Electromagnetic contactor

Abstract

To miniaturize an electromagnetic contactor in an axial direction.SOLUTION: The electromagnet 17 includes an outer yoke 23 and a bottom yoke 24. The outer yoke 23 has a U-shape that is open toward the other side in the axial direction, and distal end sides thereof face each other in the longitudinal direction when viewed from the axial direction. The bottom surface yoke 24 is connected to the other end of the outer yoke 23 in the axial direction with a surface direction orthogonal to the axial direction, both end sides protruding outward in the longitudinal direction from the outer yoke 23 are fixed to the case 12, and both end sides fixed to the case 12 are step-bent to one side in the axial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] The electromagnetic contactor shown in Patent Document 1 includes an electromagnet that opens and closes contacts along the axial direction, and the electromagnet includes a U-shaped outer yoke that opens toward the other end of the axial direction, and a plate-shaped bottom yoke that is connected to the other end of the outer yoke. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-172243 Summary of the Invention [Problem to be solved by the invention]

[0004] It is conceivable to extend the bottom yoke and fix it to the case, but there is a gap between the electromagnet and the cover that closes the other end of the case, so there is room for improvement in terms of making it smaller in the axial direction. An object of the present invention is to reduce the size of an electromagnetic contactor in the axial direction. [Means for solving the problem]

[0005] An electromagnetic contactor according to one aspect of the present invention includes a contact, an electromagnet, a case, and a cover. The contact is disposed on one side in the axial direction. The electromagnet is disposed on the other side in the axial direction and opens and closes the contact along the axial direction. The case has an open other end in the axial direction and houses the contact and the electromagnet. The cover closes the other end of the case. The electromagnet includes an outer yoke and a bottom yoke. The outer yoke is U-shaped and opens toward the other side in the axial direction, with its tip end facing vertically when viewed from the axial direction. The bottom yoke is connected to the other axial end of the outer yoke with its surface direction perpendicular to the axial direction, and both ends protruding vertically outward beyond the outer yoke are fixed to the case, and both ends fixed to the case are bent in a step toward one side in the axial direction. [Effects of the Invention]

[0006] According to the present invention, by bending both ends of the bottom yoke in steps, the electromagnet can be positioned further in the axial direction, thereby narrowing the gap between it and the cover. This allows the arc-extinguishing space to be positioned further in the axial direction, thereby making the electromagnetic contactor more compact in the axial direction. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a diagram illustrating the appearance of an electromagnetic contactor. [Figure 2] FIG. 2 is a cross-sectional view of an electromagnetic contactor in a released state. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 1 shows the assembly of an electromagnet. [Figure 6] FIG. 10 is a diagram showing the fitting of the bottom yoke and the permanent magnet. [Figure 7] FIG. 10 shows the fully assembled electromagnet. [Figure 8] FIG. [Figure 9] FIG. 10 is a diagram showing the installation of an electromagnet. [Figure 10]FIG. 10 is a diagram showing the attachment of the cover. [Figure 11] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are schematic and may differ from the actual product. Furthermore, the following embodiments exemplify devices and methods for embodying the technical concept of the present invention, and are not intended to limit the configuration to those described below. In other words, the technical concept 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 the vertical direction, the width direction, and the axial direction for convenience. FIG. 1 is a diagram showing the appearance of the electromagnetic contactor 11. As shown in FIG. Here, the electromagnetic contactor 11 is shown as viewed from one of the longitudinal directions, one of the width directions, and one of the axial directions. The electromagnetic contactor 11 includes a case 12 and a cover 13 as a sealed container. The case 12 is made of insulating resin and is formed in the shape of a deep container that is closed on both vertical sides, both width sides, and one axial side, and is open on the other axial side. The cover 13 is made of insulating resin and is formed in the shape of a shallow container that is closed on both longitudinal sides, both widthwise sides, and the other axial side, and is open on one axial side. The cover 13 is fitted to the other axial side of the case 12, and is fastened with bolts to be sealed.

