JP2007037293A - Magnet sheet and motor employing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnet sheet where a plurality of magnet pieces having a partially varied thicknesses are coupled flexibly, and to provide a motor where the magnet sheet is provided on a motor frame of an arbitrary profile with favorable positioning precision. <P>SOLUTION: In the magnet sheet 30, a plurality of magnet pieces 31a-31d having structures of unequal thicknesses are coupled integrally by flexible coupling portions. The coupling portion is a flexible coupling stripe 32 or a flexible coupling bend of a uniform thickness. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnet sheet made of a flexible magnet and a motor using the magnet sheet.

Flexible magnets (flexible permanent magnets) have begun to be used for reasons such as ease of processing and positioning of the end portion to enable overall positioning.
Conventional flexible magnets include those shown in FIGS.

  FIGS. 5A and 5B are explanatory diagrams of the conventional Patent Document 1, FIG. 5A is a development view of a magnet material, and FIG. 5B is a curling molding view of the magnet material.

  In the example of FIG. 5, a magnet material 100 made of a rubber magnet is punched into a strip from a magnet sheet having a uniform thickness. Since the magnet material 100 has flexibility, there may be a deviation in which both ends do not coincide when curled during mounting. In order to prevent this, the projection 101 is provided at one end of the magnet material 100 and the notch 102 is provided at the other end.

  FIG. 6 is an explanatory diagram of the conventional patent document 2. In FIG.

In the example of FIG. 6, a plurality of wedge-shaped notches 201 are formed on one side of a flexible bonded magnet in the form of a rolled sheet, cut at a necessary width, and curled as shown to join both ends 202. This is an example of attaching to the rotor case 203 whose adhesive has been previously applied to the bottom surface.
Japanese Patent Laid-Open No. 07-203663 Japanese Patent Laid-Open No. 10-042525

The flexible magnets disclosed in Patent Document 1 and Patent Document 2 are first formed into a sheet having a uniform thickness, and are cut out from the sheet into a necessary width and used.
Since it is formed in such a uniform thickness, the magnetization characteristics are fixed, and it is difficult to change the magnetization characteristics partially, and there are restrictions on the usage and place of use.

  Moreover, in order to suppress the cogging torque, the magnetizing characteristics of the magnet are required to be changed in a sin wave shape in the rotation direction. However, the two conventional examples have not achieved such a sin wave magnetic characteristic. . Furthermore, the flexible magnet of the above conventional example is intended for a motor frame having a cylindrical shape, and is difficult to apply to motor frames of other shapes.

  An object of the present invention is to provide a magnet sheet in which a plurality of magnet pieces having partially changed thicknesses are flexibly connected, and a motor in which the magnet sheet is provided on a motor frame of an arbitrary shape with high positioning accuracy. .

  Another object of the present invention is to provide a primary molded body of a magnet sheet in which a plurality of magnet pieces having partially changed thicknesses are flexibly connected, a manufacturing method thereof, and a primary molded body of the magnet sheet. An object of the present invention is to provide a motor provided with a positioning accuracy on a motor frame having a shape.

  The magnet sheet of the present invention has the same shape in both the primary molded body and the finished product, and has a structure in which a plurality of unequal thickness structures (structures in which the thickness is partially changed) are connected by a connecting portion, for example, A connecting strip type magnet sheet in which a plurality of magnet pieces with unequal thickness structure are connected to a long connecting strip at predetermined intervals, or adjacent magnet pieces with unequal thickness structure are connected. It has a configuration of a connected bent portion type magnet sheet sequentially connected by a bent portion, and the cross section of the magnet piece portion has a shape in which the inner side is an arc and the outer side is in close contact with the inner surface of the motor frame. The inside of the armature assembly (an amateur core with a winding coil, or a winding coil molding of a coreless motor, etc.) rotates, so that it becomes an arc of any radius, and the outside is attached with a magnet This is because the surface shape of the inner surface of the motor frame is traced. Even if the basic cross-sectional shape of the motor frame is an arbitrary polygonal shape, for example, a quadrangle, a hexagon, an octagon,... In addition, it is possible to apply a magnet sheet in which a plurality of magnet pieces having an unequal thickness structure according to the present invention are integrally connected by a connecting portion having flexibility. Basically, a preferable magnetization characteristic can be obtained by arranging the thickest part of the magnet sheet at the corner of the motor frame. In addition, since the magnet sheet flexibly connects the magnet pieces, it can be in close contact with any shape of motor frame.

