JP4906909B2 - AC generator for vehicles - Google Patents

Description

  The present invention relates to a vehicular AC generator, and more particularly to a terminal treatment of a lead conductor of a stator winding.

  In a conventional vehicle alternator, the joining piece provided on the metal terminal is caulked and fixed so that the end of the lead conductor is embraced from both sides, and the part between the joining pieces embraced from both sides is a part of the lead conductor. Was arc welded in the vicinity of the notch provided on the tip end side of the joining piece so as to expose the wire, and the lead conductor of the stator winding and the metal terminal were joined and fixed (for example, see Patent Document 1). .

JP 2001-231209 A

  However, in conventional AC generators for vehicles, since the gap between the joining pieces that embed the end of the lead conductor from both sides is arc welded in the vicinity of the notch, the gas generated during welding escapes from the notch and blows. Although the generation of holes is suppressed, the volume of the joining piece in the welding spot is small and the amount of penetration is small. As a result, the bonding strength between the lead conductor and the metal terminal is lowered, the vibration resistance of the joint between the lead conductor and the metal terminal is lowered, and long-term reliability cannot be secured. It was.

  The present invention has been made to solve the above-mentioned problems, and ensures the amount of penetration of the joining piece at the joint between the lead conductor and the metal terminal, and effectively releases the gas generated during welding to blow holes. An object of the present invention is to obtain an AC generator for a vehicle that suppresses the occurrence of the above and improves the vibration resistance of the joint portion and is excellent in reliability.

An automotive alternator according to the present invention includes a rotor rotatably supported by a bracket, a stator core, and a stator winding wound around the stator core, and surrounds the rotor. A stator supported by the bracket, and a rectifier connected to a metal terminal joined to the lead conductor of the stator winding for rectifying AC power generated in the stator winding. . The metal terminal includes a ring flat plate-shaped mounting portion connected to the rectifier, a base portion extending radially outward from the mounting portion and having a predetermined circumferential width, and an extending end portion of the base portion A pair of joining pieces extending in a direction orthogonal to the extending direction of the base and having a predetermined width in the extending direction of the base, and the end of the lead conductor is attached to the end face And is caulked and fixed in a state of being embraced from both sides by the pair of joint pieces, and arc-welded between the pair of joint pieces embracing the ends of the lead conductors. are joined integrally, notch, the periphery of the weld region by removing the welding region of the pair of joining pieces are formed by cutting out the bonding strip to expose a portion of the lead conductor ing.

  According to the present invention, the joining piece of the metal terminal is caulked and fixed to the end portion of the lead conductor from both sides, and the joining pieces that have tucked the end portion of the lead conductor are arc-welded and joined together. Therefore, the joint portion between the end portion of the lead conductor and the metal terminal has a sufficient tensile strength, the occurrence of fatigue fracture can be suppressed, and the reliability can be improved.

  The notch is formed so that a part of the lead conductor is exposed in the non-welded area around the welded area of the joint piece, and this occurs when the oxide contained in the metal terminal and lead conductor is reduced during welding. Water vapor that escapes from the cutout without staying in the molten conductor. Thereby, generation | occurrence | production of a blowhole in a molten conductor is suppressed, and the fall of the vibration resistance resulting from a blowhole and the increase in the electrical resistance of a junction part can be prevented. Moreover, the area of the joining piece in a welding spot becomes large, the amount of penetration of a joining piece increases at the time of welding, and joining strength is raised.

1 is a longitudinal sectional view showing an automotive alternator according to an embodiment of the present invention. It is a perspective view which shows the stator in the alternating current generator for vehicles which concerns on one embodiment of this invention. It is a perspective view explaining the terminal process of the lead conductor of the stator winding | coil in the alternating current generator for vehicles which concerns on one embodiment of this invention.

  Hereinafter, preferred embodiments of a stator for a vehicle alternator according to the present invention will be described with reference to the drawings.

  1 is a longitudinal sectional view showing a vehicle alternator according to an embodiment of the present invention, FIG. 2 is a perspective view showing a stator in the vehicle alternator according to an embodiment of the present invention, and FIG. These are the perspective views explaining the terminal process of the lead conductor of the stator winding | coil in the alternating current generator for vehicles which concerns on one embodiment of this invention.

  In FIG. 1, an AC generator 1 for a vehicle is supported by a housing 4 composed of an aluminum front bracket 2 and a rear bracket 3 each having a substantially bowl shape, and rotatably supported by the housing 4 via bearings 5a and 5b. A shaft 6, a pulley 7 fixed to the end of the shaft 6 extending to the front side of the housing 4, a rotor 8 fixed to the shaft 6 and disposed in the housing 4, and the rotor 8. A stator 20 fixed to the housing 4 so as to surround, a pair of slip rings 12 fixed to the rear side of the shaft 6 and supplying current to the rotor 8, and a pair sliding on the surface of each slip ring 12. The brush 13, the brush holder 14 that houses these brushes 13, and the rectifier 1 that is electrically connected to the stator 20 and converts alternating current generated in the stator 20 into direct current. If, mounted to the brush holder 14, a voltage regulator 16 for adjusting the magnitude of the AC voltage generated in the stator 20.

