Patent Publication Number: US-2023162935-A1

Title: Contact device and electromagnetic relay equipped with same

Description:
CROSS-REFERENCE OF RELATED APPLICATIONS 
     This application is the U.S. National Phase under 35 U.S.C. § 371 of International Patent Application No. PCT/JP2021/006959, filed on Feb. 25, 2021, which in turn claims the benefit of Japanese Patent Application No. 2020-036026, filed on Mar. 3, 2020, the entire disclosures of which Applications are incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a contact device and an electromagnetic relay equipped with the contact device. 
     BACKGROUND ART 
     A conventional contact device is known to include a fixed contact portion having a fixed contact, and a movable contact portion having a movable contact which moves relative to the fixed contact and can be brought into contact with or separated from the fixed contact, as disclosed in Patent Literature 1. 
     In Patent Literature 1, bringing the fixed contact and the movable contact into contact with each other and separating them from each other switches between conduction and non-conduction between the fixed contact portion and the movable contact portion. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2012-104277 
     SUMMARY OF THE INVENTION 
     As in the prior art, when switching between conduction and non-conduction between the fixed contact portion and the movable contact portion by bringing the fixed contact and the movable contact into contact with and separating them from each other, it is preferable to prevent the movable contact and the fixed contact from being affected by an arc generated at contact parting. 
     It is thus an object of the present disclosure to obtain a contact device capable of preventing contacts from being affected by arcs in a more reliably manner, and an electromagnetic relay equipped with the contact device. 
     A contact device according to the present disclosure includes a first contact, a second contact that is movable relative to the first contact and is brought into contact with or separated from the first contact, a first body part including the first contact, a second body part including the second contact, and a yoke arranged adjacent to at least one of the first body part or the second body part. At least a part of the yoke is arranged along magnetic flux generated by a current flowing through one body part of the first body part and the second body part that is adjacent to the yoke, in a region where the first body part and the second body part overlap each other when viewed along a axis in which the first contact and the second contact move relative to each other while the first contact and the second contact are in contact with each other. 
     Advantageous Effects 
     The present disclosure makes it possible to obtain a contact device capable of preventing contacts from being affected by arcs in more reliable manner, and an electromagnetic relay equipped with the contact device. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    includes schematic diagrams illustrating an electromagnetic relay according to one embodiment, where (a) is a perspective view viewed from one axis and (b) is a perspective view viewed from another axis. 
         FIG.  2    includes schematic diagrams illustrating the electromagnetic relay according to one embodiment with a cover removed, where (a) is a perspective view viewed from one axis and (b) is a perspective view viewed from another axis. 
         FIG.  3    is a diagram illustrating the electromagnetic relay according to one embodiment when exploded, which is an exploded perspective view viewed from one axis. 
         FIG.  4    is a diagram illustrating the electromagnetic relay according to one embodiment when exploded, which is an exploded perspective view viewed from another axis. 
         FIG.  5    is a rear schematic diagram illustrating a contact device according to one embodiment with contacts in a second position. 
         FIG.  6    is a rear schematic diagram illustrating a contact device according to one embodiment with contacts in a first position. 
         FIG.  7    includes diagrams illustrating a fixed contact portion according to one embodiment, where (a) is a perspective view viewed from one axis, (b) is a perspective view viewed from another axis, and (c) is a plan view. 
         FIG.  8    includes diagrams illustrating a fixed contact portion according to one embodiment, where (a) is a rear view, (b) is a side view, and (c) is a front view. 
         FIG.  9    includes schematic diagrams illustrating a movable contact maker according to one embodiment before a yoke is attached thereto, where (a) is a perspective view viewed from one axis, (b) is a perspective view viewed from another axis, and (c) is a side view. 
         FIG.  10    includes schematic diagrams illustrating the movable contact maker according to one embodiment with the yoke attached thereto, where (a) is a plan view and (b) is a rear view. 
         FIG.  11    includes schematic diagrams illustrating the movable contact maker according to one embodiment with the yoke attached thereto, where (a) is a front view, (b) is a rear view, and (c) is a side view. 
         FIG.  12    includes diagrams illustrating magnetic flux generated by a current flowing through the movable contact maker according to one embodiment, where (a) is a diagram illustrating magnetic flux generated by a current flowing to one side and (b) is a diagram illustrating magnetic flux generated by a current flowing to the other side. 
         FIG.  13    includes diagrams illustrating the fixed contact portions, the movable contact maker, and the yoke according to one embodiment, where (a) is a plan view illustrating the contacts in a first position, and (b) is a plan view illustrating the contacts in a second position. 
         FIG.  14    is a diagram illustrating the fixed contact portions, the movable contact maker, and the yoke according to one embodiment with the contacts in the first position, as viewed along a movement axis of the movable contact maker. 
         FIG.  15    is a diagram illustrating how an arc moves toward a protrusion part in the contact device according to one embodiment. 
         FIG.  16    is a diagram illustrating a relationship between a direction in which an arc moves and a base in the contact device according to one embodiment. 
         FIG.  17    is a diagram illustrating how an arc moves toward the protrusion part in a contact device according to a modification. 
         FIG.  18    includes schematic diagrams illustrating a yoke according to a first modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  19    includes schematic diagrams illustrating a yoke according to a second modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  20    includes schematic diagrams illustrating a yoke according to a third modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  21    includes schematic diagrams illustrating a yoke according to a fourth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  22    includes schematic diagrams illustrating a yoke according to a fifth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  23    includes schematic diagrams illustrating a yoke according to a sixth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  24    includes schematic diagrams illustrating a yoke according to a seventh modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  25    includes schematic diagrams illustrating a yoke according to an eighth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  26    includes schematic diagrams illustrating a yoke according to a ninth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  27    includes schematic diagrams illustrating a yoke according to a tenth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  28    includes schematic diagrams illustrating a yoke according to a eleventh modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  29    includes schematic diagrams illustrating a yoke according to a twelfth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  30    includes schematic diagrams illustrating a yoke according to a thirteenth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  31    includes schematic diagrams illustrating a yoke according to a fourteenth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  32    includes schematic diagrams illustrating a yoke according to a fifteenth modification arranged adjacent to the movable contact maker, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  33    includes schematic diagrams illustrating a yoke according to a sixteenth modification arranged adjacent to a body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  34    includes schematic diagrams illustrating a yoke according to a seventeenth modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  35    includes schematic diagrams illustrating a yoke according to an eighteenth modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  36    includes schematic diagrams illustrating a yoke according to a nineteenth modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  37    includes schematic diagrams illustrating a yoke according to a twentieth modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  38    includes schematic diagrams illustrating a yoke according to a twenty-first modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  39    includes schematic diagrams illustrating a yoke according to a twenty-second modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  40    includes schematic diagrams illustrating a yoke according to a twenty-third modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  41    includes schematic diagrams illustrating a yoke according to a twenty-fourth modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  42    includes schematic diagrams illustrating a yoke according to a twenty-fifth modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  43    includes schematic diagrams illustrating a yoke according to a twenty-sixth modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  44    includes schematic diagrams illustrating a yoke according to a twenty-seventh modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  45    includes schematic diagrams illustrating a yoke according to a twenty-eighth modification arranged adjacent to the body part having one contact, where (a) is a front view, (b) is a side view, (c) is a rear view, and (d) is a plan view. 
         FIG.  46    includes schematic diagrams illustrating a state in which an angle formed by a direction of a current flowing through a body part on which a yoke is arranged and a direction of a current flowing through a movable contact maker on which another yoke is arranged becomes  180  degrees, where (a) is a diagram viewed along an axis crossing a movement axis of the movable contact maker, and (b) is a diagram viewed along the movement axis of the movable contact maker. 
         FIG.  47    includes schematic diagrams illustrating a state in which an angle formed by a direction of a current flowing through a body part on which a yoke is arranged and a direction of a current flowing through a movable contact maker on which another yoke is arranged becomes  90  degrees, where (a) is a diagram viewed along an axis crossing a movement axis of the movable contact maker, and (b) is a diagram viewed along the movement axis of the movable contact maker. 
         FIG.  48    includes schematic diagrams illustrating a state in which an angle formed by a direction of a current flowing through a body part on which a yoke is arranged and a direction of a current flowing through a movable contact maker on which another yoke is arranged becomes an obtuse angle, where (a) is a diagram viewed along an axis crossing a movement axis of the movable contact maker, and (b) is a diagram viewed along the movement axis of the movable contact maker. 
         FIG.  49    includes schematic diagrams illustrating a state in which an angle formed by a direction of a current flowing through a body part on which a yoke is arranged and a direction of a current flowing through a movable contact maker on which another yoke is arranged becomes an acute angle, where (a) is a diagram viewed along an axis crossing a movement axis of the movable contact maker, and (b) is a diagram viewed along the movement axis of the movable contact maker. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Referring to the drawings, a detailed description is given below of embodiments according to the present disclosure. Note that the longitudinal axis of a movable contact maker is described as a Y axis (width axis; direction in which a current flows through the movable contact maker; first axis). An axis in which a fixed contact and a movable contact face each other is described as an X axis (longitudinal axis; second axis), and an axis orthogonal to the X axis and the Y axis is described as a Z axis (vertical axis; third axis). 
     A direction in which a tip of a terminal part provided in a fixed contact portion protrudes from a case is described as being below in the vertical axis, a side where the fixed contact is arranged is described as being forward in the longitudinal axis, and a side where the movable contact is arranged is described as being backward in the longitudinal axis. 
     The following embodiments and modifications thereof include similar components. Thus, in the following description, common reference numerals are assigned to these similar components, and redundant descriptions are omitted. 
     An electromagnetic relay  1  according to the present embodiment is what is called a normally open type in which contacts are initially in an off state, and includes an electromagnet device (driving unit)  20  arranged backward in the X axis (longitudinal axis; second axis) and a contact device  30  arranged forward in the X axis, as illustrated in  FIGS.  1  to  4   . The electromagnet device  20  and the contact device  30  are housed in a case  10  formed in a hollow box shape from a resin material. Note that it is also possible to use what is called a normally closed type electromagnetic relay in which the contacts are initially in an on state. 
     The case  10  includes a base  110  and a cover  120 , and has an outer surface in a substantially rectangular parallelepiped shape. The electromagnet device  20  and the contact device  30  are housed in an internal space  51  of the case  10  formed with the cover  120  attached to the base  110 . 
     Note that the shape of the outer surface of the case  10  is not limited to a rectangular parallelepiped shape and may be any shape. 
     The base  110  includes a base part  111  in a rectangular plate shape extending along a substantially horizontal plane (axis crossing Z axis; XY plane). The base  110  includes a peripheral wall  112  extending upward from the peripheral edge of the base part  111 , and a partition wall  113  formed to rise upward from a substantially central part in the X axis (longitudinal axis) (see  FIGS.  2  to  4   ). 
     The electromagnet device  20  is arranged behind the partition wall  113 , and the contact device  30  is arranged in front of the partition wall  113  (see  FIGS.  2  to  4   ). 
