JP6064923B2 - Manufacturing method of laminated iron core - Google Patents

Description

  The present invention relates to a method for manufacturing a laminated iron core and a laminated iron core for producing an iron core of a rotating machine such as a motor or a generator using a laminated steel sheet in which a steel sheet is fastened by a combination of caulking and an adhesive.

  Generally, a laminated body (laminated steel sheet) of electromagnetic steel sheets is used as an iron core of a motor or a generator. In such an iron core (laminated iron core) made of laminated steel sheets, the electromagnetic steel sheets constituting the laminated body need to be bonded (fastened) with a certain level of force when the motor or generator is manufactured and used.

  As a method for fastening steel plates, there are fixing with bolts and welding, or adhesion between steel plates, and the most frequently used method for fastening steel plates is a method called caulking. Caulking is a process of extruding each steel plate with a caulking punch to form a partially convex shape on the opposite side of the steel plate from the caulking punch (the caulking punch side is a concave shape). This is a method of fixing the steel plates to each other by fitting the portions (convex shape portions). Such a convex portion is referred to as a dowel.

  Specifically, in the caulking process, the dowel formed in the iron core pressing process is aligned with the position of the dowel from the top and bottom in the next process inside the mold or the next process provided outside the mold. The steel plates are integrated by applying pressure to fit the dowels together.

  In a laminated steel sheet manufactured by caulking in this way, if the fastening force between the laminated steel sheets is weak, the steel sheets may peel off during manufacture of the motor or generator, or the product (motor or generator) This is not preferable because the steel plate peels off during use. On the other hand, when the number of crimping points is increased so as to increase the fastening force between the steel plates, the magnetic properties of the iron core deteriorate due to processing strain and elastic stress field around the crimped portion. Therefore, it is required to increase the fastening force per caulking point.

  The peel strength (the limit value at which the steel plate peels off), which means the fastening force by caulking, is affected by the height of the dowel (caulking depth) and the clearance between the caulking punch and the die hole forming the dowel By adjusting these, it is possible to control to some extent. However, there is a limit to increasing the height of the dowel. Further, as the height of the dowel is increased, the processing area around the dowel of the steel sheet is expanded, so that the magnetic properties of the steel sheet are deteriorated. In addition, there is a limit to the clearance adjustment for stable processing. Therefore, a technique for improving the peel strength without depending on these adjustments is expected.

  In addition to peel strength, securing the rigidity of the iron core is also important in terms of ensuring product reliability and reducing noise. That is, if the iron core is deformed by electromagnetic vibration or external force of the motor itself, it causes an increase in noise due to the vibration of the iron core. Further, when the steel plates are separated from each other due to the deformation, not only the noise is increased, but also the long-term reliability of the product is lowered. Therefore, a technique for ensuring the rigidity of the iron core in addition to the peel strength is expected.

  In order to ensure the peel strength and rigidity of the iron core, it is known that it is effective to bond steel plates (iron core materials). However, various difficulties are involved in laminating and adhering after applying an adhesive on the entire surface inside the mold. For example, when trying to bond the entire surface of the iron core material, if the amount of adhesive applied is large, not only will the space factor decrease, but the adhesive will leak from the end of the iron core, causing various troubles. . On the other hand, if the amount of adhesive applied is small, the adhesive force cannot be effectively secured. For so-called impregnation adhesion, steel sheets are fixed and integrated by immersing laminated steel sheets in an adhesive (impregnating agent) in a decompressed container and filling the gaps between the steel sheets with the impregnating agent. According to this, productivity is remarkably inferior. Also, for example, as described in Patent Document 1, even when applying a steel sheet having an adhesive insulating coating on the surface of an electromagnetic steel sheet and laminating and fixing it together with caulking, high temperature and long time annealing is performed. Productivity is inferior because it is necessary.

