Patent Publication Number: US-11657995-B2

Title: Electromagnetic relay with positional securement for fixed terminals

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Patent Application No. 2021-041571, filed Mar. 15, 2021. The contents of that application are incorporated by reference herein in their entirety. 
     FIELD 
     The present disclosure relates to an electromagnetic relay. 
     BACKGROUND 
     Conventionally, electromagnetic relays are known that open and close an electric circuit. For example, the electromagnetic relay disclosed in Japanese Laid-Open Patent Publication No. 2019-67640 includes a fixed terminal having a fixed contact and a movable contact piece having a movable contact. The fixed terminal penetrates a base and a portion of the fixed terminal on which the fixed contact is disposed is placed on the base, whereby the fixed terminal is fixed to the base. 
     SUMMARY 
     However, in the electromagnetic relay disclosed in Japanese Laid-Open Patent Publication No. 2019-67640, the fixed terminal is fixed to the base only at a portion thereof that penetrates the base. This may cause a positional deviation of the fixed terminal when external force is applied to a portion of the fixed terminal exposed from the base. 
     An object of the present disclosure is to provide an electromagnetic relay capable of reducing a positional deviation. 
     An electromagnetic relay according to one aspect of the present disclosure includes a fixed terminal, a movable contact piece, and a support portion. The fixed terminal includes a fixed contact, a first terminal portion, a second terminal portion, and a first protrusion. The fixed contact is disposed on the first terminal portion. The second terminal portion extends from a first end of both ends of the first terminal portion. The fixed terminal is bent between the second terminal portion and the first terminal portion. The first protrusion is disposed on the second terminal portion. The movable contact piece includes a movable contact. The movable contact faces the fixed contact. The support portion includes a contact surface and a first side surface and supports the fixed terminal. The contact surface contacts a first terminal surface of the first terminal portion opposite to the movable contact piece. The first side surface includes a first groove into which the first protrusion is fitted. The first protrusion is disposed on a second terminal surface connected to the first terminal surface in the second terminal portion. 
     In this manner, the fixed terminal includes the first protrusion and the support portion includes the first groove into which the first protrusion is fitted, thereby reducing a positional deviation of the fixed terminal in a width direction. The support portion contacts the first terminal portion, thereby regulating a position of the fixed terminal in a direction in which the movable contact and the fixed contact face each other. 
     The first protrusion and the first groove are disposed in a space opposite to the movable contact using the fixed terminal as a reference. As a result, it is possible to reduce a positional deviation of fixed terminal without reducing the space where the movable contact is disposed by separately providing a regulating portion configured to regulate a positional deviation of the fixed terminal. 
     Even when a material forming the support portion is shaved by the first protrusion in the first groove, it is possible to reduce the scattering of shavings to the outside of the first groove by covering the first groove with the fixed terminal. 
     The first protrusion and the first groove are disposed in a space opposite to the movable contact using the fixed terminal as a reference, thereby reducing a positional deviation of the fixed terminal in a state where behavior of arc is easily controlled without hindering movement of the arc. 
     The first groove may be formed in a direction in which the second terminal portion extends from the first end of the first terminal portion. The first groove may include an opening that opens toward the contact surface. The first protrusion is to be inserted into the opening. In this case, the first protrusion is inserted from the opening, thereby easily assembling the fixed terminal to the support portion. 
     The first groove may include a disposition portion, an opening side portion, and a connection portion. The first protrusion may be disposed in the disposition portion. The opening side portion may be disposed closer to the opening than the disposition portion and a width of the opening side portion may be larger than a width of the disposition portion. The connection portion may have a width that decreases from the opening side portion toward the disposition portion. In this case, the first protrusion can be easily inserted into the first groove. 
     The fixed terminal may further include a third terminal portion. The third terminal portion may extend from a second end of the first terminal portion parallel to the second terminal portion, the second end being opposite to the first end. In this case, it is possible to reduce a position deviation of the fixed terminal having a U-shape. 
     The fixed terminal may further include a second protrusion. The second protrusion may be disposed on a third terminal surface connected to the first terminal surface in the third terminal portion. The support portion may further include a second side surface. The second side surface may include a second groove into which the second protrusion of the third terminal portion is fitted. In this case, it is possible to reduce a positional deviation with the two protrusions and the two grooves. 
     The movable contact piece may be configured to move in a first direction including a contact direction in which the movable contact approaches the fixed contact and a separation direction in which the movable contact separates from the fixed contact. The electromagnetic relay may further include a magnet portion. The magnet portion is configured to generate a magnetic field to extend an arc generated between the fixed contact and the movable contact in a second direction orthogonal to the first direction. In this case, the protrusion and the groove are disposed in a space opposite to the movable contact using the fixed terminal as a reference, thereby reducing a positional deviation of the fixed terminal in a state where behavior of arc is easily controlled without hindering movement of the arc. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an electromagnetic relay. 
