JP2006340548A - Riveted laminated core and method and apparatus for manufacture thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core formed by swaging laminated magnetic steel sheets with a rivet that is free from short-circuiting of magnetic steel sheets and deterioration in magnetic properties, and is high in riveting strength and excellent in lamination accuracy, and a method and an apparatus for manufacturing the core. <P>SOLUTION: The riveted laminated core is formed by laminating magnetic steel sheets. The magnetic steel sheets are favorably riveted by an insulator coated rivet (e.g., a metal rivet coated with insulating resin and an aluminum rivet coated with an aluminum oxide) on the core back side or the tooth side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laminated iron core in which laminated electromagnetic steel sheets are fastened with rivets, and a method and apparatus for manufacturing the same.

  When manufacturing iron cores for motors and electrical equipment by laminating and fixing a plurality of magnetic steel sheets punched into a predetermined shape, the type of fixing is important in relation to the magnetic properties of the iron core. .

  In recent years, motors and electrical equipment with higher efficiency have been demanded particularly from the viewpoint of energy saving and environmental problems such as reduction of carbon dioxide. To that end, the specific resistance of the electrical steel sheet used for the iron core is reduced. It is necessary to increase the electrical conductivity between the laminated electrical steel sheets and to reduce the iron loss as an iron core.

  Conventionally, caulking, welding, and an adhesive have been mainly used for fastening laminated electromagnetic steel sheets.

  Caulking is excellent in terms of productivity, but has a problem that the laminated electrical steel sheets are electrically conducted and the magnetic properties of the iron core may deteriorate.

  Welding is not as good in productivity as it is, but is excellent in terms of device reliability after production because the laminated electromagnetic steel sheet is firmly fixed or fastened. However, the laminated electrical steel sheet is electrically connected by welding, and the magnetic properties of the iron core are greatly deteriorated.

  Adhesives are excellent in that there is no magnetic deterioration of the iron core, because the magnetic steel sheets are firmly fastened while ensuring the insulation between the magnetic steel sheets, but there is an adhesive layer between the magnetic steel sheets As a result, the space factor of the iron core is poor, and at the same size, there is a problem that the apparatus characteristics deteriorate because the magnetic flux decreases.

  As other iron core fastening methods, there are bolt fastening and rivet fastening in which holes are formed at predetermined positions of laminated electromagnetic steel sheets and bolts and rods are penetrated and fixed. In general, bolts and rivets are used to fix a fastened laminated iron core to a case or flange. However, the productivity is lower than that of caulking, etc., and the magnetic properties of the iron core deteriorate. As a fastening method, it is not used much.

  Techniques using bolts and rivets for fastening iron cores are disclosed in Patent Documents 1 to 4.

  Patent Document 1 discloses a laminated iron core of a linear motor in which a hole is formed in a tooth portion (forming a coil insertion groove) of an iron core and fastened with an insulated bolt in the hole. This bolt tightening firmly tightens the teeth of the iron core, improving the reliability of the equipment, but it takes a lot of labor to fasten the bolt, the productivity is extremely low, and the bolt hole Since there is a gap between the bolt and the bolt, it is necessary to hold the stack with accuracy other than the bolt.

  Patent Document 2 discloses a laminated fixed iron core of a small electric motor fastened with a rivet together with an iron core and a cover for covering the iron core. In this laminated fixed iron core, a stepped through hole is formed in the iron core in advance, but since there is a gap between this through hole and the rivet, the lamination position of the steel plates may be shifted, and it is caulked separately. It is necessary to take measures such as fastening the iron core by welding or welding, which increases the process and increases the cost.

  In Patent Document 3, in a motor having a stator core in which a plurality of unit cores (iron cores) are arranged in an annular shape, when the plurality of unit cores are arranged in an annular shape, core reinforcing materials are arranged at both ends in the axial direction of the core. The core structure is disclosed in which the core reinforcing material is fastened with rivets and the core (iron core) is fastened as a result.

  However, in this structure, the iron core is fixed together with the reinforcing member by a rivet or a screw, but there is a gap between the screw and the rivet and the through hole of the laminated iron core, and the iron core may also be displaced. . Further, since the screws and rivets are generally made of a metal material, the stray current flowing through the core reinforcing member made of a metal material having a high magnetic permeability may flow through the screws and rivets, resulting in eddy current loss.

  Patent Document 4 discloses a cylindrical core (iron core) in which a laminated magnetic steel plate is fixed with a resin rivet press-fitted into a rivet hole in a stator of a magnet motor. A resin rivet has an advantage that, unlike a normal metal rivet, stray current does not flow and magnetic characteristics do not deteriorate.

