JP7412965B2 - Method for manufacturing a mold for a stator for a motor and a mold for a stator for a motor - Google Patents

Description

The present invention provides a stator for a motor that includes a core formed by laminating a plurality of annular electromagnetic steel plates and coils wound in a plurality of slots formed at predetermined intervals on the inner circumference of the core. On the other hand, there is a method for manufacturing a mold for a motor stator, which is used when molding is performed by injecting and hardening an insulating resin into at least the gap between a core and a coil, and a method for manufacturing a mold for a motor manufactured by this manufacturing method. The present invention relates to a stator mold type.

Conventionally, when molding a stator for a motor, it is known that a mold is used that includes an elongated body and a flange extending outward from one end of the body in the longitudinal direction. For example, see Patent Document 1).

When molding a motor stator, the core of the motor stator is fitted into a cylindrical frame, and the body of the mold is inserted into the core so that one longitudinal end of the frame overlaps with the flange. Next, molten insulating resin is injected and filled into the cavity formed between the mold and the frame, and the filled insulating resin is heated and hardened. After the insulating resin has hardened, it is removed from the mold to obtain a molded motor stator.

However, since the inner diameter size of each electromagnetic steel sheet that forms the core varies due to tolerances, the radial size of the inner circumference of the core is not uniform over the longitudinal direction of the motor stator. Rare. In addition, since the insulating resin is injected from one end of the motor stator in the longitudinal direction to the other end through the slots of the core, a portion of the inner circumferential surface of the insulating resin hardens inside the cavity or slot. is in close contact with the outer peripheral surface of the body of the mold.

Therefore, when the body of the mold is inserted into the core or when the motor stator is removed from the mold after molding, the outer circumferential surface of the body of the mold may be exposed to the inner circumference of the core or the hardened insulating material. It rubs against at least a portion of the inner circumference of the resin, causing wear and tear on the body of the mold. For this reason, at present, the molded type of stator for a motor is not sufficiently durable for repeated use.

Japanese Patent Application Publication No. 2018-46710

In view of the above points, the present invention provides a method for manufacturing a mold for a motor stator that can sufficiently withstand repeated use in molding a stator for a motor, and a mold for a motor stator manufactured by this manufacturing method. The task is to provide.

In order to solve the above problems, the method for manufacturing a molded mold for a motor stator according to the present invention includes a core formed by laminating a plurality of annular electromagnetic steel sheets, and a stator formed at predetermined intervals on the inner circumference of the core. Insulating resin is injected into at least the gap between the core and the coil for a motor stator comprising a coil wound in a plurality of slots and a cylindrical frame into which the core is fitted. A method of manufacturing a mold for a motor stator used when performing hardening molding, the mold having a long cylindrical shape and a body portion whose length is longer than the length of the frame ; and a flange extending outward from one end in the longitudinal direction of the body, and having a hollow part, the flange is arranged horizontally so that the body faces upward, and the body is attached to the core of the motor stator. At the same time, one longitudinal end of the frame is placed on the flange, and an insulating resin is filled in each of the upper and lower longitudinal ends of the frame between the mold and the motor stator. In a mold in which a cavity is formed, the outer circumferential surface of the body of the mold is shot peened and then electroless plated.

Further, the mold for a stator for a motor of the present invention is manufactured by the above method for manufacturing a mold for a stator for a motor, and a plating layer is formed by electroless plating on the shot-peened outer peripheral surface of the body. It is characterized by

According to the method for manufacturing a motor stator mold and the motor stator mold of the present invention, the outer periphery of the body of the mold is work-hardened by shot peening, and the friction resistance is improved. Furthermore, since the compressive stress during shot peening remains on the outer periphery of the body of the mold, the fatigue strength of the outer periphery of the body of the mold increases. Furthermore, the outer circumferential surface of the body of the mold is formed with fine irregularities, which improves the adhesion of the plating layer formed by electroless plating on the shot-peened outer circumferential surface of the body of the mold. However, problems such as peeling of the plating layer are less likely to occur. The plating layer is hard and has corrosion resistance. Therefore, when inserting the body of the mold into the core or removing the motor stator from the mold after molding, the plating layer formed on the shot-peened outer peripheral surface of the body of the mold is Even if it rubs against a portion of at least one of the inner circumference of the core or the inner circumference of the cured insulating resin, wear and tear on the body of the mold is suppressed. Therefore, the mold of the motor stator can be molded to withstand repeated use.

