JP4498686B2 - Expansion former and coil forming method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an expansion former and a method for forming a coil for extending a coil inserted into a slot of a stator core in an outer peripheral direction of the stator core. More specifically, the present invention relates to an expansion former and a method for forming a coil that can perform coil expansion molding to a position where sufficient interphase insulation can be ensured. In particular, it is suitable for manufacturing a stator by automatically inserting interphase insulating paper.
[0002]
[Prior art]
Conventionally, in the stator manufacturing process, there is a process of inserting a coil into a slot of the stator and then expanding the coil end portion of the coil inserted into the slot in the outer peripheral direction of the stator core. This process is necessary when the coil is inserted for the first time because there is nothing other than the insulator in the slot, so that the insertion of the coil is not hindered. In addition, the coil already inserted in the slot does not get in the way.
[0003]
When the coil is expanded, if the coil is damaged, insulation failure occurs. Therefore, the coil needs to be expanded so as not to damage the coil. Therefore, various methods for performing expansion molding without damaging the coil have been proposed. As one of them, for example, one disclosed in JP-A-11-27889 can be cited. As shown in FIG. 12, this expansion molding method includes a plurality of expansions that press a part of the coil end portion of the stator coil 101 inserted into the slot of the stator (stator core) from the inner peripheral side to the outer peripheral side. A former (molding die) 100 is provided, and among the stator coils inserted in a plurality of times, each expansion coil (molding) is sequentially inserted each time a stator coil other than the last inserted stator coil is inserted. The mold) 100 is subjected to expansion molding.
[0004]
In this way, using the expansion former (molding die) 100, the coil end portion corresponding to the slot position where the next coil in the coil end of the coil already inserted in the slot is inserted into the stator (stator core). By expanding and forming radially from the periphery toward the outer periphery, the coil can be expanded without damaging the coil. In addition, this expansion molding prevents the coil already inserted in the slot from getting in the way when the next phase coil is inserted.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-27889 (pages 2 and 3, FIG. 2)
[0006]
[Problems to be solved by the invention]
However, the technique disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 11-27889 has a problem that all the coils inserted into the slots cannot be normally expanded. That is, as shown in FIG. 13, several coils are deformed without being normally expanded. Thus, the coil 101a deformed without being normally expanded and formed (hereinafter referred to as the “coil coil”) 101a is detached from the interphase insulating paper 102 when the interphase insulating paper 102 is inserted, and comes into contact with the coil of the next phase. . If it becomes so, interphase insulation will fall.
[0007]
Further, the expansion former (molding die) 100 may crush the peeling coil 101a, and as shown in FIG. 14, the peeling coil 101a may remain in a shape that crosses the slot of the stator core after the coil expansion molding. . Also in this case, when the interphase insulating paper 102 is inserted, the peeling coil 101a protrudes from the interphase insulating paper 102, so that the interphase insulating property decreases due to contact with the next phase coil. In other words, in the technique disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 11-27889, the phase coils are in contact with each other, and there is a possibility that interphase insulation cannot be ensured.
[0008]
In particular, this is a problem particularly in a motor for driving a hybrid vehicle. This is because the motor for driving a hybrid vehicle has a large operating area and thus has a high operating voltage, and the standard regarding the insulation performance of the motor is stricter than that of a general motor. In addition, the motor for driving a hybrid vehicle has a tendency to increase the rotation speed in order to reduce the cost, and the use voltage tends to increase further in the future.
[0009]
For this reason, when a loose coil is generated and insulation between phases cannot be ensured, it is necessary to rework. Here, if the interphase insulating paper is inserted manually, the stray coil may be reworked when inserting the interphase insulating paper.
[0010]
However, when the interphase insulating paper is automatically inserted, it is necessary to make a correction separately from the insertion of the correlation insulating paper when the peeling coil is generated. For this reason, even if the correlation insulating paper is automatically inserted, it is necessary to rework the peeling coil, so that there is almost no change in production efficiency as compared with the case where the correlation insulating paper is manually inserted. This makes it meaningless to automatically insert interphase insulating paper in order to improve production efficiency.
