JP2017050274A - Contact switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high productivity contact switchgear in which operation characteristics are less likely to vary.SOLUTION: A contact switchgear includes an electromagnet unit 60, a holder 35, a movable shaft 43, a movable yoke 48, a movable contact piece 49 having movable contacts 49a at the opposite ends, a fixed contact 33a, and a fixed yoke 51. During magnetization of the electromagnet unit 60, the movable shaft 43 moves in the axial direction to the holder 35 side, the movable contacts 49a form a magnetic circuit by a magnetic field generated by a current flowing to the movable contact piece 49 when the movable contacts 49a comes into contact with the fixed contact 33a, in conjunction with the fixed yoke 51 and movable yoke 48, and the movable yoke 48 is attracted to the fixed yoke 51.SELECTED DRAWING: Figure 13

Description

  The present invention relates to a contact switching device, and more particularly to a contact switching device suitable for a power load relay or an electromagnetic switch.

  Conventionally, as a contact switching device, for example, as shown in FIG. 5A of Patent Document 1, a pair of through holes 61a are provided on the upper surface of a container 61 made of a heat-resistant material such as ceramic. The fixed terminals 33 and 33 are inserted into the pair of through holes 61a and brazed. A yoke body 63 is fixed between the pair of fixed terminals 33, 33 and on the inner side of the upper surface of the container 61. The yoke body 63 has a substantially rectangular parallelepiped shape made of a magnetic material such as soft iron.

  When the movable contacts 34, 34 provided on the movable contact 35 and the fixed contacts 32, 32 come into contact with each other and a current flows, a magnetic field is generated in the movable contact 35. For this reason, the holding body 81 is attracted to the yoke body 63 and the electromagnetic repulsive force generated between the movable contact 34 and the fixed contact 32 is reduced. As a result, the contact pressure is prevented from being lowered, and the movable contact and the fixed contact 32 are prevented from being welded as the contact resistance is increased. Further, the movable contact 34 and the fixed contact 32 are separated from each other with the generation of the electromagnetic repulsive force, and an arc is generated to prevent welding of the movable contact 34 and the fixed contact 32.

JP 2012-104356 A

  However, in the contact device, it is necessary to fix the yoke body 63 to the inner upper surface of the box-shaped container 61 by, for example, brazing. For this reason, skill is required for the fixing work and the assembling work is troublesome, so that the productivity is low and the manufacturing cost is high.

  Further, in the above-described assembly work, there is a problem that an assembly error is likely to occur and high positioning accuracy is difficult to obtain, and thus the operation characteristics are likely to vary.

  In view of the above-described problems, an object of the present invention is to provide a contact switching device that has high productivity and is less likely to vary in operating characteristics.

The contact switching device according to the present invention is to solve the above problems
An electromagnet unit;
A holder mounted on the electromagnet unit;
One end is inserted into the holder, the other end is inserted into the electromagnet unit, and a movable shaft supported so as to be reciprocally movable in the axial direction;
A pair of movable contacts provided at the one end of the movable shaft in the holder, housed in the holder, and disposed on the surface opposite to the electromagnet unit in the axial direction of the movable shaft A movable contact piece having
A movable yoke disposed on the back surface of the movable contact piece on the electromagnet unit side in the axial direction of the movable shaft, and assembled to the one end of the movable shaft in the holder;
A pair of fixed contacts disposed in the holder and facing the pair of movable contacts in a detachable manner;
Positioned between the pair of fixed contacts, both ends of the longitudinal direction along the direction intersecting the axial direction of the movable shaft and intersecting the longitudinal direction of the movable contact piece are placed in the holder. And a fixed yoke supported by the holder,
When the electromagnet unit is excited, the movable shaft moves from the electromagnet unit toward the holder along the axial direction, and the pair of movable contacts come into contact with the pair of fixed contacts to form the movable contact piece. A magnetic circuit is formed by the fixed yoke and the movable yoke by a magnetic field generated by a flowing current, and the movable yoke is magnetically attracted to the fixed yoke.

