JP2001204151A - Vehicle ac generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle generator which can reduce noise and improve a cooling performance. SOLUTION: Coil ends 31b are arranged into an annular shape with approximately same intervals and same heights in an axial direction. As respective quantities of insulating resin 36, applied to cover junctions 33e of which the coil ends 31b consist, are not uniform in the circumferential direction, the uniformity of pitches of the coil ends 31b is lost by the nonuniformity of the applied insulating resin 36. Therefore, gaps between the coil ends 31b are not uniform according to the variation of the applied insulating resin 36 and draft resistances are not uniform in the circumferential direction. As a result, periodical noise can be suppressed in comparison with the noise when the draft resistances are uniform in the circumferential direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternator for vehicles mounted on passenger cars, trucks and the like.

[0002]

2. Description of the Related Art As a stator winding of a vehicle alternator,
Conventionally, a winding is formed by joining a plurality of conductor segments (WO9 published by PCT).
8/54823).

According to WO 98/54823, the joints of the conductor segments are formed at equal pitches, and cooling air flows through the equal pitch spaces by a cooling fan attached to a rotor.

[0004]

In the conventional structure, no consideration has been given to preventing noise such as pitch noise generated due to interference of the cooling air with the joints at the same pitch.

In the embodiment disclosed in Japanese Patent Application Laid-Open No. 63-274335, the leading end is completely coated to leave no gap. In this case, the flow of the cooling air by the cooling fan is obstructed, and the stator, which is the heat generating portion, cannot be sufficiently cooled, so that there is a problem that the output of the vehicle alternator cannot be increased.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle alternator capable of reducing noise while securing high cooling performance and achieving high output. Is to do.

[0007]

According to the first aspect of the present invention, the coil ends are arranged at substantially the same axial height and are annularly spaced at substantially equal pitches, and the joints forming the coil ends are formed. The amount of the insulating resin that is obtained by attaching the insulating resin member covering the coil is made non-uniform in the circumferential direction, so that the uniform pitch between the coil ends is lost due to the non-uniform insulating resin attached in the circumferential direction. . Therefore, since the adhesion amount is uneven, the gap between the coil ends is unevenly formed according to the change in the adhesion amount, and the ventilation resistance becomes uneven in the circumferential direction. As a result, when the ventilation resistance is constant in the circumferential direction, Periodic noise (pitch noise, etc.)
Is suppressed.

According to a second aspect of the present invention, the insulating resin comprises:
At a position separated by a predetermined distance from the stator core, an annular connecting portion is formed by connecting a plurality of joining portions in an annular shape. At another position, a circumferential connecting portion is formed between two joining portions arranged in the circumferential direction, and can be formed irregularly due to a variation in the interval between the joining portions. In addition, since the above-mentioned annular connection part connects the coil ends in a ring shape, the vibration resistance of the coil ends forming the winding can be improved.

According to the third aspect of the present invention, since the insulating resin is connected between the plurality of coil ends arranged in the radial direction, the ventilation resistance against the cooling air sent from the inside to the outside in the radial direction is reduced. Can be suppressed.

According to the fourth aspect of the present invention, the number of the circumferential connecting portions can be formed more in the inner ring than in the outer ring. For this reason, it is easy to make the ventilation resistance non-uniform in the circumferential direction in the inner ring to which the cooling air sent from the radial inner side to the outer side hits.

According to the fifth aspect of the present invention, the insulating resin is not adhered to the skewed portion at all or not much, and the amount of the insulating resin used can be reduced.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a vehicle alternator according to an embodiment of the present invention. 1 to 4 show this embodiment. FIG. 1 is a cross-sectional view showing the overall structure of the automotive alternator according to the present embodiment, FIG. 2 is a perspective view of a conductor segment forming a stator winding, and FIG. 3 is a view of the stator viewed from the inner peripheral side. FIG. 4 is a partial perspective view showing a coil end extending from a slot of a stator core.

As shown in FIG. 1, a vehicle alternator 1
Is configured to include a stator 2, a rotor 3, a frame 4, a rectifier 5, and the like.

The stator 2 includes a stator core 32, a plurality of conductor segments 33 constituting a stator winding, and a sheet-like insulator 34 as an insulating layer. The stator core 32 is formed in a cylindrical shape by laminating thin steel sheets, and has a number of slots 35 formed on the inner peripheral surface thereof. The conductor segment 33 exposed from the stator core 32 forms the coil end 31 of the stator winding. The detailed structure of the stator 2 will be described later.

