JP2007149911A - Permanent magnet and motor equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet having insulation properties and heat resistance and capable of reducing costs, and also to provide a motor using it. <P>SOLUTION: The surface of an R-Fe-B based permanent magnet element 2 is covered with a sheet-like package member 3 having a hot gluing resin layer 4 such as thermally denatured polypropylene, and a heat resistant resin layer 5 such as biaxially oriented polyethylene naphthalate stacked thereon. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a permanent magnet having insulation properties and heat resistance and a motor using the same.

  Many electric appliances use a motor with a permanent magnet. In addition, electric vehicles (EV) and hybrid electric vehicles (HEV) use motors having permanent magnets at various sites such as driving and wheel assembly. These permanent magnets are required to have insulating properties in order to prevent generation of eddy currents and improve motor efficiency.

  Further, in these products, a cooling device such as a fan is provided in order to prevent a temperature rise in a space in which the motor is arranged, which hinders downsizing of these products. For this reason, a motor with heat resistance that can omit the cooling device is required. Furthermore, the ambient temperature of a motor disposed in an engine room or the like as a driving means for an electric vehicle or a hybrid electric vehicle reaches a high temperature state of about 200 ° C. or higher. For this reason, a motor with higher heat resistance is required.

Conventional permanent magnets are disclosed in Patent Documents 1 to 4. In these permanent magnets, a base metal film is formed on the surface of an R—Fe—B-based (R is a rare earth element) permanent magnet body, and a polyimide film is formed on the base metal film. Thereby, the permanent magnet provided with insulation and heat resistance can be obtained.
Japanese Patent Laid-Open No. 9-260120 (pages 2 to 5) JP-A-8-279407 (pages 2-6) Japanese Patent No. 3654807 (pages 2-8) JP 2001-167917 A (2nd page-9th page)

  However, according to the conventional permanent magnet, the base metal film is formed by plating, vapor deposition, or the like, and the polyimide film is formed by vapor deposition polymerization or thermosetting after coating. For this reason, there is a problem that the manufacturing process is complicated and expensive equipment is required, and the cost of the permanent magnet and the motor is increased. Further, when a film is formed on a part of the permanent magnet, it is necessary to perform film formation by mask sputtering, film removal by etching, or the like. For this reason, there existed a problem that an installation and man-hour increased and a permanent magnet and a motor became further expensive.

  An object of the present invention is to provide a permanent magnet having insulation properties and heat resistance and capable of reducing costs, and a motor using the permanent magnet.

  In order to achieve the above object, the permanent magnet of the present invention is characterized in that the surface of the permanent magnet body is covered with a sheet-like packaging material in which a heat bonding resin layer and a heat resistant resin layer are laminated.

  According to this configuration, the surface of the permanent magnet body is covered with the sheet-like packaging material. The packaging material is formed by laminating a heat bonding resin layer made of polypropylene (PP) or acid-modified polyolefin and a heat resistant resin layer made of polyethylene terephthalate (PET) or biaxially stretched polyethylene naphthalate. The permanent magnet element body may be covered with the thermal adhesive resin layer by adhering the packaging material to the surface of the permanent magnet element body. May be coated.

  According to the present invention, in the permanent magnet configured as described above, the thermal adhesive resin layer is provided on both surfaces of the heat resistant resin layer. According to this configuration, the permanent magnet element body can be covered by overlapping and adhering the thermal adhesive resin layer on the front surface of the packaging material and the thermal adhesive resin layer on the rear surface.

  Further, the present invention provides the permanent magnet having the above-described configuration, in which the heat-adhesive resin layer is provided on one surface of the heat-resistant resin layer, the heat-resistant temperature of the heat-resistant resin layer is set to 200 ° C. or higher, and It is characterized by a melting point of 90-150 ° C. According to this configuration, the heat resistance temperature of the permanent magnet can be set to 200 ° C. or higher, and the permanent magnet can be used in a motor for EV driving or HEV driving. Can be softened and bonded.

  According to the present invention, in the permanent magnet configured as described above, the thermal adhesive resin layer is made of an acid-modified polyolefin.

  According to the present invention, in the permanent magnet configured as described above, the thermal adhesive resin layer is made of acid-modified polypropylene, and the heat-resistant resin layer is made of biaxially stretched polyethylene naphthalate.

