JP2012199113A - Contact device and electromagnetic switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact device and an electromagnetic switch capable of effectively cutting off arc, without increasing the outer size.SOLUTION: A contact device 3 comprises: a contact part having a fixed contact 32 and a movable contact piece 35 which is brought into contact with and separated from the fixed contact 32; a case 31 which houses the contact part; a permanent magnet 46 which generates, in the case 31, a magnetic flux in a direction intersecting a contacting/separating direction of the movable contact piece 35; and an insulation member 37 which is provided on an inner wall surface of the case 31, and which is projected from the inner wall surface toward the contact part in a direction intersecting both the contacting/separating direction of the movable contact piece 35 and a direction of the magnetic flux generated by the permanent magnet 46.

Description

  The present invention relates to a contact device and an electromagnetic switch using the contact device.

  Conventionally, a contact device including a fixed contact, a movable contact that contacts and separates from the fixed contact, a case that stores the fixed contact and the movable contact, and a magnet that generates a magnetic field that intersects the contact and separation direction of the movable contact. There is. This contact device can extinguish arcs by stretching an arc generated when the contacts are separated by the magnetic field of the magnet (see, for example, Patent Document 1).

JP 2005-056819 A

  In such a contact device, an arc current may flow between the contacts if the movable contact is displaced away from the fixed contact while current is flowing. In order to extend and interrupt the arc, a magnet for generating a magnetic field is required, and a space for extending the arc is required between the case and the contact point. Therefore, when the maximum allowable contact current is increased, there is a problem that the outer sizes of the contact device and the electromagnetic switch are increased.

  The present invention has been made in view of the above problems, and an object thereof is to provide a contact device and an electromagnetic switch that can effectively interrupt an arc without increasing the outer size.

  The contact device of the present invention includes a fixed contact and a contact portion having a movable contactor that contacts and separates from the fixed contact, a case that houses the contact portion, and a magnetic flux that intersects the contact and separation direction of the movable contactor. A permanent magnet to be generated in the case and an inner wall surface of the case, and from the inner wall surface toward the contact portion in a direction intersecting with both the contact / separation direction of the movable contact and the direction of the magnetic flux And a projecting insulating member.

  In this contact device, the case is opposed to the first and second wall portions facing each other and the facing direction intersects the contact / separation direction of the movable contact, and the facing direction is opposed to the movable contact. And the third and fourth wall portions intersecting with both of the first and second wall portions and the opposing direction of the first and second wall portions, and the insulating member includes the first and second wall portions. The permanent magnet is provided on at least one of the inner wall surfaces, and the permanent magnet is arranged on at least one outer wall surface of the third and fourth wall portions in a direction in which the direction of the magnetic lines of force intersects the outer wall surface. Is preferably disposed.

  Alternatively, in this contact device, the case includes first and second wall portions that are provided to face each other and whose facing direction intersects with the contact / separation direction of the movable contact, and the insulating member includes The permanent magnet is provided on at least one inner wall surface of the first and second wall portions, and the permanent magnet has at least one outer wall surface of the first and second wall portions with a line of magnetic force therein. It is preferable that the orientation is arranged in a direction parallel to the outer wall surface.

  An electromagnetic switch according to the present invention includes any one of the contact devices described above and an electromagnet device that displaces the movable contact using electromagnetic force.

  The contact device and the electromagnetic switch according to the present invention can effectively interrupt the arc without increasing the outer size.

BRIEF DESCRIPTION OF THE DRAWINGS The outline of embodiment of the contact apparatus which concerns on this invention is shown, (a) is a perspective view, (b) is a top view. The embodiment of the electromagnetic switch which concerns on this invention is shown, (a) is front sectional drawing, (b) is side sectional drawing. The embodiment of the electromagnetic switch which concerns on this invention is shown, (a) is a rear view, (b) is a side view. It is explanatory drawing of the arc extinguishing by embodiment of the electromagnetic switch which concerns on this invention. 1 is a schematic plan view of an embodiment of a contact device according to the present invention. 1 is a schematic plan view of an embodiment of a contact device according to the present invention.

  Hereinafter, embodiments of a contact device and an electromagnetic switch according to the present invention will be described with reference to FIGS.

  First, the structure of the contact device 3 of this embodiment is demonstrated with reference to Fig.1 (a) and FIG.1 (b). In addition, illustration of case 31 is abbreviate | omitted in Fig.1 (a).

