JP2006042527A - Motor manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor manufacturing method that can suppress the generation of noise and vibration during driving a motor even when magnets are magnetized after mounting an armature and an end frame. <P>SOLUTION: A sheet material 22 for magnets is constituted of two magnetic pole portions 4a that are arranged in one line. In this sheet material 22, both end portions 4b in the arranged direction of the magnetic pole portions 4a in each magnetic pole portion 4a have width in the direction intersecting the arranged direction perpendicularly that gradually narrows as they go to the outside of the magnetic pole portions 4a along the arranged direction. The sheet material 22 is formed into a cylindrical shape by joining both end surfaces 4c to each other in the arranged direction of the magnetic pole portions 4a in the sheet material 22 and then fixed to the inside circumferential surface of a yoke housing. Then, after the armature and the end frame are mounted on the yoke housing, the magnetic pole portions 4a are magnetized from the outside of the yoke housing in such a way that the magnetic pole portions 4a adjacent have difference polarity to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a motor.

Some conventional DC motors have magnets fixed to the inner peripheral surface of the yoke housing. Such a motor is disclosed in Patent Document 1 and Patent Document 2, for example.
The magnet of the motor disclosed in Patent Document 1 has a cylindrical shape. This magnet is formed by magnetizing a cylindrical original member (magnet member). Specifically, first, the original member is fixed to the inner peripheral surface of the bottomed cylindrical yoke housing. Next, a columnar magnetized yoke is inserted into the yoke housing, the original member is magnetized by the magnetized yoke, and the original member becomes a magnet. Thereafter, the armature is accommodated in the yoke housing, and the opening of the yoke housing is closed by the end frame to complete the motor (see FIG. 9).

The magnet of the motor disclosed in Patent Document 2 is formed by magnetizing a strip-like flexible sheet material (magnet member). The sheet material is formed with slit-shaped absorption holes extending along a direction orthogonal to the longitudinal direction of the sheet material. This absorption hole is provided to improve the dimensional accuracy of the inner diameter of the magnet by absorbing variations in the overall length of the magnet, and is the boundary between the N pole and the S pole, and is formed at a position where there is no magnetization or weak magnetization. ing. The sheet material is curled into a cylindrical shape, and is fixed in the yoke housing in a state where both end surfaces in the longitudinal direction are butted. Thereafter, the assembly of the armature and the end frame and the magnetization of the sheet material are performed to complete the motor.
JP 2001-69702 A Japanese Utility Model Publication No. 5-55740

  However, as disclosed in Patent Document 1, if the original member is magnetized before the armature and the end frame are assembled, the yoke housing provided with the magnet does not close the opening on the production line. There is a risk that foreign matter having magnetism will be mixed into the inside of the yoke housing by the magnetic force of the magnet. For this reason, a measure for preventing foreign matter from entering is necessary, and the equipment cost increases. In addition, the assembly of the armature is deteriorated due to the influence of the magnetic force of the magnet. Therefore, in order to prevent the assembly of the armature from deteriorating, it is desirable to increase the rigidity of the assembling equipment or improve the accuracy of the assembling equipment, which further increases the equipment cost. There's a problem.

  Further, as shown in FIG. 10, the motor disclosed in Patent Document 2 can be magnetized from the outside of the yoke housing after the armature and the end frame are assembled to the yoke housing. However, for example, when the total length of the sheet material is longer than the inner circumference of the yoke housing, the flexible sheet material is bent so as to narrow the width in the longitudinal direction of the sheet material in the absorption hole, and in the circumferential direction of the absorption hole. The opposing inner surfaces are almost in contact. That is, when the sheet material is fixed to the yoke housing, the sheet material is close to a state where no absorption hole is formed. Generally, when magnetization is performed from the outside of the motor housing after the armature and the end frame are assembled, the magnetization cannot be finely controlled. Therefore, when a sheet material in a state close to a state where no absorption hole is formed is magnetized from the outside of the yoke housing, a magnet having a magnetization waveform as shown in FIG. 11 is formed. In the magnetization waveform shown in FIG. 11, the magnetization waveform is disturbed at the portion where the N pole and the S pole are switched. When a motor having a magnet with a disturbed magnetization waveform is driven in this way, the cogging torque increases due to the disturbance of the magnetization waveform, and the vibration and noise of the motor increase. This becomes a cause of increasing the vibration and noise in the passenger compartment of a vehicle equipped with such a motor.