  The magnet sheet is formed by thermosetting a primary molded body having the shape of a magnet sheet. Preferably, when the primary molded body is heat-cured, when the heat-curing is performed in a state where it is in contact with an arbitrary mating member, the mating member can be bonded by the action of the binder in the magnet sheet.

  The primary molded body of the magnet sheet is manufactured by injecting a binder having adhesiveness with the magnetic powder, for example, a thermosetting resin, specifically, an epoxy resin, into a mold and compressing them. The manufactured primary molded body has flexibility and can be bent at the connecting portion.

  In the case of FIG. 1 and FIG. 2, the cross section of the magnet piece is formed in a shape combining two arcs having different curvatures.

  The magnet pieces are magnetized in the radial direction or the rotational direction, and are arranged apart from each other on the inner side surfaces of the corners of the cylindrical portion of the motor frame described later.

  As for the cross-sectional shape of the connecting strip type magnet piece, the inner surface (surface close to the amateur core) is an arc surface formed with an arbitrary radius, for example, a radius from the shaft center, and the outer surface is a motor frame. It is formed in intimate contact with the inner surface. The connecting surface between the inner surface and the outer surface is formed on a surface orthogonal to the inner surface of the motor frame, but can be set to an arbitrary angle having a retaining action.

  When the magnet pieces are aligned with the corners of the motor frame, the space between the magnet pieces faces the side between the corners of the motor frame. In this state, there is only an air gap between the side of the motor frame and the amateur core. If it does so, if the shape of a motor frame is not changed, the outer diameter of an amateur core can be lengthened. As a result, the number of windings that can be wound around the amateur core can be increased.

  In particular, in the motor, the outer diameter of the armature core is related to the relationship between the (BH) max (maximum energy product) of the field magnet and the outer diameter of the armature core constituting the magnetic component of the rotating body, which is largely attributable to the motor characteristics. By increasing the value from the inner diameter of the motor frame to the value excluding the necessary minimum air gap, the winding area of the amateur core slot is earned, and the amount of expensive field magnets used as motor parts is reduced, The torque is increased while miniaturizing the motor shape, and the cost and the volume of the motor are reduced.

  The magnet sheet of the present invention is a primary molded body of a magnetic sheet (compressed molding of the magnetic powder and a binder) having a magnetic powder and an adhesive binder, and the primary molded body of the magnetic sheet. For example, in the case of a motor, with a heating device while being pressed against a mounting member such as a motor frame or a rotor with a pressurizing device, etc. Heat and melt the thermosetting binder of the magnet sheet to heat and melt it uniformly and firmly to the mounting member, and heat cure the primary molded body of the magnet sheet to obtain a finished magnet sheet.

  Also, the magnet sheet is configured as a binder having adhesiveness with the magnetic powder, for example, a magnet sheet of a rare earth or ferrite bond magnet configured using a thermosetting resin, specifically an epoxy resin, and the magnetic powder and the binder. Is used in a state of a primary molded body obtained by compression molding or a state in which the primary molded body is thermoset (finished product). In the state (finished product) in which the primary molded body is thermally cured, it is bonded to an attachment member, for example, a motor frame or a rotor (not shown) by an adhesive.

  The pressurizing device is a processing device for preventing an adhesion inhibiting factor such as air from entering the bonding surface, and can be omitted when not necessary.