  As shown in FIGS. 1A and 1B, the contact device 3 includes a pair of fixed contacts 32, 32 and a contact portion having a movable contact 35 that contacts and separates from the fixed contacts 32, 32, and a contact portion. , A pair of permanent magnets 46A and 46B (first permanent magnet 46A and second permanent magnet 46B), and a pair of insulating members 37A and 37B (first insulating member 37A and second insulating member). Member 37B). The permanent magnets 46A and 46B are configured to apply magnetic flux in a direction (the direction of the dotted arrow in FIG. 1B) that intersects with the contact / separation direction of the movable contact 35 (first direction; front-rear direction in FIG. 1B). It is arranged on the outer wall surface of the case 31 so as to be generated inside the case 31. Insulating members 37A and 37B according to the present embodiment project on the inner wall surface of case 31 toward the contact portion in a direction orthogonal to both the contact / separation direction of movable contact 35 and the direction of magnetic flux by permanent magnets 46A and 46B. Has been.

  The pair of fixed contacts 32 and 32 are respectively provided at the lower ends of a pair of fixed terminals 33 and 33 formed in a substantially cylindrical shape by a conductive material such as copper. In the present embodiment, the current flowing from the left fixed terminal 33 to the right fixed terminal 33 through the movable contact 35 in FIG.

  The movable contact 35 is formed in a long rectangular flat plate shape from a conductive material such as metal. The movable contact 35 is disposed so as to straddle between the pair of fixed contacts 32, 32, and can be displaced between a position contacting the fixed contacts 32, 32 and a position separated from the fixed contacts 32, 32. It has become. An insertion hole 35b penetrates in the center of the movable contact 35 in the longitudinal direction in the thickness direction of the movable contact 35 (the vertical direction in FIG. 1A).

  The case 31 is made of an insulating material having heat resistance such as ceramic. The case 31 has a first wall portion 31A and a second wall portion 31B that face each other. The opposing direction of the first wall portion 31A and the second wall portion 31B (second direction; the left-right direction in FIG. 1B) intersects the contact / separation direction of the movable contact 35. The case 31 has a third wall portion 31C and a fourth wall portion 31D that face each other. The facing direction of the third wall portion 31C and the fourth wall portion 31D (third direction; vertical direction in FIG. 1B) is the contact / separation direction of the movable contact 35 and the first wall portion 31A. , And intersects with any of the opposing directions of the second wall portion 31B. As shown in FIG. 1B, a first insulating member 37A is provided on the inner wall surface of the first wall portion 31A, and a second insulating member 37B is provided on the inner wall surface of the second wall portion 31B. It has been. The first permanent magnet 46A is disposed on the outer wall surface of the third wall portion 31C, and the second permanent magnet 46B is disposed on the outer wall surface of the fourth wall portion 31D.

  The insulating members 37A and 37B are each formed in a substantially rectangular plate shape from a heat-resistant insulating material such as ceramic. The first insulating member 37 </ b> A protrudes from the inner wall surface of the first wall portion 31 </ b> A of the case 31 toward the fixed contact 32. On the other hand, the second insulating member 37 </ b> B protrudes from the inner wall surface of the second wall portion 31 </ b> B of the case 31 toward the fixed contact 32. The insulating members 37 </ b> A and 37 </ b> B are preferably arranged at the same height as the fixed contact 32. The insulating members 37A and 37B may be formed integrally with the case 31.

