i.e., both sides in the vertical direction and both sides in the width direction. The plunger 32 is a cylindrical movable core extending in the depth direction, and is inserted into the plunger ring 43 and the sliding collar 44 in a state in which it can advance and retreat in the axial direction. The plunger 32 is longer than the winding shaft 41, and is connected to the contact support 16 at its front end in the depth direction, and to the rear end in the depth direction, is connected to the armature 46. The armature 46 is a disk-shaped yoke extending in the vertical and width directions.

[0014] The outer yoke 33 is a yoke formed in a generally U-shape that opens toward the back in the depth direction when viewed from the width direction, and is provided so as to cover both vertical sides of the spool 31 and the front in the depth direction. The front end of a plunger ring 43 fits into a round hole that penetrates the outer yoke 33 in the depth direction. The bottom yoke 34 is a plate-shaped yoke extending in the vertical and width directions, and is disposed deeper in the depth direction than the winding shaft 41 of the spool 31, and is fixed to the inner ends of both sides of the outer yoke 33. The plunger 32 passes through a circular hole penetrating the bottom yoke 34 in the depth direction.

[0015] The permanent magnet 35 is a flat plate extending in the vertical and width directions, with a circular hole formed therethrough in the depth direction, fitted inside the rib 45 and attached to the rear surface of the bottom yoke 34 . The auxiliary yoke 36 is a flat plate extending in the vertical and width directions, has a round hole penetrating in the depth direction, fits inside the rib 45, and is attracted to the rear surface of the permanent magnet 35. The armature 46 of the plunger 32 is disposed between the bottom yoke 34 and the auxiliary yoke 36. The back spring 37 is a compression coil spring that expands and contracts in the depth direction, and is interposed between the sliding collar 44 and the armature 46, and biases the plunger 32 in the depth direction via the armature 46.

[0016] With the above configuration, in a non-excited state where the coil 42 is not energized, the magnetic force of the permanent magnet 35 and the repulsive force of the back spring 37 displace the plunger 32 toward the back in the depth direction. The magnetic flux of the permanent magnet 35 passes from the front side of the permanent magnet 35 through the bottom yoke 34, the outer yoke 33, the plunger ring 43, the plunger 32, the armature 46, and the auxiliary yoke 36 in this order, and reaches the back side of the permanent magnet 35. The armature 46 is attracted to the front side of the auxiliary yoke 36 by this closed-loop magnetic circuit. Thus, when the plunger 32 is displaced toward the back in the depth direction, the contact opens via the contact support 16, and the plunger 32 is in a released state. At this time, the armature 46 is separated from the back side of the bottom yoke 34.

[0017] When the coil 42 is energized and excited from this state, the armature 46 is attracted to the rear surface of the bottom yoke 34 by the magnetic force of the coil 42. As a result, the plunger 32 is displaced toward the front in the depth direction against the magnetic force of the permanent magnet 35 and the repulsive force of the back spring 37. The magnetic flux of the coil 42 passes from the inner peripheral surface of the plunger ring 43 through the plunger 32, armature 46, bottom yoke 34, and outer yoke 33 in this order to the outer peripheral surface of the plunger ring 43. The armature 46 is attracted to the rear surface of the bottom yoke 34 by this magnetic circuit that forms a closed loop. Thus, when the plunger 32 is displaced toward the front in the depth direction, the contacts are closed via the contact support 16, and the state is closed. At this time, the armature 46 is separated from the front surface of the auxiliary yoke 36.

[0018] Next, a structure for preventing the contact portion 23 from being separated (floated) due to electromagnetic repulsive force when a short-circuit current flows will be described. The electromagnetic contactor 11 includes a fixed yoke 51 and a movable yoke 52. The fixed yoke 51 is disposed between a pair of fixed contactors 14, and at least a portion of the fixed yoke 51 is held within a body constituting the capsule case 12. The movable yoke 52 is provided on the movable contactor 15, and faces the fixed yoke 51 when the contact portion 23 is closed. The fixed yoke 51 and the movable yoke 52 attract each other by forming a magnetic path around an axis in the direction of current flow through the movable contactor 15 when the contact portion 23 is closed.