The rotor 3 includes a shaft 6 to which a pulley 20 is fixed, a rundle-shaped iron core 7 fixed to the shaft 6, and a field formed by winding an insulated copper wire cylindrically and concentrically. And a winding 8. The field winding 8 is sandwiched from both sides by a pair of pole cores 7 a and 7 b constituting the iron core 7. An axial-flow-type cooling fan 11 is attached to the front end face of the iron core 7 by welding or the like in order to discharge cooling air sucked from the front side in the axial direction and the radial direction. Similarly, a centrifugal cooling fan 12 is attached to the rear end face of the iron core 7 by welding or the like in order to blow cooling air sucked from the rear side in a radial direction.

The frame 4 accommodates the stator 2 and the rotor 3. The frame 3 supports the rotor 3 so as to be rotatable together with the shaft 6, and has a predetermined outer circumference of an iron core 7 of the rotor 3. The stator 2 is fixed via the gap.
Further, the frame 4 has a discharge hole 42 for cooling air radially outside the coil end 31 of the stator 2 and a suction hole 41 on an axial end face.

AC generator 1 for vehicle having the above-described structure
When a rotational force from an engine (not shown) is transmitted to the pulley 20 via a belt or the like, the rotor 3 rotates in a predetermined direction. In this state, by applying an excitation voltage to the field coil 8 of the rotor 3 from the outside, the respective claw portions of the iron core 7 are excited, and a three-phase AC voltage can be generated in the stator winding. A predetermined DC current is taken out from the output terminal 5.

Next, details of the stator 2 according to the embodiment of the present invention will be described below. As described above, the stator 3
A stator winding 31 and a stator core 32 which is a laminated core formed by forming a plurality of slots 35 in which the stator winding 31 is provided, and a groove-shaped slot formed in the stator core A sheet-like insulator 34 is arranged along the inner wall surface of the member 35.

The stator winding 31 is made of a copper wire having a flat cross section. The surface of the copper wire is covered with a resin film layer. Therefore, the copper wire in the slot
It is electrically insulated from the stator core 32 by its own film and the insulator 34.

The stator winding 31 has a plurality of U-shaped conductor segments 33 arranged in accordance with a predetermined rule, and ends of the plurality of conductor segments 33 are electrically connected in accordance with a predetermined rule. It is constituted by. In this embodiment, the electrical connection is formed by welding. In this embodiment, as shown in FIG. 2, two U-shaped conductor segments 33a and 33b are used as a basic unit, and a plurality of these units are arranged, so that one turn on the stator core 32 is performed. To form a series of windings.

The U-shaped conductor segment 33 has a turn portion 33c formed by bending a copper wire covered with a thin insulating film.
And a joint 33e connected by welding. The turn part 33c forms a first coil end together with the skewing part 33d following the turn part 33c. Multiple conductor segments 3
The three turn portions 33c are regularly arranged on the rear side (opposite the pulley side) shown in FIG. 1 to form a first coil end group 31a. The joining portion 33e forms a second coil end together with the skewing portion 33f that follows. The plurality of joints 33e are arranged on the front side (pulley side) shown in FIG.
1b.

The inclination angle θ1 of the inclined portion 33d in the first coil end group 31a with respect to the axial direction is smaller than the inclination angle θ2 of the inclined portion 33f in the second coil end group 31b. As a result, a larger interval is formed between the plurality of skewing portions 33f between the plurality of skewing portions 33d. As a result, even if the joining portion 33e extending straight in the axial direction is formed, the second coil end group 31b is still formed.
Can be reduced in the axial direction. For this reason, the second coil ends 31a are arranged at substantially the same axial direction height and in a ring shape at a substantially equal pitch.

In this embodiment, the first coil end group 31a is constituted mainly by a turn portion. In addition, the second coil end group 31b is configured by mainly arranging joints. However, in these, the turn part and the joint part of the basic unit are mainly arranged. In the first coil end group 31a, a joint can be partially arranged. For example, a junction for obtaining a neutral point connection and a junction for realizing a connection to the rectifier 5. Also, the second coil end group 31b includes:
The turn part can be partially arranged.

The first coil end group 31a has a thin insulating resin 3 made of the same resin member as a second insulating resin described later.
7 is attached. The thin insulating resin 37 attached to the first coil end group 31a is
It adheres to the extent that it covers the surfaces of the plurality of conductors constituting 1a. As a result, in the first coil end group 31a, a cooling air passage communicating from the radial inside to the outside in the first coil end group 31a is formed. The insulating resin 37 is provided in a range from the entire first coil end group 31a to the axial end of the stator core 32. In the first coil end group 31a, a film is partially stretched between conductors that are radially adjacent to each other and connected therebetween to increase rigidity. Further, at the end of the stator core 32, the stator core 32, the insulator 34, and the conductor segment 33 are bridged and connected to each other.

