JP3324449B2 - Method for manufacturing stator core of motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a stator core of a motor, and more particularly to a method suitable for ensuring insulation from a coil.

[0002]

2. Description of the Related Art A motor stator includes a coil having a plurality of conductive wires wound thereon and a stator core. The stator core is usually formed by laminating an annular magnetic steel plate having a comb shape inside. Then, the comb-shaped convex portions serve as magnetic poles, and conductors are arranged in slots, which are concave portions, to form coils. The magnetic steel sheet is formed by precision punching, and burrs are easily formed on the edge thereof. On the other hand, although the conductor is coated with an insulating film, it is easily damaged by burrs of a magnetic steel plate. Conventionally, insulating paper has been disposed between the inner surface of the slot and the conductive wire in order to prevent damage to the insulating coating. Further, Japanese Utility Model Application Laid-Open No. 58-183054 discloses a technique of forming an insulating layer on a slot surface of a stator core to secure insulation.

[0003]

The corners of the edges of the magnetic steel sheet are sharp, and as described above, burrs may occur.
In particular, the edge of the slot opening at the end of the stator is a portion that makes strong contact when the conductor is wound around the stator, and is a portion where the insulating coating of the conductor is easily broken. Even with the technology described in the above publication, it is difficult to form an insulating layer having the same thickness as the flat portion at the corner, and the insulating coating of the conductor is broken at the edge of the slot opening, which is the corner. As a result, it was not possible to sufficiently secure insulation at this portion.

[0004] It is an object of the present invention to provide a method of manufacturing a stator core capable of securing sufficient insulation even at the end of the stator.

[0005]

In order to solve the above-mentioned problems, a method of manufacturing a stator core of a motor according to the present invention comprises stacking magnetic steel plates to form a stator core body having a cross-sectional shape having comb-like irregularities. The magnetic steel sheet formed by a manufacturing step, a mold, and an end face of the stator core body;
A step in the cavity is filled with resin, which is detached and forming a cap that extends in the stacking direction before Symbol magnetic steel plates of the stator core body, said mold from said stator core body having the same cross-sectional shape as the Forming an insulating layer on the surface of the cap and the stator core body;
have.

By filling the cavity formed by the mold and the end face of the stator core body with resin, a cap can be easily formed at the end of the stator core.
The shape of the cap can be set to a desired shape depending on the mold, and the shape can be selected in a wide range. For example, by forming so as to be substantially smooth and continuous with the inner surface of the slot, it is possible to prevent dielectric breakdown of the coil conductor caused by corners or burrs of the magnetic steel sheet. Further, if the corner of the edge of the concave portion at the end of the cap is rounded, it is possible to prevent the dielectric breakdown of the coil conductor bent here.

The step of forming the insulating layer includes the step of heating the stator core body on which the cap is formed to a predetermined temperature, and the step of immersing the heated stator core body in a liquid insulating material for insulation. The method may include a step of applying a material, and a step of heating the stator core body to which the insulating material is applied to cure the applied resin.

By immersing the stator core in an insulating material after the stator core has been heated in advance, the viscosity of the resin around the stator core is reduced, and the adhesion of excess resin can be prevented.

[0009]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

FIG. 1 shows a stator core body 1 according to this embodiment.
0 is an exploded perspective view. The stator core main body 10 is a magnetic steel plate 12 having an annular shape and comb-shaped irregularities formed inside.
The first and second end face plates 14 and 16 are stacked on both ends of the sheet with a predetermined number of uneven shapes. The magnetic pole 18 is formed by the comb-shaped convex portion of the magnetic steel plate 12, and the slot 20 for accommodating the coil wire is formed by the concave portion.

FIG. 2 shows first and second end plates 14,1.
6 are shown in detail. The first end face plate 14 has a shape similar to that of the magnetic steel plate 12, that is, an annular shape and has comb-shaped irregularities inside. The comb-shaped convex portion of the first end face plate 14 has a width slightly smaller than that of the magnetic steel plate 12 and a slightly larger diameter at the tip end, and is formed smaller as a whole. In addition, the position of the bottom of the concave portion of the first end face plate 14 is slightly larger in diameter than that of the magnetic steel plate 12, and has a shape that is cut deeper as a whole. On the other hand, the second end face plate 16 also has a shape similar to that of the magnetic steel plate 12 and the first end face plate 14, and the dimensions such as the width of the protruding portion are intermediate values between the magnetic steel plate 12 and the first end face plate 14. Take. Therefore, as shown in FIG. 2B, the portion of the first end face plate 14 has the narrowest and narrowest shape. The first and second end plates 14, 16
Is the same material as the magnetic steel plate 12 in the present embodiment. The magnetic steel plate 12 and the first and second end plates 14 and 16 are laminated to form the stator core body 10.

FIG. 3 shows a schematic configuration of a cap forming die 22 for forming a cap on the end face of the stator core body 10. A recess 24 having substantially the same shape as the magnetic steel plate 12 is formed on the upper surface of the cap mold 22. A predetermined amount of a liquid resin material is put into the depression 24. This resin material is a material having sufficient heat resistance to the temperature during operation of the motor. In a state where the resin material is put in the cap mold 22, the above-described stator core body 10 is placed from above. Thereby, a cavity is formed by the recess 24 of the cap mold and the end face of the stator core body 10. The above-mentioned resin material is used in an amount sufficient to fill the cavity.
The cavity is filled with the resin material before placing the zero.

In this state, the resin is cured. As a curing method, in the present embodiment, a method is employed in which the resin material is a thermosetting resin and the temperature is raised to the curing temperature of the resin. Release is performed when the resin is cured. The mold is released from the central convex portion 2 of the cap mold 22.
6 can be easily performed by pulling it downward in FIG. As shown in FIG. 4, a screw rod 28 is provided upright on the lower surface side of the central convex portion 26 of the cap mold. A nut 30 is screwed into the screw rod 28, and the nut 30 is in contact with the lower surface of the cap mold 22. Therefore, if the nut 30 is turned, the central projection 26
Can be retracted downward. The above cap formation is also performed on the end face on the opposite side of the stator core body 10.

Next, an insulating layer is formed on the surface of the stator core body 10 on which the cap is formed. First, a liquid resin material for forming an insulating layer is placed in a dipping tank, and the entire dipping tank is placed in a vacuum tank to perform a defoaming treatment. This can eliminate bubbles remaining in the liquid and prevent the formation of minute holes in the insulating layer called pinholes, which are formed by the bubbles when the insulating layer is formed. The stator core body 10 heated to a predetermined temperature is immersed in the immersion tank, and then pulled up. Heated stator core body 1
With 0, the surrounding resin material is heated, thereby reducing the viscosity. Thereby, the stator core body 10
When pulling up, extra liquid does not adhere. When the amount of adhesion is large, when the liquid resin material is thermally cured, dripping occurs and the resin material is wasted, and at the same time, the surroundings are soiled. In the present embodiment, these problems can be solved. Further, only the temperature of the resin material around the heated stator core body 10 increases, and the temperature of the entire immersion tank hardly increases. Therefore, the life (pot life) of the resin material in the immersion tank can be extended. Stator core body 10 pulled up from immersion tank
Is heated to the curing temperature of the resin material, whereby an insulating layer is formed on the surface.

FIG. 5 is a sectional view of the magnetic poles of the stator core manufactured by the method described above. A resin cap 32 is formed at an end of the stator core body 10 formed by laminating the magnetic steel plates 12. The first and second end face plates 14, 16 penetrate into the cap 32, so that the cap 32 is securely connected to the end face of the stator core body 10. In the present embodiment, these end plates 14 and 16 correspond to the magnetic steel plate 1.
Thicknesses larger than 2 are used one by one, but thinner ones are also possible. Further, in the present embodiment, the constricted portion is formed by the dimensional difference between the first end face plate 14 and the second end face plate 16. However, if the coupling between the cap 32 and the stator core body 10 is sufficiently ensured, It is also possible to eliminate the dimensional difference so as not to form a constricted portion. By doing so, the cap 32 and the magnetic steel plate 12
And a smooth insulating layer 34 can be formed without generating a step. An insulating layer 34 is formed on the entire surface of the stator core body 10 on which the cap 32 is formed.

The cap 32 can be formed into various shapes depending on the shape of the cap forming die 22, but there are preferable shapes in view of the ease of release and the ease of forming the insulating layer 34. The angle θ at which these surfaces intersect at the joining point between the stator core body 10 and the cap 32 (the point indicated by C in FIG. 5) is 3 from the viewpoint of ease of mold release.
° or more. On the other hand, when the intersection angle θ increases, the liquid resin material does not sufficiently adhere to the joining points, so that the formed insulating layer 34 becomes thinner here,
In some cases, insulation between the core and the conductor cannot be ensured. FIG. 6 shows the relationship between the intersection angle θ and the ratio (t _C / t) of the thickness of the insulating layer 34 at the junction and the plane portion. From this figure, in order to set the ratio (t _C / t) to 0.5, it is necessary to set it to about 13 ° or less when using a silicone resin and to about 8 ° or less when using a polyimide resin. is there.
Therefore, the intersection angle θ at the junction C is 3 ° or more and 8
° or less.

At the corner R, if the radius of the corner is small, the insulating layer 34 may become thinner as in the case of the above-mentioned joint, and sufficient insulation may not be ensured. FIG. 7 shows the relationship between the corner radius r of the corner and the thickness ratio (t _R / t) of the insulating layer 34 between the corner and the plane. Ratio (t _R /
In order to make t) 0.5, the radius r of the corner R must be about 0.9 mm or more when using a silicone resin, and about 0.8 mm or more when using a polyimide resin. It is. Therefore, the radius r of the corner R is preferably 0.9 mm or more. However, since this corner R is formed on the cap 32, the cap 32
Is formed of an insulating resin, the insulating layer 3
Even if the thickness of 4 is small, it does not cause a serious problem in terms of formation of an insulating layer. Therefore, in such a case, 0.
It is also possible to make it 4 mm or more.

As described above, by providing the cap that allows the shape to be selected relatively freely, the insulating layer can be reliably formed over the entire stator core, particularly at the end portions, and the use of insulating paper is eliminated. Can be. Further, the thermal conductivity is improved as compared with the case where insulating paper is provided, and the motor can be used even under more severe conditions.

In this embodiment, the present invention is applied to a so-called inverting type motor in which a rotor is arranged inside a stator. However, an abduction type motor in which a rotor is arranged outside a stator. It is also possible to apply to a motor and a linear type motor.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a stator core body of the present embodiment.

FIG. 2 is a detailed view of the shape of the end face of the stator core body shown in FIG.

FIG. 3 is a perspective view showing a schematic shape of a cap mold according to the embodiment.

FIG. 4 is a sectional view of the cap mold shown in FIG. 3;

FIG. 5 is a sectional view of a magnetic pole portion of the completed stator core.

FIG. 6 is a diagram illustrating a relationship between an intersection angle θ and a thickness of an insulating layer.

FIG. 7 is a diagram showing a relationship between a corner radius r and a thickness of an insulating layer.

[Explanation of symbols]

10 stator core body, 12 magnetic steel plate, 14 first
End face plate, 16 Second end face plate, 22 Cap mold, 3
2 cap, 34 insulating layer.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02K 15/12 H02K 15/02

Claims (3)

(57) [Claims] 1. A step of stacking magnetic steel sheets to produce a stator core body having a cross-sectional shape having irregularities in a comb shape, comprising: a mold and an end face of the stator core body ;
Wherein filling the cavity with a resin having a magnetic steel plate and the same cross-sectional shape, forming a cap that extends in the stacking direction before Symbol magnetic steel plates of the stator core body, the step of separating the mold from the stator core body And forming an insulating layer on the surface of the cap and the stator core body. 2. The method for manufacturing a stator core of a motor according to claim 1, wherein the cap has a slot inner surface formed by a comb-shaped recess of the stator core body.
A method for manufacturing a stator core for a motor, wherein the stator core is substantially smoothly continuous at an end of the main body of the stator, and an edge of a concave portion at an end of the cap has rounded corners. 3. The method for manufacturing a stator core for a motor according to claim 1, wherein the insulating layer forming step includes:
Heating the stator core body having the cap formed thereon to a predetermined temperature, immersing the heated stator core body in a liquid insulating material to apply an insulating material, and applying the insulating material to the stator core. Heating the main body to cure the applied resin.