[0019] FIG. 4 is a diagram showing the fixed yoke 51 and the movable yoke 52. As shown in FIG. FIG. 1A shows the state of the fixed yoke 51 as viewed from one side in the vertical direction, one side in the width direction, and from the front side in the depth direction. The fixed yoke 51 is a flat yoke extending in the width direction and aligned in the width direction and vertical direction, and includes a large portion 53 and a small portion 54, and is formed in a substantially cross shape as viewed from the depth direction. The large portion 53 has a relatively large vertical dimension, and the small portion 54 has a relatively small vertical dimension. The shaded area is an embedded portion 55 embedded in the body of the capsule case 12, and the other area is an exposed portion 56. The large portion 53 is entirely the embedded portion 55. The small portion 54 is embedded in the width direction on the inside and in the depth direction on the front side, and exposed in the width direction on the outside and in the depth direction on the rear side. The exposed portion 56 includes both end faces in the vertical direction, an outer end face in the width direction, and a rear end face in the depth direction.

[0020] FIG. 1(b) shows the movable yoke 52 as viewed from one side in the vertical direction, one side in the width direction, and from the front in the depth direction. The movable yoke 52 is a yoke formed in a generally U-shape that opens toward the front in the depth direction when viewed from the vertical direction, and covers both sides in the width direction and the back in the depth direction of the movable contactor 15. The inner dimension of the movable yoke 52 in the width direction corresponds to the width direction dimension of the movable contactor 15, and the outer dimension in the width direction corresponds to the width direction dimension of the movable yoke 52. The tip surfaces of the walls of the movable yoke 52 that extend toward the depth direction on both sides in the width direction face the pair of exposed portions 56 of the fixed yoke 51.

[0021] FIG. 5 is a diagram showing the contact support 16. As shown in FIG. FIG. 1A shows the contact support 16 as viewed from one side in the vertical direction, one side in the width direction, and from the front in the depth direction. FIG. 1B shows the cross section of the contact support 16 along the width direction and the depth direction, passing through the center in the vertical direction, as viewed from one side in the vertical direction. The contact support 16 is formed in a substantially U-shape that opens toward the front in the depth direction as viewed from the vertical direction, and a cage 57 is integrated by insert molding on both ends in the width direction. The cage 57 is formed in a substantially U-shape that opens toward the back in the depth direction as viewed from the vertical direction, and closes the front in the depth direction of the contact support 16. Therefore, the contact support 16 and the cage 57 are formed in a substantially R-shape as viewed from the vertical direction. The cage 57 has openings 58 formed in the bent portions on both ends in the width direction. The movable contactor 15, the movable yoke 52, and the contact spring 26 are fitted inside the contact support 16 and the cage 57, in that order from the front in the depth direction, and both ends of the movable yoke 52 protrude from an opening 58 of the cage 57 to the front in the depth direction.

[0022] FIG. 6 is a diagram showing the fixed yoke 51 held by the capsule case 12. As shown in FIG. Here, a cross section of the capsule case 12 along the vertical and width directions passing deeper than the fixed contact 14 is shown as viewed from the depth direction. The fixed yoke 51 is embedded in a body 61 forming the ceiling of the capsule case 12, and exposed portions 56 on both ends of the fixed yoke 51 in the width direction are exposed. The pair of exposed portions 56 and both ends of the movable yoke 52 in the width direction face each other in the depth direction. In order to ensure the contact wipe amount, the fixed yoke 51 and the movable yoke 52 are set to be non-contact with each other when the contact portion 23 is closed.

[0023] FIG. 7 is a diagram showing the fixed yoke 51 held by the capsule case 12. As shown in FIG. FIG. 1A shows a cross section of the capsule case 12 in the vertical and width directions passing through the body 61 in the depth direction, as viewed from one side in the vertical direction, the other side in the width direction, and the back in the depth direction. FIG. 1B shows a cross section of the capsule case 12 in the vertical and width directions passing through the fixed yoke 51, as viewed from one side in the vertical direction, the other side in the width direction, and the back in the depth direction. An opening 62 is formed on both ends in the width direction of the body 61, and the small portion 54 of the fixed yoke 51 protrudes from the opening 62, exposing the exposed portion 56. That is, the body 61 has a cavity penetrating in the width direction, in which the fixed yoke 51 is held. The fixed yoke 51 is integrated with the body 61 of the capsule case 12 by insert molding, so that the embedded portion 55 is in close contact with the opening 62.

