JP2005094929A - Manufacturing method for stator core, motor having stator core manufactured by the manufacturing method, and manufacturing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance an yield and reduce an iron loss. <P>SOLUTION: At a step S102, a band-shaped oriented electromagnetic steel plate is wound and annularly laminated, and a yoke is thereby formed. At a step S106, the inner circumferential portion is cut so that a cross section of the yoke is exposed, and a joint is thereby formed. At a step 110, a tooth-shaped body in which a plurality of comb teeth are joined to one another at a coupling portion is cut out of a non-oriented electromagnetic steel plate. At a step S112, the tooth-shaped body is spirally wound and laminated in the rotative axial direction of, and a tooth is thereby formed. At a step S116, the yoke and the tooth are joined to each other so that the outer end of the tooth is joined with the joint, and a stator core is thereby formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a stator core manufacturing method, an electric motor having a stator core manufactured by the manufacturing method, and a manufacturing apparatus, and more particularly, a stator core manufacturing method in which a yoke portion and a teeth portion are divided and manufactured, and the manufacturing method thereof The present invention relates to a motor having a stator core and a manufacturing apparatus.

  2. Description of the Related Art Conventionally, as a method for manufacturing a stator core of an electric motor, a method in which an annular member punched from a thin plate is stacked in the direction of the rotation axis of a rotor is well known. However, when the annular member is punched from a thin plate, the portion in the ring of the annular member can be used for manufacturing the rotor, but the portion between the adjacent annular members has no other use, and the yield is high. Was bad. In addition, since the area of a stator core of a large-sized motor such as a motor for driving a car is large, the thin plate is easily bent when punching, and the accuracy of the roundness of the stator core is likely to deteriorate, and the punching speed can be increased. This reduces productivity. Therefore, in the method of punching the annular member, for example, a thin plate having a thickness of 0.25 mm or less or a high performance steel plate having a small iron loss such as an amorphous steel plate cannot be used for an automobile driving motor or the like. Therefore, in order to improve the yield and accuracy, there is a manufacturing method in which a tooth-shaped body in which a plurality of comb teeth are connected is punched from a strip-shaped thin plate, and the teeth-shaped body is wound in an annular shape to form a stator core.

  On the other hand, as a material for the stator core, in order to reduce the iron loss of the stator core, it is desirable to use a grain-oriented electrical steel sheet that is easily magnetized against a magnetic flux flowing in a specific direction (easy magnetization direction) and has a small iron loss. This grain-oriented electrical steel sheet is rolled from a roll-shaped steel sheet and manufactured into a strip shape. At this time, the rolling direction (longitudinal direction) at the time of manufacture becomes the easy magnetization direction. However, in a stator core having a cylindrical yoke portion and a tooth portion protruding inward in the radial direction from the yoke portion, an annular member is punched from the directional electromagnetic steel sheet to integrally form the stator core. I can't. That is, in general, magnetic flux flows in the tooth portion in the radial direction, and magnetic flux flows in the circumferential direction in the yoke portion, but since the easy magnetization direction is one direction, simply by punching the annular member, The easy magnetization directions of both yoke portions cannot coincide with the direction in which the magnetic flux flows. Therefore, there is a manufacturing method in which the yoke portion and the tooth portion are divided and formed in order to manufacture a stator core in which the easy magnetization direction and the direction of the magnetic flux flowing through the stator core coincide.

  Japanese Patent Laid-Open No. 7-135755 (Patent Document 1) discloses a method for manufacturing a stator core in which a strip-shaped thin plate is punched and core pieces for forming a stator core are continuously formed. In the method for manufacturing a stator core described in Patent Document 1, punching is performed in a state where the connecting portions are connected in the longitudinal direction of the thin plate, and each connecting portion of the connecting member is bent to obtain a core piece. A plurality of the core pieces are stacked in parallel with the axial direction of the rotor to form a stator core.

  According to the invention described in this publication, the thin plate is punched in the longitudinal direction to continuously form the core piece, so that it is not used for forming the core piece as compared to punching the annular core piece from the thin plate. The discharge of surplus parts can be reduced. Therefore, the yield is good.

  Japanese Patent Laid-Open No. 10-271716 (Patent Document 2) discloses a method for manufacturing a stator core that has a small iron loss and can increase the magnetic flux density. In the stator core manufacturing method described in Patent Document 2, the longitudinal direction of the yoke material connected by the thin-walled portion and the easy magnetization of the grain-oriented electrical steel sheet so that the direction of the magnetic flux flowing through the yoke portion coincides with the easy magnetization direction. Punched with the same orientation (longitudinal direction). In addition, the longitudinal direction of the tooth material connected by the thin-walled portion is punched so as to be orthogonal to the easy magnetization direction (longitudinal direction) of the grain-oriented electrical steel sheet so that the direction of the magnetic flux flowing through the teeth portion coincides with the easy magnetization direction. . The yoke material punched in this way and the tooth material are laminated and then formed into an annular shape, or are formed into an annular shape and then laminated, and the laminated yoke body and the laminated tooth body are coupled and fixed to form a stator core.

