JPS6199315A - Manufacture of demagnetizing frame for electric component - Google Patents

Abstract

PURPOSE:To form demagnetizing frames overlapping one another manifoldly by use of one batten by press-molding the batten into a shape of successive connection of minor arcs convexly curved in the same direction. CONSTITUTION:In a metal mold 5 having a molded surface made by connecting bent edges 3 at eight places by use of a curved surface 4 having eight faces, a batten 1 is formed in such a shape as to successively connect minor arcs convexly curved in the same direction. A molded component 6 taken out of the metal mold 5 is rolled up in a coil shape by elestic force of a material (the batten). The molded component 6 naturally rolled up by an elastic restoring force of the material is shaped in such a manner that the bent edges 3 corresponding to the molded component overlap one another at the outside and inside to form an angular pipe. In this time, the inner and outer ends of the batten 1 position at the inside and outside of the same side. The both inner and outer ends of the batten 1 positioning at the same side are spot- welded to integrate the whole. When one-fold demagnetizing frame, threefold or more demagnetizing frame or an angular pipe demagnetizing frame besides a quadrangular pipe is formed, the demagnetizing frame can be formed using the same process as the above by use of the corresponding metal mold.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for manufacturing a magnetic shield frame that covers the outer periphery of an electrical component that generates magnetism, such as a power transformer. (to rub)

(Prior art) In the case of a conventional magnetic shield frame, for example, a magnetic shield frame for a power transformer,
The one shown in FIG. 2 is known.

Figure 2 (A) shows the case of a so-called -heavy magnetic shield frame, Figure 2 (B)
) shows the case of a double magnetic shield frame, and the one shown in Fig. 2 (A) is a pair of U-shaped products formed by bending a strip made of a high magnetic permeability material such as a silicon steel plate into a U-shaped cross section. 2 (B) is made by bending a strip made of a high magnetic permeability material into an opening-shaped cross section. A pair of mouth-forming molded products are assembled so that their openings are diagonally located, and the end portions of each molded product are spot welded to form a square tube.

(Problems to be Solved by the Invention) In the case of the single magnetic shield frame shown in Figure 2 (A), since two molded products are combined and integrated, the amount of wrap must be set accurately when combining them. However, there is a problem in that it is not possible to achieve dimensional accuracy of the product.

On the other hand, in the case of the double magnetic shield frame shown in Figure 2 (B), in order to form it into a square shape, two steps are required: bending both sides of the strip and bending the center of the strip. In addition to requiring work, the work of assembling the two molded products involves fitting them into each other using a small gap created between the ends, which makes the work cumbersome. Moreover, since there are only four welding locations, there is a problem in that manufacturing efficiency is low.

Furthermore, since both of these methods involve combining two members to form a frame, there is a problem in that the dimensional accuracy of the assembled body cannot be obtained unless the finished dimensional accuracy of the folded product is precisely formed. .

In addition, when forming a magnetic shielding frame with a transformer supporting protrusion, if the protrusion is formed at a location other than the center in the height direction, two types of molds are required to form the molded product before assembly. Since each molded product must be prepared in advance, there are problems in that manufacturing is troublesome and the manufacturing cost is also high.

(Means for Solving the Problems) The present invention is a method for easily forming a magnetic shield frame without combining two members, and for this purpose, it is possible to easily form a magnetic shield frame by bending strips made of high magnetic permeability material in the same direction. A shaping process involves press forming into a shape with continuous arcs, and a rectangular cylindrical frame is created by placing the ends of the strips inside and outside with the convex curved surface facing inside. It is characterized by being comprised of a shaping step for forming a strip, and a welding step for spot welding the inner and outer ends of the strip after shaping.

(Function of the invention) In the present invention, since the band plate made of a high magnetic permeability material is press-molded into a shape with continuous inferior arcs that protrude in the same direction, the elastic restoring force of the band plate allows the convex curved surface to be turned inward. This means that each side of the frame can be formed in one step. For this reason, even in the case of a multiple magnetic shield frame, the strip plates of the negative plate are wound in a coil shape, and the end treatment can be performed at one location.

(Example) Figure 1 shows the manufacturing procedure of a double magnetically shielded frame for a power transformer. It consists of a shaping process in which the product is shaped into a rectangular tube, and a welding process in which the ends (2) of the rectangular tube shaped strips (1) are spot welded together.

The shaping step is performed using a mold (5) having a forming surface formed by connecting the bent corners (3) of the hem portion with the curved surface (4) of the hem surface.
The strip plate (1) is formed into a shape in which inferior arcs projecting in the same direction are continuous. The molded product (6) taken out from the mold (5) is
The elastic force of the material (band plate) will cause it to be rolled into a fill shape. In addition, the length of the curved surface (4) that connects the bent corners (3) in the mold (5) should be formed so that the length at the part where the outer layer is formed is longer by the thickness of the material. be.

In the shaping process, the molded product (6), which is naturally rolled up due to the elastic restoring force of the material, is shaped into a rectangular tube by shaping the corresponding bent corners (3) so that they overlap inside and out. . At this time, the inner and outer ends of the strip plate (1) are on the same side, and the inner and outer ends are 1
Your location.

In the welding process, the whole is integrated by spot welding the same side surfaces of the rectangular tube formed in the shaping process; and the inner and outer edges of the strip plate located thereon.

In addition, when making the transformer holding part protrude from the inner surface of the frame,
By providing a punching protrusion on the mold at the portion where the protrusion is to be formed, the transformer holding portion can be formed at the same time as the strip plate (1) is straightened.

When forming a single layer magnetic shield frame, a triple or more magnetic shield frame, or a rectangular cylinder magnetic shield frame other than a square cylinder, it is possible to form the magnetic shield frame in the same process as above by using an appropriate mold. can.

(Effects of the Invention) The present invention is characterized in that the band plate is shaped into a continuous shape with inferior arcs that protrude in the same direction by press forming, and the molded product after this shaping is placed in a state where the convex curved surface is on the inside. By positioning the ends of the strip inside and outside, it is shaped into a rectangular cylindrical frame, and the ends of the strip placed inside and outside are spot welded to form a magnetic shield frame. In addition to being able to form a fully bent corner of a rectangular tube in , - times of pressing,
Since the bent corners are connected to each other by a curved surface, the strip plate formed by the press winds up into a coil shape due to its elastic restoring force. A frame can be formed. Therefore, it is not necessary to combine the molded products to form the rectangular cylinder, and there is only one welding point, so the manufacturing process can be greatly simplified.

Furthermore, the dimensional accuracy of the product is determined by the dimensional accuracy of the mold, as all bent parts are formed in - times of pressing, and the incidence of defective products can be significantly reduced. can.

Furthermore, in the magnetic shield frame formed using this manufacturing method, each side surface is curved inward, so the side surface can securely hold internal parts.
Since it is possible to prevent the components from shifting, it is possible to reduce variations in the magnetic shielding properties of individual products.

Furthermore, even in the case of a magnetic shield frame in which component fixing protrusions are provided on the inner circumferential surface, it is possible to shape the frame in one step using one mold.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the procedure of the method of the present invention, and FIG. 2 is an explanatory diagram of a magnetic shield frame formed into a shape I& by a conventional method. DESCRIPTION OF SYMBOLS 1... Band plate, 2... End of (1), 3... Bent corner, 4... Convex curved surface, 5... Mold, 6... Molded product.

Claims (1)

[Claims] 1. In forming a magnetic shield frame for electrical components, there is a shaping process in which a band plate made of a high magnetic permeability material is press-molded into a shape with continuous inferior arcs that protrude in the same direction, and a molded product after this shaping. A shaping process in which the ends of the strip are placed inside and outside with the protruding curved surface facing inside to form a rectangular cylindrical frame; A method for manufacturing a magnetically shielded frame for electrical components, which includes a welding process.