JP6969407B2 - Coil film forming device - Google Patents

Description

The present invention relates to a coil film forming apparatus that forms an insulating film on the coil end portion by immersing the coil end portion of the coil in a thermosetting resin and heating the thermosetting resin.

Conventionally, this type of coil film forming apparatus is provided with an annular cap for accommodating the coil joint of the coil end, and the insulating resin is filled in the cap chamber with the coil joint accommodated and the resin is heat-cured. It has been proposed to form an insulating film on the surface of the coil joint (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-209802

By the way, as a method of forming an insulating film, the resin in the mold is heated by heating the mold with an IH coil in a state where the coil end portion is immersed in the thermosetting resin filled in the annular mold. You can think of something to cure. However, if the mold has uneven heating, the curing of the resin may vary, and the insulation quality may not be sufficiently ensured.

In the coil film forming apparatus of the present invention, the resin is heated and cured by heating the mold with an IH coil in a state where the coil end portion is immersed in the resin filled in the mold to form an insulating film on the coil end portion. The main purpose of the product is to reduce uneven heating of the mold and suppress variations in the curing of the resin.

The coil film forming apparatus of the present invention has adopted the following means in order to achieve the above-mentioned main object.

The coil film forming apparatus of the present invention is
A coil film forming apparatus that forms an insulating film on the coil end portion by heating the thermosetting resin in a state where the coil end portion of the coil is immersed in the thermosetting resin.
In a radial cross-sectional view, a circle in which a bottom portion and two side surface portions extending in the same direction from both ends of the bottom portion surround the coil end portion in a concave shape and a storage chamber filled with the thermosetting resin is formed. An annular mold and
A flat IH coil arranged so as to face the surface of the bottom surface opposite to the accommodation chamber and heating the mold by induction heating.
Equipped with
The mold has two side surface extension portions extending from both ends of the bottom surface portion to the side opposite to the extending direction of the two side surface portions, and the radial cross section is formed in an H shape.
The gist is that.

The coil film forming apparatus of the present invention includes an annular mold and a flat IH coil. In the mold, a storage chamber is formed in which the coil end portion is concavely surrounded by the bottom surface portion and the two side surface portions extending in the same direction from both ends thereof in a radial cross-sectional view, and the thermosetting resin is filled. Further, the IH coil is arranged so as to face the surface of the bottom surface opposite to the accommodation chamber, and the mold is heated by induction heating. Further, the mold is provided with two side surface extension portions extending from both ends of the bottom surface portion to the opposite side of the extension direction of the two side surface portions so that the radial cross section is formed in an H shape. As a result, the bottom surface of the mold is separated from the IH coil to suppress excessive heating to the bottom surface, and heat is transferred from the side extension portion, which is close to the IH coil and easily raises the temperature, to the bottom surface portion and the side surface portion. The temperature of the portion and the side surface portion can be raised. Therefore, the temperature difference between the bottom surface portion and the side surface portion can be reduced, the heating unevenness of the mold can be reduced, and the variation in curing of the thermosetting resin can be suppressed. As a result, the quality of the insulating film covering the coil can be further improved.

It is a schematic block diagram of the coil film forming apparatus 20 as an Example of this invention which is a part of the stator manufacturing apparatus which manufactures a stator 10 for an electric motor. It is explanatory drawing which shows the assembly procedure of the stator coil 15. It is sectional drawing of the coil film forming apparatus 20 of an Example. It is explanatory drawing which shows the mode that the magnetic force line of the IH coil 24 acts on the mold 22 of an Example. It is explanatory drawing which shows the mode that the magnetic force line of the IH coil 24 acts on the mold 122 of the comparative example. It is explanatory drawing which shows the state of the temperature change in the outer side surface part, the inner side surface part, and the bottom surface part of the accommodation chamber when the magnetic force line was applied to the mold 22 of an Example. It is explanatory drawing which shows the state of the temperature change in the outer side surface part, the inner side surface part, and the bottom surface part of the accommodation chamber when the magnetic force line was applied to the mold 122 of the comparative example. It is explanatory drawing which shows the temperature difference between each part of the outer side surface part, the inner side surface part, and the bottom surface part of the accommodation chamber when the mold 22 of an Example is heated for a predetermined time. It is explanatory drawing which shows the temperature difference between each part of the outer side surface part, the inner side surface part, and the bottom surface part of the accommodation chamber when the mold 122 of the comparative example was heated for a predetermined time.

