JPH04223313A - Manufacture of wound core - Google Patents

Abstract

PURPOSE:To easily shape up a wound core when it is manufactured using a laminated material which is formed by laminating a thin strip of amorphous magnetic alloy. CONSTITUTION:A laminating stand Ts is composed by arranging tables T on both sides of a rectangular mandrel M. After all thin strips, required for manufacture of a core, have been stacked on the laminating stand Ts, a table support is removed, the thin strips are hanged down by their own weight, and an inverted U-shaped core I' is formed. Then, a U-shaped frame is attached to the aforesaid core, the outside part of the core I' is fixed, and after the frame and the core have been inverted, the opened side of the core is closed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a wound core using an amorphous magnetic alloy ribbon.

0002

[Prior Art] Recently, amorphous magnetic alloys have been attracting attention as low-loss iron core materials, and power distribution transformers using amorphous magnetic alloy ribbons (hereinafter simply referred to as ribbons) are being manufactured. It is becoming more and more popular.

[0003] Since the amorphous magnetic alloy ribbon has a thickness of only about 20 to 30 μm, when manufacturing a wound core using this ribbon, it would be extremely difficult to handle the ribbon one by one. Work efficiency is poor. Therefore, a method of manufacturing a rectangular wound core (hereinafter referred to as core) by laminating a plurality of thin strips (more than ten to several tens of strips) together as a unit laminate, and using a plurality of these unit laminates. is taken.

[0004] In the conventional method, after winding a ribbon into a ring shape, the ring-shaped wound body is cut at one point in the circumferential direction in the stacking direction to divide it into bundles of a constant thickness. to create a unit laminate. Then, a wound core is formed by step-lap joining a large number of unit laminates thus produced. When performing step lap bonding, a series of unit laminates (called a laminate block) are formed by stacking the unit laminates by shifting them by a predetermined length in the longitudinal direction.
is wound around the outer periphery of a substantially annular or substantially rectangular mandrel, and both ends of the laminate block in the longitudinal direction are overlapped. Further, on the outside thereof, a laminate block formed by stacking a series of unit laminates in the same shifting manner as the inner laminate block is stacked, and this process is repeated.

The above method is a method of forming an iron core by winding each laminate block around a mandrel (referred to as the sequential winding method). However, as another method of forming an iron core from a unit laminate, there is As shown in No. 61-42906, all the laminate blocks are stacked on a flat surface, all of them are shaped into a U-shape, and the open sides are closed to form a rectangular wound core. A manufacturing method (referred to as a batch shaping method) has been proposed. In this method, all the laminate blocks stacked on a flat surface are inserted into a U-shaped shaping frame that opens upwards, shaped into a U-shape, and then the sides that protrude upward from the shaping frame are joined together. Then, a rectangular wound core is manufactured.

[0006]

[Problems to be Solved by the Invention] As mentioned above, there are two methods for manufacturing a wound core from a ribbon: the sequential winding method and the batch shaping method, but the batch shaping method is more difficult to process than the sequential winding method. Since it is simple, it requires less man-hours.

However, the amorphous magnetic alloy ribbon before annealing has extremely poor rigidity and is easily deformed by its own weight. When moving the entire laminate block to the position of the shaping frame and inserting it all at once into the frame, it is necessary to There was a problem in that unexpected deformation occurred and workability was significantly impaired.

[0008] An object of the present invention is to easily process a laminate block formed by laminating a plurality of unit laminates of amorphous magnetic alloy ribbons into a rectangular shape. The purpose of the present invention is to propose a method for manufacturing a wound core that makes it possible to.

[0009]

[Means for Solving the Problems] The present invention provides a unit laminate in which a predetermined number of amorphous magnetic alloy ribbons are laminated, and a plurality of laminate blocks each formed by laminating a plurality of unit laminates. This is a method for manufacturing a rectangular wound core having a structure in which both ends of each unit laminate of each laminate block are joined in an overlapping state.

In the present invention, first, an amorphous magnetic alloy ribbon is wound around a circular winding frame to form a ring-shaped laminate.
By cutting the ring-shaped laminate at one point in the stacking direction and developing it, a developed laminate S of amorphous magnetic alloy ribbons as shown in FIG. 1(A) is formed.

