JP2007207836A - Manufacturing method of laminated core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a laminated core by which the laminated core superior in occupation rate and size precision can be manufactured. <P>SOLUTION: The manufacturing method of the laminated core is provided with a process for applying a temporary adhesive to an interface of a plurality of magnetic steel boards formed in prescribed shapes so as to laminate them, and a process for bonding the respective magnetic steel boards by impregnating the adhesive in a laminated body. The adhesive is applied to at least one part in the width direction of the prescribed shapes of the magnetic steel boards. Distances from application parts which are the closest to ends in the width direction to the ends are matched at both ends in the width direction among the application parts of the temporary adhesive. In the manufacturing method of the laminated core, the shape of the laminated core is stabilized and the laminated core having the required occupation rate can be manufactured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a laminated core having excellent dimensional accuracy.

  Conventionally, laminated cores are used as cores for motors, reactors, transformers, and the like. The laminated core is configured by laminating thin plates. The laminated core is manufactured by laminating magnetic steel plates and bonding and fixing them.

  As a manufacturing method of a lamination | stacking core, it is disclosed by patent documents 1-4, for example.

  Patent Document 1 includes a step of laminating a plurality of soft magnetic steel plates obtained by punching, and a state in which the laminate is molded by restraining the laminate with a molding jig, on a part of the side surface of the laminate. The step of applying an adhesive to the laminate, temporarily fixing the laminate by drying and baking, the step of impregnating the temporarily fixed laminate with a thermosetting adhesive, and the step A step of molding the laminate by restraining it with a molding jig using a fluororesin coating plate as a release material, and drying and baking treatment on the laminate restrained by the molding jig The manufacturing method of the lamination | stacking core excellent in the dimensional accuracy characterized by having a process to perform is disclosed.

  Patent Document 2 includes a step of laminating a plurality of soft magnetic steel plates obtained by punching, and a state in which the laminate is molded by restraining the laminate with a molding jig, on a part of the side surface of the laminate. A step of applying a thermosetting adhesive, drying and baking, and temporarily fixing the laminate; impregnating the temporarily fixed laminate with a thermosetting adhesive; and The step of forming the laminate after the process is constrained by a molding jig using a fluororesin coating plate as a release material, and drying the laminate constrained by the molding jig, The manufacturing method of the lamination | stacking core excellent in the dimensional accuracy characterized by having the process of performing a baking process is disclosed.

  Patent Document 3 includes a step of laminating a plurality of soft magnetic steel plates obtained by punching, and a state in which the laminate is molded by restraining the laminate with a molding jig, on a part of the side surface of the laminate. On the other hand, a step of applying the instantaneous adhesive and temporarily fixing the laminate by drying, a step of impregnating the temporarily fixed laminate with a thermosetting adhesive, and a lamination through the step The step of molding the body by restraining with a molding jig using a fluororesin coating plate as a release material, and drying and baking treatment on the laminated body restrained by the molding jig The manufacturing method of the lamination | stacking core excellent in the dimensional accuracy characterized by having a process is disclosed.

  As described above, Patent Documents 1 to 3 disclose a method in which a plurality of soft magnetic steel plates are laminated when a laminated core is manufactured, and then a side surface of the laminated body is temporarily fixed when fixed with an adhesive. Has been. However, in the temporary fixing methods disclosed in these publications, only the side surfaces can be fixed. Therefore, in the portion away from the end surface to which the temporary fixing adhesive is applied, the soft magnetic steel plate is inclined, and a desired shape is laminated. There was a problem that the core could not be manufactured.

  Patent Document 4 discloses a method for producing a laminated core material by laminating a plurality of thin steel plates and punching them to form an adhesive layer between the plurality of thin steel plates with an adhesive. A laminated core material comprising: a step of partially adhering so as not to form a non-adhesive region surrounded by a plurality of sheets; and a step of stamping a plurality of thin steel plates bonded in the step together Production method. Is disclosed.

