JP2792418B2 - AC generator for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternator for a vehicle (hereinafter, simply referred to as an alternator), and more particularly to the reduction of discomfort to wind noise caused by a fan mounted on a rotor.

[0002]

2. Description of the Related Art FIGS.
11 shows a conventional AC generator described in Japanese Patent Publication No. 11221, FIG. 11 is a longitudinal sectional view of the AC generator, FIG. 12 is a front view, and FIGS. 13 (A) and (B) show front and rear fans, respectively. It is a front view. In the figure, reference numeral 1 denotes a stator, and a stator core 2;
And a stator coil 3. This AC generator is a three-phase AC generator, and the stator core 2 has 36 slots.

[0003] Reference numeral 4 denotes a rotor, which is configured as follows. Reference numerals 5 and 6 denote magnetic pole iron cores of different polarities, each having six magnetic pole teeth 5a and 6a protruding axially in a comb shape on the outer peripheral portion. The magnetic pole cores 5 and 6 are fitted to a rotating shaft 8 (described later) so that the magnetic pole teeth 5a and 6a are opposed to each other with a gap provided in the axial direction so as to mesh with each other to form a cylindrical peripheral wall. The gap is formed in a zigzag shape in the circumferential direction, and the number of magnetic poles is 6 pairs, that is, 12 poles in total. The side surfaces of the magnetic pole cores 5 and 6 are flat, and front and rear fans 10 and 11 to be described later are fixed thereto. 7 is an excitation coil sandwiched between the two magnetic pole cores 5 and 6, and 8 is a magnetic pole core 5, 6
A pair of slip rings 9 are fixed to the rotating shaft 8 via an insulating sleeve, and are connected to the exciting coil 7.

[0004] Reference numerals 10 and 11 denote a front fan and a rear fan, which are a pair of fans fixed to each side surface of the magnetic pole cores 5 and 6, respectively. The front fan 10 has a radiation direction as shown in detail in FIG. Curved 11 arranged at unequal angular intervals
The fan is a circular fan having a plurality of blades 10a, the outer diameter of which is circular CR1, and the inner diameter of which is circular CR2.

As shown in detail in FIG. 13B, the rear fan 11 has thirteen flat blades 11a arranged at unequal angular intervals in the radial direction. Is a circular fan having an outer diameter CR1 and an inner diameter CR2.
An embossed rib 11c is provided at the center of the blade 11a and the flat plate 11b of the fan 11 for reinforcement. 11
Reference numeral d denotes a protruding portion provided on the back side of the blade so as to protrude toward the front side of the drawing, and passes a connection line from the slip ring 9 to the excitation coil 7 between the blade and the magnetic pole core 6. In addition, the arc-shaped arrows A and B in FIG.
1 shows the rotation direction.

Returning to FIG. 11, reference numerals 12 and 13 denote bowl-shaped front and rear brackets, which are connected to the stator core 2 by tightening bolts 14. As shown in FIG. 12, the front bracket 12 has a plurality of (twelve in this example) inlet holes 12a as inlet holes, and a plurality of (20) exhaust holes 12b in an outer peripheral portion, as shown in FIG. Is provided. Although not shown, the rear bracket 13 is similarly provided with 12 intake holes 13a, which are inlet holes, and 20 exhaust holes 13b on the outer peripheral portion for ventilation. I have. The rotating shaft 8 is rotatably supported by the front bracket 12 and the rear bracket 13 via bearings 15 and 16. Reference numeral 17 denotes a pulley fixed to the rotating shaft 8, and the rotation of the engine is transmitted via a belt to rotate the rotor 4.

A rectifier 18 rectifies an AC voltage induced in the stator coil 3 into a DC voltage and outputs the rectified voltage. 19 detects a rectifier output voltage and controls an exciting current to adjust a terminal voltage of the generator to a predetermined value. Voltage regulator and rear bracket 1
3. Reference numeral 20 denotes a brush holder, which presses the held brush 21 against the slip ring 9 and passes an exciting current to the exciting coil 7.

In the AC generator, when an exciting current is supplied to the exciting coil 7 to rotate the rotor 4, the rotor 4
A total of 12 magnetic poles are formed on the peripheral wall of the stator coil 3.
, An AC voltage is induced to generate electric power. At this time, the stator coil 3 and the exciting coil 7 generate heat. Before this heat,
The cooling is performed by the ventilation by the rotation of the rear fans 10 and 11.

The cooling air generated by the rotation of the fan 10 is shown in FIG.
, The intake hole 1 of the front bracket 12 as shown by arrow C
2a, the stator 1 is cooled in the axial direction,
2b is discharged in the radial direction. Similarly, the cooling air generated by the rotation of the fan 11 is sucked from the intake hole 13a of the rear bracket 13 as shown by the arrow D, and the rectifier 18, the voltage regulator 1
9, the brush holder 20, the stator 1 is cooled, and the exhaust holes 13
b.

As described above, the front fan 10 and the rear fan 11
Has 11 and 13 blades arranged at unequal angular intervals, the number of blades is odd and different from each other, and the number of magnetic poles of the rotor is also different from 12 Have been. Accordingly, the order components of the spectrum of each wind sound by the fans 10 and 11 are dispersed, the 11th-order components do not overlap each other, and the magnetic pole teeth and gaps of the magnetic pole cores 5 and 6 (each tooth number 6, gap number 12) ), The order of the wind noise spectrum is dispersed so as not to overlap with the sixth and twelfth components of the wind noise spectrum, thereby reducing the wind noise.

Further, the number of intake holes 12a, 13a of the front bracket and the rear bracket is set to 12 as described above, and is different from the number of blades of each fan 10, 11.