Further, as shown in FIG. 1(B), on both sides of a rectangular mandrel M whose short sides are kept horizontal, there are tables T, T whose upper surfaces are located on the same horizontal plane as the upper surface of the upper short side of the mandrel M. The mandrel and the tables on both sides constitute a stacking table Ts whose upper surface forms a substantially horizontal surface. The configuration of this stacking table may be performed before forming the expanded laminate, or may be configured after forming the expanded laminate.

Next, a plurality of unit laminates are formed by dividing the expanded laminate, and a predetermined number of unit laminates are laminated in order from the shortest laminate, with their respective positions shifted in the longitudinal direction to form the laminate block. By repeating the process of forming , a plurality of laminate blocks are stacked on the laminate table Ts in order from the shortest laminate block to form a recombined laminate Sr as shown in FIG. 1(B).

Next, the longitudinal center portion of this recombined laminate Sr is restrained and fixed to the upper short side of the rectangular mandrel M.

Next, the support of the recombined laminate Sr by the tables T and T is removed, and the recombined laminate Sr is deformed into an inverted U-shape by its own weight, as shown in FIG. 1(C), thereby forming a rectangle with one side open. A shaped wound core I is formed. In this case, it is necessary to move the table to remove the support of the recombined laminate from the table, but the table can be moved in any manner. For example, the tables T and T may be lowered, or both tables may be rotated downward using the ends of the tables T and T opposite to the mandrel as fulcrums. Alternatively, the tables T, T may be removed from the recombined laminate by moving in the horizontal direction.

Next, as shown in FIG. 1(D), a frame is fitted from the outside onto the rectangular wound core I with one side open, and the sides of the rectangular wound core other than the open side are attached to the mandrel M. Fixed against.

Thereafter, the rectangular wound core I with one side opened is turned over together with the frame F, and the one side opened of the rectangular wound core is positioned on the upper side as shown in FIG. 1(E). Next, by folding and overlapping the ends of the laminate blocks, a rectangular wound core is formed as shown in FIG. 1(F).

[0017]

[Operation] As described above, a stacking table was constructed with a rectangular mandrel and tables placed on both sides of the rectangular mandrel, and a plurality of laminate blocks were stacked on this stacking table in order from the shortest one to form a recombined laminate. After that, when the support by the table is removed, the part of the recombined laminate that was supported by the table loses its support and sag under its own weight, forming an open iron core in the shape of an inverted U. Since the rigidity of the ribbon is extremely low, simply by removing the support from the table, the linear recombined laminate is easily deformed into an inverted U-shape.

[0018] In this state, when the sides of the core other than the open side are restrained by the frame and the core is inverted together with the frame, a U-shaped open core is obtained. In this state, the open side of the core is located above, so the open side can be easily closed by folding the ends of the left and right laminate blocks in order, starting from the laminate block inside the open side. be able to.

As described above, in the method of the present invention, after stacking the laminates to form a recombined laminate, the recombined laminate is restrained as it is on a mandrel, and then the whole is shaped into an inverted U shape using its own weight. After shaping, the whole is inverted while maintaining the inverted U-shape using a frame to obtain a U-shaped core, so there is no need to move the recombined laminate, which has low rigidity and is difficult to handle. Therefore, it is possible to improve the working efficiency when shaping the wound core into a rectangular shape, and by taking advantage of the characteristics of the batch shaping method that can reduce the number of man-hours, it is possible to improve the manufacturing efficiency of the wound core.

The extremely low rigidity of the amorphous magnetic alloy ribbon has been a weakness in conventional methods, but the method of the present invention effectively utilizes this property to manufacture wound cores. This improves efficiency.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

In the present invention, first, as shown in FIG. 2, an amorphous magnetic alloy ribbon A is wound around a circular winding frame (not shown) to form a ring-shaped laminate R. FIG. 2 shows a state in which the winding of the ribbon A is completed. After winding of the ribbon is completed, the ribbon is cut off at the point X shown in the figure, and the ring-shaped laminate R is taken out.

