Patent Publication Number: US-7902702-B2

Title: Magneto generator

Description:
This is a divisional of application Ser. No. 11/519,077 filed Sep. 12, 2006 now U.S. Pat. No. 7,615,899. The entire disclosure of the prior application, application Ser. No. 11/519,077 is considered part of the disclosure of the accompanying divisional application and is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a magneto generator which generates electricity under the electromagnetic induction action of a permanent magnet and a magneto coil in accordance with the rotation of a flywheel. 
     2. Description of the Related Art 
     In the past, as a magneto generator, there has been known one in which individual phase lead wires of a magneto coil, which are drawn out in an axial direction at circumferential intervals and covered with a protective tube, are pressed against the end face sides of coil ends of the individual phase lead wires by the use of bands, respectively (see, for example, a first patent document: Japanese patent application laid-open No. 2005-110364 (FIG. 2)). 
     Also, as a magneto generator, there has also been known another one which includes a flywheel that rotates about an axis of rotation, a stator core that is arranged at an inner side of the flywheel and has a plurality of teeth protruding to a diametrally outer side, a magneto coil that has a conductor wound around the teeth, respectively, and lead wires drawn outwardly from the stator core, a lead that has one end portion thereof electrically connected with a lead wire and the other end thereof electrically connected with electrical equipment, and a lead clamp that has a basal end portion fixedly secured to the stator core by a tightening element together with the lead (see, for example, a second patent document: Japanese patent application laid-open No. H8-126276 (FIG. 7)). 
     The lead clamp serves to position the lead with respect to the stator core by clamping the opposite sides of the lead in the rotation axis direction, whereby the vibration resistance strength of the lead can be ensured. 
     In the flywheel of the conventional magneto generator of the first patent document, a plurality of bands are used so as to make the vibration resistance of each lead wire, so there is a problem of requiring a lot of number of parts. 
     In addition, in the conventional magneto generator of the second patent document, there is a problem that the lead clamp serves to clamp the opposite sides of the lead, so the axial dimension of the stator, which is constituted by the stator core and the magneto coil, is large. 
     Moreover, it is also considered that a gap is generated between the lead clamp and the magneto coil, and degraded matter such as oil mist, etc., is deposited in this gap, so the lead might be broken or disconnected due to such a deposit. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is intended to obviate the problems as referred to above, and has for its object to obtain a magneto generator which is capable of reducing the number of parts required. 
     Another object of the present invention is to obtain a magneto generator in which the axial dimension of a stator is reduced to prevent the deposition of degraded matter such as oil mist, etc., in a gap. 
     A magneto generator according to one aspect of the present invention includes: a flywheel that rotates about an axis of rotation; a plurality of permanent magnets that are arranged on an inner peripheral wall surface of the flywheel in a circumferential direction thereof and fixedly secured thereto; a stator core that is arranged at a diametrally inner side of the flywheel with its outer peripheral surface being in opposition to the permanent magnets; and a three-phase magneto coil that has an conductor wound around each of teeth that are formed on an outer peripheral portion of the stator core so as to radially protrude in diametrally outer directions at equal intervals. The second phase lead wires and the third phase lead wires among individual one pair of the first, second and third phase lead wires of the magneto coil which are led out in an axial direction at circumferential intervals are bent in a circumferential direction toward the first phase lead wires, and bundled together with the first phase lead wires. The first phase lead wires, the second phase lead wires and the third phase lead wires thus bundled are respectively bent in a direction opposite to the circumferential direction. 
     In addition, a magneto generator according to another aspect of the present invention includes: a flywheel that rotates about an axis of rotation; a plurality of permanent magnets that are arranged on an inner peripheral wall surface of the flywheel in a circumferential direction thereof and fixedly secured thereto; a stator core that is arranged at a diametrally inner side of the flywheel with its outer peripheral surface being in opposition to the permanent magnets; and a magneto coil that has an conductor wound around each of teeth that are formed on an outer peripheral portion of the stator core so as to radially protrude in diametrally outer directions at equal intervals, the magneto coil also having a lead wire that is led outwardly from the stator core; a lead that has one end portion thereof electrically connected to the lead wire and the other end thereof electrically connected to electrical equipment; and a lead clamp that has a basal end fixedly attached to the stator core by a tightening element, and an opening portion that opens to the magneto coil. The lead clamp covers the lead and at the same time presses the lead toward the magneto coil through the opening portion. 
