Patent Publication Number: US-11387063-B2

Title: Contact point device and electromagnetic relay

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. national stage application of the PCT International Application No. PCT/JP2019/036815 filed on Sep. 19, 2019, which claims the benefit of foreign priority of Japanese patent application No. 2018-213165 filed on Nov. 13, 2018, the contents all of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a contact point device and an electromagnetic relay, and more particularly to a contact point device including a fixed contact and a movable contactor, and an electromagnetic relay including this contact point device. 
     BACKGROUND ART 
     The electromagnetic relay described in PTL 1 includes a pair of fixed contacts, a movable contact that contacts and separates the pair of fixed contacts, and a drive device that drives a movable shaft to cause the movable contactor to contact and separate the pair of fixed contacts. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Unexamined Japanese Patent Publication No. 2016-201286 
     SUMMARY OF THE INVENTION 
     A contact point device according to one aspect of the present disclosure includes: a fixed contact; a movable contactor that has a movable contact capable of being in contact with the fixed contact by moving in parallel with a first direction; a containing chamber that contains the fixed contact and the movable contact; and a shielding wall disposed inside the containing chamber, wherein the shielding wall is located in the first direction from the fixed contact and the movable contact when viewed in a second direction orthogonal to the first direction, the shielding wall extends along the first direction, and the shielding wall is provided with one or a plurality of through holes that penetrate the shielding wall. 
     The electromagnetic relay according to one aspect of the present disclosure includes the contact point device and an electromagnet device. The electromagnet device has an exciting coil. 
     The contact point device and the electromagnetic relay of the present disclosure can improve arc extinguishing performance. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a shielding member of an electromagnetic relay according to one exemplary embodiment. 
         FIG. 2  is a cross-sectional view of the same electromagnetic relay as viewed from the front. 
         FIG. 3  is a plan view of the shielding member of the same electromagnetic relay. 
         FIG. 4  is a cross-sectional view of the same electromagnetic relay as viewed from the side. 
         FIG. 5  is a cross-sectional view of an electromagnetic relay according to a comparative example with the one exemplary embodiment as viewed from the side. 
         FIG. 6  is an explanatory view of arc behavior in the electromagnetic relay according to the one exemplary embodiment. 
         FIG. 7A  is an explanatory view of arc behavior in an electromagnetic relay according to a comparative example with the one exemplary embodiment. 
         FIG. 7B  is an explanatory diagram of arc behavior in the electromagnetic relay according to the comparative example with the one exemplary embodiment. 
         FIG. 8  is a cross-sectional view of the electromagnetic relay according to a first modification of the one exemplary embodiment as viewed from the side. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     Hereinafter, a contact point device and an electromagnetic relay according to an exemplary embodiment will be described with reference to the drawings. However, the following exemplary embodiment is only one of the various exemplary embodiments of the present disclosure. The following exemplary embodiment can be variously modified according to design and the like as long as an object of the present disclosure can be achieved. Further, each figure described in the following exemplary embodiment is a schematic view, and each ratio of a size and a thickness of each component in the figure does not necessarily reflect an actual dimensional ratio. 
     Electromagnetic relay  1  (see  FIG. 2 ) is provided in, for example, an electric vehicle or the like. Electromagnetic relay  1  switches, for example, presence or absence of supply of a current from a power source to a motor of an electric vehicle. 
     As shown in  FIG. 2 , electromagnetic relay  1  of the present exemplary embodiment includes contact point device  2  and electromagnet device  5 . Electromagnetic relay  1  further includes housing  9  that contains contact point device  2  and electromagnet device  5 . Housing  9  is airtight. As shown in  FIG. 2 , contact point device  2  includes a plurality of (two in  FIG. 2 ) fixed contacts  211 , movable contactor  22 , and shielding member  3 . Contact point device  2  further includes a plurality of (two in  FIG. 2 ) fixed terminals  21 , contact pressure spring  23 , holder  24 , drive shaft  25 , inner case  41 , joining body  42 , and magnetic flux generator  43 . 
     In the following, a direction in which each fixed contact  211  and corresponding movable contact  222  are disposed side by side is defined as an up-down direction, and a side of fixed contact  211  as viewed from movable contact  222  is defined as an upper side, and a side of movable contact  222  as viewed from fixed contact  211  is defined as a lower side. Further, in electromagnetic relay  1 , a direction in which two fixed contacts  211  are disposed side by side is defined as a right-left direction. However, these directions are not intended to limit a direction in which electromagnetic relay  1  is used. 
     Each of the plurality of fixed terminals  21  is formed of a conductive material such as copper. A shape of each of fixed terminals  21  is cylindrical. Each of fixed terminals  21  is inserted into a through hole  411  formed in inner case  41 . Further, each of fixed terminals  21  is inserted into through hole  911  formed in housing  9 . Each of fixed terminals  21  is bonded to inner case  41  by brazing in a state where an upper end of fixed terminal  21  is protruded from an upper surface of inner case  41  and an upper surface of housing  9 . 
     The plurality of fixed terminals  21  correspond to the plurality of fixed contacts  211  one-to-one. Corresponding fixed contact  211  is attached to a lower end of each of fixed terminals  21 . Each of fixed contacts  211  may be formed integrally with fixed terminal  21 . 
     Movable contactor  22  is formed into a flat plate shape. Movable contactor  22  moves in a direction D 1  (up-down direction). Movable contactor  22  extends along direction D 2  (right-left direction) orthogonal to direction D 1 . That is, a longitudinal direction of movable contactor  22  is along the right-left direction. Movable contactor  22  has the plurality of (two in  FIG. 2 ) movable contacts  222 . The plurality of movable contacts  222  are provided at both end portions in the right-left direction on an upper surface of movable contactor  22 . The plurality of movable contacts  222  correspond to the plurality of fixed contacts  211  one-to-one. Each of movable contacts  222  faces corresponding fixed contact  211 . In the present exemplary embodiment, the plurality of movable contacts  222  are integrated with portions other than the plurality of movable contacts  222  in movable contactor  22 , but may be separate bodies. 
     Each of movable contacts  222  moves in direction D 1  (up-down direction) and forms either a state in contact with corresponding fixed contact  211  or a state separated from corresponding fixed contact  211 . More particularly, electromagnet device  5  generates an electromagnetic force that drives movable contactor  22 , and movable contactor  22  is driven, so that each of movable contacts  222  is put into the state in contact with corresponding fixed contact  211  from the state separated from corresponding fixed contact  211 . This allows two fixed contacts  211  to be electrically conducted. When electromagnet device  5  does not generate the electromagnetic force, a spring force of return spring  55  included in electromagnet device  5  puts each of movable contacts  222  into the state separated from corresponding fixed contact  211 . This puts two fixed contacts  211  into a state not electrically conducted. 
