JP2021158846A - Mold casting type jig and arrangement method of band reinforcement material - Google Patents

Abstract

To arrange a band reinforcement material reinforcing a resin without interfering with or detached from a shaft-shaped casting jig when performing a mold casting of a coil end.SOLUTION: A shaft-shaped mold casting type jig 25 inserted to an inner side in a radial direction of a stator 10 when performing a mold casting in which a coil end 31 of the stator 10 of a rotary electric machine is covered with the resin, comprises: a fitting part 25a arranged on the inner side in the radial direction of a stator iron core 1; and a mold reception part 25b arranged on the inner side in the radial direction of the coil end 31. The mold reception part 25b includes an outer peripheral face in a nearly truncated conical shape of which an outer diameter is expanded as separated to a shaft direction from the fitting part, a groove 25c extended to a nearly peripheral direction is formed by at least one periphery or larger on the outer peripheral face of the mold reception part 25b, and a band-like reinforcement material 5 is held in the groove 25c.SELECTED DRAWING: Figure 1

Description

The present invention relates to a mold casting jig used when performing mold casting in which the coil end of a stator of a rotary electric machine is covered with resin, and a method of arranging a strip-shaped reinforcing material for reinforcing the resin.

In order to improve the rated output and rated torque of the rotary electric machine, the stator of the rotary electric machine with a mold casting that covers the coil end with resin is used for the purpose of effectively releasing the heat of the coil end of the winding to the outside. Are known. Further, Patent Document 1 discloses a technique for reinforcing a resin with a band-shaped reinforcing material in order to prevent cracks from being generated in the resin covering the coil end due to repeated rises and falls in the temperature of the coil end.

FIG. 3 is a perspective view showing a stator 10 of a rotary electric machine in which a coil end of a winding is covered with a resin and molded. 4 and 5 are views disclosed in Patent Document 1. FIG. 4 is a view of the stator 10 of the rotary electric machine shown in FIG. 3 as viewed from the inside in the radial direction. FIG. 5 is a cross-sectional view taken along the line AA in FIG. This AA line cross section is the interface between the stator core 1 and the resin 2, and includes the axial end surface of the stator core 1. As shown in FIGS. 3, 4 and 5, the stator 10 has a stator core 1 in which electromagnetic steel sheets are laminated in the axial direction, a winding 3, and a stator core 1 of the windings 3 in the axial direction. The resin 2 is provided by molding to cover the coil end 31, which is a portion protruding outward from the end face.

As shown in FIG. 5, the stator core 1 is composed of a substantially annular yoke 11 and a plurality of teeth 12 projecting radially inward from the inner peripheral surface of the yoke 11. A slot 13 is formed between the teeth 12 adjacent to each other in the circumferential direction, which is a space in which the winding 3 is accommodated, and the winding 3 is wound around the teeth 12 through the slot 13. Then, as shown by a thin broken line in FIG. 4, the coil end 31 of the winding 3 is inside the resin 2.

Further, as shown in FIGS. 4 and 5, an insulating plate 4 is inserted into the slot opening 14 in order to prevent the winding 3 from protruding inward in the radial direction from the slot 13. The insulating plate 4 not only closes the slot opening 14 in this way, but also extends in the axial direction and protrudes in the axial direction from the axial end face of the stator core 1, and the stator is shown by a thick broken line in FIG. A protruding portion 41 protruding from the axial end surface of the iron core 1 is inside the resin 2.

When an alternating current is passed through the winding 3, a rotating magnetic field is generated in the stator 10 and magnetically acts on the magnetic poles of a rotor (not shown) arranged with a predetermined gap inside the stator 10 in the radial direction. The rotor rotates. In the stator 10, the temperature of the winding 3 repeatedly rises and falls by passing and stopping the current through the winding 3. Then, the temperature of the stator core 1 and the resin 2 also repeatedly rises and falls, and the thermal stress generated due to the difference in the linear expansion coefficient between the stator core 1 and the resin 2 is applied to the resin 2 and cracks may occur. be. The place where cracks are particularly likely to occur is the tooth corner portion 15 where stress is concentrated, and the resin 2 often cracks and extends in the axial direction starting from the tooth corner portion 15 shown in FIGS. 4 and 5. ..

