Patent Publication Number: US-11640889-B2

Title: Electromagnetic relay

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Patent Application No. 2020-176214, filed Oct. 20, 2020. The contents of that application are incorporated by reference herein in their entirety. 
     FIELD 
     The present invention relates to an electromagnetic relay. 
     BACKGROUND 
     Some electromagnetic relays have a movable contact piece held by a holder (see Japanese Patent Application Laid-Open No. 2017-204480). The holder is connected to a movable iron core via a shaft. An electromagnetic force acts on the movable iron core due to a magnetic field generated from a coil, and the movable iron core moves due to the electromagnetic force. The movable contact piece moves together with the shaft and the holder in accordance with the movement of the movable iron core. As a result, the contacts are opened and closed. 
     SUMMARY 
     Generally, the shaft described above is made of metal, and it is difficult to provide a large insulation distance between the shaft and the movable contact piece. An object of the present disclosure is to provide a large insulation distance from a movable contact piece in an electromagnetic relay. 
     An electromagnetic relay according to one aspect of the present disclosure includes a first fixed terminal, a first fixed contact, a second fixed terminal, a second fixed contact, a first movable contact piece, a first movable contact, a second movable contact, a moving member, a housing, a spool, a coil, a yoke, a guide member, and a movable iron core. The first fixed contact is connected to the first fixed terminal. The second fixed contact is connected to the second fixed terminal. The first movable contact is connected to the first movable contact piece and faces the first fixed contact. The second movable contact is connected to the first movable contact piece and faces the second fixed contact. 
     The moving member holds the first movable contact piece. The moving member is configured to move in a moving direction between a closed position and an open position. In a case where the moving member is located at the closed position, the first movable contact and the second movable contact come into contact with the first fixed contact and the second fixed contact respectively. In a case where the moving member is located at the open position, the first movable contact and the second movable contact are separated from the first fixed contact and the second fixed contact respectively. The moving member is made of a resin having electrical insulation. The housing slidably supports the moving member in a support direction perpendicular to the moving direction. 
     The spool includes a spool hole extending in the moving direction. The coil is wound around the spool. The yoke includes a pipe portion, a plate portion, and a yoke hole. The pipe portion is disposed in the spool hole. The plate portion extends from the pipe portion in a lateral direction and the support direction. The lateral direction is perpendicular to the support direction and the moving direction. The yoke hole extends in the moving direction through the pipe portion and the plate portion. The guide member is disposed in the yoke hole. The guide member includes a first guide portion, a second guide portion, and a step. The first guide portion is disposed in the yoke hole. The second guide portion has an inner diameter larger than an inner diameter of the first guide portion. The step is disposed between the first guide portion and the second guide portion. 
     The movable iron core is connected to the moving member. The movable iron core is configured to move in the moving direction by a magnetic force generated by the coil. The movable iron core includes a tubular portion and a shaft portion. The tubular portion includes a first end surface and a second end surface in the moving direction. The tubular portion is disposed in the guide member. The shaft portion projects from the first end surface toward the moving member. The plate portion includes a first surface and a second surface. The first surface faces the moving member. The second surface is located opposite the first surface and faces the spool. In a case where the moving member is located at the closed position, a part of the tubular portion is located in the second guide portion. In a case where the moving member is located at the closed position, the first end surface is located within a range from a first position to a second position. The first position is a position corresponding to the first surface. The second position is located at a center of the first surface and the second surface in the moving direction. 
     In the electromagnetic relay according to the present aspect, the first movable contact piece is connected to the movable iron core via the moving member. The moving member is made of a resin having electrical insulation. Therefore, a large insulation distance between the first movable contact piece and the movable iron core is provided. Further, in a case where the moving member is located at the closed position, the first end surface of the movable iron core is located within the range from the first position to the second position. Therefore, an inclination of the movable iron core is suppressed. As a result, the behavior of the first movable contact piece is stabilized, and thereby the operation of the electromagnetic relay is stabilized. In addition, the magnetic efficiency between the yoke and the movable iron core is improved. 
     The first end surface may be located in the first guide portion in a case where the moving member is located in the closed position. In this case, the inclination of the movable iron core is further suppressed. 
     The first end surface may be located outside the guide member in a case where the moving member is located at the open position. The second end surface may be located within a range from a third position to a fourth position in a case where the moving member is located at the open position. The third position may be a position corresponding to the step. The fourth position may be a position that is apart from the third position by a predetermined distance in the moving direction in the second guide portion. The predetermined distance may be one-third of a length of the second guide portion in the moving direction. In this case, the inclination of the movable iron core is further suppressed. 
     The first guide portion may protrude from the first surface toward the moving member. In this case, the inclination of the movable iron core is further suppressed. The guide member may be made of a non-magnetic material. In this case, the magnetic efficiency between the yoke and the movable iron core is further improved. 
     The moving member may include a support portion, a connecting portion, and a link portion. The support portion may support the first movable contact piece. The connecting portion may be connected to the movable iron core. The link portion may extend in the moving direction. The link portion may link the support portion and the connecting portion. In this case, a large insulation distance between the first movable contact piece and the movable iron core is provided. 
     The support portion may extend in the support direction. The link portion may be connected to a central portion of the support portion in the support direction. In this case, the inclination of the moving member is suppressed. As a result, the behavior of the first movable contact piece is stabilized, and thereby the operation of the electromagnetic relay is stabilized. 
     The electromagnetic relay may further include a third fixed contact, a fourth fixed contact, a second movable contact piece, a third movable contact, and a fourth movable contact. The third fixed contact may be connected to the first fixed terminal. The fourth fixed contact may be connected to the second fixed terminal. The third movable contact may be connected to the second movable contact piece. The third movable contact may face the third fixed contact. The fourth movable contact may be connected to the second movable contact piece. The fourth movable contact may face the fourth fixed contact. The support portion may support the second movable contact piece. The link portion may be connected to the support portion at a position between the first movable contact piece and the second movable contact piece in the support direction. In this case, the inclination of the moving member is suppressed. As a result, the behavior of the first movable contact piece is stabilized, and thereby the operation of the electromagnetic relay is stabilized. 
     The support portion may include a first slider. The first slider may protrude in the support direction. The first slider may be slidable with respect to the housing. In this case, the moving member can be moved stably. 
