JP4042386B2 - Rotating electric machine for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicular rotating electrical machine mounted on a passenger car, a truck, or the like.
[0002]
[Prior art]
In recent years, as a countermeasure against environmental problems, for vehicles driven by an engine in response to demands such as a reduction in the idling speed of the vehicle, weight reduction for improving fuel efficiency, and narrowing of an engine room for securing a vehicle interior space. In-car rotating electrical machines such as AC generators are required to be smaller and have higher output. A vehicle alternator disclosed in Japanese Patent Laid-Open No. 2000-69729 is known as a response to these requirements. In this AC generator for a vehicle, a stator winding is formed by a plurality of conductor segments, and conductor segments of different layers protruding from different slots are connected to each other, so that the stator winding can have a high linear area ratio and low. Achieves resistance.
[0003]
On the other hand, in the engine room where the vehicle alternator is mounted, there are many foreign substances such as car shampoo and salt water and electrolytes such as dust and dirt traveling, and it is necessary to maintain the performance even in such an environment. There is. In particular, the vehicle alternator cools each part with the cooling air generated by the fan, so there is a high possibility that the electrolyte and foreign matter will reach the interior of the vehicle alternator together with the cooling air. It can be said that ensuring the environmental performance of children is an important issue.
[0004]
[Problems to be solved by the invention]
By the way, in the vehicle alternator disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2000-69729, the end portions of the plurality of conductor segments of the stator winding are joined together by welding. It becomes high temperature. For example, when there is no coating at the joint and there is a coating in the vicinity thereof, the coating near the joint is deteriorated by thermal stress applied during joining. As a problem due to the coating deterioration, there is a problem that peeling or cracking is likely to occur in a portion where the coating is deteriorated, and an electrolytic solution or a foreign substance stays in a gap generated by the peeling or cracking. In addition, when a coating is present at the joint, the coating is involved by joining the coating, so that the bonding state is not stable, and peeling or cracking occurs in the portion where the coating has deteriorated due to thermal stress, resulting in an electrolyte solution or There was a problem that foreign matter stayed. In addition, it is conceivable to cover the joint with a resin material in order to improve the insulation, but if there is peeling or cracking of the film deteriorated due to thermal stress at that time, the resin material becomes difficult to adhere, Environmental properties will be reduced. Furthermore, when considering joining by welding, the molten conductor protrudes from the end face of the original conductor segment in both the circumferential direction and the radial direction at the joint and solidifies, so the distance between the joints adjacent in the circumferential direction is short. It becomes easy to short-circuit.
[0005]
The present invention has been created in view of the above points, and an object of the present invention is to provide a rotating electrical machine for a vehicle that can prevent the staying of an electrolyte or foreign matter with respect to a joint portion of a stator winding. It is in.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, a rotating electrical machine for a vehicle according to the present invention includes a rotor, a stator having a stator core and a plurality of coated conductor segments provided on the stator core, and the rotor and the stator. And a frame for supporting the child. The plurality of conductor segments have joint portions in which the end portions are arranged in an annular shape with the end portions aligned in the radial direction and the circumferential direction, and the end portions of the array portions are joined by welding. Have a bare part to be a non-coating region. The joint and its vicinity become hot during welding, but since no coating is formed on this part, there is no thermally deteriorated film, and foreign matter such as electrolyte enters the thermally degraded part of the film. Can be prevented. In addition, when there are many joints with insulating resin, there is no deteriorated film, so this insulating resin is likely to adhere to the conductor and film, and it can be covered sufficiently with a small amount, and the environmental performance is improved. Can be made. In other words, the environmental performance is improved when there is no film that has deteriorated due to peeling or cracking. In other words, it is better that the coating does not exist before joining at the joint and the portion where the coating in the vicinity thereof deteriorates, and the environment is improved by providing a bare portion at such a portion to prevent the coating from deteriorating. be able to.
[0007]
Further, it is desirable to form a gap between adjacent joints arranged in an annular shape. Thereby, it is possible to improve the cooling performance by reducing the ventilation resistance of the cooling air, and it is possible to enhance the effect of discharging foreign matter that has entered the inside of the frame.
[0008]
It is desirable that the above-described joint portion is covered with an insulating resin and has a plurality of uneven shapes along the circumferential direction. Since the deteriorated film does not exist on the surface of the conductor segment, the insulating resin is easily attached when the bonding portion is covered with the insulating resin, and the bonding portion can be sufficiently covered with a small amount of resin. Thereby, the short circuit between the junctions can be prevented and the environmental performance can be improved. In addition, by making the uneven shape, it is possible to improve the cooling performance by increasing the surface area.
