JPH0998556A - Ac generator for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the power generation efficiency by providing a protective cover for preventing a permanent magnet interposed between the claws of claw-pole from springing out thereby increasing the generating current. SOLUTION: Permanent magnets (discrete magnets) for enhancing the flux generated from a field winding are interposed between the claw parts 33N, 33S of claw-poles 3N, 3S in a rotator while touching the claw-poles 3N, 3S with the same polarity. A tubular magnetic protective cover 6 is disposed on the outer face of permanent magnet and the outer circumferential face of the claw parts 33N, 33S of claw-poles 3N, 3S in order to prevent the permanent magnet from springing out. The protective cover 6 is provided with a plurality of elongated holes 22 in order to retard eddy current being induced on the surface and secured to the claw parts 33N, 33S of claw-poles 3N, 3S by welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle AC generator, and more particularly to a vehicle AC generator suitable as an automobile power generator.

[0002]

2. Description of the Related Art Generally, a vehicular AC generator has a pair of opposed claw-shaped magnetic poles each having a plurality of claws formed at its tip and a field winding for magnetizing the claw-shaped magnetic poles. The rotor includes a rotor and a stator that is disposed at a predetermined distance from the rotor and that generates an AC voltage by magnetizing the claw-shaped magnetic poles.
In the above structure, the rotor rotates and a direct current flows through the field winding, so that an N pole and an S pole are generated in the pair of claw-shaped magnetic poles, and the N-pole claw-shaped magnetic poles come out from the claw portions. A magnetic circuit is formed in which the magnetic flux passes through the stator core of the stator and returns to the claw portion of the claw-shaped magnetic pole of the S pole. At this time, the magnetic flux of the magnetic circuit intersects the stator winding of the stator to form the stator winding. AC induced voltage is generated in the wire. In such an automotive alternator, the amount of magnetic flux that intersects the stator windings affects the generated current. Therefore, in the related art, an alternating current generator in which a permanent magnet is arranged between the claw portions of the claw-shaped magnetic pole to increase the magnetic flux generated by the field winding to increase the amount of magnetic flux intersecting the stator winding. Have been proposed.

For example, in Japanese Unexamined Patent Publication No. 4-165950 (hereinafter, referred to as first prior art), a permanent magnet is arranged between the claw portions of the claw-shaped magnetic pole, and the outer surface of the permanent magnet and the claw portion of the claw-shaped magnetic pole. A cylindrical (ring-shaped) non-magnetic restricting member for restricting radial movement of the permanent magnet is arranged on the outer peripheral surface of the magnet, or a groove is formed on the outer circumference of the claw of the claw-shaped magnetic pole. A permanent magnet is arranged between the claw portions of the claw-shaped magnetic pole, a holding member is arranged on the outer surface of the permanent magnet, and a ring-shaped non-magnetic restricting member is arranged on the outer surface of the holding member and the groove portion of the claw portion. Is listed.

Further, in Japanese Unexamined Patent Publication No. 6-178474 (hereinafter, referred to as second prior art), magnetic powder, an adhesive, a plastic, etc. are previously provided between the claw portions of the claw-shaped magnetic pole and on the bottom side of the claw portion. It is described that a cylindrical resin magnet (magnet module) made by mixing with the resin of (1) is incorporated, and a reinforcing ring for improving the centrifugal resistance of the resin magnet is arranged on the outer surface of the resin magnet.

[0005]

However, the above-mentioned prior art has the following problems. Generally, it is necessary to provide a predetermined gap (mechanical gap) between the rotor and the stator due to the relation of mechanical characteristics.
In the first half of the prior art, i.e., in which a ring-shaped non-magnetic restricting member is arranged on the outer surface of the permanent magnet and the outer peripheral surface of the claw portion of the claw-shaped magnetic pole, it is fixed by the thickness of the restricting member. The child must be installed radially offset. However, in this case, if the material of the regulating member is a non-magnetic material, the magnetic gap between the rotor and the stator becomes large, so the magnetic resistance between the rotor and the stator becomes large, and as a result, The generated current is reduced and the power generation efficiency is reduced. In the latter half of the first prior art, that is, in the case where the holding member is arranged on the outer surface of the permanent magnet, the permanent magnet arranged between the claw portions of the claw-shaped magnetic pole is inevitably small by the amount of the holding member. Therefore, the magnetizing force and the energy product (product of the residual magnetic flux density and the coercive force) of the claw-shaped magnetic pole are reduced, and as a result, the generated current is reduced and the power generation efficiency is reduced.

Further, in the second prior art, since a resin magnet is produced by solidifying magnetic powder with a resin such as an adhesive or plastic to integrally form the resin magnet, a space between the claw portions of the claw-shaped magnetic pole is formed. However, there is a problem that the content of the magnetic powder is low and the magnetizing force and energy product of the claw-shaped magnetic pole are small. For this reason, the increase in the generated current due to the permanent magnet is small, and the power generation efficiency cannot be sufficiently increased.