Next, an embodiment for carrying out the present invention will be described with reference to examples.

FIG. 1 is a schematic configuration diagram of a coil film forming apparatus 20 as an embodiment of the present invention, which is a part of a stator manufacturing apparatus for manufacturing a stator 10 for an electric motor. The stator 10 for an electric motor is combined with a rotor to form a three-phase AC power generator motor, and is used as a traveling electric motor or generator for, for example, an electric vehicle or a hybrid vehicle. As shown in FIG. 1, the stator 10 includes a stator core 12 having a plurality of slots formed at equal intervals in the circumferential direction on the inner peripheral side, and a plurality of stator coils 15 composed of a plurality of segment conductors 14, respectively. To prepare for. The stator core 12 is formed by laminating a plurality of stator plates formed by punching out non-oriented electrical steel sheets, and a plurality of teeth protruding inward in the radial direction so as to form a plurality of slots on the inner peripheral side. Have.

The segment conductor 14 is formed by bending a flat conductor into a substantially U shape as a material for the segment conductor 14. The flat conductor has a rectangular cross section formed of a highly conductive metal such as copper, and its surface is covered with an insulating film such as enamel resin in order to secure insulation with the stator core 12. Since the end portion 14e of the segment conductor 14 is joined to the end portion 14e of another segment conductor 14, the insulating film is removed.

The stator coil 15 is assembled as follows. That is, first, as shown in FIGS. 2A and 2B, one end 14e of the segment conductor 14 is inserted into the corresponding slot of the stator core 12 from one end side to the other end side in the axial direction. The other end portion 14e is inserted into another slot separated from the slot in the circumferential direction from one end side to the other end side in the axial direction. The end portion 14e of the segment conductor 14 projects outward from the other end side in the axial direction of the slot of the stator core 12. After assembling all the segment conductors 14 to the stator core 12, as shown in FIG. 2 (c), the ends of the other segment conductors 14 corresponding to the longitudinal (flatwise) side surfaces of the end 14e of the segment conductors 14e. A portion protruding from the slot of each segment conductor 14 is bent and molded using a bending molding machine (not shown) so that the side surface on the longitudinal side of the portion 14e is abutted against each other. Next, the end portion 14e of the segment conductor 14 and the end portion 14e of the corresponding other segment conductor 14 are joined by welding. As a result, a plurality of stator coils 15, that is, a U-phase coil, a V-phase coil, and a W-phase coil are formed. Then, as shown in FIG. 2D, an insulating film is formed on the coil end portion 15e of the stator coil 15 by using the coil film forming device 20 of the embodiment in order to insulate the welded portion.

As shown in FIG. 1, the coil film forming apparatus 20 of the embodiment includes a mold 22 and an IH coil 24. To form the insulating film on the coil end portion 15e, the annular storage chamber 23 of the mold 22 is filled with thermosetting resin, and the coil end portion 15e of the stator coil 15 is inserted into the storage chamber 23 to form the thermosetting resin. This is done by immersing and heating the mold 22 using the IH coil 24 to heat-cure the thermosetting resin in the storage chamber 23.

A cross-sectional perspective view of the coil film forming apparatus 20 of the embodiment is shown in FIG. As shown in FIG. 3, the mold 22 is an annular mold made of a metal (magnetic material) such as steel for a plastic mold. As shown in the figure, the mold 22 extends upward from the disk-shaped bottom surface portion 22b, the cylindrical inner side surface portion 22i extending upward from the inner peripheral edge of the bottom surface portion 22b, and the outer peripheral edge of the bottom surface portion 22b. It has a cylindrical outer surface portion 22o. The accommodation chamber 23 is an annular space that concavely surrounds the coil end portion 15e of the stator coil 15 in a radial cross-sectional view by the upper surface of the bottom surface portion 22b, the outer peripheral surface of the inner side surface portion 22i, and the inner peripheral surface of the outer surface portion 22o. It is formed.

