JP2004088954A - Three-phase magnetic generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the drop of output, the demagnetization of a magnet, and the shortening of the life of a coil caused by temperature rise by suppressing the temperature rise caused by an eddy current accompanying the increase of the number of poles of a rotor. <P>SOLUTION: A three-phase magnetic generator has a stator 200 of 3n(n:an optional natural number) in the number of poles where a coil 23 is wound, and a rotor 100 of 4n in the number of poles where a permanent magnet 13 is fixed. Here the flange 24a of a magnetic substance sheet member 24 where the coil 23 is wound in condition that the stack 21 of the stator 200 is caught is constituted to have a difference in level inward from the periphery 21b of the stacked core 21. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a three-phase magnet type generator mounted on a motorcycle (motorcycle) or the like and charging a battery and supplying power to an electric load such as a headlight.
[0002]
[Conventional or prerequisite technology]
In recent years, three-phase magnet type generators for motorcycles have been required to be reduced in size and, at the same time, to increase the output current on the low rotation speed side due to the increase in electric load.
[0003]
However, a coil having a large diameter cannot be used with a reduction in the coil winding space, and an output current on a high rotation side also increases with an increase in an output current on a low rotation side. For this reason, in the conventional three-phase magnet type generator, that is, the three-phase magnet type generator having 2n poles of the rotor and 3n poles of the stator (n: any natural number), the output current on the high rotation side is suppressed. However, there was a problem that the coil temperature became high.
[0004]
Therefore, Japanese Patent Application Laid-Open No. 2001-112226 discloses a three-phase magnet generator in which the rotor has 16 poles and the stator has 18 poles. According to this three-phase magnet generator, the frequency is increased and the voltage is increased by increasing the number of poles of the rotor from the conventional 12 to 16 poles, and the output current on the low rotation side is increased. Since the magnet per pole is reduced and the output current on the high rotation side is reduced, there is an effect that the coil temperature can be reduced. Further, Japanese Patent Application No. 2002-156919 describes a three-phase magnet generator in which the number of poles of the stator is 3n (n: any natural number) and the number of poles of the rotor is 4n. . According to this three-phase magnet type generator, the effect of being inexpensive and improving the charging performance by increasing the output current on the low rotation side and lowering the coil temperature by reducing the output current on the high rotation side can be obtained. Play.
[0005]
[Problems to be solved by the invention]
However, in Japanese Patent Application No. 2002-156919, as shown in FIG. 11, the flange portion 24a of the magnetic sheet member 24 around which the coil 23 is wound with the laminated core 21 of the stator 200 interposed therebetween forms a leakage flux loop A. However, an increase in the number of poles of the rotor 100 causes an increase in temperature due to an eddy current, and this increase in temperature causes a decrease in output, in the worst case, a demagnetization of the magnet 13, and further shortens the life of the copper wire of the coil 23. It has been found that there is a possibility that it may cause.
[0006]
The present invention solves the above-described problems of the prerequisite technology, suppresses a temperature rise due to an increase in the number of poles of the rotor, and can improve output, extend the life of a coil, and the like. It is an object to provide a three-phase magnet generator.
[0007]
[Means for Solving the Problems]
The three-phase magnet generator according to claim 1 has a stator with 3n poles (n: an arbitrary natural number) wound with a coil and a stator with 2n + m (m: an arbitrary natural number) on which a permanent magnet is fixed. A rotor, and the flange of the magnetic sheet member around which the coil is wound with the laminated core of the stator interposed therebetween, so that the flange has an inward step with respect to the outer peripheral surface of the laminated core. It is characterized by comprising.
[0008]
According to the three-phase magnet generator according to the first aspect, since the flange of the magnetic sheet member has a step inward with respect to the outer peripheral surface of the laminated core, the air gap between the permanent magnet and the flange is long. Therefore, the maximum magnetic flux density of the leakage magnetic flux loop decreases, and the temperature rise due to the eddy current can be suppressed.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
1 is a cross-sectional view of a three-phase magnet type generator according to one embodiment, FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, FIG. 3 is a coil connection diagram of a stator, and FIG. FIG. 5 is an external characteristic graph, FIG. 6 is an output current graph, FIG. 7 is a cross-sectional view of a conventional general three-phase magnet type generator as a comparative example of the present embodiment, and FIG. , A coil connection diagram of the stator of the comparative example, FIG. 9 is a vector diagram of an output voltage of the comparative example, and FIG. 10 is a graph of an experimental result.
[0011]
1 and 2, the three-phase magnet type generator according to the present embodiment includes a rotor 100 and a stator 200.
