JP3972476B2 - AC generator for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle alternator, and more particularly to a vehicle alternator capable of detecting a rotor absolute angular position.
[0002]
[Prior art]
Japanese Utility Model Laid-Open No. 62-161568 and Japanese Utility Model Laid-Open No. 2-91472 disclose magnet generators with pulsars.
This magnet generator with a pulsar includes a pulsar projection provided on the outer peripheral surface of the rotor core, a yoke member having a tip that can face the pulsar projection and supported by the housing, a pulsar coil wound around the yoke member, And a pulsar permanent magnet that forms a magnetic flux penetrating the pulsar coil through the yoke member and the rotor core. Since these magnet generators with pulsars can detect the predetermined absolute angular position of the rotor, they have the advantage that, for example, it is not necessary to use an independent crank angle sensor to generate the engine ignition signal.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional magnet generator with a pulser, the magnetic path for the pulser formed by the permanent magnet for the pulser and the magnetic path of the permanent magnet (the permanent magnet for power generation) of the magnet generator share the rotor core. There is a problem that leakage flux of the permanent magnet for power generation flows through the pulsar coil in the magnetic path, and the fluctuation of the leakage flux generates a noise voltage, and the structure is complicated and the number of parts is large.
[0004]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an automotive alternator that can obtain a rotor absolute angular position signal that has a simple structure, a small number of parts, and low noise. .
[0005]
[Means for Solving the Problems]
According to the vehicle alternator as set forth in claim 1, the high permeability magnetic pulsar projection fixed to the rotor core is formed at the tip end of the yoke member on the housing side at a predetermined rotor angular position. Forming a magnetic circuit that passes through at least the pulsar projection, yoke member, stator core, rotor / stator gap, and rotor core, and interlinks with a magnetizing means comprising a field coil or field magnet. The pulsar coil wound around is output a pulse voltage indicating the rotor position.
[0006]
The magnetic circuit can also pass through a shaft fixed to the rotor core in addition to the pulsar projection, the yoke member, the stator core, the rotor / stator gap, and the rotor core. For example, the magnetic circuit can be formed via a pulsar projection, a yoke member, a stator core, a rotor / stator gap, a rotor core, a shaft, and a pulsar projection.
[0007]
In this way, it is not necessary for the pulse generating means to be equipped with a dedicated permanent magnet for forming a magnetic flux in the magnetic circuit and a support structure for supporting the permanent magnet, reducing the number of parts and simplifying the structure and assembly process. In addition, the angular position of the rotor can be detected while realizing a reduction in the required space of the pulse generating means in the housing.
In addition, although the magnetic path of the pulse generating means and the magnetic path of the rotating electrical machine share the rotor core and the stator core, the pulse generating means does not have a dedicated permanent magnet as described above. It is possible to prevent the magnetic flux of the permanent magnet and the magnetic field coil of the rotating electrical machine or the magnetic flux of the field magnet from penetrating the pulsar coil and causing the latter magnetic flux to become a noise voltage.
[0008]
Further, in this configuration, since the pulsar projection is fixed to at least the rotor core, preferably the end face thereof, it is possible to easily support the pulsar projection and reduce the magnetic resistance between the pulsar projection and the rotor core.
As a result, according to the present invention, it is possible to realize an automotive alternator that can obtain a rotor absolute angular position signal that has a simple structure, a small number of parts, and low noise.
[0009]
Furthermore , in the present invention , the pulsar projection is fixed to a blowing blade member fixed to the end face of the rotor core.
In this way, even when the end surface of the rotor core is covered with the wing member for blowing, the pulsar projection can be attached to the end surface of the rotor core without any problem, and the pulsar projection is directly fixed to the end surface of the rotor core. Compared to the above, the mounting becomes easier, and the magnetic resistance of the rotor core is not increased.
[0010]
According to the second aspect of the present invention, in the vehicle alternator according to the first aspect , since the pulsar projection is formed integrally with the air wing member, the pulsar projection is formed as compared with the case where the pulsar projection is formed separately. The protrusion manufacturing process and the pulsar protrusion attaching process can be omitted.
