JP2009038843A - Alternator for vehicle and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alternator for reducing iron loss compared with a conventional one. <P>SOLUTION: An alternator for vehicle is provided with a stator iron core made of a laminate steel plate and having teeth and a slot, and a stator having a stator winding disposed on the slot. A portion equivalent to the teeth of a steel plate having 0.05-0.30 mm thickness and a portion equivalent to the slot thereof are formed by etching. Especially, the steel plate is preferably a silicon steel plate having crystal particles. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automotive alternator and a manufacturing method thereof, and typically relates to a technique for reducing iron loss of an automotive alternator.

  As a background art relating to reduction of iron loss, for example, one disclosed in Patent Document 1 is known. Patent Document 1 discloses a technique in which a gap is formed between the stator core and the housing, stress applied to the stator core when the stator core is press-fitted into the housing is reduced, and iron loss is reduced. Has been.

  Patent Documents 2 to 10 disclose techniques for processing a magnetic material by etching.

JP 2004-201428 A JP 2000-197320 A JP 2004-281737 A Japanese Patent Laid-Open No. 2005-300211 JP 2002-078296 A JP 2005-160231 A JP-A-11-155263 JP 09-117083 A Japanese Patent Laid-Open No. 05-284597 JP 09-275007 A

  In recent years, vehicle alternators are required to improve power generation output and power generation efficiency. In such a background, there is an aim of reducing the load on the engine, reducing NOx contained in the exhaust gas of the engine, or improving the fuel consumption of the engine by electrifying the power source of the in-vehicle auxiliary machine. is there.

  As one means for improving the power generation output and power generation efficiency of the AC generator for vehicles, for example, as in the background art, it is considered to reduce the stress applied to the stator core and reduce the iron loss of the stator core. It is done. However, recently, regulations on exhaust gas have become more and more stringent due to consideration for the global environment. Also, recently, demands for improving fuel consumption have become higher due to soaring fuel costs. For this reason, recently, the advent of an automotive alternator that can further reduce the iron loss of the stator core and further improve the power generation output and power generation efficiency over the background art is strongly desired.

  Incidentally, the iron loss can be expressed by the sum of hysteresis loss and eddy current loss. The hysteresis loss is a loss that occurs when the magnetic domain of the magnetic core changes its direction due to an alternating magnetic field, and depends on the area inside the hysteresis curve. Further, eddy current loss is caused by eddy currents generated on the surface of the iron core due to changes in magnetic flux.

  In a stator iron core of an automotive alternator, eddy current loss is reduced by forming a magnetic circuit by laminating a plurality of electromagnetic steel plates obtained by punching thin steel plates. However, in recent research, it has been found that the magnetic steel sheet obtained by punching a thin steel sheet deforms the crystal structure of the cut part and deteriorates the magnetic properties, and the area inside the hysteresis curve increases. did. As a result, it was concluded that the use of the electromagnetic steel sheet obtained by punching a thin steel sheet for the stator iron core of an automotive alternator does not improve the iron loss and the power generation output and power generation efficiency. did.

  A representative one of the present invention provides an automotive alternator capable of reducing iron loss as compared with the conventional one and a method for manufacturing the same.

  Here, a representative one of the present invention is obtained by processing a steel plate, and is opposed to at least the stator core among the respective portions of the iron core plate constituting the stator core by stacking a plurality in the thickness direction. A portion close to the rotor, that is, a portion forming a magnetic pole portion facing the rotor of the stator core is processed by etching.

  As a result, the magnetic pole portion facing the rotor of the stator core is formed by lamination of the iron core plates and a laminated section subjected to processing by etching is formed. The cross-sectional shape of the iron core plate that has been processed by etching is substantially symmetrical with respect to a plane that bisects the iron core plate in the plate thickness direction. Also, the axis of the core plate processed by etching, that is, the direction of the central axis that goes straight in the thickness direction of the core plate and extends toward the cross-section processed by etching of the core plate is It faces in almost the same direction until it reaches the cross section where the processing by etching of the plate is performed.

  According to the representative one of the present invention, since the iron core plate constituting the stator core is processed by etching, the portion forming the magnetic pole portion of the stator core close to the rotor of the iron core plate, that is, the rotation The deformation of the crystal structure in the processed part of the part that greatly contributes to the exchange of magnetic flux with the child can be suppressed, and the deterioration of the magnetic properties in the part of the iron core plate can be suppressed. Thereby, according to the typical thing of this invention, the phenomenon that the area inside a hysteresis curve becomes large can be suppressed.

  In addition, although the typical characteristic and effect of this invention were demonstrated here, the other characteristic and effect of this invention are demonstrated in the best form for implementing the following invention.

  According to the representative one of the present invention, the phenomenon that the area inside the hysteresis curve becomes large can be suppressed, so that the iron loss of the AC generator for a vehicle can be reduced as compared with the conventional case.

  Reduction of the iron loss of the vehicle alternator greatly contributes to the improvement of the power generation output and power generation efficiency of the vehicle alternator, and can greatly contribute to the electrification of the power source of the in-vehicle auxiliary machine. As a result, it can contribute to the reduction of NOx contained in the exhaust gas of the engine (reduction of the influence on the global environment) and the improvement of fuel consumption.

  Embodiments of the present invention will be described below with reference to the drawings.

  In this embodiment, the present invention is applied to an AC generator for a vehicle that is mounted on an automobile, driven by an engine that is an internal combustion engine, and used for charging a battery that is a vehicle-mounted power source and a power source for a vehicle-mounted auxiliary device that is an electric load. This will be described as an example.

  The configuration described below may be applied to a generator other than an automobile. It is particularly suitable for a generator that needs to improve power generation output and power generation efficiency.

  In addition, the configuration described below includes a rotating electric machine that combines an engine start (motor) and battery charging and an on-vehicle auxiliary power source (generator), or a drive assist (motor) for engine start and acceleration. A rotating electrical machine that combines the power of the battery and the on-vehicle auxiliary machine (generator), or an electric motor that drives a wheel (slave wheel) different from the wheel (main wheel) driven by the engine (regenerative power is applied when braking the vehicle). (It may also serve as a generator to perform). In these cases, the rectifier circuit described later is constituted by a switching element, and is replaced with an inverter circuit that converts DC power into AC power.

  In the embodiments described below, terms indicating directions are defined and used as follows using a rotation axis. Here, the axial direction indicates a direction in which the rotation axis extends. The radial direction indicates a direction in which an axis orthogonal to the rotation axis extends. Furthermore, the circumferential direction indicates the direction in which the rotation shaft rotates.

  A first embodiment of the present invention will be described with reference to FIGS.

  First, the configuration of the vehicle alternator of this embodiment will be described with reference to FIGS. 1 to 3.

  As shown in FIG. 1, the vehicle alternator 1 according to this embodiment includes a front bracket 2 arranged on the left side in the drawing and a rear bracket 3 arranged on the right side in the drawing. These brackets are bottomed cylindrical bodies having an accommodation space, that is, members formed into a bowl shape.

  The walls of the front bracket 2 and the rear bracket 3 have a plurality of holes that communicate the outer wall side (outside) and the inner wall side (accommodating space). The plurality of holes are ventilation holes for allowing air supplied and discharged by rotation of a cooling fan, which will be described later, to flow inside and outside the housing. The shape of the holes varies.

  The outer wall of the front bracket 2 and the rear bracket 3 is integrally provided with a fixing portion 5 that protrudes radially outward from the wall surface. The fixing portion 5 is formed with a fixing hole 4 penetrating in the axial direction. Bolts (not shown) are inserted into the fixing holes 4, and the bolts are screwed into screw holes on the side of the casing of the power source, for example, the engine casing. Fixed. As a result, the vehicle alternator 1 is mechanically coupled to the power source in a state of being attached to the casing of the power source.

  A rear cover 6 thinner than the bracket is attached to the axial end of the rear bracket 3 opposite to the front bracket 2 side. The rear cover 6 is a member that covers the axial end surface of the rear bracket 3 opposite to the front bracket 2 side from the axial direction. Like the brackets, the rear cover 6 has a bottomed cylindrical body having a storage space, that is, a bowl shape. It is a molded member.

  The wall facing the axial direction of the rear cover 6 has a plurality of holes that communicate the outer wall side (outside) and the inner wall side (accommodating space). The plurality of holes are air holes for allowing air supplied to and discharged from the inside and outside of the housing by rotation of a cooling fan described later to flow inside and outside the rear cover 6. The shape of the holes varies.

  A terminal 7 is attached to a part of the outer peripheral portion of the wall facing the axial direction of the rear cover 6. The terminal 7 is electrically connected to a rectifier, which will be described later, and is used for taking out the rectified DC voltage to the outside. The terminal 7 projects the rear cover 6 in the axial direction from the axial storage space to the outside. The tip of the terminal 7 is electrically connected to the in-vehicle battery via a harness (electric cable) (not shown).

  An outer ring of a ball bearing 8 a is attached to a substantially central portion of the wall facing the axial direction of the front bracket 2. An outer ring of a ball bearing 8b is attached to a substantially central portion of the wall facing the axial direction of the rear bracket 3. The outer diameter of the ball bearing 8a is larger than the outer diameter of the ball bearing 8b. A shaft 9 is inserted through the inner rings of the ball bearings 8a and 8b. Thereby, the shaft 9 is rotatably supported with respect to the front bracket 2 and the rear bracket 3.

  A pulley 10 is fixed to the front end portion of the shaft 9 on the front bracket 2 side by a bolt. As a result, the shaft 9 rotates integrally with the pulley 10. The pulley 10 is a rotation transmission member, and is connected to a power source, for example, a pulley attached to an engine crankshaft via a belt which is an endless transmission band. As a result, the rotational power of the power source is transmitted to the pulley 10 via the belt.

  The shaft 9 increases in proportion to the rotational speed of the power source in accordance with the rotational speed obtained by multiplying the rotational speed of the power source by the pulley ratio of the pulley 10 and the pulley of the crankshaft, that is, the pulley ratio of the pulley 10 and the pulley of the crankshaft. Rotate according to the number of rotations. Here, the vehicle alternator 1 of the present embodiment has a maximum rotational speed of 10,000 to 100,000 times / minute, preferably 1000 to 20,000 times / minute.

  Two slip rings 11 are juxtaposed in the axial direction on the outer peripheral surface of the portion of the shaft 9 on the rear bracket 3 side that extends to the opposite side of the front bracket 2 from the ball bearing 8b. The slip ring 11 is an annular circular conductive member and rotates integrally with the shaft 9.

  Carbon brushes 12 are arranged on the outer peripheral surfaces of the two slip rings 11. The brush 12 is a rectangular parallelepiped conductive member, is pressed against the slip ring 11 from the side opposite to the slip ring 11 side, and is in sliding contact with the slip ring 11. Thereby, the fixed brush 12 is electrically connected with respect to the rotating slip ring 11, and electric power is exchanged between both.

  A magnetic pole iron core (rotor iron core or field iron core) 13I is fitted to a substantially central portion of the shaft 9 in the axial direction. The magnetic core 13I is composed of a pair of front and rear rotor members 13F and 13R. The rotor members 13F and 13R are obtained by processing and molding a magnetic member, and are individually serrated and coupled to the shaft 9 while facing each other in the axial direction. The opposite end (axially outer side) end of the rotor members 13F and 13R is plastically flowed into an annular groove formed in a corresponding portion in the axial direction of the shaft 9. As a result, the movement of the rotor members 13F and 13R in the axial direction is restricted while the rotor members 13F and 13R are in contact with each other in the axial direction.

  Each of the rotor members 13F and 13R includes a shaft portion 13a and a plurality of claw-shaped magnetic pole portions 13b. The shaft portion 13a is a portion located on the radially inner side of the plurality of claw-shaped magnetic pole portions 13b and fitted on the outer peripheral surface of the shaft 9, and has a short cylinder (a cylinder whose height is shorter than the diameter). It is an iron core. The plurality of claw-shaped magnetic pole portions 13b are portions that are located radially outside of the shaft portion 13a and are integrally formed with the shaft portion 13a, and are iron core portions that have an L-shaped cross section in the circumferential direction. Further, the plurality of claw-shaped magnetic pole portions 13b are arranged at equal intervals in the circumferential direction on the outer peripheral side of the shaft portion 13a, and the shaft at the opposite end portion (the outer end portion in the axial direction) opposite to the opposite side of the rotor members 13F and 13R. The portion 13a extends vertically and radially from the outer peripheral surface of the portion 13a, bends from the middle toward the opposite side of the rotor members 13F and 13R, and extends in the axial direction. The portions of the plurality of claw-shaped magnetic pole portions 13b that are bent and extend in the axial direction correspond to the claw portions at the fingertips of the hand of the heel and gradually increase in radial thickness and circumferential width as they extend from the root to the tip. It has a tapered shape that becomes narrower.

  In the present embodiment, hereinafter, a portion where the plurality of claw-shaped magnetic pole portions 13b are bent and extends in the axial direction is described as a claw portion. The claw portion is a portion of the rotating magnetic pole that is closest to a stator 17 described later, and is a magnetic terminal portion that transfers magnetic flux to and from the stator 17.

