Electromagnetic contactor

Abstract

The present invention provides an electromagnetic contactor capable of preventing deterioration of arc extinguishing performance even when a large amount of metal vapor is generated when a large current is cut off, the electromagnetic contactor comprising: a box-shaped arc extinguishing wall (35) which is disposed inside a housing case (6) and accommodates a pair of fixed contacts (3a, 3b) and a movable contact (4); first and second arc extinguishing spaces (S1, S2), which are spaces surrounded by the arc extinguishing walls, and which are located on one side and the other side of the movable contact in the longitudinal direction; arc-extinguishing permanent magnets (36, 37) which are disposed so as to face each other and which extend a first arc generated between the first fixed contact and the first movable contact to the first arc-extinguishing space and extend a second arc generated between the second fixed contact and the second movable contact to the second arc-extinguishing space; first openings (40a, 40b) provided in a wall portion of the arc extinguishing wall in the direction in which the first arc is elongated; and second openings (40c, 40d) provided in the wall portion of the arc extinguishing wall in the direction in which the second arc is stretched.

Description

Technical Field

[0001] The present invention relates to an electromagnetic contactor for opening and closing a current path. Background Art

[0002] For example, the electromagnetic contactor of Patent Document 1 includes a pair of fixed contacts having fixed contacts, a movable contact having a pair of movable contacts capable of contacting and separating with the fixed contacts of the pair of fixed contacts, a contact box accommodating the pair of fixed contacts and the movable contact, an electromagnet unit connected to the movable contact via a drive shaft, and a permanent magnet for extinguishing the arc generated between the fixed contacts and the movable contact by elongating the arc in the contact box.

[0003] In the electromagnetic contactor of Patent Document 1, when an arc is generated between a pair of fixed contacts and a pair of movable contacts when the current path is cut off, the magnetic flux of the permanent magnet used to extinguish the arc crosses the arc, whereby the arc is elongated and extinguished in the contact box due to the Lorentz force caused by Fleming's left-hand rule.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 5629106 Summary of the invention

[0007] However, in the electromagnetic contactor of Patent Document 1, when an arc is generated when a large current is cut off, a large amount of metal vapor is retained in the contact box due to the melting of the fixed contact and the movable contact. There is a situation where the pressure of the metal vapor is locally increased, and a gas flow of the metal vapor is generated in the opposite direction to the direction in which the arc is stretched, that is, in the direction of pushing the arc back, and there is a risk of reduced arc extinguishing performance.

[0008] Therefore, an object of the present invention is to provide an electromagnetic contactor which can prevent the arc extinguishing performance from being deteriorated even when a large amount of metal vapor is generated when a large current is interrupted.

[0009] In order to achieve the above-mentioned purpose, an electromagnetic contactor of one embodiment of the present invention comprises: a pair of fixed contacts having first and second fixed contacts; movable contacts having first and second movable contacts capable of contacting and separating with the first and second fixed contacts at both ends in the long side direction; an electromagnet unit for driving the movable contact; and a storage shell for accommodating the pair of fixed contacts, the movable contact and the electromagnet unit. The electromagnetic contactor comprises: a box-shaped arc-extinguishing wall arranged inside the storage shell, which accommodates the pair of fixed contacts and the movable contact; the first and second arc-extinguishing spaces The invention relates to a space surrounded by an arc extinguishing wall, which is a space surrounded by an arc extinguishing wall and is located on one side and the other side of the long side direction of the movable contact; a pair of arc extinguishing permanent magnets arranged opposite to each other, which stretch the first arc generated between the first fixed contact and the first movable contact to the first arc extinguishing space, and stretch the second arc generated between the second fixed contact and the second movable contact to the second arc extinguishing space; a first opening portion, which is arranged at the wall portion of the arc extinguishing wall in the direction in which the first arc is stretched; and a second opening portion, which is arranged at the wall portion of the arc extinguishing wall in the direction in which the second arc is stretched.

[0010] Effects of the Invention

[0011] According to the electromagnetic contactor of the present invention, even if a large amount of metal vapor is generated due to an arc of a large current, it is possible to prevent the arc extinguishing performance from being deteriorated. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional view of the electromagnetic contactor according to the first embodiment of the present invention.