     The support portion may further include a second slider. The second slider may protrude in a direction opposite to the support direction. The second slider may be slidable with respect to the housing. In this case, the moving member can be stably moved regardless of the arrangement direction of the electromagnetic relay. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an electromagnetic relay according to an embodiment. 
         FIG.  2    is an exploded perspective view of the electromagnetic relay. 
         FIG.  3    is an exploded perspective view of the electromagnetic relay. 
         FIG.  4    is a vertical cross-sectional view of the electromagnetic relay. 
         FIG.  5    is a top view of the electromagnetic relay when a moving member is in an open position. 
         FIG.  6    is a top view of the electromagnetic relay when the moving member is in a closed position. 
         FIG.  7    is a perspective view of the moving member and its surroundings. 
         FIG.  8    is an exploded perspective view of the moving member. 
         FIG.  9    is an exploded perspective view of the moving member. 
         FIG.  10    is a vertical cross-sectional view of the moving member. 
         FIG.  11    is a cross-sectional view of the electromagnetic relay as seen from a first moving direction. 
         FIG.  12    is a partial cross-sectional view of a first member. 
         FIG.  13    is a cross-sectional view of the first member and a movable iron core. 
         FIG.  14    is a diagram showing a position of the movable iron core when the moving member is located at the closed position. 
         FIG.  15    is a diagram showing a position of the movable iron core when the moving member is in the open position. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an electromagnetic relay  1  according to an embodiment will be described with reference to the drawings.  FIG.  1    is a perspective view of the electromagnetic relay  1  according to the embodiment.  FIGS.  2  and  3    are exploded perspective views of the electromagnetic relay  1 .  FIG.  4    is a vertical cross-sectional view of the electromagnetic relay  1 .  FIGS.  5  and  6    are top views of the electromagnetic relay  1 . 
     The electromagnetic relay  1  includes a contact block  2 , a housing  3 , a coil block  4 , a first fixed terminal  13 , and a second fixed terminal  14 . The contact block  2  and the coil block  4  are disposed in the housing  3 . The housing  3  includes a base  11  and a case  12 . The base  11  and the case  12  are made of, for example, resin. In  FIG.  1   , the case  12  is omitted. The base  11  supports the first fixed terminal  13 , the second fixed terminal  14 , the contact block  2 , and the coil block  4 . 
     In the present embodiment, a moving direction (Y 1 , Y 2 ), a support direction (Z 1 , Z 2 ), and a lateral direction (X 1 , X 2 ) are defined as follows. The moving direction (Y 1 , Y 2 ) is a direction in which the contact block  2  and the coil block  4  are aligned with each other. The moving direction (Y 1 , Y 2 ) includes a first moving direction (Y 1 ) and a second moving direction (Y 2 ). The first moving direction (Y 1 ) is a direction from the contact block  2  toward the coil block  4 . The second moving direction (Y 2 ) is a direction opposite to the first moving direction (Y 1 ). The second moving direction (Y 2 ) is a direction from the coil block  4  toward the contact block  2 . 
     The support direction (Z 1 , Z 2 ) is a direction perpendicular to the moving direction (Y 1 , Y 2 ). The support direction (Z 1 , Z 2 ) is a direction in which the base  11  and the contact block  2  are aligned with each other. The support direction (Z 1 , Z 2 ) includes a first support direction (Z 1 ) and a second support direction (Z 2 ). The first support direction (Z 1 ) is a direction from the contact block  2  toward the base  11 . The second support direction (Z 2 ) is a direction opposite to the first support direction (Z 1 ). The second support direction (Z 2 ) is a direction from the base  11  toward the contact block  2 . Alternatively, the support direction (Z 1 , Z 2 ) may be a direction in which the base  11  and the coil block  4  are aligned with each other. 
     The lateral direction (X 1 , X 2 ) is a direction perpendicular to the moving direction (Y 1 , Y 2 ) and the support direction (Z 1 , Z 2 ). The lateral direction (X 1 , X 2 ) includes a first lateral direction (X 1 ) and a second lateral direction (X 2 ). The second lateral direction (X 2 ) is a direction opposite to the first lateral direction (X 1 ). 
     The first fixed terminal  13  and the second fixed terminal  14  are made of a conductive material such as copper. The first fixed terminal  13  and the second fixed terminal  14  extend in the support direction (Z 1 , Z 2 ), respectively. The first fixed terminal  13  and the second fixed terminal  14  are disposed apart from each other in the lateral direction (X 1 , X 2 ). The first fixed terminal  13  is fixed to the base  11 . A tip of the first fixed terminal  13  projects outward from the base  11 . The second fixed terminal  14  is fixed to the base  11 . A tip of the second fixed terminal  14  projects outward from the base  11 . 
     The first fixed contact  21  and the third fixed contact  23  are connected to the first fixed terminal  13 . The first fixed contact  21  and the third fixed contact  23  are disposed apart from each other in the support direction (Z 1 , Z 2 ) on the first fixed terminal  13 . The second fixed contact  22  and the fourth fixed contact  24  are connected to the second fixed terminal  14 . The second fixed contact  22  and the fourth fixed contact  24  are disposed apart from each other in the support direction (Z 1 , Z 2 ) on the second fixed terminal  14 . The first to fourth fixed contacts  21  to  24  are made of a conductive material such as silver or copper. 
     The contact block  2  includes a first movable contact piece  15 , a second movable contact piece  16 , and a moving member  17 . The first movable contact piece  15  and the second movable contact piece  16  extend in the lateral direction (X 1 , X 2 ). The first movable contact piece  15  and the second movable contact piece  16  are separate bodies from each other. The first movable contact piece  15  and the second movable contact piece  16  are disposed apart from each other in the support direction (Z 1 , Z 2 ). The first movable contact piece  15  is disposed between the second movable contact piece  16  and the base  11  in the support direction (Z 1 , Z 2 ). The first movable contact piece  15  and the second movable contact piece  16  are made of a conductive material such as copper. 
     The first movable contact  31  and the second movable contact  32  are connected to the first movable contact piece  15 . The first movable contact  31  and the second movable contact  32  are disposed apart from each other in the lateral direction (X 1 , X 2 ). The first movable contact  31  is disposed to face the first fixed contact  21 . The second movable contact  32  is disposed to face the second fixed contact  22 . 