FIG. 14 shows the spectrum of wind noise when using the 11- and 13-blade fans on the vertical axis, taking the power level [dBA], and setting the rotation speed of the AC generator (fan) as a parameter. The characteristic diagram shown in FIG.
Shows the spectrum when the rotation speed of the alternator is 15000 [rpm], and the numerals described in the respective maximum value parts of the curve in the figure are 6, 7,.
When the rotation speed of the alternator is changed, it changes as shown in the figure,
When the number of rotations is 15500 and 16000 [rpm], spectrums such as curves S and T are shown, and in any case, the 11, 13, and 15th-order components of both fans overlap and the power level is high. In addition,
In FIG. 14, the sixth and twelfth components are the magnetic pole teeth 5 of the rotor.
a, 6a (6 each) and the number of gaps (corresponding to the number of magnetic poles) formed by the magnetic pole teeth (12).

[0013] In order to further improve this, the invention was invented by one of the inventors of the present invention, and is disclosed in Japanese Patent Application No. 5-120.
There is an invention filed in No. 010 (unpublished). FIG.
15A and 15B show a combination of fans of this improved conventional alternator, and FIGS. 15A and 15B are front views of a front fan and a rear fan, respectively. The structure of the rotor and the like is the same as the conventional one shown in FIGS. 11 to 13, but the combination of the number of blades of the fan is improved to reduce wind noise.

In FIG. 15A, reference numeral 30 denotes a front fan fixed to the end of the magnetic pole core 5, which has the same configuration as that of the fan described in Japanese Utility Model Laid-Open No. 3-7648.
The curved blades 30a, 30b, 30c and the four planar blades 30d, 30e are provided at unequal angular intervals in the radial direction by bending, and the outer diameter and the inner diameter of the blades 30a to 30e correspond to the rotation center. It is a circular fan having circular centers CR3 and CR4. As in the case of the rear fan 11 shown in FIG. 13B, reinforcing ribs are provided by pressing, but are omitted in the figure. The fan shown in FIG. 15B is similar to the fan 11 in FIG. 13B, and has thirteen blades 11a. Also in this conventional example, twelve magnetic poles are formed on the peripheral wall of the rotor by the magnetic pole cores 5 and 6.

As described above, the front fan 30 and the rear fan 1
The number of blades of the front fan 30 is set to an even number (10), and the number of blades of the rear fan 11 is set to an odd number (1).
(3 sheets) so that the order components of the wind sound spectra of the front and rear fans are not overlapped, and the rotor has 12 poles. Wind noise is reduced by avoiding overlap with the next component.

In the case of a three-phase AC generator, the number of slots of the stator core 2 is 36, 16 when the rotor has 12 poles.
When the number of poles is 48, the number of slots is 48 (when the number of slots in each pole is 1). When the number of blades of the fan is 12, three times the 36th-order component overlaps this and the wind noise becomes large. As described above, the number of blades is not limited to twelve.

FIG. 16 is a characteristic diagram showing a spectrum of wind noise when using the ten and thirteen blade fans using the number of revolutions of the AC generator (fan) as a parameter.
For example, each of the curves U, V, and W indicates that the rotation speed of the generator is 1500.
FIG. 14 shows spectra at 0, 15500, and 16000 [rpm], where the order components are dispersed and the 11th and 15th components are particularly reduced as compared with the characteristic diagram shown in FIG.

[0018]

However, in such a conventional AC generator, the wind noise is reduced mainly by the order dispersion of the spectrum of the wind noise, that is, white noise. 1 when the number of revolutions per minute of the alternator is 15000 to 16000
2750-4000 [H by 1, 12, 15th order components
z] is relatively large (see characteristics U to W),
In particular, frequency components of 3 kHz or more result in hard and unpleasant wind noise, which may not be sufficient for noise control.

The present invention has been made to solve such a problem, and aims to disperse the order of the wind noise spectrum and to make the spectrum of the wind noise inversely proportional to the frequency, that is, a so-called 1 / f. It is an object of the present invention to obtain an AC generator capable of effectively reducing discomfort by approaching the form of fluctuation.

[0020]

An AC generator according to the present invention has a plurality of pairs of magnetic poles formed on a peripheral wall and is rotatably supported by a pair of brackets. A pair of fans each having a plurality of blades disposed therein, each of which is attached to a magnetic pole iron core, and is provided with a pair of fans for cooling the inside of the machine by introducing outside air from an introduction hole and discharging the air from an exhaust hole, and each fan fixed to a rotor. And a low-order component generating means for generating a wind sound component having a lower order than the order component of the spectrum of the wind sound generated by the blade.

Further, the rotor according to claim 1 is provided with an exciting coil and a pair of magnetic pole cores having a plurality of magnetic pole teeth protruding in the axial direction and arranged in a comb shape on the outer peripheral portion. The above-described excitation coil is sandwiched, and magnetic pole teeth are provided with a gap in the axial direction, are opposed to each other so as to mesh with each other, and are fitted to the rotating shaft to form a cylindrical peripheral wall on which a plurality of pairs of magnetic poles are formed. The low-order component generating means generates a lower-order wind sound component than any order component of the spectrum of the wind sound generated by the plurality of magnetic pole teeth and the blades of each fan.

According to a third aspect of the present invention, the blades of the pair of fans according to the first or second aspect are provided at unequal angular intervals in the radial direction, and the number of the blades of one fan is set to an even number and the other is set to the other fan. Are odd-numbered blades.

According to a fourth aspect of the present invention, the AC generator according to the third aspect is a three-phase AC generator, wherein the number of blades of one fan is ten and the number of blades of the other fan is thirteen. It is.

According to a fifth aspect of the present invention, at least one of the pair of fans according to the first to fourth aspects has a non-circular shape to provide low-order component generating means.

According to a sixth aspect of the present invention, at least one of the pair of fans according to the fifth aspect has a non-circular point symmetrical shape, and its center of gravity coincides with the rotation center of the rotor and is fixed to the rotor. This is a low-order component generation means.

According to a seventh aspect of the present invention, at least one of the pair of fans according to any one of the first to fourth aspects has a circular shape and is eccentric with respect to the rotation center of the rotor and is fixed to the rotor. This is a low-order component generation means.