     Meanwhile, the cover  120  has an approximate box shape opened downward, and the cover  120  is attached to the base  110  from above. 
     As described above, in the present embodiment, the internal space  51  of the case  10  is divided into two sections, front and back, by the partition wall  113  of the base  110 . That is, the internal space  51  of the case  10  is divided into a space S 2  formed behind the partition wall  113  and housing the electromagnet device  20 , and a space S 3  formed in front of the partition wall  113  and housing the contact device  30  (see  FIGS.  5  and  6   ). 
     The base  110  includes a separation wall  114  formed in an approximate T-shape in a plan view in front of the partition wall  113 . The separation wall  114  is for securing a creepage distance between a pair of fixed contact portions  310 ,  310  described later. 
     Note that reference numeral  117  in  FIGS.  1  to  4    is a raising member for providing a gap between the base  110  and a printed circuit board (not illustrated) when the electromagnetic relay  1  is arranged on the printed circuit board. 
     The electromagnet device (driving unit)  20  is a device for generating electromagnetic force and includes a coil  210  for generating magnetic flux when energized, and a coil bobbin  220  in a hollow cylindrical shape around which the coil  210  is wound (see  FIGS.  2  to  4   ). 
     As the coil  210 , a conductor wire is usable, for example. The coil bobbin  220  is formed from a resin, which is an insulating material, and has an insertion hole penetrating in the Z axis (vertical axis; third axis) formed in a center part of the coil bobbin  220 . The coil bobbin  220  includes a drum part in a substantially cylindrical shape, around which the coil  210  is wound on the outer surface thereof, and an upper flange part  222  in a substantially circular shape, which is provided in continuation from the upper end of the drum part to protrude outward in the radial direction of the drum part. Further, the coil bobbin  220  includes a lower flange part  223  in a substantially circular shape, which is provided in continuation from the lower end of the drum part to protrude outward in the radial direction of the drum part. 
     The electromagnet device  20  includes an iron core (fixed-side member)  230  inserted in the cylinder of the coil bobbin  220  and magnetized by the energized coil  210  (magnetic flux passes through). 
     The iron core  230  includes a shaft portion in a substantially cylindrical shape extending in the Z axis (vertical axis), and a head part  232  in a substantially cylindrical shape having a diameter larger than that of the shaft portion and provided in continuation from the upper end of the shaft portion (see  FIGS.  3  and  4   ). 
     The electromagnet device  20  further includes an armature (movable-side member)  240  arranged to face the head part  232  of the iron core  230  in the vertical axis (Z axis). 
     The armature  240  is formed from a conductive metal and is arranged to be swingable in the vertical axis (Z axis) with respect to the head part  232  of the iron core  230 . In the present embodiment, the armature  240  includes a horizontal wall part  241  facing the head part  232  of the iron core  230  in the vertical axis (Z axis), and a vertical wall part  242  extending downward from the front end of the horizontal wall part  241  in the X axis (longitudinal axis) (see  FIGS.  5  and  6   ). 
     The electromagnet device  20  includes a heel piece  250  arranged around the coil  210  wound around the drum part. The heel piece  250  is a member in a substantially plate shape made from a magnetic material, and has an approximate L-shape in a side view (in a state viewed along the Y axis). That is, in the present embodiment, the heel piece  250  includes a vertical wall part  251  arranged in front of the coil  210  wound around the drum part to extend along a substantially vertical plane, and a horizontal wall part  252  extending backward from the lower end of the vertical wall part  251  (see  FIGS.  5  and  6   ). The above-described heel piece  250  is formable through bending a single plate, for example. 
     The horizontal wall part  241  of the armature  240  is attached to the upper end of the vertical wall part  251  to be swingable in the vertical axis (Z axis). This enables the armature  240  to rotate in the vertical axis (Z axis) about a section supported by the heel piece  250 . 
     Further, in the present embodiment, the electromagnet device  20  includes a hinge spring  260  mounted over the armature  240  and the heel piece  250  so that the armature  240  is urged by the hinge spring  260  in a direction in which the horizontal wall part  241  separates from the head part  232  of the iron core  230  (see  FIGS.  5  and  6   ). 
     The electromagnet device  20  is fixed to the coil bobbin  220  and includes a pair of coil terminals  270  to which both ends of the coil  210  are connected. The electromagnet device  20  is driven by energizing the coil  210  through the pair of coil terminals  270 . 
     Specifically, the horizontal wall part  241  of the armature  240  is attracted to the head part  232  of the iron core  230  by energizing the coil  210 , and the armature  240  is rotated so that the horizontal wall part  241  approaches the head part  232  of the iron core  230 . That is, energizing the coil  210  through the pair of coil terminals  270  causes the horizontal wall part  241  of the armature  240  to rotate downward in the Z axis (vertical axis). Here, the vertical wall part  242  provided in continuation from the horizontal wall part  241  rotates forward in the X axis (longitudinal axis). 
     The swing range of the armature  240  is set between a position where the horizontal wall part  241  is farthest from the head part  232  of the iron core  230  and a position where the horizontal wall part  241  is closest to the head part  232  of the iron core  230 . 
     In the present embodiment, the swinging range of the armature  240  is set between an initial position where the horizontal wall part  241  is arranged above the head part  232  of the iron core  230  with a predetermined gap therebetween and a contact position where the horizontal wall part  241  comes in contact with the head part  232  of the iron core  230 . 
     Thus, in the present embodiment, when the coil  210  is energized, the armature  240  moves to the contact position where the horizontal wall part  241  comes in contact with the head part  232  of the iron core  230 , and when the energization to the coil  210  is stopped, the armature  240  returns to the initial position with the urging force of the hinge spring  260 . 
     As described above, the armature  240  according to the present embodiment is arranged to face the head part  232  of the iron core  230  with a predetermined gap therebetween when the coil  210  is not energized, and swings to be attracted toward the head part  232  of the iron core  230  when the coil  210  is energized. 
     By switching the driving state of the electromagnet device  20 , it is possible to switch between conduction and non-conduction between the fixed contact portions  310  and the movable contact portion  320 , which are paired with each other (having contacts that contact and separate from each other). 
     In the present embodiment, the contact device  30  is provided in front of the electromagnet device  20  to open and close the contacts as the coil  210  is energized and de-energized. 
     The contact device  30  includes the fixed contact portions (first contact portion)  310  and the movable contact portion (second contact portion)  320 . The fixed contact portions  310  each include a fixed contact (first contact)  311  and a body part (first body part)  312  having the fixed contact  311 . In contrast, the movable contact portion  320  includes movable contacts (second contact)  321  that move relative to the fixed contacts  311  and are able to contact with and separate from the fixed contacts  311 , and a movable contact maker (second body part)  322  having the movable contacts  321 . 
     In the present embodiment, the contact device  30  includes only one pair of the fixed contact portions  310  and the movable contact portion  320  paired with each other (having contacts that contact with and separate from each other) (see  FIGS.  3  and  4   ). 
     In the present embodiment, the set of the fixed contact portions  310  and the movable contact portion  320  having contacts to be brought into contact with and separated from each other is composed of the pair of fixed contact portions  310  and one movable contact portion  320 . 
     Specifically, two fixed contact portions  310  having a shape symmetrical to the XZ plane are the pair of fixed contact portions  310 . The paired two fixed contact portions  310  are fixed to the base  110  (case  10 ) while being spaced apart in the Y axis (width axis; first axis). 
     Each of the fixed contact parts  310  includes the body part  312  having one fixed contact  311  (see  FIGS.  7  and  8   ). In the present embodiment, a member intended to be a fixed contact is inserted in an insertion hole  312   d,  which is formed to penetrate the body part  312  in the plate thickness axis, rivet joining is carried out thereon, and thus the body part  312  has the fixed contact  311  (see  FIGS.  5  and  6   ). As described above, in the present embodiment, the body part  312  has a function as a fixed-side contact holder for holding the fixed contact  311 . 
     Note that the formation of the fixed contact  311  on the body part  312  is not limited to using rivet joining and can be performed with various methods. For example, it is possible to make a section, which is made to protrude through a doweling process performed on the body part  312 , function as a fixed contact. It is also possible to make a part of the flat surface of the body part  312  function as a fixed contact by adopting a configuration with which the movable contact  321  is brought into contact with the part of the flat surface of the body part  312   
     Each of the fixed contact portions  310  includes a terminal part  313  provided in continuation from the lower end of the body part  312  to be fixed to the base  110  (case  10 ) with the tip thereof protruding outward (downward) from the base  110  (case  10 ). 
     In the present embodiment, the base  110  has an insertion hole  115  formed to penetrate in the Z axis (vertical axis). The tip (lower end) of each terminal part  313  is inserted in the insertion hole  115  from above, and each fixed contact portion  310  is fixed to the base  110  (case  10 ) with the tip (lower end) of the terminal part  313  protruding outward (downward) from the base  110  (see  FIGS.  5  and  6   ). In the present embodiment, the fixed contact portions  310  are fixed to the base  110  (case  10 ) using an adhesive  116 . 
     Here, each fixed contact portion  310  is fixed to the base  110  (case  10 ) with the fixed contact  311  facing backward in the X axis (longitudinal axis). That is, the fixed contact portion  310  is fixed to the base  110  (case  10 ) with a surface  312   a  of the body part  312  on which the fixed contact  311  is formed (rear surface; first surface; surface facing the movable contact  321 ) facing backward. 
     Note that the fixed contacts  311 , the body parts  312 , and the terminal parts  313  are formable from a conductive material, such as a copper-based material. 
     As described above, in the present embodiment, the two fixed contacts (first contact)  311  are arranged side by side in the Y axis, which is an axis orthogonal to (intersecting with) the axis in which the fixed contacts (first contact)  311  and the movable contact (second contact)  321  move relative to each other. One of the two body parts (first body part)  312  has one of the fixed contacts (first contact)  311 , and the other of the two body parts has the other of the fixed contacts (first contact)  311 . 
     Meanwhile, the one movable contact portion  320  includes one movable contact maker  322 , and the movable contact maker  322  includes a pair of movable contacts  321  arranged side by side in the Y axis (width axis) (see  FIGS.  9  to  11   ). 
     In the present embodiment, a member intended to be a movable contact is inserted in each of insertion holes  322   e  formed on both ends of the movable contact maker  322 , which is in a substantially rectangular plate shape in the longitudinal axis, to penetrate in the thickness axis, rivet joining is carried out thereon, and thus the movable contact maker  322  has the movable contacts  321  (see  FIGS.  5  and  6   ). As described above, in the present embodiment, the movable contact maker  322  has a function as a movable-side contact holder for holding the movable contacts  321 . 
     Note that the formation of the movable contacts  321  on the movable contact maker  322  is not limited to using rivet joining and can be formed with various methods. For example, it is possible to make a section, which is made to protrude through a doweling process performed on the movable contact maker  322 , function as a movable contact. It is also possible to make a part of the flat surface of the movable contact maker  322  function as a movable contact by having a configuration to bring the part of the flat surface of the movable contact maker  322  into contact with the fixed contact  311 . 
