WO2019215785A1

WO2019215785A1 - Centrifugal fan, and ac generator for mounting on vehicle

Info

Publication number: WO2019215785A1
Application number: PCT/JP2018/017635
Authority: WO
Inventors: 惠介武石; 聖光永; 眞一郎南; 将之坂口
Original assignee: 三菱電機株式会社
Priority date: 2018-05-07
Filing date: 2018-05-07
Publication date: 2019-11-14
Also published as: CN112075015A; CN112075015B; DE112018007576T5; JPWO2019215785A1; JP6775611B2

Abstract

This centrifugal fan is provided with an annularly formed main plate, a plurality of arm-like plates extending radially outward from the outer periphery of the main plate, and a blade extending from each of the plurality of arm-like plates. At least one of the main plate and each of the arm-like plates is provided with an axially extending opening. Forming the opening through which air is allowed to flow axially can increase the amount of axially flowing air without increasing noise. Consequently, the cooling performance of an AC generator for mounting on a vehicle can be increased.

Description

Centrifugal fan and automotive alternator

The present invention relates to, for example, a centrifugal fan that is attached to a rotor and cools a rotating electrical machine, and an in-vehicle AC generator that includes the centrifugal fan.

An on-vehicle AC generator mounted on a vehicle performs supplementary charging of the battery while the vehicle is running and covers the power of on-vehicle electrical components. Conventionally, there is a demand for downsizing and higher output of an on-vehicle AC generator. In addition, environmental noise is regulated environmentally, and there is a demand for reducing the noise of the on-vehicle AC generator.

As the in-vehicle AC generator is downsized, the cooling centrifugal fan that rotates together with the in-vehicle AC generator rotor is downsized. When the centrifugal fan is reduced in size, the cooling air volume decreases and the cooling capacity of the on-vehicle AC generator decreases. However, if the number of centrifugal fan blades is increased to increase the air volume, noise due to wind noise will increase.

In view of this, there has been disclosed a technique for increasing the air volume and reducing noise by optimizing the shape of the blades of the centrifugal fan to generate an air flow flowing in the radial direction and the axial direction (see, for example, Patent Document 1). ).

JP-A-9-154256

The centrifugal fan disclosed in Patent Document 1 guides the air flow in the axial direction by matching the outer diameter side of at least one blade leading edge with the side surface of the claw-shaped magnetic pole of the rotor iron core. However, in a location where the outer diameter side of the blade leading edge and the side surface of the claw-shaped magnetic pole of the rotor core are not aligned, there is a problem that the effect of guiding the air flow in the axial direction is small and the cooling performance is low.

The present invention has been made to solve the above-described problems, and provides a centrifugal fan that can increase the amount of air flowing in the direction of the rotation axis without increasing noise.

A centrifugal fan according to the present invention includes a main plate formed in an annular shape, a plurality of arm-like plates extending radially outward from the outer periphery of the main plate, and a blade extending from each of the plurality of arm-like plates, An opening that penetrates in the axial direction is provided in at least one of the arm-shaped plate and the main plate.

The present invention can increase the amount of air flowing in the axial direction without increasing noise by providing an opening for passing air in the axial direction inside the blades of the centrifugal fan. Thereby, the cooling performance of the on-vehicle AC generator can be improved.

It is sectional drawing explaining the structure of the vehicle-mounted alternating current generator by which the centrifugal fan in Embodiment 1 of this invention is arrange | positioned. It is a perspective view which shows the centrifugal fan in Embodiment 1 of this invention. FIG. 3 is a cross-sectional view showing a centrifugal fan taken along line III-III in FIG. 2. It is a figure which shows the example of the opening part of the centrifugal fan in Embodiment 1 of this invention. It is a figure which shows the 1st modification of the centrifugal fan in Embodiment 1 of this invention. It is a figure which shows the 2nd modification of the centrifugal fan in Embodiment 1 of this invention. It is a figure which shows the attachment surface side of the field core of the vehicle-mounted AC generator to which the centrifugal fan in Embodiment 1 of this invention is attached. It is a figure which shows the state which attached the centrifugal fan in Embodiment 1 of this invention to the attachment surface of the field core of a vehicle-mounted AC generator. It is a figure which shows the state attached to the attachment surface of the field core of the vehicle-mounted alternating current generator of the 1st modification of the centrifugal fan in Embodiment 1 of this invention. It is a figure explaining the relationship between the opening part of a centrifugal fan, a noise, and an output in the vehicle-mounted AC generator with which the centrifugal fan was attached.