A first object of the present invention is to provide a protective cover for preventing the permanent magnets arranged between the claw portions of the claw-shaped magnetic pole from popping out, and to increase the generated current and improve the power generation efficiency. An object is to provide a vehicle alternator capable of

A second object of the present invention is to incorporate a magnet module, in which a permanent magnet disposed between the claw portions of the claw-shaped magnetic pole is integrally molded in advance with resin, between the claw-shaped magnetic pole claw portions.
An object of the present invention is to provide an alternator for a vehicle that can increase the generated current and improve the power generation efficiency.

[0009]

In order to achieve the above first object, the present invention provides a pair of opposed claw-shaped magnetic poles having a plurality of claws formed at a tip portion thereof, and the claw-shaped magnetic poles. A field winding that magnetizes a magnetic pole, a permanent magnet that is arranged between the claw portions of the claw-shaped magnetic pole to increase the magnetic flux generated by the field winding, and a permanent magnet that is arranged on the outer surface side of the permanent magnet. In a vehicle AC generator including a rotor including a protective cover for preventing popping out, and a stator arranged at a predetermined distance from the rotor to generate an AC voltage by the magnetization of the claw-shaped magnetic poles, The protective cover is disposed on the outer surface side of the permanent magnet and the outer peripheral surface of the claw portion of the claw-shaped magnetic pole, and is made of a magnetic material.

In the above, the protective cover is disposed on the outer surface side of the permanent magnet and the outer peripheral surface of the claw portion of the claw-shaped magnetic pole, and the material thereof is a magnetic material, so that the magnetic field between the rotor and the stator is magnetic. The gap corresponds to the mechanical gap, prevents the increase of the magnetic resistance between the rotor and the stator, and arranges the holding member on the outer surface of the permanent magnet between the claw portions of the conventional claw-shaped magnetic pole. The permanent magnet can be made larger to increase the magnetizing force and the energy product of the claw-shaped magnetic pole, as compared with the conventional one. At this time, since the protective cover is made of a magnetic material, a part of the magnetic flux of the permanent magnet passes through the protective cover, and the protective cover is magnetically saturated. Since only a small amount of the total magnetic flux is required, the effect of providing the permanent magnet of increasing the magnetic flux generated by the field winding is not impaired. Therefore, the amount of magnetic flux intersecting the stator windings increases, the generated current increases, and the power generation efficiency improves. Also, when viewed from the stator side, the outer peripheral surface of the rotor becomes almost a magnetic body, so the magnetic flux pulsation in the gap that occurs when the magnetic flux goes from the stator to the rotor is reduced, which causes magnetic vibration. And noise is reduced. Furthermore, when the protective cover and the claw portion of the claw-shaped magnetic pole are joined and fixed by welding, if the material of the protective cover is a non-magnetic material such as stainless steel, the joint portion is easily corroded,
Although there is a problem of lacking durability, in the present invention, since the material of the protective cover is a magnetic body as described above, the joint between the protective cover and the claw portion of the claw-shaped magnetic pole is not corroded, and durability Is improved.

In the above vehicle alternator, preferably, the protective cover is a cylindrical continuous member. This facilitates the work of attaching the protective cover to the outer surface side of the permanent magnet and the outer peripheral surface of the claw portion of the claw-shaped magnetic pole.

Preferably, a step having at least one high step portion and a low step portion in the axial direction is formed at an outer peripheral side end portion of the claw portion of the claw-shaped magnetic pole, and the protection cover is provided with the claw portion. The outer surface of the protective cover and the outer peripheral surface of the high step portion of the claw portion are arranged in the lower step portion of the same so as to be substantially flush with each other. As a result, the protective cover and the claw portion of the claw-shaped magnetic pole can be firmly fixed, the mechanical strength of the rotor is increased, and the windage loss of the rotor is reduced.

Further, preferably, the protective cover is composed of a plate having an uneven thickness. This allows
The magnetic resistance of the protective cover becomes large, and it becomes difficult for eddy currents to flow, and eddy current loss is reduced.

Further, preferably, the protective cover is formed by axially stacking a plurality of magnetic material rings containing an insulating material, or a magnetic linear member containing an insulating material is continuously wound in the axial direction. It may be As a result, similar to the above, the magnetic resistance of the protective cover is increased, eddy currents are less likely to flow, and eddy current loss is reduced.

Further, preferably, the protective cover is fixed to a claw portion of the claw-shaped magnetic pole by welding or varnish.