According to an eighth aspect of the present invention, there is provided a fan fixed to an eccentric rotor according to the seventh aspect, wherein a balance weight is provided so as to be located on a side opposite to the eccentric direction of the fan, and the fan is provided on the rotor. The thinned portion is provided so as to be located on the side of the eccentric direction.

According to a ninth aspect of the present invention, a low-order component generating means is provided by providing a low-order component generating member to at least one of the pair of fans according to the first to fourth aspects.

According to a tenth aspect of the present invention, a low-order component generating member is provided by providing the fan blade of the ninth aspect with an extending member extending radially from the blade.

According to an eleventh aspect of the present invention, the fan according to the tenth aspect is formed in a circular shape, and the blade is provided with an extending member extending radially from the blade so that the fan can be used as a rotation center of the rotor. Concentrically fixed to the rotor to form a low-order component generation member

[0031]

In the invention according to the first aspect, the low-order component generating means which rotates together with the rotor generates a wind sound component of a lower order than the order component of the spectrum of the wind sound generated by the blades of each fan. . By adding a low-order wind noise component to the wind noise generated by the fan blades, the spectral distribution of the wind noise is improved, and the intensity of the wind noise spectral component is inversely proportional to the frequency. The noise approaches the so-called 1 / f fluctuation wind noise, and discomfort is reduced.

In the invention according to claim 2, the low-order component generating means includes a lower-order wind noise component than any of the order components of the spectrum of the wind noise generated by the pair of fan blades and the magnetic pole teeth of the magnetic pole core. Occurs. By adding a low-order wind noise component to the wind noise generated by the fan blades, the spectral distribution of the wind noise is improved, and the intensity of the wind noise spectral component is inversely proportional to the frequency. The noise approaches the so-called 1 / f fluctuation wind noise, and discomfort is reduced. Since the order component of the wind noise generated by the low-order component generating means is set to be lower than the order component of the wind noise generated by the magnetic pole teeth, the order component of the wind noise is large even when the wind noise generated by the magnetic pole teeth is large. Are dispersed, and the spectral distribution is surely improved.

In the invention according to claim 3, the blades of each fan are provided at unequal angular intervals in the radial direction, and the number of blades of one fan is an even number and the number of blades of the other fan is an odd number. Therefore, the order components of the wind noise by each fan are widely dispersed. Therefore, the wind noise is reduced, and the low-order component generated by the low-order component generating means is added thereto, whereby the spectral distribution of the wind noise is improved, and the synergy between the reduction of the wind noise and the improvement of the spectral distribution reduces the wind noise. Discomfort is further reduced.

In the invention according to claim 4, since the number of blades of one fan is 10 and the number of blades of the other fan is 13, the order component of wind noise generated by both fans is Dispersion is effectively achieved to reduce wind noise, and a low-order component is added to this to further reduce discomfort to the wind noise.

In the invention according to claim 5, since the fan has a non-circular shape, a wind noise component having a low order with respect to the rotation speed of the rotor is generated with the rotation of the fan,
The spectral distribution of wind noise is improved, and discomfort to wind noise is reduced.

According to the sixth aspect of the present invention, since the fan has a non-circular point symmetrical shape and its center of gravity coincides with the rotation center of the rotor, it is not necessary to balance the rotation. In addition, even if imbalance occurs due to a manufacturing error or the like, the adjustment is easy because it is slight.

In the invention according to claim 7, the circular fan is fixed eccentrically with respect to the rotation center of the rotor. A low-order wind sound component is generated, and the spectral distribution of the wind sound is improved. Further, the fan is circular, so that it is easy to manufacture.

In the invention according to claim 8, by adjusting both the balance weight provided on the fan and the thinned portion provided on the rotor, for example, the coarse weight is adjusted by the balance weight. , And fine adjustment is performed by the thinning part, so that the rotation balance can be easily obtained. Further, the fan is circular, so that it is easy to manufacture.

According to the ninth aspect of the present invention, the low-order component generating member provided in the fan generates a low-order wind sound component to improve the spectral distribution of the wind sound. In addition,
Since the fan is provided with a low-order component generating member, the structure is simple and easy to manufacture.

According to the tenth aspect of the present invention, the extending member provided extending radially from the fan blades generates a low-order wind noise component as the fan rotates, and the wind noise spectrum distribution To improve. In addition, since the extending member extended from the blade of the fan is used as the low-order component generating member, the structure is simple and the production is easy.

According to the eleventh aspect of the present invention, the fan having a circular shape is fixed concentrically with the center of rotation of the rotary shaft, so that the efficiency of the fan is high. Is also simple, so that the production is easy.

[0042]

【Example】

Embodiment 1 FIG. FIG. 1 shows a combination of a front fan and a rear fan of an AC generator according to an embodiment of the present invention.
1A is a front view of a front fan, and FIG. 1B is a front view of a rear fan, in which a pair of front and rear fans are each formed into an elliptical shape having a non-circular point symmetric shape. The configuration of the rotor and the like is the same as the conventional one shown in FIGS.

In FIG. 1, reference numeral 40 denotes the magnetic pole core 5 (FIG. 11).
11), the eleventh curved blades 40a are arranged at unequal angular intervals, and the outer diameters of the blades 40a are longer on the horizontal axis and shorter on the vertical axis. The ratio of the minor axis length b to the minor axis ratio (hereinafter referred to as major axis / minor axis ratio) is set to about 0.9 to form an elliptical shape EC1. Similarly, the inner diameter portion of the blade 40a is formed on an ellipse having a ratio of the minor axis to the major axis of about 0.9. In the drawing, CR5 is the outer circle of the rotor. This wing 40
Is manufactured by punching a steel plate with a press, processing a reinforcing rib (not shown), and bending the steel plate forward with a jig as shown in the figure. Although not shown, reinforcing ribs are provided by pressing similarly to the rear fan 31 shown in FIG. 1B.