[0011]
Therefore, the present invention has been made to solve the above-described problems, and even when interphase insulating paper is automatically inserted, the coil is extended to a position where sufficient interphase insulation can be secured. It is an object of the present invention to provide an expansion former and a method of forming a coil that can perform the above.
[0012]
[Means for Solving the Problems]
An expansion former according to the present invention made to solve the above problems is an expansion former for expanding a coil end portion of a coil inserted into a slot of a stator core in an outer peripheral direction of the stator core. It has a contact part that expands by contact, and a protrusion protruding from the contact part, and the protrusion is provided at a stator core side end of the contact part.
[0013]
In this expansion former, the contact portion contacts the coil end portion of the coil inserted into the stator core slot. In this state, the coil is expanded. Specifically, the expansion molding of the coil is performed by moving the expansion former in the outer peripheral direction of the stator core. Here, a protrusion is formed at the end of the contact portion of the expansion former on the stator core side. For this reason, when the expansion former is moved in the outer peripheral direction of the stator core, the coil end portion is scooped up to the protrusion portion, and the coil is expanded. Therefore, since the entire coil is normally expanded, the expansion former does not crush the coil. For this reason, no loose coil is generated. As a result, even if the interphase insulating paper is automatically inserted after the expansion of the coil, the coil already inserted in the slot and the next phase coil inserted in the slot do not come into contact with each other. Therefore, sufficient interphase insulation can be ensured.
[0014]
In the expansion former according to the present invention, it is preferable that the protrusion has a substantially triangular cross section so that the protrusion can enter between the coil end portion of the coil and the stator core.
[0015]
This is because when the extension former is moved in the outer peripheral direction of the stator core, the coil end portion of the coil inserted into the slot can be surely scooped up by making the vertical cross-sectional shape of the protruding portion substantially triangular. . As a result, it is possible to reliably prevent the flaking coil from being generated.
[0016]
In the expansion former according to the present invention, it is desirable that the boundary portion between the protrusion and the contact portion has a convex shape such that the center is higher than both side ends.
[0017]
By doing so, it is possible to lift the coil that is in contact with the contact portion of the expansion former when the coil is expanded. As a result of lifting the coil in this way, when the expansion former is removed after the expansion molding of the coil, even if a return due to the spring back of the coil occurs, a sufficient interphase insulation can be secured. The coil end portion can be positioned.
[0018]
In the expansion former according to the present invention, it is desirable that both side ends of the protrusion are chamfered so that the width becomes narrower toward the tip.
[0019]
A loose coil that crosses a slot may not be able to be scooped up by a protrusion. Then, such a loose coil crossing the slot is generated in the vicinity of both end portions of the expansion former. For this reason, it is possible to prevent the stray coil from being crushed by chamfering both end portions of the expansion former so as to be cut inward. Then, the coil other than the flaking coil is expanded by the expansion former, so that the flaking coil is also lifted along the chamfered portion. That is, the loose coil is expanded and formed at the same position as the other coils. This is because the stray coil is connected to the other coil, and therefore, when the other coil portion is lifted, the stray coil is moved so as to be attracted thereto.
[0020]
In the expansion former according to the present invention, it is desirable that a protrusion is formed at the opposite end of the contact portion.
[0021]
If the coil end portion of the coil inserted into the slot is lifted by the expansion former, the interphase insulating property may be overcome when the correlation insulating paper is inserted. As a result, interphase insulation cannot be ensured. Therefore, by forming a protrusion at the opposite end of the expansion former, it is possible to restrict the coil end portion from being lifted too much during expansion molding of the coil. As a result, it is possible to reliably prevent the coil end portion from getting over the interphase insulating paper, so that sufficient interphase insulation can be ensured.
[0022]
The coil forming method according to the present invention made to solve the above-described problems is characterized in that the coil core is expanded in the outer peripheral direction of the stator core using any one of the above-described expansion formers.
[0023]
In this coil forming method, since any one of the above-described expansion formers is used to perform coil expansion forming, sufficient interphase insulation can be ensured even when interphase insulating paper is automatically inserted. it can.