  In this cylindrical core (iron core), a resin rivet is press-fitted into a rivet hole formed by a semicircular cutout, and a laminated steel plate is fixed. There is a risk that the iron core will be shifted due to the wrinkles.

JP-A-8-275413 Japanese Patent Laid-Open No. 10-14144 JP 2001-25185 A JP 2001-37112 A

  The present invention provides an iron core in which laminated electromagnetic steel sheets are fastened with rivets, and a strong iron core in which the magnetic properties of the iron core are good and there is no misalignment, and a method and apparatus for producing the same. The purpose is to do.

  As described above, riveting is a problem with general metal rivets, in which an electromagnetic circuit is formed and the magnetic properties of the iron core deteriorate due to the generation of stray currents. Although excellent in preventing deterioration of characteristics, there is a problem that the lamination is shifted because the strength is weak and wrinkles easily occur.

  Therefore, the present inventor diligently studied a method for solving the above problems. As a result, the use of metal rivets coated with an insulator completely eliminates the electromagnetic continuity between the electromagnetic steel sheets, and in addition to being able to firmly tighten the electromagnetic steel sheets, the laminated iron core is not displaced, It was found that the iron core can be held with high accuracy.

  In particular, in the case of a split core that constitutes a stator from two or more laminated blocks, two or more fastening points are required to fasten the laminated core of one block, and eddy current loss occurs in the case of welding or caulking. It was found that a significant iron loss reduction effect can be obtained when an insulator-covered rivet is used, while the iron loss is greatly deteriorated due to.

  FIG. 1 shows an “effect of suppressing deterioration of iron loss characteristics” obtained by using an insulating coating rivet.

  The "iron loss characteristic deterioration suppressing effect" shown in FIG. 1 is a non-oriented electrical steel sheet having a Si content of 1.5% and a sheet thickness of 0.5 mm in an iron core shape having an outer diameter of 50 mm and an inner diameter of 40 mm. Punching, (i) punched state, (ii) stacked 20 sheets, (iii) fixed only on the outer circumference side, (iv) fixed inner and outer circumferences, and (v) strain relief annealing at 750 ° C. for 2 hours It was obtained by measuring the magnetic properties in the state after the process ("after SRA" in FIG. 1).

  From this figure, in the iron core fixed by welding, the iron loss is greatly deteriorated in the state where the inner and outer circumferences are fixed and the state after the strain relief annealing, whereas the iron core tightened using the insulator-covered rivet It can be seen that the deterioration of the iron loss characteristics in the iron core assembling process and the deterioration of the iron loss characteristics after the stress relief annealing are almost completely suppressed.

  This invention was made | formed based on the said knowledge, and the summary is as follows.

  (1) A rivet-clamped laminated iron characterized by using an insulator-covered rivet made of a metal rivet covered with an insulating coating when fastening a unit iron core in a steel core laminated with electromagnetic steel sheets core.

  (2) The rivet according to (1), wherein the core back side of the laminated iron core for the motor is fastened with the insulator-covered rivet, and the tooth side is fastened with welding, caulking, or an adhesive. Fastened laminated iron core.

  (3) The rivet-clamped laminated iron core according to (1) or (2), wherein the insulating coating of the insulating coating rivet is an organic resin.

  (4) The rivet fastening laminate according to (1) or (2) above, wherein the insulating coating of the insulating coating rivet is a divalent or trivalent metal phosphate or oxide. Iron core.

  (5) The rivet-clamped iron core according to any one of (1) to (4), wherein one or more concave portions or convex portions are formed in a cross section of the insulator-covered rivet.

(6) In a method of manufacturing an iron core by laminating electromagnetic steel sheets punched into a predetermined shape,
(A1) A rivet hole having a portion smaller than the rivet diameter is formed and laminated at a predetermined position of the electromagnetic steel sheet,
(B1) Press-fitting the insulating coated rivet into the rivet hole of the laminated electrical steel sheet so as to fit partly or entirely, and then
(C) processing both heads of the rivet and fastening the electromagnetic steel sheet;
A method for producing a rivet-clamped laminated iron core, characterized in that

(7) In a method of manufacturing an iron core by laminating electromagnetic steel sheets punched into a predetermined shape,
(A2) Form a rivet hole at a predetermined position of the laminated electrical steel sheet,
(B2) Press-fit the rivet hole so that an insulating covering rivet having a part larger than the hole diameter is fitted in a part or all of the part, and then
(C) processing both heads of the rivet and fastening the electromagnetic steel sheet;
A method for producing a rivet-clamped laminated iron core, characterized in that

