JPH06169557A - Laminated core of skew shape variable and manufacture thereof - Google Patents

Abstract

PURPOSE:To make it possible to change the screw direction of core pieces in the height direction of a laminated core through caulking parts, by forming a skew through hole in the center in the caulking parts and forming a relief protrusion in which a slant part is formed on both the sides. CONSTITUTION:When core pieces A in which caulking parts 4 are formed are blanked and are fitted and laminated, a through hole 5 is opened in the first core piece A. The relief protrusion caulking parts 4 which interpose a skew through hole 4b in the substantially center of the bottom 4a and have a slant surface 4c on both the sides are formed in the core pieces A from the second core piece to a caulking laminated completion. When the core pieces A are blanked and a rotary die 16 is rotated and a lamination is performed, the caulking parts 4 can be stuck and laminated without generating the residual stress and a good shape can be formed. Also, when the skew through hole 4b is laminated, some deformation occurs and a fitting strength can be increased. Thus, the skew direction can be easily changed and the caulking parts 4 can be easily formed and a strong fitting can be obtained without generating the processing residual stress.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated core having a different skew shape and a method for manufacturing the same.

[0002]

2. Description of the Related Art In order to smooth the torque characteristic of a motor, a skew is formed in a laminated iron core incorporated in the motor as a rotor.

In the manufacture of laminated iron cores, the iron core pieces are connected to each other via a caulking portion formed of a cut and raised projection communicating with a skew relief hole formed in the iron core piece and a cut and raised projection hole, or a V-shaped recess. They are fitted and caulked and laminated, and a rotary die that receives the laminated core is rotated to form a predetermined skew.

Skew formed on the laminated core, for example, the laminated rotor is effective for preventing abnormal noise of the motor and stabilizing electric characteristics, but on the other hand, if the skew is vertical, the rotor of the motor will move from the stator. It may be subject to axial forces that push it out.

It is known that this problem can be solved by changing the direction of skew within the laminated core. For example, JP-A-6
In JP-A-0-72618, a punch having symmetrical protrusions for forming caulking cut-and-raised protrusions from the left and right is provided, and a protrusion on one side is used for a laminated iron core piece from the start of lamination to a skew change point. Cut-and-raised protrusions are formed, and the protrusions on the other side are used to form cut-and-raised protrusions from the changed position to the end of stacking, and these iron core pieces are indexed from the desired skew amount. It is disclosed that a contour punching die is rotated by a rotation angle to be laminated, and rotation is performed to change the direction of the skew during the production to manufacture a laminated core having a V skew.

In Japanese Utility Model Publication No. 60-41804, a V-shaped crimp is formed on an iron core piece at a position shifted from a slot according to a desired skew amount, and the iron core piece is fitted and laminated by the V-shaped crimp. It is shown that a laminated iron core with a skew direction changed by that is obtained.

With these conventional techniques, the skew can be changed in direction, and there is a corresponding effect. However, in the caulking lamination in which the cut-and-raised protrusions and the projection-removing holes are fitted, the cut-and-raised protrusions are bent and strip-shaped. Therefore, the ability to change the skew direction is small, and the allowable range of rotation control of the rotary die for matching the skew direction is narrow and difficult. Further, the V-shaped caulking is difficult to change freely because the angle of the inclined surface is affected by the change in skew. Further, in order to make the skew different, it is necessary to form the V-shaped caulking with a different inclination angle each time.

[0008]

A motor is often used as a precision control device, and a laminated iron core incorporated therein, for example, a laminated rotor, is required to have high quality, and the direction of skew can be freely changed. The shape must be excellent. An object of the present invention is to obtain a laminated iron core in which the direction of skew can be easily changed, a caulking portion can be easily formed, and a strong fit can be achieved without causing residual stress during caulking.

[0009]

SUMMARY OF THE INVENTION The gist of the present invention is to provide an iron core in which an outer shape of an iron core piece having a crimped portion is punched out and fitted and laminated, and the crimped portion has a skew through hole in the center and inclined portions on both sides thereof. The skewed shape-variable laminated core is formed by the formed projections and is fitted through the caulked portion, and the skew direction of the iron core piece is changed in the height direction of the laminated core. Another gist is a method of manufacturing an iron core in which a core piece having a crimped portion is punched out from a rotary die and fitted and laminated,
Punch a skew through hole at the planned crimping part of the iron core piece,
The skew through-hole is formed on both sides of the iron core piece by punching out both sides thereof, the iron core piece is punched out to a rotary die, and the rotary die is set to a skew angle or a stacking angle for canceling the plate thickness deviation of the iron core piece to the skew angle. There is provided a method of manufacturing a laminated core piece with a variable skew shape, in which a predetermined number of layers are added, rotated, and caulked and laminated, and when the laminated thickness reaches a skew shape change thickness, the lamination is performed by changing the rotation direction and laminating.

[0010]

In the laminated iron core piece of the present invention, the caulking portion has a skew through hole formed in the bottom and both sides of the skew through hole are substantially centered to serve as projections. Therefore, the outer shape of the iron core piece is removed and the die is rotated. When changing the direction of the skew, the caulking portion is opened at the bottom side of the inclined surface formed by stamping with a skew through hole, and the machining residual stress due to the change of the skew is released, and the skew can be freely changed. Further, at this time, the skew through hole is deformed to some extent to strengthen the fitting force.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings based on one embodiment. In the drawings, 1S is the first
At the station, the pilot hole 1 is drilled in the iron core material 2. 2S is a second station where the shaft hole 3 and the skew through hole 4b are formed.