  The first permanent magnet 46 </ b> A is formed in a substantially rectangular parallelepiped shape and is provided substantially parallel to the longitudinal direction of the movable contact 35. Similarly, the second permanent magnet 46 </ b> B is formed in a substantially rectangular parallelepiped shape and is provided substantially parallel to the longitudinal direction of the movable contact 35. In the first permanent magnet 46A, the direction of the magnetic lines of force inside thereof intersects with the outer wall surface of the case 31 (outer wall surface of the third wall portion 31C) in which the first permanent magnet 46A is disposed ( In FIG. 1 (b), the case 31 is disposed on the outer wall surface. Similarly, in the second permanent magnet 46B, the direction of the lines of magnetic force inside thereof intersects with the outer wall surface of the case 31 in which the second permanent magnet 46B is disposed (the outer wall surface of the fourth wall portion 31D). It is arranged on the outer wall surface of the case 31 in such a direction (downward in FIG. 1B). The pair of permanent magnets 46A and 46B are arranged so that the polarities of the surfaces facing each other are different. More specifically, the first permanent magnet 46A is arranged on the outside of the third wall 31C of the case 31 so that the lower surface in FIG. 1B is an N pole and the upper surface is an S pole. It is arranged on the wall surface. Similarly, the second permanent magnet 46B is arranged on the outer wall surface of the fourth wall portion 31D of the case 31 so that the lower surface in FIG. 1B is an N pole and the upper surface is an S pole. Established. Therefore, the N pole side surface of the first permanent magnet 46A and the S pole side surface of the second permanent magnet 46B are opposed to each other. The pair of permanent magnets 46 </ b> A and 46 </ b> B generates a magnetic flux in the case 31 in the direction from the top to the bottom in FIG.

  The contact device 3 further includes a contact pressure spring 36 that biases the movable contact 35 toward the fixed contacts 32 and 32, and a support member 39 that supports the contact pressure spring 36.

  The contact pressure spring 36 is a coil spring. One end (the upper end in FIG. 1A) of the contact pressure spring 36 is in contact with the longitudinal center of the movable contact 35, and the other end (the lower end in FIG. 1A) is in contact with the support member 39. . The contact pressure spring 36 is provided in a compressed state between the movable contact 35 and the support member 39, and elastically biases the movable contact 35 toward the fixed contacts 32 and 32.

  In the contact device 3 of the present embodiment, for example, the movable shaft 5 formed in a round bar shape is disposed through the insertion hole 35 b and the contact pressure spring 36 of the movable contact 35. The movable shaft 5 includes a shaft portion 51 formed from a nonmagnetic material in the shape of a long round bar that is long in the vertical direction, and an outer casing 52 formed integrally with the shaft portion 51. The diameter of the outer casing 52 is larger than the diameter of the insertion hole 35 b, and the movable contact 35 is prevented from coming off from the movable shaft 5 by the outer casing 52. The movable shaft 5 is movable in the contact / separation direction of the movable contact 35 (vertical direction in FIG. 1A). In the contact device 3 of the present embodiment, the movable contact 35 can be separated from the fixed contacts 32 and 32 by, for example, displacing the movable shaft 5 downward.

  When a forward current flows between the fixed contacts 32 and 32, if the movable contact 35 is separated from the fixed contacts 32 and 32, an arc is generated between the movable contact 35 and each fixed contact 32. There is. In the contact device 3 of the present embodiment, the permanent magnets 46A and 46B are disposed as described above. For this reason, a magnetic flux in a direction intersecting with the direction in which the arc current flows is generated at the contact portion between the movable contact 35 and the fixed contact 32. Accordingly, this arc is directed toward the first wall portion 31A or the second wall portion 31B (the direction of the white arrow in FIG. 1B) by the Lorentz force generated by the magnetic flux of the pair of permanent magnets 46A and 46B. Stretched. The stretched arc is divided by the first insulating member 37A or the second insulating member 37B and extinguished. That is, the arc generated between the left fixed contact 32 and the movable contact 35 in FIG. 1B is divided by the first insulating member 37A. Further, the arc generated between the fixed contact 32 on the right side of FIG. 1B and the movable contact 35 is divided by the second insulating member 37B. Therefore, the contact device 3 of the present embodiment can interrupt the arc in a short time. That is, the contact device 3 of the present embodiment can effectively interrupt the arc without increasing the size of the device. In addition, each of the insulating members 37A and 37B of the present embodiment is formed of a heat resistant material (for example, ceramic). Therefore, even if the arc is divided by the insulating members 37A and 37B, the insulating members 37A and 37B are not easily deformed by heat, and stable arc interruption performance can be obtained.

  Note that a pair of insulating members is not necessarily required. That is, if an insulating member is provided on one inner wall surface of the first wall portion 31A and the second wall portion 31B, the arc on the wall portion side where the insulating member is provided is divided by this insulating member. can do. Further, a pair of permanent magnets is not necessarily required. That is, if one of the first permanent magnet 46 </ b> A and the second permanent magnet 46 </ b> B is disposed on the outer wall surface of the case 31, a magnetic field is generated at the contact portion between the fixed contact 32 and the movable contact 35. be able to. Therefore, the arc between the contacts can be stretched by this magnetic field. Since the stretched arc is divided by the insulating member, the arc can be effectively interrupted.