Hereinafter, preferred embodiments of the centrifugal fan and the on-vehicle AC generator of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of an in-vehicle AC generator in which a centrifugal fan according to Embodiment 1 of the present invention is disposed as viewed from the side.

In FIG. 1, the on-vehicle AC generator has a casing 52 composed of a front housing 51 and a rear housing 50 each made of substantially bowl-shaped aluminum. The in-vehicle AC generator includes a shaft 54 rotatably supported by a casing 52 via a pair of bearings 53, and a pulley 7 fixed to an end portion of the shaft 54 protruding to the front side of the casing 52. Have. The front bearing 53 is supported by the front housing 51, and the rear bearing 53 is supported by the rear housing 50.

Furthermore, the on-vehicle AC generator is fixed to the shaft 54 and disposed in the casing 52, and the rotor 8 that rotates integrally with the shaft 54 and the fixed that is fixed to the casing 52 so as to surround the rotor 8. And a child 9. The in-vehicle AC generator is housed in a pair of slip rings 10 that supply current to the rotor 8 and the brush holder 17, and is fixed to the projecting portion of the shaft 54 that projects to the rear side of the casing 52. A pair of brushes 11 that slide on the surface of the slip ring 10 and a voltage regulator 12 that is disposed adjacent to the pair of brushes 11 and adjusts the magnitude of the AC voltage generated in the stator 9 are provided.

The on-vehicle AC generator includes a rectifier 13 that converts an AC voltage generated in the stator 9 into a DC voltage, a connector 20 that transmits and receives signals between the voltage regulator 12 and an external device, and a voltage regulator. 12 and a protective cover 27 attached to the rear housing 50 so as to cover the rectifying device 13 and the brush holder 17.

The rotor 8 is a Landel-type rotor, and is provided so as to cover the field winding 81 by being fixed to a field winding 81 that generates a magnetic flux when an excitation current flows and a shaft 54 that passes through the axial center position. And a field iron core 82 in which magnetic poles are formed by magnetic flux generated in the field winding 81.

The centrifugal fan 1 according to Embodiment 1 of the present invention is disposed on the attachment surface S of the rotor 8 on the pulley 7 side.

The stator 9 is coaxially disposed on the outer periphery of the rotor 8. The stator 9 is a cylindrical stator core 91, and a stator winding 92 that is attached to the stator core 91, and an alternating current is generated by a change in magnetic flux from the field winding 81 as the rotor 8 rotates. Is provided.

The stator core 91 is sandwiched between the front housing 51 and the rear housing 50 from both sides in the axial direction. The lead wire 92 a of the stator winding 92 is drawn from the rear housing 50 and connected to the terminal 24 a of the circuit board 24. Thereby, the rectifier 13 and the stator winding 92 are electrically connected. The rectifier 13 includes a heat sink 18 on which a plurality of rectifier elements are mounted, and a circuit board 24.

In the on-vehicle AC generator configured as described above, the rotational torque of an engine (not shown) is transmitted to the shaft 54 via the pulley 7, and the rotor 8 is rotated. At this time, a current is supplied to the field winding 81 of the rotor 8 via the brush 11 and the slip ring 10 to generate a magnetic flux.

This magnetic flux alternately forms N poles and S poles in the circumferential direction on a plurality of claw-shaped magnetic poles arranged on the outer periphery of the field core 82. Thereby, a rotating magnetic field is applied to the stator winding 92 of the stator 9, and an alternating electromotive force is generated in the stator winding 92. This AC electromotive force is supplied to the rectifier 13 via the lead wire 92a, rectified by the rectifier 13, and the magnitude thereof is adjusted by the voltage regulator 12, and supplied to the battery and the on-vehicle electrical component. The

Further, when the rotor 8 rotates, the centrifugal fan 1 fixed to the pulley 7 side of the field core 82 is rotated. As the centrifugal fan 1 rotates, outside air is taken into the casing 52 from the opening formed in the front housing 51. The outside air taken into the casing 52 flows in the axial direction in the front housing 51 and reaches the field core 82, and the front side coil ends of the field winding 81 and the stator winding 92 are cooled.

Next, centrifugal fan 1 in Embodiment 1 of the present invention will be described with reference to FIGS.

FIG. 2 is a perspective view showing the centrifugal fan 1 according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view showing the centrifugal fan 1 taken along line III-III in FIG.

