JPS63260009A - Manufacture of resin magnet - Google Patents

Abstract

PURPOSE:To manufacture a precision resin magnet with large density, mechanical strength and maximum energy product easily by a method wherein magnetic alloy which is pulverized into fine powder is sintered and molded at a specific low temperature range and in the air or under a simple atmosphere control while a specific high pressure is applied and the magnetic alloy is impregnated with resin during or after the pressurized molding. CONSTITUTION:Magnetic alloy is pulverized into fine powder whose particles are approximately unit magnetic domains. The fine alloy powder is sintered and molded at a low temperature range not less than 250 deg.C and not higher than 400 deg.C under the air or a simple atmosphere control while a high pressure not less than 3000kg/cm<2> is applied. Then the fine alloy powder is impregnated with resin during or after the pressurized sintering and molding process. A resin magnet obtained with this constitution is composed of unit magnetic domains by fine pulverization and is molded at a higher temperature than the magnet molded by a conventional resin molding so that high density, high accuracy and high strength can be provided and high maximum energy product can be obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a resin magnet manufacturing method.

[Conventional technology]

A conventional resin magnet manufacturing method involves dispersing a powdered magnet alloy in a resin, and molding the resultant in a mold at high temperature and pressure to obtain a molded body.

However, this type of manufacturing method has the problem that the magnetic alloy particles cannot be filled and solidified with a sufficiently high density, resulting in insufficient mechanical strength and magnetic force.

In addition, due to high temperature sintering, it is necessary to create an inert atmosphere to prevent oxidation loss and deterioration of the metals that make up the magnet, such as rare earth metals, making the manufacturing process and operations cumbersome. On the other hand, it had the disadvantage of being expensive.

Also, general magnets are manufactured using methods such as sintering and casting, but
These methods have insufficient machining accuracy and require finishing to produce precision parts, but many magnetic alloys are difficult to machine.

[Problems to be solved by the present invention]

The present invention has been made based on the above-mentioned viewpoints, and
The purpose is to significantly improve density, mechanical strength, and maximum energy a (MGO) compared to the conventional resin magnets mentioned above, and because it can be manufactured in air, the manufacturing process is simple and inexpensive. The object of the present invention is to provide a method for manufacturing resin magnets that allows precision molded products to be obtained.

[Means for solving problems]

Therefore, the above purpose is to provide a process of pulverizing the magnetic alloy, and heating the pulverized magnetic alloy at a temperature of 250°C or higher to 400°C.
In the low temperature range below, air or e.g. Co2 or N2
3000k with simple atmosphere control such as blowing gas
This is achieved by a resin magnet manufacturing method comprising a step of applying a high pressure of 12 g/cff or more to obtain a sintered compact, and a step of infiltrating the resin during or after the pressure molding step.

Further, in the process of obtaining the above-mentioned sintered compact, the present invention applies a magnetic flux magnet material to a predetermined position of a substrate such as the main body of an electromagnetic clutch where the case of the motor is It is desirable to sinter and form it to a predetermined size at the location and simultaneously fix it by welding or bonding.

[Function] By configuring as described above, the resin magnet produced by the method of the present invention has greater density, mechanical strength, and maximum energy product (MGO) than conventional magnets, and allows easy production of precise magnets. It can be obtained through operation.

〔Example〕

The details of the method of the present invention will be specifically explained below.

In the method of the present invention, first, in the first step, the magnetic alloy is pulverized into a substantially single magnetic domain and pulverized. After that, in the second step, the finely powdered magnetic alloy is heated in the air or under simple atmospheric control at a low temperature range of 250°C to 400°C.
A sintered compact is produced by applying a high pressure of 00 kg/cm2 or more. Next, in the third step, the resin is infiltrated during or after the pressure sintering and forming step.

This resin magnet is usually an anisotropic resin magnet molded product,
Molded using a resin magnet material by magnetic field orientation compression molding. In this case, sintering is performed in a magnetic field in the pressing direction or in a direction perpendicular to the pressing direction, if necessary.

As the magnet alloy, rare earth magnets such as barium ferrite, strontium ferrite, or samarium cobalt are typically used.

Further, as the resin, typically used are polyamide resin, polypropylene, polyvinyl chloride, polyethylene chloride, thermoplastic resin such as synthetic rubber, or thermosetting resin such as epoxy resin.

The resin magnet obtained by this method is made into a single magnetic domain size by pulverization, and is molded at a higher temperature than conventional resin molding methods, resulting in high density, high precision, high strength, and a high maximum energy product ( MGO) is obtained.

Example 1 In Example 1, a magnet alloy of 5lTIIco5 material is pulverized into fine powder having a center diameter of approximately 5 μΦ by a conventional method.

The resulting fine powder of the above magnetic alloy is filled into a mold so that it is densely and evenly distributed, and tapped in the magnetic field of IKOe (excess fine powder is removed to reduce the amount filled each time). .

After that, a pressure of 5000 kg/cm'' was applied to the fine powder of the magnetic alloy in the mold in the atmosphere at a temperature of 280°C and held for 1 minute. As a result, the Sm1CO5 material was sintered to a density of 85%. A molded product was produced.Next, in this sintering molding, a magnet with the desired performance was obtained with good workability, with little deterioration or wear and tear such as oxidation of the magnet materials Sm and Co.This pressure molding mold 1000+ polyamide resin inside
Injection impregnation under pressure at r/cm2.

Further, during this filling molding, it is desirable to apply appropriate ultrasonic vibration or impact.

The resulting resin magnet has a heat resistance of approximately 120°C, a maximum energy bond of 17M G O1, and a tensile strength of 23°C.
It was 7 kg/mm2. In addition, the corrosion resistance when immersed in water is about 100% higher than that of non-resin sintered magnets.
doubled.

Example-2 In Example-2, S
A magnetic alloy of ml CO5 material is pulverized into a fine powder with a center diameter of about 5μφ.

Furthermore, the fine powder of the above magnetic alloy obtained in the same manner as in Example-■ was filled into a mold so as to be densely and evenly distributed, and
Tasoping in the magnetic field of KOe.

Thereafter, in the same manner as in Example 1, in the atmosphere, the inner wall surface portion of the motor case where the stator magnet is attached is brought into contact with one open end of the mold, and the fine powder of the magnet alloy in the mold is heated. A pressure of 5000 kg/cm2 was applied at a temperature of 280°C and held for 1 minute. As a result, a sintered molded product made of the 5IIIIC05 material with a density of 85% could be produced in a state where it was integrally bonded and fixed to the inner wall surface of the motor case at the portion where the stator magnet was to be attached. Wear and deterioration of the magnet material were small because the magnet material was sintered and formed at a low temperature, as described above.

Next, after this pressure molding process, 1 portion of LCP resin heated to 300°C was poured into the molded body in the mold kept at a temperature of 180°C.
Inject under pressure at 1,000 kg/am.

The obtained resin magnet has a heat resistance of approximately 300°C, a maximum energy product of 18 M GO, and a tensile strength of 23
It was 16 kg/mm2 at °C. Also, Example-1
It also showed high corrosion resistance.

The structure of the present invention is not limited to the above-mentioned embodiments. For example, although Sml CO5 material is used as the magnet alloy, other known magnet alloys may be used, and polyamide material may be used as the resin material. Although resin and LCP are used, other known resin magnets may also be used. Further, the present invention can be used arbitrarily for soft resin magnets, semi-hard resin magnets, etc., and the present invention includes all modifications that can be easily conceived by a person skilled in the art from the above description within the scope of its purpose. Examples are inclusive.

〔Effect of the invention〕

The present invention is constructed as described above, and since the present invention is sintered and formed at low temperature and high pressure, it can be manufactured in the atmosphere and is different from conventional resin magnets. In comparison, accuracy, magnetic properties, and mechanical strength can be improved, and the maximum energy product (CMGO) can be greatly improved.

Claims (1)

[Claims] A step of pulverizing a magnetic alloy, and forming a compact by applying a high pressure of 3000 kg/cm^2 or more to the pulverized magnetic alloy at a temperature range of 250°C to 400°C. A method for manufacturing a resin magnet, comprising: a step of obtaining the resin, and a step of infiltrating the resin during or after the pressure molding step.