Abstract:
A starter includes a starter motor, a main circuit section, a main switch section including a main contact section to cut a current, a main plunger driven to open and close the main contact section, suction and holding coils, battery and motor terminals, and a switch terminal connected to the battery through a start switch, and opening and closing the main contact section in accordance with movement of the main plunger, a suction circuit section connected in parallel with the main circuit section and connected in series with the suction coil, a holding circuit section connected in series with the holding coil, and a breaking section connected in series with the suction coil inside the suction circuit section. The breaking section cuts electricity conduction when electricity is continuously conducted to the suction coil to bring about layer short circuit and a short circuit current flows at the suction circuit section.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a starter used in starting an engine of, for example, an automobile or the like. 
     2. Description of the Related Art 
     A starter of a background art is constructed by a constitution including a fuse in series with a suction coil constituting a starter. (Refer to, for example, JP-A-2005-54706, page 10, FIG. 2) 
     Further, also in a starter of a background art having an auxiliary switching function is constructed by a constitution including a fuse in series with a suction coil constituting the starter. (Refer to, for example, JP-A-2004-52572, page 8, FIG. 1) 
     A general starter is constructed by a constitution in which by closing a start switch provided for starting the starter, a pinion gear provided to the starter and a ring gear provided to an engine are brought in mesh with each other, and a rotating operation of the starter is transmitted to the engine and therefore, in a case in which teeth of both of the pinion gear and the ring gear collide with each other and are not brought in mesh with each other normally, and in a case in which the start switch for starting the engine is continuously closed and the suction coil is conducted with electricity for a long period of time or a case in which an operation of opening the start switch once and thereafter immediately closing the start switch is continuously carried out repeatedly and the suction coil is intermittently conducted with electricity for a long period of time, there is a concern that a temperature of the suction coil rises, an insulating coating of the suction coil is melted to bring about layer short circuit, and a short circuit current flows. 
     Therefore, according to the starter of the background art, there is used a fuse a melting temperature of which is set to be low to be connected in series with the suction coil such that electricity conduction to the suction coil is cut before bringing the suction coil into layer short circuit, however, the fuse is comparatively easily melted to cut by conducting normal current and therefore, by cutting the fuse, the starter is not operated, and the state in which the engine cannot be started is brought about frequently. 
     Further, according to the starter of the background art, a resistance value of the fuse varies widely from high and low owing to production tolerance or the like, as a result, a current having a value different from a normal value flows in the fuse, a temperature rise of the fuse is changed and also a time period of cutting the fuse becomes a different value. Hence, when the fuse is melted to cut by a time period shorter than normal, that is, there is further frequently brought about the state in which the engine cannot be started, and it is difficult to design a fuse melted to cut by a predetermined time period for avoiding the state. 
     SUMMARY OF THE INVENTION 
     The invention has been carried out in order to resolve the above-described problem and it is an object thereof to provide a starter restraining a state in which an engine cannot be started from being brought about and facilitating to design the fuse. 
     According to an aspect of the present invention, a starter includes a starter motor that is supplied with a current from a battery and generates a rotational force, a main circuit section that makes the current flow from the battery to the starter motor, a main switch section including a main contact section that is provided at the main circuit section and cuts the current in the main circuit section, a main plunger that is driven to open and close the main contact section, a suction coil that generates a magnetic force to suck the main plunger, a holding coil that generates a magnetic force to hold the sucked main plunger, a battery terminal connected to the battery and constituting one fixed contact of the main contact section, a motor terminal connected to the starter motor and constituting other fixed contact of the main contact section, and a switch terminal that is connected to the battery through a start switch and conducts electricity to the suction coil and the holding coil, the main switch section opening and closing the main contact section in accordance with movement of the main plunger, a suction circuit section connected in parallel with the main circuit section and connected in series with the suction coil between the start switch and the motor terminal, a holding circuit section connected in series with the holding coil between the switch terminal and other end of the battery, and a breaking section that is connected in series with the suction coil inside the suction circuit section and cuts electricity conduction to the suction coil. The breaking section cuts electricity conduction when electricity is continuously conducted to the suction coil to bring about layer short circuit and a short circuit current flows at the suction circuit section. 