     A direction in which each of fixed contacts  211  and corresponding movable contact  222  face each other coincides with direction D 1  in which movable contactor  22  and each of movable contacts  222  of movable contactor  22  move. 
     Holder  24  has upper wall  241  and lower wall  242 . Upper wall  241  and lower wall  242  face each other in the up-down direction. Movable contactor  22  is passed between upper wall  241  and lower wall  242 . 
     Contact pressure spring  23  is, for example, a compression coil spring. Contact pressure spring  23  is disposed between lower wall  242  of holder  24  and movable contactor  22  in a state where an expansion and contraction direction is directed in the up-down direction. Contact pressure spring  23  applies an upward spring force to movable contactor  22 . That is, contact pressure spring  23  applies, to movable contactor  22 , a spring force in a direction approaching the plurality of fixed contacts  211 . 
     A shape of drive shaft  25  is a round rod shape. An axial direction of drive shaft  25  is along the up-down direction. An upper end of drive shaft  25  is coupled to holder  24 . Drive shaft  25  is connected to movable contactor  22  via holder  24 . A lower end of drive shaft  25  is coupled to movable iron core  53  included in electromagnet device  5 . Drive shaft  25  moves in the up-down direction as a state of electromagnet device  5  switches between a state where the electromagnetic force is generated and a state where the electromagnetic force is not generated. Along with this, holder  24  moves in the up-down direction, and movable contactor  22  passed through holder  24  moves in the up-down direction. That is, movable contactor  22  moves in the direction (direction D 1 ) in which fixed contacts  211  and movable contacts  222  face each other. In short, drive shaft  25  moves movable contactor  22  in direction D 1 . Therefore, drive shaft  25  moves movable contactor  22  between the state where each of movable contacts  222  is in contact with corresponding fixed contact  211  and the state where movable contact  222  is separated from corresponding fixed contact  211 . 
     Inner case  41  is formed of a heat-resistant material such as ceramic. A shape of inner case  41  is a box shape with a lower surface open. Two through holes  411  disposed in the right-left direction are formed on the upper surface of inner case  41 . A space inside inner case  41  is containing chamber  410  that contains the plurality of fixed contacts  211  and the plurality of movable contacts  222 . That is, contact point device  2  includes containing chamber  410 . Containing chamber  410  is filled with an arc-extinguishing gas such as hydrogen, and is sealed. Containing chamber  410  does not have to be sealed and may be connected to an external environment. 
     A shape of joining body  42  is a rectangular frame shape. Joining body  42  is bonded to inner case  41  by brazing. Further, joining body  42  is bonded to yoke  54  included in electromagnet device  5  by brazing. This allows joining body  42  to be joined to inner case  41  and yoke  54 . 
     Shielding member  3  has electrical insulation. Shielding member  3  is formed of an electrically insulating material such as ceramic or synthetic resin. Shielding member  3  is contained in containing chamber  410 . Here, in contact point device  2 , when each of movable contacts  222  enters the state separated from corresponding fixed contact  211  from the state in contact with corresponding fixed contact  211 , an arc may be generated between movable contact  222  and fixed contact  211 . Shielding member  3  shields the arc generated between fixed contact  211  and movable contact  222 . Details of a configuration of shielding member  3  will be described later. 
     Magnetic flux generator  43  has a pair of permanent magnets  431 . The pair of permanent magnets  431  is disposed and fixed between an outer surface of inner case  41  and an inner surface of housing  9 . The pair of permanent magnets  431  is disposed outside two fixed contacts  211  in the direction in which two fixed contacts  211  are disposed side by side (direction D 2 ). Each of permanent magnets  431  is disposed at a position aligned with movable contactor  22  in direction D 2 . That is, the pair of permanent magnets  431  faces movable contactor  22  in the longitudinal direction (right-left direction) of movable contactor  22 . Here, the situation where the pair of permanent magnets  431  faces movable contactor  22  includes a case where a member such as inner case  41  is disposed between each of permanent magnets  431  and movable contactor  22  as in the present exemplary embodiment. The pair of permanent magnets  431  has different poles facing each other. For example, in  FIG. 2 , permanent magnet  431  on the right side has a north pole directed to the left, and permanent magnet  431  on the left side has a south pole directed to the right. The pair of permanent magnets  431  generates a magnetic flux directed in direction D 2  between each of fixed contacts  211  and corresponding movable contact  222 . The magnetic flux directed in direction D 2  preferably exists around each of fixed contacts  211  or each of movable contacts  222 . 
     Electromagnetic relay  1  further includes a pair of cross-linking portions  44 . The pair of cross-linking portions  44  is formed of a magnetic material. One of the pair of cross-linking portions  44  is disposed on a front side of a paper surface of  FIG. 2  when viewed from movable contactor  22 , and the other is disposed on a back side of the paper surface of  FIG. 2  when viewed from movable contactor  22 . The pair of cross-linking portions  44  is disposed, bridging between the pair of permanent magnets  431 . 
     Electromagnet device  5  includes exciting coil  51 , coil bobbin  52 , movable iron core  53 , yoke  54 , return spring  55 , cylindrical member  56 , and bush  57 . Further, electromagnet device  5  includes a pair of coil terminals that both ends of exciting coil  51  are connected to. Each of the coil terminals is formed of a conductive material such as copper, and is connected to a lead wire by solder or the like. 
     Coil bobbin  52  is formed of a resin or the like as a material. Coil bobbin  52  has two flanges  521 ,  522  and cylindrical portion  523 . Exciting coil  51  is wound around cylindrical portion  523 . Flange  521  extends outward in a radial direction of cylindrical portion  523  from an upper end of cylindrical portion  523 . Flange  521  extends outward in the radial direction of cylindrical portion  523  from a lower end of cylindrical portion  523 . 
     A shape of cylindrical member  56  is a bottomed cylindrical shape with an upper end open. Cylindrical member  56  is contained in cylindrical portion  523  of coil bobbin  52 . 
     Movable iron core  53  is formed of a magnetic material. A shape of movable iron core  53  is cylindrical. Movable iron core  53  is contained in cylindrical member  56 . Drive shaft  25  is passed through an inside of movable iron core  53 , and movable iron core  53  and drive shaft  25  are joined to each other. Movable iron core  53  is formed with recess  531  that is recessed downward from an upper surface. 
