JPS5849010B2 - Wound core with gap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wound core for electromagnetic induction equipment, and particularly to a wound core with a gap.

Wound cores are widely used in electromagnetic induction equipment, but in order to adjust the reactance of reactors,
In addition, in current transformers and the like, gaps are often required to be provided in the magnetic path in order to reduce residual magnetic flux and improve characteristics, as well as to obtain various other effects.

The present invention provides a structure for this type of device that allows the gap to be constructed very easily and has excellent mechanical strength.

1st... Before explaining this invention, an overview of the wound core will be explained. In order to make the most efficient use of the excellent properties of the grain-oriented silicon steel strip in the rolling direction, the wound core is very easy to assemble with the coil. It was invented in order to achieve this, and is called a so-called non-cut core, which is a magnetic steel tube wound into a circular, rectangular, or other shape and annealed to remove stress. A so-called cut core (cut core) is made by vacuum impregnating an adhesive such as epoxy resin between the coil and the further wound copper strip layer, hardening it, and cutting it in two places at the part where the magnetic core is inserted into the coil, that is, the leg. There are two types, one called CutCore), and they are widely commercially available.

An example of a conventional method of providing a gap in the magnetic path of a wound core is shown in FIGS. 1 to 3.

The wound core has a structure in which a non-magnetic plate 2 is sandwiched between the cut surfaces of cut cores 1, 1, and a pair of cut cores 1, 1 and 2 are inserted.
In order to fix the four non-magnetic plates 2, each abutting surface is joined using an adhesive 3 such as epoxy resin, and a band 4 is placed around the periphery.

This structure has a very weak bending strength in the side direction of the core around the gap as shown by the arrow in FIG.

Therefore, it is necessary to increase the strength of the band, to place it in a non-magnetic case 5 with a lid 6 as shown in FIG. 3, or to provide special reinforcement to the gap portion.

In addition, the number of parts for reinforcement is large, and the number of assembly steps is increased.

Furthermore, as shown in Figures 4 to 6, the two cut surfaces of the cut core may be off center (Figure 4) or the two surfaces may not be parallel (Figures 5 and 6). They must be manufactured and used as a pair; if one iron core is mistakenly combined with the other pair, the cut surfaces will not match perfectly.
This causes unevenness when magnetized, variations in device performance, and various other undesirable problems.

The present invention aims to obviate the above-mentioned drawbacks of the prior art.

FIG. 7 shows the structure of this invention.

As shown in the plan view of FIG. 7, the wound core 7 is cut at one point across its magnetic path.

This cutting is performed in a conventional manner using a band saw, a grindstone cutter, a milling machine, or the like.

The cut portion is then pried open and a non-magnetic plate 2 having a thickness that provides the required gap is inserted.

If a non-magnetic plate is inserted and a band 4 is placed around the iron core, the result shown in FIG. 7 is obtained.

For the wound core 7, a copper band wound and annealed may be used, but a cut core (Cu
If an adhesive such as epoxy resin is vacuum impregnated between the copper strip layers and cured and fixed in the same way as in the case of tCore), the stress caused by curing shrinkage during the curing reaction of the epoxy resin will be absorbed at the cut part of the wound core. In other words, when you put a jack-like jig inside the core, push the cut surfaces open, and insert the insulating plate, the insulating plate will not be tightened by the surrounding band. It was found that by utilizing this stress, it was possible to reduce the strength of the surrounding band tightening.

The bending strength in the lateral direction of the iron core, similar to that shown by the arrows in FIG.

In addition, since there is only one cutting point, the number of man-hours needed to manufacture the core is reduced, and the number of parts is half that of the conventional method, so the number of man-hours required for assembly is reduced.

Furthermore, unlike conventional cut cores, there are no problems such as the deviation of the cutting line from the center or the parallelism of the two cutting surfaces, and there is no need to create and use the iron core as a pair. There are many advantages such as eliminating

[Brief explanation of drawings]

Fig. 1 is a plan view showing the structure of the conventional one, and Fig. 2 is a plan view showing the structure of the conventional one.
An elevational view showing a part of the figure in cross section, Figure 3 is the 1st
A partially sectional side view showing the thing in the figure placed in a reinforcing case, Figures 4 to 6 are plan views showing various defects in the cut surface of the cut core, and Figure 7 is a gap of the present invention. FIG. 2 is a plan view showing the structure of a wound core. 1... Cut core, 2... Non-magnetic plate, 3... Adhesive, 4... Band, 5
...Case, 6...Lid, 7...
・Wound iron core.

Claims (1)

[Claims] 1. A wound core in which an adhesive is impregnated between the steel strip layers and a cut section is provided at only one location in the magnetic path, and a stress that acts to push the cut surfaces of the cut section together due to curing shrinkage during the curing reaction of the adhesive. and a non-magnetic plate sandwiched between the cut surfaces.