Therefore, as shown in FIGS. 4 and 5, the strip-shaped reinforcing member 5 is arranged on the radial inside of the coil end 31 and in the vicinity of the tooth corner portion 15 of the axial end surface of the stator core 1 for at least one circumference, and is molded. By casting, the resin 2 is integrally fixed inside in the radial direction. Since FIG. 5 is a cross-sectional view taken along the line AA in FIG. 4, the strip-shaped reinforcing member 5 should not be drawn in FIG. 5, but the strip-shaped reinforcing member 5 is arranged when viewed in the axial direction. The outer peripheral position is shown by a broken line in FIG. As the material of the strip-shaped reinforcing material 5, it is desirable that it can be integrally molded with the resin 2 in order to reinforce the resin 2. Therefore, as shown in FIG. 4, the resin 2 is permeated into a glass cloth woven cloth or a carbon fiber woven cloth. Materials that can be used are used.

When molding is performed to cover the coil end 31 of the stator 10 with the resin 2, the insulating plate 4 is inserted into the slot 13 of the stator core 1 around which the winding 3 is wound, and the reinforcing material 5 is placed at the above position. The resin 2 is poured in a state where the mold casting jig is assembled. FIG. 6 is an axial cross-sectional view of the stator 10 to which the conventional mold casting jig is assembled. The conventional mold casting jig has a shaft-shaped jig 21 for inserting the resin 2 so as not to leak inside the stator core 1 in the radial direction, and a shaft-shaped jig 21 for receiving the resin 3 under the stator 10 so as not to leak. A disk-shaped jig 22, a cylindrical jig 23 that prevents the resin 2 from leaking to the outside in the radial direction of the stator 10, a shaft-shaped jig 21 and a disk-shaped jig 22 when the resin 2 is thermally cured. It is composed of a plate-shaped jig 24 that holds down the shaft-shaped jig 21 so that no gap is formed in the axial direction of the shaft.

The shaft-shaped jig 21 includes a substantially cylindrical fitting portion 21a arranged inside the stator core 1 in the radial direction when casting a mold, and a mold receiver arranged inside the coil end 31 in the radial direction. A part 21b is provided. The fitting portion 21a has a gap between the fitting portion 21a and the inner peripheral surface of the stator core 1 at room temperature, and is heated and expanded when the fitting portion 21a is inserted inside the stator core 1 in the radial direction to perform mold casting, and is fixed. It has the role of closing the gap between the child iron core 1 and the inner peripheral surface. The mold receiving portion 21b is axially oriented from the fitting portion 21a for reasons such as avoiding interference with other parts that are structures of the unit on which the rotary electric machine is mounted and improving mold releasability after molding. It has a truncated cone-shaped outer peripheral surface whose outer diameter increases as the distance increases. Examples of the material of the shaft-shaped jig 21 include a resin having a linear expansion coefficient larger than that of the stator core 1, which can be easily fitted during heating and released from the mold during cooling.

Further, the cylindrical jig 23 and the plate-shaped jig 24 are fixed to the disk-shaped jig 22 by using fastening members such as bolts and nuts (not shown). The cylindrical jig 23 can be replaced with a water-cooled jacket (not shown) that is fitted to cool the stator 10.

As a method of arranging the strip-shaped reinforcing material 5 when performing mold casting, there is a method of pre-adhering the strip-shaped reinforcing material 5 to the radial inner surface of the protruding portion 41 of the insulating plate 4 inserted into the slot 13. A method of fixing to the resin 2 by inserting a strip-shaped reinforcing material 5 between the shaft-shaped jig 21 and the insulating plate 4 and integrally molding the resin 2 can be mentioned.

Japanese Unexamined Patent Publication No. 2017-419664.

Among the conventional methods of arranging the strip-shaped reinforcing material, the method of adhering to the radial inner surface of the protruding portion of the insulating plate is the strip-shaped reinforcing material before inserting the shaft-shaped jig into the radial inner surface of the stator. Will be fixed to the insulating plate. Generally, the coil end is formed by pressing to reduce the height. When pressed, the coil end may bulge inward in the radial direction. When the coil end bulges inward in the radial direction, the band-shaped reinforcing material is pushed inward in the radial direction by the coil end, and the band-shaped reinforcing material interferes with the shaft-shaped jig when the shaft-shaped jig is inserted. It may end up.

Also, regarding the method of inserting a strip-shaped reinforcing material between the shaft-shaped jig and the insulating plate and fixing it to the resin by integrally molding it with the resin, when the pressed coil end swells inward in the radial direction, It is difficult to insert the strip-shaped reinforcing material into the gap between the shaft-shaped jig and the insulating plate, and the workability is poor. If the outer peripheral surface of the mold receiving part of the jig remains in the shape of a truncated cone, there is a problem that it is difficult to maintain the state in which the strip-shaped reinforcing material is wound around the mold receiving part of the shaft-shaped jig. ..