Further, in order to achieve the above first and second objects, the present invention provides a pair of opposed claw-shaped magnetic poles having a plurality of claws formed at a tip portion thereof, and the claw-shaped magnetic pole. Of the permanent magnet, which is incorporated between the field winding for magnetizing the magnet and the claw portion of the claw-shaped magnetic pole and integrally molded in advance with a resin, a permanent magnet for increasing the magnetic flux generated by the field winding. A rotor that is disposed on the outer surface side and that includes a protective cover that prevents the permanent magnet from popping out; and a stator that is disposed at a predetermined distance from the rotor and that generates an AC voltage by the magnetization of the claw-shaped magnetic poles. In the vehicle alternator provided, the permanent magnet is a solid magnet, and the magnet module is formed by integrally molding the solid magnet and the protective cover arranged on the outer surface side of the solid resin.

In the above, by using a permanent magnet integrally molded as a magnet module as a solid magnet, the magnetizing force and energy product of the claw-shaped magnetic pole can be compared with the conventional magnetic powder made of resin. Becomes larger,
The magnetic flux from the claw portion of the claw-shaped magnetic pole to the stator increases, which increases the generated current and improves the power generation efficiency. Further, the magnet module is integrally molded with resin by combining the solid magnet and the protective cover arranged on the outer surface side, so that when the rotor rotates and centrifugal force acts,
The protective cover prevents the permanent magnets from popping out due to centrifugal force. Further, when assembling the rotor, it is not necessary to attach a plurality of permanent magnets one by one between the claw portions of the claw-shaped magnetic pole, and the rotor assembly efficiency is improved.

In the above-described vehicle alternator, preferably, the protective cover is provided on the outer surface side of the permanent magnet and on the inner peripheral surface side of the claw portions located at both ends of the permanent magnet. It is a member having a substantially U-shaped cross-section with a hook portion that opens to the outside at the tip.

Further, preferably, a flange portion extending in a circumferential direction is provided at an outer peripheral side end portion of the claw portion of the claw-shaped magnetic pole, and the protective cover is on the outer surface side of the permanent magnet and of the claw portion. It may be a member that is arranged on the inner peripheral side of the collar portion and has a length in the circumferential direction that is larger than the interval between the collar portion portions between the adjacent claw portions.

Further, preferably, the magnet module is fixed to a claw portion of the claw-shaped magnetic pole with a varnish.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, the vehicle alternator of the present embodiment includes a bracket 1, and the bracket 1 includes a pulley-side end bracket 1F and a non-pulley-side end bracket 1B. A shaft 41 is supported at the center of the bracket 1 via a bearing 42, a pulley 43 is attached to one end of the shaft 41, and a slip ring 10 is attached to the other end. The pulley 43 is connected to the output shaft of the engine via a belt (not shown) and rotates in proportion to the engine speed. A brush 11 is slidably attached to the slip ring 10, and electric power is supplied from the brush 11 to a field winding 4 described later.

A rotor (rotor) 2 is attached to the center of the shaft 41, and a yoke 17 is arranged inside the rotor 2. A field winding 4 is wound around the yoke 17, and the claw-shaped magnetic pole 3 is magnetized by passing a direct current from the slip ring 10 through the field winding 4. Claw pole 3, as shown in FIG. 2, oppositely disposed claw poles of a pair 3 _N, 3 consist _S, the claw poles 3 _N,
A plurality of claw portions 33 _N and 33 _S (both are collectively referred to as a claw portion 33) are formed at the tip portion of 3 _S. Claw-shaped magnetic pole 3
As shown in FIG. 3A, the claw portion 33 of the lower claw portion 33 has one low step portion 20 a and one high step portion 20 at the outer peripheral side end portion in the axial direction.
It has a structure with a step having b.

Claw portion 33 _N of claw-shaped magnetic pole 3 _{N and} claw-shaped magnetic pole 3 _S
As shown in FIG. 2, a permanent magnet 5 for auxiliary excitation is arranged on the claw portion 33 _S of the claw portion 33 _S so that the same pole is in contact with the polarity formed by the claw-shaped magnetic poles 3 _N and 3 _S. The permanent magnet 5 is a solid magnet such as a sintered magnet or a bonded magnet.

On the outer surface side of the permanent magnet 5 and the outer peripheral surface of the claw portion 33 of the claw-shaped magnetic pole 3, a magnetic material protective cover 6 for preventing the permanent magnet 5 from protruding is arranged. As shown in FIG. 2, the protective cover 6 has a cylindrical (ring-shaped) shape made of a thin plate in which a plurality of elongated holes 22 are formed in order to make it difficult for eddy currents generated on the surface of the protective cover 6 to flow. It is a continuous cover. By thus forming the protective cover 6 in the form of an integral ring, it can be easily attached to the claw-shaped magnetic pole 3 and the rotor 2 can be easily manufactured. Further, it also has an effect of preventing the rising of the claw-shaped magnetic pole 3 that occurs during high-speed rotation.

