Patent Publication Number: US-11387062-B2

Title: Electrical circuit breaker

Description:
CLAIM TO PRIORITY APPLICATIONS 
     The present application is a National Stage Application of PCT Application serial No. PCT/JP2019/016751, filed Apr. 19, 2019, which claims priority to Japanese Patent Application No. 2018-106641 Jun. 4, 2018, all of which are incorporated herein by reference in their entireties. 
     BACKGROUND 
     The present subject matter relates to an electric circuit breaker that can be used mainly for electric circuits of automobiles and the like. 
     Conventionally, an electric circuit breaker has been used to protect an electric circuit mounted on an automobile or the like and various electric components connected to the electric circuit. More specifically, when an abnormality occurs in the electric circuit, the electric circuit breaker physically cuts off the electric circuit by cutting a part of the electric circuit. 
     There are various types of the electric circuit breaker, and for example, in an electric circuit breaker  700  of Patent Literature 1 shown in  FIG. 23 , a dielectric  710  forming a part of an electric circuit is inserted through cutting chambers  721  in a housing  720  and accommodated therein, and the dielectric  710  is physically cut by a punch  730 . The punch  730  punches the dielectric  710  in the cylindrical cutting chambers  721  so as to cross the dielectric  710 , and the punched conductors  710  are in a separated state. However, there is a problem that, immediately after the dielectric  710  is punched, the distance between the punched and separated conductor  710  and the conductor  710  that remains in the housing is short, and an arc is generated between them. 
     Therefore, in view of the above problems, the present disclosure provides an electric circuit breaker capable of effectively extinguishing an arc generated immediately after an electric circuit is cut off. 
     According to the present disclosure, there is provided an electric circuit breaker, including a housing, a cut portion that is arranged in the housing and forms a part of an electric circuit, a cutting member that cuts the cut portion, and a power source arranged on a first end portion side of the housing, the electric circuit breaker including a moving body that allows the cut portion to be inserted and accommodated therein and includes the cutting member and a first arc extinguishing space adjacent to the cutting member, in which the housing includes a cylindrical portion capable of moving the moving body between the first end portion and a second end portion on a side opposite to the first end portion, in which the moving body is configured such that the cutting member provided in the moving body cuts the cut portion while the moving body moves from the first end portion toward the second end portion by the power source, and in which the first arc extinguishing space of the moving body is configured to be located between a separation piece of the cut portion that is cut and separated and a main body portion of the cut portion that remains in the housing without being separated when the moving body moves. 
     According to the above feature, the moving body itself includes the cutting member that cuts the cut portion and the first arc extinguishing space, and the first arc extinguishing space is configured to be located between the separation piece that is cut and separated and the main body portion that remains in the housing without being separated immediately after the cutting member cuts the separation piece and cuts off the electric circuit. Therefore, immediately after the electric circuit is cut off, the arc generated from the main body portion can be released into the first arc extinguishing space and extinguished. 
     According to the present disclosure, there is provided an electric circuit breaker, including a housing, a cut portion that is arranged in the housing, forms a part of an electric circuit, and is constituted by a fuse, and a power source arranged on a first end portion side of the housing, the electric circuit breaker including a moving body that allows the cut portion to be inserted and accommodated therein and includes a first arc extinguishing space filled with an arc extinguishing material, in which the housing includes a cylindrical portion capable of moving the moving body between the first end portion and a second end portion on a side opposite to the first end portion, in which the moving body is configured to cut the cut portion accommodated in the arc extinguishing space of the moving body while moving from the first end portion toward the second end portion by the power source, and in which the first arc extinguishing space of the moving body is configured to be located between a separation piece of the cut portion that is cut and separated and a main body portion of the cut portion that remains in the housing without being separated when the moving body moves. 
     According to the above feature, the moving body itself includes the first arc extinguishing space that accommodates the cut portion and in which the cut portion is cut, and the first arc extinguishing space is configured to be located between the separation piece that is cut and separated and the main body portion that remains in the housing without being separated immediately after the separation piece is cut and the electric circuit is cut off. Therefore, immediately after the electric circuit is cut off, the arc generated from the main body portion can be released into the first arc extinguishing space and effectively extinguished by the arc extinguishing material in the first arc extinguishing space. 
     In the electric circuit breaker according to the present disclosure, the moving body includes insulating spaces that are insulated from each other, and the insulating spaces are configured to face the main body portion of the cut portion when the moving body further moves toward the second end portion. 
     According to the above feature, the insulating spaces are configured to face the main body portion of the cut portion that remains in the housing after the moving body further moves. Thus, even if a high voltage is applied to the main body portions on both sides and arcs are generated from the main body portions, the arcs are confined in the insulating spaces and insulated from each other, so that it is possible to prevent the arcs from connecting between the main body portions and causing a current to flow in the electric circuit. 
     In the electric circuit breaker according to the present disclosure, the moving body includes a second arc extinguishing space on a side opposite to the first arc extinguishing space across the cutting member. 
     According to the above feature, since the second arc extinguishing space is provided on the side opposite to the first arc extinguishing space with the cutting member interposed therebetween, the arc that advances from the separation piece toward the second end is the second extinguishing space. It is released into the arc space and extinguished. 
     In the electric circuit breaker according to the present disclosure, the housing includes a third arc extinguishing space that accommodates an arc extinguishing material outside the cylindrical portion, and the third arc extinguishing space allows the main body portion to be accommodated and inserted therein. 
     According to the above feature, since the main body portion of the cut portion is inserted and accommodated in the third arc extinguishing space, the arc generated from the main body portion can be extinguished by the arc extinguishing material in the third arc extinguishing space. 
     In the electric circuit breaker according to the present disclosure, a part of the main body portion of the cut portion includes a bent portion that is bent in the third arc extinguishing space. 
     According to the above feature, since the bent portion of the main body portion of the cut portion is bent in the third arc extinguishing space, the contact area between the bent portion and the arc extinguishing material in the third arc extinguishing space is increased. As a result, the arc extinguishing performance of extinguishing the arc generated from the main body portion is improved. 
     As described above, according to the electric circuit breaker of the present disclosure, it is possible to effectively extinguish the arc generated immediately after the electric circuit is cut off. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter presented herein will now be described, by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1( a )  is an overall perspective view of a lower housing that constitutes a housing of an electric circuit breaker according to a first embodiment of the present disclosure, and; 
         FIG. 1( b )  is a plan view of the lower housing. 
         FIG. 2( a )  is a perspective view of an upper housing that constitutes the housing of the electric circuit breaker according to the first embodiment of the present disclosure as seen from the upper side, 
         FIG. 2( b )  is a perspective view of the upper housing as seen from the lower side, and; 
         FIG. 2( c )  is a bottom view of the upper housing. 
         FIG. 3( a )  is a perspective view of a moving body of the electric circuit breaker according to the first embodiment of the present disclosure, 
         FIG. 3( b )  is a front view of the moving body, and; 
         FIG. 3( c )  is a side view of the moving body. 
         FIG. 4( a )  is a perspective view of a cut portion of the electric circuit breaker according to the first embodiment of the present disclosure, and; 
         FIG. 4( b )  is a plan view of the cut portion. 
         FIG. 5  is an exploded perspective view of the electric circuit breaker according to the first embodiment of the present disclosure. 
         FIG. 6  is a cross-sectional view taken along the line A-A in a state where the electric circuit breaker shown in  FIG. 5  is assembled. 
         FIG. 7  is a cross-sectional view showing a state where the moving body moves from the state shown in  FIG. 6 . 
         FIG. 8  is a cross-sectional view showing a state where the moving body further moves from the state shown in  FIG. 7 . 
         FIG. 9( a )  is an overall perspective view of a cut portion of an electric circuit breaker according to a second embodiment of the present disclosure, and  FIG. 9( b )  is a cross-sectional view of the electric circuit breaker. 
         FIG. 10( a )  is a perspective view of a moving body of an electric circuit breaker according to a third embodiment of the present disclosure,  FIG. 10( b )  is a front view of the moving body, and  FIG. 10( c )  is a side view of the moving body. 
         FIG. 11  is an exploded perspective view of the electric circuit breaker according to the third embodiment of the present disclosure. 
         FIG. 12  is a cross-sectional view taken along the line B-B in a state where the electric circuit breaker shown in  FIG. 11  is assembled. 
         FIG. 13  is a cross-sectional view showing a state where the moving body moves from the state shown in  FIG. 12 . 
         FIG. 14( a )  is a perspective view of a moving body of and electric circuit breaker according to a fourth embodiment of the present disclosure,  FIG. 14( b )  is a front view of the moving body, and  FIG. 14( c )  is a side view of the moving body. 
         FIG. 15( a )  is a perspective view of a cut portion of the electric circuit breaker according to the fourth embodiment of the present disclosure, and  FIG. 15( b )  is a plan view of the cut portion. 
         FIG. 16  is an exploded perspective view of the electric circuit breaker according to the fourth embodiment of the present disclosure. 
         FIG. 17  is a cross-sectional view taken along the line C-C in a state where the electric circuit breaker shown in  FIG. 16  is assembled. 
         FIG. 18  is a cross-sectional view showing a state where the moving body moves from the state shown in  FIG. 17 . 
         FIG. 19( a )  is a perspective view of a moving body of an electric circuit breaker according to a fifth embodiment of the present disclosure,  FIG. 19( b )  is a front view of the moving body, and  FIG. 19( c )  is a side view of the moving body. 
         FIG. 20  is a cross-sectional view of the electric circuit breaker according to the fifth embodiment of the present disclosure. 
         FIG. 21  is a cross-sectional view showing a state where the moving body moves from the state shown in  FIG. 20 . 
