KR20190007496A - Metal plate laminate and manufacturing method thereof - Google Patents

Abstract

A step of laminating a plurality of metal plates, wherein the laminated metal plate has a slot parallel to the thickness direction of the metal plate, inserting a laminated insulating sheet formed by laminating aramid paper and a resin film in the slot, And a step of introducing skew by changing an angle and rotating the metal plate.

Description

Metal plate laminate and manufacturing method thereof

The present invention relates to a laminated body obtained by laminating a plurality of metal plates, in which an insulating sheet composed mainly of aramid paper is inserted in a slot and skew is introduced, and a method of manufacturing the laminated body, And a manufacturing method thereof.

For insulation between the slot and the coil in the stator or the rotor of the motor, a sheet-like insulating material or a resin coating method is used. When an insulating layer is formed by resin coating, a method of spraying a powder of a thermosetting resin and fixing at a high temperature is widely used. In the case of using a thermosetting resin, it is necessary to provide a dust-proofing facility which considers the safety of the operator and a curing furnace to be used for curing after resin injection. Compared to the case where the insulating sheet is adapted, since the curing furnace is used, the energy consumption is also large. When spraying the powdered resin, it is possible to form an insulating layer having a uniform thickness on the smooth surface. However, in the case of an entangled structure such as a slot, the insulating layer at the angled portion such as the end of the slot tends to be thin . For this reason, it is necessary to increase the thickness of the whole powdery resin injection. However, if the insulating layer becomes thicker, the drop rate of the coil is lowered so that the efficiency is lowered.

On the other hand, when a sheet-like insulating material is used for the insulating layer, insertion is performed in a state where the sheet-like insulating material on the strip is bent in the slot of the stator or rotor so as to conform to the shape of the slot. In the case of the sheet-like insulating material, since the insulating layer becomes thinner than when the powdered resin is sprayed, the motor can be made smaller and higher in efficiency. Insertion is widely used for continuous insertion by an automatic insertion machine with high efficiency. However, in the case of the skewed slot, since the shape of the slot is not linear, it is difficult to insert the sheet-like insulating material by the automatic inserter. Japanese Unexamined Patent Application, First Publication No. H9-196033 discloses a method of inserting an insulating sheet in a state in which a slot before skew introduction is linear and then applying a twist to the laminated steel sheet to introduce skew together with the insulating sheet. When the twist is applied, the distance between one end and the other end of the slotted end is widened. At this time, the inserted insulating sheet needs to follow the slot.

In many cases, a resin film such as a polyethylene naphthalate film or a polyethylene terephthalate film is used for the insulating sheet. In the case of using these resin films as a single unit, there is a problem that cracks and tears of the resin film are likely to occur because the angle of the slot opening portion or burr becomes a starting point. Japanese Patent Laying-Open No. 2006-197662 discloses a stator having a skew made of a laminated film of a polyethylene naphthalate (PEN) film and a polyphenylene sulfide (PPS) film as an insulating sheet.

It is an object of the present invention to provide a metal laminate body in which a high heat-resistant insulating sheet made of aramid paper and a resin film is adapted to a slot of a metal plate laminate having skew, a method of manufacturing the same, and a rotor and a stator .

The present invention includes the following aspects.

1. A process for laminating a plurality of metal plates, wherein the metal plates laminated have slots parallel to the thickness direction of the metal plate,

Inserting a laminated insulating sheet formed by laminating an aramid paper and a resin film in the slot,

A step of introducing a skew by rotating the stacked metal plate at an angle

Wherein the metal plate is a metal plate.

2. The method for producing a metal plate laminate according to the above 1, wherein the laminated insulating sheet has a two-layer structure in which aramid paper is laminated on one side of a resin film.

3. The method for producing a metal plate laminate according to the above 1, wherein the laminated insulating sheet has a three-layer structure in which aramid paper is laminated on both sides of a resin film.

4. The method of producing a laminated sheet according to any one of 1 to 3 above, wherein the laminated insulating sheet has a breaking elongation at room temperature of 15% or more.

5. The method for producing a laminate of metal sheet according to any one of 1 to 4 above, wherein the laminated insulating sheet has a thickness of 30 mu m to 2000 mu m.

(A) a plurality of laminated metal plates, wherein the laminated metal plates have slots parallel to the thickness direction of the metal plate and the slots are inclined at a predetermined angle with the rotation axis; and (b) A laminated insulating sheet including at least one resin and a resin film,

And a metal plate laminated body.