In FIG. 1B, reference numeral 41 denotes a rear fan attached to the side surface (see FIG. 10) of the magnetic pole core 6, and 13 flat blades 41a are formed at unequal angular intervals similarly to the front fan 40. Further, it is provided so as to form an elliptical EC1 having a major / minor axis ratio of about 0.9. The rear fan 41 is manufactured from a steel plate through the same process as the front fan 40. The pair of fans 40 and 41 as described above are fixed to the side surfaces of the magnetic pole cores 5 and 6 shown in FIG. 11 by caulking so that the long axes of the fans overlap each other when viewed from the axial direction and are concentric with the rotation axis. This constitutes a low-order component generation means in the present invention. Each fan has an elliptical shape and its center of gravity is fixed so that it matches the center of rotation of the magnetic pole core.Therefore, it is not necessary to balance the rotation for each fan, or imbalance due to manufacturing errors etc. Even if it occurs, it is slight and adjustment is easy.

The intake holes of the front bracket are the same as those shown in FIG. 12 and have twelve intake holes 12a, the number of which is different from the number of blades (11) of the front fan 40. I have. Although not shown, the number of intake holes of the rear bracket is also 12, and the number of blades (1
3) and an even number. Furthermore, the higher-order components of the power level of the wind noise generated by the fan do not overlap with the sixth and twelfth-order components of the spectrum of the wind noise generated by the magnetic pole teeth (12 in the example of FIG. 1) of the rotor.

Thus, the front fan 40 and the rear fan 41
And the order component of the high power level of the wind noise by the fan and the magnetic pole core 5,
The sixth-order and twelfth-order components having a high power level due to 6 do not overlap with each other, and the order dispersion of the spectrum is effectively performed to reduce wind noise. Further, as described above, the number of intake holes is made different from the number of blades of each of the corresponding fans, thereby preventing overlapping ones of higher power levels. In addition, oval fans 40 and 41
The second and fourth order components and the like generated by the above are added, the spectrum of the wind sound is improved, and the power level of the order component of the spectrum becomes inversely proportional to the frequency. As the sound approaches the sound, the unpleasant sensation is greatly reduced in combination with the decrease in the wind noise.

FIG. 2 shows the spectrum of the wind noise in the embodiment of FIG.
000, 15500, and 16000 [rpm] are shown, respectively, where the second and fourth order components generated by the elliptical fans 40 and 41 are added, so-called 1 / f
It is approaching the form of fluctuation.

Embodiment 2 FIG. 3A and 3B show a combination of a front fan and a rear fan of an AC generator according to another embodiment of the present invention. FIG. 3A is a front view of the front fan, and FIG. FIG. The shape of each fan is an elliptical shape, and the number of blades is changed between 10 and 13 blades.

In FIG. 3A, reference numeral 42 denotes a front fan fixed to the side surface of the front pole iron core. As shown, six curved blades 42a to 42c and four flat blades 42d are shown.
To 42e at unequal angular intervals and a ratio of the major axis to the minor axis of about 0.4.
8 are provided so as to form an elliptical shape. The reinforcing ribs are provided by pressing as in the case of the rear fan 41 shown in FIG. 1B, but are not shown. The blades 42 are connected to the front fan 40 shown in FIG.
It is manufactured from a steel plate in the same manner as described above.

In FIG. 3B, reference numeral 43 denotes a rear fan attached to the side surface of the rear pole iron core. Thirteen flat blades 43a are formed at unequal angular intervals and short and long like the front fan 42. It is provided so as to form an elliptical shape having an axial ratio of about 0.8. Central part of blade 43a and fan 4
The third flat plate portion 43b is provided with an embossed rib 43c for reinforcement. Reference numeral 43d denotes a protruding portion provided on the back side of the blade so as to protrude toward the front side of the paper surface, and passes a connection line from the slip ring to the exciting coil between the protruding portion and the side surface of the magnetic pole core. In addition, arc-shaped arrows A and B in FIG.
Indicates the rotation direction of each fan 42, 43. The rear fan 43 is manufactured from a steel plate through the same process as the front fan 42. Fans 42 and 43 are rotated by 180 degrees so that their major axes are orthogonal to each other when viewed from the axial direction, and the rotation centers of the rotation shafts are aligned with the centers of the rotation centers and are the same as pole iron cores 5 and 6 shown in FIG. The low-order component generating means according to the present invention is fixed to the side surface of the magnetic pole core by caulking.

Although not shown, the intake hole of the front bracket has a fan shape similar to that of the intake hole 12a shown in FIG. 12, but the angle of the fan portion is slightly narrowed so that an odd number of 17 holes is formed. The number of blades of the front fan 42 (10) does not match. The spectrum of the wind noise due to the magnetic pole teeth (12 in the example of FIG. 1) of the rotor has sixth and twelfth-order components, but does not overlap with the tenth-order component due to the front fan. In addition, the number of intake holes of the rear bracket is 12,
The number is set to an even number so as not to match the number of blades (13) of the rear fan 43.

FIG. 4 is a spectrum of wind noise in the embodiment of FIG.
000, 15500, and 16000 [rpm] are shown, but the order components having high power levels of the wind noise by the fans 42 and 43 do not overlap each other, and the orders of the power levels of the wind noise by the fans are high. The components do not overlap with the sixth and twelfth-order components having high power levels of the wind sound spectrum by the magnetic pole cores 5 and 6, and the order dispersion of the spectrum is more effectively performed. The generated secondary and quaternary components and the like are added, approaching the so-called 1 / f fluctuation form, and the unpleasant feeling is further reduced in combination with the reduction of the wind noise.

Embodiment 3 FIG. FIG. 5 shows a combination of a front fan and a rear fan of an AC generator according to another embodiment of the present invention. FIG. 5 (A) is a front view of the front fan, and FIG. FIG. The shape of each fan is a non-circular point symmetrical athletic stadium racetrack, and the number of blades is 1
These are two and ten. In addition,
The shape of the rotor and the like is the same as that of the first embodiment shown in FIG.