[0012]
The rotor 100 includes a rotor 11 made of a magnetic material. The rotor 11 is finished by cutting after hot forging. Inside the boss 11a at the center of the rotor 11, a tapered portion 11b fitted to a crankshaft of an engine (not shown) is formed. In addition, the boss portion 11a has an end surface 11c serving as a fastening seat surface when the rotor 11 is fastened and fixed to the crankshaft using a nut (not shown) or the like, and a punch used when the rotor 11 is removed from the crankshaft. A screw portion 11d is formed. The end face 11e of the rotor 11 is provided with a plurality of cooling window holes 11f. The cylindrical outer peripheral portion 11g of the rotor 11 constitutes a yoke. A ring-shaped spacer 12 made of a nonmagnetic material, a plurality of permanent magnets 13 arranged at equal intervals in the circumferential direction, and a nonmagnetic material pressed into the rotor outer peripheral portion 11g are provided inside the rotor outer peripheral portion 11g. The ring-shaped positioning cases 14 are sequentially arranged along the axial direction of the crankshaft. The plurality of permanent magnets 13 are positioned at equal intervals in the circumferential direction by convex portions 14a formed on the positioning case 14, and a magnet protection ring 15 is pressed into the inside of the permanent magnets 13 so that a rotor outer peripheral portion 11g is formed. Is fixed to the rotor 11 by crimping the tip 11h of the rotor. The magnet protection ring 15 is formed by pressing a stainless steel plate.
[0013]
The stator 200 is provided inside the rotor 100. The stator 200 includes the laminated core 21. The laminated core 21 is formed by laminating a plurality of pressed iron plates. The laminated core 21 is sandwiched between the magnetic sheet members 24 and integrated by caulking the rivets 22. The surface of the laminated core 21 is insulated with an epoxy resin or the like. A copper wire for winding is wound around the magnetic sheet member 24 to form a power generation coil 23. The stator 200 is fixed to an engine case (not shown) by screwing a mounting bolt (not shown) into a screw hole 21 a formed in the laminated core 21 and the magnetic sheet member 24.
[0014]
The flange portion 24a of the magnetic sheet member 24 according to the present embodiment is configured such that the outer peripheral surface 24b has a step X inward with respect to the outer peripheral surface 21b of the laminated core 21. On the other hand, the outer peripheral surface 24b of the flange 24a of the magnetic sheet member 24 shown in FIG. 11 is substantially flush with the outer peripheral surface 21b of the laminated core 21. For this reason, in the three-phase magnet type generator shown in FIG. 11, since the air gap between the flange 24a and the permanent magnet 13 is small, the maximum magnetic flux density of the leakage magnetic flux loop A passing through the flange 24a increases, and the temperature rise due to eddy current On the other hand, in the present embodiment, since the air gap between the flange 24a and the permanent magnet 13 is large, the maximum magnetic flux density of the leakage flux loop A passing through the flange 24a is reduced, and the temperature rise due to eddy current is suppressed. You.
[0015]
Next, based on FIG. 2 to FIG. 4, regarding the number of poles of the stator 200, the coil connection method, the number of poles of the rotor 100, and the output voltage of the stator 200 of the three-phase magnet type generator according to the present embodiment, The description will be made in comparison with a general three-phase magnet type generator (FIGS. 7 to 9).
[0016]
The number of poles of the stator 200 in this embodiment is 3n (n: any natural number). On the other hand, the number of poles of the stator 200 of the conventional general three-phase magnet generator is also 3n. Therefore, when n = 4, the number of poles of the stator 200 of the present embodiment is 12, which is the same as the number of poles of the conventional stator 200, as is apparent with reference to FIGS.
[0017]
The method of connecting the coils 23 of the stator 200 in the present embodiment is as shown in FIG. 3 and is the same as the method of connecting the coils 23 of the conventional stator 200 shown in FIG. The winding direction is the same, and the jumper is wired with two poles. Therefore, since the length of the crossover wire is only two poles, a longer crossover wire is not required as compared with the related art (Japanese Patent Application Laid-Open No. 2001-112226), and the coil is not drawn out as compared with the conventional technology (Japanese Patent Application Laid-Open No. 2001-112226). Shaping becomes easy.
[0018]
On the other hand, the number of poles of the rotor 100 in the present embodiment is 4n (n: any natural number). On the other hand, the number of poles of the rotor 100 of the conventional general three-phase magnet type generator is 2n. Therefore, when n = 4, the number of poles of the conventional rotor 100 is eight, whereas the number of poles of the rotor 100 in the present embodiment is sixteen, as is apparent from FIGS. It becomes.
[0019]
Therefore, when n = 4, as shown in FIGS. 2 and 7, the mechanical angle of the conventional stator 200 is 30 ° and the electrical angle is 120 °, whereas the mechanical angle of the stator 200 in this embodiment is 30 °. The angle is 30 °, the electrical angle is 240 °, and the mechanical angle of the conventional rotor 100 is 45 ° and the electrical angle is 180 °, whereas the mechanical angle of the rotor 100 in the present embodiment is 22. 5 °, and the electrical angle is 180 °. Therefore, as apparent from FIGS. 4 and 9, the output voltage of the stator 200 in the present embodiment is different from the output voltage of the conventional stator 200 in the order of the phase, although the order of the phases is reversed. The phase difference is 120 °, and no phase difference occurs in the same phase. Therefore, no loss in output voltage due to the phase difference occurs, and it is not necessary to increase the size of the permanent magnet to compensate for the loss as in the related art (Japanese Patent Application Laid-Open No. 2001-112226).
