JP2022078367A - Stator of rotary electric machine and manufacturing method thereof - Google Patents

Abstract

To provide a stator coil in which weld portions are in close contact and that has gaps in the other parts.SOLUTION: A stator of a rotary electric machine includes a plurality of segment coils including adjacent first and second coils, and a core portion having a space in which the segment coil is arranged, and each of the segment coils has a coated portion covered with an insulator and an exposed portion in which a conductor is exposed, and the exposed portion is formed with a protruding portion protruding from the side surface of the coated portion. The protruding portion of the first coil and the protruding portion of the second coil are in surface contact with each other, and the coated portion of the first coil is arranged with a gap between the coated portion of the first coil and the coated portion of the second coil.SELECTED DRAWING: Figure 6

Description

The present invention relates to a stator of a rotary electric machine.

The following prior arts are the background technologies in this technical field. In Patent Document 1 (Japanese Unexamined Patent Publication No. 2006-333562), in the joint surface portion facing the bonded electric wire (joined conductor), the exposed portion of the conductor at the tip and the insulating film surface in the vicinity thereof are flush with each other or the exposed portion of the conductor. A stator of a rotary electric wire having a structure in which the conductor is deformed from the tip of the central shaft to the joint surface side is described in a state in which the conductor is projected.

Japanese Unexamined Patent Publication No. 2006-333562

In the stator of the rotary electric machine described in Patent Document 1 described above, since the coated portions of the bonded electric wire (stator coil) are in close contact with each other, a phase-to-phase short circuit may occur if the insulating film is damaged. .. Therefore, an arrangement with a gap between the stator coils has been proposed. In this case, since there is a gap in the connection portion at the tip of the stator coil, it is necessary to bend and weld the connection portion so that the connection portion is in close contact with the connection portion.

For this reason, a stator coil is desired in which the welded portion is in close contact with each other and a gap is left in the other portion.

A typical example of the invention disclosed in the present application is as follows. That is, it is a stator of a rotary electric machine, and includes a plurality of segment coils including a first coil and a second coil arranged adjacent to each other, and a core portion having a space in which the segment coils are arranged. Each segment coil has a covering portion covered with an insulator and an exposed portion in which the conductor is exposed, and the exposed portion is formed with a protruding portion protruding from the side surface of the covering portion. The protruding portion of the 1 coil and the protruding portion of the second coil are in surface contact with each other, and the covering portion of the first coil is arranged with a gap between the covering portion of the second coil. It is characterized by that.

According to one aspect of the present invention, the segment coil 20 can be arranged in the stator so that the protruding portions are closely connected by welding and there is a gap in other portions (for example, the covering portion), and short circuit between phases can be prevented. .. Issues, configurations and effects other than those mentioned above will be clarified by the description of the following examples.

It is a perspective view which shows the schematic structure of the rotary electric machine assembly used in the electric power steering apparatus as an example to which this invention is applied. It is a figure which shows the schematic structure of the stator of this Example. It is a figure which shows the segment coil of this Example. It is a partial plan view which looked at the stator core which mounted the segment coil of this Example from the welding side. It is a perspective view of the weld side of the stator core which mounted the segment coil of this Example. It is a perspective view which shows the tip part of the segment coil of this Example. It is a figure which shows the tip part of the process of manufacturing the segment coil of this Example. It is a figure which shows the tip part of the process of manufacturing the segment coil of this Example. It is a figure which shows the tip part of the process of manufacturing the segment coil of this Example.

Hereinafter, examples will be described with reference to the drawings.

FIG. 1 is a perspective view showing a schematic configuration of a rotary electric machine assembly 10 used in an electric power steering device as an example to which the present invention is applied.

In FIG. 1, the rotary electric machine assembly 10 is composed of a rotary electric machine 11 and an inverter control unit 12 that drives and controls the rotary electric machine 11. The rotary electric machine assembly 10 is used, for example, as an electric power steering motor (EPS motor).

The inverter control unit 12 has a built-in power semiconductor element constituting an inverter circuit, a drive circuit for driving the power semiconductor element, a control circuit for controlling the drive circuit, and the like. The inverter control unit 12 is fixed to the rotary electric machine 11, and the rotary electric machine assembly 10 in which both are integrated is attached to an in-vehicle device (for example, a power steering device (not shown)) with bolts or the like.

