Electromagnetic relay

Abstract

This electromagnetic relay comprises a yoke (35), a fixed iron core (33), and a movable iron core (34). The fixed iron core (33) has a first base part (E1) and a first protruding part (E2). The first protruding part (E2) protrudes downward from the first base part (E1). The movable iron core (34) has a second base part (E4) and a second protruding part (E5). The second protruding part (E5) protrudes upward from the second base part (E4). The second protruding part (E5) of the movable iron core (34) is positioned outside the first protruding part (E2) of the fixed iron core (33) in a plan view from a vertical direction (Y2). The second protruding part (E5) of the movable iron core (34) comes into contact with the first base part (E1) of the fixed iron core (33) when the movable iron core (34) moves upward.

Description

Electromagnetic relay

[0001] The present disclosure generally relates to electromagnetic relays, and more specifically relates to an electromagnetic relay including a fixed core and a movable core.

[0002] Conventionally, electromagnetic relays including a fixed core and a movable core are known (see, for example, Patent Document 1). In the electromagnetic relay described in Patent Document 1, the fixed core has a protrusion located on an outer side, and the movable core has a protrusion located on an inner side.

[0003] Japanese Patent Laid-Open No. 2007-294262

[0004] However, in the conventional electromagnetic relay described in Patent Document 1, since the fixed core and the movable core contact each other on the inner side, the magnetic path of a magnetic circuit formed by a plurality of magnetic members including a yoke, the fixed core and the movable core becomes long, and it is difficult to increase the magnetic efficiency of the magnetic circuit.

[0005] An electromagnetic relay according to an aspect of the present disclosure includes a pair of fixed terminals, a movable contact, a holder, a movable shaft, a yoke, a fixed core, and a movable core. The pair of fixed terminals have a pair of fixed contacts. The pair of fixed contacts are arranged in the left-right direction. The movable contact has a pair of movable contacts. The pair of movable contacts come into contact with and separate from the pair of fixed contacts in the up-down direction. The up-down direction is a direction orthogonal to the left-right direction. The holder holds the movable contact. The movable shaft moves the holder in the up-down direction such that the pair of movable contacts come into contact with and separate from the pair of fixed contacts. The movable core is located below the fixed core so as to face the fixed core in the up-down direction. The fixed core includes a first base portion and a first protrusion. The first protrusion protrudes downward from the first base portion. The movable core includes a second base portion and a second protrusion. The second protrusion protrudes upward from the second base portion. The second protrusion of the movable core is located outside the first protrusion of the fixed core in a plan view from the up-down direction. The second protrusion of the movable core contacts the first base portion of the fixed core when the movable core moves upward.

[0006] According to the electromagnetic relay of the above embodiment of the present disclosure, the magnetic efficiency of a magnetic circuit formed by a plurality of magnetic members including a yoke, a fixed core, and a movable core can be increased.

[0007] Figure 1 is a cross-sectional view of the electromagnetic relay according to the embodiment, taken along the line X1-X1 in Figure 2. Figure 2 is an external perspective view of the same electromagnetic relay. Figure 3 is a cross-sectional view of the same electromagnetic relay, taken along the line X2-X2 in Figure 2. Figure 4 is an enlarged cross-sectional view of the main part of the same electromagnetic relay.

[0008] The electromagnetic relay 1 and contact device 2 according to the embodiment will be described below with reference to the drawings. The figures referenced in the following embodiments are schematic diagrams, and the ratios of the size and thickness of each component shown in the figures do not necessarily reflect the actual dimensional ratios.

[0009] (Embodiment) (1) Electromagnetic relay The electromagnetic relay 1 according to this embodiment comprises a pair of fixed terminals 21, a movable contact 22, a holder 23, a movable shaft 24, a yoke 35, a fixed core 33, and a movable core 34. The pair of fixed terminals 21 have a pair of fixed contacts 211. The pair of fixed contacts 211 are aligned in the left-right direction Y1. The movable contact 22 has a pair of movable contacts 221. The pair of movable contacts 221 move toward and away from the pair of fixed contacts 211 in the up-down direction Y2. The up-down direction Y2 is perpendicular to the left-right direction Y1. The holder 23 holds the movable contact 22. The movable shaft 24 moves the holder 23 in the up-down direction Y2 so that the pair of movable contacts 221 move toward and away from the pair of fixed contacts 211. The movable core 34 is located below the fixed core 33 so as to face the fixed core 33 in the up-down direction Y2. The fixed core 33 has a first base E1 and a first projection E2. The first projection E2 protrudes downward from the first base E1. The movable core 34 has a second base E4 and a second projection E5. The second projection E5 protrudes upward from the second base E4 and is located outside the first projection E2 of the fixed core 33. When the movable core 34 moves upward, the second projection E5 of the movable core 34 comes into contact with the first base E1 of the fixed core 33.

[0010] According to the electromagnetic relay 1 of this embodiment, the magnetic efficiency of the magnetic circuit, which is formed by a plurality of magnetic members including a yoke 35, a fixed core 33, and a movable core 34, can be increased.

[0011] (2) Components of the electromagnetic relay The electromagnetic relay 1 according to this embodiment comprises a contact device 2, an electromagnet device 3, and a housing 4, as shown in Figures 1 to 3.

[0012] The components of the electromagnetic relay 1 according to this embodiment will be described below with reference to the drawings.

[0013] (2.1) Contact device The contact device 2, as shown in Figures 1 and 3, comprises a pair of fixed terminals 21, a movable contactor 22, a holder 23, a movable shaft 24, a case 25, a connecting body 26, two permanent magnets 27, and two bridging portions 28.