         FIG.  2    is a perspective view illustrating an internal configuration of the electromagnetic relay. 
         FIG.  3    is a front view of the internal configuration of the electromagnetic relay as viewed from the front. 
         FIG.  4    is a perspective view of a contact device and a drive device as viewed from the front. 
         FIG.  5    is a front view of a first fixed terminal as viewed from the front. 
         FIG.  6    is a bottom view of the first fixed terminal as viewed from below. 
         FIG.  7    is a diagram illustrating a positional relationship between a magnet portion and a movable contact piece, the first fixed terminal, and a second fixed terminal. 
         FIG.  8    is a partial perspective view of a base as viewed from above. 
         FIG.  9    is a view illustrating attachment of the first fixed terminal to a first terminal support portion. 
         FIG.  10    is a plan view of the first terminal support portion as viewed from above. 
         FIG.  11    is a side view of the first terminal support portion as viewed from the right. 
         FIG.  12    is a view illustrating a state where the first fixed terminal is attached to the first terminal support portion. 
         FIG.  13    is a view illustrating the fixed terminal having an L shape and a terminal support portion. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of an electromagnetic relay according to one aspect of the present disclosure will be described with reference to the drawings. In each of the drawings, a direction indicated by Z2 is referred to as “up”, a direction indicated by Z1 is referred to as “down”, a direction indicated by X1 is referred to as “left”, a direction indicated by X2 is referred to as “right”, a direction indicated by Y1 is referred to as “front”, and a direction indicated by Y2 is referred to as “back”. These directions are defined for convenience of description and are not intended to limit the directions in which the electromagnetic relay is disposed. 
     &lt;Configuration&gt; 
     (Overview of Electromagnetic Relay  1 ) 
       FIG.  1    is a perspective view of an electromagnetic relay  1 .  FIG.  2    is a perspective view illustrating a state where a case is removed from the electromagnetic relay  1 .  FIG.  3    is a side view of  FIG.  2   . 
     As illustrated in  FIGS.  1  to  3   , the electromagnetic relay  1  includes a base  2 , a case  10 , a contact device  3 , a drive device  4 , and a magnet portion  5 . 
     The base  2  is made from an insulating material such as resin. The base  2  supports the contact device  3  and the drive device  4 . The contact device  3  and the drive device  4  are covered with the case  10  attached to the base  2 . As illustrated in  FIG.  4    described later, the contact device  3  includes two fixed terminals, i.e., a first fixed terminal  6  and a second fixed terminal  7 , and a movable contact piece  8  that is configured to interconnect the first fixed terminal  6  and the second fixed terminal  7 . The drive device  4  moves the movable contact piece  8  so that the movable contact piece  8  contacts the first fixed terminal  6  and the second fixed terminal  7  or separates from the first fixed terminal  6  and the second fixed terminal  7 . The magnet portion  5  extends an arc generated with the separation of contacts by the Lorentz force. 
     (Contact Device  3 ) 
       FIG.  4    is a perspective view of the contact device  3  and the drive device  4  as viewed from the front. 
     The contact device  3  includes the first fixed terminal  6  (an example of a fixed terminal), the second fixed terminal  7  (an example of a fixed terminal), the movable contact piece  8 , and a movable unit  9 . The first fixed terminal  6 , the second fixed terminal  7 , and the movable contact piece  8  are terminals having a plate shape and are made from a conductive material such as copper. The first fixed terminal  6  and the second fixed terminal  7  are fixed to the base  2 . The movable contact piece  8  is configured to contact the first fixed terminal  6  and the second fixed terminal  7  or separate from the first fixed terminal  6  and the second fixed terminal  7 . The movable unit  9  moves the movable contact piece  8  between a contact position where the movable contact piece  8  contacts the first fixed terminal  6  and the second fixed terminal  7  and a separation position where the movable contact piece  8  separates from the first fixed terminal  6  and the second fixed terminal  7 . 
     (First Fixed Terminal  6  and Second Fixed Terminal  7 ) 
     As illustrated in  FIGS.  2  and  3   , the first fixed terminal  6  has a shape bent in a U-shape when viewed from the front-back direction. The first fixed terminal  6  is disposed on the base  2 . The disposition of the first fixed terminal  6  with respect to the base  2  will be described later. 
     As illustrated in  FIG.  3   , the first fixed terminal  6  includes a contact support portion  61  (an example of a first terminal portion), a first fixed contact  62 , and a pair of first external connection portion  63  (an example of a second terminal portion) and a second external connection portion  64  (an example of a third terminal portion), a first protrusion  65 , and a second protrusion  66 . 