  The magnet piece has an arcuate shape in which the outer portion of the cross-sectional shape is joined to the corner of the inner surface of the motor frame, and the inner portion of the cross-sectional shape is an amateur assembly (such as an amateur core or a coiled coil molded body of a coreless motor). Is formed in a circular arc shape facing the path of the outermost peripheral surface through a minimum air gap g, and the whole is formed in a substantially strip shape long in the length direction of the cylindrical portion of the motor frame.

  The thickest position of the magnet piece is positioned at the deepest position in the radial direction of the corner of the motor frame. Thereby, the magnetization characteristic of a magnet can be made into a powerful and appropriate sin wave characteristic without obstructing the rotation of the amateur assembly.

  The primary molded body of the magnet sheet is composed of, for example, a compression-molded compound composed mainly of rare earth or ferrite magnet powder and a flexible thermosetting binder.

  The magnet sheet of the present invention, for example, compression-molds a compound mainly composed of a rare earth or ferrite magnet powder and a flexible thermosetting binder to heat-cure the binder component, and performs rolling or stamping or rolling and It is formed by a bonded magnet (for example, see Japanese Patent Application Laid-Open No. 2004-47872) that forms from a solid object to be stamped to a sheet. The sheet magnet will be described later.

  The binder essentially includes a powdery resin component having at least a thermocompression bonding function and a thermosetting functional group. The compound integrates the magnet powder by the adhesive force of the binder component, and gives a role of preventing mechanical separation of the binder and the magnet powder before compression molding. As a specific means for that purpose, the binder is at least a solid epoxy oligomer at room temperature and a thermocompression-bonding polyamide or polyamide-imide powder or polyamide and polyamide-imide powder imparted with stickiness at room temperature, and a powder form to be added as necessary. The latent epoxy curing agent is preferably used.

  In the present invention, the tackiness and thermocompression bonding property of the polyamide or polyamideimide powder or the polyamide and polyamideimide powder is determined by adding a tackifier or the like and first binding the magnet powder in a compound state before compression molding. The agent is fixed by its adhesive force. Next, when the compound is compressed to form a primary molded body, polyamide or polyamideimide or polyamide and polyamideimide are accelerated by heat softening of the polyamide and polyamideimide, and the wettability between joint surfaces is improved to improve the polyamide or polyamideimide or It increases the thermocompression bonding of polyamide and polyamideimide or epoxy oligomer. In addition, other components such as a plasticizer are appropriately used in the binder component.

  The magnet sheet of the present invention has a primary molded body formed by compression molding a compound mainly composed of a rare earth or ferrite magnet powder and a flexible thermosetting binder, disposed on a predetermined inner surface in a motor frame, and disposed. In this state, heating is performed while applying pressure as necessary to melt the primary molded body and adhere it to the inner surface of the motor frame, and the primary molded body is thermally cured to obtain a magnet finished product. Since the primary molded body of the present invention can be compression-molded to a thickness of, for example, about 0.3 to 2.5 mm, the shape design becomes easy.

  The motor frame has a constant plate thickness and a cross-sectional shape of 2 (n + 1) square. However, n is an arbitrary natural number. For example, when the cross-sectional shape is a quadrangle, the motor frame has a cylindrical part that has a shape in which the corners are crushed inward while leaving a part of each side of the square cross-section.

  The shape in which the cross-sectional shape of the motor frame is crushed inward while leaving a part of each side of the quadrangle is a shape in which the adjacent sides are connected by an arc of an arbitrary shape, or the adjacent sides A shape connected by an arc having an arbitrary ratio to the length of the radius of the arc forming the arc surface, or a shape connecting the adjacent sides by a straight line, or of the adjacent sides The space between the shafts is connected by a concentric arc from the center of the shaft.

  The shape of the motor frame is basically the same as the number of magnetic poles of the field magnet, for example, a quadrangle, thereby reducing the thickness of the center part of the field magnet pole (center part in the rotation direction). Without increasing the permeance coefficient of the corner, it is possible to form a sin wave-like magnetization curve along the rotational direction necessary for the field magnet.

