Magneto generator with arrangements for lead wires of three-phase windings

In a magneto generator, second phase lead wires (10a, 10b) and third phase lead wires (11a, 11b) among individual one pair of first, second and third lead wires (9a, 9b; 10a, 10b; 11a, 11b) are covered with first protective tubes (12a, 12b), respectively. The second phase lead wires (10a, 10b) and the third phase lead wires (11a, 11b) covered with the first protective tubes (12a, 12b) are bent toward the first phase lead wires (9a, 9b) in a circumferential direction and bundled together with the first phase lead wires (9a, 9b). The first phase lead wires (9a, 9b), the second phase lead wires (10a, 10b) and the third phase lead wires (11a, 11b) thus bundled are bent in a direction opposite to the circumferential direction and covered with second protective tubes (22a, 22b, 22c), respectively.

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.

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.

Referring to the drawings and first toFIG. 1, therein is shown a magneto generator according to a first embodiment of the present invention.FIG. 2is a cross sectional side elevational view of the magneto generator ofFIG. 1, andFIG. 3is a partial side elevational view when a stator2is seen from the direction of arrow A inFIG. 1.

This magneto generator is provided with a rotor1connected with an internal combustion engine.

The rotor1is provided with a bowl-shaped flywheel3and permanent magnets29(shown inFIG. 2). The flywheel3rotates about an axis of rotation B-B. A boss portion5is 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 portion6of the flywheel3. 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 material4is filled into between the opposite end sides in the direction of the axis of rotation B-B of each permanent magnet29, and between individual adjoining permanent magnets29. The plurality of permanent magnets29and the guard ring are fixedly secured to the inner peripheral surface of the cylindrical portion6of the flywheel3by means of the resin material4.

The stator2has a hollow cylindrical stator core7and three-phase magneto coils8. On the outer peripheral portion of the stator core7, there are formed a plurality of teeth13that radially protrude in a diametrally outside direction at equal intervals.

The stator core7having the plurality of teeth13formed on its outer peripheral portion is composed of a laminated iron core16which 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 plate17and a second end plate18superposed on the opposite side surfaces of the laminated core16, respectively, in intimate contact therewith.

The first end plate17and the second end plate18of a hollow configuration made of cold rolled steel sheet, etc., have their outer and inner peripheral portions respectively bent toward the magneto coil8so as to hold the magneto coil8.

Three through holes19are formed through the laminated iron core16and the first and second end plates17,18in parallel to the axis of rotation B-B. The laminated iron core16and the first and second end plates17,18are integrated with one another by means of bolts (not shown) inserted through the through holes19and nuts (not shown) threaded on the bolts, respectively.

The magneto coil8is formed by winding conductors having their surfaces coated with enamel on the circumferential side surfaces of the teeth13of the stator core7. The magneto coil8is 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 coil8is covered with a resin molding material20.

A pair of first phase lead wires9a,9b, a pair of second phase lead wires10a,10b, and a pair of third phase lead wires11a,11bare led out in an axial direction at circumferential intervals.

The pair of second phase lead wires10a,10band the pair of third phase lead wires11a,11bhave their tip ends covered with the first protective tubes12a,12b, respectively. The second phase lead wires10a,10band the third phase lead wires11a,11b, after being bent to the first phase lead wires9a,9b(in a counterclockwise direction inFIG. 1), are bundled together with the first phase lead wires9a,9b, and the first phase lead wires9a,9b, the second phase lead wires10a,10band the third phase lead wires11a,11bthus bundled are again bent to the second phase lead wires10a,10b(in a clockwise direction inFIG. 1).

The first phase lead wires9a,9b, the second phase lead wires10a,10band the third phase lead wires11a,11bthus bent are covered with second protective tubes22a,22b,22c, respectively.

Here, note that the first protective tubes12a,12band the second protective tubes22a,22b,22care excellent in thermal resistance and insulation performance, and are formed by impregnating varnish into tubes woven with polyester fiber.

The first protective tubes12a,12bcovering the second phase lead wires10a,10band the third phase lead wires11a,11bare fixedly attached or bonded to an end face of a coil end14of the magneto coil8by a bonding member21comprising epoxy resin or varnish. Also, the first protective tubes12a,12band the first phase lead wires9a,9bare attached or bonded to each other by means of the bonding member21.