[0013] Figure 2 It is a perspective view showing the shape of an arc extinguishing wall constituting an electromagnetic contactor.

[0014] Figure 3 It is a perspective view showing a pair of arc extinguishing permanent magnets and a pair of magnetic pole plates mounted on an arc extinguishing wall.

[0015] Figure 4 yes Figure 1 AA line view.

[0016] Figure 5 It is a cross-sectional view of an electromagnetic contactor according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0017] Next, the embodiments of the present invention are described with reference to the accompanying drawings. In the following description of the drawings, the same or similar reference numerals are attached to the same or similar parts. However, it should be noted that the drawings are schematic, and the relationship between thickness and plane size, the ratio of thickness of each layer, etc. are different from the actual ones. Therefore, the specific thickness and size should be judged with reference to the following description. In addition, the drawings also include parts with different relationship or ratio of size.

[0018] In addition, the embodiments shown below illustrate the devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention does not limit the material, shape, structure, configuration, etc. of the constituent parts to those described below. Various changes can be made to the technical concept of the present invention within the technical scope specified in the claimed scope of rights.

[0019] In addition, terms indicating directions such as “upper”, “lower”, “left” and “right” described in the following description are used with reference to directions in the drawings.

[0020] [First embodiment]

[0021] Figure 1 An electromagnetic contactor 1 according to a first embodiment of the present invention is shown.

[0022] The electromagnetic contactor 1 is a sealed high-voltage contactor that uses electromagnetic force to open and close the main circuit. It includes a sealed container 2 made of electrically insulating resin, and a pair of fixed contacts 3, a movable contact 4 and an electromagnet unit 5 contained in the sealed container 2. The electromagnet unit 5 drives the movable contact 4 in the direction of contact and separation with the pair of fixed contacts 3.

[0023] The sealed container 2 is composed of a case 6 and a cover 7, and an arc extinguishing gas is sealed inside the sealed container 2. The storage case of the present invention corresponds to the sealed container 2.

[0024] The housing 6 is Figure 1 A square cylindrical member with an open lower end (one end) and a closed upper end (the other end). The cover 7 is a cover-shaped member. The lower end of the housing 6 and the cover 7 are fitted with each other at their open ends and bonded with an adhesive.

[0025] A pair of fixed contacts 3a, 3b are electrodes formed of a conductive metal in a substantially cylindrical shape, and are integrated by insert molding in a state of penetrating the wall of the housing 6. Screw holes 8 are formed on the upper parts of the pair of fixed contacts 3a, 3b, and are exposed to the outside of the housing 6. Terminal bolts (not shown) on the primary and secondary sides of the main circuit are engaged with these screw holes 8. The lower sides of the pair of fixed contacts 3a, 3b protrude into the interior of the housing 6, and fixed contacts 9a, 9b are formed on their lower parts. In addition, the first and second fixed contacts of the present invention correspond to the fixed contacts 9a, 9b.

[0026] The movable contact 4 is a conductive metal. Figure 1 The movable contact 4 is formed in a flat plate shape extending in the left-right direction and arranged opposite to the pair of fixed contacts 3. A pair of movable contacts 10a, 10b are formed at both ends in the left-right direction of the movable contact 4 and can contact and separate with the fixed contacts 9a, 9b of the pair of fixed contacts 3a, 3b.

[0027] The movable contact 4 is connected to the electromagnet unit 5 via a contact support 11. The contact support 11 includes a base 12 connected to the electromagnet unit 5, a pressing member 13 for holding the movable contact 4, and a contact spring 14 for applying contact pressure to the movable contact 4. The contact spring 14 is a compression spring, which is sandwiched between the base 12 and the movable contact 4 and applies contact pressure to the movable contact 4. Figure 1 In this way, the contact spring 14 elastically supports the movable contact 4, thereby keeping the contact pressure between the movable contacts 10a, 10b and the fixed contacts 9a, 9b constant.

[0028] The electromagnet unit 5 includes a bobbin 20 , a sliding bush 21 , a movable plunger 22 , an armature 23 , a pair of outer yokes 24 a , 24 b , a pair of bottom yokes 25 a , 25 b , a plunger ring 26 , a return spring 27 , a permanent magnet 28 , and an auxiliary yoke 29 .

