Stator and method for manufacturing the same

Abstract

To provide a stator and a stator manufacturing device capable of reducing the overall time required for resin molding of a plurality of insulating resins that insulate the joint ends of coil conductors, while suppressing the occurrence of shape defects that cause the resin inlet of the insulating resin to swell.SOLUTION: A stator 100 has a stator core 1, a coil conducting wire 2, a plurality of joint ends 3 that join opposing surfaces 20b of ends 20a of the two coil conducting wires 2 via joint parts 3a, and a plurality of insulating resins 4 formed by resin molding and covering two adjacent joint ends 3. The insulating resin 4 is arranged between two end resin parts 40 that cover the joint end part 3 and the two end resin parts, includes a gate resin part 42 extending in the cross direction that intersects the opposing surface 20b and a connecting resin part 41 that branches off from the gate resin part and connects the gate resin part 42 to the two end resin parts 40. In the cross direction, a length L1 of the gate resin part 42 is larger than a thickness L2 of the connecting resin part 41.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a stator and a method for manufacturing a stator. [Background technology]

[0002] BACKGROUND ART Conventionally, a stator is known that includes an insulating resin that covers the ends of coil conductors arranged in slots of a stator core (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a stator including a stator core, coil conductors arranged in slots, a plurality of joint end portions formed by joining the ends of the coil conductors, and a plurality of insulating resins covering the two adjacent joint end portions. The insulating resin of this stator is formed by resin molding using a mold. The insulating resin includes two covering portions that cover the joint end portions and a resin injection portion (gate portion) arranged between the two covering portions. The insulating resin also includes a connecting portion that branches from the resin injection portion and connects the resin injection portion to the two covering portions. The multiple insulating resins of the stator are molded one by one in order using a mold that moves circumferentially around the stator core. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-106828 Summary of the Invention [Problem to be solved by the invention]

[0005] Although not explicitly stated in Patent Document 1, in the field of stators, there has been a need to shorten the overall time required for resin molding of multiple insulating resins by setting the time from mold clamping to mold opening relatively short. However, in the stator of Patent Document 1, when filling resin in a mold, the portion from near the center of the connecting portion to the injection port, which is the end of the resin injection portion (gate portion), is filled with resin in the final stage after the start of filling. Therefore, if the time from mold clamping to mold opening is set relatively short as described above, the temperature of the portion from near the center of the connecting portion to the injection port is likely to become relatively high, and the mold may be opened while the resin in the portion from near the center of the connecting portion to the injection port remains fluid. In such a case, the resin near the center of the connecting portion may flow back toward the injection port, causing a shape defect in which the resin injection port bulges. Therefore, there has been a need for an improvement that can shorten the overall time required for resin molding of multiple insulating resins while preventing a shape defect in which the resin injection port bulges. If a defective shape occurs due to swelling of the resin injection port, a subsequent step of removing the swollen portion is required, which is not preferable.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a stator and a stator manufacturing device that can reduce the overall time required for resin molding of multiple insulating resins that insulate the joint ends of coil conductors, while suppressing the occurrence of shape defects caused by swelling of the resin inlet of the insulating resin. [Means for solving the problem]

[0007] In order to achieve the above object, a stator in a first aspect of the present invention includes an annular stator core having a plurality of slots, a plurality of coil conductors arranged in the slots, a plurality of joint end portions that join opposing surfaces of ends of two coil conductors via joint portions, and a plurality of insulating resins formed by resin molding and covering two adjacent joint end portions, wherein the insulating resin includes two end resin portions that cover the joint end portions, a gate resin portion that has an inlet through which resin is injected during resin molding and is arranged between the two end resin portions and extends in an intersecting direction that intersects with the opposing surfaces, and a connecting resin portion that branches off from the gate resin portion and extends and connects the gate resin portion and the two end resin portions, and the length of the gate resin portion in the intersecting direction is greater than the thickness of the connecting resin portion. The insulating resin is provided between the gate resin portion and the end resin portion, and includes a recess that tapers from the gate resin portion side toward the connecting resin portion. .

