JPH0549218A - Manufacture of laminated core for rotating electric machine - Google Patents

Abstract

PURPOSE:To permit the good and uniform forming of all slot opening rims by a method wherein the slot opening rims are formed on only the thin sheet of a core, which is laminated at the end of a laminated core, so as to have round corners by a forming station provided in a sequentially transfer mold. CONSTITUTION:A lifter pin 39 is constituted so as to be capable of appearing and disappearing frequently from a die plate 29. When the mold of a forming station is functioned as a playing station, in which the forming is not requested, the forming surface of a forming mold 33 is sunken into the die plate 29 by the pushing of a spring 32 whereby the forming of slots 3 bored on thin sheet materials 24 is not effected. On the other hand, when thin sheets 2a of a core, which are laminated at the end of the bur-side of a laminated core 1, are formed, the forming surface of the forming mold 33 is appeared from the die plate 29 by a slid cam 37 whereby the projection 34 of the molding mold 33 is entered deeply the slots 3 bored on the thin sheet materials 24, the forming surface is abutted against the opening rims 4 of the slots by pressure and the opening rims 4 of the slots are formed so as to have round corners.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine such as an electric motor, and more particularly to a method for manufacturing a laminated core having slots formed by punching.

[0002]

2. Description of the Related Art A rotary electric machine such as an electric motor is constructed by mounting a coil in a slot of a laminated iron core through an insulating paper. As shown in FIG. 5, the laminated iron core 1 is obtained by punching out an iron core thin plate 2 having a plurality of slots 3 from a thin plate material such as a strip steel plate,
A predetermined number of the iron core thin plates 2 are laminated and fixed. As a means for stacking and fixing, the iron core thin plate 2 is punched at the same time with a caulking projection (not shown) and is superposed.

FIG. 6 shows a vertical cross section of the laminated core 1. As shown in FIG. 6, the punched surface of each iron core thin plate 2 is composed of a sheared portion and a fractured portion, and burrs 7 are formed on the fractured side. Further, the sagging portion 23 generated on the shearing side is not a smooth rounded shape, but the surface is sharply formed. Therefore, the laminated core 1
In the iron core thin plate 2a laminated at the end in the laminating direction of
The burr 7 is projected on the opening edge 4 of the slot 3,
Since the sharp sloping portion 23 is formed,
The insulating paper mounted in this slot 3 is easily damaged.

In order to solve this, the slot opening edge 4 of the laminated iron core 1 may be formed into a round shape before mounting the insulating paper or the coil, for example, Japanese Examined Patent Publication No. 63-26619.
The method is disclosed in the publication. The molding method will be described with reference to FIG. First, a brief explanation of the molding device is as follows.
A mandrel 10 and a blade 11 are attached to the lower base material 8 to guide the slot opening 6 in the laminated iron core 1. Also, the lower base material 8 and the upper base material 9
The springs 12 and 13 are interposed in each of the
4, 15 are mounted so as to be able to float, and the molding die 16,
17 is mounted. The convex portions 18 of the molding dies 16 and 17,
Numeral 19 is to be inserted into the slot 3 of the laminated core 1 from the opening of the end thereof, and a plurality of 19 are provided corresponding to the slots 3 of the laminated core 1. This convex portion 18, 1
The root portion of 9 is formed into a smooth rounded shape and serves as molding surfaces 20 and 21 for molding the slot opening edge 4.

Next, a molding procedure using the above apparatus will be described. First, when the laminated core 1 is placed on the pressing body 14, the tip end of the convex portion 18 of the molding die 16 is located in the slot 3. Next, when the upper base material 9 is lowered by the press ram 22, the pair of upper and lower pressing bodies 14 and 15 come into contact with the end faces of the yoke portion 5 in the laminated iron core 1, and the yoke portion 5 is tightened. Next, when the lowering of the upper base material 9 further continues, the molding surfaces 20 and 21 of the molding dies 16 and 17 are pressed against the slot opening edges 4 of the laminated iron core 1 to form the slot opening edges 4.