  The rotor members 13F and 13R are arranged so that the end faces of the shaft portion 13a in the facing direction are in contact with each other in the axial direction, and the claw portions are alternately arranged in the circumferential direction with a space therebetween. The claw-shaped magnetic pole portion 13b is engaged with each other to form a Rundel type rotor 13. Since the six claw-shaped magnetic pole portions 13b are formed in each of the rotor members 13F and 13R, the number of poles of the rotor 13 is twelve.

  On the outer peripheral side of the claw portion (opposite side to the stator 17 described later), the planar shape viewed from the radial direction is a triangular or trapezoidal curved surface (an arc surface centered on the axial center of the shaft 9). . A plurality of concave portions and a plurality of convex portions are formed on the outer peripheral surface of the claw portion. The concave portions and the convex portions are alternately arranged in the axial direction, and each extend continuously in the circumferential direction. Thus, a plurality of streak-like grooves are formed on the outer peripheral surface of the claw portion.

  The groove (uneven portion) is formed to reduce eddy current flowing on the outer peripheral surface of the claw portion and to reduce eddy current loss which is one of iron losses. The groove (uneven portion) may be formed by performing mechanical processing, for example, cutting or etching processing on the outer peripheral surface of the nail portion and peeling off the outer peripheral surface of the nail portion.

  In machining, a groove extending linearly in one direction can be formed. On the other hand, in the etching process, a groove having any shape can be formed. Fine grooves can also be formed. For example, when a 0.5 mm groove is machined at a pitch of 1 mm, if etching is used, the depth of the groove can be made smaller than that of machining, so that mass productivity can be improved. In order to reduce the eddy current loss, one of the iron losses, and improve the efficiency, the groove formed on the outer peripheral surface of the claw portion is formed by etching, so the groove width can be reduced to 0.1 mm or less. There is no decrease in the equivalent gap length of the circuit, and the eddy current can be reduced efficiently.

  A chamfered portion (beveled) 13c is applied to an edge (a skew portion extending in the axial direction while extending in the rotational direction) on the opposite side (the rear side in the rotational direction) of the outer peripheral surface of the claw portion. At the edge opposite to the rotation direction side of the claw part, the magnetic flux density in the gap between the innermost circumferential side of the stator and the outermost circumferential side of the rotor is large, and the fluctuation of the magnetic flux density due to the slot ripple during rotation is also large. large. When the fluctuation of the magnetic flux density increases, the eddy current loss, which is one of iron losses, increases in proportion to the square of the fluctuation of the magnetic flux density, and the efficiency decreases. In order to solve this, it is necessary to make the magnetic flux density uniform in the vicinity of the edge on the side opposite to the rotation direction of the claw portion and to reduce the fluctuation of the magnetic flux density. Therefore, in this embodiment, the gap between the innermost peripheral side of the stator and the outermost peripheral side of the rotor is increased in the vicinity of the edge opposite to the rotational direction side of the claw portion, and the rotational direction of the claw portion is increased. A chamfered portion 13c is provided on the edge of the claw portion on the side opposite to the rotation direction side so that the magnetic flux density in the vicinity of the edge opposite to the side is made uniform.

  The circumferential width of the chamfered portion 13c is constant from the base to the tip of the claw portion. The angle of the chamfered portion 13c with respect to the plane perpendicular to the radial direction is equal to the angle of the skew portion of the claw portion with respect to the rotation axis. Thus, noise can be reduced by making the angle of the chamfered portion 13c equal to the angle of the skew portion of the claw portion. In this embodiment, the chamfered portion 13c is provided only on the edge (skew portion) on the opposite side (rear side in the rotational direction) of the claw portion, but on the rotational direction side (front side in the rotational direction) of the claw portion. You may provide in the edge (skew part). In this case, the circumferential width of the chamfered portion is smaller than the circumferential width of the chamfered portion 13c.

  On the outer peripheral surface of the shaft portion 13a butted in the axial direction (the gap between the outermost peripheral surface of the shaft portion 13a and the innermost peripheral surface of the claw portion), a field winding 15 is provided via an insulating bobbin. Are wound in the circumferential direction. Both ends of the field winding 15 are led out to the outside through the claw-shaped magnetic pole portions 13b of one of the rotor members 13F and 13R (the one disposed on the slip ring 11 side), and are electrically connected to the slip ring 11 respectively. It is electrically connected to the lead wiring connected to. As a result, the field current supplied to one of the brushes 12 flows to the field winding 15 via one of the slip ring 11 and one of the lead wires, thereby exciting the field winding 15. Thereafter, the field current flows from the field winding 15 to the other side of the brush 12 via the other lead wire and the other slip ring 11. When the field winding 15 is excited by the field current, one of the claw-shaped magnetic pole portions 13b of the rotor members 13F and 13R is magnetized to the N pole, and the other claw-shaped magnetic pole portion 13b is magnetized to the S pole. A magnetic pole is formed.

  A fan 14a is attached to the side end surface of the rotor member 13F opposite to the side facing the rotor member 13R. A fan 14b is attached to the side end surface of the rotor member 13R opposite to the side facing the rotor member 13F. The fans 14a and 14b are centrifugal fans that circulate air that has circulated to the inner peripheral side of a plurality of blades to the outer peripheral side of the blades by centrifugal force, and rotate integrally with the rotor members 13F and 13R. As a result, air flows into the machine through the plurality of ventilation holes located at the inner side of the outer diameter of the blade among the plurality of ventilation holes formed in the front bracket 2, and the outer side of the outer diameter of the blade. Air flows out of the machine through the plurality of ventilation holes at the position. Of the plurality of ventilation holes provided in the rear cover 6 and the plurality of ventilation holes formed in the rear bracket 3, air is introduced into the machine through the plurality of ventilation holes located on the inner side of the outer diameter of the blades. Air flows out and air flows out of the machine through a plurality of ventilation holes located outside the outer diameter of the blades among the plurality of ventilation holes formed in the rear bracket 3. The outside air taken into the machine as a cooling medium cools a stator 17 described later, a rectifier circuit 16 described later, a voltage regulator (IC regulator) not shown, and the like.

  The fan 14a is a metal fan including an annular disk (substrate) welded to the rotor member 13F and a plurality of projection plates (blades) integrally formed on the outer peripheral side of the annular disk. The plurality of protruding plates extend in the radial direction from the outer peripheral side of the annular disk of the fan 14a, and are arranged radially in the circumferential direction. The surface of the front end portion of the plurality of protruding plates (the side opposite to the annular disc side) is formed into a substantially arc shape by pressing, and is inclined in one direction with respect to the surface perpendicular to the radial direction, and the rotor member When attached to 13F, it is bent at a substantially right angle with respect to the annular disk so as to be disposed on the side opposite to the rotor member 13F side.

  The fan 14b is a resin provided with an annular mounting bracket that is welded to the rotor member 13R, and a resin molded body that is molded by an insert molding method so that the welded portion of the annular mounting bracket is exposed and other portions are embedded. Made of fan. The resin molded body has an annular disk (substrate) embedded with an annular mounting bracket so that the welded portion is exposed, and an outer peripheral side of one surface of the annular disk (the surface opposite to the mounting surface to the rotor member 13R). And a plurality of integrally formed blades. The plurality of blades are plate-like members provided perpendicular to the annular disk, and extend in the radial direction from the outer peripheral side of the annular disk toward the inner peripheral side, and gradually in one direction as approaching the inner peripheral side. And are arranged radially in the circumferential direction.

  A stator 17 is disposed opposite to the outer peripheral side of the magnetic pole iron core 13I (rotor 13) that is rotatably supported. A slight gap is provided between the outer peripheral side of the magnetic pole core 13I (rotor 13) and the inner peripheral side of the stator 17. The stator 17 includes a stator core 18 constituting a magnetic path on the stator 17 side, and a stator winding 19 in which a voltage is induced by a magnetic flux flowing through the stator core 18, and the front bracket 2 and the rear bracket 3. It is sandwiched and fixed between the opposite axial end portions from both axial sides.

  As shown in FIG. 3 (b), the stator core 18 includes a core back 181 that is an annular cylindrical core, and a plurality of teeth 182 that are tooth-shaped cores and are provided on the inner peripheral side of the core back 181. It has.

  The core back 181 is provided at the outermost peripheral position of the stator 17 and is a part that connects the plurality of teeth 182 and magnetically connects the plurality of teeth 182, and may also be called a yoke. Steps are formed on the outer periphery of both axial ends of the core back 181. The step is formed in an annular shape, and is engaged with an annular step provided at the opposite axial end portions of the front bracket 2 and the rear bracket 3. Accordingly, the core back 181 is held from both sides in the axial direction by the front bracket 2 and the rear bracket 3 so that the outer peripheral surface thereof is exposed to the outside. As a result, the stator 17 is fixed by the front bracket 2 and the rear bracket 3.

  The plurality of teeth 182 are formed integrally with the core back 181 and are arranged at equal intervals in the circumferential direction so as to project radially from the inner peripheral side of the core back 181 toward the radially inner side (rotor 13 side). Has been. At the tips (inner peripheral ends) of the plurality of teeth 182, extending portions are provided that extend in a divergent shape in both circumferential directions. The plurality of teeth 182 constitutes a fixed magnetic pole closest to the magnetic pole core 13I, and is a magnetic terminal portion that transfers magnetic flux to and from the magnetic pole core 13I.

  A slot 183 for accommodating the stator winding 19 is formed between the teeth 182 adjacent in the circumferential direction. The stator winding 19 is led out from both ends of the stator core 18 in the axial direction to the outside of the slot 183 and turned back, and is again introduced into the inside of the slot 183, that is, on the side surfaces of both ends of the stator core 18 in the axial direction. The coil end portion is housed in the slot 183 so that the coil end portion is formed in the facing region.

  As will be described later, as shown in FIG. 3A, the stator core 18 is formed by laminating a plurality of thin steel plates having a portion corresponding to the core back 181 and a portion corresponding to the teeth 182 in the axial direction. Has been configured.

  The stator winding 19 is formed by star (Y) connection or delta (Δ) connection of three-phase windings of U phase, V phase, and W phase. Each of the three-phase windings is electrically connected to a rectifier circuit 16 attached in the rear cover 6. The rectifier circuit 16 is electrically connected to an in-vehicle electric load including a battery via the terminal 7. The rectifier circuit 16 is a bridge circuit configured by connecting a series circuit for one phase in which two diodes are connected in series for three phases in parallel. The three-phase AC voltage induced in the stator winding 19 is full-wave rectified by the rectifier circuit 16 and converted to a DC voltage. The converted DC voltage is supplied to an on-vehicle electric load including a battery via the terminal 7.

  In this embodiment, the case where the rectifier circuit 16 is configured by a diode bridge circuit has been described as an example. However, a bridge circuit in which the diode is replaced with a switching semiconductor such as a MOSFET (metal oxide semiconductor field effect transistor) is used. The rectifier circuit 16 may be configured.

  There are various methods for winding the stator winding 19 around the stator core 18. In this embodiment, distributed wave winding is adopted. Distributed wave winding is a method in which phase windings wound around a plurality of slots 183 spaced apart in the circumferential direction according to a predetermined pitch (rotating magnetic pole pitch) are wound so as to cross between a plurality of slots 183 in a wave shape. is there. Specifically, when the first slot 183 is crossed over several slots 183 to reach the second slot 183, a winding transition portion is arranged at one end in the axial direction of the stator core 18. In the case where the second slot 183 is crossed over several slots 183 to reach the third slot 183, a transition part of the winding is disposed at the other axial end of the stator core 18. This is a method of winding by repeatedly repeating the state in the circumferential direction.

  In addition, there are two methods for constructing a phase winding of distributed wave winding for a plurality of slots 183 spaced in the circumferential direction according to a predetermined pitch (rotating magnetic pole pitch). One of them is a method of configuring a phase winding by inserting continuous winding conductors from the inner peripheral side (slot opening) of the slot 183 in accordance with the slot order with respect to a plurality of spaced apart slots 183. . The other is that a plurality of segment conductors formed in a U-shape or V-shape are inserted from two axially different slots 183, respectively, and the segment conductors are arranged in the circumferential order. Therefore, it is a method of forming a phase winding by welding between adjacent terminals of segment conductors arranged adjacently in the circumferential direction. In the present embodiment, the case where the latter is adopted will be described as an example, but the former may be adopted.

  As a winding method of the stator winding 19, in addition to the distributed wave winding, a plurality of winding conductors are wound between two slots spaced apart in the circumferential direction according to a predetermined pitch (rotating magnetic pole pitch), Distributed lap windings that form phase windings by electrically connecting in-phase ones, or winding conductors between two slots that are adjacent in the circumferential direction across the teeth. There are concentrated windings that are electrically connected to form a phase winding. These may be adopted instead of the distributed wave winding.

