KR840002384B1 - The multipolar magentization of a material in strips - Google Patents

Abstract

A strip of hard magnetic material is magnetised by proximity to a stack of alternate flat permanent magnets and trapezoidal pole pieces of soft magnetic material. The pole pieces extend around the permanent magnets forming a kind of comb. in contact with field magnets are magnetised in a direction parallel to the movement of the strip and perpendicular to the magnetisation to the permanent magnets. The magnetomotive force due to the permanent magnets, and the field in the air gap, are consequently increased.

Description

Multipolar magnetization method of strip material

1 is a cross-sectional view of a strip magnetized in the transverse direction.

2 is a cross sectional view of a strip magnetized in a non-lateral direction.

3 is a cross-sectional view taken along line bb 'of a transverse device with a single stack of trapezoidal elements.

4 is a cross-sectional view taken along line aa 'of a transverse magnetizer with a single stack of trapezoidal elements.

5 is a cross-sectional view taken along the line dd 'of a transverse magnetizer with a single layer of discotic element.

6 is a cross-sectional view taken along the line cc 'of a transverse magnetizer with a single stack of disk elements.

FIG. 7 is a partial side cross-sectional view cut along the line ee '(FIG. 9) of a comb-shaped non-lateral magnetizer. FIG.

8 is a front view of a comb-shaped device for transverse magnetization to form a stack that is movable near the strip.

9 is a plan view of the apparatus shown in FIG.

10 shows a magnetization medium having a magnet thickness of 4 mm and a pole piece thickness of 6.25 mm.

The present invention relates to a method for multipolar magnetization of a magnetizable material in the form of a sheet or strip, in particular in the form of a relatively thin soft strip of magnetic rubber type.

It is well known to cause alternating magnetic poles on the surface of the strip to be magnetized by causing the strip material to be magnetized to be moved in the immediate vicinity of the active part of the magnetizer or in the pores of the device to produce a suitable magnetic field. It is obtained in this way. The polarization can be transverse, meaning that the two sides of the strip or sheet exhibit approximately the same magnetic attraction. On the other hand, it may be non-lateral, in which case only one side of the sheet or strip represents the main magnetic attraction, while the other side is preserved for other uses, for example with some decoration, paint or adhesive or soft magnetic material. I can accept a sheet.

In order to magnetize a material, it is necessary to apply an appropriate magnetic field to the material, the strength of which relates to the material's inherent coerciveforce and the direction of the magnetic field to the magnetic field lines generated in the material.

According to the conventional magnetization process ("permanent magnets and magnetics" D. Hadfield, Iliffe books 1962, London, Chapter 9), this magnetic field can be generated in two ways:

(1) The magnetic field is generated by direct and arbitrary shock currents using the discharge of electromagnets, coils or capacitors. Devices of a type specific to the magnetization of such sheets or strips are described in French Patents Nos. 1,471,725, 2,106,214, 2,211,731 or US Pat. No. 3,127,544.

However, these systems are essentially for single sided magnetization (exception, US Pat. No. 3,127,544). However, they are complex, expensive and fragile, heat rises, energy-consuming, and dangerous. And they limit the number of poles and the possible active surface due to the problem of the insulation of the conductors and the electromagnetic field applied to them. Moreover, the production rate is limited to strip speeds of 1 m / min or less, even more so in the case of double-sided multipole magnetization.

(2) The magnetic field is also generated by permanent magnets, in which case the following advantages are obtained.

장치로부터 스트립을 추출하는데 필요한 기계적 에너지로 제한되는 매우 낮은 에너지 소모율

Very low energy consumption rate limited by the mechanical energy required to extract strips from the device

작동시의 높은 신뢰성,

High reliability in operation,

사용시의 높은 안정성(고압이 걸리지 않음),

High stability at the time of use (it does not take high pressure),

장치에 있어서 내부융력의 제거.

Removal of internal forces in the device.

However, the main drawbacks of systems with Alnico or ferrite permanent magnets are as follows.

-It is difficult to magnetize strong ferromagnetic materials due to the generation of relatively weak magnetic fields.

It is difficult to obtain multipolar magnetization of the sheet-shaped magnetic body described above.

The present invention relates to a magnetization method of a sheet or strip-like material to solve all the above disadvantages, wherein the magnetic field can magnetize the strongly ferromagnetic material and perform various forms of multipolar magnetization, and also the movement of the strip. For example, they are produced by permanent magnets that can be very fast at tens of meters per minute.

A method for multipolarizing a strip-like material on one side or on two sides of the present invention involves creating one or two stacks on a large parallel plane of flat footnote elements, the footnote elements being referred to as " main magnets " There is an alternating pole piece made of a known permanent magnet with a large coercive field and a magnetically weak material, and the magnetization direction of the main magnet has a component perpendicular to the large face of the element and in the case of two main magnets adjacent to the same pole It is in the opposite direction.