[0009]
Two or more rows of the conductor segments described above are arranged along the radial direction in slots provided in the stator core, and the length along the radial direction of the joint portion is in the radial direction of the conductor segment to be joined. Desirably shorter than the sum of the lengths along. Thereby, the distance between the joint parts adjacent to each other in the radial direction or between the outermost joint part and the outer frame inner wall can be secured, and a short circuit between them can be prevented.
[0010]
Moreover, as for the bare part provided in the joined two conductor segments, it is desirable that the adjacent surface is a plane. Thereby, the stability of joining can be improved.
[0011]
Moreover, as for the bare part provided in two joined conductor segments, it is desirable that the opposing surface of an adjacent surface is a plane. Thereby, the clearance gap between the junction parts along a radial direction can be ensured, and the short circuit between junction parts can be prevented.
[0012]
Moreover, as for the bare part provided in the joined two conductor segments, it is desirable that the side surface of the adjacent surface is a plane. As a result, a gap between joints adjacent in the circumferential direction can be secured, and the cooling performance can be improved by reducing the ventilation resistance of the cooling air, and the foreign matter intruding inside the frame can be discharged. Can be increased.
[0013]
Moreover, it is desirable that the above-described cross section of the bare portion has a substantially polygonal shape. Since the adjacent surface of the bare part can be made small, the insulating resin can easily adhere to other surfaces, and the environmental performance can be improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an AC generator for a vehicle according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings.
[0015]
FIG. 1 is a cross-sectional view showing the overall structure of an automotive alternator according to an embodiment. As shown in the figure, the vehicle alternator 1 of this embodiment includes a rotor 2, a stator 3, a frame 4, a rectifier 5, and the like.
[0016]
The rotor 2 has a configuration in which a field coil 8 in which an insulated copper wire is wound in a cylindrical and concentric manner is sandwiched from both sides through a shaft 6 by a pole core 7 having six claws. is doing. An axial flow type cooling fan 11 is attached to the end face of the front pole core 7 by welding or the like in order to discharge the 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 end face of the pole core 7 on the rear side by welding or the like in order to discharge the cooling air sucked from the rear side in the radial direction.
[0017]
The stator 3 includes a stator core 32, a plurality of conductor segments 33 that constitute the stator winding 31, and an insulator 34 that electrically insulates between the stator core 32 and the conductor segments 33. The stator core 32 is formed by superposing thin steel plates, and a plurality of groove-like slots are formed on the inner peripheral surface thereof. A sheet-like insulator 34 is disposed along the inner wall surface of the groove-like slot. In the slot, the conductor segment 33 is electrically insulated from the stator core 32 by an insulating film formed on its surface and the insulator 34. Further, a coil end 35 of the stator winding 31 is formed by the conductor segment 33 exposed from the stator core 32. The detailed structure of the stator 3 will be described later.
[0018]
The frame 4 accommodates the rotor 2 and the stator 3, and the rotor 2 is supported so as to be rotatable around the shaft 6, and a predetermined gap is provided on the outer peripheral side of the pole core 7 of the rotor 2. The stator 3 arranged via is fixed. The frame 4 is provided with a cooling air discharge hole 42 at a portion facing the coil end 35 of the stator 3 and a suction hole 41 at an axial end face.
[0019]
In the vehicle alternator 1 having the above-described structure, the rotor 2 rotates in a predetermined direction when a rotational force from an engine (not shown) is transmitted to the pulley 20 via a belt or the like. By applying an excitation voltage from the outside to the field coil 8 of the rotor 2 in this state, each claw portion of the pole core 7 is excited, and a three-phase AC voltage can be generated in the stator winding 31. A predetermined direct current is taken out from the output terminal of the rectifier 5.
[0020]
Next, details of the stator 3 will be described. The stator winding 31 of the present embodiment is configured by arranging a plurality of U-shaped conductor segments 33 according to a predetermined rule and electrically connecting these end portions.
[0021]
FIG. 2 is a perspective view schematically showing the conductor segment 33 constituting the stator winding. The stator winding 31 is formed by using two conductor segments 33a and 33b as a basic unit and arranging a plurality of these units.
[0022]
The U-shaped conductor segment 33 has a turn portion 33c and an end portion 33e. The turn part 33c forms a coil end 35 on the rear side (non-pulley side) together with the skew part 33d that follows the turn part 33c. The end portion 33e forms a drive-side (pulley side) coil end 35 together with the following skew portion 33f.
[0023]
The end portions 33e of the conductor segments 33 are preferably joined together by, for example, TIG (tungsten inert-gas) welding. FIG. 3 is a perspective view showing the end portion before joining the conductor segments. FIG. 4 is a perspective view showing an end portion after joining the conductor segments.
[0024]
As shown in FIG. 3, the end portions 33e of the adjacent conductor segments 33 are arranged adjacent to each other, and are melted locally by bringing a tungsten electrode close together and generating an arc between the base material. Solidify again. As a result, as shown in FIG. 4, a joint 33g having a droplet-like portion as a melt mark is formed. At this time, since the joint portion 33g is melted and formed into a drop shape by welding, the length L2 along the radial direction of the joint portion 33g after joining is longer than the length L1 along the radial direction of the end portion 33e before joining. Is shorter.