Therefore, in the present invention, when performing mold casting in which the coil end is covered with resin, the band-shaped reinforcing material for reinforcing the resin does not interfere with the shaft-shaped mold casting jig, and the shaft-shaped mold casting cure. The purpose is to make it possible to place it without coming off the tool.

The mold casting jig according to the present invention is a shaft-shaped mold casting jig that is inserted inside the stator in the radial direction when performing mold casting in which the coil end of the stator of a rotary electric machine is covered with resin. The diameters of the fitting portion and the coil end arranged inside the stator core of the stator in a state of being inserted inside the stator in the radial direction for performing the mold casting. The mold receiving portion includes a mold receiving portion arranged inside in the direction, and the mold receiving portion has a substantially truncated cone-shaped outer peripheral surface whose outer diameter increases as the distance from the fitting portion in the axial direction increases. The outer peripheral surface is characterized in that a groove extending in a substantially circumferential direction is formed at least once.

In this way, a groove extending in the substantially circumferential direction is formed on the outer peripheral surface of the mold receiving portion of the axial mold casting jig at least once, so that the strip-shaped reinforcing material is radially inward by the coil end. Even when pressed, the strip-shaped reinforcing material adhered to the insulating plate escapes into the groove when the shaft-shaped mold casting jig is inserted inside the stator in the radial direction, and the strip-shaped reinforcing material is the shaft-shaped mold. It is possible to avoid interfering with the casting jig. Further, since the movement of the band-shaped reinforcing material is restricted by fitting the band-shaped reinforcing material into the groove on the outer peripheral surface of the mold receiving portion of the mold casting jig, the band-shaped reinforcing material is applied to the shaft-shaped mold casting jig. Can be kept wrapped. Therefore, in the mold casting jig according to the present invention, the strip-shaped reinforcing material for reinforcing the resin does not interfere with the shaft-shaped mold casting jig when the mold casting is performed by covering the coil end with the resin. It can be arranged without coming off from the shaft-shaped mold casting jig.

In one aspect of the mold casting jig according to the present invention, the groove of the mold receiving portion may be formed in a spiral shape.

In one aspect of the mold casting jig according to the present invention, a step may be provided on the outer peripheral surface of the mold receiving portion by the groove that goes around in the circumferential direction.

In the method of arranging the strip-shaped reinforcing material according to the present invention, when the mold casting is performed using the mold casting jig, the mold casting integrates the resin with the resin inside in the radial direction. It is a method of arranging a strip-shaped reinforcing material to be fixed, and is characterized in that the reinforcing material is wound along the groove of the mold receiving portion.

By winding the band-shaped reinforcing material along the groove of the mold receiving portion of the shaft-shaped mold casting jig in this way, the band-shaped reinforcing material fits into the groove and the movement of the band-shaped reinforcing material is restricted. It is possible to maintain a state in which a strip-shaped reinforcing material is wrapped around a shaft-shaped mold casting jig.

In the present invention, when performing mold casting in which the coil end is covered with resin, the strip-shaped reinforcing material that reinforces the resin does not interfere with the shaft-shaped mold casting jig, and the shaft-shaped mold casting jig is used. It can be arranged without coming off.

It is a perspective view of the shaft-shaped mold casting jig of 1st Embodiment. It is a perspective view of the shaft-shaped mold casting jig of the 2nd Embodiment. It is a perspective view of the stator of a rotary electric machine. It is a figure which looked at the stator of the rotary electric machine shown in FIG. 3 from the inside in the radial direction. FIG. 4 is a cross-sectional view taken along the line AA in FIG. It is an axial sectional view of the stator of the rotary electric machine which assembled the conventional mold casting jig.

<First Embodiment>
The mold casting jig 25 of the first embodiment will be described with reference to the drawings. FIG. 1 is a perspective view of the mold casting jig 25. The mold casting jig 25 is inserted inside the stator 10 in the radial direction when performing mold casting in which the coil end 31 of the stator 10 of the rotary electric machine shown in FIGS. 3, 4 and 5 is covered with the resin 2. This is a shaft-shaped mold casting jig. When mold casting is performed using the shaft-shaped mold casting jig 25, the insulating plate 4 is inserted into the slot 13 of the stator core 1 around which the winding 3 is wound, and the reinforcing material 5 is arranged. Instead of the shaft-shaped jig 21 shown in FIG. 6, a shaft-shaped mold casting jig 25 is inserted inside the stator 10 in the radial direction, and a disk-shaped jig 22, a cylindrical jig 23, and a plate-shaped jig 23 are inserted. The resin 2 is poured in a state where the jig 24 of the above is assembled to the stator 10.