     The contact support portion  61  includes a flat surface orthogonal to the up-down direction. The first fixed contact  62  is supported by the contact support portion  61 . The first fixed contact  62  protrudes upward from the contact support portion  61 . The first fixed contact  62  may be integrated with the contact support portion  61 , the first external connection portion  63 , and the second external connection portion  64 . As described later in detail, as illustrated in  FIG.  3   , the base  2  contacts a surface  61   a  (an example of a first terminal surface) of the contact support portion  61  opposite to the movable contact piece  8 . 
       FIG.  5    is a view of the first fixed terminal  6  as viewed from the front.  FIG.  6    is a view of the first fixed terminal  6  as viewed from below. In  FIGS.  5  and  6   , the first fixed contact  62  is omitted. 
     As illustrated in  FIG.  5   , the first external connection portion  63  extends downward from a right end  61   b  (an example of a first end) of both ends of the contact support portion  61  in the left-right direction at angles with respect to the contact support portion  61 . The first fixed terminal  6  is bent between the first external connection portion  63  and the contact support portion  61 . As illustrated in  FIG.  4   , the first external connection portion  63  includes a tip  631  having a narrower width and protruding downward from the base  2 . 
     As illustrated in  FIG.  5   , the second external connection portion  64  extends downward from a left end  61   c  (an example of a second end) of both ends of the contact support portion  61  in the left-right direction at angles with respect to the contact support portion  61 . The first fixed terminal  6  is bent between the second external connection portion  64  and the contact support portion  61 . As illustrated in  FIG.  4   , the second external connection portion  64  includes a tip  641  having a narrower width and protruding downward from the base  2 . 
     The first external connection portion  63  and the second external connection portion  64  are disposed facing each other in the left-right direction. The first external connection portion  63  and the second external connection portion  64  are disposed parallel to each other. The tips  631  and  641  protruding from the base  2  (see  FIG.  3   ) are electrically connected to an external device (not illustrated). The terms of “parallel” and “vertical” used in this specification include a mechanical error and a range generally accepted as parallel and vertical. 
     As illustrated in  FIGS.  5  and  6   , the first external connection portion  63  includes a surface  63   a  (an example of a second terminal surface) connected to the surface  61   a  of the contact support portion  61 . The first protrusion  65  is disposed on the surface  63   a . The first protrusion  65  has, for example, a cylindrical shape. The first protrusion  65  protrudes from the first external connection portion  63  in a direction in which the contact support portion  61  extends (the left direction). The first protrusion  65  is formed toward the second external connection portion  64 . The first protrusion  65  is disposed closer to the contact support portion  61  than the tip  631 . 
     The second external connection portion  64  includes a surface  64   a  (an example of a third terminal surface) connected to the surface  61   a  of the contact support portion  61 . The second protrusion  66  is disposed on the surface  64   a . The second protrusion  66  has, for example, a cylindrical shape. The second protrusion  66  protrudes from the second external connection portion  64  in a direction in which the contact support portion  61  extends (the right direction). The second protrusion  66  is formed toward the first external connection portion  63 . The second protrusion  66  is disposed closer to the contact support portion  61  than the tip  641 . 
     The first protrusion  65  and the second protrusion  66  are disposed facing each other. The first protrusion  65  and the second protrusion  66  are positioned inside the U-shape of the first fixed terminal  6  bent in a U-shape. 
     As illustrated in  FIG.  4   , the second fixed terminal  7  is supported by the base  2  at a position apart from the first fixed terminal  6  in the front-back direction. The second fixed terminal  7  is disposed behind the first fixed terminal  6  and apart from the first fixed terminal  6 . The second fixed terminal  7  has a same shape as the first fixed terminal  6 . As illustrated in  FIG.  4   , the second fixed terminal  7  includes a contact support portion  71 , a second fixed contact  72 , a pair of a first external connection portions  73  and a second external connection portion  74 , a first protrusion (not illustrated) and a second protrusion  76 . The second fixed terminal  7  has a same configuration as the first fixed terminal  6 , and therefore the description thereof is omitted. 
     (Movable Contact Piece  8 ) 
     As illustrated in  FIG.  4   , the movable contact piece  8  extends in the front-back direction. The movable contact piece  8  is coupled to the movable unit  9 . The movable contact piece  8  is disposed above the first fixed terminal  6  and the second fixed terminal  7 . 
     The movable contact piece  8  includes a contact support member  83  and a pair of a first movable contact  81  and a second movable contact  82 . The contact support member  83  has a plate shape and extends in the front-back direction. 
     The first movable contact  81  is disposed on a front end portion of the contact support member  83 . The first movable contact  81  is disposed above and facing the first fixed contact  62 . The first movable contact  81  is configured to contact the first fixed contact  62 . 
     The second movable contact  82  is disposed on a back end portion of the contact support member  83 . The second movable contact  82  is disposed above and facing the second fixed contact  72 . The second movable contact  82  is configured to contact the second fixed contact  72 . The first movable contact  81  and the second movable contact  82  may be integrated with the contact support member  83 . 
