HK1189100B - Manufacturing method for helical core for rotating electrical machine and manufacturing device for helical core for rotating electrical machine - Google Patents

Description

Method for manufacturing helical core for rotating electrical machine and device for manufacturing helical core for rotating electrical machine

Technical Field

The present invention relates to a method for manufacturing a helical core for a rotating electrical machine. In particular, the present invention is suitable for manufacturing a helical core (spiral core) used in a rotating electrical machine.

Background

A core of a stator of a rotating electrical machine such as a generator or a motor (hereinafter, referred to as a stator core as needed) is formed by laminating metal plates such as electromagnetic steel sheets, and includes a yoke extending in a circumferential direction of the stator core and a plurality of teeth extending from an inner circumferential surface of the yoke in a direction of a rotating shaft. In order to manufacture such a stator core, core pieces having the same shape as the yoke and the teeth when viewed in the thickness direction (shape on the plate surface) are punched out of a metal plate, and these core pieces are laminated in the thickness direction.

In the stator core manufactured in this way, since elastic deformation in the plane direction does not occur at the time of manufacturing, the magnetic characteristics thereof are excellent. However, the outer periphery of the yoke is circular, and the portion of the yoke inside the inner periphery is open except for the portion where the teeth are formed. Therefore, when the stator core is manufactured in this manner, many unused portions are generated in the metal plate used for punching. Therefore, the material yield of the metal plate is reduced, and the material cost is increased.

Therefore, in a rotating electrical machine such as a generator for an automobile, a helical core is used as a stator core. The helical core is formed by spirally processing and laminating strip-shaped metal plates formed in shapes corresponding to the yoke and the teeth by bending in the plate surface. For example, such a helical core is suitable for a core for a rotating electrical machine having a diameter of 50mm to 300 mm. In this case, a strip-shaped metal plate having a plate thickness of 0.15mm to 0.80mm is used as the metal plate for the helical core, for example. However, when the band-shaped metal plate is subjected to the in-plane bending process, the outer peripheral side of the portion of the band-shaped metal plate corresponding to the yoke is stretched larger than the inner peripheral side, and the outer peripheral side of the band-shaped metal plate (yoke) may have a thickness smaller than the inner peripheral side.

Therefore, in patent document 1, magnetic powder is filled into a gap formed on the outer peripheral side of the core by extending a portion of the strip-shaped metal plate corresponding to the yoke to a larger extent on the outer peripheral side than on the inner peripheral side. This allows the magnetic properties and rigidity of the core to be recovered.

In patent document 2, a strip-shaped metal plate formed in a shape corresponding to the yoke and the teeth is divided into a plurality of core pieces. The outer periphery of each core segment (the outer periphery of the portion corresponding to the yoke) is formed in an arc shape corresponding to the shape of the yoke. The core segments adjacent to each other are connected to each other by a connecting portion formed on the outer peripheral side of the side end portions of the core segments, and the core segments connected to each other by the connecting portion extend linearly. When such a plurality of core sheets are spirally processed by bending in a plate surface, regions on the inner peripheral side of the connection portion in the side surfaces of the portions corresponding to the yokes of the core sheets adjacent to each other are joined together, and the connection portion is bent and deformed. This prevents the outer peripheral side of the portion of the strip-shaped metal plate corresponding to the yoke from being thinner than the inner peripheral side.

In patent document 3, a unit core plate material is manufactured by punching a long strip-shaped silicon steel plate and forming teeth and notches at one time so as to leave bridge portions. Further, after a laminated core is formed from the unit core plates, an insulating layer is formed on the laminated core. By forming such a notch in the unit core plate material, the loss of material in the unit core plate material is reduced, and by forming the insulating layer on the laminated core, the strength of the laminated core, which changes as the notch is formed, is improved.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-185014

Patent document 2: japanese laid-open patent publication No. 2009-153266

Patent document 3: japanese patent laid-open publication No. 2000-116037

Disclosure of Invention

Problems to be solved by the invention

However, in the technique disclosed in patent document 1, since a step of filling magnetic powder is required, it is difficult to sufficiently reduce the cost of the helical core for the rotating electric machine.

In the technique disclosed in patent document 2, the outer periphery of each core segment is arc-shaped, and the metal plate between the core segments is redundant except for the portion corresponding to the coupling portion. Therefore, it cannot be said that the portion of the punched metal plate that is not used as the stator core is sufficiently reduced. That is, in the technique disclosed in patent document 2, even if a helical core is used as the stator core, it cannot be said that the material yield of the metal plate is sufficiently reduced. Further, the band-shaped metal plate disclosed in patent document 2 has a complicated shape. Therefore, according to the technique disclosed in patent document 2, it is also difficult to sufficiently reduce the cost of the helical core for the rotating electric machine.

Further, in the technique disclosed in patent document 3, since the teeth and the notches are punched out simultaneously, the strength of the unit core plate material decreases from the step of punching out the silicon steel plate to the step of forming the laminated core, and there is a concern that the unit core plate material is deformed (flexed) when the unit core plate material passes. At this time, the shape of the laminated core deteriorates, and the magnetic characteristics of the laminated core deteriorate.

The present invention has been made in view of these problems, and an object thereof is to reduce the cost of a helical core for a rotating electrical machine compared with the conventional one.

Means for solving the problems

(1) A method for manufacturing a helical core for a rotating electrical machine according to an aspect of the present invention includes: a first step of forming a yoke portion extending in one direction and a plurality of tooth portions protruding in the width direction from one side edge of the yoke portion in the width direction, in a band-shaped metal plate extending in the one direction; a second step of forming notches at positions between the teeth of the yoke part after the first step; and a third step of, after the second step, spirally processing the strip-shaped metal plate by bending the strip-shaped metal plate in order from a portion where the notch is formed to bend the strip-shaped metal plate in the width direction, wherein in the third step, a distance between a position where the bending is started and a position where the notch is formed is limited to a predetermined dimension.

(2) In the method for manufacturing a helical core for a rotating electrical machine according to the above (1), the method may further include a step of heating the strip-shaped metal plate before the third step and after the second step.

(3) In the method for manufacturing a helical core for a rotating electrical machine according to the item (1) or (2), the method may further include a step of heating the strip-shaped metal plate to perform stress relief annealing during or after the third step.

(4) In the method for manufacturing a helical core for a rotating electrical machine according to the item (1) or (2), the depth dimension of the notch may be 1/2 times or more of the width dimension of the yoke portion and may be smaller than the width dimension of the yoke portion.

(5) In the method of manufacturing a helical core for a rotating electrical machine according to the item (1) or (2), the shape of the notch on the plate surface may be an isosceles triangle or a regular triangle having a base at the one side edge in the width direction of the yoke portion.