     Yoke  54  forms at least a part of a magnetic circuit through which a magnetic flux generated in exciting coil  51  passes when exciting coil  51  is energized. Yoke  54  includes plate-shaped first yoke  541  (one yoke), plate-shaped second yoke  542 , and a pair of plate-shaped third yokes  543 . First yoke  541  is disposed between movable contactor  22  and exciting coil  51 . First yoke  541  is in contact with an upper surface of coil bobbin  52 . Second yoke  542  is in contact with a lower surface of coil bobbin  52 . The pair of third yokes  543  extends from right and left ends of second yoke  542  to first yoke  541 . A shape of first yoke  541  is a rectangular plate shape. Insertion hole  544  is formed in a substantially center of first yoke  541 . Drive shaft  25  is passed through insertion hole  544 . 
     Return spring  55  is, for example, a compression coil spring. A first end of return spring  55  in an expansion and contraction direction (up-down direction) is in contact with first yoke  541 , and a second end is in contact with a bottom surface of recess  531  of movable iron core  53 . Return spring  55  applies a spring force to movable iron core  53  to move movable iron core  53  downward. 
     Bush  57  is formed of a magnetic material. A shape of bush  57  is cylindrical. Bush  57  is disposed between an inner peripheral surface of coil bobbin  52  and an outer peripheral surface of cylindrical member  56 . Bush  57 , together with first to third yokes  541  to  543  and movable iron core  53 , forms the magnetic circuit through which the magnetic flux generated when exciting coil  51  is energized passes. 
     When exciting coil  51  is energized, the magnetic flux generated by exciting coil  51  passes through the magnetic circuit, so that movable iron core  53  moves to make a magnetic resistance of the magnetic circuit smaller. Specifically, when exciting coil  51  is energized, movable iron core  53  moves upward to fill a gap between first yoke  541  and the upper end of movable iron core  53  in the magnetic circuit. More particularly, the electromagnetic force that moves movable iron core  53  upward exceeds the force (spring force) by return spring  55  pushing movable iron core  53  downward, so that movable iron core  53  moves upward. As a result, movable contactor  22  moves upward, and each of movable contacts  222  enters the state in contact with corresponding fixed contact  211 . That is, movable contactor  22  moves above the position in  FIG. 2  together with holder  24 , drive shaft  25 , and movable iron core  53 . 
     When exciting coil  51  enters a state not energized from a state energized, the electromagnetic force that moves movable iron core  53  upward disappears, so that movable iron core  53  moves downward due to the spring force of return spring  55 . As a result, movable contactor  22  moves downward, and each movable contact  222  enters the state separated from corresponding fixed contact  211  (position shown in  FIG. 2 ). 
     Next, shielding member  3  will be described in detail with reference to  FIG. 1 . 
     As shown in  FIG. 1 , shielding member  3  has base  31 , a plurality of (two in  FIG. 1 ) side walls  32 , and a plurality of (two in  FIG. 1 ) partition walls  33 . Further, contact point device  2  includes wall portion  34 . Wall portion  34  is integrally formed with shielding member  3 . 
     A shape of base  31  is a rectangular plate shape. A longitudinal direction of base  31  is along the longitudinal direction (right-left direction) of movable contactor  22 . A thickness direction of base  31  is along direction D 1  (up-down direction). Here, the longitudinal direction of movable contactor  22  is along direction D 2 . That is, movable contactor  22  extends in direction D 2 . Direction D 2  is orthogonal to direction D 1 . The thickness direction of base  31  is along a thickness direction of first yoke  541  (see  FIG. 2 ), and base  31  is in contact with first yoke  541 . Base  31  (cover) is disposed between first yoke  541  and movable contactor  22 , and covers first yoke  541 . Further, base  31  has electrical insulation. 
     The plurality (two) of side walls  32  protrude from one surface  310  (upper surface) of base  31  in the thickness direction of base  31 . That is, side walls  32  protrude upward from upper surface  310  of base  31 . A shape of each of side walls  32  is tubular. A part of a lower opening of side wall  32  is covered with a plate-shaped bottom wall  315  (described later). One of side wall  32  is provided on one side (left side) of base  31  in the longitudinal direction, and other side wall  32  is provided on the other side (right side) of base  31  in the longitudinal direction. Here, the longitudinal direction of base  31  coincides with direction D 2 . 
     An axial direction of tubular wall portion  34  is along the thickness direction of base  31 . Here, the thickness direction of base  31  coincides with direction D 1 . Wall portion  34  is disposed between two side walls  32 . As shown in  FIG. 1 , drive shaft  25  (see  FIG. 2 ) is passed through hole  341  surrounded by wall portion  34  and formed through base  31 . 
     In the following, unless otherwise specified, a description will focus on one side wall  32  of two side walls  32 , but other side wall  32  also has the same configuration. 
     Side wall  32  includes first side wall  321 , second side wall  322 , third side wall  323 , and fourth side wall  324 . First side wall  321  and third side wall  323  face each other. Second side wall  322  and fourth side wall  324  face each other. Second side wall  322  and fourth side wall  324  connect first side wall  321  and third side wall  323 . When viewed from the thickness direction of base  31  (direction D 1 ), a shape of side wall  32  is a substantially rectangular shape having first side wall  321 , second side wall  322 , third side wall  323 , and fourth side wall  324  as four sides. 
     In the present exemplary embodiment, a corner formed by second side wall  322  and third side wall  323  is rounded. Similarly, a corner formed by third side wall  323  and fourth side wall  324  is also rounded. 
     Side wall  32  extends in the direction (direction D 1 ) in which fixed contact  211  and movable contact  222  face each other. Specifically, side wall  32  has a plurality of surfaces along direction D 1 . More particularly, in each of first side wall  321 , second side wall  322 , third side wall  323 , and fourth side wall  324 , surfaces on both sides in the thickness direction are along direction D 1 . 
     An internal space of side wall  32  (that is, a space surrounded by first side wall  321 , second side wall  322 , third side wall  323 , and fourth side wall  324 ) is a shielded chamber that the arc generated between fixed contact  211  and movable contact  222  can enter. That is, the shielded chamber is extension space  320  where the arc can be extended. Each of partition wall  33 , first side wall  321 , second side wall  322 , third side wall  323 , and fourth side wall  324  is a part of shielding wall  35  that shields the arc, and faces extension space  320 . Shielding wall  35  is disposed inside containing chamber  410 . Inside containing chamber  410 , first side wall  321 , second side wall  322 , third side wall  323 , and fourth side wall  324  of side wall  32  surround extension space  320 . First side wall  321 , second side wall  322 , third side wall  323 , and fourth side wall  324  form a boundary between an inside and an outside of extension space  320 . The arc is extended toward extension space  320 , so that an arc voltage increases. Increasing the arc voltage makes it easier for the arc to release energy and reduces time required for extinction of the arc. In addition, magnitudes of a current and a voltage that can be shielded in contact point device  2  increase. 
