JPS6144417Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of an iron core device that can increase the core space factor.

Conventional iron core devices include those shown in FIGS. 1 and 2. In the figure, 1 is a laminated core, 2
3 is a holding plate, and 3 is a tightening member, which is composed of a through rod 31 passing through the iron core 1, a tightening nut 32 and a tightening washer 33 screwed onto the through rod 31. 4
5 is an insulating plate interposed between the laminated iron core 1 and the holding plate 2, and 5 is an insulating plate interposed between the clamping member 3 and the holding plate 2.

Next, the effect will be explained. The laminated core 1 is held against a presser plate 2 via an insulating plate 4 and is tightened by a tightening member 3. Incidentally, the reason why the insulating plate 4 is necessary is that the laminated iron core 1 ultimately needs to be grounded at a predetermined position in order to prevent the potential from floating. However, if multiple earthing occurs at this time, the iron core 1
Since a one-turn coupling circuit is formed through the holding plate 2 and the iron core 1 for the magnetic flux passing through the magnetic flux, a circulating current flows through the circuit and a large magnetic loss is generated.

Since this conventional iron core device is constructed as described above, the thickness of the insulating plate 4 must be set to about 3 to 4 mm, which has the disadvantage that the core space factor cannot be increased. The reason why the insulating plate 4 is required to be 3 to 4 mm is that it must be able to prevent the formation of a one-turn coupling circuit, as described above. And tests are needed to reliably verify this. That is, generally, a voltage of about 1000 volts is applied between the laminated iron core 1 and the holding plate 2 for about 1 minute, and the quality of the insulating plate 4 is determined based on whether there is an electrical short circuit. ing. Although the thickness of the insulating plate 4 varies somewhat depending on the insulating material, if the voltage is about 1000 volts, a thickness of about 0.5 to 0.8 mm is enough to withstand penetration breakdown. However, in dry type transformers, etc., there are cases where creepage breakdown occurs, that is, creepage occurs on the surface of the insulating plate. Considering the conditions for the decrease in
A thickness of approximately 4 mm is required.

This invention was made to eliminate the above-mentioned drawbacks, and provides an iron core device that can increase the core space factor by improving the insulating plates.

The figures will be explained below. In Figure 3,
1, 3 to 5 are the same as before. Reference numeral 6 denotes a holding plate having an insertion hole 6a of a predetermined depth and a through hole 6b penetrating approximately the center of the insertion hole 6a.
The through hole 6b is fitted into the through rod 31 so that the through hole 6b faces the insulating plate 4. 7 is an insulating washer having a cylindrical collar 7a at one end and a cylindrical projection 7b at the other end, as shown in FIG. and is inserted into the through hole 6b.

Next, the operation of the present invention will be explained. The laminated iron core 1 is fixed by fitting an insulating washer 7 into an insertion hole 6a of a holding plate 6 via an insulating plate 4, and tightening it with a tightening member 3. The reason why the insulating plate 4 is necessary is as explained above, so it will be omitted here, but the thickness of the insulating plate 4 has been thinned from the conventional 3 to 4 mm to 0.5 to 0.8 mm, which is sufficient to prevent the penetration failure described above. It has been done. However, as explained above, the thickness of the insulating plate needs to be 3 to 4 mm due to creepage damage.
The distance to prevent creepage failure, that is, the creep distance, must be increased as the thickness of the insulating plate becomes thinner. Therefore, the creepage distance is increased by increasing the dimension l of the insulating plate 4 as shown in FIG. 8 by the amount that the width of the insulating plate is thinner. Further, the washer 7 is attached to the penetrating rod 31 so that the protrusion 7b of the washer 7 protrudes in the opposite direction to the insulating plate 4.
The creepage distance between the presser plate 6 and the iron core 1 becomes the sum of the creepage distance of the protrusion 7b of the washer 7 and the creepage distance in the thickness direction of the insulating plate 4. Even if the thickness is made thinner, the creepage distance can be sufficiently increased by making the protruding portion 7b longer. Therefore, by adopting the above structure, creepage failure can be prevented. In other words, the occurrence of a one-turn coupling circuit can be prevented.

In the above embodiment, the insulating plate 4 in FIG.
5, the insulating plate 5 is replaced with the insulating washer 7 of the present invention, as shown in FIG.
By changing to , the space factor can be increased more easily.

According to this idea, the thickness of the insulating plate is 3~
Since the thickness has been reduced from 4 mm to 0.5 to 0.8 mm, the number of cores can be increased accordingly, and the core space factor can be increased. In addition, the thickness of the insulating plate is
Since the thickness is reduced to about 1/4, the loosening of the core tightening portion due to withering of the insulating plate is reduced, and an extremely reliable core tightening structure is obtained.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional iron core device, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view showing an embodiment of this invention, and Fig. 4 is a main part of this invention. FIG. 5 is a sectional view showing another embodiment. In the figure, 1 is an iron core, 3 is a tightening member, 31 is a penetrating rod, 4 and 5 are insulating plates, 6 is a holding plate, 6a is an insertion hole, 6b is a through hole, 7 is an insulating washer, and 7a is a collar. . Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] a laminated iron core, a tightening member having a through rod passing through the iron core and tightening the iron core, an insulating plate fitted into the through rod and in contact with the outermost layer of the iron core;
A presser plate having a through hole approximately in the center of the insertion hole of a predetermined depth, and the through hole is inserted into the through rod so that the insertion hole faces the insulating plate, and one end of the cylindrical shape An iron core device comprising: a flange; the flange is placed in the insertion hole so that the flange faces the iron core; and an insulating washer is fitted into the through hole.