In addition, the first protective tubes12a,12bcovering the second phase lead wires10a,10band the third phase lead wires11a,11bare wound with and bundled by one first phase lead wire9aof the pair of first phase lead wires9a,9b, together with the other first phase lead wire9b.

The first phase lead wires9a,9b, the second phase lead wires10a,10band the third phase lead wires11a,11bare electrically connected to three lead portions, respectively, of strand structure that together form a lead23, inside the second protective tubes22a,22b,22c. Accordingly, after the first phase lead wires9a,9b, the second phase lead wires10a,10band the third phase lead wires11a,11bare electrically connected to the three lead portions, respectively, the second protective tubes22a,22b,22care inserted, respectively.

By means of these second protective tubes22a,22b,22c, the individual phase lead wires9a,9b,10a,10b,11a,11bare electrically insulated from one another, and at the same time, individual connecting portions between these lead wires9a,9b,10a,10b,11a,11band the three lead portions are also electrically insulated.

An end of the lead23for leading out to electrical equipment (not shown) is covered with a third protective tube24. The lead23is fixedly held by a lead clamp26through a third protective tube24. The lead clamp26is fixedly fastened to the stator core7by a screen25.

In the magneto generator as constructed above, the flywheel3is 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 coil8by 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 wires10a,10band the third phase lead wires11a,11bcovered with the first protective tubes12a,12bare bent toward the first phase lead wires9a,9bin a counterclockwise direction inFIG. 1. The second phase lead wires10a,10band the third phase lead wires11a,11bthus bent are bundled together with the first phase lead wires9a,9b, and the first phase lead wires9a,9b, the second phase lead wires10a,10band the third phase lead wires11a,11bthus bundled are bent in a clockwise direction inFIG. 1and covered with the second protective tubes22a,22b,22c, respectively.

As a result, with the lead23being fixedly held by the lead clamp26, the second protective tubes22a,22b,22carranged in a line along a diametral direction act to press the first protective tubes12a,12bagainst the end face of the coil end14, and the second protective tubes22a,22b,22care placed in intimate contact with the first protective tubes12a,12b, whereby an increase in the axial dimension of the stator2can be prevented.

In addition, vibrations of the individual lead wires9a,9b,10a,10b,11a,11bare prevented, thus making unnecessary those parts which are conventionally required and exclusively used for vibration resistance.

Moreover, since the first protective tubes12a,12bare fixedly attached or fastened to the end face of the coil end14by means of the bonding member21, the vibrations of the second phase lead wires10a,10band the third phase lead wires11a,11bare prevented in a reliable manner without requiring additional parts.

Further, the bonding member21has thermal resistance, and hence contributes to improvements in thermal resistance of the second phase lead wires10a,10band the third phase lead wires11a,11b.

Furthermore, the first phase lead wires9a,9b, the second phase lead wires10a,10band the third phase lead wires11a,11bprotrude from between the individual teeth13, respectively, so the winding space of the conductor wound around each tooth13can be ensured.

In addition, the first phase lead wires9a,9bare arranged at locations more apart from the lead23than the second phase lead wires10a,10b, and the third phase lead wires11a,11b, and the lead23is positioned in a direction of extension of the lead-out individual phase lead wires9a,9b,10a,10b,11a,11bcovered with the second protective tubes22a,22b,22c,23. With such an arrangement, the ends of the individual phase lead wires9a,9b,10a,10b,11a,11band the end of lead23can be electrically connected to one another in a smooth manner, and useless elongation of these lead wires9a,9b,10a,10b,11a,11band the lead23can be prevented.

Moreover, the one first phase lead wire9ais wound around the first protective tubes12a,12btogether with the other first phase lead wire9bto bundle them together, so the first protective tubes12a,12bare tightly secured by a bent portion15, thus making it possible to improve vibration resistance of the first protective tubes12a,12bin the bent portion15.

FIG. 4is 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 lead23for connection to electrical equipment is located at the right of the magneto generator, as shown inFIG. 1, but in contrast, in this second embodiment, the lead-out direction of the lead23for connection to electrical equipment is located at the left of the magneto generator, as shown inFIG. 4.

