Patent Publication Number: US-9412540-B2

Title: Switch

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of International Application No. PCT/JP2012/007221 filed Nov. 12, 2012, the contents of all of which are incorporated herein by reference in their entirety. 
     TECHNICAL FIELD 
     The present invention relates to a switch that includes a movable contact bonded with a movable contactor, a fixed contact bonded with a fixed contactor, and an arc runner. 
     BACKGROUND ART 
     A switch includes movable contacts bonded with both ends of a movable contactor, and a fixed contact bonded with an end of a fixed contactor and located to face each of the movable contacts, and an arc is generated between the movable contact and the fixed contact when current is cut off. The arc shortens the electrical life of switch, and degrades insulation performance of molded parts used for interphase insulation thereby provoking the interphase short circuit. Therefore, an arc runner serving as an arc-extinguishing metal plate for attracting the arc to promptly extinguish it is provided in some of the switches. 
     Specifically, there has been a switch that includes a first arc runner and a second arc runner (for example, see Patent Document 1). The first arc runner has a U-shape portion in which an opening is provided at a contact side for shielding between a fixed contact and a movable contact, and also has an expanded portion which is extended in a fixed contactor side of the U-shape portion by the intervention of a bent step portion. The second arc runner is provided to stand in parallel with the expanded portion of first arc runner so as to cover the neighborhood of fixed contactor tip. In addition, an arc runner is disclosed which is configured with a gutter-shaped curved surface or multiple surfaces in which an angle between the neighboring surfaces is an obtuse angle and which is disposed in parallel with a contact or leave direction so that a depressed portion of the curved surface or multiple surfaces faces the movable contactor end portion (for example, see Patent Document 2). 
     PRIOR ART DOCUMENT 
     Patent Document 
     Patent Document 1: Japanese Unexamined Patent Application Publication No. S59-112513 (P. 2-P. 3, FIG. 4, FIG. 5) 
     Patent Document 2: Japanese Unexamined Patent Application Publication No. S59-181421 (P. 2-P. 3, FIG. 7, FIG. 9) 
     SUMMARY OF THE INVENTION 
     Problem that the Invention is to Solve 
     In a conventional arc runner, part of the arc runner is disposed at a space between a movable contact and interphase barriers which are insulators disposed at both right and left sides of the movable contact. Thus, only a large-size switch which has some space between the interphase barrier and the movable contact can equip the arc runner. On the other hand, since a downsized switch, especially the one having a downsized width, has a small space between the interphase barrier and the movable contact, an open space large enough to dispose the arc runner cannot be secured. Therefore, in a case where a model that needs an arc runner is to be downsized, it is necessary to remove the arc runner, and thus problems occur that the electrical life is shortened and degradation of insulation performance of molded parts used for interphase insulation provokes the interphase short circuit. 
     In order to solve the above-described problems, an objective of the present invention is to provide a small-size switch that includes an arc runner. 
     Means for Solving the Problem 
     A switch according to the present invention includes fixed contacts each of which is bonded with each one end of fixed contactors; movable contacts each of which is bonded with each of movable contactors and each of which can contact with or leave from each of the fixed contacts; an interphase barrier that is disposed so as to partition the movable contacts one by one and that is an insulator; and an arc runner that has an arc extinguish portion, that is disposed so as not to intrude in a space where the interphase barrier and the movable contactor are most closely located, and that has the arc extinguish portion. 
     Advantageous Effects of the Invention 
     In the present invention, an arc runner is disposed along an operating direction of a movable contact so as not to laterally overlap with interphase barriers which are insulators disposed at both right and left sides of the movable contact, thereby enabling the downsizing of a switch that includes an arc runner. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a lateral cross-sectional view of a switch in Embodiment 1 of the present invention. 
         FIG. 2  is a perspective view of an arc runner according to the switch in Embodiment 1 of the present invention. 
         FIG. 3  is a front view of a movable contactor, a movable contact, a fixed contactor, a movable contactor carrier, and the arc runner in the switch in Embodiment 1 of the present invention. 
         FIG. 4  is an enlarged lateral cross-sectional view of part of the switch according to Embodiment 1 of the present invention. 
         FIG. 5  is a perspective view of an arc runner according to a switch in Embodiment 3 of the present invention. 
         FIG. 6  is a perspective view of a movable contactor, a movable contact, a fixed contactor, a fixed contact, and the arc runner in the switch in Embodiment 3 of the present invention. 
         FIG. 7  is a front view of the movable contactor, the movable contact, the fixed contactor, a movable contactor carrier, and the arc runner in the switch in Embodiment 3 of the present invention. 
