JP3362694B2 - AC generator for vehicles - Google Patents

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 mounted on a passenger car, a truck or the like.

[0002]

2. Description of the Related Art In a general vehicle alternator,
A rectifying device is incorporated to rectify an AC induced voltage generated in the stator windings wound around the stator core when the rotor is rotated. For example, when the stator winding is composed of three phases, a rectifying device including two rectifying elements, two for each phase, totaling six rectifying devices is provided, and three-phase full-wave rectification is performed by this rectifying device. . For example, in French Laid-Open Publication No. 2734425, a positive-side radiating plate in which a positive-side rectifying element is press-fitted, a negative-side radiating plate in which a negative-side rectifying element is press-fitted, a positive-side radiating plate, and a negative-side radiating plate are disclosed. And a wiring member electrically connecting one ends of the rectifying elements press-fitted into each of the above.

[0003]

By the way, the rectifier used in the vehicle alternator disclosed in the above publication is attached to the negative-side heat radiating plate just outside the outer peripheral edge of the positive-side heat radiating plate. Since the leads of the rectifying element are located at the rear side, if foreign matter such as water or electrolyte enters the interior of the vehicle alternator from the rear side, it will flow on the surface of the heat sink on the positive side and the rectifying element on the negative side. There is a problem in that these liquids are likely to adhere to the gap portion formed between the joint portion and the outer peripheral edge of the positive electrode side heat dissipation plate, resulting in poor insulation.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle alternator capable of preventing the occurrence of insulation failure in a rectifier.

[0005]

In order to solve the above-mentioned problems, a vehicle AC generator of the present invention electrically connects a radiator plate to which a rectifying element is attached, a rectifying element and a stator winding. A rectifying device having a terminal block having a wiring member to be connected is provided, and a part of the terminal block included in the rectifying device is extended in the rotation axis direction of the rotor, so that the rectifying element is a wiring member. A partition wall is formed between the heat radiating plate and the joint that is joined to. By arranging a partition wall extending from the terminal block in the rotation axis direction between the above-mentioned joining portion and the heat dissipation plate, foreign matter such as electrolytic solution that invades along the heat dissipation plate adheres and stays near the joining portion. Since this can be prevented, it becomes possible to reduce the insulation failure that occurs in the rectifier.

The partition wall is formed so as to face the covering member that covers the rectifying device, and the height of the partition wall is higher than the position of the end surface of the heat dissipation plate adjacent to the partition wall in the direction of the rotation axis or the joint portion. It is desirable to set the position higher than the end position in the rotation axis direction. By setting the formation direction and the height of the partition wall in this way, it is possible to effectively prevent the water, the electrolytic solution, and the like that have entered along the heat dissipation plate from reaching the joint portion.

Further, the above-mentioned covering member is a cover for covering from outside the rectifying device attached to the outside of the frame for indicating the stator in a rotatable state, and sandwiching the partition wall,
It is desirable to dispose the suction window of the cover on the radially inner side and the joint portion on the radially outer side. When the suction window of the cover and the respective joints of the rectifying device are arranged in this way, foreign matter such as water or electrolytic solution that enters through the suction window will flow radially outward along the heat dissipation plate. Since the above-mentioned partition walls prevent these foreign matters from reaching the joint, it is possible to prevent the occurrence of insulation failure or the like that occurs near the joint.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A vehicle alternator according to an embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing the overall construction of a vehicle AC generator. 2 is a view of the vehicular AC generator shown in FIG. 1 as viewed from the rear side, and shows a state in which the rear cover is removed. Vehicle AC generator 1 of the present embodiment
Includes a stator 2, a rotor 3, frames 4, 5, a rectifying device 6, a brush device 7, a voltage regulator 8, a rear cover 9 and the like.

The stator 2 includes a stator core 22, a three-phase stator winding 23, and an insulator 24 that electrically insulates the stator core 22 and the stator winding 23 from each other.