     The third movable contact  33  and the fourth movable contact  34  are connected to the second movable contact piece  16 . The third movable contact  33  and the fourth movable contact  34  are disposed apart from each other in the lateral direction (X 1 , X 2 ). The third movable contact  33  is disposed to face the third fixed contact  23 . The fourth movable contact  34  is disposed to face the fourth fixed contact  24 . The first to fourth movable contacts  31  to  34  are made of a conductive material such as silver or copper. 
     The moving member  17  holds the first movable contact piece  15  and the second movable contact piece  16 . The moving member  17  is made of resin having electrical insulation. The moving member  17  is made of nylon, for example. However, the moving member  17  may be made of a material other than nylon. The moving member  17  is supported by the housing  3  in the support direction (Z 1 , Z 2 ). The moving member  17  is slidable in the moving direction (Y 1 , Y 2 ) with respect to the housing  3 . The moving member  17  is configured to move between a closed position and an open position. In  FIG.  5   , the moving member  17  is located at the open position. When the moving member  17  is located at the open position, the movable contacts  31  to  34  are separated from the fixed contacts  21  to  24 , respectively. In  FIG.  6   , the moving member  17  is located at the closed position. When the moving member  17  is located in the closed position, the movable contacts  31  to  34  contact the fixed contacts  21  to  24 , respectively. 
     The coil block  4  moves the first movable contact piece  15  and the second movable contact piece  16  by an electromagnetic force. The coil block  4  moves the first movable contact piece  15  and the second movable contact piece  16  in the first moving direction (Y 1 ) and the second moving direction (Y 2 ). The first moving direction (Y 1 ) is a direction in which the movable contacts  31  to  34  contact the fixed contact  21  to  24  in the moving direction (Y 1 , Y 2 ). The second moving direction (Y 2 ) is a direction in which the movable contacts  31  to  34  are separated from the fixed contacts  21  to  24  in the moving direction (Y 1 , Y 2 ). The coil block  4  includes a coil  61 , a spool  62 , a movable iron core  63 , a fixed iron core  64 , and a yoke  65 . 
     The coil  61  is wound around the spool  62 . An axis of the coil  61  extends in the moving direction (Y 1 , Y 2 ). The coil  61  is connected to the coil terminals  66  and  67 . As illustrated in  FIGS.  2  and  3   , the coil terminals  66  and  67  project from the coil block  4  in the first support direction (Z 1 ). The coil terminals  66  and  67  project outward from the base  11 . 
     As illustrated in  FIG.  4   , the spool  62  includes a spool hole  621  extending in the moving direction (Y 1 , Y 2 ). At least a part of the movable iron core  63  is disposed in the spool hole  621  of the spool  62 . The movable iron core  63  is configured to move in the first moving direction (Y 1 ) and the second moving direction (Y 2 ). The fixed iron core  64  is disposed in the spool hole  621  of the spool  62 . The fixed iron core  64  is disposed to face the movable iron core  63  in the moving direction (Y 1 , Y 2 ). The coil  61  generates an electromagnetic force that moves the movable iron core  63  in the first moving direction (Y 1 ) by being energized. 
     The movable iron core  63  is connected to the moving member  17 . The first movable contact piece  15  and the movable iron core  63  are electrically insulated by the moving member  17 . The second movable contact piece  16  and the movable iron core  63  are electrically insulated by the moving member  17 . The movable iron core  63  moves integrally with the moving member  17  in the moving direction (Y 1 , Y 2 ). The movable iron core  63  moves in the first moving direction (Y 1 ) according to the magnetic force generated from the coil  61 . With the movement of the movable iron core  63 , the moving member  17  moves to the closed position. As the moving member  17  moves, the first movable contact piece  15  and the second movable contact piece  16  move in the first moving direction (Y 1 ) or the second moving direction (Y 2 ). 
     The yoke  65  is disposed so as to surround the coil  61 . The yoke  65  is disposed on a magnetic circuit generated by the coil  61 . The yoke  65  includes a first yoke  73 , a second yoke  74 , a third yoke  75 , and a fourth yoke  76 . The first yoke  73  includes a pipe portion  73   a , a plate portion  73   b , and a yoke hole  73   c . The pipe portion  73   a  is disposed in the spool hole  621 . The pipe portion  73   a  has a circular tubular shape. 
     The plate portion  73   b  extends from the pipe portion  73   a  in the lateral direction (X 1 , X 2 ) and the support direction (Z 1 , Z 2 ). The plate portion  73   b  faces the spool  62  in the moving direction (Y 1 , Y 2 ). The plate portion  73   b  faces the moving member  17  in the moving direction (Y 1 , Y 2 ). The plate portion  73   b  includes a first surface  731  and a second surface  732 . The first surface  731  faces the moving member  17 . The second surface  732  is located opposite to the first surface  731 . The second surface  732  faces the spool  62 . The yoke hole  73   c  extends in the moving direction (Y 1 , Y 2 ). The yoke hole  73   c  extends through the pipe portion  73   a  and the plate portion  73   b . The movable iron core  63  is disposed in the yoke hole  73   c.    
     The second yoke  74  extends in the lateral direction (X 1 , X 2 ) and the support direction (Z 1 , Z 2 ). The second yoke  74  faces the coil  61  in the moving direction (Y 1 , Y 2 ). The coil  61  is located between the plate portion  73   b  of the first yoke  73  and the second yoke  74  in the moving direction (Y 1 , Y 2 ). The second yoke  74  is connected to the fixed iron core  64 . 
     The third yoke  75  and the fourth yoke  76  extend in the moving direction (Y 1 , Y 2 ) and the support direction (Z 1 , Z 2 ). The third yoke  75  and the fourth yoke  76  face the coil  61  in the lateral direction (X 1 , X 2 ). The coil  61  is located between the third yoke  75  and the fourth yoke  76  in the lateral direction (X 1 , X 2 ). 