Further, the mold 22 has an inner side surface extension portion 22ie extending from the inner peripheral edge of the bottom surface portion 22b to the side opposite to the extending direction (lower side in the drawing) of the inner side surface portion 22i, and the outer peripheral edge of the bottom surface portion 22b. It has an outer surface extension portion 22oe that extends to the side (lower side in the figure) opposite to the extending direction of the surface portion 22o. The mold 22 has a substantially H-shaped radial cross section formed by a bottom surface portion 22b, an inner side surface portion 22i, an outer surface portion 22o, an inner side surface extension portion 22ie, and an outer surface extension portion 22oe.

The IH coil 24 is a flat and annular IH coil installed so as to face the surface (rear surface) of the bottom surface portion 22b opposite to the accommodation chamber 23, and has an outer diameter larger than the outer diameter of the mold 22. And has an inner diameter smaller than the inner diameter of the mold 22. A power supply is connected to the IH coil 24 via an inverter circuit (not shown), and a high-frequency alternating current is applied to the IH coil 24 by controlling switching of the switching element of the inverter circuit. As a result, an eddy current is generated in the mold 22 by the magnetic force lines (magnetic field) generated around the IH coil 24, and the mold 22 is heated by Joule heat.

4 and 5 are explanatory views showing how the magnetic force lines of the IH coil 24 act on the mold. Note that FIG. 4 shows a state when the mold 22 of the embodiment is used as the mold, and FIG. 5 shows a state when the mold 122 of the comparative example is used as the mold. As shown in FIG. 5, the mold 122 of the comparative example does not have the inner side surface extension portion 22ie and the outer surface extension portion 22oe, and the radial cross section is formed in a square U shape. Was used. As shown in FIG. 5, the mold 122 of the comparative example does not have the inner side surface extension portion 22ie and the outer surface extension portion 22oe, so that the magnetic force lines passing through the bottom surface portion 22b near the IH coil 24 are the inner side surface portion 22i and the outer surface portion. It will be more than 22o. Therefore, the temperature of the bottom surface portion 22b of the mold 122 is significantly higher than that of the inner side surface portion 22i and the outer surface portion 22o, and the thermosetting resin in the accommodation chamber 23 is heated unevenly. On the other hand, in the mold 22 of the embodiment, as shown in FIG. 4, the bottom surface portion 22b is separated from the IH coil 24 by the inner side surface extension portion 22ie and the outer surface extension portion 22oe as compared with the mold 122 of the comparative example. It is in a separated state. Therefore, in the mold 22 of the embodiment, the number of magnetic force lines passing through the bottom surface portion 22b is smaller than that of the mold 22 of the comparative example, and excessive temperature rise of the bottom surface portion 22b can be suppressed. Further, in the mold 22 of the embodiment, the temperature of the inner side surface extension portion 22ie and the outer surface extension portion 22oe closer to the IH coil 24 is higher than that of the bottom surface portion 22b, and the heat generated in the inner side surface extension portion 22ie is generated by the bottom surface portion 22b. And the heat is transferred to the inner side surface portion 22i, and the heat generated in the outer surface extension portion 22oe is transferred to the bottom surface portion 22b and the outer surface portion 22o. Therefore, in the mold 22 of the embodiment, the temperature difference between the bottom surface portion 22b and the inner side surface portion 22i and the outer surface portion 22o can be reduced as compared with the mold 122 of the comparative example, and the thermosetting in the accommodation chamber 23 can be performed. It is possible to reduce uneven heating of the resin.

