JP2006174536A - Wound core and its manufacturing method, motor core and its manufacturing method, and sr motor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wound core, where the magnetic characteristics of a curved angle mode disordered at rewinding of an electromagnetic steel plate is improved effectively, and its manufacturing method, a motor core and its manufacturing method, and an SR motor and its manufacturing method. <P>SOLUTION: The sectional form in a direction perpendicular to the axis of the wound core 2 is substantially the shape of a rectangle or a square which is equipped with an opening 24 at the center and is composed of a straight part 22 and a curved angle 23; and for an electromagnetic steel plate, a directional electromagnetic steel plate 21 with its rolling direction being along the sectional form is used; and varnish 5 is filled and hardened between adjacent turns of the directional electromagnetic steel plate 21. Tension arises at the curved angle 23 due to the shrinkage and hardening of the varnish 5 of the straight part 22, and the magnetic characteristics of the curved angle 23 disordered at rewinding of the directional electromagnetic steel plate 21 is improved. The motor cores 3 are manufactured by halving the wound core 2, and the motor cores 3 are mounted on the side of a stator and the side of a rotor so as to manufacture the SR motor 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wound core and a method for manufacturing the same, a motor core and a method for manufacturing the same, an SR motor and a method for manufacturing the same, and in particular, the magnetic characteristics of the curved corners that are disturbed during winding of the electrical steel sheet are effectively improved. The wound core, the motor core, the SR motor including the motor core, and the manufacturing method thereof.

  A conventional SR motor (switched reluctance motor) energizes a coil formed around a plurality of teeth protruding radially inward of a ring-shaped back yoke constituting a stator, thereby magnetizing a central rotor. A configuration of rotating with suction force is common. This stator is formed by laminating a plurality of electromagnetic steel sheets obtained by punching a slot between a central portion of a circular electromagnetic steel sheet and teeth. Since the magnetic field generated by energizing the coil needs to flow in the direction toward the radial direction of the stator in the teeth and in the circumferential direction of the stator in the back yoke, the magnetic steel sheet used is non-directional electromagnetic A steel plate was used. In this non-oriented electrical steel sheet, the crystal axis directions are arranged as randomly as possible. On the other hand, a magnetic steel sheet having the easy axis of magnetization aligned in the rolling direction as much as possible is a grain-oriented magnetic steel sheet, and this grain-oriented magnetic steel sheet has excellent magnetic properties in the rolling direction of the steel sheet. Patent Document 1 discloses an invention in which this grain-oriented electrical steel sheet is applied to an SR motor. This SR motor has a configuration in which a winding core formed by winding an electromagnetic steel sheet is divided into two to form a motor core, a predetermined number of the motor cores are mounted on the stator and the rotor, and the rotor and the stator are arranged to face each other in the plane direction. It is a motor.

  On the other hand, the inventors have intensively studied and succeeded in developing an SR motor using a grain-oriented electrical steel sheet as described above. This SR motor is formed by dividing a winding core into two to form a motor core and mounting the motor core on a stator and a rotor. The motor core has a substantially U-shaped cross-sectional view in a direction orthogonal to the axial direction of the motor core, and the motor core mounted on the stator is disposed so that the open side of the substantially U-shaped side faces the central rotor side. The motor core mounted on the rotor is disposed such that the substantially U-shaped open side faces the outer stator side. That is, the motor has a configuration in which the rotor is disposed inside the stator. On both the stator side and the rotor side, the motor cores are stacked one above the other, and a coil is wound around a substantially U-shaped hollow portion of the two motor cores on the stator side, thereby forming salient poles (for example, 4-phase 8-pole stator × 6-pole rotor (8/6 configuration)).

  Here, the rolling direction of the grain-oriented electrical steel sheet used is directed in a direction along a substantially U-shape.

By the way, the above-described wound core has a cross-sectional shape in a direction orthogonal to the axial direction, and is formed in a substantially rectangular shape or a substantially square shape having an opening at the center and a straight line portion and a curved corner portion. Yes. By dividing this into two in the axial direction of the winding core, a motor core having a substantially U-shaped sectional view as described above is formed. When manufacturing this wound core, deformation stress tends to concentrate at the corners of the curve described above, resulting in a problem that the magnetic properties of the electromagnetic steel sheet are deteriorated. In addition, regarding the SR motor disclosed in Patent Document 1, there is no description of a measure for eliminating the magnetic characteristic reduction that occurs at the corner portion of the curve.
JP 2004-248370 A

  The present invention has been made in view of the above-described problems, and in a motor core obtained by dividing a wound electromagnetic steel sheet into two, a winding in which a decrease in magnetic characteristics that may occur at a curved corner portion of the motor core is improved. It is an object of the present invention to provide a core, a motor core, an SR motor including the motor core, and a manufacturing method thereof.