[0025]
FIG. 5 is a plan view of the stator 3 as viewed from the joint 33g side. As shown in FIG. 5, the joint portions 33g of the two conductor segments 33 are arranged in a ring in a row. Further, since the stator winding 31 of this embodiment has two conductor segments 33a and 33b as a basic unit as shown in FIG. 2, there are two joint portions 33g in the radial direction. These joint portions 33g are arranged in two rows of concentric and annular shapes.
[0026]
FIG. 6 is a diagram showing the state of the coating in the vicinity of the joint 33g. Moreover, FIG. 7 is a figure which shows the state of the film of the vicinity of the conventional junction part. The conductor segment 33 of the present embodiment has a bare portion 33h where no coating is formed so as to be adjacent to the joint portion 33g. By providing the bare portion 33h, it is possible to prevent peeling of the thermally deteriorated film and generation of cracks when the joint portion 33g is formed by TIG welding. On the other hand, as shown in FIG. 7, when the coating of only the minimum region necessary for joining is removed, the coating 33k in the region 33i adjacent to the joint 33g deteriorates due to heat transmitted during welding, and peeling occurs. And cracks. It should be noted that the extent to which the bare portion 33h should be secured depends on the range of the region 33i where the coating has deteriorated by performing TIG welding using a conductor segment in which a coating is formed up to the vicinity of the joint 33g as shown in FIG. It can be set by checking
[0027]
In the embodiment shown in FIG. 8, the bare portion is provided up to a range that does not reach the first intersecting segment with a predetermined interval and is covered with resin. However, when the amount of heat input at the time of bonding is increased in order to further increase the strength of the bonded portion, the thermally deteriorated portion of the film often reaches the first intersecting portion 33p with a predetermined interval with the adjacent segment. For this reason, even if the heat-degraded portion of the film is covered with resin, it is considered that the resin is poorly adhered to the heat-degraded portion and insulation from adjacent segments becomes insufficient due to the entry of water or the like from the outside. In this case, as shown in FIG. 11, durability can be ensured by setting the bare portion to a portion 33p that first intersects with a segment adjacent from the tip of the joint portion and covering it with a resin. . That is, it is possible to ensure durability by covering the portion 33q near the second intersection from the joint with resin.
[0028]
In the embodiment of FIG. 11, the bare portion is provided from the joint tip to the portion that first intersects with the adjacent segment at a predetermined interval. However, depending on the heat input conditions, the bare part range and the resin covering range may be set wider, from the joint part to the second and third intersecting parts.
[0029]
Further, as shown in FIGS. 3 and 4, the bare portion 33h described above is adjacent to the adjacent surface (surface 33M shown in FIG. 2) in the joint portion 33g, the joint portion 33g adjacent in the radial direction and the circumferential direction. The opposing surfaces (surfaces 33L and 33N shown in FIGS. 3 and 4) are preferably flat surfaces. By making the surface 33M a flat surface, it becomes possible to improve the stability of joining. Further, by forming the surface 33L as a flat surface, a gap is secured between the joint portion 33g and the bare portion 33h adjacent in the radial direction or between the outermost joint portion 33g and the bare portion 33h and the inner wall of the frame 4. be able to. Furthermore, by making the surface 33N a flat surface, a gap can be secured between the joint portion 33g and the bare portion 33h adjacent in the circumferential direction. By securing the clearance in this way, it is possible to prevent short circuit, improve cooling performance, and improve environmental performance.
[0030]
FIG. 8 is a diagram showing the stator winding 31 in which the joint portion 33g is covered with an insulating resin. As shown in FIG. 8, in the present embodiment, after the joint portion 33 g is formed, the entire joint portion 33 g is covered with the insulating resin 36. In addition, a gap is formed between each joint portion 33g adjacent in the circumferential direction, and the tip portion is substantially uneven.
[0031]
Thus, since each conductor segment 33 of the stator winding 31 of the present embodiment is provided with the bare portion 33h, the coating does not undergo thermal degradation on the surface of the conductor segment 33 adjacent to the joint portion 33g. . For this reason, it can prevent that foreign materials, such as electrolyte solution, permeate into the thermally deteriorated part of a film, and stay. Further, even when the bonding portion 33g is covered with the insulating resin 36, the insulating resin 36 has good adhesion, and the bonding portion 33g can be sufficiently covered with a small amount, so that the material cost is reduced and the environment is improved. Can be achieved.