     According to the invention, the breaking section is not cut before the suction coil is brought into layer short circuit and the breaking section is cut after the suction coil is brought into layer short circuit and the short circuit current flows at the breaking section. Further, even when a current value conducted to the suction coil becomes a different value owing to a tolerance in fabricating the breaking section or the like and also a time period of bringing the suction coil into layer short circuit differs from normal, in order to bring the suction coil into layer short circuit, a time period sufficiently longer than a time period of breaking a fuse applied to the starter of the background art is needed to restrain a state in which the breaking section is cut and an engine cannot be started from being brought about. 
     Further, when the short circuit current flows at the breaking section, a temperature of the breaking section rapidly rises to reach a melting temperature in a short period of time and therefore, a change in a temperature rise produced owing to a tolerance of fabricating the breaking section or the like is restrained, and also an error in a time period required until the suction coil is brought into layer short circuit and the breaking section is melted to cut is reduced. Therefore, design of the breaking section is facilitated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an electric wiring diagram of a starter according to Embodiment 1 of the invention; 
         FIG. 2  is a half sectional view of a side face of the starter shown in  FIG. 1 ; 
         FIG. 3  is a half side view of the starter according to Embodiment 1 of the invention; 
         FIGS. 4A to 4C  illustrate constitution view s of a breaking section provided at the starter shown in  FIG. 1 ; 
         FIGS. 5A and 5B  are characteristic diagrams of the breaking section applied to the starter according to Embodiment 1 of the invention; 
         FIG. 6  is an electric wiring diagram of a starter according to Embodiment 2 of the invention; 
         FIG. 7  is a half sectional view of a side face of the starter shown in  FIGS. 4A to 4C ; 
         FIG. 8  is a half side view of the starter according to Embodiment 2 of the invention; 
         FIG. 9A to 9C  illustrates constitution views of a breaking section provided at the starter according to Embodiment 2 of the invention; and 
         FIGS. 10A and 10B  are a characteristic diagram of the breaking section applied to the starter according to Embodiment 2 of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiment 1 
       FIG. 1  is an electric wiring diagram of a starter according to Embodiment 1 of the invention.  FIG. 2  is a half sectional view of a side face of the starter shown in  FIG. 1 .  FIG. 3  is a half side view of the starter shown in  FIG. 1 .  FIGS. 4A to 4C  are constitution views of a breaking section provided at the starter shown in  FIG. 1 .  FIGS. 5A and 5B  are diagrams showing a characteristic of the breaking section according to Embodiment 1. 
     First, a structure of the starter according to Embodiment 1 of the invention will be described. 
     In  FIG. 1 , a starter motor  3  provided at a starter  1  is electrically connected to a battery  2  by way of a main circuit section  4 . The main circuit section  4  includes a main contact section  7  connected with a field coil  47  for opening and closing electric connection from the battery  2  to the starter motor  3 . 
     A suction circuit section  5  includes a suction coil  8  for generating a magnetic flux for opening and closing the main contact section  7 . Further, the suction circuit section  5  is connected in parallel with the main circuit section  4  and a start switch  16  and the suction coil  8  and a breaking section  61  are provided on the suction circuit section  5 . 
     A holding circuit section  38  includes a holding coil  17  one end of which is connected to a switch terminal  34  constituting a connection point between the start switch  16  and the suction coil  8  and other end of which is connected to a minus side terminal of the battery  2 . 
     The main contact section  7  includes a battery side fixed contact  9  constituted at a battery terminal  28 , a starter motor side fixed contact  10  constituted at a motor terminal  29  and a movable contact  11  provided movably to contact and separate the battery side fixed contact  9  and the starter motor side fixed contact  10  constituted at the motor terminal  29 . The movable contact  11  is attached to a main plunger  12  in a rod-like shape driven by conducting electricity to the suction coil  8  and the holding coil  17 . A main switch section  42  operated as an electromagnetic switch is constituted from the main contact section  7 , the suction coil  8 , the holding coil  17  and the main plunger  12 . 
     Successively, as shown by  FIG. 2 , the starter motor  3  is attached to a housing  39  along with the main switch section  42 . An output shaft of the starter motor  3  is connected with a pinion gear  23  brought in mesh with a ring gear  26  connected to an engine by way of an overrunning clutch  22 . Further, the main switch section  42  is provided contiguously to the starter motor  3  such that an axis line of the main plunger  12  is in parallel with an axis line of the starter motor  3 . According to the main plunger  12 , one end portion  12   a  thereof is attached with the movable contact  11  and other end portion  12   b  thereof is formed with a locking section  25  having a small diameter section  25   a  and a circular plate section  25   b.    