     The one movable contact portion  320  is arranged to be positioned behind the paired two fixed contact portions  310  in the X axis (longitudinal axis) with the plate thickness axis substantially aligned in the X axis (longitudinal axis) and with the longitudinal axis substantially aligned in the Y axis (width axis) (see  FIGS.  3  to  6   ). Here, the movable contact portion  320  is arranged in such a state that the movable contacts  321  are opposed to the fixed contacts  311  in the X axis (longitudinal axis). Specifically, the movable contact maker  322  is arranged such that the movable contact  321  formed on one side in the Y axis (width axis) is opposed in the X axis (longitudinal axis) to the fixed contact  311  of the fixed contact portion  310  arranged on the one side in the Y axis (width axis). In a similar manner, the movable contact maker  322  is arranged such that the movable contact  321  formed on the other side in the Y axis (width axis) is opposed in the X axis (longitudinal axis) to the fixed contact  311  of the fixed contact portion  310  arranged on the other side in the Y axis (width axis). Thus, one movable contact (second contact)  321  is brought into contact with and separated from one fixed contact (first contact)  311  of the two fixed contacts (first contact)  311 , and the other movable contact (second contact)  321  is brought into contact with and separated from the other fixed contact (first contact)  311  of the two fixed contacts (first contact)  311 . One movable contact maker (second body part)  322  is made to have two movable contacts (second contact)  321 . 
     Note that the movable contacts  321  and the movable contact maker  322  are formable from a conductive material, such as a copper-based material. 
     The pair of fixed contact portions  310  and one movable contact portion  320 , having the above-described configuration is housed in the above-described space S 3  (see  FIGS.  5  and  6   ) as a set. 
     Here, the movable contact portion  320  is arranged in the space S 3  to be swingable in the X axis (longitudinal axis) relative to the pair of fixed contact portions  310 . 
     Specifically, the contact device  30  includes a movable body  330  that swings in the X axis (longitudinal axis) as the armature  240  swings. The movable body  330  holds the movable contact portion  320 , and thus the movable contact portion  320  swings in the X axis (longitudinal axis) relative to the pair of fixed contact portions  310 . 
     In the present embodiment, the movable body  330  is formed from an insulating resin material and includes a holder part  331  whose upper part is provided in continuation from the vertical wall part  242  of the armature  240 , a movable plate  332  provided in continuation from the lower part of the holder portion  331 , and a movable spring  333  connecting the movable plate  332  and the movable contact maker  322 . 
     With such a configuration, the movable contact portion  320  swings in the X axis (longitudinal axis) relative to the pair of fixed contact portions  310  as the armature  240  swings. Thus, the movable contacts  321  pivot in an arc centered on the upper end of the vertical wall part  242 . 
     Therefore, in the present embodiment, the tangential axis of the arc (movement path of the movable contacts  321 ) drawn by the movable contacts  321  while swinging is the axis in which the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  move relative to each other. 
     Thus, strictly speaking, the axis in which the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  move relative to each other is different between when the armature  240  is in the initial position and when the armature  240  is in the contact position. 
     However, in the present embodiment, the angle (central angle) of the arc drawn by the movable contacts  321  while swinging is relatively small, and the movable contacts  321  are configured to be positioned at the lowest end between when the armature  240  is in the initial position and when the armature  240  is in the contact position (see  FIGS.  5  and  6   ). Thus, the tangential axis of the arc drawn by the movable contacts  321  while swinging is substantially parallel to the X axis. 
     Therefore, in the present embodiment, it is possible for the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other to be approximated by the X axis (longitudinal axis; axis in which the fixed contact  311  and the movable contact  321  are opposed each other). 
     Thus, when the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other is approximated by the X axis, the state seen along the axis in which the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  move relative to each other can also be approximated by the state seen along the X axis. Thus, in the following description, the state seen along the axis in which the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  move relative to each other is in some cases described as the state seen along the X axis. 
     Next, an example of the operation of the electromagnetic relay  1  (the electromagnet device  20  and the contact device  30 ) having the above-described configuration is described. 
     First, when the coil  210  is not energized, the horizontal wall part  241  of the armature  240  moves away from the head part  232  of the iron core  230  through the elastic force of the hinge spring  260 . Here, since the vertical wall part  242  of the armature  240  is located behind in the X axis (longitudinal axis), the movable body  330  is also located behind in the X axis (longitudinal axis). That is, the movable contact portion  320  held by the movable body  330  is separated from the fixed contact portions  310 , and the movable contacts  321  are separated from the fixed contacts  311  (see  FIG.  5   ). 
     When the coil  210  is energized from this off state, the horizontal wall part  241  of the armature  240  is attracted downward (the iron core  230  side) by the electromagnetic force and moves close to the head part  232  of the iron ore  230  against the elastic force of the hinge spring  260 . The vertical wall part  242  rotates forward with the downward rotation of the horizontal wall part  241  (iron core  230  side), and the movable body  330  rotates forward with the forward rotation of the vertical wall part  242 . As a result, the movable contact maker  322  held by the movable body  330  rotates forward toward the fixed contact portion  310 , and the movable contacts  321  of the movable contact maker  322  are brought into contact with the fixed contacts  311  of the fixed contact portions  310 . Thus, the pair of fixed contact portions  310  are electrically connected by the movable contact portion  320  (see  FIG.  6   ). 
     In contrast, when the energization to the coil  210  is stopped, the horizontal wall part  241  of the armature  240  rotates upward (away from the iron core  230 ) due to the urging force of the hinge spring  260  and returns to the initial position. 
     The vertical wall part  242  rotates backward with the upward rotation of the horizontal wall part  241 , and the movable body  330  rotates backward with the backward rotation of the vertical wall part  242 . As a result, the movable contact maker  322  held by the movable body  330  rotates backward away from the fixed contact portions  310 , and the movable contacts  321  of the movable contact maker  322  are separated from the fixed contacts  311  of the fixed contact portions  310 . In this way, the electrical connection between the pair of fixed contact portions  310 ,  310  is disconnected. 
     As described above, in the present embodiment, when the armature  240  is in the initial position, the movable contacts  321  and the fixed contacts  311  are separated from each other in a second position (see  FIG.  5   ). In contrast, when the armature  240  is in the contact position, the movable contacts  321  and the fixed contacts  311  are in contact in a first position (see  FIG.  6   ). 
     Thus, during the period when the coil  210  is not energized, the pair of fixed contact portions  310 ,  310  are insulated, and during the period when the coil  210  is energized, the pair of fixed contact portions  310 ,  310  are electrically connected. As described above, in the present embodiment, the movable contacts (second contact)  321  are configured to reciprocate (rotate) in the second axis (X axis; longitudinal axis) relative to the fixed contacts (first contact)  311  between the first position and the second position. 
     Here, when the movable contacts  321  and the fixed contacts  311  are positioned in the first position in contact with each other, a current I flows through the movable contact maker  322  mainly along the longitudinal axis (Y axis). 
     Here, for example, as illustrated in  FIG.  12 ( a ) , when the current I flows from the movable contact  321  on the left side (front side in  FIG.  12 ( a ) ) to the movable contact  321  on the right side (rear side in  FIG.  12 ( a ) ), magnetic flux B is generated from above to below on a surface (first surface)  322   a  of the movable contact maker  322  on which the movable contacts  321  are formed. Note that the surface  322   a  of the movable contact maker  322  on which the movable contacts  321  are formed is a surface located to face the opposing body part (first body parts  312 ) and is referred to as a front surface  322   a  in some cases below. 
     When the energization to the coil  210  is stopped, contact parting is started in which the movable contacts  321  are separated from the fixed contacts  311  (moved from the state in  FIG.  13 ( a )  to the state in  FIG.  13 ( b ) ). 
     When the contact parting is started, an arc A is generated between the movable contacts  321  and the fixed contacts  311  in the initial stage of the contact parting, and the arc A causes the current to be continued in the energized state (see  FIG.  13 ( b ) ). 
     Here, when the current I flows from the movable contact  321  on the right side to the movable contact  321  on the left side in  FIG.  13 ( b )  (when a current flows in the same direction as in  FIG.  12 ( a ) ), the current I flowing from the movable contact  321  toward the fixed contact  311  on the left side in  FIG.  13 ( b )  flows through the arc A generated at the movable contact  321  and the fixed contact  311 . 
     In contrast, the current I flowing from the fixed contact  311  toward the movable contact  321  on the right side in  FIG.  13 ( b )  flows through the arc A generated at the movable contact  321  and the fixed contact  311 . 
     As described above, magnetic flux B flowing from above to below is generated near the front surface  322   a  of the movable contact maker  322 , that is, in the space where the arcs A exist. 
     Thus, the current I flowing from the movable contact  321  toward the fixed contact  311  on the left side in  FIG.  13 ( b )  and the magnetic flux B flowing from above to below cause a Lorentz force to the left side (outside in the Y axis) to be applied to the arc A generated at the movable contact  321  and the fixed contact  311 . 
     As a result, the arc A generated at the movable contact  321  and the fixed contact  311  on the left side in  FIG.  13 ( b )  is extended to the left side (outside in the Y axis) in  FIG.  13 ( b ) . 
     The current I flowing from the fixed contact  311  toward the movable contact  321  on the right side in  FIG.  13 ( b )  and the magnetic flux B flowing from above to below causes a Lorentz force to the right side (outside in the Y axis) to be applied to the arc A generated at the movable contact  321  and the fixed contact  311 . 
     As a result, the arc A generated at the movable contact  321  and the fixed contact  311  on the right side in  FIG.  13 ( b )  is extended to the right side (outside in the Y axis) in  FIG.  13 ( b ) . 
     Then, the arcs A generated in respective sets of the movable contact  321  and the fixed contact  311  are each extended outward in the Y axis to be extinguished. In this way, the current between the fixed contact portions  310  and the movable contact portion  320  is cut. 
     Note that although not illustrated, when the current I flows from the movable contact  321  on the left toward the movable contact  321  on the right in  FIG.  13 ( b )  (when the current flows in the same direction as in  FIG.  12 ( b ) ), the current I flowing from the fixed contact  311  toward the movable contact  321  on the left in  FIG.  13 ( b )  flows through the arc A generated at the movable contact  321  and the fixed contact  311 . 
     The current I flowing from the movable contact  321  toward the fixed contact  311  on the right side in  FIG.  13 ( b )  flows through the arc A generated at the movable contact  321  and the fixed contact  311 . 
     In this case, as described above, the magnetic flux B flowing from below to above is generated near the front surface  322   a  of the movable contact maker  322 , that is, in the space where the arcs A exist. 
     Thus, the current I flowing from the fixed contact  311  toward the movable contact  321  on the left side in  FIG.  13 ( b )  and the magnetic flux B flowing from below to above causes a Lorentz force to the left side (outside in the Y axis) to be applied to the arc A generated at the movable contact  321  and the fixed contact  311 . 
     As a result, the arc A generated at the movable contact  321  and the fixed contact  311  on the left side in  FIG.  13 ( b )  is extended to the left side (outside in the Y axis) in  FIG.  13 ( b ) . 