     Since contact point device  2  is provided with two side walls  32 , contact point device  2  is also provided with two extension spaces  320 . Two extension spaces  320  correspond to two fixed contacts  211  one-to-one, and correspond to two movable contacts  222  one-to-one. Unless otherwise specified, a relationship between one of two extension spaces  320 , and fixed contact  211  and movable contact  222  corresponding to one extension space  320  will be described below. However, a relationship between other extension space  320 , and fixed contact  211  and movable contact  222  corresponding to other extension space  320  is also similar. 
     Extension space  320  is provided at a position facing one of fixed contact  211  and movable contact  222  in the direction (direction D 1 ) in which fixed contact  211  and movable contact  222  face each other. Extension space  320  is provided in a region on a side opposite to a side where the other contact (here, fixed contact  211 ) is located with respect to one of fixed contact  211  and movable contact  222  (here, movable contact  222 ).  FIG. 3  illustrates a state where fixed contacts  211  are projected onto projection surfaces P 1  with the-up-down direction (direction D 1 : see  FIG. 2 ) as a normal line. Extension spaces  320  are provided at positions overlapping projection surfaces P 1 . 
     Partition wall  33  has electrical insulation. Partition wall  33  has a plate shape. Partition wall  33  is disposed in extension space  320 , and divides extension space  320  into a plurality of spaces (first space SP 1  and second space SP 2 ). Partition wall  33  is a part of shielding wall  35  that shields the arc. Partition wall  33  is disposed at a center of extension space  320 . Partition wall  33  is disposed at a position overlapping each of projection surfaces P 1 . That is, partition wall  33  is disposed at a position overlapping fixed contact  211  when viewed in direction D 1 . Shielding wall  35  and partition wall  33  of shielding wall  35  are disposed in a region on the side opposite (lower side of movable contact  222 ) to the side where the other (here, fixed contact  211 ) is located (upper side of movable contact  222 ) with respect to any one of fixed contact  211  and movable contact  222  (here, movable contact  222 ). 
     More particularly, partition wall  33  is located below movable contactor  22 . Partition wall  33  is formed to bridge first side wall  321  and third side wall  323 . That is, partition wall  33  extends along direction D 2  when viewed in direction D 1 . Further, partition wall  33  is connected to base  31 . A thickness direction of partition wall  33  is along direction D 3 . Direction D 3  is a direction orthogonal to first direction D 1  and direction D 2 . Partition wall  33  has surface  331  along the direction (direction D 1 ) in which fixed contact  211  and movable contact  222  face each other. Partition wall  33  divides between first space SP 1  and second space SP 2  inside containing chamber  410  in direction D 3  when viewed in direction D 2 . More particularly, partition wall  33  divides extension space  320  into two spaces. That is, partition wall  33  divides extension space  320  into first space SP 1  between partition wall  33  and second side wall  322  and second space SP 2  between partition wall  33  and fourth side wall  324  (see  FIG. 1 ). Therefore, extension space  320  includes first space SP 1  and second space SP 2 . At least one of first space SP 1  and second space SP 2  is at least a part of extension space  320  where the arc can be extended. 
     Partition wall  33  is formed with through hole  332  that penetrates partition wall  33  in a direction intersecting with direction D 1 . Specifically, through hole  332  penetrates partition wall  33  in direction D 3  orthogonal to direction D 1 . First space SP 1  and second space SP 2  are connected by through hole  332 . Partition wall  33  has first end  337  (upper end) and second end  338  (lower end) in the direction (direction D 1 ) in which fixed contact  211  and movable contact  222  face each other. In partition wall  33 , through hole  332  is formed in second end  338  of first end  337  and second end  338 , which is located on a side farther from fixed contact  211 . In other words, through hole  332  is provided at a lower (in the first direction) end portion of partition wall  33 . 
     In shielding member  3 , side wall  32  and bottom wall  315  form an outer wall of extension space  320 . Bottom wall  315  is a part of base  31 . Side wall  32  and bottom wall  315  divide containing chamber  410  (see  FIG. 4 ) into extension space  320  and an external space adjacent to extension space  320 . Bottom wall  315  faces extension space  320  in direction D 1 . That is, bottom wall  315  faces first space SP 1  and second space SP 2 . Bottom wall  315  covers a lower opening of tubular side wall  32 . A thickness direction of bottom wall  315  is along the direction in which fixed contact  211  and movable contact  222  face each other (direction D 1 ). 
     Extension space  320  is a space between movable contact  222  and bottom wall  315 . Partition wall  33  is disposed in extension space  320 . That is, partition wall  33  of shielding wall  35  is disposed between movable contact  222  and bottom wall  315  when viewed in direction D 2 . Bottom wall  315  and shielding wall  35  are connected. Partition wall  33  of shielding wall  35  protrudes in the thickness direction (upward) from bottom wall  315 . Side wall  32  of shielding wall  35  protrudes from a peripheral edge of bottom wall  315  in the thickness direction (upward) of bottom wall  315 . That is, side wall  32  protrudes from the peripheral edge of bottom wall  315  along the direction in which fixed contact  211  and movable contact  222  face each other (direction D 1 ). 
     Passage hole  316  is formed in bottom wall  315 . Passage hole  316  is a through hole that penetrates bottom wall  315  in direction D 1  (the thickness direction of bottom wall  315 ). Passage hole  316  is provided at a position overlapping partition wall  33  in bottom wall  315  when viewed in direction D 1 . Passage hole  316  in bottom wall  315  is connected to through hole  332  in partition wall  33  of shielding wall  35 . Passage hole  316  is covered with first yoke  541  (see  FIG. 2 ). 
     In the present exemplary embodiment, through hole  332  is formed by partition wall  33  having a cutout in the lower end portion. 
     Passage hole  316  is formed at a position straddling first space SP 1  and second space SP 2  of extension space  320 . Therefore, first space SP 1  and second space SP 2  are connected through passage hole  316 . As mentioned above, passage hole  316  is covered with first yoke  541  (see  FIG. 2 ). However, passage hole  316  forms a space at least as thick as bottom wall  315  between first space SP 1  and second space SP 2 . Therefore, passage hole  316  contributes to movement of gas between first space SP 1  and second space SP 2 . 
