JPH0563024U - Transformer - Google Patents

Abstract

(57) [Summary] [Purpose] Good productivity and low iron loss. [Structure] First and second magnetic core halves 11 and 12 in which E-shaped magnetic plates are laminated are butted against each other, and an outer edge of the butted surface 13 is welded. An insulating sheet 18 is interposed so as to equally divide the magnetic plates in the stacking direction,
Therefore, the welded portion is divided into a plurality in the stacking direction. Primary and secondary windings 15 and 16 are wound around the center leg of the magnetic core.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention is used for neon transformers, power transmission and distribution transformers for commercial power sources, ignition transformers for combustion appliances, corona discharge transformers for ozone generators, etc. The present invention relates to a transformer in which a primary winding and a secondary winding are wound around a magnetic core assembled by welding parts.

[0002]

[Prior Art]

 FIG. 3 shows a conventional transformer. A first magnetic core half body 11 in which E-shaped thin magnetic plates are stacked and a second magnetic core half body 12 in which similarly E-shaped thin magnetic plates are stacked are connected to each other at the end faces of their three legs. Butt and part of the outer circumference of the butted surface 13 is welded to form an integral magnetic core 14, and a primary winding 15 and a secondary winding 16 are wound around the central leg of the magnetic core 14. .. Actually, after passing the primary winding 15 and the secondary winding 16 over the central leg of the magnetic core halves 11 and 12, both magnetic core halves are welded.

[0003]

[Problems to be solved by the device]

 As the magnetic plate, for example, a silicon steel plate is used. The reason why the magnetic plates are laminated in this manner is to reduce iron loss (eddy current loss, hysteresis loss). When a so-called assembled iron core in which the ends of the first and second magnetic core halves 11 and 12 are alternately stacked one by one is used as a magnetic core, for example, a neon transformer in which the weight of the magnetic core 14 is about 1.5 kg is used. The loss is 6W. However, the workability of assembling the magnetic core 14 in this manner is extremely poor.

From this point of view, as shown in FIG. 3, a welding electrode is provided along the outer periphery of the abutting surface 13 and the magnetic core half body is welded as the other electrode to assemble the magnetic core 14. Workability is good when assembled by welding in this way, but there was a problem that the loss increased to 12 W in the case of the neon transformer. In addition, when the loss is large like this, the temperature rises during use, so it is necessary to improve heat dissipation, resulting in a large size and a large amount of expensive compound with good heat resistance and insulating properties. There was also.

[0005]

[Means for Solving the Problems]

 According to this invention, a part of the abutting surfaces of the first and second magnetic core halves are welded, and the welded portion is divided into a plurality in the stacking direction of the magnetic plates.

[0006]

【Example】

 FIG. 1 shows an embodiment of the present invention, in which parts corresponding to those in FIG. 3 are designated by the same reference numerals. In this embodiment, the welded portion of the abutting surface 13 is divided into four in the stacking direction of the magnetic plates. For this reason, in this example, when the magnetic plates of the first and second magnetic core halves 11 and 12 are stacked, three insulating sheets 18 are interposed so as to be equally divided into four in the stacking direction. As a result, when the butt surfaces 13 are welded, the insulating sheet 18 does not become a continuous and integrated body on both sides, but the welded portion is divided into four by the insulating sheet 18. As the insulating sheet 18, for example, a mica sheet or a synthetic resin sheet having a thickness of about 0.13 mm is used. The welding depth is 0. It may be about 6 to 0.7 mm. Further, as in the conventional case, the welding points may be only two points on the two outer edges of the three butting surfaces 13 on the outer sides.

In order to divide the welded portion, a piece such as a chisel may be punched in and cut without using the insulating sheet 16. Since the welding is shallow, it can be easily cracked. By dividing the welded portion in this manner, the eddy current loss generated at this portion is reduced. FIG. 2 shows the effect of this device. This is as follows: primary voltage and primary power (corresponding to iron loss) when there is no load for a neon transformer with a magnetic core of S23 silicon steel sheet, primary side is 100V, 50Hz, secondary side is 15kV. It shows the relationship between. As a result, the iron core with a stack of silicon steel sheets one by one has the lowest iron loss, and the conventional one in which the abutting surfaces are simply welded has the highest iron loss, which is about 20% higher than the iron core. Both the iron core obtained by dividing the welded portion into two and the iron core obtained by dividing the welded portion into four cores have a lower iron loss than the conventional simply welded core, and are only a few percent of the loss of the assembled core. It can also be seen that the loss decreases as the number of divisions increases.

In the above description, E-shaped magnetic cores are used as the first and second magnetic core halves 11 and 12, but a combination of E-shaped magnetic cores and I-shaped magnetic cores, U-shaped magnetic cores and U-shaped magnetic cores, or U-shaped magnetic cores. The present invention can be applied to a combination of a magnetic core and an I-shaped magnetic core. Further, this idea can be applied not only to the two-phase transformer but also to the three-phase transformer and the transformer in which the primary coil and the secondary coil are integrated. From the practical point of view, the number of divisions of the welded portion is preferably 2 to 6, but it may be more.

[0009]

[Effect of the device]

 As described above, according to the present invention, by dividing the welded portion, the iron loss can be considerably reduced as compared with the case where the welded portion is not divided, and the productivity does not decrease so much. Since the iron loss is reduced, the size is reduced, the amount of the compound used is reduced, and the cost can be reduced. If the core loss is the same, a core material cheaper than the conventional one can be used.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining the effect of this invention when no load is applied.
The figure which shows the relationship between secondary electric power (iron loss) and primary voltage.

FIG. 3 is a perspective view showing a conventional transformer.

Claims (1)

[Scope of utility model registration request] 1. A magnetic core which is obtained by abutting first and second magnetic core halves on which thin magnetic plates of the same shape are laminated, and abutting a part of the abutting faces to be integrated, and is wound around the magnetic core. A transformer having a primary winding and a secondary winding, wherein the welded portion is divided into a plurality in the laminating direction of the magnetic plates.