Although not shown in FIG. 1, the rotary electric machine 11 is provided with a rotatable rotor and a stator that generates a rotational force in the rotor. As the rotor, a surface magnet type rotor using a general permanent magnet or an embedded magnet type structure is used. On the other hand, the stator is composed of a wave winding structure in which a segment coil is inserted with an integrated core.

FIG. 2 is a diagram showing a schematic configuration of the stator of this embodiment.

In FIG. 2, the segment coil 20 is inserted in the axial direction from the end surface 22A on the non-welding side of the stator core 22, and the coil of the portion protruding to the end surface 22B on the welding side on the opposite side is bent in the circumferential direction by TIG welding or the like. Connect to form a wave winding.

At this time, the coil end portion 28 is formed between the end surface 22A on the non-welding side and the tip of the hairpin portion 23 of the segment coil 20. The coil lead wire 21 is connected to the inverter control unit 12.

FIG. 3 is a diagram showing a segment coil 20 of this embodiment.

In FIG. 3, for the segment coil 20, it is preferable to use a flat wire whose two sides face each other in the cross section. The segment coil 20 has slot insertion portions 24 inserted into the slots of the stator core 22 on both ends, and is formed in a substantially U-shape by hairpin portions 23 provided with one or more bending points connecting them. The flat wire constituting the segment coil 20 forms a covering region covered with an insulator such as enamel in the hairpin portion 23 and the slot insertion portion 24, and the coating is peeled off at the tip thereof to form a mother. The copper material forms an exposed exposed area.

As shown in FIG. 5, the segment coil 20 is inserted into the stator core 22 and bent in the circumferential direction at a portion protruding from the stator core 22 to form a bent portion 20B. The area between the hairpin portion 23 and the bent portion 20B of the segment coil 20 is a covering region covered with an insulator, and the portion between the ends beyond the bent portion 20B is an exposed region. That is, the exposed region is provided at a portion where the two segment coils 20 (first coil 210 and second coil 220) are substantially parallel and adjacent to each other.

FIG. 4 is a partial plan view of the stator core 22 equipped with the segment coil 20 as viewed from the welded side, FIG. 5 is a perspective view of the stator core 22 equipped with the segment coil 20 on the welded side, and FIG. 6 is a segment. It is a perspective view of the tip part of a coil 20.

The segment coil 20 (first coil 210, second coil 220) is bent in the circumferential direction at a portion protruding from the stator core 22 to form a bent portion 20B. In the exposed area provided at the tip of the first coil 210 and the second coil 220, the first coil 210 and the second coil 220 project in the opposite direction, and a projecting portion 212 or 222 wider than the covering area is formed. The protruding portions 212 and 222 are provided at a portion where the first coil 210 and the second coil 220 to be welded at the tip portion are substantially parallel to each other and face each other. The first coil 210 and the second coil 220 are in contact with each other on a plane formed on the protrusion 212 and a plane formed on the protrusion 222 to form a welded portion 201.

Further, the protruding portion 212 and the protruding portion 222 are welded at the welding portion 201 which is the boundary surface thereof, and the first coil 210 and the second coil 220 are electrically connected to form a magnetic circuit.

Then, as shown in FIG. 4, a gap 205 is formed in the covering region between the first coil 210 and the second coil 220 in a state of being aligned with the slot of the stator core 22. Therefore, the insulation distance between the first coil 210 and the second coil 220 can be secured by the gap 205, and even if the coating is damaged in the covering region, a short circuit between phases can be prevented.

Further, on the opposite side of the protruding portions 212 and 222 of the first coil 210 and the second coil 220, removing portions 213 and 223 from which the base material is removed so as to narrow the width of the exposed region are formed. That is, the base material on the opposite side of the position where the first coil 210 and the second coil 220 come into contact with each other is removed, and the steps 214 and 224 form the removed portions 213 and 223. The shape of the removal portions 213 and 223 is not limited to the step shape shown in the figure, and even if a slope is formed on the side surface of the exposed region and the removal portions 213 and 223 are formed so that the width becomes narrower toward the tip of the exposed region. good. Further, the side surface on the opposite side of the protruding portion 212 and 222 may be formed in the same shape as the protruding portion side. In this way, the base material on the tip end side of the exposed region is removed in the width direction by the removing portions 213 and 223, and the tip end side of the exposed region is formed to be narrower or the same width as the covering region. By reducing the volume of the tip portion of the segment coil 20, the heat capacity of the welded portion 201 of the segment coil 20 is reduced so that the first coil 210 and the second coil 220 can be reliably welded even with a small amount of heat.