[0029] The bobbin 20 is a winding frame formed of a resin having electrical insulating properties, and a coil 31 is wound around a cylindrical winding shaft 30 extending in the up-down direction.

[0030] The sliding bush 21 is formed into a cylindrical shape using a resin having electrical insulation properties, and is inserted and fitted into the inner side of the winding shaft 30 from the lower side in the vertical direction.

[0031] The movable plunger 22 is formed as a movable iron core in a cylindrical shape extending in the vertical direction, and is guided to move forward and backward in the axial direction by fitting with the inner side of the sliding bushing 21. The upper side of the movable plunger 53 in the vertical direction is connected to the base 12 of the contact support 11 via the connecting portion 32. The armature 23 is a disc-shaped yoke, and is fixed to the lower end of the movable plunger 22.

[0032] The pair of outer yokes 24 are plate-shaped yokes fixed on the left and right sides of the winding shaft 30. The pair of bottom yokes 25a and 25b extend and are fixed on the left and right sides of the lower parts of the pair of outer yokes 24a and 24b on the same extension line.

[0033] The plunger ring 26 is a cylindrical yoke extending in the vertical direction, and is inserted and fitted into the inner side of the winding shaft 30 from the upper side in the vertical direction, and is fixed to the upper yoke piece in the upper part in the vertical direction of the pair of outer yokes 24. The inner diameter of the plunger ring 26 is larger than the outer diameter of the movable plunger 22, and is set to maintain a predetermined gap relative to the movable plunger 22.

[0034] The return spring 27 is a compression spring, and is inserted through the movable plunger 22 in a state of being sandwiched between the armature 23 and the sliding bushing 21 , so as to urge the movable plunger 22 downward in the vertical direction with respect to the bobbin 20 .

[0035] The permanent magnet 28 is a rectangular plate with a circular hole formed therein, and is arranged to contact the lower portions of the pair of bottom yokes 25a and 25b so as to surround the armature 23. The auxiliary yoke 29 is a plate-shaped yoke, and is attached to the lower portion of the permanent magnet 28.

[0036] Then, in the electromagnetic contactor of this embodiment, an arc extinguishing wall 35 is arranged to surround the pair of fixed contacts 3 a , 3 b and the movable contact 4 , and a pair of arc extinguishing permanent magnets 36 , 37 and a pair of magnetic pole plates 38 , 39 are mounted on the arc extinguishing wall 35 .

[0037] Arc extinguishing wall 35 Figure 2 As shown, the box body is made of ceramic or synthetic resin, and has a rectangular plate-shaped cover 35a in which a pair of contact holes 35a1 are formed to allow a pair of fixed contacts 3a and 3b to be inserted, short side walls 35b and 35c and long side walls 35d and 35e extending in the same direction from four edge portions of the cover 35a, and a mounting plate 35f extending outward at right angles from the front ends of the short side walls 35b and 35c and the long side walls 35d and 35e. In addition, there is no corner at the intersection of adjacent short side walls and long side walls (for example, adjacent short side walls 35b and long side walls 35e), and four corner openings 40a to 40d extending linearly in the same direction as the direction in which the short side walls 35b and 35c and the long side walls 35d and 35e extend. In addition, the first opening portion of the present invention corresponds to the corner opening portions 40a and 40b, and the second opening portion of the present invention corresponds to the corner opening portions 40c and 40d.

[0038] A pair of permanent magnets 36 and 37 for arc extinguishing are provided. Figure 3 As shown, it is arranged so as to abut against the short side walls 35b and 35c of the arc extinguishing wall 35 and be placed on the placement plate 35f.