     The current I flowing from the movable contact  321  toward the fixed contact  311  on the right side in  FIG.  13 ( b )  and the magnetic flux B flowing from below to above causes a Lorentz force to the right side (outside in the Y axis) to be applied to the arc A generated at the movable contact  321  and the fixed contact  311 . 
     As a result, the arc A generated at the movable contact  321  and the fixed contact  311  on the right side in  FIG.  13 ( b )  is extended to the right side (outside in the Y axis) in  FIG.  13 ( b ) . 
     Then, the arcs A generated in respective sets of the movable contact  321  and the fixed contact  311  are each extended outward in the Y axis to be extinguished 
     As described above, the contact device  30  according to the present embodiment is configured such that arcs A generated between the movable contacts  321  and the fixed contacts  311  are extended outward in the Y axis to be extinguished regardless of the direction of the current. 
     Thus, even when an AC current flows through the contact device  30  as in an AC relay, it is possible to extend the arcs A generated between the movable contacts  321  and the fixed contacts  311  outside in the Y axis and extinguish the arcs. 
     When an arc A is generated between the movable contact  321  and the fixed contact  311 , the movable contact  321  and the fixed contact  311  may be welded by the arc heat. The movable contact  321  and the fixed contact  311  may be deteriorated by the arc heat. 
     Thus, when the arcs A are generated between the movable contacts  321  and the fixed contacts  311 , the contacts (the movable contacts  321  and the fixed contacts  311 ) may be affected by the arcs. In particular, in an electromagnetic relay in which a large current flows, contacts (movable contacts  321  and fixed contacts  311 ) are to be affected to a great extent by the arcs. 
     Thus, it is preferable to extinguish the arcs A generated between the movable contacts  321  and the fixed contacts  311  in a more reliable and more quick manner and to prevent the contacts (the movable contacts  321  and the fixed contacts  311 ) from being affected by the arcs. 
     Thus, the present embodiment makes it possible to extinguish the arcs A generated between the movable contacts  321  and the fixed contacts  311  in a more reliable and quick manner Specifically, a yoke  40  is arranged adjacent to at least one of the body parts (first body part)  312  or the movable contact maker (second body part)  322 . 
     Arranging the yoke  40  to face at least one of the body parts  312  or the movable contact maker  322  makes it possible to enhance the intensity of the magnetic flux B generated around the body part adjacent to the yoke  40 , and to extinguish the arcs A in a more reliable and quick manner. 
     In the present embodiment, as illustrated in  FIGS.  9  to  11   , the yoke  40  is arranged adjacent to the movable contact maker (second body part)  322 , which is the body part of at least one of the body parts  312  or the movable contact maker  322 . 
     At least a part of the yoke  40  is arranged along the magnetic flux B that is generated by the current I flowing through the movable contact maker (the body part adjacent to the yoke  40 )  322  and is generated in the region R 1 . 
     Note that the region R 1  is a region where the body parts (first body part)  312  and the movable contact maker (second body part)  322  overlap each other when the state in which the fixed contacts  311  and the movable contact  321  are in contact with each other is viewed along the X axis (as viewed along the axis in which the fixed contacts  311  and the movable contact  321  move relative to each other) (see  FIG.  14   ). 
     As described above, in the present embodiment, at least a part of the yoke  40  is arranged along the magnetic flux B generated around the movable contact maker (second body part)  322  in a space belonging to the region R 1  of the space near the movable contact maker (second body part)  322 . 
     Arranging the yoke  40  as described above makes it possible to concentrate the magnetic flux B generated around the movable contact maker (second body part)  322  in the yoke  40 . Consequently, it is possible to increase the intensity of the magnetic flux B generated around the movable contact maker (second body part)  322  (the magnetic field around the movable contact maker  322  is strengthened) and to extinguish the arcs A generated between the movable contact  321  and the fixed contacts  311  in a more reliable and quick manner. 
     Further, in the present embodiment, the yoke  40  includes a section arranged adjacent to a surface (second surface)  322   b  of the movable contact maker  322  opposite to the surface where the movable contacts  321  are formed. Note that the surface of the movable contact maker  322  opposite to the surface where the movable contacts  321  are formed is a surface located on the opposite side to the side facing the opposing body part (first body part  312 ) and is referred to as a back surface  322   b  in some cases below. 
     In the present embodiment, the yoke  40  includes a sidewall  410  in a substantially rectangular shape elongated in the Y axis, a top wall  420  provided in continuation from the upper end of the sidewall  410 , and a bottom wall  430  provided in continuation from the lower end of the sidewall  410  and extending in the same direction as the top wall  420 . 
     A front surface  411  of the side wall  410  is arranged to face the back surface  322   b  of the movable contact maker  322  with a tip  421  of the top wall  420  and a tip  431  of the bottom wall  430  facing forward in the X axis (longitudinal axis). 
     Thus, in the present embodiment, the side wall  410  of the yoke  40  is the section arranged adjacent to the surface (second surface)  322   b  of the movable contact maker  322  opposite to the surface where the movable contacts  321  are formed. 
     Here, the side wall  410  of the yoke  40  is arranged to overlap with the contacts (movable contacts  321 ) of the body part (movable contact maker  322 ) to face the yoke  40 , when viewed along the X axis (viewed along the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other). Thus, the side wall  410  of the yoke  40  is arranged to overlap a contact region R 2  where the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  come into contact, when viewed along the X axis (viewed along the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other). 
     Thus, in the present embodiment, a section of the side wall  410  of the yoke  40  is a part that overlaps the contact region R 2  where the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  come into contact, when viewed along the axis in which the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  move relative to each other (see  FIG.  14   ). Here, the side wall  410  is arranged to overlap the entire area of the contact region R 2 . 
     Here, in the present embodiment, one movable contact maker  322  includes two movable contacts (second contact)  321  arranged side by side in the Y axis (the axis crossing the axis in which the first contact and the second contact move relative to each other). Further, one (for example, on the left side in  FIG.  14   ) of the two body parts (first body part)  312  has one fixed contact (first contact)  311 , and the other (for example, on the right side in  FIG.  14   ) of the two body parts  312  has the other fixed contact (first contact)  311 . 
     One movable contact  321  of the two movable contacts (second contact)  321  contacts with and separates from one fixed contact  311  of the two fixed contacts (first contact)  311 , and the other movable contact  321  contacts with and separates from the other fixed contact  311 . 
     Thus, in the present embodiment, the yoke  40  includes a first yoke  440  arranged on one end where one fixed contact  311  and one movable contact  321 , which contact with and separate from each other, are located, and a second yoke  450  arranged on the other end where the other fixed contact  311  and the other movable contact  321 , which contact with and separate from each other, are located. The first yoke  440  and the second yoke  450  are connected by a connecting section  460 . 
     As described above, in the present embodiment, one in which the first yoke  440  and the second yoke  450  are integrated by the connecting section  460  is exemplified as the yoke  40 . 
     In the present embodiment, the yoke  40  has a shape in which a notch  40   a  is provided at the center part in the Y axis, and the length in the Z axis of the center part in the Y axis is shorter than those of both end parts in the Y axis. The notch  40   a  is provided to prevent the yoke  40  from interfering with the movable body  330 . 
     A section where the notch  40   a  is formed at the center part in the Y axis serves as the connecting section  460 , and sections at both ends in the Y axis serve as the first yoke  440  and the second yoke  450 . Making the length of the connecting section  460  in the Z axis shorter than those of the first yoke  440  and the second yoke  450  as described above enables the magnetic flux B generated around the movable contact maker  322  to be concentrated toward the first yoke  440  and the second yoke  450  in a more efficient manner, thereby enhancing the intensity of the magnetic flux B generated around the contacts (the fixed contacts  311  and the movable contacts  321  contacting and separating each other). 
     In the present embodiment, the yoke  40  is fixed to the movable contact maker (the body part adjacent to the yoke  40 )  322 . 
     Specifically, the movable contact maker  322  is held between the top wall  420  and the bottom wall  430  to fix the yoke  40  to the movable contact maker  322 . Note that the yoke  40  may be fixed to the movable contact maker  322  by means of caulking, brazing, adhesive, or the like. 
     Then, by holding the movable contact maker  322  between the top wall  420  and the bottom wall  430 , a lower surface  420   a  of the top wall  420  comes in surface contact with an upper surface (third surface)  322   c  provided in continuation from the front surface  322   a  and the rear surface  322   b  of the movable contact maker  322 . The upper surface  430   a  of the bottom wall  430  comes in surface contact with a lower surface (third surface)  322   c  provided in continuation from the front surface  322   a  and the rear surface  322   b  of the movable contact maker  322 . 
     As described above, in the present embodiment, the top wall  420  and the bottom wall  430  of the yoke  40  constitute a section arranged along the third surface provided in continuation from the front surface  322   a  and the rear surface  322   b  of the movable contact maker  322 . 
     The tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are made to protrude forward (outward) from the front surface (first surface)  322   a  of the movable contact maker  322 . 
     In the present embodiment, since the movable contact  321  is formed in the movable contact maker  322  through rivet joining, a gap is formed between the front surface  411  of the side wall  410  and the back surface (outer surface)  322   b  of the movable contact maker (the body part adjacent to the yoke  40 )  322  with the yoke  40  fixed to the movable contact maker  322 . 
     Thus, in the present embodiment, the side wall  410  of the yoke  40  is also a section spaced apart from the outer surface (back surface  322   b ) of the body part (movable contact maker  322 ) to face the yoke  40 . 
     Note that in the present embodiment, the yoke  40  is arranged on the movable contact maker (second body part)  322  as an example, but the yoke  40  may be arranged on the body parts (first body part)  312 . 
     In this case, the front surface  312   a  of the body part  312 , which is a surface to face the opposing body part (second body part  322 ), serves as the first surface. The back surface  312   b  of the body part  312 , which is a surface opposite to the surface to face the opposing body part (first body part  312 ), serves as the second surface. The upper surface  312   c  provided in continuation from the front surface  312   a  and the rear surface  312   b  of the body part  312  serves as the third surface. 
     The present embodiment has a configuration that enables the arcs A generated between the movable contacts  321  and the fixed contacts  311  to be moved more quickly away from the movable contacts  321  and the fixed contacts  311 . 
     Specifically, as illustrated in  FIGS.  7 ,  8 , and  15   , each body part (first body part)  312  has a first protrusion part  3121  protruding toward the movable contact maker (second body part)  322  formed at an end part of the body part in the Y axis (an axis crossing the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other). 
     In the present embodiment, the first protrusion part  3121  is formed on the body part  312  by forming a notch  3122  extending in the Y axis and opening outward in the Y axis below the fixed contact  311 , and by bending the end at the outward side in the Y axis and above the notch  3122  backward (toward the movable contact maker  322 ). 
     Here, the first protrusion part  3121  is formed so that a tip  3121   a  of the first protrusion part  3121  is located to the rear (closer to the movable contact maker  322 ) of a tip (top)  311   a  of the fixed contact  311 . 
     Second protrusion parts  3221  protruding toward the body parts (first body part)  312  are formed at both ends of the movable contact maker (second body part)  322  in the Y axis (an axis crossing the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other). 