[0008] In a stator according to a first aspect of the present invention, as described above, the insulating resin formed by resin molding and covering two adjacent joint ends includes two end resin portions covering the joint ends, a gate resin portion having an inlet through which resin is injected during resin molding and disposed between the two end resin portions, extending in a cross direction intersecting the opposing surfaces, and a connection resin portion branching off and extending from the gate resin portion and connecting the gate resin portion to the two end resin portions, the length of the gate resin portion in the cross direction being greater than the thickness of the connection resin portion. This allows the length of the gate resin portion to be relatively large, ensuring a relatively large contact area between the gate resin portion and the inner surface (the surface forming the cavity) of the mold used for resin molding, and effectively reducing the temperature of the gate resin portion. This reduces the fluidity of the resin filled in the gate resin portion located between the inlet and the center of the connection resin portion, thereby suppressing backflow of resin from the center of the connection resin portion toward the inlet. As a result, the insulating resin insulating the joint ends of the coil conductor can be prevented from having a shape defect caused by the resin inlet bulging. Furthermore, because the fluidity of the resin filled in the gate resin portion can be reduced, the mold can be opened even when the resin near the center of the connection resin portion remains fluid. In other words, the molding of the next insulating resin can be started without waiting for the resin near the center of the connection resin portion to solidify, thereby shortening the overall time required to mold the multiple insulating resins that insulate the joint ends of the coil conductor. As a result, the overall time required to mold the multiple insulating resins that insulate the joint ends of the coil conductor can be shortened while preventing the occurrence of shape defects caused by bulging of the resin inlet.

[0009] In the stator according to the first aspect, preferably, in a cross direction intersecting with the opposing surface, the gate resin portion is connected to the connecting resin portion at a position opposite to the inlet side of the joint end portion that joins the ends of the two coil conductors together.

[0010] By configuring it in this manner, the length of the gate resin portion can be increased to the extent that, in the intersecting direction, the gate resin portion is connected to the connecting resin portion at a position on the opposite side of the joint end from the inlet side of the joint portion that joins the ends of the two coil conductors.This makes it possible to more reliably increase the length of the gate resin portion and more reliably suppress backflow of resin from near the center of the connecting resin portion toward the inlet side.

[0011] In the aforementioned stator according to the first aspect, the length of the gate resin portion in a direction intersecting the opposing surface is preferably greater than half the thickness of the insulating resin.

[0012] With this configuration, the length of the gate resin portion can be increased in the cross direction to a degree that is greater than half the thickness of the insulating resin, thereby more reliably increasing the length of the gate resin portion and more reliably suppressing backflow of resin from near the center of the connection resin portion toward the inlet side.

[0013] In the stator according to the first aspect, the insulating resin is preferably provided between the gate resin portion and the end resin portion, and includes a recess recessed from the gate resin portion side toward the connecting resin portion, and the depth of the recess from the inlet in a cross direction intersecting the opposing surface is greater than the thickness of the connecting resin portion.

[0014] With this configuration, the convex portion of the mold is inserted into the recess provided between the gate resin portion and the end resin portion during resin molding with the mold in a state where it contacts the gate resin portion, and the convex portion ensures a larger contact area between the gate resin portion and the mold, thereby more effectively reducing the temperature of the gate resin portion, thereby more effectively suppressing backflow of resin from near the center of the connection resin portion toward the inlet side.

[0015] In a configuration in which the gate resin portion is connected to the connecting resin portion at a position opposite the inlet side of the joint end portion relative to the joint portion, preferably, in a cross section along the opposing surface, the cross-sectional area of ​​the end portion of the gate resin portion connected to the connecting resin portion is smaller than the cross-sectional area of ​​the connecting resin portion.

[0016] This configuration allows the entire gate resin portion from the resin inlet of the resin-molded connecting resin portion to the end connected to the connecting resin portion to be relatively thin, thereby effectively reducing the temperature of the gate resin portion and further suppressing backflow of resin from near the center of the connecting resin portion toward the inlet side.

[0017] A method for manufacturing a stator in a second aspect of the present invention is a method for manufacturing a stator including an annular stator core having a plurality of slots and a plurality of coil conductors arranged in the slots, the method comprising: a joining step of joining opposing surfaces of ends of two coil conductors via joints to form a plurality of joint end portions; and a resin molding step of integrally molding two end resin portions covering the joint end portions by injecting resin into a mold with two adjacent joint end portions arranged in the mold, thereby covering the two adjacent joint end portions with insulating resin, a gate resin portion arranged between the two end resin portions and extending in an intersecting direction intersecting the opposing surfaces, and a connection resin portion branching off from the gate resin portion and extending to connect the gate resin portion and the two end resin portions, wherein the resin molding step includes a step of forming the length of the gate resin portion in the intersecting direction to be greater than the thickness of the connection resin portion. The resin molding step includes a step of forming a recess between the gate resin portion and the end resin portion, the recess tapering from the gate resin portion side toward the connection resin portion. .

