JPH06141492A - Laminated iron core for motor - Google Patents

Abstract

PURPOSE:To provide a precision motor with laminated iron core indispensable which is excellent in the shape property such as the squareness, the parallelism, etc., of the laminated iron core, and in which the air gap between a stator iron core and a rotor iron core is small, and the step rotation of which can be done accurately with its angle of rotation small. CONSTITUTION:The laminated iron core for a motor is made by manufacturing one or both of stator iron core pieces 7 and rotor core pieces 5 so that they may include the regions where thin places 10 are made coaxially and pressed and extended flat, and laminating the stator iron core pieces 7 and rotor iron core pieces 5, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated core of an electric motor having excellent electric characteristics.

[0002]

2. Description of the Related Art A laminated iron core in which iron core pieces are laminated and wound is used for an electric motor. There are various types of electric motors, and for example, stepping motors, small motors, etc. are required to have precise rotation control.

As is well known, the stepping motor is stepwise rotated at a certain rotation angle, and the rotation angle is required to accurately match a desired rotation angle. Especially in the case of precise rotation, the step angle is small, for example 2
It is less than 3 degrees. In the laminated core of such a stepping motor, it is necessary that the stator core piece has a large number of tooth poles at the magnetic pole tips and the rotor core piece also has many teeth. Furthermore, the air gap between the stator core and the rotor core must be narrowed.

When the stator core piece and the rotor core piece are punched from the same thin metal plate, the gap becomes small and there are various problems. For example, the punching scrap between the iron core pieces may become narrow and may break during the punching process and may not be dropped below the die of the die, and may be punched twice, and the die may be damaged due to the scrap being caught. There is a fear.

Further, due to the narrowing of the gap, for example, the tooth poles of the stator core piece may not be punched into a desired many shapes. In such a case, the stator core piece and the rotor core piece must be punched from different thin metal plates, respectively, which reduces the yield of the material. Otherwise, a desired laminated core cannot be manufactured, and a stepping motor that can rotate at a precise step angle cannot be obtained.

As a conventional technique for the problem of the narrowing of the gap, there is, for example, Japanese Patent Laid-Open No. 1-190235. Before punching a rotor core piece from a thin metal plate, a bead-shaped throttle part is formed at a position larger than the diameter of the rotor core piece, and then the rotor core piece is stamped to flatten the throttle part. Then, the stator core piece is punched out. With this, when the stator core piece is punched later, since the thin metal plate is stretched as described above, the gap allowance is widened, that is, the scrap width is secured and the scrap may be cut off during punching. Instead, the problem of dropping twice each withdrawal stroke is eliminated.

[0006]

Although the above-mentioned technique has the above-described operation and effect, the throttle portion, that is, the bead is formed on the outer side of the rotor core piece to be punched, and the throttle portion is punched after the rotor core piece is punched. When flattening by pressing, undulations remain on the plate after pressing, and the core laminated with the stator core pieces punched from this may not always have a good shape and may show an inclination. Is reduced.

A stepping motor such as a stepping motor which has an extremely narrow air gap between the stator core and the rotor core may be defective if the accuracy of the core shape is deteriorated. In order to enable precise rotation control, it is necessary to form a large number of tooth poles on the stator core piece in order to reduce the step rotation angle.However, if the stator core piece has undulations, the tooth poles of the laminated core are aligned. Is not good and the desired product cannot be obtained.

The present invention has no such problems and has excellent shape characteristics such as squareness and parallelism of the laminated iron core, has a narrow air gap, and can accurately perform step rotation at a small rotation angle, which is indispensable for a precise motor. The purpose is to obtain an iron core.

[0009]

DISCLOSURE OF THE INVENTION The gist of the present invention includes a region where one or both of a stator core piece and a rotor core piece are thinly formed concentrically and flattened and extended. It is a laminated iron core of an electric motor formed by laminating a child iron core piece and a rotor iron core piece.

[0010]

In the stator core piece and the rotor core piece of the present invention, one or both of them are provided with concentrically thin portions by pressing, pinching, stamping or the like to form a flat and extended region in the plate surface direction. Since it is stamped and formed by using, the laminated core of this has excellent shape accuracy such as squareness and parallelism, and the punching gap between the stator core piece and the rotor core piece is widened. Punched under the circumstances, both core pieces have many tooth poles, but their shape is good. Further, since the stator core piece and the rotor core piece are stamped from the same metal material, the yield is improved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment with reference to the drawings. In the figure, 1 is a metal thin plate from which a rotor core piece and a stator core piece are punched, and 2 is a pilot hole punched at station A.

Numeral 3 is a shaft hole which is punched at the station B.
Reference numeral 4 denotes a rotor core piece crimped portion, which in this embodiment is round and is formed at the station C. The crimped portion 4 is punched into the through hole in the rotor core piece of the first laminated sheet, and is formed in a half-blanked shape from the second sheet onward to a predetermined number. The through hole and half blanking are performed, for example, by changing the protruding height of a punch (not shown). The caulking portion 4 is not limited to the round shape,
A square shape, a V-shape, a cut-and-raised shape or the like can be adopted.

At station D, the rotor core piece 5 is punched and laminated and caulked. The lamination may be either direct lamination or rotation lamination, and the rotor core piece 5 is punched to form tooth poles 6 on the outer periphery.

After that, the stator core piece 7 is punched out from the thin metal plate 1 on which the rotor core piece 5 is punched out. The difference between the outer diameter of the rotor core piece 5 and the inner diameter of the stator core piece 7 is the air gap. And greatly affects, for example, the excitation circuit and the static torque of the stepping motor. In order to make the air gap extremely small so as to improve these electric characteristics, and to make the step angle small and control the precision rotation, it is necessary to form a large number of tooth poles 8 on the inner diameter side of the stator core piece 7. This means that the inner diameter of the stator core piece 7 is punched into a complicated shape in a region where the punching margin is extremely small, and breakage or floating occurs due to narrowing of the width of the punched scrap, and double punching is performed. There are also things to do.

Therefore, before the slot 9 is punched at the station E and then the inner diameter of the stator core piece 7 is punched, the outer shape of the rotor core piece 5 and A thin portion 10 is formed by concentrically pressing, pinching, or stamping to reduce the plate thickness of the relevant portion and flatten it to the inner diameter side. This is done at station F, for example with an annular punch. The thin portion 10 may be in a portion where the stator core piece is to be formed, but the tooth pole 8 of the stator core piece 7 formed at the inner diameter end is densely laminated on the tooth pole 6 of the rotor core piece 5. It is preferable to be inside the inner diameter end so as to face each other.

Reference numeral 11 denotes a caulked portion of the stator core piece 7, which is formed at the station G. The crimped portion 11 is punched into the through hole in the first laminated sheet, and is formed in a half-blanked shape from the second and subsequent sheets to a predetermined number. As in the case of the rotor core piece crimping portion 4, the through hole and the half blank can be replaced by changing the protruding height of the punch. Further, although the caulking is round in this embodiment, it is not limited to this, and a square, V-shaped, cut-and-raised shape or the like can be adopted.

The inner diameter of the stator core piece 7 is punched at the station H to form the tooth pole 8. At this time, the stator core piece formation-scheduled portion is flattened to the side from which the rotor core piece 5 has been extracted as described above to secure the scrap width, and the stator core piece 7 has a flatness. High and extremely excellent in shape.

Next, the stator core piece 7 is attached to the station I.
The outer diameter is punched out and caulked and laminated. Stacking may be direct stacking or transposing.

The laminated rotor core 12 is as shown in FIG. 2, and the stator core 13 is as shown in FIG. 3, and after the stator core 13 is wound (not shown), the rotor core 12 is inserted on the inner diameter side. . The stator core piece 7 includes the pressed and extended portion as described above, but the shape of the core is
The posture is excellent, the narrow air gap with the rotor core 12 is precisely ensured, and the electric characteristics are excellent.

Although there is a thinned portion in the stator core piece 7 and a slight gap is formed in the laminated body, magnetic flux passes from the rotor core 12 with the densely laminated tooth poles 8 as the inlet / outlet surface, and Since the magnetic flux passes through the iron core piece having a small resistance in the iron core, the electric characteristics are not deteriorated by the existence of the air gap.

In this embodiment, the rotor core piece 5 was punched out first, and then the stator core piece side was concentrically formed with a thin portion and pushed flat to extend the stator core piece 7, but instead of this, Then, the stator core piece 7 is punched out first, and then the metal thin plate 1 on the rotor core piece side is circularly pressed to extend to the stator core piece removal side, and the rotor core piece 5 is punched and laminated. That is, the same effect can be obtained even with a laminated core in which the rotor core piece 5 has a thin portion. If necessary, the thin portions may be formed on both the rotor core piece 5 and the stator core piece 7.

[0022]

As described above, the stator core piece and the rotor core piece of the present invention are punched out by forming a thin portion and pushing it flat to widen the originally narrow gap between them. Therefore, an iron core obtained by laminating the iron core pieces is excellent in formability, does not cause end face wobbling, and the air gap between the iron core pieces is secured with high accuracy, and is suitable for a precision motor.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of a laminated core in one embodiment of the present invention.

FIG. 2 is a diagram showing a rotor core according to one embodiment of the present invention.

FIG. 3 is a diagram showing a stator core according to one embodiment of the present invention.

FIG. 4 is a top view of a stator core and a rotor core assembled in one embodiment of the present invention.

[Explanation of symbols]

 1 Metal thin plate 2 Pilot hole 3 Shaft hole 4 Rotor piece caulking part 5 Rotor core piece 6 Teeth pole 7 Stator core piece 8 Teeth pole 9 Slot 10 Thin section 11 Crimping part 12 Rotor core 13 Stator core

Claims (1)

[Claims] 1. A stator core piece, a rotor core piece, or one or both of which includes thin regions formed concentrically with each other and flattened and extended, and the stator core piece and the rotor core piece are respectively provided. Laminated iron cores for laminated electric motors.