  Then, the technique which adhere | attaches an iron core material partially, performing the fastening of an iron core by crimping is disclosed. For example, Patent Document 2 describes a technique in which an adhesive is used to fix between a steel plate that is formed by alternately laminating caulking and a steel plate that has been jumping cut.

JP 2002-191142 A JP 2009-72014 A

  However, in the technique described in Patent Document 2, the dowel position and the fixing position by the adhesive are different positions, and thus the peel strength per caulking point cannot be increased.

  This invention is made | formed in view of the above, Comprising: It aims at providing the manufacturing method of the laminated core which can manufacture the laminated core which has high peeling strength and rigidity. Another object of the present invention is to provide a laminated iron core having high peel strength and rigidity.

  In order to solve the above-described problems and achieve the object, a method for manufacturing a laminated iron core according to the present invention forms a convex dowel on each of a plurality of iron core materials using steel plates, and the dowels between the iron core materials are formed. Is a method for manufacturing a laminated iron core that is integrated with each other by inserting a dowel between the iron core materials, and then infiltrating an adhesive from the outer peripheral surface of the iron core material in the stacking direction to the center direction. And a step of fixing the dowels to each other with the adhesive.

  Further, in the method for manufacturing a laminated core according to the present invention, in the above invention, 30% or more of a plurality of dowels formed on the core material is fixed with the adhesive.

  Moreover, the manufacturing method of the laminated iron core which concerns on this invention WHEREIN: In the said invention, the center position of the dowel fixed by the said adhesive agent is formed in the position within 8 mm from the outer peripheral surface of the lamination direction of the said iron core material. Features.

  The method for manufacturing a laminated core according to the present invention is characterized in that, in the above invention, the adhesive has a viscosity of 200 mPa · s or less.

  Moreover, the laminated iron core according to the present invention is manufactured by the above-described invention.

  The laminated core according to the present invention is characterized in that, in the above invention, the thickness of the core material is 0.50 mm or less.

  In the above invention, the laminated core according to the present invention is characterized in that the diameter or the maximum length is larger than 100 mm.

  According to the present invention, a laminated iron core having high peel strength and rigidity can be obtained.

FIG. 1 is a schematic diagram showing a schematic configuration of a laminated core manufactured by a method for manufacturing a laminated core according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a cross section in the short side direction of the dowel of the laminated iron core of the present embodiment. FIG. 3 is a schematic diagram showing each part around the dowel in the present embodiment. FIG. 4 is a schematic diagram showing a schematic configuration of a laminated core used for peel strength measurement of this example. FIG. 5 is a diagram for explaining the peel strength measuring method of this example.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. Moreover, in description of drawing, the same code | symbol is attached | subjected and shown to the same part.

  The laminated iron core according to an embodiment of the present invention is manufactured by laminating a plurality of iron core materials. A steel plate (magnetic steel plate) is punched into a predetermined shape of the iron core material by a die in a pressing process, and at the same time, a convex dowel is formed at a predetermined position of the iron core material S by a caulking punch descending from above the steel plate. The Next, a plurality of iron core materials in which dowels are formed are stacked so that the dowels overlap each other, and are pushed in from above, whereby the upper iron core material S dowels are inside the dowels of the lower iron core material S (concave portion). To fit.

  In the present embodiment, the dowel has a rectangular planar shape and a V-shaped cross-section in the long side direction. Thereby, the laminated iron core by V caulking is manufactured.

  FIG. 1 is a top view of the laminated core of the present embodiment in the lamination direction. In the manufacturing process of the laminated core of the present embodiment, the adhesive A is applied to the outer peripheral surface R in the laminating direction of the laminated core C in which the plurality of iron cores S are laminated as described above. Infiltrate in the center direction of the iron core material S. Here, the outer peripheral surface R means the surface of the laminated core C excluding the upper and lower surfaces in the lamination direction. As a result, among the dowels D indicated by rectangles in FIG. 1, the adhesive A penetrates to the positions of the dowels D formed around the outer peripheral surface R of each iron core material S, and the upper and lower dowels D at each position adhere to each other. To do.