Further, the copper of the base material can be exposed on the opposite side of the protrusions 212 and 222, and the electrodes can be brought into contact with each other as a ground to which a current at the time of welding is applied.

Further, since the opposite side of the protrusions 212 and 222 is recessed from the side surface of the covering region, a gap 205 is created between the exposed regions, an insulation distance from the adjacent segment coil 20 can be secured, and even if the segment coil 20 is displaced, the phase spacing is established. A short circuit can be prevented.

Next, a method of manufacturing the segment coil 20 of this embodiment will be described. 7, 8 and 9 are views showing the tip of the process of manufacturing the segment coil 20 of this embodiment.

(Procedure 1) First, a copper wire having a circular cross section is bent into a shape suitable for insertion into the stator core 22 to form a segment coil 20 having the shape shown in FIG.

(Procedure 2) After that, as shown in FIG. 7, the bent segment coil 20 is pressed to form a flat wire having two sides facing each other in the cross section, and the tip portion is strongly pressed. To create a wide tip. Further, the press working for forming the flat wire and the press working for widening the tip portion may be performed at the same time. By applying pressure to the segment coil 20 during press working, the hardness of the base material in the peeled region can be improved, deformation of the protrusions 212 and 222 can be prevented during welding, and the first coil 210 and the second coil 220 can be reliably connected. Can be welded. Further, the segment coil 20 may be formed by bending an already processed flat wire and pressing the tip. In this case, the tip of the segment coil 20 having a bent flat wire is pressed to create a wide tip.

(Procedure 3) After that, the insulating film on the surface of the exposed area is removed. Specifically, the region (side surface of the exposed region) shown by hatching in FIGS. 8 and 9 is removed, and the coatings on the front surface and the back surface of the exposed region are removed to remove the protrusions 212 and 222 and the removal portions 213 and 223. To form. The removal of the tip portion may be cut by a pressing process or may be scraped off by a cutting process. By removing a part of the tip portion, the tip portion having the shape shown in FIG. 4 is formed. Either the step of removing the side surface of the exposed region and the step of removing the front surface and the back surface may be performed first.

Either the procedure 1 for bending the segment coil 20 or the procedures 2 to 3 for forming the protrusions 212 and 222 may be performed first.

(Procedure 4) After that, the segment coil 20 formed in a desired shape is inserted into the slot of the stator core 22, and the segment coil 20 protruding toward the weld side of the stator core 22 is bent to bend the protruding portion 212 of the two segment coils 20. It is processed so that the flat surfaces of 222 come into contact with each other, and welded at the welded portion 201. This constitutes a stator in which a coil is wound around the stator core 22.

As described above, in the stator of the rotary electric machine according to the embodiment of the present invention, a plurality of segment coils 20 including the first coil 210 and the second coil 220 arranged adjacent to each other, and the segment coils 20 are arranged. Each segment coil 20 has a coated portion (covered region) covered with an insulator and an exposed portion (exposed region) where the conductor is exposed. A protruding portion 212 or 222 protruding from the side surface of the covering portion is formed in the exposed portion, and the protruding portion 212 of the first coil 210 and the protruding portion 222 of the second coil 220 are in surface contact with each other. The covering portion of the first coil 210 is arranged with a gap 205 from the covering portion of the second coil 220. Therefore, the protrusions 212 and 222 are in close contact with each other without bending so that the welded surfaces of the segment coil 20 are close to each other, and the first coil 210 and the second coil 220 can be connected by welding. Further, in a state where the covering region is in contact with each other due to bending, a phase-to-phase short circuit may occur due to damage to the insulating coating, but in this embodiment, the protruding portions 212 and 222 of the exposed region protrude from the covering region. In other portions (for example, the covering region), the segment coil 20 can be arranged on the stator core 22 so that a gap 205 is provided between the adjacent segment coils 20, and a short circuit between phases can be prevented.

Further, since the protruding portions 212 and 222 are formed in the portions where the first coil 210 and the second coil 220 are arranged in parallel, the adhesion of the protruding portions 212 and 222 is improved and stable welding can be performed.

Further, since the exposed portion is formed by removing the insulator by cutting the wire rod constituting the segment coil 20, the exposed portion can be accurately formed in a short time.

Further, on the tip end side of the exposed portion, a removing portion 213 and 223 are provided on the opposite side of the protruding portion 212 and 222, and the exposed portion is formed in the removing portion 213 and 223 to be narrower or the same as the width of the covering portion. Therefore, the heat capacity of the welded portion 201 of the segment coil 20 can be reduced, and the first coil 210 and the second coil 220 can be reliably welded even with a small amount of heat.