     In the present embodiment, the second protrusion parts  3221  are formed on the movable contact maker  322  by forming the movable contact maker  322  in a shape in which both ends in the Y axis of a substantially rectangular plate-like member elongated in the Y axis are bent forward (toward the body parts  312 ). 
     Here, the second protrusion parts  3221  are formed so that tips  3221   a  of the second protrusions  3221  are located in front (closer to the body part  312 ) of tips (tops)  321   a  of the movable contacts  321 . 
     In the present embodiment, the tip  3221   a  of the second protrusion part  3221  is positioned more inwardly in the Y axis (the axis crossing the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other) than the tip  3121   a  of the first protrusion part  3121  (see  FIG.  15   ). 
     By forming the body parts (first body part)  312  and the movable contact maker (second body part)  322  in the shape described above, when an arc A is generated between the movable contact  321  and the fixed contact  311 , starting points (discharge point) A 1  of the arc A are respectively moved toward the first protrusion part  3121  and the second protrusion part  3221  from the movable contact  321  and the fixed contact  311 . 
     Specifically, a Lorentz force outwardly in the Y axis acts on the arc A generated between the movable contact  321  and the fixed contact  311 , so that the arc A is elongated outwardly in the Y axis, and thus the arc A generated between the movable contact  321  and the fixed contact  311  moves to the first protrusion part  3121  and the second protrusion part  3221 . 
     Here, in the present embodiment, the notch  3122  is formed below the fixed contact  311  of the body part  312 , and the first protrusion part  3121  is formed above the notch  3122 . 
     Thus, by providing the notch  3122  in the body part  312 , the arc A moves outward in the Y axis along the notch  3122  with the Lorentz force acting on the arc A. This enables the arc A to be moved away from the fixed contact  311  more quickly. 
     In the present embodiment, since the tip  3221   a  of the second protrusion part  3221  is located more inward in the Y axis than the tip  3121   a  of the first protrusion part  3121 , the arc A moved to the first protrusion part  3121  and the second protrusion part  3221  is thus extended outward in the Y axis and backward in the X axis. 
     Thus, in the present embodiment, as illustrated in  FIG.  16   , a space is formed outside the first protrusion parts  3121  and the second protrusion parts  3221  in the Y axis and behind them in the X axis with the body parts  312  and the movable contact maker  322  housed in the case  10 . 
     In this way, it is possible to prevent in a more reliable manner the case  10  and members housed in the case  10  from being affected by the arc A extended outward in the Y axis and backward in the X axis. 
     Note that as illustrated in  FIG.  17   , the tip of the second protrusion part may be located more outside than the tip of the first protrusion part in the axis crossing the axis in which the first contact and the second contact move relative to each other. 
     For example, when a space is formed outside the first protrusion part  3121  and the second protrusion part  3221  in the Y axis and in front of them in the X axis with the body parts  312  and the movable contact maker  322  housed in the case  10 , the configuration illustrated in  FIG.  17    is preferable. 
     Note that in the present embodiment, both the body parts (first body part)  312  and the movable contact maker (second body part)  322  are provided with protrusions as an example, but either of them may be provided with protrusions, or no protrusions may be provided. 
     Next, with reference to  FIGS.  18  to  45   , description is given of a various arrangement pattern of the yoke  40 . Note that,  FIGS.  18  to  45    are given of the movable contact maker (second body part)  322  as the body part adjacent to the yoke  40 . However, it is also possible to make the body parts (first body part)  312  as the body part adjacent to the yoke  40 . 
     At least a part of each yoke  40  shown in  FIGS.  18  to  45    is arranged along the magnetic flux B that is generated by the current I flowing through the movable contact maker (the body part adjacent to the yoke  40 )  322  and is generated in the region R 1 . 
     Here,  FIGS.  18  to  32    are given of the arrangement pattern of the yoke  40 , when the movable contact maker (the body part adjacent to the yoke  40 )  322  has two contacts (when one body part has two contacts). 
     First, it is possible to arrange the yoke  40  shown in  FIG.  18    adjacent to the movable contact maker  322  having two contacts. 
     The yoke  40  shown in  FIG.  18    has substantially the same structure as the yoke  40  described in the above embodiment. That is, one in which the first yoke  440  and the second yoke  450  are integrated by the connecting section  460  is exemplified as the yoke  40  shown in  FIG.  18   . Note that the yoke  40  shown in  FIG.  18    has a shape in which a notch  40   a  is not provided and the length in the vertical axis of the connecting section  460  is the same as that of the first yoke  440  and the second yoke  450 . 
     Further, the yoke  40  shown in  FIG.  18    includes the sidewall  410 , the top wall  420  and the bottom wall  430 , and is fixed to the movable contact maker  322 . 
     Then, the front surface  411  of the side wall  410  is arranged to face the back surface (second surface)  322   b  of the movable contact maker  322  with the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  facing the opposing body part (in  FIG.  18   , body part  312 ). 
     The side wall  410  is also arranged to overlap the entire area of the contact region R 2  where the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  come into contact, when viewed along the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other. 
     Here, the yoke  40  shown in  FIG.  18    is arranged in such a state that the front surface  411  of the side wall  410  comes in surface contact with the back surface (second surface)  322   b  of the movable contact maker  322 . Thus, when the front surface  411  of the side wall  410  comes in surface contact with the back surface (second surface)  322   b  of the movable contact maker  322 , it is possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Also, in the yoke  40  shown in  FIG.  18   , the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are made to protrude outward from the front surface (first surface)  322   a  of the movable contact maker  322 . 
     Further, in the yoke  40  shown in  FIG.  18   , the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are made to protrude outward from tips (tops)  321   a  of the movable contacts  321 . This makes it possible to exist the yoke  40  concentrating the magnetic flux B upward and downward of the arc A. Therefore, it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  19    may be realized. The yoke  40  shown in  FIG.  19    also has substantially the same structure as the yoke  40  shown in  FIG.  18   . 
     Here, in the yoke  40  shown in  FIG.  19   , the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are not made to protrude outward from the front surface (first surface)  322   a  of the movable contact maker  322 . 
     Note that, in  FIG.  19   , the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are substantially flush with the front surface (first surface)  322   a  of the movable contact maker  322  as an example, but at least one of the tip  421  of the top wall  420  or the tip  431  of the bottom wall  430  may be located inside to the front surface (first surface)  322   a  of the movable contact maker  322 . 
     Alternatively, the yoke  40  shown in  FIG.  20    may be realized. The yoke  40  shown in  FIG.  20    does not include the top wall  420  and the bottom wall  430 , only includes the sidewall  410 . 
     That is, the yoke  40  shown in  FIG.  20    is only arranged to the back surface (second surface)  322   b  of the movable contact maker  322 . This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  21    may be realized. The yoke  40  shown in  FIG.  21    has a shape in which the section of the top wall  420  and the bottom wall  430  protruded outward from the movable contact maker  322  extend to the movable contacts  321 . 
     That is, the yoke  40  shown in  FIG.  21    is arranged so as to surround the movable contact maker  322 . This makes it possible to more concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to more increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, in the yoke  40  shown in  FIG.  21   , a section that the movable contacts  321  is formed has a belt-shaped exposed part (part uncovered in the yoke  40 ) extended from one end to the other end in the longitudinal axis when viewed from the front surface (first surface)  322   a  of the movable contact maker  322 . That is, the yoke  40  shown in  FIG.  21    has an approximate C-shape in a state viewed along the longitudinal axis of the movable contact maker  322 . This makes it possible to fix the yoke  40  to the movable contact maker  322  without interfering with the movable contacts  321 . 
     Alternatively, the yoke  40  shown in  FIG.  22    may be realized. In the yoke  40  shown in  FIG.  22   , the tip  421  of the top wall  420  is made to protrude outward from tips (tops)  321   a  of the movable contacts  321 , but the tip  431  of the bottom wall  430  is not made to protrude outward from the front surface (first surface)  322   a  of the movable contact maker  322 . 
     That is, the yoke  40  shown in  FIG.  22    has an asymmetrical shape in the vertical axis when viewed along the longitudinal axis of the movable contact maker  322 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, in the yoke  40  shown in  FIG.  22   , the tip  421  of the top wall  420  is made to protrude outward from tips (tops)  321   a  of the movable contacts  321  as an example, but the tip  421  of the top wall  420  may be made not to protrude outward from tips (tops)  321   a  of the movable contacts  321 . 
     Alternatively, the yoke  40  shown in  FIG.  23    may be realized. The yoke  40  shown in  FIG.  23    has substantially the same structure as the yoke  40  shown in  FIG.  18   . 
     Here, the yoke  40  shown in  FIG.  23    is arranged to overlap the movable contact maker  322  between outer end of one movable contacts  321  and outer end of the other movable contacts  321 , when viewed along the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other. 
     That is, in  FIG.  23   , the yoke  40  is arranged so as to surround a region where the two movable contacts  321  are formed in the movable contact maker  322 . 
     This makes it possible to prevent from concentrating the magnetic flux B outer side of the movable contacts  321  where the arc A is not generated. Therefore, it is possible to more concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to more increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, the yoke  40  shown in  FIG.  23    is arranged to overlap the entire area of the contact region R 2  where the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  come into contact, when viewed along the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other. 
     Alternatively, the yoke  40  shown in  FIG.  24    may be realized. The yoke  40  shown in  FIG.  24    also has substantially the same structure as the yoke  40  shown in  FIG.  23   . 
     Here, the yoke  40  shown in  FIG.  24    is arranged to overlap a part of the contact region R 2  where the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  come into contact, when viewed along the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other. 
     This also makes it possible to more concentrate the magnetic flux B near the movable contacts  321 , and it is possible to more increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, in  FIG.  24   , only inner ends in the longitudinal axis of the two movable contacts  321  are overlapped to the yoke  40  as an example, but substantially inner half portions in the longitudinal axis of the two movable contacts  321  may be overlapped to the yoke  40 . 
     Alternatively, the yoke  40  shown in  FIG.  25    may be realized. In  FIG.  25   , the yoke (yoke separated into two parts)  40  in which the first yoke  440  and the second yoke  450  are not integrated by the connecting section  460  is exemplified. 
     That is, in the yoke  40  shown in  FIG.  25   , the first yoke  440  arranged on the side where one movable contact  321  of the two movable contacts  321  is located and the second yoke  450  arranged on the side where the other movable contact  321  is located are formed separately. 
     Thus, when the first yoke  440  and the second yoke  450  are not integrated by the connecting section  460 , the magnetic flux B that will be generated around the connecting section  460  can be taken into the first yoke  440  or the second yoke  450 . Therefore, it is possible to more concentrate the magnetic flux B near the movable contacts  321 , and it is possible to more increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, in  FIG.  25   , both the first yoke  440  and the second yoke  450  are arranged to overlap the entire area of the contact region R 2  when viewed along the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other, but at least one of the first yoke  440  or the second yoke  450  may be arranged to overlap a part of the contact region R 2 . 
     Alternatively, the yoke  40  shown in  FIG.  26    may be realized. In the yoke  40  shown in  FIG.  26   , the first yoke  440  and the second yoke  450  are formed separately as in the yoke  40  shown in  FIG.  25   . 