In 3S, the caulking portion 4 is formed at the third station, but the through hole 5 is formed in the iron core piece A to be laminated on the first sheet, and the iron core piece A from the second sheet to the completion of the caulking lamination is formed. As shown in FIG. 3, the projection protrusion caulking portion 4 having the inclined surfaces 4c is formed on both sides of the skew through hole 4b at the substantially central portion of the bottom 4a.

4S is a fourth station, in which a slot 6 is bored in this embodiment, the outer shape of the core piece A is punched out at the fifth station 5S, and as shown in FIG. It

Next, the production of laminated core will be described. Reference numeral 7 is a pilot hole punch, 8 is an axial hole punch, 9 is a skew through hole punch, and 10 is a stripper.

Numeral 11 is a punching-out projection punch, and the length of elevation of the punch tip to the lower surface of the stripper 10 can be adjusted through a slide plate (not shown), and the punch tip is largely lowered to stack the first sheet. The through hole 5 is formed in the core piece A. As shown in FIG. 4, the punching punch projection punch 11 has an inclined surface 13 on both sides of the tip 12, and when the length of the punch tip 12 descending to the lower surface of the stripper 10 is reduced, the punch 9 for punching the skew is punched. The caulking portion 4 which becomes the inclined surface 4c is formed on both sides of the provided skew through hole 4b as a center. Reference numeral 14 is a slot punch, and 15 is a punch for punching the outer shape of the iron core piece.

Reference numeral 16 denotes a rotary die into which the iron core piece A whose outer shape has been removed is drawn, 17 a die plate, 18 a die holder, and 19 a bearing rotatably supporting the rotary die 16. 20 is a sprocket provided on the outer periphery of the rotary die 16, 21 is a timing belt for transmitting a rotational force,
Reference numeral 22 is a rotary drive device such as a servo motor. The drive system of the rotary die 16 is not limited to this embodiment, and means for rotating the rotary drive device 22 and the rotary die 16 by connecting them with a gear, or an index device for rotating them via a stroke signal of the press of the outer shape punch 15 is used. A rotary drive means or the like is adopted.

A rotation control device 23 receives, for example, a press stroke signal, a plate thickness signal of the iron core material 2, and a plate thickness deviation signal, and outputs a rotation operation signal each time the stroke signal is input. Further, the skew angle is input in advance to the rotation control device 23 and a command signal is output to the rotation driving device 22 to rotate the rotary die 16 at the angle. Further, the laminated iron core thickness is calculated and calculated from the stroke signal and the plate thickness signal of the iron core material 2, and when the thickness reaches a predetermined skew shape change laminated iron core thickness, a rotation direction change command is output to the rotary drive device 22 for rotation. The shape of the skew is changed by reversing the rotation direction of the die 16.

The plate thickness deviation signal is used as a rotation control device 23.
Is compared with a preset allowable plate thickness deviation value, and the rotation angle of rotation, for example 90 degrees, is added to the skew angle and output so as to eliminate the plate thickness deviation depending on the size. As a result, when the core die A is laminated while the rotary die 16 also serves as a stack, the laminated core has an excellent shape without a difference in height between the left and right sides.

[0019]

As described above, according to the present invention, in the iron core piece, the caulking portion is provided with a skew through hole at the bottom and is punched out at the center thereof, and has a skew through hole at the lower end of the inclined surface. Therefore, when the outer shape of the iron core piece is removed and the rotating die is rotated to change the skew direction, the caulking portion can be laminated well without causing residual stress in the rotation for skew change, and the skew can be freely changed. The laminated core has an excellent shape. In addition, the skew through holes have the effect of being slightly deformed at the time of stacking and strengthening the fitting.

When the iron core material has a plate thickness deviation, the deviation can be eliminated and stacked, and the skew can be changed.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of an iron core piece according to one embodiment of the present invention.

FIG. 2 is a diagram showing an iron core laminated mold device according to one embodiment of the present invention.

FIG. 3 is a diagram showing a crimped portion of an iron core piece according to an embodiment of the present invention.

FIG. 4 is an enlarged view showing a part of a punch for a caulking part in one embodiment of the present invention.

FIG. 5 is a diagram showing skew change of a laminated iron core according to one embodiment of the present invention.

[Explanation of symbols]

 1 Pilot hole 2 Iron core material 3 Shaft hole 4 Caulking part 5 Through hole 6 Slot 7 Punch for pilot hole 8 Punch for shaft hole 9 Punch for skew through hole 10 Stripper 11 Stamping punch projection 12 Punch tip 13 Sloping surface 14 Slot punch 15 External Punch 16 Rotating Die 17 Die Plate 18 Die Holder 19 Bearing 20 Sprocket 21 Timing Belt 22 Rotation Drive Device 23 Rotation Control Device

Claims (2)

[Claims] 1. An iron core in which an outer shape of an iron core piece having a crimped portion is punched out and fitted and laminated, wherein the crimped portion comprises a punching projection having a skew through hole in the center and inclined portions formed on both sides thereof, the crimped portion. The skewed shape of the laminated core is changed in the height direction of the laminated core through the laminated core with variable skew shape. 2. A method of manufacturing an iron core, wherein an iron core piece having a crimped portion is punched out on a rotary die and fitted and laminated. In a method of manufacturing an iron core, a skew through hole is punched at a predetermined location of the crimped portion of the iron core piece, and the skew through hole is included. Form both sides of the iron core by punching out the iron core piece into a rotary die, and rotate the rotary die by adding the skew angle or the stacking angle that offsets the plate thickness deviation of the iron core piece to the skew angle and rotate it. A method for manufacturing a laminated core piece with a variable skew shape, which comprises laminating several caulks and changing the rotation direction when the thickness becomes a skew shape change thickness.