     According to a magneto generator of the present invention, there is obtained an advantageous effect that the number of parts required can be reduced. 
     In addition, according to a magneto generator of the present invention, the axial dimension of a stator is reduced so that degraded matter such as oil mist, etc., is not likely to deposit in a gap. 
     The above and other objects, features and advantages of the present invention will become more readily apparent to those skilled in the art from the following detailed description of preferred embodiments of the present invention taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front elevational view showing a magneto generator according to a first embodiment of the present invention. 
         FIG. 2  is a cross sectional arrow view along line II-II of  FIG. 1 . 
         FIG. 3  is a partial side elevational view when a stator of  FIG. 1  is seen from the direction of arrow A. 
         FIG. 4  is a front elevational view showing a magneto generator according to a second embodiment of the present invention. 
         FIG. 5  is a front elevational view showing a stator of a magneto generator according to a third embodiment of the present invention. 
         FIG. 6  is a front elevational view showing a stator of a magneto generator according to a fourth embodiment of the present invention. 
         FIG. 7  is a cross sectional side elevational view of a magneto generator of  FIG. 6 . 
         FIG. 8  is an enlarged view of essential portions of the magneto generator of  FIG. 7 . 
         FIG. 9  is a view when the stator of  FIG. 6  is seen from the direction of arrow C. 
         FIG. 10  is a side elevational view showing a magneto generator according to a fifth embodiment of the present invention. 
         FIG. 11  is a side elevational view of essential portions of a magneto generator according to a sixth embodiment of the present invention. 
         FIG. 12  is a side elevational view of essential portions of a magneto generator according to a seventh embodiment of the present invention. 
         FIG. 13  is a side elevational view of essential portions of a magneto generator according to an eighth embodiment of the present invention. 
         FIG. 14  is a side elevational view of essential portions of a magneto generator according to a ninth embodiment of the present invention. 
         FIG. 15  is a side elevational view of essential portions of a magneto generator according to a tenth embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Now, preferred embodiments of the present invention will be described in detail while referring to the accompanying drawings. Throughout respective figures, the same or corresponding members or parts are identified by the same reference numerals and characters. 
     Embodiment 1 
     Referring to the drawings and first to  FIG. 1 , therein is shown a magneto generator according to a first embodiment of the present invention.  FIG. 2  is a cross sectional side elevational view of the magneto generator of  FIG. 1 , and  FIG. 3  is a partial side elevational view when a stator  2  is seen from the direction of arrow A in  FIG. 1 . 
     This magneto generator is provided with a rotor  1  connected with an internal combustion engine. 
     The rotor  1  is provided with a bowl-shaped flywheel  3  and permanent magnets  29  (shown in  FIG. 2 ). The flywheel  3  rotates about an axis of rotation B-B. A boss portion  5  is fixedly secured to a rotation shaft (not shown) which is driven to rotate by the internal combustion engine. 
     A plurality of (i.e., four) permanent magnets are fixedly secured to the inner peripheral surface of a cylindrical portion  6  of the flywheel  3 . As for the permanent magnet, two magnets each polarized in order of N pole, S pole and N pole, and two magnets each polarized in order of S pole, N pole and S pole, are alternately arranged at mutually equal angular intervals around the axis of rotation B-B. The plurality of permanent magnets are polarized in such a manner that adjoining permanent magnets have mutually opposite polarities, whereby in an inner side space of the permanent magnet, there is generated a magnetic field, the direction of which changes alternately. 