       FIG.  7    is a perspective view of the moving member  17  and its surroundings. The moving member  17  includes a support portion  25 , a connecting portion  26 , and a link portion  27 . The support portion  25  supports the first movable contact piece  15  and the second movable contact piece  16 . The connecting portion  26  is connected to the movable iron core  63 . The link portion  27  is located between the support portion  25  and the connecting portion  26 . The link portion  27  connects the support portion  25  and the connecting portion  26 . The link portion  27  is connected to a central portion of the support portion  25  in the support direction (Z 1 , Z 2 ). The link portion  27  is connected to the support portion  25  at a position between the first movable contact piece  15  and the second movable contact piece  16  in the support direction (Z 1  and Z 2 ). The link portion  27  extends in the moving direction (Y 1 , Y 2 ). 
     The support portion  25  extends in the support direction (Z 1 , Z 2 ). The support portion  25  extends from the first movable contact piece  15  toward the base  11  in the first support direction (Z 1 ). As illustrated in  FIG.  4   , the support portion  25  extends from the second movable contact piece  16  toward a top surface  123  of the case  12  in the second support direction (Z 2 ). The support portion  25  includes a first support hole  28 , a second support hole  29 , and a partition wall  30 . The first movable contact piece  15  is disposed in the first support hole  28 . The first movable contact piece  15  is supported by the support portion  25  between the first movable contact  31  and the second movable contact  32 . The first movable contact piece  15  extends from the support portion  25  in the first lateral direction (X 1 ) and the second lateral direction (X 2 ). 
     The second movable contact piece  16  is disposed in the second support hole  29 . The second movable contact piece  16  is supported by the support portion  25  between the third movable contact  33  and the fourth movable contact  34 . The second movable contact piece  16  extends from the support portion  25  in the first lateral direction (X 1 ) and the second lateral direction (X 2 ). The partition wall  30  partitions the first support hole  28  and the second support hole  29 . The partition wall  30  is disposed between the first movable contact piece  15  and the second movable contact piece  16 . 
     As illustrated in  FIGS.  2  and  4   , the base  11  includes a bottom surface  55 , a first wall  56 , a second wall  57 , a third wall  58 , and a fourth wall  59 . The bottom surface  55  supports the contact block  2  and the coil block  4  in the support direction (Z 1 , Z 2 ). The bottom surface  55  is located in the first support direction (Z 1 ) with respect to the contact block  2  and the coil block  4 . The first wall  56 , the second wall  57 , the third wall  58 , and the fourth wall  59  extend from the bottom surface  55  in the second support direction (Z 2 ). 
     The first wall  56  and the second wall  57  are disposed apart from each other in the moving direction (Y 1 , Y 2 ). The first wall  56  and the second wall  57  face the support portion  25  of the moving member  17  in the moving direction (Y 1 , Y 2 ). The support portion  25  is located between the first wall  56  and the second wall  57  in the moving direction (Y 1 , Y 2 ). The first wall  56  and the second wall  57  extend in the lateral direction (X 1 , X 2 ). The third wall  58  and the fourth wall  59  face the support portion  25  in the lateral direction (X 1 , X 2 ). The support portion  25  is located between the first wall  56  and the second wall  57  in the lateral direction (X 1 , X 2 ). The third wall  58  and the fourth wall  59  extend in the moving direction (Y 1 , Y 2 ). 
     The moving member  17  includes a first member  17   a  and a second member  17   b . The first member  17   a  and the second member  17   b  are separate bodies from each other. The second member  17   b  is connected to the first member  17   a  by snap fitting. The first support hole  28  and the second support hole  29  are provided between the first member  17   a  and the second member  17   b . The first movable contact piece  15  and the second movable contact piece  16  are held between the first member  17   a  and the second member  17   b  in the moving direction (Y 1 , Y 2 ). The first member  17   a  is connected to the link portion  27 . The first member  17   a  is integrally formed with the link portion  27  and the connecting portion  26 . 
       FIGS.  8  and  9    are exploded perspective views of the moving member  17 . As illustrated in  FIGS.  8  and  9   , the first member  17   a  includes a first main body  40 , a first protrusion  41 , and a second protrusion  42 . The first main body  40  holds the first movable contact piece  15 . The first main body  40  includes a first plate  47 , a pair of first ends  48   a  and  48   b , a second plate  49 , and a pair of second ends  50   a  and  50   b . The first plate  47  extends in the moving direction (Y 1 , Y 2 ). The pair of first ends  48   a  and  48   b  are the ends of the first member  17   a  in the first support direction (Z 1 ). The pair of first ends  48   a  and  48   b  are disposed apart from each other in the lateral direction (X 1 , X 2 ). The pair of first ends  48   a  and  48   b  project from the first plate  47  in the first support direction (Z 1 ). The first protrusion  41  projects from the first plate  47  in the first support direction (Z 1 ). 
     The second plate  49  extends in the moving direction (Y 1 , Y 2 ). The pair of second ends  50   a  and  50   b  are the ends of the first member  17   a  in the second support direction (Z 2 ). The pair of second ends  50   a  and  50   b  are disposed apart from each other in the lateral direction (X 1 , X 2 ). The pair of second ends  50   a  and  50   b  project from the second plate  49  in the second support direction (Z 2 ). The second protrusion  42  projects from the second plate  49  in the second support direction (Z 2 ). 
       FIG.  10    is a vertical cross-sectional view of the moving member  17 . As illustrated in  FIG.  10   , the first protrusion  41  includes a first locking surface  410  and a first tapered surface  411 . The first locking surface  410  extends from the first main body  40  in the first support direction (Z 1 ). The first tapered surface  411  is inclined with respect to the first support direction (Z 1 ). The second protrusion  42  includes a second locking surface  420  and a second tapered surface  421 . The second locking surface  420  extends from the first main body  40  in the second support direction (Z 2 ). The second tapered surface  421  is inclined with respect to the second support direction (Z 2 ). 
     The first member  17   a  includes first sliders  68   a  and  68   b  and a pair of second sliders  69   a  and  69   b . The first sliders  68   a  and  68   b  project from the first ends  48   a  and  48   b  in the first support direction (Z 1 ) and are slidable with respect to the base  11 . The first sliders  68   a  and  68   b  extend in the moving direction (Y 1 , Y 2 ), respectively. The first sliders  68   a  and  68   b  are disposed apart from each other in the lateral direction (X 1 , X 2 ). The pair of second sliders  69   a  and  69   b  project from the second ends  50   a  and  50   b  in the second support direction (Z 2 ) and are slidable with respect to the case  12 . The pair of second sliders  69   a  and  69   b  extend in the moving direction (Y 1 , Y 2 ), respectively. The pair of second sliders  69   a  and  69   b  are disposed apart from each other in the lateral direction (X 1 , X 2 ). 