  Further, the protruding direction of the insulating members 37A and 37b does not necessarily need to be orthogonal to the direction of the movable contact 35 and the direction of the magnetic flux by the permanent magnets 46A and 46B. The insulating members 37 </ b> A and 37 </ b> B only need to project from the inner wall surface of the case 31 so that the stretched arc is divided.

  Further, the shape of the insulating members 37A and 37B is not limited to a substantially rectangular plate shape. The insulating members 37A and 37B may be formed, for example, in a semicircular shape whose radial direction is the protruding direction, or may be formed in an elliptical column shape whose vertical direction is the protruding direction.

  The contact device 3 of the said embodiment is used for an electromagnetic switch as shown in FIG. 2, FIG. 3, for example.

  The electromagnetic switch includes an electromagnet device 2, the contact device 3, the movable shaft 5, and a housing 4 that houses the electromagnet device 2, the contact device 3, and the movable shaft 5. Hereinafter, description will be made assuming that the top, bottom, left, and right in FIG.

  The electromagnet device 2 includes a coil bobbin 21, an excitation winding 22, a pair of coil terminals 23 and 23, a fixed iron core 24, a movable iron core 25, a yoke 26, a return spring 27, and a cylindrical member 28. Prepare.

  The coil bobbin 21 has a cylindrical portion 21c formed in a hollow cylindrical shape from an insulating material such as a resin material. An upper collar portion 21a is formed at the upper end of the cylindrical portion 21c, and a lower collar portion 21b is formed at the lower end of the cylindrical portion 21c. An exciting winding (conductive wire) 22 is wound around the outer periphery of the cylindrical portion 21c. A cylindrical member 28 is disposed inside the cylindrical portion 21 c of the coil bobbin 21. The cylindrical member 28 is made of a nonmagnetic material, and includes a cylindrical portion 28b having a bottomed cylindrical shape and a flange portion 28a formed at the upper end of the cylindrical portion 28b.

  The pair of coil terminals 23 is made of a conductive material such as copper, and is connected to both ends of the exciting winding 22. An external power source is connected to the coil terminal 23.

  The fixed iron core 24 is formed in a substantially cylindrical shape from a magnetic material, and an insertion hole 24 b penetrates in the axial direction of the fixed iron core 24. Further, a flange 24 a is formed at the upper end of the fixed iron core 24. The fixed iron core 24 is fixed in the cylindrical portion 28 b of the cylindrical member 28. The fixed iron core 24 is magnetized by the energized winding 22 for excitation.

  The movable iron core 25 is formed in a substantially cylindrical shape from a magnetic material, and a screw hole 25a is formed in the axial direction. The movable iron core 25 is disposed in the cylindrical portion 28b of the cylindrical member 28, and faces the fixed iron core 24 in the cylindrical portion 28b. The movable iron core 25 is attracted to the fixed iron core 24 in response to turning on / off of the energization winding 22, and moves in the axial direction within the cylindrical portion 28b.

  The yoke 26 is made of a magnetic material and is disposed so as to surround the coil bobbin 21. That is, as shown in FIG. 2A, the yoke 26 has a substantially rectangular plate-like first yoke plate 26 </ b> A disposed on the upper end side of the coil bobbin 21 and a substantially lower surface disposed on the lower end side of the coil bobbin 21. A second yoke plate 26B having a rectangular plate shape and a pair of third yokes 26C, 26C that extend upward from the left and right ends of the second yoke plate 26B and are connected to the first yoke plate 26A. It consists of.

  A recess 26a is formed in the approximate center of the upper surface of the first yoke plate 26A, and an insertion hole 26c is formed in the approximate center of the recess 26a. The flange portion 28a of the cylindrical member 28 is airtightly joined to the lower surface of the first yoke plate 26A. Further, the fixed iron core 24 is inserted into the insertion hole 26c, and the flange portion 24a of the fixed iron core 24 is fitted into the recess 26a of the first yoke plate 26A.