     A plurality of (two in  FIG. 1 ) through holes  328  are formed in first side wall  321  of side wall  32 . Through holes  328  in first side wall  321  penetrate in the direction intersecting with direction D 1 . Particularly, through holes  328  penetrate in direction D 2  orthogonal to direction D 1 . One of through holes  328  is connected to first space SP 1  of extension space  320 , and other through hole  328  is connected to second space SP 2  of extension space  320 . First space SP 1  and second space SP 2  of extension space  320  are connected to the outside of extension space  320  by the plurality of through holes  328 . More particularly, first space SP 1  and second space SP 2  are connected, by the plurality of through holes  328 , to a space where tubular wall portion  34  is disposed. 
     Base  31  is formed with a plurality of (four, see  FIG. 3 ) base holes  318 . Each of the plurality of base holes  318  penetrates base  31  in the thickness direction (direction D 1 ) of base  31 . The plurality of base holes  318  correspond to two through holes  328  in each of two side walls  32  (i.e., a total of four through holes  328 ) one-to-one. Each of base holes  318  is connected to corresponding through hole  328 . Base  31  may not have base holes  318 . 
     Wall portion  34  is aligned with side walls  32  in the direction (direction D 2 ) orthogonal to the direction in which fixed contacts  211  and movable contacts  222  face each other (direction D 1 ). Wall portion  34  surrounds drive shaft  25  (see  FIG. 2 ) in containing chamber  410 . When foreign matter is scattered due to an air flow or the like generated by the arc, it is difficult for the foreign matter to intrude a side of drive shaft  25  beyond wall portion  34 , so that driving of drive shaft  25  can be prevented from being hindered by the intrusion of the foreign matter. 
       FIG. 4  is a cross-sectional view of electromagnetic relay  1  along a plane (hereinafter referred to as plane P 2 . See  FIG. 3 ) along the direction (direction D 1 ) in which fixed contact  211  and movable contact  222  face each other. In  FIG. 4 , virtual route R 5  is a route inside containing chamber  410  and is a route on plane P 2 . Virtual route R 5  goes around movable contact  222  on plane P 2  to connect fixed contact  211  and movable contact  222 . Virtual route R 5  is a route that bypasses outside a space between fixed contact  211  and movable contact  222 . Virtual route R 5  may go around fixed contact  211  instead of movable contact  222  to connect fixed contact  211  and movable contact  222 . This virtual route R 5  exemplifies a route followed by the arc generated between fixed contact  211  and movable contact  222  when partition wall  33  is not disposed in extension space  320 . Virtual route R 5  connects one end  218  of fixed contact  211  in direction D 3  (an end on the left side of a paper surface in  FIG. 4 ) and one end  228  of movable contact  222  on a side opposite to a side where one end  218  of fixed contact  211  is located in direction D 3  (an end on the right side of the paper surface in  FIG. 4 ). Here, direction D 3  is a direction orthogonal to direction D 1  and direction D 2 . Direction D 2  is a direction that intersects with plane P 2  running along direction D 1 . 
     One end  218  of fixed contact  211  in direction D 3  is, for example, a region of a surface of fixed contact  211  whose normal direction is along the left direction. That is, one end  218  of fixed contact  211  in direction D 3  corresponds not only to a point located at a most end (here, the left end in this case) on the surface of fixed contact  211 , but also to the region including this point. One end  228  of movable contact  222  is, as one example, a region of a surface of movable contact  222  whose normal direction is along the right direction. That is, one end  228  of movable contact  222  in direction D 3  corresponds not only to a point located at a most end (here, the right end) on the surface of movable contact  222 , but also to the region including this point. 
     Partition wall  33  is disposed on virtual route R 5 . Specifically, partition wall  33  has a plate shape, and the thickness direction of partition wall  33  is a direction (direction D 3 ) along plane P 2  along direction D 1 . Partition wall  33  extends in a direction orthogonal to plane P 2 . 
     The magnetic flux generated by the pair of permanent magnets  431  (see  FIG. 2 ) of magnetic flux generator  43  (see  FIG. 2 ) intersects with plane P 2 . That is, the pair of permanent magnets  431  generates, around fixed contact  211 , the magnetic flux intersecting with plane P 2 . In short, between fixed contact  211  and movable contact  222 , the direction of the magnetic flux is direction D 2  (a depth direction of the paper surface in  FIG. 4 ). The pair of permanent magnets  431  faces movable contactor  22  in the direction intersecting with plane P 2  (direction D 2 ). 
     Next, one example of arc behavior when the arc is generated between fixed contact  211  and movable contact  222  in containing chamber  410  will be described with reference to  FIGS. 4, 5 . In  FIG. 4 , alternate long and short dash lines A 1  to A 3  virtually represent movement routes of the generated arc. Similarly, in  FIG. 5 , alternate long and short dash lines A 5 , A 6  virtually represent movement routes of the generated arc.  FIG. 5  is a view showing electromagnetic relay  1 Q as a comparative example with electromagnetic relay  1  of the exemplary embodiment. Electromagnetic relay  1 Q differs from electromagnetic relay  1  of the exemplary embodiment in that electromagnetic relay  1 Q includes, instead of shielding member  3 , shielding member  3 Q that does not have partition wall  33 . 
     In  FIG. 4 , the arc moves due to Lorentz force. That is, the magnetic flux generated by the pair of permanent magnets  431  (see  FIG. 2 ) of magnetic flux generator  43  (see  FIG. 2 ) is along direction D 2 . Since a direction of a current in the arc is approximately along direction D 1 , the Lorentz force in direction D 3  (toward the left of the paper surface in  FIG. 4 ) orthogonal to direction D 1  and direction D 2  acts on the arc extending in direction D 1 . 
     The arc is extended by the Lorentz force. White arrows shown in  FIG. 4  represent a process in which the arc is extended. That is, the generated arc is extended from a position indicated by alternate long and short dash line A 1  to a position indicated by alternate long and short dash line A 3  via a position indicated by alternate long and short dash line A 2  inside containing chamber  410 . By being extended in this way, the arc reaches extension space  320 . 
     Here, since partition wall  33  is disposed in extension space  320 , it is difficult for the arc to move beyond partition wall  33  from first space SP 1  to second space SP 2 . Therefore, as compared with a case without partition wall  33 , a possibility is higher that a state is maintained where the arc is extended on a front side of partition wall  33  (on the left side of the paper surface in  FIG. 4 ) (in other words, stays in first space SP 1 ) in extension space  320 . 