As shown in FIG. 2, the centrifugal fan 1 includes a main plate 2, six arm-like plates 3 extending radially outward from the outer periphery of the main plate 2, and a blade 4 extending from each arm-like plate 3. .

The main plate 2 is formed in a ring shape with a through hole provided in the center. The main plate 2 is fixed to the rotor 8 of the on-vehicle AC generator shown in FIG. 1 through the through hole, for example. A step portion 2a is formed at the outer edge of the through hole.

Each arm plate 3 extends radially outward from the outer peripheral end of the main plate 2. Each arm-shaped plate 3 and the main plate 2 are connected to the front and back without any step. As shown in FIG. 2, the six arm-shaped plates 3 are arranged at unequal intervals in the circumferential direction of the main plate 2. The radial width of each arm-shaped plate 3 is formed such that the front side in the rotation direction RD is narrow and the rear side in the rotation direction RD is wide.

Each blade 4 extends from the outer peripheral side of each arm-shaped plate 3 to the same side in the axial direction at a substantially right angle. Each blade 4 has a rear edge 4b located on the rear side in the rotational direction RD and a front edge 4a located on the front side in the rotational direction RD. The distance from the rotation center C of the centrifugal fan 1 to the rear edge 4b of each blade 4 is longer than the distance from the rotation center C to the front edge 4a of each blade 4. That is, each blade 4 is formed so that the leading edge 4a is inclined in the direction toward the rotation center C.

By tilting the blades 4 in this way, the impact caused by the front edges 4a colliding with the air when the centrifugal fan 1 is rotated can be reduced. Thereby, the wind noise by each blade | wing 4 can be reduced.

In addition, each blade 4 is formed in a gentle arc shape whose shape projected onto a plane perpendicular to the rotation axis is convex toward the rotation center C with respect to a line connecting the front edge 4a and the rear edge 4b. The

The centrifugal fan 1 in which the main plate 2, each arm plate 3, and each blade 4 are arranged in this way generates an air flow that flows radially outward along each blade 4. Thereby, the centrifugal fan 1 converts the air flow toward the central portion of the main plate 2 into an air flow toward the radially outer side.

In addition, the shape of the main plate 2 is not limited to the annular shape, and the step portion 2a may not be provided. Further, the central portion of the main plate 2 may have a bowl-like shape.

Also, the number of arm-shaped plates 3 is not limited to six. For example, the number of arm-shaped plates 3 may be eight or more, or may be an odd number. Further, the arm plates 3 may be arranged at equal intervals, or reinforcing ribs may be provided on the arm plates 3.

And the shape projected on the surface perpendicular to the rotation axis of each blade 4 may be linear or S-shaped, or the shape of each blade 4 may be different. Further, each blade 4 may be extended from an intermediate position of each arm plate 3. Further, an annular shroud may be arranged on the outer side in the radial direction of each blade 4.

As shown in FIG. 2, the arm plate 32, which is one of the six arm plates 3 included in the centrifugal fan 1, is provided with an opening 5 penetrating in the axial direction on the radially inner side of the blade 4. . The opening 5 is formed along the blade 4 in a range of 50% to 95% of the circumferential length of the blade 4.

As shown in FIG. 3, a round or chamfer R is formed on the outer edge constituting the opening 5. Thereby, the resistance added to the air flow which passes the opening part 5 can be reduced, and the fall of the flow velocity of the air which flows into an axial direction can be suppressed.

When the centrifugal fan 1 generates an air flow toward the radially outer side, the radially outer side of each blade 4 has a positive pressure, and the radially inner side of each blade 4 has a negative pressure. Therefore, a part of the air flow that flows radially outward from the central portion of the centrifugal fan 1 is sucked to the opening 5 by the negative pressure formed on the radially inner side of the blade 4 and passes through the opening 5 in the axial direction. Washed away.

As described above, according to the centrifugal fan 1 of the first embodiment, the opening 5 is provided in the arm plate 3 of the centrifugal fan 1. Then, the opening 5 is allowed to pass through a part of the airflow that flows radially outward from the center of the centrifugal fan 1. As a result, the flow rate of the air flowing in the axial direction of the centrifugal fan 1 can be increased without increasing noise. Therefore, the ability of the centrifugal fan 1 to cool the field coil 81 of the field iron core 82 and the front coil end of the stator coil 92 is improved.

The opening 5 has two arm-shaped plates that minimize the angle θ formed by two straight lines connecting the outer edges of the adjacent two arm-shaped plates 3 in the rotational direction and the rotation center C of the main plate 2. 3 may be provided.

For example, as shown in FIG. 2, two

adjacent arm plates

31 and 32 are closest to each other among the six arm plates 3. Therefore, a straight line connecting the outer edge 31a on the front side in the rotation direction of the arm plate 31 and the rotation center C of the main plate 2 and a straight line connecting the outer edge 32a on the front side in the rotation direction of the arm plate 32 and the rotation center C of the main plate 2. Is smaller than the angle θ formed by the combination of the other arm-shaped plates 3. Therefore, the opening 5 is provided in one of the two arm-shaped

plates

31 and 32. Here, the opening 5 is provided in the arm-shaped plate 32.

By arranging the opening 5 in this way, the weight of the portion of the centrifugal fan 1 where the adjacent arm plates 3 are approaching can be reduced. Thereby, when the weight distribution in the circumferential direction of the centrifugal fan 1 is biased, it is possible to prevent a rotational load from being applied to the on-vehicle AC generator when the centrifugal fan 1 is rotated.

FIG. 4 is a diagram showing an example of the shape of the opening 5. In FIG. 4, the distance t2 of the shortest part between the outer edge of the opening 5 and the end 3a on the rear side in the rotation direction RD of the arm plate 3 is preferably 1 mm or more. The distance t3 of the shortest portion between the outer edge of the opening 5 and the base of the blade 4 is preferably 1 mm or more. Thereby, the fall of the intensity | strength of the arm-shaped board 3 and the blade | wing 4 can be reduced.

The shape of the opening 5 is not limited to that shown in FIG. For example, the shape of the opening 5 may be circular, elliptical, or polygonal.

In the first embodiment, the opening 5 is provided in the arm-shaped plate 3, but the position of the opening 5 is not limited to this. For example, the opening 5 may be formed over the main plate 2 or may be formed only in the main plate 2. When adjacent arm plates 3 are close to each other, the two adjacent arm plates 3 may be integrated to form the opening 5 in the integrated arm plate 3.

Furthermore, in the first embodiment, the openings 5 are provided in only one arm-like plate 32, but the number of openings 5 is not limited to one. For example, one opening 5 may be provided in each arm-shaped plate 3 or may be disposed every other arm-shaped plate 3 disposed on the circumference. A plurality of openings 5 may be provided in one arm-like plate 3. And you may make the shape of each opening part 5 different. Thereby, the centrifugal fan 1 can be reduced in weight.

The center of gravity of the centrifugal fan 1 can be brought close to the rotation center C by increasing the opening 5 in this way. Thereby, rotation of the centrifugal fan 1 can be stabilized. In this case, the size of the opening 5 provided in each arm plate 3 is determined in consideration of the weight balance in the circumferential direction of the centrifugal fan 1.

Further, the opening 5 may be a notch 6 that opens to the rear side in the rotational direction RD, like the centrifugal fan 1A of the first modification shown in FIG. Furthermore, the opening part 5 is good also as the notch 6B opened to the front side of rotation direction RD like the centrifugal fan 1B of the 2nd modification shown in FIG. In the centrifugal fan 1A of the first modification and the centrifugal fan 1B of the second modification, the same effect as that of the centrifugal fan 1 of the first embodiment can be obtained.

In addition, as for the shape of the centrifugal fan 1A of the 1st modification and the centrifugal fan 1B of the 2nd modification, the width | variety of the circumferential direction of the connection part of arm-shaped

board

3A, 3B and blade |

wing

4A, 4B is narrow. For this reason, the intensity | strength of the connection part of arm-shaped

board

3A, 3B and blade |

wing

4A, 4B falls. Therefore, the lengths of the

notches

6 and 6B in the direction along the

blades

4A and 4B, that is, the depths of the

notches

6 and 6B are preferably about 50% of the length of the

blades

4A and 4B.

Next, an in-vehicle AC generator equipped with the centrifugal fan 1 according to Embodiment 1 of the present invention will be described with reference to FIGS.

FIG. 7 is a view showing the mounting surface S side of the centrifugal fan 1 in the field core 82 of the in-vehicle AC generator. The mounting surface S of the centrifugal fan 1 is provided on the side opposite to the side on which the eight claw-shaped magnetic poles provided in the field iron core 82 extend.