         FIG. 8  is a perspective view of an arc runner according to a switch in Embodiment 4 of the present invention. 
         FIG. 9  is a perspective view of an arc runner according to a switch in Embodiment 5 of the present invention. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Embodiment 1 
       FIG. 1  is a lateral cross-sectional view of a switch. The left side of the figure is a front side of the switch, and the right side of figure is a rear side of switch. The exterior of the switch in the present invention is formed by a rear case  1  and a case  5  which are insulators manufactured by plastic molding, for example. In the rear case  1 , there are provided a fixed iron core  2  having an E-shape, an electromagnetic coil  3  and a coil bobbin  13  which are disposed to circle around the fixed iron core  2 , and a movable iron core  4 , having the E-shape, disposed at a position facing the fixed iron core  2 . 
     The inside of case  5  has a vertically symmetric structure, and there are disposed a movable contactor carrier  8 , fixed contactors  6 U and  6 L, screws  11 U and  11 L, a movable contactor  9 , and arc runners  12 U and  12 L. The movable iron core  4  is connected, via a movable iron core connection plate  14 , to the movable contactor carrier  8  being a molded part, and the movable contactor  9  is held so that the center portion thereof is pressed against the movable contactor carrier  8  by a forcing spring  15  interposed into a holding hole of movable contactor carrier  8 . While the structure of the upper side will be explained hereinafter, that of the lower side is similarly obtained by replacing the suffix “U” with “L”. The fixed contactor  6 U is mounted to the case  5  at a rear side of the switch relative to the movable contactor  9 , and a fixed contact  7 U bonded with an end of the fixed contactor  6 U can contact with or leave from a movable contact  10 U bonded with either end of the movable contactor  9  in its longitudinal direction. There is a hole at the other end of the fixed contactor  6 U, and the screw  11 U for connecting to a terminal of an external device is inserted to the hole. The arc runner  12 U being a metal plate is fixed to the case  5  and is disposed, at an end portion side of the movable contactor  9 , along an operating direction of the movable contactor  9  (direction indicated by arrows) so as to face the movable contact  10 U. Note that a general switch has a structure in which a plurality of movable contactors, fixed contactors, etc. is arranged in a direction perpendicular to the sheet of  FIG. 1  (transverse direction). 
       FIG. 2  is a perspective view of an arc runner  12  according to Embodiment 1. The arc runner  12  is configured with an arc extinguish portion  12 A for attracting the arc, a heat radiation portion  12 B for dissipating arc heat, and a U-shaped portion  12 C for bonding the arc extinguish portion  12 A with the heat radiation portion  12 B. In this embodiment, the arc extinguish portion has a plate-like shape. The arc runner  12  is fixed to the case  5  by the heat radiation portion  12 B. The heat radiation portion  12 B has a shape whose side length along an operating direction of the movable contact  10  (direction indicated by arrows) is longer than the length of arc extinguish portion  12 A. Thus, a heat radiation effect is increased and an arc can be promptly extinguished. 
       FIG. 3  is a front view of the fixed contactor  6 U, case  5 , arc runner  12 U, movable contactor  9 , movable contact  10 U, and movable contactor carrier  8  disposed at the upper half of  FIG. 1 . Since the fixed contactor  6 L, case  5 , arc runner  12 L, movable contactor  9 , movable contact  10 L, and movable contactor carrier  8  disposed at the lower half of  FIG. 1  has the similar structure of being turned upside down, only the upper side will be explained here. As shown in  FIG. 3 , the movable contactor carrier  8  has a pair of partition portions  80 , each of which partitions the movable contactor  9  from a neighboring movable contactor  91 , at the right and left sides of movable contactor  9  so as to be adjacent thereto. The partition portion  80  of movable contactor carrier  8  protrudes from the center portion of movable contactor  9  toward the end portion thereof so as to sandwich the movable contactor  9 . Also, in the case  5  being a molded part same as the movable contactor carrier  8 , a partition portion  51  is provided and disposed, in an alternate manner, to be sandwiched by the partition portion  80  and the partition portion  81  adjacent to the neighboring movable contactor  91 . The partition portions  80 ,  81  of movable contactor carriers  8  and the partition portion  51  of case  5  partition the movable contacts one by one, and function as interphase barriers. In a small-size model, an open space, surrounded by the partition portions  80  of movable contactor carrier  8  and the partition portions  51  of case  5 , where the movable contactor  9  is disposed is small, and especially the partition portion  80  of movable contactor carrier  8  is located in proximity to the movable contactor  9 . 