[0020]
Next, comparing the external characteristics of the three-phase magnet generator (FIGS. 1 to 4) according to the present embodiment with the external characteristics of the conventional general three-phase magnet generator (FIGS. 7 to 9), FIG. As shown in the experimental results in FIG. 5, in the case of the three-phase magnet type generator according to the present embodiment, the current decreases from low rotation (1000 rpm) to high rotation (5000 rpm) as compared with the conventional general three-phase magnet type generator. And the voltage increases. Such experimental results show that the current decreases because the size of the permanent magnet 13 per pole is reduced, and the voltage decreases as the size of the permanent magnet 13 decreases. It is considered that the frequency is doubled because the number of poles is doubled, and as a result, the voltage is increased.
[0021]
Further, when the output current is measured with the voltage V kept constant, as shown in FIG. 6, at low rotation speed (1000 rpm), the output current according to the present embodiment becomes larger than the output current according to the related art, and as a result, the battery is charged. The current increases. On the other hand, at a high rotation speed (5000 rpm), the output current according to the present embodiment is smaller than the output current according to the related art, and as a result, the coil temperature is significantly reduced.
[0022]
FIG. 10 shows a glass representing the result of an experiment for examining the relationship between the size of the step X and the temperature of the flange 24a. In this experiment, a thermocouple was attached to the outer peripheral surface 24b of the flange portion 24a, and the temperature was measured after operating at 6000 rpm for 5 minutes. As a result, in the premise generator having the step X of 0 mm, the temperature of the outer peripheral surface 24b of the flange portion 24a was as high as 196 ° C. (this is an estimated value because demagnetization occurred during the experiment). In the invention generator provided with X, the temperature of the outer peripheral surface 24b of the flange portion 24a is measured as 144 ° C. when the step X is 0.4 mm and 128 ° C. when the step X is 0.9 mm, and the temperature rise is suppressed. The effect proved.
[0023]
As described above, the three-phase magnet type generator according to the present embodiment has the stator 200 with the number of poles 3n (n: any natural number) wound with the coil 23 and the number of poles with the permanent magnet 13 fixed. 4n of the rotor 100, and the flange 24 a of the magnetic sheet member 24 around which the coil 23 is wound with the laminated core 21 of the stator 200 sandwiched therebetween, with respect to the outer peripheral surface 21 b of the laminated core 21. It was configured to have a step X inward. For this reason, the air gap between the permanent magnet 13 and the flange portion 24a becomes longer, so that the maximum magnetic flux density of the leakage magnetic flux loop A decreases, temperature rise due to eddy current can be suppressed, and output due to temperature rise can be reduced. It is possible to prevent the reduction, the demagnetization of the magnet 13, and the shortening of the life of the coil 23. Note that the present embodiment is not limited to the rotor 100 having 4n poles, but a three-phase magnet generator having the rotor 100 having 2n + m (m: any natural number) larger than the conventional pole 2n. Is widely applicable.
[0024]
【The invention's effect】
According to the three-phase magnet generator of the present invention, a decrease in the maximum magnetic flux density of the leakage magnetic flux loop can suppress an increase in temperature due to an eddy current due to an increase in the number of poles of the rotor. Demagnetization and shortening of the life of the coil can be prevented.
[Brief description of the drawings]
FIG. 1 is a sectional view of a three-phase magnet type generator according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along the line II-II shown in FIG.
FIG. 3 is a coil connection diagram of a stator.
FIG. 4 is a vector diagram of an output voltage.
FIG. 5 is an external characteristic graph.
FIG. 6 is an output current graph.
FIG. 7 is a cross-sectional view of a conventional general three-phase magnet generator as a comparative example of the present embodiment.
FIG. 8 is a coil connection diagram of the stator of the comparative example.
FIG. 9 is a vector diagram of an output voltage of the comparative example.
FIG. 10 is a graph of an experimental result showing a relationship between a step X and a temperature.
FIG. 11 is a cross-sectional view of a three-phase magnet generator described in Japanese Patent Application No. 2002-156919, which is a premise of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 100 Rotor 11 Rotor 13 Permanent magnet 200 Stator 21 Laminated core 21b Outer surface 23 Power generation coil 24 Magnetic sheet member 24a Flange portion 24b Outer surface X step

Claims (1)

It has a stator with a number of poles of 3n (n: an arbitrary natural number) around which a coil is wound, and a rotor with a number of poles of 2n + m (m: an arbitrary natural number) to which a permanent magnet is fixed. A three-phase magnet generator, wherein a flange of a magnetic sheet member around which the coil is wound with the laminated core interposed therebetween has a step inward with respect to an outer peripheral surface of the laminated core. .

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