7 indicates a range in which the field winding 81 of the field iron core 82 can be effectively cooled. Therefore, the cooling performance of the centrifugal fan 1 is higher as the portion where the projection area and the area 84 overlap when the centrifugal fan 1 is attached to the attachment surface S and the opening 5 is projected onto the attachment surface S is increased.

The region 84 is formed in a range of a width t1 along the outer edge 83 around the outer edge 83 connecting the two adjacent claw-shaped

magnetic poles

821 and 822. A region 84 in the claw-shaped magnetic pole 821 on the rear side in the rotation direction RD is a range from the rotation center C to the distance Rj1 radially outward. On the other hand, a region 84 in the claw-shaped magnetic pole 822 on the front side in the rotation direction RD is a range from the rotation center C to the distance Rj2 radially outward.

Here, the width t1 of the region 84 is set to 20 mm or less. The region 84 has an outer diameter of the field iron core 82 of R0, a minimum radius of the mounting surface S on the root side of the claw-shaped

magnetic poles

821 and 822, R1, and a maximum of the mounting surface S on the tip side of the claw-shaped

magnetic poles

821 and 822. When the radius is R2, and the larger value of R0 × 0.9 and R2 is R2m,
Rj1 ≦ (R0 + R1) / 2
Rj2 ≦ R2m
Is set to a range that satisfies the above relationship.

In FIG. 7, the negative pressure generated between the root of the claw-shaped magnetic pole 821 of the field iron core 82 and the root of the claw-shaped magnetic pole 822 is the lowest. Therefore, in the region 84, the air flow passing through the side closer to the rotation center C has a higher cooling effect than the air flow passing through the side far from the rotation center C. Thus, region 84 is further
Rj2 ≦ (R0 + R1) / 2
The opening 5 of the centrifugal fan 1 may be formed so as to overlap the region 84.

FIG. 8 is a view showing a state in which the centrifugal fan 1 according to the first embodiment is attached so that the opening 5 of the centrifugal fan 1 overlaps the region 84 of the field iron core 82. FIG. 9 is a view showing a state in which the centrifugal fan 1A of the first modified example is attached so that the notch 6 of the centrifugal fan 1A overlaps the region 84 of the field iron core 82.

By attaching the centrifugal fan 1 and the centrifugal fan 1A to the field iron core 82 in this way, the flow rate of the air flowing in the axial direction is increased without increasing the wind noise generated by the centrifugal fan 1 and the centrifugal fan 1A. Can do. Therefore, the cooling capacity of the field coil 81 of the field iron core 82 and the front side coil ends of the stator coil 92 can be improved. Thereby, the power generation output of the on-vehicle AC generator can be increased.

Next, the result of the effect confirmation by the centrifugal fan 1 according to the first embodiment of the present invention will be described.

The graph of FIG. 10 is a diagram showing the results of measuring noise and power generation output with two types of centrifugal fans attached to the same in-vehicle AC generator. The horizontal axis of the graph indicates the value of the noise N, and the noise value increases toward the right of the horizontal axis. The vertical axis of the graph indicates the value of the power generation output P, and indicates that the value of the power generation output increases toward the top of the vertical axis.

In the graph of FIG. 10, the measured values of the centrifugal fan in which the opening 5 is not provided are indicated by square marks, and the measured values of the centrifugal fan 1 according to Embodiment 1 of the present invention are indicated by triangular marks and circle marks. The opening 5 of the centrifugal fan 1 indicated by a circle is larger than the opening 5 of the centrifugal fan 1 indicated by a triangle.

In addition, the centrifugal fan of the measurement value group F1 connected by the dotted line and the centrifugal fan of the measurement value group F2 connected by the broken line are different in the shape of the blades 4, and the centrifugal fan of F1 is more than the centrifugal fan of F2. The maximum air volume is large.

In the graph of FIG. 10, the measured value of the noise and the measured value of the power generation output of the centrifugal fan in which the opening 5 is not provided, which is indicated by the square mark of the measured value group F1, are each set to “0”.

Referring to the result of FIG. 10, the opening 5 is provided for the measurement value (square mark) of the centrifugal fan in which the opening 5 is not provided in any of the measurement value group F1 and the measurement value group F2. It can be seen that the measured value (triangle mark, circle mark) of the centrifugal fan 1 of the first embodiment has a smaller noise N value and a larger power generation output P value. Further, in both the measurement value group F1 and the measurement value group F2, the measurement value (circle) of the centrifugal fan 1 having the large opening 5 is larger than that of the centrifugal fan 1 having the small opening 5. It can be seen that the value of the noise N is smaller and the value of the power generation output P is larger than the measured value (triangle mark).