     In the present invention, the arc runner  12 U is disposed so as not to laterally overlap with the partition portion  80  of movable contactor carrier  8 . Or, the arc runner  12 U is disposed so as not to overlap with the interphase barrier  80  at a position where the interphase barrier  80  and the movable contact  10 U are most closely located laterally. Here, “laterally” means a direction perpendicular to both the longitudinal direction of movable contactor  9  and the operating direction of movable contactor  9 , and is a direction perpendicular to the sheet of  FIG. 1 . Or, it is a direction in which a plurality of movable contacts is arranged, and is a right and left direction with respect to the sheet of  FIG. 3 . It can be expressed also as a direction in which the partition portion  80  of movable contactor carrier  8  and the movable contactor  9  are adjacently disposed. Namely, the arc runner  12 U is disposed at the end portion side (upper side in  FIG. 3 ) of movable contactor  9  relative to the partition portion  80  of movable contactor carrier  8 . In other words, the arc runner  12 U is disposed so that part of the arc runner  12 U does not intrude in an open space where the movable contactor  9  and the partition portion  80  of movable contactor carrier  8  are most closely located. Thus, even in a small-size switch in which an arc runner cannot be disposed between the movable contactor  9  and the partition portion  80  of movable contactor carrier  8 , an arc runner can be disposed similar to a conventional large-size model. 
     Next, an operation will be explained with reference to  FIG. 1 . While the operation in the upper side will be explained, that of the lower side is similarly obtained by replacing the suffix “U” with “L”, since the inside of case  5  has a vertically symmetric structure. When voltage is applied to the electromagnetic coil  3 , the movable iron core  4  is attracted by the fixed iron core  2 , and the movable contactor carrier  8 , movable contactor  9 , and movable contact  10 U are also attracted toward a fixed iron core side, and thus the movable contact  10 U contacts the fixed contact  7 U. If the fixed contact  7 U contacts the movable contact  10 U, current flows through the screw  11 U, fixed contactor  6 U, fixed contact  7 U, movable contact  10 U, and movable contactor  9 , and the movable contactor  9 , movable contact  10 L, fixed contact  7 L, fixed contactor  6 L, and screw  11 L become a conduction state. Since the screw  11 U is connected to a terminal of an external device, current flows the external device. When excitation of the electromagnetic coil  3  is stopped, the fixed iron core  2  is separated from the movable iron core  4  and the movable contact  10 U is separated from the fixed contact  7 U by return spring (not shown) force, and an arc is generated between the contacts. Since the arc shortens the electrical life of switch and causes the interphase short circuit brought by insulation performance degradation of movable contactor carrier  8  and case  5  used for interphase insulation, it is necessary to extinguish the arc promptly. 
     Next, an operation of an arc will be explained with reference to  FIG. 4 .  FIG. 4  is an enlarged view of part of  FIG. 1  (fixed contactor  6 , fixed contact  7 , movable contactor  9 , movable contact  10 , and arc runner  12 ). An arc  16  generated between the movable contact  10  and the fixed contact  7  is attracted to the arc extinguish portion  12 A of arc runner  12 , and becomes an arc  16 A. The arc  16 A is further attracted to the arc extinguish portion  12 A, and is separated into an arc  16 B and an arc  16 C. The arc  16 B and the arc  16 C are respectively moved to the front side and the upper side by driving force of a magnetic field generated by current flowing through the arc runner  12 , and become an arc  16 D and an arc  16 E. Thus, since the arc  16  is separated into the arc  16 D and the arc  16 E, the arc is cooled and the arc voltage is increased so that the arc can be extinguished. 
     Thus, since the arc runner  12  is shaped and disposed so as not to laterally overlap with the movable contactor carrier  8 , an arc runner can be equipped even in a small-size switch not having enough space between the movable contactor carrier  8  and the movable contactor  9 , as shown in  FIG. 3 . Also, since the heat radiation portion  12 B dissipates the arc heat generated by the arc, the increase in arc voltage can be accelerated, so that the arc can be promptly extinguished. In addition, since the side length, along the operating direction of movable contact  10 , of heat radiation portion  12 B is longer than the length of arc extinguish portion  12 A, the arc can be more promptly extinguished. Note that, in a small-size low-current model, the arc runner  12  may have a structure without the U-shaped portion  12 C and heat radiation portion  12 B. That is, whether or not the U-shaped portion  12 C and heat radiation portion  12 B are necessary can be determined depending on the performance of the model. If determined to be unnecessary, only the arc extinguish portion  12 A is needed to be disposed, thereby enabling downsizing also in the vertical direction. In this case, the arc extinguish portion  12 A of arc runner  12  may be fixed to the case  5 . 