       FIG.  11    is a cross-sectional view of the electromagnetic relay  1  as seen from the first moving direction (Y 1 ). As illustrated in  FIG.  11   , the housing  3  includes a first receiving surface  110  and a second receiving surface  120 . The first receiving surface  110  is provided on the base  11 . The first receiving surface  110  is located between the third wall  58  and the fourth wall  59 . The first receiving surface  110  faces the first sliders  68   a  and  68   b . The first receiving surface  110  has curved and recessed portions facing the first sliders  68   a  and  68   b . The first sliders  68   a  and  68   b  are slidable on the first receiving surface  110 . 
     The second receiving surface  120  is provided on the case  12 . The case  12  includes a first guide wall  121  and a second guide wall  122 . The first guide wall  121  and the second guide wall  122  extend from the top surface  123  of the case  12  in the first support direction (Z 1 ). The first guide wall  121  and the second guide wall  122  extend in the moving direction (Y 1 , Y 2 ). The second receiving surface  120  is located between the first guide wall  121  and the second guide wall  122 . The second receiving surface  120  faces the second sliders  69   a  and  69   b . The second receiving surface  120  has curved and recessed portions facing the second sliders  69   a  and  69   b . The second sliders  69   a  and  69   b  are slidable on the second receiving surface  120 . 
     As illustrated in  FIGS.  8  and  9   , the second member  17   b  includes a second main body  80 , a first locking portion  81 , a pair of first arms  82   a  and  82   b , a second locking portion  83 , and a pair of second arms  84   a  and  84   b . The second main body  80  holds the first movable contact piece  15 . The second main body  80  includes the partition wall  30  described above. The second main body  80  forms the first support hole  28  and the second support hole  29  together with the first main body  40 . The second main body  80  includes a first surface  85  and a second surface  86 . The first surface  85  is an end surface of the second main body  80  in the first support direction (Z 1 ). The second surface  86  is an end surface of the second main body  80  in the second support direction (Z 2 ). 
     The first locking portion  81  extends in the lateral direction (X 1 , X 2 ). The first locking portion  81  is connected to the pair of first arms  82   a  and  82   b . The pair of first arms  82   a  and  82   b  connect the second main body  80  and the first locking portion  81 . The pair of first arms  82   a  and  82   b  are disposed apart from each other in the lateral direction (X 1 , X 2 ). The first arms  82   a  and  82   b  project from the second main body  80  in the first support direction (Z 1 ). Specifically, the first arms  82   a  and  82   b  project from the first surface  85  in the first support direction (Z 1 ). The first arms  82   a  and  82   b  have a shape bent in the first moving direction (Y 1 ). The first arms  82   a  and  82   b  are connected to the ends of the first locking portion  81  in the lateral direction (X 1 , X 2 ), respectively. First steps  87   a  and  87   b  are provided between the first locking portion  81  and the first arms  82   a  and  82   b . The first arms  82   a  and  82   b  include the first corners  88   a  and  88   b . The first corners  88   a  and  88   b  are rounded. As illustrated in  FIG.  9   , the first surface  85  includes a surface  85   a  located between the first arms  82   a  and  82   b , a surface  85   b  located in the first lateral direction (X 1 ) of the first arms  82   a , and a surface  85   c  located in the second lateral direction (X 2 ) of the first arm  82   b . The surface  85   a  is located at the same height as the surfaces  85   b  and  85   c  in the support direction (Z 1 , Z 2 ). As a result, the flexibility of the first arms  82   a  and  82   b  is improved. 
     The second locking portion  83  extends in the lateral direction (X 1 , X 2 ). The second locking portion  83  is connected to the pair of second arms  84   a  and  84   b . The pair of second arms  84   a  and  84   b  connect the second main body  80  and the second locking portion  83 . The pair of second arms  84   a  and  84   b  are disposed apart from each other in the lateral direction (X 1 , X 2 ). The second arms  84   a  and  84   b  project from the second main body  80  in the second support direction (Z 2 ). Specifically, the second arms  84   a  and  84   b  project from the second surface  86  in the second support direction (Z 2 ). The second arms  84   a  and  84   b  have a shape bent in the first moving direction (Y 1 ). The second arms  84   a  and  84   b  are connected to the ends of the second locking portion  83  in the lateral direction (X 1 , X 2 ), respectively. Second steps  89   a  and  89   b  are provided between the second locking portion  83  and the second arms  84   a  and  84   b . The second arms  84   a  and  84   b  include second corners  90   a  and  90   b . The second corners  90   a  and  90   b  are rounded. As illustrated in  FIG.  8   , the second surface  86  includes a surface  86   a  located between the second arms  84   a  and  84   b , a surface  86   b  located in the first lateral direction (X 1 ) of the second arms  84   a , and a surface  86   c  located in the second lateral direction (X 2 ) of the second arm  84   b . The surface  86   a  is located at the same height as the surfaces  86   b  and  86   c  in the support direction (Z 1 , Z 2 ). As a result, the flexibility of the second arms  84   a  and  84   b  is improved. 
     As illustrated in  FIG.  10   , a thickness A 1  of the first arms  82   a  and  82   b  in the support direction (Z 1 , Z 2 ) is smaller than a thickness A 2  of the first locking portion  81  in the support direction (Z 1 , Z 2 ). A radius R 1  of the roundness of the first corners  88   a  and  88   b  is larger than the thickness A 1  of the first arms  82   a  and  82   b  in the support direction (Z 1  and Z 2 ). A thickness A 3  of the second arms  84   a  and  84   b  in the support direction (Z 1 , Z 2 ) is smaller than a thickness A 4  of the second locking portion  83  in the support direction (Z 1 , Z 2 ). A radius R 2  of the roundness of the second corners  90   a  and  90   b  is larger than the thickness A 3  of the second arms  84   a  and  84   b  in the support direction (Z 1 , Z 2 ). 
