JPH06269149A - Manufacture of core piece for motor - Google Patents

Abstract

PURPOSE:To provide a manufacturing method for the core piece for a motor, wherein the inner cut surface of the core piece of a stator is relatively uniform, the magnetic characteristics are excellent and the manufacturing process is relatively easy. CONSTITUTION:A rotor core piece 14, wherein a plurality of pole teeth are formed around the core piece, and a starot core piece 20, wherein the inner diameter is slightly larger than the outer diameter of the rotor core piece 14 and has a plurality of pole teeth in which a plurality of small teeth are formed at the inner surface are provided, are sequentially molded from a continuous strip member 10 in the this manufacturing method for the core piece for a motor. After the rotor core piece 14 is punched, a shaving part is provided at the inner surface of the stator core piece 20, and circular semi-punching is performed. Thereafter, the small teeth are created by the punching at the inner side of the stator core piece and press machining including shaving.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an iron core piece for a motor such as a stepping motor having a very small magnetic pole distance between a rotor and a stator.

[0002]

2. Description of the Related Art In a stepping motor or the like, a gap between an inner rotor and an outer stator is extremely small (usually about 0.05 to 0.1 mm), and a large number of pole teeth are formed on the outer periphery of the rotor. Since the pitch of many small teeth formed at the tips of the pole teeth of the stator is different, in the iron core piece such as the stepping motor, the pole teeth and the small teeth of the intermediate product made by the conventional punching method are After the tip separation surface is cut / fractured and a smooth surface cannot be obtained, it is manufactured by press working and then machined (grinding, broaching, etc.) as the subsequent processing to cut the inner and outer circumferences of each and smooth the surface. A product of given dimensions having a face was being manufactured.

[0003]

However, the manufacturing method in which the press working and the mechanical working are performed is extremely troublesome and requires a large number of man-hours.
Further, since it is necessary to manufacture the rotor and the stator from separate strips, there is a drawback that the materials are wasteful. Therefore, the present inventor has conducted extensive research to manufacture the rotor and the stator by press work, and as a result,
Normal gap between punch and die (20-25μ on one side)
When the core piece is punched out by the pressing process having m),
When the shoulders are in the upper part, the sheared surface is in the middle part, and the fractured surface is in the lower part, and they are laminated, unevenness occurs on the surface, the gap between the rotor and the stator (air gap) varies, and the magnetic characteristics deteriorate. I found that there was a problem.
On the other hand, when press working is performed while maintaining the gap between the punch and the die at 10 μm or less, many sheared surfaces with a uniform surface appear on the cut surface, and the magnetic characteristics of the iron core are improved, but this is large for pressing. There is a drawback that the pressing force is required and the life of the punch and the die is short. Therefore, if a punching process is performed in advance with a press leaving a small cutting allowance (shaving allowance), and then a shaving press process is performed,
Although a large pressing pressure is not required for shaving press processing, since a strip material with a small gap previously punched from the rotor is used, micron-order fine chips separated by shaving press processing are generated, and processing is performed. There was a problem that I was in trouble. The present invention has been made in view of the above circumstances, and provides a method of manufacturing an iron core piece for a motor, in which the inner cut surface of the stator iron core piece is relatively uniform, the magnetic characteristics are good, and the manufacturing process is relatively easy. With the goal.

[0004]

A method according to the above-mentioned object.
The method for manufacturing an iron core piece for a motor described above includes a rotor core piece having a plurality of pole teeth formed around a continuous strip and an inner diameter slightly larger than the outer diameter of the rotor core piece, and A method of manufacturing an iron core piece for a motor, which sequentially forms a stator iron core piece having a plurality of pole teeth having a plurality of small teeth formed thereon, wherein the inner periphery of the stator iron core piece is punched after the rotor iron piece is punched out. Is provided with a shaving allowance to perform circular half blanking, and thereafter, the inner teeth of the stator core piece are punched to form the small teeth by press working including shaving. Here, since the small teeth of the pole teeth of the stator core piece do not affect the performance even if they have some fracture surfaces, the shaving press work is performed only on the inner peripheral side of the stator core piece, and the small teeth part is punched. It also includes the case where a normal gap is provided between the die and the die to reduce the pressing pressure at that portion. Further, in the method for manufacturing a motor iron core piece according to a second aspect of the present invention, a rotor iron core piece having a plurality of pole teeth formed around a continuous strip and an inner diameter slightly larger than the outer diameter of the rotor iron core piece. A method of manufacturing an iron core piece for a motor, which sequentially forms a stator iron core piece having a plurality of pole teeth having a plurality of small teeth formed on an inner periphery thereof, the method comprising: It is configured such that the inner shape including the small teeth of the iron core piece is half-punched while leaving a shaving allowance, and then the inner shape is punched to create the small teeth by shaving press working. In the above, the half blanking refers to a state in which the mesh between the punch and the die is stopped halfway and the piece to be treated is partially joined to the original plate material.

[0005]

According to the method of manufacturing an iron core piece for a motor according to claim 1, the strip material after punching out the rotor core piece is subjected to circular half blanking while leaving a shaving margin on the inner circumference of the stator core piece. After that, the inner circumference of the stator core piece is perpendicular to the plate surface of the strip because the inner teeth of the stator core piece with the small teeth are punched out by shaving press to create the small teeth. There are more shear planes, which improves the magnetic properties. Further, in the punching of the inner circumference, since the half blanking process is performed in advance, the press pressure can be relaxed in performing the shaving press process. In the method for manufacturing an iron core piece for a motor according to claim 2, after the rotor iron core piece is punched out, half-drawing is performed from the inner shape including the small teeth of the stator iron core piece leaving a shaving allowance, and then the small tooth Since the inner shape of the stator core piece including the core is shaving press-processed, the inner circumference of the stator core piece is of course, and the small teeth also have many shear planes perpendicular to the strip surface. This makes it possible to manufacture an iron core having better magnetic characteristics. In this case, since the half-blanking process is performed inside with the shaving margin left before the shaving press working, the press pressure of the shaving press working can be significantly reduced.

[0006]

Embodiments of the present invention will now be described with reference to the accompanying drawings to provide an understanding of the present invention. 1 is a schematic plan view showing a method of manufacturing a motor core piece according to an embodiment of the present invention, FIG. 2 is a partially enlarged view of a stator core piece in the same method, and FIG. 3 is another embodiment of the present invention. FIG. 6 is a partially enlarged view of the stator core piece in the method of manufacturing the motor core piece according to the example.

As shown in FIG. 1A, a pilot hole 11 is formed in a strip 10 made of a silicon steel plate having a predetermined thickness and a predetermined width, and a central shaft hole 12 and a caulking projection of a rotor core piece are formed. 13 is formed. Then, as shown in FIG. 2B, the rotor core piece 14 is formed with the pole teeth formed around the rotor core piece 14.
Are punched out and laminated in a process not shown. The rotor core piece 14 may be formed by shaving press using a strong pressing force, or may be formed by a conventional punching process having a normal gap between a punch and a die. Alternatively, the outer diameter may be slightly increased and the finishing may be performed by machining.

Then, as shown in FIGS. 3D to 3G, the round holes 15, the slots 16 and the caulking projections 1 necessary for the periphery are formed.
After forming 7, the half blanking is performed along the circle indicated by the chain line N as shown in FIG. In this embodiment, the cutting is performed at a portion slightly inside the outer circumference of the cut rotor core piece (that is, the shaving margin), but since it is a half blanking process, a large number of protruding pieces 19 are not separated. Held in.

Next, in the step shown in FIG. 1H, as shown by a chain double-dashed line M in FIG. 2, an internal process including the inner groove 21 of the stator core piece 20 is performed to form the small teeth 22. In this case, the shaving press working is performed on the inner circumference portion of the stator core 20 so that the gap between the punch and the die is 1/100 mm or less. As a result, the inner circumference of the stator core piece 20 has a sheared surface and is perpendicular to the stator core piece 20, so that the magnetic characteristics of the product are improved. In this case, it is not always necessary to perform the shaving press processing on the inner groove 21 portion, and a normal gap (one side 20
It may be a conventional press working having about 25 μm).

FIG. 3 shows a method of manufacturing a stator core piece according to another embodiment of the present invention.
As shown by the broken line P in FIG. 3, the final stator core piece 20
Half blanking is performed at a portion of about 5/100 to 1/10 from the inner shape of. As a result, the large number of protruding pieces 19 are held in a state where they are not separated. Then, in the step shown in FIG. 1 (H), as shown by a chain double-dashed line Q in FIG. 3, the inner shape of the stator core piece 20 including the small teeth 22 is shaving pressed. In this case, since the half-blanking process is performed in advance in the vicinity position, the press process can be performed without increasing the press pressure. Here, it is possible to perform full blanking instead of the half blanking, but in this case, extremely small whisker-like chips that cause various obstacles are generated. It can be prevented.

[0011]

As is apparent from the above description, the method of manufacturing the motor iron core piece according to the first aspect of the invention has a shaving margin from the inner circumference of the stator iron core piece on the strip material after the rotor iron core piece is punched out. Since it is provided to perform a half-circular punching process and punching the inside of the stator core piece with the small teeth formed by shaving press processing, the inner circumference of the stator core piece (particularly the small teeth) is There are more shear planes perpendicular to the plate surface of the strip, which improves the magnetic properties. In the punching of the inner circumference, since half blanking is performed in advance, the press pressure can be relaxed when performing shaving press working, and the cut piece is connected to the inner part by the half blanked portion. Therefore, it does not generate minute chips. In the method of manufacturing an iron core piece for a motor according to claim 2, after the rotor iron core piece is punched out,
Since half punching is performed on the part of the stator core piece that is a little distance from the inner shape that includes the small teeth, and the inner shape of the stator core piece that includes the small teeth is punched by shaving press processing. Not only the inner circumference but also the small tooth portion can have many shear planes perpendicular to the strip surface, which makes it possible to manufacture an iron core having better magnetic characteristics. In this case, since half-blanking is performed on the inside with the shaving margin left before the shaving press working, the press pressure for the shaving press working is small, and the cut pieces are also partially connected at the half-blanked part. Therefore, it is difficult to generate minute cutting chips. Therefore, according to the manufacturing method of the motor iron core piece according to the first and second aspects, the stator iron core piece whose inner periphery has been machined conventionally can be formed by press working, so that the production efficiency can be improved. .

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a method for manufacturing an iron core piece for a motor according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of a stator core piece in the same method.

FIG. 3 is a partially enlarged view of a stator core piece in a method of manufacturing a motor core piece according to another embodiment of the present invention.

[Explanation of Codes] 10 Strip Material 11 Pilot Hole 12 Shaft Hole 13 Caulking Projection 14 Rotor Iron Core Piece 15 Round Hole 16 Slot 17 Caulking Projection 19 Projecting Piece 20 Stator Iron Core Piece 21 Inner Groove 22 Small Teeth

Claims (2)

[Claims] 1. A rotor core piece having a plurality of pole teeth formed around a continuous strip, and an inner diameter slightly larger than the outer diameter of the rotor core piece, and a plurality of small teeth formed on the inner circumference. A method of manufacturing an iron core piece for a motor, which sequentially forms a stator iron core piece having a plurality of pole teeth formed by punching the rotor iron core piece, and then providing a shaving allowance on the inner circumference of the stator iron core piece. A method for manufacturing an iron core piece for a motor, which comprises performing a circular half blanking, and thereafter, punching the inside of the stator core piece by press working including shaving to create the small teeth. 2. A rotor core piece having a plurality of pole teeth formed around a continuous strip, and an inner diameter slightly larger than the outer diameter of the rotor core piece, and a plurality of small teeth formed on the inner circumference. A method of manufacturing a motor core piece for sequentially molding a stator core piece having a plurality of pole teeth formed therein, and shaving into an inner shape including an inner groove of the stator core piece after punching the rotor core piece. A method for manufacturing an iron core piece for a motor, characterized in that half punching is performed while leaving a margin, and thereafter, the inner shape punching is performed by shaving press to create small teeth.