JPS6339950Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a radial block core constituting a reactor core.

As is well known, the reactor core includes a plurality of legs 3 made up of block cores 1 of uniform height and spacers 2 stacked alternately, as shown in FIG. It consists of a yoke portion 4 that magnetically couples the end portions in the same direction to each other. This invention relates to an improvement in a radial core in which the fringing magnetic flux in the spacer piece always enters and exits in the thickness direction of the magnetic plate forming the block core, thereby reducing eddy current loss.

As shown in Fig. 2, a conventional radial core is a fan-shaped core in which magnetic plates 21 of equal length (the axial dimension of the legs) and different widths are arranged in order of size with one end of the length and width aligned. A plurality of units 22 are arranged radially to form an annular core 23. Then, the circular outer periphery is restrained with a band 24 such as cotton tape to maintain its shape, and the thermosetting resin liquid is applied from below.
A radial block iron core 26 was constructed by impregnating the block iron core 5 with heat and curing it.

However, in the conventional method described above, the impregnated resin 25 that has penetrated into the gap between the magnetic plates shrinks as it gels or hardens during the heat process, resulting in cracks as shown in Figure 3 at the weakest point of the bonded steel plate. 31 may occur. These cracks not only generate large noises due to the magnetic flux passing through the block core, but also significantly weaken the strength of the block core. To prevent this, heat-shrinkable tape was applied to the outer periphery of the radially arranged magnetic plates so that when the resin between the magnetic plates hardens and contracts, the magnetic plates can easily follow the shrinkage. It has been proposed to wind the material by winding it to apply a force directed toward the center.

However, this method is used to maintain the strength of the band to maintain the shape of the core in the event that the adhesive between the magnetic plates peels off and cracks due to an external force such as tightening the block core in its axial direction. However, since the shrinkable tape generally has low mechanical strength, it is necessary to wrap it in multiple layers, which has the drawback of not only being expensive but also large in size.

The object of this invention is to overcome the above-mentioned drawbacks of the prior art and to provide a radial block core that is inexpensive and small in size. This objective was achieved by the following configuration. That is, a bind tape impregnated with a resin that hardens and shrinks more slowly than the resin of the iron core, and a bind tape that cures and shrinks the outer peripheral surface of the iron core faster than the resin of the tape but slower than the resin of the iron core. Wrap and tighten alternately with shrinkable heat-shrinkable tape, and combine with a heat process at the same time.

FIGS. 4 to 6 show examples of this invention, in which the same reference numerals indicate the same functions as those described above. In the figure, a plurality of fan-shaped units 22 are arranged radially in which magnetic plates 21 of equal length and different widths are arranged in a stepped manner with one end of the length and width aligned, and the thermosetting resin 2
The circular outer periphery of the annular core 23 impregnated with resin 5 is alternately wrapped and tightened with glass bind tape 41 impregnated with resin and heat shrink tape 42. For example, use glass bind tape 41 to
Tighten it twice and then tighten it an appropriate number of times with the heat shrink tape 42, or overlap the glass bind tape 41 and the heat shrink tape 42, with the glass bind tape 41 on the inside. You may tighten it an appropriate number of times. Then, heating is performed to unite them, and during the heating process, the resin 25 impregnated into the annular core 23 begins to harden, then the heat shrink tape 41 begins to shrink, and finally the glass bind tape 42 The materials are selected so that the resin 25 of the core starts to harden, and then the resin 25 of the bare iron core, the heat shrink tape 41, and the glass bind tape 42 end in this order. By configuring like this,
First, when the resin 25 of the annular core 23 hardens and shrinks, the heat shrink tape 42 contracts and compresses the annular core 23 through the glass bind tape 41, causing each magnetic plate 21 to move toward the center. Applying force toward the magnetic plate 21 allows the magnetic plate 21 to easily follow the contraction of the resin. At this time, the glass bind tape 42 shrinks less than the heat shrink tape 42 on the outside, so the glass bind tape 41 is inserted between the heat shrink tapes or between the tape and the bare iron core 23. It hardens while being bent in a wavy manner to maintain its strength. Therefore, compared to the previously proposed method of wrapping and tightening the outer periphery of the annular core 23 using only heat shrink tape, this method requires fewer windings, is smaller in size, is less expensive, and may be susceptible to cracking due to external force. It is also possible to obtain a reinforced radial block core 43 that can sufficiently maintain its shape.

[Brief explanation of the drawing]

Fig. 1 is a front view of the reactor core, Fig. 2 is a plan view of a conventional radial block iron core, Fig. 3 is a plan view of a block iron core with cracks, and Fig. 4 is a plan view of an embodiment of this invention. 5 is a side view of FIG. 4, and FIG. 6 is a partial sectional view of FIG. 5. 21... Magnetic plate, 22... Unit, 23...
Annular core, 25... thermosetting resin, 41... bind tape, 42... heat shrink tape, 43...
Radial block iron core.

Claims (1)

[Claims for Utility Model Registration] (1) An annular element formed by radially arranging a plurality of fan-shaped units in which magnetic plates of equal length and different widths are arranged in a stepped manner with one end of the length and width aligned. In the case where the iron core is bonded and integrated with a resin, the circular outer periphery of the bare iron core is alternately wrapped and tightened with resin-impregnated glass bind tape and heat shrink tape, and both tapes and the above-mentioned bare iron core are wrapped and tightened alternately. A radial block iron core characterized by being integrated with the resin liquid of the iron core through the same heat process. (2) In the utility model registration claim described in paragraph 1, the resin liquid in the bare iron core, the heat shrink tape, and the resin in the glass bind tape begin to harden and shrink in the above order during the same thermal process. A radial block iron core characterized in that it is selected to end in a radial block.