Thus, in the first embodiment, the bent portion15for the first protective tubes12a,12bare formed at the left of the lead clamp26inFIG. 1, but in contrast, in this second embodiment, the bent portion15is formed at the right of the lead clamp26inFIG. 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 wires9a,9bare arranged at locations more apart from the lead23than the second phase lead wires10a,10b, and the third phase lead wires11a,11b, and the lead23is positioned in a direction of extension of the individual lead-out phase lead wires9a,9b,10a,10b,11a,11bcovered with the second protective tubes22a,22b,22c,23. With such an arrangement, the ends of the individual phase lead wires9a,9b,10a,10b,11a,11band the ends of the individual lead portions of the lead23can be electrically connected to one another in a smooth manner, and useless elongation of these lead wires9a,9b,10a,10b,11a,11band the lead23can be prevented.

FIG. 5is 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 teeth13of a stator core7to form an ignition signal coil. Signal lead wires27a,27bof this ignition signal coil are led out in an axial direction, and covered with fourth protective tubes28a,28b.

Similar to the first protective tubes12a,12band the second protective tubes22a,22b,22c, the fourth protective tubes28a,28bare formed by impregnating varnish into tubes woven with polyester fiber.

The signal lead wires27a,27bprotruded in the axial direction are first bent in a clockwise direction inFIG. 5, and are then bundled by one first phase lead wire9awound therearound together with the other first phase lead wire9b, the second phase lead wires10a,10band the third phase lead wires11a,11bcovered with the first protective tubes12a,12b.

The construction of this third embodiment other than the above is similar to that of the first embodiment.

In this embodiment, the signal lead wires27a,27bare tightly secured by the one first phase lead wire9atogether with the other first phase lead wire9b, the second phase lead wires10a,10band the third phase lead wires11a,11b. 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 wires27a,27bcan be improved.

FIG. 6is a front elevational view that shows a stator of a magneto generator according to a fourth embodiment of the present invention.FIG. 7is a cross sectional side elevational view of the magneto generator ofFIG. 6, andFIG. 8is an enlarged view of essential portions of the magneto generator ofFIG. 7.FIG. 9is a view when the stator ofFIG. 6is seen from the direction of arrow C.

In this embodiment, a lead clamp26A has a base end portion thereof fixedly fastened to a stator core7by means of a tightening element in the form of a screen25. The lead clamp26A made of resin has a bent portion26Aa whose diametral outermost portion is bent toward a magneto coil8, and also has an opening portion formed at a side near the magneto coil8. The lead clamp26A covers the lead23and at the same time presses the lead23toward a coil end8aof the magneto coil8through the opening portion. In addition, the lead clamp26A is arranged between adjoining teeth13when seen along the direction of the axis of rotation.

According to the magneto generator of this fourth embodiment, the lead clamp26A covers the lead23covered with the third protective tube24and at the same time presses the lead23toward the coil end8aof the magneto coil8through the opening portion, whereby the lead23is placed into intimate contact with the magneto coil8through the third protective tube24, thereby making it possible to reduce the axial dimension of the stator2.

In addition, there is no gap formed between the lead23and the coil end8aof the magneto coil8, 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 lead23.

Also, the lead clamp26A is arranged between the adjoining teeth13when viewed along the direction of the axis of rotation, so the lead23being pressed by the lead clamp26A is inserted into between the teeth13by bending deformation, and the adjoining teeth13, the lead clamp26A and the lead23are much more integrated with one another. Accordingly, the axial dimension of the stator2is further reduced, and the displacement in the circumferential direction of the lead23due to its vibration can be prevented, whereby the break or disconnection of the lead23and the lead wires10a,10b,11a,11b,12a,12bresulting from the difference in the vibration frequencies of the teeth13, the lead clamp26A and the lead23can be reduced.

Further, since the lead23has the bent portion26Aa whose diametral outermost portion is bent toward the magneto coil8, the diametral position adjustment of the lead23can be easily carried out by adjusting the length in the direction of the bending of the bent portion26Aa.

FIG. 10is 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 clamp26B made of resin has protrusions26Ba formed at opposite side edges of a surface pressing against a coil end8a.