  The winding conductors constituting the stator winding 19 include a round wire having a circular cross section perpendicular to the central axis, a rectangular wire having a rectangular cross section perpendicular to the central axis, and a hexagonal cross section perpendicular to the central axis. There are a square wire and a forming wire formed by flattening a round wire from a relative direction. In this embodiment, the case where a rectangular wire is used as the winding conductor will be described as an example. However, other winding conductors such as a round wire, a polygonal square wire, and a forming wire may be used. If a square wire is adopted as the winding conductor, the winding conductors can be aligned and wound in the slot 183, so that the space factor of the stator winding 19 in the slot 183 can be improved and high efficiency can be achieved. The same effect can be obtained by squashing the round line in the slot 183.

  The surface of the winding conductor constituting the stator winding 19 is provided with enamel insulation coating. Each of the plurality of slots 183 is provided with insulating paper for insulating between the stator core 18 and the stator winding 19.

  Next, the operation of the vehicle alternator 1 of this embodiment will be described.

  When the engine is started and the rotational power of the engine is transmitted from the engine crankshaft to the shaft 9 via the belt and the pulley 10, the rotor 13 rotates. In this state, when a direct current is supplied from the brush 12 to the field winding 15 via the slip ring 11 and the lead wiring, the inside and outside of the field winding 15 are centered on the center of the circumferential cross section of the field winding 15. Magnetic flux that circulates around the circumference is generated. As a result, one of the rotor members 13L and 13R is magnetized to the N pole and the other is magnetized to the S pole. From the claw magnetic pole portion 13b on the N pole side, a gap is formed between the rotor 13 and the stator 17, and the N pole side A gap is formed between the teeth 182 facing the claw portion of the claw magnetic pole portion 13b, the core back 181, the teeth 182 facing the claw portion of the claw magnetic pole portion 13b on the S pole side, and the rotor 13 and the stator 17. A magnetic circuit reaching the claw magnetic pole portion 13b on the S pole side is formed. When the magnetic circuit is formed in this way, the magnetic flux generated by the excitation of the field winding 15 is linked to the winding conductor housed in the slot 183. As a result, an alternating current flows through the winding conductor housed in the slot 183 to induce an alternating voltage. As a result, a three-phase AC voltage is output from the stator winding 19.

  The three-phase AC voltage output from the stator winding 19 is full-wave rectified by the rectifier circuit 16 and converted into a DC voltage. The converted DC voltage is supplied to an on-vehicle electric load including a battery via the terminal 7.

  Note that the magnitude of the AC voltage induced in the stator winding 19 changes in conjunction with the field current supplied to the field winding 15 and the rotational speed of the rotor 13. In order to make the voltage supplied to the in-vehicle electric load including the battery constant, the field current supplied to the field winding 15 is controlled according to the rotation speed of the rotor 13. The field current supplied to the field winding 15 is controlled by a voltage regulator (IC regulator) (not shown). The voltage regulator (IC regulator) is built in the rectifier circuit 16, or provided separately from the rectifier circuit 16 and disposed inside the rear cover 6.

  Next, the structure of the steel plate shown in FIG.

  The plate thickness of the steel plate used for the vehicle alternator is usually 0.30 to 0.6 mm. On the other hand, the thickness of the steel plate of the present embodiment is thinner than the thickness of the steel plate used in a general vehicle AC generator, and is 0.05 to 0.30 mm, preferably 0.1 to 0.2 mm. It is. In this embodiment, the silicon steel plate is etched to form a steel plate having the shape shown in FIG. 3A, that is, a steel plate having the same shape as the core back 181 and the teeth 182. Etching is preferably performed on the entire steel sheet, but a specific portion that affects the characteristics of the generator, at least the inner peripheral end surface of the tooth 182 closest to the rotor 13 (a laminated cross-section, the surface facing the rotor 13) ).

  In this embodiment, photoetching is employed as edging, but other edging may be employed.

  Conventionally, punching is generally employed for forming steel sheets. However, in the punching process, the edge (processed cross section) of the steel plate is plastically deformed, resulting in distortion such as burrs, sagging, and crushing. On the other hand, in the etching process, there is almost no plastic deformation, and distortion such as burrs, sagging and crushing does not occur. A plurality of steel plates formed by edging are laminated in the thickness direction as iron core plates. Thereby, the stator core 18 in which the etching process part was given to the inner peripheral end surface of the teeth 182 at least can be obtained.

  Of each part of the steel plate, at least the cross-sectional shape subjected to the edging process of the part forming the inner peripheral end surface of the tooth 182 closest to the rotor 13 is the surface that bisects the iron core plate in the plate thickness direction. Are almost symmetrical. In other words, the direction of the central axis extending in the direction of the axis of the steel sheet in the relevant part, that is, the direction of the thickness of the iron core plate, and extending toward the cross section where the iron plate is etched is processed by the etching of the iron plate. It faces in almost the same direction until it reaches the cross-section where is marked. In this regard, in the prior art in which a steel plate is formed by punching, the central axis is displaced or the shape of the processed cross section is asymmetric due to distortions such as burrs, sagging and crushing caused by plastic deformation.

  In the stator core 18 of the present embodiment using steel plates formed by edging, the steel sheet thickness (mm) × number of sheets (sheets) ÷ core height (mm) × 100 is defined as the laminated core density (%). The laminated core density is 90.0 to 99.9%, preferably 93.0 to 99.9%. Specifically, the number of steel plates is 80 to 400 (sheets), and the height of the stator core 18 is 20 to 100 mm.

  As a means for improving the laminated core density, it is conceivable to compress a mechanically laminated stator core. However, such means is not preferable because the iron loss increases. In this embodiment, the laminated core density is improved without taking such measures.

The steel sheet has the following composition. That is, C: 0.001 to 0.060% by weight
Mn: 0.1 to 0.6% by weight
P: 0.03 wt% or less S: 0.03 wt% or less Cr: 0.1 wt% or less Al: 0.8 wt% or less Si: 0.5-7.0 wt%
Cu: 0.01 to 0.20% by weight
And the balance consists of inevitable impurities and Fe. Inevitable impurities are oxygen and nitrogen gas components.

The steel plate is preferably a silicon steel plate (magnetic steel plate) having crystal grains, and has the following composition. That is, C: 0.002 to 0.020% by weight
Mn: 0.1 to 0.3% by weight
P: 0.02% by weight or less S: 0.02% by weight or less Cr: 0.05% by weight or less Al: 0.5% by weight or less Si: 0.8 to 6.5% by weight
Cu: 0.01 to 0.1% by weight
And the balance consists of impurities and Fe.

  When determining the composition of the silicon steel sheet, particularly when determining from the viewpoint of reducing iron loss, the contents of Si and Al are important. When Al / Si is defined from such a viewpoint, the ratio is preferably defined to be 0.01 to 0.60. More preferably, it is defined as 0.01 to 0.20.

  Depending on the type of AC generator for vehicles, the AC generator for vehicles in which the silicon concentration of the silicon steel sheet is 0.8 to 2.0% by weight, and the AC for vehicles having 4.5 to 6.5% by weight. It can be properly used for the generator.

  Moreover, the magnetic flux density of the silicon steel sheet is improved by lowering the silicon content. In this embodiment, it can be 1.8 to 2.2T.

Furthermore, when the silicon content is small, the rolling processability is improved. Thereby, since the plate | board thickness of a steel plate can be made thin, an iron loss reduces. On the other hand, when the content of silicon is large, the rolling processability is reduced, but the problem is solved by adding a silicon or the like after the rolling process, and the iron loss is reduced.

  Furthermore, the concentration distribution of silicon contained in the silicon steel plate may be distributed almost uniformly in the thickness direction of the silicon steel plate, but may be partially increased. For example, the surface portion is made higher than the inside in the thickness direction of the silicon steel plate.

  Between the laminated steel plates, an insulating coating having a thickness of 0.01 to 0.2 μm, which is thinner than the thickness of the steel plates, is interposed.

  Depending on the type of AC generator for vehicles, the thickness of the insulating coating interposed between the laminated steel plates is 0.1 to 0.2 μm, preferably 0.12 to 0.18 μm. An AC generator for a vehicle and an AC generator for a vehicle having a diameter of 0.01 to 0.05 μm, preferably 0.02 to 0.04 μm, can be selectively used.

  Further, when the thickness of the insulating coating is 0.1 to 0.2 μm, it is preferable to use an organic or inorganic film as the insulating coating. As the material for the insulating coating, an organic material, an inorganic material, or a hybrid material obtained by mixing these materials can be used.

  In addition, when the thickness of the insulating coating is 0.01 to 0.05 μm, it is preferable to use an oxide coating as the insulating coating. In particular, an iron-based oxide film is preferable.

  Thus, in this embodiment, the thickness of the insulating coating is reduced as the thickness of the silicon steel plate is reduced. This is due to the following reason.

  Conventionally, insulating coatings on electrical steel sheets can be maintained even after punching processing, and at the same time, lubricity to improve punching workability itself, adhesion of steel plates, heat resistance during annealing after punching processing, have been laminated The thickness and components of the insulating film were adjusted in consideration of properties other than insulation, such as weldability when welding an electromagnetic steel plate to form an iron core. For this reason, the thickness of the insulating coating was about 0.3 μm.

  However, when the silicon steel sheet is thinned as in this embodiment, it is necessary to reduce the thickness of the insulating film so that the magnetic flux density does not decrease. This is because when the insulating coating having the same thickness as the conventional one is used for the thinned silicon steel plate, the volume ratio of the insulating coating increases relative to the volume ratio of the silicon steel plate.

  Therefore, in this embodiment, the thickness of the insulating coating is reduced as the thickness of the silicon steel plate is reduced. When thinning the electromagnetic steel sheet, the thickness of the insulating coating is generally increased. However, this example is completely different from such a concept, and even if the electromagnetic steel sheet is thinned, the insulating coating is not thickened. At the same time, the idea is to reduce the thickness. Thereby, in this embodiment, the laminated core density is also improved.

  The vehicle alternator 1 of the present embodiment has a stator core 18 with a diameter of 100 to 300 mm and a maximum output of 200 kW or less, and is operated at a variable speed. The vehicle alternator 1 according to the present embodiment having such a configuration is preferably applied to a vehicle alternator having a maximum rotational speed operating range of about 20000 times / minute (rpm).

  Between the rotation speed and the iron loss, there is a relationship that the higher the rotation speed, the higher the alternating frequency of the magnetic flux and the more the iron loss. For this reason, the alternating current generator for vehicles with a high rotational speed tends to increase the iron loss as compared with a rotating electrical machine with a low rotational speed. Therefore, in the AC generator for vehicles, it is necessary to consider the content of silicon in the silicon steel sheet in consideration of such points.

  Silicon contained in the silicon steel sheet may be uniformly added to the electromagnetic steel sheet by a melting method, but it is locally added to the electromagnetic steel sheet by a method such as surface modification, ion implantation, or CVD (chemical vapor deposit). For example, you may make it add to a surface part rather than the inside of an electromagnetic steel plate.

  Further, the electrical steel sheet of the present example is used on the stator core 18 that constitutes the stator 17 and has the teeth 182 and the slots 183, and has a thickness of 0.05 to 0.05. The teeth 182 and the slots 183 can be formed by 0.30 mm by etching.

  In the etching process, a resist is applied to an electromagnetic steel sheet having a width of 100 to 300 cm, the shape of the teeth 182 and the slot 183 is exposed and developed on the electromagnetic steel sheet, and the resist is removed based on the shape of the teeth 182 and the slot 183. Then, the portion where the resist is removed by the etching solution is dissolved to form the electromagnetic steel sheet into the shape of the stator core, and then the remaining resist is removed.

  Vehicle alternators are being improved in efficiency and performance by applying rare earth magnets and optimal design using three-dimensional magnetic field analysis. In order to further improve the efficiency and performance of automotive alternators, it is necessary to develop new material technologies. As for the electromagnetic steel sheet, which is a material for the stator core, a material having a high magnetic flux density and a low iron loss is being developed as represented by a silicon steel sheet.

  The thinning of silicon steel sheets, which is advantageous for reducing iron loss, has resulted in a significant increase in cost on an industrial scale due to poor rolling workability of silicon steel sheets and poor punching workability, which is a process for punching silicon steel sheets. It has been considered impossible to achieve without this. For this reason, when silicon steel sheets are used as electromagnetic steel sheets for high efficiency and high performance AC generators for small and medium-sized vehicles, the thicknesses of silicon steel sheets are centered on 0.50 mm and 0.35 mm for a long time. There was no progress in thinning the silicon steel sheet.

  However, in this example, the punching process was not used for forming the silicon steel sheet, and the etching process was used, thereby enabling the silicon steel sheet to be thinned without significantly increasing the cost on an industrial scale. Reduced loss.

  In this example, in order to reduce the iron loss of the stator core, in addition to the use of a silicon steel plate with a small iron loss, the adjustment of the silicon content in consideration of the rolling process, the plate in consideration of the rolling process of the silicon steel plate Considering the thickness reduction, forming of silicon steel sheet by applying etching process, reducing the iron loss of each silicon steel sheet constituting the laminated core, and the insulation film formed between silicon steel sheet and silicon steel sheet Considering reduction of iron loss of laminated core.