7. The metal plate laminate according to 6 above, wherein the laminated insulating sheet (b) has a two-layer structure in which aramid paper is laminated on one side of the resin film.

8. The metal plate laminate according to 6 above, wherein the laminated insulating sheet (b) has a three-layer structure in which aramid paper is laminated on both sides of a resin film.

9. The metal plate laminate according to any one of 6 to 8 above, wherein the laminated insulating sheet (b) has a breaking elongation at room temperature of 15% or more.

10. The metal plate laminate according to any one of 6 to 9 above, wherein the laminated insulating sheet (b) has a thickness of 30 占 퐉 to 2000 占 퐉.

11. A stator or rotor comprising the metal plate laminate according to any one of the items 6 to 10 above.

1 is a metal plate laminate model of Example 1. Fig.
2 is a photograph of a metal plate laminate on which skew is formed.
3 is a cross-sectional view showing an example of a laminated insulating sheet having a three-layer structure.

(Laminated insulating sheet)

The laminated insulating sheet is a laminated sheet having at least two layers or more laminated sheets obtained by bonding one side or both sides of a resin film to an aramid paper. 3 is a cross-sectional view showing an example of a laminated insulating sheet having a three-layer structure. The laminated insulating sheet 10 has a three-layer structure of aramid paper-resin film-aramid paper in which the aramid paper 11 is adhered to each of the front surface and back surface of the resin film 12.

The thickness of the insulating laminated sheet is preferably 30 占 퐉 to 2000 占 퐉, preferably 35 占 퐉 to 600 占 퐉, and more preferably 40 占 퐉 to 200 占 퐉.

The elongation at break of the laminated insulating sheet at room temperature is preferably 15% or more, and more preferably 20% or more.

A two-layered product obtained by bonding one sheet of resin film and one sheet of aramid paper can provide a thin insulating layer, so that the motor and the generator can be miniaturized. Since aramid has excellent long-term heat resistance as compared with general-purpose resin films, it is preferable to dispose aramid paper on the side which becomes higher in temperature. Since the three-layered laminated insulating sheet having a structure in which one sheet of resin film is supported by sandwiching two sheets of aramid paper has an object structure in the thickness direction, there is an advantage that warping does not easily occur even after bonding, Is also suitable for use.

(Method for manufacturing laminated insulating sheet)

Adhesion of the aramid paper to the resin film can be carried out using an adhesive. The adhesive is not particularly limited, and a commercially available epoxy resin type, phenol resin type or acrylic resin type curing type adhesive can be used. The adhesive may be applied or impregnated to either or both of the resin film and the aramid paper to bond the resin film and the aramid paper.

(Aramid)

In the present invention, aramid means a linear polymer compound in which at least 60% of amide bonds are directly bonded to aromatic rings. Examples of such an aramid include, for example, polymetaphenylene isophthalamide and copolymers thereof, polyparaphenylene terephthalamide and copolymers thereof, and copolypaphenylene 3,4'-diphenyl ether terephthalamide and the like. .

These aramids are industrially produced by, for example, a solution polymerization method by a condensation reaction with an aromatic acid dicarboxylic acid and an aromatic diamine, a two-stage interfacial polymerization method and the like, and they are available as commercial products, no. Of these aramids, poly (metaphenylene isophthalamide) is preferable in that it has good molding processability, flame retardancy and heat resistance.

(Aramid Fibreid)

In the present invention, an aramid fibril is a film-like microparticle containing an aramid and may be referred to as an aramid pulp. Examples of the production method include those described in Japanese Patent Publication No. 35-11851, Japanese Patent Publication No. 37-5732, and the like. The aramid fiber reed has the same superabsorbent properties as ordinary wood pulp, so it can be dispersed in water and then formed into a sheet form by a paper machine. In this case, so-called high-temperature treatment can be carried out for the purpose of maintaining a quality suitable for grass. This treatment can be carried out by disc refiner, beater, and other paper cutting machines with mechanical cutting action. In this operation, the change in the shape of the flew leads can be monitored with the Yeosu degree (freeness) specified in JIS P8121.

In the present invention, it is preferable that the freeness of the aramid fleece after the high-temperature treatment is in the range of 10 to 300 cm 3 (Canadian Standard Freeness). By controlling the freeness degree to 300 cm 3 or less, the strength of the sheet to be formed from the sheet becomes high. By setting the freeness to 10 cm 3 or more, utilization efficiency of the mechanical power to be input can be increased, and the throughput per unit time can be increased. In addition, appropriate fine fibrillation can be realized and deterioration of binder function is suppressed.