     The movable contact piece  8  is configured to move in a first direction. The first direction includes a contact direction in which the first movable contact  81  and the second movable contact  82  approach the first fixed contact  62  and the second fixed contact  72  and a separation direction in which the first movable contact  81  and the second movable contact  82  separate from the first fixed contact  62  and the second fixed contact  72 . In the present embodiment, the first direction is the up-down direction, the contact direction is the direction indicated by Z1 (the down direction) and the separation direction is the direction indicated by Z2 (the up direction). 
     The movable contact piece  8  is configured to move between an open position where the pair of the first movable contact  81  and the second movable contact  82  separates from the first fixed contact  62  and the second fixed contact  72  and a closed position where the pair of the first movable contact  81  and the second movable contact  82  contact the first fixed contact  62  and the second fixed contact  72 . 
     (Movable Unit  9 ) 
     As illustrated in  FIG.  4   , the movable unit  9  extends in the up-down direction. The movable unit  9  is coupled to the movable contact piece  8  between the first movable contact  81  and the second movable contact  82 . The movable unit  9  is disposed at the center of the movable contact piece  8  in the front-back direction. 
     As illustrated in  FIGS.  2  and  4   , the movable unit  9  includes a movable member  91 , a cover member  92 , a contact spring  93 , and a return spring  94 . The movable member  91  extends in the up-down direction. The movable member  91  and the cover member  92  are made from an insulating material such as resin. 
     The movable member  91  includes a pressed part  911 , a disposition part  912 , and a sliding part  913 . The pressed part  911  is disposed on an upper part of the movable member  91 . The pressed part  911  is a part pressed downward by a movable iron piece  45  of the drive device  4 . 
     The disposition part  912  is a substantially center part of the movable member  91  in the up-down direction. The contact spring  93  and the movable contact piece  8  are disposed in the disposition part  912 . The disposition part  912  has a disposition space  912   a  with its right side wall open and the contact spring  93  is disposed in the disposition space  912   a . At a lower end of the disposition space  912   a , a cutout  914  is formed in the side walls in the front-back direction. The movable contact piece  8  is disposed through the cutout  914  at the side walls of the disposition space  912   a  and the disposition space  912   a.    
     The sliding part  913  is a lower end portion of the movable member  91 . The sliding part  913  is guided by a guide portion  24  (see  FIG.  8    described later) on the base  2 . The guide portion  24  is recessed downward on the upper surface of the base  2 . The sliding part  913  slides in the guide portion  24 , thereby guiding the movable member  91 . 
     As illustrated in  FIGS.  2  and  3   , the cover member  92  covers the right side of the disposition space  912   a . The cover member  92  restricts the movable contact piece  8  from protruding rightward from the movable member  91 . 
     As illustrated in  FIG.  4   , the contact spring  93  is a coil spring and is disposed in the disposition space  912   a  in the up-down direction. The upper end of the contact spring  93  is coupled to an upper surface of the disposition space  912   a . The lower end of the contact spring  93  is coupled to the movable contact piece  8  between the first movable contact  81  and the second movable contact  82 . The contact spring  93  is disposed between the upper surface of the disposition space  912   a  and the movable contact piece  8  in a compressed state. Accordingly, the contact spring  93  urges the movable contact piece  8  toward the contact direction. The movable contact piece  8  is pressed against a lower surface of the disposition space  912   a  by the contact spring  93 . 
     The contact spring  93  is provided in order to increase contact pressure of the first movable contact  81  against the first fixed contact  62  and contact pressure of the second movable contact  82  against the second fixed contact  72 . 
     The return spring  94  is disposed between the sliding part  913  of the movable member  91  and the guide portion  24  of the base  2 . The return spring  94  urges the movable member  91  upward. The return spring  94  moves the movable member  91  upward when the movable member  91  is released from the pressing by the drive device  4 . Accordingly, the movable contact piece  8  moves from the contact position to the separation position. 
     (Drive Device  4 ) 
     As illustrated in  FIG.  2   , the drive device  4  is disposed at the left side of the contact device  3 . The drive device  4  moves the movable contact piece  8  in the up-down direction via the movable unit  9 . As illustrated in  FIGS.  2  and  3   , the drive device  4  includes a coil  41 , a bobbin  42 , a fixed iron core  43 , a yoke  44 , a movable iron piece  45 , a spring  46 , and a stopper member  47 . 
     The coil  41  is wound around the outer circumference of the bobbin  42 . The bobbin  42  extends in the up-down direction. The bobbin  42  is fixed to the base  2 . The fixed iron core  43  is disposed in the inner circumference of the bobbin  42 . The yoke  44  has a substantially L-shape when viewed in the front-back direction and is disposed so as to cover the left side of the coil  41 . The yoke  44  is connected to the lower end of the fixed iron core  43 . 