[0024] <Action and Effect> Next, main effects of the embodiment will be described. The electromagnetic contactor 11 includes a capsule case 12, a pair of fixed contacts 14, a movable contact 15, a fixed yoke 51, and a movable yoke 52. The capsule case 12 is made of resin. The pair of fixed contacts 14 are fixed through the capsule case 12, and a fixed contact 21 is formed on one end side inside the capsule case 12. The movable contact 15 has movable contacts 22 facing the fixed contacts 21 on both ends, and opens and closes a contact section 23 consisting of the movable contact 22 and the fixed contact 21 when displaced along the depth direction inside the capsule case 12. The fixed yoke 51 is disposed between the pair of fixed contacts 14, and at least a part of the fixed yoke 51 is held in a body 61 constituting the capsule case 12. The movable yoke 52 is provided on the movable contact 15 and faces the fixed yoke 51. The fixed yoke 51 and the movable yoke 52 attract each other by forming a magnetic path around an axis in the direction of current flow through the movable contact 15 when the contact section 23 is closed. According to this, since the fixed yoke 51 is held in the body 61 constituting the resin capsule case 12, even if the fixed yoke 51 and the movable yoke 52 attract each other, the force in the inserting direction by the electromagnet part 17 is not reduced. Therefore, it is possible to more effectively suppress the separation of the contact parts 23 when a short circuit occurs. By making the capsule case 12 out of resin, the degree of freedom in design is improved in the structure for holding the fixed yoke 51 in the body 61.

[0025] An opening 62 is formed in the body 61 to expose a portion of the fixed yoke 51. This allows the fixed yoke 51 to be attached to a mold by the portion exposed after molding during insert molding. The fixed yoke 51 is formed in a flat plate shape extending in a direction perpendicular to the movable contact 15 when viewed from the depth direction, and includes an embedded portion 55 and an exposed portion 56. The embedded portion 55 is embedded in a body 61. The exposed portion 56 protrudes from an opening 62. This allows the fixed yoke 51 to be attached to a mold by the part protruding from the opening 62 after molding during insert molding. In particular, since the exposed portion 56 has end faces on both sides in the vertical direction, an outer end face in the width direction, and a rear end face in the depth direction, it is possible to position the fixed yoke 51 relative to the mold.

[0026] The embedded portion 55 is larger than the opening 62 when viewed from the protruding direction of the exposed portion 56. This makes it possible to prevent the fixed yoke 51 from shifting in position with respect to the body 61 or falling off. The embedded portion 55 of the fixed yoke 51 is in close contact with the inside of the body 61. This makes it possible to prevent the fixed yoke 51 from rattling. The movable yoke 52 is formed in a U-shape that opens toward the fixed yoke 51 when the movable contactor 15 is viewed from the current flow direction. This allows a magnetic path to be formed around the axis of the current flow direction through the movable contactor 15 when the contact portion 23 is closed. In addition, in a configuration in which the fixed yoke 51 side is formed in a U-shape, the movable contactor 15 is inserted inside the fixed yoke when the contact portion 23 is closed, and high precision operation is required, which increases the design cost. In contrast, in a configuration in which the movable yoke 52 side is formed in a U-shape, the movable contactor 15 is fitted into the movable yoke 52 and integrated, so high precision operation is not required when the contact portion 23 is closed, and the design cost can be reduced.

[0027] The capsule case 12 is gas-barrier coated with a laminated film of clay crystals, which suppresses the permeation of gas molecules such as hydrogen and nitrogen, and prevents leakage of pressurized barrier gas. The fixed yoke 51 is integrated into the body 61 by insert molding. This allows the embedded portion 55 of the fixed yoke 51 to be tightly attached to the body 61, suppressing rattling of the fixed yoke 51. In addition, it is no longer necessary to assemble the fixed yoke 51 into the body 61, and the joining strength is improved.

