JPH06113505A - Ac generator for vehicle - Google Patents

Abstract

PURPOSE:To provide an AC generator for vehicle in which cooling performance is enhanced by increasing the flow rate of cooling air. CONSTITUTION:Extending parts 15a, 15b of flanges 13a, 13b on the opposite ends of a coil bobbin 11 are inserted into a U-groove part 14 defined by adjacent pole cores 9a, 9a and 9b, 9b to constitute the bottom part in the axial direction of the U-groove part 14 thus producing fan effect on the side faces at the shoulder parts of the pole cores 9a, 9b. Furthermore, cooling fans 16a, 16b are fixed not to interfere with the U-groove part 14 thus feeding the cooling air smoothly and increasing the flow rate of cooling air. Joule's heat transmitted from a field winding 10 to the extending parts 15a, 15b is discharged to the cooling air through the extending parts 15a, 15b functioning as radiation fins.

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.

[0002]

2. Description of the Related Art The cooling of the field winding of a conventional internal fan type AC generator for a vehicle is performed by forced ventilation on the surface of the field winding. Then, a shield plate is provided so that the cooling air sucked from the drive end side and the cooling air sucked from the rear end side are not interfered with each other, so that the cooling air can be smoothly introduced and the cooling effect can be enhanced. 60-134
No. 77 publication.

[0003]

However, in order to meet the demand for miniaturization and high output of the vehicle alternator, the excitation AT (ampere turn) is increased by increasing the wire diameter of the field winding and the number of windings. Is required. Therefore, the outer diameter of the field winding is increased to increase the ventilation resistance, while the size of the frame is suppressed, so that the cooling air volume is reduced and a sufficient cooling effect cannot be obtained. .
The present invention has been made to solve the above problems,
It is an object of the present invention to provide a vehicle alternator in which the cooling air volume is increased and the cooling performance is improved.

[0004]

As a concrete means for achieving the above object, a coil bobbin around which a field winding is wound is formed of a high thermal conductive material, and an outer peripheral portion of a rotor on which the coil bobbin is fitted. Of the flange of the coil bobbin between the pole cores of the above, to form a conductive heat radiation fin that radiates heat generated by energization of the field winding, and a cooling fan fixed to the side end surface of the heat radiation fin and the pole core. There is provided a vehicle alternator characterized by preventing the interference with the axial direction.

[0005]

According to the above vehicle alternator, the Joule heat generated in the field winding due to energization is conducted from the coil bobbin formed of the high thermal conductive material to the pole core, and is cooled by the cooling air sent by the cooling fan. To be done. Further, since the radiation fins and the cooling fan fixed to the side end surface of the pole core do not interfere with each other in the axial direction, the cooling air flows between the pole cores and promotes the radiation of the Joule heat conducted to the cooling fins.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The overall structure of a vehicle AC generator of the present invention will be described with reference to FIG. The shape of the drive frame 1 forming the outer shell of the vehicle alternator is roughly a bowl shape, and the rear end frame 3 made of aluminum die cast with the opening on the rear end side as the ventilation hole 2 for the cooling air is the end frame connecting bolt. They are connected by fastening means such as 4. A stator 5 is fixed inside the drive frame 1 by a method such as press fitting. The stator 5 is composed of a stator core 5a and a stator coil 5b wound around the stator core 5a.

A cylindrical bearing portion 1a is formed in the central portion of the side surface of the drive frame 1 on the drive end side to form a bearing 6
Is installed. In addition, the rear end frame 3
A cylindrical bearing 3a is formed in the center of the bearing, and a bearing 7 is attached to the bearing. The shaft 8 is rotatably supported by these bearings 6 and 7. A pair of pawl-attached pole cores 9a and 9b are fixedly fitted to the shaft 8 so as to be located inside the stator 5, and the pawls are inserted between the opposing pawls. A coil bobbin 11 having a field winding 10 wound thereon is externally fitted and fixed to the central portions of the pole cores 9a and 9b. The shaft 8 and the pole cores 9a, 9
The rotor 12 is constituted by b, the coil bobbin 11, and the like.

The coil bobbin 11 is formed of a material such as a copper plate which is non-magnetic and has high thermal conductivity. Then, as shown in FIG. 3, the flanges 13a and 13b at both ends have an extension portion 15 having a shape matching the U-shaped groove portion 14 formed by the adjacent pole cores 9a and 9a and 9b and 9b.
a and 15b are provided. These extensions 15a and 15b
Are respectively inserted into the U-shaped groove portions and form the axial bottom portions of the U-shaped groove portions. Each pole core 9 adjacent to the side surfaces of the drive frame 1 and the rear end frame 3
On the side end surfaces of a and 9b, the cooling fans 16a and 16b do not interfere with the U-shaped groove portion 14 (cooling fans 16a and 16b).
16b and the extension portions 15a and 15b of the flanges 13a and 13b of the coil bobbin 11 are attached so as not to overlap each other in the axial direction).