  The rotor 8 includes a field winding 9 that generates a magnetic flux when an excitation current is passed, a pole core 10 that is provided so as to cover the field winding 9, and a magnetic pole is formed by the magnetic flux, and an axis of the pole core 10. And a shaft 6 penetrating in the center position. The fan 11 is fixed to both axial end surfaces of the pole core 10 by welding or the like.

  The stator 20 is sandwiched between the front bracket 2 and the rear bracket 3 from both sides in the axial direction, and is disposed so as to surround the pole core 10 while ensuring a uniform gap with the outer peripheral surface of the pole core 10 of the rotor 8. A stator core 21 and a stator winding 22 wound around the stator core 21.

Next, the structure of the stator 20 will be described with reference to FIG.
The stator core 21 includes an annular core back portion 21a, teeth portions 21b extending radially inward from the inner peripheral surface of the core back portion 21a and arranged at an equiangular pitch in the circumferential direction, and the core back It has a slot 21c defined by the portion 21a and the adjacent tooth portion 21b.

  The phase winding 23 constituting the stator winding 22 has one conductor wire 30 extending from the slot 21c to one side in the axial direction, extending on one end surface of the stator core 21 to one side in the circumferential direction, and having three slots. A predetermined wave winding is applied so that the slot 21c is separated, extends from the slot 21c to the other side in the axial direction, extends on the other end surface of the stator core 21 in the circumferential direction, and enters the slot 21c separated by three slots. After turning around, the conductor wire 30 extending from the slot 21c to one side in the axial direction extends on one end surface of the stator core 21 to the other side in the circumferential direction and enters the slot 21c separated by three slots, and from the slot 21c. A distributed winding formed by wrapping a predetermined number of turns around a wave winding so as to extend into the other side in the axial direction and extend on the other end surface of the stator core 21 to the other side in the circumferential direction and enter a slot 21c separated by three slots. It is configured.

  In FIG. 2, only a part of the phase winding 23 is wound around the stator core 21, but in actuality, the phase winding 23 is a slot group composed of slots 21 c for every three slots. It is wound around each. That is, the three phase windings 23 are wound around the stator core 21 by shifting the slots 21c to be wound respectively by one slot.

  End portions of the conductor wires 30 corresponding to the start of winding of the phase windings 23 are joined and integrated to form a neutral point 24. Thereby, the stator winding | coil 22 is comprised by the three-phase alternating current winding formed by Y-connecting the three phase windings 23. FIG. The end portion of the conductor wire 30 corresponding to the winding end of each phase winding 23 constitutes the lead conductor 25 of each phase. Further, the metal terminal 26 is electrically fixed to the leading end portion of each lead conductor 25 in a connected state. Here, the conductor wire 30 is an insulation coated conductor wire produced by coating a copper wire 31 having a rectangular cross section with an insulating coating 32 made of a high heat resistant resin such as a polyimide amide resin.

  The stator 20 configured as described above has a stator core 21 sandwiched between the front bracket 2 and the rear bracket 3 from both sides in the axial direction, and ensures a uniform gap between the outer peripheral surface of the pole core 10 of the rotor 8. Are disposed so as to surround the pole core 10. The metal terminal 26 fixed to the tip of the lead conductor 25 is fastened and fixed to the circuit board 15 a of the rectifier 15 with the screw 17, and the stator winding 22 is electrically connected to the rectifier 15.

In the vehicle alternator 1 configured as described above, a field current is supplied from a battery (not shown) to the field winding 9 via the brush 13 and the slip ring 12 to generate a magnetic flux. By this magnetic flux, the claw-shaped magnetic poles of the pole core 10 are magnetized alternately into the N pole and the S pole in the circumferential direction.
On the other hand, the rotational torque of the engine is transmitted to the shaft 6 via a belt (not shown) and the pulley 7, and the rotor 8 is rotated. Therefore, a rotating magnetic field is applied to the stator winding 22 of the stator 20, and an electromotive force is generated in the stator winding 22. Then, the alternating electromotive force generated in the stator winding 22 is rectified to direct current by the rectifier 15 and the magnitude of the output voltage is adjusted by the voltage regulator 16 and supplied to the battery or the on-vehicle electric load. .

Next, terminal processing of the lead conductor 25 of the stator winding 22 will be described with reference to FIG.
The metal terminal 26 is made of copper, a copper alloy, or the like, and has a ring flat plate-shaped attachment portion 27 and a crimping portion 28 that extends radially outward from the attachment portion 27. The caulking portion 28 extends radially outward from the attachment portion 27 and has a rectangular flat plate-like base portion 28a having a predetermined circumferential width, and is orthogonal to the extending direction of the base portion 28a from the extending end portion of the base portion 28a. A pair of joining pieces 28b, 28c extending in the direction. The pair of joining pieces 28b and 28c are formed in a shape in which corners on the rear end side of a rectangular flat plate having a predetermined width in the extending direction of the base portion 28a are cut out. Thus, when the copper wire 31 from which the pair of joining pieces 28b and 28c are exposed is held from both sides, a part of the copper wire 31 is disposed on the rear end side between the joining pieces 28b and 28c, that is, on the side opposite to the mounting portion 27 Is now exposed.

  The insulating coating 32 is removed from the end portion of the lead conductor 25 and the copper wire 31 is exposed. Then, the end portion of the lead conductor 25 is directed to the crimping portion 28 with its end surface facing the attachment portion 27, and is crimped and fixed in a state of being held from both sides by the joining pieces 28b and 28c. Next, arc welding such as TIG welding is performed on the distal end side between the joining pieces 28b and 28c, and the end portion of the lead conductor 25 and the metal terminal 26 are welded and fixed. In FIG. 3, an arrow A indicates a welding region. At this time, the notch 29 is formed on the side opposite to the attachment portion 27 between the joining pieces 28b, 28c that embed the exposed copper wire 31 from both sides, and a part of the copper wire 31 is exposed.

  In the terminal treatment structure of the lead conductor 25, after the end portions of the lead conductor 25 are caulked and fixed in a state of being embraced from both sides by the joining pieces 28b and 28c, arc welding is performed between the joining pieces 28b and 28c. . Therefore, the joint portion between the end portion of the lead conductor 25 and the metal terminal 26 has a sufficient tensile strength, the occurrence of fatigue fracture can be suppressed, and the reliability can be improved.

  A notch 29 is formed on the rear end side between the joining pieces 28b, 28c that embed the end portion of the lead conductor 25 from both sides. Therefore, the water vapor generated by the reduction of the oxide contained in the metal terminal 26 and the conductor wire 30 during welding escapes from the notch 27 without remaining in the molten conductor. Thereby, generation | occurrence | production of a blowhole in a molten conductor is suppressed, and the fall of the vibration resistance resulting from a blowhole and the increase in the electrical resistance of a junction part can be prevented. Moreover, since the notch 29 is formed, the volume of the joining pieces 28b, 28c is reduced accordingly. Therefore, at the time of welding, the heat incident on the welding region A of the joining pieces 28b and 28c is efficiently transmitted to the copper wire 31, the joining pieces 28b and 28c and the copper wire 31 are simultaneously melted, and the joining strength is increased. The electrical resistance of the junction is reduced.

The tip side between the joining pieces 28b and 28c is arc welded. Therefore, the insulating coating 32 positioned on the rear end side of the metal terminal 26 is less likely to be thermally deteriorated, and a decrease in the corrosion resistance of the lead conductor 25 is suppressed.
Since the notch 29 is formed outside the welding area A, the area of the joining pieces 28b and 28c in the welding area A, that is, the welding spot, is increased. Therefore, during welding, the amount of penetration of the joining pieces 28b and 28c increases, and the joining strength is increased.

  In the above embodiment, the notch is formed on the rear end side of the joining piece. However, the position where the notch is formed is not limited to the rear end side of the joining piece. What is necessary is just to be formed in the non-welding area | region of the welding area periphery.

In the above embodiment, a conductor wire having a rectangular cross section is used. However, the conductor wire is not limited to a rectangular cross section, and may be a circular cross section. It may be plastically deformed into a rectangular cross section.
Further, in the above embodiment, one conductor wire is held by a pair of joining pieces from both sides and welded and fixed, but depending on the configuration of the winding, a plurality of conductor wires may be paired with a pair of joining pieces. It will be held in place and welded and fixed.

  2 Front bracket, 3 Rear bracket, 8 Rotor, 15 Rectifier, 20 Stator, 21 Stator core, 22 Stator winding, 25 Lead conductor, 26 Metal terminal, 28b, 28c Joint piece, 29 Notch, A Welding area.

Claims (2)

A rotor rotatably supported by the bracket;
A stator core, and a stator winding wound around the stator core, the stator supported by the bracket so as to surround the rotor, and
A metal terminal joined to the lead conductor of the stator winding, and a rectifier that rectifies AC power generated in the stator winding, and
The metal terminal includes a ring flat plate-shaped attachment portion connected to the rectifier, a base portion extending radially outward from the attachment portion and having a predetermined circumferential width, and an extending end portion of the base portion. Extending in a direction perpendicular to the extending direction of the base, and having a pair of joining pieces having a predetermined width in the extending direction of the base,
The end portion of the lead conductor is directed to the base portion with its end surface facing the mounting portion, and is caulked and fixed in a state of being embraced from both sides by the pair of joining pieces,
Between the pair of joining pieces that embrace the end of the lead conductor is arc-welded and joined and integrated,
Notch, the periphery of the weld region by removing the welding region of the pair of joining pieces, characterized in that it is formed by notching the bonding strip to expose a portion of the lead conductor AC generator for vehicles. The lead conductor and the metal terminal are integrated by arc welding at the tip side between the joining pieces embedding the end of the lead conductor ,
2. The vehicle alternator according to claim 1 , wherein the notch is formed by notching a rear end corner of the pair of joining pieces .

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