     The first locking portion  81  locks to the first protrusion  41  in the moving direction. Specifically, the first locking portion  81  locks to the first locking surface  410  of the first protrusion  41  in the moving direction (Y 1 , Y 2 ). The second locking portion  83  locks to the second protrusion  42  in the moving direction (Y 1 , Y 2 ). Specifically, the second locking portion  83  locks to the second locking surface  420  of the second protrusion  42  in the moving direction (Y 1 , Y 2 ). That is, the locking direction by snap fitting coincides with the moving direction (Y 1 , Y 2 ) of the moving member  17 . 
     As illustrated in  FIG.  4   , the contact block  2  includes a first contact spring  51  and a second contact spring  52 . The first contact spring  51  is disposed between the first movable contact piece  15  and the support portion  25 . The first contact spring  51  is disposed in the first support hole  28 . In a state where the first movable contact  31  is in contact with the first fixed contact  21  and the second movable contact  32  is in contact with the second fixed contact  22 , the first contact spring  51  presses the first movable contact piece  15  toward the first fixed terminal  13  and the second fixed terminal  14 . The first contact spring  51  is a coil spring, and is in a state of natural length when the moving member  17  is located in the open position. The first movable contact piece  15  is connected to the moving member  17  via the first contact spring  51 . 
     The second contact spring  52  is disposed between the second movable contact piece  16  and the support portion  25 . The second contact spring  52  is disposed in the second support hole  29 . In a state where the third movable contact  33  is in contact with the third fixed contact  23  and the fourth movable contact  34  is in contact with the fourth fixed contact  24 , the second contact spring  52  presses the second movable contact piece  16  toward the first fixed terminal  13  and the second fixed terminal  14 . The second contact spring  52  is a coil spring, and is in a state of natural length when the moving member  17  is located in the open position. The second movable contact piece  16  is connected to the moving member  17  via the second contact spring  52 . 
     The connecting portion  26  extends in the lateral direction (X 1 , X 2 ). As illustrated in  FIG.  7   , the connecting portion  26  includes a core connector  37 , a first mount  38 , and a second mount  39 . The core connector  37  is located between the first mount  38  and the second mount  39 . The core connector  37  is connected to the link portion  27 . As illustrated in  FIGS.  4  and  7   , the core connector  37  includes a hole  43  and a locking groove  44 . The hole  43  extends in the support direction (Z 1 , Z 2 ). The hole  43  is opened toward the first support direction (Z 1 ). The locking groove  44  communicates with the hole  43  and extends in the second support direction (Z 2 ). A width of the locking groove  44  is narrower than a width of the hole  43 . 
     The movable iron core  63  includes a tubular portion  71 , a protruding portion  72 , a shaft portion  77 , and a head  78 . The protruding portion  72  protrudes from the tubular portion  71  toward the fixed iron core  64 . An outer diameter of the protruding portion  72  is smaller than an outer diameter of the tubular portion  71 . The protruding portion  72  has a tapered shape toward the fixed iron core  64 . The shaft portion  77  projects from the tubular portion  71  toward the moving member  17 . An outer diameter of the shaft portion  77  is smaller than the outer diameter of the tubular portion  71 . An outer diameter of the head  78  is larger than the outer diameter of the shaft portion  77 . The outer diameter of the head  78  is larger than a width of the locking groove  44 . The shaft portion  77  is disposed in the locking groove  44 . The head  78  is disposed in the hole  43 . 
       FIG.  12    is a partial cross-sectional view of the first member  17   a .  FIG.  13    is a cross-sectional view taken along the line XIII-XIII of the first member  17   a  and the movable iron core in  FIG.  4   . As illustrated in  FIGS.  12  and  13   , a locking projection  91  is provided on an inner surface of the hole  43 . The locking projection  91  projects from the inner surface of the hole  43  in the first moving direction (Y 1 ). The locking projection  91  has a shape extending in the support direction (Z 1 , Z 2 ). As illustrated in  FIG.  4   , the locking projection  91  is longer than the locking groove  44  in the support direction (Z 1 , Z 2 ). In the support direction (Z 1 , Z 2 ), the locking projection  91  is longer than the head  78  of the movable iron core  63 . The locking projection  91  has a curved shape in a cross section perpendicular to the support direction (Z 1 , Z 2 ). The locking projection  91  presses the head  78  of the movable iron core  63  in the locking groove  44 . As a result, the head  78  of the movable iron core  63  is fixed to the connecting portion  26  by press fitting. 
     As illustrated in  FIG.  7   , the first mount  38  extends from the core connector  37  in the first lateral direction (X 1 ). The first mount  38  includes a first protrusion  45 . The first protrusion  45  projects from the first mount  38  toward the coil block  4 . The second mount  39  extends from the core connector  37  in the second lateral direction (X 2 ). The second mount  39  includes a second protrusion  46 . The second protrusion  46  projects from the second mount  39  toward the coil block  4 . 
     The electromagnetic relay  1  includes a first return spring  53  and a second return spring  54 . The first return spring  53  and the second return spring  54  are disposed between the moving member  17  and the coil block  4 . The first return spring  53  is located in the first lateral direction (X 1 ) with respect to the core connector  37 . The second return spring  54  is located in the second lateral direction (X 2 ) with respect to the core connector  37 . In other words, the core connector  37  is located between the first return spring  53  and the second return spring  54  in the lateral direction (X 1 , X 2 ). The first return spring  53  and the second return spring  54  urge the moving member  17  in the second moving direction (Y 2 ). The first return spring  53  is attached to the first protrusion  45 . The second return spring  54  is attached to the second protrusion  46 . 
       FIG.  14    is an enlarged view showing the configuration of the movable iron core  63  and its surroundings. As illustrated in  FIG.  14   , the electromagnetic relay  1  includes a guide member  92 . The guide member  92  is fixed to the first yoke  73 . For example, a fluorine-based lubricant is applied to the inner surface of the guide member  92 . The guide member  92  is made of a non-magnetic material such as stainless steel, brass, or copper. The guide member  92  is disposed in the spool hole  621 . The guide member  92  includes a first guide portion  93 , a second guide portion  94 , and a step  95 . 
     The first guide portion  93  has a circular tubular shape. The first guide portion  93  extends in the moving direction (Y 1 , Y 2 ). The first guide portion  93  is disposed in the yoke hole  73   c . The first guide portion  93  may protrude from the first surface  731  toward the moving member  17 . In that case, when assembling the electromagnetic relay  1 , it can be easily detected that the guide member  92  is securely assembled. The first guide portion  93  includes the first guide end  931 . The first guide end  931  is an end of the guide member  92  in the second moving direction (Y 2 ). The first guide end  931  faces the moving member  17  in the moving direction (Y 1 , Y 2 ). The first guide end  931  is located outside the yoke hole  73   c.    