The protective cover 6 is shown in FIGS. 3 (a) and 3 (b).
As shown in FIG. 4, the outer surface of the protective cover 6 and the outer peripheral surface of the higher step portion 20b of the claw portion 33 have substantially the same thickness H as the step T of the claw portion 33. It is attached so as to become one, and the end portion of the protective cover 6 and the claw portion 3
It is fixed by welding at the welded portion 21 between the high step portions 20b of No. 3 of FIG. At this time, when the material of the protective cover is non-magnetic stainless steel as in the past, if the iron claw-shaped magnetic pole and the stainless steel protective cover are joined by welding, the joint is easily corroded and lacks durability. Will end up. In the present embodiment, since the material of the protective cover 6 is the same magnetic material as the claw-shaped magnetic pole 3, the protective cover 6 and the claw portion 33 of the claw-shaped magnetic pole 3 are used.
Even if and are joined by welding, the joint portion 21 does not corrode, and the durability is improved. Further, by providing a step on the claw portion 33 and disposing the protective cover 6 on the lower step portion 20a of the claw portion 33, the protective cover 6 and the claw-shaped magnetic pole 3 can be firmly fixed, and the mechanical strength of the rotor 2 can be increased. Goes up. Further, by making the outer surface of the protective cover 6 and the outer peripheral surface of the high step portion 20b of the claw portion 33 substantially flush with each other, the outer peripheral surface of the rotor 2 has no irregularities, and occurs when the rotor 2 rotates. Wind loss can be reduced.

Returning to FIG. 1, the pulley side end bracket 1
A stator 7 is provided between F and the end bracket 1B on the side opposite to the pulley.
4, the stator 7 is arranged with a small gap (mechanical gap) K from the rotor 2 as shown in FIG. This mechanical gap K is a predetermined interval required from the relationship of mechanical characteristics. The stator 7 has an uneven stator core 8, and a stator winding 9 is wound in three phases in a recess of the stator core 8. When the engine is driven, the claw-shaped magnetic pole 3 rotates. When magnetized, three-phase induced voltages are generated in the stator winding 9.

A rectifier circuit 12 and a voltage regulator 13 are disposed inside the end pulley 1B on the side opposite to the pulley. The rectifier circuit 12 has a B terminal 14 connected to the positive electrode of the battery (not shown) and a ground terminal 15 connected to the negative electrode of the battery, and rectifies the AC induced voltage generated in the stator winding 9 to generate a direct current. Convert to voltage.
The voltage regulator 13 controls the field winding current so that the DC voltage rectified by the rectifier circuit 12 to charge the battery is maintained at a constant voltage of about 14.3V.

In the vehicle AC generator configured as described above, when the pulley 43 rotates due to the driving of the engine, the shaft 41 rotates together with the slip ring 10 and the rotor 2, and the DC current from the brush 11 rotates. The field winding 4 inside the child 2 is energized, and the field winding 4 operates so as to form the N pole and the S pole in the claw-shaped magnetic poles 3 _N and 3 _S. The magnetic flux generated by the field winding 4 is as shown by the solid line in FIG.
What comes out of the claw portion 33 _{N of the} N-pole claw-shaped magnetic pole 3 _N forms a magnetic circuit which passes through the stator core 8 and returns to the claw portion 33 _S of the S-pole claw-shaped magnetic pole 3 _S. At this time, the magnetic flux of the permanent magnet 5 for auxiliary excitation is arranged in parallel with the magnetic flux generated by the field winding 4, and as shown by the wavy line in FIG. 4, enters from the N pole to the S pole. It has a function of increasing the magnetic flux generated by the field winding 4, and as a result, the amount of magnetic flux in the magnetic circuit increases. When the magnetic flux of this magnetic circuit crosses the stator winding 9, a three-phase induced voltage is generated in the stator winding 9. The three-phase induced voltage is converted into a DC voltage by the rectifier circuit 12, and the rectified DC voltage is adjusted by the voltage adjuster 13 and kept at a constant voltage of about 14.3V.

In the above, the protective cover 6 is arranged on the lower step portion 20a of the claw portion 33 so that the outer surface of the protective cover 6 and the outer peripheral surface of the higher step portion 20b of the claw portion 33 are substantially flush with each other. The magnetic gap between the rotor 2 and the stator 7 matches the mechanical gap K, and the reluctance between the rotor 2 and the stator 7 does not increase. At this time, since the protective cover 6 is made of a thin plate made of a magnetic material, a part of the magnetic flux of the permanent magnet 5 is short-circuited through the protective cover 6 as shown by the wavy line in FIG. The magnetic flux is magnetically saturated, but the amount of magnetic flux that magnetically saturates the protective cover 6 is only a small amount of the total magnetic flux of the permanent magnet 5, and the permanent magnet 5 that increases the magnetic flux generated by the field winding 4 is provided. It does not impair the effect. By the way, comparing this embodiment with a conventional one in which a holding member is arranged on the outer surface of the permanent magnet between the claw portions of the claw-shaped magnetic pole, the conventional one has a smaller permanent magnet by the amount of the holding member arranged. Inevitably, the magnetizing force and energy product (product of residual magnetic flux density and coercive force) of the claw-shaped magnetic pole 3 becomes small. The loss due to the reduction of the magnetization force and the energy product is larger than the loss due to the short circuit of a part of the magnetic flux of the permanent magnet 5, and as a result, the effect of providing the permanent magnet in the conventional one is smaller than that in the present embodiment. Get smaller. As described above, the amount of magnetic flux of the magnetic circuit that intersects the stator winding 9 increases, the generated current increases, and the power generation efficiency improves.