  In order to achieve the above object, the wound core according to the present invention is a wound core formed by winding an electromagnetic steel sheet, and varnish is filled and cured between adjacent electromagnetic steel sheets. To do.

  The wound core of the present invention is formed by winding a predetermined number of directional electrical steel sheets and non-oriented electrical steel sheets having directionality in the winding direction. Between the adjacent electrical steel sheets, varnishes generally used for fixing windings such as unsaturated polyesters and modified polyesters are filled and hardened, and the electrical steel sheets are secured by interposition of the varnishes. Can do.

  Further, in a preferred embodiment of the wound core according to the present invention, the cross-sectional shape of the wound core in the direction perpendicular to the axial center is a substantially rectangular or substantially square shape having an opening at the center and comprising a straight portion and a curved corner portion. The electromagnetic steel sheet is composed of a directional electromagnetic steel sheet in which the direction along the cross-sectional shape is the rolling direction of the electromagnetic steel sheet, and varnish is filled and hardened between the adjacent electromagnetic steel sheets. The magnetic characteristics of the curved corner portion disturbed during winding of the magnetic steel sheet are improved by the tension generated in the curved corner portion by hardening of the varnish.

  At the curved corners of the wound core, as described above, the magnetic properties are disturbed when the electromagnetic steel sheet is wound. By the way, it is a well-known fact that magnetic properties are improved in a direction that is stable in terms of potential energy by applying tension to a site where the magnetic properties are disturbed. In particular, in a grain-oriented electrical steel sheet having directionality, by applying a tension along the direction, the behavior of the magnetic moment is easily aligned with the magnetization direction, and the improvement in magnetic properties is remarkable. . In addition, it is desirable that the tension is equal to or lower than the critical tension that becomes the elastic deformation limit of the electrical steel sheet, for example.

  Of the wound core, the area of the straight part is larger than the area of the corner part of the curve, and the straight part is more easily filled with varnish between the electromagnetic steel sheets, so that the varnish of the straight part shrinks and hardens. As a result, a tension is generated as a reaction at the corner of the curve. Such tension can improve the magnetic characteristics disturbed at the corners of the curve.

  In addition, according to experiments by the inventors, it has been demonstrated that improvement in motor performance (magnetic flux density with respect to magnetic field strength) is achieved by filling and hardening varnish between electromagnetic steel sheets. The results of this experiment will be described later.

  In the motor core according to the present invention, the winding core is divided into two in the axial direction, so that the cross-sectional shape in the direction orthogonal to the axial direction is formed in a substantially U-shape. And

  The motor core of the present invention is used for an SR motor developed by the inventors as described above. It is formed by dividing the winding core with improved magnetic characteristics at the corners of the curve into two in the axial direction.

  The SR motor according to the present invention is characterized in that the motor core is mounted on a rotor and a stator.

  This SR motor has an appropriate number of poles, such as a three-phase 6-pole stator × 4-pole rotor (6/4 configuration) and a 4-phase 8-pole stator × 6-pole rotor (8/6 configuration). A motor can be selected. On both the stator side and the rotor side, the motor core is vertically stacked, and a coil is wound around a substantially U-shaped hollow portion of the two motor cores on the stator side.

  An SR motor with high output performance can be obtained by using a motor core with improved magnetic characteristics at the corners of the curve as the SR motor provided in the rotor and stator.

  Moreover, the manufacturing method of the winding core by this invention is a manufacturing method of the winding core formed by winding an electromagnetic steel plate, Comprising: The wound electromagnetic steel plate is immersed in a varnish.

  In the present invention, a final wound core is manufactured by winding a magnetic steel sheet to form a wound core in the manufacturing process, immersing the entire wound core in the manufacturing process in a varnish tank, and then performing a baking process. . When the varnish in the straight part of the wound core is contracted and hardened during the baking process, a tension acts on the corner of the curve, and the magnetic properties of the part are improved. It has been proved by the inventors that the effect of improving the magnetic properties is more remarkable in the grain-oriented electrical steel sheet than in the non-oriented electrical steel sheet.

