SI21630A - Multipole magnetizing device and procedure for its manufacture - Google Patents

Abstract

The multipole magnetizing device uses a massive multipole magnetizing head for magnetizing permanent magnets from highly coercitive materials, like hardmagnet ferrites and materials based on rare earth compounds, which for achieving the magnetic saturation point require a very large magnetic field, concentrated at precisely defined sections. The magnetizing process is performed inside the multipole magnetizing head in such a way that on the permanent magnet a series of symmetrical and alternating facing poles is provided. The magnetizing head is made in the shape of a hollow cylinder-shaped body from electrically conductive material. By adequate geometry of the series of vertical notches on the hollow cylinder-shaped body, a series of facing current circuits is created. The shape of the current circuits ensures that the majority of the electric current is close enough to the surface of the magnetizing material. The width of the magnetic poles is defined by the distance between the notches.

Description

MULTIPLE MAGNETIC DEVICE AND MANUFACTURING PROCEDURE

The invention belongs to the field of devices and processes for magnetization and demagnetization of solid magnetic materials, more specifically to the field of multipole magnetic devices.

A technical problem that is solved by the present invention is the construction solution and the manufacturing process of a device for the multipolar magnetization of rigid magnetic materials, such as rare earths and ferrites, which require very high magnetic field strength concentrated in specific areas to reach a point of magnetic saturation. The device must withstand the high mechanical stresses resulting from the magnetic forces of a strong magnetic field. This occurs at high current pulses, which causes the magnetic device to heat up intensively during magnetization. The design and manufacturing process must ensure a precise and symmetrical geometric shape of the magnet device and efficient release of the released heat.

U.S. Pat. The openings are designed to provide the winding with a firm support and to prevent displacement or deformation despite the strong magnetic fields generated by high-current impulse discharge. The windings may be designed to create a variety of pole patterns on flat magnets or on cylindrical magnets for which suitable openings are provided on the supporting structure.

It is known that highly coercive magnetic materials are primarily magnetized by large current pulses through an electrically conductive material, which is designed to form, in the case of a circular magnet around it, a series of current loops and, in the case of a flat magnet, a sequence of current loops adjacent to it. The magnetic field is thus generated in the material to be magnetized by said current loops, which are generally made of wire in known magnetic devices.

The essence of the multipole magnet device according to the invention is that it allows the magnetization of highly coercive magnetic materials, such as rare earths, which require a high magnetic field strength to reach the material saturation point. The device is designed to concentrate the magnetic field in very narrow areas, allowing the formation of magnetic poles at small intervals, so that in the case of a cylindrical magnet, a sequence of half pairs can be made at its periphery and, in the case of a flat magnet, at its surface. The precision of the geometric shape of the magnet head ensures the stability of the magnetization process and a smaller spread between the widths and amplitudes of the magnetic field of the individual poles.

The multipolar magnet device and the manufacturing process according to the invention will now be described in more detail with the aid of the following figures:

Figure 1 is an outline of the device according to the invention, partly in the middle section;

Figure 2 - outline of body 8;

Figure 3 is a side view of the body 8 of a multipolar magnet head 6;

Figure 4 is a plan view of the body 8 of the multipole magnet head 6;

Figure 5 is a cross-sectional view of A-A of body 8;

Figure 6 - diagram of magnetic potential and magnetic density in the magnetic gap; Figure 7 - representation of the bulk of the electric current by pulse magnetization

The supporting structure of a multipole magnet device consists of a carrier 1, a carrier column 2 and a carrier column 3, which are fixed at the edges of the carrier 1, and a cooling plate 14, which is secured to the carrier 2 and 3 by clamps 14a. In the center of bracket 1, a bracket 4 is attached to the mandrel 5, on which a magnet is mounted which is magnetized. The magnet head 6 is mounted in the center of the mechanical guard 7 so that its longitudinal axis is covered by the longitudinal axis of the mandrel 5. The mechanical guard 7 with the magnetic head 6 is mounted on the columns 2 and 3 so that it can be moved along the columns. It is made of an electrically non-conductive and non-magnetic material of adequate mechanical strength to which the magnetic head 6 rests in a radial direction so that it can withstand the high forces of a strong magnetic field generated by large current pulses.