     Here, in  FIG.  26   , the shape of the first yoke  440  and the shape of the second yoke  450  are different from each other. 
     Specifically, the shape of the first yoke  440  is such that the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are not made to protrude outward from the front surface (first surface)  322   a  of the movable contact maker  322 . In contrast, the shape of the second yoke  450  is such that the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are made to protrude outward from the front surface (first surface)  322   a  of the movable contact maker  322 . 
     This makes it possible that the magnetic flux B that will be generated around the connecting section  460  can be taken into the first yoke  440  or the second yoke  450 . Therefore, it is possible to more concentrate the magnetic flux B near the movable contacts  321 , and it is possible to more increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, in  FIG.  26   , at least one of the first yoke  440  or the second yoke  450  may be arranged to overlap a part of the contact region R 2 . 
     Alternatively, the first yoke  440  and the second yoke  450  can be different in shape in various ways. 
     Alternatively, the yoke  40  shown in  FIG.  27    may be realized. The yoke  40  shown in  FIG.  27    also has substantially the same structure as the yoke  40  shown in  FIG.  21   . That is, the yoke  40  shown in  FIG.  27    has a shape in which the section of the top wall  420  and the bottom wall  430  protruded outward from the movable contact maker  322  extend to the movable contacts  321 . 
     Here, in  FIG.  27   , the yoke  40  is composed of two yokes  470 , 480  which are vertically divided into two. 
     Specifically, the yoke  40  shown in  FIG.  27    has a shape such that the sidewall  410  of the yoke  40  shown in  FIG.  21    is separated at the central part in the vertical axis. 
     Then, a section that the movable contact  321  is formed has a belt-shaped exposed part (part uncovered in the yoke  40 ) extended from one end to the other end in the longitudinal axis when viewed from the front surface (first surface)  322   a  of the movable contact maker  322  in a state where the two yokes  470 , 480  which are vertically divided into two are fixed to the movable contact maker  322 . 
     Further, a central part in the vertical axis has a belt-shaped exposed part (part uncovered in the yoke  40 ) extended from one end to the other end in the longitudinal axis when viewed from the back surface (second surface)  322   b  of the movable contact maker  322  in a state where the two yokes  470 , 480  which are vertically divided into two are fixed to the movable contact maker  322 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Further, when the yoke  40  which surround the movable contact maker  322  is divided into two in the vertical axis, it is possible that the yoke  40  is fixed to the movable contact maker  322  more easily. 
     Alternatively, the yoke  40  shown in  FIG.  28    may be realized. The yoke  40  shown in  FIG.  28    also has substantially the same structure as the yoke  40  described in the above embodiment. That is, one in which the first yoke  440  and the second yoke  450  are integrated by the connecting section  460  is exemplified as the yoke  40  shown in  FIG.  28   . 
     Also, in the yoke  40  shown in  FIG.  28   , the notch  40   a  is provided at the connecting section  460 . 
     Here, in the yoke  40  shown in  FIG.  28   , the notch  40   a  is formed not only at the top wall  420  but also at the bottom wall  430 . 
     That is, in the yoke  40  shown in  FIG.  28   , the first yoke  440  and the second yoke  450  are connected only the sidewall  410 . 
     This makes it possible to become the length of the connecting section  460  in the vertical axis shorter, and to prevent from concentrating the magnetic flux B near the connecting section  460 . Therefore, it is possible to more concentrate the magnetic flux B near the movable contacts  321 , and it is possible to more increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  29    may be realized. In the yoke  40  shown in  FIG.  29   , the top wall  420  is arranged on one side in the longitudinal axis and the bottom wall  430  is arranged on the other side in a state of being fixed to the movable contact maker  322 . 
     Then, the top wall  420  and the bottom wall  430  arranged in an offset state in the longitudinal axis are connected by the side wall  410  on the back surface (second surface)  322   b  side of the movable contact maker  322 . 
     In  FIG.  29   , the side wall  410  is formed so as to extend diagonally along the diagonal line of the movable contact maker  322  when viewed from the back surface (second surface)  322   b  of the movable contact maker  322 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  30    may be realized. The yoke  40  shown in  FIG.  30    also has substantially the same structure as the yoke  40  shown in  FIG.  18   . 
     Here, in the yoke  40  shown in  FIG.  30   , the side wall  410 , the top wall  420 , and the bottom wall  430  are formed as separate parts respectively. 
     Here, the yoke  40  may be composed of the side wall  410 , the top wall  420 , and the bottom wall  430 , which are separately formed by using the same material, or the side wall  410 , the top wall  420  and the bottom wall  430  may be formed by using different materials respectively. Alternatively, any one of the side wall  410 , the top wall  420  and the bottom wall  430  may be formed by using a material different from the other two. 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  31    may be realized. In the yoke  40  shown in  FIG.  31   , the side wall  410 , the top wall  420 , and the bottom wall  430  are formed as separate parts respectively as in the yoke  40  shown in  FIG.  30   . 
     Here, the yoke  40  shown in  FIG.  31    is arranged so as to surround the movable contact maker  322  with a gap formed between the top wall  420  and the side wall  410  and between the bottom wall  430  and the side wall  410 . 
     Specifically, the side wall  410  is arranged so as to be separated from the back surface (second surface)  322   b  of the movable contact maker  322 . By doing so, the gap is formed between the top wall  420  and the side wall  410  and between the bottom wall  430  and the side wall  410 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Further, when the side wall  410  is separated from the back surface (second surface)  322   b  of the movable contact maker  322 , the yoke  40  (side wall  410 ) is arranged in a space where the distance from the movable contact maker  322  becomes long and the strength of the magnetic flux B becomes weak. This makes it possible to concentrate the magnetic flux B around the movable contact maker  322  more efficiently. 
     Note that, in  FIG.  31   , the gap is formed between the top wall  420  and the side wall  410  and between the bottom wall  430  and the side wall  410  as an example, but either one of the top wall  420  and the bottom wall  430  may be in contact with the side wall  410 . 
     Further, any one or more parts selected from the side wall  410 , the top wall  420 , and the bottom wall  430  may be separated from the movable contact maker  322 . 
     Alternatively, the yoke  40  shown in  FIG.  32    may be realized. The yoke  40  shown in  FIG.  32    also has substantially the same structure as the yoke  40  shown in  FIG.  18   . 
     Here, in  FIG.  32   , the yoke  40  in which the side wall  410 , the top wall  420 , and the bottom wall  430  are integrated is used, and the entire yoke  40  is separated from the outer surface of the movable contact maker  322  in such a state that the yoke  40  is arranged so as to surround the movable contact maker  322 . 
     That is, in  FIG.  32   , a gap is formed between the yoke  40  and movable contact maker  322 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Next, with reference to  FIGS.  33  to  45   , description is given of a various arrangement pattern of the yoke  40 . 
     Here,  FIGS.  33  to  45    are given of the arrangement pattern of the yoke  40 , when the movable contact maker (the body part adjacent to the yoke  40 )  322  has one contact (when one body part has only one contact). 
     First, it is possible to arrange the yoke  40  shown in  FIG.  33    adjacent to the movable contact maker  322  having one contact. 
     The yoke  40  shown in  FIG.  33    has substantially the same structure as the yoke  40  shown in  FIG.  18   . 
     Specifically, the yoke  40  shown in  FIG.  33    includes the sidewall  410 , the top wall  420  and the bottom wall  430 , and is fixed to the movable contact maker  322 . 
     Then, the front surface  411  of the side wall  410  is arranged to face the back surface (second surface)  322   b  of the movable contact maker  322  with the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  facing the opposing body part (in  FIG.  33   , body part  312 ). 
     The side wall  410  is also arranged to overlap the entire area of the contact region R 2  where the fixed contacts (first contact)  311  and the movable contacts (second contact)  321  come into contact, when viewed along the axis in which the fixed contacts  311  and the movable contacts  321  move relative to each other. 
     Here, the yoke  40  shown in  FIG.  33    is also arranged in such a state that the front surface  411  of the side wall  410  comes in surface contact with the back surface (second surface)  322   b  of the movable contact maker  322 . Thus, when the front surface  411  of the side wall  410  comes in surface contact with the back surface (second surface)  322   b  of the movable contact maker  322 , it is possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Also, in the yoke  40  shown in  FIG.  33   , the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are made to protrude outward from the front surface (first surface)  322   a  of the movable contact maker  322 . 
     Further, in the yoke  40  shown in  FIG.  33   , the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are made to protrude outward from tips (tops)  321   a  of the movable contacts  321 . This makes it possible to exist the yoke  40  concentrating the magnetic flux B upward and downward of the arc A. Therefore, it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  34    may be realized. The yoke  40  shown in  FIG.  34    also has substantially the same structure as the yoke  40  shown in  FIG.  33   . 
     Here, in the yoke  40  shown in  FIG.  34   , the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are not made to protrude outward from the front surface (first surface)  322   a  of the movable contact maker  322 . 
     Note that, in  FIG.  34   , the tip  421  of the top wall  420  and the tip  431  of the bottom wall  430  are substantially flush with the front surface (first surface)  322   a  of the movable contact maker  322  as an example, but at least one of the tip  421  of the top wall  420  or the tip  431  of the bottom wall  430  may be located inside to the front surface (first surface)  322   a  of the movable contact maker  322 . 
     Alternatively, the yoke  40  shown in  FIG.  35    may be realized. The yoke  40  shown in  FIG.  35    does not include the top wall  420  and the bottom wall  430 , only includes the sidewall  410 . 
     That is, the yoke  40  shown in  FIG.  35    is only arranged to the back surface (second surface)  322   b  of the movable contact maker  322 . This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  36    may be realized. The yoke  40  shown in  FIG.  36    has a shape in which the section of the top wall  420  and the bottom wall  430  protruded outward from the movable contact maker  322  extend to the movable contact  321 . 
     That is, the yoke  40  shown in  FIG.  36    is arranged so as to surround the movable contact maker  322 . This makes it possible to more concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to more increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, in the yoke  40  shown in  FIG.  36   , a section that the movable contact  321  is formed has a belt-shaped exposed part (part uncovered in the yoke  40 ) extended from one end to the other end in the longitudinal axis when viewed from the front surface (first surface)  322   a  of the movable contact maker  322 . That is, the yoke  40  shown in  FIG.  36    has an approximate C-shape in a state viewed along the longitudinal axis of the movable contact maker  322 . This makes it possible to fix the yoke  40  to the movable contact maker  322  without interfering with the movable contact  321 . 
     Alternatively, the yoke  40  shown in  FIG.  37    may be realized. In the yoke  40  shown in  FIG.  37   , the tip  421  of the top wall  420  is made to protrude outward from tip (top)  321   a  of the movable contact  321 , but the tip  431  of the bottom wall  430  is not made to protrude outward from the front surface (first surface)  322   a  of the movable contact maker  322 . 