     If partition wall  33  is not disposed in extension space  320  as shown in  FIG. 5 , the arc may be further extended and go around movable contactor  22  as indicated by alternate long and short dash line A 5 . Then, there is a higher possibility that the extended arc reaches one end  228  of movable contact  222  on the side opposite to the side where one end  218  of fixed contact  211  is located in direction D 3 . When the arc reaches one end  228  of movable contactor  22 , the arc may transfer to a position that linearly connects fixed contact  211  and movable contact  222  (see alternate long and short dash line A 6  in  FIG. 5 ). That is, the extended arc indicated by alternate long and short dash line A 5  can return to an arc having a shorter length. When such a relatively short arc is generated, there is a possibility that the arc voltage decreases, that the time required for extinguishing the arc increases or the like, and that arc extinguishing performance of electromagnetic relay  1 Q deteriorates. 
     In electromagnetic relay  1  of the present exemplary embodiment, as indicated by alternate long and short dash line A 3  in  FIG. 4 , it is easy to maintain the arc in the extended state without transferring the arc. Therefore, electromagnetic relay  1  of the present exemplary embodiment has higher arc extinguishing performance than electromagnetic relay  1 Q according to the comparative example. 
     Next, a function of through hole  332  formed in partition wall  33  will be described with reference to  FIGS. 6, 7A, 7B . In order to make it easier to compare electromagnetic relay  1 R shown in  FIG. 6  with electromagnetic relay  1 S shown in  FIGS. 7A, 7B , in electromagnetic relays  1 R,  1 S, through holes  328  (see  FIG. 4 ) are not formed in first side walls  321 R,  321 S of shielding members  3 R,  3 S, and passage holes  316  are not formed in bottom walls  315 R,  315 S. In electromagnetic relay  1 R shown in  FIG. 6 , through hole  332  is formed in partition wall  33 . On the other hand, in electromagnetic relay  1 S shown in  FIGS. 7A, 7B , through hole  332  is not formed in partition wall  33 S. 
     In electromagnetic relay  1 R shown in  FIG. 6 , the arc generated between fixed contact  211  and movable contact  222  passes the positions indicated by alternate long and short dash lines A 1 , A 2 , A 3  as indicated by the white arrows in  FIG. 6 , and extends to first space SP 1  of extension space  320 . Here, there is a possibility that the arc generates an air flow of gas in containing chamber  410 . The air flow generated in first space SP 1  of extension space  320  easily flows to second space SP 2  through hole  332  as indicated by arrow  100 . Therefore, in the arc, the air flow generated in first space SP 1  is hard to be pushed back to the side of fixed contact  211 , and the extended state is easily maintained as indicated by alternate long and short dash line A 3 . 
     On the other hand, in electromagnetic relay  1 S shown in  FIG. 7A , as in electromagnetic relay  1 R shown in  FIG. 6 , the arc generated between fixed contact  211  and movable contact  222  passes the positions indicated by alternate long and short dash lines A 1 , A 2 , A 3 , and is extended to first space SP 1  of extension space  320  (see white arrows in  FIG. 7A ). Here, when an air flow is generated by the arc, the arc may be pushed back to the side where fixed contact  211  and movable contact  222  are located by a pressure of the air flow, as indicated by a white arrow in  FIG. 7B , and an arc length may be relatively short as indicated by alternate long and short dash line A 7 . Therefore, it is difficult for the arc to be maintained in the extended state inside extension space  320  as compared with electromagnetic relay  1 R shown in  FIG. 6 . 
     In electromagnetic relay  1  according to the present exemplary embodiment shown in  FIG. 4 , the air flow generated in extension space  320  can flow out through the plurality of through holes  328  in side wall  32  and passage hole  316  in bottom wall  315 . Therefore, it is possible to reduce the possibility that the arc that has moved from a vicinity of fixed contact  211  to extension space  320  is pushed back to the side of fixed contact  211  by the air flow. As a result, the arc is more easily extended than the case where the plurality of through holes  328  and passage hole  316  do not exist, so that the arc extinguishing performance of electromagnetic relay  1  is improved. Further, the air flow generated in extension space  320  can also flow out through hole  332  in partition wall  33 . Therefore, the possibility that the arc is pushed back to the side of fixed contact  211  by the air flow can be further reduced. 
     Further, in the present exemplary embodiment, it is assumed that a current flows through movable contactor  22  from left to right. When the direction of the current flowing through movable contactor  22  is opposite to that of the present exemplary embodiment, a direction of the Lorentz force acting on the arc is opposite, so that the arc is extended to the right side of the paper surface in  FIG. 4 . In this case, similarly to the present exemplary embodiment, the movement of the arc can also be restricted by partition wall  33 , and the state where the arc is extended can be maintained. That is, first space SP 1  and second space SP 2  divided by partition wall  33  can be used as extension spaces where the arc can be extended. Electromagnetic relay  1  can be used as a bipolar electromagnetic relay having an arbitrary direction of a current flow. Here, a shape of shielding member  3  is line-symmetrical in direction D 3  (right-left direction of the paper surface in  FIG. 4 ). Therefore, electromagnetic relay  1  can exhibit the similar performance regardless of the direction in which the current flows. 
     (First Modification of the Exemplary Embodiment) 
     Next, a first modification of the exemplary embodiment will be described with reference to  FIG. 8 . Similar components as those in the exemplary embodiment are designated by the same reference numerals, and description thereof will be omitted. 
     In electromagnetic relay  1 A and contact point device  2 A of the present modification, disposition of the pair of permanent magnets  431  is different from the disposition in the exemplary embodiment. The pair of permanent magnets  431  is disposed on both sides of movable contactor  22  in direction D 3 . That is, permanent magnets  431  are disposed at positions aligned with movable contactor  22  in direction D 3 . More particularly, the pair of permanent magnets  431  is disposed and fixed between the outer surface of inner case  41  and the inner surface of housing  9 . 
     The pair of permanent magnets  431  has the same poles facing each other. For example, in  FIG. 8 , permanent magnet  431  on the right side of the paper surface has a north pole facing left, and permanent magnet  431  on the left side of the paper surface has a north pole facing right. The pair of permanent magnets  431  generates a magnetic flux around fixed contact  211  that intersects with plane P 2  along direction D 1  (plane substantially parallel to the paper surface of  FIG. 8 ). More particularly, the pair of permanent magnets  431  generates, around fixed contact  211 , the magnetic flux along the longitudinal direction of movable contactor  22  (a depth direction of the paper surface in  FIG. 8 ). 
     In this modification, the direction of the magnetic flux around fixed contact  211  is the same as that of the exemplary embodiment, so that the arc generated between fixed contact  211  and movable contact  222  is extended similarly to the exemplary embodiment. 
     (Other Modifications of the Exemplary Embodiment) 
     Next, other modifications of the exemplary embodiment are listed. The following modifications may be achieved in appropriate combinations. Further, the following modifications may be achieved in combination with the first modification of the exemplary embodiment as appropriate. 