     A cylindrical guard ring (not shown) is fitted into the inner peripheral surface of each permanent magnet in intimate contact therewith. A resin material  4  is filled into between the opposite end sides in the direction of the axis of rotation B-B of each permanent magnet  29 , and between individual adjoining permanent magnets  29 . The plurality of permanent magnets  29  and the guard ring are fixedly secured to the inner peripheral surface of the cylindrical portion  6  of the flywheel  3  by means of the resin material  4 . 
     The stator  2  has a hollow cylindrical stator core  7  and three-phase magneto coils  8 . On the outer peripheral portion of the stator core  7 , there are formed a plurality of teeth  13  that radially protrude in a diametrally outside direction at equal intervals. 
     The stator core  7  having the plurality of teeth  13  formed on its outer peripheral portion is composed of a laminated iron core  16  which is formed of a multitude of thin hollow magnetic steel plates in the form of cold rolled steel plates laminated one over another in the direction of the axis of rotation B-B, and a first end plate  17  and a second end plate  18  superposed on the opposite side surfaces of the laminated core  16 , respectively, in intimate contact therewith. 
     The first end plate  17  and the second end plate  18  of a hollow configuration made of cold rolled steel sheet, etc., have their outer and inner peripheral portions respectively bent toward the magneto coil  8  so as to hold the magneto coil  8 . 
     Three through holes  19  are formed through the laminated iron core  16  and the first and second end plates  17 ,  18  in parallel to the axis of rotation B-B. The laminated iron core  16  and the first and second end plates  17 ,  18  are integrated with one another by means of bolts (not shown) inserted through the through holes  19  and nuts (not shown) threaded on the bolts, respectively. 
     The magneto coil  8  is formed by winding conductors having their surfaces coated with enamel on the circumferential side surfaces of the teeth  13  of the stator core  7 . The magneto coil  8  is in the form of a three-phase magneto coil having individual coil portions connected with one another through a delta connection. The circumferential side surface of the magneto coil  8  is covered with a resin molding material  20 . 
     A pair of first phase lead wires  9   a ,  9   b , a pair of second phase lead wires  10   a ,  10   b , and a pair of third phase lead wires  11   a ,  11   b  are led out in an axial direction at circumferential intervals. 
     The pair of second phase lead wires  10   a ,  10   b  and the pair of third phase lead wires  11   a ,  11   b  have their tip ends covered with the first protective tubes  12   a ,  12   b , respectively. The second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b , after being bent to the first phase lead wires  9   a ,  9   b  (in a counterclockwise direction in  FIG. 1 ), are bundled together with the first phase lead wires  9   a ,  9   b , and the first phase lead wires  9   a ,  9   b , the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  thus bundled are again bent to the second phase lead wires  10   a ,  10   b  (in a clockwise direction in  FIG. 1 ). 
     The first phase lead wires  9   a ,  9   b , the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  thus bent are covered with second protective tubes  22   a ,  22   b ,  22   c , respectively. 
     Here, note that the first protective tubes  12   a ,  12   b  and the second protective tubes  22   a ,  22   b ,  22   c  are excellent in thermal resistance and insulation performance, and are formed by impregnating varnish into tubes woven with polyester fiber. 
     The first protective tubes  12   a ,  12   b  covering the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  are fixedly attached or bonded to an end face of a coil end  14  of the magneto coil  8  by a bonding member  21  comprising epoxy resin or varnish. Also, the first protective tubes  12   a ,  12   b  and the first phase lead wires  9   a ,  9   b  are attached or bonded to each other by means of the bonding member  21 . 
     In addition, the first protective tubes  12   a ,  12   b  covering the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  are wound with and bundled by one first phase lead wire  9   a  of the pair of first phase lead wires  9   a ,  9   b , together with the other first phase lead wire  9   b.    
     The first phase lead wires  9   a ,  9   b , the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  are electrically connected to three lead portions, respectively, of strand structure that together form a lead  23 , inside the second protective tubes  22   a ,  22   b ,  22   c . Accordingly, after the first phase lead wires  9   a ,  9   b , the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  are electrically connected to the three lead portions, respectively, the second protective tubes  22   a ,  22   b ,  22   c  are inserted, respectively. 