     The movable iron piece  45  is disposed above the fixed iron core  43 . The left end of the movable iron piece  45  is rotatably supported by the yoke  44 . The movable iron piece  45  rotates while the upper end of the yoke  44  acts as a fulcrum. As illustrated in  FIG.  4   , a tip of the right end of the movable iron piece  45  contacts the pressed part  911  of the movable unit  9  from above. 
     The spring  46  is disposed at the upper end of the yoke  44  in the front-back direction. The spring  46  is disposed above the movable iron piece  45 . The spring  46  urges the movable iron piece  45  in a direction in which the movable iron piece  45  separates from the fixed iron core  43 . 
     The stopper member  47  is attached to an attachment portion  42   a  formed upward from the right end of the bobbin  42 . The stopper member  47  has a plate shape and is disposed in the front-back direction. The stopper member  47  is disposed above the movable iron piece  45 . The stopper member  47  restricts the upward movement of the movable iron piece  45  due to the urging force of the spring  46  by a predetermined amount or more. 
     (Magnet Portion  5 ) 
     The magnet portion  5  generates a magnetic field to extend an arc generated between the first fixed contact  62  and the first movable contact  81  and an arc generated between the second fixed contact  72  and the second movable contact  82  in the front-back direction. The magnet portion  5  is disposed around the case  10 . 
       FIG.  7    is a diagram illustrating a disposition relationship between the magnet portion  5  and the first fixed contact  62 , the second fixed contact  72 , the first movable contact  81  and the second movable contact  82 .  FIG.  7    is the diagram as viewed from the right. 
     The magnet portion  5  includes a first magnet  51 , a second magnet  52 , a first yoke  53 , and a second yoke  54 . The first magnet  51  and the second magnet  52  are permanent magnets. The first magnet  51  is disposed on the front surface of the case  10 . The first magnet  51  is disposed in front of the contact device  3 . The second magnet  52  is disposed on the back surface of the case  10 . The second magnet  52  is disposed behind the contact device  3 . The second magnet  52  and the first magnet  51  are disposed so that the opposite poles thereof face each other in the front-back direction with the movable contact piece  8  in between. For example, the south pole of the first magnet  51  is disposed facing the movable contact piece  8  and the north pole of the second magnet  52  is disposed facing the movable contact piece  8 . As a result, a magnetic flux flows between the first magnet  51  and the second magnet  52  from the second magnet  52  toward the first magnet  51  (see arrow B). 
     As illustrated in  FIGS.  1  and  7   , the first yoke  53  has a substantially L-shape when viewed in the left-right direction and is attached to the case  10 . The first yoke  53  is connected to the first magnet  51  so as to cover the outer side (front side) and the upper side of the first magnet  51 . As illustrated in  FIGS.  1  and  7   , the second yoke  54  has a substantially L-shape when viewed in the left-right direction and is attached to the case  10 . The second yoke  54  is connected to the second magnet  52  so as to cover the outer side (back side) and the upper side of the second magnet  52 . In  FIG.  2   , only the second magnet  52  and the second yoke  54  at the back side are illustrated and the first magnet  51  and the first yoke  53  at the front side are omitted. 
     Due to the magnet portion  5  described above, the arc generated between the first fixed contact  62  and the first movable contact  81  and the arc generated between the second fixed contact  72  and the second movable contact  82  extend in the front-back direction (an example of a second direction). 
     (Base  2 ) 
       FIG.  8    is a perspective view illustrating a state where the first fixed terminal  6 , the second fixed terminal  7 , the movable contact piece  8 , and the movable unit  9  are removed from the base  2 . 
     The base  2  includes a bottom surface  21 , a pair of first terminal support portion  22  (an example of the support portion) and second terminal support portion  23  (an example of the support portion). 
     The case  10  is attached to the bottom surface  21 . As illustrated in  FIG.  2   , the drive device  4  is mounted on the bottom surface  21 . As illustrated in  FIG.  8   , the guide portion  24  in which the sliding part  913  of the movable member  91  slides is disposed on the center of the right end of the bottom surface  21 . A pair of walls  26  and  27  is upwardly formed at the left and right sides of the guide portion  24 . A pair of walls  28  and  29  is upwardly formed at the front and back sides of the guide portion  24 . The guide portion  24  is surrounded by the walls  26 ,  27 ,  28 , and  29 . 
     The first terminal support portion  22  supports the first fixed terminal  6 . The second terminal support portion  23  supports the second fixed terminal  7 . The first terminal support portion  22  and the second terminal support portion  23  are disposed in the vicinity of the right end of the bottom surface  21 . The first terminal support portion  22  and the second terminal support portion  23  are disposed facing each other in the front-back direction with the guide portion  24  in between. The first terminal support portion  22  is integrally formed with the wall  28  at the front side of the wall  28 . The second terminal support portion  23  is integrally formed with the wall  29  at the back side of the wall  29 . 