  In punching, which is a punching method using a mold, a work-hardened layer, a plastic deformation layer called burr or sagging (hereinafter referred to as “burr etc.”) is formed in the vicinity of the cut portion, and residual strain or Residual stress is generated. The residual stress generated during the punching process destroys the regularity of the arrangement of the molecular magnets, that is, destroys the magnetic domains and significantly increases the iron loss. An annealing process is required to remove the residual stress. However, the annealing process results in a further increase in the manufacturing cost of the stator core.

  On the other hand, in this embodiment, the plastic deformation layer is hardly formed, and residual strain and residual stress are not generated. Therefore, the arrangement state of the crystal particles is hardly disturbed, the damage of the arrangement of the molecular magnets, that is, the arrangement of the magnetic domains can be prevented, and the deterioration of the hysteresis characteristic which is a magnetic characteristic can be prevented.

  The stator core 18 is formed by laminating processed silicon steel plates. The magnetic characteristics of the stator core 18 can be further improved by suppressing the occurrence of residual strain and residual stress of the laminated silicon steel plates.

  Therefore, the vehicular AC generator of the present embodiment can realize low iron loss, high output, and small size and light weight. Moreover, the electromagnetic steel sheet used for the vehicle AC generator is a good one having almost no burrs at the edge portion.

  A burr or the like is one of the plastic deformation layers and projects sharply in the spatial direction from the plane direction of the steel sheet along the cut part. May break the insulation.

  Moreover, since an unnecessary space | gap is made between the laminated steel plates by a burr | flash etc., the increase in a laminated iron core density is inhibited, As a result, a magnetic flux density falls. The decrease in magnetic flux density hinders the reduction in size and weight of an automotive alternator.

  After laminating electromagnetic steel sheets, it is conceivable to compress the iron core in the thickness direction to crush burrs and improve the density of the laminated iron core, but the residual stress increases due to pressure compression and the iron loss increases, The problem of dielectric breakdown due to burrs and the like remains.

  In this embodiment, since burrs and the like hardly occur, the laminated core density can be improved without causing pressure compression, and dielectric breakdown does not occur. Therefore, iron loss can be reduced in this embodiment.

  Theoretically, the iron loss is lowest when the silicon content in the silicon steel sheet is 6.5% by weight. However, when the silicon content increases, rolling workability and punching workability are remarkably deteriorated. For this reason, even if the iron loss is somewhat high, considering the rolling workability and punching workability, the silicon content in the silicon steel sheet is generally about 3.0% by weight.

  In this embodiment, since the thickness of the silicon steel sheet can be reduced to 0.3 mm or less, the iron loss can be reduced even if the silicon content is 2.0% by weight or less.

  Conventionally, when the thickness of the silicon steel sheet is set to 0.3 mm or less, special processes such as rolling and annealing have been required for the production of the silicon steel sheet. On the other hand, in the manufacture of the silicon steel sheet of this embodiment, such a special process is not required, so that the manufacturing cost of the silicon steel sheet can be reduced. Moreover, in the manufacture of the stator core according to the present embodiment, punching is not required, so that the manufacturing cost can be further reduced.

  An amorphous material is known as a magnetic material different from the silicon steel plate which is the main material of the stator core. Amorphous materials are limited in use for special applications as ultrathin electromagnetic materials, and are extremely expensive. In addition, since amorphous materials have a special process for rapidly solidifying molten metal to produce foils, it is possible to produce ultra-thin 0.05mm thickness or less and very small quantities of about 300mm width. However, it is considered impossible to manufacture materials with a thickness or width greater than this on an industrial scale.

  As described above, the amorphous material is a hard and brittle material and is too thin, so that punching cannot be performed, and the magnetic flux density is low due to the restriction of chemical components, and thus cannot be the main material of the stator core.

  Unlike such an amorphous material, the electromagnetic steel plate of this example has crystal particles.

  In addition, the electrical steel sheet of this example is thin, which is advantageous for low iron loss, reduced distortion, high output, improved dimensional accuracy, which is advantageous for miniaturization and weight reduction, and core lamination density, which is advantageous for high magnetic flux density. It is also possible to simultaneously improve

  According to the present embodiment, it is possible to provide a stator core that can realize high output, small size and light weight as well as reduction of iron loss.

  Here, the relationship between the thickness of the magnetic steel sheet and the iron loss is shown in FIG.

  As is apparent from FIG. 4, there is a relationship between the plate thickness and the iron loss that the iron loss increases as the plate thickness increases.

  Among the thicknesses of silicon steel plates, the thicknesses of general silicon steel plates are two types of 0.50 mm and 0.35 mm in consideration of rolling and punching workability.

  In silicon steel plates having two types of thicknesses widely used in the manufacture of stator cores, it is necessary to perform rolling and annealing in order to reduce iron loss. Further, in order to realize further thinning, it is necessary to repeat rolling and annealing although the number of repetitions varies depending on the shape and size of the target stator core. Thus, in a general silicon steel sheet, it is necessary to add special processes such as rolling and annealing in order to realize thinning. Therefore, with a general silicon steel sheet, the manufacturing cost becomes high.

  Since the stator core of the present embodiment can reduce the manufacturing cost and solve the problem in processing the silicon steel sheet, it can be mass-produced on an industrial scale.

  In this embodiment, the stator core is manufactured using a silicon steel plate having a thickness of 0.05 to 0.30 mm. Preferably, a silicon steel plate having a thickness of 0.1 to 0.2 mm is used and formed into the shape of a stator core by etching.

  For reference, FIG. 4 also shows the thickness region of the amorphous material. Amorphous material has a special process for rapidly solidifying molten metal and is manufactured as a foil, so it is suitable for the manufacture of ultrathin plate thicknesses of 0.05 mm or less, It is not suitable for manufacturing a plate thickness larger than this because rapid cooling becomes difficult. Further, only a narrow plate having a width of about 300 mm can be manufactured, and the manufacturing cost is significantly increased in combination with a special manufacturing process.

  In addition, the amorphous material can reduce the iron loss, but the magnetic flux density also decreases. This is because chemical components are limited due to the special manufacturing process of solidifying by rapid cooling.

  In this embodiment, a silicon steel plate having crystal particles is used without using an amorphous material.

  Next, a typical manufacturing process of a silicon steel plate will be described.

Steel sheet material that can be used for electrical steel sheets is manufactured. For example, a steel plate material having the following composition is used. That is, C: 0.005% by weight
Mn: 0.2% by weight
P: 0.02% by weight
S: 0.02% by weight
Cr: 0.03 wt%
Al: 0.03 wt%
Si: 2.0% by weight
Cu: 0.01% by weight
A steel plate material is used, the balance being Fe and some impurities.

  Then, the steel plate material is subjected to continuous casting, hot rolling, continuous annealing, pickling, cold rolling, and continuous annealing, so that silicon having a plate width of 50 to 200 cm, in particular, a plate width of 50 cm and a plate thickness of 0.2 mm. Manufacture steel sheets.

  Further, 4.5 to 6.5% by weight of silicon may be added to the surface of the silicon steel sheet to reduce the iron loss.

  Thereafter, an organic resin having a thickness of 0.1 μm is coated on the surface of the silicon steel plate to produce a silicon steel plate with an insulating coating.

  Alternatively, an oxide film having a thickness of 0.01 to 0.05 μm may be formed on the surface of the silicon steel sheet without performing a special insulating film coating.

  The insulating coating is preferably applied after the etching process.

  The silicon steel plate is formed in a flat plate shape, a coil shape, or a roll shape.

  Next, a typical manufacturing process of the stator core will be described.

  First, a pretreatment is performed on the manufactured silicon steel sheet, and a resist is applied to the surface of the silicon steel sheet. Next, the resist is exposed to the shape of the teeth and the slot using a mask and developed, and the resist is removed based on the shape of the teeth and the shape of the slot. Next, it processes with an etching liquid. Thereafter, the remaining resist is removed, and a silicon steel sheet having a desired tooth shape and slot shape is manufactured. For such production, for example, photo-etching is effective, and it is also effective to use a method of precisely processing fine holes using a metal mask.

  Next, a plurality of silicon steel plates having the desired teeth shape and slot shape are laminated, and the laminated silicon steel plates are fixed by welding or the like, thereby manufacturing a stator core.

  In addition, in welding, it is preferable to perform welding with little heat input, such as a fiber laser.

  Further, a rotor core and a stator core can be sampled simultaneously from a silicon steel plate formed in a flat plate shape, a coil shape, or a roll shape, and a plurality of shapes of iron cores can be sampled simultaneously.

  A silicon steel sheet having teeth and slots of a desired shape with extremely high processing accuracy, for example, an error of ± 10 μm or less, preferably ± 5 μm or less, by forming a silicon steel sheet having a tooth shape and a slot shape by etching. Can be manufactured.

  Further, when the error is expressed by roundness, it is 30 μm or less, preferably 15 μm or less, more preferably 10 μm or less. Roundness refers to the magnitude of deviation from a geometric circle in a circular part. When the circular part is sandwiched between two concentric geometric circles, the area between the two circles is minimized. The difference in radius.

  Here, the relationship between the silicon content and the iron loss in the silicon steel sheet is shown in FIG.

  As is apparent from FIG. 5, the silicon steel sheet having a silicon content of 6.5% by weight has the smallest iron loss. However, with a silicon steel plate having a large amount of silicon of 6.5% by weight, rolling is difficult, and it becomes difficult to manufacture a silicon steel plate having a desired thickness. Rolling workability tends to deteriorate as the amount of silicon contained in the electromagnetic steel plate increases. From such a background, in this embodiment, a silicon steel sheet containing 3.0% by weight of silicon is used in consideration of the balance between iron loss and rolling workability.

  In this embodiment, the thickness of the silicon steel plate is reduced to reduce the iron loss of the silicon steel plate, and the influence of the iron loss based on the silicon content is reduced.

  Therefore, the silicon steel sheet of this example has good rolling processability, and by reducing the thickness of the sheet, the degree of freedom of silicon content in the silicon steel sheet having a large influence of iron loss increases. As a result, the silicon content in the silicon steel sheet can be in the range of 0.5 to 7.0 wt%, such as 0.8 to 2.0 wt% and 4.5 to 6.5 wt%. The silicon steel sheets having extremely different contents can be selectively used depending on the specification of the stator core or the use of the AC generator for the vehicle.

  Next, the processed cross-sectional shape of the silicon steel sheet will be described with reference to FIGS. FIG. 6 shows a typical processed cross-sectional shape by etching. FIG. 7 shows a typical processed cross-sectional shape by punching.

  As shown in FIG. 6 (a), the silicon steel sheet is etched, there is no plastic deformation layer such as burrs in the vicinity of the processed cross section dissolved with the acid solution, and the processed cross section is in the thickness direction of the silicon steel sheet. It can be formed substantially perpendicular to the plane.

  Further, in the advanced photoetching process, the shape of the dissolved portion can be controlled as shown in FIGS. That is, a predetermined taper can be formed, or irregularities can be formed in a direction perpendicular to the plate thickness direction. Here, FIG. 6B is an arc-shaped convex section, FIG. 6C is an arc-shaped concave section, and FIG. 6D is a V-shaped convex section.

  The etched silicon steel sheet has almost no residual stress due to the processing, and there is almost no plastic deformation layer, the amount of plastic deformation in the plate thickness direction, and the amount of plastic deformation in the vicinity of the processed cross section is almost zero. is there.

  Further, in the etching process, the shape of the processed cross section of the silicon steel sheet can be controlled, and a cut cross sectional shape can be formed in which the residual stress due to the processing is almost zero and the plastic deformation amount in the vicinity of the processed cross section is almost zero. .

  Further, in the etching process, the fine crystal structure, mechanical characteristics, and surface portion of the silicon steel sheet can be optimized. Thereby, it is possible to optimize the magnetic characteristics of the stator core in consideration of the anisotropy of the crystal structure of the silicon steel sheet and the anisotropy of the magnetic characteristics based thereon.

  On the other hand, as shown in FIG. 7, in the case of punching a silicon steel plate, the vicinity of the processed cross section is remarkably deformed by shear stress during plastic processing, and burrs, sagging, and crushing of about 10 to 100 μm are formed.

  In punching, the dimensional accuracy of the silicon steel plate in the plate thickness direction is limited by the dimensional accuracy of the mold, and is usually sheared with a gap of about 5% of the plate thickness of the silicon steel plate. The dimensional accuracy in the thickness direction decreases. In punching, the accuracy decreases with time due to wear of the mold during mass production. Furthermore, in the punching process, the thinner the silicon steel sheet, the more difficult it is to process.

  However, in this embodiment to which the etching process is applied, such a problem of the processing accuracy is solved, and the deterioration of the accuracy with time is also eliminated.