  The inner diameter of the motor frame is set to a diameter obtained by adding the minimum air gap g necessary for the rotation of the armature core to the outer diameter of the armature core because there is a space between the magnet pieces when using the coupling band type. .

  In the case of a fold-fold type, the inner diameter is obtained by adding the thickness of the magnet sheet to the diameter in the case of the connecting band type.

Specifically, the following means are used.
(1) The magnet sheet is characterized in that a plurality of magnet pieces having an unequal thickness structure are integrally connected by a connecting portion having flexibility.
(2) The magnet sheet according to (1) is characterized in that the connecting portion is a connecting band portion having flexibility.
(3) The magnet sheet according to (1) is characterized in that the connecting portion is a connected bent portion having a uniform thickness and having flexibility.
(4) The magnet sheet according to any one of the above (1) to (3), wherein the magnet sheet is injected with at least a thermosetting binder having adhesiveness with a magnetic powder into a mold and compressed. It is characterized by being molded and thermoset.
(5) The magnet sheet according to (4) is characterized in that the thermosetting binder contains at least an epoxy oligomer.
(6) The magnet sheet according to (4) is characterized in that the thermosetting binder contains at least polyamide.
(7) The motor according to any one of (4) to (6), wherein a plurality of the magnet piece portions are integrally connected to an inner surface of a cylindrical portion of the motor frame by the connecting portion having flexibility. The magnetic sheet described above is provided.
(8) The motor is any one of the above (4) to (6), in which a plurality of the magnet piece portions are integrally connected to the inner side surface of the cylindrical portion of the motor frame by the connecting band portion having flexibility. The magnet sheet described in the item is provided.
(9) In the motor, (4) to (6), in which a plurality of the magnet pieces are integrally connected to the inner side surface of the cylindrical portion of the motor frame by the connecting bent portion having a uniform thickness having flexibility. The magnet sheet according to any one of the above is fixed.
(10) The motor according to any one of the above (7) to (9) has a constant plate thickness and a shape in which a corner is crushed inward while leaving a part of each side having a square cross section. The magnet piece portion of the magnet sheet is disposed on the inner side surface of the corner portion crushed inside the motor frame having a cylindrical portion, and the magnet sheet is connected to the inner side surface of each side of the motor frame. It is characterized by arranging the parts.

  The primary molded body of the magnet sheet of the present invention is, for example, a compression molding of a compound mainly composed of rare earth or ferrite magnet powder and a flexible thermosetting binder, and can take a fine shape by itself. In addition, since it has flexibility, a minute air gap can be formed accurately, and it can be in close contact with the shape of the mounting counterpart and can be positioned and mounted easily. This is particularly effective when the magnet pieces are continuously arranged in a sheet shape.

  Since the magnet sheet is provided with the magnet piece part continuously connected with a connecting band part or a connecting bent part with high dimensional accuracy, the magnet sheet part can be easily manufactured and positioned with respect to an arbitrary mating member such as a motor frame. Can be done with high accuracy.

  The primary molded body of the magnet sheet is inserted and arranged in the cylindrical portion of the motor frame, and heated while applying pressure as necessary in a state where it is in contact with the inner surface of the cylindrical portion, and the binder of the primary molded body is applied. Since the primary molded body is melted and bonded to the motor frame, and the primary molded body is thermally cured, the magnet sheet can be bonded to the motor frame and the primary molded body can be thermally cured simultaneously, facilitating manufacturing. Since a separate adhesive layer different from the binder of the primary molded body is not used, the magnetic circuit is not affected by the adhesive layer, and the magnetic circuit can be constructed with high accuracy, and the process Can be manufactured easily without any increase.