[0010] Pressurized barrier gases such as hydrogen and nitrogen are sealed inside the case 12 and cover 13. Therefore, the case 12 and cover 13 are fixed together with an epoxy adhesive, and the entire outer surface, including the bonded area, is gas-barrier coated with a laminated film of clay crystals. Specifically, the interlayer ions of purified smectite are replaced and bound together with an organic binder such as PVA (polyvinyl alcohol) or water-soluble nylon, creating a labyrinth effect that prevents the permeation of gas molecules such as hydrogen and nitrogen. The laminated film is layered in the thickness direction, with a thickness of, for example, 2 μm. The gas-barrier coating is achieved, for example, by spraying a coating liquid into a mist and applying it to the case 12 and cover 13, followed by baking at a temperature of, for example, 150°C or higher, at which the interlayer ions are incorporated into the clay crystals.

[0011] FIG. 2 is a cross-sectional view of the electromagnetic contactor 11 in the released state. Here, a cross section of the electromagnetic contactor 11, passing through the center in the width direction and along the vertical and axial directions, is shown as viewed from one side in the width direction. First, the basic structure of the electromagnetic contactor 11 will be described. The electromagnetic contactor 11 includes a pair of fixed contacts 14, a movable contactor 15, a contact support 16, and an electromagnet 17. The pair of fixed contacts 14 are made of a conductive metal, are formed into a cylindrical shape extending in the axial direction, and are provided on one axial side of the case 12. The pair of fixed contacts 14 are aligned at a distance from each other in the vertical direction, penetrate from the inside to the outside of the case 12, and are integrated with the case 12 by insert molding. The end face of the fixed contact 14 facing the other axial side becomes the fixed contact point.

[0012] The surface of the fixed contact 14 is formed with micron-sized irregularities by chemical etching. This allows the molten resin to penetrate the irregularities during insert molding, and as the resin solidifies, the metal and resin are bonded at the interface, creating a complex bond through a labyrinth effect that prevents leakage of gas molecules such as hydrogen and nitrogen. An example of a metal surface treatment technology is "AMALPHA" (registered trademark) by MEC Co., Ltd. Note that similar surface treatments are also applied to all other metal components insert-molded into the case 12, such as the pipe used to evacuate and seal in the interrupter gas, and the coil terminal connected to the electromagnet 17.

[0013] The movable contactor 15 is made of a conductive metal, extends in the vertical direction, and is formed in the shape of a plate along the vertical and width directions, and is disposed on the other side of the pair of fixed contactors 14 in the axial direction. Both vertical ends of the end face of the movable contactor 15 facing one side in the axial direction become movable contacts facing the fixed contacts. The fixed contact of the fixed contactor 14 and the movable contact of the movable contactor 15 form contact 18, and contact 18 is opened or closed by displacement of the movable contact along the axial direction. The contact support 16 holds the movable contact 15 and a contact spring 19. The contact spring 19 is a compression coil spring that expands and contracts in the axial direction, and biases the movable contact 15 in one axial direction.

[0014] The electromagnet 17 is disposed on the other side of the contact support 16 in the axial direction, and includes a spool 21, a plunger 22, an outer yoke 23, a bottom yoke 24, a permanent magnet 25, an auxiliary yoke 26, and a back spring 27. The spool 21 is made of insulating resin, and has a coil 32 wound around a cylindrical winding shaft 31 extending in the axial direction. A cylindrical sliding collar 34 is fitted inside the winding shaft 31. The plunger 22 is a cylindrical movable iron core extending in the axial direction, and is inserted into a sliding collar 34 in a state in which it can move back and forth in the axial direction. A shaft 35 is fitted into a threaded hole formed in one axial end of the plunger 22, and the shaft 35 is connected to the contact support 16. An armature 36 is connected to the other axial end of the plunger 22. The armature 36 is a disk-shaped yoke that extends in the vertical and width directions.