Further, when viewed from the side of the stator 7, the outer peripheral surface of the rotor 2 is almost magnetic, so that the rotor 2 and the stator 7 are
The magnetic resistance between the two becomes almost constant, and the magnetic flux pulsation between the rotor 2 and the stator 7 that occurs when the magnetic flux of the magnetic circuit goes from the stator 7 to the rotor 2 is reduced, which causes magnetic vibration. To reduce noise.

According to the present embodiment configured as described above, the protective cover 6 is made of a magnetic material, so that the power generation current can be increased and the power generation efficiency can be improved. Also,
Noise can be reduced by reducing magnetic vibrations between the rotor 2 and the stator 7. Further, the joint between the protective cover 6 and the claw-shaped magnetic pole 3 does not corrode, and the rotor 2
Can be improved in durability.

Further, since the protective cover 6 has a ring shape, the rotor 2 can be easily manufactured and the claw-shaped magnetic pole 3 can be prevented from rising up at the time of high speed rotation. In addition, the protective cover 6 is attached to the lower step portion 20 of the claw portion 33.
Since the outer surface of the protective cover 6 and the outer peripheral surface of the high step portion 20b of the claw portion 33 are arranged to be substantially flush with a, the protective cover 6 and the claw-shaped magnetic pole 3 can be firmly fixed, and The windage loss of the rotor 2 can be reduced. Further, since a plurality of elongated holes 22 are formed in the protective cover 6, the magnetic resistance of the protective cover 6 becomes large, and it becomes difficult for eddy current to flow, and the eddy current loss of the protective cover 6 can be reduced.

The protective cover 6 is not limited to one made of a thin plate having a plurality of elongated holes 22, and may be a thin plate having a plurality of elongated grooves or a thin plate having irregularities, which may be generated on the surface. Any thin plate having a non-uniform thickness may be used to make it difficult to flow.

A second embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment in that instead of the magnetic material protective cover being a ring made of a thin plate having a plurality of elongated holes, thin plates of the magnetic substance including an insulating material are stacked in the axial direction. It is a laminated core. In the figure,
The same members as those of FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 5, the protective cover 6 of this embodiment is shown.
A is an axial stack of silicon steel plates punched in a cylindrical shape so as to prevent the generation of eddy currents. In addition,
The silicon steel sheet contains several percent of insulating material. At this time,
The protection cover 6A and the claw-shaped magnetic pole 3 are fixed by welding, epoxy resin or the like.

Further, as a modification of this embodiment, the protective cover 6A is formed by continuously winding a rod-shaped plate containing an insulating material having a thickness of about 0.5 to 1.0 mm, or by insulating a bind wire or the like. A metal wire (magnetic wire) may be continuously wound. Also in this case, similarly to the above, the protective cover 6A and the claw-shaped magnetic pole 3 are fixed by welding, epoxy resin or the like. Further, when the protective cover 6A is produced by continuously winding the metal wire, it is necessary to perform varnish treatment or the like on the wound metal wire to improve the strength.

Also in this embodiment having the above-described structure, the same effect as that of the first embodiment can be obtained.

A third embodiment of the present invention will be described with reference to FIGS. In this embodiment, instead of disposing one ring-shaped protective cover on the outer peripheral surface of the claw portion of the claw-shaped magnetic pole in the first embodiment, two ring-shaped protective covers are arranged. In the figure, the same members as those of FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.

6 and 7, the claw-shaped magnetic pole 3G (N
Claw portion 33G of the claw-shaped magnetic pole 3G _N of the pole and the claw-shaped magnetic pole 3G _{S of the S} pole (the claw portion 33G _{N of the N} pole and the claw portion 33G _{S of the} S pole)
At the outer peripheral side end of the two low step portions 20 in the axial direction.
A step having a and a high step portion 20b is formed. A protective cover 6B made of a thin plate having a plurality of holes of the same type as that shown in FIG. 2 is attached to the two lower step portions 20a of the claw portion 33G, and is fixed by welding at the welding portion 21. ing.

