JPH0748937B2 - Method for producing magnetically anisotropic conductive material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention does not change the magnetic permeability depending on the position, so that the space factor of the magnetic material can be improved and the space ratio of the magnetic material and the conductive material can be easily set. The present invention relates to a method of producing a magnetically anisotropic conductive material, which can produce a magnetically anisotropic material that can be produced by a simple process.

[Prior Art and Problems] As a magnetic anisotropic conductive material, for example, there is a material used for an induction motor as disclosed in JP-A-57-46656. 7 and 8 show examples of magnetic anisotropic conductive materials used as members constituting the rotor 20 of the induction motor, and the rotor 20 has an energization jacket coaxial with the rotating shaft. twenty one
And a rotor core 22 are provided. As shown by the enlarged portion Q, the energization jacket 21 has an iron wire 24 made of a magnetic material extending in the radial direction and a copper material 25 made of a conductive material filling the space between them.
The main part is made of a magnetic anisotropic conductive material.

With the above configuration, a rotor having a radial magnetic permeability μr larger than the circumferential magnetic permeability μθ (μr >> μθ) and a small axial resistivity ρz can be obtained. Here, when this induction motor is driven, magnetic coupling with less magnetic fluctuation is obtained between the stator and the stator due to the large magnetic permeability μr with little variation in the radial direction, and driving with less vibration noise can be performed. Moreover, since the winding is omitted from the rotor, it is possible to reduce the size and weight.

Further, the magnetic permeability and the resistivity can be controlled according to the space factor of the magnetic material and the conductive material.

FIG. 9 shows the relationship between the space factor of the magnetic material in the conductive material and the electromagnetic property from one experimental result.

This magnetic anisotropic conductive material is, for example, a large number of iron or steel magnetic materials having a predetermined length in the radial direction are radially arranged, and a conductive material such as copper or aluminum is cast between them. It is molded.

However, according to the above-described method for manufacturing the magnetic anisotropic conductive material, it is difficult to radially arrange the magnetic materials, which may disturb the alignment of the magnetic materials. Therefore, a uniform magnetic permeability is obtained. It is difficult to manufacture the magnetically anisotropic conductive material described above, and when the arrangement density of the magnetic materials is increased in order to improve the space factor of the magnetic materials (specifically, for example, they are closely packed and arranged), Not only the gap between the magnetic materials becomes smaller, but sometimes they may come into contact with each other, so that the permeability of the molten conductive material deteriorates, forming cavities inside the molded product, and degrading the characteristics due to uneven magnetic permeability. There is a problem that occurs. Therefore, in the conventional manufacturing method, the space factor of the magnetic material is limited to 20 to 30%. Further, in this casting method, there is a problem that the oxidation of the steel wire surface has a great influence on the permeability and adhesion state of copper, and as a result, the higher the density of the magnetic material made of iron wire or steel wire, the more difficult it becomes to cast. is there.

[Object of the Invention] The present invention has been made in view of the above, and has a uniform magnetic permeability as a whole without generation of cavities and characteristic deterioration, and
To provide a method for producing a magnetic anisotropic conductive material capable of easily producing a magnetic anisotropic conductive material capable of improving the space factor of the magnetic material and setting the space factor of the magnetic material and the conductive material by a simple process. With the goal.

[Summary of the Invention] In the method for producing a magnetic anisotropic conductive material of the present invention, a large number of composite wires coated with a conductive material on the circumference of a magnetic material are densely arranged in a certain direction, and It is characterized in that the gap is filled with a powder of the same conductive material as the conductive material, and then the whole is heated and pressurized to be metallurgically integrated.

Further, another method for producing a magnetic anisotropic conductive material of the present invention is to set a central axis, and to arrange a large number of composite wires coated with a conductive material on the circumference of the magnetic material with the central axis as the center. Radially closely aligned in a radial direction and filling the gaps of these composite wires with a powder of the same conductive material as the above-mentioned conductive material, and then heating and pressing the whole to metallurgically integrate them. It is characterized by.

In the present invention, as the composite wire in which the conductive material is coated on the circumference of the magnetic material, for example, copper-covered steel or steel wire, aluminum-covered steel or steel wire is used, and therefore, as the conductive material powder, copper is used. Powder or aluminum powder is used. It should be noted that the powder of the conductive material also includes a slurry in which a binder is contained in the powder.

Metallurgically unifying means that the metals are literally in a metal-bonded state, and simply keeping the metals in a mechanically bonded or mixed state is usually said to be metallurgically united. Absent. Although a slurry-like powder containing a binder is originally not preferable from the viewpoint of quality, it has the following advantages from the viewpoint of manufacturing technology. That is, it is generally technically very difficult to arrange a number of composite wires in a powder in a certain direction and stack them, but the powder does not contain a binder properly. If it is in the form of a slurry, such alignment work can be performed relatively easily. That is, when the slurry type is used, there is an advantage that the composite wire can be easily positioned and, as a result, the composite wire can be easily arranged and arranged.

In addition to using slurry-like powder as the powder for such alignment work, spacers made of the same conductive material as the powder can be used to prevent deviation of the composite wire and facilitate alignment work. Has a great effect on These spacers serve as so-called spacers or carriers that prevent the composite wires from being easily displaced when the composite wires are aligned and arranged, and after heating and pressing, they are integrated with the powder into the composite wires. The role of the spacer is over.

[Examples] The present invention will be described below with reference to Examples shown in Figs. 1 to 6.

First, as a composite wire in which a conductive material is coated on the circumference of a magnetic material, as shown in FIG. 3, a steel wire 1 having a diameter of 1.4 mm and a copper coating 2 on the circumference of a composite wire 3 having an outer diameter of 1.6 mm 3 are used. The composite wire 3 is cut into a length of 25 mm, and a required number of the composite wire 3 is prepared and surface treatment is performed by washing.

On the other hand, as the powder of the conductive material, a copper slurry is prepared in which a 3% aqueous solution of methylcellulose is contained as a binder in copper powder having a particle size of 350 mesh and kneading is performed to add 30cc of methylcellulose to 100g of the copper powder. .

After completing the above preparation, the composite wire 3 and the copper slurry 5 (see FIG. 4) are packed in the pressurizing device 4 shown in FIG. 1, and pressurization is performed by the powder metallurgy method.

That is, first, 65 g of copper slurry 5 is put into an annular space 8 formed between a mold core (outer diameter 54 mm) 6 and a mold case (inner diameter 112 mm) 7 of the pressurizing device 4 and laid smoothly. .
In order to lay the copper slurry 5 evenly, it is advisable to lightly press the copper slurry 5 using the pressing die 9.

Next, when the copper slurry 5 is smoothed, 106 composite wires 3 are radially and densely arranged in a radial direction around the core 6 as shown in FIG. In the case of this example, this alignment work was done manually by marking on the smoothed copper slurry. After this is completed, the pressing wire 9 is used again to push the composite wire 3 into the copper slurry 5 to fix it. By alternately inserting the copper slurry 5 and the composite wire 3 into the annular space 8 in the same manner, a large number of composite wires 3 are stacked three-dimensionally while filling the gaps between the composite wires with copper slurry. Go. FIG. 4 shows a part of this in cross section.

FIG. 1 shows a state in which the composite wire 3 and the copper slurry 5 are densely packed up to a predetermined height in the annular space 8. In this way, the composite wire 3 and the copper slurry 5 are put into an atmosphere furnace with an indoor temperature of 50 to 100 ° C. as they are. Preheat for 24 hours. 10 is a heater for the atmosphere furnace. After the preheating is completed, the composite wire 3 and the copper slurry 5 in the annular space 8 are pressed using the pressing die 9 and the hydraulic cylinder 11. After pressing, the room temperature is now 900-1000 ℃
After holding in the atmosphere furnace for 2 hours and holding for 2 hours, pressing is performed again. This method itself may be considered to be the same as the method for pressure-sintering powder (metal).

After the pressurization and sintering are completed in this way, the temperature is lowered, and the product is finished into a predetermined shape and size and used as a magnetic anisotropic material.

Here, since the filling amount of the copper slurry is related to the space factor of the magnetic material as well as the coating thickness of the composite wire 3, the size of the composite wire 3, the product formed of the magnetic anisotropic material, for example, the shape of the rotor, It is desirable to adjust it arbitrarily according to the performance.