[0014] (2.1.1) Fixed terminals Each of the pair of fixed terminals 21 is made of a conductive material such as copper, as shown in Figures 1 and 3. Each fixed terminal 21 has a fixed contact 211 and a terminal body 212. The terminal body 212 is cylindrical. Each fixed terminal 21 is positioned to pass through the through hole 251 of the first body 41 and the case 25. Each fixed terminal 21 is joined to the case 25 by brazing with its upper end protruding from the upper surface of the case 25 and the upper surface of the first body 41.

[0015] Each of the pair of fixed contacts 211 is attached to the lower end of the terminal body 212, as shown in Figures 1 and 3. More specifically, each fixed contact 211 is fixed to the lower end of the terminal body 212. The pair of fixed contacts 211 are arranged in the left-right direction Y1 (first direction). Each fixed contact 211 may be formed integrally with the terminal body 212.

[0016] (2.1.2) Movable Contact The movable contact 22 moves toward and toward a pair of fixed contacts 211, as shown in Figures 1 and 3. More specifically, the movable contact 22 moves toward and toward the pair of fixed contacts 211 in the vertical direction Y2 (second direction), which is perpendicular to the left-right direction Y1 (first direction). The movable contact 22 has a pair of movable contacts 221. The pair of movable contacts 221 are located at both the left and right ends of the left-right direction Y1. In other words, the pair of movable contacts 221 are the ends of the movable contact 22 in the left-right direction Y1. The pair of movable contacts 221 are formed in the vertical direction Y2, facing the pair of fixed contacts 211 with a predetermined distance between them.

[0017] The material of the movable contact 22 is a conductive material such as copper. Alternatively, the material of the movable contact 22 may be a non-magnetic material.

[0018] (2.1.3) Holder The holder 23, as shown in Figures 1 and 3, has an upper yoke 51, a lower yoke 52, two side plates 53, a spring receiving portion 54, and a contact pressure spring 55.

[0019] (2.1.4) Upper Yoke The upper yoke 51 is formed in the shape of a rectangular parallelepiped, for example, as shown in Figures 1 and 3. The material of the upper yoke 51 is a magnetic material. An example of a magnetic material is electromagnetic soft iron or SPCC (Steel Plate Cold Commercial). The upper yoke 51 is placed on the upper surface of the central part of the movable contactor 22 in the left-right direction Y1. Note that the upper yoke 51 is not limited to being formed in the shape of a rectangular parallelepiped and may be formed in other shapes.

[0020] (2.1.5) Lower Yoke The lower yoke 52, as shown in Figure 1, is made of a magnetic material and is formed in a U-shape with an open top when viewed from the left-right direction Y1. The lower yoke 52 is positioned below the central part of the movable contact 22 so as to clamp the central part of the movable contact 22 from the front-rear direction Y3.

[0021] (2.1.6) Side Plates The two side plates 53 protrude upward from the spring receiving portion 54, as shown in Figure 3. The material of the two side plates 53 is, for example, metal. The two side plates 53 face each other in the front-rear direction Y3. The upper ends of the two side plates 53 are connected by an upper yoke 51. A movable contact 22 is passed between the upper yoke 51 and the spring receiving portion 54.

[0022] The upper yoke 51, located above the movable contact 22, and the lower yoke 52, located below the movable contact 22, are made of a magnetic material, while the side plate 53 is made of a non-magnetic material. As a result, when the fixed contact 211 and the movable contact 221 come into contact and current flows through the movable contact 22, a magnetic flux is formed around the movable contact 22, passing through the upper yoke 51 and the lower yoke 52 with the movable contact 22 as the center. A magnetic attractive force acts between the upper yoke 51 and the lower yoke 52, and this magnetic attractive force suppresses the electromagnetic repulsive force generated between the fixed contact 211 and the movable contact 221, thereby suppressing a decrease in contact pressure between the fixed contact 211 and the movable contact 221.

[0023] (2.1.7) Spring support portion As shown in Figures 1 and 3, the spring support portion 54 is located on the side of the movable contact 22 opposite to the pair of fixed contacts 211.

[0024] The spring support portion 54 comprises a base portion 541, a positioning projection 542, a protruding portion 543, and a partition wall 544. The partition wall 544 is formed, for example, in a cylindrical shape and extends from the base portion 541 along the axial direction of the movable shaft 24.

[0025] The spring support portion 54 is made of an insulating material. The insulating material is, for example, a synthetic resin. A disc-shaped positioning projection 542 is formed in the center of the upper surface of the base portion 541 of the spring support portion 54. The spring support portion 54 is positioned relative to the contact spring 55 by fitting the positioning projection 542 of the spring support portion 54 into the inner diameter of the lower end side of the contact spring 55.

[0026] (2.1.8) Contact pressure spring The contact pressure spring 55 is positioned between the spring receiving portion 54 and the movable contact 22 with its expansion and contraction direction oriented in the vertical direction Y2, as shown in Figures 1 and 3. The contact pressure spring 55 is a coil spring. The contact pressure spring 55 applies an upward spring force to the movable contact 22.

[0027] (2.1.9) Movable shaft As shown in Figure 1, the movable shaft 24 moves the holder 23 in the vertical direction Y2 (second direction) so that the movable contact 22 moves toward and toward the pair of fixed contacts 211. In other words, the movable shaft 24 moves axially (vertical direction Y2) so that the movable contact 22 moves toward and toward the pair of fixed contacts 211. That is, the movable shaft 24 is connected to the holder 23 and moves in the vertical direction Y2 (second direction) so that the movable contact 22 moves toward and toward the pair of fixed contacts 211. The movable shaft 24 is formed in the shape of a long round rod in the vertical direction Y2. The movable core 34 of the electromagnet device 3 is connected to the lower end of the movable shaft 24. The upper end of the movable shaft 24 is connected to the spring receiving part 54. The movable shaft 24 is fixed to the movable core 34 while being inserted through the fixed core 33, the return spring 36 and the movable core 34.