According to the invention described in this publication, the direction of the magnetic flux flowing through the stator core coincides with the easy magnetization direction of the grain-oriented electrical steel sheet constituting the yoke portion and the tooth portion, so that a stator core with a small iron loss can be manufactured.
JP 7-135755 A JP-A-10-271716

  However, in the stator core manufacturing method described in Patent Document 1, only the improvement in yield is considered, and the direction of magnetic flux flowing through the stator core and the direction of easy magnetization of the steel sheet are not taken into consideration.

  In the stator core manufacturing method described in Patent Document 2, a strip-shaped yoke material is punched from a grain-oriented electrical steel sheet, and the yoke material is formed into an annular shape and laminated to form a yoke portion. Therefore, although the yield is better than that of punching the annular member, there is no change in punching the yoke material, and there is a problem that the yield is poor. Furthermore, in the method for manufacturing a stator core described in Patent Document 2, it is struck so that the longitudinal direction of the teeth material is orthogonal to the longitudinal direction of the directional electromagnetic steel sheet, that is, coincides with the width direction of the directional electromagnetic steel sheet. Unplugged. Therefore, it is necessary to set the width of the grain-oriented electrical steel sheet to be long according to the tooth material. The longer the width of the grain-oriented electrical steel sheet, the more easily the direction-oriented electrical steel sheet bends when punched, so the distortion of the teeth material, that is, the distortion of the tooth portion increases, and the iron loss increases as the strain increases. There was a problem.

  The present invention has been made to solve the above-mentioned problems, and its object is to produce a stator core with good yield and low iron loss, an electric motor having a stator core produced by the production method, and It is to provide a manufacturing apparatus.

  A stator core manufacturing method according to a first aspect of the present invention is a stator core manufacturing method in which a yoke portion and a teeth portion are divided and manufactured. This manufacturing method includes a step of forming a yoke part by laminating directional electromagnetic steel sheets in an annular shape so that the direction of easy magnetization of the band-shaped directional electromagnetic steel sheets is a circumferential direction, and a strip-shaped non-directional property. Teeth portion forming step of forming a tooth portion by continuously punching a tooth shape body in which a plurality of comb teeth are connected from an electromagnetic steel sheet in the longitudinal direction of the non-oriented electromagnetic steel sheet, and winding the tooth shape body in a spiral shape; And a joining step for joining the yoke part and the tooth part. The teeth-shaped body is a band-shaped member after being punched by a press when forming a tooth portion and before being wound and laminated.

  According to the first invention, since the yoke portion is formed by laminating the directional electromagnetic steel sheet in an annular shape without punching, the yield can be improved. Further, since the easy magnetization direction is oriented in the circumferential direction and coincides with the direction of the magnetic flux flowing through the yoke portion, the iron loss can be reduced. Since the tooth-shaped body is punched in the longitudinal direction of the non-oriented electrical steel sheet, the width of the non-oriented electrical steel sheet does not need to match the length of the tooth-shaped body, and may be adjusted to the width of the tooth-shaped body. Therefore, when punching the teeth-shaped body, the non-oriented electrical steel sheet is less likely to bend than when the teeth-shaped body is punched in the width direction, so that a tooth portion with less strain can be formed. At this time, since the tooth-shaped body is punched from the non-oriented electrical steel sheet, there is no easy magnetization direction in the teeth portion, and the direction in which the magnetic flux flows and the easy magnetization direction are not orthogonal. Therefore, iron loss does not increase. As a result, it is possible to provide a method for manufacturing a stator core with good yield and low iron loss.

  In the stator core manufacturing method according to the second aspect of the invention, in addition to the configuration of the first aspect, the teeth portion forming means is provided on the inner peripheral portion of the yoke portion so that the cross section of the yoke portion and the tooth portion are joined. Forming a joint with the tooth portion.

  According to 2nd invention, the cross section of a yoke part and a teeth part can be joined by joining a teeth part to the joined part formed in the inner peripheral part of a yoke part. Thereby, since the magnetic flux which flows from a teeth part to a yoke part flows in from the cross section of a yoke part, it will flow in into the cross section of a grain-oriented electrical steel sheet. Here, an eddy current is generated along with the flow of magnetic flux. However, since the cross section of the grain-oriented electrical steel sheet has a smaller area than the inner peripheral surface of the yoke portion, the eddy current hardly flows. Therefore, when magnetic flux flows into the cross section of the yoke portion, eddy current loss is smaller than when magnetic flux flows perpendicularly to the tangential direction of the inner peripheral surface of the yoke portion. As a result, it is possible to flow the magnetic flux in a direction in which the iron loss is difficult to increase.

  In the stator core manufacturing method according to the third aspect of the invention, in addition to the configuration of the first or second aspect of the invention, the joining step includes a step of joining the yoke part and the tooth part with a force spreading in the radial direction of the tooth part.

  According to the third invention, the tooth portion and the yoke portion can be joined by the force spreading in the radial direction of the tooth portion. For this reason, the teeth portion tends to be in close contact with the yoke portion. As a result, the gap between the joint portion of the tooth portion and the yoke portion can be reduced, and the magnetic flux flowing from the tooth portion to the yoke portion can be made easier to flow.

  In the stator core manufacturing method according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the yoke portion forming step includes a step of fixing the laminated grain-oriented electrical steel sheets.