The rotor 3 has six field windings 31, each of which is a cylindrical and concentric winding of an insulated copper wire.
By the pole core 32 having the individual claw portions, the rotating shaft 33
It has a structure sandwiched from both sides. Also,
A cooling fan 35 for discharging the cooling air sucked from the front side in the axial direction and the radial direction is attached to the end surface of the front side pole core 32 by welding or the like. Similarly, a cooling fan 36 for radially discharging the cooling air sucked from the rear side is attached to the end surface of the rear side pole core 32 by welding or the like. In the vicinity of the rear end of the rotating shaft 33, two slip rings 37 electrically connected to both ends of the field winding 31,
38 is formed, these slip rings 37,
Power is supplied from the brush device 7 to the field winding 31 via 38.

The frames 4 and 5 accommodate the stator 2 and the rotor 3, and the rotor 3 is supported in a rotatable state about a rotation shaft 33, and the pole core 32 of the rotor 3 is supported. The stator 2 arranged on the outer peripheral side with a predetermined gap is fixed. These frames 4, 5
Stator winding 2 protruding from the axial end surface of the stator core 22
3 has cooling air discharge windows 41 and 51 in a portion facing 3
Suction windows 42 and 52 are provided on the axial end faces.

The rectifying device 6 is for rectifying a three-phase AC voltage generated by the three-phase stator winding 23 to obtain a DC current. In addition, the rear cover 9 as a protective member
Is attached so as to cover the rectifying device 6, the brush device 7, and the voltage regulator 8 which are attached to the outside of the frame 5, and protects these from foreign matter. Detailed structures of the rectifying device 6 and the rear cover 9 will be described later.

A vehicle alternator 1 having the above-mentioned structure.
When the rotational force from the engine (not shown) is transmitted to the pulley 20 via the belt or the like, the rotor 3 rotates in a predetermined direction. By applying an exciting voltage from the outside to the field winding 31 of the rotor 3 in this state, each claw portion of the pole core 32 is excited and a three-phase AC voltage can be generated in the stator winding 23. A predetermined DC power is taken out from the output terminal of the rectifier circuit 6.

Next, detailed shapes of the rectifying device 6 and the rear cover 9 will be described. FIG. 3 is a diagram showing a detailed shape of the terminal block included in the rectifying device 6, and shows a plan view of the terminal block as seen from the rear side (rear cover side).

As shown in FIGS. 1 and 2, the rectifying device 6
Is a negative-side heat dissipation plate 62 having a predetermined distance in the rotation axis direction.
And a positive electrode side heat dissipation plate 63, a terminal block 61 arranged between them, a plurality of (for example, four) negative electrode side rectifying elements 65 attached to the negative electrode side heat dissipation plate 62, and a positive electrode side heat dissipation plate 63. It is configured to include a plurality of (for example, four) positive electrode side rectifying elements 66 attached.

The heat sink 62 on the negative electrode side has an arc shape having an outer diameter substantially equal to the inner diameter of the rear cover 9, and the negative electrode side rectifying elements 65 are soldered at four positions along the circumferential direction at predetermined intervals. It is attached by joining by welding or welding. Wiring lead wires 68 extend from the non-joining surfaces of the four negative electrode side rectifying elements 65, and the wiring lead wires 68 are joined to the wiring electrodes 69 exposed from the terminal block 61 by welding or the like.

The positive-side heat dissipation plate 63 has an arc shape having an outer diameter smaller than the outer diameter of the negative-side heat dissipation plate 62, and the positive-side rectifying element is provided at four positions along the circumferential direction at predetermined intervals. 6
6 is attached by joining by soldering or welding. Wiring lead wires extend from the non-joining surfaces of the four positive electrode side rectifying elements 66, and the wiring lead wires are joined to the wiring electrodes 69 exposed from the terminal block 61 by welding or the like. Further, the outer diameter of the positive electrode side heat dissipation plate 63 is set to be larger than the inner diameter of the negative electrode side heat dissipation plate 62, and the positive electrode side heat dissipation plate 63 and the negative electrode side heat dissipation plate 62 partially overlap along the rotation axis direction. Are arranged.

The negative electrode side rectifying element 65 and the positive electrode side rectifying element 66 described above are provided in total of four sets, one set being located close to each other, and one set is included in each set. The negative electrode side rectifying element 65 and one positive electrode side rectifying element 66 are joined to a common wiring electrode 69 provided inside and outside the terminal block 61. The wiring electrode 69 is connected to a lead wire drawn from the stator winding 23 by screwing or the like, and the four lead wires of the stator winding 23 (for each phase of the three-phase winding). Each of the three lead wires drawn from the end and the lead wire drawn from the neutral point connecting the respective phases of the three-phase windings is connected to each of the four wiring electrodes 69 corresponding to each set. Connections are made in a one-to-one correspondence.