According to the configuration of claim 3, in the vehicle alternator according to claim 1 or 2 , the pulsar projection is further provided in the axial direction at the radially inner end of the blower blade member, and the yoke member is In the axial cross section of the generator, it is disposed around the outside of the wing member for blowing air.
[0011]
In this way, the blowing blade member can be provided on the end surface of the rotor core on the side having the pulse generating device without causing any trouble in the operation of the pulse generating device, and the air formed by the blowing blade member is formed. Less disturbs the flow.
According to the fourth aspect of the present invention, the vehicle alternator according to the first aspect further includes a shaft engaging portion that is integrally formed with the pulsar projection and engages the shaft so that the mounting angle can be defined.
[0012]
In this way, the absolute rotational angular position of the pulsar projection can be defined directly on the shaft, not via the rotor core, so that the positioning between the pulsar projection and the rotor core and the alignment between the rotor core and the shaft can be achieved. No positioning is required between the two, and the manufacturing process can be greatly simplified.
According to the fifth aspect of the present invention, in the vehicle alternator according to the fourth aspect of the present invention , the pulsar projection, the air blowing blade member, and the shaft engaging portion are integrally formed.
[0013]
In this way, the number of parts can be further reduced.
According to the configuration of claim 6, in the vehicle alternator according to claim 5 , the shaft further includes a chamfered portion on which the shaft engaging portion is fitted so as to be positioned and a crankshaft of the engine so that the crankshaft can be positioned. And a chamfered portion to be worn.
In this way, the angle between the crankshaft and the pulsar projection can be accurately defined by a very simple manufacturing process.
According to the configuration of claim 7, a cylindrical stator core fixed to the housing, a stator coil wound around the stator core, a rotor core rotatably supported on the housing through a shaft in the stator, and the rotor core In the vehicle alternator, comprising: magnetizing means fixed to form a magnetic pole on the stator facing portion of the rotor core; and pulse generating means for generating a signal voltage at a predetermined absolute angular position of the rotor core. Is supported by the housing with a highly permeable pulsar projection fixed to the rotor core, a distal end portion that can face the pulsar projection at a predetermined rotor angular position, and a proximal end portion that is close to the stator core. Soft magnetic yoke member, a pulsar coil wound around the yoke member, and the pulsar projection A yoke circuit, a stator core, a rotor / stator gap, a magnetic circuit that surrounds the magnetizing means through at least the rotor core, and a shaft engaging portion that is formed integrally with the pulsar projection and engages the shaft so that the mounting angle can be defined. It is characterized by having.
In this way, as described above, the absolute rotation angle position of the pulsar projection can be defined directly on the shaft, not via the rotor core, thereby positioning the pulsar projection between the pulsar projection and the rotor core, and The positioning between the rotor core and the shaft becomes unnecessary, and the manufacturing process can be greatly simplified.
[0014]
In a preferred embodiment, the chamfered portion on the pulsar projection engaging side and the chamfered portion on the crankshaft engaging side are made in the same cutting process, and the positioning between the two chamfered portions can be omitted. It is advantageous. Further, it is simplest if the double-sided portion is a parallel surface or the same plane and is sequentially cut with the same cutting tool.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the invention are illustrated by the following examples.
[0016]
【Example】
Hereinafter, with reference to FIG. 1, the Example of the alternating current generator for vehicles of this invention is described.
(Constitution)
This vehicle alternator is a so-called alternator Randellcore type ordinary three-phase alternator for vehicles, wherein 1 is a housing, 2 is a stator core, 3 is a three-phase stator coil, 4 is a rotor core, and 5 is a field magnet. Coil (magnetizing means), 7 is a rotating shaft (shaft), 8 is a pair of springs, 9 is a brush, 10 is a rectifier, 11 is a centrifugal cooling fan on the front side, 12 is a centrifugal cooling fan on the rear side (air blowing blade member) ). The housing 1 includes a front frame 13 and a rear frame 14, and a rear end opening of the rear frame 14 is shielded by an end cover 15.