(6) In the method of manufacturing a helical core for a rotating electrical machine according to the item (1) or (2), the shape of the notch on the plate surface may be a shape in which a circle or an ellipse is added to an apex angle of an isosceles triangle or an equilateral triangle having a base at the one side edge in the width direction of the yoke portion.

(7) In the method for manufacturing a helical core for a rotating electrical machine according to the above (1) or (2), at least a part of the other side edge of the yoke portion in the width direction may be linear.

(8) In the method for manufacturing a helical core for a rotating electrical machine according to the above (1) or (2), the predetermined dimension may be 10mm or more and 1000mm or less.

(9) An apparatus for manufacturing a helical core for a rotating electrical machine according to an aspect of the present invention includes: a first processing unit configured to form a yoke portion extending in one direction and a plurality of tooth portions protruding in the width direction from one side edge of the yoke portion in the width direction, in a strip-shaped metal plate extending in the one direction; a second machining unit configured to form a notch at a position between the teeth of the yoke portion; and a helical processing unit that bends the strip-shaped metal plate in order from a portion where the notch is formed to bend the strip-shaped metal plate in the width direction to form a helical shape, wherein a distance between a position where the bending is started by the helical processing unit and a position where the notch is formed by the second processing unit is within a predetermined dimension.

(10) The apparatus for manufacturing an iron core for a rotating electrical machine according to item (9) above, wherein a heating unit for heating the strip-shaped metal plate may be further provided between the second processing unit and the helical processing unit.

(11) The apparatus for manufacturing a helical core for a rotating electrical machine according to (9) or (10) above, may further include stress relief heating means for heating the strip-shaped metal plate to perform stress relief annealing during or after the strip-shaped metal plate is processed into a helical shape by the helical processing means.

(12) In the apparatus for manufacturing a helical core for a rotating electrical machine according to the above (9) or (10), a guide that supports the strip-shaped metal plate at least from a vertically lower side may be further provided between the first processing unit and the helical processing unit.

(13) In the apparatus for manufacturing a helical core for a rotating electrical machine recited in the above (9) or (10), the predetermined dimension may be 10mm or more and 1000mm or less.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the band-shaped steel sheet (band-shaped metal sheet) forming the helical core for the rotating electrical machine is formed with the notch portion in addition to the yoke portion and the tooth portion. The notch portion is formed at a position between the respective tooth portions of the yoke portion. By forming such a notch portion in the strip-shaped steel sheet, it is possible to prevent the thickness of the outer peripheral side of the yoke of the spiral core for a rotating electrical machine from being thinner than the thickness of the inner peripheral side when the spiral core for a rotating electrical machine is formed. Further, when the strip-shaped steel sheet is processed into a spiral shape, stress can be concentrated in a region on the outer peripheral side of the yoke portion with respect to the notch portion. Therefore, it is not always necessary to perform a special treatment after the strip steel sheet is spirally processed, or to process the shape of the strip steel sheet to be spirally processed into a complicated shape, as in the conventional case. Further, a spiral core for a rotating electric machine having excellent characteristics can be obtained, and the cost of the spiral core for a rotating electric machine can be reduced.

In manufacturing such a spiral core for a rotating electrical machine, since the yoke portion, the tooth portion, and the notch portion are formed in the strip-shaped steel plate, and the strip-shaped steel plate is processed into a spiral shape at a position within a predetermined dimension from the notch portion formed in the strip-shaped steel plate, the bending of the strip-shaped steel plate after the notch is formed can be suppressed as much as possible, and strip-shaped steel strips of various numbers (1 to a plurality) can be flexibly manufactured from 1 strip. Therefore, the magnetic characteristics, the material yield, and the production flexibility of the spiral core for the rotating electric machine can be improved, and the cost of the spiral core for the rotating electric machine can be further reduced.

Drawings

Fig. 1 is a schematic diagram showing an example of a configuration of a rotating electric machine according to an embodiment of the present invention.

Fig. 2A is a schematic view showing an example of a strip steel sheet before being processed into a spiral shape in the method for manufacturing a helical core for a rotating electrical machine according to an embodiment of the present invention.

Fig. 2B is an enlarged view of the vicinity of the dashed line portion shown in fig. 2A.

Fig. 3 is a schematic diagram showing an example of the structure of an apparatus for manufacturing a helical core for a rotating electrical machine according to an embodiment of the present invention.

Fig. 4A is a schematic diagram showing an example of a case (a cutting position) in which a yoke portion and a tooth portion are formed on a rectangular strip-shaped steel plate in the method for manufacturing a helical core for a rotating electrical machine according to the embodiment of the present invention.

Fig. 4B is a schematic diagram showing an example of a case (a cutting position) in which a yoke portion and a tooth portion are formed on a rectangular strip-shaped steel plate in the method for manufacturing a spiral core for a rotating electrical machine according to the embodiment of the present invention.

Fig. 5 is a schematic diagram showing an example of a configuration of a rotating electric machine according to an embodiment of the present invention.

Fig. 6A is a schematic view showing an example of a strip steel sheet before being processed into a spiral shape in the method for manufacturing a helical core for a rotating electrical machine according to the embodiment of the present invention.

Fig. 6B is an enlarged view of the vicinity of the dashed line portion shown in fig. 6A.

Fig. 7A is a schematic view of an example (first arrangement example) of a manufacturing apparatus of a helical core for a rotating electric machine having a plurality of helical processing units, as viewed from above in the vertical direction.

Fig. 7B is a schematic view of an example (second arrangement example) of an apparatus for manufacturing a helical core for a rotating electrical machine having a plurality of helical processing units, as viewed in the horizontal direction.

Fig. 7C is a schematic view of an example (third arrangement example) of an apparatus for manufacturing a helical core for a rotating electrical machine having a plurality of helical processing units, as viewed in the horizontal direction.

Fig. 8 is a schematic diagram showing an example of the structure of an apparatus for manufacturing a helical core for a rotating electrical machine according to a modification of the present embodiment.

Detailed Description

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, an example of the helical core manufactured by the method for manufacturing a helical core for a rotating electrical machine according to the present embodiment will be described.

Fig. 1 is a schematic diagram showing an example of a structure of a rotating electric machine as an application example of a helical core for a rotating electric machine. Specifically, fig. 1 shows a cross-sectional view of the rotating electric machine taken along a direction perpendicular to the rotating shaft thereof.

In fig. 1, a rotating electrical machine 10 includes a stator (stator)11, a rotor (rotor)12, a housing 13, and a rotating shaft 14. In fig. 1, members such as coils are omitted for convenience of illustration.