  The present invention has been made in view of such circumstances, and its object is to suppress the generation of noise and vibration during motor driving even if the magnet is magnetized after the armature and end frame are assembled. An object of the present invention is to provide a method for manufacturing a motor capable of achieving the above.

  In order to solve the above-mentioned problem, the invention described in claim 1 includes a yoke housing having an opening, an end frame that closes the opening, and a sheet-like magnet fixed to the inner peripheral surface of the yoke housing. A method of manufacturing a motor including an armature that is rotatably accommodated in the yoke housing and is opposed to the magnet, wherein the method includes magnetic pole portions arranged in a row, and the magnetic pole portions in the magnetic pole portions. The magnet sheet material for forming the magnet sheet material whose cross-sectional area in the direction orthogonal to the arrangement direction is gradually narrowed toward the outside of the magnetic pole part along the arrangement direction A molding step, a magnet sheet material assembling step for fixing the magnet sheet material to the inner peripheral surface of the yoke housing, and the yoke housing Assembling the armature to face the magnet sheet material and closing the opening with an end frame, and a plurality of adjacent magnetic poles to have different polarities The magnetic pole portion is magnetized, and the magnet sheet material is used as the magnet.

  According to a second aspect of the present invention, in the motor manufacturing method according to the first aspect, in the magnet sheet material forming step, both end portions of the magnetic pole portions in the arrangement direction of the magnetic pole portions are orthogonal to the arrangement direction. As the width in the direction to go toward the outside of the magnetic pole portion along the arrangement direction, it is gradually narrowed.

According to a third aspect of the present invention, in the motor manufacturing method according to the second aspect, in the magnet sheet material forming step, the magnetic pole portion is formed into an octagonal shape.
According to a fourth aspect of the present invention, in the motor manufacturing method according to the first to third aspects, in the magnet sheet material forming step, the magnet sheet material is formed by cutting the sheet material.

  According to a fifth aspect of the present invention, in the motor manufacturing method according to any one of the first to fourth aspects, in the magnet sheet material forming step, the plurality of magnetic pole portions are arranged in series. The magnet sheet material is formed.

A sixth aspect of the present invention is the motor manufacturing method according to any one of the first to fifth aspects, wherein the magnet sheet material has elasticity.
(Function)
According to the first aspect of the present invention, in the sheet material forming step, the magnet sheet material composed of a plurality of magnetic pole portions is formed. Then, both end portions of each magnetic pole portion in the magnetic pole portion arrangement direction are formed such that a cross-sectional area in a direction orthogonal to the arrangement direction gradually becomes narrower toward the outside of the magnetic pole portion along the arrangement direction. The When magnetizing a magnet sheet material composed of such magnetic pole portions, the portion where the N pole and the S pole are switched, that is, in the magnetic pole portion arrangement direction in each magnetic pole portion, without finely controlling the magnetization. At both ends, the magnetic flux is magnetized so that the magnetic flux gradually decreases toward the point where the N pole and the S pole are switched. Therefore, the disturbance of the magnetization waveform is suppressed. Therefore, even if the armature is assembled to the yoke housing and the opening of the yoke housing is closed by the end frame, and then the magnet sheet material is magnetized from the outside of the yoke housing, the magnetization waveform may be disturbed. Therefore, it is possible to suppress the cogging torque from being increased due to the disturbance of the magnetization waveform. As a result, it is possible to suppress the generation of noise and vibration when the motor is driven.