FIG. 1 is a perspective view of an embodiment of a mold type of a stator for a motor according to the present invention. (a) and (b) are a schematic cross-sectional view of the state during molding, and a schematic cross-sectional view when the motor stator is removed from the mold, respectively.

Referring to FIG. 1, a mold 1 for a motor stator according to the present embodiment will be described. The mold 1 is a hollow mold, and includes an elongated cylindrical body 11 and a flange 12 extending outward from one longitudinal end of the body 11. A refrigerant such as air is passed through the hollow portion 1a of the mold 1 after molding, so that the motor stator can be cooled together with the mold 1 by the refrigerant.

Both the body part 11 and the collar part 12 of the mold 1 are made of metal, and can be integrally formed by die-casting aluminum, for example. Further, in the body portion 11, the outer peripheral surface 11a is shot peened, as shown in the cross section of the main part within the dotted circle in FIG. Shot peening is a metal processing method in which a large number of metal spheres collide with the surface of a metal product at high speed. When the sphere collides with the sphere, a concave portion is formed in the collided portion of the metal product due to plastic deformation, and the surface of the metal product is formed with fine irregularities. On the other hand, the plastic deformation in the recessed portion is restrained by a portion other than the collided portion and a portion located inside the surface portion than the recessed portion, and compressive residual stress is generated in the collided portion. As a result, the impacted portion of the metal product after shot peening is hardened due to changes in the metal structure due to plastic deformation, and has high friction resistance. Additionally, residual compressive stress increases fatigue strength. Therefore, the outer circumference 11b of the body 11 of the mold 1 has higher friction resistance and fatigue strength than conventional products.

Furthermore, in the mold 1, the shot-peened outer peripheral surface 11a of the body 11 is electroless plated. Electroless plating is a plating method in which an object to be plated is immersed in a plating solution, and a film is deposited on the surface of the object using electrons released by oxidation of a reducing agent contained in the plating solution. The plating layer 11c, which is a deposited film, is hard and has corrosion resistance. In addition, since the shot-peened outer circumferential surface 11a of the body 11 of the mold 1 is formed with fine irregularities, the adhesion of the plating layer 11c is improved, and problems such as peeling of the plating layer 11c occur. It's getting harder. Note that nickel is preferably exemplified as the main component forming the plating layer 11c.

Such a mold 1 of a stator for a motor is manufactured by subjecting the outer circumferential surface 11a of the body portion 11 to shot peening and then electroless plating. Examples of electroless plating include electroless nickel plating.

Next, with reference to FIGS. 2(a) and 2(b), molding of the motor stator 2 using the mold 1 shown in FIG. 1 will be described. In the motor stator 2, the core 21 is fitted into a cylindrical frame 22 by shrink fitting or the like, and the coils 23 are wound around a plurality of slots 21a formed at predetermined intervals on the inner circumference of the core 21. There is. During mold forming, the mold 1 is arranged horizontally with the flange 12 so that the body 11 faces upward, and the body 11 of the mold 1 is inserted into the core 21 of the motor stator 2 to form the longitudinal axis of the frame 22. One end in the direction is placed on the flange 12 of the mold 1 (FIG. 2(a)). The length of the body 11 of the mold 1 is longer than the length of the frame 22, and between the mold 1 and the motor stator 2, cavities 4a and 4b filled with the insulating resin 3 are provided along the longitudinal direction of the frame 22. are formed at each of the upper and lower ends of the direction.

Then, an AC current is applied to the coil 23 of the motor stator 2 from an AC power source (not shown) to generate heat in the coil 23, and the heat is conducted to the mold 1 together with the core 21 and the frame 22 to preheat it. , perform molding. During molding, molten insulating resin 3 is injected from the cavity 4a located at the upper end in the longitudinal direction of the frame 22, filling the cavity 4a with the insulating resin 3, and at the same time, the core 21 and coil 23 in the slot 21a are injected. The cavity 4b located at the lower end of the frame 22 in the longitudinal direction is also filled through the gap between the conductors forming the coil 23 and the gap between the conductors forming the coil 23. Thereafter, the motor stator 2 is heated together with the mold 1 in the same manner as the preheating, and the insulating resin 3 is cured.