[0018] In a stator manufacturing method according to a second aspect of the present invention, as described above, two adjacent joint ends are placed in a mold, and resin is injected into the mold to coat the two adjacent joint ends with insulating resin. This results in a resin molding step of integrally molding two end resin portions covering the joint ends, a gate resin portion positioned between the two end resin portions and extending in a cross direction intersecting the opposing surfaces, and a connection resin portion branching off from the gate resin portion and connecting the gate resin portion to the two end resin portions. The resin molding step includes a step of forming the gate resin portion to have a length in the cross direction greater than a thickness of the connection resin portion. This allows the length of the gate resin portion to be relatively long, thereby ensuring a relatively large contact area between the gate resin portion and the inner surface (the surface forming the cavity) of the mold used for resin molding, and effectively reducing the temperature of the gate resin portion. This reduces the fluidity of the resin filled in the gate resin portion located between the inlet and the vicinity of the center of the connection resin portion, thereby suppressing backflow of resin from the vicinity of the center of the connection resin portion toward the inlet. As a result, the occurrence of defective shapes, such as bulging of the resin inlet, can be suppressed in the insulating resin that insulates the joint ends of the coil conductor. Furthermore, because the fluidity of the resin filled in the gate resin portion can be reduced, the mold can be opened even when the resin near the center of the connection resin portion remains fluid. In other words, molding of the next insulating resin can be performed without waiting for the resin near the center of the connection resin portion to solidify, thereby shortening the overall time required for molding multiple insulating resins that insulate the joint ends of the coil conductor. As a result, the occurrence of defective shapes, such as bulging of the resin inlet, can be suppressed while shortening the overall time required for molding multiple insulating resins that insulate the joint ends of the coil conductor. Therefore, it is possible to easily manufacture insulating resin with high dimensional accuracy that does not require a post-process to remove defective shapes while shortening the overall time required for molding the insulating resin.

[0019] In the above-described method for manufacturing a stator according to the second aspect, the resin molding step preferably includes a mold opening step of opening the mold under temperature conditions such that the temperature at the center of the gate resin portion is near the resin solidification temperature, which is lower than the temperature at the inlet of the gate resin portion and the temperature at the center of the connection resin portion.

[0020] This configuration allows the temperature of the center of the gate resin portion, located between the inlet and the center of the connecting resin portion, to be near the resin solidification temperature at which the resin loses its fluidity, thereby more reliably suppressing backflow of resin from near the center of the connecting resin portion toward the inlet. Furthermore, the mold opening process, in which the mold is opened at a relatively early stage when the temperatures of the inlet of the gate resin portion and the center of the connecting resin portion are relatively high, can be performed. As a result, the time required for resin molding can be shortened. [Effects of the Invention]

[0021] According to the present invention, as described above, it is possible to reduce the overall time required for resin molding of multiple insulating resins that insulate the joint ends of the coil conductor, while suppressing the occurrence of defective shapes caused by the resin inlet of the insulating resin swelling. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a perspective view of a stator according to an embodiment. [Figure 2] FIG. 2 is a perspective view of a coil conductor according to an embodiment. [Figure 3] FIG. 2 is a perspective view of a joining end portion (one molding die and the other molding die) according to the embodiment. [Figure 4] FIG. 2 is a plan view of an insulating resin according to an embodiment. [Figure 5] FIG. 2 is a cross-sectional view of an insulating resin according to an embodiment. [Figure 6] FIG. 2 is a perspective view of an insulating resin according to an embodiment. [Figure 7] 10A and 10B are diagrams for explaining the temperature distribution of the insulating resin when the mold is opened according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0024] [Present embodiment] (Stator configuration) The configuration of a stator 100 according to this embodiment will be described with reference to FIGS.

[0025] In the following description, the "axial direction" refers to the direction along the rotational center axis O (Z direction) of the stator core 1 (see FIG. 1). The axial direction is also the direction (longitudinal direction) in which the gate resin portion 42 extends. The axial direction is also the direction (hereinafter referred to as the intersecting direction) (orthogonal direction) of the opposing surfaces 20b (see FIG. 5) of the end portions 20a of the two coil conductors 2. The opposing opposing surfaces 20b are arranged parallel to each other via the joint portion 3a. The end portions 20a of the two coil conductors 2 are joined facing each other in the axial direction.

[0026] Moreover, the "circumferential direction" means the circumferential direction of the stator core 1 (direction A).

[0027] Additionally, "radially inward" and "inner diameter side" refer to the direction toward the center of the stator core 1 (direction B1). Additionally, "radially outward" and "outer diameter side" refer to the direction toward the outside of the stator core 1 (direction B2).