  According to the second aspect of the present invention, in the magnet sheet material forming step, both ends of each magnetic pole portion in the magnetic pole portion arrangement direction have a width in a direction perpendicular to the arrangement direction along the magnetic pole portion. It is shaped so that it gradually becomes narrower toward the outside of the part. By forming each magnetic pole portion in this manner, the cross-sectional area in the direction orthogonal to the arrangement direction at both ends of each magnetic pole portion in the magnetic pole portion arrangement direction is directed to the outside of the magnetic pole portion along the arrangement direction. A shape that gradually narrows along with it is easily formed. When magnetizing a magnet sheet material composed of such magnetic pole portions, the portion where the N pole and the S pole are switched without finely controlling the magnetization, that is, the arrangement of the magnetic pole portions in each magnetic pole portion. At both ends in the direction, the magnetic flux is magnetized so that the magnetic flux gradually decreases as it goes to the point where the N pole and the S pole are switched. Therefore, the disturbance of the magnetization waveform is suppressed.

  According to the invention described in claim 3, in the magnet sheet material forming step, the magnetic pole portion is formed in an octagonal shape. Therefore, at both end portions of each magnetic pole portion in the magnetic pole portion arrangement direction, a shape in which the width in the direction orthogonal to the arrangement direction gradually narrows toward the outside of the magnetic pole portion along the arrangement direction is easily formed. The Moreover, since it is a simple shape called an octagonal shape, the magnetic pole part is easily formed.

  According to the fourth aspect of the present invention, since the magnet sheet material is formed by cutting the sheet material, the magnet sheet material is formed more easily than when the magnet sheet material is formed by, for example, injection molding.

  According to the fifth aspect of the present invention, since the magnet sheet material is formed such that a plurality of magnetic pole portions are arranged in series, in the magnet sheet material assembling step, the magnet sheet material having separated magnetic pole portions is used. It is more easily fixed to the inner peripheral surface of the yoke housing than when it is fixed.

  According to invention of Claim 6, the sheet material for magnets has elasticity. Therefore, the magnet sheet material is easily deformed into a shape corresponding to the shape of the inner peripheral surface of the yoke housing while bending itself. Further, since the elastic force can be used for the fixing force of the magnet sheet material, it is not necessary to use an adhesive to fix the magnet sheet material to the inner peripheral surface of the yoke housing.

  ADVANTAGE OF THE INVENTION According to this invention, the magnet can be magnetized after an armature and an end frame assembly | attachment, and the manufacturing method of the motor by which generation | occurrence | production of the noise and vibration at the time of a motor drive can be suppressed can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
First, the configuration of the motor 1 of the present embodiment will be described. FIG. 1 shows a motor 1 of this embodiment. The motor 1 includes a bottomed cylindrical yoke housing 2 composed of a cylindrical cylindrical portion 2a and a bottom portion 2b that closes the upper end of the cylindrical portion 2a. The opening 2c of the yoke housing 2 is closed by a disc-shaped end frame 3.

  A sheet-like magnet 4 is fixed to the inner peripheral surface of the cylindrical portion 2a. As shown in FIG. 2, the magnet 4 fixed to the cylindrical portion 2a has a cylindrical shape along the inner peripheral surface of the cylindrical portion 2a. The magnet 4 has a sheet shape as shown in FIG. 3A, and the sheet-like magnet 4 is deformed into a cylindrical shape as shown in FIG. 3B, so that the inner periphery of the cylindrical portion 2a is obtained. It is fixed to the surface. Incidentally, the magnet 4 has elasticity.