[0024]
In the coil forming method according to the present invention, it is desirable to move the extension former in the axial direction of the stator core and away from the stator core after the coil end portion of the coil is extended.
[0025]
In this coil molding method, after the expansion former is moved in the outer peripheral direction of the stator core and expanded, the expansion former is moved in the axial direction of the stator core and away from the stay core, so that the coil end portion can be lifted more. it can. As a result, when the expansion former is removed after the expansion molding of the coil, the coil end portion can be positioned at a position where sufficient inter-phase insulation can be ensured even if the coil springback returns.
[0026]
When the coil is expanded by this molding method, it is desirable to use an expansion former in which a protruding portion is formed at the opposite end. As described above, when the coil end portion of the coil inserted into the slot is lifted, when the correlation insulating paper is inserted, the interphase insulating paper may be crossed, so a protrusion is formed at the opposite end. This is because by using the expansion former, it is possible to restrict the coil end portion from being lifted up excessively during the expansion molding of the coil.
[0027]
Further, in the coil molding method according to the present invention, it is desirable that the expansion former is disposed on the inner side of the inner peripheral surface of the stator core before coil expansion molding, and thereafter the expansion former is moved in the outer peripheral direction of the stator core.
[0028]
In this expansion molding method, the expansion former is moved from the inner peripheral surface to the outer peripheral direction from the inner peripheral surface of the stator core, so that it can be surely picked up by the protruding portion without stepping over the coil. As a result, the coil can be expanded to a position where sufficient interphase insulation can be ensured.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a most preferred embodiment in which an expansion former and a method for forming a coil of the present invention are embodied will be described in detail with reference to the drawings. In the present embodiment, the present invention is applied to a manufacturing process of a stator that is manufactured by automatically inserting interphase insulating paper.
[0030]
First, a stator manufactured by applying the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view showing a schematic configuration of the stator 50. FIG. 2 is a diagram showing a part (1/4 arc portion) of the stator core 52, in which a U-phase coil 51U and an interphase paper 60 for interphase insulation between the U-phase coil 51U and the V-phase coil 51V are inserted. Shows the state.
[0031]
As shown in FIG. 1, this stator 50 is a three-phase stator including a U-phase coil 51U, a V-phase coil 51V, and a W-phase coil 51W. The stator 50 is disposed between the stator core 52, the above-described three-phase coils 51U, 51V, 51W disposed on the stator core 52, and between the phases of the coils (between the U phase and the V phase and between the V phase and the W phase). Interphase paper 60, 60.
[0032]
Here, the stator core 52 has an annular shape formed by laminating and integrally bonding a plurality of steel plates (see FIG. 2). As shown in FIG. 2, a plurality of slots 53 for arranging the phase coils 51U, 51V, 51W are formed on the inner peripheral surface of the stator core 52 at predetermined intervals. On the other hand, the coils 51U, 51V, 51W of each phase are formed by winding enameled wires. The coils 51U, 51V, 51W of the respective phases are inserted into the slots 53 of the stator core 52 through the interphase paper 60. As will be described later, since the interphase paper 60 is automatically inserted, it is necessary to prevent the flaking coil from being generated when the coil is expanded.
[0033]
Therefore, in order to prevent the flaking coil from being generated during the expansion molding of the coil, the coil expansion molding using an expansion former described below is performed. First, FIG. 3 shows a schematic configuration of the extension former according to the present embodiment. FIG. 3 is a perspective view showing the expansion former. As shown in FIG. 3, the expansion former 10 is a substantially rectangular parallelepiped mold, and includes a contact portion 11 and a projection portion 12.
[0034]
The abutting portion 11 is a portion that abuts on a coil end portion protruding from the stator core among the coils inserted in the slots of the stator core. Since the contact portion 11 is in contact with the coil, the surface thereof is mirror-polished so that the coil is not damaged. The protrusion 12 is formed at the lower end of the contact portion 11 in FIG. 3 and protrudes in the coil extending direction (outer circumferential direction of the stator core). As shown in FIG. 3, the vertical cross-sectional shape of the protrusion 12 is a substantially triangular shape. Accordingly, when the expansion former 10 is moved in the outer peripheral direction of the stator core when the coil is expanded, the tip of the protrusion 12 enters between the coil end portion and the stator core, and the coil end portion of the coil can be lifted. It can be done.