FIG. 4 shows a vehicle AC generator 1 according to this embodiment.
It is a connection diagram of. As shown in FIG. 4, one end of each of the four negative electrode side rectifying elements 65 is commonly connected by a negative electrode side heat dissipation plate 62, and is grounded via the frame 5.
Further, the four positive electrode side rectifying elements 66 are commonly connected at one end thereof by the positive electrode side heat dissipation plate 63, and are connected to the output terminal 73 fixed to a part of the positive electrode side heat dissipation plate 63.

In the terminal block 61 whose detailed shape is shown in FIG. 3, the wiring electrode 69-1a and the wiring electrode 69-1 are provided.
b corresponds to a pair of the negative electrode side rectifying element 65 and the positive electrode side rectifying element 66 arranged at the end portion in the counterclockwise direction, and together with the wiring electrodes 69-1c provided in the vicinity thereof, the terminal block 61 It is commonly connected inside the. Similarly, the wiring electrode 69-2a and the wiring electrode 69-2b correspond to one set of the negative electrode side rectifying element 65 and the positive electrode side rectifying element 66 arranged second from the end in the counterclockwise direction. , And the wiring electrodes 69-2c provided in the vicinity thereof are commonly connected inside the terminal block 61. Wiring electrode 6
9-3a and the wiring electrode 69-3b are arranged second from the end in the clockwise direction to form a set of negative electrode side rectifying elements 65.
Corresponding to the positive electrode side rectifying element 66, and is commonly connected inside the terminal block 61 together with the wiring electrodes 69-3c provided in the vicinity thereof. A pair of the negative electrode side rectifying element 65 and the positive electrode side rectifying element 66 in which the wiring electrode 69-4a and the wiring electrode 69-4b are arranged at the ends in the clockwise direction.
And is commonly connected inside the terminal block 61 together with the wiring electrodes 69-4c provided in the vicinity thereof.

Further, the terminal block 61 of the present embodiment has four wiring electrodes 69-1a, 69-2a, 69-3a, 69.
-4a has four partition walls 71 corresponding to each. In each partition wall 71, when the rectifying device 6 is assembled, the joint portion 72 between any one of the wiring electrodes 69-1a to 69-4a and each negative electrode side rectifying element 65 has the positive electrode side heat radiating plate 6.
It is formed between the joint portion 72 and the outer peripheral edge of the positive-side heat dissipation plate 63 so as to be sufficiently separated from the outer peripheral edge of 3. Further, each partition 71 includes a positive-side heat dissipation plate 63 and a negative-side heat dissipation plate 6.
It is formed integrally with the terminal block 61 disposed at a position sandwiched between the two, and the direction of the rotation axis is so as to block the periphery of the corresponding joint portion 72 and the outer peripheral edge of the positive-side heat dissipation plate 63. It is formed as a curved surface-shaped partition extending to the. For example,
The partition wall 71 is formed by molding the terminal block 61 with a resin material.
Although it is desirable to integrally form the mold by devising this mold shape, the separately formed partition 71 may be assembled by welding or the like after the terminal block 61 having no partition 71 is molded.

FIG. 5 is a view showing the axial height of the partition wall 71, and shows a partially enlarged cross section of the rectifying device 6 including the joint 72 and the partition wall 71. As shown in FIG. 5, the height of the partition wall 71 along the rotation axis direction needs to be higher than the surface position of the adjacent positive electrode side heat dissipation plate 63 (A> 0). By projecting the partition wall 71 from the surface position of the adjacent positive electrode side heat dissipation plate 63 along the rotation axis direction, water, an electrolytic solution, or the like that permeates into the joint portion 72 side along the surface of the positive electrode side heat dissipation plate 63. It is possible to prevent the joint portion 72 from directly reaching. Further, the height of the partition wall 71 along the rotation axis direction is preferably the same as or higher than that of the adjacent joint portion 72 (B ≧ 0).
By forming the partition wall 71 so that the joint 72 is completely covered when viewed from the infiltration direction of the water or the electrolytic solution flowing along the surface of the positive-side heat dissipation plate 63, the water intruded into the inside of the rear cover 9 It is possible to reliably prevent the electrolytic solution and the like from reaching the joint portion 72. The upper limit of the height of the partition wall 71 along the direction of the rotation axis is the position where it comes into contact with the rear cover 9, but in order to prevent the infiltration of water, electrolytic solution, etc., a small gap is formed between the partition wall 71 and the rear cover 9. It is desirable to set the height of the partition wall 71 so that the partition wall 71 is formed or completely contacts the rear cover 9.