  As shown in FIG. 3A, the magnet 4 is composed of a plurality (two in this embodiment) of magnetic pole portions 4a. The two magnetic pole portions 4a are arranged in a line. Then, both end portions 4b of the magnetic pole portions 4a in the arrangement direction of the magnetic pole portions 4a (the left-right direction in FIG. 3A) have the width in the direction orthogonal to the arrangement direction (the vertical direction in FIG. 3A). It forms so that it may become narrow gradually as it goes to the outer side of the magnetic pole part 4a along a direction. Each magnetic pole part 4a is formed so that the width in the direction orthogonal to the arrangement direction is gradually narrowed toward the outside of the magnetic pole part 4a along the arrangement direction at both ends 4b in the arrangement direction. The cross-sectional area in the direction orthogonal to the arrangement direction is formed so as to gradually become narrower toward the outside of the magnetic pole part 4a along the arrangement direction. When the magnet 4 is fixed to the inner peripheral surface of the cylindrical portion 2a, the arrangement direction of the magnetic pole portions 4a and the circumferential direction of the cylindrical portion 2a are the same.

  In this embodiment, each magnetic pole part 4a is formed in an octagonal shape, so that both end parts 4b in the arrangement direction of the magnetic pole part 4a have a width in a direction perpendicular to the arrangement direction of the magnetic pole part 4a. It is narrowed linearly toward the outside. In the present embodiment, as shown in FIG. 2, the two magnetic pole portions 4a cover the inner peripheral surface of the cylindrical portion 2a by 180 ° in the circumferential direction. And each magnetic pole part 4a is formed so that the width | variety of the direction orthogonal to a sequence direction may be narrowed in the range (both ends 4b) of 30 degrees of both sides of the sequence direction in this magnetic pole part 4a among 180 degrees. In addition, each magnetic pole portion 4a has a constant width in a direction orthogonal to the arrangement direction within a central 120 ° range excluding a 30 ° range on both sides in the arrangement direction of each magnetic pole portion 4a.

  As shown in FIG. 3 (a), these two magnetic pole portions 4a are formed so as to be connected to each other at the end portions of the magnetic pole portions 4a facing each other at the narrow end portions. ing. That is, the magnet 4 is formed as a single sheet by integrally forming the two magnetic pole portions 4a.

  As shown in FIG. 3B, such a magnet 4 has an inner peripheral surface of the yoke housing 2 in a state in which both end surfaces 4c in the arrangement direction of the magnetic pole portions 4a of the magnet 4 are made cylindrical. It is fixed to. Each magnetic pole part 4a is magnetized so as to have a different polarity from the adjacent magnetic pole part 4a when fixed to the yoke housing 2.

  As shown in FIG. 1, an armature 5 is rotatably accommodated inside the magnet 4 configured as described above while facing the magnet 4. The armature 5 includes a rotating shaft 6, a core 7 and a commutator 8 fixed to the rotating shaft 6, and a winding 9 wound around the core 7. The armature 5 is rotatably supported by supporting the rotary shaft 6 with a bearing 10 provided in the center of the bottom 2b and a bearing 11 provided in the center of the end frame 3.

  A brush 13 held by a brush holder 12 fixed to the end frame 3 is in sliding contact with the commutator 8. The commutator 8 supplies drive power to the winding 9 from the outside via the brush 13. When a driving power is supplied to the winding 9, a rotating magnetic field is generated in the core 7, and the armature 5 rotates according to the rotating magnetic field.

  Next, a method for manufacturing the motor 1 configured as described above will be described. The motor manufacturing method of the present embodiment includes a magnet sheet material forming step, a magnet sheet material assembling step, an armature assembling step, and a magnetizing step.

  First, a magnet sheet material forming step is performed. In this magnet sheet material forming step, the magnet sheet material 22 is formed by cutting the rectangular sheet material 21 shown in FIG. Specifically, the sheet material 21 is made of a magnetic material having elasticity and has a uniform thickness. The sheet material 21 is cut at a portion indicated by a broken line in FIG. Thereby, as shown to Fig.3 (a), the sheet material 22 for magnets comprised from the two magnetic pole parts 4a arranged in a line is shape | molded. In this magnet sheet material 22, both end portions 4b of each magnetic pole portion 4a in the arrangement direction of the magnetic pole portions 4a gradually increase in width in the direction orthogonal to the arrangement direction toward the outside of the magnetic pole portion 4a along the arrangement direction. It has become narrower. In the present embodiment, the two magnetic pole portions 4a constituting the magnet sheet material 22 are formed in an octagonal shape, and are connected at the tip portions of the portions where the width is narrow at the ends of the magnetic pole portions 4a facing each other. It has become. That is, the magnet sheet material 22 is formed into a single sheet having a series of two magnetic pole portions 4a.