[0039] like Figure 3 As shown, one magnetic pole plate 38 is a member having a magnet contact plate 38a and a pair of parallel plate portions 38d and 38e extending parallel to each other from the left and right directions of the magnet contact plate 38a via bent portions 38b and 38c. Figure 3 As shown, the magnetic pole plate 38 is configured such that the magnet abutment plate 38a abuts against the permanent magnet 36 for arc extinguishing, and a pair of parallel plate portions 38d and 38e are placed on the mounting plate 35f in a state of abutting against the long side walls 35d and 35e of the arc extinguishing wall 35. Moreover, the curved portions 38b and 38c of the magnetic pole plate 38 are opposite to the corner openings 40 of the arc extinguishing wall 35, thereby forming outer connecting spaces 41a and 41b outside the two corner openings 40a and 40b. In addition, as shown in FIG. Figure 3As shown, the other magnetic pole plate 39 is also a component having a magnet abutment plate 39a and a pair of parallel plate portions 39d and 39e extending parallel to each other from the left and right directions of the magnet abutment plate 39a via curved portions 39b and 39c. The magnetic pole plate 39 is also configured so that the magnet abutment plate 39a abuts against the arc extinguishing permanent magnet 37 configured on the short side wall 35c of the arc extinguishing wall 35, and the pair of parallel plate portions 39d and 39e abut against the long side walls 35d and 35e of the arc extinguishing wall 35 and are placed on the placement plate 35f. Moreover, the curved portions 39b and 39c of the magnetic pole plate 39 are opposite to the corner opening 40 of the arc extinguishing wall 35, thereby forming two outer connecting spaces 41c and 41d outside the two corner openings 40c and 40d. In addition, the first outside communication space of the present invention corresponds to the outside communication spaces 41 a and 41 b , and the second outside communication space of the present invention corresponds to the outside communication spaces 41 c and 41 d .

[0040] Then, if Figure 4 As shown, an arc extinguishing wall 35 integrally configured with a pair of arc extinguishing permanent magnets 36 , 37 and a pair of magnetic pole plates 38 , 39 is mounted on the inner wall of the housing 6 in a state surrounding the pair of fixed contacts 3 a , 3 b and the movable contact 4 .

[0041] The magnetic pole surface of the arc extinguishing permanent magnet 36 that contacts the short side wall 35b is an S pole, and the magnetic pole surface of the arc extinguishing permanent magnet 37 that contacts the short side wall 35c is an N pole.

[0042] When the fixed contact 9a of one fixed contact 3a and the movable contact 10a of the movable contact 4 that contacts and separates with the fixed contact 9a are referred to as the contact portion 42a, and the fixed contact 9b of the other fixed contact 3b and the movable contact 10b of the movable contact 4 that contacts and separates with the fixed contact 9b are referred to as the contact portion 42b, the magnetic flux ( Figure 4 The dashed arrow) crosses the contact portions 42a, 42b.

[0043] The contact portion 42a is Figure 4 The space surrounded by the arc-extinguishing wall 35 on the left side is referred to as the first arc-extinguishing space S1. In addition, the space surrounded by the arc-extinguishing wall 35 on the right side relative to the contact portion 42b is referred to as the second arc-extinguishing space S2. The first arc-extinguishing space S1 and the second arc-extinguishing space S2 are connected to four outer connecting spaces 41a to 41d formed by a pair of magnetic pole plates 38 and 39 via four corner openings 40a to 40d formed in the arc-extinguishing wall 35. Moreover, the four outer connecting spaces 41a to 41d are connected to the space accommodating the electromagnet unit 5 in the sealed container 2 (shell 6).

[0044] Next, refer to Figure 4The operation of the electromagnetic contactor 1 according to the present embodiment will be described.

[0045] In the electromagnetic contactor 1 of the present embodiment, one fixed contact 3 a is connected to a positive (+) terminal, and the other fixed contact 3 b is connected to a negative (−) terminal.

[0046] Now, it is assumed that the coil 31 of the electromagnet unit 5 is in a non-excitation state, and is in a released state in which no excitation force is generated by the electromagnet unit 5 to move the movable plunger 22 upward. In this released state, the movable plunger 22 is urged downward by the return spring 27, and the armature 23 is attracted to the auxiliary yoke 29 by the action of the permanent magnet 28. Therefore, the movable contact 4 connected to the movable plunger 22 is spaced downward by a predetermined distance relative to the pair of fixed contacts 3a and 3b. Therefore, the current path between the pair of fixed contacts 3a and 3b is in a cut-off state, and the contact portions 42a and 42b are in an open state (open state of the contact portions 42a and 42b).