Next, the ring-shaped laminate R is cut in the radial direction along a straight line extending radially through the center point of the ring-shaped laminate R. That is, the ring-shaped laminate R is cut in the radial direction at one location in the circumferential direction. The cut ring-shaped laminate R is then developed in a straight line as shown in FIG. 3 to form a developed laminate S.

When the unfolded laminate S manufactured in this way is viewed from the front, its contour shape becomes an isosceles trapezoid symmetrical with respect to the reference line L, as shown in FIG.

Next, the developed laminate S is separated into a plurality of unit laminates U1, U2, . . . by separating the developed laminate S into a plurality of unit laminates U1, U2, . To divide. In this case, the thickness of each unit laminate is 0.5 mm to 1.5 mm.
It is appropriate to set it to about 0 mm. Here, the unit laminates are denoted by U1, U2,... in descending order of length.
It is expressed as

Next, these unit laminates U1, U2,
A recombinant laminate Sr shown in FIG. 4 is formed using... In forming the recombinant laminate Sr, as shown in FIG.
Tables T, T each having a flat upper surface are arranged on the left and right extensions of the upper short sides (upper sides) of the table.

The length of the table T is considerably larger than the short side dimension b of the rectangular mandrel M, and the length of the two tables T
, T and the dimension b of the short side of the rectangular mandrel M is set to be sufficiently longer than the outer circumferential length of the ring-shaped laminate R. The upper surface of the upper short side of the rectangular mandrel M and the table T,
It is on the same horizontal plane as the top surface of T, and the rectangular mandrel M
A stacking table Ts is constituted by the tables T and T.

In this example, in an iron core whose main constituent is an amorphous magnetic alloy ribbon, the innermost layer of the amorphous magnetic alloy ribbon A and the outermost layer of the amorphous magnetic alloy ribbon A are used. An inner protective sheet P1 and an outer protective sheet P are placed on the outside of the
Place 2. Although these protective sheets are not essential, they are preferably used because they have a great effect of protecting the amorphous alloy magnetic ribbon A, which has become extremely brittle due to annealing.

As the inner protective sheet P1 and the outer protective sheet P2, stainless steel thin plates with a thickness of about several tens of μm are suitable, and the width thereof is made equal to the width of the amorphous magnetic alloy ribbon A. . The length of the inner protection sheet P1 is set to be a predetermined length (several tens of mm) longer than the length of the innermost thin strip, and the length of the outer protection sheet P2 is set to be a predetermined length longer than the length of the outermost thin strip. Make it longer by the length of (several tens of mm).

In forming the recombinant laminate, first, as shown in FIG.
Lay it on top. In this case, the longitudinal center of the inner protective sheet P1 is positioned approximately at the center of the short side (direction of dimension b in FIG. 4) of the rectangular mandrel M (see FIG. 4).

Next, the upper side (
From the short side) to the specified lamination thickness (0.5 mm to 1.0 mm
) (the first one separated becomes the unit laminate U1), swap the positions of the top and bottom surfaces, and place the end surface of the shorter ribbon in the stacking direction on the inner protective sheet. Place it on the stacking table Ts in contact with P1.

In this case, the widthwise position of the unit laminate U1 is aligned with the inner protective sheet P1. Further, the position of the unit laminate U1 in the length direction is determined so that the reference line L of the unit laminate U1 is located near one end of the upper side of the rectangular mandrel M.

Next, the second unit laminate U2 is separated from the developed laminate S, and the positions of its upper and lower surfaces are swapped, and the end face in the stacking direction of the one with the shorter length of the ribbon is placed in the unit laminate U1.
It is placed on top of the unit laminate U1 in a state where it is in contact with the upper surface of the unit laminate U1. In this case, the position of the reference line L of the unit laminate U2 is shifted by a predetermined distance (reference shift dimension ΔLs) from the position of the reference line L of the unit laminate U1 to the other end of the upper side of the rectangular mandrel M.
) The unit laminate U2 is positioned in the longitudinal direction so that it is shifted by a distance of .