In FIG. 5A, reference numeral 44 denotes a front fan fixed to the side surface of the front pole iron core. As shown, the outer diameter of the blade is between the left and right semicircular portions FC1A, FC1C and the two radial portions. And the inner diameter of the blade is left and right semi-circular portions FC2
A, straight section F provided between FC2C and both radial sections
C2B is formed, and a total of 12 planar blades 44a are provided at unequal angular intervals in the left and right semicircular portions.

That is, the circular fan having twelve blades 44a provided at unequal angular intervals is bisected into two semicircular portions FC1A and FC1C, each having a center point Q of each semicircle.
1 and Q2 are shifted from the rotation center P of the rotor by δ to the left and right, respectively, and have a straight portion FC1B therebetween. The fan blades 44a and the flat plate portion 44b of FIG.
In the same manner as the rear fan 41 shown in (B), there is provided a reinforcing rib 44c punched out by pressing. Note that CR5
Is a circle similar to that of FIG. 1 showing the outer diameter of the rotor. The blades 44 are manufactured by punching from a steel plate in the same manner as the front fan 40 shown in FIG.

In FIG. 5B, reference numeral 45 denotes a rear fan mounted on the side surface of the rear pole iron core, and includes six curved blades 45a to 45c and four flat blades 45d and 45d.
e and semi-circular portions FC2A, FC2A, FC2A, FC2A, and FC1A at the same angular interval and semi-circular portions FC1A and FC1C.
It is provided so as to form a competitive road having FC2C and straight section FC2B. The rear fan 45 is connected to the front fan 44.
It is manufactured from a steel plate through the same process. Fan 44,
45 are added to the side surfaces of the magnetic pole cores 5 and 6 shown in FIG. 11 so that the long axis sides of the magnetic cores overlap each other when viewed from the axial direction of the rotor, and the rotation centers of the rotary shafts and the centers thereof are aligned. The low-order component generating means of the present invention is fixed by fastening.

Embodiment 4 FIG. 6 and 7 show still another embodiment of the present invention. FIG. 6 (A) is an explanatory view showing attachment of a front fan to a pole iron core, and FIG. 6 (B) is a front fan and a pole iron core. Explanatory diagram showing the weight for balance and the thinned portion provided in the
FIG. 7 is a front view showing the front fan fixed to the magnetic pole core. The shape of each fan is circular, and the number of poles of the rotor and the point eccentric to the rotation axis are attached to the magnetic pole iron core.
The difference is that it has six poles. For other configurations, see FIG.
This is the same as Example 1 shown in FIG.

In FIG. 6, reference numeral 50 denotes a front pole iron core, which is similar to the pole iron core 5 shown in FIG.
It has eight magnetic pole teeth 50a (see FIG. 7), and a 16-pole rotor is formed by 16 magnetic pole teeth in combination with 8 magnetic pole teeth of a rear magnetic pole core (not shown). Diameter is CR6
Make The magnetic pole core 50 has a circular protruding portion 50b provided on a side surface thereof so as to be concentric with the rotation center P of the magnetic pole core 50. 50c is a magnetic pole tooth 50a for balancing rotation.
This is a thinned portion provided on the outer peripheral portion.

6 and 7, reference numeral 51 denotes a magnetic pole core 50.
Of the magnetic pole iron core 50 through a circular eccentric hole 51g of the front fan provided with the dimension δ eccentric from the geometric center Q of the front fan as shown in the figure. 50b and fixed by caulking.
The front fan 51 is the same as the conventional front fan 30 shown in FIG. 15 (A), except that the diameter of the front fan 30 is a circle CR7 which is slightly smaller than the diameter CR6 of the rotor 50. As shown in FIG. A total of 10 blades including the curved blades 51a to 51c and the four flat blades 51d and 51e form angles θ1 to θ5.
The outer diameter portion and the inner diameter portion of each blade are each provided at an unequal angular interval. Reference numeral 51f denotes a balance weight welded to the inside of the blades 51b and 51c of the front fan 51, and has a rod-like shape having a triangular cross section when viewed from the front side of the figure as shown in FIG. The weight 51f for balance is determined in advance by the weight of the front fan and its eccentric value δ.
The weight is adjusted to a predetermined value according to.

Although not shown, the outer shape of the conventional rear fan 11 shown in FIG. 15 (B) is the same as the front fan 51. , The rear fan is fixed to the rear magnetic pole core by caulking so that the geometric center of the rear fan coincides with the geometric center Q of the front fan when viewed from the axial direction. This constitutes low-order component generation means in the present invention.

The rotor to which the front and rear fans as described above are attached can be finely adjusted in rotational balance by providing a thinned portion on the outer periphery of the magnetic pole teeth 50a of the magnetic pole core.
With the rotation of the front and rear fans, wind noise including first-order and third-order components is generated, and the spectrum of the wind noise is improved.

Embodiment 5 FIG. FIG. 8 is a mounting view of a front fan showing still another embodiment of the present invention. In the figure, 5
Reference numeral 2 denotes a front fan, which is six curved blades 30a, 30b, 3 and 3 which are bent in the anti-rotational direction toward the outer diameter direction similarly to the conventional front fan 30 shown in FIG.
0c and the four flat blades 30d and 30e are arranged at unequal angular intervals of angles θ1 to θ5 as shown in FIG.
The outer diameter portion and the inner diameter portion of each blade are made concentric. 52f (left side) is an extension member which is an extension member in the present invention provided by extending the blade 30b in the inner diameter direction.

The front fan 52 is preliminarily extended by a length corresponding to the extension member 52f when punching the blade 30b (left side) from a steel plate.
At the same time as 0b, the extension member 52f as the extension member in the present invention is formed. Since the front fan 52 is circular and the extension member 52f is formed as described above, it is easy to manufacture.