[0017]
As shown in FIG. 4, the rotating shaft 7 has a spline portion 71 to which the crankshaft 100 is fitted at a front end portion thereof, and a part of the spline portion 71 serves as a planar chamfered portion 72 for positioning. Yes. The crankshaft 100 also has a spline portion 101, and a part of the spline portion 101 is a planar chamfered portion 72 for positioning. And the rotation angle is determined.
[0018]
Centrifugal cooling fan 12 is formed by press-molding a mild steel plate, has a central hole portion 121 in which rotating shaft 7 is fitted on the inner periphery, and centrifugal blade portion 122 on the outer periphery, and is welded to the rear end surface of rotor core 4. ing.
Since the configuration and operation of the above-described vehicle alternator are well known, further explanation is omitted.
[0019]
Hereinafter, the characteristic part of the vehicle alternator of this embodiment will be described below.
This vehicle alternator includes pulse generation means A that generates a signal voltage at a predetermined absolute angular position of the rotor core 4. The pulse generating means A includes the pulsar projection 16, the yoke member 17, the pulsar coil 18, the stator core 2, the rotor core 4, and the field coil 5 as constituent members.
[0020]
As shown in FIGS. 2 and 3, the pulsar projection 16 is integrally formed on the inner peripheral portion of the centrifugal cooling fan 12. More specifically, it is formed in an L shape in the radial direction and then substantially in the circumferential direction at a predetermined position of the inner peripheral end 121 of the centrifugal cooling fan 12 to form three sides, and the remaining one side is bent at a right angle and protrudes rearward in the axial direction. .
The yoke member 17 is configured by bending a long soft iron piece having a thickness of 0.5 mm and a width of 1 mm. The tip projection 71 of the yoke member 17 can face the pulsar projection 16 with a small gap in the axial direction at a predetermined rotor rotation position, and the base end 172 is in contact with the inner peripheral surface of the rear frame 14. It is press-fitted between the outer peripheral surface of the stator core 2. In order to facilitate the press-fitting, a groove may be provided on either the inner peripheral surface of the rear frame 14 or the outer peripheral surface of the stator core 2. A central portion of the yoke member 17 extends axially rearward from the base end portion 172 along the inner peripheral surface of the rear frame 14, extends radially inward behind the centrifugal cooling fan 12, and further, the rear frame 14. Is extended forward in the axial direction along the outer peripheral surface of the bearing tube 141. In order to fix the position of the yoke member 17, a groove is formed in the axial direction on the outer peripheral surface of the bearing tube portion 141 of the rear frame 14, and the yoke member 17 is accommodated in this groove, or the bearing tube portion 141 of the rear frame 14. Alternatively, the yoke member 17 may be welded.
[0021]
The pulsar coil 18 is wound around the yoke member 17 so as to be positioned outside the diameter of the bearing tube portion 141 of the rear frame 14, that is, in the air suction window of the centrifugal cooling fan 12 that opens toward the rear side.
The operation of this pulse generating means A will be described below.
When the field coil 5 is energized, the pulsar projection 16, the yoke member 17, the stator core 2, the rotor / stator gap, the rotor core 4, and the pulsar projection 16 are formed in this order. At the time of facing the tip 171 of the yoke member 17, the magnetic flux penetrating through the pulsar coil 18 is increased, and a pulse voltage is induced in the pulsar coil 18, whereby the absolute rotational angle position of the crankshaft can be known.
[0022]
In this embodiment, the field current supplied to the field coil does not become zero after the ignition switch is turned on. Of course, a field magnet may be used as the magnetizing means instead of the field coil.
[0023]
[Example 2]
Another embodiment of the vehicle alternator according to the present invention will be described with reference to FIG. In this embodiment, since only the shape of the centrifugal cooling fan 12 is changed in the first embodiment, only the changed portion will be described below.
The crankshaft 7 has a flat chamfer 73 for positioning the angular position of the centrifugal cooling fan 1, and a linear chamfer closely contacting the chamfer 73 on the inner peripheral surface 121 of the centrifugal cooling fan 12. A portion 122 is formed.