FIG. 6 is a plan view showing the detailed shape of the rear cover 9. As shown in FIG. 6, the rear cover 9 is formed so as to cover the entire rectifying device 6, and
A plurality of suction windows 91 for taking in outside air (cooling air) for cooling are provided at positions corresponding to the positive electrode side heat dissipation plate 63. That is, the suction window 91 of the rear cover 9 is arranged on the radially inner side with the partition wall 71 interposed therebetween, and the wiring lead wire 68 of the negative side rectifying element 65 and the wiring electrode 69 of the terminal block 61 are arranged on the radially outer side. The joining portion 72 that joins is arranged. Therefore, the cooling air taken in through these suction windows 91 and foreign matters such as water and electrolytic solution taken in together with the cooling air mainly flow radially outward along the positive-side heat dissipation plate 63, and then, on the negative-electrode side. It reaches the heat sink 62. At that time, since the partition wall 71 is formed in the vicinity of a part of the outer peripheral edge of the positive electrode side heat dissipation plate 63, the flow of the cooling air and the foreign matter described above is partially blocked by the partition wall 71. Also becomes difficult to reach the joint portion 72 arranged on the outer peripheral side.

As described above, in the vehicular AC generator 1 of the present embodiment, by extending a part of the terminal block 61 included in the rectifying device 6 in the rotational axis direction, the positive electrode side heat dissipation plate 6 is formed.
In the space between the outer peripheral edge of No. 3 and the joint 72, four partition walls 71 are provided.
Is formed. Therefore, the suction window 91 of the rear cover 9
Even when foreign matter such as water or electrolytic solution infiltrates with the cooling air, it is possible to prevent these foreign matter from reaching the joint portion 72 along the surface of the positive electrode side heat dissipation plate 63. Therefore, even when the joint portion 72 is not subjected to the insulation treatment, it is possible to prevent the occurrence of a defect such as a defective insulation due to the adhesion of the foreign matter in the vicinity of the joint portion 72, and the environment resistance. Can be improved. Even when the joint 72 is subjected to insulation treatment, the insulation treatment layer may deteriorate due to long-term use, or may have uneven coating from the beginning and thus may not function effectively. Therefore, forming the above-described partition wall 71 in the vicinity of the joint portion 72 is an effective means for preventing the occurrence of insulation failure and the like.

FIG. 7 is a plan view showing a modified example of the rectifying device 6 used in the vehicle alternator described above. Also,
FIG. 8 is a partially enlarged view of the rectifying device 6A shown in FIG. 7, and shows a detailed structure near the partition wall. As shown in FIGS. 7 and 8, the rectifying device 6A includes a negative-side heat dissipation plate 162 to which six negative-side rectifying elements 65 are attached and a positive-side heat dissipation plate to which six positive-side rectifying elements 66 are attached. 16
3 and two negative electrode side rectifying elements 62 and two positive electrode side rectifying elements 63 as a set, and a terminal block 161 for wiring.

Negative-side rectifying elements 65 are attached to the negative-side heat dissipation plate 162 at six positions along the circumferential direction at predetermined intervals by joining such as soldering or welding, and the joining positions are even. Instead of being dispersed, two pieces are arranged unevenly. Similarly, the positive-side heat sink 163
The positive electrode side rectifying elements 66 are attached at six positions along the circumferential direction at predetermined intervals by joining by soldering, welding, or the like, but the joining positions are not uniform, and the above-described negative electrode side heat dissipation plate is used. In 162, the two negative electrode side rectifying elements 65 are arranged in a biased manner.