[0028] (2.1.10) Case The case 25 is box-shaped with an open bottom, as shown in Figures 1 and 3. The material of the case 25 is a heat-resistant material such as ceramic. The case 25 houses a pair of fixed contacts 211 and a movable contact 22. Two through holes 251 are formed on the top surface of the case 25, aligned in the left-right direction Y1. An arc-extinguishing gas such as hydrogen is sealed inside the case 25. The inside space of the case 25 does not have to be sealed and may be connected to the external environment.

[0029] (2.1.11) Connecting Body As shown in Figures 1 and 3, the first end of the connecting body 26 is joined to the opening periphery of the case 25 by brazing. The second end of the connecting body 26 is joined to the first yoke plate 351 of the yoke 35 of the electromagnet device 3 by brazing. In this way, the connecting body 26 connects the case 25 and the yoke 35.

[0030] (2.1.12) Permanent Magnets The two permanent magnets 27 are positioned and fixed between the outer surface of the case 25 and the inner surface of the housing 4, as shown in Figure 1. The two permanent magnets 27 are aligned in the left-right direction Y1. One of the two permanent magnets 27 is positioned to the left of the movable contact 22, and the other is positioned to the right of the movable contact 22.

[0031] The two permanent magnets 27 have opposite poles facing each other. For example, the left permanent magnet 27 has its north pole pointing to the right, and the right permanent magnet 27 has its south pole pointing to the left. The two permanent magnets 27 apply a magnetic field along the left-right direction Y1 between the movable contact 22 and the fixed contact 211.

[0032] (2.1.13) Bridging section Of the two bridging sections 28 shown in Figure 3, one is positioned in front of the movable contact 22, and the other is positioned behind the movable contact 22. The material of the two bridging sections 28 is a magnetic material. When viewed from the vertical direction Y2, each bridging section 28 is U-shaped. The two bridging sections 28 are positioned to span between the two permanent magnets 27. Furthermore, the two bridging sections 28 hold the two permanent magnets 27. Together with the two permanent magnets 27, the two bridging sections 28 form an annular magnetic circuit.

[0033] (2.2) Electromagnet Device Next, the electromagnet device 3 will be described in detail with reference to the drawings.

[0034] As shown in Figures 1 and 3, the electromagnet device 3 drives the movable shaft 24 so that the movable contact 22 moves toward and away from a pair of fixed contacts 211.

[0035] The electromagnet device 3 comprises a coil 31, a coil bobbin 32, a fixed core 33, a movable core 34, a yoke 35, a return spring 36, and a cylindrical member 37. The electromagnet device 3 also includes a pair of coil terminals to which both ends of the coil 31 are connected.

[0036] (2.2.1) As shown in Figure 1, the coil 31 has its ends connected to a pair of terminals provided on the flange portion 321 of the coil bobbin 32, and is connected to a pair of coil terminals via lead wires connected to the terminals. Each coil terminal is made of a conductive material such as copper and is connected to a lead wire by solder or the like.

[0037] (2.2.2) Coil Bobbin As shown in Figure 1, the coil bobbin 32 has two flanges 321 and 322 and a cylindrical portion 323. The material of the coil bobbin 32 is, for example, synthetic resin. The cylindrical portion 323 is cylindrical. The coil 31 is wound around the cylindrical portion 323. The flange 321 extends outward in the radial direction of the cylindrical portion 323 from the upper end of the cylindrical portion 323. The flange 322 extends outward in the radial direction of the cylindrical portion 323 from the lower end of the cylindrical portion 323.

[0038] (2.2.3) Fixed core The fixed core 33 is cylindrical, as shown in Figure 1. The material of the fixed core 33 is a magnetic material. The fixed core 33 is placed and fixed inside the coil bobbin 32. More specifically, the fixed core 33 is provided inside a cylindrical member 37 housed in the cylindrical portion 323 of the coil bobbin 32.

[0039] (2.2.4) Movable Core The movable core 34 is cylindrical, as shown in Figure 1. The material of the movable core 34 is a magnetic material. The movable core 34 is positioned in the coil bobbin 32 so as to face the fixed core 33 in the vertical direction Y2. More specifically, the movable core 34 is housed in a cylindrical member 37. The movable core 34 is fixed to the movable shaft 24 and moves in the vertical direction Y2 in response to the energization of the coil 31. More specifically, when the coil 31 is energized, the movable core 34 moves upward. On the other hand, when the energization of the coil 31 is cut off, the movable core 34 moves downward.

[0040] (2.2.5) Yoke As shown in Figures 1 and 3, the yoke 35 forms at least a part of the magnetic circuit through which the magnetic flux generated in the coil 31 passes when the coil 31 is energized. The yoke 35 has a first yoke plate 351 (upper yoke plate), a second yoke plate 352 (lower yoke plate), and two third yoke plates 353 (side yoke plates). The first yoke plate 351 is positioned between the movable contact 22 and the coil 31. The first yoke plate 351 is in contact with the upper surface of the coil bobbin 32. The first yoke plate 351 is rectangular in shape. An insertion hole 354 is formed in the center of the first yoke plate 351. The movable shaft 24 passes through the insertion hole 354. The second yoke plate 352 is in contact with the lower surface of the coil bobbin 32. The second yoke plate 352 is plate-shaped. One of the two third connecting iron plates 353 extends from the left end of the second connecting iron plate 352 to the first connecting iron plate 351. The other of the two third connecting iron plates 353 extends from the right end of the second connecting iron plate 352 to the first connecting iron plate 351. Each third connecting iron plate 353 is plate-shaped.