[0024]
In this way, the angular position of the pulsar projection 16 can be directly positioned with respect to the rotating shaft 7 without passing through the rotor core 4, and the pulsar projection 16 can be positioned only through the rotating shaft 7.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of an automotive alternator according to the present invention.
FIG. 2 is a partial front view of the centrifugal cooling fan 12 shown in FIG.
3 is a schematic partial plan view of a pulsar projection 16 and a yoke member 17 in FIG.
4 is a radial cross-sectional view showing how the rotary shaft 7 and the crankshaft 100 shown in FIG. 1 are fitted together. FIG.
FIG. 5 is a partial front view of a centrifugal cooling fan 12 according to a second embodiment.
[Explanation of symbols]
1 is a housing, 2 is a stator core, 4 is a rotor core, 5 is a field coil (magnetizing means), 7 is a rotating shaft (shaft), 12 is a centrifugal cooling fan 12 (blade member for air blowing), A is a pulse generating means, 16 Is a pulsar projection, 17 is a yoke member, and 18 is a pulsar coil.

Claims (7)

A cylindrical stator core fixed to the housing, a stator coil wound around the stator core, a rotor core rotatably supported on the housing through a shaft in the stator, and fixed to the rotor core on a stator facing portion of the rotor core In a vehicle AC generator comprising magnetizing means for forming magnetic poles and pulse generating means for generating a signal voltage at a predetermined absolute angular position of the rotor core,
The pulse generating means includes
A highly magnetic pulsar projection fixed to the rotor core;
A soft magnetic yoke member supported by the housing having a distal end portion capable of facing the pulsar projection at a predetermined rotor angular position and a proximal end portion close to the stator core;
A pulsar coil wound around the yoke member;
A magnetic circuit surrounding the magnetizing means through at least the pulsar projection, the yoke member, the stator core, the rotor / stator gap, and the rotor core;
Equipped with a,
The vehicle alternator according to claim 1, wherein the pulsar projection is fixed to a blowing blade member fixed to an end face of the rotor core . In claim 1 Symbol alternator for placing a vehicle,
The vehicle alternator according to claim 1, wherein the pulsar projection is formed integrally with the air blowing blade member. In the vehicle alternator according to claim 1 or 2 ,
A wing member for blowing fixed to an end face of the rotor core;
The pulsar projection is protruded in the axial direction at the inner end of the airfoil wing member,
The vehicular AC generator, wherein the yoke member has a base end portion inserted between the stator core and the housing, and a central portion wrapping around the outside of the air wing member. . In the vehicle alternator according to claim 1 ,
An AC generator for a vehicle, comprising a shaft engaging portion that is formed integrally with the pulsar projection and engages with the shaft so as to define an attachment angle. In the vehicle AC generator according to claim 4 ,
The vehicle alternator according to claim 1, wherein the pulsar projection, the blowing blade member, and the shaft engaging portion are integrally formed. In the vehicle alternator according to claim 5 ,
2. The vehicle alternator according to claim 1, wherein the shaft includes a chamfered portion into which the shaft engaging portion is fitted so as to be positioned and a chamfered portion into which the crankshaft of the engine is fitted so as to be positioned.   A cylindrical stator core fixed to the housing, a stator coil wound around the stator core, a rotor core rotatably supported on the housing through a shaft in the stator, and fixed to the rotor core on a stator facing portion of the rotor core In a vehicle AC generator comprising magnetizing means for forming magnetic poles and pulse generating means for generating a signal voltage at a predetermined absolute angular position of the rotor core,
  The pulse generating means includes
  A highly magnetic pulsar projection fixed to the rotor core;
  A tip portion capable of facing the pulsar projection at a predetermined rotor angular position and the stator core A soft magnetic yoke member having a proximal end portion adjacent to the housing and supported by the housing;
  A pulsar coil wound around the yoke member;
  A magnetic circuit surrounding the magnetizing means through at least the pulsar projection, the yoke member, the stator core, the rotor / stator gap, and the rotor core;
  An AC generator for a vehicle, comprising: a shaft engaging portion that is integrally formed with the pulsar projection and engages with the shaft so as to define an attachment angle.

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