Further, as shown in FIG. 8, two lower step portions 20a of the claw portion 33G are made by axially stacking cylindrical punched silicon steel plates of the same type as that shown in FIG. You may arrange | position the protective cover 6C.

Also in the present embodiment having the above-mentioned configuration, the same effect as that of the first embodiment can be obtained. Further, in this embodiment, since the protective covers 6B and 6C are not arranged on the outer surface side of the central portion of the permanent magnet 5, it is effective for cooling the central portion of the permanent magnet 5.

A ring-shaped protective cover 6B; 6C
Is not limited to being provided at two positions on the outer peripheral surface of the claw portion 33G of the claw-shaped magnetic pole 3G, and may be provided at three or more positions on the outer peripheral surface of the claw portion 33G.

In the first to third embodiments described above, the ring-shaped magnetic material protective covers 6; 6A; 6
Although B; 6C is attached to the claw-shaped magnetic pole 3 by welding, the present invention is not limited to this, and it may be attached by means such as varnish, shrink fit, and press fitting.

Also, the claw-shaped magnetic pole 3; claw portion 33; 33 of 3G.
G has a structure having a step in the axial direction, and the protective cover 6; 6A; 6B; 6C has a claw portion 33;
The outer surface of the protective cover 6; 6A; 6B; 6C and the claw portion 3
3; 33G is mounted so that the outer peripheral surface of the high step portion 20b is flush, but the invention is not limited to this, and the protective cover may be provided on the claw portion of the claw-shaped magnetic pole without forming a step on the claw portion of the claw-shaped magnetic pole. You may attach to the outer peripheral surface of a part. Here, when the above-mentioned structure is compared with the conventional one in which the material of the protective cover is a non-magnetic material, the magnetic gap between the rotor 2 and the stator 7 in the conventional one is the thickness of the protective cover. It becomes larger than the mechanical gap K by that amount, the magnetic resistance between the rotor 2 and the stator 7 increases, and the amount of magnetic flux that intersects the stator winding 7 decreases. The amount of decrease in the amount of magnetic flux is larger than the amount of magnetic flux in which the permanent magnet 5 magnetically saturates the protective cover 6; 6A; 6B; 6C of the magnetic body. The effect of providing is reduced.

Further, the protective cover 6; 6A; 6B; 6C
However, the present invention is not limited to this, and the ring is formed by using a plurality of protective covers arranged on the outer peripheral surface of one claw portion 33; 33G and the outer surface side of one permanent magnet 5, for example. You may make it a state.

A fourth embodiment of the present invention will be described with reference to FIGS. In the figure, the same members as those of FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

9 and 10, the vehicle alternator of the present embodiment is provided with a rotor 2 *, and the rotor 2 * has a plurality of claw portions 33 * _N , 33 * _S (both are provided at the tip end portion thereof. Are collectively referred to as claw portions 33 *), and N-pole and S-pole claw-shaped magnetic poles 3 * _N and 3 * _S (both are collectively referred to as claw-shaped magnetic poles 3 *) are included. Further, as shown in FIG. 11, a permanent magnet 5 *, which is a solid magnet such as a sintered magnet or a bond magnet, is provided between the claw portions 33 * of the claw-shaped magnetic pole 3 * and the claw-shaped magnetic pole 3 * _N and the claw-shaped magnetic pole. Three
* The claw 33 * _N and claw 3 with the largest power generation effect between _S and _N
The protective cover 6 * having a substantially U-shaped cross-sectional shape, which is disposed between the 3 * _{S and has} the hook portion 23 that opens to the outside at the tip of the leg portion, is provided on the outer surface side of the permanent magnet 5 * and the claw portion 33 *. _N ,
A ring-shaped magnet module 30 in which a plurality of permanent magnets 5 * and a protective cover 6 * are integrally molded with a resin (mold material) 16 such as an adhesive so as to be arranged on the inner surface side of 33 * _S is incorporated. There is. This magnet module 30
Is fixed to the claw-shaped magnetic pole 3 * with a varnish so that the outer peripheral surface of the magnet module 30 is not higher than the outer peripheral surface of the claw portion 33 * of the claw-shaped magnetic pole 3 *.

The protective cover 6 * is arranged such that the hook portion 23 is located on the inner peripheral side of the claw-shaped magnetic poles 3 * _N and 3 * _S , and when the rotor 2 * rotates and centrifugal force acts. , Hook 2
3 is caught on the inner peripheral surfaces of the claw-shaped magnetic poles 3 * _N and 3 * _S , which prevents the permanent magnet 5 * from popping out due to centrifugal force. Other configurations of the vehicle alternator of the present embodiment,
It is the same as that shown in FIG.