     Through holes  21   a  into which the tips of the first fixed terminal  6  are inserted are formed in the bottom surface  21  at the left and right sides of the first terminal support portion  22 . Through hole  21   b  into which the tips of the second fixed terminal  7  are inserted are formed in the bottom surface  21  at the left and right sides of the second terminal support portion  23 . 
     The first terminal support portion  22  and the second terminal support portion  23  are disposed symmetrically in the front-back direction, and therefore the first terminal support portion  22  will be described as an example. 
       FIG.  9    is an exploded perspective view of the first terminal support portion  22  and the first fixed terminal  6 .  FIG.  10    is a plan view of the first terminal support portion  22  as viewed from above.  FIG.  11    is a side view of the first terminal support portion  22  as viewed from the right. 
     The first terminal support portion  22  is disposed so as to protrude upward from the bottom surface  21 . The first terminal support portion  22  is fitted inside the U-shape of the first fixed terminal  6 . 
     The first terminal support portion  22  has a substantially rectangular parallelepiped shape. As illustrated in  FIGS.  8  and  10   , the first terminal support portion  22  includes a contact surface  22   a , a first side surface  22   b , a first inclined surface  22   c , a second side surface  22   d , a second inclined surface  22   e , and a third side surface  22   f.    
     The contact surface  22   a  is a surface perpendicular to the up-down direction. The contact surface  22   a  contacts the surface  61   a  of the contact support portion  61  of the first fixed terminal  6  when the first fixed terminal  6  is attached to the first terminal support portion  22  (see  FIG.  3   ). 
     The first side surface  22   b  is the right side surface of the first terminal support portion  22 . The first side surface  22   b  is perpendicular to the left-right direction. The first side surface  22   b  faces the first external connection portion  63  of the first fixed terminal  6  when the first fixed terminal  6  is attached to the first terminal support portion  22 . 
     The first inclined surface  22   c  is disposed between the contact surface  22   a  and the first side surface  22   b . The first inclined surface  22   c  is inclined to the lower right. 
     The second side surface  22   d  is the left side surface of the first terminal support portion  22 . The second side surface  22   d  is perpendicular to the left-right direction. The second side surface  22   d  faces the second external connection portion  64  of the first fixed terminal  6  when the first fixed terminal  6  is attached to the first terminal support portion  22 . 
     The second inclined surface  22   e  is disposed between the contact surface  22   a  and the second side surface  22   d . The second inclined surface  22   e  is inclined to the lower left. 
     The third side surface  22   f  is disposed between the first side surface  22   b  and the second side surface  22   d . The right end of the third side surface  22   f  is connected to the first side surface  22   b . The left end of the third side surface  22   f  is connected to the second side surface  22   d . The third side surface  22   f  is perpendicular to the front-back direction. 
     The contact surface  22   a  includes a recess  22   g . The first fixed contact  62  is disposed in a through hole  61   d  formed in the contact support portion  61  (see  FIG.  6   ), and a portion of the first fixed contact  62  that protrudes from the contact support portion  61  opposite to the first movable contact  81  is disposed in the recess  22   g  (see  FIG.  3   ). The recess  22   g  extends to the third side surface  22   f.    
     As illustrated in  FIGS.  9  and  11   , the first side surface  22   b  includes a first groove  221 . The first groove  221  is formed in the up-down direction. The lower end of the first groove  221  is closed and the upper end of the first groove  221  is open at the first inclined surface  22   c . The open part is indicated as an opening  221   a . The first groove  221  includes a first groove portion  221   b  (an example of an opening side portion), a second groove portion  221   c  (an example of a connection portion), and a third groove portion  221   d  (an example of a disposition portion) from the top. 
     The upper end of the first groove portion  221   b  corresponds to the opening  221   a . As illustrated in  FIG.  11   , a width W 1  of the first groove portion  221   b  in the front-back direction is constant. 
     The third groove portion  221   d  is a portion on which the first protrusion  65  is disposed when the first fixed terminal  6  is attached to the first terminal support portion  22 . In  FIG.  11   , the first protrusion  65  when the first fixed terminal  6  is attached to the first terminal support portion  22  is indicated by a chain double-dashed line. Although the first protrusion  65  is disposed in the vicinity of the lower end of the first groove  221 , a position of the first fixed terminal  6  in the up-down direction is determined by the contact surface  22   a , and thus the position of the first protrusion  65  is not limited to the vicinity of the lower end. As illustrated in  FIG.  11   , a width W 3  of the third groove portion  221   d  in the front-back direction is constant. The width W 3  of the third groove portion  221   d  in the front-back direction is slightly larger than the length of the first protrusion  65  on the first external connection portion  63  in the front-back direction. 