A plurality of air inlets 17a and an air outlet 17b are formed on the drive end side of the drive frame 1, and a plurality of air outlets 17c are formed on the rear end side. A pulley 18 is fastened to an end of the shaft 8 on the drive end side by a nut 19, and the pulley 18 transmits the rotation of an engine (not shown) to the shaft 8.

On the rear end side of the other end of the shaft 8,
A slip ring 20 is fitted on the outer side of the rear end frame 3. A brush holder 22 that slides on the slip ring 20 and internally holds a brush 21 that supplies an exciting current to the field winding 10 is provided. A rectifying device 24 is mounted between the rear end frame 3 and a rear end cover 23 that covers the rear end frame 3. The rear end cover 23 is formed with a plurality of air inlets 25 for taking in the air for cooling the generator and a ventilation port 26 for letting the cooling air applied to the rectifying device 24 through.

The field winding 10 is directly wound when the coil bobbin 11 is made of a non-conductive material.
If it is made of a conductive material, the coil bobbin 11
The outer surface of is subjected to thin film insulation treatment such as electrodeposition coating, and the field winding 10 is wound while maintaining mutual insulation.

Next, the operation of the above embodiment will be described. Field winding 1 via brush 21 and slip ring 20
When the shaft 8 is rotated by the engine via the pulley 18 and the rotor 12 is rotated while the current is supplied to 0, an alternating current is induced in the stator coil 5b. The induced alternating current is rectified by the rectifier 24 and output to the load. At this time, the stator coil 5 of the generator
b, Joule heat is generated in the field winding 10 and the rectifying device 24, and the temperature thereof rises. The Joule heat generated in the field winding 10 is conducted from the coil bobbin 11 to the pole cores 9a and 9b, and also directly to the extension portion 1 of the flanges 13a and 13b.
Conducted to 5a and 15b.

With the rotation of the shaft 8, the cooling fan 16
On the drive end side of the drive frame 1, the cooling fan 16a causes the air introduction port 17a to rotate.
The cooling air flowing from the air outlet 17b to the air outlet 17b is generated. Also,
The cooling fan 16b allows cooling air to flow through the rear end cover 23.
It is forcibly taken in from the air introduction port 25 and the ventilation port 26 formed in the above. The air taken in from the air inlet 25 is
Air exhaust port 17c through the ventilation port 2 of the rear end frame 3
The cooling air exhausted from the stator cools the stator 5 and the pole cores 9a and 9b.

Flanges 13 at both ends of the coil bobbin 11
The extension portions 15a and 15b provided on the a and 13b are inserted into the U-shaped groove portion 14 formed by the adjacent pole cores 9a and 9a and 9b and 9b, and the U-shaped groove portion 14 has an axial bottom portion. , The fan effect is generated on the side surfaces of the shoulder portions of the pole cores 9a, 9b, and the cooling fans 16a, 1
Since 6b is attached so as not to interfere with the U-shaped groove, the flow of the cooling air becomes smooth,
The cooling air volume increases. In addition, the extension portions 15a and 15b
The Joule heat of the field winding 10 that has been conducted to the cooling air is radiated to the cooling air from the extension portions 15a and 15b that act as radiation fins. The cooling air from the ventilation port 26 is rectified by the rectifying device 2
4 is cooled and discharged from the air discharge port 17c.

Although the entire coil bobbin 11 is made of a metal material having high thermal conductivity in the above embodiment, only the extension portions 15a, 15b of the flanges 13a, 13b are made of a metal material having high thermal conductivity. Good.

[0016]

As described above, the vehicular AC generator of the present invention has a structure in which the extension portion provided on the flange of the coil bobbin made of a highly heat-conductive material faces the adjacent pole cores as a heat radiation fin. A fan effect is generated on the side surface of the shoulder, and the cooling fan is installed so as not to interfere with the heat radiation fins, so that the flow of cooling air becomes smooth and the amount of cooling air increases, resulting in the heat radiation from the cooling fins. This has the effect of being promoted and improving the cooling performance.

[Brief description of drawings]

FIG. 1 is a front view of a vehicle alternator showing a cross section of an upper half and a part of a rear side.

FIG. 2 is a perspective view of a rotor.

FIG. 3 is a front view of a part of the coil bobbin.

[Explanation of symbols]

9a, 9b ... Pole core, 10 ... Field winding, 11 ...
Coil bobbin, 12 ... Rotor, 13a, 13b ... Flange, 15a, 15b ... Extension part (radiation fin), 16
a, 16b ... Cooling fan.

Claims (1)

[Claims] 1. A coil bobbin around which a field winding is wound is formed of a material having high thermal conductivity, and an extended portion of a flange of the coil bobbin is faced between pole cores of an outer periphery of a rotor on which the coil bobbin is fitted. A heat radiation fin that conducts and discharges heat generated by energization of the field winding is provided, and the heat radiation fin and a cooling fan fixed to a side end surface of the pole core do not interfere in the axial direction. AC generator for vehicles.