JPS58131721A - Manufacture of stator magnet - Google Patents

Abstract

PURPOSE:To attain conservation of a magnet material, and to facilitate manufacture of the stator magnet by a method wherein the solid solution treatment of an ingot of iron, chrome, cobalt is performed, then elemental pieces of the plural sheets obtained through the punching process from an elemental plate performed with cold rolling are laminated one upon another, the aging process is performed to the substance unified in one body by calking the laminated elemental pieces thereof, and then magnetization is performed. CONSTITUTION:After the solid solution treatment is performed, the elemental plate 1 having arbitrary width, thickness as shown in the figure is obtained according to cold rolling, and then the ovally punched elemental pieces 2 having calking holes 3 are obtained from the elemental plate 1 thereof according to the punching process. After then, the elemental pieces thereof are laminated to form in the shape as shwon in the Fig. 3, and the elemental pieces 2 of the plural sheets are constituted into the unified substance utilizing the calking holes 3. Then the laminated substances thereof are made to stand in a row in the longitudinal direction, and the aging process is performed in a magnetic field. Finally the substances are magnetized in the longitudinal direction according to a magnetizer to complete the stator magnet 4. Cold rolling at this process is performed for regulation of the shape of crystal grains. Moreover the oval shape is to intended to obtain the effect of conservation and reduction of weight of the magnet material. Because, by constituting the necessary magnet body according to the lamination of the fundamentally elemental pieces, the magnet body corresponding to necessary magnetic flux can be easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a stator magnet for a two-pole magnet motor, such as a coreless motor. The purpose is to save magnet material and facilitate manufacturing in the manufacture of the stator, as well as to reduce the weight of the stator and increase flexibility in changing dimensions.

The features of the present invention and comparison with conventional examples will be described using a coreless stator as an example. Conventionally, a cylindrical alnico magnet or a rare earth wound magnet as shown in FIG. 1 has been used for the stator. These are produced by casting or sintering, but
With these methods, precise dimensional accuracy cannot be obtained and polishing is always required. This not only increases the polishing cost, but also makes it difficult to obtain a non-circular cross-sectional shape during the polishing process.

On the other hand, considering the characteristics of the coreless motor, the stator magnet does not need to have a circular cross section, and may be a magnet with a round-shaped cross section, for example. This has the advantage of saving materials, reducing the weight of the stator, and ultimately reducing the weight of the motor.

Hereinafter, the present invention will be explained based on the drawings.

Although the above-mentioned alnico magnets and rare earth wound magnets have high performance, they are both hard and brittle, and the reality is that casting is limited to sintering.

By the way, in recent years, magnets whose main components are iron, chromium, and cobalt and which can be plastically worked have been put into practical use.

However, the magnetic properties are slightly inferior to those of alnico magnets and the like.

Iron, chromium, and cobalt-based magnets are usually melted to obtain ingots, which are then subjected to solution treatment and finally aged! ! (in magnetic field)
It is manufactured through a post-polishing process.

In the present invention, after solution treatment, a blank plate 1 having an arbitrary width and thickness as shown in FIG. Obtain blank piece 2.

Thereafter, the pieces are stacked in the shape shown in FIG. 3, and the plurality of pieces 2 are integrated into one piece through the caulking holes 3.

This laminate is then aligned in the longitudinal direction and subjected to an aging treatment in a magnetic field. Finally, the stator magnet 4 is completed by magnetizing it in the longitudinal direction using a magnetizing device.

Although the above embodiment is extremely simple, the insertion of cold rolling has an essentially important meaning in terms of improving characteristics when applying iron, chromium, and cobalt magnets to stator magnets of coreless motors.

That is, when forming N and S poles only on the − axis,
It is important that magnetization is easy only in this direction. The method of imparting an easy direction of magnetization is usually 4) aligning the axis of easy magnetization of the crystal and elongating the shape of the crystal grain in this direction.
), and it is effective to lengthen the overall shape of the magnet in this direction.

The cold rolling in the present invention is for i) adjusting the shape of crystal grains. In addition to reducing magnet material and weight, the round shape essentially achieves the above effect (i).

As can be seen from the above description, the present invention proposes a magnet shape and structure suitable for rationalizing the stator, and also provides measures to improve the characteristics of iron, chromium, and cobalt magnets when applied to stators.

Furthermore, an important feature of the present invention is that the required magnet body is constructed by laminating basic pieces, so by adjusting the number of laminated layers, it is possible to easily obtain a magnet body that corresponds to the required magnetic flux. It's at the point where you get used to it.

Furthermore, another feature is that polishing is not required in magnet production. This has a great effect on reducing magnet manufacturing costs.

A stator magnet having the above features obtained by the present invention is used, for example, in a coreless motor configured as shown in No. 450. Here, 4 is a stator magnet, 5 is a rotor coil, and 6 is an external yoke.

Examples of this invention will be given below.

<Example> Cr 25%, CO 18%, balance Fe(y) alloy 120
After solution treatment at 0°C, hot rolling was performed at 950-1050°C to a thickness of 2cm, and then cold rolling to a thickness of 0.8cm.

Next, a cobalt magnet piece of 16φ x BW was punched out from the rolled material by cold punching, and 20 pieces of this were laminated to form a 16 mm long magnet block.

This block was aged in a magnetic field at 650°C for 60 minutes,
Subsequently, it was cooled from this temperature to 500°C at a cooling rate of 5°C/Hr, and held at 500°C for 10 hours.

After cooling to room temperature, this block was magnetized in the longitudinal direction by a normal magnetization method to form a bipolar magnet.

When this magnet was used in place of a conventionally cast magnet, a 5-10% increase in torque was obtained.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional stator magnet, Fig. 2 is a plan view showing a blank plate and a stator piece from which a stator piece according to an embodiment of the present invention is obtained, and Fig. 3 is a plan view showing a stator piece. FIG. 4 is a perspective view showing a laminated integral body, and a plan view of a coreless motor using stator magnets according to the present invention. Patent applicant Matsushita Electric Works Co., Ltd. Representative patent attorney Toshimaru Takemoto (and 2 others)

Claims (1)

[Claims] (11L When manufacturing chromium and cobalt-based stator magnets, iron, chromium, and cobalt are melted to obtain an ingot, this ingot is solution-treated, and then cold pressure is applied to obtain a blank plate. A blank piece is obtained from a blank plate through a punching process,
Laminate several of these pieces and sew them together to form a single piece.
A method for manufacturing a stator magnet characterized by subjecting this one piece to an aging treatment and then magnetizing it.