[0041] (2.2.6) Return spring The return spring 36 is, for example, a compression coil spring, as shown in Figure 1. The first end of the return spring 36 in the direction of expansion and contraction (vertical direction Y2) is in contact with the fixed core 33, and the second end is in contact with the movable core 34. The return spring 36 applies spring force to the movable core 34 and moves the movable core 34 downward.

[0042] (2.2.7) Cylindrical Member The cylindrical member 37 is formed in the shape of a bottomed cylinder, as shown in Figure 1. The cylindrical member 37 has a flange portion 371 and a cylindrical portion 372. The cylindrical portion 372 is housed in the cylindrical portion 323 of the coil bobbin 32. The flange portion 371 is formed at the upper end of the cylindrical portion 372. The flange portion 371 is located between the flange portion 321 of the coil bobbin 32 and the first joint plate 351. A fixed core 33 is provided at the upper end of the cylindrical portion 372. A movable core 34 is provided at the lower end of the cylindrical portion 372 of the cylindrical member 37.

[0043] (2.3) Housing Next, the housing 4 will be described in detail with reference to the drawings.

[0044] As shown in Figures 1 to 3, the housing 4 has a first body 41 and a second body 42.

[0045] (2.3.1) First Body As shown in FIG. 2, the first body 41 is formed into a box shape having an opening on the lower surface. The material of the first body 41 is a resin material. A partition portion 412 that divides the upper surface portion 411 into two parts in the left-right direction is formed on the upper surface portion 411 of the first body 41. A pair of insertion holes 413 through which the fixed terminals 21 are respectively inserted are formed in the upper surface portion 411 divided into two parts by the partition portion 412.

[0046] (2.3.2) Second Body As shown in FIG. 2, the second body 42 is formed into a box shape having an opening on the upper surface. A partition portion 412 that divides the upper surface portion 411 into two parts in the left-right direction is formed on the upper surface portion 411 of the first body 41. A pair of insertion holes 413 through which the fixed terminals 21 are respectively inserted are formed in the upper surface portion 411 divided into two parts by the partition portion 412.

[0047] The second body 42 has a pair of protrusions 421. The pair of protrusions 421 are provided on the left and right side walls. Each of the pair of protrusions 421 has an insertion hole used when fixing the electromagnetic relay 1 to a mounting surface by screwing.

[0048] (2.4) Electromagnetic Relay According to the detailed embodiment, as shown in FIG. 1, the electromagnetic relay 1 includes a pair of fixed terminals 21, a movable contact 22, a holder 23, a movable shaft 24, a yoke 35, a fixed core 33, and a movable core 34.

[0049] As shown in FIG. 1, the pair of fixed terminals 21 are arranged side by side in the left-right direction Y1. Each fixed terminal 21 has a fixed contact 211. That is, the pair of fixed terminals 21 have a pair of fixed contacts 211. The pair of fixed contacts 211 are arranged side by side in the left-right direction Y1.

[0050] As shown in FIG. 1, the movable contact 22 has a pair of movable contacts 221. The pair of movable contacts 221 are arranged side by side in the left-right direction Y1 on the movable contact 22. The pair of movable contacts 221 come into contact with and separate from the pair of fixed contacts 211 in the up-down direction Y2. The up-down direction Y2 is a direction orthogonal to the left-right direction Y1.

[0051] As shown in Figure 1, the holder 23 holds the movable contactor 22. As described above, the holder 23 has an upper yoke 51, a lower yoke 52, two side plates 53, a spring receiving portion 54, and a contact pressure spring 55.

[0052] As shown in Figure 1, the movable shaft 24 moves the holder 23 in the vertical direction Y2 such that a pair of movable contacts 221 move toward and away from a pair of fixed contacts 211.

[0053] As shown in Figures 1 and 4, the fixed core 33 is positioned above the movable core 34 in the vertical direction Y2, facing the movable core 34. The fixed core 33 is fixed by being inserted through the insertion hole 354 of the yoke 35.

[0054] As shown in Figure 4, the fixed core 33 has a first base portion E1, a first projection portion E2, and an upper projection portion E3.

[0055] The first base E1 is cylindrical. The first base E1 is housed within the cylindrical member 37. The first base E1 has an upper surface E11 and a lower surface E12. The upper surface E11 and the lower surface E12 face each other in the vertical direction Y2. The first base E1 has a through hole E13. The through hole E13 is located in the center of the first base E1 in a plan view from the vertical direction Y2. The through hole E13 is circular in a plan view from the vertical direction Y2. A movable shaft 24 is inserted into the through hole E13.

[0056] The first base portion E1 has a contact portion E14 that is in contact with the yoke 35. The contact portion E14 is located on the upper surface E11 of the first base portion E1.

[0057] Furthermore, the first base E1 has a contact portion E15 that comes into contact with the movable core 34 when the movable core 34 moves upward. The contact portion E15 is located on the lower surface E12 of the first base E1.

[0058] The first projection E2 protrudes downward from the first base E1. The first projection E2 is cylindrical. The first projection E2 is housed within the cylindrical member 37. The first projection E2 has a recess E21. The recess E21 is located in the center of the first projection E2 in a plan view from the vertical direction Y2. The recess E21 is circular in a plan view from the vertical direction Y2. The recess E21 communicates with the through hole E13 of the first base E1. A movable shaft 24 is inserted into the recess E21. Furthermore, a part (upper part) of the return spring 36 is inserted into the recess E21.