The stator 11 includes a stator core having a yoke extending in the circumferential direction of the rotating electrical machine and teeth extending from an end (end surface) on the inner circumferential side of the yoke in the direction of the rotating shaft 14. In the slot, which is an area between the teeth adjacent to each other in the circumferential direction of the rotating electrical machine, a coil (not shown) is inserted so as to be wound around the teeth. The stator core is a helical core. In fig. 1, the case where the number of teeth is 12 is shown as an example, but the number of teeth is not limited to the example shown in fig. 1.

As shown in fig. 1, in the present embodiment, at intermediate positions in the circumferential direction of each slot, tangential lines 15a to 15l (15) are formed from the inner circumferential surface toward the outer circumferential surface of the stator 11. The surfaces of the respective tangents 15a to 15l facing each other are juxtaposed, and there is almost no gap between the respective tangents 15a to 15 l. In the present embodiment, the stress is concentrated in the region on the outer peripheral side of the stator 11 with respect to the tangent lines 15a to 15 l. Therefore, the stress generated in each of the tangent lines 15a to 15l is preferably as small as possible in a range smaller than the stress generated in the region on the outer peripheral side of the stator 11, and most preferably 0.

It is preferable that the length (in the radial direction) of the tangent line 15(15a to 15l) is as long as possible within a range that does not damage the shape of the stator 11 when the stator 11 is formed by a method described later. By reducing the area on the outer peripheral side of the stator 11 with respect to the tangent 15 as much as possible (i.e., extending the tangent 15 as much as possible), the area can be prevented from being included in the magnetic path.

Specifically, the length of the tangent 15 is at least 1/2 times the length of the yoke in the radial direction. The length of the tangent 15 is preferably 3/4 times or more the length of the yoke in the radial direction, and more preferably 4/5 times or more the length of the yoke in the radial direction. But the length of the tangent 15 is smaller than the length of the yoke in the radial direction.

The rotor 12 is disposed at a position where its outer peripheral surface and a tip end surface of a tooth of the stator 11 (i.e., an inner peripheral surface of the stator 11) face each other with a predetermined gap therebetween. The axial center (rotation axis 14) of the rotor 12 and the axial center (center of gravity) of the stator 11 substantially coincide with each other. In the present embodiment, the stator 11 is described as an example of a characteristic portion of the helical core, and thus fig. 1 schematically shows the structure of the rotor 12.

The housing 13 may be assembled by shrink-fitting or the like so that the housing 13 is tightly joined to the stator 11 from the periphery (outer periphery) of the stator 11 to fix the stator 11, or the stator 11 may be fixed to the housing 13 by welding or bolt fastening. The housing 13 is made of, for example, soft iron or stainless steel.

Fig. 2A and 2B are schematic diagrams showing an example of a strip steel sheet before being processed into a spiral shape. Specifically, fig. 2A is a view of the steel strip as viewed from a direction perpendicular to the plate surface of the steel strip. Fig. 2B is an enlarged view of an area surrounded by a broken line in fig. 2A. The steel sheet (strip steel sheet) is an example of a metal sheet (strip metal sheet), and specific examples of the metal sheet include an electromagnetic steel sheet, a cold-rolled steel sheet, and a hot-rolled steel sheet.

As shown in fig. 2A, a yoke portion 22 corresponding to a yoke of the stator 11, tooth portions 23a to 23e (23) corresponding to teeth of the stator 11, and notch portions 24a to 24d (24) are formed on a strip-shaped steel plate 21 extending in one direction. In fig. 2A, only 5 teeth 23 are shown, but the same number of teeth 23 as the number of teeth of the stator 11 are formed on the strip steel plate 21. In fig. 2A, only 4 cutout portions 24 are shown, but the same number of cutout portions 24 as the number of the cut lines 15a to 15l are formed in the strip steel plate 21.

The width direction of the yoke portion 22 coincides with the longitudinal direction (extending direction) of the tooth portion 23, and the longitudinal direction of the yoke portion 23 coincides with the width direction of the tooth portion 23 (direction perpendicular to the longitudinal direction of the tooth portion 23).

As shown in fig. 2A, the tooth portions 23 are formed at equal intervals along the longitudinal direction (extending direction) of the steel strip 21 so as to protrude from one side edge (end portion) of the yoke portion 22 in the width direction.

The notch portion 24 (notch) is formed at a position between the respective tooth portions 23 on the yoke portion 22. In the present embodiment, since the helical core is used as the stator core, the notch portion 24 is formed at a position at an end portion inside the yoke portion 22 (an end portion at one end in the width direction of the yoke portion 22 and at a side of the yoke portion 22 where the tooth portions 23 are formed) and at an intermediate position in the longitudinal direction of the end portion of the yoke portion 22 corresponding to the bottom of each slot (an intermediate position between the tooth portions 23 adjacent to each other). Further, the notch portion 24 is formed in 1 in each of all regions corresponding to the slot (end portions of the yoke portion 22 corresponding to the bottom of the slot).

Further, the outer end portion of the yoke portion 22 of the steel strip 21 (the other end in the width direction of the yoke portion 22, and the end portion of the yoke portion 22 on the side where the tooth portion 23 is not formed) is linear. By making the outer end of the yoke portion 22 of the steel strip 21 straight, deformation and unexpected displacement due to uneven pressure can be prevented when the steel strip 21 is processed into a spiral shape, and the shape accuracy of the steel strip 21 can be improved. Therefore, at least a part of the outer end of the yoke portion 22 of the steel strip 21 is preferably linear. Further, an attachment groove for attaching to the housing 13 may be provided at an outer end of the yoke portion 22 of the steel strip 21, for example.

The shape of the notch portion 24 on the plate surface is an isosceles triangle or a regular triangle having a base at an end (one end in the width direction) inside the yoke portion 22 (on the tooth portion 23 side). The width W (width dimension) of the notch 24 at the inner end of the yoke 22 is a value corresponding to (proportional to) the difference between the length of the outer periphery and the length of the inner periphery of the stator 11. It is preferable that the length (depth dimension) D of the notch portion 24 is as long as possible within a range that does not damage the shape of the stator 11 when the stator 11 is formed by a method described later. As described above, in this case, the region 25 where the stress is concentrated by spirally processing the steel strip 21 can be reduced as much as possible (see fig. 2B). Specifically, since the length D of the notch portion 24 corresponds to the length of the tangent 15, the length D (depth dimension) of the notch portion 24 is at least 1/2 times or more the length of the yoke portion 22 in the width direction (width dimension: the length between the inner (tooth portion 23 side) end and the outer end of the yoke portion 22). The length D of the cutout 24 is preferably 3/4 times or more the length of the yoke 22 in the width direction, and more preferably 4/5 times or more the length of the yoke 22 in the width direction. However, the length D of the notch 24 is smaller than the length of the yoke portion 22 in the width direction.