         FIG. 22  is a cross-sectional view showing a state where the moving body further moves from the state shown in  FIG. 21 . 
         FIG. 23  is a cross-sectional view of a conventional electric circuit breaker.
           300  housing     310  cylindrical portion     320  first end portion     330  second end portion     400  cut portion     420  separation piece     430  main body portion     500  moving body     511  cutting member   P power source   X 1  first arc extinguishing space   M arc extinguishing material       

     
    
    
     DETAILED DESCRIPTION 
     Each of embodiments of the present disclosure will be described below with reference to the drawings. The shape, material, etc. of each member of an electric circuit breaker according to the embodiments described below are examples, and the present disclosure is not limited to these. 
     First Embodiment 
     First,  FIG. 1  shows a lower housing  100  that constitutes a housing  300  according to a first embodiment of the present disclosure.  FIG. 1( a )  is an overall perspective view of the lower housing  100 , and  FIG. 1( b )  is a plan view of the lower housing  100 . The lower housing  100  is a substantially quadrangular prism body made of synthetic resin, and includes a cylindrical lower cylindrical portion  110 , and a third arc extinguishing space X 3  formed in an annular shape around the lower cylindrical portion  110 . The lower cylindrical portion  110  extends from an upper surface  120  of the lower housing  100  toward a lower surface  130 , and is configured to be able to accommodate a moving body  500  described later. In addition, an inner surface  111  of the lower cylindrical portion  110  is a smooth curved surface so that the moving body  500  can slide therein in the vertical direction. Further, at a part of the upper end of the lower cylindrical portion  110 , mounting portions  113  that are recessed according to the shapes of main body portions  430  are provided so that the main body portions  430  of a cut portion  400  described later can be mounted. The mounting portions  113  are arranged so as to face each other on both sides of the lower cylindrical portion  110 , and the mounting portions  113  support the linearly extending cut portion  400  on both sides. 
     The third arc extinguishing space X 3  has the shape of a groove extending from the upper surface  120  of the lower housing  100  toward the lower surface  130 , and surrounds the outer side of the lower cylindrical portion  110  in an annular shape. The third arc extinguishing space X 3  is configured to be able to accommodate an arc extinguishing material described later. The third arc extinguishing space X 3  is formed in an annular shape so as to surround the periphery of the lower cylindrical portion  110 , but is not limited to this, and, for example, the outer arc extinguishing space X 3  may be partially formed in only portions adjacent to the mounting portions  113  of the lower cylindrical portion  110 . As will be described later, an arc is generated from the end portion  431  of the main body portion  430 , which is a boundary with a separation piece  420  of the cut portion  400  as a starting point. Thus, if the third arc extinguishing space X 3  is provided in the portions adjacent to the mounting portions  113  in which the maim body portions  430  are accommodated, arc extinguishing materials in the third arc extinguishing space X 3  can extinguish the arc. 
     Further, at the upper surface  120  of the lower housing  100 , mounting portions  121  that are recessed according to the shapes of the main body portions  430  are provided so that the main body portions  430  of the cut portion  400  described later can be mounted. The mounting portions  121  are arranged so as to face each other on both sides of the upper surface  120 , and are linearly aligned with the mounting portions  113 . Therefore, the mounting portions  121  can support the linearly extending cut portion  400  on both sides. Further, connecting holes B 1  are formed at four corners of the upper surface  120  of the lower housing  100 , and the connecting holes B 1  are arranged so as to vertically match connecting holes B 2  of an upper housing  200  described later. 
     Next,  FIG. 2  shows the upper housing  200  that constitutes the housing  300  according to the first embodiment of the present disclosure.  FIG. 2( a )  is a perspective view of the upper housing  200  seen from an upper surface  220  side,  FIG. 2( b )  is a perspective view of the upper housing  200  seen from a lower surface  230  side, and  FIG. 2( c )  is a bottom view of the upper housing  200 . 
     The upper housing  200  is a substantially quadrangular prism body made of synthetic resin and forms a pair with the lower housing  100  shown in  FIG. 1  Then, the upper housing  200  includes a cylindrical upper cylindrical portion  210  and a third arc extinguishing space X 3  formed in an annular shape around the upper cylindrical portion  210 . The upper cylindrical portion  210  extends from the lower surface  230  of the upper housing  200  toward the upper surface  220 , and is configured to be able to accommodate the moving body  500  described later. In addition, an inner surface  211  of the upper cylindrical portion  210  is a smooth curved surface so that the moving body  500  can slide therein in the vertical direction. As will be described later, the upper cylindrical portion  210  is arranged with the lower cylindrical portion  110  of the lower housing  100  in a vertical relationship to form a linearly extending cylindrical portion  310 , and the inner diameter of the upper cylindrical portion  210  matches the inner diameter of the lower cylindrical portion  110 . Therefore, the moving body  500  can smoothly move up and down in the cylindrical portion  310 . 
     Further, at a part of the end portion of the upper cylindrical portion  210 , mounting portions  213  that are recessed according to the shapes of the main body portions  430  of the cut portion  400  described later are provided. The mounting portions  213  are arranged so as to face each other on both sides of the upper cylindrical portion  210 , and are arranged at positions corresponding to the mounting portions  113  of the lower housing  100 . Therefore, the mounting portions  213  are fitted from above onto the main body portions  430  of the cut portion  400  placed on the mounting portions  113  of the lower housing  100 . 
     The third arc extinguishing space X 3  has the shape of a groove extending from the lower surface  230  of the upper housing  200  toward the upper surface  220 , and surrounds the outer side of the upper cylindrical portion  210  in an annular shape. The third arc extinguishing space X 3  is configured to be able to accommodate the arc extinguishing material. The third arc extinguishing space X 3  of the upper housing  200  is arranged at a position corresponding to the third arc extinguishing space X 3  of the lower housing  100 . When the lower housing  100  and the upper housing  200  are connected and fixed, the third arc extinguishing space X 3  of the lower housing  100  and the third arc extinguishing space X 3  of the upper housing  200  communicate with each other. 
     In addition, the lower surface  230  of the upper housing  200  includes mounting portions  231  that are recessed according to the shapes of the main body portions  430  of the cut portion  400  described later. The mounting portions  231  are arranged so as to face each other on both sides of the lower surface  230 , and are linearly aligned with the mounting portions  213 . Further, the mounting portions  231  are arranged at positions corresponding to the mounting portions  121  of the lower housing  100 . Therefore, the mounting portions  231  are fitted from above onto the main body portions  430  of the cut portion  400  placed on the mounting portions  121  of the lower housing  100 . 
     Further, at a part of the upper surface  220  of the upper housing  200 , a power source accommodating portion  221  for accommodating a power source P is formed. A communication hole  222  that communicates with the upper surface of the upper cylindrical portion  210  is formed on the bottom surface side of the power source accommodating portion  221 . As will be described later in detail, power such as air pressure generated from the power source P accommodated in the power source accommodating portion  221  is transmitted to the inside of the upper cylindrical portion  210  through the communication hole  222 , and moves the moving body  500  inside the upper cylindrical portion  210 . Furthermore, through holes B 3  are formed in the upper surface  220 , and these through holes B 3  communicate with the third arc extinguishing space X 3  inside the upper housing  200 . Therefore, after the housing  300  is assembled, the arc extinguishing material can be flowed into the third arc extinguishing spaces X 3  from the outside through the through holes B 3 . The lower housing  100  and the upper housing  200  are substantially rectangular prism bodies made of synthetic resin, but are not limited to this, and other materials may be used to form any shape as long as they have high insulation and strength that can withstand use. 
     Next,  FIG. 3  shows the moving body  500  according to the first embodiment of the present disclosure.  FIG. 3( a )  is a perspective view of the moving body  500 ,  FIG. 3( b )  is a front view of the moving body  500 , and  FIG. 3( c )  is a side view of the moving body  500 . The moving body  500  is a substantially columnar body made of synthetic resin and having an upper surface  560  and a lower surface  520 . The outer diameter of the moving body  500  is equal to or smaller than the inner diameter of the cylindrical portion  310 , and an outer surface  530  of the moving body  500  is a smooth surface corresponding to the inner surface shape of the cylindrical portion  310 , so that the moving body  500  can slide the inside of the cylindrical portion  310  smoothly without gaps. 
     Further, on the lower surface  520  side of the moving body  500 , there is provided a penetrating portion  540  which penetrates the moving body  500  from one part of the outer surface  530  to another part of the outer surface  530  on the opposite side, that is, from the front surface to the back surface of the moving body  500 , and the penetrating portion  540  is surrounded by a lower wall  541 , a side wall  542 , a side wall  543 , and an upper wall  544 . Furthermore, inside the penetrating portion  540 , protruding portions  510  protrude from the upper wall  544  toward the lower wall  541 . First arc extinguishing spaces X 1  that are recessed inward from the outer surface  530  are formed on the root sides of the protruding portions  510 . A space between a cutting member  511  of the penetrating portion  540  and the lower wall  541  is larger than the cut portion  400  so that the separation piece  420  and the main body portions  430  of the cut portion  400  can be inserted, as will be described later. 
     Further, the cutting member  511  is formed on the tip sides of the protruding portion  510 . As shown in  FIG. 3( b ) , the cutting member  511  has a substantially U-shaped vertical cross section, and has an abutment surface  512  that comes into abutment against the surface of the separation piece  420  of the cut portion  400 , and holding surfaces  513  that protrude from both sides of the abutment surface  512  and are configured to sandwich side surfaces  423  of the separation piece  420 . 