(8) In an apparatus for producing a rivet-clamped laminated iron core by fastening laminated magnetic steel sheets with rivets,
(A1) means for forming and laminating rivet holes having a portion smaller than the rivet diameter at a predetermined position of the electromagnetic steel sheet;
(B1) Press-fitting means for press-fitting the insulating-coated rivet into the rivet holes of the laminated electrical steel sheets so as to fit partly or entirely, and then
(C) fastening means for processing both heads of the rivet and fastening the electromagnetic steel sheet;
An apparatus for producing a rivet-clamped laminated iron core, comprising:

(9) In an apparatus for producing a rivet-clamped laminated iron core by fastening laminated electromagnetic steel sheets with rivets,
(A1) Laminating means for laminating two or more electromagnetic steel sheets in a mold,
(A2) punching means for forming rivet holes at predetermined positions of the laminated electrical steel sheet;
(B) means for press-fitting an insulating-coated rivet having a portion larger than the hole diameter into a rivet hole of the laminated electrical steel sheet so as to fit in a part or all of the part;
(C) fastening means for processing both heads of the rivet and fastening the electromagnetic steel sheet;
An apparatus for producing a rivet-clamped laminated iron core, comprising:

  According to the present invention, in an iron core obtained by caulking laminated electromagnetic steel sheets with rivets and the production thereof, the lamination accuracy is high and a strong iron core can be produced, and the electric steel sheets are not short-circuited after caulking. It is possible to provide an “iron core without deterioration of loss characteristics” and a manufacturing method and apparatus thereof.

  The rivet-clamped laminated iron core of the present invention (the iron core of the present invention) is characterized in that laminated electromagnetic steel sheets are fastened with rivets covered with an insulating agent or an insulator.

  The insulating coated metal rivet used in the present invention is not particularly limited in the type of metal, but aluminum, mild steel, stainless steel, etc. are suitable. In particular, aluminum and mild steel can easily form an insulating coating. It is suitable.

  As the insulating agent for covering the rivet used in the present invention, an organic resin, an inorganic compound, or the like can be used. In particular, an organic resin or a divalent or trivalent metal phosphate and an oxide are used. Is effective. Specifically, as the organic resin, polyester, polyurethane, polyethylene, polypropylene, epoxy resin, acrylic resin, silicon resin, fluorine resin, and the like are suitable. In particular, silicone resin and fluorine resin are suitable because they have heat resistance. is there.

  Moreover, as the inorganic compound, a phosphate compound of a divalent or trivalent metal such as zinc phosphate, iron phosphate, or nickel phosphate is preferable. In addition, phosphoric acid such as phosphate glass is used. Containing compounds are also applicable. In addition, oxides such as alumina, silica, and titania are also suitable, and oxides such as enamel and boric acid glass are also applicable.

  Further, the metal rivet itself may be subjected to an oxidation treatment such as anodizing or bluing treatment to form an oxide film on the surface of the metal rivet to form an insulating coating agent.

  Furthermore, a composite material in which an inorganic compound such as silica or magnesia is added to an organic resin can also be used. In particular, a material in which colloidal silica or alumina is added is preferable because of improved heat resistance.

  The insulating coating material of the present invention does not need to cover the entire rivet, and there is no problem even if there is a gap, and the form of the coating is not particularly limited. Moreover, there is no problem even if there is no covering for the rivet head (the portion that does not contact the laminated iron core).

  The amount of the insulating material coating is not particularly limited because it varies depending on the physical properties of the coating, but it is suitably 0.1 μm or more. If the thickness is less than 0.1 μm, the insulating property is low and stray current may flow. Therefore, the upper limit of the adhesion amount is not particularly limited as long as the adhesion can be secured.

  The type of rivet used in the present invention is not particularly limited, and a general rivet can be used. However, a blind rivet is preferable because it has good workability and good appearance.

  The size (diameter) of the rivet is set to such a size that the insulator-covered rivet can be easily inserted by press-fitting. Preferably, a part larger than the diameter of the rivet hole is formed in a part or all of the rivet.

  The insulating material coating material described above works not only in the insulating property, but also works effectively at the rivet hole and rivet meshing area described later, and improves the accuracy of the laminated iron core by smooth slipping at the time of fastening (elimination of laminating misalignment) And / or a strong strength after fastening can be maintained.