     By means of these second protective tubes  22   a ,  22   b ,  22   c , the individual phase lead wires  9   a ,  9   b ,  10   a ,  10   b ,  11   a ,  11   b  are electrically insulated from one another, and at the same time, individual connecting portions between these lead wires  9   a ,  9   b ,  10   a ,  10   b ,  11   a ,  11   b  and the three lead portions are also electrically insulated. 
     An end of the lead  23  for leading out to electrical equipment (not shown) is covered with a third protective tube  24 . The lead  23  is fixedly held by a lead clamp  26  through a third protective tube  24 . The lead clamp  26  is fixedly fastened to the stator core  7  by a screen  25 . 
     In the magneto generator as constructed above, the flywheel  3  is caused to rotate in conjunction with the rotation of the rotation shaft (not shown) which is driven to rotate by the internal combustion engine, whereby electric power is generated in the magneto coil  8  by means of an alternating field generated by the permanent magnets. An AC output thus generated is rectified by an unillustrated rectifier diode, and fed to a load such as a battery mounted on a vehicle. 
     According to the magneto generator of the above-mentioned construction, the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  covered with the first protective tubes  12   a ,  12   b  are bent toward the first phase lead wires  9   a ,  9   b  in a counterclockwise direction in  FIG. 1 . The second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  thus bent are bundled together with the first phase lead wires  9   a ,  9   b , and the first phase lead wires  9   a ,  9   b , the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  thus bundled are bent in a clockwise direction in  FIG. 1  and covered with the second protective tubes  22   a ,  22   b ,  22   c , respectively. 
     As a result, with the lead  23  being fixedly held by the lead clamp  26 , the second protective tubes  22   a ,  22   b ,  22   c  arranged in a line along a diametral direction act to press the first protective tubes  12   a ,  12   b  against the end face of the coil end  14 , and the second protective tubes  22   a ,  22   b ,  22   c  are placed in intimate contact with the first protective tubes  12   a ,  12   b , whereby an increase in the axial dimension of the stator  2  can be prevented. 
     In addition, vibrations of the individual lead wires  9   a ,  9   b ,  10   a ,  10   b ,  11   a ,  11   b  are prevented, thus making unnecessary those parts which are conventionally required and exclusively used for vibration resistance. 
     Moreover, since the first protective tubes  12   a ,  12   b  are fixedly attached or fastened to the end face of the coil end  14  by means of the bonding member  21 , the vibrations of the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  are prevented in a reliable manner without requiring additional parts. 
     Further, the bonding member  21  has thermal resistance, and hence contributes to improvements in thermal resistance of the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b.    
     Furthermore, the first phase lead wires  9   a ,  9   b , the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  protrude from between the individual teeth  13 , respectively, so the winding space of the conductor wound around each tooth  13  can be ensured. 
     In addition, the first phase lead wires  9   a ,  9   b  are arranged at locations more apart from the lead  23  than the second phase lead wires  10   a ,  10   b , and the third phase lead wires  11   a ,  11   b , and the lead  23  is positioned in a direction of extension of the lead-out individual phase lead wires  9   a ,  9   b ,  10   a ,  10   b ,  11   a ,  11   b  covered with the second protective tubes  22   a ,  22   b ,  22   c ,  23 . With such an arrangement, the ends of the individual phase lead wires  9   a ,  9   b ,  10   a ,  10   b ,  11   a ,  11   b  and the end of lead  23  can be electrically connected to one another in a smooth manner, and useless elongation of these lead wires  9   a ,  9   b ,  10   a ,  10   b ,  11   a ,  11   b  and the lead  23  can be prevented. 
     Moreover, the one first phase lead wire  9   a  is wound around the first protective tubes  12   a ,  12   b  together with the other first phase lead wire  9   b  to bundle them together, so the first protective tubes  12   a ,  12   b  are tightly secured by a bent portion  15 , thus making it possible to improve vibration resistance of the first protective tubes  12   a ,  12   b  in the bent portion  15 . 