  A preferred embodiment of the method for manufacturing a wound core according to the present invention is a method for manufacturing a wound core formed by winding an electromagnetic steel sheet, and after dropping varnish on the already wound electromagnetic steel sheet The magnetic steel sheet is wound.

  In the present invention, when winding the electromagnetic steel sheet, a predetermined amount of varnish is dropped onto the already wound electromagnetic steel sheet, and then the electromagnetic steel sheet is wound. Compared to the method in which the entire winding core is immersed in the varnish tank after winding the electromagnetic steel sheet, the varnish is surely interposed between the adjacent electromagnetic steel sheets, and the curve corner is closer to the desired tension. It becomes possible to act. After winding the magnetic steel sheet, a wound core is manufactured through a baking process.

  Further, a preferred embodiment of the method for manufacturing a wound core according to the present invention is a method for manufacturing a wound core formed by winding an electromagnetic steel plate, characterized by winding the electromagnetic steel plate after being immersed in a varnish. And

  In the present invention, when winding the electromagnetic steel sheet, the electromagnetic steel sheet is first passed through a varnish tank. By passing the electromagnetic steel sheet coming out of the varnish tank between two rollers arranged opposite to each other, it is possible to make the varnish on the surface of the electromagnetic steel sheet uniform and adjust the amount of attached varnish. The electromagnetic steel sheet after passing between the two rollers is wound, and then baking is performed.

  According to the present invention, the amount of varnish on the surface of the electrical steel sheet can be adjusted with high accuracy, and a desired tension can be applied to the curved corner.

  Further, the motor core manufacturing method according to the present invention is such that the winding core manufactured by the winding core manufacturing method is divided into two in the axial direction so that the cross-sectional shape in the direction perpendicular to the axial direction is substantially the same. A U-shaped motor core is manufactured.

  Furthermore, the SR motor manufacturing method according to the present invention is characterized in that the SR motor is manufactured by mounting the motor core manufactured by the motor core manufacturing method on a rotor and a stator.

  As can be understood from the above description, according to the wound core, the motor core, the SR motor including the motor core, and the manufacturing method thereof according to the present invention, the varnish is filled and cured in the electromagnetic steel sheet. It is possible to effectively improve the magnetic characteristics of the curved corner portions that are disturbed during winding, and as a result, it is possible to improve the output performance of the motor. Moreover, the improvement effect of output performance becomes more remarkable by using a grain-oriented electrical steel sheet as an electrical steel sheet.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an embodiment of the SR motor of the present invention, and FIG. 2 is a schematic diagram showing contraction force and tension acting on the wound core. 3-5 is the figure which showed embodiment of the manufacturing method of the winding core of this invention, respectively. FIG. 6 shows an output of an SR motor made of a non-oriented electrical steel sheet in which no varnish is interposed between the magnetic steel sheets, and an SR motor made of a non-oriented electrical steel sheet manufactured by the method for manufacturing a wound core of the present invention. FIG. 7 is a graph showing the relationship between the magnetic field strength and the magnetic flux density. FIG. 7 is a graph showing the relationship between the magnetic field strength and the magnetic flux density. It is the experimental result which compared the output performance with the SR motor which consists of a grain-oriented electrical steel sheet manufactured by the manufacturing method of the winding core of invention, The graph which showed each magnetic field intensity and the relationship of magnetic flux density is each shown. It should be noted that the SR motor shown in the drawing is an outline of the SR motor, and the SR motor of the present invention is not limited to the motor of the four-phase type 8-pole stator × 6 pole rotor configuration shown in the drawing. It is.

  FIG. 1 schematically shows an embodiment of an SR motor 1 according to the present invention. Eight salient poles are formed by arranging eight sets of motor cores 3, 3,... At equal intervals in the circumferential direction on the stator on the outer periphery constituting the SR motor 1, Six sets of motor cores 3, 3,... Are similarly arranged at equal intervals in the circumferential direction to form six salient poles. The motor core 3 has a substantially U-shaped cross-section in a direction perpendicular to the axial direction, and two sets of motor cores 3 and 3 are vertically stacked on the stator side and the rotor side. The pole is formed. The stator-side motor core 3 and the rotor-side motor core 3 are arranged such that their opening sides face each other. Further, in the motor cores 3 and 3 on the stator side, a coil 4 is formed by winding a conductive wire which is schematically shown between both hollow portions. By sequentially energizing the coil 4, a magnetic field is generated, and the rotor cores 3 and 3 are attracted by a magnetic attractive force, whereby the rotor can be rotated.