  The magnet sheet material 22 formed in the magnet sheet material forming step is fixed to the inner peripheral surface of the cylindrical portion 2a of the yoke housing 2 in the magnet sheet material assembling step. First, as shown in FIG. 3 (b), the magnet sheet material 22 aligns both end surfaces 4c of the magnet sheet material 22 in the arrangement direction of the magnetic pole portions 4a while bending the magnet sheet material 22 itself. To be cylindrical. Thereafter, the cylindrical magnet sheet material 22 is inserted into the yoke housing 2 and fixed to the inner peripheral surface of the cylindrical portion 2a. At this time, the magnet sheet material 22 is fixed to the inner peripheral surface of the cylindrical portion 2a with its own elastic force as a fixing force.

  In the armature assembling process, the armature 5 and the end frame 3 are assembled to the yoke housing 2 in which the magnet sheet material 22 is assembled. The armature 5 is assembled inside the yoke housing 2 so that the core 7 faces the magnet sheet material 22. Next, the end frame 3 is assembled so as to close the opening 2 c of the yoke housing 2.

  After the armature assembly process is completed, a magnetization process is performed. In the magnetizing process, the two magnetic pole portions are arranged so that the adjacent magnetic pole portions 4a have different polarities from the outside of the yoke housing 2 in a state where the armature 5 is assembled and the opening 2c is closed by the end frame 3. 4a is magnetized. Thereby, the magnet sheet material 22 becomes the magnet 4. When this magnetization process is completed, the motor 1 is completed.

  The magnetization waveform of the magnet 4 thus magnetized is shown in FIG. Both end portions 4b of the magnetic pole portions 4a in the arrangement direction of the magnetic pole portions 4a correspond to portions where the N pole and the S pole are switched. Generally, when a magnet sheet material having a constant axial width is magnetized from the outside of the yoke housing, the magnetization cannot be finely controlled, so the entire magnet sheet material has a certain strength. In the portion where the N pole and the S pole are switched, the magnetization waveform is disturbed. However, in the present embodiment, both end portions 4b of the magnetic pole portions 4a in the arrangement direction of the magnetic pole portions 4a gradually narrow as the width in the direction orthogonal to the arrangement direction goes to the outside of the magnetic pole portions 4a along the arrangement direction. It is shaped as follows. Therefore, when the entire magnet sheet material 22 is magnetized with a certain strength without finely controlling the magnetization, the magnetic pole portion 4a in which the N pole and the S pole are switched has N The magnetic flux is magnetized so that the magnetic flux gradually decreases toward the point where the pole and the S pole are switched. As a result, since the magnetic flux is reduced at both end portions 4b of the magnetic pole portions 4a in the arrangement direction of the magnetic pole portions 4a where the magnetization waveform is likely to be disturbed, the occurrence of the disturbance of the magnetization waveform is suppressed.

As described above, the present embodiment has the following effects.
(1) In the sheet material forming step, the magnet sheet material 22 composed of the two magnetic pole portions 4a is formed. Then, both end portions 4b of the magnetic pole portions 4a in the arrangement direction of the magnetic pole portions 4a, that is, portions where the N pole and the S pole are switched have a width in a direction perpendicular to the arrangement direction along the arrangement direction. It is shaped so that it gradually becomes narrower as it goes outward. When magnetizing the magnet sheet material 22 composed of such a magnetic pole portion 4a, the N pole and the S pole are switched at both ends 4b of the magnetic pole portion 4a without switching the magnetization. The magnetic flux is magnetized so that the magnetic flux gradually decreases toward the point where the pole and the S pole are switched. Therefore, the disturbance of the magnetization waveform is suppressed. Accordingly, even when the armature 5 is assembled to the yoke housing 2 and the opening 2c of the yoke housing 2 is closed, and the magnet sheet material 22 is magnetized from the outside of the yoke housing 2, the magnetization waveform is disturbed. Since generation | occurrence | production is suppressed, it can suppress that a cogging torque is increased by disturbance of a magnetization waveform. As a result, it is possible to suppress the generation of noise and vibration when the motor 1 is driven.