The minimum value of the reference shift dimension ΔLs is determined by the thickness of the unit laminate. Standard shift dimension ΔLs
is required to be at least several times the thickness of the unit laminate, but if this standard shift dimension is too large, the number of laminate blocks, which will be described later, will increase, which is undesirable. Normally, the reference shift dimension ΔLs is set to a value of several mm to several tens of mm. Here, the distance between the reference lines L is ΔLs, and a series of unit laminates U1 to U4, U5 to
Each of U8, . . . will be referred to as a laminate block. These laminate blocks are represented by symbols B1, B2, B3, . . . from the inside to the outside of the core. FIG. 11 shows an enlarged view of the state in which unit laminates are stacked to form laminate blocks B1, B2,..., and the figure also shows how to shift the unit laminates and how to shift between the laminate blocks. The direction is shown.

In FIG. 11, for convenience, each unit laminate is shown as extending linearly in the horizontal direction.
In reality, each unit laminate has almost no rigidity and easily sag due to its own weight. Therefore, as shown in Figs. It is in a state where it hangs down to the sheet P1 side. Figure 1
2 shows the vicinity of the left end of FIG. 11, and FIG. 13 shows the vicinity of the right end of FIG.

As is clear from FIG. 11, the unit laminates in the same laminate block are stacked such that each unit laminate is shifted in the same direction by the reference shift dimension ΔLs. Here, if the number of unit laminates constituting one laminate block is Nub, the position of the reference line L of the innermost unit laminate of the block and the position of the reference line L of the outermost unit laminate of the block is shifted by ΔLs (Nub-1) in the longitudinal direction of the unit laminate. The total deviation dimension ΔLs (Nu
b-1) needs to be slightly smaller than the short side dimension b of the rectangular mandrel M within a few laminate blocks from the innermost side, but for the laminate blocks outside that, I see, the total deviation size can be increased.

When the number of laminate blocks is large, the total displacement dimension of the unit laminates of the outer laminate blocks may be larger than the length b of the short side of the mandrel. Therefore, the number Nu of unit laminates constituting the laminate block
b can be made larger toward the outer laminate blocks. However, in this embodiment, it is assumed that the number Nub of unit laminates is constant in all laminate blocks.

In this embodiment, a case is shown in which the number Nub of unit laminates constituting one laminate block is 4, but the present invention is not limited to this. In the case of Nub=4, unit laminates U3 and U4
The unit laminate U2 is also stacked in accordance with the unit laminate U2, and the position of the reference line L of the unit laminate U4 and the position of the reference line L of the unit laminate U1 are shifted by 3ΔLs in the longitudinal direction of the unit laminate. The unit laminates U1 to U4 constitute a laminate block B1.

Next, a laminate block B2 is formed using the unit laminates U5 to U8. Unit laminate U5
The position of the reference line L returns to the position of the reference line L of the unit laminate U1.

[0040] Below, unit laminates U6, U7 and U8
The position of the reference line L in each unit laminate U2 is
, U3 and U4. After forming the laminate block B2, the laminate blocks B3, B4, . . . are formed in the same manner as described above. In this way, in the process of forming the recombinant laminate Sr, the process of dividing the developed laminate S into unit laminates U and the process of stacking the unit laminates U to form the recombinant laminate Sr are carried out in parallel. will be carried out.

When all the laminate blocks have been stacked, the outer protective sheet P2 is placed on the outermost laminate block. In this case, the longitudinal center of the outer protective sheet P2 is positioned approximately at the center of the short side of the rectangular mandrel M.

The schematic shape of the completed recombinant laminate Sr viewed from the front is as shown in FIG. Recombinant laminate S
The end face portions at both longitudinal ends of r have a complicated shape as shown in FIGS. 12 and 13, but are shown in a simplified manner in FIG. Further, in FIG. 4, illustration of the inner protection sheet P1 and the outer protection sheet P2 and the reference line L are omitted.

As can be understood from the states shown in FIGS. 12 and 13, the amorphous magnetic alloy ribbon before annealing has extremely poor rigidity and easily deforms under its own weight. In conventional methods, the lack of rigidity of this amorphous magnetic alloy ribbon impairs workability, but in the present invention, this lack of rigidity can be reversed in the shaping process of the recombined laminate described below. To facilitate rectangular shaping of the iron core by utilizing the roughness.