  In the etching process, it is preferable to provide a mark or a reference hole related to the rolling direction of the electrical steel sheet when the teeth and slots are exposed using a predetermined pattern.

  When laminating electromagnetic steel sheets, it is necessary to average the electromagnetic steel sheets in the rolling direction in order to improve the characteristics of the AC generator for vehicles. For example, when the magnetic steel sheets are laminated by changing the position of the mark or the reference hole by a predetermined amount with respect to the rolling direction, the magnetic characteristics of the vehicle AC generator are improved by aligning the position of the mark or the reference hole.

  The structure of the electromagnetic steel sheet forming the stator core 18 and the manufacturing method thereof have been described above, but the rotor 13 is also laminated with a steel sheet having a thickness of 0.05 to 0.30 mm from the viewpoint of improving the magnetic properties. Thus, it is desirable to form the magnetic pole core 13I. However, with the Rundel type rotor 13, the magnetic core 13I is manufactured by bending a thick plate so that deformation of the claw magnetic pole portion 13b can be suppressed as much as possible even if a large centrifugal force acts on the claw magnetic pole portion 13b during high-speed rotation. is doing. For this reason, in this embodiment, a groove is provided on the surface of the claw magnetic pole portion 13b facing the stator 17 by etching. As a result, in this embodiment, it is possible to prevent the regular crystal arrangement from being broken and to prevent an increase in hysteresis loss.

  In the formation of a steel sheet by punching, the thinner the steel sheet, the greater the disorder of the cut portion, for example, the crushing, burrs, and sagging, and the hysteresis loss increases. In punching processing, only a simple shape such as a circle or a straight line can be processed. This is because it is extremely difficult to form a mold necessary for punching into a complicated curve. Further, when polishing a mold, a mold having a complicated curved shape cannot be polished well. For this reason, in punching, the electromagnetic steel sheet can be thinned for the purpose of reducing eddy current loss, but hysteresis loss increases and iron loss cannot be reduced. On the other hand, the etching process can suppress hysteresis loss and reduce eddy current loss.

  In the vehicle alternator 1 of the present embodiment, the groove provided on the surface of the claw magnetic pole portion 13b facing the stator 17 is formed by etching, so that the overall efficiency of the vehicle alternator can be further improved. it can. Etching has the effect of improving the characteristics of the AC generator for vehicles by greatly improving the processing accuracy, in addition to the effect of preventing the breakage of the regular crystal arrangement in the steel sheet and reducing the hysteresis loss. In addition, if only the efficiency is improved by etching the opposing portions of the stator core 18 and the magnetic pole core 13I so that the shape of the gap between the stator core 18 and the magnetic core 13I becomes high accuracy, In addition, effects such as improved performance such as reduced pulsation and improved noise characteristics can be expected.

  The stator winding is preferably a three-phase winding. If a three-phase winding is used, the efficiency of the vehicle alternator is improved. In addition to this, if the stator core is etched, the efficiency of the entire vehicle AC generator is further improved.

  Furthermore, in this embodiment, the laminated core density of the stator core is 90.0 to 99.9%. Preferably it is 93.0 to 99.9%. The laminated core density can also be improved by compressing mechanically laminated cores. However, the method of compressing the laminated iron cores is not preferable because the iron loss increases. In this embodiment, the laminated core density can be improved without providing such a special process.

  A second embodiment of the present invention will be described with reference to FIGS.

  In addition, the same code | symbol as the previous example is attached | subjected to the structure similar to a previous example, the same name is used, and the description is abbreviate | omitted.

  First, the structure of the stator 17 is demonstrated using FIG. 8 thru | or FIG.

  In the present embodiment, the iron core unit shown in FIG. 9 is configured for each of the three phases of the U phase, the V phase, and the W phase, and the iron core units of each phase are arranged side by side in the axial direction. A stator 17 is configured. In the following description, the U-phase stator 17U will be described, but the other-phase stators have the same configuration.

  The U-phase stator 17U includes a stator core 18U and a stator winding 19U as its constituent elements, as in the previous example. However, the shape of the stator core 18U and the winding state of the stator winding 19U are greatly different from the previous examples.

  The stator core 18U is configured such that a pair of stator core members 18a and 18b divided in the axial direction is opposed to each other in the axial direction. The stator core members 18a and 18b are respectively a core back 184 that is an annular short cylindrical core and a plurality of stator claw magnetic poles 185 that are claw-shaped magnetic cores and are provided on the inner peripheral side of the core back 184. And the overall cross-sectional shape in the circumferential direction is a U-shape.

  The core back 184 is provided at the outermost peripheral position of the U-phase stator 17U and is a part that magnetically connects the plurality of stator claw magnetic poles 185.

  The plurality of stator claw magnetic poles 185 are portions formed integrally with the core back 184, and are iron core portions whose cross-sectional shape in the circumferential direction is L-shaped. Further, the plurality of stator claw magnetic poles 185 are arranged at equal intervals in the circumferential direction on the inner circumferential side of the core back 184, and are perpendicular to the radially inner side (rotor 13 side) from the inner circumferential side of the core back 184. While extending radially, it bends substantially perpendicularly from the middle toward the opposite side of the stator core members 18a, 18b and extends in the axial direction. The portions of the plurality of stator claw magnetic poles 185 that are bent and extend in the axial direction correspond to the claw portions at the fingertips of the hand of the heel, and have a tapered shape that gradually decreases in width in the circumferential direction from the root to the tip ( Skew shape).

  In the present embodiment, hereinafter, a portion where the plurality of stator magnetic poles 185 are bent and extends in the axial direction is described as a claw portion. The claw portion is a portion that is closest to the rotor 136 among the portions of the fixed magnetic pole, and is a magnetic terminal portion that transfers magnetic flux to and from the rotor 13.

  The stator core members 18a, 18b are in contact with each other so that the end faces of the core back 184 in the facing direction are in contact with each other in the axial direction, and the claws are alternately arranged in the circumferential direction with a space therebetween. When the stator claw magnetic poles 185 are engaged with each other, a claw pole type or claw teeth type 185 U-phase stator 17U is formed. Since six stator claw magnetic poles 185 are formed on each of the stator core members 18a and 18b, the number of poles of the U-phase stator 17U is 12 and the same as the number of magnetic poles of the rotor.

  The stator core members 18a and 18b are welded to the contact portions between the core backs 184 with the stator winding 19U mounted therein, or resin is formed in a gap formed between the stator claw magnetic poles 185. It is fixed by filling and molding. Further, by forming engaging portions, for example, irregularities or providing marks on the contact surfaces of the core backs 184, the circumferential positioning of both members is facilitated.

  The inner peripheral side of the claw portion (the side facing the rotor 13) is a curved surface (arc surface centered on the central axis of the shaft 9) having a triangular or trapezoidal planar shape when viewed from the radial direction. A plurality of concave portions and a plurality of convex portions are formed on the inner peripheral front surface of the claw portion. The concave portions and the convex portions are alternately arranged in the axial direction and the circumferential direction. The concavo-convex portions alternately arranged in the axial direction respectively extend continuously in the circumferential direction. The uneven portions alternately arranged in the circumferential direction continuously extend radially from the tip of the claw portion toward the root so as to follow the skew shape of the claw portion. As a result, a plurality of intersecting grooves are formed on the inner peripheral surface of the claw portion.

  As will be described later, the stator core 18U is configured by laminating a plurality of thin steel plates each having a portion corresponding to the core back 184 and a portion corresponding to the stator magnetic pole 185 in the thickness direction. . Further, since the cross-sectional shape in the circumferential direction of the stator core 18U is U-shaped, the stacking direction of the claw portions of the core back 184 and the stator magnetic pole 185 is radial, and the claw portion of the stator magnetic pole 185 and the core back 184 are connected. The stacking direction of the connecting portions is the axial direction.

  The stator winding 19U (U-phase winding) is annularly wound in a space formed between the inner peripheral side of the core back 184 and the outer peripheral side of the stator claw magnetic pole 185. The winding conductors constituting the stator winding 19U include a round wire having a circular cross section perpendicular to the central axis, a rectangular wire having a rectangular cross section perpendicular to the central axis, and a hexagonal cross section perpendicular to the central axis. Either a square wire or a round wire is crushed from the relative direction to form a flat wire. Here, if a square wire is adopted as the winding conductor, the winding conductor is aligned and wound in the space between the inner peripheral side of the core back 184 and the outer peripheral side of the stator claw magnetic pole 185, and therefore the core back 184 is wound. The space factor of the stator winding 19U in the space between the inner peripheral side of the stator and the outer peripheral side of the stator claw magnetic pole 185 is improved, and high efficiency can be achieved. The same effect can be obtained by squashing the round line in the space between the inner peripheral side of the core back 184 and the outer peripheral side of the stator claw magnetic pole 185.

  An enamel insulation coating is applied to the surface of the winding conductor constituting the stator winding 19U. Insulating paper for insulating between the stator core 18U and the stator winding 19U is mounted in the space between the inner peripheral side of the core back 184 and the outer peripheral side of the stator claw magnetic pole 185. In addition, the stator core 18U and the stator winding 19U are insulated from each other by winding the stator winding 19U around a bobbin which is a resin molded product (non-magnetic material) and connecting this to the inner peripheral side of the core back 184. It can also be ensured by mounting it in the space between the stator claw magnetic pole 185 and the outer peripheral side.

  The stator core 18U is configured by laminating steel plates having a thickness of 0.05 to 0.30 mm, as in the previous example.

  As shown in FIG. 10, the steel plate of this example is formed by etching. The steel plate has an annular disc portion 186 formed in an annular shape, and six convex plate portions that protrude radially from the inner peripheral side of the annular disc portion 186 toward the radially inner side and are arranged at equal intervals in the circumferential direction. 187. The annular disk portion 186 eventually becomes the core back 184 and is formed in the same shape as the core back 184. The convex plate portion 187 eventually becomes the stator claw magnetic pole 185 and is formed in the same shape as the stator claw magnetic pole 185.

  The surface of the convex plate portion 187 is slitted to form a plurality of concave and convex portions. The plurality of concavo-convex portions form the above-described intersecting grooves, and are formed in a plurality of width direction grooves extending in the circumferential width direction of the convex plate portion 187 and radially from the tip of the convex plate portion 187 toward the root. A plurality of radial grooves extending in the radial direction are formed so as to intersect each other. These grooves are formed by etching simultaneously with the etching of the steel sheet. The depth of each groove is shallower than the thickness of the steel plate. When these grooves are formed by etching, the depth of the grooves can be processed very shallow. In addition, if these grooves are formed by etching, the grooves can be formed simultaneously with the forming of the steel sheet, and the manufacturing process can be reduced as much as possible. However, considering the ease of the manufacturing process, the steel sheet manufacturing process and the groove manufacturing process are performed. It may be divided. Also, when designing a magnetic circuit, if the frequency is low, the effect of reducing the eddy current is greater when the groove depth is increased. In this case, the grooves may be completely narrowed, but it is necessary to devise the shape of the intersecting grooves so as to form a continuous steel plate.

  As described above, in this embodiment, grooves are provided in the convex plate portion 187 to prevent eddy currents. When the groove is not provided in the convex plate portion 187, an eddy current freely flows on the surface of the stator claw magnetic pole 185 formed by bending a steel plate. The intersecting grooves are formed to reduce eddy current flowing on the surface of the convex plate portion 187 and reduce eddy current loss which is one of iron losses. The intersecting grooves are formed by performing etching on the surface of the convex plate portion 187 and peeling off the surface of the convex plate portion 187.

  If the groove that inhibits eddy current is etched on the surface of the laminated steel sheet as in this example, in addition to reducing iron loss, eddy current loss can be reduced and complex curved shapes can be processed, resulting in improved characteristics. And performance can be improved. The pitch and depth of the grooves are related to the reduction of eddy current, and if the groove width can be narrowed, the deterioration of magnetic characteristics can be minimized. In this embodiment, since the groove is formed by etching, the width of the groove can be very small. On the other hand, in machining such as pressing and polishing, there is a limit to make the tip of the grindstone thin, and groove processing of about 0.1 mm is impossible. Moreover, in press work, since the surface on the opposite side to press protrudes, it cannot be used for what is comprised with a laminated steel plate.

  In addition, it is not necessary to provide a crossing groove in all the steel plates laminated | stacked, What is necessary is just to provide in the surface facing the rotor of the steel plate nearest to a rotor at least. This can also contribute to reduction of eddy current. What is necessary is just to determine the number of the steel plates which provide an intersection groove | channel according to the specification of the alternating current generator for vehicles.

  The annular disc portion 186 is provided with a plurality of fastening portions 20. The fastening portion 20 is formed by pressing one of the plate surfaces (side surfaces) of the annular disc portion 186 in the plate thickness direction so as to be depressed and projecting the other plate surface (side surface) in the plate thickness direction. Moreover, the fastening part 20 is formed in six places of the circumferential direction at equal intervals, and is arrange | positioned at the intermediate position of the circumferential direction between the convex board parts 187 adjacent to the circumferential direction. A plurality of steel plates to be stacked can be integrated by engaging a protrusion of another steel plate to be stacked with the recess of the fastening portion 20 of the steel plate. This is performed for the number of stacked sheets.