     Further, the main plunger  12  and the output shaft of the starter motor  3  are connected by a lever  27 . The lever  27  is pivotably provided at a pin member  36  arranged between the axis line of the main plunger  12  and the axis line of the starter motor  3 . Further, according to the lever  27 , one end portion  27   a  thereof is arranged at the small diameter section  25   a  of the locking section  25  and other end portion  27   b  thereof is arranged between the starter motor  3  and the overrunning clutch  22 . 
     Here, as shown by  FIG. 3  a metal plate  18  is provided for connecting a connecting terminal  32  at one end of the suction coil  8  and the motor terminal  29 . The metal plate  18  serves also as a breaking section  61  melted to cut by making a short circuit current flow. The breaking section  61  is melted to cut when the suction coil  8  is brought into layer short circuit by melting an insulating coating of the suction coil  8  and the short circuit current flows at the suction circuit section  5 . Further, according to the breaking section  61 , a width of a portion of the metal plate is formed to be narrower than that of other portion. Further, the width and a material (example: copper or brass) are determined in accordance with a current value of melting to cut the breaking section  61 . Further, as shown by  FIGS. 4A to 4C , a cover  33  made of a resin is fixed to the metal plate  18  so as to cover the breaking section  61  by utilizing a claw portion  331  formed at the cover  33  for fixing the metal plate  18  and a cut portion  332  provided to facilitate to fix to the metal plate  18 . Further, the suction circuit section  5  is connected to the starter motor  3  by way of a grommet  49  after connected to the main circuit section  4  by the motor terminal  29 . 
     Operation of the starter according to Embodiment 1 will be explained as follows. 
     According to the starter  1 , by closing the start switch  16 , electricity is conducted from the battery  2  to the suction circuit section  5  and the holding circuit section  38 , thereby, a magnetic flux is generated by the suction coil  8  and the holding coil  17  provided to the main switch section  42 . By the magnetic flux, the main plunger  12  and the movable contact  11  are driven to the main contact section  7 . 
     When the main contact section  7  is closed by the movable contact  11 , that is, when the movable contact  11  is brought into contact with the battery side fixed contact  9  and the starter motor side fixed contact  10 , electricity is started to be conducted from the battery  2  to the field coil  47  and an armature coil  48  provided to the starter motor  3  by way of the main contact section  7  and the main circuit section  4 . Further, the pinion gear  23  is brought in mesh with the ring gear  26  by pushing the overrunning clutch  22  and the pinion gear  23  to an outer side in an axial direction of the starter motor  3  by driving the lever  27  connected to the main plunger  12  by constituting a fulcrum by the pin member  36  in accordance with driving the main plunger  12 . 
     Further, when the main contact section  7  is closed, potentials at the both ends of the suction coil  8  become equal and therefore, electricity conduction to the suction coil  8  is stopped. However, electricity conduction to the holding coil  17  is continued to maintain a state of closing the main contact section  7  by a magnetic flux produced by the holding coil  17 . 
     Successively, when the start switch  16  is opened, the magnetic flux is nullified by stopping to conduct electricity to the suction coil  8  and the holding coil  17  and therefore, the main contact section  7  is opened by pushing back the movable contact  11  and the main plunger  12  by a spring, not illustrated. Simultaneously with nullifying electricity conducted to the starter motor  3 , the lever  27  is driven to finish the state of bringing the ring gear  26  and the pinion gear  23  in mesh with each other. 
     In this way, by conducting electricity to the starter motor  3  by way of the main circuit section  4 , the starter motor  3  is started to rotate and a rotational force thereof is transmitted to the engine, not illustrated, by way of the ring gear  26  and the pinion gear  23 . 
     When by some cause, for example, teeth of the ring gear  26  and the pinion gear  23  collide with each other and the state of closing the switch  16  continues, the main contact section  7  is not closed. 
     When the state continues, temperatures of the suction circuit section  5  and the holding circuit section  38  rise, the insulating coating of the suction coil  8  is melted to be brought into layer short circuit and a short circuit current flows at the suction circuit section  5 . When the short circuit current flows, the breaking section  61  provided at the metal plate  18  connected to the suction circuit section  5  is melted to cut. 