In the present embodiment configured as described above, the magnetic powder is not added to all the molding materials as in the prior art to integrally mold them, but the claw-shaped magnetic pole 3 * _N and the claw-shaped magnetic pole 3 are used.
* The claw 33 * _N and claw 3 with the largest power generation effect between _S and _N
Since the magnet module 30 is formed by disposing the individual magnets 5 * between 3 * _S and integrally molding, the claw-shaped magnetic poles 3
The magnetizing force and energy product of * increases, and the nail 33 *
_The magnetic flux from _N to the stator 2 increases. Therefore, the amount of magnetic flux intersecting the stator winding 7 increases, the generated current increases, and the power generation efficiency improves.

Since a plurality of permanent magnets 5 * and a plurality of protective covers 6 * are combined and integrally molded with the molding material 16, a ring-shaped magnet module 30 is obtained.
Permanent magnet 5 * and protective cover 6 * 1 claw pole 3
It is not necessary to mount between the * _N and 3 * _S claw portions 33 * _N and 33 * _S, and the assembly efficiency of the rotor 2 * can be improved. Further, since the protective cover 6 * is provided with the hook portion 23 and the hook portion 23 is integrally formed so as to be located on the inner peripheral side of the claw-shaped magnetic poles 3 * _N and 3 * _S , the permanent magnet 5 * is generated by centrifugal force. It can prevent popping out.

A fifth embodiment of the present invention will be described with reference to FIG. This embodiment is the same as the fourth embodiment except that the protective cover built in the magnet module 30 is replaced. In the figure, the same members as those of FIG. 11 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 12, an N-pole claw-shaped magnetic pole 3 * G _N
And claw-shaped magnetic pole 3 * G _S of _S pole 33 * G _N , 33 *
A collar portion 24 extending in the circumferential direction is provided at the outer peripheral side end portion of G _S. In the present embodiment, the individual magnets 5 * are arranged between the claw portions 33 * _GN and the claw portions 33 * G _S , and the claw portions 33 have a circumferential length on the outer surface side of each individual magnet 5 *. * G
As the protective cover 6 * A is arranged greater than the distance between the flange portion 24 portion between the _N and the claw portion 33 * G _S, these plurality of permanent magnets 5 * and the protective cover 6 * A is the molding material 16 It is integrally molded and configured as a ring-shaped magnet module 30A. Protective cover 6 * A is arranged so as to be located on the inner peripheral side of the flange portion 24 of the claw portion _{33 * G N, 33 * G} S, when the rotor 2 * worked centrifugal force by rotation, When the protective cover 6 * A is caught by the brim portion 24, the permanent magnet 5 * is prevented from popping out by the centrifugal force. Other configurations are the same as those in the fourth embodiment.

Also in the present embodiment having the above-mentioned configuration, the same effect as that of the fourth embodiment can be obtained.

In the fourth and fifth embodiments described above, the magnet modules 30; 30A are formed by integrally molding the protective covers 6 *; 6 * A, but the protective covers built in the magnet modules are The present invention is not limited to these, as long as the permanent magnet 5 * can be prevented from jumping out due to centrifugal force. Also, the magnet module 30; 30A
In the above, the permanent magnet 5 * and the protective cover 6 *; 6 * A are combined and integrally molded, but the present invention is not limited to this, and only the permanent magnet 5 * may be integrally molded. However, in this case, the claw-shaped magnetic poles 3 *; 3 * G claw portions 33 *; 33
It is necessary to attach a ring-shaped magnetic body protective cover as shown in the first to third embodiments to the outer peripheral surface of * G and the outer surface of the magnet module 30; 30A.

[0055]

According to the present invention, in the case where the protective cover for preventing the permanent magnets arranged between the claw portions of the claw-shaped magnetic pole from popping out is provided, the protective cover is provided on the outer surface side of the permanent magnet and the claw-shaped magnetic pole. Since the protective cover is arranged between the claws and the material of the protective cover is magnetic, the generated current is increased and the power generation efficiency is improved.

Further, in the case where the permanent magnets arranged between the claw portions of the claw-shaped magnetic pole are integrally molded with resin in advance and the magnet module is incorporated between the claw portions of the claw-shaped magnetic pole, the magnet module is arranged between the claw portions of the claw-shaped magnetic pole. Since the permanent magnet to be used is a solid magnet, the power generation current is increased and the power generation efficiency is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a vehicle AC generator according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a claw portion of the claw-shaped magnetic pole shown in FIG.

3 is a sectional view of a claw portion of the claw-shaped magnetic pole shown in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a perspective view of a claw portion of a claw-shaped magnetic pole according to a second embodiment of the present invention.

FIG. 6 is a perspective view of a claw portion of a claw-shaped magnetic pole according to a third embodiment of the present invention.

7 is a cross-sectional view of a claw portion of the claw-shaped magnetic pole shown in FIG.

FIG. 8 is a perspective view of a claw-shaped magnetic pole portion according to a modification of the third embodiment of the present invention.