  In the permanent magnet having the above-mentioned configuration, the heat-resistant resin layer and the heat-adhesive resin layer are laminated via an adhesive layer containing an aminated phenol polymer, a trivalent chromium compound, and a phosphorus compound. It is said.

  According to the present invention, in the permanent magnet configured as described above, the permanent magnet body is an R-Fe-B system (R is a rare earth element).

  A motor according to the present invention is characterized by including the permanent magnets having the above-described configurations.

  According to the present invention, since the surface of the permanent magnet body is covered with the sheet-shaped packaging material in which the heat-adhesive resin layer and the heat-resistant resin layer are laminated, it is possible to easily obtain a permanent magnet having insulation and heat resistance. The cost of a motor used for driving a permanent magnet, an electric vehicle, or a hybrid electric vehicle can be reduced. Further, a part of the permanent magnet can be easily covered, and the cost of the permanent magnet partially insulated and heat-resistant can be reduced.

  Further, according to the present invention, since the heat-bonding resin layers are provided on both surfaces of the heat-resistant resin layer, the front and back surfaces of the packaging material can be easily stacked and bonded. Therefore, the adhesion portion is not projected from the permanent magnet, and the permanent magnet can be reduced in size.

  Moreover, according to the present invention, the heat-adhesive resin layer is provided on one side of the heat-resistant resin layer, the heat-resistant resin layer has a heat-resistant temperature of 200 ° C. or higher, and the melting point of the heat-adhesive resin layer is 90 to 150 ° C. The heat bonding resin layer thermally insulated by the heat resistant resin layer can be bonded at a low temperature. Accordingly, the heat resistance temperature of the permanent magnet can be set to 200 ° C. or higher, and the permanent magnet can be used for an EV driving motor or HEV driving motor, and the permanent magnet body can be easily covered.

  According to the present invention, since the heat bonding resin layer is made of acid-modified polyolefin, the adhesive force between the permanent magnet element made of an alloy and the packaging material can be improved.

  According to the present invention, since the heat resistant resin layer is made of biaxially stretched polyethylene naphthalate, the water vapor barrier property and oxygen barrier property of the packaging material can be improved, and the corrosion resistance of the permanent magnet can be improved. Moreover, since the heat bonding resin layer is made of acid-modified polypropylene, a high interlayer adhesion strength can be obtained between the biaxially stretched polyethylene naphthalate and the heat bonding resin layer.

  According to the present invention, the heat-resistant resin layer and the thermal adhesive resin layer are laminated via the adhesive layer containing an aminated phenol polymer, a trivalent chromium compound and a phosphorus compound, so that biaxially stretched polyethylene naphthalate and acid-modified Interlayer adhesion strength with polypropylene can be further improved.

  In addition, according to the present invention, since the permanent magnet element body is made of an R—Fe—B system, the permanent magnet has excellent magnetic characteristics and a highly efficient motor can be obtained.

  Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a perspective view and a cross-sectional view showing the permanent magnet of the first embodiment. In the permanent magnet 1, the surface of a prismatic permanent magnet body 2 is covered with a sheet-like packaging material 3. The permanent magnet body 2 may have other shapes such as a columnar shape, a spherical shape, and an arch shape. The permanent magnet body 2 is made of an R—Fe—B system such as Nd—Fe—B, an R—Co system such as Sm—Co (R is a rare earth element), or the like.

  When the permanent magnet 1 is used for a motor for driving an electric vehicle (EV) or a hybrid electric vehicle (HEV), an R-Fe-B permanent magnet element body 2 may be used. Thereby, the permanent magnet 1 having excellent magnetic characteristics can be obtained at a relatively low cost, and a highly efficient motor can be realized at a low price.

  The packaging material 3 has a heat bonding resin layer 4 laminated on one surface of a heat resistant resin layer 5 via an adhesive layer (not shown). The adhesive layer is applied on the heat resistant resin layer 5 and baked and dried. After drying the adhesive layer, the thermal adhesive resin layer 4 is extruded and applied on the adhesive layer with a T-die extruder to form the packaging material 3. The heat-resistant resin layer 5 and the thermoadhesive resin layer 4 are made of resin materials having thicknesses of 12 μm and 30 μm, for example, and have high insulation properties. Therefore, the permanent magnet body 2 can be easily electrically insulated from the outside.