Similar to the shaft-shaped jig 21 described above, the shaft-shaped mold casting jig 25 is inserted into the stator 10 in the radial direction in order to perform mold casting, and the stator core 1 has a shaft-shaped mold casting jig 25. A cylindrical fitting portion 25a arranged inside in the radial direction and a mold receiving portion 25b arranged inside the coil end 31 in the radial direction are provided. The fitting portion 25a has a gap between the fitting portion 25a and the inner peripheral surface of the stator core 1 at room temperature, and is heated and expanded when the fitting portion 25a is inserted inside the stator core 1 in the radial direction to perform mold casting, and is fixed. It has the role of closing the gap between the child iron core 1 and the inner peripheral surface. As shown in FIG. 1, the mold receiving portion 25b has a substantially truncated cone-shaped outer peripheral surface whose outer diameter increases as the distance from the fitting portion 25a in the axial direction increases. A groove 25c extending in a substantially circumferential direction is spirally formed on the outer peripheral surface of the mold receiving portion 25b at least once.

As described above, when a method of adhering the band-shaped reinforcing material 5 to the radial inner surface of the protruding portion 41 of the insulating plate 4 is adopted as a method of arranging the band-shaped reinforcing material 5 when performing mold casting. In addition, the strip-shaped reinforcing member 5 may be pushed inward in the radial direction by the coil end 31 that bulges inward in the radial direction. However, even if the strip-shaped reinforcing member 5 is pushed inward in the radial direction by the coil end 31 in this way, the groove 25c is formed on the outer peripheral surface of the mold receiving portion 25b as described above, and the shaft-shaped mold is formed. When the casting jig 25 is inserted inside the stator 10 in the radial direction, the band-shaped reinforcing material 5 escapes into the groove 25c, so that the band-shaped reinforcing material 5 interferes with the shaft-shaped mold casting jig 25. Can be avoided.

Further, when a method of inserting the band-shaped reinforcing material 5 between the shaft-shaped mold casting jig 25 and the insulating plate 4 is adopted as a method of arranging the band-shaped reinforcing material 5 when performing the mold casting, when the method of inserting the band-shaped reinforcing material 5 is adopted. Since the width of the band-shaped reinforcing material 5 is made the same as the width of the groove 25c and the band-shaped reinforcing material 5 is wound and fitted so as to be pressed along the groove 25c, the movement of the band-shaped reinforcing material 5 is restricted. The state in which the strip-shaped reinforcing material 5 is wound around the shaft-shaped mold casting jig 25 can be maintained.

As described above, in the mold casting jig 25 of the present embodiment, when the coil end 31 is covered with the resin 2 and the mold casting is performed, the strip-shaped reinforcing material 5 for reinforcing the resin 2 is a shaft-shaped mold casting jig. It can be arranged without interfering with the shaft 25 and without coming off from the shaft-shaped mold casting jig 25.

<Second embodiment>
The mold casting jig 26 of the second embodiment will be described with reference to the drawings. FIG. 2 is a perspective view of the mold casting jig 26. The mold casting jig 26 is inserted inside the stator 10 in the radial direction when performing mold casting in which the coil end 31 of the stator 10 of the rotary electric machine shown in FIGS. 3, 4 and 5 is covered with the resin 2. This is a shaft-shaped mold casting jig. When mold casting is performed using the shaft-shaped mold casting jig 26, the insulating plate 4 is inserted into the slot 13 of the stator core 1 around which the winding 3 is wound, and the reinforcing material 5 is arranged. Instead of the shaft-shaped jig 21 shown in FIG. 6, a shaft-shaped mold casting jig 26 is inserted inside the stator 10 in the radial direction, and a disk-shaped jig 22, a cylindrical jig 23, and a plate-shaped jig 23 are inserted. The resin 2 is poured in a state where the jig 24 of the above is assembled to the stator 10.