  According to the fourth invention, the laminated directional electromagnetic steel sheets are fixed to each other, whereby the laminated directional electromagnetic steel sheets can be prevented from being separated from each other, and the yoke portion can be prevented from being separated.

  In the stator core manufacturing method according to the fifth aspect of the invention, in addition to the configuration of any one of the first to third aspects of the invention, the teeth portion forming step abuts on the inner peripheral surface of the yoke portion to move the yoke portion in the radial direction. Forming a contact portion to be held in the tooth portion;

  According to the fifth aspect, the tooth portion can be brought into contact with the inner peripheral surface of the yoke portion. For this reason, a yoke part is hold | maintained from an internal peripheral surface by the teeth part. As a result, it is possible to prevent the formed yoke portion from being scattered.

  In the stator core manufacturing method according to the sixth aspect of the invention, in addition to the configuration of any one of the first to third aspects of the invention, the yoke portion forming step includes a step of holding the yoke portion in the radial direction from the inner peripheral side.

  According to the sixth aspect, the yoke portion can be held in the radial direction from the inner peripheral side. As a result, it is possible to prevent the laminated yoke portions from being scattered.

  In the stator core manufacturing method according to the seventh aspect of the invention, in addition to the configuration of the first aspect of the invention, the teeth portion forming step is such that the connecting portion connecting the comb teeth is located on the inner peripheral side and the connecting portion is deformed. A step of spirally winding the teeth-shaped body.

  According to the seventh invention, since the teeth-shaped body is spirally wound so that the connecting portion for connecting the comb teeth is located on the inner peripheral side and the connecting portion is deformed, the connecting portion is plastically deformed. To do. Thereby, losses, such as an iron loss in a connection part, increase and the magnetic flux which flows between comb teeth is suppressed.

  In the stator core manufacturing method according to the eighth invention, in addition to the structure of any one of the first to seventh inventions, the coil combined with the stator core is a coil that is wound around each comb tooth independently.

  According to the eighth invention, since the coil is wound around each comb tooth independently, it is not necessary to wind the coil over a plurality of comb teeth, and the coil can be easily wound, so that the workability is improved.

  An electric motor according to a ninth aspect of the invention has a stator core manufactured according to any one of the first to eighth aspects of the invention.

  According to the ninth invention, the electric motor has the stator core manufactured according to any one of the first to eighth inventions. As a result, it is possible to provide an electric motor having a stator core with good yield and low iron loss.

  In the electric motor according to the tenth invention, in addition to the structure of the ninth invention, the material of the tooth portion is a material having a smaller iron loss than the material of the yoke portion.

  According to the tenth invention, the non-oriented electrical steel sheet is made of a material having a smaller iron loss than that of the directional electrical steel sheet, and can be made smaller than the iron loss in the teeth portion. As a result, for example, when the magnetic flux density of the magnetic flux flowing through the tooth portion is larger than the magnetic flux density of the magnetic flux flowing through the yoke portion, the iron loss of the tooth portion is preferentially reduced to improve the performance of the electric motor efficiently. be able to.

  A stator core manufacturing apparatus according to an eleventh aspect of the present invention is a stator core manufacturing apparatus that divides and manufactures a yoke part and a tooth part. This manufacturing apparatus includes a yoke portion forming means for forming the yoke portion by laminating the directional electromagnetic steel plates in an annular shape so that the easy magnetization direction of the belt-shaped directional electromagnetic steel plates is a circumferential direction, A non-oriented electrical steel sheet is formed by continuously punching a tooth-shaped body in which a plurality of comb teeth are connected in the longitudinal direction of the non-oriented electrical steel sheet and winding the tooth-shaped body in a spiral shape to form a tooth portion. Teeth part forming means and joining means for joining the yoke part and the tooth part are included. The teeth-shaped body is a band-shaped member after being punched by a press when forming a tooth portion and before being wound and laminated.

  According to the eleventh invention, since the yoke portion is formed by laminating the directional electromagnetic steel sheets in an annular shape without punching, the yield can be improved. Further, since the easy magnetization direction is oriented in the circumferential direction and coincides with the direction of the magnetic flux flowing through the yoke portion, the iron loss can be reduced. In addition, since the tooth-shaped body is punched in the longitudinal direction of the non-oriented electrical steel sheet, the width of the non-oriented electrical steel sheet does not need to match the length of the tooth-shaped body. Good. Therefore, when punching the teeth-shaped body, the non-oriented electrical steel sheet is less likely to bend than when the teeth-shaped body is punched in the width direction, so that a tooth portion with less distortion can be formed. At this time, since the tooth-shaped body is punched from the non-oriented electrical steel sheet, there is no easy magnetization direction in the teeth portion, and the direction in which the magnetic flux flows and the easy magnetization direction are not orthogonal. Therefore, iron loss does not increase. As a result, it is possible to provide a stator core manufacturing apparatus with good yield and low iron loss.

  In the stator core manufacturing apparatus according to the twelfth aspect of the invention, in addition to the configuration of the eleventh aspect of the invention, the teeth portion forming means includes an inner peripheral portion of the yoke portion so that the cross section of the grain-oriented electrical steel sheet and the teeth portion are joined. Means for forming a joint portion with the tooth portion.