[0028] Next, a comparative example will be described. Here, a comparative example will be described in which a fixed yoke is fixed to a holder that moves with the movable core, and the movable yoke is fixed to a movable contact. In this configuration in which the fixed yoke is fixed to a holder that moves with the movable core, the fixed yoke displaces together with the movable core. Therefore, when the fixed yoke and the movable yoke attract each other, the force in the closing direction by the electromagnet part is reduced, and there is a possibility that the separation of the contact parts due to the electromagnetic repulsive force cannot be effectively suppressed.

[0029] <<Variation>> In the embodiment, the fixed contact 14 is formed in a cylindrical shape, but the present invention is not limited to this. That is, the shape of the fixed contact 14 is arbitrary, and for example, the fixed contact 14 may be formed in a flat plate shape extending in the vertical direction and aligned in the vertical and width directions. In the embodiment, a partition wall is provided inside the capsule case 12 to separate the contact portion 23 and the permanent magnet 27, but the present invention is not limited to this. That is, a configuration in which the contact portion 23 and the permanent magnet 27 are separated by adding an insulating holder serving as an arc barrier inside the capsule case 12 may be adopted.

[0030] Although the above description has been given with reference to a limited number of embodiments, the scope of the invention is not limited thereto, and modifications of the embodiments based on the above disclosure will be obvious to those skilled in the art. [Explanation of symbols]

[0031] 11...electromagnetic contactor, 12...capsule case, 13...capsule cover, 14...fixed contactor, 15...movable contactor, 17...electromagnet part, 21...fixed contact, 22...movable contact, 23...contact part, 26...contact spring, 27...permanent magnet, 28...yoke, 31...spool, 32...plunger, 33...outer yoke, 34...bottom yoke, 35...permanent magnet, 36...auxiliary yoke, 37...back spring, 41...winding shaft, 42...coil, 43...plunger ring, 44...sliding collar, 45...rib, 46...armature, 51...fixed yoke, 52...movable yoke, 53...large part, 54...small part, 55...buried part, 56...exposed part, 57...cage, 58...opening, 61...body, 62...opening

Claims

1. A plastic container, a pair of fixed contacts that are fixed to the container and have fixed contacts formed on one end side that is inside the container; a movable contactor that is formed on both ends of the container with movable contacts facing the fixed contacts and that opens and closes a contact portion formed of the movable contacts and the fixed contacts when the movable contactor is displaced in a depth direction within the container; a fixed yoke disposed between the pair of fixed contacts and at least a portion of which is held within a body constituting the container; a movable yoke provided on the movable contact and facing the fixed yoke; An electromagnetic contactor characterized in that the fixed yoke and the movable yoke attract each other by forming a magnetic path around an axis in the direction of current flow through the movable contactor when the contact portion is closed.

2. 2. The electromagnetic contactor according to claim 1, wherein the body has an opening through which a part of the fixed yoke is exposed.

3. The fixed yoke is formed in a flat plate shape extending in a direction perpendicular to the movable contact when viewed from the depth direction, A buried portion buried in the body; The electromagnetic contactor according to claim 2 , further comprising an exposed portion protruding from the opening.

4. The electromagnetic contactor according to claim 3 , wherein the embedded portion is larger than the opening when viewed from a protruding direction of the exposed portion.

5. 4. The electromagnetic contactor according to claim 3, wherein the embedded portion of the fixed yoke is in intimate contact with the interior of the body.

6. 4. The electromagnetic contactor according to claim 3, wherein the movable yoke is formed in a U-shape that opens toward the fixed yoke when the movable contactor is viewed from the direction of current flow.

7. 2. The electromagnetic contactor according to claim 1, wherein the container is gas-barrier coated with a laminated film of clay crystals.

8. 2. The electromagnetic contactor according to claim 1, wherein the fixed yoke is integrated into the body by insert molding.

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