  A cylindrical bush 26D made of a magnetic material is fitted into a gap formed between the inner peripheral surface on the lower end side of the coil bobbin 21 and the outer peripheral surface of the cylindrical member 28. In the electromagnet device 2 of the present embodiment, a magnetic circuit is formed by the fixed iron core 24, the movable iron core 25, the yoke 26, and the bush 26D.

  A metal cap member 45 is provided on the upper surface of the first yoke plate 26A. The peripheral edge of the cap member 45 is fixed to the first yoke plate 26A. In addition, a convex portion 45a that protrudes upward is provided at the approximate center of the cap member 45, and the flange portion 24a of the fixed iron core 24 is accommodated in the convex portion 45a. The cap member 45 prevents the fixed iron core 24 from coming off.

  The return spring 27 is disposed in the insertion hole 24 b of the fixed iron core 24. The lower end of the return spring 27 is in contact with the upper surface of the movable iron core 25, and the upper end is in contact with the lower surface of the cap member 45. The return spring 27 is provided in a compressed state between the movable iron core 25 and the cap member 45, and elastically biases the movable iron core 25 in a direction away from the fixed iron core 24 (downward in FIG. 2).

  In this electromagnet device 2, when the exciting winding 22 is not energized, the movable iron core 25 is separated from the fixed iron core 24 by the spring force of the return spring 27 (see FIG. 2). On the other hand, when the exciting winding 22 is energized by an external power source connected to the coil terminal 23, an electromagnetic force acts between the fixed iron core 24 and the movable iron core 25, and the movable iron core 25 approaches the fixed iron core 24. It is displaced in the direction (upward in FIG. 2).

  As described above, the contact device 3 includes a contact portion having a pair of fixed contacts 32 and 32 and a movable contact 35 that contacts and separates from the fixed contacts 32 and 32, and a case (sealing container) 31 that stores the contact portions. And a pair of permanent magnets 46A and 46B and a pair of insulating members 37A and 37B. The contact device 3 includes a contact pressure spring 36 made of a coil spring that urges the movable contact 35 toward the fixed contacts 32 and 32, and a support member 39 that supports the contact pressure spring 36.

  The case 31 is formed from a heat-resistant insulating material such as ceramic in a rectangular box shape with one side opened. On the upper surface of the case 31, a pair of through holes 31a and 31a are arranged in parallel. As described above, the case 31 includes the first wall portion 31A, the second wall portion 32A, the third wall portion 31C, and the fourth wall portion 31D. A pair of fixed contacts 32, 32 and a movable contact 35 are accommodated in the case 31.

  As described above, the first insulating member 37A protrudes toward the fixed contact 32 on the inner wall surface of the first wall portion 31A, and the fixed contact point on the inner wall surface of the second wall portion 31B. A second insulating member 37 </ b> B is protruded toward 32. Further, as described above, the first permanent magnet 46A is disposed on the outer wall surface of the third wall portion 31C, and the second permanent magnet 46B is disposed on the outer wall surface of the fourth wall portion 31D. Has been. A first yoke 47A is provided on the outer surface side of the first permanent magnet 46A, and a second yoke 47B is provided on the outer surface side of the second permanent magnet 46B.

  Each fixed terminal 33 is formed in a substantially cylindrical shape using a conductive material such as copper, a flange 33a is formed on the upper end, and a fixed contact 32 is provided on the lower surface. Each fixed terminal 33 is recessed with a terminal portion 33b from its upper surface in the axial direction. A terminal such as an external load can be connected to the terminal portion 33b. Each fixed terminal 33 is inserted into the through hole 31a with the flange 33a protruding from the upper surface of the case 31, and is hermetically joined to the case 31 by brazing or the like.

  The movable contact 35 is formed in a long rectangular flat plate shape from a conductive material such as copper or copper alloy. The movable shaft 5 is inserted into the insertion hole 35b formed in the movable contact 35 as described above. The movable shaft 5 is movable in the contact / separation direction (vertical direction in FIG. 2) of the movable contact 35.

  The contact pressure spring 36 is disposed between the movable contact 35 and the support member 39. One end of the contact pressure spring 36 is in contact with the lower surface of the movable contact 35. The contact pressure spring 36 is provided in a compressed state between the movable contact 35 and the support member 39, and elastically biases the movable contact 35 toward the fixed contacts 32 and 32.

  As shown in FIG. 2, the case 31 and the first yoke plate 26 </ b> A are each airtightly joined to a joining member 38 formed in a substantially cylindrical shape by a metal material. That is, one end portion (upper end portion in FIG. 2) of the joining member 38 is hermetically joined to the opening end portion of the case 31, and the other end portion (lower end portion in FIG. 2) of the joining member 38 is connected to the first yoke plate 26A. Airtight joined. The first yoke plate 26A, the cylindrical member 28, the case 31, the pair of fixed terminals 33 and 33, and the joining member 38 are used to house the fixed iron core 24, the movable iron core 25, the fixed contacts 32 and 32, and the movable contact 35. A hermetic space is formed. In this hermetic space, a gas mainly composed of hydrogen is hermetically sealed.

  The support member 39 is formed of an insulating material such as ceramic or synthetic resin into a substantially rectangular box shape having an upper surface opened. A rectangular frame 39a is formed substantially at the center of the lower surface of the support member 39, and the convex portion 45a of the cap member 45 is fitted into the concave portion formed by the rectangular frame 39a. Further, since the upper end side of the peripheral wall of the support member 39 is in contact with the inner surface of the peripheral wall of the case 31, the joint portion composed of the case 31 and the joint member 38 from the contact portion having the fixed contacts 32, 32 and the movable contact 35. Insulation is planned. A circular frame 39 c is formed at the center of the support member 39. The inner diameter of the frame portion 39 c is substantially the same size as the outer diameter of the contact pressure spring 36. Since the other end of the contact pressure spring 36 is fitted into the recess in the frame portion 39c, the displacement of the contact pressure spring 36 is prevented. In addition, an insertion hole 39 b through which the movable shaft 5 is inserted is formed in the central portion of the support member 39.

  The movable shaft 5 includes a shaft portion 51 that is formed in the shape of a long round bar that is long in the vertical direction from a nonmagnetic material, and the outer casing 52 that is formed integrally with the shaft portion 51. A screw part 51 a is formed at the lower end of the shaft part 51. The shaft portion 51 is inserted into the insertion hole 24 b of the fixed iron core 24, the insertion hole 45 b of the cap member 45, and the insertion hole 35 b of the movable contact 35. The movable shaft 5 is coupled to the movable iron core 25 by screwing the screw portion 51 a into the screw hole 25 a of the movable iron core 25. Thereby, the movable shaft 5 is displaced in conjunction with the displacement of the movable iron core 25. Of course, the movable iron core 25 and the movable shaft 5 may be fixed by a method other than a screw, for example, welding.

  The housing 4 is formed in a substantially rectangular box shape by a resin material. The housing 4 includes a hollow box-type housing main body 41 whose upper surface is open and a hollow box-type cover 42 whose lower surface is open. The cover 42 is attached to the housing body 41 so as to cover the opening of the housing body 41.

  Projections 141 and 141 are formed on the left and right side walls of the housing body 41. Each protrusion 141 is formed with an insertion hole 141a. By inserting a screw (not shown) through the insertion hole 141a and screwing this screw to an arbitrary attachment surface (not shown), the electromagnetic switch can be fixed to the attachment surface. Further, a step portion 41 a is formed at the opening peripheral edge of the upper end side of the housing body 41, and the outer periphery of the upper end side of the housing body 41 is smaller than the lower end side. As shown in FIG. 3A, a pair of protrusions 41 c and 41 c are juxtaposed in the left-right direction on the rear surface of the housing main body 41.

  The cover 42 is formed in a hollow box shape having an open bottom surface, and a pair of holes 42a and 42a are formed on the rear surface. The cover 42 can be attached to the housing main body 41 by fitting the protrusions 41c and 41c of the housing main body 41 into the holes 42a and 42a. On the upper surface of the cover 42, a partition portion 42 c that divides the upper surface into two substantially right and left is formed. A pair of insertion holes 42b and 42b through which the fixed terminals 33 and 33 are inserted are formed on the upper surface of the cover 42 divided into two by the partition portion 42c.

  A substantially rectangular lower cushion rubber 43 is interposed between the flange 21 b at the lower end of the coil bobbin 21 and the bottom surface of the housing body 41. An upper cushion rubber 44 is interposed between the case 31 and the cover 42. These cushion rubbers 43 and 44 can suppress the impact caused by the contact between the fixed contacts 32 and 32 and the movable contact 35 and the impact caused by the contact between the movable iron core 25 and the fixed iron core 24 from being transmitted to the housing 4.