  In addition, the cross-sectional shape of the magnet piece is configured with the gap length between the inner surface of the motor frame and the outer surface of the amateur assembly excluding the air gap length that does not hinder the rotation of the amateur assembly (The radial width in the cross section of the magnet is the thickest at the corner of the motor frame, and the thickness gradually decreases as it goes away from the corner), and the magnetization characteristics in the rotational direction are sin-wave shaped. The magnet housing space can be reduced, the outer diameter of the amateur assembly can be increased, and the number of windings that can be wound around the amateur assembly can be increased to increase the output. In addition, the magnetization characteristic in the rotation direction of the magnet becomes a sin wave shape, a preferable magnetization characteristic can be obtained, and the cogging torque can be reduced.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is an explanatory view of a magnet sheet in which magnet pieces of the present invention are integrally connected by a connecting band portion. 1A is a perspective view of a magnet sheet, FIG. 1B is a front view seen from the direction of arrow b in FIG. 1A, and FIG. 1C is seen from the direction of arrow c in FIG. FIG.

  FIG. 3 is a mounting explanatory view of a magnet sheet in which the magnet pieces of the present invention are integrally connected by a connecting band portion. 3A is a cross-sectional view of the motor in the shaft direction, FIG. 3B is a cross-sectional view taken along line BB in FIG. 3A, and FIG. 3C is a cross-sectional view taken along line CC in FIG. FIG.

  The motor 1 in FIG. 3A includes an amateur assembly 22 and a frame assembly 23.

  The amateur assembly 22 includes a shaft 2, an armature core 3 provided on the shaft 2, armature windings 6 wound around slots 5 on both sides of the salient pole 4 of the armature core 3, and a rectification provided on the shaft 2. It has a child unit 9.

  A commutator unit 9 provided on the shaft 2 is equipped with a current limiting varistor 7 and a commutator piece 8. One end of the shaft 2 is pivotally supported by a bearing 12 attached to the central opening of the end plate portion 11 of the motor frame 10, and the other end is pivotally supported by a bearing 14 attached to the end block 13. The end plate part 11 is provided with screw holes 15 for attachment at symmetrical positions with the shaft 2 as the center. The end block 13 is provided with a terminal 17 having a brush 16. The brush 16 is disposed in contact with the commutator piece 8.

  The motor frame 10 has a constant plate thickness, a cylindrical portion 20 having a shape in which a corner portion 19 is crushed inward while leaving a part of each side 18 having a square cross section, and a continuous portion to the cylindrical portion 20. It consists of an end plate part 11. In the cross section of the cylindrical portion 20, the adjacent sides 18 are connected by an arc.

The shape of the cylindrical portion 20 of the motor frame 10 is basically a square having the same number as the number of magnetic poles of the field magnet 21 so that the field magnet 21 for obtaining sin wave-like magnetization characteristics in the rotational direction can be obtained. The motor can be miniaturized without reducing the thickness of the central part of the magnetic pole.
Only the minimum necessary air gap g is provided at the position closest to the outer surface of the armature core 3 with respect to the inner surface of the cylindrical portion 20 of the motor frame 10, in the center portion of each side 18 in the first embodiment. Set to exist. This setting is performed at the center of each side 18 in the example of FIG.

  The air gap g is mainly determined by the accuracy of two parts, that is, the inner diameter accuracy of the motor frame 10 and the outer diameter accuracy of the armature core 3. For this reason, the air gap g has a value of about 0.1 mm to 0.5 mm as an actual dimension.

  The radius of the arc on the inner side of the corner portion 19 of the motor frame 10 is an arbitrary value between 5% and 85% of the length from the center of the shaft 2 to the arc surface of the inner portion 21a on the shaft 2 side of the field magnet 21. Set to value. As a result, the armature core 3 can be arranged as an increased structure without being restricted by the placement location by the field magnet 21. Therefore, the number of turns of the armature winding 6 can be increased to increase the generated torque. Can do. Preferably, the inner radius of the arc of the corner portion 19 of the motor frame 10 is 65% to 85% of the length from the center of the shaft 2 to the arc surface of the inner portion 21a on the shaft 2 side of the field magnet 21. Set to any value between.