  In this way, when the inside of the dowel D (the inner and outer peripheries of the upper and lower dowels D) is fixed with the adhesive A, the peel strength between the iron core materials S of the manufactured laminated core C increases. This is thought to be due to an increase in resistance to shear stress when the upper and lower dowels D are about to peel off.

  FIG. 2 is a schematic diagram showing a cross section in the short side direction of the dowel D of the iron core material S that is fastened. In the following, as shown in FIG. 3, the peripheral portions of the dowel D are referred to as dowel upper surface d1, dowel lower surface d2, dowel convex side surface d3, dowel concave side surface d4, iron core material upper surface c1, and iron core material lower surface c2. . As shown in FIG. 2, when the block of the iron core material S1 and the iron core material S2 and the block below the iron core material S3 are to be peeled, an arrow is shown in FIG. 2 between the iron core material S2 and the iron core material S3. The peeling force f1 works. Further, the dowel convex side surface d3 and the dowel concave side surface d4 which are opposed to each other are fixed by the adhesive A, so that the side surface of the dowel D (the dowel convex side surface d3 and the dowel concave side surface d4) is filled. A shearing force f2 indicated by an arrow in FIG. In this case, it is considered that the peel strength is increased as compared with the case where the iron core material S2 and the iron core material S3 are about to peel without the dowel convex side surface d3 and the dowel concave side surface d4 being fixed.

  By adjusting the position of the dowel D and the viscosity of the adhesive A, the number of dowels D fixed by the adhesive A is set to 30% or more of the total number of dowels D. The peel strength of the laminated iron core C is improved by setting the number ratio of the dowels D having high peel strength to 30% or more.

  Further, the adhesive A applied to the outer peripheral surface R under atmospheric pressure penetrates from the outer peripheral surface R to the position of about 8 mm in the central direction of each iron core material S regardless of the viscosity. Therefore, the center position of the dowel D fixed by the adhesive A is formed at a position where the distance from the outer peripheral surface R (the shortest distance from the outer peripheral surface R to the center of the dowel D) is within 8 mm.

  Moreover, the viscosity of the adhesive agent A shall be 200 mPa * s or less. According to the adhesive A having a higher viscosity than this, depending on the degree of the gap between the iron core materials S, the adhesive A does not sufficiently penetrate into the center direction of the iron core material S, and thus sufficient peel strength may not be obtained.

  As described above, according to the manufacturing process of the laminated core of the present embodiment, the gap between the iron cores S can be easily achieved by applying the adhesive A to the outer peripheral surface R after laminating the iron cores S. Adhesive A (impregnating agent) can be permeated into. Thereby, the laminated iron core which has high peeling strength and rigidity can be obtained rather than the laminated steel plate fastened only by the frictional force of fitting of dowels D.

  In particular, in the laminated iron core manufactured using the thin iron core material S having a thickness of 0.50 mm or less, the strength at the dowel D position is lowered and the peel strength is lowered. However, the laminated iron core according to the present embodiment is reduced. According to this manufacturing process, it is possible to improve the peel strength.

  The present invention can be applied to any normal caulking process, such as round caulking with a rounded convex dowel D, in addition to the above-described V caulking.

  Further, the laminated core C manufactured according to the present invention is effective for a large core whose diameter (or maximum length) exceeds 100 mm. This is because, when the outer diameter of the iron core is large, when the local stress acts on the iron core, the distance from the acting point to the fastening point becomes long, so the torque acting as a peeling force increases, and the iron core material S peels off. This is because the deformation is likely to occur and the amount of deformation accompanying the decrease in the rigidity of the iron core also increases.

  Moreover, the laminated iron core C manufactured by this invention is suitable for the iron core for motors and generators. This is because the iron cores for motors and generators are noisy due to electromagnetic vibrations, are resistant to vibrations, require long-term reliability, and require a strong fastening force.