  According to the twelfth aspect, the cross section of the yoke part and the tooth part can be joined by joining the tooth part to the joint part formed on the inner peripheral part of the yoke part. Thereby, since the magnetic flux which flows from a teeth part to a yoke part flows in from the cross section of a yoke part, it will flow in into the cross section of a grain-oriented electrical steel sheet. Here, an eddy current is generated along with the flow of magnetic flux. However, since the cross section of the grain-oriented electrical steel sheet has a smaller area than the inner peripheral surface of the yoke portion, the eddy current hardly flows. Therefore, when magnetic flux flows into the cross section of the yoke portion, eddy current loss is smaller than when magnetic flux flows perpendicularly to the tangential direction of the inner peripheral surface of the yoke portion. As a result, it is possible to flow the magnetic flux in a direction in which the iron loss is difficult to increase.

  In the stator core manufacturing apparatus according to the thirteenth aspect of the invention, in addition to the configuration of the eleventh or twelfth aspect of the invention, the joining means includes means for joining the yoke portion with a force spreading in the radial direction of the tooth portion.

  According to the thirteenth aspect, the tooth portion and the yoke portion can be joined by the force spreading in the radial direction of the tooth portion. For this reason, the teeth portion tends to be in close contact with the yoke portion. As a result, the gap between the joint portion of the tooth portion and the yoke portion can be reduced, and the magnetic flux flowing from the tooth portion to the yoke portion can be made easier to flow.

  In the stator core manufacturing apparatus according to the fourteenth invention, in addition to the configurations of the eleventh to thirteenth inventions, the yoke portion forming means includes means for fixing the laminated grain-oriented electrical steel sheets.

  According to the fourteenth invention, the laminated directional electromagnetic steel sheets are fixed to each other, whereby the laminated directional electromagnetic steel sheets can be prevented from being separated from each other, and the yoke portion can be prevented from being separated.

  In the stator core manufacturing apparatus according to the fifteenth aspect of the invention, in addition to the configuration of any of the eleventh to thirteenth aspects of the invention, the teeth portion forming means abuts against the inner peripheral surface of the yoke portion and causes the yoke portion to move in the radial direction. Means for forming the holding contact portion on the tooth portion is included.

  According to the fifteenth aspect, the teeth portion can be brought into contact with the inner peripheral surface of the yoke portion. For this reason, a yoke part is hold | maintained from an internal peripheral surface by the teeth part. As a result, it is possible to prevent the formed yoke portion from being scattered.

  In the stator core manufacturing apparatus according to the sixteenth invention, in addition to the structure of any of the eleventh to thirteenth inventions, the yoke portion forming means includes a step of holding the yoke portion in the radial direction from the inner peripheral side.

  According to the sixteenth aspect, the yoke portion can be held in the radial direction from the inner peripheral side. As a result, it is possible to prevent the laminated yoke portions from being scattered.

  In the stator core manufacturing apparatus according to the seventeenth aspect of the invention, in addition to the configuration of the eleventh aspect of the invention, the teeth portion forming means deforms the connecting portion so that the connecting portion connecting the comb teeth is located on the inner peripheral side. Means for spirally winding the teeth-shaped body.

  According to the seventeenth aspect, since the teeth-shaped body is spirally wound so that the connecting portion connecting the comb teeth is located on the inner peripheral side and the connecting portion is deformed, the connecting portion is plastically deformed. To do. Thereby, losses, such as an iron loss in a connection part, increase and the magnetic flux which flows between comb teeth is suppressed.

  In the stator core manufacturing apparatus according to the eighteenth aspect of the invention, in addition to the structure of any of the eleventh to seventeenth aspects, the coil combined with the stator core is a coil that is wound around each comb tooth independently.

  According to the eighteenth aspect, since the coil is wound around each comb tooth independently, it is not necessary to wind the coil over a plurality of comb teeth, the coil can be easily wound, and workability is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
Referring to FIG. 1, the electric motor according to the present embodiment includes an outer case 100, a stator core 102 accommodated in the outer case 100, a coil 104 wound around the stator core 102, and the stator core 102. And a rotor 108 that rotates about a rotation shaft 106.

  Stator core 102 includes a yoke portion 110 and a tooth portion 112 joined to the inner peripheral portion of yoke portion 110. After yoke part 110 and teeth part 112 are formed separately, teeth part 112 is joined to the inner peripheral part of yoke part 110, and stator core 102 is formed. The coil 104 is wound around the tooth portion 112. When an alternating current is passed through the coil 104, magnetic flux flows through the yoke portion 110 in the circumferential direction and through the tooth portion 112 in the radial direction, as indicated by arrows in the figure.

  With reference to FIG. 2, the manufacturing method of the yoke part 110 is demonstrated in detail. Here, as the material of the yoke portion 110, a grain-oriented electrical steel sheet 300 having an easy magnetization direction with little iron loss with respect to magnetic flux flowing in a specific direction, and rolled and annealed is used. The grain-oriented electrical steel sheet 300 is also an adhesive steel sheet having an adhesive 302 applied on both sides.

  The yoke part 110 includes a feed roller 200 that feeds the directional electromagnetic steel sheet 300, a winding machine 202 that winds the rolled directional electromagnetic steel sheet 300, a heater 204 that heats the yoke part 110, and the yoke part 110. It is formed through a manufacturing process using a grinder 205 that forms a joint 114 around the periphery.