  Patent Document 4 discloses that a temporary adhesive is applied to a bonding surface of a laminated core at a uniform pitch and temporarily fixed. However, since the shape of the core is not considered in the temporary fixing method disclosed in Patent Document 4, an inclination occurs in the soft magnetic steel plate at a portion away from the end face to which the temporary fixing adhesive is applied, and a desired shape is obtained. There was a problem that a laminated core having a shape could not be manufactured.

Furthermore, there is a problem that the amount of the temporary adhesive applied varies, and the ratio of the soft magnetic steel plate to the laminated core (core space factor) varies.
Japanese Patent Laid-Open No. 2005-19640 JP 2005-19641 A JP 2005-19642 A Japanese Patent Application Laid-Open No. 2003-264962

  The present invention has been made in view of the above circumstances, and in a manufacturing method for manufacturing a laminated core by laminating magnetic steel plates formed in a predetermined shape, a laminated core capable of producing a laminated core having excellent space factor and dimensional accuracy. It is an object to provide a method for manufacturing a core.

  In order to solve the above-mentioned problems, the present inventors have studied the method of temporarily fixing a soft magnetic steel sheet when laminating the soft magnetic steel sheets, and as a result, have reached the present invention.

  That is, the method for manufacturing a laminated core according to the present invention includes a step of applying a temporary adhesive to the interfaces of a plurality of magnetic steel plates formed in a predetermined shape and laminating the laminate, and impregnating the laminate with the adhesive to bond each magnetic steel plate. And a step of bonding, wherein the adhesive is applied to at least one place in the width direction of the predetermined shape of the magnetic steel sheet, and the end portion in the width direction of the application portion of the temporary adhesive The distance between the coating portion and the end portion closest to each other is the same at both end portions in the width direction.

  In the method for manufacturing a laminated core of the present invention, when a magnetic steel plate having a predetermined shape is temporarily fixed, the thickness of the laminated body can be within a predetermined range. Thereby, the thickness of the laminated core formed by impregnating the laminated body with the adhesive can be set within a certain range. Thereby, the shape of the laminated core is stabilized. Moreover, the position of the application part can be determined from the allowable range of the dimensions of the laminated body, and a laminated core having a necessary space factor can be manufactured.

  The method for manufacturing a laminated core according to the present invention includes a step of applying a temporary adhesive to the interfaces of a plurality of magnetic steel plates formed in a predetermined shape and laminating them, and impregnating the laminate with an adhesive to bond each magnetic steel plate. And a process. That is, in the method for manufacturing a laminated core according to the present invention, a magnetic steel plate having a predetermined shape is temporarily fixed with a temporary adhesive, and thereafter, the laminated body is integrally bonded by impregnating the adhesive between the laminated magnetic steel plates.

  The magnetic steel plate used in the production of the laminated core of the present invention is a steel plate that can be used as a core of a motor, a reactor, a transformer, etc. when the laminated core is formed. Further, the magnetic steel sheet used in the production method of the present invention is preferably as thin as possible. A preferred thickness is 0.2 mm or less, and a more preferred thickness is 0.1 mm or less.

  In the laminated core manufacturing method of the present invention, the temporary adhesive is applied to at least one position in the width direction of the predetermined shape of the magnetic steel plate, and is closest to the end in the width direction among the application portions of the temporary adhesive. It is applied at a position where the distance between the applied portion and the end portion coincides at both end portions in the width direction. That is, the distance from the position where the temporary adhesive is applied to the end in the width direction is the same. Thereby, variation does not arise in the increase amount of the thickness of the laminated body of the temporarily fixed state. Specifically, in the temporarily fixed laminate, the portion where the temporary adhesive is not applied is not restrained by the temporary adhesive, so air remains between the magnetic steel plates, and the laminate Thickness increases partially. For this reason, when the distance between the application part and the end part of the temporary adhesive is different, a difference occurs in the thickness of the laminated body at the end part. On the other hand, in the manufacturing method of the invention, the distance between the application portion and the end portion of the temporary adhesive matches at both ends in the width direction at the time of temporary fixing, so the increase in the thickness of the laminate matches in the width direction. It will be. That is, no variation occurs in the thickness of the laminate. As a result, in the manufacturing method of the present invention, when the thickness of the laminated body after temporary fixing is constant, the number of laminated steel sheets can be increased. That is, a laminated core having a large core space factor can be manufactured.