  In the plurality of steel plates integrated and laminated by the fastening portion 20, the convex plate portion 187 is bent at a right angle in the plate thickness direction of the steel plate, and the annular disc portion 186 is perpendicular to the same direction as the convex plate portion 187. Can be folded. As a result, stator core members 18a and 18b including the core back 184 and the stator claw magnetic pole 185 are formed.

  In addition, when bending the laminated steel plate, the steel plate arranged outside and the steel plate arranged inside are different in size and bending position. For this reason, in this embodiment, the annular disk portion 186 and the convex plate portion 187 are bent in a state where the steel plates having different sizes are stacked. By doing so, the laminated surface can be aligned without causing any deviation in the laminated surface. Moreover, since it is not necessary to prepare a some type | mold if an etching process is used, the steel plate from which a magnitude | size differs can be manufactured cheaply.

  As another method, steel sheets of the same size can be laminated, and the laminated surface at the bent portion can be cut to align the laminated surfaces. Furthermore, instead of folding the steel plates after laminating, the steel plates may be folded by changing the position where the steel plates are folded one by one, and then the steel plates are laminated. In this way, by laminating later, the curvature of the part to be bent can be made as small as possible, so that the stator claw magnetic pole 185 can be brought close to the rotor with as large an area as possible. Thereby, the amount of magnetic flux flowing from the rotor to the stator claw magnetic pole 185 can be increased.

  As described above, the stator core constituent members 18a and 18b are manufactured. Thereafter, the stator winding 19 wound in an annular shape in advance is integrated with a bobbin, insulating paper, or the like, and this is integrated with the inner peripheral side of the core back 184 of the pair of stator core components 18a and 18b and the stator claw magnetic poles. It is mounted in the space with the outer peripheral side of 185.

  And the contact part of stator core structural member 18a, 18b is welded from outer periphery, and both are fixed integrally. Thereby, the U-phase stator 17U can be manufactured. The V-phase stator 17V and the W-phase stator 17W can be manufactured in the same manner. As a method of fixing the stator core constituent members 18a and 18b integrally, there is also a method of filling the gap between the stator claw magnetic poles 185 with resin and fixing.

  Finally, by arranging the stators 17U to 17W of each phase in the axial direction via the annular spacer 21, one stator 17 can be configured. The spacer 21 is a non-magnetic material and is provided to prevent the magnetic flux from going back and forth between the iron core units adjacent in the axial direction. As the spacer 21, in order to prevent eddy current, it is desirable to employ a resin that is non-metallic.

  In addition, a plurality of convex portions are provided on the side surfaces on both sides in the axial direction of the spacer 21. The plurality of convex portions are arranged in the circumferential direction at the same interval as the fastening portion 20 so as to be engaged with the fastening portion 20 (concave portion side) of the stator adjacent in the axial direction, and on the side surface of the spacer 21 The arrangement position in the circumferential direction is different between one convex portion and the other convex portion. The circumferential positions of the stators 17U to 17W of the respective phases are determined by engaging the fastening portions 20 with the convex portions of the spacers 21. The circumferential positions of the stators 17U to 17W of the respective phases are arranged such that the electrical phase of the three-phase winding is shifted by 120 degrees with respect to the magnetic poles of the rotor.

As shown in FIG. 8, the stator 17 manufactured as described above is then disposed in a state where the rotor 13 is rotatably opposed to the inner peripheral side via a gap as shown in FIG. Next, the structure of the rotor will be described with reference to FIGS. 8 and 12. The rotor is sandwiched and fixed in an annular step provided on the front bracket 2 and the rear bracket 3 from the axial direction.

  In the previous example, no other magnetic material was provided between the claw portions of the claw-shaped magnetic pole portions 13b adjacent in the circumferential direction. However, in this embodiment, the claw-shaped magnetic pole portions 13b adjacent in the circumferential direction are not provided. A permanent magnet 22 is inserted between them. The permanent magnet 22 suppresses leakage of magnetic flux generated by the field winding 15 between the claw portions of the claw-shaped magnetic pole portions 13b adjacent in the circumferential direction, and the magnetic flux of the claw-shaped magnetic pole portions 13b is transferred from the claw portions to the stator 17 side. It is provided to facilitate flow. Thereby, the electric power generation output of the vehicle alternator can be improved. Since it is necessary to use a permanent magnet 22 having relatively excellent heat resistance, a ferrite magnet, a neodymium magnet, or the like is employed. The permanent magnet may be used in accordance with the requirements of the power generation characteristics for the vehicle alternator, and may not be used depending on the specifications of the vehicle alternator.

  In this embodiment, a spacer 21 is provided between the stators 17U to 17W of each phase to prevent leakage of magnetic flux to phases adjacent in the axial direction. However, in practice, there is also a magnetic flux that leaks to an axially adjacent phase. For this reason, when the stators 17U to 17W of the respective phases are arranged in the axial direction in the order of the U phase, the V phase, and the W phase, the U phase stator 17U and the W phase are used in the V phase stator 17V arranged in the center. Magnetic flux leaks to both the stator 17W, and the output is smaller than that of the U-phase stator 17U and the W-phase stator 17W. Such an unbalance of the stator 17 can be eliminated by providing the permanent magnet 22 disposed between the claw portions of the claw-shaped magnetic pole portion 13b only in a portion facing the V-phase stator 17V.

  Next, the magnetic flux path in the vehicle alternator will be described.

  The magnetic flux generated by the excitation of the field winding 15 passes through the stator claw magnetic pole 185 extending from one side in the axial direction of the stator 17 from the claw portion of the claw-shaped magnetic pole portion 13b on the N pole side. , Reaches the stator claw magnetic pole 185 extending from the other side in the axial direction, and finally flows through the magnetic circuit reaching the claw portion of the claw-shaped magnetic pole portion 13b on the S pole side. Thereby, the magnetic flux generated by the excitation of the field winding 15 is linked with the stator winding 19 of each phase. As a result, an alternating current flows through the stator winding 19 of each phase, and an alternating voltage is induced.

  Note that the stator claw magnetic pole 185 formed by laminating steel plates receives an attractive force from the claw-shaped magnetic pole portion 13b. For this reason, the stator claw magnetic pole 185 needs to join the laminated steel plates. For example, it is conceivable that the laminated surface of the stator claw magnetic pole 185 is molded with a non-magnetic material such as resin or bonded with an adhesive.

  As described above, in this embodiment, the iron loss can be reduced as in the previous example. Further, in this embodiment, since a plurality of types of steel plates are formed by etching, there is no need to prepare a plurality of forming dies, and the stator 17 can be manufactured at low cost. Furthermore, when a thick steel plate is bent, the corner portion is distorted. This strain reduces the adhesion of the steel plates to be laminated, and causes an increase in iron loss. However, in this example, since the steel plates having a thickness of 0.05 to 0.30 mm are laminated, the iron loss is not increased, and the workability and adhesion at the final machining are also improved. improves.

  Further, in this embodiment, since the groove (uneven portion) for reducing eddy current loss is formed on the steel plate by etching, a very thin and shallow groove (uneven portion) can be formed on the steel plate, and the eddy current loss can be formed. The reduction effect can be increased.

  Next, an automotive alternator according to a third embodiment of the present invention will be described with reference to FIGS.

  In addition, the same code | symbol as the previous example is attached | subjected to the structure similar to a previous example, the same name is used, and the description is abbreviate | omitted.

  First, the structure of the stator 17 is demonstrated using FIG. 13 thru | or FIG.

  In the previous example, the stator 17 is formed by arranging a U-phase stator 17U, a V-phase stator 17V, and a W-phase stator 17W in parallel in the axial direction. In contrast, in this embodiment, the stator 17 is replaced with the iron core unit shown in FIG. 16, that is, the U-phase stator 17U, the V-phase stator 17V, and the W-phase stator 17W as shown in FIGS. It is formed side by side at intervals of about 120 degrees in the circumferential direction. As shown in FIG. 13, the U-phase stator 17U, the V-phase stator 17V, and the W-phase stator 17W are positioned in the circumferential direction and are axially moved by the annular steps of the front bracket 2 and the rear bracket 3 as shown in FIG. It is pinched and fixed.

  In the following description, the U-phase stator 17U will be described, but the stators of the other phases have the same configuration.

  The U-phase stator 17U includes a stator core 18 and a stator winding 19 as its constituent elements as in the previous example.

  The stator core 18 is configured such that a pair of first stator core constituent members 188 divided in the axial direction is opposed to each other in the axial direction. The first stator core constituting member 188 is configured such that a pair of second stator core constituting members 18a and 18b divided in the axial direction is opposed to each other in the axial direction. That is, the stator core 18 of the present embodiment is composed of four second stator core constituent members having the same shape.

  The second stator core constituent members 18a and 18b are each formed of a strip-shaped core portion 189a formed in an arc shape, and a stator yoke 189b provided so as to protrude from the axial end of the strip-shaped core portion 189a to the inner peripheral side. And a stator claw magnetic pole 185 extending in the axial direction from the inner peripheral side of the stator yoke 189b. The strip-shaped iron core portion 189a, the stator yoke 189b, and the stator claw magnetic pole 185 are integrally formed.

  Three stator claw magnetic poles 185 are provided for each of the second stator core constituting members 18a and 18b, and all have the same shape. The planar shape seen from the radial direction of the stator claw magnetic pole 185 is a triangular shape or a trapezoidal shape that is a tapered shape (skew shape), like the claw portion of the previous example. The stator claw magnetic poles 185 are arranged at equal intervals in the circumferential direction from one circumferential end of the stator yoke 189b, and are not arranged at the other circumferential end of the stator yoke 189b.

  In the second stator core constituent members 18a and 18b, the end faces of the strip-shaped core portions 189a in the opposing direction are in contact with each other in the axial direction, and the stator claw magnetic poles 185 are alternately spaced in the circumferential direction. The first stator iron core constituting member 188 is formed by meshing the stator claw magnetic poles 185 with each other.

  Further, the two first stator core constituent members 188 are symmetrical to each other, that is, the end surfaces of the second stator core constituent members 18b are in contact with each other in the axial direction, and the second stator core configuration is provided. The U-phase stator 17U is formed by being juxtaposed in the axial direction so that the stator claw magnetic poles 185 provided on the member 18b come into contact with each other. In this embodiment, since the stator claw magnetic poles 185 of the stator core constituting member 18b are in contact with each other, the mechanical strength can be improved and the utilization factor of the magnetic flux is improved and the output is improved.

  On the inner peripheral surface of the stator claw magnetic pole 185 (the surface facing the rotor 13), in order to prevent eddy currents, a crossing groove formed by uneven portions is formed as in the previous example.

  In the space between the inner peripheral side of the belt-shaped iron core portion 189a, the stator yoke 189b, and the outer peripheral side of the stator claw magnetic pole 185, a cylindrical winding conductor is deformed into an elliptical shape, A stator winding 19 that is curved in the circumferential direction and shaped like a bowl is wound. The winding conductor has a round line with a cross section perpendicular to the central axis, a rectangular flat line with a cross section perpendicular to the central axis, a polygonal square line such as a hexagon with a cross section perpendicular to the central axis, and a round line. One of the forming wires that are crushed from the relative direction and formed into a flat rectangular shape is employed. Here, if a square wire is adopted as the winding conductor, the winding conductors are aligned in the space between the inner peripheral side of the strip-shaped iron core 189a, the stator yoke 189b, and the outer peripheral side of the stator claw magnetic pole 185. As a result, the space factor of the stator winding 19 in the space between the inner peripheral side of the belt-shaped iron core portion 189a, the stator yoke 189b, and the outer peripheral side of the stator claw magnetic pole 185 is improved. Efficiency can be achieved. The same effect can be obtained by squashing the round line in the space between the inner peripheral side of the belt-shaped iron core portion 189a, the stator yoke 189b, and the outer peripheral side of the stator claw magnetic pole 185.

  The surface of the winding conductor constituting the stator winding 19 is provided with enamel insulation coating. In the space between the inner peripheral side of the belt-shaped iron core portion 189a, the stator yoke 189b, and the outer peripheral side of the stator claw magnetic pole 185, the stator core 18 and the stator winding 19 are insulated from each other. Insulation paper is installed. The stator core 18 and the stator winding 19 are insulated from each other by winding the stator winding 19 around a bobbin, which is a resin molded product (non-magnetic material), and connecting the stator winding 19 to the inner periphery of the strip-shaped core portion 189a. This can also be ensured by mounting in the space between the side, the stator yoke 189b, and the outer peripheral side of the stator claw magnetic pole 185.

  The stator winding 19 is wound in a flat shape that is narrow in the radial direction and wide in the axial direction, and includes a pair of coil end portions 191 formed at both ends in the circumferential direction, and a coil end portion. 191 and a pair of circumferential winding portions 192.

  The circumferentially wound portion 192 includes the second stator core constituent members 18a and 18b so as to be disposed between the strip-shaped core portion 189a and the stator claw magnetic pole 185 of the separate first stator core constituent members 188. Assemble around the stator winding 19. For this reason, the stator claw magnetic pole 185 passes through the inner peripheral side opening and the outer peripheral side of the stator winding 19 and protrudes toward the rotor 13. The second stator core constituent members 18a and 18b have a stator claw magnetic pole 185 at one circumferential end, but do not have a stator claw magnetic pole 185 at the other circumferential end. For this reason, the coil end portion 191 protrudes greatly at one end side in the circumferential direction of the stator core 18, but hardly protrudes at the other end side in the circumferential direction of the stator core 18. According to such a configuration, the number of claw magnetic poles in the stator 17 can be increased as much as possible. In the present embodiment, the V-phase stator 17V and the W-phase stator 17W are configured to include six stator claw magnetic poles 185, similarly to the U-phase stator 17U. The total number is 18 poles.

  Next, the structure of the rotor 13 is demonstrated using FIG. 13 and FIG.

  As shown in FIGS. 13 and 14, the rotor 13 has no permanent magnet mounted between the claw portions of the claw-shaped magnetic pole portions 13b adjacent in the circumferential direction. Further, the number of claw-shaped magnetic pole portions 13b of the rotor 13 is 20. In this embodiment, the number of claw-shaped magnetic pole portions 13b of the rotor 13 is 20, whereas the number of stator claw magnetic poles 185 of the stator 17 is 18, The stator 17 has two fewer magnetic poles. Here, as a characteristic of the AC generator for a vehicle, the ratio of the number of magnetic poles of the rotor to the number of magnetic poles of the stator is preferably large. In this embodiment, since the number of magnetic poles of the stator 17 is 18 and the number of magnetic poles of the rotor 13 is 20, the ratio of the number of magnetic poles of the rotor to the number of magnetic poles of the stator can be made relatively large, 0.9. The circumferential widths of the stator claw magnetic pole 185 of the stator 17 and the claw-shaped magnetic pole portion 13b of the rotor 13 are substantially equal. For this reason, the width of the stator 17 corresponding to the smaller number of the two stator claw magnetic poles 185 is a gap in the circumferential direction between the stators 17U, 17V, and 17W of each phase.

  In the present embodiment, the fan 14b is provided only on the rear bracket 3 side of the rotor 13. Further, the outer diameter of the fan 14 b is larger than the outer diameter of the rotor 13. The fan 14b is for flowing cooling air from the inner peripheral side to the outer peripheral side. For this reason, even if the fans 14 b are provided on both axial sides of the rotor 13, the cooling air does not effectively pass around the stator 17. Therefore, in this embodiment, a fan 14b having an outer diameter larger than that of the rotor 13 is provided only on the rear bracket 3 side of the rotor 13 so that cooling air passes between the stators 17 of the respective phases. . According to such a configuration, the rectifier circuit 16 can also be cooled.

  Next, the manufacturing method of the stator 17 is demonstrated using FIG.

  In the present embodiment, as in the previous example, the stator core 18 is formed by laminating steel plates having a thickness of 0.05 to 0.30 mm.

  The steel plate used for the stator core 18 of the present embodiment is formed into the shape shown in FIGS. 17A and 17B by etching. Here, the steel plate shown in FIG. 17 (a) is the one disposed on the innermost side of the stator core 18. The steel plate shown in FIG. 17 (b) shows that disposed on the outermost side of the stator core 18. As can be seen by comparing these steel sheets, the steel sheet disposed inside the stator core 18 and the steel sheet disposed outside are slightly different in shape. This is because, as in the previous example, when the steel plates are bent in one direction in the final laminated state, the laminated surfaces are aligned.

  The shape of the steel plate formed by etching is basically a shape obtained by dividing the shape of the steel plate of the previous example into approximately three equal parts in the circumferential direction. Specifically, the coil of the stator winding 19 is more than 120 degrees. The shape is divided at a small angle by the end portion 191. As shown in FIGS. 17 (a) and 17 (b), the steel plate has an arcuate plate portion 1861 formed in an arc shape and three convex plates projecting toward the inner peripheral side of the arcuate plate portion 1861. A shape having a portion 187 is formed. Eventually, the arc-shaped plate portion 1861 becomes the band-shaped iron core portion 189a and the stator yoke 189b, and the convex plate portion 187 becomes the stator claw magnetic pole 185. The convex plate portion 187 matches the shape of the stator claw magnetic pole 185 as in the previous example. Further, as is clear from comparison between FIG. 17 (a) and FIG. 17 (b), the protruding length in the radial direction of the convex plate portion 187 and the circumferential width of the arc-shaped plate portion 1861 are slightly between them. Is different.

  As shown in FIG. 17A, the surface of the convex plate portion 187 of the steel plate disposed on the innermost side of the stator core 18 is subjected to slit processing to form a plurality of uneven portions. The plurality of concavo-convex portions form the above-described intersecting grooves, and a plurality of width-direction grooves extending in the circumferential width direction of the convex plate portion 187 and a plurality of vertical portions extending substantially perpendicular to the width-direction grooves. Forming a groove. These grooves are formed by etching simultaneously with the etching of the steel sheet. The depth of each groove is shallower than the thickness of the steel plate. Further, as shown in the AA ′ cross section of FIG. 17A, the width of the groove is slightly wider on the opening side than on the bottom side.

  On the other hand, as shown in FIG. 17B, the surface of the convex plate portion 187 of the steel plate disposed on the outermost side of the stator core 18 is not provided with irregularities. This is because the influence of the eddy current is small on the outer peripheral side of the stator core 18. In the laminated steel plate, whether or not the unevenness is formed on the surface of the convex plate portion 187 can be changed according to the specification of the vehicle alternator. Depending on the specifications of the vehicular AC generator, irregularities may be formed on the surfaces of the convex plate portions 187 of all the steel plates. The effect of the groove (uneven portion) is the same as the previous example.

  The arcuate plate portion 1861 is provided with a plurality of fastening portions 20. The configuration of the fastening portion 20 is the same as the previous example. The fastening portions 20 are formed at three equal intervals in the circumferential direction, and are disposed at intermediate positions in the circumferential direction between the convex plate portions 187 adjacent in the circumferential direction.

  In the plurality of steel plates integrated and laminated by the fastening portion 20, the convex plate portion 187 is bent at right angles to the plate thickness direction of the steel plate, and the outer peripheral side of the arc-shaped plate portion 1861 is also the convex plate portion 187. Folded at right angles in the same direction. FIG. 17C shows a state where the convex plate portion 187 and the arc-shaped plate portion 1861 are bent from the front. As can be seen from FIG. 17 (c), since the shapes of all the steel plates are changed, the laminated surfaces are aligned to be the same surface. In the production of laminated steel sheets, the same size steel sheets may be laminated, the laminated surface of the bent part may be cut and the laminated surface may be aligned, or the folded position may be changed instead of folding after the steel sheets are laminated. The steel plates may be bent one by one, and then the steel plates may be laminated. Thus, the second stator core constituting members 18a and 18b are manufactured.

  After that, the stator winding 19 wound in the circumferential direction, that is, in the shape of a bowl, is integrated with a bobbin, insulating paper, or the like, and two second stator core constituent members 18b are connected from the inner peripheral side. insert. At this time, the two second stator core constituent members 18b are inserted into the inner periphery of the stator winding 19 from the side of the strip-shaped core portion 189a with the outer sides of the stator yoke 189b in contact with each other in the axial direction. The When the two second stator core constituent members 18b are inserted into the inner periphery of the stator winding 19, the contact portions of the two band-shaped core portions 189a may be integrated in advance by welding or the like. They may be integrated after being inserted into the inner periphery of the wire 19. When the two second stator core constituent members 18b are integrated after being inserted into the inner periphery of the stator winding 19, the two second stator core constituent members 18b are connected to the stator claw magnetic pole 185 side from the stator. It can also be inserted into the inner periphery of the winding 19.

  When the two second stator core constituent members 18b are inserted into the inner periphery of the stator winding 19, the axial width of the strip-shaped core portions 189a of the two second stator core constituent members 18b is formed short. If the axial widths of the strip-shaped core portions 189a of the two second stator core constituent members 18a disposed on the outside are formed to be longer by that amount, the strip-shaped core portions 189a of the two second stator core constituent members 18b are formed. Easy to insert from the side.

  Next, with respect to each of the laminated surfaces of the strip-shaped core portions 189a of the two second stator core constituting members 18b inserted in the inner periphery of the stator winding 19, the strip-shaped core portions of the second stator core constituting member 18a. The laminated surface of 189a is brought into contact, and the contact portion is fixed by welding or the like, and the two second stator core constituting members 18a and 18b are fixed integrally. Thereby, as shown in FIG. 16, U-phase stator 17U can be manufactured. The V-phase stator 17V and the W-phase stator 17W can be manufactured similarly. As a method of fixing the two second stator core constituent members 18a and 18b integrally, there is a method of filling the gap between the stator claw magnetic poles 185 with resin and fixing. Moreover, the stator claw magnetic pole 185 needs to join the laminated steel plates. As the bonding method, there are a method of bonding the laminated surface of the stator claw magnetic pole 185 with a non-magnetic material such as resin, and a method of bonding with an adhesive.

  Further, another method can be applied to the joining of the belt-like core portions 189a of the second stator core constituent members 18a and 18b. This will be described below with reference to FIG.

  As shown in FIG. 18, the laminated surface in the strip-shaped core part 189a of the second stator core constituting member 18a is formed by alternately laminating long steel sheets and short steel sheets as shown on the right side in the drawing. On the other hand, the laminating surface of the second stator core constituent member 18a in the strip-shaped core portion 189a is laminated such that a long steel plate and a short steel plate are opposite to the second stator core constituent member 18a. Yes. Thereby, the strip | belt-shaped iron core parts 189a are faced | matched to an axial direction, and the long steel plate extended from the laminated surface of the strip | belt-shaped iron core part 189a can be piled up alternately and can be joined. According to such joining, magnetic flux can easily pass and efficiency can be improved. In addition, the reason why the long steel plates extending from the laminated surface of the strip-shaped iron core portion 189a can be alternately stacked and joined is that the etching process is used. If etching is used, a highly accurate processed surface free from sagging or burrs can be obtained. Therefore, joining as shown in FIG. 18 is possible. Further, as shown in FIG. 13, the stator 17 is finally sandwiched and fixed between the front bracket 2 and the rear bracket 3 in the axial direction, so that the second stator core constituent members 18a and 18b are fixed to each other. Can be assembled without falling apart. Thereby, the welding of the lamination | stacking surfaces in the strip | belt-shaped iron core part 189a can also be omitted.

  Next, countermeasures against eddy currents generated in the stator claw magnetic pole 185 will be described with reference to FIGS. 18 and 19.

  The eddy current is generated so as to draw a circle on the surface of the stator claw magnetic pole 185. For this reason, in the groove | channel provided in one direction, since it becomes easy to flow in the direction which does not provide a groove | channel, sufficient effect is not acquired. Since conventional grooving uses rotation of a lathe or a threading machine, machining in the same direction was only possible. However, the pattern can be freely selected by using etching. For example, as shown in the enlarged view on the lower side in FIG. 18, it is possible to perform a lattice-like processing that is shallower than the plate thickness and has a very narrow groove width. In this embodiment, since a large number of vertical and horizontal grooves having a groove pitch of 0.3 mm and a groove width of 50 μm are provided, the effect of reducing eddy current is great.

  If etching is used, the groove pattern is not limited to a lattice pattern, and various patterns can be employed. A typical example is shown in FIG. The patterns shown in FIG. 19A are arranged in a substantially cross shape, and the positions of the substantially cross pattern are different depending on the columns. More specifically, the second row of substantially cross-shaped patterns is positioned in the middle of the first row of adjacent substantially cross-shaped patterns. In addition to the substantially cross-shaped pattern, a spiral-shaped pattern as shown in FIG. 19 (b), or a substantially rectangular pattern formed by opposing a substantially L-shaped pattern as shown in FIG. 19 (c), Further, the same effect can be obtained by using a star-shaped groove as shown in FIG. As described above, the eddy current can be effectively reduced by forming a pattern having two or more types of directions with a plurality of grooves. Furthermore, the eddy current can be reduced more effectively if the arrangement of these patterns is continuous in one direction and has a phase difference in the other direction.

  As described above, according to the present embodiment, the same effect as the previous example can be obtained. Further, in this embodiment, as in the previous example, the stators 17 of the respective phases are not juxtaposed in the axial direction, but are juxtaposed in the circumferential direction, so that variations in magnetic flux between the respective phases can be suppressed. In addition, in this embodiment, since the cooling air by the fan 14b can be flowed between the stators 17 of the respective phases, the cooling performance of the stator 17 can be improved.