  The feed roller 200 feeds the belt-shaped grain-oriented electrical steel sheet 300 in the longitudinal direction. At this time, in the grain-oriented electrical steel sheet 300, the feeding direction, that is, the longitudinal direction is the easy magnetization direction.

  The winding machine 202 winds the band-shaped directional electromagnetic steel sheet 300 and stacks it in the radial direction to form the yoke portion 110. For this reason, the easy magnetization direction of the yoke part 110 is oriented in the circumferential direction and coincides with the direction of the magnetic flux flowing through the yoke part 110. In addition, as shown in FIG. 2B, the directional electromagnetic steel sheet 300 and the adhesive 302 are alternately stacked on the yoke part 110.

  The heater 204 heats the yoke portion formed by the winding machine 202 and adheres (fixes) the laminated grain-oriented electrical steel sheets 300 to each other with the adhesive 302. By adhering the directional electromagnetic steel plates 300 in this way, even when the inner peripheral portion of the yoke portion 110 is cut out when forming the joint 114 described later, the laminated directional electromagnetic steel plates 300 are not scattered, The shape of the yoke part 110 can be maintained. In addition, instead of the bonded steel sheet, the directional electromagnetic steel sheets 300 are laminated, and then a sticking agent such as an adhesive is applied, or a capillary phenomenon or surface tension is used to adhere to the gaps between the directional electromagnetic steel sheets 300. An agent may be permeated.

  The grinder 205 cuts the inner peripheral portion of the yoke portion 110 into a V shape and exposes the cross section of the yoke portion 110 to form the joint portion 114 as shown in FIG. The outer end of the tooth portion 112 is joined to the joint portion 114.

  With reference to FIG. 3, the manufacturing method of the teeth part 112 is demonstrated in detail. Here, a non-oriented electrical steel sheet 304 having no easy magnetization direction is used as the material of the tooth portion 112. The teeth portion 112 includes a feed roller 206 that feeds the non-oriented electrical steel sheet 304, a press 208 that presses the non-oriented electrical steel sheet 304 and punches the tooth-shaped body 310, and a winding machine 210 that winds the tooth-shaped body 310. It is formed through a manufacturing process.

  The feed roller 206 feeds a strip-shaped non-oriented electrical steel sheet 304 in the longitudinal direction. The press machine 208 presses the non-oriented electrical steel sheet 304 fed by the feed roller 206 and punches the teeth-shaped body 310 in the longitudinal direction of the non-oriented electrical steel sheet 304. At this time, as shown in FIG. 3 (B), the teeth-shaped body 310 is punched out so that a plurality of comb teeth 306 having a triangular tip are connected by a connecting portion 308. Further, the press 208 punches two teeth-shaped bodies 310 from one non-oriented electrical steel sheet 304.

  The winding machine 210 winds the teeth-shaped body 310 punched out by the press machine 208 in a spiral shape so that the comb teeth 306 are on the outer peripheral side (the connecting portion 308 is on the inner peripheral side), and FIG. ), The teeth portion 112 is formed by laminating in the direction of the rotation axis. The coil 104 is wound by a coil winding machine (not shown) independently of each comb tooth 306 of the formed tooth portion 112.

  At this time, by spirally winding, distortion occurs in the plastically deformed part and increases the loss in the electromagnetic steel sheet, but in this structure, the connecting part 308 is deformed, so the loss of the connecting part 308 increases, Magnetic flux is difficult to flow. Thereby, since the magnetic flux which flows between the comb teeth 306 is suppressed, performance deterioration, such as the loss increase by winding, is not caused.

  As shown in FIG. 4A, the yoke part 110 and the tooth part 112 formed separately are wound around the coil 104, or after inserting a cassette-like coil separately manufactured, It joins in the state which the teeth part 112 has been arrange | positioned inside. When the tooth portion 112 is disposed, the tooth portion 112 is formed by spirally winding the tooth-shaped body 310, so that as shown by the arrow in FIG. Trying to spread radially outward. Therefore, the tips of the comb teeth 306 are in close contact with the joint portion 114 of the yoke portion 110. As a result, as shown in FIG. 4B, the gap between the yoke portion 110 and the tooth portion 112 is smaller than immediately after the placement of the tooth portion 112 (indicated by a broken line in the figure). Thereby, the magnetic flux flowing from the tooth portion 112 can easily flow to the yoke portion 110, and the magnetic flux loss at the joint portion 114 can be suppressed. After the teeth portion 112 is in close contact with the yoke portion 110, the whole is fixed by a mold or the like. In addition, since it is sufficient to use a well-known general technique for disposing and fixing the tooth portion 112 inward in the radial direction of the yoke portion 110, detailed description thereof will not be repeated here. Further, the teeth portion 112 may be disposed radially inward of the yoke portion 110 by an operator's manual work.

  Here, since the tooth part 112 is joined to the cross section of the yoke part 110, the magnetic flux flowing from the tooth part 112 to the yoke part 110 flows in a direction in which iron loss is unlikely to occur. This will be described in detail with reference to FIG.