In order to magnetize the strip, the strip is made to move almost parallel to the large face of the flat element in the immediate vicinity of the stack, with respect to the stack, or in the gap between the two stacks, the plane of the strip being generally perpendicular to the large face of the element. to be.

As the main magnet, it is preferable to select a magnet made of a rare earth-cobalt alloy such as samarium-cobalt (SmCOs). The magnetically weak material used as the pole piece is preferably a soft iron or an iron-nickel alloy, but it is also possible to use a permalloy iron-nickel alloy, silicon steel, carbon steel or soft ferrite, depending on the required magnetic permeability. .

To achieve lateral magnetization, the strips are made to pass through the voids defined by the laminations facing each other. On the other hand, to obtain two non-lateral magnetizations, it is sufficient to use a single stack or to replace the second stack with a soft iron block (or other ferromagnetic material) or any other nonmagnetic element that allows displacement and guidance of, for example, strips or sheets.

The planar element is defined by two large parallel planes, and a stack is made on these large planes. As the strip moves near the voids or active portions of the magnetizing medium, the strip is generally located in a plane perpendicular to these large planes and advances in a direction known as a "movement axis" parallel to the plane of the large planes. If the strip has a new direction of curvature in the immediate vicinity of the magnetizing medium or in the air gap, the terms "strip plane" and "moving axis" refer to the face and leading face of the strip, respectively, along the busbar of the strip closest to the magnetic medium. The tangent to the forward curve at a point on the strip located at the tangent plane.

The magnetization direction of the main magnets is not parallel to the large surface of these magnets and the adjacent electrode pieces. When two main magnets are located on both sides of the same pole piece, the N-S magnetization direction is reversed. N poles and S separated by neutral zones located on the same width of the strip at the point where the pole pieces appear on the surface of the magnetizing medium, because the pole pieces pass the magnetic flux generated by the opposing magnet towards the surface of the pores or magnetization medium. There are alternating poles. For lateral magnetization to be obtained, the two stacks must face each other so that similar elements of each stack face each other and the magnetization N-S directions of the two opposing main magnets are opposite to each other.

The invention may be better understood from the accompanying drawings, which illustrate only certain non-limiting embodiments.

As shown in FIG. 1, if the strip of magnetizable material has a series of alternating N and S poles separated by neutral zones on two sides, the strip has transverse magnetization. If this arrangement is periodic, the distance between two adjacent poles forms the polarity phase of magnetization. In this case the magnetic field lines traverse the thickness of the strip and are generally perpendicular to the faces.

On the other hand, if there is a series of alternating N and S poles separated by the same width of the strip and the neutral zone on one side as shown in FIG. 2, the magnetization is non-lateral and the magnetic field line ends on the back side and the thickness of the strip Do not cross.

The apparatus shown in FIGS. 3 and 4 is a flat plate in which a permanent magnet (1) made of a cobalt-rare earth alloy having a large coercive field (1) and a ferromagnetic pole piece (2) made of an iron-cobalt alloy containing 35% cobalt are alternately formed. It consists of two layers on the large side of the element.

As shown in FIG. 4, the large faces of these flat elements have a trapezoidal contour in the vicinity of the strip 3, with the trapezoidal small bottom 4 facing the strip 3. Each stack is supported by a support 5 made of soft iron or a magnetically weak material. The two magnets 1 located on both sides of the same pole piece 2 have a total magnetization direction perpendicular to and opposite to the plane of the large side of the stack. The strip 3 moves in a direction (or axis of movement) generally parallel to the small bottom 4 of the flat trapezoidal element in a plane generally perpendicular to the large side of the stack. Both stacks form voids 6. Each main magnet (1) and pole piece (2) of one of the two laminations is located against the magnets and pole pieces of different similar laminations. However, when two magnets face on either side of the void 6, the directions of magnetization are opposite to each other. Therefore, this produces a series of alternating magnetic field lines in the air gap perpendicular to the pole side, the alternating direction being a series of alternating N separated by the breadth neutral zone of the strip 3 moving in the air gap 6. It is indicated by the arrows representing the pole and the S pole.

It is sufficient to use only half of the magnetization medium to obtain non-lateral magnetization. The use of a single stack is sufficient and the other half is removed, or replaced by a block of wrought iron or other magnetically weak material, or by a nonmagnetic element that allows for the numbering and guiding of a sheet or strip, for example.

In the strains shown in FIGS. 5 and 6, each layer is in the form of a disc which is movable around a flat element, side 7, having a single cylindrical side and rotating at a speed such that the strip does not slip against the magnetizing medium. It consists of the main magnet 1 and the curved piece 2.

In the comb-shaped device shown in Figs. 7, 8 and 9, the stacking of the main magnet 1 and the trapezoidal curved piece 2 in the vicinity of the strip 3, and the trapezoidal small bottom 4 facing the strip 4 There is).

The pole piece 2 has a larger cross-sectional area than the magnet 1, and extends into a stack, and completely surrounds the magnet 1 to form a comb shape. These pole pieces 2 are in contact with the long magnetic field 8 which transfers some magnetic potential to them. The magnetization direction of these long magnets 8 is parallel to the moving axis 11 of the strip 3. That is, since it is parallel to the large surface of the stack and the plane of the strip, it is perpendicular to the magnetization direction of the magnet 1 as shown in FIG.

The presence of the long magnet 8 increases the magnetic force generated by the magnet 1 and thus increases the magnetic field of the voids. In addition, the magnetic flux generated by the long magnetic field 8 passes through the strip 3 due to the presence of the main magnet 1.

The active part of this comb-like system may take the form of a disk stack that rotates about an axis, but as shown in FIG. 8, the long magnetic field 8 and the adjacent polar part remain stationary.

In order to reduce the leakage between the two comb-like systems, the pole pieces located between the two main magnets 1 are replaced by intermediate magnets 9. This intermediate magnet is in the form of a bar connected to the two main magnets 1 and perpendicular to the plane of the strip 3 located alternately in front of and behind the layer with respect to the strip movement axis. In this way, the S-shape continuation of the main magnet 1 and the intermediate magnet 9 is obtained as shown in FIG. 9, the latter being arranged in a zigzag form at the end of the adjacent magnet 1.

The magnetization direction of these intermediate magnets 9 is parallel to the magnetization direction of the long magnet 8 but is the opposite direction or alternately parallel and opposite to the moving axis 11 of the strip 3. In this way, concentration in the magnetic lines of force is obtained at the portion of the pole piece located in the center of the stack, which passes through the pole piece toward the small trapezoidal bottom 4 near the strip.

In the plane parallel to the strip plane there is a concentration of the north and south poles in the zone 10 alternately at the center of the pole pieces of the stack. In order to obtain lateral magnetization, a magnetizing medium consisting of two similar stacks located opposite each other and forming a pore in which the strip 3 moves is used. In addition, the main magnets 1 of each stack face each other like the pole pieces, and the magnetization directions of the two opposing magnets on both sides of the void are not parallel to the plane and consequently the opposite direction. To obtain non-lateral magnetization, only half of the magnetization medium is used, and the other half is removed or replaced by a nonmagnetic element that allows displacement and guidance of rolls, sheets or strips of soft iron. The results obtained using the apparatus and method according to the invention are shown in the following examples.

Example 1

A lamination is made of stator magnets made of SmCO ₄ alloy, about 2.5 mm thick, and pole pieces made of Fe-CO alloy, about 2 mm thick. Derivation of 0.4 Tesla (4000 Gauss) for non-lateral magnetization and 0.65 Tesla (6500 Gauss) for lateral magnetization is obtained for 3 mm thick flexible strips.

Example 2

A stack of about 20 mm diameter manipulators with respect to the axis is made, which alternates with a 1.2 mm thick pole piece made of a 1.3 mm thick SmCO ₄ magnet and a Fe-CO alloy. This type of device contains barium ferrite and causes the magnetic rubber bands having a thickness of 1 mm or less to become magnetized in the transverse or non- transverse direction to become saturated. The magnetic field value in the void reaches 380 KA / m at a distance of 4 mm and reaches 100 KA / m at a distance of 0.8 mm.

Example 3

The magnetization medium is made up of two cylinders formed of 4 mm thick "CORAMAG" (SmCO ₅ structure) and pole pieces made of 6.25 mm thick mild steel (ie, 10.25 mm polarity steps). This device is used to magnetize a 55.0 mm wide, 2 mm thick instrip at a speed of 30 m / min in the configuration shown in FIG. 10, which is characteristic of the strip drive system and the magnetizer is not limited.

The attraction force measured as a function of the distance from the magnetizing strip to its head on the magnetizing contact key located in the hole of this strip is 1.2 N for distance 0, 0.75 N for 1 mm and 0.35 for 2 mm N, this value is a strip of equal thickness that is magnetized in an electromagnetic device with a polarity step of 11.5 mm but with a significantly lower travel speed (V = 1 m / min) and is limited by the responsiveness of the capacitor layer and the force the electromagnetic saturator receives. Matches the value obtained in phase.

Example 4

A comb-like system is made with an intermediate magnet having the same characteristics as in the single lamination system in Example 1. The magnetic field in the void is then increased by 10%. In all the previous embodiments, it is possible to magnetize the transverse direction a strip consisting of Ba, Sr or Pb petite which is essentially at least as thick as the height of the pole piece b if the diameter of the pole piece is larger than the height.

Claims (1)

In the method of multipole magnetization of ferromagnetic material in the form of a strip or sheet (3), the material is arranged to move in the direction (11) in the vicinity of at least one stack consisting of flat elements lying on a large parallel bottom, The elements are alternately formed of pole pieces (2) made of a main permanent magnet with a large coercive field and a weak magnetic material, and the permanent magnet has a magnetization component perpendicular to the large bottom, which is adjacent to the same plane. In the case of two main magnets, the polarization method of the strip material, characterized in that the opposite direction.

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