[0028] 1, the stator 100 includes an annular stator core 1, a plurality of coil conductors 2, a plurality of joint ends 3 (shown), and a plurality of insulating resins 4. As an example, the stator 100 constitutes a part of an inner rotor type rotating electrical machine, and the stator core 1 is disposed so as to face a rotor core 5 in the radial direction.

[0029] (Configuration of stator core) The stator core 1 has a plurality of slots 10. A coil conductor 2 is arranged in each of the plurality of slots 10. The width of the slot 10 in the circumferential direction is approximately constant along the radial direction. This allows the slot 10 to be configured so that the coil conductor 2 can be inserted from the radially inner side.

[0030] The stator core 1 includes a back yoke 11 that connects the radially outer sides of the slots 10 in an annular shape, and a plurality of teeth 12 that are provided between adjacent slots 10 and extend radially inward from the back yoke 11.

[0031] (Coil conductor configuration) As shown in Fig. 2, as an example, the coil conductor 2 is formed of a flat conductor 20. Also, as an example, the coil conductor 2 is configured as a cassette coil having a substantially hexagonal shape in which the flat conductor 20 is wound concentrically multiple times, and the slot-receiving portions 21 of two coil conductors 2 are arranged in each slot 10 so as to overlap in the radial direction.

[0032] Furthermore, the plurality of coil conductors 2 are formed by joining one end 20a and the other end 20a of the flat conductor wires 20 together to form a coil assembly.

[0033] More specifically, each of the coil conductors 2 includes a pair of slot-receiving portions 21 that are received in different slots 10, and a coil end portion 22 that connects the pair of slot-receiving portions 21. The coil conductor 2 also includes an inner diameter side lead wire portion 23 that includes one end 20a of the concentrically wound flat conductor wire 20 and is formed so as to extend from the radially inner side to the radially outer side of the stator core 1, and an outer diameter side lead wire portion 24 that includes the other end 20a of the concentrically wound flat conductor wire 20 and is arranged on the outer diameter side of the stator core 1.

[0034] As shown in FIG. 3, one end 20a and the other end 20a extend in the radial direction.

[0035] (Configuration of joint end) The joint end portion 3 joins the opposing surfaces 20b (see FIG. 5) of the ends 20a of the two coil conductors 2 via a joint portion 3a to electrically connect the two coil conductors 2. Specifically, the joint end portion 3 joins one end 20a of the inner diameter side lead wire portion 23 of one of the multiple coil conductors 2 to the other end 20a of another of the multiple coil conductors 2 by welding. The joint portion 3a is formed as a result of welding. The ends of the coil conductors 2 are joined with their insulating coatings removed. The ends of the coil conductors 2 are joined in a state where they overlap in the axial direction.

[0036] (Insulating resin composition) The insulating resin 4 shown in Figs. 4 to 6 is formed by resin molding. The insulating resin 4 covers two circumferentially adjacent joint end portions 3. The insulating resin 4 covers two joint end portions 3 of the same phase. The insulating resin 4 has the function of ensuring insulation between the joint end portions 3 and other objects and between the joint end portions 3 and the ground. As an example, the insulating resin 4 is made of a resin (resin molding) containing PPS (polyphenylene sulfide resin).

[0037] The insulating resin 4 includes two end resin portions 40, a connection resin portion 41, a gate resin portion 42, and a recess 43. The two end resin portions 40, the gate resin portion 42, and the connection resin portion 41 are integrally formed by resin molding using a mold 9. The gate resin portion 42 has an inlet 42a through which resin is injected during resin molding using the mold 9.

[0038] (Configuration of the "end resin part" of the insulating resin) The two end resin portions 40 cover two circumferentially adjacent joining end portions 3. The two end resin portions 40 form a pair spaced apart in the circumferential direction. When viewed from the axial direction, the end resin portions 40 are configured in a chamfered, generally rectangular shape.

[0039] (Configuration of the "connection resin part" of the insulating resin) The connecting resin part 41 branches off from the gate resin part 42 extending in the axial direction (intersecting direction) and extends in the arrangement direction (circumferential direction) of two adjacent joint end parts 3. The connecting resin part 41 connects the gate resin part 42 and the two end part resin parts 40.

[0040] (Configuration of the "gate resin part" of the insulating resin) 5, the gate resin part 42 is disposed between the two end resin parts 40 and extends in an intersecting direction (axial direction) that intersects with the opposing surface 20b. The gate resin part 42 is connected to the connecting resin part 41 via an arc (R) shaped part 42b. The end part 42c of the gate resin part 42 connected to the connecting resin part 41 is located at a point P where the inclination of the arc shaped part 42b coincides with the arrangement direction (approximately the circumferential direction) of the two joining end parts 3.