(Aramid staple fibers)

In the present invention, aramid staple fiber is a fiber obtained by cutting an aramid-based fiber to a predetermined length. Examples of such fibers include "NOMEX (registered trademark)", "Kevlar (registered trademark) (Registered trademark) " and " TECOLOR (registered trademark) " of Deijin Co., Ltd., but the present invention is not limited thereto.

The aramid staple fibers may preferably have a fineness in the range of 0.05 dtex to less than 25 dtex. Fibers having a fineness of 0.05 dtex or more are less prone to agglomeration in manufacturing (described below) in the wet process, and the fibers having a fineness of less than 25 dtex have a suitable fiber diameter. For example, when the density is 1.4 g / cm and the diameter is 45 micrometers or more, there is a fear that the aspect ratio is lowered, the mechanical reinforcement effect is reduced, and the uniformity of the aramid paper is poor.

The length of the aramid short fibers is preferably selected in the range of 1 mm or more and less than 25 mm. If the length of the short fibers is 1 mm or more, the mechanical properties of the aramid paper become sufficient. If the length of the short fibers is less than 25 mm, the occurrence of entanglement, binding, and the like at the time of producing the aramid paper in the wet method described later can be suppressed.

(Aramid paper)

In the present invention, the aramid paper is a sheet-like article composed mainly of the above-mentioned aramid fibril and aramid staple fibers, and generally has a thickness of 20 탆 to 1000 탆, preferably 25 탆 to 500 탆, And has a thickness of 30 mu m to 100 mu m.

The aramid paper has a basis weight of generally 10 g / m 2 to 1000 g / m 2, preferably a basis weight of 15 g / m 2 to 400 g / m 2, more preferably 20 g / m 2 to 100 g / m 2. Here, the mixing ratio of the aramid fibril and the aramid staple fibers may be arbitrarily selected, but it is preferable that the ratio (mass ratio) of the aramid fibril / aramid staple fibers is 1/9 to 9/1, 8 to 8/2, but it is not limited to this range.

The aramid paper is generally produced by mixing the above-mentioned aramid fiber lid and aramid staple fiber followed by sheeting. Specifically, for example, there are a method of dry-blending the aramid fiber lid and the aramid staple fiber followed by forming a sheet using an air current, a method of dispersing and mixing the aramid fiber lid and the aramid staple fiber in a liquid medium, A method of discharging a liquid onto a support, for example, a net or a belt to form a sheet, and drying the liquid except for the liquid. Among them, a wet aging method using water as a medium is preferably selected.

In the wet embedding method, an aqueous slurry of a single or a mixture containing at least aramid fibrids and aramid staple fibers is fed and dispersed in a paper machine, followed by dewatering, embedding, and drying. Examples of the paper machine include a paper machine, a paper machine, an inclined paper machine, and a combination paper machine in combination. In the case of production in a combination paper machine, a composite sheet containing a plurality of strands can be obtained by sheet-forming and combining slurries having different blending ratios. Additives such as a dispersant improver, antifoaming agent, and soil strength enhancer are used at the time of nailing.

The aramid obtained as described above can be thermally pressurized at a high temperature and a high pressure between a pair of rolls to improve density and mechanical strength. For example, in the case of using a metal roll, the conditions of the hot pressure may be within the range of 100 to 400 占 폚 and linear pressure of 50 to 400 kg / cm, but are not limited thereto. A plurality of aramid papers may be laminated under heat pressure. The above-described hot-press working may be performed a plurality of times in an arbitrary order.

(Resin film)

As the resin film in the present invention, a polyethylene terephthalate film, a polyethylene naphthalate film, and a polyphenylene sulfide film can be used. The resin film preferably has a breaking elongation at room temperature of 60% or more, more preferably 100% or more, and more preferably 150% or more. The thickness is not particularly limited, but is preferably 10 Mu m to 1000 mu m, more preferably 20 mu m to 600 mu m, more preferably 30 mu m to 200 mu m, and still more preferably 30 mu m to 100 mu m. As such a film, for example, "Teflex (registered trademark)", "Teijin (registered trademark) Tetron (registered trademark), film", "Teonex (registered trademark)" of Deijin Du Pont Film Co., And "Trainer (registered trademark) film" of Toray Co., Ltd., but the present invention is not limited thereto.