[0059] The upper projection E3 protrudes upward from the first base E1. The upper projection E3 is cylindrical. The upper projection E3 has a through hole E31 and a recess E32. The through hole E31 is located in the center of the upper projection E3 in a plan view from the vertical direction Y2. The through hole E31 is circular in a plan view from the vertical direction Y2. The through hole E31 communicates with the through hole E13 of the first base E1. The movable shaft 24 is inserted into the through hole E31. The recess E32 is located in the center of the upper projection E3 in a plan view from the vertical direction Y2. The recess E32 is circular in a plan view from the vertical direction Y2. The recess E32 communicates with the through hole E31. A part (lower part) of the spring receiving portion 54 is inserted into the recess E32. A portion of the outer surface of the upper projection E3 is in contact with the side surface of the first yoke plate 351 of the yoke 35. The upper projection E3 is not housed within the cylindrical member 37, but is located outside the cylindrical member 37. The tip (upper end) of the upper projection E3 protrudes above the yoke 35 in the vertical direction Y2.

[0060] As shown in Figures 1 and 4, the movable core 34 is located below the fixed core 33 so as to face the fixed core 33 in the vertical direction Y2.

[0061] As shown in Figure 4, the movable core 34 has a second base E4 and a second projection E5. The movable core 34 also has an internal space E6.

[0062] The second base E4 is cylindrical. The second base E4 is housed within the cylindrical member 37. The second base E4 has a through hole E41. The through hole E41 is located in the center of the second base E4 when viewed from the vertical direction Y2. A movable shaft 24 is inserted into the through hole E41.

[0063] The second projection E5 protrudes upward from the second base E4. The second projection E5 is cylindrical. The second projection E5 is housed within the cylindrical member 37.

[0064] In a plan view from the vertical direction Y2, the second projection E5 is located outside the first projection E2 of the fixed core 33. More specifically, in a plan view from the vertical direction Y2, the upper surface E51 of the second projection E5 is located outside the outer surface E22 of the first projection E2 of the fixed core 33.

[0065] The internal space E6 is the space enclosed by the second protrusion E5. The internal space E6 is in communication with the through hole E41 of the second base E4. The movable shaft 24 is inserted into the internal space E6. Furthermore, a part (lower part) of the return spring 36 is inserted into the internal space E6.

[0066] As shown in Figure 4, the fixed core 33 has a first protrusion E2 and the movable core 34 has a second protrusion E5, which increases the area of ​​contact between the fixed core 33 and the movable core 34. More specifically, in the example where the fixed core does not have a first protrusion and the movable core does not have a second protrusion (comparative example), the fixed core and the movable core face each other in a plane normalized to the vertical direction Y2. On the other hand, in the embodiment, the lower surface E12 of the first base E1 of the fixed core 33 and the upper surface E51 of the second protrusion E5 of the movable core 34 face each other, and furthermore, the outer surface E22 of the first protrusion E2 of the fixed core 33 and the inner surface E52 of the second protrusion E5 of the movable core 34 face each other. As a result, the embodiment allows for a larger area of ​​contact between the fixed core 33 and the movable core 34 than the comparative example.

[0067] Furthermore, since the fixed core 33 has a first protrusion E2 and the movable core 34 has a second protrusion E5, the gap between the fixed core 33 and the movable core 34 can be reduced when the movable core 34 is in a lower position, that is, when current is first supplied to the coil 31 (startup). The gap length E7 between the fixed core 33 and the movable core 34 can be made shorter than the stroke length E8 (travel distance) of the movable core 34. This makes it possible to increase the attractive force of the fixed core 33 on the movable core 34 during startup.

[0068] The second projection E5 of the movable core 34 comes into contact with the fixed core 33 when the movable core 34 moves upward. In other words, the upper surface E51 of the second projection E5 of the movable core 34 is the contact point that comes into contact with the first base E1 of the fixed core 33.

[0069] As the movable core 34 moves upward, the upper surface E51 of the second projection E5 of the movable core 34 comes into contact with the lower surface E12 of the first base E1 of the fixed core 33. The fixed core 33 comes into contact with the yoke 35 at the contact point E14.

[0070] As a result, the contact portions E14 and E15 of the fixed core 33 can reduce the magnetic resistance of the magnetic circuit formed by multiple magnetic members including the yoke 35, the fixed core 33, and the movable core 34. The magnetic resistance of the magnetic circuit can be reduced compared to when the lower surface E12 of the first base E1 of the fixed core 33 and the upper surface E51 of the second protrusion E5 of the movable core 34 are separated.

[0071] Furthermore, since the fixed core 33 and the movable core 34 can be brought into contact on the outside, the magnetic path length of the magnetic circuit can be shortened. As a result, the magnetic resistance of the magnetic circuit can be reduced, thereby increasing the magnetic efficiency of the magnetic circuit. More specifically, the magnetic path length of the magnetic circuit can be shortened and the magnetic efficiency of the magnetic circuit can be increased compared to the case where the fixed core and the movable core are brought into contact on the inside.

[0072] In the electromagnetic relay 1 according to this embodiment, as shown in Figure 4, the fixed core 33 is provided between the contact portion E14 with the yoke 35 and the contact portion E15 with the movable core 34 in the vertical direction Y2. In other words, the first base portion E1 of the fixed core 33 is located between the contact portion E14 and the contact portion E15 in the vertical direction Y2.

[0073] This makes it possible to further shorten the magnetic path length of the magnetic circuit, which is formed by multiple magnetic members including the yoke 35, the fixed core 33, and the movable core 34. More specifically, it is possible to shorten the magnetic path length of the magnetic circuit compared to when there is a gap between the contact portion E14 and the contact portion E15.