     Embodiment 2 
       FIG. 4  is a front elevational view that shows a magneto generator according to a second embodiment of the present invention. In the first embodiment, the lead-out direction of the lead  23  for connection to electrical equipment is located at the right of the magneto generator, as shown in  FIG. 1 , but in contrast, in this second embodiment, the lead-out direction of the lead  23  for connection to electrical equipment is located at the left of the magneto generator, as shown in  FIG. 4 . 
     Thus, in the first embodiment, the bent portion  15  for the first protective tubes  12   a ,  12   b  are formed at the left of the lead clamp  26  in  FIG. 1 , but in contrast, in this second embodiment, the bent portion  15  is formed at the right of the lead clamp  26  in  FIG. 4 . 
     The construction of this second embodiment other than the above is similar to that of the first embodiment. 
     In this embodiment, too, the first phase lead wires  9   a ,  9   b  are arranged at locations more apart from the lead  23  than the second phase lead wires  10   a ,  10   b , and the third phase lead wires  11   a ,  11   b , and the lead  23  is positioned in a direction of extension of the individual lead-out phase lead wires  9   a ,  9   b ,  10   a ,  10   b ,  11   a ,  11   b  covered with the second protective tubes  22   a ,  22   b ,  22   c ,  23 . With such an arrangement, the ends of the individual phase lead wires  9   a ,  9   b ,  10   a ,  10   b ,  11   a ,  11   b  and the ends of the individual lead portions of the lead  23  can be electrically connected to one another in a smooth manner, and useless elongation of these lead wires  9   a ,  9   b ,  10   a ,  10   b ,  11   a ,  11   b  and the lead  23  can be prevented. 
     Embodiment 3 
       FIG. 5  is a front elevational view that shows a stator of a magneto generator according to a third embodiment of the present invention. 
     In this embodiment, a conductor is wound around the circumferential side surfaces of teeth  13  of a stator core  7  to form an ignition signal coil. Signal lead wires  27   a ,  27   b  of this ignition signal coil are led out in an axial direction, and covered with fourth protective tubes  28   a ,  28   b.    
     Similar to the first protective tubes  12   a ,  12   b  and the second protective tubes  22   a ,  22   b ,  22   c , the fourth protective tubes  28   a ,  28   b  are formed by impregnating varnish into tubes woven with polyester fiber. 
     The signal lead wires  27   a ,  27   b  protruded in the axial direction are first bent in a clockwise direction in  FIG. 5 , and are then bundled by one first phase lead wire  9   a  wound therearound together with the other first phase lead wire  9   b , the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b  covered with the first protective tubes  12   a ,  12   b.    
     The construction of this third embodiment other than the above is similar to that of the first embodiment. 
     In this embodiment, the signal lead wires  27   a ,  27   b  are tightly secured by the one first phase lead wire  9   a  together with the other first phase lead wire  9   b , the second phase lead wires  10   a ,  10   b  and the third phase lead wires  11   a ,  11   b . As a result, there can be obtained, in addition to the advantageous effects of the first embodiment, a further advantageous effect that the vibration resistance of the signal lead wires  27   a ,  27   b  can be improved. 
     Embodiment 4 
       FIG. 6  is a front elevational view that shows a stator of a magneto generator according to a fourth embodiment of the present invention.  FIG. 7  is a cross sectional side elevational view of the magneto generator of  FIG. 6 , and  FIG. 8  is an enlarged view of essential portions of the magneto generator of  FIG. 7 .  FIG. 9  is a view when the stator of  FIG. 6  is seen from the direction of arrow C. 
     In this embodiment, a lead clamp  26 A has a base end portion thereof fixedly fastened to a stator core  7  by means of a tightening element in the form of a screen  25 . The lead clamp  26 A made of resin has a bent portion  26 Aa whose diametral outermost portion is bent toward a magneto coil  8 , and also has an opening portion formed at a side near the magneto coil  8 . The lead clamp  26 A covers the lead  23  and at the same time presses the lead  23  toward a coil end  8   a  of the magneto coil  8  through the opening portion. In addition, the lead clamp  26 A is arranged between adjoining teeth  13  when seen along the direction of the axis of rotation. 