[0041] That is, the length L1 of the gate resin part 42 in the intersecting direction (axial direction) corresponds to the distance from the inlet 42a to the point P where the inclination of the arc-shaped part 42b coincides with the arrangement direction (circumferential direction) of the two joining end parts 3.

[0042] Gate resin portion 42 of stator 100 is formed to be longer in the axial direction (transverse direction) than the insulating resin gate of a conventional general stator. In other words, gate resin portion 42 of stator 100 is configured to ensure a larger contact area with mold 9 than the insulating resin gate of a conventional general stator.

[0043] Specifically, in the intersecting direction (axial direction), the length L1 of the gate resin part 42 is greater than the thickness L2 of the connecting resin part 41. As an example, the length L1 of the gate resin part 42 in the intersecting direction (axial direction) is approximately 3 mm, and the thickness L2 of the connecting resin part 41 is approximately 2 mm.

[0044] Furthermore, in the intersecting direction (axial direction), the length L1 of the gate resin portion 42 is greater than half the thickness L3 of the insulating resin 4. As an example, the thickness L3 of the insulating resin 4 is about 5 mm.

[0045] Furthermore, the length L1 of the gate resin part 42 in the intersecting direction (axial direction) is approximately the same as the diameter L4 near the inlet 42a of the gate resin part 42. In order to improve releasability from the mold 9, the gate resin part 42 is provided with a draft of a predetermined angle (for example, 2 degrees) so that the diameter gradually increases from the inlet 42a side.

[0046] In the intersecting direction (axial direction), the gate resin part 42 is connected to the connecting resin part 41 at a position opposite the inlet 42a side of the joint end part 3, rather than the joint part 3a that joins the ends 20a of the two coil conductors 2 together.

[0047] That is, in the intersecting direction (axial direction), the entire connecting resin part 41 is positioned on the opposite side (Z2 direction side) of the inlet 42a of the joint end part 3 from the joint part 3a (opposing surface 20b on the Z2 direction side), and a part of the gate resin part 42 is positioned on the Z2 direction side from the joint part 3a.

[0048] In a cross section along the opposing surface 20b, the cross-sectional area S1 of the end 42c of the gate resin portion 42 connected to the connecting resin portion 41 is smaller than the cross-sectional area S2 of the connecting resin portion 41.

[0049] (Configuration of "recesses" in insulating resin) The recesses 43 are provided between the gate resin portion 42 and the end portion resin portion 40. That is, one recess 43 is provided on one side of the gate resin portion 42 in the A direction and one on the other side of the gate resin portion 42 in the A direction. The recesses 43 are recessed from the gate resin portion 42 side toward the connecting resin portion 41 (Z2 direction). In the intersecting direction (axial direction), the depth L5 of the recesses 43 from the inlet 42a is greater than the thickness L2 of the connecting resin portion 41.

[0050] (Mold configuration) The mold 9 includes one molding die 9a on the nozzle 9c side and another molding die 9b on the opposite side to the nozzle 9c side. The mold 9 is configured so that resin is filled from the nozzle 9c into cavities in the one molding die 9a and the other molding die 9b with two circumferentially adjacent joining end portions 3 arranged. Then, the mold 9 is opened after a relatively short predetermined time (for example, about 2.0 to 5.0 seconds) set as a cooling time has elapsed.

[0051] 7, the temperature distribution of the insulating resin 4 when the mold 9 is opened is such that the temperature of the insulating resin 4 at the center C1 of the gate resin portion 42 is near the resin solidification temperature t, which is lower than the temperature of the inlet 42a of the gate resin portion 42 and the temperature of the center C2 of the connection resin portion 41.

[0052] (Method of manufacturing a stator) Next, a method for manufacturing the insulating resin 4 of the stator 100 will be described.

[0053] First, as shown in FIG. 3, in the joining step, the ends 20a of two coil conductors 2 are joined together via joints 3a to form a plurality of joint ends 3.

[0054] Next, in the resin molding process, two adjacent joint ends 3 are placed in the mold 9, and resin is injected into the mold 9, thereby coating the two adjacent joint ends 3 with insulating resin 4, and two end resin parts 40 covering the joint ends 3, a gate resin part 42 placed between the two end resin parts 40 and extending in an intersecting direction (axial direction) intersecting the opposing surface 20b, and a connecting resin part 41 branching off and extending from the gate resin part 42 and connecting the gate resin part 42 and the two end resin parts 40 are integrally molded.