[0015] The outer yoke 23 is provided to cover both longitudinal sides and one axial side of the spool 21, and is a yoke formed in a generally U-shape that opens toward the other axial side when viewed in the width direction. The tip side of the outer yoke 23 is a pair of side plates extending in the width and axial directions that face each other in the longitudinal direction. A shaft 35 is inserted through a round hole that penetrates in the axial direction in the flat plates of the outer yoke 23 extending in the longitudinal and width directions. The bottom yoke 24 is a flat yoke extending in the vertical and width directions, and is located on the other side of the axial direction from the winding shaft 31 of the spool 21, and is fixed to the other axial end of the outer yoke 23. The plunger 22 is inserted through the bottom yoke 24 via a circular hole that penetrates in the axial direction.

[0016] The permanent magnet 25 is a flat plate extending in the vertical and width directions, has a circular hole passing through in the axial direction, and is attached to the surface of the bottom yoke 24 facing the other axial direction. The auxiliary yoke 26 is a flat plate extending in the vertical and width directions, has a circular hole passing through it in the axial direction, and is attracted to the surface of the permanent magnet 25 facing the other axial direction. The armature 36 is disposed between the bottom yoke 24 and the auxiliary yoke 26. The back spring 27 is a compression coil spring that expands and contracts in the axial direction, and is interposed between the sliding collar 34 and the armature 36, and biases the plunger 22 in the other axial direction via the armature 36.

[0017] With the above configuration, when the coil 32 is not energized and is in a non-excited state, the magnetic force of the permanent magnet 25 and the repulsive force of the back spring 27 cause the plunger 22 to be displaced in the other axial direction. The magnetic flux of the permanent magnet 25 passes from one side of the permanent magnet 25 through the bottom yoke 24, outer yoke 23, plunger 22, armature 36, and auxiliary yoke 26 in this order to the other side of the permanent magnet 25. This closed-loop magnetic circuit attracts the armature 36 to one side of the auxiliary yoke 26. Thus, when the plunger 22 is displaced in the other axial direction, the contacts are opened via the contact support 16, resulting in a released state. At this time, the armature 36 is separated from the bottom yoke 24.

[0018] When the coil 32 is energized and excited, the magnetic force of the coil 32 attracts the armature 36 to the other surface of the bottom yoke 24. As a result, the plunger 22 is displaced to one side in the axial direction against the magnetic force of the permanent magnet 25 and the repulsive force of the back spring 27. The magnetic flux of the coil 32 flows from the plunger 22, through the armature 36 and the bottom yoke 24, and then to the outer yoke 23. This closed-loop magnetic circuit attracts the armature 36 to the other surface of the bottom yoke 24. When the plunger 22 is displaced to one side in the axial direction, the contacts close via the contact support 16, resulting in a closed state. At this time, the armature 36 is separated from the auxiliary yoke 26.

[0019] FIG. 3 is a diagram showing the spool 21. As shown in FIG. FIG. 1A shows the spool 21 as viewed from the other longitudinal direction, one widthwise direction, and the other axial direction. FIG. 1B shows the spool 21 as viewed from the other axial direction. The spool 21 has a flange 41 formed at the other axial end of the reel 31. The flange 41 is formed as a plate extending in the longitudinal and axial directions and is substantially rectangular when viewed axially. The flange 41 has a pair of ribs 42 formed opposite each other in the widthwise direction. The ribs 42 extend in the longitudinal direction, are formed as plates extending in the longitudinal and axial directions, and are formed at both ends of the flange 41 in the widthwise direction. Each rib 42 has a protrusion 43 formed on each longitudinal side, which protrudes inward in the widthwise direction and extends in the axial direction. The protrusion 43 is formed in a semicircular shape when viewed axially. A binding terminal 46 is attached to the outer peripheral surface of the rib 42 facing outward in the widthwise direction.

[0020] FIG. 4 is a diagram showing the bottom yoke 24. As shown in FIG. (b) in the figure shows the bottom yoke 24 as viewed from the other side in the vertical direction, one side in the width direction, and the other side in the axial direction. (b) in the figure shows the bottom yoke 24 as viewed from the other side in the axial direction. (c) in the figure shows the bottom yoke 24 as viewed from one side in the width direction. The bottom yoke 24 is a substantially rectangular shape that is long in the vertical direction when viewed from the axial direction, and the width dimension corresponds to the distance between the ribs 42. The bottom yoke 24 has four arms 51 formed on it. At both ends in the vertical direction, the arms 51 protrude outward in the vertical direction from both sides in the width direction and are bent in a step toward one side in the axial direction. A round through-hole 52 that penetrates in the axial direction is formed at the tip side of the arm 51.