     The second guide portion  94  has a circular tubular shape. The second guide portion  94  extends in the moving direction (Y 1 , Y 2 ). The second guide portion  94  is disposed in the spool hole  621 . The second guide portion  94  is located outside the yoke hole  73   c . The second guide portion  94  has an inner diameter larger than an inner diameter of the first guide portion  93 . The inner diameter of the second guide portion  94  is larger than the diameter of the yoke hole  73   c . An outer diameter of the second guide portion  94  is smaller than an outer diameter of the pipe portion  73   a . The second guide portion  94  is disposed between the pipe portion  73   a  and the fixed iron core  64 . The second guide portion  94  includes the second guide end  941 . The second guide end  941  is an end of the guide member  92  in the first moving direction (Y 1 ). The second guide end  941  faces the fixed iron core  64  in the moving direction (Y 1 , Y 2 ). The step  95  is disposed between the first guide portion  93  and the second guide portion  94 . The step  95  extends in the radial direction of the guide member  92 . The step  95  is connected to the first guide portion  93  and the second guide portion  94 . 
     The tubular portion  71  of the movable iron core  63  is disposed in the guide member  92 . The tubular portion  71  includes a first end surface  711  and a second end surface  712  in the moving direction (Y 1 , Y 2 ). The first end surface  711  is the end surface of the tubular portion  71  in the second moving direction (Y 2 ). The first end surface  711  faces the moving member  17  in the moving direction (Y 1 , Y 2 ). The second end surface  712  is located opposite to the first end surface  711  in the moving direction (Y 1 , Y 2 ). The second end surface  712  is the end surface of the tubular portion  71  in the first moving direction (Y 1 ). The second end surface  712  faces the fixed iron core  64  in the moving direction (Y 1 , Y 2 ). 
     Next, the operation of the electromagnetic relay  1  will be described. When the coil  61  is not energized, the coil block  4  is not excited. In this case, the moving member  17  is pressed in the second moving direction (Y 2 ) by the elastic force of the return springs  53  and  54  together with the movable iron core  63 , and the moving member  17  is located at the open position illustrated in  FIG.  5   . In this state, the first movable contact piece  15  and the second movable contact piece  16  are also pressed in the second moving direction (Y 2 ) via the moving member  17 . Therefore, when the moving member  17  is located at the open position, the first movable contact  31  and the second movable contact  32  are separated from the first fixed contact  21  and the second fixed contact  22 . Similarly, when the moving member  17  is located at the open position, the third movable contact  33  and the fourth movable contact  34  are separated from the third fixed contact  23  and the fourth fixed contact  24 . 
     When the coil  61  is energized, the coil block  4  is magnetized. In this case, due to the electromagnetic force of the coil  61 , the movable iron core  63  moves in the first moving direction (Y 1 ) against the elastic force of the return springs  53  and  54 . As a result, the moving member  17 , the first movable contact piece  15 , and the second movable contact piece  16  move in the first moving direction (Y 1 ). Therefore, as illustrated in  FIG.  6   , the moving member  17  moves to the closed position. As a result, when the moving member  17  is located in the closed position, the first movable contact  31  and the second movable contact  32  contact the first fixed contact  21  and the second fixed contact  22 , respectively. Similarly, when the moving member  17  is located in the closed position, the third movable contact  33  and the fourth movable contact  34  contact the third fixed contact  23  and the fourth fixed contact  24 , respectively. As a result, the first movable contact piece  15  and the second movable contact piece  16  are electrically connected to the first fixed terminal  13  and the second fixed terminal  14 . 
     When the current to the coil  61  is stopped and degaussed, the movable iron core  63  is pressed in the second moving direction (Y 2 ) by the elastic force of the return springs  53  and  54 . As a result, the moving member  17 , the first movable contact piece  15 , and the second movable contact piece  16  move in the second moving direction (Y 2 ). Therefore, as illustrated in  FIG.  5   , the moving member  17  moves to the open position. As a result, when the moving member  17  is located at the open position, the first movable contact  31  and the second movable contact  32  are separated from the first fixed contact  21  and the second fixed contact  22 . Similarly, when the moving member  17  is located in the open position, the third movable contact  33  and the fourth movable contact  34  are separated from the third fixed contact  23  and the fourth fixed contact  24 . 
       FIG.  14    shows a position of the movable iron core  63  when the moving member  17  is located at the closed position.  FIG.  15    shows a position of the movable iron core  63  when the moving member  17  is located at the open position. In  FIGS.  14  and  15   , the first to fourth positions P 1  to P 4  are defined as follows. The first position P 1  is a position corresponding to the first surface  731 . The second position P 2  is located at the center of the first surface  731  and the second surface  732  in the moving direction (Y 1 , Y 2 ). The second position P 2  is a position apart from the first surface  731  by a first distance D 1  in the first moving direction (Y 1 ). The first distance D 1  is half the thickness T 1  of the plate portion  73   b  in the moving direction (Y 1 , Y 2 ). The third position P 3  is a position corresponding to the inner surface of the step  95 . The fourth position P 4  is a position in the second guide portion  94  that is apart from the third position P 3  by a second distance D 2  in the first movement direction (Y 1 ). The second distance D 2  is one-third of the length L 1  of the second guide portion  94  in the moving direction (Y 1 , Y 2 ). 
     As illustrated in  FIG.  14   , in a case where the moving member  17  is located at the closed position, a part of the tubular portion  71  is located in the second guide portion  94 . In a case where the moving member  17  is located at the closed position, the first end surface  711  is located in the first guide portion  93 . In a case where the moving member  17  is located at the closed position, the first end surface  711  exceeds the first position P 1  in the first moving direction (Y 1 ). In a case where the moving member  17  is located at the closed position, the first end surface  711  is located within the range from the first position P 1  to the second position P 2 . In a case where the moving member  17  is located at the closed position, the second end surface  712  exceeds the fourth position P 4  in the first moving direction (Y 1 ). 