Further, the method for manufacturing the stator of the rotary electric machine according to the embodiment of the present invention includes step 1 of press working so that the tip of a flat wire having at least a part of a flat surface formed on a flat surface is wide, and the press working. Steps 2 to 3 for forming the projecting portions 212 and 222 having a flat surface protruding from the side surface of the flat wire on the side surface of the tip portion, and the segment coil 20 on which the projecting portions 212 and 222 are formed are arranged on the stator core 22. Since the procedure 4 for forming the winding is included, the exposed portion can be accurately formed in a short time by a simple process.

Further, in the procedure 3 for forming the protrusions 212 and 222, the insulator on the surface is removed by cutting the side surface of the pressed tip portion to form the protrusions 212 and 222, so that the protrusions 212 and 222 are formed in a short time. The exposed part can be formed accurately.

It should be noted that the present invention is not limited to the above-mentioned examples, but includes various modifications and equivalent configurations within the scope of the attached claims. For example, the above-mentioned examples have been described in detail in order to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to those having all the described configurations. Further, a part of the configuration of one embodiment may be replaced with the configuration of another embodiment. Further, the configuration of another embodiment may be added to the configuration of one embodiment. In addition, other configurations may be added / deleted / replaced with respect to a part of the configurations of each embodiment.

10 Rotating electric machine assembly 11 Rotating electric machine 12 Inverter control part 20 Segment coil 20B Bending part 21 Leading wire 22 Stator core 22A, 22B End face 23 Hairpin part 24 Slot insertion part 28 Coil end part 201 Welding part 205 Gap 210 First coil 220 Second Coil 212, 222 Protruding part 213, 223 Removal part 214, 224 Step

Claims (8)

It is a stator of a rotary electric machine,
A plurality of segment coils including the first coil and the second coil arranged adjacent to each other,
A core portion having a space in which the segment coil is arranged is provided.
Each of the segment coils has a covering portion covered with an insulator and an exposed portion with an exposed conductor.
A protruding portion protruding from the side surface of the covering portion is formed in the exposed portion.
The protruding portion of the first coil and the protruding portion of the second coil are in surface contact with each other.
A stator of a rotary electric machine, wherein the covering portion of the first coil is arranged with a gap between the covering portion of the first coil and the covering portion of the second coil. The stator of the rotary electric machine according to claim 1.
The protrusion is a stator of a rotary electric machine, characterized in that the first coil and the second coil are formed in a portion where the first coil and the second coil are arranged in parallel. The stator of the rotary electric machine according to claim 1.
The exposed portion is a stator of a rotary electric machine, characterized in that the wire rod constituting the segment coil is cut to remove the insulator. The stator of the rotary electric machine according to claim 1.
On the tip end side of the exposed portion, a removing portion is provided on the opposite side of the protruding portion.
The exposed portion is a stator of a rotary electric machine, characterized in that the exposed portion is formed in the removing portion to be narrower or the same as the width of the covering portion. The stator of the rotary electric machine according to claim 4, wherein the stator
The segment coil is
At least part of the side surface is formed from a flat line composed of planes,
Rotation characterized in that the width of the plane constituting the side surface of the exposed portion is gradually narrowed and the region covered with the insulator is gradually widened from the protruding portion on the removing portion side to the covering portion. Electric stator. The stator of the rotary electric machine according to claim 1.
The segment coil is formed of a flat wire having at least a part of a side surface formed of a flat surface.
A stator of a rotary electric machine, characterized in that the width of a plane constituting the side surface of the protruding portion is gradually narrowed from the protruding portion to the covering portion, and the region covered with the insulator is gradually widened. It is a manufacturing method of the stator of a rotary electric machine.
The procedure of pressing so that the tip of the flat wire having at least a part of the side surface formed on a flat surface is wide, and
A procedure for forming a protrusion having a plane protruding from the side surface of the flat wire on the side surface of the pressed tip portion, and a procedure for forming the protrusion portion.
A method for manufacturing a stator of a rotary electric machine, which comprises a procedure of arranging a segment coil in which a protrusion is formed on a stator core to form a winding. The method for manufacturing a stator of a rotary electric machine according to claim 7.
The procedure for forming the protrusion is characterized in that the side surface of the pressed tip is cut to remove the insulator on the surface of the protrusion to form the protrusion. How to make a stator.

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