[0074] In the electromagnetic relay 1 according to this embodiment, as shown in Figure 4, the fixed core 33 and the movable core 34 do not come into contact inside the contact portion E15 of the fixed core 33 with the movable core 34. When the movable core 34 is positioned downwards, the fixed core 33 and the movable core 34 do not come into contact either on the outside or the inside. Even when the movable core 34 moves upwards and the fixed core 33 and the movable core 34 come into contact on the outside, the first protrusion E2 of the fixed core 33 and the second protrusion E5 of the movable core 34 do not come into contact inside the contact portion E15 of the fixed core 33.

[0075] This concentrates the magnetic flux at the contact point E15 between the fixed core 33 and the movable core 34, that is, on the outside of the fixed core 33 and the movable core 34, thereby increasing the magnetic flux density on the outside of the fixed core 33 and the movable core 34. As a result, the magnetic efficiency of the magnetic circuit formed by multiple magnetic members including the yoke 35, the fixed core 33, and the movable core 34 can be further increased.

[0076] In the electromagnetic relay 1 according to this embodiment, the first projection E2 of the fixed core 33 has a tapered shape. More specifically, the first projection E2 has a tapered shape such that its width narrows from the base end (up) to the tip (down). In other words, the outer surface E22 is inclined such that its width narrows from the base end (up) to the tip (down).

[0077] The second projection E5 of the movable core 34 has a tapered shape. More specifically, the second projection E5 has a tapered tip E53. The tip E53 has a tapered shape such that its width narrows from the base (down) to the tip (up). In other words, the inner surface E52 is inclined such that the width of the second projection E5 narrows from the base (down) to the tip (up).

[0078] When the movable core 34 moves upward and its second projection E5 contacts the first base E1 of the fixed core 33, the first projection E2 of the fixed core 33 and the second projection E5 of the movable core 34 are separated. More specifically, as the movable core 34 moves upward, the second projection E5 of the movable core 34 contacts the first base E1 of the fixed core 33 at the contact portion E15 of the fixed core 33. When the second projection E5 of the movable core 34 is in contact with the first base E1 of the fixed core 33, the second projection E5 of the movable core 34 and the first projection E2 of the fixed core 33 do not contact. The second projection E5 of the movable core 34 and the first projection E2 of the fixed core 33 are facing each other while separated. Specifically, the inner surface E52 of the second projection E5 of the movable core 34 and the outer surface E22 of the first projection E2 of the fixed core 33 are facing each other while separated from each other.

[0079] This increases the area of ​​the portion where the fixed core 33 and the movable core 34 face each other, thereby further improving the magnetic efficiency of the magnetic circuit formed by multiple magnetic members including the yoke 35, the fixed core 33, and the movable core 34.

[0080] In the electromagnetic relay 1 according to this embodiment, as shown in Figure 4, the first projection E2 of the fixed core 33 is spaced apart from the movable shaft 24. The first projection E2 of the fixed core 33 is not in contact with the movable shaft 24. The width of the recess E21 in the first projection E2 of the fixed core 33 is greater than the width of the movable shaft 24. The width of the recess E21 refers to the length of the recess E21 in a plan view from the vertical direction Y2.

[0081] Furthermore, the first base E1 of the fixed core 33 is separated from the movable shaft 24, as shown in Figure 4. The first base E1 of the fixed core 33 is not in contact with the movable shaft 24. The width of the through hole E13 in the first base E1 of the fixed core 33 is greater than the width of the movable shaft 24. The width of the through hole E13 refers to the length of the through hole E13 in a plan view from the vertical direction Y2.

[0082] Furthermore, the upper projection E3 of the fixed core 33 is spaced apart from the movable shaft 24, as shown in Figure 4. The upper projection E3 of the fixed core 33 is not in contact with the movable shaft 24. The width of the through hole E31 and the width of the recess E32 in the upper projection E3 of the fixed core 33 are greater than the width of the movable shaft 24. The width of the through hole E31 refers to the length of the through hole E31 in a plan view from the vertical direction Y2. The width of the recess E32 refers to the length of the recess E32 in a plan view from the vertical direction Y2.

[0083] In the electromagnetic relay 1 according to this embodiment, as shown in Figure 4, the area of ​​the contact portion E14 between the fixed core 33 and the yoke 35 is larger than the area of ​​the contact portion E15 between the fixed core 33 and the movable core 34. The area of ​​the upper surface E51 of the second protrusion E5 of the movable core 34 is smaller than the area of ​​the lower surface of the first base E1 of the fixed core 33. Therefore, the area of ​​the contact portion E15 is smaller than the area of ​​the contact portion E14.

[0084] As a result, even if the contact portion E15 between the fixed core 33 and the movable core 34 shifts when the movable core 34 moves upward, the magnetic path length of the magnetic circuit formed by multiple magnetic members including the yoke 35, the fixed core 33 and the movable core 34 can be shortened, thereby accurately improving the magnetic efficiency of the magnetic circuit.

[0085] (3) Operation of the electromagnetic relay Next, the operation of the electromagnetic relay 1 according to this embodiment will be described with reference to Figures 1 and 3.

[0086] First, when the movable shaft 24 is displaced upward by the electromagnet device 3, the holder 23 connected to the movable shaft 24 is displaced upward along with the displacement of the movable shaft 24. As the holder 23 is displaced, the movable contact 22 moves upward. Then, the movable contact 22 comes into contact with the pair of fixed contacts 211, and electrical conductivity is established between the contacts.

[0087] First, in the electromagnet device 3, when no current flows through the coil 31, the movable core 34 moves downward due to the biasing force of the return spring 36. As the movable core 34 moves, the movable shaft 24 also moves downward. When the movable shaft 24 moves downward, the holder 23 also moves downward. The movable contact 22 moves downward together with the holder 23. When the movable contact 22 is moving downward, the movable contact 221 is separated from the fixed contact 211.

[0088] Next, in the electromagnet device 3, when the coil 31 is energized, the movable core 34 is attracted to the fixed core 33 and moves upward. As the movable core 34 moves, the movable shaft 24 also moves upward. As the movable shaft 24 moves upward, the holder 23 also moves upward. The movable contact 22 moves upward together with the holder 23. When the movable contact 22 is moving upward, the movable contact 221 comes into contact with the fixed contact 211, and electrical conductivity is established between the fixed contact 211 and the movable contact 221.

[0089] Subsequently, when the power supply to the coil 31 is cut off, the movable core 34 moves downward due to the biasing force of the return spring 36, and the movable shaft 24 and holder 23 also move downward along with the movement of the movable core 34. Along with the above movement of the holder 23, the movable contact 22 also moves downward, and the fixed contact 211 and the movable contact 221 are separated.

[0090] (4) Effects In the electromagnetic relay 1 according to the embodiment, the second projection E5 of the movable core 34 is located outside the first projection E2 of the fixed core 33 in a plan view from the vertical direction Y2, and when the movable core 34 moves upward, it comes into contact with the first base E1 of the fixed core 33. As a result, the fixed core 33 and the movable core 34 can be brought into contact on the outside, so the magnetic path length of the magnetic circuit formed by a plurality of magnetic members including the yoke 35, the fixed core 33 and the movable core 34 can be shortened. As a result, the magnetic resistance of the magnetic circuit can be reduced, and the magnetic efficiency of the magnetic circuit can be increased.

[0091] Furthermore, in the electromagnetic relay 1 according to this embodiment, the fixed core 33 has a first protrusion E2, and the movable core 34 has a second protrusion E5. This makes it possible to reduce the gap between the fixed core 33 and the movable core 34 when energizing the coil 31 starts (startup). This makes it possible to increase the attractive force of the fixed core 33 on the movable core 34 during startup.

[0092] In the electromagnetic relay 1 according to this embodiment, the fixed core 33 is provided between the contact portion E14 between the fixed core 33 and the yoke 35 and the contact portion E15 between the fixed core 33 and the movable core 34 in the vertical direction Y2. This makes it possible to further shorten the magnetic path length of the magnetic circuit formed by a plurality of magnetic members including the yoke 35, the fixed core 33 and the movable core 34.

[0093] In the electromagnetic relay 1 according to this embodiment, the fixed core 33 and the movable core 34 do not come into contact inside the contact area E15 between the fixed core 33 and the movable core 34. As a result, the magnetic flux density at the contact area E15 between the fixed core 33 and the movable core 34, i.e., the outer area, can be increased by preventing the fixed core 33 and the movable core 34 from coming into contact internally. This further increases the magnetic efficiency of the magnetic circuit formed by a plurality of magnetic members including the yoke 35, the fixed core 33, and the movable core 34.

[0094] In the electromagnetic relay 1 according to this embodiment, the first protrusion E2 of the fixed core 33 and the second protrusion E5 of the movable core 34 have a tapered shape, and when the movable core 34 moves upward and the second protrusion E5 of the movable core 34 comes into contact with the first base E1 of the fixed core 33, the first protrusion E2 of the fixed core 33 and the second protrusion E5 of the movable core 34 are facing each other while separated. As a result, the area of ​​the parts where the fixed core 33 and the movable core 34 face each other can be increased, and the magnetic efficiency of the magnetic circuit can be further increased.

[0095] In the electromagnetic relay 1 according to this embodiment, the first protrusion E2 of the fixed core 33 is spaced apart from the movable shaft 24.

[0096] In the electromagnetic relay 1 according to this embodiment, the area of ​​the contact portion E14 between the fixed core 33 and the yoke 35 is larger than the area of ​​the contact portion E15 between the fixed core 33 and the movable core 34. As a result, even if the contact portion E15 between the fixed core 33 and the movable core 34 shifts when the movable core 34 moves upward, the magnetic path length of the magnetic circuit formed by multiple magnetic members including the yoke 35, the fixed core 33, and the movable core 34 can be shortened, thereby accurately improving the magnetic efficiency of the magnetic circuit.

[0097] (5) Modifications Below, modifications of the embodiments will be described.

[0098] In the contact device 2 of the electromagnetic relay 1 according to this embodiment, the pair of movable contacts 221 are part of the movable contact 22 and are provided integrally with the movable contact 22. However, as a modification of the embodiment, the pair of movable contacts may be provided separately from the movable contact 22. In such a contact device 2 as well, the movement of the movable shaft 24 causes the movable contacts, which are provided separately from the movable contact 22, to move integrally with the movable contact 22, and the movable contacts move toward and away from the fixed contact 211.

[0099] The contact device 2 and electromagnetic relay 1 according to the above modified example also provide the same effects as the contact device 2 and electromagnetic relay 1 according to the embodiment.

[0100] The embodiments and modifications described above are only a part of the various embodiments and modifications of this disclosure. Furthermore, the embodiments and modifications can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved.

[0101] (Aspects) The following aspects are disclosed in this specification.