[0047] When the coil 31 of the electromagnet unit 5 is energized from the disconnected state of the contact parts 42a, 42b, the electromagnet unit 5 generates an excitation force, which pushes the movable plunger 22 upward against the adsorption force of the permanent magnet 28 on the auxiliary yoke 29 and the action of the return spring 27, and the armature 23 is adsorbed on the bottom yokes 25a, 25b.

[0048] In this way, the movable plunger 22 moves upward, thereby the movable contact 4 connected to the movable plunger 22 also moves upward, and the movable contacts 10a, 10b of the movable contact 4 come into contact with the fixed contacts 9a, 9b of a pair of fixed contacts 3a, 3b due to the contact pressure of the contact spring 14, and the contact parts 42a, 42b become closed.

[0049] Then, from the closed state of the contact parts 42a, 42b, when a large current flows in the main circuit and the energization of the coil 31 of the electromagnet unit 5 is stopped, the excitation force of the electromagnet unit 5 that moves the movable plunger 22 upward disappears, and the movable plunger 22 moves downward due to the force of the return spring 27, and the armature 23 is attracted to the auxiliary yoke 29 due to the action of the permanent magnet 28. When the movable plunger 22 moves downward, the movable contact 4 connected to the movable plunger 22 enters a disconnection start state in which it is separated downward from the pair of fixed contacts 3a, 3b.

[0050] When a large current flows in the main circuit and the contact parts 42a and 42b begin to be disconnected, a first arc is generated between the contact parts 42a, and a second arc is generated between the contact parts 42b. Due to the first and second arcs, the current conduction state continues. The current direction of the first arc is from the fixed contact 9a to the movable contact 10a, and the current direction of the second arc is from the movable contact 10b to the fixed contact 9b.

[0051] At this time, the magnetic flux starting from the N pole of the arc extinguishing permanent magnet 37 and flowing to the S pole of the arc extinguishing permanent magnet 36 crosses the first arc and the second arc. According to the relationship between the flow of the current of the first arc and the magnetic flux, according to Fleming's left-hand rule, the magnetic flux flows to the first arc and the second arc. Figure 4 The Lorentz force F1 is generated on the side of the corner opening 40a of the arc extinguishing wall 35 toward the upper left side of the first arc extinguishing space S1. In addition, according to the relationship between the flow of the current of the second arc and the magnetic flux, according to Fleming's left-hand rule, Figure 4 A Lorentz force F2 is generated on the side of the corner opening 40d of the arc extinguishing wall 35 facing the lower right side of the second arc extinguishing space S2.

[0052] When the Lorentz force F1 is generated, the first arc is directed toward the first arc extinguishing space S1. Figure 4 The first arc is greatly elongated toward the corner opening 40a of the arc extinguishing wall 35 on the upper left side, and is gradually cooled by contact with the arc extinguishing gas. Then, the greatly elongated first arc is gradually cooled by contacting the curved portion 38b of the magnetic pole plate 38 forming the outer connecting space 41a from the corner opening 40a. In addition, when the Lorentz force F2 is generated, the second arc is greatly elongated toward the corner opening 40d of the arc extinguishing wall 35 on the lower right side of the second arc extinguishing space S2, and is gradually cooled by contact with the arc extinguishing gas. Then, the greatly elongated second arc is gradually cooled by contacting the curved portion 39c of the magnetic pole plate 39 forming the outer connecting space 41d from the corner opening 40d.

[0053] On the other hand, when a large current flows in the main circuit and the contact parts 42a and 42b are in the open state, the fixed contact 9b and the movable contact 10b in the contact part 42a melt due to the temperature rise of the first arc and generate a large amount of high-temperature metal vapor. In addition, the fixed contact 12a and the movable contact 13b in the contact part 42b also melt due to the temperature rise of the second arc and generate a large amount of high-temperature metal vapor.

[0054] The metal vapor generated at the contact portion 42a flows to the first arc extinguishing space S1. Figure 4 As shown, the metal vapor flows from the corner openings 40a and 40b of the arc extinguishing wall 35 through the outer communicating spaces 41a and 41b to the space accommodating the electromagnet unit 5. In addition, the metal vapor generated at the contact portion 42b flows to the second arc extinguishing space S2, and flows from the corner openings 40c and 40d of the arc extinguishing wall 35 through the outer communicating spaces 41c and 41d to the space accommodating the electromagnet unit 5. The metal vapor flowing through the outer communicating spaces 41a to 41d is gradually cooled by contacting with the curved portions 38b, 38c, 39b, and 39c of the magnetic pole plates 38 and 39 forming the outer communicating spaces 41a to 41d.