  In the production method of the present invention, the distance between the coated part to which the temporary adhesive is applied and the end of the magnetic steel sheet is the distance between the edge of the temporary adhesive and the end of the magnetic steel sheet in the applied state. Alternatively, it may be either the distance between the application center when applying the temporary adhesive and the end of the magnetic steel plate to be applied. The distance between the coating center and the end of the magnetic steel plate to be applied is more preferable.

  In the manufacturing method of the present invention, the width direction of the predetermined shape of the magnetic steel sheet indicates a direction substantially perpendicular to the direction in which the shape of the magnetic steel sheet of the predetermined shape extends. When the predetermined shape forms at least a part of an annular shape, the width direction substantially coincides with the circumferential direction of the annular shape.

  In the production method of the present invention, the number of provision portions of the temporary adhesive in the width direction of the magnetic steel sheet is not particularly limited. That is, when the length in the width direction is short, the temporary adhesive may be applied to one place in the center of the width direction, and when the length in the width direction is long, the temporary adhesive is applied to the place to be taken in the width direction. do it.

  It is preferable that the distance between the temporarily bonded application portion and the end portion in the width direction is determined based on the thickness of the laminate. As described above, in the temporarily fixed laminate, the thickness of the laminate increases as the distance from the application portion of the temporary adhesive increases. That is, the distance from the application part of temporary adhesive has a correlation with the thickness of a laminated body, and the distance of an application part and an edge part is determined from the thickness of the laminated body which can obtain a desired core space factor.

  Since the distance between the temporarily bonded application portion and the end portion in the width direction differs depending on the magnetic steel plate and the temporary adhesive to be laminated, it cannot be determined unconditionally. For example, in a state where a laminated body of magnetic steel sheets is temporarily fixed with a temporary adhesive, an increase rate of the thickness of the laminated body according to a distance from an application portion where the temporary adhesive is applied is measured and shown in FIG. The laminate shown in FIG. 1 was formed in the same manner as Example 1 described later.

  As shown in FIG. 1, the thickness of the laminated body of the application part of a temporary adhesive was set to a. The thickness increases by 2.2% at a position away from the application part by the thickness a of the application part of the laminate, and the thickness increases by 4.4% at a position away from the application part by the distance 2a. I understand that. That is, the thickness of the laminated body is increased as the distance from the temporary bonding portion increases.

  That is, when the thickness of the laminated body sufficient to obtain a desired core space factor is determined, the distance between the application part and the end part is calculated, and the temporary adhesive is applied to the part corresponding to this distance. Thus, a laminated core having a desired core space factor can be obtained.

  In the manufacturing method of the present invention, the application position of the temporary adhesive in the extending direction of the predetermined shape of the magnetic steel sheet is not particularly limited, but is determined based on the thickness of the laminate as in the width direction. It is preferred that

  When the surface of the magnetic steel sheet to which the temporary adhesive is applied is defined as 100%, the area of the application part is preferably 25% or less. A high core space factor can be obtained when the area of the application part is 25% or less. Here, when the area of the application part of a temporary adhesive increases, the ratio of the temporary adhesive to a laminated body will increase, and a core space factor will fall. Here, the smaller the area of the application portion, the smaller the area occupied by the temporary adhesive. A more preferable area of the application part is 15% or less, and a more preferable area of the application part is 10% or less. In addition, in this invention, the area of the application part formed by apply | coating a temporary adhesive shows the area in the state which applied the temporary adhesive to the surface of a magnetic steel plate. Furthermore, when the temporary adhesive is composed of an adhesive component and a volatile solvent in which the adhesive component is dispersed, the mass of the adhesive component is 25% when the mass of the temporary adhesive is 100%. The above is preferable.

  In the production method of the present invention, the temporary adhesive for temporarily fixing the laminated body of magnetic steel plates may be any adhesive that can temporarily fix the magnetic steel plates, and conventionally known temporary adhesives can be used. Examples of such temporary adhesives include adhesives such as butyral thermosetting resin adhesives and epoxy thermosetting resin adhesives.