[0035]
As shown in FIG. 4, the expansion former 10 having the above configuration is arranged and used in a circumferential shape. FIG. 4 is a plan view showing the arrangement position of the expansion former 10. In the present embodiment, eight expansion formers 10 are arranged at equal intervals in order to expand and mold the eight coil end portions simultaneously. Specifically, the expansion former is attached to a coil expansion molding apparatus.
[0036]
Therefore, the coil expansion molding apparatus will be briefly described with reference to FIG. FIG. 5 is a front view showing a schematic configuration of the coil expansion molding apparatus. As shown in FIG. 5, the coil expansion molding apparatus includes an expansion former holding portion 20 for holding the expansion former 10 and a taper member 21 that contacts and separates from the expansion former holding portion 20.
[0037]
As shown in FIG. 5, a taper (a taper whose diameter is reduced downward in FIG. 5) is formed inside the extended former holding portion 20. Note that eight extension former holding units 20 are provided so that eight extension formers 10 can be held, but only one is shown in FIG. Each of these extended former holding units 20 is movable in the vertical direction in FIG.
[0038]
Further, the taper member 21 is formed with a taper similar to that of the extended former holding portion 20. And this taper member 21 moves to the up-down direction in FIG. Thus, when the taper member 21 is moved downward in FIG. 5 when the coil is expanded, the taper member 21 comes into contact with the expansion former holding portion 20 and further moves downward from that state so that the expansion former holding portion 20 moves in the outer circumferential direction. It has become.
[0039]
The operation of this coil expansion molding apparatus will be briefly described. First, the stator core 52 in which the coil is inserted is fixed to the coil expansion molding apparatus. At this time, the coil end portions of the coils protrude above and below the stator core 52. Next, in a state where the taper member 21 is raised, the expansion former holding portion 20 to which the expansion former 10 is attached is disposed on the inner side of the inner peripheral surface of the stator core 52 (see FIG. 4). As a result, the expansion former 10 is moved from the inner side to the outer side of the inner peripheral surface of the stator core 52, so that the protrusion 12 can be surely scooped up without stepping over the coil. Therefore, the coil can be expanded to a position where sufficient interphase insulation can be ensured.
[0040]
Next, the taper member 21 is lowered and brought into contact with the taper surface of the expansion former holding member 20. Then, the taper member 21 is further lowered from this state. Thereby, the extended former holding part 20 is pushed out in the outer circumferential direction of the stator core 52. For this reason, the expansion former 10 also moves in the outer peripheral direction of the stator core 52. Thereby, the expansion molding of the coil by the expansion former 10 is performed. At this time, first, the protruding portion 12 of the expansion former 10 enters the stator core 52 and the coil end portion of the coil. Subsequently, the contact portion 11 of the expansion former 10 contacts the coil end portion of the coil. The coil end portion is pushed out toward the outer periphery of the stator core 52 while the end portion of the coil end portion is lifted. Thereafter, when the movement of the expansion former 10 in the outer circumferential direction is completed, the expansion former holding unit 20 is raised. As a result, the expansion former 10 is also raised, so that the coil end portion of the coil is lifted.
[0041]
Here, focusing on the movement of the expansion former in the coil expansion molding apparatus, the expansion former 10 moves as shown in FIG. 6 to perform coil expansion molding. FIG. 6 is a diagram for explaining the movement trajectory of the expansion former. That is, first, the expansion former 10 moves from the inner side toward the outer peripheral direction from the inner peripheral surface of the stator core 52. When the movement in the outer peripheral direction is completed, the movement is in the axial direction of the stator core 52 and away from the stator core 52. By moving the expansion former 10 in this way and performing coil expansion molding, it is possible to reliably prevent the occurrence of a flaking coil and to ensure sufficient interphase insulation even if the coil is returned by springback. A coil end part can be located in the position which can do.