The second insulating resin 37 is provided with a copper wire for obtaining at least a neutral point connection and a copper wire for realizing a connection to the junction and the rectifier 5 to the first coil end group 31a. It may be merely attached and fixed to the extent of increasing rigidity.

At the joining portion 33e of the second coil end,
As shown in FIG. 3, a thick insulating resin 36 is attached as the first insulating resin. The range of the attachment is formed so as to cover the joining portion 33e with the end near the tip end side of the inclined rear portion 33f as a terminal so as to suppress the amount of the attached insulating resin 36. This insulating resin 36 secures insulation between the adjacent joints 33e. Moreover, the state of adhesion of the insulating resin in the circumferential direction is divided into two layers depending on the position h that is apart from the stator core 32.

First, the first layer is located at the position h1 indicated by the dashed line on the terminal side where the insulating resin is attached.
Numeral 6 connects the plurality of joints 33e in a ring shape. The ring-shaped connecting portion 36h1, which is the first layer, connects the coil end 31b in a ring shape by connecting the joining portion 33e in a ring shape, and the resistance of the coil end 31b forming the winding is increased. Vibration can be improved. This allows
When a claw portion of the iron core 7 is excited by applying an excitation voltage to the field coil 8 of the rotating rotor 3 from the outside to generate a three-phase AC voltage in the stator winding, the field coil 8 and the alternating current flowing through the coil end 31b forming the stator winding interfere with each other to prevent vibration of the coil end generated.

Next, in the second layer, at a position h2 indicated by a two-dot chain line on the front side of the first layer, a portion forming a gap between the joining portions 33e and a portion filling the gap with the insulating resin 36 are included. They are mixed irregularly. Moreover, 2 arranged in the circumferential direction
The insulating resin 36 connecting the two joining portions 33e has an uneven shape. Further, the coil end 31b has a remarkably non-uniform shape on the tip side. For example, in FIG. 3A, some gaps are filled between the joints 33e, some gaps are half filled as shown in b, and some gaps are filled in as shown in c. In some cases, the insulating resin 36 is attached in a cross-linked shape.

Further, a plurality of joining portions 33 arranged in a ring shape
The distance between e is slightly non-uniform, and the insulating resin 36 having a non-uniform adhesion amount depending on those distances has a non-uniform shape. An embodiment in which the insulating resin 36 is not uniformly attached will be described later.

Further, the second coil end group 31b includes:
A thin insulating resin 37 as a second insulating resin adheres to the whole. In particular, as shown in FIG. 3, of the second coil end 31 b, the skewed portion 33 f as a conductor not covered with the insulating resin 36 is covered with only the insulating resin 37. The insulating resin 37 forms a space 37a at the base of the second coil end group 31b near the stator core 32.

The insulating resin 37 can be formed by attaching a liquid resin having a relatively low viscosity and curing the liquid resin.

As described above, the second insulating resin 37
Is attached only to the neutral point or the like of the first coil end group 31a, and the adhesion of the insulating resin 37 to the second coil end group 31b is reduced. Thus, the space 37a may be widely arranged between the skewed portions f.

The insulating resin 3 which is a feature of the embodiment of the present invention
The uneven attachment state of No. 6 will be described below with reference to FIG. First, the insulating resin 36 adheres unevenly in the circumferential direction. The insulating resin 36 forms a circumferential connecting portion 36a between two joining portions 33e arranged in the circumferential direction. At this time, the insulating resin 36 is connected to the two joining portions 33 arranged in the circumferential direction.
e, due to the subtle differences in the distance between
6a may or may not occur. For this reason, the equal pitch property of the coil ends 31b which are arranged at substantially the same axial height and are annularly spaced apart at a substantially equal pitch may not be formed due to the uneven amount of the insulating resin 36 attached in the circumferential direction. Lost due to uniform shape. Therefore, since the adhesion amount is non-uniform, the gap between the coil ends 31b is formed non-uniformly according to the change in the adhesion amount, and the ventilation resistance becomes non-uniform in the circumferential direction. Periodic noise (such as pitch noise) is suppressed.

Due to the variation in the interval between the joints 33e described in the later-described manufacturing method, the circumferential connecting portions 3 are irregularly formed.
6a.