[0021] The bottom yoke 24 is formed with a round hole 53, a recess 54, a connecting hole 55, and a threaded hole 56. The round hole 53 penetrates the center of the bottom yoke 24 in the axial direction and has a diameter larger than that of the plunger 22 but smaller than that of the armature 36. The recesses 54 are located on both vertical sides of the bottom yoke 24 in the width direction, are recessed toward the inside in the width direction, and are shaped to fit into the protrusions 43 of the ribs 42 from the other side in the axial direction. The connecting holes 55 penetrate the bottom yoke 24 in the axial direction on both widthwise sides of the bottom yoke 24 in the vertical direction and are square when viewed from the axial direction. The threaded holes 56 penetrate the bottom yoke 24 in the axial direction on both widthwise sides of the bottom yoke 24 in the vertical direction and have female threads formed on their inner peripheral surfaces.

[0022] FIG. 5 shows the assembly of the electromagnet 17. As shown in FIG. This figure shows the disassembled electromagnet 17 as viewed from the other side in the vertical direction, one side in the width direction, and the other side in the axial direction. The outer yoke 23 has bifurcated crimping portions 61 formed at the tips of a pair of side plates, protruding from both sides in the width direction toward the other side in the axial direction. The crimping portions 61 are inserted into the connecting holes 55 of the bottom yoke 24 and crimped, joining the outer yoke 23 and the bottom yoke 24. The permanent magnet 25 is attached to the other side of the bottom yoke 24, and with the armature 36 positioned inside the permanent magnet 25, the auxiliary yoke 26 is attached to the other side of the permanent magnet 25. Fixing holes 66 are formed at the four corners of the auxiliary yoke 26, penetrating in the axial direction. Hexagonal socket bolts 67 are inserted into the fixing holes 66 and fastened to the threaded holes 56, fixing the auxiliary yoke 26 to the bottom yoke 24.

[0023] FIG. 6 is a diagram showing the fit between the bottom yoke 24 and the permanent magnet 25. As shown in FIG. Here, the bottom yoke 24 and permanent magnet 25 fitted into the ribs 42 are shown as viewed from the other axial direction. The widthwise position of the bottom yoke 24 is restricted by fitting between a pair of ribs 42, and the vertical position is restricted by fitting the four recesses 54 into the protrusions 43. The permanent magnet 25 is approximately rectangular when viewed from the axial direction, and has four chamfered corners. The widthwise position of the permanent magnet 25 is restricted by fitting between a pair of ribs 42, and the vertical position is restricted by fitting the four chamfered corners into the protrusions 43. FIG. 7 shows the electromagnet 17 after assembly is complete. Here, the electromagnet 17 is shown as viewed from the other side in the vertical direction, one side in the width direction, and the other side in the axial direction.

[0024] FIG. 8 is a diagram showing case 12. (a) in the figure shows the case 12 as viewed from the other side in the vertical direction, one side in the width direction, and the other side in the axial direction. Stud bolts 71 and embedded nuts 72 are insert-molded into the case 12. The stud bolts 71 are arranged at the four corners of the case 12 and extend along the axial direction. (b) in the figure shows a cross section passing through the center of the stud bolt 71 along the vertical and axial directions, as viewed from one side in the width direction. The embedded nuts 72 are arranged at the four corners of the case 12 and extend along the axial direction. (c) in the figure shows a cross section passing through the center of the embedded nut 72 along the vertical and axial directions, as viewed from one side in the width direction.