  First, it is assumed that the joint portion is not formed on the inner peripheral portion of the yoke portion 110 and the tip of the tooth portion 112 is in contact with the tangential direction of the inner peripheral surface of the yoke portion 110 perpendicularly. In this case, the magnetic flux flowing through the tooth portion 112 flows perpendicularly to the tangential direction of the inner peripheral surface of the yoke portion 110 as shown in FIGS. On the other hand, when the joint portion 114 is formed and the tooth portion 112 is joined to the cross section of the yoke portion 110, the magnetic flux flowing from the tooth portion 112 is as shown in FIGS. It is input from the cross section of the yoke part 110, that is, the cross section of the grain-oriented electrical steel sheet 300.

When the magnetic flux flows through the yoke portion 110, as shown in FIGS. 5B and 5D, an eddy current is generated in the yoke portion 110 in the clockwise direction with respect to the direction of the magnetic flux according to the right-handed screw law. Occur. When the power value consumed by the eddy current is W, the voltage value of the eddy current is V, and the resistance value of the yoke portion 110 to the eddy current is R, W = V ² / R. Therefore, when the tip of the tooth part 112 is joined to the cross section of the yoke part 110 (FIG. 5C), it is in contact with the tangential direction of the inner peripheral surface of the yoke part 110 (FIG. 5). Compared with (A)), the area through which the eddy current flows is small and the resistance to the eddy current is large. For this reason, the power value consumed by the eddy current is small, and the eddy current loss is small. As a result, the tooth portion 112 can flow the magnetic flux flowing from the tooth portion 112 to the yoke portion 110 in a direction in which iron loss is unlikely to occur by joining the cross section of the yoke portion 110.

  The magnetic flux density of the magnetic flux flowing through each of the yoke part 110 and the tooth part 112 of the stator core 102 formed in this way will be described. An example of the magnetic flux density of the tooth portion 112 is shown in FIG. 6A, and an example of the magnetic flux density of the yoke portion 110 is shown in FIG. In these graphs, the vertical axis represents the magnetic flux density. The horizontal axis represents the order of the sine wave obtained by Fourier expansion of the waveform (distortion wave) of the magnetic flux density. Here, the fundamental wave has the order of 1. A harmonic having an order greater than 1 (a frequency that is an integer multiple of the fundamental wave) is a harmonic.

  Comparing the magnetic flux density flowing through the tooth portion 112 and the magnetic flux density flowing through the yoke portion 110, the magnetic flux density flowing through the tooth portion 112 is larger in both the fundamental wave and the harmonic. In particular, since the harmonics of the yoke part 110 are less than the teeth part 112, the iron loss generated in the yoke part 110 is smaller than the iron loss generated in the tooth part 112. Therefore, in order to improve the performance of the electric motor, it is more effective to reduce the iron loss of the tooth portion 112 than to reduce the iron loss of the yoke portion 110. Therefore, if an expensive material (for example, an amorphous steel plate) having a smaller iron loss is used only for the material of the tooth portion 112 and the iron loss of the tooth portion 112 is preferentially reduced, the iron loss of the yoke portion 110 is not reduced. However, the performance of the electric motor can be improved. That is, by making the material of the teeth portion 112 a material having a smaller iron loss than that of the yoke portion 110, it is possible to improve the performance of the electric motor while suppressing an increase in cost. Conversely, the material of the yoke part 110 may be a material having a larger iron loss than the material of the tooth part 112. Further, the thickness of the non-oriented electrical steel sheet 304 may be made thinner than that of the directional electrical steel sheet 300.

  With reference to FIG. 7, the manufacturing method of the stator core 102 of the electric motor which concerns on this Embodiment is demonstrated using a flowchart.

  In S100, the grain-oriented electrical steel sheet 300 is fed by the roller 200.

  In S102, the grain-oriented electrical steel sheet 300 is wound by the winding machine 202 and laminated in an annular shape. Thereby, the yoke part 110 is formed.

  In S <b> 104, yoke unit 110 is heated by heater 204. Thereby, the laminated grain-oriented electrical steel sheets 300 are bonded together.

  In S106, the inner peripheral part of the yoke part 110 is cut off by the grinder 205, and the joint part 114 is formed.

  In S <b> 108, the non-oriented electrical steel sheet 304 is fed by the roller 206.

  In S110, the tooth-shaped body 310 is punched from the non-oriented electrical steel sheet 304 by the press machine 208.

  In S112, the tooth-shaped body 310 is spirally wound by the winding machine 210 and stacked in the direction of the rotation axis. Thereby, the teeth part 112 is formed.

  In S114, the coil 104 is wound around the comb teeth 306 of the tooth portion 112.

  At S116, yoke portion 110 and teeth portion 112 are joined to form stator core 102.