[0006]

As is well known, there is a plate thickness deviation in a core thin plate material such as a strip-shaped steel plate manufactured by rolling, and when the laminated core 1 is formed, the deviation is accumulated, A great variation in the product thickness occurs in the circumferential direction of the laminated core. Due to this stack thickness deviation, in the conventional molding method for the slot opening edge of the laminated core, the pressure of the molding press acts only on the large stack thickness portion, and it is not possible to mold the small stack thickness portion, There is a problem that the radius is small. If this is attempted to be molded at all points by increasing the pressure of the press, the laminated core will be distorted, which is not preferable.

Of course, for the iron core thin plate 2 having a 180 ° symmetry, a method of forming the laminated iron core 1 by rotating the iron core thin plate by 180 ° to offset the diagonal deviation can be applied. However, even with this method, the deviation is not sufficiently resolved, and in many cases, the accumulated thickness is partially increased or decreased.

Further, in the case of the laminated core 1 in which the protrusions for caulking provided on the iron core thin plate 2 are stacked and fixed (hereinafter referred to as caulking laminating) at the time of punching, since the caulking laminating is performed in the progressive die, The method of rotating the iron core thin plate is not generally applicable because it delays the laminating time significantly and hinders the productivity, and it is mechanically impossible. A large stack thickness deviation occurs. Therefore, in either case, the molding of the slot opening edge becomes insufficient.

Further, when the slot opening edge of the laminated iron core is formed by crimping and laminating, the slot opening edge 4 is formed in a depressed state as compared with the yoke portion 5 by compressing the gap existing between the laminated layers. As a result, the warp occurs in several core thin plates at the end including the core thin plate 2a. As a result, the caulking projections of the iron core thin plate near the end part come off from the iron core thin plate in the center part, resulting in a defective product or requiring repair, which is a factor of increasing the cost of the product.

[0010]

The present invention relates to a laminated core for a rotary electric machine, which is formed by punching out a thin iron core plate having a predetermined shape from a thin plate material by progressive press working, and laminating and fixing the iron core thin plate in a predetermined number. Provided is a novel manufacturing method for forming a slot opening edge into a round shape. That is, in the present invention, in order to avoid the accumulation of the plate thickness deviation of the thin plate material, the molding is performed not on the laminated iron core but on the slot of one iron thin plate. Since it is desirable that this molding be accomplished without requiring man-hours, a molding station is actually provided in the progressive die to mold the slot punched in the thin plate material. Further, since it is sufficient to perform molding on one or several sheets laminated on the end of the laminated core, the slot die in the progressive die is configured to be retractable so as to reduce wear of the die. The control is performed so that molding is performed only on the core thin plate at the end of the laminated core.

[0011]

[Function] Since molding is performed on one thin plate material,
The absolute value of the plate thickness deviation is small and its influence is slight. As a result, the pressing force of the molding acts substantially uniformly, and good and uniform molding is performed on all slot opening edges.

[0012]

EXAMPLE A progressive die press working is performed by using a die composed of an upper die having a plurality of punches and a lower die having a plurality of dies facing the punches. Iron core thin plates of a predetermined shape are sequentially punched from the thin plate material that is intermittently supplied between the lower molds, and each iron core thin plate is sequentially crimped and laminated by the caulking protrusions formed on this iron core thin plate at the same time, and the prescribed number of laminations is completed. Then, the laminated core is taken out.

FIG. 4 shows a part of the punching layout of the thin plate material 24. The thin plate material 24 is positioned by the pilot holes 25 and is intermittently fed from the upper part to the lower part of the drawing. In the figure, A is a forming station, and at the stage up to this station A, the rotor outer diameter 26 is punched out and the rotor core thin plate is pulled out,
Further, a stator slot 3 is bored. In the forming station A, the opening edge 4 of the slot 3 is formed into a round shape by a forming die only when forming an iron core thin plate to be laminated at the end of the laminated iron core, and when forming another iron core thin plate Become a station. At the station B after the molding station A, the inner diameter 27 of the stator is punched out. By arranging such stations, in the forming station A, since the slot opening 6 has not yet occurred, the internal defect portion is connected, and it is possible to prevent the core thin plate from being distorted due to the forming. is there.