[0025] FIG. 9 is a diagram showing the attachment of the electromagnet 17. As shown in FIG. Here, the case 12 and the electromagnet 17 are shown as viewed from the other side in the vertical direction, one side in the width direction, and the other side in the axial direction. The electromagnet 17 is fastened to the case 12 by fitting the embedded bolt 71 into the through hole 52 of the arm 51 and fastening it with a nut 73. FIG. 10 is a diagram showing the attachment of the cover 13. Here, the case 12 and cover 13 are shown as viewed from the other side in the vertical direction, one side in the width direction, and the other side in the axial direction. Through holes 74 that pass through in the axial direction are formed in the four corners of the cover 13. Hexagon socket head bolts 75 are inserted into the through holes 74 and fastened to embedded nuts 72, thereby fastening the cover 13 to the case 12.

[0026] <<Action and Effect>> Next, the main effects of the embodiment will be described. The electromagnetic contactor 11 includes a contact 18, an electromagnet 17, a case 12, and a cover 13. The contact 18 is disposed on one side in the axial direction. The electromagnet 17 is disposed on the other side in the axial direction and opens and closes the contact 18 along the axial direction. The case 12 and cover 13 are made of resin and enclose the contact 18 and the electromagnet 17. The other axial end of the case 12 is open and houses the contact 18 and the electromagnet 17. The cover 13 closes the other end of the case 12. The electromagnet 17 includes an outer yoke 23 and a bottom yoke 24. The outer yoke 23 is U-shaped and opens toward the other side in the axial direction, with the tip end facing vertically when viewed from the axial direction. The bottom yoke 24 is connected to the other axial end of the outer yoke 23 with its surface direction perpendicular to the axial direction, and both ends that protrude outward in the vertical direction from the outer yoke 23 are fixed to the case 12, with both ends fixed to the case 12 bent in a step in one direction in the axial direction. By bending both ends of the bottom yoke 24 in a step in this way, the electromagnet 17 can be positioned further in the axial direction, and the gap between it and the cover 13 can be reduced. Since the arc-extinguishing space can also be positioned in the other direction in the axial direction by that amount, the electromagnetic contactor 11 can be made smaller in size in the axial direction.

[0027] The electromagnet 17 includes a spool 21. The spool 21 has a coil 32 wound around a cylindrical winding shaft 31, and a pair of ribs 42 that face each other in the width direction as viewed from the axial direction are formed on the other axial side of the winding shaft 31. The bottom yoke 24 fits between the ribs 42 from the other axial direction. This allows even a stepped bottom yoke 24 to be easily assembled to the spool 21. Rib 42 is formed with convex portions 43 that protrude inward in the width direction and extend in the axial direction. Bottom yoke 24 is formed with concave portions 54 on both sides in the width direction when viewed from the axial direction, which fit into convex portions 43. This makes it easy to position bottom yoke 24 in the vertical direction, improving the concentricity of electromagnet 17 with respect to the axis.

[0028] The electromagnet 17 includes a plunger 22, a permanent magnet 25, and an auxiliary yoke 26. The plunger 22 is inserted inside the winding shaft 31 and is movable back and forth. The permanent magnet 25 is provided on the surface of the bottom yoke 24 facing the other axial direction. The auxiliary yoke 26 is provided on the surface of the permanent magnet 25 facing the other axial direction and attracts the plunger 22 to maintain the open state of the contact 18 when the coil 32 is not energized and is in a non-energized state. The protrusions 43 are formed at two locations on the rib 42 that are spaced apart in the vertical direction. The permanent magnet 25 is fitted from the other axial direction between the ribs 42 that are spaced apart in the width direction and between the protrusions 43 that are spaced apart in the vertical direction. This facilitates vertical positioning of the permanent magnet 25 and improves the concentricity of the plunger 22 with respect to the axis.

[0029] The auxiliary yoke 26 is fastened to the bottom yoke 24 at both vertical ends by bolts 67 extending along the axial direction. This makes it easy to position the auxiliary yoke 26, improving the concentricity of the plunger 22 with respect to its axis. Stud bolts 71 are insert-molded into the case 12 along the axial direction on both vertical ends. The bottom yoke 24 is fastened to the stud bolts 71. This makes torque management easier than when fastening with tapping screws, and also avoids the risk of cracks occurring in the resin case 12. Embedded nuts 72 are insert-molded into the case 12 along the axial direction at each of the four corners as viewed from the axial direction. The cover 13 is fastened to the embedded nuts 72. This makes torque management easier than when fastening with tapping screws, and also avoids the risk of cracks occurring in the resin case 12.