  As described above, in the stator core of the electric motor according to the present embodiment, the yoke portion 110 is formed by laminating the directional electromagnetic steel sheets in an annular shape without punching, so there is no wasteful cutting and the yield is good. . Moreover, since the easy magnetization direction is oriented in the circumferential direction and coincides with the direction of the magnetic flux flowing through the yoke portion, the iron loss can be reduced. The teeth-shaped body 310 is punched in the longitudinal direction of the non-oriented electrical steel sheet 304. Thereby, it is not necessary to match the width of the non-oriented electrical steel sheet 304 with the length of the tooth-shaped body 310, and it is sufficient to match the width of the tooth-shaped body 310. Therefore, when the tooth-shaped body 310 is punched, the non-oriented electrical steel sheet 304 is less likely to bend than when the tooth-shaped body 310 is punched in the width direction, so that the tooth portion 112 with less strain can be formed. At this time, since the tooth-shaped body 310 is punched from the non-oriented electrical steel sheet 304, there is no easy magnetization direction in the tooth portion 112, and the direction in which the magnetic flux flows and the easy magnetization direction are not orthogonal. Therefore, iron loss does not increase. As a result, it is possible to provide a method for manufacturing a stator core with good yield and low iron loss.

<Second Embodiment>
The second embodiment will be described with reference to FIG. In the stator core 102 of the electric motor according to the present embodiment, no adhesive is applied to both surfaces of the grain-oriented electrical steel sheet 300. As shown in FIG. 8A, the tooth portion 112 includes a contact portion 116 for contacting the inner peripheral surface of the yoke portion 110. Other hardware configurations are the same as those in the first embodiment described above. The function about them is the same. Therefore, detailed description thereof will not be repeated here.

  As shown in FIG. 8B, the tooth-shaped body 312 is punched out by the press 208 so as to have the contact portions 116 on both sides of the comb teeth 306. As shown in FIG. 8C, the tooth-shaped body 312 is spirally wound and laminated. The contact part 116 contacts the inner peripheral surface of the yoke part 110 and holds the yoke part 110 from the inner peripheral surface side. Note that, until the yoke part 110 and the tooth part 112 are joined, the yoke part 110 may be held by a detachable jig (not shown).

  With reference to FIG. 9, the manufacturing method of the stator core 102 of the electric motor which concerns on this Embodiment is demonstrated using a flowchart.

  In S <b> 200, the grain-oriented electrical steel sheet 300 is fed by the roller 200.

  In S202, the grain-oriented electrical steel sheet 300 is wound by the winding machine 202 and laminated in an annular shape. Thereby, the yoke part 110 is formed.

  In S204, the yoke part 110 is held from the inner peripheral surface side by a jig (not shown).

  In S206, the inner peripheral part of the yoke part 110 is cut off by the grinder 205, and the joint part 114 is formed.

  In S208, the non-oriented electrical steel sheet 304 is fed by the roller 206.

  At S <b> 210, the tooth-shaped body 312 is punched from the non-oriented electrical steel sheet 304 by the press machine 208 so as to have the contact portion 116.

  In S212, the tooth-shaped body 312 is spirally wound by the winding machine 210 and stacked in the direction of the rotation axis. Thereby, the teeth part 112 is formed.

  In S214, the coil 104 is wound around the comb teeth 306 of the teeth portion 112.

  In S216, the yoke portion 110 and the tooth portion 112 are joined so that the contact portion 116 contacts the inner peripheral surface of the yoke portion 110, and the stator core 102 is formed.

  In S218, a jig (not shown) is removed.

  As described above, in stator core 102 of the electric motor according to the present embodiment, teeth portion 112 holds yoke portion 110 from the inner peripheral surface. As a result, even when the inner peripheral portion of the yoke portion 110 is cut out when forming the joint portion 114, the yoke portion 110 is not peeled off and separated inward in the radial direction.

<Third Embodiment>
The third embodiment will be described with reference to FIG. In the stator core 102 of the electric motor according to the present embodiment, the directional electromagnetic steel sheet 300 is not coated with an adhesive on both surfaces. The yoke part 110 is held from the inner peripheral surface side by the holder 118. Other hardware configurations are the same as those in the first embodiment described above. The function about them is the same. Therefore, detailed description thereof will not be repeated here.

  The holding tool 118 holds the yoke part 110 from the inner peripheral surface side. In this case, as shown in FIG. 10B, when the joint 114 is formed, the inner peripheral portion of the yoke 110 is cut together with the holder 118 by the grinder 205 to form the joint 114. Further, as shown in FIG. 10C, a bolt hole 120 is provided in the holder 118, the bolt hole 120 and the bolt hole 124 of the outer case 122 are made to coincide with each other, the bolt is inserted, and the nut is screwed. Thus, the outer case 122 may be attached.

  Referring to FIG. 11, a method for manufacturing stator core 102 of the electric motor according to the present embodiment will be described using a flowchart. In the present embodiment, S104 in the first embodiment described above is replaced with S300. Since other flows are the same as those in the first embodiment, detailed description thereof will not be repeated here.

  In S300, the holder 118 is inserted radially inward of the yoke portion 110 so as to come into contact with the inner peripheral surface of the yoke portion 110.