[0102] The electromagnetic relay (1) according to the first embodiment comprises a pair of fixed terminals (21), a movable contact (22), a holder (23), a movable shaft (24), a yoke (35), a fixed core (33), and a movable core (34). The pair of fixed terminals (21) have a pair of fixed contacts (211). The pair of fixed contacts (211) are arranged in the left-right direction (Y1). The movable contact (22) has a pair of movable contacts (221). The pair of movable contacts (221) move toward and away from the pair of fixed contacts (211) in the up-down direction (Y2). The up-down direction (Y2) is perpendicular to the left-right direction (Y1). The holder (23) holds the movable contact (22). The movable shaft (24) moves the holder (23) in the vertical direction (Y2) so that a pair of movable contacts (221) move toward and away from a pair of fixed contacts (211). The movable core (34) is located below the fixed core (33) so as to face the fixed core (33) in the vertical direction (Y2). The fixed core (33) has a first base (E1) and a first projection (E2). The first projection (E2) protrudes downward from the first base (E1). The movable core (34) has a second base (E4) and a second projection (E5). The second projection (E5) protrudes upward from the second base (E4). In a plan view from the vertical direction (Y2), the second projection (E5) of the movable core (34) is located outward from the first projection (E2) of the fixed core (33). The second projection (E5) of the movable core (34) comes into contact with the first base (E1) of the fixed core (33) when the movable core (34) moves upward.

[0103] According to the first embodiment of the electromagnetic relay (1), the magnetic efficiency of the magnetic circuit, which is formed by a plurality of magnetic members including a yoke (35), a fixed core (33), and a movable core (34), can be increased.

[0104] In the electromagnetic relay (1) according to the second embodiment, in the first embodiment, the fixed core (33) is provided between the contact portion (E14) of the fixed core (33) with the yoke iron (35) and the contact portion (E15) of the fixed core (33) with the movable core (34) in the vertical direction (Y2).

[0105] According to the electromagnetic relay (1) of the second embodiment, the magnetic path length of the magnetic circuit, which is formed by a plurality of magnetic members including a yoke (35), a fixed core (33), and a movable core (34), can be further shortened.

[0106] In the electromagnetic relay (1) according to the third embodiment, in the first or second embodiment, the fixed core (33) and the movable core (34) do not come into contact inside the contact portion (E15) of the fixed core (33) with the movable core (34).

[0107] According to the electromagnetic relay (1) of the third embodiment, the magnetic efficiency of the magnetic circuit, which is formed by a plurality of magnetic members including a yoke (35), a fixed core (33), and a movable core (34), can be further increased.

[0108] In the electromagnetic relay (1) according to the fourth embodiment, in the third embodiment, the first projection (E2) of the fixed core (33) has a tapered shape. The second projection (E5) of the movable core (34) has a tapered shape. When the movable core (34) moves upward and the second projection (E5) of the movable core (34) comes into contact with the first base (E1) of the fixed core (33), the first projection (E2) of the fixed core (33) and the second projection (E5) of the movable core (34) are facing each other while separated.

[0109] According to the electromagnetic relay (1) of the fourth embodiment, the area of ​​the portion where the fixed core (33) and the movable core (34) face each other can be increased, so the magnetic efficiency of the magnetic circuit formed by a plurality of magnetic members including the yoke (35), the fixed core (33), and the movable core (34) can be further increased.

[0110] In the electromagnetic relay (1) according to the fifth embodiment, in any one of the first to fourth embodiments, the first projection (E2) of the fixed core (33) is separated from the movable shaft (24).

[0111] In the electromagnetic relay (1) according to the sixth embodiment, in any one of the first to fifth embodiments, the area of ​​the contact surface between the fixed core (33) and the yoke (35) is greater than the area of ​​the contact surface between the fixed core (33) and the movable core (34).

[0112] According to the electromagnetic relay (1) of the sixth embodiment, the magnetic efficiency of a magnetic circuit formed by a plurality of magnetic members including a yoke (35), a fixed core (33), and a movable core (34) can be increased with precision.

[0113] 1 Electromagnetic relay 21 Fixed terminal 211 Fixed contact 22 Movable contact 221 Movable contact 23 Holder 24 Movable shaft 33 Fixed core E1 First base E14 Contact area E15 Contact area E2 First projection 34 Movable core E4 Second base E5 Second projection 35 Yoke Y1 Left / right direction Y2 Up / down direction

Claims

1. An electromagnetic relay comprising: a pair of fixed terminals having a pair of fixed contacts arranged in the left-right direction; a pair of movable contacts having a pair of movable contacts that move toward and toward the pair of fixed contacts in an up-down direction perpendicular to the left-right direction; a holder for holding the movable contacts; a movable shaft for moving the holder in the up-down direction so that the pair of movable contacts move toward and toward the pair of fixed contacts; a yoke; a fixed core; and a movable core located below the fixed core so as to face the fixed core in the up-down direction, wherein the fixed core has a first base and a first projection projecting downward from the first base; the movable core has a second base and a second projection projecting upward from the second base; the second projection of the movable core is located outside the first projection of the fixed core in a plan view from the up-down direction, and contacts the first base of the fixed core when the movable core moves upward.

2. The electromagnetic relay according to claim 1, wherein, in the vertical direction, the fixed core is provided between the contact portion of the fixed core with the yoke and the contact portion of the fixed core with the movable core.

3. The electromagnetic relay according to claim 1 or 2, wherein the fixed core and the movable core do not come into contact with each other inside the contact portion of the fixed core with the movable core.

4. The electromagnetic relay according to claim 3, wherein the first projection of the fixed core has a tapered shape, the second projection of the movable core has a tapered shape, and when the movable core moves upward and the second projection of the movable core contacts the first base of the fixed core, the first projection of the fixed core and the second projection of the movable core are facing each other while separated.

5. The first projection of the fixed core is spaced apart from the movable shaft, the electromagnetic relay according to any one of claims 1 to 4.

6. The electromagnetic relay according to any one of claims 1 to 5, wherein the area of ​​the contact portion between the fixed core and the yoke is greater than the area of ​​the contact portion between the fixed core and the movable core.

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