FIG. 5 and FIG. 6 respectively show examples in which the copper powder 12 is used instead of the copper slurry. in this case,
As is clear from the above explanation, it is very difficult to align and stack composite wires in the powder (the position of the composite wires is easily misaligned and not stable). Composite wire 3 using spacers 13 or 14 of
It is intended to stabilize the position of. It is desirable to use the grooved spacer 14 as shown in FIG. 6 from the viewpoint of preventing the positional deviation of the composite wire 3 to the left and right. Since the spacers 13 and 14 are sintered together with the copper powder after pressure sintering, when looking at the product of the magnetic anisotropic conductive material, the spacers 13 and 14 are
The existence of 14 is unknown.

In addition to the above, pressing by powder metallurgy includes hot isostatic pressing (Hot Isostatic Press), but if this method is used for pressing and sintering under the following conditions, the bending strength and hardness are improved. Therefore, it can be expected that the quality of the material will be improved.

・ Sky: 0.1-0.01mmHg ・ Pressure: 1000-2000Kg / cm ²・ Heating temperature: 500-900 ℃ ・ Time: 2-5Hr In the above examples, magnetic materials were mainly installed radially in the radial direction. Although the magnetic anisotropic material having a structure has been described, it goes without saying that the present invention can be applied to a magnetic anisotropic material having a structure in which magnetic materials are arranged in parallel.

[Effects of the Invention] As described above, according to the method for producing a magnetic anisotropic conductive material of the present invention, since a composite wire in which a conductive material is coated on the periphery of a magnetic material is used as a material, the occurrence of cavities and Magnetic anisotropy that has a sound structure with no deterioration of properties, has a uniform magnetic permeability overall, and can easily improve the space factor of the magnetic material and set the space ratio of the magnetic material and the conductive material. The conductive material can be manufactured by a simple process, for example, by arranging the composite wires densely and facilitating the alignment work.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of a method for producing a magnetic anisotropic material of the present invention, FIG. 2 is a sectional view taken along the line AA ′ in FIG. 1, FIG. 3 is a structural explanatory view of a composite wire, and FIG. 1 is an enlarged sectional view taken along line BB 'in FIG. 1, FIGS. 5 and 6 are explanatory views of another embodiment of the method of the present invention, and FIG. 6 is an explanatory view of another embodiment of the method of the present invention, and FIG. FIG. 7 is a partially cutaway perspective view showing an electromechanical component,
8 is an enlarged perspective view showing the inside of the Q frame of FIG. 7. FIG. 9 is a curve diagram showing the relationship between the space factor of iron and the rate at that time and the resistivity. 1: Copper wire, 2: Copper coating, 3: Composite wire, 4: Pressurizing device, 5: Copper slurry, 6: Mold core, 7: Mold case, 8: Annular space, 9: Stamping mold,
10: Heater, 11: Hydraulic cylinder, 12: Copper powder, 13, 14: Spacer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kainuma 1500 Kawajiri-cho, Hitachi City, Ibaraki Prefecture Toraura Plant, Hitachi Cable Co., Ltd. (72) Inventor Takeshi Seya 1500 Kawajiri-cho, Hitachi City, Ibaraki Hitachi Cable Co., Ltd. In Toyoura Factory (56) Reference JP-A-57-46656 (JP, A)

Claims (2)

[Claims] 1. A plurality of composite wires coated with a conductive material on the circumference of a magnetic material are densely arranged in a fixed direction, and a powder of the same conductive material as the conductive material is placed in the gap between the composite wires. A method for producing a magnetically anisotropic conductive material, which comprises filling and then heating and pressurizing the whole to be metallurgically integrated. 2. A center axis is set, and a large number of composite wires coated with a conductive material on the circumference of a magnetic material are radially and densely arranged in a radial direction centered on the axis and these composite wires are arranged. A method for producing a magnetic anisotropic conductive material, characterized in that a gap between lines is filled with a powder of the same conductive material as the above-mentioned conductive material, and then the whole is heated and pressed to be metallurgically integrated.