     It is not essential that shielding member  3  is provided with both of through hole  332  and through hole  328 , and at least one of through hole  332  and through hole  328  may be provided, and a number of through holes  332  or through holes  328  may be at least one. 
     Further, the direction in which through hole  328  penetrates side wall  32  is not limited to direction D 2 , and may be, for example, direction D 3 . Further, through hole  328  is not limited to being formed only on first side wall  321 , and through hole  328  may be formed on at least one of first side wall  321 , second side wall  322 , third side wall  323 , and fourth side wall  324 . 
     Further, it is not essential that shielding member  3  is provided with passage hole  316 . 
     Further, passage hole  316  may be covered with an insulating sheet having electrically insulation. That is, the insulating sheet may be sandwiched between shielding member  3  and yoke  54 . In this case, a possibility that the arc reaches yoke  54  can be reduced. 
     Further, shielding member  3  may have a conductive material such as, for example, metal. That is, at least a part of shielding member  3  may have conductivity. 
     Further, shielding member  3  may be provided with a member having a shape different from the shape of partition wall  33  instead of partition wall  33 . That is, a function of partition wall  33  in the exemplary embodiment is to limit the movement of the arc that has entered extension space  320 , and a member for limiting the movement of the arc is not limited to the wall-shaped member such as partition wall  33 , but a member having a different shape can be adopted. For example, instead of partition wall  33 , a rod-shaped member may be provided, bridging between first side wall  321  and third side wall  323 . 
     Further, shielding member  3  may be provided with a cover member that covers second space SP 2  of extension space  320  from above instead of partition wall  33 . In this case, it is possible to reduce the possibility that the arc entering first space SP 1  passes through second space SP 2  and then moves beyond the cover member to one end  228  of movable contact  222 . Further, shielding member  3  may be provided with a cover member in addition to partition wall  33 . Further, the cover member may be formed with a through hole. Further, the cover member may cover first space SP 1  from above instead of covering second space SP 2  from above. 
     Further, in the exemplary embodiment, extension space  320  is divided into first space SP 1  and second space SP 2  by partition wall  33 , but one of first space SP 1  and second space SP 2  may not be hollow. For example, a portion corresponding to second space SP 2  may be filled with a resin. Even in this case, at least for the arc entering first space SP 1 , the possibility that the state where the arc is extended is maintained can be increased. 
     Further, it is not essential that housing  9  containing contact point device  2  and electromagnet device  5  has airtightness. 
     Further, a number of each of fixed contacts  211  and movable contacts  222  is not limited to two, and may be one, or equal to or more than three. 
     Further, when permanent magnet  431  faces movable contactor  22  in the longitudinal direction of movable contactor  22 , a number of permanent magnets  431  may be one. That is, permanent magnet  431  may be disposed only on one end side of both ends of movable contactor  22  in the longitudinal direction. 
     Further, the number of permanent magnets  431  is not limited to one or two, but may be equal to or more than three. 
     (Conclusion) 
     From the exemplary embodiment described above and the like, the following aspects are disclosed. 
     Contact point device  2  according to one aspect includes movable contactor  22  that has movable contact  222  capable of being in contact with fixed contact  211  by moving in parallel with a first direction (here, downward), containing chamber  410  that contains fixed contact  211  and movable contact  222 , and shielding wall  35  disposed inside containing chamber  4100 . Shielding wall  35  is located below fixed contact  211  and movable contact  222  when viewed in direction D 2  orthogonal to direction D 1 . Shielding wall  35  is extended along direction D 1 . Shielding wall  35  is provided with one or a plurality of through holes (through hole  332 , through hole  328 , and the like) that penetrate shielding wall  35 . 
     According to the above configuration, when an air flow is generated in containing chamber  410  by the arc generated between fixed contact  211  and movable contact  222 , the air flow can be released through the through holes (through hole  332 , through hole  328 , and the like). Therefore, it is possible to reduce the possibility that the air flow pushes the arc back from a periphery of shielding wall  35  to the side where fixed contact  211  and movable contact  222  are located. This increases the possibility that the state where the arc length is long can be maintained. As a result, the state where the arc voltage is relatively large can be maintained, so that the arc extinguishing performance of contact point device  2  (or  2 A) is improved. 
     Further, in contact point device  2  (or  2 A) according to another aspect, containing chamber  410  has first space SP 1  and second space SP 2 . Shielding wall  35  faces first space SP 1  and second space SP 2 . Shielding wall  35  includes partition wall  33  located between first space SP 1  and the second space. Partition wall  33  is provided with through hole  332  that is one of the one or plurality of through holes (through hole  332 , through hole  328 , and the like). First space SP 1  and second space SP 2  are connected to each other through hole  332 . 
     According to the above configuration, the arc may be shielded by partition wall  33 . As a result, the possibility that the state where the arc length is long can be maintained is increased, as compared with the case where the arc is not shielded by partition wall  33 . As a result, the state where the arc voltage is relatively large can be maintained, so that the arc extinguishing performance of contact point device  2  (or  2 A) is further improved. 
     Further, in contact point device  2  (or  2 A) according to another aspect, shielding wall  35  includes side wall  32  facing first space SP 1  or second space SP 2 , and side wall  32  is provided with through hole  328  that is one of the one or plurality of the through holes (through hole  332 , through hole  328 , and the like). 
     According to the above configuration, the air flow generated in first space SP 1  or second space SP 2  can be released from through hole  328  to an outside of first space SP 1  or second space SP 2 . 
     Further, in contact point device  2  (or  2 A) according to another aspect, side wall  32  is further provided with other through hole  328  that is one of the one or plurality of through holes (through hole  332 , through hole  328 , and the like), through hole  328  is connected to first space SP 1 , and other through hole  328  is connected to second space SP 2 . 
     According to the above configuration, when the air flow is generated in any of the plurality of spaces (first space SP 1  and second space SP 2 ), the air flow can be released from any of through holes  328 . 
     Further, in contact point device  2  (or  2 A) according to another aspect, at least a part of partition wall  33  overlaps with fixed contact  211  when viewed from below. 
     According to the above configuration, the arc can be shielded by partition wall  33 . 
     Further, in contact point device  2  (or  2 A) according to another aspect, the one or plurality of through holes (through hole  332 , through hole  328 , and the like) are cutouts provided in the end portion (second end  338 ) on a lower side of shielding wall  35 . 
     According to the above configuration, in the case where through hole  332  is formed in second end  338 , a possibility that the arc passes through hole  332  can be reduced, as compared with a case where through hole  332  is formed in first end  337 , second end  338  being an end portion farther from fixed contact  211  of first end  337  and second end  338 , and first end  337  being an end portion closer to fixed contact  211  of first end  337  and second end  338 . 