  According to the present invention, since both ends of the fixed yoke are placed in the holder, the fixed yoke is supported by the holder. Therefore, as in the conventional example, the fixed yoke is attached to the inner upper surface of the box-shaped container. There is no need to fix by brazing. For this reason, assembly work is simple, productivity is high, and manufacturing costs are low.

  Further, since both ends of the fixed yoke need only be placed in the holder, a contact opening / closing device is obtained in which assembly errors are less likely to occur and operational characteristics are less likely to vary.

1 is an overall perspective view showing a contact switching apparatus according to an embodiment of the present invention. It is a disassembled perspective view of the contact switching apparatus shown in FIG. It is a perspective view which shows the state which removed the case and the outer cover from the contact switching apparatus shown in FIG. It is a perspective view which shows the state which removed the inner cover from the perspective view shown in FIG. It is a perspective view which shows the state which removed the metal cylindrical flange from the perspective view shown in FIG. It is a perspective view which shows the state which removed the ceramic plate, the stationary contact terminal, and the gas vent pipe from the perspective view shown in FIG. It is a perspective view which shows the state which removed the cover body from the perspective view shown in FIG. It is a perspective view which shows the state which removed the fixed yoke from the perspective view shown in FIG. It is a perspective view which shows the state which removed the position control board from the perspective view shown in FIG. It is a front longitudinal cross-sectional view before the operation | movement of the perspective view shown in FIG. FIG. 4 is a side longitudinal sectional view before operation of the perspective view shown in FIG. 3. It is a front longitudinal cross-sectional view after the operation | movement of the perspective view shown in FIG. FIG. 4 is a side longitudinal sectional view after the operation of the perspective view shown in FIG. 3. FIG. 4 is a partially enlarged perspective view of the electromagnet unit shown in FIG. 3. It is a perspective view of the holder shown in FIG. FIG. 5 is a partial side sectional perspective view of the perspective view shown in FIG. 4. FIG. 5 is a partial front cross-sectional perspective view of the perspective view shown in FIG. 4. It is a front longitudinal cross-sectional view before the operation | movement which shows the contact switching apparatus which concerns on other embodiment of this invention. It is a side surface longitudinal cross-sectional view of the contact switching apparatus of FIG.

  A case where the contact switching device according to the embodiment of the present invention is applied to a sealed electromagnetic relay will be described with reference to the accompanying drawings of FIGS.

  The sealed electromagnetic relay according to the present embodiment includes at least an electromagnet unit 60, a holder 35, a movable shaft 43, a movable contact piece 49, a movable yoke 48, a pair of fixed contacts 33a, and a fixed yoke 51. It is prepared for. Specifically, as shown in FIGS. 1 to 5, the contact mechanism unit 30 and the electromagnet unit 60 are assembled in a housing formed by assembling the outer cover 20 to the case 10.

  As shown in FIG. 2, the case 10 is an approximately square box-shaped insulating resin molded product, and a pair of notches 11 are formed on one side of the opening edge. In addition, the case 10 is provided with a total of two pairs of locking holes 12 at both ends of the opening edge portion on the opposite side surface.

  The outer cover 20 has an insulating rectangular box shape having a planar shape that can cover the opening of the case 10. The outer cover 20 is provided with terminal holes 22 on both sides of an insulating partition wall 21 projecting from the center of the upper surface thereof. Further, the outer cover 20 is provided with a fitting tongue piece 23 which is fitted to the notch portion 11 of the case 10 on one side surface thereof. Further, the outer cover 20 has two pairs of locking claws 24 extending from the opening edge portions of the opposing side surfaces to the two pairs of locking holes 12 of the case 10. .

  The contact mechanism unit 30 includes a holder 35, a cylindrical fixed iron core 42, a movable shaft 43, a movable iron core 45, and a movable contact piece 49, a metal cylindrical flange 31, a ceramic plate 32, and a plate-shaped first yoke. 41 and a bottomed cylindrical body 46 are incorporated in a sealed space.