It is a side cross section of the alternating current generator for vehicles in the 1st example. The rotor in 1st Example is represented with the perspective view. It is a figure explaining the rotor stator core in 1st Example. It is a figure which shows the relationship between the board thickness of an electromagnetic steel plate, and an iron loss. It is a figure which shows the relationship between the silicon content and iron loss in a silicon steel plate. It is a figure which shows the typical process cross-sectional shape by an etching process. It is a figure which shows the typical process cross-sectional shape by a punching process. It is a side cross section of the AC generator for vehicles in the 2nd example. The stator of the one phase in 2nd Example is represented with the perspective view. It is a figure which shows the steel plate which comprises the stator core in 2nd Example. The stator for 3 phases in 2nd Example is represented with the perspective view. The stator and rotor in 2nd Example are represented with the perspective view. It is a side cross section of the AC generator for vehicles in the 3rd example. The stator and rotor in 3rd Example are represented with the perspective view. Only the stator in 3rd Example is represented with the perspective view. The stator of the one phase in 3rd Example is represented with the perspective view. It is a figure which shows the steel plate which comprises the stator core in 3rd Example. It is a figure which shows other embodiment of the stator core in 3rd Example. It is a figure which shows the other groove pattern shape | molded using the etching process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle alternator 13 Rotor 13b Claw magnetic pole part 15 Field winding 17 Stator 18 Stator iron core 19 Stator winding 20 Fastening part 181 Core back 182 Teeth 183 Slot 185 Stator claw magnetic pole

Claims (34)

A rotor that rotates by receiving rotational power;
A stator core disposed opposite to the rotor via a gap, and a stator winding mounted on the stator core, and voltage is induced in the stator winding by the action of magnetic flux from the rotor. Having a stator, and
The stator core is formed by laminating a plurality of core plates obtained by processing a steel plate in the thickness direction of the core plate,
Of each part of the iron core plate, the shape of the cross section subjected to the processing of at least the part close to the rotor is substantially symmetric with respect to a plane that bisects the iron core plate in the plate thickness direction.
A vehicle alternator characterized by the above. In the vehicle alternator according to claim 1,
The steel plate has a thickness of 0.05 to 0.30 mm.
A vehicle alternator characterized by the above. In the vehicle alternator according to claim 1,
The steel plate is an electromagnetic steel plate, C is 0.001 to 0.060 wt%, Mn is 0.1 to 0.6 wt%, P is 0.03 wt% or less, S is 0.03 wt% or less, Containing 0.1% by weight or less of Cr, 0.8% by weight or less of Al, 0.5 to 7.0% by weight of Si, 0.01 to 0.20% by weight of Cu, and the remainder is inevitable Consisting of various impurities and Fe,
A vehicle alternator characterized by the above. In the vehicle alternator according to claim 1,
Between the core plates adjacent to each other in the stacking direction of the stator core, the insulating coating in which the thickness in the stacking direction of the stator core is thinner than the thickness of the core plate is applied,
A vehicle alternator characterized by the above. In the vehicle AC generator according to claim 4,
The thickness of the insulating film in the stacking direction of the stator core is 0.01 to 0.2 μm.
A vehicle alternator characterized by the above. In the vehicle alternator according to claim 1,
The rotor is a Rundel type rotor including an iron core having a plurality of claw-shaped rotating magnetic poles close to the stator, and a field winding wound around the iron core,
A plurality of grooves are formed on a surface of the claw-shaped rotating magnetic pole facing the stator.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 6,
The plurality of grooves are formed by peeling off the surface of the claw-shaped rotating magnetic pole facing the stator by edging.
A vehicle alternator characterized by the above. A rotor that rotates by receiving rotational power;
A stator core disposed opposite to the rotor via a gap, and a stator winding mounted on the stator core, and voltage is induced in the stator winding by the action of magnetic flux from the rotor. Having a stator, and
The stator core is formed by laminating a plurality of iron core plates obtained by processing a steel plate in the thickness direction of the iron core plate, and further in the circumferential direction in the vicinity of the rotor. A plurality of fixed magnetic poles and a yoke connecting the fixed magnetic poles on the side opposite to the rotor side,
Of each part of the iron core plate, at least the shape of the cross-section subjected to the processing of the part forming the magnetic pole is substantially symmetric with respect to a plane that bisects the iron core plate in the thickness direction.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 8, wherein
The yoke is a cylindrical core part formed by laminating the iron core plate in the same direction as the direction in which the rotation axis of the rotor extends.
The fixed magnetic pole is a tooth-shaped core that is disposed in a circumferential direction along a circumferential surface of the yoke on the rotor side and extends from the rotor side of the yoke toward the rotor. The iron core plate is laminated in the same direction as the direction in which the rotation axis of the rotor extends along the peripheral surface of the yoke on the rotor side,
The stator winding is composed of a winding conductor housed between fixed magnetic poles adjacent in the circumferential direction.
A vehicle alternator characterized by the above. In the vehicle alternator according to claim 9,
The rotor is a Rundel type rotor including an iron core having a plurality of claw-shaped rotating magnetic poles close to the stator, and a field winding wound around the iron core.
A vehicle alternator characterized by the above. In the vehicle AC generator according to claim 10,
A plurality of grooves are formed on the surface of the claw-shaped rotating magnetic pole facing the stator,
The plurality of grooves are formed by peeling off the surface of the claw-shaped rotating magnetic pole facing the stator by edging.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 8, wherein
The stator core is configured by combining a plurality of iron core units including the yoke and the fixed magnetic pole in the same direction as the direction in which the rotation axis of the rotor extends,
The yoke in each of the iron core units is a short ring iron core portion formed by laminating the iron core plate in the radial direction of the rotor,
The fixed magnetic pole in each of the iron core units is arranged in a circumferential direction along the circumferential surface of the yoke on the rotor side, and extends from the rotor side of the yoke to the rotor side, Furthermore, a claw-shaped iron core portion having a plurality of claw portions arranged in the circumferential direction along the circumferential surface on the rotor side of the yoke at the extended tip, and closest to the rotor,
The plurality of claw portions in each of the iron core units are formed by laminating the iron core plates in a direction facing the rotor,
The stator winding is constituted by a winding conductor housed between the yoke and the plurality of claws in each of the iron core units.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 12,
The rotor is a Rundel type rotor including an iron core having a plurality of claw-shaped rotating magnetic poles close to the stator, and a field winding wound around the iron core.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 13,
A plurality of grooves are formed on the surface of the claw-shaped rotating magnetic pole facing the stator,
The plurality of grooves are formed by stripping the surface of the claw-shaped rotating magnetic pole facing the stator in a streak shape by edging.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 12,
A plurality of grooves extending in a plurality of directions are formed on a surface of the plurality of claw portions facing the rotor.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 15,
The plurality of grooves are formed by peeling off the surface of the surface facing the rotor by edging.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 12,
Each of the iron core units is provided with a fastening portion with an adjacent iron core unit,
A vehicle alternator characterized by the above. The vehicle alternator according to claim 15,
The depth of the groove is shallower than the thickness of the iron core plate,
A vehicle alternator characterized by the above. The vehicle alternator according to claim 8, wherein
The stator core is configured by combining a plurality of iron core units including the yoke and the fixed magnetic pole in the circumferential direction along the rotor,
The yoke in each of the iron core units is a short arc shaped iron core portion formed by laminating the iron core plate in the radial direction of the rotor,
The fixed magnetic pole in each of the iron core units is arranged in a circumferential direction along an arc surface on the rotor side of the yoke, and extends from the rotor side of the yoke to the rotor side, Furthermore, a claw-shaped iron core portion having a plurality of claw portions arranged in the circumferential direction along the circumferential surface on the rotor side of the yoke at the extended tip, and closest to the rotor,
The plurality of claw portions in each of the iron core units are formed by laminating the iron core plates in a direction facing the rotor,
The stator winding is constituted by a winding conductor housed between the yoke and the plurality of claws in each of the iron core units.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 19,
The rotor is a Rundel type rotor including an iron core having a plurality of claw-shaped rotating magnetic poles close to the stator, and a field winding wound around the iron core.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 20,
A plurality of grooves are formed on the surface of the claw-shaped rotating magnetic pole facing the stator,
The plurality of grooves are formed by stripping the surface of the claw-shaped rotating magnetic pole facing the stator in a streak shape by edging.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 19,
A plurality of grooves extending in a plurality of directions are formed on a surface of the plurality of claw portions facing the rotor.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 22,
The plurality of grooves are formed by peeling the surface of the surface facing the rotor by edging.
A vehicle alternator characterized by the above. The vehicle alternator according to claim 22,
The depth of the groove is shallower than the thickness of the iron core plate,
A vehicle alternator characterized by the above. A rotor that rotates by receiving rotational power;
A stator core disposed opposite to the rotor via a gap, and a stator winding mounted on the stator core, and voltage is induced in the stator winding by the action of magnetic flux from the rotor. Having a stator, and
The stator iron core is formed by laminating a plurality of iron core plates obtained from steel plates in the thickness direction of the iron core plates,
The iron core plate has a thickness of 0.05 to 0.30 mm.
The laminated core density (%) defined by the thickness (mm) of the iron core plate × the number of the iron core plates (sheets) ÷ the height (mm) of the stator core in the lamination direction of the iron core plates × 100. 0.0-99.9%,
A vehicle alternator characterized by the above. A rotor that rotates by receiving rotational power;
A stator core disposed opposite to the rotor via a gap, and a stator winding mounted on the stator core, and voltage is induced in the stator winding by the action of magnetic flux from the rotor. Having a stator, and
The stator iron core is formed by laminating a plurality of iron core plates obtained by processing steel plates in the thickness direction of the iron core plates,
Among the portions of the iron core plate, it is an axis line at least in a portion close to the rotor, and is orthogonal to the plate thickness direction of the iron core plate and extends toward a cross section where the processing of the iron core plate is performed. The direction of the central axis is directed in substantially the same direction until reaching the cross-section of the iron core plate that has been processed.
A vehicle alternator characterized by the above. A rotor that rotates by receiving rotational power;
A stator core disposed opposite to the rotor via a gap, and a stator winding mounted on the stator core, and voltage is induced in the stator winding by the action of magnetic flux from the rotor. Having a stator, and
The stator iron core is formed by laminating a plurality of iron core plates obtained from steel plates in the thickness direction of the iron core plates,
Of each part of the stator core, at least the magnetic pole portion facing the rotor, the laminated cross section formed by the lamination of the iron core plates is subjected to processing by etching,
A vehicle alternator characterized by the above. A rotor that rotates by receiving rotational power;
A stator core disposed opposite to the rotor via a gap, and a stator winding mounted on the stator core, and voltage is induced in the stator winding by the action of magnetic flux from the rotor. Having a stator, and
The stator iron core is formed by laminating a plurality of iron core plates obtained by etching a steel plate in the thickness direction of the iron core plate, and at least the processed portion by the etching is the rotation. Provided in the laminated cross section formed by the lamination of the iron core plate of the magnetic pole portion facing the child,
A vehicle alternator characterized by the above. A rotor disposed opposite to a stator core and a stator having a stator winding mounted on the stator core via a gap rotates by receiving rotational power, and magnetic flux from the rotor A method of manufacturing an AC generator for a vehicle that generates electricity by inducing a voltage in the stator winding by an action,
A plurality of iron core plates constituting the stator core, a forming step for obtaining a steel plate, and
A stacking step of manufacturing the stator core by stacking the plurality of core plates in the thickness direction of the core plate;
A winding step of winding the stator winding around the stator core;
A combination process of combining the stator and the rotor,
In the molding step, a portion of the iron core plate that is close to the rotor is molded by at least etching.
A method of manufacturing an AC generator for a vehicle. The method for manufacturing an AC generator for a vehicle according to claim 29,
Obtaining the plurality of iron core plates from a steel plate having a thickness of 0.05 to 0.30 mm;
A method of manufacturing an AC generator for a vehicle. The method for manufacturing an AC generator for a vehicle according to claim 29,
As the rotor, an iron core having a plurality of claw-shaped rotating magnetic poles close to the stator and a Rundel-type rotor having a field winding wound around the iron core are prepared. Including a processing step of forming a plurality of grooves on the surface facing the stator by etching,
A method of manufacturing an AC generator for a vehicle. The method for manufacturing an AC generator for a vehicle according to claim 29,
Including a processing step of forming a plurality of grooves by etching on the surface of the surface of the stator iron core that faces the rotor at a portion close to the rotor,
A vehicle alternator characterized by the above. In the manufacturing method of the alternator for vehicles according to claim 32,
Performing the processing step simultaneously in the molding step;
A method of manufacturing an AC generator for a vehicle. The method for manufacturing an AC generator for a vehicle according to claim 29,
The molding step includes
Applying a resist to the steel sheet;
After exposing and developing the shape of the stator core to the resist, removing a part of the resist based on the shape of the stator core; and
The step of producing the iron core plate having the same shape as the shape of the stator core by dissolving the portion of the steel plate from which the resist is removed with an etching solution;
Removing the resist remaining on the iron core plate,
A method of manufacturing an AC generator for a vehicle.

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