The front fan 52 constructed as described above is fixed to the magnetic pole core 5 (see FIG. 10) concentrically with the rotating shaft.
The rotation balance can be achieved by providing the thinned portions 53 on the magnetic pole teeth of the magnetic pole core as shown in the figure. When the front fan rotates, wind noise components of the first, third, etc. order are generated. Although the description is omitted, one of the blades 11a of the rear fan 11 shown in FIG. 15B and provided with an extension member in the same manner is the rear fan in the fifth embodiment. In addition, since such a front fan does not need to be eccentric with respect to the rotation center of the rotor, the outer diameter can be increased in accordance with the outer diameter CR6 (see FIG. 6) of the magnetic pole core. The efficiency of the fan is good because of the circular shape.

Embodiment 6 FIG. In the fifth embodiment shown in FIG. 8, the extension member 52f is provided on one of the blades 30b of the fan 52. However, the extension member 52f may be provided on the other blade 30b located at a point symmetric position with respect to this blade and the rotation center. in this case,
Wind noise including low-order components such as second-order and fourth-order components with respect to the rotation speed is generated. Further, since the extending members are provided on the two blades 30b which are point-symmetric with respect to the center of rotation, adjustment of the rotational balance is not basically required,
Even when the rotational balance needs to be adjusted due to a manufacturing error, it can be easily adjusted.

Embodiment 7 FIG. FIG. 9 is a mounting view of a front fan showing still another embodiment of the present invention. In the figure, 5
Reference numeral 4 denotes a front fan, which is similar to the front fan 51 shown in FIG. 7 and has six curved blades 51a, 51b, 51c and four planes bent in the anti-rotational direction toward the outer diameter direction. The blades 51d and 51e have angles θ1 to θ as shown in the figure.
In addition, the blades are arranged at unequal angular intervals, and the outer diameter portion and the inner diameter portion of each blade are formed to be concentric around the center of rotation. Reference numerals 54a and 54b denote extension members provided by extending the curved blades 51c on the left side of the drawing in the outer diameter direction and the inner diameter direction, respectively.

The front fan 54 is previously extended by a length corresponding to the extension members 54a and 54b when punching the blade 51c from the steel plate, and is bent at the same time as the blade 51c according to the present invention. In this embodiment, extension members 54a and 54b as extension members are formed. The front fan 54 has a circular shape and the extension members 54a and 54b are formed as described above, so that the front fan 54 is easy to manufacture.

The front fan 54 as described above is eccentrically fixed to the magnetic pole core 50 in the same manner as in the fourth embodiment shown in FIG. 7, and a thinned portion (not shown) is attached to the right magnetic pole tooth 50a in FIG. The rotation balance can be obtained by providing. Since the size of the extension members 54a and 54b is increased, the thickness of the thinned portion may be small or the extension members 54a and 54b
The size of 4b can be appropriately designed so as to eliminate the necessity of providing a thinned portion. When the front fan 54 rotates, wind noise including first-order, third-order, and other order components is generated. Although the explanation is omitted, the outer diameter of the fan 11 is made slightly smaller than the outer diameter CR6 of the rotor after the fan 11 shown in FIG. 15 (B), and one of the blades is similarly provided with an extension member. The rear fan in the sixth embodiment is mounted eccentrically with respect to the rotation shaft.

Embodiment 8 FIG. FIG. 10 is a longitudinal sectional view of an AC generator showing still another embodiment of the present invention. 10, 61 is a rear bracket, 61a is a plurality of outside air supply holes provided on the outer surface of the rear bracket, and 61b is provided on the outer periphery of the rear bracket and discharges outside air supplied into the machine from the air supply holes 61a. It is an exhaust hole. Reference numeral 62 denotes a bowl-shaped cover, which has an intake hole 62a on the outer end surface thereof and covers the slip ring 9, the rectifier 18, the voltage regulator 19, and the brush holder 20 disposed outside the rear bracket 61. . The front side of the pole core 5 on the front side has an elliptical ten-blade front fan 42 shown in FIG. 3A, and the side face of the pole core 6 on the rear side is shown in FIG. A rear fan 43 is fixed to the rear of the thirteen elliptical blades. Other configurations are the same as those of the AC generator shown in FIG.

The cooling air generated by the rotation of the rear fan 43 is taken in from the intake hole 62a of the cover 62 as shown by the arrow D.
The air is introduced (supplied) into the machine through the air supply holes 61a of the rear bracket 61, cooled inside the machine, and discharged from the exhaust holes 61b. That is, it is not an essential requirement that the fan be provided inside the bracket, and the same effect can be obtained even if the fan is provided outside the bracket as in this embodiment. In addition,
In the present invention, the outside air suction and suction holes described in Examples 1 to 7 and the outside air supply and supply holes described in Example 8 are collectively referred to as outside air introduction and introduction holes.

In the fifth and seventh embodiments shown in FIGS. 8 and 9, the extension members 52f or 54a, 54a
b is punched out of a steel plate integrally with the blade 30b or 51c. However, another member may be welded to the blade to form an extension member, or further formed separately from the blade by a steel plate or the like. The low-order component generating member may be provided on the flat plate portion of the fan (see the flat plate portion 41b in FIG. 1B) by welding or the like. The number to be provided is 3 if necessary.
It may be individual or more.

Further, the fan is formed by stamping out a steel plate by a press. However, the present invention is not limited to this. For example, the fan may be a cast product of an aluminum alloy or a molded product of a synthetic resin. In the case of casting, the thickness of the left blades 51b, 51c, 51d and the like in FIG. 7 can be made thicker than the right blades 51b, 51c, 51d so as to also serve as a balance weight.

In the first to eighth embodiments, the blades have a shape such as an elliptical shape, a race road shape, or a circular shape provided with an extending member, and the number of blades is 10, 11, 13, or the like. Although the fan provided with the extension member is fixed to the magnetic pole core concentrically or eccentrically with the rotation axis of the rotor, the combination of the front fan and the rear fan is limited to these examples. Rather, as long as the object of the present invention is not impaired, the shape of the fan, the number of blades, the concentric or eccentric fixation to the rotor, the number of the extending members, the way of providing, etc. The effect of (1) can be achieved.