  As shown in FIG. 2, the metal cylindrical flange 31 has a substantially rectangular cylindrical shape formed by pressing a metal plate. The metal cylindrical flange 31 has the ceramic plate 32 brazed to the outer peripheral edge at the upper end thereof. The metallic cylindrical flange 31 is integrated with a first yoke 41, which will be described later, by welding at the outer peripheral edge of the lower end thereof.

  The ceramic plate 32 has a planar shape that can be brazed to an upper end opening edge of the metal cylindrical flange 31. The ceramic plate 32 is provided with terminal holes 32a and 32a and a gas vent hole 32b. The ceramic plate 32 has a metal layer (not shown) formed at the opening edge of the terminal hole 32a and the opening edge of the gas vent hole 32b. As shown in FIG. 10, the ceramic plate 32 is brazed with a fixed contact terminal 33 having a fixed contact 33a fixed to the lower end portion of the terminal hole 32a. Therefore, the fixed contact 33a is disposed in the holder 35 and faces the movable contact 49a so as to be able to come into contact with and to be separated from the movable contact 49a. Further, as shown in FIG. 11, the ceramic plate 32 has a gas vent pipe 34 brazed to the gas vent hole 32b.

  The holder 35 is mounted on the electromagnet unit 60, is formed of a heat-resistant insulating material having a rectangular box shape, and is accommodated in the metal cylindrical flange 31 (FIG. 10). As shown in FIG. 15, the holder 35 has pocket portions 35 a that can hold the permanent magnets 36 on the opposite outer side surfaces thereof. The holder 35 is provided with a central square recess 35b at the center of the bottom surface that is one step lower than the bottom surface. The central recess 35b has a cylindrical insulating portion 35c (FIG. 10) protruding downward from the center thereof. When the arc is generated, the cylindrical insulating portion 35c is configured to have a cylindrical fixed iron core even if a high voltage is applied along the path of the metal cylindrical flange 31, the plate-shaped first yoke 41, and the cylindrical fixed iron core 42. By insulating 42 and the movable shaft 43, welding and integration of both are prevented. Furthermore, the holder 35 is provided with a pair of pedestal portions 35d at the bases of the inner surfaces facing each other. Each pedestal portion 35 d is configured by a protrusion having the same height protruding from the base portion of each inner surface of the holder 35. A slit 35e for supporting a position restricting plate 37 described later is provided between each pedestal portion 35d and the central recess 35b. Further, the holder 35 is provided with a recess 35f between the central recess 35b and the pocket portion 35a in which an arc erasing piece 38 to be described later can be disposed. Furthermore, position restricting ribs 35g and 35g are provided on both sides of the movable contact piece 49 in the longitudinal direction of each pedestal portion 35d. Then, as shown in FIG. 2, the holder 35 is placed on a plate-like first yoke 41, which will be described later, via a rectangular plate-like spacer 39 and a pair of rectangular plate-like cushioning members 40.

  As shown in FIG. 2, the position restricting plate 37 is made of an elastic metal plate having a substantially rectangular front surface, and both side edges thereof are cut and raised to form elastic claws. The position restricting plate 37 is press-fitted into the slit 35e of the holder 35, presses against the movable yoke 48 within the holder 35, and applies a pressing force to the movable contact piece 49 via the movable yoke 48, which will be described later. The idle rotation of the movable contact piece 49 and the movable yoke 48 is regulated.

  As shown in FIG. 2, the arc erasing piece 38 has a gate-shaped cross section (U-shape) formed by pressing a thin metal plate. The arc erasing piece 38 is installed in the recess 35f (FIG. 15) of the holder 35 in order to quench the arc generated when the contact is opened and closed and to erase it efficiently.

  As shown in FIG. 2, the buffer material 40 is a plate-like body made of an elastic material. The buffer material 40 is sandwiched between the bottom surface of the holder 35 and the plate-shaped first yoke 41 covered with the spacer 39.