1 and 2 show the molding station A described above.
2 is a cross-sectional view showing an example of the progressive die in FIG. 1, FIG. 1 showing a state during molding, and FIG. 2 showing a state when molding is not required. In these drawings, 28 is a stripper plate for guiding the upper punch, 29 is a lower die plate, and a thin plate material 24 is supplied between the upper die and the lower die. Reference numeral 39 is a lifter pin that is configured to be retractable from the die plate 29 and supports the conveyance of the thin plate material 24. A mold 33 held by a mold holder 30 is provided in the die plate 29. The mold holder 30 and the mold 33 are fixed to a holder guide pin 31 pressed downward by a spring 32, It is configured to be able to move up and down. The molding die 33 is moved up and down by sliding a cam 37 held by a cam holder 36 by a solenoid 38.

As shown in FIG. 3, the molding die 33 is provided with a plurality of convex portions 34 formed so as to be inserted into the slots 3 formed in the thin plate material 24. The plurality of convex portions 34 are plural. It is provided corresponding to the slot 3. In addition, the convex portion 34
The root part of is formed into a smooth rounded shape and serves as a molding surface 35 for molding the slot opening edge 4 into a rounded shape. Since this molding die 33 has less wear than the punching die, it can be easily attached to and detached from the die plate 29 as shown in the drawing, and is removed when polishing the die.
Further, in accordance with this mold polishing, the contact surface with the mold holder 30 is polished to adjust the height.

When the mold of the molding station configured as described above is used as a play station that does not require molding, as shown in FIG. Since the plate 3 is submerged in the plate 29, the slot 3 formed in the thin plate material 24 is not formed. On the other hand, when forming the iron core thin plate 2a to be laminated on the burr side end of the laminated iron core 1, as shown in FIG.
3, the molding surface 35 of the mold 3 comes out of the die plate 29, the convex portion 34 of the molding die 33 enters deeply into the slot 3 formed in the thin plate material 24, and the molding surface 35 is pressed against the slot opening edge 4. The slot opening edge 4 is rounded.

In FIGS. 1 and 2, the lower die of the progressive die is provided with the forming die, but the upper die may be provided with another forming station. ..
The configuration of the molding die in this case is as shown in FIG.
Also, since the arrangement is symmetrical with the case of FIG. 2, detailed description will be omitted. Generally, by focusing only on the lower mold side where the burr 7 is generated, the damage of the insulating paper mounted in the slot 3 can be considerably improved.

Further, the molding of the slot opening edge 4 may be carried out only for one sheet which becomes the core thin plate 2a at the end portion of the laminated iron core 1, but it is more complete if it is carried out for several end portions. Become.

[0019]

According to the present invention, when the slot opening edge of the end portion of the laminated iron core is formed into a rounded shape, it is not affected by the stack thickness deviation, so that good and uniform forming can be performed. It is possible to form a laminated core without distortion or detachment of the caulking projections. Further, by providing a molding station in the progressive die, there is a feature that the conventional molding process is unnecessary and the number of manufacturing steps can be reduced.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an example of a progressive die used in the present invention, showing a state at the time of molding.

FIG. 2 is a longitudinal cross-sectional view of relevant parts showing a state in which the progressive die shown in FIG. 1 does not require molding.

FIG. 3 is a perspective view of a main part showing an example of a molding die used in the present invention.

FIG. 4 is a layout diagram showing an example of punching a thin plate material.

FIG. 5 is a partial perspective view of a laminated iron core.

FIG. 6 is an enlarged vertical cross-sectional view of a laminated core.

FIG. 7 is a vertical sectional view showing a conventional method.

[Explanation of symbols]

 1 Laminated Iron Core 2 Iron Core Thin Plate 3 Slot 4 Slot Opening Edge 6 Slot Opening 24 Thin Plate Material 33 Forming Die 34 Convex 35 Forming Surface

Claims (2)

[Claims] 1. A method of manufacturing a laminated iron core for a rotary electric machine, comprising: punching a thin iron core plate having a predetermined shape from a thin plate material by progressive die pressing; and laminating and fixing a predetermined number of the thin iron core plates by a forming station provided in a progressive die. A method for manufacturing a laminated core for a rotary electric machine, characterized in that the slot opening edge of the core thin plate laminated on the end of the laminated core is formed into a rounded shape. 2. The molding station is arranged at a station after punching a slot to be molded and before punching to open a slot opening of the slot. Manufacturing method of laminated iron core for rotating electric machine.