[0055] Next, the effects of the electromagnetic contactor 1 according to the present embodiment will be described.

[0056] When a large current is cut off, when the first arc is generated at the contact portion 42a, a Lorentz force F1 is generated toward the side of the corner opening 40a of the arc extinguishing wall facing the first arc extinguishing space S1 according to the relationship between the flow of the current of the first arc and the magnetic flux, and the first arc can be greatly elongated. In addition, when the second arc is generated at the contact portion 42b, a Lorentz force F2 is generated toward the side of the corner opening 40d of the arc extinguishing wall 35 facing the second arc extinguishing space S2 according to the relationship between the flow of the current of the second arc and the magnetic flux, and the second arc can also be greatly elongated.

[0057] Then, even if a large amount of high-temperature metal vapor is generated in the contact portions 42a and 42b when a large current is cut off, the metal vapor generated in the contact portion 42a flows from the corner openings 40a and 40b of the arc extinguishing wall 35 to the outer communicating spaces 41a and 41b, and flows to the space accommodating the electromagnet unit 5. In addition, the metal vapor generated in the contact portion 42b also flows from the corner openings 40c and 40d of the arc extinguishing wall 35 to the outer communicating spaces 41c and 41d, and flows to the space accommodating the electromagnet unit 5. In this way, the metal vapor generated in the contact portions 42a and 42b does not stay in the first arc extinguishing space S1 and the second arc extinguishing space S2, and the pressure does not rise. By generating airflow in the direction of the corner openings 40a and 40d of the arc extinguishing wall 35, the first arc and the second arc are further elongated.

[0058] Therefore, the first and second arcs are efficiently extended along the gas flow of the metal vapor, so that the interruption performance can be improved.

[0059] In addition, the greatly extended first arc is further cooled by contacting the curved portion 38b of the magnetic pole plate 38 forming the outer connecting space 41a from the corner opening 40a, and the greatly extended second arc is further cooled by contacting the curved portion 38c of the magnetic pole plate 39 forming the outer connecting space 41d from the corner opening 40d, so that the circuit breaking performance can be further improved.

[0060] In addition, the metal vapor flowing from the corner openings 40a, 40b of the arc extinguishing wall 35 to the outer connecting spaces 41a, 41b, and the metal vapor flowing from the corner openings 40c, 40d of the arc extinguishing wall 35 to the outer connecting spaces 41c, 41d are efficiently cooled and changed into liquid or solid by contact with the curved portions 38b, 38c, 39b, 39c of the magnetic pole plates 38, 39 forming the outer connecting spaces 41a~41d. The pressure and temperature inside the closed container 2 are reduced in a short time, so that the arc extinguishing performance can be prevented from being reduced, and the secondary arcing of the first and second arcs can be prevented.

[0061] [Second Embodiment]

[0062] then, Figure 5 The main part of the electromagnetic contactor 1 of the second embodiment of the present invention is shown. In this embodiment, there is a pair of arc extinguishing permanent magnets 45 and 46 having a structure different from the pair of arc extinguishing permanent magnets 36 and 37 of the first embodiment. The other structures are the same as those of the first embodiment, and the same figure marks are added and the description is omitted.

[0063] In this embodiment, the magnetic pole surface of one arc extinguishing permanent magnet 45 abutting the short side wall 35b of the arc extinguishing wall 35 is an N pole, and the magnetic pole surface of the other arc extinguishing permanent magnet 46 abutting the short side wall 35c is an N pole.

[0064] An arc extinguishing permanent magnet 45, such as Figure 5 As shown by the dotted line, a magnetic flux is generated from the short side wall 35b of the arc extinguishing wall 35 to the long side walls 35d and 35e, and another arc extinguishing permanent magnet 46 generates a magnetic flux from the short side wall 35c of the arc extinguishing wall 35 to the long side walls 35d and 35e.

