JPH0448530B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Use The present invention relates to a method for manufacturing a laminated core using an in-mold caulking method.

Conventional structure and problems The steel strips used in the production of laminated cores are manufactured by slitting wide rolled plates, but due to the deflection of the rolling rollers, the cross section becomes trapezoidal as shown in Figure 1. Therefore, the cross section of the steel strip is also trapezoidal. When plates with such a cross-sectional shape are punched out and laminated in that state, the core becomes trapezoidal as shown in FIG. 2, which poses a problem in terms of product performance.

Therefore, in the conventional method of manufacturing a laminated core using the in-mold caulking method, blanking dies 2a, 2b, and 2c provided in the mold 1 shown in Fig. 3 are rotated by the crankshaft of the press at each prescribed stroke. It was rotated in the field so that deviations in the thickness of the iron core were offset.

However, in the above configuration, since the blanking dies 2a, 2b, and 2c rotate at fixed positions, the directions of use of the steel strips in the same line in the advancing direction are not the same. Although the plate thickness deviation of the iron core is canceled out, the blanking dies 2a, 2b, and 2c always use materials on the same line in the traveling direction of the steel strip corresponding to each position, so it depends on the location where the steel strip is used. Since the sheet thickness deviations are not canceled out, there is a drawback that the deviations in the stacked thicknesses of the respective blanking dies become large. Incidentally, the thickness deviation in the transverse direction of the material, the steel strip, is 0.02 mm, which is 50 mm.
When forming an iron core by laminating sheets, the deviation of the stacking thickness is 1
mm, which adversely affects product performance and assembly.

Furthermore, since the steel strips are used on the same line along the direction of movement, anisotropy in magnetic properties due to the rolling direction, etc., also affects quality.

Additionally, as the number of cavities increases, the installation space for the blanking die becomes extremely large, resulting in larger molds, an increase in the driving force required to rotate the dies, and a shorter engagement length of the timing belt. It had the disadvantage of reduced accuracy.

OBJECTS OF THE INVENTION In view of the above drawbacks, the present invention provides a method for manufacturing a laminated iron core with less deviation in stack thickness.

Structure of the Invention The method for manufacturing a laminated iron core of the present invention includes punching out an iron core using a plurality of blanking dies at a plurality of locations on a strip-like iron plate, and at the same time caulking the iron cores to each other in the blanking dies and laminating them. A method for manufacturing a laminated core, in which each of the plurality of blanking dies is simultaneously moved to the position of an adjacent blanking die every predetermined press stroke, and the deviation in stacking thickness between the blanking dies is corrected. It also has the unique effect of reducing anisotropy in magnetic properties due to the rolling direction of the material, making the mold smaller, reducing the driving force required to rotate the die, and increasing rotation accuracy.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 shows a portion where the core is punched out and caulked at the same time in the method for manufacturing a laminated core according to an embodiment of the present invention. In Figure 5, 3a, 3b, 3
c is foil ranking die, 4 is blanking die 3
5 is a sprocket attached to the holder 4, 6 is an index, 7 is a sprocket, and 8 is a timing belt placed around the sprockets 5 and 7.

The operation of the laminated core manufacturing apparatus configured as above will be described below.

First, the workpiece is fed one pitch, then punched and caulked at the same time by blanking dies 3a, 3b, and 3c, and held in each blanking die. After repeating this operation a predetermined number of times, the holder 4 is rotated 120 degrees counterclockwise by the index 6, and the blanking die 3a is returned to the original position of the blanking die 3b, and the blanking die 3b is returned to the original position of the blanking die 3b. Blanking die 3c is placed in the original position of blanking die 3c.
a moves to its original position. Then repeat these actions.

As described above, according to this embodiment, the three blanking dies arranged in the process of punching the iron core and simultaneously caulking and laminating the iron cores are rotated every predetermined press stroke, and the adjacent blanking dies are rotated every predetermined press stroke. By moving the die to a certain position, the laminated core is formed by punching from three locations along the width direction of the workpiece, the center and both ends, so deviations in the thickness of the workpiece can be prevented. It is possible to manufacture a laminated core with reduced anisotropy in magnetic properties, which is offset by each other and has a small deviation in stack thickness.

In this embodiment, the number of holes is three, but it goes without saying that the number of holes may be two or more.

Effects of the Invention As described above, in the method of the present invention, a plurality of blanking dies arranged in the step of punching an iron core and caulking the iron cores with each other are rotated every predetermined press stroke, and each adjacent blanking die is By moving the core to the blanking die position, a laminated core is formed by punching out each part of the workpiece, so deviations in stack thickness can be reduced and anisotropy in magnetic properties can be reduced. It can be done, and its practical effects are great.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a strip iron plate used for manufacturing a laminated iron core, Figure 2 is a cross-sectional view of a laminated iron core formed using a part of the belt iron plate shown in Figure 1, and Figure 3 is a cross-sectional view of a laminated iron core formed using a part of the belt iron plate shown in Figure 1. A plan view of a laminated core manufacturing apparatus using the in-mold caulking method, FIG. 4 is a sectional view of a laminated core manufactured by the laminated core manufacturing apparatus shown in FIG. 3, and FIG. 5 is a method according to an embodiment of the present invention. FIG. 3a, 3b, 3c...blanking die, 4...
...Holder, 5...Sprocket, 6...Index, 7...Sprocket, 8...Timing belt.

Claims (1)

[Claims] 1 At the same time, punch out the iron core using multiple blanking dies at multiple locations on the strip iron plate,
A method for manufacturing a laminated core in which the cores are caulked and laminated together in the blanking die, wherein each of the plurality of blanking dies is simultaneously moved to the position of an adjacent blanking die every predetermined press stroke. A manufacturing method for laminated iron cores.