By configuring the steel strip 21 as described above, the difference between the length of the outer periphery and the length of the inner periphery of the stator 11 can be corrected by the notch 24, and when the steel strip 21 is spirally processed by a method described later, the oblique sides 26 and 27 (see fig. 2B) of the notch 24 facing each other can be matched with each other.

When the strip steel plate is processed into a spiral shape, if the oblique sides of the notch portions facing each other can be matched with each other, the shape of the notch portion may be different from the shape of the notch portion 24. An example of the notch portion having a shape different from that of the notch portion 24 will be described below. Note that, except for the notch portion, the same configuration as that in the above description may be used, and the same reference numerals as those in fig. 1 are used for the same portions as those in the above description, and detailed description thereof is omitted.

Fig. 5 is a schematic diagram showing an example of a structure of a rotating electric machine as an application example of a helical core for a rotating electric machine. This fig. 5 corresponds to fig. 1.

In fig. 5, the rotating electrical machine 50 includes a stator 51, a rotor 12, a housing 13, and a rotating shaft 14.

As shown in fig. 5, in the present embodiment, at the intermediate position in the circumferential direction of each slot, tangential lines 52a to 52l (52) are formed from the inner circumferential surface toward the outer circumference of the stator 51, and cylindrical or elliptic cylindrical holes 53a to 53l (53) are formed at the tips (the side close to the end portion on the outer circumferential side of the stator 51) of the tangential lines 52a to 52 l. The surfaces of the respective tangent lines 52a to 52l facing each other are preferably aligned with each other, and the stress generated on the facing surfaces (the respective tangent lines 52a to 52l) is preferably as small as possible in a range smaller than the stress generated in the region on the outer peripheral side of the stator 51, and most preferably 0. It is preferable that the total value of the lengths (in the radial direction) of the tangent line 52 and the hole 53 is as long as possible within a range that does not damage the shape of the stator 51 when the stator 51 is formed by a method described later.

Fig. 6A and 6B are schematic diagrams showing an example of a strip steel sheet before being processed into a spiral shape. Fig. 6A and 6B correspond to fig. 2A and 2B, respectively.

As shown in fig. 6A, the yoke portion 22, the tooth portions 23a to 23e (23), and the notch portions 62a to 62d (62) are formed in the strip steel plate 61.

Since the helical core is used as the stator core, the notch 62 (notch) is formed at a position corresponding to an end portion inside the yoke portion 22 (one end in the width direction of the yoke portion 22 and an end portion of the yoke portion 22 on the side where the tooth portions 23 are formed) and an intermediate portion in the longitudinal direction of the end portion of the yoke portion 22 corresponding to the bottom of each slot (an intermediate portion between the tooth portions 23 adjacent to each other). Further, 1 notch portion 62 is formed in each of all regions corresponding to the slot (end portions of the yoke portion 22 corresponding to the bottom of the slot).

The shape of the notch 62 on the plate surface is a shape obtained by adding a circle or an ellipse to the vertex of an isosceles triangle or an equilateral triangle having a base at the end (one end in the width direction) inside the yoke portion 22 (tooth portion 23 side). That is, in the notch portion 62, a circle or an ellipse is arranged so as to include the apex angle of an isosceles triangle or a regular triangle. The width W of the notch 62 at the inner end of the yoke portion 22 is a value corresponding to (proportional to) the difference between the length of the outer circumference and the length of the inner circumference of the stator 51. It is preferable that the length (depth dimension) D of the notch portion 62 is as long as possible within a range that does not damage the shape of the stator 51 when the stator 51 is formed by a method described later.

Even if the above-described notch 62 is formed in the yoke portion 22, the same effect as that of forming the notch 24 in the yoke portion 22 can be obtained.

The plate surface shapes of the steel strip 21 shown in fig. 2A and the steel strip 61 shown in fig. 6A can be obtained by a processing method (cutting process) such as a slitting cutting process by a roll blade (rollblade), punching, or a processing by a laser. Hereinafter, for the sake of simplifying the description, a case of manufacturing a helical core for a rotating electrical machine from the strip-shaped steel sheet 21 shown in fig. 2A will be described.

First, basic configurations of a method and an apparatus for manufacturing a helical core for a rotating electrical machine will be described.

Fig. 3 is a schematic diagram showing an example of a structure of an apparatus for manufacturing a helical core (stator 11) for a rotating electrical machine. The hollow arrows shown in fig. 3 indicate the direction in which the steel strip moves.

In fig. 3, the apparatus for manufacturing a helical core for a rotating electrical machine includes a shape processing unit 31 (first processing unit), a notch processing unit 32 (second processing unit), and a helical processing unit 33.

The shape processing means 31 performs processing such as slitting and cutting with a roller blade on a rectangular strip-shaped steel plate 34 to form the yoke portion 22 and the tooth portion 23 shown in fig. 2A. At this stage, the notch portion 24 is not formed.

The notch processing unit 32 performs a process such as punching on the strip steel plate 35 on which the yoke portion 22 and the tooth portion 23 are formed, and sequentially forms the notch portions 24 shown in fig. 2A by a predetermined number (1 or 2 or more), respectively. The notch processing unit 32 (the position where the notch portion 24 is formed) is disposed at a position that does not interfere with the screw processing unit 33 and is located within a predetermined distance (predetermined dimension) from the position where the strip-shaped steel plate 36 is processed into a spiral shape. If the distance between the notch 24 formed in the strip steel plate 35 and the strip steel plate 36 being processed into a spiral shape is long, the strip steel plate 36 may be bent before being processed into a spiral shape due to the notch 24. In particular, the longer the length D of the notch portion 24, the higher the possibility that the steel strip 36 will deflect. When the steel strip 36 is bent in this way, the steel strip 36 is deformed, or when the steel strip is spirally processed, the oblique sides of the notch portions facing each other cannot be matched with each other, and a gap is formed in the tangent line 15 of the spiral core.

At this time, the magnetic properties of the strip steel plate 36 themselves are degraded, or the magnetic properties of the helical core are degraded. Further, since the steel strip 36 is processed into a spiral shape in a state of being bent in the stacking direction, a gap is generated in the stacking direction of the steel strip 36, and the shape of the spiral core is deteriorated. In addition, when such a shape of the helical core is forcibly corrected, a large processing stress is introduced into the helical core, and thus the magnetic characteristics of the helical core are greatly reduced. Therefore, in order to suppress the decrease in magnetic properties due to the deflection, it is preferable that the distance (the predetermined dimension) x between the winding position (the position where the bending process starts) of the spiral process and the end surface of the notch processing unit 32 on the side close to the winding position of the notch portion 24 be 1000mm or less. In order to further improve the magnetic characteristics of the helical core, the distance x is more preferably 500mm or less, and most preferably 300mm or less. The distance x may be set as appropriate according to the strength and thickness of the steel strip and the depth of the notch. For example, when the length D of the notch portion 24 is 3/4 times or more the length of the yoke portion 22 in the width direction, the distance x may be set to 500mm or less. The distance x may be set to 10mm or more to prevent the notch processing unit 32 from interfering with the screw processing unit 33 (or the steel strip 36 to be screw processed).