[0030] Next, a comparative example will be described. FIG. 11 is a diagram showing a comparative example. Here, a cross section of electromagnetic contactor 81 passing through the center in the width direction and along the vertical and axial directions is shown, as viewed from one side in the width direction. The comparative example has the same configuration as the embodiment except that it uses a flat bottom yoke 24 that is not stepped at both ends in the vertical direction, so the same reference numerals are used and detailed description will be omitted. In this way, when a flat bottom yoke 24 is used, there is a gap between cover 13 closing the other end of case 12 and electromagnet 17, which leaves room for improvement in terms of axial size reduction.

[0031] Although the present invention has been described above 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]

[0032] 11...electromagnetic contactor, 12...case, 13...cover, 14...fixed contact, 15...movable contact, 16...contact support, 17...electromagnet, 18...contact, 19...contact spring, 21...spool, 22...plunger, 23...outer yoke, 24...bottom yoke, 25...permanent magnet, 26...auxiliary yoke, 27...back spring, 31...winding shaft, 32...coil, 34...sliding collar, 35...shaft, 36...armature, 41...flange, 42...rib, 43...convex portion, 46...terminal, 51...arm, 52...through hole, 53...round hole, 54...recess, 55...connecting hole, 56...screw hole, 61...crimping portion, 66...fixing hole, 67...bolt, 71...embedded bolt, 72...embedded nut, 73...nut, 74...through hole, 75...bolt, 81...electromagnetic contactor

Claims

1. a contact point disposed on one side in the axial direction; an electromagnet disposed on the other side of the axial direction for opening and closing the contacts along the axial direction; a resin case and cover that seal the contacts and the electromagnet, the other axial end of the case is open, and the contacts and the electromagnet are accommodated therein; the cover closes the other end of the case; The electromagnet is an outer yoke having a U-shape that opens toward the other side in the axial direction, and a tip side facing in the vertical direction when viewed from the axial direction; a bottom yoke whose surface direction is perpendicular to the axial direction and which is connected to the other axial end of the outer yoke, whose both end sides which protrude vertically outward from the outer yoke are fixed to the case, and whose both end sides fixed to the case are stepped in one direction in the axial direction.

2. The electromagnet is a spool having a coil wound around a cylindrical winding shaft, and a pair of ribs formed on the other axial side of the winding shaft so as to face each other in the width direction as viewed from the axial direction; 2. The electromagnetic contactor according to claim 1, wherein the bottom yoke is fitted between the ribs from the other side in the axial direction.

3. The rib has a protrusion that protrudes inward in the width direction and extends in the axial direction, 3. The electromagnetic contactor according to claim 2, wherein the bottom yoke has recesses formed on both sides in the width direction when viewed from the axial direction, the recesses fitting with the protrusions.

4. The electromagnet is a plunger inserted inside the winding shaft and movable forward and backward; a permanent magnet provided on a surface of the bottom yoke facing the other axial direction; an auxiliary yoke provided on a surface of the permanent magnet facing the other axial direction, the auxiliary yoke attracting the plunger to maintain the contacts in an open state when the coil is not energized and is in a non-excited state; The protrusions are formed at two locations on the rib that are spaced apart in the vertical direction, 4. The electromagnetic contactor according to claim 3, wherein the permanent magnets are fitted from the other axial direction between the ribs spaced apart in the width direction and between the protrusions spaced apart in the vertical direction.

5. 5. The electromagnetic contactor according to claim 4, wherein both longitudinal ends of the auxiliary yoke are fastened to the bottom yoke by bolts extending in the axial direction.

6. The case has stud bolts insert-molded along the axial direction on both ends in the vertical direction, 2. The electromagnetic contactor according to claim 1, wherein the bottom yoke is fastened to the stud bolt.

7. The case has embedded nuts insert-molded along the axial direction at the four corners as viewed from the axial direction, 2. The electromagnetic contactor according to claim 1, wherein the cover is fastened to the embedded nut.

Images