[0042]
Next, an operation of assembling the stator 50 using the extended former having the above-described configuration will be described with reference to FIGS. FIG. 7 is a diagram illustrating a state where the U-phase coil has been expanded. FIG. 8 is a diagram illustrating a state after one interphase sheet 60 is inserted into the stator core 52. First, the U-phase coil 51 </ b> U is inserted into the slot 53 of the stator core 52. Then, the U-phase coil 51U is expanded by the above-described coil expansion molding apparatus. The expansion molding of the U-phase coil 51U is performed by the expansion former 10.
[0043]
Specifically, the extension former 10 held by the extension former holding part 20 is arranged on the inner side of the inner peripheral surface of the stator core 52. Then, the taper member 21 is lowered, and the extended former holding portion 20 is pushed out in the outer circumferential direction of the stator core 52. Thereby, the expansion former 10 is moved in the outer circumferential direction of the stator core 52. At this time, the projecting portion 12 of the expansion former 10 enters the stator core 52 and the coil end portion of the coil, so that the end portion of the coil end portion of the U-phase coil 51 is pushed up toward the outer periphery of the stator core 52. Thereafter, the extended former holding unit 20 is moved in the axial direction of the stator core 52 and away from the stator core 52. Accordingly, the expansion former 10 is also moved in the axial direction of the stator core 52 and away from the stator core 52, so that the end portion of the coil end portion of the U-phase coil 51 is further lifted by the protrusion 12.
[0044]
Thus, when the expansion molding of the U-phase coil 51U is completed, the state shown in FIG. 7 is obtained. As shown in FIG. 7, by performing expansion molding using the expansion former 10 according to the present embodiment, it is possible to perform expansion molding normally without generating a loose coil.
[0045]
When the expansion molding of the U-phase coil 51U is completed, the interphase paper 60 for U-V interphase insulation is inserted into the stator core 52. The insertion of the interphase paper 60 is automatically performed using an insertion jig (not shown). That is, the interphase paper 60 held by the insertion jig is disposed on the inner peripheral side of the stator core 52, and the interphase paper 60 held by the insertion jig is inserted into the stator core 52. Here, when the U-phase coil 51U is expanded, expansion is normally performed without generating a staggered coil. Therefore, even if the correlation paper 60 is automatically inserted, the U-phase coil 51U does not protrude from the correlation paper 60. . Thereafter, the correlation paper 60 is automatically inserted sequentially. In the present embodiment, eight interphase sheets 60 are inserted into the stator core 52 in which the U-phase coil 51U is inserted. As a result, the interphase paper 60 is disposed around the entire circumference of the stator core 52 so that the U-phase coil 51U is covered.
[0046]
Next, the V-phase coil 51 </ b> V is inserted into the slot 53 of the stator core 52. In the same manner as described above, the interphase paper 60 disposed between the V phase and the W phase is automatically inserted into the stator core 52 after the V-phase coil 51V is expanded. Further, W-phase coil 51 </ b> W is inserted into stator core 52. Thereafter, final molding is performed to complete the three-phase stator 50. As described above, the expansion molding of the U-phase coil 51U and the V-phase coil 51V is normally performed, so that no flaking coil is generated. Therefore, even if the correlation paper 60 is automatically inserted and the stator 50 is manufactured, the interphase insulation is achieved. Can be secured sufficiently.
[0047]
Here, a modified example of the expansion former will be described. First, a first modification will be described. FIG. 9 shows a schematic configuration of the extension former according to the first modification. FIG. 9 is a perspective view showing the expansion former 10a. As shown in FIG. 9, the expansion former 10 a has a contact portion 11 and a projection portion 12, similar to the expansion former 10. However, unlike the expansion former 10, the boundary portion 13 between the contact portion 11 and the projection portion 12 has a convex shape such that the center is higher than both side ends. That is, the center part of the upper end of the protrusion 12 is raised.
[0048]
By making the contact part 11, the protrusion part 11, and the boundary part 13 into such shapes, the coil end part of the coil can be lifted more when the expansion former 10a is moved in the outer peripheral direction of the stator core. As a result of lifting the coil in this way, when the expansion former is removed after the expansion molding of the coil, even if a return due to the spring back of the coil occurs, a sufficient interphase insulation can be secured. The coil end portion can be positioned.