The construction of this fifth embodiment other than the above is similar to that of the fourth embodiment.

In this embodiment, the protrusions26Ba are formed on the opposite side edges of the lead clamp26B, and the lead23is pressed toward the coil end8aby means of the protrusions26Ba at two locations, so in particular, the displacement in the circumferential direction of the lead23can be prevented.

FIG. 11is 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 clamp26C made of resin has its central portion26Ca bent into a V-shaped configuration, so that a third protective tube24is pressed by the central portion26Ca and opposite ends26Cb of the lead clamp26C.

The construction of this sixth embodiment other than the above is similar to that of the first embodiment.

Since in this embodiment, the lead clamp26C is bent into the V-shaped configuration, the lead23being pressed by the lead clamp26C is inserted into between the teeth13by bending deformation, and the adjoining teeth13, the lead clamp26A and the lead23are much more integrated with one another in comparison with the fourth embodiment. Accordingly, the break or disconnection of the lead23and the lead wires10a,10b,11a,11b,12a,12bresulting from the difference in the vibration frequencies of the teeth13, the lead clamp26C and the lead23can be reduced in comparison with the fourth embodiment.

FIG. 12is 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 clamp26D made of rolled steel plate has a diametrally extending concavo-convex portion26Da formed at a central portion of a surface pressing against a coil end8a.

The construction of this seventh embodiment other than the above is similar to that of the fourth embodiment.

Since in this embodiment, the lead clamp26D has the concavo-convex portion26Da formed on the central portion, the lead23being pressed by the lead clamp26D is more deeply inserted into between the teeth13in comparison with the fourth embodiment, whereby the adjoining teeth13, the lead clamp26D and the lead23are much more integrated with one another in comparison with the fourth embodiment.

In addition, the concavo-convex portion26Da can be easily formed by press working.

FIG. 13is 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 clamp26E made of rolled steel plate has a bulged curved portion26Ea pressing against a coil end8a.

The construction of this eighth embodiment other than the above is similar to that of the fourth embodiment.

In this embodiment, since the lead clamp26E is formed with the bulged or curved portion26Ea, the lead23being pressed by the lead clamp26E can be inserted into between the teeth13without being subject to forced stress.

FIG. 14is 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 clamp26F made of rolled steel plate has a diametrally extending concavo-convex portion26Fb formed at a central portion of a surface pressing against a coil end8a, and is formed at its opposite ends with bent portions26Fa bent to a side opposite to the coil end8a.

The construction of this ninth embodiment other than the above is similar to that of the fourth embodiment.

Since in this embodiment, the lead clamp26F has the concavo-convex portions26Fb formed on the central portion, the lead23being pressed by the lead clamp26F is more deeply inserted into between the teeth13in comparison with the fourth embodiment, so that the adjoining teeth13, the lead clamp26F and the lead23are much more integrated with one another in comparison with the fourth embodiment.

In addition, since the lead clamp26F is formed at its opposite ends with the bent portions26Fa, the rigidity of the lead clamp26F becomes high, so that the amount of flexible deformation of the lead clamp26F generated when the lead clamp26F is pressed against the coil end8acan be reduced, and a hold-down force to the lead23can be transmitted in a more reliable manner.

FIG. 15is 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 end8aof the lead clamp26F of the sixth embodiment is enclosed by an elastic member30.

The construction of this tenth embodiment other than the above is similar to that of the fourth embodiment.

In this embodiment, the lead clamp26F 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 coil8in an axial direction of the stator2has variations depending upon the winding condition of the conductor, etc., the elastic member30enclosing the lead clamp26F serves to absorb such variations, whereby the lead clamp26F can press the lead23toward the coil end8ain a stable manner.

Although in the above-mentioned respective embodiments, reference has been made to the three-phase magneto coil8with 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 clamps26A,26B,26C,26D,26E,26F is arranged between adjoining ones of the teeth4when 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 clamps26A,26B,26C,26D,26E,26F and the coil end8aof the magneto coil8, each of the lead clamps26A,26B,26C,26D,26E,26F may of course be arranged on the teeth13when viewed along the direction of the axis of rotation.