     According to the magneto generator of this fourth embodiment, the lead clamp  26 A covers the lead  23  covered with the third protective tube  24  and at the same time presses the lead  23  toward the coil end  8   a  of the magneto coil  8  through the opening portion, whereby the lead  23  is placed into intimate contact with the magneto coil  8  through the third protective tube  24 , thereby making it possible to reduce the axial dimension of the stator  2 . 
     In addition, there is no gap formed between the lead  23  and the coil end  8   a  of the magneto coil  8 , so it is possible to prevent the deposition of degraded matter such as oil mist, etc., in the gap, and hence the resultant break or disconnection of the lead  23 . 
     Also, the lead clamp  26 A is arranged between the adjoining teeth  13  when viewed along the direction of the axis of rotation, so the lead  23  being pressed by the lead clamp  26 A is inserted into between the teeth  13  by bending deformation, and the adjoining teeth  13 , the lead clamp  26 A and the lead  23  are much more integrated with one another. Accordingly, the axial dimension of the stator  2  is further reduced, and the displacement in the circumferential direction of the lead  23  due to its vibration can be prevented, whereby the break or disconnection of the lead  23  and the lead wires  10   a ,  10   b ,  11   a ,  11   b ,  12   a ,  12   b  resulting from the difference in the vibration frequencies of the teeth  13 , the lead clamp  26 A and the lead  23  can be reduced. 
     Further, since the lead clamp  26 A has the bent portion  26 Aa whose diametral outermost portion is bent toward the magneto coil  8 , the diametral position adjustment of the lead  23  can be easily carried out by adjusting the length in the direction of the bending of the bent portion  26 Aa. 
       FIG. 10  is a side elevational view of essential portions of a magneto generator according to a fifth embodiment of the present invention. 
     In this magneto generator, a lead clamp  26 B made of resin has protrusions  26 Ba formed at opposite side edges of a surface pressing against a coil end  8   a.    
     The construction of this fifth embodiment other than the above is similar to that of the fourth embodiment. 
     In this embodiment, the protrusions  26 Ba are formed on the opposite side edges of the lead clamp  26  B, and the lead  23  is pressed toward the coil end  8   a  by means of the protrusions  26 Ba at two locations, so in particular, the displacement in the circumferential direction of the lead  23  can be prevented. 
     Embodiment 6 
       FIG. 11  is a side elevational view of essential portions of a magneto generator according to a sixth embodiment of the present invention. 
     In this magneto generator, a lead clamp  26 C made of resin has its central portion  26 Ca bent into a V-shaped configuration, so that a third protective tube  24  is pressed by the central portion  26 Ca and opposite ends  26 Cb of the lead clamp  26 C. 
     The construction of this sixth embodiment other than the above is similar to that of the first embodiment. 
     Since in this embodiment, the lead clamp  26 C is bent into the V-shaped configuration, the lead  23  being pressed by the lead clamp  26 C is inserted into between the teeth  13  by bending deformation, and the adjoining teeth  13 , the lead clamp  26 A and the lead  23  are much more integrated with one another in comparison with the fourth embodiment. Accordingly, the break or disconnection of the lead  23  and the lead wires  10   a ,  10   b ,  11   a ,  11   b ,  12   a ,  12   b  resulting from the difference in the vibration frequencies of the teeth  13 , the lead clamp  26 C and the lead  23  can be reduced in comparison with the fourth embodiment. 
     Embodiment 7 
       FIG. 12  is a side elevational view of essential portions of a magneto generator according to a seventh embodiment of the present invention. 
     In this magneto generator, a lead clamp  26 D made of rolled steel plate has a diametrally extending concavo-convex portion  26 Da formed at a central portion of a surface pressing against a coil end  8   a.    
     The construction of this seventh embodiment other than the above is similar to that of the fourth embodiment. 
