JPH05284702A - Ac generator for vehicle - Google Patents

Abstract

PURPOSE:To facilitate the increase of an output current at the time of a low speed rotation by a method wherein stator tooth parts and the poles of a magnetic pole core are provided along a circumferential direction so as to have four poles correspond to three tooth parts. CONSTITUTION:Tooth parts 310a, 310b and 310c and nail-type poles (IM) 7a, 8a and 8b are provided along a circumferential direction so as to have four poles 7a, 8a and 8b correspond go three tooth parts 310a, 310b and 310c. Magnetic fluxes PHI' are made to pass from the IM 7a which is magnetized to be an N-pole to the S-poles of the IM's 8a and 8b through the tooth part 310a of a stator core 310. The flux PHI' interlinks with the 1 coil 320a of a phase-A which is wound around the tooth part 310a. The IM's 7a, 8a and 8b turn to the direction of an arrow Z and the magnitudes and the directions of the fluxes PHI' vary to induce an electromotive force in the 1 coil 320a of the phase-A. As the IM's turn so as to have the N-pole and the S-pole face the tooth part 310a alternately, an AC electromotive force is induced in the 1 coil 320a of the phase-A. AC electromotive forces are also induced in the 1 coil 320b of a phase-B and the 1 coil 320c of a phase-C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle alternator installed in an engine of a vehicle such as an automobile.

[0002]

2. Description of the Related Art FIG. 4 is a cross-sectional view of a conventional vehicle alternator, in which 31 is a stator core, 32 is a stator coil wound around a stator core 31, and 3 is a stator core 31 fixed to the stator core 31. The stators 1 and 2 including the child coil 32 are a pair of first and second brackets 1a and 2a having a substantially bowl shape.
Are suction holes provided in the end surfaces of the first and second brackets 1 and 2, 1b and 2b are discharge holes provided in the outer peripheral portions of the first and second brackets 1 and 2, and 20 is a first hole. It is a bolt that fits the open ends of the first and second brackets 1 and 2 to both ends of the outer circumference of the stator core 31 and clamps and fixes the stator 3 for clamping.

4, 5 are first and second brackets 1, 1.
Bearings fitted and fixed to the central portions on both side surfaces of 2, 6
Is a shaft rotatably supported by bearings 4 and 5,
Reference numerals 7 and 8 denote magnetic pole cores fixed to the shaft 6 and located inside the stator 3, 9 denotes an exciting coil (not shown) sandwiched between the inner circumferences of the magnetic pole cores 7 and 8, and 10a and 10b denote magnetic pole cores 7, A pair of fans fixed to each end surface of 8 and rotating with the rotation of the shaft 6, 11 a slip ring fixed to the shaft 6, 12 a shaft 6, magnetic pole cores 7 and 8, an exciting coil 9, a fan 10a , 10b and a slip ring 11.

Reference numeral 13 is a current collector for holding a brush 13a which is in sliding contact with the slip ring 11 and is provided on the inner end surface of the second bracket 3, and 14 is a brush 13a.
An exciting current is supplied to the exciting coil 9 through the slip ring 11, and the exciting coil 9 and the exciting cores 7 and 8 are induced in the stator coil 32 by being rotated by the engine (not shown) via the pulley 15. A rectifier that rectifies an alternating current and converts it into a direct current, 14a is a heat sink that radiates heat generated in the rectifier 14, 16 is a voltage regulator that detects a generator voltage, controls an exciting current, and adjusts a terminal voltage to a predetermined value. , 16a are heat sinks that radiate the heat generated by the voltage regulator 16.

FIG. 5 is a schematic view of the stator 3 for explaining the structure of the magnetic circuit and the winding method of the conventional vehicle alternator, and shows the structure of three phases, 12 poles and 36 slots.
The three phases are A phase, B phase, and C phase, respectively, and 32a is 1 of A phase.
Coil, 32b represents one coil of B phase, and 32c represents one coil of C phase. 31a, 31b, 31
c, 31d, 31e, 31f, 31g are stator cores 31
7a and 8a, 8b forming part of the magnetic path of
Is a claw-shaped magnetic pole that constitutes the magnetic pole cores 7 and 8 respectively facing the tooth portions 31a to 31g.
The a is magnetized to the N pole, and the claw-shaped magnetic poles 8a and 8b are magnetized to the S pole.

Next, the operation of the conventional vehicle alternator will be described. By supplying an exciting current to the exciting coil 9 via the brush 13a and the slip ring 11, the claw-shaped magnetic pole 7a is magnetized to the N pole, and the claw-shaped magnetic poles 8a and 8b are magnetized to the S-pole. From the N pole through the tooth portions 31a, 31b, 31c of the stator core 31, the claw-shaped magnetic pole 8a,
The magnetic flux Φ passes through the S pole of 8b. Tooth portions 31a, 31b, 31
Since the A-phase 1 coil 32a is wound around c, the A-phase 1 coil 32a and the teeth 31a, 31b, 31
The magnetic flux Φ passing through c is interlinked, and the claw-shaped magnetic poles 7a, 8a, 8b are rotationally moved in the direction of arrow Z, so that the magnitude and direction of the interlinking magnetic flux Φ are changed. One coil 32 of A phase due to the change of the interlinkage magnetic flux Φ
An induced electromotive force is generated in a. Tooth portions 31a, 31b, 31
c claw-shaped magnetic pole 7a of N pole and claw-shaped magnetic pole 8a of S pole with respect to c,
Since 8b and 8b are alternately moved face-to-face, one coil of A phase 32
AC electromotive force is induced in a, and similarly, one B-phase coil 3
AC electromotive force is also induced in the 2b and 1-phase C coil 32c. Six coils are connected in series to each of the A-phase, B-phase, and C-phase, and the alternating electromotive force induced in each of the six coils is superposed, so that the superposed alternating electromotive force is generated. An alternating current is generated, the alternating current is rectified by the rectifier 14 and output as a direct current, and the voltage at that time is adjusted to a constant value by the voltage regulator 16.

Next, the cooling structure will be described. When the rotor 12 is rotated via the pulley 15 by an engine (not shown), the fans 10 a, 10 fixed to the rotor 12
b is rotated, and the cooling air is drawn into the suction hole 1a of the first bracket 1.
Flows in as shown by an arrow a, cools the bearing 4, the magnetic pole core 7, the exciting coil 9, the stator core 31 and the stator coil 32, and is discharged to the outside from the discharge hole 1b. At the same time, cooling air flows in from the suction hole 2a of the second bracket 2 as shown by the arrow b, and the bearing 5 and the voltage regulator 1
6, the rectifier 14, the magnetic pole core 8, the exciting coil 9, the stator core 31 and the stator coil 32 are cooled and discharged from the discharge hole 2b.

[0008]

According to the conventional vehicular AC generator, the number of the claw portions 7a, 8a, 8b of the magnetic pole cores 7, 8 is 12 and the number of the tooth portions 31a of the stator core 31 is 32. 31
There are 36 b ..., The number of slots of the stator core 31 is large, and the size of the teeth 31a, 31b ... Therefore, in order to improve the quietness in the passenger compartment, the speed increasing ratio of the generator tends to be reduced in order to suppress the noise caused by the fan of the vehicle alternator, and it is difficult to obtain the output current at the predetermined low speed rotation. There was a problem called.

The present invention has been made to solve the above problems, and an object thereof is to obtain a vehicle alternator capable of increasing the current output particularly at low speed rotation.

[0010]

The vehicle alternator of the present invention is one in which the number of magnetic poles of the magnetic pole core is four in the circumferential direction with respect to the number of stator teeth of three. is there.

[0011]

In the present invention, the amount of magnetic flux per magnetic pole of the magnetic pole core increases, so that the output current at low rotation speed increases.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention and is a schematic diagram for explaining the configuration of a magnetic circuit and a winding method.
The configuration of the phase, 12 poles and 9 slots is shown. The three phases are A phase, B phase, and C phase respectively, and 320a is one coil of A phase,
320b is a B-phase one coil, and 320c is a C-phase one coil. 310a, 310b, 310c are the stator core 3
A tooth portion forming a part of the magnetic path 10 has a tooth portion 310a.
A-phase one coil 320a is concentratedly wound around the. In addition, one coil 32 of B phase is provided around the tooth portion 310b.
0b is a C-phase one coil 320c around the tooth portion 310c.
Are concentrated.

FIG. 2 is a diagram obtained by developing and comparing FIGS. 5 and 1 and showing the positional relationship of each of A phase, B phase and C phase.

By the way, the tooth width of the tooth portion 310a in FIG.
Since the tooth width of the tooth portion 31b of the conventional device of FIG. 5 is about 3 times, and the facing area between the claw-shaped magnetic pole 7a and the tooth portion 310a is large, the tooth portion 31a of the conventional device, Three
The amount of magnetic flux per pole, Φ, which is the total of the magnetic fluxes passing through 1b and 31c, has a relationship of Φ ′> Φ, which is the amount of magnetic flux Φ ′ passing through the tooth portion 310a of the embodiment of the present invention. Further, in the conventional apparatus of FIG. 5 and the embodiment of the present invention of FIG.
In the present invention, the ratio of the number of turns in each tooth portion of the phase and the C phase is set to 2 in the present invention in order to make it the same as the number of conductors connected in series in one phase.

In this embodiment, from the claw-shaped magnetic pole 7a magnetized to the N pole, through the tooth portion 310a of the stator core 310,
Since the magnetic flux Φ'passes to the S poles of the claw-shaped magnetic poles 8a and 8b, the A-phase 1 coil 320a wound around the tooth portion 310a and the magnetic flux Φ'link. 7a,
By the rotational movement of 8a and 8b in the direction of arrow Z,
The magnitude and direction of this interlinkage magnetic flux Φ ′ will change, and an induced electromotive force will be generated in the A-phase one coil 320a.
Since the N pole and the S pole alternately move face-to-face with respect to the tooth portion 310a, similarly to the case where the AC electromotive force is induced in the A-phase 1 coil 320a, the B-phase 1 coil 320b and the C-phase 1 coil 320a.
AC electromotive force is also induced in the coil 320c.

In this embodiment, as in the conventional device, A
The same number of conductors are connected in series to the phase, B phase, and C phase, and the alternating electromotive force induced in the coils of the same number of conductors connected in series is superimposed to generate an alternating current. The alternating current is rectified by the rectifier 14 and output as a direct current.

By the way, in a three-phase AC generator such as the conventional device, the one-phase no-load generation voltage V is

V∝Z · f · ΦZ: Number of one-phase series conductors f: Frequency [HZ] Φ: Amount of magnetic flux per pole [wb]

As can be expressed by the following equations, it is proportional to the number of one-phase series conductors Z, the frequency f, and the amount of magnetic flux per pole Φ. Therefore, as shown in one embodiment of the present invention, a three-phase AC generator is used, and the magnetic circuit is configured so that the magnetic flux amount Φ ′ per pole is larger than that of the conventional device, and the one-phase series conductor is used. Since the number Z and the frequency f (that is, the number of poles and the number of revolutions) are the same, the experimental result according to the embodiment of the present invention shows that the output current up to about 1700 rpm increases by about 7 A at the maximum as shown in FIG. Was obtained.

[0020]

As described above, according to the vehicle alternator of the present invention, the number of magnetic poles of the magnetic pole core is four in the circumferential direction with respect to the number of teeth of the stator core being three. Placed in
Since the amount of magnetic flux per magnetic pole is increased, there is an effect that the output current can be increased at a low rotation speed.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a schematic diagram for explaining a magnetic circuit configuration and a winding system of a stator core.

FIG. 2 is a schematic diagram for explaining a winding method in which the embodiment of FIG. 1 is compared with a conventional example.

FIG. 3 is a diagram showing a relationship between a rotation speed and an output current, comparing the embodiment of FIG. 1 with a conventional example.

FIG. 4 is a vertical sectional view showing an example of a conventional vehicle AC generator.

5 is a schematic diagram for explaining a magnetic circuit configuration and a winding system of a stator core in the conventional example of FIG.

[Explanation of symbols]

 7a Claw-shaped magnetic pole 8a Claw-shaped magnetic pole 8c Claw-shaped magnetic pole 310 Stator iron core 310a Teeth 310b Teeth 310c Teeth 320a A-phase 1 coil 320b B-phase 1 coil 320c C-phase 1 coil

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[Procedure amendment]

[Submission date] July 9, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 2

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

Reference numeral 13 is a current collector for holding a brush 13a, which is in sliding contact with the slip ring 11, inside the second bracket 2 , and 14 is a brush 13a.
An exciting current is supplied to the exciting coil 9 through the slip ring 11, and the exciting coil 9 and the exciting cores 7 and 8 are induced in the stator coil 32 by being rotated by the engine (not shown) via the pulley 15. A rectifier that rectifies an alternating current and converts it into a direct current, 14a is a heat sink that radiates heat generated in the rectifier 14, 16 is a voltage regulator that detects a generator voltage, controls an exciting current, and adjusts a terminal voltage to a predetermined value. , 16a are heat sinks that radiate the heat generated by the voltage regulator 16.

Claims (3)

[Claims] 1. An alternating current for a vehicle, comprising: a magnetic pole core fixed to a shaft and excited by an exciting coil; and a stator core surrounding the magnetic pole core and having a three-phase stator coil mounted on its teeth. An alternator for a vehicle, characterized in that, in the generator, the number of magnetic poles of the magnetic pole core is four in the circumferential direction with respect to the number of teeth of three. 2. An AC generator for a vehicle, comprising: a magnetic pole iron core fixed to a shaft and excited by an exciting coil coil; and a stator iron core surrounding the magnetic pole iron core and having a stator coil attached to a tooth portion. , The number of the magnetic poles of the magnetic pole iron core is four in the circumferential direction with respect to the number of the three tooth portions, and one of the three-phase stator coils is provided for each tooth portion. An alternator for vehicles, characterized in that only the stator coils of the phases are wound. 3. The vehicle alternator according to claim 1, wherein a stator coil is concentratedly wound around the tooth portion.