The screw processing unit 33 bends the strip-shaped steel plates 36 in order from the portion where the notch portion 24 is formed by the notch processing unit 32, bends the strip-shaped steel plates 36 in the plate width direction (the direction perpendicular to the sheet passing direction and the plate thickness direction), processes the bent strip-shaped steel plates into a spiral shape, and laminates the strip-shaped steel plates 36. Specifically, the screw processing unit 33 can process the steel strip 36 into a spiral shape by using a non-uniform pressure roller (nonreforming roller) or forcibly process the steel strip 36 into a spiral shape along a guide so that the length of the yoke portion 22 in the longitudinal direction (circumferential direction) is longer than the length of the tooth portion 23 in the width direction (circumferential direction). Thus, the yoke portion 22 is disposed on the outer peripheral side of the stator 11, and the tooth portion 23 is disposed on the inner peripheral side of the stator 11. The steel strip 36 processed and laminated by the screw processing unit moves vertically downward while being wound around a mandrel bar (not shown) of the screw processing unit. In this way, the steel strip 34 can be passed through without changing the pass height of the steel strip 34.

The spirally processed strip-shaped steel plates 36 are joined at predetermined portions (for example, in the stacking direction) by a joining method such as caulking, bonding, welding, or the like. The joining of the steel strip 36 thus helically processed is completed, and a predetermined process is performed as necessary, thereby forming the stator 11.

As described above, in the present embodiment, after the yoke portion 22 and the tooth portion 23 are formed on the strip steel plate 34, the notch portion 24 is formed on the strip steel plate 35 at a position immediately before the strip steel plate 36 is processed into a spiral shape. For example, if the notch 24 is formed in the steel strip at one time together with the yoke 22 and the tooth 23, the steel strip is deformed before the steel strip reaches the helical processing unit 33 because the rigidity of the steel strip is reduced, and the magnetic characteristics and the shape of the helical core are deteriorated. Further, since the cutout portion 24 is formed together with the yoke portion 22 and the tooth portion 23, it is difficult to reuse a processing unit (for example, a die and CAD data) due to a change in size such as the length D of the cutout portion 24, and there is a concern that the cost increases. Even immediately before the band steel plate is processed into a spiral shape at the position where the yoke portion 22, the tooth portion 23, and the notch portion 24 are formed at one time, it is difficult to manufacture a plurality of band steel plates 41 and 42 from 1 rectangular band steel plate 34A shown in fig. 4A, and therefore, the production flexibility of the helical core is lowered.

In addition, the method and apparatus for manufacturing a helical core for a rotating electrical machine according to the present embodiment may have the following configuration as a modification of the present embodiment, in addition to the basic mechanism described above.

The apparatus for manufacturing a helical core for a rotating electrical machine may further include a guide for suppressing deformation of the strip steel plates 35 and 36. For example, the guide is disposed between the shape processing unit 31 and the screw processing unit 33 so as to support the steel strip plates 35 and 36 (for example, a guide 37 shown in fig. 8) at least from the lower side in the vertical direction. The guide may support the steel strip plates 35 and 36 from the upper side and the lower side in the vertical direction.

When a steel sheet (particularly, a 3% Si-based electromagnetic steel sheet) that is hard such as an electromagnetic steel sheet is processed into a spiral shape, as shown in fig. 8, a heating unit 38 that heats the strip-shaped steel sheet 36 may be disposed between the notch processing unit 32 and the spiral processing unit 33, and the strip-shaped steel sheet 36 may be heated after the notch processing. By heating the steel strip 36 just before the steel strip 36 is spirally formed, workability of the steel strip 36 can be temporarily improved, and the steel strip 36 can be efficiently and reliably formed into a spiral shape. The heating temperature of the heating unit 38 may be determined according to the steel plate. For example, the heating temperature is about 300 ℃ in the case of a 3% Si-based electrical steel sheet.

Further, the helical core is subjected to stress (for example, press stress or bending stress) by the above-described processing. Since this stress reduces the magnetic characteristics of the helical core, it is preferable to remove the stress by heating. For example, as shown in fig. 8, immediately after the strip steel sheet 36 is processed by the helical processing unit 33, the strip steel sheet 36 may be wound around a mandrel bar (not shown) of the helical processing unit 33, and the stress relief heat treatment (SRA) may be performed online by a stress relief heating unit 39 such as an induction heating furnace. Further, for example, the stress relief heat treatment may be performed on the iron core having finished the helical working by another production line using an external heating means such as an induction heating furnace or a box furnace. In this case, stress generated by a bonding method such as caulking, bonding, or welding can be removed. Preferably, the stress relief annealing is appropriately performed according to the characteristics required for the helical core and the type of steel of the steel strip 36. For example, the annealing temperature for stress relief annealing is about 750 ℃.

Further, the notch processing unit may be provided so as to be movable or rotatable in the width direction of the strip steel plate passing therethrough. In this case, the depth of the notch and the position of the notch can be flexibly adjusted without changing the processing unit.

Fig. 4A and 4B are schematic diagrams showing an example of a case (a cutting position) in which the yoke portion 22 and the tooth portion 23 are formed on a rectangular strip-shaped steel plate 34.

In fig. 4A, the rectangular steel band plates 34A are processed such that the tip sides of the teeth 23 of one steel band plate 41(42) are arranged in regions corresponding to the slots of the other steel band plate 42(41) (i.e., the teeth 23 of one steel band plate 41(42) and the teeth 23 of the other steel band plate 42(41) are arranged to be offset from each other). In this case, the unnecessary portions of the steel strip 34 can be reduced as much as possible, and the decrease in the yield of the steel strip 34a can be prevented as much as possible. In this case, for example, the shape of one steel strip 41(42) may be different from the shape of the other steel strip 42 (41). For example, dimensions such as the length of the tooth portion 23 in the longitudinal direction and the width of the yoke portion 22 can be appropriately changed.