  As shown in FIG. 2, the plate-like first yoke 41 has a planar shape that can be fitted to the opening edge of the case 10. Further, the plate-like first yoke 41 is provided with a caulking hole 41a at the center thereof. And the said plate-shaped 1st yoke 41 is integrated by welding the outer peripheral part of the lower end of the said metal cylindrical flange 31 to the outer peripheral part of the upper surface. Further, the upper end of the cylindrical fixed iron core 42 is fixed to the caulking hole 41a of the plate-like first yoke 41.

  The movable shaft 43 has one end inserted into the holder 35 and the other end inserted into the electromagnet unit 60 and is supported so as to be reciprocally movable in the axial direction of the movable shaft 43. Specifically, as shown in FIG. 10, the cylindrical fixed iron core 42 slides the movable shaft 43 in the axial direction through the cylindrical insulating portion 35c of the holder 35 in the through hole 42a. Inserted as possible. The movable shaft 43 has an annular flange 43a at the top thereof. The movable shaft 43 has a return spring 44 inserted through a lower portion thereof, and a movable iron core 45 fixed to a lower end portion thereof.

  The movable contact piece 49 is provided at one end of the movable shaft 43 and is housed in the holder 35, and at both ends (that is, perpendicular to) the direction intersecting (for example, orthogonal to) the axial center direction of the movable shaft 43 (that is, the movable shaft 43). A pair of movable contacts 49a and 49a are provided on the surface (upper surface) opposite to the electromagnet unit 60 in the axial direction. Specifically, as shown in FIG. 10, the movable shaft 43 is configured to lock the contact spring 47, the movable yoke 48, and the movable contact piece 49, which are sequentially inserted from the upper end thereof, with an annular flange 45a. The stopper ring 50 fixed to the upper end portion prevents the stopper from coming off.

  The movable yoke 48 is opposite to the protruding direction of the pair of movable contacts 49a, 49a provided on the movable contact piece 49 (that is, the back surface (lower surface of the movable contact piece 49 on the electromagnet unit 60 side in the axial direction of the movable shaft 43). )) And assembled to one end of the movable shaft 43. Specifically, as shown in FIG. 11, the movable yoke 48 is formed by bending and raising both end portions of a plate-like magnetic material 90 degrees in the same direction and in parallel to form bent portions 48a and 48a. Yes, it has a cross-sectional gate shape (U-shape). The movable yoke 48 is in contact with the lower surface of the movable contact piece 49.

  Further, the movable contact piece 49 is provided with movable contacts 49a and 49a by protruding processing at both ends in the longitudinal direction of the upper surface thereof. The movable contacts 49a and 49a face the fixed contacts 33a and 33a of the fixed contact terminal 33 disposed in the holder 35 so as to be able to contact and separate from each other.

  As shown in FIG. 10, the bottomed cylindrical body 46 that accommodates the movable iron core 45 in the vicinity of the lower end portion thereof has an opening edge portion in the vicinity of the lower surface edge portion of the caulking hole 41 a provided in the plate-like first yoke 41. Airtight joined. And after sucking internal air from the said degassing pipe 34, it fills with gas and seals, A sealed space is formed.

  The fixed yoke 51 is located between the pair of fixed contacts 33a and 33a so as to be separated from the pair of fixed contacts 33a and 33a, and in a direction intersecting (for example, orthogonal to) the axial center direction of the movable shaft 43 and movable contact. Both ends in the longitudinal direction along a direction intersecting (for example, orthogonal to) the longitudinal direction of the piece 49 are supported so as to be bridged in the holder. Specifically, as shown in FIG. 2, the fixed yoke 51 has a substantially I-shaped plane, and a cross-sectional gate-shaped (U-shaped) plate having protrusions 51 a that protrude 90 degrees at both ends in the longitudinal direction. It is a magnetic material. Further, the longitudinal dimension of the fixed yoke 51 is longer than the longitudinal dimension of the movable yoke 48. For this reason, since the fixed yoke 51 overlaps in the longitudinal direction so as to cover the entire movable yoke 48, magnetic flux leakage is small and magnetic efficiency is good. The fixed yoke 51 is placed on the pair of pedestals 35d of the holder 35 shown in FIG. 8 with the pair of protrusions 51a (FIG. 16) placed thereon. Further, as shown in FIG. 17, each end portion of the fixed yoke 51 is a pair of position regulating ribs 35 g disposed on both sides of the pair of adjacent pedestal portions 35 d and 35 d, and the longitudinal direction of the movable contact piece 49. The position is restricted so as not to move in the direction.