FIG. 9 is a diagram showing an overall configuration of a vehicle AC generator according to a fourth embodiment of the present invention.

10 is a perspective view of a claw portion of the claw-shaped magnetic pole shown in FIG.

11 is a cross-sectional view of a claw portion and a magnet module of the claw-shaped magnetic pole shown in FIG.

FIG. 12 is a sectional view of a claw portion of a claw-shaped magnetic pole according to a fifth embodiment of the present invention.

[Explanation of symbols] 2 rotor 2 * rotor 3,3 _N , 3 _S , 3G, 3G _N , 3G _S claw-shaped magnetic pole 3 *, 3 * _N , 3 * _S claw-shaped magnetic pole 4 field winding 5 permanent Magnet 5 * Permanent magnet 6,6A, 6B, 6C Protective cover 6 *, 6 * A Protective cover 7 Stator 8 Stator core 9 Stator winding 16 Mold material 17 Yoke 20a Low step part 20b High step part 21 Welded part 22 hole 23 hook 24 flange portion 30,30A magnet modules _{33,33 N, 33 S, 33G,} 33G N, 33G S claw portion _{33 * N, 33 * S,} 33 * G N, 33 * G S claw portion

Claims (11)

[Claims] 1. A pair of opposed claw-shaped magnetic poles having a plurality of claws formed at a tip portion thereof, a field winding for magnetizing the claw-shaped magnetic poles, and claws of the claw-shaped magnetic poles. A rotor that includes a permanent magnet that is arranged to increase the magnetic flux generated by the field winding, and a rotor that is arranged on the outer surface side of the permanent magnet and that includes a protective cover that prevents the permanent magnet from popping out, the rotor and a predetermined rotor. In a vehicular AC generator provided with a stator arranged at a distance to generate an AC voltage by the magnetization of the claw-shaped magnetic poles, the protective cover includes an outer surface side of the permanent magnet and a claw portion of the claw-shaped magnetic poles. An alternator for a vehicle, which is disposed on the outer peripheral surface of the vehicle and is made of a magnetic material. 2. The vehicle alternator according to claim 1, wherein the protective cover is a cylindrical continuous member. 3. The vehicle alternator according to claim 1, wherein a step having at least one high-step portion and a low-step portion in the axial direction is formed at an outer peripheral side end portion of the claw portion of the claw-shaped magnetic pole. However, the protective cover is arranged at the lower step portion of the claw portion such that the outer surface of the protective cover and the outer peripheral surface of the higher step portion of the claw portion are substantially flush with each other. . 4. The vehicle alternator according to claim 1, wherein the protective cover is formed of a plate having an uneven thickness. 5. The vehicle alternator according to claim 1, wherein the protective cover is formed by axially stacking a plurality of magnetic material rings containing an insulating material. . 6. The vehicle alternator according to claim 1, wherein the protective cover is formed by continuously winding axially a magnetic linear member containing an insulating material. AC generator. 7. The vehicle alternator according to claim 1, wherein the protective cover is fixed to a claw portion of the claw-shaped magnetic pole by welding or varnish. 8. A pair of opposed claw-shaped magnetic poles having a plurality of claws formed at the tip, field windings for magnetizing the claw-shaped magnetic poles, and claws of the claw-shaped magnetic poles. It includes a magnet module incorporated with a permanent magnet for pre-molding a permanent magnet that increases the magnetic flux generated by the field winding, and a protective cover that is arranged on the outer surface side of the permanent magnet and prevents the permanent magnet from popping out. In a vehicle alternator comprising a rotor and a stator that is arranged at a predetermined distance from the rotor and generates an AC voltage by the magnetization of the claw-shaped magnetic poles, wherein the permanent magnet is a solid magnet, The AC module for a vehicle, wherein the magnet module is formed by combining the solid magnet and the protective cover arranged on the outer surface side and integrally molding the resin. 9. The vehicle alternator according to claim 8, wherein the protective cover is arranged on an outer surface side of the permanent magnet and an inner peripheral surface side of a claw portion located on both end sides of the permanent magnet. An alternator for vehicles, which is a member having a substantially U-shaped cross-sectional shape in which hook portions that open to the outside are provided at the tips of the leg portions. 10. The vehicular AC generator according to claim 8, wherein a circumferentially extending flange portion is provided at an outer peripheral side end portion of the claw portion of the claw-shaped magnetic pole, and the protective cover is the permanent magnet. Is disposed on the outer surface side of the claw portion and on the inner peripheral side of the collar portion of the claw portion, and is a member having a circumferential length that is larger than the interval between the collar portion portions between the adjacent claw portions. AC generator for vehicles. 11. The vehicular AC generator according to claim 8, wherein the magnet module is fixed to a claw portion of the claw-shaped magnetic pole with a varnish.