  In the electromagnetic switch having the above configuration, a coil spring having a spring constant larger than the spring constant of the contact pressure spring 36 is used as the return spring 27. Therefore, when the electromagnet device 2 is not energized without energizing the exciting winding 22, the movable iron core 25, the outer shaft 52 of the movable shaft 5, and the movable contact 35 are mainly driven by the urging force of the return spring 27. It will be located below. At this time, the movable contact 35 is held in contact with the outer flange 52 of the movable shaft 5 while being pressed toward the fixed contacts 32, 32 by the spring force of the contact pressure spring 36. At this time, the movable contact 35 is separated from each fixed contact 32, 32 by a predetermined distance, and the electromagnetic switch is in an OFF state.

  When the exciting coil 22 is energized and the electromagnet device 2 is excited, an electromagnetic force acts between the fixed iron core 24 and the movable iron core 25, and the movable iron core 25 is displaced in a direction approaching the fixed iron core 24. At this time, the movable shaft 5 connected to the movable iron core 25 is displaced in a direction approaching the fixed contacts 32, 32 (upward in FIG. 2), and the outer casing 52 is separated from the movable contact 35. The movable contact 35 is displaced in a direction approaching the fixed contacts 32, 32 by the spring force of the contact pressure spring 36, and contacts the pair of fixed contacts 32, 32. As a result, the pair of fixed contacts 32 and 32 are electrically connected to each other via the movable contact 35, and the electromagnetic switch is turned on.

  When energization of the exciting winding 22 is stopped and the electromagnet device is de-energized, the movable shaft 5 is displaced in a direction away from the fixed contacts 32, 32 (downward in FIG. 2) mainly by the spring force of the return spring 27. . The movable contact 35 is pushed by the outer flange 52 of the movable shaft 5 and is separated from the fixed contacts 32, 32.

  By the way, if the electromagnet device 2 is de-energized while a current is flowing between the fixed contacts 32 and 32, an arc current may flow between the fixed contact 32 and the movable contact 35. Here, the electromagnetic switch of the present embodiment includes the permanent magnets 46A and 46B and the insulating members 37A and 37B as described above. Therefore, as shown in FIG. 4, the arcs 100A and 100B stretched by the permanent magnets 46A and 46B can be divided by the insulating members 37A and 37B and extinguished. Therefore, the electromagnetic switch according to the present embodiment can effectively interrupt the arc without increasing the external size of the device.

  The configuration of the contact device 3 is not limited to that shown in FIG.

  For example, the contact device may be configured as shown in FIG. In the embodiment shown in FIG. 5, a third permanent magnet 46C and a fourth permanent magnet 46D are provided in place of the first permanent magnet 46A and the second permanent magnet 46B. In the embodiment shown in FIG. 5, the first insulating member 37A is provided on the inner wall surface of the first wall portion 31A, and the second insulating member 37B is provided on the inner wall surface of the second wall portion 31B. . A third permanent magnet 46C is disposed on the outer wall surface of the first wall portion 31A, and a fourth permanent magnet 46D is disposed on the outer wall surface of the second wall portion 31B. The third permanent magnet 46C has a direction in which the direction of the magnetic lines of force inside thereof is parallel to the outer wall surface of the case 31 (outer wall surface of the first wall portion 31A) in which the third permanent magnet 46C is disposed. (Upward in FIG. 5) and disposed on the outer wall surface of the case 31. Similarly, the direction of the magnetic lines of force of the fourth permanent magnet 46D is parallel to the outer wall surface of the case 31 (outer wall surface of the second wall portion 31B) in which the fourth permanent magnet 46D is disposed. Is arranged on the outer wall surface of the case 31 in such a direction (upward in FIG. 5). The pair of permanent magnets 46C and 46D are arranged in directions in which the directions of the magnetic lines of force inside each other are equal. Specifically, the third permanent magnet 46C is arranged on the outer wall surface of the first wall portion 31A of the case 31 so that the lower surface in FIG. 5 is the S pole and the upper surface is the N pole. Established. Similarly, the fourth permanent magnet 46D is disposed on the outer wall surface of the second wall portion 31B of the case 31 so that the lower surface in FIG. 5 is the S pole and the upper surface is the N pole. . Therefore, the pair of permanent magnets 46 </ b> C and 46 </ b> D generates a magnetic flux in the case 31 in the direction from the top to the bottom in FIG. 5. A yoke 47C that connects the N pole sides of the pair of permanent magnets 46c and 46D is provided on the outer wall surface of the third wall portion 31C, and a pair of permanent magnets 46C and 46D is provided on the outer wall surface of the fourth wall portion 31D. A yoke 47D is provided for connecting the south pole sides of the permanent magnets 46C and 46D.