[0055] The resin molding step includes a step of forming the length L1 of the gate resin portion 42 in the intersecting direction to be greater than the thickness L2 of the connection resin portion 41. That is, in the resin molding step, resin molding is performed using the mold 9 so that the length L1 of the gate resin portion 42 is relatively large.

[0056] The resin molding process also includes a mold opening process in which the mold 9 is opened under temperature conditions such that the temperature of the center C1 of the gate resin portion 42 is near a resin solidification temperature t that is lower than the temperature of the inlet 42a of the gate resin portion 42 and the temperature of the center C2 of the connection resin portion 41. That is, in the resin molding process, the mold 9 is opened in a state in which the center C1 of the gate resin portion 42 has been cooled to a degree that impairs its fluidity, and the mold 9 is opened at a relatively early timing when the inlet 42a of the gate resin portion 42 and the center C2 of the connection resin portion 41 have fluidity.

[0057] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0058] In this embodiment, as described above, the insulating resin 4 is formed by resin molding and covers two adjacent joint ends 3. The insulating resin 4 is provided with two end resin portions 40 covering the joint ends 3, a gate resin portion 42 having an inlet 42a through which resin is injected during resin molding and disposed between the two end resin portions 40 and extending in an intersecting direction (Z direction) intersecting the opposing surface 20b, and a connection resin portion 41 branching off and extending from the gate resin portion 42 and connecting the gate resin portion 42 and the two end resin portions 40. In this manner, the length L1 of the gate resin portion 42 in the intersecting direction is made larger than the thickness L2 of the connection resin portion 41. This allows the length L1 of the gate resin portion 42 to be relatively large, thereby ensuring a relatively large contact area between the gate resin portion 42 and the inner surface (surface forming the cavity) of the mold 9 used for resin molding, and effectively reducing the temperature of the gate resin portion 42. Therefore, the fluidity of the resin filled in the gate resin portion 42 located between the inlet 42a and the vicinity of the center C2 of the connection resin portion 41 can be reduced, thereby preventing backflow of resin from the vicinity of the center C2 of the connection resin portion 41 toward the inlet 42a. As a result, the occurrence of defective shape caused by bulging of the resin inlet 42a of the insulating resin 4 that insulates the joint end 3 of the coil conductive wire 2 can be prevented. Furthermore, the fluidity of the resin filled in the gate resin portion 42 can be reduced, allowing the mold 9 to be opened even when the resin near the center C2 of the connection resin portion 41 remains fluid. In other words, molding of the next insulating resin 4 can be performed without waiting for the resin near the center C2 of the connection resin portion 41 to solidify, thereby shortening the overall time required for molding the multiple insulating resins 4 that insulate the joint end 3 of the coil conductive wire 2. As a result, the occurrence of defective shape caused by bulging of the resin inlet 42a of the insulating resin 4 can be prevented while shortening the overall time required for molding the multiple insulating resins 4 that insulate the joint end 3 of the coil conductive wire 2.

[0059] In the present embodiment, as described above, in the intersecting direction intersecting the opposing surface 20b, the gate resin portion 42 is connected to the connection resin portion 41 at a position on the opposite side of the inlet 42a of the joint end portion 3 from the joint portion 3a that joins the ends 20a of the two coil conductive wires 2 together. This allows the length L1 of the gate resin portion 42 to be increased to an extent that the gate resin portion 42 is connected to the connection resin portion 41 at a position on the opposite side of the inlet 42a of the joint end portion 3 from the joint portion 3a that joins the ends 20a of the two coil conductive wires 2 together in the intersecting direction. This more reliably increases the length L1 of the gate resin portion 42, making it possible to more reliably suppress backflow of resin from near the center C2 of the connection resin portion 41 toward the inlet 42a side.

[0060] In this embodiment, as described above, in the intersecting direction intersecting the opposing surface 20b, the length L1 of the gate resin portion 42 is greater than half the thickness L3 of the insulating resin 4. This allows the length L1 of the gate resin portion 42 to be increased to an extent that it is greater than half the thickness L3 of the insulating resin 4 in the intersecting direction, thereby more reliably increasing the length L1 of the gate resin portion 42 and more reliably suppressing the backflow of resin from near the center C2 of the connecting resin portion 41 toward the inlet 42a.