     Further, the first arc extinguishing spaces X 1  are arranged so as to be adjacent to the cutting member  511  on the side opposite to the separation piece  420  across the cutting members  511 , and have a shape recessed inward from the outer surface  530  of the moving body  500 . An arc extinguishing material can be optionally accommodated in the first arc extinguishing spaces X 1 . Further, an arc extinguishing material can be optionally accommodated in a second arc extinguishing space X 2  between the cutting member  511  and the lower wall  541 . Similarly, an arc extinguishing material can be optionally accommodated in a fourth arc extinguishing space X 4  between the protruding portion  510  and each of the side wall  542  and the side wall  543 . Therefore, the periphery of the separation piece  420  of the cut portion  400  arranged so as to come into abutment against the cutting member  511  can be surrounded by the arc extinguishing material. 
     Further, insulating spaces  550  that are recessed inward from the outer surface  530  are formed on the upper surface  560  side of the moving body  500 . The insulating spaces  550  are formed at opposite positions on the outer surface  530 . The insulating spaces  550  are each surrounded by a lower wall  551 , a side wall  552 , a side wall  553 , an upper wall  554 , and a rear wall  555 . As shown in  FIG. 3( c ) , the insulating spaces  550  arranged so as to face each other are shielded from each other by the rear wall  555 , and are spaces insulated from each other. An arc extinguishing material is not accommodated in the insulating spaces  550 , and an arc is confined and shielded as will be described later. Further, the insulating spaces  550  and the penetrating portion  540  are shielded from each other by the lower walls  551  and the upper walls  544 , and are independent spaces that are insulated from each other. Similarly, the insulating spaces  550  and the first arc extinguishing spaces X 1  are also shielded from each other by the lower walls  551  and the upper walls  544 , and are independent spaces insulated from each other. 
     Note that the moving body  500  has a columnar shape made of synthetic resin, but is not limited to this, and other materials may be used to form any shape as long as it has high insulation and strength that can withstand use. 
     Next,  FIG. 4  shows the cut portion  400  that constitutes a part of an electric circuit which is cut off by an electric circuit breaker  600  according to the first embodiment of the present disclosure.  FIG. 4( a )  is a perspective view of the cut portion  400 , and  FIG. 4( b )  is a plan view of the cut portion  400 . The cut portion  400  is entirely made of a metal conductor in order to electrically connect to an electric circuit, and includes the main body portions  430  for connecting to the electric circuit at both ends, and the separation piece  420  to be cut and separated at substantially the center. Connection holes  410  used for connection to an electric circuit are formed at the end portions of the main body portions  430 . Further, notches  421  are formed on both sides of the separation piece  420  so that the separation piece  420  can be easily cut and separated. The abutment surface  512  of the cutting member  511  of the moving body  500  shown in  FIG. 3  come into abutment against a surface  422  of the separation piece  420 , and the holding surfaces  513  of the cutting member  511  come into abutment against the side surfaces  423  on both sides. 
     Next, how to assemble the electric circuit breaker  600  of the present disclosure will be described with reference to  FIG. 5 .  FIG. 5  shows an exploded perspective view of the electric circuit breaker  600 . 
     First, in the penetrating portion  540  of the moving body  500 , the main body portions  430  of the cut portion  400  are inserted between the cutting member  511  and the lower wall  541 , and the cut portion  400  is inserted up to a position at which the separation piece  420  of the cut portion  400  faces the cutting member  511  of the moving body  500 . Then, as shown in  FIG. 5 , the separation piece  420  of the cut portion  400  is inserted and accommodated inside the moving body  500 . 
     Next, the moving body  500  is inserted from the lower surface  520  side into the lower cylindrical portion  110  of the lower housing  100 . Then, the main body portions  430  of the cut portion  400  are placed so as to be fitted into the mounting portions  113  and the mounting portions  121  of the lower housing  100 , and the moving body  500  is fixed inside the lower cylindrical portion  110 . Next, the upper housing  200  is fitted from above the lower housing  100  so that the upper surface  560  of the moving body  500  is inserted into the upper cylindrical portion  210  of the upper housing  200 . Then, by pushing the upper housing  200  toward the lower housing  100 , the mounting portions  213  and the mounting portions  231  of the upper housing  200  are fitted to the main body portions  430  of the cut portion  400 . The connecting holes B 1  and the connecting holes B 2  arranged vertically are connected and fixed by a connecting member or the like, so that the housing  300  including the lower housing  100  and the upper housing  200  is assembled under a state of accommodating the cut portion  400  and the moving body  500  therein. 
     Further, the power source P is mounted to the power source accommodating portion  221  of the upper housing  200 . When an abnormality signal is input from the outside when an abnormal current flowing in the electric circuit is detected, the power source P explodes, for example, explosive powder inside the power source P, and the air pressure resulting from the explosion causes the moving body  500  to be instantly pushed out inside the cylindrical portion  310  so as to be moved. The power source P is not limited to a power source using explosive powder as long as it generates power to move the moving body  500 , and other known power sources may be used. 
     Next, the internal structure of the electric circuit breaker  600  according to the first embodiment of the present disclosure will be described with reference to  FIG. 6 .  FIG. 6  is a cross-sectional view taken along the line A-A in a state where the electric circuit breaker  600  shown in  FIG. 5  is assembled. 
     As shown in  FIG. 6 , the moving body  500  is accommodated inside the cylindrical portion  310  composed of the lower cylindrical portion  110  and the upper cylindrical portion  210  which are linearly arranged. The cylindrical portion  310  extends from a first end portion  320  of the housing  300  to a second end portion  330  on a side opposite to the first end portion  320 . Since the moving body  500  is arranged on the first end portion  320  side where the power source P is arranged, the second end portion  330  side of the cylindrical portion  310  is hollow. Therefore, as will be described later, the moving body  500  can move toward the second end portion  330  side while cutting and separating the separation piece  420 . In addition, the upper surface  560  of the moving body  500  is adjacent to the power source P mounted inside the power source accommodating portion  221 . As will be described later, the air pressure due to the explosion of the explosive powder in the power source P is transmitted to the upper surface  560  of the moving body  500  via the communication hole  222 . 
     Further, the separation piece  420  of the cut portion  400  is accommodated by being inserted through the inside of the moving body  500 , and the main body portions  430  of the cut portion  400  are inserted and accommodated inside the third arc extinguishing spaces X 3 . The second arc extinguishing space X 2  is arranged on the side opposite to the first arc extinguishing spaces X 1  across the cutting member  511 . As shown in  FIG. 6 , a granular arc extinguishing material M is accommodated in the first arc extinguishing spaces X 1  and the third arc extinguishing spaces X 3 . Moreover, since the arc extinguishing material M is filled in the penetrating portion  540  of the moving body  500 , the arc extinguishing material M is also to be accommodated in the second arc extinguishing space X 2  and the fourth arc extinguishing spaces X 4  (see  FIG. 3 ) of the penetrating portion  540 . In  FIGS. 6 to 8 , although the first arc extinguishing spaces X 1 , the second arc extinguishing space X 2 , the third arc extinguishing spaces X 3 , and the fourth arc extinguishing spaces X 4  are filled with the arc extinguishing material M, only a part of the arc extinguishing material M is shown on the drawing for the sake of visibility, 
     Although the arc extinguishing material M is accommodated in the first arc extinguishing spaces X 1 , the present disclosure is not limited to this, and the arc extinguishing material M may not be accommodated. The first arc extinguishing spaces X 1  are spaces that are recessed inward, and arcs generated from the end portions  431  of the main body portions  430  are released into the first arc extinguishing spaces X 1  as will be described later. Then, the arcs consume energy as they travel through the air in the first arc extinguishing spaces X 1 , and are eventually extinguished. Therefore, even if the arc extinguishing material M is not accommodated in the first arc extinguishing spaces X 1 , the first arc extinguishing spaces X 1  can sufficiently extinguish the arcs. Similarly, although the arc extinguishing material M is accommodated in the second arc extinguishing space X 2  and the fourth arc extinguishing spaces X 4 , the present disclosure is not limited to this, and the arc extinguishing material M may not be accommodated. 
     Furthermore, when the arc extinguishing material M is accommodated in the first arc extinguishing spaces X 1 , the second arc extinguishing space X 2 , the third arc extinguishing spaces X 3 , or the fourth arc extinguishing spaces X 4 , the arc extinguishing material M is not limited to a granular solid arc extinguishing material such as silica sand, and a gaseous arc extinguishing material that can effectively extinguish an arc such as nitrogen gas may be filled in each space. 
     Next, a usage mode of the electric circuit breaker  600  according to the first embodiment of the present disclosure will be described with reference to  FIG. 7 .  FIG. 7  is a cross-sectional view showing a state where the moving body  500  moves from the state shown in  FIG. 6 . As shown in  FIG. 7 , when an abnormality such as an overcurrent flowing in the electric circuit is detected, an abnormality signal is input to the power source P, and the explosive powder in the power source P explodes. Then, the air pressure due to the explosion is instantaneously transmitted to the upper surface  560  of the moving body  500  via the communication hole  222 . Then, due to this air pressure, the moving body  500  is swiftly fused from the first end portion  320  toward the second end portion  330 , and instantaneously moves inside the cylindrical portion  310  toward the second end portion  330 . 