     When the breaking section  61  is melted to cut in this way, spark is generated at the melted to cut portion. In order to restrain the spark from being scattered, as shown by  FIG. 3 , the cover  33  is provided at a surrounding of the breaking section  61 . As shown by  FIG. 4B , the cover  33  is provided with the claw portion  331  and the cut portion  332 . Four of the claw portions are provided and the claw portions are squeezed to inner sides from both sides of the metal plate  18  to be fixedly attached thereto. As shown by  FIG. 4C , the cover  33  is fixed to the metal plate  18  by using the claw portions. A lower portion of  FIG. 4C  shows a sectional view cut by a line X-X. Thereby, the spark can be avoided from being scattered to other constituent element provided at a vicinity of the metal plate  18 . 
       FIGS. 5A and 5B  illustrate diagrams for comparing characteristics of the breaking section  61  used in the starter according to the invention and the fuse used in JP-A-2005-54706. In  FIG. 5A , the abscissa designates an elapsed time and the ordinate designates a value of a current conducted to the suction circuit section  5 . In  FIG. 5B , the abscissa designates the elapsed time and the ordinate designates a change in a temperature of the breaking section  61 . 
     As shown by  FIGS. 5A and 5B , the fuse of JP-A-2005-54706 is cut when a current I 11  equal to or smaller than 90% of a starting current to the suction coil  8  (example: 45 amperes) continuously for 60 seconds. In contrast thereto, according to the starter of the invention, when the current I 11  is conducted continuously for, for example, 120 seconds, the insulating coating of the suction coil  8  is melted to bring about layer short circuit and a short circuit current I 12  flows, the breaking section  61  is immediately melted to cut electricity conduction. 
     Successively, as shown by  FIG. 5B , according the fuse of JP-A-2005-54706, when the current I 11  (example: 45 amperes) is conducted continuously for 60 seconds, since a temperature of the fuse is set to be low to be melted to cut at θ1 degrees (example: 300 degrees) and therefore, the fuse is comparatively easily melted to cut. Further, in the case of the elapsed time (60 seconds) of cutting the fuse of JP-A-2005-54706, an inclination of the graph shown in  FIG. 5B  is small, in addition thereto, a conducted current value of the fuse becomes a different value owing to a tolerance in fabricating the fuse or the like, and there is brought about an error of T11 seconds (example: 10 seconds) in a time period by which the temperature of the fuse reaches θ1 degrees. Therefore, there is a concern of frequently bringing about a state in which the fuse is melted to cut by a short period of time and the engine cannot be started and it is difficult to design the fuse which is melted to cut by a predetermined time period in order to avoid the state. 
     In contrast thereto, according to the breaking section  61  used in the invention, when the temperature of the suction coil  8  reaches a temperature θ2 for melting the film to bring about layer short circuit and the short circuit current I 12  flows, the temperature of the breaking section  61  is set to be higher than that of JP-A-2005-54706 to be melted to cut at θ3 degrees (example: 1000 degrees) and a frequency of melting to cut the breaking section  61  can be restrained. Further, in the case of the elapsed time of cutting the breaking section  61  (120 seconds), the inclination of the graph shown in  FIG. 5B  becomes larger than that at 60 seconds, even when the value of the current conducted to the breaking section  61  becomes a different value owing to the error of fabricating the fuse or the like, since the inclination of the graph is large, the error becomes T12 (example: 1 through 2 seconds) and can be made to be smaller than the error time T 11 . Further, even when the time period of bringing the suction coil into layer short circuit owing to a different current value of electricity conduction differs from normal, for bringing the suction coil into layer short circuit, a time period sufficiently longer than the time period of melting the fuse applied to the starter of the background art is needed to restrain the state in which the engine cannot be started by cutting the breaking section from being brought about. 
     Further, although according to Embodiment 1, there is described the constitution of providing the breaking section  61  between the connection terminal  32  at the one end of the suction coil  8  and the motor terminal  28 , a similar effect can be achieved even in a case in which the breaking section  61  is provided at an arbitrary location of the suction circuit section  5 . 
     Further, by providing the portion of deforming the metal plate  18  as the breaking section  61 , there can be provided a starter capable of providing the breaking section without increasing a number of constituent elements of the starter of the background art. 
     Further, although an explanation has been given of the starter provided with the field coil  47  according to Embodiment 1, a similar effect can be achieved even in a case of applying the invention to a starter when a permanent magnet is provided in place of the field coil  47 . 
     Embodiment 2 
     According to the embodiment, a case of applying the invention to a starter provided with an auxiliary switch at the suction circuit section to be described as an example of the starter according to the invention. 