[0061] In this embodiment, as described above, the insulating resin 4 includes a recess 43 provided between the gate resin portion 42 and the end portion resin portion 40, recessed from the gate resin portion 42 toward the connecting resin portion 41, and the depth L5 of the recess 43 from the inlet 42a in the intersecting direction intersecting the opposing surface 20b is greater than the thickness L2 of the connecting resin portion 41. As a result, when the mold 9 is used to mold the resin, the protrusion of the mold 9 is inserted into the recess 43 provided between the gate resin portion 42 and the end portion resin portion 40 in a state of contacting the gate resin portion 42. This ensures a larger contact area between the gate resin portion 42 and the mold 9, thereby more effectively reducing the temperature of the gate resin portion 42. As a result, backflow of resin from the vicinity of the center C2 of the connecting resin portion 41 toward the inlet 42a can be more effectively suppressed.

[0062] In this embodiment, as described above, in a cross section along the opposing surface 20b, the cross-sectional area S1 of the end 42c of the gate resin portion 42 connected to the connecting resin portion 41 is smaller than the cross-sectional area S2 of the connecting resin portion 41. This allows the entire gate resin portion 42, from the resin inlet 42a of the resin-molded connecting resin portion 41 to be relatively thin, thereby more effectively reducing the temperature of the gate resin portion 42. This makes it possible to more effectively suppress backflow of resin from near the center C2 of the connecting resin portion 41 toward the inlet 42a.

[0063] In this embodiment, as described above, by placing two adjacent joint ends 3 in the mold 9 and injecting resin into the mold 9, the two adjacent joint ends 3 are coated with the insulating resin 4, and a resin molding process is provided to integrally mold two end resin portions 40 that cover the joint ends 3, a gate resin portion 42 that is placed between the two end resin portions 40 and extends in an intersecting direction that intersects with the opposing surface 20b, and a connection resin portion 41 that branches off from the gate resin portion 42 and extends to connect the gate resin portion 42 and the two end resin portions 40. The resin molding process includes a step of forming the length L1 of the gate resin portion 42 to be greater than the thickness L2 of the connection resin portion 41 in the intersecting direction. This allows the length L1 of the gate resin portion 42 to be relatively large, thereby ensuring a relatively large contact area between the gate resin portion 42 and the inner surface (the surface that forms the cavity) of the mold 9 used for resin molding, and effectively reducing the temperature of the gate resin portion 42. Therefore, the fluidity of the resin filled in the gate resin portion 42 located between the inlet 42a and the vicinity of the center C2 of the connection resin portion 41 can be reduced, thereby preventing backflow of resin from the vicinity of the center C2 of the connection resin portion 41 toward the inlet 42a. As a result, the occurrence of defective shape caused by bulging of the resin inlet 42a of the insulating resin 4 that insulates the joint end 3 of the coil conductive wire 2 can be prevented. Furthermore, the fluidity of the resin filled in the gate resin portion 42 can be reduced, allowing the mold 9 to be opened even when the resin near the center C2 of the connection resin portion 41 remains fluid. In other words, molding of the next insulating resin 4 can be performed without waiting for the resin near the center C2 of the connection resin portion 41 to solidify, thereby shortening the overall time required for molding the multiple insulating resins 4 that insulate the joint end 3 of the coil conductive wire 2. As a result, the occurrence of defective shape caused by bulging of the resin inlet 42a of the insulating resin 4 can be prevented while shortening the overall time required for molding the multiple insulating resins 4 that insulate the joint end 3 of the coil conductive wire 2. Therefore, the overall time required for resin molding of the insulating resin 4 can be reduced, and the insulating resin 4 can be easily manufactured with high dimensional accuracy, eliminating the need for a post-process to remove portions with defective shapes.

[0064] In this embodiment, as described above, the resin molding process includes a mold-opening process in which the mold 9 is opened under temperature conditions such that the temperature of the center C1 of the gate resin portion 42 is near the resin solidification temperature t, which is lower than the temperatures of the inlet 42a of the gate resin portion 42 and the center C2 of the connection resin portion 41. This allows the temperature of the center C1 of the gate resin portion 42, which is located between the inlet 42a and the center C2 of the connection resin portion 41, to be near the resin solidification temperature t, at which the fluidity of the resin is impaired. This more reliably prevents the resin from flowing back from near the center C2 of the connection resin portion 41 toward the inlet 42a. Furthermore, the mold-opening process in which the mold 9 is opened can be performed at a relatively early stage when the temperatures of the inlet 42a of the gate resin portion 42 and the center C2 of the connection resin portion 41 are relatively high. As a result, the time required for resin molding can be shortened.

[0065] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0066] For example, in the above embodiment, the gate resin portion is connected to the connecting resin portion at a position on the opposite side of the joint end from the inlet side in the cross direction from the joint portion, but the present invention is not limited to this. In the present invention, the gate resin portion may be connected to the connecting resin portion at a position on the inlet side of the joint end from the joint portion in the cross direction.

