JP2009252795A - Method of manufacturing iron core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a substantially square iron core without carrying out plastic shaping with regard to an iron core constituted by inserting an inner core into an outer core. <P>SOLUTION: In an iron core constituted by inserting an inner core into an outer core, a circular large core 1a becoming the outer core is pushed from the longitudinal direction and the lateral direction and deformed, and then the central part of a circular small core 2a becoming the inner core is caught from the opposite sides by means of a chuck and the small core 2b deformed in the form of a gourd is inserted into the deformed large core 1b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a wound core used in a three-phase transformer.

In the three-phase transformer, insert the inner and outer iron cores into the concentric high-voltage coil and low-voltage coil, and install the iron core clamp and coil fixing parts to produce the contents of the three-phase transformer. is doing.
The inner iron core and outer iron core used above are formed after winding an electromagnetic steel sheet around a core to form an iron core, housed in a frame, heated to high temperature in an inert gas atmosphere, and then cooled. Later, it was disassembled.

Conventionally, a three-phase wound core in which two inner cores are inserted into the window of the outer core has been manufactured by the following procedure.
(1) First, the four corners of a circular small core that becomes the inner iron core are press-molded to produce a small core. Similarly, the four corners of a circular large core that will be the outer iron core are press-molded to produce a large core. In the above press molding, the four corners are locally plastic molded so that the core shape can be maintained even after the press is completed.
(2) Next, the small core is inserted into the large core (using a crane or the like). When inserting the second small core into the large core, use a spatula or other tool to widen the frontage. When pushing into the large core, use a spatula or other tool to widen the frontage, Push into.
(3) Next, a metal core is put into the hole of the small core in the wound core in the core insertion completed state. Then, the vertical plate is applied to the straight portion of the large core, and the straight portion of the large core is tightened inward with an iron band or the like.
(4) Next, after annealing the core core in a state where the core is tightened, the cored bar, the vertical plate, the iron band, etc. are removed to complete the core.

Further, there is a method disclosed in Patent Document 1 as a manufacturing method of a three-phase wound core in which two inner cores are inserted into a window of the outer core.
The manufacturing method of the three-phase wound core of Patent Document 1 is to form a rounded inner core by pressurizing it into an oval shape, and then placing two inner cores side-by-side and binding them together with a band to form a substantially square shape. By inserting into the outer wound core, removing the band, pressurizing and integrating the inner and outer wound cores, and then annealing, the space in the annealing furnace can be reduced, and productivity is improved. Is.

JP 58-141516 A

The small and large cores manufactured as described above have a shape (rectangular shape) in which the four corners are locally plastic-molded in order to maintain the core shape after molding. There was a problem that the electrical characteristics were inferior to
In addition, regarding the square-shaped product, the inner diameter of the large core has to be increased as compared with the R-shaped product, and there is a problem that more materials are used.
Also, in the work of inserting the second small core into the large core, there is not enough room for the insertion part of the large core with respect to the external dimension of the small core, so a tool such as a spatula is used. There was a problem that it took a lot of time.

  In addition, the above-mentioned Patent Document 1 solves the conventional manufacturing method of a three-phase wound core, in which the inner wound core and the outer wound core are each pressed into a substantially rectangular shape and separately annealed. There is a problem in that an operation step of cutting the band is required after the inner wound iron core, in which two iron cores are juxtaposed and bound together with a band, is inserted into the outer wound core.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method for easily manufacturing a substantially square wound iron core without plastic forming.

  In the manufacturing method of the wound core according to the present invention, the circular large core is pushed and deformed from the vertical direction and the horizontal direction, the central portion of the circular small core is gripped from both sides by the chuck inside the deformed large core, A small core deformed into a substantially gourd shape with a narrow part and wide sides is inserted.

  The method for manufacturing a wound core according to the present invention can obtain a wound core having good electrical characteristics without plastic forming the four corners of the small core and the large core.

Embodiment 1 FIG.
FIG. 1 is a flowchart showing a method of manufacturing a wound core according to Embodiment 1 of the present invention. FIG. 2 is a view for explaining the chucking state of the circular small core in the manufacturing method of the wound core according to Embodiment 1 of the present invention. In the figure, reference numeral 10 denotes a chuck for gripping the central portion of the small core from both sides. . FIG. 3 is a view showing the configuration of a core bar used in the method for manufacturing a wound core according to Embodiment 1 of the present invention. In the figure, reference numeral 11 denotes a cored bar to be inserted into a hole portion of a small core, which is composed of a cored bar core 11a and cored bar inserts 11b and 11c.