     As illustrated in  FIG.  15   , in a case where the moving member  17  is located at the open position, the first end surface  711  is located outside the yoke hole  73   c . In a case where the moving member  17  is located at the open position, the first end surface  711  exceeds the first position P 1  in the second moving direction (Y 2 ). In a case where the moving member  17  is located at the open position, the first end surface  711  is located outside the guide member  92 . In a case where the moving member  17  is located at the open position, the second end surface  712  is located within the range from the third position P 3  to the fourth position P 4 . 
     In the electromagnetic relay  1  according to the present embodiment described above, the first movable contact piece  15  is connected to the movable iron core  63  via the moving member  17 . The moving member  17  is made of a resin having electrical insulation and is directly connected to the movable iron core  63 . Therefore, a large insulation distance between the first movable contact piece  15  and the movable iron core  63  is provided. 
     In a case where the moving member  17  is located at the closed position, the first end surface  711  of the movable iron core  63  is located within the range from the first position P 1  to the second position P 2 . Therefore, the inclination of the movable iron core  63  is suppressed when the moving member  17  is located at the closed position. As a result, the behavior of the first movable contact piece  15  is stabilized, and thereby the operation of the electromagnetic relay  1  is stabilized. Further, the magnetic efficiency of the yoke  65  and the movable iron core  63  is improved. Further, in a case where the moving member  17  is located at the open position, the second end surface  712  is located within the range from the third position P 3  to the fourth position P 4 . Therefore, the inclination of the movable iron core  63  is suppressed when the moving member  17  is located at the open position. 
     Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. 
     In the above embodiment, the coil block  4  pushes the moving member  17  in the second moving direction (Y 2 ), so that the movable contacts  31  to  34  are separated from the fixed contacts  21  to  24 . Further, the coil block  4  pulls the moving member  17  in the first moving direction (Y 1 ), so that the movable contacts  31  to  34  contact the fixed contacts  21  to  24 . However, the operating direction of the moving member  17  for opening and closing the contacts may be opposite to that of the above embodiment. That is, the coil block  4  may push the moving member  17  in the second moving direction (Y 2 ) so that the movable contacts  31  to  34  may contact the fixed contacts  21  to  24 . The coil block  4  may pull the moving member  17  in the first moving direction (Y 1 ) so that the movable contacts  31  to  34  may be separated from the fixed contacts  21  to  24 . 
     The shapes or arrangements of the first fixed terminal  13 , the second fixed terminal  14 , the first movable contact piece  15 , and the second movable contact piece  16  may be changed. For example, the first fixed terminal  13  and the second fixed terminal  14  may protrude from the base  11  in a direction different from that of the above embodiment. The first movable contact piece  15  and the second movable contact piece  16  may be integrated with each other. That is, the first to fourth movable contacts  31  to  34  may be connected to the integrated movable contact piece. Alternatively, the second movable contact piece  16 , the third and fourth movable contacts  33  and  34 , and the third and fourth fixed contacts  23  and  24  may be omitted. 
     The shapes or arrangements of the coil  61 , the spool  62 , the movable iron core  63 , the fixed iron core  64 , or the yoke  65  may be changed. The shapes or arrangements of the first to fourth fixed contacts  21  to  24  may be changed. The shapes or arrangements of the first to fourth movable contacts  31  to  34  may be changed. The shape of the base  11  may be changed. 
     The first fixed contact  21  and/or the third fixed contact  23  may be integrated with the first fixed terminal  13 . The first fixed contact  21  and/or the third fixed contact  23  may be a part of the first fixed terminal  13  and may be flush with other part of the first fixed terminal  13 . The second fixed contact  22  and/or the fourth fixed contact  24  may be integrated with the second fixed terminal  14 . The second fixed contact  22  and/or the fourth fixed contact  24  may be a part of the second fixed terminal  14  and may be flush with other part of the second fixed terminal  14 . 
     The first movable contact  31  and/or the second movable contact  32  may be integrated with the first movable contact piece  15 . The first movable contact  31  and/or the second movable contact  32  may be a part of the first movable contact piece  15  and may be flush with other part of the first movable contact piece  15 . The third movable contact  33  and/or the fourth movable contact  34  may be integrated with the second movable contact piece  16 . The third movable contact  33  and/or the fourth movable contact  34  may be a part of the second movable contact piece  16  and may be flush with other part of the second movable contact piece  16 . 
     The shape of the moving member  17  is not limited to that of the above embodiment, and may be changed. The shape of the first member  17   a  may be changed. For example, the first member  17   a  may be a separate body from the link portion  27  and the connecting portion  26 . The shape of the second member  17   b  may be changed. The shape of the link portion  27  may be changed. The shape of the connecting portion  26  may be changed. 
     The position of the movable iron core  63  in a case where the moving member  17  is located at the closed position is not limited to that of the above embodiment, and may be changed. The first end surface  711  may be located at the first position P 1  in a case where the moving member  17  is located at the closed position. The first end surface  711  may be located at the second position P 2  in a case where the moving member  17  is located at the closed position. The position of the movable iron core  63  in a case where the moving member  17  is located at the open position is not limited to that of the above embodiment, and may be changed. The second end surface  712  may be located at the third position P 3  in a case where the moving member  17  is located at the open position. The second end surface  712  may be located at the fourth position P 4  in a case where the moving member  17  is located at the open position. 
     REFERENCE SIGNS LIST 
       3 : Housing,  13 : First fixed terminal,  14 : Second fixed terminal,  15 : First movable contact piece,  16 : Second movable contact piece,  17 : Moving member,  21 : First fixed contact,  22 : Second fixed contact,  23 : Third fixed contact,  24 : Fourth fixed contact,  25 : Support portion,  26 : Connecting portion,  27 : Link portion,  31 : First movable contact,  32 : Second movable contact,  33 : Third movable contact,  34 : Fourth movable contact,  61 : Coil,  62 : Spool,  63 : Movable iron core  63 ,  71 : Tubular portion,  73 : First yoke,  73   a : Pipe portion,  73   b : Plate portion,  77 : Shaft portion,  92 : Guide member,  93 : first guide portion,  94 : second guide portion,  95 : Step,  621 : Spool hole,  711 : First end surface,  712 : Second end surface,  731 : First surface,  732 : Second surface, P 1 : First position, P 2 : Second position, P 3 : Third position, P 4 : Fourth position