  (2) Since the armature 5 is assembled to the yoke housing 2 and the opening 2c is closed by the end frame 3, magnetization is performed after the magnetic force of the magnet 4 causes a foreign matter having magnetism from the opening 2c to the yoke housing 2. Can be prevented from being mixed in the inside of the container. Therefore, no measures for preventing foreign matter from entering the yoke housing 2 are required, and the cost for the measures can be reduced. Further, since the armature 5 is assembled before the magnetic pole portion 4a is magnetized, there is no possibility that the assembling property of the armature 5 is deteriorated by the magnetic force of the magnet 4. Therefore, it is not necessary to increase the rigidity of the assembling facility or improve the accuracy of the assembling facility in order to prevent the assembly of the armature 5 from deteriorating. As a result, equipment costs can be reduced.

  (3) In the magnet sheet material forming step, each magnetic pole portion 4a is formed in an octagonal shape. Therefore, at both end portions 4b of the magnetic pole portions 4a in the arrangement direction of the magnetic pole portions 4a, the width in the direction orthogonal to the arrangement direction gradually narrows toward the outside of the magnetic pole portions 4a along the arrangement direction. It can be formed easily. Moreover, since it is a simple shape called octagonal shape, the magnetic pole part 4a can be shape | molded easily. Furthermore, when each magnetic pole part 4a is made into an octagonal shape, it is easy to ensure a part where the width in the direction orthogonal to the arrangement direction is constant in the central part of the arrangement direction of each magnetic pole part 4a.

  (4) Since the magnet sheet material 22 is formed by cutting the sheet material 21, it can be formed more easily than when the magnet sheet material 22 is formed by, for example, injection molding.

  (5) In the magnet sheet material forming step, the magnet sheet material 22 is formed such that the two magnetic pole portions 4a are arranged in series. Accordingly, in the magnet sheet material assembling step, the magnet sheet material 22 can be easily fixed to the inner peripheral surface of the cylindrical portion 2a, compared to the case where the magnetic pole portions 4a are fixed to separate magnetic sheet materials. it can.

  (6) Since the magnet sheet material 22 has elasticity, the magnet sheet material 22 is easily deformed into a shape corresponding to the shape of the inner peripheral surface of the cylindrical portion 2a while bending itself. Therefore, the magnet sheet material 22 can be easily fixed to the inner peripheral surface of the cylindrical portion 2a. Further, since the elastic force can be used for the fixing force of the magnet sheet material 22, it is not necessary to use an adhesive to fix the magnet sheet material 22 to the inner peripheral surface of the cylindrical portion 2a.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, each magnetic pole part 4a is formed so as to narrow the width in the direction orthogonal to the arrangement direction within a range of 30 ° on both sides in the arrangement direction of the magnetic pole part 4a, but is not limited thereto. Each magnetic pole part 4a may be formed so as to narrow the width in the direction orthogonal to the arrangement direction within an angle range larger than 30 ° on both sides in the arrangement direction, and conversely, it is smaller than 30 ° on both sides in the arrangement direction. You may form so that the width | variety of the direction orthogonal to the sequence direction may be narrowed in the range of an angle.

  In the above embodiment, the magnet sheet material 22 is formed by cutting the sheet material 21, but is not limited thereto. For example, the magnet sheet material 22 may be formed by injection molding.