     The width W 1  of the first groove portion  221   b  in the front-back direction is larger than the width W 3  of the third groove portion  221   d  in the front-back direction. The second groove portion  221   c  connects the first groove portion  221   b  and the third groove portion  221   d . The width of the second groove portion  221   c  gradually decreases from the first groove portion  221   b  toward the third groove portion  221   d . In the present embodiment, the side walls of the second groove portion  221   c  have a curved shape, but may have a linear shape. 
     As illustrated in  FIG.  9   , the second side surface  22   d  includes a second groove  222  having an opening  222   a  in the second inclined surface  22   e . The second groove  222  has a same shape as the first groove  221 , and therefore the description thereof will be omitted. 
     When the first fixed terminal  6  is attached to the first terminal support portion  22 , as illustrated in  FIG.  9   , the first fixed terminal  6  disposed above the first terminal support portion  22  moves downward with respect to the first terminal support portion  22 . At this time, the first protrusion  65  on the first external connection portion  63  is inserted into the first groove  221  via the opening  221   a  and the second protrusion  66  on the second external connection portion  64  is inserted into the second groove  222  via the opening  222   a . At the same time, the tips  631  and  641  are inserted into the through holes  21   a.    
     Then, the first fixed terminal  6  moves downward until the surface  61   a  of the contact support portion  61  of the first fixed terminal  6  contacts the contact surface  22   a  of the first terminal support portion  22 . As a result, as illustrated in  FIG.  12   , the first fixed terminal  6  is attached to the first terminal support portion  22 . 
     Similarly to the mentioned above, the second fixed terminal  7  is attached to the second terminal support portion  23 . 
     &lt;Operation&gt; 
     Next, an operation of the electromagnetic relay  1  will be described. 
     In a state where no voltage is applied to the coil  41 , the movable member  91  is pressed in the separation direction by elastic force of the return spring  94  and the movable contact piece  8  is positioned at the open position. 
     When a voltage is applied to the coil  41  and the drive device  4  is excited, the movable iron piece  45  is attracted to the fixed iron core  43  and rotates, whereby the movable member  91  is pressed in the contact direction. Accordingly, the movable member  91  moves in the contact direction against the elastic force of the return spring  94 . 
     As the movable member  91  moves in the contact direction, the movable contact piece  8  moves to the closed position. Accordingly, the first movable contact  81  contacts the first fixed contact  62  and the second movable contact  82  contacts the second fixed contact  72 . At this time, the movable contact piece  8  is urged in the contact direction by the contact spring  93 , thereby sufficiently securing contact pressure of the first movable contact  81  against the first fixed contact  62  and contact pressure of the second movable contact  82  against the second fixed contact  72 . When the application of the voltage to the coil  41  is stopped, the movable member  91  moves in the separation direction by the elastic force of the return spring  94  and the movable contact piece  8  returns to the open position. 
     In the embodiment described above, the first fixed terminal  6  includes the first protrusion  65  and the first terminal support portion  22  includes the first groove  221  into which the first protrusion  65  is fitted. As a result, even when external force is applied to a part of the first fixed terminal  6  exposed outside the case  10 , it is possible to reduce a positional deviation of the first fixed terminal  6  in the width direction (the front-back direction). Further, a positional deviation of the first fixed terminal  6  in the up-down direction is regulated by the contact surface  22   a  of the first terminal support portion  22  contacting the surface  61   a  of the contact support portion  61  opposite to the movable contact piece  8 . 
     As illustrated in the front view of  FIG.  3   , the first protrusion  65  and the first groove  221  are disposed in the space opposite to the movable contact piece  8  using the first fixed terminal  6  as a reference. As a result, it is possible to reduce a positional deviation of first fixed terminal  6  without reducing the space where the movable contact piece  8  is disposed by separately providing a regulating portion configured to regulate a positional deviation of the first fixed terminal  6 . 
     Even when a material forming the first terminal support portion  22  is shaved by the first protrusion  65  in the first groove  221 , it is possible to reduce the scattering of shavings to the outside of the first groove  221  by covering the first groove  221  with the first fixed terminal  6 . 
     The first protrusion  65  and the first groove  221  are disposed in the space opposite to the movable contact piece  8  using the first fixed terminal  6  as a reference, whereby it is possible to easily control behavior of arc by the magnet portion  5  without hindering the movement of the arc. 
     The first groove  221  is formed in the direction (the down direction) in which the first external connection portion  63  extends from the end  61   b  of the contact support portion  61 . The first groove  221  includes the opening  221   a  that opens at the end of both ends thereof closer to the contact surface  22   a . The first protrusion  65  is to be inserted into the opening. As a result, the first protrusion  65  can be inserted from the opening  221   a , thereby easily assembling the first fixed terminal  6  to the first terminal support portion  22 . 