  By the way, when the fixed contact 33a and the movable contact 49a are opened and closed, the abrasion powder generated by the contact and separation of the fixed contact 33a and the movable contact 49a is scattered by the arc generated between the fixed contact 33a and the movable contact 49a ( Hereinafter referred to as scattered powder). For example, when the fixed yoke is directly fixed to the ceramic plate by brazing or the like, if scattered powder accumulates between the fixed contact terminal and the fixed yoke, the space between the fixed contact terminal and the fixed yoke is scattered via the scattered powder. As a result, a short-circuit path is formed, and the insulation of the contact switchgear is significantly reduced.

  In the contact switching device, as shown in FIGS. 10 and 12, the fixed yoke 51 is held by the resin holder 35 in a state where the insulating securing gap 80 is formed between the fixed yoke 51 and the ceramic plate 32. Yes. As a result, even if scattered powder accumulates between the fixed contact terminal 33 and the fixed yoke 51, the insulating securing gap 80 is not filled, and the fixed contact terminal and the fixed yoke are interposed via the scattered powder. It is difficult to form a short-circuit path, and it is possible to prevent a decrease in insulation of the contact switching device.

  As shown in FIG. 6, the lid body 52 is an insulating plate-like body having a planar shape that can be fitted into the opening of the holder 35. The lid 52 is provided with a through hole 52b between a pair of terminal holes 52a and 52a into which the pair of fixed contact terminals 33 and 33 are inserted.

  The inner cover 53 is an insulating elastic body having a three-dimensional shape that can cover the metal cylindrical flange 31 to which the ceramic plate 32 is brazed. For the inner cover 53, for example, a rubber material that easily absorbs a collision sound between the movable contact 49a and the fixed contact 33a may be used. The inner cover 53 is provided with a through hole 53b through which the gas vent pipe 34 passes between a pair of terminal holes 53a, 53a through which the fixed contact terminal 33 passes, provided on the ceiling surface.

  As shown in FIG. 2, the electromagnet unit 60 is formed by winding a coil 61 around a body portion 62 a of an insulating spool 62. An upper flange portion 62b and a lower flange portion 62c are provided at both ends of the body portion 62a in the axial direction. The coil terminals 63 and 64 are press-fitted and fixed to the pair of slits 62d and 62d provided in the upper flange 62b, respectively. Further, the lead wire of the coil 61 is soldered by being bound to the binding portions 63a and 64a of the coil terminals 63 and 64. The coil terminals 63 and 64 project the terminal portions 63b and 64b laterally. Then, as shown in FIG. 10, the bottomed cylindrical body 46 is inserted through a through hole 62 e provided in the body portion 62 a of the spool 62. Next, the lower end portion of the bottomed cylindrical body 46 is fitted into the fitting hole 65 a of the second yoke 65. Then, the upper end portions of both arm portions 65b, 65b of the second yoke 65 are respectively engaged with both end portions of the plate-like first yoke 41 and fixed. Examples of the fixing method include caulking, press fitting, or welding. Thereby, the electromagnet unit 60 and the contact mechanism unit 30 are integrated.

  Next, the operation of the sealed electromagnetic relay having the above-described configuration will be described.

  First, as shown in FIG. 10, when no voltage is applied to the coil 61, the movable iron core 45 is biased downward by the spring force of the return spring 44 against the cylindrical fixed iron core 42. Has been. For this reason, the movable shaft 43 integral with the movable iron core 45 is pushed downward with respect to the cylindrical fixed iron core 42, and the movable contact piece 49 is pulled down in the holder 35. At this time, the annular flange 43 a of the movable shaft 43 is engaged with the bottom surface of the central recess 35 b of the holder 35. For this reason, the pair of movable contacts 49 a are separated from the pair of fixed contacts 33 a, but the movable iron core 45 is not in contact with the bottom surface of the bottomed cylindrical body 46.

  Next, when a voltage is applied to the coil 61 for excitation, the movable iron core 45 is magnetically attracted to the cylindrical fixed iron core 42 as shown in FIGS. For this reason, the movable shaft 43 slides upward against the spring force of the return spring 44 along the axial direction. The pair of movable contacts 49a come into contact with the pair of fixed contacts 33a, and the movable shaft 43 is pushed up against the spring force of the return spring 44 and the contact spring 47. For this reason, a predetermined contact pressure can be secured between the pair of movable contacts 49a and the pair of fixed contacts 33a. Further, the movable yoke 48 approaches the fixed yoke 51. However, the fixed yoke 51 and the movable yoke 48 are not in direct contact with each other, and constitute a magnetic circuit while maintaining a predetermined contact reliability ensuring gap 90. This is because the contact reliability ensuring gap 90 ensures the contact reliability. In order to reliably form such a configuration, as an example, the opposing distance between the opposed fixed yoke 51 and the movable yoke 48 is configured to be greater than the distance between the movable contact 49a and the fixed contact 33a. Yes.

  The collision sound generated when the movable contact 49 a comes into contact with the fixed contact 33 a is absorbed and alleviated by the inner cover 53. For this reason, a silent electromagnetic relay is obtained.

  In this embodiment, even when the movable yoke 48 overlaps the fixed yoke 51 when the contact is closed, the magnetic circuit is configured while maintaining the contact reliability ensuring gap 90 between the two members 48 and 51. For this reason, magnetic lines of force flow through the movable yoke 48 and the fixed yoke 51 to form a magnetic field. As a result, even if a large current flows through the movable contact piece 49 and an electromagnetic repulsive force is generated between the fixed contact 33a and the movable contact 49a, the magnetic field formed by the fixed yoke 51 and the movable yoke 48 A suction force is generated. With this attractive force, the movable yoke 48 is magnetically attracted to the fixed yoke 51, and the electromagnetic repulsive force is suppressed. Therefore, there is an advantage that the contact pressure can be reduced and the contact can be prevented from being released when the contact is closed, and arcing and contact welding can be prevented.

  In particular, as shown in FIG. 16, the fixed yoke 51 placed and laid on the pedestals 35d and 35d of the holder 35 is fixed via a ceramic plate 32 provided with a lid 52 and a fixed contact 33a. Yes. On the other hand, the movable yoke 48 is in contact with the lower surface of the movable contact piece 49 provided with the movable contact 49a. Therefore, when the movable contact 49a comes into contact with the fixed contact 33a, the contact reliability ensuring gap 90 between the fixed yoke 51 and the movable yoke 48 can be formed with high dimensional accuracy. For this reason, there exists an advantage that the electromagnetic relay which a variation in an operating characteristic does not produce easily is obtained.

  When the application of the voltage to the coil 61 is stopped and the excitation is released, the movable iron core 45 is separated from the cylindrical fixed iron core 42 by the spring force of the contact spring 47a and the return spring 44. Therefore, after the movable shaft 43 slides downward and the movable contact 49a is separated from the fixed contact 33a, the annular flange 43a of the movable shaft 43 engages with the central recess 35b of the holder 35, and the original The state is restored (FIGS. 10 and 11).

  In the present embodiment, the height dimension of the pedestal portion 35 d of the holder 35, the height dimension of the bending raising portion 48 a of the movable yoke 48, the thickness dimension of the movable contact piece 49, and the protrusion 51 a of the fixed yoke 51 are provided. If adjusted appropriately, a desired contact reliability ensuring gap 90 can be formed. For this reason, there exists an advantage that the freedom degree of design is large.

  According to the present embodiment, since the pair of protrusions 51a (FIG. 16) of the fixed yoke 51 is placed in the holder 35, the fixed yoke 51 is supported by the holder 35. Therefore, as in the conventional example. There is no need to fix the fixing yoke to the inner upper surface of the box-shaped container by brazing or the like. For this reason, assembly work is simple, productivity is high, and manufacturing costs are low.

  Further, since both ends of the fixed yoke need only be placed in the holder, a contact opening / closing device is obtained in which assembly errors are less likely to occur and operational characteristics are less likely to vary.

  Further, according to the present embodiment, the pair of protrusions 51a of the fixed yoke 51 are placed on the pair of pedestals 35d, so that the assembly work of the fixed yoke is facilitated.

  As another embodiment of the present invention, the length dimension of the fixed yoke in the longitudinal direction may be longer than the length dimension of the movable yoke in the longitudinal direction.

  According to the present embodiment, the fixed yoke overlaps in the longitudinal direction so as to cover the entire movable yoke, so that a contact switching device with less magnetic flux leakage and good magnetic efficiency can be obtained.

  As another embodiment of the present invention, the opposing distance between the opposed fixed yoke and the movable yoke may be greater than the distance between the movable contact and the fixed contact.

  According to this embodiment, even when a pair of movable contacts come into contact with a pair of fixed contacts, the movable yoke does not contact the fixed yoke, so that the contact between the pair of movable contacts and the pair of fixed contacts is not hindered. . For this reason, a contact switching device with high contact reliability is obtained.

  In another embodiment of the present invention, when the movable contact comes into contact with the fixed contact, contact reliability is ensured so that the fixed yoke and the movable yoke are not in direct contact between the fixed yoke and the movable yoke. A working gap may be provided.

  According to this embodiment, even when a pair of movable contacts come into contact with a pair of fixed contacts, the movable yoke does not contact the fixed yoke, so that the contact between the pair of movable contacts and the pair of fixed contacts is not hindered. . For this reason, a contact switching device with high contact reliability is obtained.

  As a new embodiment of the present invention, the movable yoke may contact one surface of the movable contact piece opposite to the protruding direction of the movable contact.

  Further, according to the present embodiment, since the movable yoke 48 is in contact with the movable contact piece 49, the magnetic resistance of the magnetic circuit constituted by the fixed yoke 51 and the movable yoke 48 is reduced. For this reason, the contact switching device which has good magnetic efficiency and can suppress the electromagnetic repulsion force with a large magnetic force is obtained.

  Further, according to the present embodiment, the collision force of the movable shaft 43 is absorbed and alleviated by the buffer material 40 via the holder 35. In particular, even when the movable shaft 43 returns to the original state, the movable iron core 45 does not contact the bottom surface of the bottomed cylindrical body 46. For this reason, the impact sound of the movable shaft 43 is absorbed and alleviated by the holder 35, the buffer material 40, the cylindrical fixed iron core 42, the inner cover 53, the electromagnet unit 60, and the like. Thereby, there exists an advantage that the sealed electromagnetic relay with a small opening-and-closing sound is obtained.

  Further, according to the position restricting plate 37 of the present embodiment, the movable contact piece 49 moves up and down as the movable shaft 43 moves up and down as shown in FIG. At this time, even if the movable contact piece 49 and the movable yoke 48 are shaken, the movable yoke 48 abuts on the position restricting plate 37 press-fitted into the slit 35e (FIG. 15) of the holder 35 and is regulated. . For this reason, the movable contact piece 49 and the movable yoke 48 do not directly contact the resin holder 35. As a result, resin powder does not occur and contact failure does not occur. In particular, since the position restricting plate 37 is made of a metal material, abrasion powder is hardly generated.

  In the contact switching device of the embodiment, the fixed yoke 51 is held by the holder 35 made of an insulating material, but is not limited thereto. For example, as shown in FIGS. 18 and 19, the fixed yoke 51 may be held by being connected to the ceramic plate 32 via a ceramic connecting portion 70. Even in this case, even if the scattered powder generated when the fixed contact 33a and the movable contact 49a are opened and closed accumulates between the fixed contact terminal 33 and the fixed yoke 51, the insulating securing gap 80 is not filled, and the scattered powder. Thus, it is difficult to form a short-circuit path between the fixed contact terminal 33 and the fixed yoke 51, and it is possible to prevent a decrease in insulation of the contact switching device.