     Then, the cutting member  511  of the moving body  500  cuts the separation piece  420  and separate it from the main body portions  430  by the force of pushing out the moving body  500  toward the second end portion  330 . Then, the separation piece  420  moves toward the second end portion  330  together with the moving body  500 , and separates from the main body portions  430 . Further, as shown in  FIG. 7 , when the moving body  500  moves inside the cylindrical portion  310  toward the second end portion  330 , the first arc extinguishing spaces X 1  formed above and adjacent to the cutting member  511  move up to the positions facing the main body portions  430 . Therefore, the first arc extinguishing spaces X 1  are each configured to be located between the separation piece  420  and the main body portion  430  immediately after the cutting member  511  of the moving body  500  cuts the separation piece  420 . Then, immediately after the cutting member  511  of the moving body  500  cuts the separation piece  420 , since the physical distance between the separation piece  420  and the main body portion  430  is short. Therefore, an arc may be generated between the separation piece  420  and the end portion  431  of the main body portion  430  which is the boundary with the separation piece  420 . However, as shown in  FIG. 7 , the arc generated from the end portion  431  of the main body portion  430  is released to the first arc extinguishing space X 1  located between the separation piece  420  and the main body portion  430 , and is extinguished. Further, since the arc extinguishing material M is accommodated in the first arc extinguishing spaces X 1 , the arc can be extinguished more effectively, 
     Next, a state where the moving body  500  further moves toward the second end portion  330  will be described with reference to  FIG. 8 .  FIG. 8  is a cross-sectional view showing a state where the moving body  500  further moves from the state shown in  FIG. 7 . As shown in  FIG. 8 , when the moving body  500  moves inside the cylindrical portion  310  toward the second end portion  330 , the insulating spaces  550  formed above the first arc extinguishing spaces X 1  move up to positions facing and adjacent to the main body portions  430 . Even if a high voltage is applied between the main body portions  430  on both sides and arcs are generated from the end portions  431  of the main body portions  430 , the arcs are confined in the insulating spaces  550 . The arcs generated between the main body portions  430  on both sides are confined in the insulating spaces  550  and insulated from each other, so that it is possible to prevent the arcs from connecting between the main body portions  430  on both sides and causing a current to flow in the electric circuit. The description that the arcs are confined in the insulating spaces  550  and insulated from each other specifically refers to a state where the insulating spaces  550  are dents (see  FIG. 3 ) each surrounded by the lower wall  551 , the side wall  552 , the side wall  553 , the upper wall  554 , and the rear wall  555 , and hence the arc generated from the end portion  431  of the main body portion  430  on one side is blocked from traveling by the insulating space  550  and cannot travel toward the main body portion  430  on an opposite side. 
     It is desirable that the arc extinguishing material M be not accommodated in the insulating spaces  550 . If the arc extinguishing material M is accommodated in the insulating spaces  550 , the arc extinguishing material M may be exposed to high temperature and carbonized by the arcs generated from the main body portion  430 . Then, the carbonized portion becomes a path through which an electric current can flow, and the arc easily leaks from the insulating space  550 . Then, the arc leaking from the insulating space  550  may travel along the outer surface  530  of the moving body  500  and may be connected to the arc generated from the main body portion  430  on the opposite side. Therefore, it is desirable not to accommodate the arc extinguishing material M in the insulating spaces  550 . Further, the insulating spaces  550  may contain a material that is not carbonized by an arc. 
     As described above, according to the electric circuit breaker  600  of the present disclosure, the moving body  500  itself includes the cutting member  511  that cuts the cut portion  400  and the first arc extinguishing spaces X 1 , and the first arc extinguishing spaces X 1  are each configured to be located between the separation piece  420  that is cut and separated and the main body portion  430  that remains in the housing  300  without being separated immediately after the cutting member  511  cuts the separation piece  420  and cut off the electric circuit. Therefore, immediately after the electric circuit is cut off, the arcs generated from the main body portions  430  can be released into the first arc extinguishing spaces X 1  and extinguished. 
     Furthermore, when the arc extinguishing material M is accommodated in the first arc extinguishing spaces X 1 , the arcs generated from the main body portions  430  can be extinguished more effectively. 
     In the prior art shown in  FIG. 23 , in order to extinguish an arc, it is also conceivable to enclose a granular solid arc extinguishing material in cutting chambers  721 . However, if the arc extinguishing material is enclosed in the cutting chambers  721 , it may disturb a punching operation of a punch  730 , so that it is difficult to fill the arc extinguishing material in the cutting chambers  721 . However, in the present disclosure, unlike the prior art, the arc extinguishing material M can be accommodated in the moving body  500  itself together with the cutting member  511  instead of in the cylindrical portion  310 , so that the operation of the moving body  500  that moves inside the cylindrical portion  310  and cuts the separation piece  420  is not disturbed. Further, since the separation piece  420  is accommodated in the moving body  500  and moves together with the moving body  500 , there is no risk of disturbing the punching operation of the punch unlike the prior art. Since the arc extinguishing material M and the separation piece  420  are both accommodated in the moving body  500  and move together with the moving body  500 , a large amount of the arc extinguishing material M can be accommodated in the moving body  500  unlike the prior art. Furthermore, since the first arc extinguishing spaces X 1  can be expanded according to the volume inside the moving body  500 , a large amount of the arc extinguishing material M can be accommodated and the arc extinguishing performance is extremely high. 
     Further, according to the electric circuit breaker  600  of the present disclosure, the insulating spaces  550  are configured to face the main body portions  430  of the cut portion  400  that remain in the housing  300  after the moving body  500  further moves. Thus, even if a high voltage is applied to the main body portions  430  on both sides and arcs are generated from the main body portions  430 , the arcs are confined in the insulating spaces  550  and insulated from each other, so that it is possible to prevent the arcs from connecting between the main body portions  430  and causing a current to flow in the electric circuit. 
     Further, according to the electric circuit breaker  600  of the present disclosure, since the second arc extinguishing space X 2  are provided on the side opposite to the first arc extinguishing spaces X 1  across the cutting member  511 , the arcs traveling from the separation piece  420  toward the second end portion  330  are released into the second arc extinguishing space X 2  and extinguished. Furthermore, when the arc extinguishing material M is accommodated in the second arc extinguishing space X 2 , the arcs can be extinguished more effectively. Further, since the second arc extinguishing space X 2  is located on the lower surface side of the separation piece  420 , the arc generated in the separation piece  420  is extinguished over a wide range by the arc extinguishing material M in the second arc extinguishing space X 2 . 
     Furthermore, according to the electric circuit breaker  600  of the present disclosure, since the main body portions  430  of the cut portion  400  are inserted and accommodated in the third arc extinguishing spaces X 3 , the arcs generated from the main body portions  430  can be extinguished by the arc extinguishing material M in the third arc extinguishing spaces X 3 . In particular, the arcs generated between the separation piece  420  and the main body portions  430  can be extinguished by the first arc extinguishing spaces X 1 , but in the case of enhancing the arc extinguishing performance, it is required to expand the first arc extinguishing spaces X 1  to increase the arc extinguishing areas. However, if the first arc extinguishing spaces X 1  are expanded, the moving body  500  including the first arc extinguishing spaces X 1  and the structure around the cylindrical portion  310  that moves the moving body  500  also become large. However, it is desirable that the drive parts such as the cylindrical portion  310  and the moving body  500  be made as small as possible in view of the performance and safety of the electric circuit breaker  600 . Therefore, by providing the third arc extinguishing spaces X 3  that accommodate the main body portions  430  of the cut portion  400  outside the cylindrical portion  310  that moves the moving body  500 , the extinguishing performance of the arcs generated from the main body portions  430  is improved without increasing the sizes of the cylindrical portion  310  and the moving body  500 . 
     In the first embodiment shown in  FIG. 1  to  FIG. 8 , the insulating spaces  550  are provided at positions above and adjacent to the first arc extinguishing spaces X 1 , but the present disclosure is not limited to this, and the insulating spaces  550  may not be provided. In that case, the first arc extinguishing spaces X 1  are extended to the positions of the insulating spaces  550 . The configuration will be described later in more detail with reference to  FIGS. 10 to 13 . 
     Second Embodiment 
     Next, an electric circuit breaker  600 A according to a second embodiment of the present disclosure will be described with reference to  FIG. 9 .  FIG. 9( a )  is an overall perspective view of a cut portion  400 A of the electric circuit breaker  600 A according to the second embodiment of the present disclosure, and  FIG. 9( b )  is a cross-sectional view of the electric circuit breaker  600 A according to the second embodiment in a manner similar to the cross-sectional view of the electric circuit breaker  600  according to the first embodiment shown in  FIG. 8 . Further, the configuration of the electric circuit breaker  600 A according to the second embodiment is basically the same as the configuration of the electric circuit breaker  600  according to the first embodiment, except for the configuration of the cut portion  400 A, and hence description of the same configurations will be omitted. 
     As shown in  FIG. 9 , the cut portion  400 A of the electric circuit breaker  600 A includes a separation piece  420 A at the center and main body portions  430 A on both sides of the separation piece  420 A. Further, a part of each of the main body portions  430 A is a bent portion  440 A that is bent so as to rise from the separation piece  420 A. As shown in  FIG. 9( b ) , the bent portions  440 A of the cut portion  400 A are bent in third arc extinguishing spaces X 3 A of a housing  300 A along the up-down direction in which the third arc extinguishing spaces X 3 A extend. Therefore, the contact area between the bent portion  440 A and an arc extinguishing material MA in the third arc extinguishing space X 3 A is increased as compared to the contact area between the main body portion  430  and the arc extinguishing material M that are linearly inserted through the third arc extinguishing space X 3  shown in  FIG. 6 . As a result, in the electric circuit breaker  600 A, the arc extinguishing performance for extinguishing the arcs generated from the main body portions  430 A is improved. 
     In addition, in  FIG. 9 , the bent portions  440 A of the cut portion  400 A have a shape that rises from the separation piece  420 A and bends along the up-down direction in which the third arc extinguishing spaces X 3 A extend, but the present disclosure is not limited to this. The bent portions  440 A may have any shape as long as it bends in the third arc extinguishing spaces X 3 A so as to increase the contact areas with the arc extinguishing material MA. 