(Rotor, stator)

A motor is a device that converts electrical energy into kinetic energy using magnetic repulsion between the rotor and the stator. In the case of a driving motor or a small motor such as an automobile, a coil is introduced into a slot of a rotor or a stator, and a method of rotating the rotor by flowing current is used Widely used. A metal conductor or a magnet is used for the rotor or the stator, but a laminate of a metal plate laminated with a thin steel plate is used particularly for reducing eddy currents. Methods for fixing the laminated metal plate include a method of applying an adhesive to each of the metal plates and bonding them together, a method of integrating the laminated plates by caulking by applying a force in the axial direction of the laminated body, and the like.

Further, in order to protect the coil and suppress the leakage current, it is necessary to form an insulating layer between the coil and the stator or between the coil and the rotor. The optimum insulating layer is selected according to the applied voltage or the amount of generated heat. In the present invention, a laminated insulating sheet comprising aramid paper and a resin film is used for a plurality of metal plate laminated bodies.

(Skew)

In a DC motor, when the slot is parallel to the rotating shaft, the torque in the rotating direction varies depending on the position of the rotor, which may cause noise or vibration of the motor. By imparting an angle to the rotation axis of the slot, the electromagnetic force generated by flowing a current through the coil is dispersed over a wide range, so that it is possible to reduce the fluctuation of the torque at the time of rotation. The state of the slanted slot with an angle to the rotation axis of the slot is referred to as skew. There are two main methods of applying skew to a rotor or a stator.

One is a method of laminating the metal plates by rotating them at predetermined angles when stacking the metal plates, and fixing each layer to give skew. In this case, the insertion of the coil occurs after the skew is formed. Another method of skewing is a method of skewing by shifting the respective laminated plates after the metal plates are stacked without shifting. As a method of shifting the laminated plate, there is a method in which irregularities are previously formed on each laminated plate so as to rotate at a predetermined angle, and a twist is generated in the uppermost layer and the lowermost layer after lamination, or a method in which a pin is passed through all laminated laminated plates, Thereby shifting each laminated plate. In this case, the insertion of the coil may be performed before or after skewing.

In the present invention, skew can be introduced by inserting the laminated insulating sheet into the slots of the metal plate laminate after shifting the metal plate without shifting, and then shifting each laminated plate.

Hereinafter, the present invention will be described more specifically with reference to examples. Furthermore, these embodiments are merely examples, and are not intended to limit the scope of the present invention at all.

Example

[Reference Example]

(Raw material manufacture)

A fibrid of poly (meta-phenylene isophthalamide) was produced by using a pulp particle production apparatus (wet type precipitator) composed of a combination of a stator and a rotor described in Japanese Patent Laid-Open No. 52-15621. The length-weighted average fiber length was adjusted to 0.9 mm by treating it with a stirrer and a separator. The degree of freeness of the obtained aramid fibrids was 90 cm 3. On the other hand, meta-aramid fiber (Nomex (registered trademark), mono-filament yarn of 2 denier manufactured by DuPont) was cut to a length of 6 mm (hereinafter referred to as "aramid staple fibers").

(Preparation of aramid paper)

The aramid fibrids and the aramid short fibers prepared as described above were dispersed in the respective water to prepare a slurry. These slurries were mixed so that the aramid fibrids and the aramid staple fibers had a blending ratio (weight ratio) of 1/1, and the sheet product was produced at the initial stage of tapping (sectional area of 625 cm 2). The basis weight and thickness of the aramid paper were adjusted by changing the amount of slurry. Subsequently, this was subjected to a pressure treatment at a temperature of 330 DEG C and a linear pressure of 300 kg / cm with a calender roll made of metal to obtain aramid paper as shown in Examples 1 and 2 and Comparative Examples 1 and 2 in Table 1.

[Example 1]

(Basis weight: 27.2 g / m 2, thickness: 0.042 mm, density: 0.64 g / cm 3) and a polyethylene terephthalate film (manufactured by Daikin DuPont Films Co., (Registered trademark) FT, thickness 50 탆, and elongation at break of 220% at room temperature) were bonded with an adhesive to obtain a three-layer laminate of aramid paper-polyethylene terephthalate film-aramid paper. The main characteristics of the thus obtained laminate were evaluated by the following methods.

[How to measure]

(1) Basis weight, thickness, density

This was carried out in accordance with JIS C 2323-2, and the density was calculated by (basis weight / thickness).

(2) Tensile strength, elongation at break at room temperature

JIS C 2323-2.