  The radius from the center of the shaft 2 to the inner side surface 10a of the motor frame 10 is the same as the radius from the center of the shaft 2 to the arc surface of the inner portion 21a of the field magnet 21.

  The radius from the center of the shaft 2 to the inner side surface 10a of the motor frame 10 is made the same as the shortest radius from the center of the shaft 2 to the arc surface of the inner portion 21a of the arbitrary curvature of the field magnet 21.

  Further, a cross-sectional shape of the motor frame 10 in which the corners 19 are crushed inward while leaving a part of each side 18 of the quadrangle, a shape in which the adjacent sides 18 are connected by an arc of an arbitrary shape, or adjacent. A shape in which the sides 18 are connected by an arc having an arbitrary ratio to the length of the radius of the arc forming the arc (having a radius from the shaft center to the arc surface of the field magnet), or adjacent to the side 18 A shape in which the sides are connected by a straight line or a shape in which the adjacent sides 18 are connected by a concentric arc from the center of the shaft 2 is used. An end block 13 is attached to the open end of the cylindrical portion 20 opposite to the end plate portion 11 of the motor frame 10.

  The frame assembly 23 includes a motor frame 10, a bearing 12, and a field magnet 21.

  The field magnet 21 is composed of a magnet piece portion of a magnet sheet, is magnetized in the radial direction or the rotational direction, and is disposed at four corners 19 of the cylindrical portion 20 having a square cross section.

  The field magnet 21 has a cross-sectional shape (a cross-sectional shape in a plane orthogonal to the length direction of the shaft 2), an inner portion (side close to the armature core 3) 21a formed in an arc shape and an outer portion 21b formed in a motor frame. It forms in the shape closely_contact | adhered to the inner surface 10a of 10 cylindrical parts. The connecting portion 21c between the inner portion 21a and the outer portion 21b is formed at an angle that is orthogonal to the inner side surface 10a of the motor frame 10 in the first embodiment, but may be any angle. The field magnet 21 is arranged in a space S between the inner side surface 10a of the motor frame 10 and the radially outermost surface of the armature core 3, and an inner portion 21a that is arcuate in the cross section of the field magnet 21 and the motor frame. It has the connection part 21c which connects each of the outer side part 21b provided closely_contact | adhered to the inner surface 10a. As shown in FIG. 3A, the field magnet 21 is disposed in the length direction of the cylindrical portion 20 so as to face the armature core 3.

  In particular, in the motor 1, the relationship between the (BH) max (maximum energy product) of the field magnet 21 and the outer diameter of the armature core 3 constituting the magnetic component of the rotating body, which has a great influence on the motor characteristics, is optimal. For this purpose, the outer diameter of the armature core 3 is increased by increasing the outer diameter of the armature core 3 to a value obtained by removing the necessary minimum air gap g from the inner diameter of the cylindrical portion 20 of the motor frame 10. By increasing the number of turns, the effective magnetic flux per slot of the amateur core 3 can be increased. Further, the winding area of the slot 5 of the armature core 3 can be increased, and an expensive field magnet can be used as a motor component. The amount of magnet 21 used is suppressed, the torque is increased while the motor shape is reduced, and the cost and motor volume are reduced.

  The connection band part type magnet sheet 30 constituting the field magnet 21 connects a plurality of magnet pieces 31a to 31d by a single connection band 32 having flexibility or flexibility. The magnet pieces 31a to 31d have an axial length facing the armature assembly 22, a width in the rotational direction, and a cross-sectional shape in the radial direction. The material and the like of the magnet sheet 30 are as described above.

  The magnet pieces 31a to 31d have an arcuate shape in which the outer portion 33b of the cross-sectional shape is joined to the corner 19 of the inner surface 10a of the motor frame 10, and the inner portion 33a of the cross-sectional shape is an amateur assembly 22 (an amateur core or a coreless). Formed in a circular arc shape that opposes the path of the outermost peripheral surface of the winding coil formed body of the motor, etc. via the minimum air gap g, and the whole is substantially long in the length direction of the cylindrical portion 20 of the motor frame 10. It is formed in a strip shape.