As described above, the negative-side rectifying element 65 and the positive-side rectifying element 66 included in the above-described rectifying device 6A each have two sets, and a total of four sets are provided as a total of three sets. There is. The two negative electrode side rectifying elements 65 and the two positive electrode side rectifying elements 66 included in each set are the terminal block 16
It is joined to each of the plurality of wiring electrodes 169 provided in the No. 1. Further, the wiring electrode 169 is connected to each of the three lead wires drawn from the stator winding. For example, in the rectifying device 6A shown in FIG. 7, each lead wire drawn from the stator winding has a wiring electrode 169.
Are joined by soldering or welding. In this embodiment, three wiring electrodes 169-1, 169-2, 169-3 are provided corresponding to the three sets of rectifying elements. For example, in the wiring electrode 169-2, as shown in FIG. 8, the terminal 169-2a is connected to the lead wire of the stator winding, and the terminals 169-2b and 169-2c are connected to the rectifying elements 65 and 65, respectively. It

FIG. 9 is a wiring diagram of a vehicle AC generator using the rectifying device 6A shown in FIG. As shown in FIG. 9, one end of the two negative electrode side rectifying elements 65 and one end of the two positive electrode side rectifying elements 66 are commonly connected corresponding to each phase of the three-phase stator winding. ing. The other ends of the six negative electrode side rectifying elements 65 are commonly connected by the negative electrode side heat dissipation plate 162, and are grounded via the frame.
The other ends of the six positive-side rectifying elements 66 are commonly connected by the positive-side heat dissipation plate 163, and are connected to an output terminal (not shown) fixed to a part of the positive-side heat dissipation plate 163. . As shown in FIG. 9, when a rectifying device that does not include a rectifying element corresponding to the neutral point of the stator winding is used, a stator winding having a Y connection is used instead of a fixed winding having a Δ connection. You may make it use a child winding.

Further, the terminal block 161 included in the above-described rectifying device 6A has the negative electrode side rectifying element 65 and the wiring electrode 169.
It has a partition 171 formed so as to block between a joining portion 172 that joins and the outer peripheral edge of the positive electrode side heat dissipation plate 163 located around the joining portion 172. This partition 17
1 corresponds to the partition wall 71 shown in FIG.
The height thereof is set higher than the surface position of the positive electrode side heat dissipation plate 163 or higher than the end position of the joint 172. By forming the partition wall 171, it is possible to prevent foreign matters such as water and electrolyte flowing along the surface of the positive-side heat dissipation plate 163 from reaching the joint 172.

The terminal block 161 has the partition wall 17 described above.
In addition to No. 1, a joining portion 173 where any lead wire of the stator winding and the wiring electrode 169 are joined, and the joining portion 173.
The partition wall 174 is formed so as to shield the outer peripheral edge of the positive-side heat dissipation plate 163 located around the. For example, the partition wall 174 is formed in a U shape so as to cover the joint portion 173 as shown in FIG. 8, and its height is higher than the surface position of the positive electrode side heat dissipation plate 163, or the joint portion 173. Is set higher than the end position. By forming the partition wall 174 as described above, the positive electrode side heat dissipation plate 16
Foreign matter such as water or electrolyte flowing along the surface of the joint 3
It is possible to prevent 73 from being reached. In this embodiment, two partition walls 171 are arranged on both sides of a partition wall 174 that surrounds a joint 173 that joins the wiring electrode 169 and the lead wire of the stator winding, and these partition walls 174, 171.
Three joining work places surrounded by are provided.

As shown in FIG. 8, two partition walls 171 and 1 are provided.
By forming the two partition walls 174 at close positions,
There is an advantage that the rigidity of this portion can be increased. In addition, a slit 175 is formed between the adjacent partition walls 171 and 174.
Alternatively, it is desirable to form a gap portion instead of this. By forming the slits 175 and the like, the water and the electrolytic solution that have infiltrated along the surface of the positive electrode side heat dissipation plate 163 can be separated from the partition wall 1.
It is possible to prevent staying in a dense portion of 71 or 174. In this embodiment, partition walls 171 and 174 are provided for all of the plurality of joint portions 172 and 173, which are nine in total.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention. In the rectifying devices 6 and 6A of the above-described embodiments, the partition walls 71 and 171 have a curved surface shape extending in the rotation axis direction, but the partition wall 71 and the like may be configured by a flat surface. In this case, in addition to the case where the partition 271A is composed of one flat plate as shown in FIG. 10, two flat plates are crossed at a right angle or at another angle as shown in FIG. There may be a case where the partition wall 271B having a die-shaped cross-sectional shape is formed, or a case where a partition wall 271C having a U-shaped cross-sectional shape is formed by intersecting three flat plates as shown in FIG.
In order to reliably prevent the intrusion of water, electrolytic solution, etc. into the joint portion, a partition wall 27 in which at least two flat plates are combined is used.
It is desirable to use 1B or 271C.