     Further, contact point device  2  (or  2 A) according to another aspect further includes bottom wall  315 . Bottom wall  315  is connected to shielding wall  35 . At least a part of shielding wall  35  protrudes upward from bottom wall  315 . Shielding wall  35  is located between bottom wall  315  and movable contact  222 . 
     According to the above configuration, since the arc is difficult to move beyond bottom wall  315 , a possibility that the arc that has moved to the side of bottom wall  315  further spreads can be reduced. 
     Further, in contact point device  2  (or  2 A) according to another aspect, bottom wall  315  is provided with a through hole (passage hole  316 ) that penetrates bottom wall  315 . 
     According to the above configuration, the air flow generated by the arc can be released through the through hole (passage hole  316 ) formed in bottom wall  315 . 
     Further, in contact point device  2  (or  2 A) according to another aspect, the through hole (passage hole  316 ) in bottom wall  315  is connected to through hole  332  in shielding wall  35 . 
     According to the above configuration, the air flow generated by the arc can be more easily released through hole  332  in shielding wall  35  and the through hole (passage hole  316 ) in bottom wall  315 . 
     Further, contact point device  2  (or  2 A) according to another aspect further includes bottom wall  315  connected to shielding wall  35 , and side wall  32  protrudes upward from a peripheral edge of bottom wall  315 . 
     According to the above configuration, since side wall  32  and bottom wall  315  can be integrated, a number of parts of contact point device  2  (or  2 A) can be reduced. 
     Further, contact point device  2  (or  2 A) according to another aspect further includes drive shaft  25  and wall portion  34 . Drive shaft  25  moves movable contactor  22  along direction D 1 . Wall portion  34  has a tubular shape. Wall portion  34  surrounds drive shaft  25  in containing chamber  410 . 
     According to the above configuration, when foreign matter is scattered due to the air flow or the like generated by the arc, it is difficult for the foreign matter to intrude to the side of drive shaft  25  beyond wall portion  34 , so that driving of drive shaft  25  can be prevented from being hindered by the intrusion of the foreign matter. 
     Further, contact point device  2  (or  2 A) according to another aspect further includes permanent magnet  431  that generates a magnetic flux in direction D 2  between fixed contact  211  and movable contact  222 . Movable contactor  22  is extended along direction D 2 . 
     According to the above configuration, the arc can be extended by the Lorentz force generated by permanent magnet  431 . 
     Further, in contact point device  2  according to another aspect, permanent magnet  431  is disposed in alignment with movable contactor  22  in direction D 2 . 
     According to the above configuration, the magnetic flux along the direction in which movable contactor  22  extends is generated around movable contactor  22 , and the Lorentz force generated by this magnetic flux can be applied to the arc to extend the arc. 
     Further, in contact point device  2 A according to another aspect, permanent magnet  431  is disposed at a position aligned with movable contactor  22  in direction D 3 . Direction D 3  is orthogonal to both direction D 1  and direction D 2 . 
     According to the above configuration, the magnetic flux along the direction in which movable contactor  22  extends is generated around movable contactor  22 , and the Lorentz force generated by this magnetic flux can be applied to the arc to extend the arc. 
     Further, contact point device  2  (or  2 A) according to another aspect further includes other fixed contact  211 , and movable contactor  22  further includes other movable contact  222 . By pressing movable contactor  22 , other fixed contact  211  and other movable contact  222  are brought into contact with each other. 
     According to the above configuration, two-point cutting type contact point device  2  (or  2 A) can be configured. 
     Further, electromagnetic relay  1  (or  1 A) according to one aspect includes above-described contact point device  2  (or  2 A) and electromagnet device  5  located below contact point device  2  (or  2 A). Electromagnet device  5  has exciting coil  51 . 
     According to the above configuration, when an air flow is generated inside containing chamber  410  by the arc generated between fixed contact  211  and movable contact  222 , the air flow can be released from through hole  328 . Therefore, it is possible to reduce the possibility that the air flow pushes the arc back from a periphery of shielding wall  35  to the side where fixed contact  211  and movable contact  222  are located. This increases the possibility that the state where the arc length is long can be maintained. As a result, since the state where the arc voltage is relatively large can be maintained, the arc extinguishing performance of contact point device  2  (or  2 A) in electromagnetic relay  1  (or  1 A) is improved. 
     Further, in electromagnetic relay  1  (or  1 A) according to another aspect, electromagnet device  5  has yoke  54  that the magnetic flux generated by exciting coil  51  passes through. Yoke  54  includes first yoke  541  disposed between movable contactor  22  and exciting coil  51 . Contact point device  2  (or  2 A) further includes a cover (base  31 ) that has electrical insulation, and is located between first yoke  541  and movable contactor  22  to cover first relay  541 . 
     According to the above configuration, since the arc is difficult to move beyond the cover (base  31 ), yoke  54  can be protected from the arc. 
     REFERENCE MARKS IN THE DRAWINGS 
     
         
         
           
               1 ,  1 A,  1 Q,  1 R,  1 S electromagnetic relay 
               2 ,  2 A contact point device 
               21  fixed terminal 
               211  fixed contact 
               218  one end 
               22  movable contactor 
               222  movable contact 
               228  one end 
               24  holder 
               241  upper wall 
               242  lower wall 
               25  drive shaft 
               3 ,  3 Q,  3 R shielding member 
               31  base (cover) 
               32  side wall 
               33 ,  33 S partition wall 
               34  wall portion 
               35  shielding wall 
               310  one surface (upper side) 
               315 ,  315 R,  315 S bottom wall 
               316  passage hole 
               318  base hole 
               320  extension space 
               321  first side wall 
               322  second side wall 
               323  third side wall 
               324  fourth side wall 
               328  through hole 
               331  surface 
               332  through hole 
               337  first end 
               338  second end 
               341  through hole 
               41  inner case 
               410  containing chamber 
               411  through hole 
               42  joining body 
               43  magnetic flux generator 
               431  permanent magnet 
               44  cross-linking portion 
               5  electromagnet device 
               51  exciting coil 
               52  coil bobbin 
               521  flange 
               523  cylindrical portion 
               53  movable iron core 
               531  recess 
               54  yoke 
               541  first yoke (yoke) 
               542  second yoke 
               543  third yoke 
               544  insertion hole 
               55  return spring 
               56  cylindrical member 
               57  bush 
               9  housing 
               911  through hole 
             D 1  direction 
             D 2  direction 
             D 3  direction 
             P 1  projection plane 
             P 2  plane 
             R 5  virtual route 
             SP 1  first space (space) 
             SP 2  second space (space)