       FIG. 6  is an electric wiring diagram of a starter according to Embodiment 2 of the invention.  FIG. 7  is a half section view of a side face of the starter shown in  FIG. 6 .  FIG. 8  is a half side view of the starter shown in  FIG. 6 .  FIG. 9A to 9C  are constitution views of a breaking section provided at the starter shown in  FIG. 6 .  FIGS. 10A and 10B  are diagrams showing a characteristic of the breaking section according to Embodiment 2. 
     Successively, a structure of the starter according to Embodiment 2 of the invention will be described. In the following drawings, portions the same as those of Embodiment 1 are attached with the same notations and an explanation thereof will be omitted. 
     In  FIG. 6 , an auxiliary contact section  13  provided to a starter  46  is provided on the suction circuit section  5  and between the battery terminal  28  and the switch terminal  34  and includes a first fixed contact  19  constituted at an auxiliary battery terminal  30 , a second fixed contact  20  constituted at an auxiliary switch output terminal  31 , and an auxiliary movable contact  21  provided movably for contacting and separating the first fixed contact  19  and the second fixed contact  20 . The auxiliary movable contact  21  is attached to an auxiliary plunger  44  in a rod-like shape driven by conducting electricity to the suction coil  15 . An auxiliary switch section  37  operated as an electromagnetic switch is constituted from the auxiliary contact section  13 , the auxiliary suction coil  15  and the auxiliary plunger  44 . 
     A start circuit section  14  includes an auxiliary suction coil  15  connected to both ends of the battery  2  for generating a magnetic flux for opening and closing the auxiliary contact section  13 . Further, the start switch  16  is provided on the start circuit section  14  for switching electricity conduction to the auxiliary suction coil  15 . 
     Here, as shown by  FIG. 7 , the auxiliary switch section  37  according to the embodiment is attached to the housing  39  byway of an attaching member  40 . Further, the auxiliary switch section  37  can naturally be attached to an arbitrary location other than being attached to the housing  39 . 
     Successively, as shown by  FIG. 8 , the metal plate  18  serves also as a breaking section  62  melted to cut by a temperature rise by conducting electricity. The breaking section  62  is provided with a hole portion and the hole portion and a surrounding of the hole portion are covered by a metal having a melting temperature lower than that of the material (example: copper or brass) of the metal plate  18  although not illustrated. By providing the hole portion, the metal having the low melting temperature can easily be fixed to the breaking section  62 . 
     Operation of the starter according to Embodiment 2 will be explained as follows. 
     According to the starter  46 , by closing the start switch  16 , electricity is conducted from the battery  2  to the start circuit section  14 , thereby, a magnetic flux is generated by the auxiliary suction coil  15  provided to the auxiliary switch section  37 . Thereby, the auxiliary plunger  44  and the auxiliary movable contact  21  are driven. 
     When the auxiliary contact section  13  is closed by the auxiliary movable contact  21 , that is, when the movable contact  21  is brought into contact with the first fixed contact  19  the second fixed contact  20 , electricity is started to conduct from the battery  2  to the suction coil  8  by way of the suction circuit section  5 , and electricity is started to conduct to the holding coil  17  by way of the holding circuit section  38 . When the main contact section  7  is closed by driving the main plunger  12  and the movable contact  11  to the main contact section  7  by the magnetic flux, electricity is started to be conducted from the battery  2  to the starter motor  3  by way of the main contact section  7  and the main circuit section  4 . 
     Further, the current conducted to the suction coil  8  is sufficient for rotating the starter motor  3  and even when the pinion gear  23  and the ring gear  26  collide with each other, by conducting electricity to the field coil  47  and the armature coil  48  provided to the starter motor  3  by way of the suction circuit section  5 , the pinion gear  23  can be rotated to be brought in mesh with the ring gear  26  normally. 
     Successively, when the start switch  16  is opened, electricity conduction to the auxiliary suction coil  15  is stopped and the magnetic flux is nullified and therefore, the auxiliary contact section  13  is opened by pushing back the auxiliary movable contact  21  and the auxiliary plunger  44  by a spring, not illustrated. Thereby, also electricity conduction to the suction coil  8  and the holding coil  17  is stopped and therefore, the main contact section  7  is opened and electricity is not conducted to the starter motor  3 . Simultaneously therewith, the lever  27  is driven to finish the state of bringing the ring gear  26  and the pinion gear  23  in mesh with each other. 
     By conducting electricity to the starter motor  3  by way of the main circuit section  4  in this way, the starter motor  3  is started to rotate and the rotational force is transmitted to the engine, not illustrated, by way of the ring gear  26  and the pinion gear  23 . 
     When by some cause, for example, teeth of the ring gear  26  and the pinion gear  23  collide with each other and a state of closing the switch  16  is continued, the main contact section  7  is not closed. 
     When the state continues, temperatures of the suction circuit section  5  and the holding circuit section  38  rise, the insulating coating of the suction coil  8  is melted to bring about layer short circuit and the short circuit current flows at the suction circuit section  5 . After making the short circuit current flow, the breaking section  62  provided at the metal plate  18  connected to the suction circuit section  5  is melted to cut. 
     When the breaking section  62  is melted to cut in this way, spark is generated at the melted to cut portion. In order to restrain the spark from being scattered, as shown by  FIG. 8 , a cover  45  is provided at a surrounding of the breaking section  62 . As shown by  FIG. 9B , the cover  45  is provided with a claw portion  451  and a cut portion  452 . Two of the claw portions  451  are provided and formed to be provided with a width of the connecting terminal  32  and the motor terminal  29  of the suction coil connected with the metal plate  18 . As shown by  FIG. 9C , the cover is fixed to the metal plate  18  by using the claw portion  451 . A sectional view cut by a linear line Y-Y is shown at a lower portion of  FIG. 9C . Thereby, the spark is restrained from being scattered to be able to avoid the spark from being scattered to other constituent element provided at a vicinity of the metal plate  18 . 
       FIGS. 10A and 10B  show diagrams for comparing characteristics of the breaking section  62  used in the starter according to the invention and the fuse used in JP-A-2004-52572. In  FIG. 10A , the abscissa designates an elapsed time and the ordinate designates a value of a current conducted to the breaking section  62 . In  FIG. 10B , the ordinate designates a temperature change of the breaking section  62  and the abscissa designates the elapsed time of electricity conduction. 
     As shown by  FIG. 10A , the fuse of JP-A-2004-52572 is cut when a current I 21  (example: 300 amperes) to the suction coil  8  is conducted continuously for 15 seconds. In contrast thereto, according to the starter of the invention, when electricity is conducted continuously for, for example, 30 seconds, the insulating coating of the suction coil  8  is melted to bring about layer short circuit and the short circuit current I 22  flows, the breaking section  62  is immediately melted to cut electricity conduction. 
     Successively, as shown by  FIG. 10B , according the fuse of JP-A-2004-52572, when the current I 21  (example: 300 amperes) is conducted continuously for 15 seconds, since the temperature of the fuse is set to be low to be melted to cut at θ4 degrees (example: 800 degrees) and therefore, the fuse of JP-A-2004-52572 is comparatively easily be melted to cut. Further, in a case of an elapsed time (15 seconds) of cutting the fuse of JP-A-2004-52572, an inclination of a graph shown in  FIG. 10B  is small, in addition thereto, a conducting current value of the fuse becomes a different value owing to a tolerance in fabricating the fuse or the like to bring about an error of T21 seconds (example: 10 seconds) in a time period by which the temperature of the fuse reaches θ4 degrees. Therefore, there is a concern that the fuse is melted to cut by a short period of time to frequently bring about a state in which the engine cannot be started and it is difficult to design the fuse melted to cut by a predetermined time period in order to avoid the state. 
     In contrast thereto, according to the breaking section  62  used in the invention, when the temperature of the suction coil  8  reaches the melting temperature θ5 of the film and a short circuit current I 22  flows, by bringing about layer short circuit, the temperature of the breaking section  62  is set to be higher than that of JP-A-2004-52572 to be melted to cut at θ6 degrees (example: 1000 degrees) and a frequency of melting to cut the breaking section  62  can be restrained. Further, in a case of an elapsed time (30 seconds) for breaking the breaking section  62 , an inclination of a graph shown in  FIG. 10B  becomes larger than that of the elapsed time of 15 seconds and even when a current value conducted to the breaking section  62  differs owing to a tolerance in fabricating the fuse or the like, since the inclination of the graph is large, the error becomes T 22  (example: 1 through 2 seconds) and can be made to be smaller than the error time period T 21 . Further, even when a time period by which the suction coil is brought into layer short circuit owing to the different conducting current value differs from normal, in order to bring the suction coil into layer short circuit, a time period sufficiently longer than the time period of melting the fuse applied to the starter of the background art is needed to restrain the state in which the breaking section is cut and the engine cannot be started from being brought about. 
     Thereby, also in the starter  46  provided with the auxiliary switch  37 , an effect similar to that of Embodiment 1 can be achieved.