     Third Embodiment 
     Next, an electric circuit breaker  600 B according to a third embodiment of the present disclosure will be described with reference to  FIGS. 10 to 13 .  FIG. 10( a )  is a perspective view of a moving body  500 B of the electric circuit breaker  600 B according to the third embodiment of the present disclosure,  FIG. 10( b )  is a front view of the moving body  500 B, and  FIG. 10( c )  is a side view of the moving body  500 B. Further, the configuration of the electric circuit breaker  600 E according to the third embodiment is basically the same as the configuration of the electric circuit breaker  600  according to the first embodiment except that the moving body  500 B does not includes the insulating space, and a housing  300 B does not include a third arc extinguishing spaces X 3 , and hence detailed description of the same configurations will be omitted. 
     As shown in  FIG. 10 , the moving body  500 B is a substantially rectangular parallelepiped made of synthetic resin and having an upper surface  560 B and a lower surface  520 B. Further, from the upper surface  560 B side to the lower surface  520 B side of the moving body  500 B, there is provided a penetrating portion  540 B which penetrates the moving body  500 B from one part of the outer surface  530 B to another part of the outer surface  530 B on the opposite side, that is, from the front surface to the back surface of the moving body  500 B, and the penetrating portion  540 B is surrounded by a lower wall  541 B, a side wall  542 B, a side wall  543 B, and an upper wall  544 B. 
     Furthermore, inside the penetrating portion  540 B, a protruding portion  510 B protrudes from the upper wall  544 B toward the lower wall  541 B. A cutting member  511 B are formed on the tip side of the protruding portion  510 B, and the lower surface of the cutting member  511 B is a flat abutment surface  512 B that comes into abutment against a surface of a separation piece  420 B of a cut portion  400 B. Further, first arc extinguishing spaces X 1 B that are recessed inward from the outer surface  530 B are formed on the root side of the protruding portion  510 B. 
     The first arc extinguishing spaces X 1 B is a long space extending from the cutting member  511 B toward the upper surface  560 B, and an arc extinguishing material can be optionally accommodated inside the space. Further, the arc extinguishing material can be accommodated in a second arc extinguishing space X 2 B between the cutting member  511 B and the lower wall  541 B. Similarly, an arc extinguishing material can be accommodated in a fourth arc extinguishing space X 4 B between the protruding portion  510 B and each of the side wall  542 B and the side wall  543 B. Therefore, the periphery of the separation piece  420 B of the cut portion  400 B arranged so as to come into abutment against the cutting members  511  can be surrounded by the arc extinguishing material. Although an arc extinguishing material MB is accommodated in the first arc extinguishing spaces X 1 B, the present disclosure is not limited to this, and the arc extinguishing material MB may not be accommodated. Similarly, although the arc extinguishing material MB is accommodated in the second arc extinguishing space X 2 B and the fourth arc extinguishing spaces X 4 B, the present disclosure is not limited to this, and the arc extinguishing material MB may not be accommodated. 
     Next, how to assemble the electric circuit breaker  600 B of the present disclosure will be described with reference to  FIG. 11 .  FIG. 11  shows an exploded perspective view of the electric circuit breaker  600 B. 
     First, in the penetrating portion  540 E of the moving body  500 B, main body portions  430 B of the cut portion  400 B are inserted between the cutting member  511  and the lower wall  541 B, and the cut portion  400 B is inserted up to a position where the separation piece  420 B of the cut portion  400 B faces the cutting member  511 B of the moving body  500 B. Then, as shown in  FIG. 11 , the separation piece  420 B of the cut portion  400 E is inserted and accommodated inside the moving body  500 B, 
     Next, the moving body  500 B is inserted from the lower surface  520 B side into a lower cylindrical portion  110 B of a lower housing  100 B. Then, the main body portions  430 B of the cut portion  400 B are placed so as to be fitted into mounting portions  121 B of the lower housing  100 B, and the moving body  500 B is fixed inside the lower cylindrical portion  110 B. Next, an upper housing  200 B is fitted from above the lower housing  100 B so that the upper surface  560 B of the moving body  500 B is inserted into the upper cylindrical portion  210 B of the upper housing  200 B. Then, by connecting and fixing the upper housing  200 B and the lower housing  100 B to each other, the housing  300 B including the lower housing  100 B and the upper housing  200 B is assembled under a state of accommodating the cut portion  400 B and the moving body  500 B therein, 
     Further, a power source PB is mounted to a power source accommodating portion  221 B of the upper housing  200 B. The lower cylindrical portion  110 B of the lower housing  100 B and the upper cylindrical portion  210 B of the upper housing  200 B have a substantially quadrangular cylindrical shape in cross section according to the shape of the moving body  500 B so that the moving body  500 B can be accommodated and slid therein. Further, a third arc extinguishing space is not formed around the lower cylindrical portion  110 B and the upper cylindrical portion  210 B, but may be formed as needed. 
     Next, the internal structure of the electric circuit breaker  600 B according to the third embodiment of the present disclosure will be described with reference to  FIG. 12 .  FIG. 12  is a cross-sectional view taken along the line B-B in a state where the electric circuit breaker  600 B shown in  FIG. 11  is assembled. 
     As shown in  FIG. 12 , the moving body  500 B is accommodated inside the cylindrical portion  310 B composed of the lower cylindrical portion  110 B and the upper cylindrical portion  210 B which are linearly arranged. The cylindrical portion  310 B extends from a first end portion  320 B of the housing  300 B to a second end portion  330 B on a side opposite to the first end portion  320 B. Since the moving body  500 B is arranged on the first end portion  320 B side where the power source PB is arranged, the moving body  500 B can move to the second end portion  330 B side while cutting and separating the separation piece  420 B, as will be described later. 
     Further, as shown in  FIG. 12 , the granular arc extinguishing material MB is accommodated in the first arc extinguishing spaces X 1 B. Moreover, since the arc extinguishing material MB is filled in the penetrating portion  540 B of the moving body  500 B, the arc extinguishing material M is also to be accommodated in the second arc extinguishing space X 2 B and the fourth arc extinguishing spaces X 4 B (see  FIG. 10 ) of the penetrating portion  540 B. 
     Next, a usage mode of the electric circuit breaker  600 B according to the third embodiment of the present disclosure will be described with reference to  FIG. 13 .  FIG. 13  is a cross-sectional view showing a state where the moving body  500 B moves from the state shown in  FIG. 12 . As shown in  FIG. 13 , when an abnormality such as an overcurrent flowing in the electric circuit is detected, an abnormality signal is input to the power source PB, and the explosive powder in the power source PB explodes. Then, the air pressure due to the explosion is instantaneously transmitted to the upper surface  560 B of the moving body  500 B via a communication hole  222 B, and the moving body  500 B is swiftly fused from the first end portion  320 B toward the second end portion  330 B, and instantaneously moves inside the cylindrical portion  310 B toward the second end portion  330 B. 
     Then, the cutting member  511 B of the moving body  500 B cuts the separation piece  420 B and separate it from the main body portions  430 B by the force of pushing out the moving body  500 B toward the second end portion  330 B. Then, the separation piece  420 B moves toward the second end portion  330 B together with the moving body  500 B, and separates from the main body portions  430 B. Further, as shown in  FIG. 13 , when the moving body  566 E moves inside the cylindrical portion  316 E toward the second end portion  330 B, the first arc extinguishing spaces X 1 B formed adjacent to the cutting member  511 B move up to the positions facing the main body portions  430 B. Therefore, the first arc extinguishing spaces X 1 B are each configured to be located between the separation piece  420 B and the main body portion  430 B immediately after the cutting member  511 B of the moving body  500 B cuts the separation piece  420 B. Then, even if arcs are generated between the separation piece  420 B and the end portions  431 B of the main body portions  430 B immediately after the cutting member  511 B of the moving body  500 B cuts the separation piece  420 B, the arcs generated from the end portions  431 B of the main body portions  430 B are released into the first arc extinguishing spaces X 1 B located between the separation piece  420 B and the main body portions  430 B, and are extinguished. Further, since the arc extinguishing material MB is accommodated in the first arc extinguishing spaces X 1 B, the arc can be extinguished more effectively. 
     As described above, according to the electric circuit breaker  600 B of the present disclosure, the moving body  500 B itself includes the cutting member  511 B that cuts the cut portion  400 B and the first arc extinguishing spaces X 1 B, and the first arc extinguishing spaces X 1 B are each configured to be located between the separation piece  420 B that is cut and separated and the main body portion  430 B that remains in the housing  300 B without being separated immediately after the cutting member  511 B cuts the separation piece  420 B and cut off the electric circuit. Therefore, immediately after the electric circuit is cut off, the arcs generated from the main body portions  430 B can be released into the first arc extinguishing spaces X 1 B and extinguished. 
     Furthermore, when the arc extinguishing material M is accommodated in the first arc extinguishing spaces X 1 B, the arcs generated from the main body portions  430 E can be extinguished more effectively. 
     In the prior art shown in  FIG. 23 , in order to extinguish an arc, it is also conceivable to enclose a granular solid arc extinguishing material in cutting chambers  721 . However, if the arc extinguishing material is enclosed in the cutting chambers  721 , it may disturb a punching operation of a punch  730 , so that it is difficult to fill the arc extinguishing material in the cutting chambers  721 . However, in the present disclosure, unlike the prior art, the arc extinguishing material MB can be accommodated in the moving body  500 B itself together with the cutting member  511 B instead of in the cylindrical portion  310 , so that the operation of the moving body  500 E that moves inside the cylindrical portion  310 E and cuts the separation piece  420 B is not disturbed. Further, since the separation piece  420 E is accommodated in the moving body  500 B and moves together with the moving body  500 B there is no risk of disturbing the punching operation of the punch unlike the prior art. Since the arc extinguishing material MB and the separation piece  420 B are both accommodated in the moving body  500 B and move together with the moving body  500 B, a large amount of the arc extinguishing material MB can be accommodated in the moving body  500 B unlike the prior art. Furthermore, since the first arc extinguishing spaces X 1 B can be expanded according to the volume inside the moving body  500 B, a large amount of the arc extinguishing material MB can be accommodated and the arc extinguishing performance is extremely high. 