[0067] In the above embodiment, the intersecting direction coincides with the axial direction of the stator core, but the present invention is not limited to this. In the present invention, the intersecting direction does not have to coincide with the axial direction of the stator core.

[0068] In the above embodiment, the intersecting direction is perpendicular to the opposing surface, but the present invention is not limited to this. In the present invention, the intersecting direction does not have to be perpendicular to the opposing surface. In other words, the intersecting direction may be inclined with respect to the opposing surface.

[0069] In the above embodiment, the ends of the coil conductor are welded together, but the present invention is not limited to this. In the present invention, the ends of the coil conductor may be brazed, ultrasonically bonded, crimped, or the like.

[0070] In the above embodiment, the coil is formed of a rectangular conductor wire, but the present invention is not limited to this. In the present invention, the coil may be formed of a conductor wire other than a rectangular conductor wire. [Explanation of symbols]

[0071] 1 stator core 2 Coil conductors 3 Joint end 3a joint 4. Insulating resin 9. Mold 10 slots 20a (Coil conductor) end 20b Opposite side 40 End resin part 41 Connecting resin part 42 Gate resin part 42a (Gate resin part) inlet 42c (connected to the connecting resin part of the gate resin part) end 43 Recess 100 Stator C1 (Gate resin part) center C2 (Center of connecting resin part) L1 (Gate resin part) length L2 (connection resin part) thickness L3 (insulating resin) thickness L5 Depth (from the inlet of the recess) S1 Cross-sectional area (of the end of the gate resin part connected to the connection resin part) S2 (cross-sectional area of ​​the connecting resin part) t Resin solidification temperature

Claims

1. an annular stator core having a plurality of slots; a plurality of coil conductors disposed in the slots; a plurality of joint ends that join opposing surfaces of the ends of the two coil conductors via joints; a plurality of insulating resins formed by resin molding and covering the two adjacent joint ends, The insulating resin is two end resin portions covering the joint end portions; a gate resin portion having an inlet into which resin is injected during the resin molding, the gate resin portion being disposed between the two end resin portions and extending in a direction intersecting the opposing surfaces; a connecting resin portion that branches off and extends from the gate resin portion and connects the gate resin portion and the two end resin portions, a length of the gate resin portion in the intersecting direction is greater than a thickness of the connection resin portion; The insulating resin is provided between the gate resin portion and the end resin portion and includes a recess that tapers from the gate resin portion side toward the connecting resin portion.

2. 2. The stator according to claim 1, wherein, in the intersecting direction intersecting with the opposing surface, the gate resin portion is connected to the connecting resin portion at a position opposite the inlet side of the joint end portion that joins the ends of the two coil conductors together.

3. 3. The stator according to claim 1, wherein a length of the gate resin portion in the intersecting direction intersecting with the opposing surface is greater than half a thickness of the insulating resin.

4. A stator described in any one of claims 1 to 3, wherein in the intersecting direction intersecting with the opposing surface, the depth of the recess from the inlet is greater than the thickness of the connecting resin portion.

5. 3. The stator according to claim 2, wherein a cross-sectional area of ​​an end of the gate resin portion connected to the connecting resin portion in a cross section along the opposing surface is smaller than a cross-sectional area of ​​the connecting resin portion.

6. A method for manufacturing a stator including an annular stator core having a plurality of slots and a plurality of coil conductors arranged in the slots, the method comprising: a joining step of joining opposing surfaces of the ends of the two coil conductors via joints to form a plurality of joint ends; a resin molding process in which, with the two adjacent joining end portions arranged in the mold, resin is injected into the mold to coat the two adjacent joining end portions with insulating resin, thereby integrally molding two end resin portions covering the joining end portions, a gate resin portion arranged between the two end resin portions and extending in an intersecting direction intersecting the opposing surfaces, and a connection resin portion branching off and extending from the gate resin portion and connecting the gate resin portion and the two end resin portions, the resin molding step includes a step of forming the gate resin portion so that the length of the gate resin portion is greater than the thickness of the connection resin portion in the intersecting direction, The resin molding process includes a process of forming a recess between the gate resin portion and the end resin portion, the recess tapering from the gate resin portion side toward the connection resin portion.

7. 7. The method for manufacturing a stator according to claim 6, wherein the resin molding process includes a mold opening process in which the mold is opened under temperature conditions in which the temperature at the center of the gate resin portion is near a resin solidification temperature that is lower than the temperature at the inlet of the gate resin portion and the temperature at the center of the connection resin portion.

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