  In the above embodiment, the magnet 4 (magnet sheet material 22) is composed of the two magnetic pole portions 4a, but is not limited thereto. For example, as shown in FIG. 6, it is good also as the magnet 31 (sheet | seat material 32 for magnets) comprised from the four magnetic pole parts 31a. The four magnetic pole portions 31a are formed in an octagonal shape and all have the same shape. Moreover, it is good also as the magnet 4 (sheet | seat material 22 for magnets) which has more magnetic pole parts 4a than this.

  In the above embodiment, the magnetic pole part 4a is formed in an octagonal shape. However, the present invention is not limited thereto, and the cross-sectional area in the direction orthogonal to the arrangement direction is arranged at both ends 4b of the magnetic pole part 4a in the arrangement direction of each magnetic pole part 4a. What is necessary is just to shape | mold so that it may become narrow gradually as it goes to the outer side of the magnetic pole part 4a along a direction. For example, the magnetic pole portion may have the shape shown in FIGS. The magnetic pole portion 41a of the magnet 41 (magnet sheet material 42) shown in FIG. 7 has a width in a direction perpendicular to the arrangement direction along the arrangement direction at both ends 41b of the magnetic pole portion 41a in the arrangement direction of the magnetic pole portion 41a. It is shaped so as to gradually narrow in a curved manner toward the outside of the portion 41a. Further, the magnetic pole portion 51a of the magnet 51 (magnet sheet material 52) shown in FIG. 8 is provided with a triangular cutout portion 51b whose width gradually decreases inward from both ends in the arrangement direction of the magnetic pole portion 51a. The width of both end portions 51c of the magnetic pole portion 51a in the arrangement direction of the magnetic pole portions 51a is gradually narrowed. Incidentally, in the magnetic pole part 51a, the width of the both end parts 51c in the direction orthogonal to the arrangement direction of the magnetic pole parts 51a is the sum of the widths of the parts excluding the notch parts 51b, and in FIG. The width x in the direction orthogonal to the arrangement direction of 51a is the total length of the width x1 and the width x2.

  In the above embodiment, the two magnetic pole portions 4a are formed in a series, but may be a magnet 4 (magnet sheet material 22) composed of discrete magnetic pole portions 4a.

  In the above embodiment, the yoke housing 2 has a bottomed cylindrical shape, but is not limited thereto. For example, the yoke housing 2 may have a cylindrical shape and both ends may be closed by end frames. Further, the yoke housing 2 may have a flat cylindrical shape in addition to the cylindrical shape.

The technical idea that can be grasped from the above embodiment will be described below.
(A) A yoke housing having an opening, an end frame that closes the opening, a sheet-like magnet fixed to the inner peripheral surface of the yoke housing, and a rotatable housing inside the yoke housing. A motor having a magnet and an armature opposed to the magnet, wherein the magnet is composed of a plurality of magnetic pole portions arranged in a line and alternately magnetized with either N poles or S poles. Both end portions of the magnetic pole portion in the arrangement direction of the magnetic pole portion have a cross-sectional area in a direction orthogonal to the arrangement direction gradually narrowing toward the outside of the magnetic pole portion along the arrangement direction. Motor.

  If comprised in this way, the both end parts of the magnetic pole part arrangement direction in a magnetic pole part will become narrow gradually as the cross-sectional area of the direction orthogonal to the said arrangement direction goes to the adjacent magnetic pole part along the said arrangement direction. On the contrary, both end portions of the magnetic pole portions in the magnetic pole portion arrangement direction gradually become wider as the cross-sectional area in the direction orthogonal to the arrangement direction moves away from the adjacent magnetic pole portions along the arrangement direction. When magnetizing these magnetic pole portions, even if the magnetization is not finely controlled, the portion where the N pole and the S pole are switched, that is, the N pole and the S pole at both ends of each magnetic pole portion in the magnetic pole portion arrangement direction. Thus, the magnetic flux is magnetized so that the magnetic flux gradually decreases as it goes to the point at which it switches. Therefore, the disturbance of the magnetization waveform is suppressed. Therefore, when the armature is assembled to the yoke housing and the opening of the yoke housing is closed by the end frame and then the magnetic pole portions are magnetized from the outside of the yoke housing, the magnetization waveform may be disturbed. The cogging torque is suppressed from being increased due to the disturbance of the magnetization waveform. As a result, it is possible to suppress the generation of noise and vibration when the motor is driven.