(3) Rupture during skew formation

The elongation of skew was measured using a metal plate laminate model simulating a rotor of a motor. As shown in Fig. 1, the model of the metal plate laminate body is composed of 50 sheets of stainless steel disks each having a thickness of 2 mm and a diameter of 100 mm, and a central shaft 3 for rotatably supporting the rotating shaft 3, And a top cover 4 to which a handle 5 is attached. Each metal plate is provided with a slot 2 at the same position of the circumference. A screw hole 7 is formed in the upper cover 4 on the upper side of the slot 2 and the base 6 on the lower side.

By rotating the upper handle 5 in the circumferential direction, a rotating column connected to the upper lid 4 rotated the metal plates at the same angle to form a skew. The laminated insulating sheet 8 on which the holes 9 are opened is inserted along the curved surface of the slot 2 and the holes 9 of the laminated insulating sheet and the holes of the upper lid 4 and the base 6 7) and fixed with a screw and washer. The handle was rotated up to 60 占 to check whether the laminated insulating sheet 8 was broken.

[Example 2]

(Basis weight: 41.2 g / m 2, thickness: 0.058 mm, density: 0.71 g / cm 3) and a polyethylene terephthalate film (manufactured by Daikin DuPont Films Co., (Registered trademark) FT, thickness 80 占 퐉, and elongation at break at room temperature of 220%) were bonded with an adhesive to obtain a two-layer laminate of an aramid paper-polyethylene terephthalate film. The main characteristics of the thus obtained laminate were evaluated in the same manner as in Example 1. [

[Comparative Example 1]

Aramid paper (basis weight: 115 g / m 2, thickness: 0.134 mm, density: 0.86 g / cm 3) produced by the method described in Reference Example was evaluated in the same manner as in Example 1.

Table 1 shows the results of the rupture at the time of skew formation in Examples 1 and 2 and Comparative Example 1. [ As shown in Table 1, it has been found that the elongation at breakage is significantly improved by bonding a polyethylene terephthalate film to an aramid paper as compared with an aramid paper having an equivalent thickness. From the above results, when the insulating sheet is adapted to the skewed metal plate laminate, it is considered effective to use an insulating sheet having a large elongation as shown in the examples. Since the obtained three-layer insulating sheet has a structure in which aramid paper is disposed on the surface, it is expected to be used as a rotor or a stator of a motor which requires high heat resistance.

1: Metal plate laminate model
2: Slot
3:
4: Top cover
5: Handle
6: Foundation
7: Vis hole
8: Insulation sheet on strip
9: hole
10: laminated insulating sheet
11: Aramid paper
12: Resin film

Claims (11)

A step of laminating a plurality of metal plates, wherein the laminated metal plate has slots parallel to the thickness direction of the metal plate,
Inserting a laminated insulating sheet formed by laminating an aramid paper and a resin film in the slot,
A step of introducing a skew by rotating the stacked metal plate at an angle
Wherein the metal plate is a metal plate. The method of manufacturing a laminated sheet according to claim 1, wherein the laminated insulating sheet has a two-layer structure in which aramid paper is laminated on one side of a resin film. The method of manufacturing a laminated sheet according to claim 1, wherein the laminated insulating sheet has a three-layer structure in which aramid paper is laminated on both sides of a resin film. The method of producing a laminated sheet according to any one of claims 1 to 3, wherein the laminated insulating sheet has a breaking elongation at room temperature of 15% or more. The method according to any one of claims 1 to 4, wherein the laminated insulating sheet has a thickness of 30 占 퐉 to 2000 占 퐉. (a) a plurality of stacked metal plates, wherein the stacked metal plates have slots parallel to the thickness direction of the metal plate and the slots are inclined at a constant angle with the rotation axis, and
(b) a laminated insulating sheet comprising at least one layer of aramid paper and a resin film inserted in the slots,
And a metal plate laminated body. The metal plate laminate according to claim 6, wherein the laminated insulating sheet (b) has a two-layer structure in which aramid paper is laminated on one side of a resin film. The metal plate laminate according to claim 6, wherein the laminated insulating sheet (b) has a three-layer structure in which aramid paper is laminated on both sides of a resin film. 9. The metal plate laminate according to any one of claims 6 to 8, wherein the laminated insulating sheet (b) has a breaking elongation at room temperature of 15% or more. 10. The metal plate laminate according to any one of claims 6 to 9, wherein the laminated insulating sheet (b) has a thickness of 30 mu m to 2000 mu m. A stator or rotor comprising the metal plate laminate according to any one of claims 6 to 10.

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