The number of poles of the rotor is generally 12 poles, 16 poles or the like in this type of three-phase AC generator, but has other poles such as 8 poles or 24 poles. Alternatively, the AC generator may be a single-phase AC generator. The rotor is configured such that the pole teeth arranged in a comb shape of the pole core are axially opposed to each other via a gap (groove), and the gap (the same number as the total number of pole teeth of the front and rear pole cores) is provided. And the groove between the magnetic pole teeth provided on each magnetic pole iron core generates a wind noise having the number of magnetic poles and an order of an integral multiple of the number of magnetic pole teeth, so that the order of the wind sound depends on the number of poles. The number of blades of each fan may be selected so that the components are dispersed. It should be noted that the gap (groove) between the magnetic pole teeth is filled with a resin or the like to smooth the peripheral wall surface of the rotor to reduce wind noise, or a permanent magnet type rotor may be used. A similar effect is achieved.

[0075]

According to the first aspect of the present invention, there is provided an AC generator having a cylindrical rotor having a plurality of pairs of magnetic poles formed on a peripheral wall surface and rotatably supported by a pair of brackets.
A pair of fans that have a plurality of blades arranged in the radial direction and are attached to the rotor and that cool the inside of the machine by ventilating the inside by introducing outside air from the introduction hole and discharging from the exhaust hole, and fixed to the magnetic pole core And a low-order component generating means for generating a wind sound component having a lower order than the order component of the wind sound spectrum generated by the blades of each fan. An order component lower than the order component of the spectrum of the generated wind sound is added to the wind sound of the fan, and the intensity of the spectrum component of the wind sound is inversely proportional to the frequency, ie, a so-called 1 / f fluctuation wind sound. And discomfort is reduced.

According to a second aspect of the present invention, there is provided an AC generator having a pair of magnetic pole cores having an exciting coil on a rotor and a plurality of magnetic pole teeth protruding in an axial direction on an outer peripheral portion and arranged in a comb shape. The pair of magnetic pole irons sandwiches the exciting coil, and the magnetic pole teeth are provided with a gap in the axial direction, are opposed to each other so as to mesh with each other, and are fitted to the rotary shaft to form a plurality of pairs of magnetic poles. Since the peripheral wall is formed and the low-order component generation means is configured to generate a lower-order component than the order component of the spectrum of the wind sound generated by the plurality of magnetic pole teeth and the blades of each fan, the wind generated by the magnetic pole teeth is reduced. The so-called 1 / f
It approaches the wind noise of fluctuation, and discomfort to the wind noise is reduced.

According to a third aspect of the present invention, in the AC generator, the blades of the pair of fans are provided at unequal angular intervals in the radial direction, and the number of blades of one fan is set to an even number and the number of blades of the other fan is reduced. Since the number of sheets is an odd number, the order components of the wind noise by each fan are dispersed and the wind noise is reduced, and the low-order component generated by the low-order component generation means is added thereto, whereby the spectrum of the wind noise is improved. Therefore, the unpleasant sensation to the wind noise is further reduced by the synergistic effect of the reduction of the wind noise and the improvement of the spectrum distribution.

According to a fourth aspect of the present invention, in the AC generator, the AC generator is a three-phase AC generator, and the blades of the pair of fans are provided at unequal angular intervals in the radial direction. Since the number of blades is 10 and the number of blades of the other fan is 13, the order components of the wind noise generated by both fans are dispersed, the wind noise is effectively reduced, and the generation of low-order components is further reduced. In addition, discomfort to wind noise is further reduced.

In the AC generator according to the fifth aspect of the present invention, at least one of the pair of fans has a non-circular shape to serve as a low-order component generating means. A wind noise component is generated, the spectral distribution of the wind noise is improved, and discomfort to the wind noise is reduced.

In the alternator according to claim 6 of the present invention, since at least one of the pair of fans has a non-circular point symmetric shape, it is not essential to provide a balancer.

According to a seventh aspect of the present invention, in the AC generator, at least one of the pair of fans has a circular shape and is eccentric with respect to the rotation axis of the rotor and is fixed to the rotor so that the low-order component is reduced. Since the generating means is used, the structure is simple, and since the shape is circular, the manufacturing is easy.

According to an eighth aspect of the present invention, in the AC generator, a circular weight fixed to the rotor is provided with a balance weight so as to be located on the opposite side to the eccentric direction and the eccentric direction of the fan. Since the rotor is provided with a wall-thinning portion so as to be positioned on the side, by adjusting both the balance weight provided in the fan and the wall-thinning portion provided in the rotor, for example, the balance weight is provided. By performing the coarse adjustment with the weight and the fine adjustment with the thinned portion, the rotation balance can be easily obtained. Furthermore, since the fan is circular, the structure is simple and easy to manufacture.

According to the ninth aspect of the present invention, at least one of the pair of fans is provided with a low-order component generating member to serve as low-order component generating means.
The structure is simple and easy to manufacture.

According to a tenth aspect of the present invention, in the AC generator, at least one of the pair of fans is provided with an extending member radially extending from the blade on the blade of the at least one fan to reduce the length of the extending member. Since the order component generating member is used, the structure is simple and the production is easy.

According to an eleventh aspect of the present invention, in the AC generator, at least one of the pair of fans is formed in a circular shape, and the blade is provided with an extending member extending radially from the blade. Is concentric with the center of rotation of the rotor and is fixed to the rotor, and this extended member is used as a low-order component generating member, so that the fan works effectively and the fan efficiency is good, and the fan shape extends in a circular shape. Since the structure of the member is also simple, manufacture is easy.

[Brief description of the drawings]

FIG. 1 shows a combination of an elliptical front fan and a rear fan showing an AC generator according to a first embodiment of the present invention;
(A) is a front view of the front fan, and (B) is a front view of the rear fan.

FIG. 2 is a characteristic diagram showing a spectrum of a wind sound in the first embodiment of FIG. 1;

FIG. 3 shows a combination of an elliptical front fan and a rear fan according to a second embodiment of the present invention. FIG. 3 (A) is a front view of the front fan, and FIG. 3 (B) is a front view of the rear fan. is there.