  Since the temporary adhesive is composed of the adhesive component and the solvent, the adhesive component can be applied to the magnetic steel sheet by volatilizing the solvent after the application, so that the temporary adhesive is easily handled. Further, by dispersing the adhesive component in the solvent, the excessive adhesive component is not applied to the magnetic steel sheet.

  Moreover, a solvent should just consist of a material which can disperse | distribute an adhesive agent component and can volatilize after application | coating, and a conventionally well-known solvent can be used. Examples of such a solvent include methyl ethyl ketone.

  When the mass of the adhesive component in the temporary adhesive is 25% or more, a high core space factor can be obtained. Here, when the mass of the adhesive component of the temporary adhesive decreases to 25% or less, the adhesive component becomes too small and temporary fixing becomes insufficient. However, when the proportion of the temporary adhesive in the laminate increases, the core space factor decreases. Here, the smaller the proportion of the adhesive component, the better the area occupied by the temporary adhesive. A more preferable ratio of the adhesive component is 50% or less, and a more preferable area of the coated portion is 40% or less.

  In the production method of the present invention, when the temporary adhesive consists of an adhesive component and a volatile solvent in which the adhesive component is dispersed, It is more preferable that the area of the coated part is 10% or less when the mass of the component is 25 to 40% and the surface of the magnetic steel sheet to which the temporary adhesive is applied is 100%.

  The production method of the present invention can be the same as a conventionally known method for producing a laminated core except that a magnetic steel plate is temporarily fixed.

  In the step of adhering each magnetic steel sheet by impregnating the laminated body of magnetic steel sheets with an adhesive, a conventionally known adhesive can be used as the adhesive. For example, an adhesive such as an acrylic thermosetting resin adhesive or an epoxy thermosetting resin adhesive can be used.

  The laminate impregnated with the adhesive is preferably subjected to a step of drying the adhesive. Thereby, the laminated core which the laminated body adhered can be manufactured.

  Hereinafter, the present invention will be described using examples.

  A laminated core was manufactured as an example of the present invention.

Example 1
First, a magnetic steel plate 1 having a thickness of 0.1 mm was manufactured by a method such as punching into a substantially U shape. The obtained magnetic steel sheet 1 is shown in FIG. As shown in FIG. 2, the magnetic steel sheet 1 has a shape in which a central portion 11 having a width of 2B is connected to both end portions 10 and 10 having a width of 2A. Moreover, the both ends 10 and 10 and the center part 11 are connected in the state orthogonal, respectively.

  Then, a temporary adhesive was applied to four locations on one surface of the magnetic steel plate 1. The temporary adhesive has a widthwise central portion (distance to the widthwise end portion A) at both end portions with a width of 2A (application positions a and d in the figure) and a central portion with a width of 2B (width direction). The coating was carried out with the distance to the end of B being the target at positions B) and (coating positions b and c in the figure). In other words, the temporary adhesive droplets were applied by dropping a predetermined amount around each application position a, b, c, d.

  Then, 300 magnetic steel plates 1 coated with a temporary adhesive were laminated, pressed in the thickness direction and held, and a laminate in which the magnetic steel plates were temporarily fixed with the temporary adhesive was manufactured.

  As the temporary adhesive, an adhesive prepared by dispersing a butyral thermosetting resin adhesive in methyl ethyl ketone as a solvent so that the adhesive component was 33% was used.

  The manufactured laminate was impregnated with an adhesive made of an acrylic thermosetting resin adhesive, and then dried and heated to solidify. In addition, the conventionally well-known method was used for the impregnation of this adhesive agent and subsequent drying and solidification.

  Thereby, the laminated core of the present Example was manufactured.

  When the laminated core of this example was temporarily fixed with a temporary adhesive, the thickness of the laminated body at the end in the width direction of the magnetic steel sheet 1 extending in a substantially U shape was the same at both ends. And since it fixed with the adhesive agent in this state, it became the lamination | stacking core excellent in the stability of a shape. Moreover, in the present Example, since the increase rate of the thickness of the laminated body could be kept small at the time of temporary fixing with the temporary adhesive, the laminated core had an excellent core space factor.