  The primary molded body of the magnet sheet 30 is manufactured by injecting a binder having adhesiveness with magnetic powder, for example, a thermosetting resin, specifically, an epoxy resin into a mold (not shown), and compressing them. .

  The connecting band portion 32 is usually formed with a constant width and a constant thickness, and is set to the length of the inner side surface 10a of the cross section of the cylindrical portion 20 of the motor frame 10 (the surface perpendicular to the length direction of the cylindrical portion). . The connection band part 32 is integrally formed on one outer part of the end part where the cross sections of the magnet pieces 31a to 31d can be seen. As a result, the connecting band portion 32 comes into contact with the inner side surface 10 a when mounted on the motor frame 10.

  This mounting state will be described with reference to FIG.

  As shown in FIG. 1, a primary molded body obtained by compression molding a compound mainly composed of rare earth or ferrite magnet powder and a flexible thermosetting binder is connected to four magnet pieces 31a to 31d. The magnet sheet 30 is integrally formed to the shape of the magnet sheet 30. The primary molded body is bent so that the center of each magnet piece portion 31 a to 31 d is aligned with the corner portion 19 of the motor frame 10, and the connecting band portion 32 is an end plate at the back of the cylindrical portion 20 of the motor frame 10. Insert it to the position where it abuts on the part 11 and make it closely contact the inner surface 10a. The motor frame 10 and the magnet sheet primary molded body are heated, and the thermosetting binder (epoxy oligomer, etc.) in the primary molded body is melted and adhered to the motor frame 10, and the thermosetting binder is heated. Curing to make the magnet sheet 30 a finished product. Thereafter, the parts are assembled in the motor frame 10.

  Thus, the accurate positioning and adhesion of the magnet pieces 31a to 31d to the corner portion 19 of the motor frame 10 can be easily and firmly performed, and a separate adhesive layer is not provided. It can be formed efficiently.

  FIG. 2 is an explanatory view of a magnet sheet in which the magnet pieces of the present invention are integrally connected by a connecting bent portion. 2 (a) is a perspective view of the magnet sheet, FIG. 2 (b) is a front view seen from the direction of arrow b in FIG. 2 (a), and FIG. 2 (c) is seen from the direction of arrow c in FIG. 2 (a). FIG.

  FIG. 4 is a mounting explanatory view of a magnet sheet in which the magnet pieces of the present invention are integrally connected by a connecting bent portion.

  The connected bent part type magnet sheet 40 connects adjacent magnet pieces 41a to 41d via connected bent parts 42a to 42c having a predetermined narrow width and a uniform thickness. The connecting bent portions 42a to 42c are formed integrally with the magnet piece portions 41a to 41d, and have a flexible characteristic and flexibility by being thin. The connecting bent portions 42a to 42c preferably have a shape that fills the space between the adjacent magnet pieces 41a to 41d without any gap, but may have a gap such as a slit partially.

  The magnet pieces 41a to 41d have an axial length facing the armature assembly 22, a width in the rotational direction, and a cross-sectional shape in the radial direction. The cross-sectional shape has a shape in which the arc of the inner portion 43a and the arc of the outer portion 43b are connected at both ends, and the inner portion 43a of the cross-section of the magnet pieces 41a to 41d is the same as in the first embodiment. A configuration may be adopted in which a connecting portion having a thickness that can be bent flexibly is provided at a place where both ends of the outer portion 43b are connected. The material of the magnet sheet 40 is as described above.