Next, a method for shaping the recombined laminate Sr into a rectangle will be described. As shown in Figure 4, the recombinant laminate Sr
is completed, a clamp plate Cp is attached above the rectangular mandrel M across the recombined laminate Sr, and the central part of the recombined laminate Sr is tightened between the rectangular mandrel M and the clamp plate Cp. to bound.

Next, by moving the tables T, T, for example, downward, the support of the recombined laminate by the tables T, T is removed. At this time, as shown in FIG. 5, the part of the recombined laminate Sr that has lost its support from the tables T, T sag due to the weight of the thin strip, and the recombined laminate Sr deforms into an inverted U shape, with one of the four sides becomes the open iron core I'. One open side of this iron core I' is the joint side (joint part Ij
This joint side constitutes one yoke part of the iron core. Further, the side to which the clamp plate Cp is attached constitutes the other yoke portion.

Next, frame F is attached to iron core I'. As shown in FIG. 8, the frame F has a U-shaped frame plate F1, a support plate F2 fixed to the frame plate and fixed to the frame plate F1, which is provided so as to straddle the opposite sides of the frame plate F1. A reinforcing plate F3 is attached to the outside of the opposite side. F
1a is a cutout groove to prevent the clamp plate Cp from hitting the frame plate F1, and F3a is a hole for hooking, etc. during movement.

When attaching the frame F, as shown in FIG. 6, the frame F is lowered from above the iron core I', and the frame F is fitted onto the iron core I' from the outside. FIG. 7 shows a state in which the frame is inserted into the iron core I' with one side open, and in this state, the clamp plate Cp is removed. Note that the clamp plate Cp does not necessarily have to be removed at this point, but may be removed at any time after the frame F is attached. The three sides of the iron core (both legs and the other yoke) are tightened and restrained by a rectangular mandrel on the inside and by a frame F on the outside.

Next, the frame F into which the iron core has been inserted is turned upside down, and the open yoke portion (one of the yoke portions) is positioned upward. In this state, the iron core is closed as shown in FIG. First, the inner protective sheet P1 is superimposed on the short side of the rectangular mandrel M, and then the laminate blocks B1, B2,
Fold the ends of both legs in this order and close the iron core sequentially from the inside to the outside. After all the laminate blocks are closed, both ends of the outer protective sheet P2 are overlapped. Since it is necessary to keep the iron core closed until the winding is inserted in the subsequent process, it is preferable that the overlapping portion of the outer protective sheet P2 be fixed by spot welding or the like. FIG. 10 shows the iron core in a completely closed state.

Referring to FIG. 14, the joint Ij of the iron core
The vicinity is shown enlarged. In the figure, g indicates a gap. The black dot drawn at the junction Ij in FIGS. 9 and 10 represents this gap.

[0050] Thereafter, the core, together with the frame, is placed in an annealing furnace and annealed in a magnetic field. Figure 10 shows the posture of the iron core during magnetic field annealing.
This is a posture with the front side facing up and the support plate F2 facing down.

[0051] The outer side of the joint Ij of the iron core is simply wrapped with an outer protective sheet P2, and is not tightened with a presser plate or the like. This makes it easier to open the core in a later process, and the ribbon is less likely to be damaged. After magnetic field annealing, the frame F and rectangular mandrel M are removed. After that, the three sides of the core other than the joint sides are covered with insulating paper (not shown), and a frame member (not shown) is fitted into the inner circumference of the core, the joint sides are opened, and the windings (not shown) are inserted into the legs of the core.
Close the core again to form the transformer body.

[0052] If the unit laminate U is not handled properly during the process of separating the unit laminate U from the developed laminate S,
Unintended deviations may occur between the ribbons in the unit laminate. In order to prevent this, it is effective to form an adhesive layer film by applying a thin layer of soft adhesive to both or one side of the laminated surfaces near the center in the longitudinal direction after forming the expanded laminate S. It is true.

For example, a diluted solution of Plyobond (trade name) is applied to the laminated surface at the center of the developed laminate S over a width of about several tens of mm. In this way, when handling the laminate, the adhesive force necessary to prevent the ribbons from shifting is maintained. Furthermore, when separating the unit laminates from the developed laminate, the ribbons can be separated with almost no resistance.