  The motor core 3 shown in FIG. 1 is formed by dividing the winding core 2 shown in FIG. 2 into two along the axial direction. The winding core 2 is formed, for example, by winding a directional electrical steel sheet 21 having directionality in the winding direction. Here, the varnish is filled and cured between the directional electromagnetic steel sheets 21 to be overlaid. In order to shape the motor core 3 so that its cross-sectional shape is substantially U-shaped, the wound core 2 has a cross-sectional shape in the direction perpendicular to the axial direction as shown in FIG. While having an opening 24, it is formed into a substantially rectangular shape (or a substantially square shape) composed of straight portions 22, 22, 22, 22 and curved corner portions 23, 23, 23, 23.

  When the winding core 2 is wound, the magnetic properties of the grain-oriented electrical steel sheet 21 are disturbed in the vicinity of the curved corner portion 23 as compared with the straight portion 22, and as a result, the flow of magnetic flux is hindered, and the output performance of the motor is reduced. It leads to decline. Therefore, a varnish is interposed between the directional electromagnetic steel sheets 21 to be overlaid, and cured by baking. In that case, the area of the straight line portion 22 is larger than the area of the curved corner portion 23, and the straight line portion 22 is more easily filled with varnish. In the direction of arrow X), the curved corner portion 23 is subjected to tension as a reaction (in the direction of arrow Y). Such a tension improves the disturbed magnetic characteristics in the vicinity of the curved corner portion 23.

  Next, a method for interposing (filling) varnish between the superposed directional electromagnetic steel sheets 21 will be described with reference to FIGS.

  In FIG. 3, after the directional electromagnetic steel sheet 21 is wound in advance to form the entire shape of the wound core 2, the wound core 2 is immersed in the varnish tank 7 and the varnish 5 is impregnated in the directional electromagnetic steel sheet 21. Shows how. The wound core 2 is manufactured by immersing the wound core 2 in the varnish tank 7 for a predetermined time and then removing it from the varnish tank 7 and baking the entire wound core 2.

  On the other hand, in FIG. 4, when winding the directional electromagnetic steel sheet 21, the varnishes 5, 5 are automatically dropped from the nozzles 6, 6 onto the already wound directional electromagnetic steel sheet 21, and the directional electromagnetic steel sheet 21. This shows how to perform winding. In such a method, it is necessary to adjust the winding speed and the dripping amount of the varnish 5. Furthermore, it is also necessary to adjust the number of nozzles 6 and the arrangement interval so that there is no unfilled portion of the varnish when the varnish 5 after dropping is spread by the directional electrical steel sheet 21 wound around. It becomes.

  FIG. 5 shows that the directional electromagnetic steel sheet 21 is first passed through the varnish tank 7, and then the directional electromagnetic steel sheet 21 coming out of the varnish tank 7 is passed between the two rollers 8 and 8 facing each other, and then wound. It shows how to do it. The interval between the rollers 8 is set so that the varnish 5 attached to the surface of the grain-oriented electrical steel sheet 21 is uniform over the entire surface and has a desired thickness.

  According to this method, fine adjustment of the amount of varnish required for generating a desired tension can be managed with high accuracy.

  Next, experimental results conducted by the inventors will be described. This experiment compares the magnetic flux density with respect to a certain magnetic field strength when the varnish is filled between magnetic steel sheets and when it is not filled. Here, an experiment was conducted in the case of using a grain-oriented electrical steel sheet (FIG. 7) and the case of using a non-oriented electrical steel sheet (FIG. 6). Furthermore, in a motor in which varnish is filled between electromagnetic steel sheets, a motor is manufactured for each of the three methods described above as a varnish filling method and compared. Hereafter, the method of immersing the winding core in the varnish tank shown in FIG. 3 is Method 1, the method of dripping the varnish shown in FIG. 4 is Method 2, and the electromagnetic steel sheet passed through the varnish tank shown in FIG. 5 is wound. The method is abbreviated as method 3 respectively.