  FIG. 2 shows one aspect of the rivet used in the present invention. The rivet shaft portion a has a protrusion b, and the above-described insulator coating c is applied to the surface of the protrusion b in the rivet shaft portion a.

  When the present invention is used for a motor stator, the core back side is fitted with rivets and the teeth side is fastened with welding, caulking, or adhesive, so that it is extremely strong and has excellent magnetic properties. A wick is obtained.

  When ordinary rivets are used, magnetic properties deteriorate significantly due to eddy currents flowing when welding and caulking are used on the teeth side, and stray currents are generated between the rivets even when the teeth side is used as an adhesive. As a result, the magnetic properties deteriorate.

  When the teeth side is a rivet, the insulating rivet is present in the rivet of the present invention, so that the flow of magnetic flux in the teeth portion is hindered and the characteristics are deteriorated.

  In the iron core manufacturing method of the present invention, either a rivet hole may be formed at a predetermined position of the magnetic steel sheet and then laminated, or a rivet hole after lamination may be formed. There is a feature between.

  In a normal rivet, the rivet hole is larger, and there is a very small gap between the rivet and the rivet hole.

  The feature of the manufacturing method of the present invention is that the rivet hole and the rivet are partially formed in advance, so that the fitting is performed with high accuracy, the iron core stacking accuracy is dramatically improved, and the steel plates are bonded to each other. The strength is also increased. Further, due to the above-described action of the insulating material coating agent, it is difficult to cause a stacking deviation from a portion where the rivet hole and the rivet partially engage with each other, and the fitting is performed with high accuracy.

  Furthermore, by forming a convex part in the cross-sectional shape of the rivet and making the diameter of this part larger than that of the rivet hole, the end surface of the electromagnetic steel sheet forming the convex part and the rivet hole can be meshed with the insulating insulation coating. A strong bond is produced including the action. In the present invention, since insulating coating rivets are used, both insulation and lamination accuracy can be achieved.

  Even if a portion smaller than the rivet diameter is formed in the rivet hole, the same effect can be obtained, but it is not necessary to form the meshing portion in the entire rivet hole, and the portion is formed partially. As a result, a significant improvement in strength can be expected, and as a result, the stacking accuracy is greatly improved.

  Specifically, the diameter of the rivet can be partially made larger than the diameter of the rivet hole by tapering the diameter along the axial direction of the rivet or using a blind rivet.

  When fixing the split core, if the split iron core block can be fixed with high accuracy by other methods, such as welding or caulking, it is not always necessary to firmly fit the rivet. Even if it is slightly spaced, there is no problem, and the eddy current suppressing effect by the insulating coating rivet of the present invention can be obtained.

  In the apparatus for carrying out the method of the present invention (the apparatus of the present invention), (i) a punching means for forming a rivet hole at a predetermined position of the electrical steel sheet, and a laminating means for laminating the electrical steel sheet having the rivet hole in a mold (a1) In addition to (ii) laminating means for laminating two or more electromagnetic steel sheets in a mold, and punching means for forming rivet holes at predetermined positions of the laminated electromagnetic steel sheets (implementing step a2), Press-fitting means for press-fitting an insulator-covered rivet having a portion larger than the hole diameter into the rivet hole of the laminated electromagnetic steel sheet (implementing steps b1 and b2), and processing both heads of the rivet It is characterized by comprising fastening means for fastening (implementing step c).

  In the device of the present invention, the difference from a normal rivet device is that a laminated iron core is fitted and fastened using a rivet having a diameter portion partially larger than that of a rivet hole. The thing of a site | part may be used, and the thing which expands a diameter at the time of a fitting after inserting in a rivet hole may be used.

  Any type of rivet that matches the apparatus of the present invention can be used, but a blind rivet is preferable from the viewpoint of workability. Because the blind rivet can be fitted only with a supply device installed on one side, the device is simple and excellent in maintainability, and the rivet diameter increases due to the fitting. A laminated iron core can be firmly fastened.

  Next, although an Example is described, the conditions etc. which were used in the Example are one example of conditions which were adopted in order to confirm the feasibility of the present invention and the remarkable suppression effect of iron loss characteristics. Is not limited to these conditions. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

Example 1
A non-oriented electrical steel sheet having a Si content of 0.5% and a thickness of 0.5 mm is provided with semicircular protrusions having an outer diameter of 120 mm, an inner diameter of 80 mm, and a length of 10 mm and a width of 25 mm at three positions every 120 °. It was punched into a donut shape with a unit iron core. A circular rivet hole having a diameter of 4.8 mm was formed at the center of the semicircular protrusion simultaneously with the punching.