[0065] In the electromagnetic contactor 1 of the present embodiment, when a large current flows in the main circuit and the contact parts 42a and 42b begin to be disconnected, a first arc is generated between the contact parts 42a, and a second arc is generated between the contact parts 42b. Due to the first and second arcs, the current conduction state continues, and the current direction of the first arc is from the fixed contact 9a toward the movable contact 10a, and the current direction of the second arc is from the movable contact 10b toward the fixed contact 9b.

[0066] At this time, according to the relationship between the flow of the current of the first arc and the magnetic flux of one of the arc extinguishing permanent magnets 45, a Lorentz force F1 is generated on the side of the corner opening 40b of the arc extinguishing wall 35 facing the lower left side of the first arc extinguishing space S1 according to Fleming's left-hand rule. In addition, according to the relationship between the flow of the current of the second arc and the magnetic flux of the other arc extinguishing permanent magnet 46, a Lorentz force F2 is generated on the side of the corner opening 40d of the arc extinguishing wall 35 facing the lower right side of the second arc extinguishing space S2 according to Fleming's left-hand rule.

[0067] When the Lorentz force F1 is generated, the first arc is greatly extended to the corner opening 40b side of the arc extinguishing wall 35 on the lower left side of the first arc extinguishing space S1, and gradually cools down due to contact with the arc extinguishing gas. Then, the greatly extended first arc gradually cools down by contacting the curved portion 38c of the magnetic pole plate 38 forming the outer connecting space 41b from the corner opening 40b. In addition, when the Lorentz force F2 is generated, the second arc is greatly extended to the corner opening 40d side of the arc extinguishing wall 35 on the lower right side of the second arc extinguishing space S2, and gradually cools down due to contact with the arc extinguishing gas. Then, the greatly extended second arc gradually cools down by contacting the curved portion 39c of the magnetic pole plate 39 forming the outer connecting space 41d from the corner opening 40d.

[0068] In addition, the metal vapor generated at the contact portion 42a flows to the first arc extinguishing space S1, and flows from the corner openings 40a and 40b of the arc extinguishing wall 35 through the outer communicating spaces 41a and 41b to the space accommodating the electromagnet unit 5. In addition, the metal vapor generated at the contact portion 42b flows to the second arc extinguishing space S2, and flows from the corner openings 40c and 40d of the arc extinguishing wall 35 through the outer communicating spaces 41c and 41d to the space accommodating the electromagnet unit 5. The metal vapor flowing through the outer communicating spaces 41a to 41d is gradually cooled by contacting the bent portions 38b, 38c, 39b and 39c of the magnetic pole plates 38 and 39 forming the outer communicating spaces 41a to 41d.

[0069] According to the electromagnetic contactor 1 of this embodiment, when the first arc is generated at the contact portion 42a during large current interruption, a Lorentz force F1 is generated toward the side of the corner opening 40b of the arc extinguishing wall 35 facing the first arc extinguishing space S1 according to the relationship between the flow of the current of the first arc and the magnetic flux of an arc extinguishing permanent magnet 45, and the first arc can be greatly elongated. In addition, when the second arc is generated at the contact portion 42b, a Lorentz force F2 is generated toward the side of the corner opening 40d of the arc extinguishing wall 35 facing the second arc extinguishing space S2 according to the relationship between the flow of the current of the second arc and the magnetic flux, and the second arc can also be greatly elongated.

[0070] Then, even if a large amount of high-temperature metal vapor is generated at the contact portions 42a and 42b when a large current is cut off, the metal vapor generated at the contact portion 42a flows from the corner openings 40a and 40b of the arc extinguishing wall 35 to the outer communicating spaces 41a and 41b, and flows to the space accommodating the electromagnet unit 5. In addition, the metal vapor generated at the contact portion 42b also flows from the corner openings 40c and 40d of the arc extinguishing wall 35 to the outer communicating spaces 41c and 41d, and flows to the space accommodating the electromagnet unit 5. Thus, the first and second arcs are efficiently elongated along the airflow of the metal vapor, and the circuit breaking performance can be improved.

[0071] Also, similarly to the first embodiment, the first arc is further cooled by contact with the bent portion 38 c of the magnetic pole plate 38 , and the second arc is further cooled by contact with the bent portion 39 c of the magnetic pole plate 39 , so that the interruption performance can be further improved.