The inventors of the present application heated the mold 22 of the example and the mold 122 of the comparative example with the IH coil 24, respectively, and measured the temperatures of the outer surface portion, the inner side surface portion, and the bottom surface portion of the storage chamber 23. 6 and 7 are explanatory views showing the state of temperature change in the outer surface portion, the inner side surface portion, and the bottom surface portion of the accommodation chamber when the magnetic force lines are applied to the mold, and FIGS. 8 and 9 show the mold for a predetermined time. It is explanatory drawing which shows the temperature difference between each part of the outer side surface part, the inner side surface part, and the bottom surface part of the accommodation chamber at the time of heating. 6 and 8 show the temperature change and the temperature difference in the mold 22 of the example, and FIGS. 7 and 9 show the temperature change and the temperature difference in the mold 122 of the comparative example. As shown in the figure, when the mold 22 of the embodiment is used, any of the bottom surface portion and the outer surface portion of the accommodation chamber 23, the bottom surface portion, the inner side surface portion, and the inner side surface portion and the outer surface portion of the comparative example is used. It was confirmed that the temperature difference was smaller than that when the mold 122 was used.

In the coil film forming apparatus 20 of the present embodiment described above, the mold 22 has a coil end portion formed by a bottom surface portion 22b and an inner side surface portion 22i and an outer surface portion 22o extending in the same direction from both ends thereof in a radial cross-sectional view. A storage chamber 23 is formed which surrounds 15e in a concave shape and is filled with a thermosetting resin. Further, the mold 22 has an inner side surface extension portion 22ie and an outer side surface extension portion 22ie extended from the bottom surface portion 22b to the side opposite to the extending direction of the inner side surface portion 22i and the outer surface portion 22o so that the radial cross section has an H shape. A side extension 22oe is provided. Then, the IH coil 24 is arranged so as to face the surface of the bottom surface portion 22b opposite to the accommodation chamber 23, and the mold 22 is heated by induction heating. As a result, the bottom surface portion 22b of the mold 22 can be separated from the IH coil 24 to suppress excessive heating to the bottom surface portion 22b. Further, heat transfer from the inner side surface extension portion 22ie and the outer surface extension portion 22oe, which is close to the IH coil 24, to the bottom surface portion 22b, the inner side surface portion 22i, and the outer surface portion 22o causes the bottom surface portion 22b, the inner side surface portion 22i, and the outer surface portion 22o. Can be heated. Therefore, the temperature difference between the bottom surface portion 22 and the inner side surface portion 22i and the outer surface portion 22o can be reduced, the heating unevenness of the mold 22 can be reduced, and the variation in curing of the thermosetting resin can be suppressed. As a result, the quality of the insulating film covering the coil can be further improved.

The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the bottom surface portion 22b corresponds to the “bottom surface portion”, the inner side surface portion 22i and the outer surface portion 22o correspond to the “side surface portion”, the storage chamber 23 corresponds to the “containment chamber”, and the mold 22 corresponds to the “mold”. The IH coil 24 corresponds to the "IH coil", and the inner side surface extension portion 22ie and the outer surface extension portion 22oe correspond to the "side surface extension portion".

As for the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of means for solving the problems of the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to the embodiments, the present invention is not limited to these examples, and the present invention is not limited to these embodiments, and various embodiments are used without departing from the gist of the present invention. Of course it can be done.

The present invention can be used in the manufacturing industry of coil film forming apparatus.

10 stator, 12 stator core, 14 segment conductor, 14e end part, 15 stator coil, 15e coil end part, 20 coil film forming device, 22,122 mold, 22b, 122b bottom part, 22i, 122i inner side surface part, 22o, 122o Outer side, 22ie inner side extension, 22oe outer side extension, 23 containment chamber, 24 IH coil.

Claims (1)

A coil film forming apparatus that forms an insulating film on the coil end portion by heating the thermosetting resin in a state where the coil end portion of the coil is immersed in the thermosetting resin.
In a radial cross-sectional view, a circle in which a bottom portion and two side surface portions extending in the same direction from both ends of the bottom portion surround the coil end portion in a concave shape and a storage chamber filled with the thermosetting resin is formed. An annular mold and
A flat IH coil arranged so as to face the surface of the bottom surface opposite to the accommodation chamber and heating the mold by induction heating.
Equipped with
The mold has two side surface extension portions extending from both ends of the bottom surface portion to the side opposite to the extending direction of the two side surface portions, and the radial cross section is formed in an H shape.
Coil film forming device.

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