[0054]

As described above, according to the present invention, after stacking the laminates to form a recombined laminate, the recombined laminate is restrained as it is on a mandrel, and then the whole is turned upside down using its own weight. After shaping into a U-shape, the entire structure was inverted while maintaining the inverted U-shape using a frame to obtain a U-shaped core.The process of moving the recombined laminate, which lacks rigidity and is difficult to handle, was then carried out. There's no need. Therefore, it is possible to improve the work efficiency when shaping the winding core into a rectangular shape, and by taking advantage of the characteristics of the batch shaping method that can reduce the number of man-hours, it is possible to improve the manufacturing efficiency of the winding core. be.

[Brief explanation of the drawing]

FIG. 1 (A) to (F) are process explanatory diagrams sequentially showing the steps of the method of the present invention.

FIG. 2 is a front view showing a state in which a ring-shaped laminate is formed by winding thin ribbons.

FIG. 3 is a front view of a developed laminate formed in one step of the embodiment of the present invention.

FIG. 4 is a front view schematically showing a stacking table used in an example of the present invention and a recombined stacked body constructed thereon.

FIG. 5 is a front view showing a state in which both ends of the recombined laminate whose center portion is fixed to a rectangular mandrel hang down due to its own weight, forming an inverted U-shaped iron core with one side open.

FIG. 6 is a front view showing a state immediately before a frame is attached to an inverted U-shaped iron core.

FIG. 7 is a front view showing a state in which a frame is attached to an inverted U-shaped iron core.

FIG. 8 is a perspective view showing the appearance of a frame used in an embodiment of the present invention.

FIG. 9 is a front view showing a state in which the joint sides of the iron core are being closed.

FIG. 10 is a front view showing a state in which the iron core is completely closed.

FIG. 11 is a partially enlarged front view showing how to shift the unit laminates and laminate blocks in the recombined laminate.

12 is a front view of main parts showing the actual shape near the left end of FIG. 11. FIG.

13 is a front view of main parts showing the actual shape near the right end of FIG. 11; FIG.

FIG. 14 is a partially enlarged front view showing the vicinity of the joint of the closed iron core.

[Explanation of symbols]

A Amorphous magnetic alloy ribbon R
Ring-shaped laminate S
Expanded laminates U1, U2,...
Unit laminates B1, B2,... laminate blocks Sr
Recombinant laminate M
Rectangular mandrel T
Table Ts Stacking stand I
iron core

Claims (1)

[Claims] Claim 1: A predetermined number of laminated amorphous magnetic alloy ribbons are laminated as a unit laminate, and a plurality of laminate blocks each formed by laminating a plurality of unit laminates are further laminated, and each laminate block is In a method for manufacturing a rectangular wound core having a structure in which both ends of each unit laminate are overlapped and joined, after a ring-shaped laminate is formed by winding an amorphous magnetic alloy ribbon around a circular winding frame, By cutting the ring-shaped laminate at one point in the stacking direction and rolling it out, a spread laminate of amorphous magnetic alloy ribbons is formed, and the top surface is placed on both sides of a rectangular mandrel with the short sides kept horizontal. A table positioned on the same horizontal plane as the top surface of the upper short side of the mandrel is arranged, and the mandrel and the tables on both sides constitute a stacking table whose top surface is substantially horizontal, and the developed stack is divided. By repeating the process of forming a plurality of unit laminates, and stacking a predetermined number of unit laminates in order from the shortest laminates by shifting their respective positions in the longitudinal direction to form the laminate block, A recombined laminate is formed by stacking a plurality of laminate blocks in order from the shortest laminate blocks on a table, and the central part of the recombined laminate in the longitudinal direction is restrained and fixed to the upper short side of the rectangular mandrel. Then, the support of the recombined laminate by the table is removed, and the recombined laminate is deformed into an inverted U-shape by its own weight to form a rectangular wound core with one side open. Fitting a frame to the rectangular wound core from the outside, fixing sides of the rectangular wound core other than the open side to the mandrel, and inverting the rectangular core with one side open together with the frame, A method for manufacturing a wound core, characterized in that a rectangular wound core is formed by positioning one open side of the rectangular wound core on the upper side and folding and overlapping the ends of the laminate blocks.