     Since in this embodiment, the lead clamp  26 D has the concavo-convex portion  26 Da formed on the central portion, the lead  23  being pressed by the lead clamp  26 D is more deeply inserted into between the teeth  13  in comparison with the fourth embodiment, whereby the adjoining teeth  13 , the lead clamp  26 D and the lead  23  are much more integrated with one another in comparison with the fourth embodiment. 
     In addition, the concavo-convex portion  26 Da can be easily formed by press working. 
     Embodiment 8 
       FIG. 13  is a side elevational view of essential portions of a magneto generator according to an eighth embodiment of the present invention. 
     In this magneto generator, a lead clamp  26 E made of rolled steel plate has a bulged curved portion  26 Ea pressing against a coil end  8   a.    
     The construction of this eighth embodiment other than the above is similar to that of the fourth embodiment. 
     In this embodiment, since the lead clamp  26 E is formed with the bulged or curved portion  26 Ea, the lead  23  being pressed by the lead clamp  26 E can be inserted into between the teeth  13  without being subject to forced stress. 
     Embodiment 9 
       FIG. 14  is a side elevational view of essential portions of a magneto generator according to a ninth embodiment of the present invention. 
     In this magneto generator, a lead clamp  26 F made of rolled steel plate has a diametrally extending concavo-convex portion  26 Fb formed at a central portion of a surface pressing against a coil end  8   a , and is formed at its opposite ends with bent portions  26 Fa bent to a side opposite to the coil end  8   a.    
     The construction of this ninth embodiment other than the above is similar to that of the fourth embodiment. 
     Since in this embodiment, the lead clamp  26 F has the concavo-convex portions  26 Fb formed on the central portion, the lead  23  being pressed by the lead clamp  26 F is more deeply inserted into between the teeth  13  in comparison with the fourth embodiment, so that the adjoining teeth  13 , the lead clamp  26 F and the lead  23  are much more integrated with one another in comparison with the fourth embodiment. 
     In addition, since the lead clamp  26 F is formed at its opposite ends with the bent portions  26 Fa, the rigidity of the lead clamp  26 F becomes high, so that the amount of flexible deformation of the lead clamp  26 F generated when the lead clamp  26 F is pressed against the coil end  8   a  can be reduced, and a hold-down force to the lead  23  can be transmitted in a more reliable manner. 
     Embodiment 10 
       FIG. 15  is a side elevational view of essential portions of a magneto generator according to a tenth embodiment of the present invention. 
     In this magneto generator, the surface pressing against the coil end  8   a  of the lead clamp  26 F of the sixth embodiment is enclosed by an elastic member  30 . 
     The construction of this tenth embodiment other than the above is similar to that of the fourth embodiment. 
     In this embodiment, the lead clamp  26 F similar to that of the ninth embodiment, and hence has advantageous effects similar to those of the ninth embodiment. 
     In addition, although the dimension of the magneto coil  8  in an axial direction of the stator  2  has variations depending upon the winding condition of the conductor, etc., the elastic member  30  enclosing the lead clamp  26 F serves to absorb such variations, whereby the lead clamp  26 F can press the lead  23  toward the coil end  8   a  in a stable manner. 
     Although in the above-mentioned respective embodiments, reference has been made to the three-phase magneto coil  8  with its individual phase coil portions being connected with one another by a delta connection, the present invention can be applied to a three-phase magneto coil with its individual phase coil portions being connected with one another by a star connection. 
     In addition, in the above-mentioned fourth through tenth embodiments, reference has been made to an example in which each of the lead clamps  26 A,  26 B,  26 C,  26 D,  26 E,  26 F is arranged between adjoining ones of the teeth  4  when viewed along the direction of the axis of rotation, but if focus is placed only on the elimination of a gap between each of the lead clamps  26 A,  26 B,  26 C,  26 D,  26 E,  26 F and the coil end  8   a  of the magneto coil  8 , each of the lead clamps  26 A,  26 B,  26 C,  26 D,  26 E,  26 F may of course be arranged on the teeth  13  when viewed along the direction of the axis of rotation. 
     While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims.