FI72833B - MAGNETIC SCREWS ELLER DEL AV MAGNETIC SCREWS FOR FREQUENCY FOER DESS FRAMSTAELLNING. - Google Patents

Description

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Magnetic circuit or part of a magnetic circuit and method of manufacturing the same. - Magnetic precipitators or magnetic solids and ferrous plates.

The invention relates to a magnetic circuit or a part of a magnetic circuit formed by a disc stack formed by disc pieces. The invention also relates to a method for manufacturing a magnetic circuit or a part of a magnetic circuit by forming a plate pack from disc pieces.

The magnetic circuit according to the invention or a part thereof is intended for use as magnetic cores for chokes or transformers, but it can also be used in other machines in which magnetic circuits are used.

It is known that when a crystal-oriented transformer plate is used, the core packs have to be manufactured so that the magnetic flux in the core is parallel to the rolling direction of the plate. This can be realized, for example, by stacking a plate stack from plate pieces according to Figure 1. This results in four plate pieces in the O-heart. The accurate measurement of such pieces of sheet metal generally results in a loss of material and, in addition, the large number of pieces of sheet metal results in high manufacturing costs. This has limited the use of such disk cores, especially in small transformers or chokes.

Another known way is to make a magnetic core from a sheet web by winding (cf. Figure 2). In connection with the winding of the heart, the iron losses of the crystal-oriented sheet material increase, which is why they usually always have to be heat-treated. If this method produces a choke core, then the ring core must be sawn open to form an air gap. These factors greatly increase the manufacturing cost of such cores.

The object of the invention is to provide a magnetic circuit or a part thereof by means of which a magnetic core can be manufactured from a small number of 2,72833 pieces of plates so that the cold working of the plates is as small as possible, without having to heat-treat the plates, resulting in significantly lower manufacturing costs.

This object is achieved on the basis of the features of the invention set out in the appended claims.

The invention will now be described with reference to the accompanying drawings, in which Figure 1 shows an O-core assembled from four separate plate stacks and Figures 2a and 2b show ring cores formed by winding a plate strip to illustrate the prior art.

Figure 3 shows various alternatives a to j for forming the bending point k on the plates.

Fig. 4a shows a plate pack assembled from plate pieces according to the invention before bending and Fig. 4b shows a plate pack after bending.

Figure 5 shows a plan view of a piece of plate with three bending points k.

Figure 6 shows a ring core according to an embodiment of the invention.

Figures 7a-d, 8a-f, 9a and 9b and 10a-f show different alternatives for forming the ring core by the method according to the invention.

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Figure 11 shows an embodiment of a ring core made by the method according to the invention.

Figure 12 shows a choke or transformer core assembled from annular cores made by the method of the invention.

The method according to the invention makes a magnetic circuit of a choke or transformer by making plate pieces of suitable length, in which bending points k are made according to Figure 5. Each plate piece is made with the necessary number of bending points so that a magnetic circuit of the desired shape is obtained by bending from these points.

The bending points can be made as continuous grooves (Figures 3a, 3c, 3d, 3e, 3f, 3g and 3j) or intermittently with an intact plate (3b, 3i) left between them.

When the bending points of adjacent plates are placed on the same line 1 (Fig. 4), such a bundle of plates can be easily bent at one time to the desired angle. In a preferred embodiment of the invention, the bending point is formed by a V-groove (Fig. 3c) or a blunt V-groove (Fig. 3j), the plates being superimposed as shown in Fig. 4a so that one side of the V-grooves rests on a line 1 forming an angle with the plates. b, which is half the angle between the sides of the V-grooves. Contrary to saying = 2 x β. In this case, the angle between the sides of the V-groove makes it possible to bend the plates or the entire plate stack to an angle «2 (Fig. 4b) so that the angle is equal to or greater than α 2 in order to obtain a good magnetic connection. The tight joint ensures low additional losses and it is also found that the plates are only machined in a small area at the bending point, so bending the plate does not cause an increase in iron losses elsewhere. The bending can also be left incomplete, i.e. 0 (2 is smaller than a ^ if it is desired to increase the magnetic resistance of the circuit.

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The sheets can also be bent individually or in smaller bundles before being stacked into a finished sheet stack.

The magnetic resistance of the bending point can also be increased by other suitable shapes of the bending point, e.g. by making holes in the bending point of the plates (Fig. 3i). The bending point can also be made by cutting partially cut-off tongues into the plate (Fig. 3h).

From the above it is understandable how the ring cores according to Figures 6, 7, 8 and 9 are made by bending the plate packs from one or more bending points k formed in with separate disc bundle R.

In the embodiment of Fig. 8, the annular magnetic cores are made of two U-shaped plate stacks, which in turn are made using bending points k formed according to the invention. The mutually formed ends p of the U-forms are placed opposite each other.

The embodiment of Fig. 10 differs from Fig. 8 only in that the branches of the U-cones are of different lengths and their opposing surfaces p are located symmetrically with respect to the center O.

In the embodiment of Figure 11, the annular magnetic core consists of two L-shaped stacks of plates, each made using bending points k according to the invention. The lengths of the plates are chosen so that the opposing surfaces p fit together.

The ring core formation methods described above are characterized in that the coil can be placed around the ring leg before the ring is finally closed.

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According to Fig. 12, the ring cores formed according to the invention can be placed in parallel to form the magnetic core of the choke or transformer.

Claims (12)

1. A magnetic circuit or part of the magnetic circuit consisting of a disk package formed by disk pieces, characterized in that the disk pieces have pre-fabricated bending positions (k) in the plane of the discs and that the corresponding bending points of the magnetic circuit or its part are adjacent. the same line (1) along which the disk pack discs are bent. 2. A magnetic circuit or part of a magnetic circuit according to claim 1, characterized in that the discs of the disk pack consist of a crystal-directed dynamo disk. A method for producing a magnetic circuit or a portion of the magnetic circuit according to claim 1 or 2 by forming a disk package, characterized in that a disk package is prefabricated in the disk bits in the bending points (k) of the discs and the magnetic circuit of the disk unit. or the corresponding bending points of its adjacent discs are placed on the same line (1) (Figs. 5 and 4a) along which the discs of the disc pack are bent. Method according to claim 3, characterized in that the prefabricated bending point (k) is made by forming a latch in each sheet. 5. A method according to claim 4, characterized in that a V-bar or a blunt V-bar is manufactured in each plate, where the angle (ck 2) between the sides substantially corresponds to the angle (o discs bend. 6. A method according to claim 3, 4 or 5, characterized in that an annular magnetic core is made so that in the annular disk pack one or more bending points (k) are made and that part of the pre-fabricated bending points of the disk pack is bent to close the ring first. after winding is installed, so that the disk pack's support jibs (p) come opposite