  The permeation treatment in which the adhesive A penetrates from the outer peripheral surface R toward the center of the iron core material S is performed under atmospheric pressure instead of applying the adhesive A to the outer peripheral surface R after laminating the iron core material S as described above. A method of immersing the laminated iron core C in the adhesive A (impregnating agent) may be used. In addition, although the laminated iron core C may be immersed in the adhesive agent A (impregnating agent) under reduced pressure, performing the impregnation work in a reduced-pressure atmosphere has poor work efficiency. Therefore, it is desirable to perform the penetration treatment of the adhesive A under atmospheric pressure from the viewpoint of manufacturing cost reduction.

  In addition, after the core materials S are integrated by caulking and then subjected to strain relief annealing, it is possible to further increase the peel strength by performing the penetration treatment of the adhesive A as described above.

  The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited to these embodiments. Various modifications according to specifications and the like are within the scope of the present invention. It is obvious from the above description that various other embodiments are possible within the scope of the above.

[Example]
In this embodiment, a magnetic core having a thickness (0.35 mm, 0.20 mm) shown in Table 1 is used as the iron core material S, and the fixed iron core (diameter 200 mm, back yoke width) of the concentrated winding brushless DC motor shown in FIG. 15 mm) was manufactured, and the peel strength was measured. At that time, dowels D were formed at positions indicated by rectangles in FIG. The dowel D has a short side of 1 mm, a long side of 3 mm, and the dowel height is V-shaped 1.5 times the plate thickness, and the distance Xk to the center of the dowel D closest to the outer peripheral surface R is in the range of 5 to 12 mm. It was changed with. Next, an adhesive A having a different viscosity was applied from the outer peripheral surface R under atmospheric pressure, and left for 3 hours to penetrate between the iron core materials S to fix the iron core materials S to each other. As the peel strength, as indicated by an arrow in FIG. 5, the laminated iron core C was pulled parallel to the axial direction, and the force when the peel occurred was measured. The average value of the width (penetration distance) Xs of the penetration area of the adhesive A by peeling off the iron core material S, and the ratio (number ratio) of the number of dowels D formed in the penetration area to the total dowel D Asked.

  Table 1 shows the measurement results of the peel strength under each of the above conditions. As shown in Table 1, according to the present invention, it was confirmed that a high peel strength was obtained as compared with the case of simply caulking, impregnation by infiltration from the side surface, or a combination of both. In addition, if the distance Xk between the adhesive A application surface (the outer peripheral surface R of the iron core S) and the center of the dowel D is 8 mm or less, the peel strength even when the viscosity of the adhesive A is higher than 200 mPa · s. The effect of improvement was recognized. Further, if the adhesive A has a viscosity of 200 mPa · s or less, it is peeled even when the distance between the center of the dowel D and the adhesive A application surface (the outer peripheral surface R of the iron core material S) is larger than 8 mm. The effect of strength improvement was recognized.

S Iron core material C Laminated iron core D Dowel A Adhesive

Claims (3)

A method of manufacturing a laminated iron core in which a convex dowel is formed on each of a plurality of iron core materials using steel plates, and the dowels between iron core materials are fitted and integrated,
After fitting the dowels of the core material to each other, by infiltrating the adhesive toward the center from the outer peripheral surface of the stacking direction of the core member, viewed including the step of securing said dowels together with adhesive, the 30% or more of a plurality of dowels formed on an iron core material is fixed with the adhesive, and a method for producing a laminated iron core is provided. The center position of the dowel which is fixed by the adhesive, the manufacturing method of the laminated core according to claim 1, characterized in that it is formed at a position within 8mm from the outer circumferential surface of the laminated direction of the core material. The method for producing a laminated core according to claim 1 or 2 , wherein the adhesive has a viscosity of 200 mPa · s or less.

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