[0049]
Next, a second modification will be described. FIG. 10 shows a schematic configuration of the extension former according to the second modification. FIG. 10 is a perspective view showing the expansion former 10b. As shown in FIG. 10, the expansion former 10 b has almost the same shape as the expansion former 10 a and has a contact portion 11 and a projection portion 12. However, unlike the expansion former 10 a, chamfered portions 12 b are formed at both end portions of the protruding portion 12. The chamfered portion 12a is formed by chamfering the protruding portion 12 so that the width becomes narrower toward the tip (lower end in FIG. 10).
[0050]
In this way, by chamfering both side ends of the protrusion 12 to form the chamfered portion 12 a, the coil that crosses the slot 53 of the stator core 52 is not crushed. Then, the coil other than the loose coil is expanded by the expansion former 10b, and the loose coil is lifted along the chamfered portion 12a. This is because the stray coil is connected to the other coil, and therefore, when the other coil portion is lifted, the stray coil is moved so as to be attracted thereto. Therefore, the loose coil can be normally expanded and formed at the same position as the other coils.
[0051]
Finally, a third modification will be described. FIG. 11 shows a schematic configuration of the extension former according to the third modification. FIG. 11 is a perspective view showing the expansion former 30. As shown in FIG. 11, the expansion former 30 includes a contact portion 11 and a projection portion 12, similar to the expansion former 10. However, unlike the expansion former 10, the protrusion 14 is also provided at the opposite end where the protrusion 12 is provided. That is, the protrusions 12 and 14 are formed at the upper and lower ends in FIG.
[0052]
Thus, by providing the protrusion 14 at the opposite end where the protrusion 12 is provided, it is possible to restrict the coil end portion from being lifted too much during the expansion molding of the coil. As a result, it is possible to reliably prevent the coil end portion from getting over the interphase paper, so that sufficient interphase insulation can be ensured. In particular, as described above, the extension former 30 may be used when the extension former is moved in the outer circumferential direction of the stator core and then moved away from the stator core.
[0053]
As described above in detail, the expansion former 10 according to the embodiment includes the contact portion 11 that extends by contacting the coil end portion of the coil, and the protrusion 12 that protrudes from the contact portion 11. Since the protrusion 12 is provided at the end of the abutment 12 on the stator core side, the coil end is scooped up by the protrusion 12 when the expansion former 10 is moved in the outer peripheral direction of the stator core. Expansion molding is performed. Accordingly, since the entire coil is normally expanded, the expansion former 10 does not step over the coil. For this reason, since no flaking coil is generated, even if the interphase paper 60 is automatically inserted after the expansion of the coil, the coil already inserted in the slot 53 and the next phase coil inserted in the next slot may come into contact with each other. Absent. Therefore, sufficient interphase insulation can be ensured.
[0054]
And since the protrusion part 12 is formed in the substantially triangular shape in the longitudinal cross-section so that it may enter between the coil end part of a coil and a stator core, when moving the expansion former 10 to the outer peripheral direction of a stator core, it becomes a slot. The coil end portion of the inserted coil can be reliably picked up.
[0055]
Further, since the coil forming method according to the embodiment performs the coil expansion molding using the above-described expansion former 10, sufficient interphase insulation is ensured even when the interphase paper 60 is automatically inserted. be able to.
[0056]
In the coil molding method according to the embodiment, after the expansion former 10 is moved in the outer peripheral direction of the stator core and the coil end portion of the coil is expanded, the expansion former 10 is moved in the axial direction of the stator core and the stator core. Therefore, the coil end portion can be lifted more. As a result, when the expansion former is removed after the expansion molding of the coil, the coil end portion can be positioned at a position where sufficient inter-phase insulation can be ensured even if the coil springback returns.
[0057]
Further, in the coil forming method according to the embodiment, the expansion former 10 is arranged on the inner side of the inner peripheral surface of the stator core before the coil expansion molding, and then the expansion former 10 is moved in the outer peripheral direction of the stator core. It is possible to surely scoop up the protrusions 12 without stepping on. As a result, the coil can be expanded to a position where sufficient interphase insulation can be ensured.