It is not necessary to form a plurality of steel strip plates 41 and 42 from 1 rectangular steel strip plate 34A as shown in fig. 4A, and 1 steel strip plate 43 may be formed from 1 rectangular steel strip plate 34B as shown in fig. 4B. At this time, since the outer end portion (one end) of the yoke portion 22 is linear, even if the strip-shaped steel plate 43 is formed as shown in fig. 4B, the unnecessary portion of the rectangular strip-shaped steel plate 34B can be reduced in comparison with the conventional technique in the region on the outer side (the one end side) of the yoke portion 22.

In the present embodiment, when a plurality of steel strips 41 and 42 are formed from 1 rectangular steel strip 34A as shown in fig. 4A, for example, as shown in fig. 7A to 7C, the apparatus for manufacturing a spiral core for a rotating electrical machine may include a plurality of spiral processing units 33(33a and 33b) and a plurality of notch processing units 32(32a and 32 b). Fig. 7A is a schematic view of an example (first arrangement example) of a manufacturing apparatus of a helical core for a rotating electric machine having a plurality of helical processing units, as viewed from above in the vertical direction. In fig. 7A, 2 screw processing units 33a and 33b are arranged in a horizontal direction, and a notch processing unit 32a (32b) is arranged immediately before each screw processing unit 33a (33 b). The steel strip plates 41 and 42 formed by the shape processing unit 31 are separated and conveyed in different directions. The steel strip plates 41(42) are processed by the notch processing unit 32a (32b) and the helical processing unit 33a (33b), respectively, to manufacture helical cores. Fig. 7B is a schematic view of an example (second arrangement example) of an apparatus for manufacturing a helical core for a rotating electrical machine having a plurality of helical processing units, as viewed in the horizontal direction. In fig. 7B, 2 screw processing units 33a and 33B are arranged in the vertical direction, and a notch processing unit 32a (32B) is arranged immediately before each screw processing unit 33a (33B). In this case, for example, the centers of the helical cores can be aligned, and therefore, the same power can be applied to the helical processing units 33a and 33 b. As shown in fig. 7C, one screw processing unit in fig. 7B may be shifted in the horizontal direction. The method of arranging the 2 screw processing units is not particularly limited as long as a condition that the strip steel is not deformed before the strip steel reaches the screw processing unit 33 is satisfied (for example, a distance from the notch processing unit 32a (32b) to the screw processing unit 33a (33b) is within a predetermined dimension).

In the above-described arrangement example, since the strip-shaped steel plates 41 and 42 are separated and conveyed in different directions, if the conveying distance from the shaping unit to the helical processing unit is shortened, the strip-shaped steel plates 41 and 42 are deformed, and the magnetic properties and the shape of the helical core may be deteriorated. Therefore, it is preferable that the conveying distance from the shape processing unit 31 to the screw processing unit 33 is a predetermined value or more so as to sufficiently reduce the angle formed by the conveying directions when the strip-shaped steel plates 41 and 42 are separated. As described above, when the yoke portion 22, the tooth portion 23, and the notch portion 24 are formed in the steel strip at one time, the steel strip is deformed before the steel strip reaches the helical processing unit because the rigidity of the steel strip is reduced, and the magnetic characteristics and the shape of the helical core are deteriorated. At this time, when the plurality of steel strips 41 and 42 are formed from 1 rectangular steel strip 34a, the transfer distance from the shape processing unit 31 to the screw processing unit 33 becomes long. Therefore, in the present arrangement example, as shown in fig. 7A to 7C, a plurality of notch processing units 32(32a, 32b) are required, unlike the shape processing unit 31, and each notch processing unit 32 is arranged at a position within a predetermined distance (predetermined size) from each screw processing unit 33(33a, 33 b). In this case, by switching the production line, 1 piece of the rectangular steel strip 34a can be formed, and the amount of the made wire can be flexibly adjusted. Further, by appropriately adding the screw processing means 33 and the notch processing means 32 corresponding to the screw processing means, it is possible to form a plurality of strip-shaped steel plates of different shapes from 1 rectangular strip-shaped steel plate 34 a. In this case, for example, different types of helical processing units 33(33b) can be added to manufacture helical cores having different diameters. As described above, the method and apparatus for manufacturing a spiral core for a rotating electrical machine according to the present embodiment can be applied to spiral cores (strip-shaped steel sheets) having various shapes.

As described above, in the present embodiment, after the yoke portion 22 and the tooth portion 23 are formed by the shape processing unit 31, the notch portion 24 is formed by the notch processing unit 32 at a position immediately before the formation of the spiral shape, and the strip-shaped steel plate is processed into the spiral shape while giving curvature to the strip-shaped steel plate in order from the portion where the notch portion 24 is formed at a position within a predetermined distance (predetermined dimension) from the position where the notch portion 24 is formed. Therefore, the strip steel plate can be prevented from being bent by the presence of the notch 24 before the strip steel plate is processed into a spiral shape.

In the helical core manufactured by the method of manufacturing a helical core for a rotating electrical machine according to the present embodiment, the steel strip 21 used to form the helical core for a rotating electrical machine includes the rectangular yoke portion 22, the tooth portions 23 protruding from one end of the yoke portion 22 in the width direction at equal intervals, and the notch portions 24. The notch 24 is formed at an end (the one end) of the yoke 22 on the side where the tooth 23 is formed, and at a position intermediate between the adjacent teeth 23. When the strip steel plate 21 is processed into a spiral shape, the oblique sides 26 and 27 of the notch 24 that face each other are matched with each other. In the stator 11 (helical core for a rotating electrical machine) of this type, the thickness of the yoke on the outer peripheral side can be prevented from being thinner than the thickness on the inner peripheral side. When the strip steel plate 21 is processed into a spiral shape, stress can be concentrated in a region 25 on the outer peripheral side of the yoke portion 22 (yoke) with respect to the notch portion 24 (tangent line 15).

Therefore, in the spiral core, it is not always necessary to perform special processing after the strip steel plate is processed into a spiral shape, or to process the shape of the strip steel plate to be processed into a complicated shape, as in the conventional case. In the method of manufacturing a spiral core for a rotating electrical machine according to the present embodiment, a spiral core for a rotating electrical machine having good characteristics (for example, a spiral core for a rotating electrical machine having excellent dimensional accuracy such as roundness and thickness and magnetic characteristics) can be obtained, and the cost of the spiral core for a rotating electrical machine can be reduced. Further, since the steel strip 41 shown in fig. 4A can be formed, the unnecessary portion of the rectangular steel strip 34A can be further reduced, and the cost of the helical core for the rotating electrical machine can be further reduced.

In the method and apparatus for manufacturing a helical core for a rotating electrical machine described in the present embodiment, a helical core for a rotor can be manufactured in addition to a stator of a rotating electrical machine.