  After 20 unit iron cores were laminated to form a laminated iron core, a blind rivet having a diameter of 4.8 mm, in which an insulating coating was formed with zinc phosphate, was press-fitted into the rivet hole and fitted. The film thickness of zinc phosphate was about 1 μm.

As a result of measuring the magnetic properties of the iron core by winding a copper wire, the W _15/50 was 7.4 (W / kg). The result of welding the semicircular protrusions instead of fastening the same iron core with rivets was 9.6 (W / kg).

Further, in the case of an iron core that is fastened with an uncoated rivet that is generally commercially available instead of the rivet of the present invention, W _15/50 was 8.1 (W / kg). A maximum deviation of 0.5 mm occurred on the lamination surface, and sufficient lamination accuracy could not be obtained.

  There was almost no misalignment of the iron core of the present invention, and sufficient strength was obtained.

(Example 2)
A non-oriented electrical steel sheet having a Si content of 1.5% and a plate thickness of 0.35 mm is provided with semicircular projections having an outer diameter of 120 mm and an inner diameter of 80 mm at three locations of 10 mm in length and 25 mm in width every 3 degrees. It was punched into a donut shape with a unit iron core. A circular rivet hole having a diameter of 4.8 mm was formed at the center of the semicircular protrusion simultaneously with the punching.

  After laminating 20 unit iron cores to form a laminated iron core, a rivet having a diameter of 4.8 mm in which an insulating coating was formed with a fluororesin was press-fitted into the rivet hole and fitted. The thickness of the fluororesin was about 15 μm. A part of the rivet was formed with a projection of 0.5 mm, and the part was larger than the rivet hole.

A copper wire was wound and the magnetic properties of the iron core were measured. As a result, W _15/50 was 4.1 (W / kg). A similar iron core was welded with a semicircular projection instead of being fastened with rivets, and the result was 5.4 (W / kg).

  The strength of the laminated iron core of the present invention was firm, and there was no occurrence of iron core collapse, diagonal stacking, or misalignment.

(Example 3)
A non-oriented electrical steel sheet having a Si content of 0.1% and a thickness of 0.5 mm is formed into a circle having an outer diameter of 120 mm and an inner diameter of 80 mm, with a diameter of 4.8 mm and an inner diameter of 6 mm at intervals of 120 ° and 2 mm from the outer periphery. A rivet-like hole was formed at the same time as punching. The donut-shaped iron core was further divided into six equal parts so that the rivet holes were separated.

Mild steel with a diameter of 4.8 mm in which six unit iron cores are laminated to form a laminated block, and the inner circumference side is joined by _Tig welding, and the outer circumference side is chromate to form an insulating coating. A blind rivet made of metal was press-fitted into the rivet hole and fitted. The chromate film thickness was about 0.3 μm.

A copper wire was wound and the magnetic properties of the iron core were measured. As a result, the W _15/50 was 7.9 (W / kg). As a result of welding a semicircular protrusion instead of fastening the same iron core with rivets, the result was 26.1 (W / kg).

  The laminated iron core of the present invention has no problem with almost no misalignment.

Example 4
FIG. 3 shows one embodiment of the apparatus of the present invention. A hoop obtained by processing a non-oriented electrical steel sheet having a Si thickness of 0.1% and a thickness of 0.5 mm into a slit shape having a width of 70 mm is shown. FIG. 5 is a cross-sectional explanatory view of a state in which a laminated iron core is manufactured by punching, stacking, and fitting and fastening with an insulating coating rivet.

  In FIG. 3, 1 is a non-oriented electrical steel sheet hoop, 2 and 3 are a pair of molds for forming a rotor punching, 4 and 5 are a pair of molds for forming a teeth punching of a stator, and 6 and 7 are outer circumferences of the stator. It is a pair of metal mold | die which substantially cuts from a hoop. The lower mold 13 and the upper mold 15 finally completely separate the electromagnetic steel sheet into an iron core shape. The upper mold 15 pushes the laminated iron core 12 onto the iron core receptacle 14 and laminates them. 2, 4, 6, and 15 are arranged on the upper mold base 16, and 3, 5, 7, and 13 are arranged on the lower mold base 8.