  The permanent magnet 1 is sealed by bonding portions 3a and 3b obtained by bonding the heat bonding resin layers 4 at the end portions of the packaging material 3 together. The packaging material 3 may be adhered to the permanent magnet element body 2 by the heat bonding resin layer 4, and the packaging material 3 and the permanent magnet element body 2 may not be adhered.

  The heat-resistant resin layer 5 includes polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polymethylpentene (TPX (registered trademark)), polyacetal (POM), cyclic polyolefin, polypropylene (PP) A non-stretched or stretched film such as can be used depending on the application.

  When a material having a heat resistant temperature of 200 ° C. or higher is selected for the heat resistant resin layer 5, the heat resistant temperature of the permanent magnet 1 can be increased to 200 ° C. or higher. Thereby, the permanent magnet 1 can be used for the motor for EV drive and HEV drive which become high temperature.

Biaxially stretched polyethylene naphthalate has a melting point of 269 ° C. and a water vapor permeability of 6.7 g / (m ² · 24 hr) (thickness 25 μm, measurement method conforms to JISZ0208). For this reason, biaxially stretched polyethylene naphthalate has high heat resistance and water vapor barrier properties, and further has high oxygen barrier properties. Therefore, it is more preferable to use biaxially stretched polyethylene naphthalate for the heat resistant resin layer 5 because the permanent magnet body 2 can be prevented from being rusted and oxidized to improve the corrosion resistance of the permanent magnet 1.

  The thermoadhesive resin layer 4 is made of a thermoplastic resin that is softened by heating. Polyolefins such as polyethylene (PE) and polypropylene (PP), and acid-modified polyolefins such as acid-modified polypropylene can be used according to applications. The heat bonding resin layer 4 is thermally insulated by the heat resistant resin layer 5. For this reason, when the heat resistant temperature of the permanent magnet 1 is set to 200 ° C. or higher by the heat resistant resin layer 5 having a heat resistant temperature of 200 ° C. or higher, a material having a melting point of 90 to 150 ° C. may be selected as the heat bonding resin layer 4. it can. Thereby, the heat bonding resin layer 4 can be adhere | attached at low temperature, and the permanent-magnet body 2 can be coat | covered easily.

  In addition, since acid-modified polyolefin has high adhesive strength with metal, when acid-modified polyolefin is used as the thermal adhesive resin layer 4, the packaging material 3 can be firmly bonded to the permanent magnet body 2 made of an alloy.

  As an adhesive layer between the heat-resistant resin layer 5 and the thermal adhesive resin layer 4, triphenylmethane-4,4 ′, 4 ″ -triisocyanate, polymethylene polyphenyl polyisocyanate, tris (P-isocyanatephenyl) thiophos Fate, polyethyleneimine, a two-component curable material using polycarbodiimide as a main agent as a crosslinking agent, a material containing an aminated phenol polymer, a trivalent chromium compound, and a phosphorus compound can be used.

  The biaxially stretched polyethylene naphthalate having heat resistance can be obtained with acid-modified polypropylene and high interlayer adhesive strength by appropriately selecting the adhesive layer. For this reason, when the heat-resistant resin layer 5 is made of biaxially stretched polyethylene naphthalate, it is more preferable that the heat-adhesive resin layer 4 is made of acid-modified polypropylene because the adhesive strength between the layers is improved. In particular, an adhesive layer containing an aminated phenol polymer, a trivalent chromium compound and a phosphorus compound can remarkably improve the interlayer adhesive strength between biaxially stretched polyethylene naphthalate and acid-modified polypropylene.

  According to the present embodiment, since the surface of the permanent magnet body 2 is covered with the sheet-like packaging material 3 in which the heat bonding resin layer 4 and the heat resistant resin layer 5 are laminated, the permanent magnet having insulation and heat resistance is provided. 1 can be easily obtained. Therefore, the cost of the permanent magnet can be reduced, and the cost of a motor used for an electric appliance, a motor used for driving an electric vehicle or a hybrid electric vehicle, or for incorporating a wheel can be reduced.

  Next, FIGS. 3 and 4 are a perspective view and a sectional view showing the permanent magnet of the second embodiment. FIG. 5 is a detailed view of part A of FIG. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. In the permanent magnet 1 of the present embodiment, the permanent magnet body 2 is covered with a packaging material 3 in which a heat bonding resin layer 4 is provided on both surfaces of a heat resistant resin layer 5.