     Further, since the first arc extinguishing spaces X 1 B extend in a long shape upward from the cutting member  511 B, a large amount of the arc extinguishing material MB can be accommodated therein. Further, even in the process in which the moving body  500 B moves toward the second end portion  330 B on the lower side, the first arc extinguishing spaces X 1 B extending vertically in a long shape can be reliably positioned between the separation piece  420 B and the main body portions  430 B. 
     Fourth Embodiment 
     Next, an electric circuit breaker  600 C according to a fourth embodiment of the present disclosure will be described with reference to  FIGS. 14 to 18 . In the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure, the bent portions  440 A can be used together, like the cut portion  400 A of the electric circuit breaker  600 A according to the second embodiment shown in  FIG. 9 . 
     First, in the electric circuit breaker  600  according to the first embodiment, as shown in  FIG. 7 , the cut portion  400 , which is a conductor electrically connected to the electric circuit, is physically cut to cut off the electric circuit. For example, when a relatively low abnormal current flows in the electric circuit, if the electric circuit is to be cut off, the cut portion  400  may be physically cut by the electric circuit breaker  600  according to the first embodiment. On the other hand, if a relatively high abnormal current flows in the electric circuit, if the electric circuit is to be cut off, a fuse of a specified rating is connected in the electric circuit and the fuse is fused due to the abnormal current so that the electric circuit may be cut off. As described above, in the electric circuit, the electric circuit breaker  600  according to the first embodiment and the fuse are connected in series. If a relatively low abnormal current flows, the electric circuit breaker  600  cuts off the electric circuit, and if a relatively high abnormal current flows, the fuse is fused and the electric circuit is cut off. Even if the electric circuit breaker  600  does not operate normally and the electric circuit cannot be cut off, the fuse connected in series to the electric circuit breaker  600  will be eventually fused, so that the electric circuit can be reliably protected. 
     However, in order to deal with each of the predetermined abnormal currents, if the cut portion  400  to be cut by the electric circuit breaker  600  according to the first embodiment and the fuse which is fused by the predetermined abnormal current are connected in series to the electric circuit, a space for arranging both the electric circuit breaker  600  and the fuse in series is required in the electric circuit, which causes a problem that the manufacturing cost of the electric circuit and peripheral members increases and the installation space becomes bulky. 
     Therefore, as will be described later in detail, the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure can solve the above problem. The electric circuit breaker  600 C according to the fourth embodiment of the present disclosure also solves the problem solved by the disclosure of the first to third embodiments “effectively extinguishing the arc generated immediately after the electric circuit is cut off” at the same time. 
     Now, in  FIGS. 14 to 18  below, the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure will be specifically described. Note that  FIG. 14( a )  is a perspective view of a moving body  500 C of the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure,  FIG. 14( b )  is a front view of the moving body  500 C, and  FIG. 14( c )  is a side view of the moving body  500 C. Further, since the configuration of the electric circuit breaker  600 C according to the fourth embodiment is different from the configuration of the electric circuit breaker  600  according to the first embodiment in the configuration of the moving body  500 C and the configuration of a cut portion  400 C, but other configurations are basically the same as those of the electric circuit breaker  600  according to the first embodiment, and hence detailed description of the same configurations will be omitted. 
     First, as shown in  FIG. 14 , the moving body  500 C is a substantially columnar body made of synthetic resin having an upper surface  560 C and a lower surface  520 C. The outer diameter of the moving body  500 C is equal to or smaller than the inner diameter of the cylindrical portion  310 C of the housing  300 , and an outer surface  530 C of the moving body  500 C is a smooth surface corresponding to the inner surface shape of the cylindrical portion  310 C, so that the moving body  500 C can slide the inside of the cylindrical portion  310 C smoothly without gaps. 
     Further, at substantially the center of the moving body  500 C, there is provided a penetrating portion  540 C which penetrates the moving body  500 C from one part of the outer surface  530 C to another part of the outer surface  530 C on the opposite side, that is, from the front surface to the back surface of the moving body  500 C, and the penetrating portion  540 C is surrounded by a lower wall  541 C, a side wall  542 C, a side wall  543 C, and an upper wall  544 C. A space surrounded by the lower wall  541 C, the side wall  542 C, the side wall  543 C, and the upper wall  544 C and recessed inward from the outer surface  530 C is a first arc extinguishing space X 1 C. Then, in the first arc extinguishing space X 1 C, a separation piece  420 C of the cut portion  400 C described later can be inserted and accommodated. Further, in the first arc extinguishing space X 1 C, since an arc extinguishing material described later is filled, the periphery of the separation piece  420 C of the cut portion  400 C accommodated in the first arc extinguishing space X 1 C can be completely surrounded by the arc extinguishing material. 
     The moving body  500 C is not provided with a cutting member for cutting the separation piece  420 C of the cut portion  400 C. Further, the moving body  500 C has a columnar shape made of synthetic resin, but is not limited to this, and other materials may be used to form any shape as long as it has high insulation and strength that can withstand use. 
     Next,  FIG. 15  shows the cut portion  400 C that constitutes a part of an electric circuit which is cut off by the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure.  FIG. 15( a )  is a perspective view of the cut portion  400 C, and  FIG. 4( b )  is a plan view of the cut portion  400 C. The cut portion  400 C is entirely made of a metal fuse in order to electrically connect to an electric circuit, and includes main body portions  430 C for connecting to the electric circuit at both ends, and the separation piece  420 C to be cut and separated at substantially the center. Connection holes  410 C used for connection to an electric circuit are formed at the end portions of the main body portions  430 C. Further, notches  421 C and through holes  424 C are provided at the center and both ends of the separation piece  420 , and fusing portions  425 C having a locally narrowed width are formed. The fusing portions  425 C are portions that generate heat and are fused when an abnormal current flows in the electric circuit. 
     The cut portion  400 C having the fuse function shown in  FIG. 15  is thinner than the cut portion  400  not having the fuse function shown in  FIG. 4 . By reducing the thickness of the cut portion  400 C, the thickness of the fusing portions  425 C is also reduced, which facilitates fusing when an abnormal current flows. 
     Next, how to assemble the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure will be described with reference to  FIG. 16 .  FIG. 16  shows an exploded perspective view of the electric circuit breaker  600 C. 
     First, the main body portions  430 C of the cut portion  400 C are inserted into the first arc extinguishing space X 1 C of the moving body  500 C, and the cut portion  400 C is insert up to a position where the separation piece  420 C of the cut portion  400 C is accommodated in the first arc extinguishing space X 1 C of the moving body  500 . 
     Next, the moving body  500 C is inserted from the lower surface  520 C side into the lower cylindrical portion  110  of the lower housing  100 . Then, the main body portions  430 C of the cut portion  400 C are placed so as to be fitted into the mounting portions  113  and the mounting portions  121  of the lower housing  100 , and the moving body  500 C is fixed inside the lower cylindrical portion  110 . Next, the upper housing  200  is fitted from above the lower housing  100  so that the upper surface  560 C of the moving body  500 C is inserted into the upper cylindrical portion  210  of the upper housing  200 . Then, by pushing the upper housing  200  toward the lower housing  100 , the mounting portions  213  and the mounting portions  231  of the upper housing  200  are fitted to the main body portions  430 C of the cut portion  400 C. The connecting holes B 1  and the connecting holes B 2  arranged vertically are connected and fixed by a connecting member or the like, so that the housing  300  including the lower housing  100  and the upper housing  200  is assembled under a state of accommodating the cut portion  400 C and the moving body  500 C therein. 
     Further, the power source P is mounted to the power source accommodating portion  221  of the upper housing  200 . When an abnormality signal is input from the outside when an abnormal current flowing in the electric circuit is detected, the power source P explodes, for example, explosive powder inside the power source P, and the air pressure resulting from the explosion causes the moving body  500 C to be instantly pushed out inside the cylindrical portion  310  so as to be moved. The power source P is not limited to a power source using explosive powder as long as it generates power to move the moving body  500 C, and other known power sources may be used. 
     Next, the internal structure and the usage mode of the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure will be described with reference to  FIG. 17 .  FIG. 17  is a cross-sectional view taken along the line C-C in a state where the electric circuit breaker  600 C shown in  FIG. 16  is assembled. 
     As shown in  FIG. 17 , the moving body  500 C is accommodated inside the cylindrical portion  310  composed of the lower cylindrical portion  110  and the upper cylindrical portion  210  which are linearly arranged. The cylindrical portion  310  extends from a first end portion  320  of the housing  300  to a second end portion  330  on a side opposite to the first end portion  320 . Since the moving body  500 C is arranged on the first end portion  320  side where the power source P is arranged, the second end portion  330  side of the cylindrical portion  310  is hollow. Therefore, as will be described later, the moving body  500 C can move toward the second end portion  330  side while cutting and separating the separation piece  420 C. In addition, the upper surface  560 C of the moving body  500 C is adjacent to the power source P mounted inside the power source accommodating portion  221 . As will be described later, the air pressure due to the explosion of the explosive powder in the power source P is transmitted to the upper surface  560 C of the moving body  500 C via the communication hole  222 . 