[0032]
Moreover, since the clearance gap between the adjacent junction parts 33g can be expanded by reducing the insulating resin 36 to be used, the ventilation resistance of a cooling wind can be reduced, cooling property is improved, and the inside of flame | frame 4 is improved. It is possible to enhance the effect of discharging foreign matter that has entered the environment, and to further improve the environmental performance.
[0033]
Moreover, by setting the length in the radial direction of the joint portion 33g to be shorter than the length in the radial direction of the end portion 33e before joining, the joint portion between the joint portions 33g adjacent in the radial direction or the outermost joint portion. The effect of preventing a short circuit between 33 g and the inner wall of the radially outer frame 4 can also be enhanced.
[0034]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible in the range of the summary of this invention. For example, in the above-described embodiment, the U-shaped conductor segment 33 is used. However, as shown in FIG. 9, a conductor segment 331 having no turn portion may be used to join both end portions 331 e. .
[0035]
In the above-described embodiment, the number of the conductor segments 33 in the slot is four, and two rows of annular joints are formed. However, the number of conductor segments is changed according to the required output characteristics, and the joints The number of annular rows may be changed.
[0036]
Further, in the above-described embodiment, as shown in FIG. 3, the length along the radial direction of the end portion 33 e of the conductor segment 33 is the same as that of other portions of the conductor segment 33, but is shown in FIG. 10. As described above, by providing a notch or the like on the side opposite to the contact surface between the end portions 33e ′, the radial length of the joint portion may be further shortened. In this case, since it is possible to ensure a larger gap between the joints adjacent in the radial direction, or between the outermost joint and the inner wall surface of the frame 4, to prevent a short circuit, Cooling and environmental performance can be improved.
[0037]
In the above-described embodiment, the cross-sectional shape of the bare portion 33h is formed in a quadrangle, but may be formed in a polygonal shape that is equal to or greater than a quadrangle. Since the contact surface between the naked portions can be further reduced, the insulating resin can easily enter the gap formed between the adjacent naked portions, and the environmental performance can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the overall structure of an automotive alternator according to an embodiment.
FIG. 2 is a perspective view schematically showing a conductor segment constituting a stator winding.
FIG. 3 is a perspective view showing an end portion before joining conductor segments.
FIG. 4 is a perspective view showing an end portion after joining conductor segments.
FIG. 5 is a plan view of the stator as viewed from the joint side.
FIG. 6 is a diagram illustrating a state of a coating in the vicinity of a joint portion.
FIG. 7 is a view showing a state of a film in the vicinity of a conventional joint.
FIG. 8 is a diagram showing a stator winding in which a joint is covered with an insulating resin.
FIG. 9 is a perspective view showing a conductor segment without a turn portion.
FIG. 10 is a perspective view showing another example of an end portion of a conductor segment.
FIG. 11 is a view showing another example of a stator winding in which a joint portion is covered with an insulating resin.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Rotor 3 Stator 4 Frame 31 Stator winding 32 Stator iron core 33 Conductor segment 33e End 33g Joint part 33h Bare part 34 Insulator

Claims (8)

In a rotating electrical machine for a vehicle having a rotor, a stator having a stator core and a plurality of coated conductor segments mounted on the stator core, and a frame that supports the rotor and the stator,
The plurality of conductor segments have an end portion (33e) followed by a skew portion (33f),
The plurality of conductor segments have a joint portion in which the end portions are arranged in an annular shape with the end portions arranged in a radial direction and a circumferential direction, and the end portions are joined by welding. in have a bare portion comprising a non-formation region of the film as the film to portions first intersect with the oblique portion a predetermined distance adjacent the said end is not degraded,
The rotating electrical machine for a vehicle, wherein the joint portion and the bare portion are covered with an insulating resin . In claim 1,
A vehicular rotating electrical machine characterized in that a gap is formed between the adjacent joints arranged in an annular shape. In claim 1 or 2,
The vehicular rotating electrical machine characterized in that the joint portion is covered with an insulating resin and has a plurality of concave and convex shapes along a circumferential direction. In any one of Claims 1-3,
The conductor segments are arranged in two or more rows along the radial direction in a slot provided in the stator core,
The length of the said junction part along the radial direction is shorter than the total value of the length along the radial direction of the said conductor segment joined, The rotary electric machine for vehicles characterized by the above-mentioned. In any one of Claims 1-4,
The vehicular rotating electrical machine according to claim 1, wherein the bare portions provided in the two joined conductor segments have flat surfaces adjacent to each other. In any one of Claims 1-5,
The vehicular rotating electrical machine according to claim 1, wherein the bare portions provided on the two conductor segments joined to each other have a flat opposing surface. In any one of Claims 1-6,
The vehicular rotating electrical machine according to claim 1, wherein the bare portions provided in the two joined conductor segments have flat side surfaces adjacent to each other. In any one of Claims 1-7,
The vehicular rotating electrical machine characterized in that a cross section of the bare portion has a substantially polygonal shape.

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