     That is, the yoke  40  shown in  FIG.  37    has an asymmetrical shape in the vertical axis when viewed along the longitudinal axis of the movable contact maker  322 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, in the yoke  40  shown in  FIG.  37   , the tip  421  of the top wall  420  is made to protrude outward from tip (top)  321   a  of the movable contact  321  as an example, but the tip  421  of the top wall  420  may be made not to protrude outward from tip (top)  321   a  of the movable contact  321 . 
     Alternatively, the yoke  40  shown in  FIG.  38    may be realized. 
     The yoke  40  shown in  FIG.  38    is arranged to overlap the movable contact maker  322  between outer end of the movable contact  321  in the longitudinal axis and an end of center side, when viewed along the axis in which the fixed contact  311  and the movable contact  321  move relative to each other. 
     This makes it possible to prevent from concentrating the magnetic flux B outer side of the movable contacts  321  where the arc A is not generated. Therefore, it is possible to more concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to more increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, the yoke  40  shown in  FIG.  38    is arranged to overlap the entire area of the contact region R 2  where the fixed contact (first contact)  311  and the movable contact (second contact)  321  come into contact, when viewed along the axis in which the fixed contact  311  and the movable contact  321  move relative to each other. 
     Alternatively, the yoke  40  shown in  FIG.  39    may be realized. 
     The yoke  40  shown in  FIG.  39    is arranged to overlap a part of the contact region R 2  where the fixed contact (first contact)  311  and the movable contact (second contact)  321  come into contact, when viewed along the axis in which the fixed contact  311  and the movable contact  321  move relative to each other. 
     This also makes it possible to more concentrate the magnetic flux B near the movable contact  321 , and it is possible to more increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, in  FIG.  39   , only end of center side in the longitudinal axis of the movable contact  321  is overlapped to the yoke  40  as an example, but substantially half portion of center side in the longitudinal axis of the movable contact  321  may be overlapped to the yoke  40 . 
     Alternatively, the yoke  40  shown in  FIG.  40    may be realized. The yoke  40  shown in  FIG.  40    also has substantially the same structure as the yoke  40  shown in  FIG.  36   . That is, the yoke  40  shown in  FIG.  40    has a shape in which the section of the top wall  420  and the bottom wall  430  protruded outward from the movable contact maker  322  extend to the movable contact  321 . 
     Here, in  FIG.  40   , the yoke  40  is composed of two yokes  470 , 480  which are vertically divided into two. 
     Specifically, the yoke  40  shown in  FIG.  40    has a shape such that the sidewall  410  of the yoke  40  shown in  FIG.  36    is separated at the central part in the vertical axis. 
     Then, a section that the movable contact  321  is formed has a belt-shaped exposed part (part uncovered in the yoke  40 ) extended from one end to the other end in the longitudinal axis when viewed from the front surface (first surface)  322   a  of the movable contact maker  322  in a state where the two yokes  470 , 480  which are vertically divided into two are fixed to the movable contact maker  322 . 
     Further, a central part in the vertical axis has a belt-shaped exposed part (part uncovered in the yoke  40 ) extended from one end to the other end in the longitudinal axis when viewed from the back surface (second surface)  322   b  of the movable contact maker  322  in a state where the two yokes  470 , 480  which are vertically divided into two are fixed to the movable contact maker  322 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Further, when the yoke  40  which surround the movable contact maker  322  is divided into two in the vertical axis, it is possible that the yoke  40  is fixed to the movable contact maker  322  more easily. 
     Alternatively, the yoke  40  shown in  FIG.  41    may be realized. 
     The yoke  40  shown in  FIG.  41    includes the sidewall  410 , the top wall  420  and the bottom wall  430 . 
     Here, in the yoke  40  shown in  FIG.  41   , the top wall  420  and the bottom wall  430  are formed only at the section that the movable contact  321  of the movable contact maker  322  is formed. 
     That is, the yoke  40  shown in  FIG.  41    has a shape in which a section (top wall  420  and bottom wall  430 ) arranged on a section of the movable contact maker  322  where the movable contact  321  is not formed is cut off. 
     In this way, the length of the circumference of the yoke  40  arranged on the section of the movable contact maker  322  where the movable contact  321  is not formed is shorter than the length of the circumference of the yoke  40  arranged on a section of the movable contact maker  322  where the movable contact  321  is formed. Therefore, it is possible to more concentrate the magnetic flux B near the movable contact  321 , and to more increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  42    may be realized. In the yoke  40  shown in  FIG.  42   , the top wall  420  is arranged on one side in the longitudinal axis and the bottom wall  430  is arranged on the other side in a state of being fixed to the movable contact maker  322 . 
     Then, the top wall  420  and the bottom wall  430  arranged in an offset state in the longitudinal axis are connected by the side wall  410  on the back surface (second surface)  322   b  side of the movable contact maker  322 . 
     In  FIG.  42   , the side wall  410  is formed so as to extend diagonally along the diagonal line of the movable contact maker  322  when viewed from the back surface (second surface)  322   b  of the movable contact maker  322 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  43    may be realized. The yoke  40  shown in  FIG.  43    also has substantially the same structure as the yoke  40  shown in  FIG.  33   . 
     Here, in the yoke  40  shown in  FIG.  43   , the side wall  410 , the top wall  420 , and the bottom wall  430  are formed as separate parts respectively. 
     Here, the yoke  40  may be composed of the side wall  410 , the top wall  420 , and the bottom wall  430 , which are separately formed by using the same material, or the side wall  410 , the top wall  420  and the bottom wall  430  may be formed by using different materials respectively. Alternatively, any one of the side wall  410 , the top wall  420  and the bottom wall  430  may be formed by using a material different from the other two. 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Alternatively, the yoke  40  shown in  FIG.  44    may be realized. In the yoke  40  shown in  FIG.  44   , the side wall  410 , the top wall  420 , and the bottom wall  430  are formed as separate parts respectively as in the yoke  40  shown in  FIG.  43   . 
     Here, the yoke  40  shown in  FIG.  44    is arranged so as to surround the movable contact maker  322  with a gap formed between the top wall  420  and the side wall  410  and between the bottom wall  430  and the side wall  410 . 
     Specifically, the side wall  410  is arranged so as to be separated from the back surface (second surface)  322   b  of the movable contact maker  322 . By doing so, the gap is formed between the top wall  420  and the side wall  410  and between the bottom wall  430  and the side wall  410 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Further, when the side wall  410  is separated from the back surface (second surface)  322   b  of the movable contact maker  322 , the yoke  40  (side wall  410 ) is arranged in a space where the distance from the movable contact maker  322  becomes long and the strength of the magnetic flux B becomes weak. This makes it possible to concentrate the magnetic flux B around the movable contact maker  322  more efficiently. 
     Note that, in  FIG.  44   , the gap is formed between the top wall  420  and the side wall  410  and between the bottom wall  430  and the side wall  410  as an example, but either one of the top wall  420  and the bottom wall  430  may be in contact with the side wall  410 . 
     Further, any one or more parts selected from the side wall  410 , the top wall  420 , and the bottom wall  430  may be separated from the movable contact maker  322 . 
     Alternatively, the yoke  40  shown in  FIG.  45    may be realized. The yoke  40  shown in  FIG.  45    also has substantially the same structure as the yoke  40  shown in  FIG.  33   . 
     Here, in  FIG.  45   , the yoke  40  in which the side wall  410 , the top wall  420 , and the bottom wall  430  are integrated is used, and the entire yoke  40  is separated from the outer surface of the movable contact maker  322  in such a state that the yoke  40  is arranged so as to surround the movable contact maker  322 . 
     That is, in  FIG.  45   , a gap is formed between the yoke  40  and movable contact maker  322 . 
     This also makes it possible to concentrate the magnetic flux B near the outer surface of the movable contact maker  322 , and it is possible to increase the intensity of the magnetic flux B acting on the arc A. 
     Note that, in the above embodiment and its modifications, the yoke  40  is arranged adjacent to the body part (first body part)  312  or the movable contact maker (second body part)  322  as an example. That is, the yoke  40  is arranged adjacent to only one of the first body part  312  and the second body part  322  as an example. 
     However, the configuration of the contact device  30  is not limited to the configuration in which the yoke  40  is arranged adjacent to only one body part, and the yoke  40  may be arranged adjacent to both of the body part (first body part)  312  and the movable contact maker (second body part)  322  (see  FIGS.  46  to  49   ). 
     Further, in  FIGS.  46  to  49   , the body part (first body part)  312  and the movable contact maker (second body part)  322  are arranged so that the direction in which the current I flows in the region R 1  of the body part (first body part)  312  is different from the direction in which the current I flows in the region R 1  of the movable contact maker (second body part)  322 . That is, the body part (first body part)  312  and the movable contact maker (second body part)  322  are arranged so that an angle formed between the vector of the current I flowing through the body part (first body part)  312  and the vector of the current I flowing through the movable contact maker (second body part)  322  is larger than 0° and less than or equal to 180°. 
     Here, the region R 1  is a region where the body part (first body part)  312  and the movable contact maker (second body part)  322  overlap each other when viewed along the axis in which the fixed contact (first contact)  311  and the movable contact (second contact)  321  move relative to each other. 
     In  FIG.  46   , an angle formed between the direction of the current I flowing through the body part (first body part)  312  in which the yoke  40  is arranged and the direction of the current I flowing through the movable contact maker (second body part)  322  in which the other yoke  40  is arranged is 180° as an example. That is, the body part (first body part)  312  and the movable contact maker (second body part)  322  are arranged so that the current I flowing through the body part (first body part)  312  and the current I flowing through the movable contact maker (second body part)  322  flow in opposite directions to each other. 
     In  FIG.  47   , an angle formed between the direction of the current I flowing through the body part (first body part)  312  in which the yoke  40  is arranged and the direction of the current I flowing through the movable contact maker (second body part)  322  in which the other yoke  40  is arranged is 90° as an example. That is, the body part (first body part)  312  and the movable contact maker (second body part)  322  are arranged so that the current I flowing through the body part (first body part)  312  and the current I flowing through the movable contact maker (second body part)  322  flow in orthogonal directions to each other. 
     In  FIG.  48   , an angle formed between the direction of the current I flowing through the body part (first body part)  312  in which the yoke  40  is arranged and the direction of the current I flowing through the movable contact maker (second body part)  322  in which the other yoke  40  is arranged is an obtuse angle (larger than 90° and less than 180°) as an example. 
     In  FIG.  49   , an angle formed between the direction of the current I flowing through the body part (first body part)  312  in which the yoke  40  is arranged and the direction of the current I flowing through the movable contact maker (second body part)  322  in which the other yoke  40  is arranged is an acute angle (larger than 0° and less than 90°) as an example. 
     In this way, when the direction of the current flowing through each main body parts is different, it is possible to prevent the contact device  30  from increasing in size in one axis (for example, the direction of the current flowing through the first main body part). 
     Further, when the direction of the current flowing through each main body parts is different, it is preferable that an angle formed between the vectors of the two currents is larger than or equal to 90° and less than or equal to 180°. This makes it possible to prevent the contact device  30  from increasing in size in one axis more reliably. 