FIG. 4 is a characteristic diagram showing a spectrum of a wind sound in the second embodiment of FIG. 3;

5A and 5B show a combination of a front fan and a rear fan on a competitive road showing a third embodiment of the present invention. FIG. 5A is a front view of the front fan, and FIG. is there.

FIG. 6 is an explanatory view illustrating a circular front fan eccentrically fixed to a magnetic pole core according to a fourth embodiment of the present invention.

FIG. 7 is a front view showing a circular front fan eccentrically fixed to a pole iron core according to a fourth embodiment of the present invention.

FIG. 8 is a front view showing a front fan fixed to a magnetic pole core according to a fifth embodiment of the present invention.

FIG. 9 is a front view showing a front fan fixed to a magnetic pole core according to a seventh embodiment of the present invention.

FIG. 10 is a longitudinal sectional view showing an AC generator according to an eighth embodiment of the present invention.

FIG. 11 is a longitudinal sectional view showing a conventional AC generator.

FIG. 12 is a front view showing the conventional AC generator of FIG. 11;

13A and 13B show a front fan and a rear fan of a conventional AC generator. FIG. 13A is a front view of the front fan, and FIG. 13B is a front view of the rear fan.

FIG. 14 is a characteristic diagram showing a spectrum of a wind sound in the conventional example of FIG.

15A and 15B show a combination of a front fan and a rear fan of a conventional improved AC generator. FIG. 15A is a front view of the front fan, and FIG. 15B is a front view of the rear fan.

FIG. 16 is a characteristic diagram showing a wind noise spectrum in the conventional improved alternator of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator 4 Rotor 5 and 6 Magnetic pole core 5a, 6a Magnetic pole tooth 7 Exciting coil 8 Rotating shaft 12 Front bracket 12a, 12b Intake hole, exhaust hole 13 Rear bracket 13a, 13b Intake hole, exhaust hole 15, 16 Bearing 40 ellipse Shaped front fan 40a Blade (11 pieces) 41 Elliptical rear fan 41a Blade (13 pieces) 42 Elliptical front fan 42a to 42e Blade (10 pieces) 43 Elliptical rear fan 43a Blade (13 pieces) 44 Competition Road-shaped front fan 44a Blade (12 pieces) 45 Competitive road-shaped rear fan 45a to 45e Blade (10 pieces) 50 Magnetic pole core 50c Magnetic pole core thinned portion 51 Circular front fans 51a to 51e Blade (10 pieces) 51f Weight for balance 52 Circular front fan 52a to 52e Blade (10 pieces) 52f Extension member 54 Circular front fan 54a, 54b Member 61 after the bracket 61a, 61b supply hole, an exhaust hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 9/00-9/28

Claims (11)

(57) [Claims] 1. A stator on which a stator coil is mounted, a plurality of introduction holes provided on a side surface, and a plurality of exhaust holes provided on an outer peripheral portion, the stator being provided on both sides of the stator. A pair of brackets, a plurality of pairs of magnetic poles formed on the peripheral wall surface and a cylindrical rotor rotatably supported by the pair of brackets, and a plurality of blades arranged in a radial direction. A pair of fans respectively attached to the rotor for cooling the inside of the machine by introducing outside air from the introduction hole and discharging the air from the exhaust hole, and wind noise generated by the blades of the respective fans fixed to the rotor. An alternator for a vehicle, comprising: a low-order component generating unit that generates a wind noise component of a lower order than the order component of the spectrum of (1). 2. A rotor is provided with a pair of magnetic pole cores having a plurality of magnetic pole teeth protruding in the axial direction and arranged in a comb shape on an outer peripheral portion, and the exciting coil is sandwiched between the pair of magnetic cores. At the same time, the magnetic pole teeth are provided with a gap in the axial direction, are opposed to each other so as to mesh with each other, and are fitted to the rotating shaft so as to form a cylindrical peripheral wall on which a plurality of pairs of magnetic poles are formed. 2. The alternator for a vehicle according to claim 1, wherein the component generating means generates a wind noise component of a lower order than any of the order components of the spectrum of the wind noise generated by the plurality of magnetic pole teeth and the blades of each fan. . 3. The method according to claim 1, wherein the blades of the pair of fans are provided at unequal angular intervals, and the number of blades of one fan is even and the number of blades of the other fan is odd. Or the vehicle alternator according to claim 2. 4. The vehicle AC generator is a three-phase AC generator, wherein one fan has 10 blades and the other fan has 13 blades. Vehicle alternator. 5. The alternator for a vehicle according to claim 1, wherein at least one of the pair of fans has a non-circular shape to serve as low-order component generating means. 6. A low-order component generating means wherein at least one of the pair of fans is a non-circular point-symmetric fan and its center of gravity is fixed to the rotor so as to coincide with the center of rotation of the rotor. The vehicle alternator according to claim 5, characterized in that: 7. A low-order component generating means, wherein at least one of the pair of fans has a circular shape and is eccentric with respect to the rotation center of the rotor and is fixed to the rotor. The vehicle alternator according to any one of claims 1 to 4. 8. A balance weight is provided on the fan so as to be located on the side opposite to the eccentric direction of the fan, and a thinning portion is provided on the rotor so as to be located on the eccentric side of the fan. The vehicle alternator according to claim 7. 9. The alternator for a vehicle according to claim 1, wherein a low-order component generation member is provided on at least one of the pair of fans to form a low-order component generation unit. . 10. The vehicle according to claim 9, wherein the fan blade has an extension member extending radially from the blade, and the extension member serves as a low-order component generation member. Alternator. 11. A fan having a circular shape and a blade provided with an extending member extending radially from the blade, and fixing the fan to the rotor so as to be concentric with the rotation center of the rotor. The alternator for a vehicle according to claim 10, wherein the stationary member is a low-order component generating member.