The embodiments of the present invention described above are merely specific examples for carrying out the present invention, and the technical scope of the present invention should not be interpreted in a limiting manner. That is, the present invention can be implemented in various forms without departing from the main features thereof.

Example 1

From SPCC-SD (0.02% C) specified in JIS G3141, a 0.50mm thick product coil and 0.002% C, 0.1% Si, 0.35mm thick electromagnetic steel sheet product coils, a strip steel sheet having the shape shown in FIG. 2A was produced, and a 30mm thick helical core stator was produced. In the helical core stator, the outer diameter of the stator isThe inner diameter of the root portion (including the inner diameter of the bottom of the socket) isNote that the depth dimension of the tangent 15 shown in fig. 1 is changed to various dimensions with respect to the length (width dimension) of the yoke in the width direction (hereinafter, the depth dimension of the tangent 15 with respect to the length of the yoke in the width direction is referred to as a ratio of the notch portion). Further, as a comparative example of these, an integral round-punched (integrated-punched) core was also manufactured. The results of evaluation of the ratios of the notch portions and the shapes of the steel sheets in the region 25 (stress concentration portion) shown in fig. 2B are shown in table 1(SPCC-SD) and table 2 (electromagnetic steel sheets) for the helical core stators manufactured from the respective product coils. In the stress concentration portions in tables 1 and 2, the case where the notch portion was not formed was set to "0", and the case where the notch portion having a ratio of 0.9 was formed was set to "10", and the evaluation was performed in 10 grades according to the ratio (shape) improved by forming the notch portion. The larger the number, the better the shape of the stress concentration portion. As can be seen from tables 1 and 2, when the notch portion is formed in the yoke portion, the shape of the steel sheet in the region 25 (stress concentration portion) is good. In particular, when the ratios of the notch portions are changed to 0.5, 0.75, and 0.80, respectively, the shape of the stress concentration portion is greatly improved. In addition, table 1 and table 2 also show the ratio of the notched portion and the material utilization rate of the stator ("excellent" or "impossible"). In addition, the material yield of the stator is improved in the case of manufacturing the spiral core, compared to the case of punching the circular punched core from each product coil. Further, since the notch processing unit is disposed immediately before the screw processing unit, even when the notch portion is formed in the yoke portion and the ratio of the notch portion is increased, the material yield of the stator is good.

[ Table 1]

[ Table 2]

Example 2

A strip-shaped steel sheet having a shape shown in fig. 2A was produced from a product coil having a thickness of 0.35mm and 35a210(3.1% Si) defined in jis c2552, and a helical core stator having a thickness of 30mm was produced. In the helical core stator, the outer diameter of the stator isThe root part has an inner diameter ofNote that the depth of the tangent 15 shown in fig. 1 is changed to various dimensions with respect to the length of the yoke in the width direction (hereinafter, the depth of the tangent 15 with respect to the length of the yoke in the width direction is referred to as a ratio of the notch portion). Further, as a comparative example of these, an integral round punched core was also manufactured. Table 3 shows the ratio of the notch portion and the evaluation results of the shape of the steel sheet in the region 25 (stress concentration portion) shown in fig. 2B. The evaluation method was carried out using the same criteria as those of example 1. As can be seen from table 3, when the notch portion is formed in the yoke portion, the shape of the steel sheet in the region 25 (stress concentration portion) is good. In particular, when the ratios of the notch portions are changed to 0.5, 0.75, and 0.80, respectively, the shape of the stress concentration portion is greatly improved. In addition, the material yield of the stator is good in the case of manufacturing the spiral core, compared to the case of punching the circular punched core from the product coil. Further, since the notch processing unit is disposed immediately before the screw processing unit, even when the notch portion is formed in the yoke portion and the ratio of the notch portion is increased, the material yield of the stator is good.

[ Table 3]

Example 3

A strip-shaped steel plate having a shape shown in fig. 6A was produced from 50a470(2.0% Si) and a 0.50mm thick product coil stock defined in jis c2552 and 50a800(0.8% Si) and a 0.50mm thick product coil stock defined in jis c2552, and a 30mm thick helical core stator was produced. In the helical core stator, the outer diameter of the stator isThe root part has an inner diameter ofNote that the depth of the tangent line 52 shown in fig. 5 is changed to various dimensions with respect to the length of the yoke in the width direction (hereinafter, the depth of the tangent line 15 with respect to the length of the yoke in the width direction is referred to as a ratio of the notch portion). Further, as a comparative example of these, an integral round punched core was also manufactured. The results of evaluation of the ratios of the notch portions and the shapes of the steel plates in the stress concentration portions near the circular portions of the notch portions 62 shown in fig. 6B are shown in table 4(50a470) and table 5(50a800) for the helical core stators manufactured from the respective product coils. The evaluation method was carried out using the same criteria as those of example 1. As can be seen from tables 4 and 5, when the notch 62 is formed in the yoke portion, the shape of the steel plate at the stress concentration portion near the circular portion of the notch 62 is good. In particular, when the ratio of the notch portion is changed to 0.5, 0.75, and 0.80, respectively, the shape of the stress concentration portion is greatly improved. In addition, the material yield of the stator is good in the case of manufacturing the spiral core, compared to the case of punching the circular punched core from the product coil. Further, since the notch processing unit is disposed immediately before the screw processing unit, even if the notch portion is formed in the yoke portion, the notch is improvedThe ratio of the portion is also good in the yield of the stator.

[ Table 4]

[ Table 5]

Example 4

Using the same product coils (SPCC-SD and electromagnetic steel sheets) as in example 1, yoke portions and tooth portions were formed on a strip steel sheet by a die (punching) in stage 1, thereby producing 2 strip steel sheets shown in fig. 4A. Further, after forming the notch portion shown in fig. 2A for each strip-shaped steel plate by 2 dies at stage 2, 2 helical core stators 30mm thick were manufactured by 2 uneven pressure rollers. In these helical core stators, the outer diameter of the stator isThe inner diameter of the root portion (including the inner diameter of the bottom of the socket) isThe ratio of the notch portion was set to 0.5. Further, the helical core is manufactured by changing the distance from the die on which the notch portion is formed to the uneven pressure roller for performing the helical processing to various distances. In the apparatus for manufacturing a helical core, the distances from the mold in the 1 st stage to the uneven pressure roller are set to be the same for 2 lines. Further, 1 production line of the same apparatus for manufacturing a helical core was selected, and 1 piece of the strip-shaped steel sheet having been subjected to shape processing shown in fig. 4B was also manufactured. Further, as a comparative example, the mold was used for simultaneous moldingThe helical core is manufactured under the condition of forming the yoke portion, the tooth portion, and the notch portion (the condition of not arranging a die as a notch processing unit). At this time, in order to manufacture 2 pieces of the strip-shaped steel plates having undergone shape processing from 1 piece of the strip-shaped steel plate and smoothly introduce them into 2 uneven pressure rollers, respectively, the distance from the die to the uneven pressure rollers needs to be at least 2500 mm. Therefore, the distance from the die to the uneven pressure roller at this time was set to 2500 mm.