[0058]
It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. In the above-described embodiment, the present invention is applied when the correlation paper 60 is automatically inserted and the stator 50 is manufactured. However, the present invention is also applied when the stator is manufactured without automatically inserting the correlation paper. can do.
[0059]
【The invention's effect】
As described above, according to the expansion former according to the present invention, in the expansion former for expanding the coil end portion of the coil inserted into the slot of the stator core in the outer peripheral direction of the stator core, the expansion former abuts on the coil end portion of the coil. And a protrusion protruding from the contact portion, and the protrusion is provided at the end of the contact portion on the stator core side. Then, the coil is expanded so that the coil end portion is scooped up by the protruding portion. Therefore, since the entire coil is normally expanded, the expansion former does not crush the coil. For this reason, no loose coil is generated. As a result, even if the interphase insulating paper is automatically inserted after the expansion of the coil, the coil already inserted in the slot and the next phase coil inserted in the slot do not come into contact with each other. Therefore, sufficient interphase insulation can be ensured.
[0060]
Further, since the coil forming method according to the present invention is expanded in the outer peripheral direction of the stator core using the above-described expansion former, sufficient interphase insulation is ensured even when interphase insulating paper is automatically inserted. Can do.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of a stator manufactured by using an expansion former and a molding method according to an embodiment.
FIG. 2 is a plan view showing a schematic configuration of the stator of FIG. 1;
FIG. 3 is a perspective view showing a schematic configuration of an expansion former according to the embodiment.
FIG. 4 is a plan view showing an arrangement position of an expansion former.
FIG. 5 is a diagram showing a schematic configuration of a coil expansion molding apparatus to which an expansion former is attached.
FIG. 6 is a diagram for explaining a movement trajectory of an expansion former.
FIG. 7 is a diagram showing a state of the stator core after the U-phase coil is expanded.
FIG. 8 is a diagram showing a state after inserting interphase paper into a stator core.
FIG. 9 is a perspective view showing a first modification of the expansion former.
FIG. 10 is a perspective view showing a second modification of the expansion former.
FIG. 11 is a perspective view showing a third modification of the expansion former.
FIG. 12 is a view for explaining a conventional coil forming method.
FIG. 13 is a diagram showing a schematic configuration of a conventional expansion former and a stray coil.
FIG. 14 is a view showing a state of a coil (peeling coil) crossing a slot.
[Explanation of symbols]
10 Extended former
11 Contact part
12 Protrusion
50 stator
52 Stator core
53 slots
60 correlation paper

Claims (7)

In the expansion former for expanding the coil end portion of the coil inserted into the slot of the stator core in the outer peripheral direction of the stator core,
An abutting portion that abuts and expands on a coil end portion of the coil;
A protrusion protruding from the contact portion,
The protrusion is provided at the stator core side end of the contact portion,
The expansion former, wherein a boundary portion between the protrusion and the contact portion has a convex shape such that the center is higher than both ends in the axial direction of the stator core. In the extended former according to claim 1,
The extension former is characterized in that the protrusion has a substantially triangular cross-sectional shape so as to be inserted between a coil end portion of the coil and the stator core. In the extended former according to claim 1 or 2,
Both side ends of the protrusions are chamfered so that the circumferential width of the stator becomes narrower toward the tip, which is the direction in which the protrusions are formed in the axial direction of the stator core. A featured extended former. In any one expansion former as described in Claim 1-3,
The abutment, extended former, wherein the second protrusion on the other axial end of the said projection part is formed ends stator core is formed.   A coil forming method, wherein a coil end portion of a coil inserted into a slot of a stator core is expanded in an outer peripheral direction of the stator core using any one expansion former according to claim 1. . In the method of forming a coil according to claim 5,
A method for forming a coil, comprising: extending the coil end portion of the coil; and moving the extension former in an axial direction of the stator core and away from the stator core. In the method for forming a coil according to claim 5 or 6,
A method for forming a coil, comprising: disposing the expansion former inside an inner peripheral surface of the stator core before coil expansion molding, and then moving the expansion former in an outer peripheral direction of the stator core.

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