  Even in this case, the arc generated when a current flows in the forward direction can be stretched in the direction toward the insulating members 37A and 37B by the Lorentz force, and can be divided by the insulating members 37A and 37B. Therefore, the arc can be effectively interrupted.

  In addition, the wall part which protrudes an insulating member is not restricted to the wall part (1st wall part 31A and 2nd wall part 31B) which cross | intersects the direction which connects a pair of fixed contacts 32 and 32. FIG. For example, as shown in FIG. 6, the permanent magnets 46 </ b> E and 46 </ b> F are arranged so as to generate a magnetic flux in the direction connecting the fixed contacts 32 and 32 (the left-right direction in FIG. 6), and the third wall portion 31 </ b> C, Insulating members 37 </ b> C and 37 </ b> D that protrude in a direction intersecting with the magnetic flux may be provided on the four wall portions 31 </ b> D.

  In addition, you may arrange | position a pair of permanent magnet so that the same pole may oppose. For example, a pair of permanent magnets are arranged on the third wall portion 31C and the fourth wall portion 31D so that the N poles face each other, and the third wall portion 31C and the fourth wall portion 31D You may provide the insulating member which protrudes in the direction which cross | intersects a magnetic flux. In this case, in the contact portion between the movable contact 35 and the fixed contact 32, a magnetic flux in a direction parallel to the N pole surface of the permanent magnet is generated by the pair of permanent magnets. Therefore, the arc generated between the movable contact 35 and the fixed contact 32 is stretched toward the third wall portion 31C or the fourth wall portion 31D. Since these arcs are divided by the insulating members protruding from the third wall portion 31C and the fourth wall portion 31D, the arcs can be effectively interrupted. Of course, you may arrange | position a pair of permanent magnet so that S poles may oppose. Or you may arrange | position a pair of permanent magnet in 31 A of 1st wall parts, and the 2nd wall part 31B so that the same pole may oppose.

  In the above embodiment, the contact device having a pair of fixed contacts (that is, having two fixed contacts) has been described, but the number of fixed contacts is not limited to two. The number of fixed contacts of the contact device may be one.

2 Electromagnet Device 3 Contact Device 31 Case 32 Fixed Contact 35 Movable Contact 37A, 37B Insulating Member 46A, 46B Permanent Magnet

Claims (4)

  A contact part having a fixed contact and a movable contact contacting and separating from the fixed contact, a case storing the contact part, and a permanent generating a magnetic flux in a direction crossing the contact and separation direction of the movable contact in the case A magnet and an insulating member provided on the inner wall surface of the case and projecting from the inner wall surface toward the contact portion in a direction intersecting with either the contact / separation direction of the movable contact or the direction of the magnetic flux; A contact device comprising: The case is opposed to the first and second wall portions facing each other and the facing direction intersects the contact / separation direction of the movable contact, and is opposed to each other and the facing direction is the contact / separation direction of the movable contact. Having third and fourth wall portions that intersect with both of the opposing directions of the first and second wall portions,
The insulating member is provided on an inner wall surface of at least one of the first and second wall portions,
The permanent magnet is arranged on the outer wall surface of at least one of the third and fourth wall portions so that the direction of the magnetic lines of force inside thereof intersects with the outer wall surface. The contact device according to claim 1. The case has first and second wall portions that are provided to face each other and whose facing direction intersects with the contact / separation direction of the movable contact,
The insulating member is provided on an inner wall surface of at least one of the first and second wall portions,
The permanent magnet is arranged on at least one outer wall surface of the first and second wall portions so that the direction of the magnetic lines of force inside thereof is parallel to the outer wall surface. The contact device according to claim 1.   An electromagnetic switch comprising: the contact device according to claim 1; and an electromagnet device that displaces the movable contact using electromagnetic force.

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