  FIG. 6 shows the experimental results when a non-oriented electrical steel sheet is used. The graph X shows an SR motor made of a motor core not filled with varnish, and the graph Y shows a motor core manufactured by the method 1. A graph Z shows an SR motor composed of a motor core manufactured by the method 2, and a graph W shows an SR motor composed of a motor core manufactured by the method 3. Moreover, FIG. 7 is an experimental result at the time of using a grain-oriented electrical steel sheet, and the graphs X, Y, Z, and W have shown the same case as FIG.

  6 and 7, the magnetic flux density for a constant magnetic field strength (constant current) is higher when the varnish is filled, which is due to the improvement of the magnetic characteristics at the corners of the curve described above. It is. In addition, the magnetic flux density tends to increase in the order of methods 1, 2, and 3. This is because the varnish filled between the electromagnetic steel sheets is uniformly filled in the entire surface of the electromagnetic steel sheets in the order of this method. This is because the desired varnish thickness management is performed with higher accuracy.

  Further, by comparing FIG. 6 and FIG. 7, it can be understood that a larger motor output can be obtained when the directional electromagnetic steel sheet is used, and the SR motor equipped with the motor core made of the directional electromagnetic steel sheet is newly obtained. It can be seen that the output performance is excellent.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

The schematic diagram which showed one Embodiment of SR motor of this invention. The schematic diagram which showed the contraction force and tension which act on a winding core. The figure which showed one Embodiment of the manufacturing method of the winding core of this invention. The figure which showed other embodiment of the manufacturing method of the winding core of this invention. The figure which showed other embodiment of the manufacturing method of the winding core of this invention. The output performance of an SR motor made of a non-oriented electrical steel sheet in which no varnish is interposed between the electrical steel sheets and an SR motor made of a non-oriented electrical steel sheet manufactured by the method for manufacturing a wound core of the present invention were compared. It is an experimental result and the graph which showed the relationship between each magnetic field strength and magnetic flux density. Experimental results comparing the output performance of an SR motor made of a directional electromagnetic steel sheet in which no varnish is interposed between the electromagnetic steel sheets and an SR motor made of a directional electromagnetic steel sheet manufactured by the method for manufacturing a wound core of the present invention. The graph which showed the relationship between each magnetic field intensity and magnetic flux density.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... SR motor, 2 ... Winding core, 21 ... Directional electrical steel sheet, 22 ... Straight line part, 23 ... Curve corner part, 24 ... Opening part, 3 ... Motor core, 4 ... Coil, 5 ... Varnish, 6 ... Dropper, 7 ... Varnish tank, 8 ... Roller

Claims (9)

A wound core formed by winding a magnetic steel sheet,
A wound core characterized in that varnish is filled and hardened between adjacent electromagnetic steel sheets.   The cross-sectional view shape in the direction perpendicular to the axis of the wound core is a substantially rectangular or substantially square shape having an opening at the center and a straight portion and a curved corner portion, and the electromagnetic steel sheet follows the cross-sectional shape. It is made of a directional electrical steel sheet that has the rolling direction of the electrical steel sheet, varnish is filled and cured between adjacent electrical steel sheets, and due to the tension generated in the curved corner by the hardening of the varnish in the straight part, A wound core characterized in that the magnetic properties of a corner portion of a curved line disturbed during winding of an electrical steel sheet are improved.   The winding core according to claim 1 or 2 is divided into two in the axial direction, so that a cross-sectional shape in a direction perpendicular to the axial direction is formed into a substantially U-shape. Motor core to do.   An SR motor, wherein the motor core according to claim 3 is mounted on a rotor and a stator. A method of manufacturing a wound core formed by winding a magnetic steel sheet,
A method for producing a wound core, comprising immersing a wound electrical steel sheet in a varnish. A method of manufacturing a wound core formed by winding a magnetic steel sheet,
A method for manufacturing a wound core, comprising: winding a magnetic steel sheet after dropping a varnish on an already wound magnetic steel sheet. A method of manufacturing a wound core formed by winding a magnetic steel sheet,
A method for producing a wound core, characterized by winding a magnetic steel sheet after being immersed in a varnish.   The winding core manufactured by the method for manufacturing a winding core according to any one of claims 5 to 7 is divided into two in the axial direction so that a cross-sectional view shape in a direction perpendicular to the axial direction is substantially A motor core manufacturing method, wherein a motor core having a letter shape is manufactured.   An SR motor manufacturing method, wherein an SR motor is manufactured by mounting a motor core manufactured by the motor core manufacturing method according to claim 8 on a rotor and a stator.

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