Further, an inner annularly arranged joint portion 33 is provided.
Since the same number of conductor segments are arranged in a ring as the distance between e and the distance between the outer joints 33e, the distance between the inner rings is smaller than the distance between the outer rings. For this reason, the connecting portion 36a in the circumferential direction is formed more in the inner annular shape than in the outer annular shape. For example, the circumferential connecting portion 3 in FIG.
6a has eight of A to H. Of these, the inner rings are AE
And the outer rings are F to H, and the inner ring has many circumferential connecting portions 36a. This makes it possible to achieve more circumferential non-uniformity in the inner ring with respect to the amount of the insulating resin 36 attached, so that the cooling air blown from the inside to the outside by the cooling fan 11 is annularly arranged inside. Immediately after hitting the coil end 31b, the ventilation resistance becomes uneven in the circumferential direction, so that periodic noise can be easily suppressed.

Next, also in the radial direction, the insulating resin 36 has the following features. The insulating resin 36 forms an inner / outer connecting portion 36b between the joining portions 33e arranged inward and outward in the radial direction. Therefore, when the cooling air blown from the inside to the outside by the cooling fan 11 passes through the coil end 31b, the flow of the cooling air becomes as shown by an arrow A in FIG. Resistance can be suppressed.

A manufacturing method for forming a non-uniform adhesion state of the insulating resin 36, which is a feature of this embodiment, will be described below.
The viscosity of the insulating resin 36 is adjusted so that the coil ends 31b, which are arranged at substantially the same axial height and are spaced apart at a substantially equal pitch in an annular shape, are coated with the insulating resin 36 having an uneven amount of adhesion in the circumferential direction. The amount and the separation distance between the joints 33e are adjusted and provided. The thick insulating resin 36
It can be formed by a step of attaching a liquid resin having a relatively high viscosity and curing it, or a step of attaching a powder resin and melting and curing the resin.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the overall structure of an automotive alternator according to an embodiment of the present invention.

FIG. 2 is a perspective view of a conductor segment forming a stator winding in FIG. 1;

FIG. 3 is a plan view showing a partial external appearance of the stator shown in FIG. 1 as viewed from an inner peripheral side.

FIG. 4 is a partial perspective view showing a coil end extending from a slot of a stator core of the stator in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Stator 3 Rotor 4 Frame 7 Iron core 8 Field winding 11, 12 Cooling fan 31 Stator winding 31a First coil end group (turn part side) 31b Second coil end group (Coil end according to claims; joint side) 33e Joint (at the tip of the sloping portion, the tip) 33d, 33f Skew portion 32 Stator core 33 Conductor segment 34 Insulator 41 Suction hole 42 Discharge hole 35 Slot 36 first insulating resin (insulating resin member, insulating resin according to claims) 37 second insulating resin

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) PP25

Claims (5)

[Claims] 1. A stator comprising a rotor, a stator core arranged opposite to the rotor, and a stator winding provided on the stator core, and a frame supporting the rotor and the stator. In the automotive alternator having: a stator winding, an inner conductor accommodated in a slot of the stator core, and a coil end exposed in the axial direction from the slot and extending on both sides in the circumferential direction. The conductor segment has a turn portion, a skew portion that intersects another conductor segment at the coil end, and a tip end of the tip of the skew portion. The coil end has substantially the same axial direction height, and is annularly arranged at a substantially equal pitch and has a joining portion in which a plurality of the distal end portions of another conductor segment are joined. , Insulation Coated with butter member, vehicle AC generator, wherein the deposition amount of the insulating resin is heterogeneous in the circumferential direction. 2. The method according to claim 1, wherein the insulating resin annularly connects the plurality of joints at a position apart from the stator core by a predetermined distance, and further includes the plurality of joints at a position different from the annular joint. The alternator for a vehicle according to claim 1, wherein the joints are connected irregularly. 3. The joining part is arranged in a multiple ring shape, and the insulating resin covering the joining parts arranged inside and outside is connected between them to have an inside / outside connecting part. The vehicle alternator according to any one of claims 1 to 2. 4. The vehicle according to claim 2, wherein the irregularly-connected circumferential connecting portions are formed in the inner ring in the circumferential direction more than in the outer ring. For alternator. 5. The method according to claim 5, wherein the insulating resin adheres to the skewed portion more sparsely than the joint portion, or has no adhesion to the skewed portion, with the vicinity of the tip end of the skewed portion as an end. The vehicle alternator according to any one of claims 1 to 4, characterized in that: