JPH08275466A - Manufacture of rotor core - Google Patents

Abstract

PURPOSE: To obtain a rotor core that allows dimensional accuracy to be determined mainly by lower die without being influenced by upper die-lower die compound factors, and that facilitates accuracy adjustment after re-polishing, by placing a shaft punch and an outside diameter die on a progressive lower die. CONSTITUTION: A shaft punch 3 is installed on a progressive lower die 2, and a shaft punching die 4 is installed on a progressive upper die. Each time stamping is performed against the shaft punching die 4 on the upper die, shaft hole scrap 5 is pushed in by the shaft punch 3, and is discharged upward through a shaft hole scrap chute 10. As a result shaft holes are formed in electromagnetic steel plate material 9 remaining in the progressive dies, and therefore, dimensional accuracy is determined mainly by the shaft punch 3 installed on the progressive lower die 2. This obtains a rotor core 8 wherein the dimensional accuracy of its shaft hole and outside diameter and the accuracy of their correlative positions are determined mainly by the lower die. This reduces variation in correlative positional accuracy that occurs at each time of polishing, and enables the reduction of time required for die adjustment.

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 rotor core which has good dimensional accuracy and is of a progressive type and which can be easily maintained and adjusted.

[0002]

2. Description of the Related Art A rotor core of an electric motor is manufactured by punching an electromagnetic steel plate in a progressive die together with a stator core, and then die-casting the aluminum bars in the slots of the outer periphery of the rotor core and end rings at both ends. Is formed and becomes a rotor.

The rotor core punching process is shown in FIG.
The shaft hole 14 and the outer diameter of the rotor are punched in this order, and the punching punch is arranged in the progressive die upper die 1 and the die in the progressive die lower die 2.
When the shaft hole 14 is punched out, the shaft hole portion is discharged as scrap 5 below the lower die 4, and the shaft hole 14 is formed toward the electromagnetic steel sheet material 9 remaining in the die. It is mainly determined by the shaft punching punch 3 of the upper die 1. On the other hand, the outer diameter of the rotor is punched from the electromagnetic steel sheet material 9 punched in the shaft hole 14, and is not the electromagnetic steel sheet material 9 remaining in the mold in the opposite direction to the shaft hole 14, but is the one punched out. Is determined by the outer diameter cutting die 7 of the lower mold 2.

Therefore, the dimensional accuracy of the rotor core 8 is determined by the shaft hole punch 3, die 4 and outer diameter punch 6, die 7.
Not only the size of the above, but also the mutual position of the two affected, and it became a composite of the two, and it was difficult to maintain them. Also, in order to hold the punching bur within a certain size,
It is customary to re-polish after punching a prescribed number of sheets,
Re-polishing was done separately for both the upper and lower dies, and reassembly was required after re-polishing, so much time was required to maintain and adjust dimensional accuracy.

Although the above description has been made on the general progressive type, the same can be said for the laminated rotor core which is caulked and fitted by the cut-and-raised protrusions, and caulking and mating which is not cut after die casting. Since the dimensional accuracy is more important in the laminated rotor core, it takes much more time to maintain and adjust it.

[0006]

In the conventional method of manufacturing a rotor core described above, the shaft hole size is mainly determined by the shaft punching punch arranged in the upper die, and the outer diameter of the outer die arranged in the lower die is determined. Since the outer diameter dimension is mainly determined by the punching die, its dimensional accuracy and mutual positional accuracy are a composite of the two, and adjustment is extremely difficult, and it takes a lot of time to maintain it after each re-polishing. . It is an object of the present invention to provide a rotor core manufacturing method in which the dimensional accuracy is not affected by the combined factors of both the upper mold and the lower mold, is mainly determined only by the lower mold, and the accuracy adjustment after regrinding is easy.

[0007]

In order to achieve the above object, the present invention provides a progressive die for punching a shaft hole and a rotor outer diameter, in which a shaft hole punch is installed in a lower die and a die is installed in an upper die. The scrap in the shaft hole is discharged above the upper mold, the rotor outer diameter punch is installed in the upper mold, and the die is installed in the lower mold.Dimensional accuracy and mutual positional accuracy are mainly determined by the lower mold. An object of the present invention is to obtain a method for manufacturing a characteristic rotor core.

[0008]

In the rotor core manufacturing method of the present invention, the shaft punching punch whose size is mainly determined by the punching punch is installed in the lower die because it is formed toward the electromagnetic steel sheet material remaining in the die,
The outer diameter die, whose dimensions are mainly determined by the die because it is punched from the electromagnetic steel sheet, is installed in the lower die as in the past, so the rotor core shaft hole, outer diameter dimensional accuracy, and mutual positional accuracy are mainly Since it is decided by the lower mold, the dimensional accuracy and mutual positional accuracy are less likely to change each time re-grinding or re-assembling, and the time required for dimensional adjustment can be shortened.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing a shaft hole punching portion and an outer diameter punching portion of a progressive punching die according to an embodiment of the present invention, which will be described in detail below with reference to FIG. Although the shaft hole is punched at the shaft punching station, the shaft punching punch 3 is installed in the progressive die lower die 2 and the shaft punching die 4 is installed in the progressive die upper die 1. 10 indicates a chute for discharging the shaft hole scrap 5 upward, and 12 indicates an I.D. It is a D stripper that prevents the electromagnetic steel sheet material 9 from sticking to the lower mold 2 by the compression spring 1
It is prevented through 3 At this station,
Each time the shaft hole scrap 5 is punched into the upper shaft hole die 4, the shaft hole scrap 3 is pushed by the shaft hole punch 3 and discharged upward through the shaft hole scrap chute 10. Since the shaft hole is formed in the electromagnetic steel sheet material 9 remaining in the progressive die, the dimensional accuracy is mainly determined by the shaft hole punch 3 installed in the progressive die lower die 2.

At the rotor outer diameter cutting station, the rotor core 8 is punched, but the outer diameter punching punch 6 is installed in the progressive die upper die 1, and the outer diameter punching die 7 is installed in the progressive die lower die 2. Has been done. The rotor core 8 is punched from the electromagnetic steel plate material 9 punched in the slots and shaft holes 14, and is pushed into the outer diameter punching die 7 by the outer diameter punching 6. Therefore, the dimensional accuracy is mainly determined by the outer diameter cutting die 7.

[0011]

As described above, since the shaft punching punch 3 and the outer diameter punching die 7 are installed in the progressive die lower die 2, the shaft hole of the rotor core 8, the outer diameter dimension accuracy, and the mutual positional accuracy. Is mainly determined by the lower die, and the rotor core 8 having the same precision as the lower die can be obtained. Moreover, the accuracy of the positional relationship between the shaft hole and the outer diameter is re-ground every time the re-polishing is performed.
As shown in, the shaft punching punch 3 is a progressive die upper die 1
Further, since the outer diameter cutting die 7 is provided in the progressive die lower die 2, the change is reduced, and the time required for adjusting the die can be greatly shortened. Therefore, it is possible to provide a rotor core having high productivity, low cost and high quality.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a progressive die showing an embodiment of a method for manufacturing a rotor core according to the present invention.

FIG. 2 is a partial cross-sectional view of a progressive die illustrating a conventional method for manufacturing a rotor core.

[Explanation of symbols] 1 progressive die upper die 2 progressive die lower die 3 shaft punching punch 4 shaft punching die 5 shaft hole scrap 6 outer diameter punching 7 outer diameter punching die 8 rotor core 9 electromagnetic steel sheet material 10 Shaft hole scrap chute 11 Stripper 12 I. D stripper 13 Compression spring 14 Shaft hole 15 Die plate 16 Backing plate

Claims (1)

[Claims] 1. A progressive type in which a rotor core is punched,
A method for manufacturing a rotor core, characterized in that a shaft punch is installed in the same lower die as the outer diameter die, and shaft hole scrap is discharged above the shaft hole die installed in the upper die.