The mounting state of the magnet sheet will be described with reference to FIG.
As shown in FIG. 2, a primary molded body of a magnet sheet 40 formed by compression molding a compound mainly composed of a rare earth or ferrite magnet powder and a flexible thermosetting binder has four magnet pieces 41a to 41d. Is formed into the shape of the magnet sheet 40 that is integrally connected via the connecting bent portions 42a to 42c. The primary molded body is bent so that the centers of the magnet pieces 41a to 41d are aligned with the corners 19 of the motor frame 10, inserted into the cylindrical portion 20 of the motor frame 10, and brought into close contact with the inner surface 10a. . The motor frame 10 and the primary molded body are heated, and the thermosetting binder (epoxy oligomer, etc.) in the primary molded body is melted and adhered to the motor frame 10, and the primary molded body is thermoset. The magnet sheet 40 is completed. Thereafter, the parts are assembled in the motor frame 10.

  Accordingly, accurate positioning and adhesion of the magnet pieces 41a to 41d to the corner portion 19 of the motor frame 10 can be easily and firmly performed, and a separate adhesive layer is not provided. It can be formed well.

It is explanatory drawing of the magnet sheet | seat which connected the magnet piece part of this invention integrally by the connection belt | band | zone part. It is explanatory drawing of the magnet sheet | seat which connected the magnet piece part of this invention integrally by the hinge part. It is mounting explanatory drawing of the magnet sheet | seat which connected the magnet piece part of this invention integrally by the connection belt | band | zone part. It is mounting explanatory drawing of the magnet sheet | seat which integrally connected the magnet piece part of this invention with the hinge part. It is explanatory drawing of the conventional patent document 1. FIG. It is explanatory drawing of the conventional patent document 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Shaft 3 Amateur core 4 Salient pole 5 Slot 6 Armature winding 7 Varistor 8 Commutator piece 9 Commutator unit 10 Motor frame 10a Inner side surface 11 End plate part 12, 14 Bearing 13 End block 15 Screw hole 16 Brush 17 Terminal 18 Side 19 Corner portion 20 Tubular portion 21 Field magnet 21a Inner portion 21b Outer portion 21c Connecting portion 22 Amateur assembly 23 Frame assembly g Air gap 30, 40 Magnet sheets 31a, 31b, 31c, 31d, 41a, 41b , 41c, 41d Magnet piece 32 Connection band 33a, 43a Inner part 33b, 43b Outer part 42a, 42b, 42c Connection bent part

Claims (10)

A magnet sheet characterized in that a plurality of magnet pieces having an unequal thickness structure are integrally connected by a connecting portion having flexibility. The magnet sheet according to claim 1, wherein the connecting portion is a connecting band portion having flexibility. The magnet sheet according to claim 1, wherein the connecting portion is a connecting bent portion having a uniform thickness and having a uniform thickness. 4. The magnet sheet is manufactured by injecting at least a thermosetting binder having adhesiveness with magnetic powder into a mold, compressing and thermosetting the same. The magnet sheet of any one of these. The magnet sheet according to claim 4, wherein the thermosetting binder contains at least an epoxy oligomer. The magnet sheet according to claim 4, wherein the thermosetting binder contains at least polyamide. The magnet sheet according to any one of claims 4 to 6, wherein a plurality of the magnet piece portions are integrally connected to the inner side surface of the cylindrical portion of the motor frame by the connecting portion having flexibility. Characteristic motor. The magnet sheet according to any one of claims 4 to 6, wherein a plurality of the magnet piece parts are integrally connected to the inner side surface of the cylindrical part of the motor frame by the connecting band part having flexibility. A motor characterized by The magnet according to any one of claims 4 to 6, wherein a plurality of the magnet piece portions are integrally connected to the inner side surface of the cylindrical portion of the motor frame by the connecting bent portion having a uniform thickness having flexibility. A motor characterized by a fixed seat. The inner side surface of the corner portion crushed to the inside of the motor frame having a cylindrical portion having a constant plate thickness and a shape in which the corner portion is crushed inward while leaving a part of each side having a square cross section The magnet piece portion of the magnet sheet is disposed on the inner surface of the motor frame, and the connecting portion of the magnet sheet is disposed on an inner surface of each side of the motor frame. motor.

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