     Embodiment 2 
     The difference between this embodiment and Embodiment 1 is that no partition portion  80  of movable contactor carrier  8  is provided next to the movable contactor  9  and only the partition portion  51  of case  5  is provided, and the other configuration is the same as that in Embodiment 1. The arc runner  12 U is disposed so as not to laterally overlap with the movable contactor  9 . That is, the arc runner  12 U is disposed so as not to laterally overlap with the movable contactor  9  in a direction in which the partition portion  51  of case  5  and the movable contactor  9  are adjacently disposed. Or, the arc runner  12 U is disposed so that part of the arc runner  12 U does not intrude between the movable contactor  9  and the partition portion  51  of case  5 . Namely, the arc runner  12  is disposed, without contacting the movable contactor  9 , at an end portion side in a longitudinal direction of the movable contactor  9 . Thus, compared to Embodiment 1, a switch can be further downsized by the width of partition portion  80  of movable contactor carrier  8 . 
     Embodiment 3 
       FIG. 5  is a perspective view of the arc runner  12  according to Embodiment 3. The only difference between this embodiment and Embodiment 1 is the shape of arc runner  12 , and the arc extinguish portion  12 A in Embodiment 1 is replaced by an arc extinguish portion  12 D configured with gutter-shaped multiple surfaces in which an angle between the neighboring surfaces is an obtuse angle. The other configuration and the operation of switch are similar to those in Embodiment 1.  FIG. 6  is a perspective view of the movable contactor  9 , movable contact  10 , fixed contactor  6 , fixed contact  7 , and arc runner  12 , and a depression of the arc extinguish portion  12 D is disposed so as to face the movable contact.  FIG. 7  is a front view of the fixed contactor  6 , arc runner  12 , movable contactor  9 , movable contact  10 , and movable contactor carrier  8 , and single movable contactor  9  is only illustrated. The arc runner  12  is disposed, along an operating direction of the movable contact  10  (direction perpendicularly penetrating a plane in the figure), so as not to laterally overlap with the movable contactor carrier  8 . 
     By employing such a configuration, in addition to the effects similar to those in Embodiment 1, the arc can be more promptly extinguished since the distance between the movable contactor  9  and each of end portions of arc extinguish portion  12 D becomes short. Note that, similar to Embodiment 1, the arc runner  12  may have a structure without the U-shaped portion  12 C and heat radiation portion  12 B depending on the performance of a switch. Here, the effects obtained in a case where the arc runner  12  has the structure without the U-shaped portion  12 C and heat radiation portion  12 B are similar to those in Embodiment 1 or Embodiment 2, and the arc runner  12  may be attached by fixing the arc extinguish portion  12 D to the case  5 . 
     Embodiment 4 
       FIG. 8  is a perspective view of the arc runner  12  according to Embodiment 4. The only difference between this embodiment and Embodiment 1 is the shape of arc runner  12 , and the arc extinguish portion  12 A in Embodiment 1 is replaced by an arc extinguish portion  12 E configured with a gutter-shaped curved surface. The other configuration and the operation of switch are similar to those in Embodiment 1. Also in this case having such a shape, similar to Embodiment 2, the arc can be more promptly extinguished since the distance between the movable contactor  9  and each of end portions of arc extinguish portion  12 E becomes short. Note that, similar to Embodiments 1 and 2, the necessity of U-shaped portion  12 C and heat radiation portion  12 B can be determined depending on the performance of a model, and only the extinguish portion  12 E may be provided if determined to be unnecessary. In such a case, the arc runner  12  may be attached by fixing the arc extinguish portion  12 E to the case  5 . 
     Embodiment 5 
       FIG. 9  is a perspective view of an arc runner according to a switch in Embodiment 5. In this embodiment, a structure is employed in which an opening  12 G is provided at the heat radiation portion  12 B in Embodiments 1 through 3, as shown in  FIG. 9 , and the other portions are similar to those in Embodiments 1 through 3. In this case, the arc gas generated between the movable contact  10  and the fixed contact  7  is discharged to the outside through the opening  12 G. Since the arc can be easily cut off by the discharge of arc gas, the arc is promptly extinguished. By employing such a configuration, in addition to the effects similar to those in Embodiments 1 through 3, the arc can be more promptly extinguished. Note that, while  FIG. 9  shows a case, as an example, where an opening is provided to the structure in Embodiment 1, an opening may be provided at the heat radiation portion  12 B in Embodiment 2 or 3. 
     REFERENCE NUMERALS 
       6  fixed contactor;  7  fixed contact;  8  movable contactor carrier;  9  movable contactor;  10  movable contact; and  12  arc runner.