[0072] Furthermore, similarly to the first embodiment, metal vapor contacts the bent portions 38b, 38c, 39b, 39c of the magnetic pole plates 38, 39 forming the outer communicating spaces 41a to 41d, thereby preventing a decrease in arc extinguishing performance and preventing secondary arcing of the first and second arcs.

[0073] Description of Reference Numerals

[0074] 1Electromagnetic contactor

[0075] 2 airtight containers

[0076] 3a, 3b fixed contacts

[0077] 4 movable contacts

[0078] 5 Electromagnet unit

[0079] 6 Shell

[0080] 7 Cover

[0081] 8 screw holes

[0082] 9a, 9b fixed contacts

[0083] 10a, 10b movable contacts

[0084] 11Contact support

[0085] 12 Base

[0086] 13 Pushing parts

[0087] 14 Contact spring

[0088] 20 Winding rack

[0089] 21 Sliding bushing

[0090] 22 Movable plunger

[0091] 23 Armature

[0092] 24a, 24b outer yoke

[0093] 25a, 25b bottom yoke

[0094] 26 Plunger ring

[0095] 27 Return spring

[0096] 28 Permanent magnet

[0097] 29 Auxiliary yoke

[0098] 30 Winding shaft

[0099] 31 Coil

[0100] 32 Connection

[0101] 35 Arc extinguishing wall

[0102] 35a Cover

[0103] 35a1 contact hole

[0104] 35b, 35c Short side wall

[0105] 35d, 35e long side wall

[0106] 35f loading board

[0107] 36, 37, 45, 46 Permanent magnets for arc extinguishing

[0108] 38, 39 magnetic pole plates

[0109] 38a, 39a Magnet abutment plate

[0110] 38b, 38c, 39b, 39c bending part

[0111] 38d, 38e, 39d, 39e parallel plate portion

[0112] 40a~40d Corner opening

[0113] 41a~41d External connecting space

[0114] 42a, 42b contact portion

[0115] F1, F2 Lorentz force

[0116] S1 first arc extinguishing space

[0117] S2 second arc extinguishing space.

Claims

1. An electromagnetic contactor, comprising: A pair of fixed contacts having a first fixed contact and a second fixed contact; movable contacts having a first movable contact and a second movable contact that can contact and separate with the first fixed contact and the second fixed contact are arranged at both ends in the long side direction; an electromagnet unit that drives the movable contact; and a housing housing for accommodating the pair of fixed contacts, the movable contact and the electromagnet unit, wherein the electromagnetic contactor comprises: A box-shaped arc-extinguishing wall disposed inside the housing housing, accommodating the pair of fixed contacts and the movable contact; A first arc extinguishing space and a second arc extinguishing space, which are spaces surrounded by the arc extinguishing wall and are located on one side and the other side in the long side direction of the movable contact; a pair of arc extinguishing permanent magnets disposed opposite to each other, which extend a first arc generated between the first fixed contact and the first movable contact to the first arc extinguishing space, and extend a second arc generated between the second fixed contact and the second movable contact to the second arc extinguishing space; a first opening portion provided on a wall portion of the arc extinguishing wall in a direction in which the first arc is elongated; and The second opening is provided on a wall portion of the arc extinguishing wall in a direction in which the second arc is elongated.

2. The electromagnetic contactor according to claim 1, characterized in that: The arc-extinguishing wall is in a rectangular box shape, and the first opening and the second opening are formed at corners of the arc-extinguishing wall.

3. The electromagnetic contactor according to claim 1 or 2, characterized in that: A first outer communicating space communicating with the first arc extinguishing space via the first opening and a second outer communicating space communicating with the second arc extinguishing space via the second opening are formed outside the arc extinguishing wall.

4. The electromagnetic contactor according to claim 3, characterized in that: The first outer communicating space and the second outer communicating space are formed by magnetic pole plates arranged to surround the outer side of the arc extinguishing wall.

5. The electromagnetic contactor according to claim 4, characterized in that: The first outside communication space and the second outside communication space communicate with an inner space of the storage case in which the electromagnet unit is accommodated.

6. The electromagnetic contactor according to claim 1 or 2, characterized in that: Arc extinguishing gas is sealed in the housing case.

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