     As shown in  FIG. 17 , the granular arc extinguishing material M is accommodated in the first arc extinguishing space X 1 C and the third arc extinguishing spaces X 3 . Since the separation piece  420 C of the cut portion  400 C is accommodated by being inserted through the inside of the first arc extinguishing space X 1 C of the moving body  500 C, the arc extinguishing material M covers the peripheries of the fusing portions  425 C of the cut portion  400 C. Further, the main body portions  430 C of the cut portion  400 C are accommodated by being inserted through the insides of the third arc extinguishing spaces X 3 . In  FIGS. 17 and 18 , although the entire first arc extinguishing space X 1 C and the entire third arc extinguishing spaces X 3  are filled with the arc extinguishing material M, only a part of the arc extinguishing material M is shown on the drawing for the sake of visibility. 
     Then, when a relatively high abnormal current flows in the electric circuit, the fusing portions  425 C of the cut portion  400 C connected to the electric circuit generate heat and are fused. Therefore, the electric circuit is cut off and protected from an overcurrent. Further, even when arcs are generated from the peripheries of the remaining fusing portions  425 C during or after the fusing portions  425 C of the cut portion  400 C are fused, the arcs are effectively extinguished by the arc extinguishing material M in the peripheries of the fusing portions  425 C. Further, the cut portion  400 C is accommodated in the first arc extinguishing space X 1 C filled with the arc extinguishing material M, and the cut portion  400 C is not held in direct contact with the moving body  500 C in the first arc extinguishing space X 1 C. Therefore, even when an arc is generated from the cut portion  400 C, it is possible to prevent the moving body  500 C made of synthetic resin from being carbonized. 
     Further, as shown in  FIG. 17 , there are slight gaps between the mounting portions  213  of the upper housing  200  and the mounting portions  113  of the lower housing  100 , and the arc extinguishing material M can be accommodated in the gaps. In these gaps, the arc extinguishing material M is filled around the main body portions  430 C of the cut portion  400 C, so that the main body portions  430 C are not held in direct contact with the mounting portions  213  of the upper housing  200  and the mounting portions  113  of the lower housing  100 . Therefore, even when arcs are generated from the peripheries of the main body portions  430 C of the cut portion  400 C, the arc extinguishing material M accommodated in the gaps extinguishes the arcs, and the mounting portions  213  of the upper housing  200  and the mounting portions  113  of the lower housing  100  are prevented from being carbonized. Since the arc generation state changes depending on the magnitude of the voltage applied to the cut portion  400 C, depending on the arc generation state, gaps may not be provided, and the main body portions  430 C of the cut portion  400 C may be held in direct contact with the mounting portions  213  of the upper housing  200  and the mounting portions  113  of the lower housing  100 . 
     In this way, when a relatively high abnormal overcurrent flows in the electric circuit, the cut portion  400 C constituted by the fuse is fused to cut off the electric circuit. On the other hand, when an overcurrent below the rating of the fuse flows in the electric circuit, for example, when a relatively low abnormal overcurrent flows in the electric circuit, the cut portion  400 C constituted by the fuse is not fused. Therefore, as will be described with reference to  FIG. 18 , the cut portion  400 C itself is physically cut by the electric circuit breaker  600 C. 
       FIG. 18  is a cross-sectional view showing a state where the moving body  500 C moves from the state shown in  FIG. 17 . Further, in the above description, when a relatively high abnormal overcurrent flows, the cut portion  400 C constituted by the fuse is fused to cut off the electric circuit, and when a relatively low abnormal overcurrent flows, the cut portion  400 C itself is physically cut by the electric circuit breaker  600 C. However, the present disclosure is not limited to this. By changing the rating of the fuse or the setting of the abnormal signal input to the power source P, when a relatively low abnormal overcurrent flows, the cut portion  400 C constituted by the fuse may be fused to cut off the electric circuit, and when a relatively high abnormal overcurrent flows, the cut portion  400 C may be physically cut by the electric circuit breaker  600 C. Therefore, in the following description, the overcurrent when the cut portion  400 C constituted by the fuse is fused is referred to as a predetermined first overcurrent, and the overcurrent when the cut portion  400 C itself is physically cut by the electric circuit breaker  600 C is referred to as a predetermined second overcurrent. The first overcurrent and the second overcurrent can be set to any values. 
     As shown in  FIG. 18 , when an abnormality such as the predetermined second overcurrent flowing in the electric circuit is detected, an abnormality signal is input to the power source P, and the explosive powder in the power source P explodes. Then, the air pressure due to the explosion is instantaneously transmitted to the upper surface  560 C of the moving body  500 C via the communication hole  222 . Then, due to this air pressure, the moving body  500 C is swiftly fused from the first end portion  320  toward the second end portion  330 , and instantaneously moves inside the cylindrical portion  310  toward the second end portion  330 . 
     Then, the moving body  500 C cuts the separation piece  420 C and separates it from the main body portions  430 C by the force of pushing out the moving body  500 C toward the second end portion  330 . Specifically, since the arc extinguishing material M is filled inside the first arc extinguishing space X 1 C, when the moving body  500 C moves, the separation piece  420 C is also instantly pushed out with a strong force toward the second end portion  330  together with the arc extinguishing material M in the vicinity and is cut from the main body portions  430 C. Then, the separation piece  420 C moves toward the second end portion  330  together with the moving body  500 C, and separates from the main body portions  430 C. The cut portion  400 C constituted by the fuse is relatively thinly formed because it is fused when an overcurrent flows. Therefore, the separation piece  420 C can be sufficiently cut without the cutting member  511  as shown in  FIG. 3 . Further, the arc extinguishing material M in the first arc extinguishing space X 1 C is not limited to a granular solid arc extinguishing material such as silica sand, and any arc extinguishing material can be adopted as long as it can transmit, to the separation piece  420 C, the force when the moving body  500 C moves so that the separation piece  420 C can be cut. 
     Further, as shown in  FIG. 18 , the first arc extinguishing space X 1 C is located at a position facing the main body portions  430 C even when the moving body  500 C moves inside the cylindrical portion  310  toward the second end portion  330 . Therefore, the first arc extinguishing space X 1 C is configured to be located between the separation piece  420 C and the main body portions  430 C immediately after the moving body  500 C cuts the separation piece  420 C. Then, immediately after the moving body  500 C cuts the separation piece  420 C, since the physical distance between the separation piece  420 C and the main body portions  430 C is short. Therefore, arcs may be generated between the separation piece  420 C and the end portions  431 C of the main body portions  430 C which are the boundaries with the separation piece  420 C. However, as shown in  FIG. 18 , the arcs generated from the end portions  431 C of the main body portions  430 C are released to the first arc extinguishing space X 1 C located between the separation piece  420 C and the main body portions  430 C, and is extinguished by the arc extinguishing material M in the first arc extinguishing space X 1 C. 
     Further, the first arc extinguishing space X 1 C which extends vertically is located at a position facing the main body portions  430 C even when the moving body  500 C further moves inside the cylindrical portion  310  toward the second end portion  330 . Therefore, even if a voltage is applied between the main body portions  430 C on both sides, and arcs are generated from the end portions  431 C of the main body portions  430 C, the arcs are extinguished by the arc extinguishing material M in the first arc extinguishing space X 1 C, and it is possible to prevent the arcs from connecting between the main body portions  430 C and causing a current to flow in the electric circuit. If a high voltage is applied between the main body portions  430 C on both sides and the arcs cannot be effectively extinguished with the arc extinguishing material M, a mode in which the arcs are effectively confined by insulating spaces  550 D as described later with reference to  FIG. 22  may be adopted. 
     As described above, according to the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure, the moving body  500 C itself cuts the cut portion  400  and includes the first arc extinguishing space X 1  filled with the arc extinguishing material M, and the first arc extinguishing space X 1  is configured to be located between the separation piece  420 C that is cut and separated and the main body portions  430 C that remain in the housing  300  without being separated immediately after the separation piece  420  is cut and the electric circuit is cut off. Therefore, the arcs generated from the main body portions  430 C can be effectively extinguished by the arc extinguishing material M in the first arc extinguishing space X 1  immediately after the cut portion  400  is cut and the electric circuit is cut off. 
     Further, according to the electric circuit breaker  600 C of the present disclosure, when the predetermined first overcurrent flows, the cut portion  400 C constituted by the fuse can be fused to cut off the electric circuit, and when the predetermined second overcurrent flows, the cut portion  400 C itself can be physically cut by the electric circuit breaker  600 C to cut off the electric circuit. Since the cut portion  400 C having the fuse function is accommodated in the electric circuit breaker  600 C, a space for arranging and connecting both the fuse and the electric circuit breaker in series is unnecessary, 
     Further, since the cut portion  400 C is accommodated in the first arc extinguishing space X 1 C filled with the arc extinguishing material M, when the cut portion  400 C constituted by the fuse is fused by the predetermined first overcurrent, even if an arc is generated from the cut portion  400 C, the arc extinguishing material M in the first arc extinguishing space X 1 C effectively extinguishes the arc. 
     In the mode of the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure, the cut portion  400 C having the fuse function is accommodated in the electric circuit breaker  600 C, but the present disclosure is not limited to this. A mode in which the electric circuit breaker  600  according to the first embodiment of the present disclosure and the fuse are connected in series may be adopted, and any mode can be appropriately adopted. 
     In the prior art shown in  FIG. 23 , in order to extinguish an arc, it is also conceivable to enclose a granular solid arc extinguishing material in cutting chambers  721 . However, if the arc extinguishing material is enclosed in the cutting chambers  721 , it may disturb a punching operation of a punch  730 , so that it is difficult to fill the arc extinguishing material in the cutting chambers  721 . However, in the present disclosure, unlike the prior art, the arc extinguishing material M can be accommodated in the moving body  500 C itself instead of in the cylindrical portion  310 , so that the operation of the moving body  500 C that moves inside the cylindrical portion  310  and cuts the separation piece  420 C is not disturbed. Further, since the separation piece  420 C is accommodated in the moving body  500 C and moves together with the moving body  500 C, there is no risk of disturbing the punching operation of the punch unlike the prior art. Since the arc extinguishing material M and the separation piece  420 C are both accommodated in the moving body  500 C and move together with the moving body  500 C, a large amount of the arc extinguishing material M can be accommodated in the moving body  500 C unlike the prior art. Furthermore, since the first arc extinguishing space X 1 C can be expanded according to the volume inside the moving body  500 C, a large amount of the arc extinguishing material M can be accommodated and the arc extinguishing performance is extremely high. 