  As described above, in stator core 102 of the electric motor according to the present embodiment, holder 118 holds yoke portion 110 from the inner peripheral surface. As a result, even when the inner peripheral portion of the yoke portion 110 is cut out when forming the joint portion 114, the yoke portion 110 is not peeled off and separated inward in the radial direction.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the structure of the electric motor which concerns on 1st Embodiment. It is a figure which shows the manufacturing process of a yoke part. It is a figure which shows the manufacturing process of a teeth part. It is a figure which shows the state which the yoke part and the teeth part joined. It is a figure which shows the magnetic flux which flows between a yoke part and a teeth part. It is the graph which showed the magnetic flux density of the magnetic flux which flows through a yoke part and a teeth part. It is a flowchart which shows the manufacturing method of the stator core of the electric motor which concerns on 1st Embodiment. It is a figure which shows the teeth part in the stator core of the electric motor which concerns on 2nd Embodiment. It is a flowchart which shows the manufacturing method of the stator core of the electric motor which concerns on 2nd Embodiment. It is a figure which shows the holder which hold | maintains the yoke part in the stator core of the electric motor which concerns on 3rd Embodiment. It is a flowchart which shows the manufacturing method of the stator core of the electric motor which concerns on 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 102 Stator core, 110 Yoke part, 112 teeth part, 114 joint part, 116 contact part, 118 holder, 202 winding machine, 204 heating machine, 205 grinder, 208 press machine, 210 winding machine, 300 directionality electrical steel sheet , 302 Adhesive, 304 Non-oriented electrical steel sheet, 306 comb teeth, 308 connection part, 310, 312 Teeth shape body.

Claims (18)

A stator core manufacturing method in which a yoke portion and a teeth portion are divided and manufactured,
A yoke portion forming step of forming the yoke portion by laminating the directional electromagnetic steel plates in an annular shape so that the easy magnetization direction of the band-shaped directional electromagnetic steel plates is a circumferential direction;
From the strip-shaped non-oriented electrical steel sheet, a plurality of comb-shaped teeth-shaped bodies are continuously punched in the longitudinal direction of the non-oriented electrical steel sheet, and the teeth-shaped body is spirally wound to form the teeth portion. Teeth portion forming step for forming,
A method for manufacturing a stator core, comprising: a joining step for joining the yoke part and the tooth part.   The tooth portion forming step includes a step of forming a joint portion with the tooth portion on an inner peripheral portion of the yoke portion so that a cross section of the yoke portion and the tooth portion are joined. Manufacturing method of stator core.   3. The method of manufacturing a stator core according to claim 1, wherein the joining step includes a step of joining the yoke part and the tooth part with a force spreading in a radial direction of the tooth part.   The stator core manufacturing method according to any one of claims 1 to 3, wherein the yoke portion forming step includes a step of fixing the laminated grain-oriented electrical steel sheets together.   The tooth portion forming step includes a step of forming, on the tooth portion, a contact portion that contacts the inner peripheral surface of the yoke portion and holds the yoke portion in the radial direction. The manufacturing method of the stator core as described in 2.   The stator core manufacturing method according to claim 1, wherein the yoke portion forming step includes a step of holding the yoke portion in a radial direction from an inner peripheral side.   The teeth portion forming step includes a step of winding the teeth-shaped body in a spiral shape so that a connecting portion connecting the comb teeth is located on an inner peripheral side and deforming the connecting portion. Item 2. A method for producing a stator core according to Item 1.   The method of manufacturing a stator core according to any one of claims 1 to 7, wherein the coil combined with the stator core is a coil wound around each of the comb teeth independently.   The electric motor which has a stator core manufactured by the manufacturing method of the stator core in any one of Claim 1 thru | or 8.   The electric motor according to claim 9, wherein a material of the tooth portion is a material having a smaller iron loss than a material of the yoke portion. A stator core manufacturing apparatus that divides and manufactures a yoke part and a tooth part,
Yoke part forming means for forming the yoke part by laminating the directional electromagnetic steel sheets in an annular shape so that the easy magnetization direction of the band-shaped directional electromagnetic steel sheets is a circumferential direction;
From the strip-shaped non-oriented electrical steel sheet, a teeth-shaped body in which a plurality of comb teeth are connected is continuously punched in the longitudinal direction of the non-oriented electrical steel sheet, and the teeth-shaped body is spirally wound to form the teeth portion. Teeth part forming means for forming
An apparatus for manufacturing a stator core, comprising joining means for joining the yoke part and the tooth part.   The teeth portion forming means includes means for forming a joint portion with the tooth portion on an inner peripheral portion of the yoke portion so that a cross section of the grain-oriented electrical steel sheet and the tooth portion are joined. Item 12. A stator core manufacturing apparatus according to Item 11.   The stator core manufacturing apparatus according to claim 11 or 12, wherein the joining means includes means for joining the yoke part and the tooth part with a force spreading in a radial direction of the tooth part.   The stator core manufacturing apparatus according to any one of claims 11 to 13, wherein the yoke portion forming means includes means for fixing the laminated directional electromagnetic steel sheets together.   The teeth portion forming means includes means for forming, on the teeth portion, an abutting portion that abuts on an inner peripheral surface of the yoke portion and holds the yoke portion in a radial direction. The stator core manufacturing apparatus according to any one of the above.   The stator core manufacturing apparatus according to claim 11, wherein the yoke portion forming means includes means for holding the yoke portion in a radial direction from an inner peripheral side.   The teeth portion forming means includes means for spirally winding the teeth-shaped body so that a connecting portion for connecting the comb teeth is located on an inner peripheral side and the connecting portion is deformed. The stator core manufacturing apparatus according to claim 11. The stator core manufacturing apparatus according to any one of claims 11 to 17, wherein the coil combined with the stator core is a coil wound around each of the comb teeth independently.

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