A method for manufacturing a wound iron core according to Embodiment 1 of the present invention will be described with reference to FIGS.
(1) In Step 1, a magnetic steel sheet is wound around a winding core to produce a large circular core 1a serving as an outer iron core and a small circular core 2a serving as an inner iron core. (Fig. 1 (a))

(2) In step 2, as shown in FIG. 2, the center portion of the circular small core 2a is grasped from both sides by the chuck 10 and deformed into the gourd-shaped small core 2b. When the chuck 10 is deformed into the gourd-shaped small core 2b, the chuck 10 has a shape that is not outside the outer width (A dimension). (Fig. 1 (b))
(3) In step 3, the circular large core 1a is pressed from the vertical and horizontal directions or from the four corners by pressing, and the vertical inner dimension is larger than the outer height (dimension B) of the gourd small core 2b and the horizontal direction The inner dimension is deformed to be larger than twice the outer width (dimension A) of the gourd-shaped small core 2b to form a deformed large core 1b.
Two gourd-shaped small cores 2b are suspended from the deformed large core 1b, and the chuck 10 is loosened and removed. Thereby, the gourd-shaped small core 2b spreads sideways and becomes the long hole-shaped small core 2c. (Fig. 1 (c))

(4) In step 4, the press that has pushed the deformed large core 1b from the lateral direction is returned.
(5) In step 5, the core metal 11 having a three-part taper is inserted into the elongated hole-shaped small core 2c, and the elongated hole-shaped small core 2c and the deformed large core 1b are molded to the specified dimensions. (Fig. 1 (d))
Here, as shown in FIG. 3, the core metal 11 to be inserted into the long hole-shaped small core 2c is composed of a core metal core 11a and core metal inserts 11b and 11c, and has a wedge shape.
While pushing the deformable large core 1b from the vertical direction and the horizontal direction, the core metal cores 11b and 11c are inserted into the long hole-shaped small core 2c inside the deformed large core 1b, and the core metal core 11a is pushed from above. Then, the cored bar inserts 11b and 11c spread sideways, the long hole-shaped small core 2c is pushed and widened, and the long hole-shaped small core 2c and the deformed large core 1b are formed to the specified dimensions.
In this operation, the wound core 3a in a state where the core insertion is completed is manufactured by integrating the square large core 1c and the square small cores 2d and 2d.

(6) In step 6, the vertical plate 12 is applied to the linear portion of the large rectangular core 1c, and the linear portion of the large rectangular core 1c is tightened inward with an iron band 13 or the like.
In this operation, the wound core 3b in the core tightened state is manufactured.
(7) In Step 7, the large rectangular core 1c and the small rectangular cores 2d and 2d that have been tightened in Step 6 are annealed.

(8) In step 8, the prismatic small cores 2e and 2e are inserted inside the rectangular large core 1d by removing the ate board 12, the iron band 13, and the core metal 11 from the cooled wound core 3b. The wound core 3c having the configuration is completed.

Next, the large rectangular core 1d and the small rectangular cores 2e and 2e constituting the wound iron core 3c are disassembled.
The disassembled rectangular small cores 2e and 2e and the large rectangular core 1d are inserted into a concentric high voltage coil (not shown) and low voltage coil (not shown), and an iron core fastening bracket (not shown). Then, the contents (not shown) of the three-phase transformer are manufactured by attaching coil fixing parts (not shown) and the like.

  In the method of manufacturing the wound core according to the first embodiment of the present invention, the small core deformed into a gourd shape is inserted into the large core serving as the outer core by gripping the center of the circular small core from both sides. Therefore, there is no need to press the four corners of the conventional circular small cores, or to place two circular small cores side-by-side and fasten them together with a band, and then form them into a substantially square shape. can do.

  Further, in the method of manufacturing the wound core according to the first embodiment of the present invention, two small cores having a gourd shape can be inserted by pressing and deforming the large circular core from the vertical and horizontal directions or from the four corners. Since it was made into the shape, the diameter of a circular large core can be made small.

  Moreover, in the manufacturing method of the wound core which concerns on Embodiment 1 of this invention, since the four corners of a small core and a large core are not plastic-molded, a wound core with a favorable electrical property can be obtained.

  The method of manufacturing a wound core according to the present invention can simplify the insertion work requiring a lot of time by using a tool for inserting a small core into a large core, and easy to manufacture the wound core. become.

It is a flowchart which shows the manufacturing method of the wound iron core which concerns on Embodiment 1 of this invention. FIG. 6 is a diagram for explaining a chucking state of a small circular core in the method for manufacturing a wound core according to the first embodiment of the present invention. It is a figure which shows the structure of the metal core used with the manufacturing method of the wound core which concerns on Embodiment 1 of this invention.

Explanation of symbols

  1a, 1b, 1c, 1d large core, 2a, 2b, 2c, 2d, 2e small core, 3a, 3b, 3c wound core, 10 chuck, 11 cored bar, 11a cored core, 11b, 11c cored bar metal , 12 ate board, 13 iron band.

Claims (2)

In the wound core formed by inserting the inner core inside the outer core,
Push the circular large core that will be the outer iron core from the vertical and horizontal directions and deform it, inside the deformed large core,
A method of manufacturing a wound core, characterized in that a small core deformed into a substantially gourd shape with a narrow center part and wide sides on both sides is held by holding the center part of a circular small core as an inner iron core from both sides.   2. The method of manufacturing a wound iron core according to claim 1, wherein the chuck for gripping the central portion of the circular small core from both sides has a shape that is not outside the outer width of the small core deformed into a substantially gourd shape.

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