     Note that, in  FIGS.  46  to  49   , the yokes  40  are arranged adjacent to both of the body part (first body part)  312  and the movable contact maker (second body part)  322  as an example, but the yoke  40  may be arranged adjacent to only one of the body part (first body part)  312  and the movable contact maker (second body part)  322 . That is, it is possible that the direction of the current flowing through each main body parts is different, while being arranged the yoke  40  adjacent to only one of the body part (first body part)  312  and the movable contact maker (second body part)  322 . This also makes it possible to prevent the contact device  30  from increasing in size in one axis. 
     [Action/Effect] 
     The following describes characteristic configurations of the contact device and the electromagnetic relay illustrated in the above embodiments and its modifications, and the effect obtained by the configurations. 
     (1) The contact device according to the present embodiment and modifications thereof includes a first contact, a second contact that is movable relative to the first contact and is brought into contact with or separated from the first contact, a first body part including the first contact, a second body part including the second contact, and a yoke arranged adjacent to at least one of the first body part or the second body part. 
     At least a part of the yoke is arranged along magnetic flux generated by a current flowing through one body part of the first body part and the second body part that is adjacent to the yoke, in a region where the first body part and the second body part overlap each other when viewed along an axis in which the first contact and the second contact move relative to each other while the first contact and the second contact are in contact with each other. 
     Thus, it is possible to concentrate the magnetic flux generated around the body part adjacent to the yoke in the yoke. Consequently, it is possible to increase the intensity of the magnetic flux generated around the body part adjacent to the yoke (the magnetic field is strengthened) and to extinguish the arcs generated between the first contact and the second contact in a more reliable and quick manner. 
     As described above, the present embodiment and its modifications make it possible to obtain a contact device capable of preventing the contacts from being affected by arcs in more reliable manner. 
     (2) In the contact device according to the above (1), the body part adjacent to the yoke may include a first surface that faces an opposing body part, and a second surface on an opposite side to the first surface that faces the opposing body part. The yoke may include a section arranged adjacent to the second surface. 
     Thus, it is possible to concentrate the magnetic flux generated around the body part adjacent to the yoke in the yoke in a more efficient manner. 
     It is possible to arrange the yoke around the body part without disturbing the contact and separation between the first contact and the second contact. 
     (3) In the contact device according to the above (1) or (2), the yoke may include a section that overlaps with a contact region in which the first contact and the second contact make contact with each other when viewed along the axis in which the first contact and the second contact move relative to each other. 
     Thus, it is possible to increase the intensity of the magnetic flux generated around the first contact and the second contact (the magnetic field is strengthened) and to extinguish the arcs generated between the first contact and the second contact in a more reliable and quick manner. 
     (4) In the contact device according to any one of the above (1) to (3), the yoke may be arranged to overlap with a contact of the body part adjacent to the yoke when viewed along the axis in which the first contact and the second contact move relative to each other. 
     Thus, it is possible to increase the intensity of the magnetic flux generated around the first contact and the second contact (the magnetic field is strengthened) and to extinguish the arcs generated between the first contact and the second contact in a more reliable and quick manner. 
     (5) In the contact device according to any one of the above (1) to (4), the body part adjacent to the yoke may include a first surface that faces an opposing body part, a second surface on an opposite side to the first surface that faces the opposing body part, and a third surface provided in continuation from the first surface and the second surface. The yoke may include a section arranged along the third surface. 
     Thus, it is possible to further concentrate the magnetic flux around the body part adjacent to the yoke. Consequently, it is possible to increase the intensity of the magnetic flux generated around the body part adjacent to the yoke (the magnetic field is strengthened) and to extinguish the arcs generated between the first contact and the second contact in a more reliable and quick manner. 
     (6) In the contact device according to (5), the section arranged along the third surface of the yoke may protrude outward from the first surface. 
     Thus, it is possible to increase the intensity of the magnetic flux acting on the arcs. 
     (7) In the contact device according to any one of the above (1) to (6), the yoke may include a section arranged spaced apart from an outer surface of the body part adjacent to the yoke. 
     Thus, the yoke is arranged in a space that is farther from the body part adjacent to the yoke and has a weaker intensity of the magnetic flux, and thus it is possible to concentrate the magnetic flux around the body part in a more efficient manner 
     (8) In the contact device according to any one of the above (1) to (7), the yoke may be fixed to the body part adjacent to the yoke. 
     Thus, it is possible to prevent the yoke from being displaced from the body part and to concentrate the magnetic flux around the body part in a more reliable manner 
     (9) In the contact device according to any one of the above (1) to (8), the first contact may include two first contacts, the second contact includes two second contacts, the first body part includes two first body parts, and the second body part includes one second body part. One second contact of the two second contacts may be brought into contact with and is separated from one first contact of the two first contacts, and the other second contact of the two second contacts is brought into contact with and is separated from the other first contact of the two first contacts, The two first contacts may be arranged side by side in an axis intersecting an axis in which the first contacts and the second contacts, which are brought into contact with and are separated from each other, move relative to each other. One of the two first body parts may have the one first contact, and the other of the two first body parts has the other first contact. The one second body part may include the two second contacts. 
     Thus, it is possible to obtain a contact device having a plurality of contacts that are brought into contact with and are separated from each other and capable of preventing the contacts from being affected by arcs in a more reliable manner. 
     (10) In the contact device according to the above (9), the yoke may include a first yoke arranged near where the one first contact and the one second contact, which are brought into contact with and are separated from each other, are located, and a second yoke arranged near where the other first contact and the other second contact, which are brought into contact with and are separated from each other, are located. 
     Thus, it is possible to concentrate the magnetic flux generated around the body part adjacent to the yoke around contacts on one end and around contacts on the other end. 
     (11) In the contact device according to the above (10), the yoke may include a connecting section connecting the first yoke and the second yoke. 
     Thus, even in the contact device including a plurality of contacts to be brought into contact with and be separated from each other, it is possible to arrange the yoke around the body part in an easier manner. 
     (12) In the contact device according to any one of the above (1) to (11), the first body part may include a first protrusion part that protrudes toward the second body part at an end part of the first body part in an axis crossing the axis in which the first contact and the second contact move relative to each other. 
     Thus, it is possible to move the discharge point (ignition point) on the first body part of the arc generated between the first contact and the second contact to the first protrusion. 
     (13) In the contact device according to the above (12), a tip of the first protrusion part may be located closer to the second body part than a tip of the first contact to the second body part. 
     Thus, it is possible to move the discharge point (ignition point) on the first body part of the arc generated between the first contact and the second contact to the first protrusion in a more reliable manner 
     (14) In the contact device according to any one of the above (1) to (11), the second body part may include a second protrusion part that protrudes toward the first body part at an end part of the second body part in an axis crossing the axis in which the first contact and the second contact move relative to each other. 
     Thus, it is possible to move the discharge point (ignition point) on the second body part of the arc generated between the first contact and the second contact to the second protrusion. 
     (15) In the contact device according to the above (14), a tip of the second protrusion part may be located closer to the first body part than a tip of the second contact to the first body part. 
     Thus, it is possible to move the discharge point (ignition point) on the second body part of the arc generated between the first contact and the second contact to the second protrusion in a more reliable manner. 
     (16) In the contact device according to any one of the above (1) to (11), the first body part may include a first protrusion part that protrudes toward the second body part at an end part of the first body part in an axis crossing the axis in which the first contact and the second contact move relative to each other. The second body part may include a second protrusion part that protrudes toward the first body part at an end part of the second body part in an axis crossing the axis in which the first contact and the second contact move relative to each other. 
     Thus, it is possible to move the discharge point (ignition point) on the first body part of the arc generated between the first contact and the second contact to the first protrusion, and the discharge point (ignition point) on the second body part to the second protrusion. That is, it is possible to pull away the arcs generated between the first contact and the second contact from the first contact and second contact. 
     (17) In the contact device according to the above (16), a tip of the second protrusion part may be located outside a tip of the first protrusion part in an axis intersecting the axis in which the first contact and the second contact move relative to each other. 
     Thus, it is possible to pull away the arcs generated between the first contact and the second contact from the first contact and the second contact while extending outward in an axis intersecting the axis in which the first contact and the second contact move relative to each other and toward the first body. 
     (18) In the contact device according to the above (16), a tip of the second protrusion part may be located inside a tip of the first protrusion part in an axis intersecting the axis in which the first contact and the second contact move relative to each other. 
     Thus, it is possible to pull away the arcs generated between the first contact and the second contact from the first contact and the second contact while extending outward in an axis intersecting the axis in which the first contact and the second contact move relative to each other and toward the second body part. 
     (19) In the contact device according to any one of the above (16) to (18), a tip of the first protrusion part may be located closer to the second body part than a tip of the first contact to the second body part. 
     Thus, it is possible to move the discharge point (ignition point) on the first body part of the arc generated between the first contact and the second contact to the first protrusion in a more quick and reliable manner 
     (20) In the contact device according to any one of the above (16) to (19), a tip of the second protrusion part may be located closer to the first body part than a tip of the second contact to the first body part. 
     Thus, it is possible to move the discharge point (ignition point) on the second body part of the arc generated between the first contact and the second contact to the second protrusion in a more quick and reliable manner 
     (21) In the contact device according to any one of the above (1) to (20), the yoke may be arranged adjacent to only one of the first body part and the second body part. 
     Thus, it is possible to extinguish the arcs generated between the first contact and the second contact in a more reliable and quick manner with a simpler configuration. 
     (22) In the contact device according to any one of the above (1) to (20), the yoke may include a plurality of yokes arranged adjacent to the first body part and the second body part. 
     Thus, it is possible to increase the intensity of the magnetic flux acting on the arcs. 
     (23) In the contact device according to any one of the above (1) to (22), a direction of a current flowing through the first body part may be different from a direction of a current flowing through the second body part in a region where the first body part and the second body part overlap when viewed along the axis in which the first contact and the second contact move relative to each other. 
     Thus, it is possible to prevent the contact device from being enlarged in one axis. 
     (24) An electromagnetic relay according to the present embodiment is an electromagnetic relay including the contact device according to any one of the above (1) to (23). 
     Thus, it is possible to obtain an electromagnetic relay equipped with the contact device capable of performing the actions and effects described in the above (1) to (23). 
     [Others] 
     Although the contents of the contact device and the electromagnetic relay according to the present disclosure have been described above, it is obvious to those skilled in the art that various modifications and improvements are possible without being limited to the description. 
     For example, configurations illustrated in the above-described embodiment and its modifications may be combined in a suitable manner 
     Although the above embodiment and its modifications exemplify a contact device provided with only one pair of the fixed contact portions  310  and the movable contact portion  320  that are paired with each other (having contacts that contact each other and separate from each other), the contact device may be provided with multiple pairs. 
     The specification of the first body part, the second body part, and other details (shape, size, layout, and the like) can be changed in a suitable manner 
     The present application claims priority under Japanese Patent Application No. 2020-036026 filed Mar. 3, 2020, and the entire contents thereof are incorporated herein by reference. 
     INDUSTRIAL APPLICABILITY 
     According to the present disclosure, it is possible to obtain a contact device capable of preventing the contacts from being affected by arcs in a more reliable manner, and an electromagnetic relay equipped with the contact device.