Sectional drawing of the motor of this embodiment. Sectional drawing which cut the motor of this embodiment along the radial direction. (A) is a front view of a magnet (magnet sheet material) having a magnetic pole part, (b) is a perspective view of the magnet. The front view of a sheet material. The conceptual diagram which shows the magnetization waveform of the magnet of this embodiment. The front view which shows the magnet (sheet material for magnets) which has a magnetic pole part of another form. The front view which shows the magnet (sheet material for magnets) which has a magnetic pole part of another form. The front view which shows the magnet (sheet material for magnets) which has a magnetic pole part of another form. The flowchart in the case of assembling an armature and an end frame after magnetizing the member for magnets. The flowchart in the case of magnetizing the member for magnets after an armature and an end frame are assembled | attached. The conceptual diagram which shows the magnetization waveform of the conventional magnet at the time of magnetizing the member for magnets after attaching an armature and an end frame.

Explanation of symbols

  2 ... yoke housing, 2c ... opening, 3 ... end frame, 4, 31, 41, 51 ... magnet, 4a, 31a, 41a, 51a ... magnetic pole part, 4b, 41b, 51c ... both ends of the magnetic pole part in the arrangement direction 5 ... armature, 21 ... sheet material, 22, 32, 42, 52 ... sheet material for magnet, x ... magnetic pole part at both ends in the magnetic pole part arrangement direction in each magnetic pole part of another form of magnet shown in FIG. The width in the direction perpendicular to the array direction.

Claims (6)

A yoke housing having an opening;
An end frame that closes the opening;
A sheet-like magnet fixed to the inner peripheral surface of the yoke housing;
A method of manufacturing a motor including an armature that is rotatably accommodated in the yoke housing and faces the magnet,
The magnetic pole portions are arranged in a line, and both end portions of the magnetic pole portions in the arrangement direction of the magnetic pole portions have cross-sectional areas in a direction perpendicular to the arrangement direction toward the outside of the magnetic pole portions along the arrangement direction. A magnet sheet material forming process for forming a magnet sheet material that is gradually narrowed along with,
A magnet sheet material assembling step for fixing the magnet sheet material to the inner peripheral surface of the yoke housing;
An armature assembling step for assembling the armature so as to face the magnet sheet material inside the yoke housing, and closing the opening with an end frame;
And a magnetizing step of magnetizing the plurality of magnetic pole portions so that the adjacent magnetic pole portions have different polarities and using the magnet sheet material as the magnet. . In the manufacturing method of the motor according to claim 1,
In the magnet sheet material forming step, both end portions of the magnetic pole portions in the arrangement direction of the magnetic pole portions have a width in a direction orthogonal to the arrangement direction toward the outside of the magnetic pole portions along the arrangement direction. A method for manufacturing a motor, characterized in that the motor is gradually narrowed. In the manufacturing method of the motor according to claim 2,
In the magnet sheet material forming step, the magnetic pole portion is formed in an octagon shape. In the manufacturing method of the motor according to any one of claims 1 to 3,
In the magnet sheet material forming step, the magnet sheet material is formed by cutting the sheet material. In the manufacturing method of the motor according to any one of claims 1 to 4,
In the magnet sheet material forming step, the magnet sheet material is formed such that a plurality of the magnetic pole portions are arranged in series. In the manufacturing method of the motor according to any one of claims 1 to 5,
The method for manufacturing a motor according to claim 1, wherein the magnet sheet material has elasticity.

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