Similar to the mold casting jig 25 of the first embodiment, the shaft-shaped mold casting jig 26 is inserted inside the stator 10 in the radial direction in order to perform mold casting, and the stator A cylindrical fitting portion 26a arranged inside the iron core 1 in the radial direction and a mold receiving portion 26b arranged inside the coil end 31 in the radial direction are provided. Similar to the fitting portion 25a of the mold casting jig 25 of the first embodiment, the fitting portion 26a has a gap between the fitting portion 26a and the inner peripheral surface of the stator core 1 at room temperature, and the fitting portion 26a has a gap between the fitting portion 26a and the stator core 1. It is heated and expanded when it is inserted inward in the radial direction to perform mold casting, and has a role of closing the gap between the stator core 1 and the inner peripheral surface. As shown in FIG. 2, the mold receiving portion 26b has a substantially truncated cone-shaped outer peripheral surface whose outer diameter increases as the distance from the fitting portion 26a in the axial direction increases. A groove 26c extending in the circumferential direction is formed on the outer peripheral surface of the mold receiving portion 26b, and the groove 26c causes a step on the outer peripheral surface of the mold receiving portion 26b.

When a method of adhering the band-shaped reinforcing material 5 to the radial inner surface of the protruding portion 41 of the insulating plate 4 is adopted as a method of arranging the band-shaped reinforcing material 5 when performing mold casting, the band-shaped reinforcing material 5 is used. Even if 5 is pushed inward in the radial direction by the coil end 31, a step is generated on the outer peripheral surface of the mold receiving portion 26b as described above, and the shaft-shaped mold casting jig 26 is provided with the diameter of the stator 10. Since the strip-shaped reinforcing member 5 escapes into the recess of the step when it is inserted inward in the direction, it is possible to prevent the strip-shaped reinforcing member 5 from interfering with the shaft-shaped mold casting jig 26.

Further, when a method of inserting the band-shaped reinforcing material 5 between the shaft-shaped mold casting jig 26 and the insulating plate 4 is adopted as a method of arranging the band-shaped reinforcing material 5 when performing the mold casting, when the method of inserting the band-shaped reinforcing material 5 is adopted. The width of the band-shaped reinforcing material 5 is made the same as the axial width of the groove 26c on the outer peripheral surface of the mold receiving portion 26b, and the band-shaped reinforcing material 5 is wound and fitted so as to be pressed along the groove 26c. Since the movement of the reinforcing material 5 is restricted, the state in which the strip-shaped reinforcing material 5 is wound around the shaft-shaped mold casting jig 26 can be maintained.

As described above, in the mold casting jig 26 of the present embodiment, when the coil end 31 is covered with the resin 2 and the mold casting is performed, the strip-shaped reinforcing material 5 for reinforcing the resin 2 is a shaft-shaped mold casting jig. It can be arranged without interfering with the 26 and without coming off from the shaft-shaped mold casting jig 26.

<Supplement to the embodiment>
The axial mold casting jig of the present disclosure is not limited to the above-described form, and can be implemented in various forms within the scope of the gist of the present disclosure. For example, the shape of the groove provided on the outer peripheral surface of the mold receiving portion may be formed in a shape different from that of the first embodiment and the second embodiment.

1 Stator core, 2 Resin, 3 windings, 4 Insulation plate, 5 Reinforcing material, 10 Stator, 11 yoke, 12 teeth, 13 slots, 14 slot openings, 15 teeth corners, 21, 25, 26 shafts Jig, 21a, 25a, 26a fitting part, 21b, 25b, 26b mold receiving part, 22 disk-shaped jig, 23 cylindrical jig, 24 plate-shaped jig, 25c, 26c groove, 31 coil End, 41 protrusions.

Claims (4)

A shaft-shaped mold casting jig that is inserted inside the stator in the radial direction when performing mold casting that covers the coil end of the stator of a rotary electric machine with resin.
In a state of being inserted inside the stator in the radial direction for performing the mold casting, in a fitting portion arranged inside the stator core of the stator in the radial direction and inside the coil end in the radial direction. With a mold receiving part to be arranged,
The mold receiving portion has a substantially conical trapezoidal outer peripheral surface whose outer diameter increases as the distance from the fitting portion in the axial direction increases, and the outer peripheral surface of the mold receiving portion has at least a groove extending in the substantially circumferential direction. A mold casting jig characterized in that it is formed for one round or more. The mold casting jig according to claim 1.
A mold casting jig characterized in that the groove of the mold receiving portion is formed in a spiral shape. The mold casting jig according to claim 1.
A mold casting jig characterized in that a step is provided on the outer peripheral surface of the mold receiving portion by the groove that goes around in the circumferential direction. When the mold casting is performed using the mold casting jig according to claim 1, a band-shaped reinforcing material fixed to the inside of the resin in the radial direction by the mold casting together with the resin is provided. It ’s a way of arranging
A method for arranging a strip-shaped reinforcing material, which comprises winding the reinforcing material along the groove of the mold receiving portion.

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