  Of course, the contact switching device according to the present invention is not limited to the above-described electromagnetic relay, but may be applied to other contact switching devices.

DESCRIPTION OF SYMBOLS 10 Case 11 Notch part 12 Locking hole 20 Outer cover 21 Partition wall 22 Terminal hole 23 Fitting tongue piece 24 Locking claw part 30 Contact mechanism unit 31 Metal cylindrical flange 32 Ceramic plate 32a Terminal hole 32b Gas vent hole 33 fixed contact terminal 33a fixed contact 34 degassing pipe 35 holder 35a pocket portion 35b central recess 35c cylindrical insulating portion 35d pedestal portion 35e slit 35f recess 35g position restricting rib 36 permanent magnet 37 position restricting plate 38 arc erasing piece 39 Spacer 40 Buffer material 41 Plate-shaped first yoke 41a Caulking hole 42 Cylindrical fixed iron core 43 Movable shaft 43a Annular flange 44 Return spring 45 Movable iron core 46 Bottomed cylinder 47 Contact spring 48 Movable yoke 48a Bending part 49 Movable Contact piece 49a Movable contact 50 Retaining ring 51 fixed yoke 51a protrusion 52 lid 52a terminal hole 52b through hole 53 inner cover 53a terminal hole 53b through hole 60 electromagnet unit 61 coil 62 spool 62a trunk 62b collar 62c collar 62d slit 62e through hole 63, 64 coil terminal 63a, 64a Tying portion 63b, 64b Terminal portion 62e Through hole 65 Second yoke 65a Fitting hole 65b Arm portion 70 Connecting portion 80 Insulation ensuring gap 90 Contact reliability ensuring gap

Claims (6)

An electromagnet unit;
A holder mounted on the electromagnet unit;
One end is inserted into the holder, the other end is inserted into the electromagnet unit, and a movable shaft supported so as to be reciprocally movable in the axial direction;
A pair of movable contacts provided at the one end of the movable shaft in the holder, housed in the holder, and disposed on the surface opposite to the electromagnet unit in the axial direction of the movable shaft A movable contact piece having
A movable yoke disposed on the back surface of the movable contact piece on the electromagnet unit side in the axial direction of the movable shaft, and assembled to the one end of the movable shaft in the holder;
A pair of fixed contacts disposed in the holder and facing the pair of movable contacts in a detachable manner;
Positioned between the pair of fixed contacts, both ends of the longitudinal direction along the direction intersecting the axial direction of the movable shaft and intersecting the longitudinal direction of the movable contact piece are placed in the holder. And a fixed yoke supported by the holder,
When the electromagnet unit is excited, the movable shaft moves from the electromagnet unit toward the holder along the axial direction, and the pair of movable contacts come into contact with the pair of fixed contacts to form the movable contact piece. A contact switching device, wherein a magnetic circuit is formed by the fixed yoke and the movable yoke by a magnetic field generated by a flowing current, and the movable yoke is magnetically attracted to the fixed yoke.   The contact switching device according to claim 1, wherein both ends of the fixed yoke are placed on pedestal portions respectively provided on opposing inner side surfaces of the holder.   The contact switching apparatus according to claim 1 or 2, wherein a length dimension of the fixed yoke in the longitudinal direction is longer than a length dimension of the movable yoke in the longitudinal direction.   4. The contact switching device according to claim 1, wherein a facing distance between the fixed yoke and the movable yoke facing each other is larger than a distance between the movable contact and the fixed contact.   5. The gap according to claim 1, wherein a gap is provided between the fixed yoke and the movable yoke so that the fixed yoke and the movable yoke are not in direct contact with each other when the movable contact contacts the fixed contact. The contact switchgear according to item 1.   6. The contact switching device according to claim 1, wherein the movable yoke is in contact with one surface of the movable contact piece opposite to the protruding direction of the movable contact. 7.

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