The results of evaluating the distance from the die for forming the notch portion to the uneven pressure roller, the shape of the helical core, and the magnetic properties of the helical core stator manufactured from each product coil are shown in table 6(SPCC-SD) and table 7 (electromagnetic steel sheet). In the method for evaluating the shape and magnetic properties of the helical core, the case where the yoke portion, the tooth portion, and the notch portion are simultaneously formed by the mold (the case where the mold serving as the notch processing unit is not provided) is set to "0", the case where the distance from the mold (the notch processing unit) where the notch portion is formed to the unevenness pressure roller (the helical processing unit) is 20mm is set to "10", and the evaluation is performed in 10 steps according to the ratio (the shape and magnetic properties) improved by reducing the distance between the mold where the notch portion is formed and the unevenness pressure roller. The larger the number of them, the better the shape and magnetic properties of the helical core. As is apparent from tables 6 and 7, the shape and magnetic characteristics of the helical core are significantly improved when the mold for forming the yoke portion and the tooth portion and the mold for forming the notch portion are used, as compared with the case where the mold for forming the yoke portion, the tooth portion, and the notch portion simultaneously is used. In particular, when the distances between the mold for forming the notch portion and the uneven pressure roller are changed to 1000, 500, and 300mm, respectively, the shape and magnetic characteristics of the helical core are greatly improved. Table 6 and table 7 also show the relationship between the distance from the die on which the cutout portion is formed to the uneven pressure roller and the material utilization rate ("good", or "not good") of the stator. The material utilization ratio of the stator was good under all conditions, and the material utilization ratio was further improved by manufacturing 2 pieces of the strip-shaped steel plates from 1 piece of the strip-shaped steel plate.

[ Table 6]

[ Table 7]

Industrial applicability of the invention

Compared with the conventional art, the magnetic characteristics, material utilization rate and production flexibility of the spiral core for the rotating electric machine can be improved, and the cost of the spiral core for the rotating electric machine can be reduced.

Description of the symbols

10. 50 rotating electric machine

11. 51 stator

12 rotor

13 outer cover

14 rotating shaft

15 tangent line

21. 61 strip steel plate

22 magnetic yoke part

23 tooth system

24. 62 gap part (notch)

31 shape processing unit (first processing unit)

32 gap processing unit (second processing unit)

33 spiral machining unit

37 guide member

38 heating unit

39 stress relief heating unit

52 tangent line

53 holes

Claims (11)

1. A method of manufacturing a helical core for a rotating electrical machine,

the method comprises the following steps:

a first step of forming a yoke portion extending in one direction and a plurality of tooth portions protruding in the width direction from one side edge of the yoke portion in the width direction, in a band-shaped metal plate extending in the one direction;

a second step of forming notches at positions between the teeth of the yoke part after the first step;

a third step of, after the second step, spirally processing the strip-shaped metal plate by bending the strip-shaped metal plate in order from the portion where the notch is formed so as to bend the strip-shaped metal plate in the width direction, and

a step of heating the strip-shaped metal plate before the third step and after the second step to temporarily improve the workability of the strip-shaped metal plate;

in the third step, the distance between the position where the bending is started and the position where the notch is formed is set to 1000mm or less.

2. The method of manufacturing a helical core for a rotating electrical machine according to claim 1, wherein the step of forming the helical core is performed by a method of forming a helical core for a rotating electrical machine,

during or after the third step, the method further includes a step of heating the strip-shaped metal plate to perform stress relief annealing.

3. The method of manufacturing a helical core for a rotating electrical machine according to claim 1, wherein the step of forming the helical core is performed by a method of forming a helical core for a rotating electrical machine,

the depth dimension of the notch is 1/2 times or more of the width dimension of the yoke portion and is smaller than the width dimension of the yoke portion.

4. The method of manufacturing a helical core for a rotating electrical machine according to claim 1, wherein the step of forming the helical core is performed by a method of forming a helical core for a rotating electrical machine,

the shape of the notch on the plate surface is an isosceles triangle or a regular triangle having a base at the one side edge of the yoke portion in the width direction.

5. The method of manufacturing a helical core for a rotating electrical machine according to claim 1, wherein the step of forming the helical core is performed by a method of forming a helical core for a rotating electrical machine,

the shape of the notch on the plate surface is a shape obtained by adding a circle or an ellipse to the vertex angle of an isosceles triangle or an equilateral triangle having a base at the one side edge in the width direction of the yoke portion.

6. The method of manufacturing a helical core for a rotating electrical machine according to claim 1, wherein the step of forming the helical core is performed by a method of forming a helical core for a rotating electrical machine,

at least a portion of the other side edge of the yoke portion in the width direction is linear.

7. The method of manufacturing a helical core for a rotating electrical machine according to claim 1, wherein the step of forming the helical core is performed by a method of forming a helical core for a rotating electrical machine,

the distance between the position where the bending is started and the position where the notch is formed is 10mm or more.

8. An apparatus for manufacturing a helical core for a rotating electrical machine, comprising:

a first processing unit configured to form a yoke portion extending in one direction and a plurality of tooth portions protruding in the width direction from one side edge of the yoke portion in the width direction, in a strip-shaped metal plate extending in the one direction;

a second machining unit configured to form a notch at a position between the teeth of the yoke portion;

a spiral processing unit that bends the strip-shaped metal plate in order from a portion where the notch is formed to bend the strip-shaped metal plate in the width direction to form a spiral shape; and

a heating unit provided between the second processing unit and the spiral processing unit and heating the strip-shaped metal plate for temporarily improving the workability of the strip-shaped metal plate;

the distance between the position where the bending is started by the screw processing unit and the position where the notch is formed by the second processing unit is 1000mm or less.

9. The manufacturing apparatus of a helical core for a rotary electric machine according to claim 8,

and a stress-relief heating means for heating the strip-shaped metal plate to perform stress-relief annealing while or after the strip-shaped metal plate is processed into a spiral shape by the spiral processing means.

10. The manufacturing apparatus of a helical core for a rotary electric machine according to claim 8,

the first processing unit and the spiral processing unit further include a guide for supporting the strip-shaped metal plate at least from a vertically lower side.

11. The manufacturing apparatus of a helical core for a rotary electric machine according to claim 8,

the distance between the position where the bending is started and the position where the notch is formed is 10mm or more.