As described above, the on-vehicle AC generator to which the centrifugal fan 1 according to Embodiment 1 of the present invention is attached generates noise to the on-vehicle AC generator to which the centrifugal fan not provided with the opening 5 is attached. It was confirmed that the effect of reducing and the effect of improving the power generation output can be obtained. Further, in the in-vehicle AC generator to which the centrifugal fan 1 according to the first embodiment is attached, the effect of reducing noise and the effect of improving power generation output are increased as the size of the opening 5 provided in the centrifugal fan 1 is larger. It was confirmed to be large.

1, 1A, 1B centrifugal fan, 2, 2A, 2B main plate, 2a step, 3, 3A, 3B arm plate, 3a end, 4, 4A, 4B blade, 4a front edge, 4b rear edge, 5

opening

6, 6B cutout, 7 pulley, 8 rotor, 9 stator, 10 slip ring, 11 brush, 12 voltage regulator, 13 rectifier, 17 brush holder, 18 heat sink, 20 connector, 24 circuit board, 24a terminal , 27 Protective cover, 31, 32 Arm-shaped plate, 31a, 32a outer edge, 50 rear housing, 51 front housing, 52 casing, 53 bearing, 54 shaft, 81 field winding, 82 field iron core, 83 outer edge, 84 region 91 stator core, 92 stator winding, 92a lead wire, 821,822 nail shape The pole.

Claims

A main plate formed in an annular shape;
A plurality of arm-shaped plates extending radially outward from the outer periphery of the main plate;
A centrifugal fan comprising blades extending from each of the plurality of arm-shaped plates,
Among each arm-shaped plate and the main plate, at least one plate is provided with an opening through which air passes in the axial direction.
Centrifugal fan.
The opening is provided radially inward of the blade,
The centrifugal fan according to claim 1.
The opening is formed on one of the two arm-shaped plates that has the smallest angle formed by two straight lines connecting the outer edges of the two adjacent arm-shaped plates in the rotational direction and the rotation center of the main plate. Provided,
The centrifugal fan according to claim 1 or 2.
The outer edge of the opening is rounded or chamfered,
The centrifugal fan according to any one of claims 1 to 3.
The distance of the shortest part between the outer edge of the opening and the base of the blade is 1 mm or more,
The centrifugal fan according to any one of claims 1 to 4.
The distance of the shortest part between the outer edge of the opening and the outer edge on the rear side in the rotation direction of the arm-shaped plate is 1 mm or more.
The centrifugal fan according to any one of claims 1 to 5.
The opening is a notch that opens rearward in the rotational direction.
The centrifugal fan according to any one of claims 1 to 5.
The opening is a notch that opens forward in the rotational direction.
The centrifugal fan according to any one of claims 1 to 6.
An on-vehicle AC generator having the centrifugal fan according to any one of claims 1 to 8,
Comprising a field core in which a plurality of claw-shaped magnetic poles are arranged in the circumferential direction
The centrifugal fan is attached to an attachment surface provided on the side opposite to the side on which the plurality of claw-shaped magnetic poles of the field core extends.
The opening is
Projection area when projecting the opening on the mounting surface,
Formed in a shape overlapping the region along the outer edge centering on the outer edge connecting between two adjacent claw-shaped magnetic poles,
The region is
The region of the claw-shaped magnetic pole on the front side in the rotation direction of the field core is a range from the rotation center of the field core to a distance Rj2 radially outward.
The region in the claw-shaped magnetic pole on the rear side in the rotation direction of the field iron core is a range from the rotation center to a distance Rj1 radially outward.
The outer diameter of the field iron core is R0,
R1 is the minimum radius of the mounting surface on the base side of the plurality of claw-shaped magnetic poles,
The maximum radius of the mounting surface on the tip side of the plurality of claw-shaped magnetic poles is R2,
When the larger value of R0 × 0.9 and R2 is R2m,
Rj1 ≦ (R0 + R1) / 2
Rj2 ≦ R2m
Satisfy the relationship
Automotive alternator.
The region further comprises:
Rj2 ≦ (R0 + R1) / 2
Satisfy the relationship
The in-vehicle AC generator according to claim 9.
The width of the region in the direction perpendicular to the outer edge connecting the two adjacent claw-shaped magnetic poles is 20 mm or less,
The in-vehicle AC generator according to claim 9 or 10.