Further, in the above-described embodiment, the rectifier in which the positive-side heat sink is arranged on the rear side of the negative-side heat sink is used, but the negative-side heat sink is on the rear side of the positive-side heat sink. You may make it use the rectification | straightening device arrange | positioned at.

Further, in the above-described embodiment, the partition 71 and the positive-side heat dissipation plate 6 are arranged more than the spacing between the partition 71 and the joint 72.
Although it is illustrated in FIG. 2 and the like so that the distance between the partition wall 71 and the outer peripheral edge of the partition wall 3 is narrower,
It may be wider than the space between the outer peripheral edge of the positive electrode side heat dissipation plate 63. In this case, even when water droplets such as an electrolytic solution adhere to the vicinity of the partition wall 71, they pass through the gap between the partition wall 71 and the outer peripheral edge of the positive electrode side heat dissipation plate 63, which are set to a wider interval. Since the water droplets are sucked into the heat sink 62 on the negative electrode side, the partition wall 71 and the joint 72 located on the opposite side are absorbed.
It is possible to prevent the water droplets from staying in the gap portion between and.

[Brief description of drawings]

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

FIG. 2 is a view of the vehicle AC generator shown in FIG. 1 viewed from the rear side with a rear cover removed.

FIG. 3 is a diagram showing a detailed shape of a terminal block included in the rectifying device.

FIG. 4 is a connection diagram of the vehicle alternator of the present embodiment.

FIG. 5 is a diagram showing an axial height of a partition wall.

FIG. 6 is a plan view showing a detailed shape of a rear cover.

FIG. 7 is a plan view showing a modified example of the rectifying device.

FIG. 8 is a partially enlarged view of the rectifying device shown in FIG.

9 is a connection diagram of a vehicle AC generator that uses the rectifier shown in FIG. 7.

FIG. 10 is a perspective view showing a modified example of the partition wall formed on the terminal block of the rectifying device.

FIG. 11 is a perspective view showing a modified example of the partition wall formed on the terminal block of the rectifying device.

FIG. 12 is a perspective view showing a modified example of the partition wall formed on the terminal block of the rectifying device.

[Explanation of symbols]

1 Vehicle AC generator 2 stator 3 rotor 4,5 frames 6 Rectifier 9 Rear cover 61 terminal block 62 Negative heat sink 63 Positive heat sink 65 Negative side rectifier 66 Positive side rectifier 71 partition

Claims (4)

(57) [Claims] 1. A vehicular AC generator comprising: a rectifying device that rectifies an AC voltage induced in a stator winding by rotating a rotor; and a covering member that covers the rectifying device. A heat sink with a rectifying element attached,
It has a terminal block having a wiring member that electrically connects the rectifying element and the stator winding, by extending a part of the terminal block in the rotation axis direction of the rotor, A vehicular AC generator, characterized in that a partition wall is formed between the heat dissipation plate and a joint for joining a rectifying element to the wiring member. 2. The partition wall according to claim 1, wherein the partition wall is formed toward the covering member, and the height of the partition wall is set higher than an end surface position of the heat dissipation plate adjacent to the partition wall in the rotation axis direction. An alternator for vehicles, which is characterized by: 3. The partition wall according to claim 1, wherein the partition wall is formed toward the covering member, and a height of the partition wall is higher than an end position of the joint portion adjacent to the partition wall in the rotation axis direction. Vehicle alternator characterized by setting. 4. The cover member according to claim 1, wherein the covering member is a cover that covers the rectifying device, which is attached to an outer side of a frame that supports the stator in a rotatable state, from the outside. An AC generator for a vehicle, comprising: a cooling air intake window formed in the cover on the radially inner side and a joint portion on the radially outer side with the partition wall interposed therebetween.