  Thereby, the packaging material 3 which covers the periphery of the permanent magnet element body 2 is folded, and the packaging material 3 is bonded by the bonding portion 3c in which the front surface and the back surface are overlapped. Further, the front surface and the back surface of the packaging material 3 are overlapped and bonded also to the folded portion (B portion in the figure). The materials and other parts of the permanent magnet body 2, the heat resistant resin layer 5 and the heat bonding resin layer 4 are the same as those in the first embodiment.

  According to the present embodiment, in addition to the same effects as those of the first embodiment, since the heat-bonding resin layer 4 is provided on both surfaces of the heat-resistant resin layer 5, the front surface and the back surface of the packaging material 3 are overlapped and easily bonded. be able to. Therefore, the bonding portions 3a and 3b (see FIG. 1) do not protrude from the permanent magnet 1, and the permanent magnet 1 can be downsized. Thereby, the motor using the permanent magnet 1 of this embodiment can be reduced in size.

  Next, FIG. 6 is a perspective view showing the permanent magnet of the third embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. In the present embodiment, the peripheral surface of the cylindrical permanent magnet body 2 is covered with the same packaging material 3 as in the first embodiment. The materials and other parts of the permanent magnet body 2, the heat resistant resin layer 5 and the heat bonding resin layer 4 are the same as those in the first embodiment.

  The packaging material 3 is bonded to the peripheral surface of the permanent magnet element body 2 with a thermal adhesive resin 4. As a result, a part of the permanent magnet 1 can be easily covered, and the cost of the permanent magnet 1 that is partially insulated and heat-resistant can be reduced. Further, the adhesive portions 3a and 3b (see FIG. 1) are not projected, and the permanent magnet 1 can be downsized. Thereby, the motor using the permanent magnet 1 of this embodiment can be reduced in size.

  It is more preferable to use an acid-modified polyolefin having a high adhesive strength with the permanent magnet body 2 made of an alloy as the thermal bonding resin 4. Moreover, you may use the packaging material 3 which provided the heat bonding resin 4 on both surfaces of the heat resistant resin 5 similarly to 2nd Embodiment. In addition, the permanent magnet body 2 may be adhered to the entire surface by a plurality of packaging materials 3, and in this case, the packaging materials 3 provided with the thermal adhesive resin 4 on both surfaces of the heat resistant resin 5 may be adhered to each other. .

  According to the present invention, it can be used for a permanent magnet that requires insulation, heat resistance and corrosion resistance. Moreover, according to this invention, it can utilize for the motor etc. which are used for the motor used for electrical appliances, the drive of an electric vehicle, a hybrid type electric vehicle, or a foil.

The perspective view which shows the permanent magnet of 1st Embodiment of this invention. Sectional drawing which shows the permanent magnet of 1st Embodiment of this invention. The perspective view which shows the permanent magnet of 2nd Embodiment of this invention. Sectional drawing which shows the permanent magnet of 2nd Embodiment of this invention. Part A detail view of FIG. The perspective view which shows the permanent magnet of 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Permanent magnet 2 Permanent magnet body 3 Packaging material 3a, 3b, 3c Bonding part 4 Thermal bonding resin layer 5 Heat resistant resin layer

Claims (8)

  A permanent magnet comprising a surface of a permanent magnet body covered with a sheet-like packaging material in which a heat-bonding resin layer and a heat-resistant resin layer are laminated.   The permanent magnet according to claim 1, wherein the thermal adhesive resin layer is provided on both surfaces of the heat resistant resin layer.   The thermal adhesive resin layer is provided on one side of the heat resistant resin layer, the heat resistant temperature of the heat resistant resin layer is 200 ° C. or higher, and the melting point of the thermal adhesive resin layer is 90 to 150 ° C. The permanent magnet according to claim 1.   The permanent magnet according to any one of claims 1 to 3, wherein the thermal adhesive resin layer is made of an acid-modified polyolefin.   The permanent magnet according to claim 4, wherein the heat-bonding resin layer is made of acid-modified polypropylene, and the heat-resistant resin layer is made of biaxially stretched polyethylene naphthalate.   The permanent magnet according to claim 5, wherein the heat-resistant resin layer and the thermal adhesive resin layer are laminated via an adhesive layer containing an aminated phenol polymer, a trivalent chromium compound, and a phosphorus compound.   The permanent magnet according to any one of claims 1 to 6, wherein the permanent magnet body is an R-Fe-B system (R is a rare earth element).   A motor comprising the permanent magnet according to claim 1.

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