     Fifth Embodiment 
     Next, an electric circuit breaker  600 D according to a fifth embodiment of the present disclosure will be described with reference to  FIGS. 19 to 22 . In the electric circuit breaker  600 D according to the fifth embodiment of the present disclosure, the bent portions  440 A can be used together, like the cut portion  400 A of the electric circuit breaker  600 A according to the second embodiment shown in  FIG. 9 . Further,  FIG. 19( a )  is a perspective view of a moving body  500 D of the electric circuit breaker  600 D according to the fifth embodiment of the present disclosure,  FIG. 19( b )  is a front view of the moving body  500 D, and  FIG. 19( c )  is a side view of the moving body  500 D. Further, the configuration of the electric circuit breaker  600 D according to the fifth embodiment is basically the same as the configuration of the electric circuit breaker  600 C according to the fifth embodiment, except that the moving body  500 D has insulating spaces, and hence detailed description of the same configurations will be omitted. Further, the insulating spaces  550 D of the moving body  500 D according to the fifth embodiment have the same configuration as the insulating spaces  550  of the moving body  500  shown in  FIG. 3 , and exhibit the same effect. 
     First, the moving body  500 D is a substantially columnar body made of synthetic resin and having an upper surface  560 D and a lower surface  520 D. Further, on the lower surface  520 D side of the moving body  500 D, there is provided a penetrating portion  540 D which penetrates the moving body  500 D from one part of the outer surface  530 D to another part of the outer surface  530 D on the opposite side, that is, from the front surface to the back surface of the moving body  500 D, and the penetrating portion  540 D is surrounded by a lower wall  541 D, a side wall  542 D, a side wall  543 D, and an upper wall  544 D. A space surrounded by the lower wall  541 D, the side wall  542 D, the side wall  543 D, and the upper wall  544 D and recessed inward from the outer surface  530 D is a first arc extinguishing space X 1 D. Then, in the first arc extinguishing space X 1 D, the separation piece  420 C of the cut portion  400 C described later can be inserted and accommodated. Further, in the first arc extinguishing space X 1 D, since an arc extinguishing material described later is filled, the periphery of the separation piece  420 C of the cut portion  400 C accommodated in the first arc extinguishing space X 1 D can be completely surrounded by the arc extinguishing material 
     Further, insulating spaces  550 D that are recessed inward from the outer surface  530 D are formed on the upper surface  560 D side of the moving body  500 D. The insulating spaces  550 D are formed at opposite positions on the outer surface  530 D. The insulating spaces  550 D are each surrounded by a lower wall  551 D, a side wall  552 D, a side wall  553 D, an upper wall  554 D, and a rear wall  555 D. As shown in  FIG. 19( c ) , the insulating spaces  550 D arranged so as to face each other are shielded from each other by the rear wall  555 D, and are spaces insulated from each other. An arc extinguishing material is not accommodated in the insulating spaces  550 D, and an arc is confined and shielded as will be described later. Further, the insulating spaces  550 D and the first arc extinguishing space X 1 D are also shielded from each other by the lower walls  551 D and the upper walls  544 D, and are independent spaces insulated from each other. 
     Next, the internal structure and the usage mode of the electric circuit breaker  600 D according to the fifth embodiment of the present disclosure will be described with reference to  FIG. 20 . The electric circuit breaker  600 D according to the fifth embodiment of the present disclosure is assembled in the same manner as the electric circuit breaker  600 C according to the fourth embodiment of the present disclosure, and the assembly of the electric circuit breaker  600 D is completed by replacing the moving body  500 C of the electric circuit breaker  600 C shown in  FIG. 17  with the moving body  500 D of the electric circuit breaker  600 D shown in  FIG. 19 .  FIG. 20  is a cross-sectional view showing the electric circuit breaker  600 D according to the fifth embodiment of the present disclosure, in which the moving body  500 C of  FIG. 17  is replaced with the moving body  500 D. 
     As shown in  FIG. 20 , the moving body  500 D is accommodated inside the cylindrical portion  310  composed of the lower cylindrical portion  110  and the upper cylindrical portion  210  which are linearly arranged. The granular arc extinguishing material M is accommodated in the first arc extinguishing space X 1 D and the third arc extinguishing spaces X 3 . Since the separation piece  420 C of the cut portion  400 C is accommodated by being inserted through the inside of the first arc extinguishing space X 1 D of the moving body  500 D, the arc extinguishing material M covers the periphery of the fusing portion  425 C of the cut portion  400 C. In  FIGS. 20 to 22 , although the entire first arc extinguishing space X 1 D and the entire third arc extinguishing spaces X 3  are filled with the arc extinguishing material M, only a part of the arc extinguishing material M is shown on the drawing for the sake of visibility. 
     Then, when the predetermined first overcurrent (for example, a relatively high abnormal overcurrent) flows in the electric circuit, the fusing portion  425 C of the cut portion  400 C connected to the electric circuit heats and is fused, and the electrical circuit is cut off and protected from an overcurrent. Further, even when an arc is generated from the periphery of the fusing portion  425 C during or after the fusing portion  425 C of the cut portion  400 C is fused, the arc is effectively extinguished by the arc extinguishing material M in the periphery of the fusing portion  425 C. Further, the cut portion  400 C is accommodated in the first arc extinguishing space X 1 D filled with the arc extinguishing material M, and the cut portion  400 C is not held in direct contact with the moving body  500 D. Therefore, even when an arc is generated from the cut portion  400 C, it is possible to prevent the moving body  500 D made of synthetic resin from being carbonized, 
     On the other hand, as shown in  FIG. 21 , when an abnormality such as the predetermined second overcurrent (for example, a relatively low abnormal overcurrent) flowing in the electric circuit is detected, an abnormality signal is input to the power source P, and the explosive powder in the power source P explodes. Then, the air pressure due to the explosion is instantaneously transmitted to the upper surface  560 D of the moving body  500 D via the communication hole  222 , and instantaneously moves inside the cylindrical portion  310  toward the second end portion  330 .  FIG. 21  is a cross-sectional view showing a state where the moving body  500 D moves from the state shown in  FIG. 20 . 
     Then, the moving body  500 D cuts the separation piece  420 C and separates it from the main body portions  430 C by the force of pushing out the moving body  500 C toward the second end portion  330 . Specifically, since the arc extinguishing material M is filled inside the first arc extinguishing space X 1 D, when the moving body  500 D moves, the separation piece  420 C is also instantly pushed out with a strong force toward the second end portion  330  together with the arc extinguishing material M in the vicinity and is cut from the main body portions  430 C. Then, the separation piece  420 C moves toward the second end portion  330  together with the moving body  500 D, and separates from the main body portions  430 C. 
     Further, as shown in  FIG. 21 , the first arc extinguishing space X 1 D is located at a position facing the main body portions  430 C immediately after the moving body  500 D moves inside the cylindrical portion  310  toward the second end portion  330 . Therefore, the first arc extinguishing space X 1 D is configured to be located between the separation piece  420 C and the main body portions  430 C immediately after the moving body  500 D cuts the separation piece  420 C. Then, immediately after the moving body  500 D cuts the separation piece  420 C, since the physical distance between the separation piece  420 C and the main body portions  430 C is short. Therefore, arcs may be generated between the separation piece  420 C and the end portions  431 C of the main body portions  430 C which are the boundaries with the separation piece  420 C. However, as shown in  FIG. 21 , the arcs generated from the end portions  431 C of the main body portions  430 C are released to the first arc extinguishing space X 1 D located between the separation piece  420 C and the main body portions  430 C, and is extinguished by the arc extinguishing material M in the first arc extinguishing space X 1 D. 
     Next, a state where the moving body  500 D further moves toward the second end portion  330  will be described with reference to  FIG. 22 .  FIG. 22  is a cross-sectional view showing a state where the moving body  500 D further moves from the state shown in  FIG. 21 . As shown in  FIG. 22 , when the moving body  500 D further moves inside the cylindrical portion  310  toward the second end portion  330 , the insulating spaces  550 D formed above the first arc extinguishing space X 1  move up to positions facing and adjacent to the main body portions  430 . Even if a high voltage is applied between the main body portions  430 C on both sides and arcs are generated from the end portions  431 C of the main body portions  430 C, the arcs are confined in the insulating spaces  550 D. The arcs generated between the main body portions  430 C on both sides are confined in the insulating spaces  550 D and insulated from each other, so that it is possible to prevent the arcs from connecting between the main body portions  430 C on both sides and causing a current to flow in the electric circuit. 
     It is desirable that the arc extinguishing material M be not accommodated in the insulating spaces  550 D. When the arc extinguishing material M is accommodated in the insulating spaces  550 D, the arc extinguishing material M may be exposed to high temperature and carbonized by the arcs generated from the main body portions  430 C, and the carbonized portion becomes a path through which an electric current can flow, so that the arcs easily leak from the insulating spaces  550 D. Further, in the insulating spaces  550 D, instead of the arc extinguishing material M, an insulating material that is not carbonized by an arc may be accommodated, 
     Further, the electric circuit breaker of the present disclosure is not limited to the above-described examples, various modifications and combinations are possible within the scope described in the claims and the scope of the embodiments, and the these modifications and combinations are included in the scope of right.