(Example 2)
First, a magnetic steel plate having a thickness of 0.1 mm was formed into a rectangular shape. The magnetic steel sheet is shown in FIG. As shown in FIG. 3, the magnetic steel sheet has a size of 2C × 2D.

  And the temporary adhesive was apply | coated to four places of the one surface. The temporary adhesive has four positions (positions in the drawing) in which the positions from both ends in the long side direction of the rectangular shape are 0.5C, respectively, and the positions from both ends in the short side direction are each 0.5D. The coating was carried out with the position e, f, g, h) as the target.

  200 magnetic steel plates 1 coated with a temporary adhesive were laminated to produce a laminate in which the magnetic steel plates were temporarily fixed.

  The manufactured laminate was impregnated with an adhesive made of an acrylic thermosetting resin adhesive, and then dried and heated to solidify. In addition, the conventionally well-known method was used for the impregnation of this adhesive agent and subsequent drying and solidification.

  Thereby, the laminated core of the present Example was manufactured.

  The temporary adhesive and the adhesive were the same as those used in Example 1.

  When the laminated core of this example was temporarily fixed with a temporary adhesive, the thicknesses of the laminated bodies at the ends in the long side direction and the short side direction of the magnetic steel sheet were matched at both ends. And since it fixed with the adhesive agent in this state, it became the lamination | stacking core excellent in the stability of a shape similarly to the time of Example 1. FIG. Moreover, in the present Example, since the increase rate of the thickness of the laminated body could be kept small at the time of temporary fixing with the temporary adhesive, the laminated core had an excellent core space factor.

(Application area and concentration of temporary adhesive)
In Example 2, a laminated core was manufactured by changing the application area of the temporary adhesive to the magnetic steel sheet and the concentration of the temporary adhesive. And the space factor of the manufactured laminated core was measured. The measurement results are shown in Table 1.

  As shown in Table 1, it can be seen that the core space factor increased as the application area of the temporary adhesive decreased. Moreover, it turns out that the core space factor became high, so that the density | concentration of the adhesive component of temporary adhesive became low. And it turns out that it becomes a high core space factor when the application area of temporary adhesive is 17.5% and 8.8%.

  In particular, when the application area of the temporary adhesive is 8.8% and the concentration of the temporary adhesive is 33%, the core space factor is as high as 95%.

It is the figure which showed the relationship between the distance from the temporary fixing part of the laminated body of a magnetic steel plate, and the thickness of a laminated body. It is the figure which showed the shape of the magnetic steel plate of the lamination | stacking core of Example 1, and the application part of temporary adhesive. It is the figure which showed the shape of the magnetic steel plate of the lamination | stacking core of Example 2, and the application part of temporary adhesive.

Explanation of symbols

1: Magnetic steel plate 10: End portion 11: Center portion

Claims (4)

Applying and laminating a temporary adhesive to the interface of a plurality of magnetic steel sheets formed in a predetermined shape; and
Adhering the magnetic steel sheet by impregnating the laminate with an adhesive; and
A method for producing a laminated core comprising:
The temporary adhesive is applied to at least one place in the width direction of the predetermined shape of the magnetic steel sheet,
A manufacturing method of a laminated core, wherein a distance between the application portion closest to the end portion in the width direction and the distance between the end portions in the width direction is the same among the application portions of the temporary adhesive.   The method for manufacturing a laminated core according to claim 1, wherein a distance between the application portion of the temporary adhesion and an end portion in the width direction is determined based on a thickness of the laminated body.   2. The method for manufacturing a laminated core according to claim 1, wherein an area of the application part is 25% or less when a surface of the magnetic steel sheet to which the temporary adhesive is applied is 100%.   When the temporary adhesive consists of an adhesive component and a volatile solvent in which the adhesive component is dispersed, the mass of the adhesive component when the mass of the temporary adhesive is 100% The manufacturing method of the laminated core of Claim 1 whose is 25% or more.

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