  The insulating coating rivet is pneumatically transferred from the rivet supply device 11 using the rivet supply pipe 10 and set on the rivet setter 9. When the number of laminated iron cores 12 reaches a predetermined number, the laminated iron core 12 is held from above and below by the upper mold 15 and the iron core receiver 14, and the laminated iron core 12 is insulated by rivets with the rivet setter 9 arranged in 15. Are fitted.

  According to the present invention, in the iron core obtained by caulking laminated electromagnetic steel sheets with rivets and the production thereof, the lamination accuracy is high and a strong iron core can be produced, and the electric steel sheets are not short-circuited after caulking. It is possible to provide an “iron core without deterioration of loss characteristics” and a manufacturing method and apparatus thereof.

  Therefore, the present invention greatly contributes to the establishment of production technology for producing high-efficiency motors and electrical devices that contribute to solving environmental problems at low cost.

It is a figure which shows the "deterioration suppression effect of an iron loss characteristic" obtained by using an insulator covering rivet. It is a figure which shows the one aspect | mode of the rivet used by this invention. It is a figure which shows one embodiment of this invention apparatus.

Explanation of symbols

a Rivet shaft b Projection c Insulation coating 1 Magnetic steel sheet hoop 2, 3 Rotor punching die pair 4, 5 Stator teeth punching die pair 6, 7 Stator outer periphery punching die pair 8 Lower die base 9 Rivet Setter 10 Rivet supply pipe 11 Rivet supply device 12 Laminated iron core 13 Lower mold 14 Iron core receiver 15 Upper mold 16 Upper mold base

Claims (9)

  A rivet-clamped laminated iron core comprising an insulating-coated rivet made of a metal rivet covered with an insulating coating when a unit iron core is fastened in an iron core laminated with electromagnetic steel sheets.   The rivet-clamped laminated iron according to claim 1, wherein the core back side of the laminated iron core for a motor is fastened with the insulator-covered rivet and the teeth side is fastened with welding, caulking, or an adhesive. core.   The rivet-clamped laminated iron core according to claim 1 or 2, wherein the insulating coating of the insulating coating rivet is an organic resin.   The rivet-clamped laminated iron core according to claim 1 or 2, wherein the insulating coating of the insulating coating rivet is a divalent or trivalent metal phosphate or oxide.   The rivet-clamped laminated iron core according to any one of claims 1 to 4, wherein one or more concave portions or convex portions are formed in a cross section of the insulator-covered rivet. In a method of manufacturing an iron core by laminating electromagnetic steel sheets punched into a predetermined shape,
(A1) A rivet hole having a portion smaller than the rivet diameter is formed and laminated at a predetermined position of the electromagnetic steel sheet,
(B1) Press-fitting the insulating coated rivet into the rivet hole of the laminated electrical steel sheet so as to fit partly or entirely, and then
(C) processing both heads of the rivet and fastening the electromagnetic steel sheet;
A method for producing a rivet-clamped laminated iron core, characterized in that In a method of manufacturing an iron core by laminating electromagnetic steel sheets punched into a predetermined shape,
(A2) Form a rivet hole at a predetermined position of the laminated electrical steel sheet,
(B2) Press-fit the rivet hole so that an insulating covering rivet having a part larger than the hole diameter is fitted in a part or all of the part, and then
(C) processing both heads of the rivet and fastening the electromagnetic steel sheet;
A method for producing a rivet-clamped laminated iron core, characterized in that In an apparatus for manufacturing a rivet-clamped laminated iron core by fastening laminated magnetic steel sheets with rivets,
(A1) means for forming and laminating rivet holes having a portion smaller than the rivet diameter at a predetermined position of the electromagnetic steel sheet;
(B1) Press-fitting means for press-fitting the insulating-coated rivet into the rivet holes of the laminated electrical steel sheets so as to fit partly or entirely, and then
(C) fastening means for processing both heads of the rivet and fastening the electromagnetic steel sheet;
An apparatus for producing a rivet-clamped laminated iron core, comprising: In an apparatus for manufacturing a rivet-clamped laminated iron core by fastening laminated magnetic steel sheets with rivets,
(A1) Laminating means for laminating two or more electromagnetic steel sheets in a mold,
(A2) punching means for forming rivet holes at predetermined positions of the laminated electrical steel sheet;
(B) means for press-fitting an insulating-coated rivet having a portion larger than the hole diameter into a rivet hole of the laminated electrical steel sheet so as to fit in a part or all of the part;
(C) fastening means for processing both heads of the rivet and fastening the electromagnetic steel sheet;
An apparatus for producing a rivet-clamped laminated iron core, comprising:

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