After the insulating resin 3 has hardened, a refrigerant such as air is circulated through the hollow portion 1a of the mold 1, and if necessary, the refrigerant such as air is also sprayed onto the outer peripheral surface of the frame 22, thereby forming the stator for the motor. 2 is cooled together with mold 1. Next, the molded motor stator 2 is pulled upward and removed from the mold 1 (FIG. 2(b)).

By the way, as mentioned above, the size of the inner diameter of each electromagnetic steel sheet forming the core 21 of the motor stator 2 varies due to tolerances, and the radial size of the inner peripheral part of the core 21 is different from that of the motor stator 2. is rarely uniform in the longitudinal direction. Further, since the insulating resin 3 is also filled into the cavity 4b via the cavity 4a and the slot 21a of the core 21, a part of the inner circumference of the hardened insulating resin 3 is as shown in FIG. It comes into close contact with the outer circumferential surface 11d of the plating layer 11c formed on the shot-peened outer circumferential surface 11a of the body 11 of the mold 1.

However, in the mold 1 of this embodiment, as described above, the outer circumferential portion 11b of the body portion 11 is work-hardened by shot peening and has improved friction resistance. Moreover, since the compressive stress during shot peening remains in the outer circumference 11b of the body 11, the fatigue strength of the outer circumference 11b of the body 11 is high. Further, fine irregularities are formed on the outer circumferential surface 11a of the body 11 of the mold 1, which improves the adhesion of the plating layer 11c formed by electroless plating on the outer circumferential surface 11a of the body 11 after shot peening. , problems such as peeling of the plating layer 11c are less likely to occur. The plating layer 11c is hard and has corrosion resistance. Therefore, when inserting the body 11 of the mold 1 into the core 21 or removing the motor stator 2 from the mold 1 after molding, the shot-peened outer peripheral surface 11a of the body 11 of the mold 1 Even if the plating layer 11c formed on the plated layer 11c rubs against at least a part of the inner circumference of the core 21 or the inner circumference of the cured insulating resin 3, wear and tear on the body 11 of the mold 1 is suppressed. . Therefore, the mold 1 of the motor stator 2 can sufficiently withstand repeated use in molding. By making it possible to use the mold 1 repeatedly, the manufacturing cost of the motor stator can be reduced.

Although the present invention has been described above with respect to one embodiment, the present invention is not limited to the above embodiment. The molded motor stator 2 may be removed from the mold 1 by pulling down the mold 1. Furthermore, the mold 1 only needs to include at least the body 11 and the flange 12, and the details can be changed as appropriate. Further, the metal forming the mold 1 is not limited to aluminum, and similarly, the main component of the plating layer 11c formed by electroless plating is not limited to nickel.

DESCRIPTION OF SYMBOLS 1... Mold type, 11... Body part, 11a... Outer peripheral surface, 11c... Plating layer, 12... Flange part, 2... Motor stator, 21... Core, 21a... Slot, 23... Coil, 3... Insulating resin.

Claims (2)

A core formed by laminating multiple annular electromagnetic steel sheets, a coil wound around multiple slots formed at predetermined intervals on the inner circumference of the core, and a cylindrical core into which the core is fitted. 1. A method for manufacturing a mold for a motor stator, which is used when molding an insulating resin injected into a gap between at least a core and a coil and hardening the motor stator comprising a frame. ,
The mold has an elongated, cylindrical body and a length longer than the length of the frame , and a flange extending outward from one end of the body in the longitudinal direction, and has a hollow part. The flange is arranged horizontally so that the body faces upward, and the body is inserted into the core of the motor stator, and one longitudinal end of the frame is placed on the flange, and the mold and motor In the case where a cavity filled with insulating resin is formed between the frame and the stator at the upper and lower ends in the longitudinal direction of the frame,
A method for manufacturing a mold for a stator for a motor, characterized in that the outer peripheral surface of the body of the mold is shot peened and then electroless plated. A mold for a motor stator manufactured by the method for manufacturing a mold for a motor stator according to claim 1, wherein a plating layer is formed by electroless plating on the shot-peened outer peripheral surface of the body. Type.

Images