     The first groove  221  includes the third groove portion  221   d , the first groove portion  221   b , and the second groove portion  221   c . The first protrusion  65  is disposed on the third groove portion  221   d . The first groove portion  221   b  is disposed closer to the opening  221   a  than the third groove portion  221   d  and the width of the first groove portion  221   b  is larger than the width of the third groove portion  221   d . The width of the second groove portion  221   c  decreases from the first groove portion  221   b  toward the third groove portion  221   d . As a result, the first protrusion  65  can be easily inserted into the first groove  221 . 
     The above-mentioned effects in the first protrusion  65  and the first groove  221  are also achieved in the second protrusion  66  and the second groove  222 . 
     The above-mentioned effects in the configuration of the first terminal support portion  22  and the first fixed terminal  6  are also achieved in the configuration of the second terminal support portion  23  and the second fixed terminal  7 . 
     The first fixed terminal  6  further includes the second external connection portion  64 . The second external connection portion  64  extends from the end  61   c  of the contact support portion  61  parallel to the first external connection portion  63  and the end  61   c  is opposite to the end  61   b . In such the first fixed terminal  6  having a U-shape, it is possible to reduce a positional deviation. 
     As illustrated in  FIG.  5   , the first fixed terminal  6  includes the second protrusion  66 . The second protrusion  66  is disposed on the surface  64   a  connected to the surface  61   a  in the second external connection portion  64 . The first terminal support portion  22  further includes the second side surface  22   d . The second side surface  22   d  includes the second groove  222  into which the second protrusion  66  is fitted. In this case, it is possible to reduce a positional deviation with the two protrusions and the two grooves. 
     As illustrated in  FIG.  3   , the first protrusion  65  and the first groove  221  are disposed in the space opposite to the movable contact piece  8  using the first fixed terminal  6  as a reference. Further, the second protrusion  66  and the second groove  222  are disposed in the space opposite to the movable contact piece  8  using the first fixed terminal  6  as a reference. As a result, it is possible to reduce a positional deviation of the first fixed terminal  6  in a state where behavior of arc can be easily controlled without hindering movement of the arc by the magnet portion  5 . 
     Other Embodiments 
     Although the embodiment of the electromagnetic relay according to one aspect of the present disclosure has been described above, the present disclosure is not limited to the above embodiment and various modifications can be made without departing from the gist of the present disclosure. For example, the configurations of the contact device  3  or the drive device  4  may be changed. 
     In the electromagnetic relay  1  of the above embodiment, the first fixed terminal  6  includes the first protrusion  65  and the second protrusion  66 , but may include either one of them. In this case, only one groove to one protrusion may be provided. 
     As described above, even when only one set of the protrusion and the groove is provided, it is possible to reduce a positional deviation of the first fixed terminal  6  in the front-back direction. 
     In the electromagnetic relay  1  of the above embodiment, the fixed terminal having a U-shape is used, but the shape is not limited to the U-shape and a fixed terminal having an L-shape may be used.  FIG.  13    is a diagram illustrating a first fixed terminal  6 ′ having an L-shape and a first terminal support portion  22 ′ supporting the first fixed terminal  6 ′. The first fixed terminal  6 ′ includes the contact support portion  61 , the first fixed contact  62 , the first external connection portion  63  and the first protrusion  65 . However, unlike the first fixed terminal  6 , the first fixed terminal  6 ′ does not include the second external connection portion  64  or the second protrusion  66 . Unlike the first terminal support portion  22 , the first terminal support portion  22 ′ does not include the second groove  222  in the second side surface  22   d  and only includes the first groove  221  in the first side surface  22   b . The first protrusion  65  is fitted into the first groove  221 . As a result, it is possible to regulate a positional deviation in the front-back direction. 
     In the electromagnetic relay  1  of the above embodiment, the first protrusion  65  and the second protrusion  66  have a cylindrical shape, but the shape is not limited to this and may have a polygonal pillar shape such as quadrangular prism. 
     In the electromagnetic relay  1  of the above embodiment, the first groove  221  and the second groove  222  are formed symmetrically in the front-back direction, but may not be formed symmetrically. For example, the back ends of the first groove portion  221   b , the second groove portion  221   c , and the third groove portion  221   d  may be formed linearly in the up-down direction, and the positions of their front ends may be different in each of the grooves. 
     In the first groove  221  of the electromagnetic relay  1  of the above embodiment, the width of the first groove portion  221   b  and the width of the third groove portion  221   d  are constant and the width of the first groove  221  decreases in the second groove portion  221   c . However, the width of the first groove  221  may gradually decrease entirely. The width of the second groove  222  may gradually decrease entirely. 
     REFERENCE NUMERALS 
     
         
           1 : Electromagnetic relay 
           6 : First fixed terminal 
           8 : Movable contact piece 
           22 : First terminal support portion 
           22   a : Contact surface 
           22   b : First side surface 
           61 : Contact support portion 
           61   a : Surface 
           62 : First fixed contact 
           63 : First external connection portion 
           63   a : Surface 
           65 : First protrusion 
           221 : First groove