In the middle of the cooling plate 14, which has a longitudinal drainage pipe 16 for draining the coolant, there is a clamped cooling mandrel 15 having a cooling system designed so that a tube 15b is inserted in the hollow interior of the mandrel 15 which is slightly thinner than the cylindrical mandrel cavity 15 and is inclined below. The coolant thus flows down the pipe 15b downwards, faces upward at the bottom of the cylindrical mandrel 15 and flows in the space between the outer wall of the mandrel 15b and the wall of the mandrelated mandrel 15 against the drainage pipe 16 in the cooling plate 14.

The multipolar magnet head 6 is made in the form of a hollow cylindrical body 8 made of electrically conductive solid material. The body 8 has a uniformly spaced vertical notches 9 and 11, which follow each other and are notched throughout the thickness of the wall of the body 8, and in the vertical direction, their length is approximately 8/9 of the height of the body 8, with the notches 9 beginning at the top of the body 8, notches 11 then the bottom of the body 8.. Between the first and last notches 9, on which the connectors 12 and 13 are connected, runs instead of the notch 11 of the notch 10, all along the height of the body 8.

The sequence of notches 9, 10 and 11 forms a series of electrically conductive columns in the body 8. The geometric shape of the columns forms a current loop starting at the notch 10. Through the terminals 12 and 13, current flows through the current loops in the columns of the magnetic head 6 such that direction of flow in adjacent columns opposite. The shape of the pillars that form the current loop ensures that the bulk of the electrical current during pulse magnetization is sufficiently close to the surface of the magnetic material, as can be seen from Figure 6. The width of the magnetic poles is determined by the notches 9, 10 and 11 along the circumference of the body 8, i.e. means with comma spaces. The most favorable conditions can be obtained in the case of the laminating of the body 8, which allows, at large current pulses of the order of 80 kA, a magnetic flux density on the surface of a magnetic material of the order of 2 T.

The notches 9, 10 and 11 on the body 8 of the magnet head 6 may be made by wire or submersible erosion or by some other material removal process. These make it possible to produce geometrically precise symmetrical current paths that provide the symmetry of the magnetic poles. This also achieves focusing of the magnetic field on narrow sections of magnetic material. The symmetry of the magnetic poles is also important due to the compensation of the large transverse forces generated by the large current pulses through the magnetic head 8. Effective compensation of the transverse forces extends the life of the magnetic device. Adequate mechanical strength is provided by the precise geometric shape of the body 8 with notches 9, 10 and 11, which ensure the symmetry of the flow paths and thus the even distribution of force on the supporting walls of the mechanical shield 7.

The discharges in the grooves 9, 10 and 11, which separate the individual flow paths, are filled with synthetic glass fiber reinforced resin or Kevlar® fibers.

Since the current-conducting part, in which a large amount of energy is released during magnetization, is surrounded by heat-permeable material to compensate for the high mechanical forces, heat dissipation is carried out by a cooling mandrel 15 from a thermally conductive material, which is further cooled by an integrated cooling mandrel. to a system that extracts heat from it. Said cooling rod 15 is clamped in the cooling plate 14, into which it further extracts heat through the supply of coolant. After the magnetization is complete, the mechanical shield 7 with the integrated magnet head 6 moves to the cooling mandrel 15 so that it is seated in the discharge, where a permanent magnet was inserted during the magnetization process. Thorn 15 thus physically touches the pillars of the body 8, that is, the flow paths, and, because of the large temperature difference, rapidly receives excess thermal energy from the magnetic device. Cooling time is defined to maintain an operating temperature of about 100 ° C, which ensures longer device life and a stable magnetization process.

According to variant I, the body 8 is made of well electrically conductive and insulated tape, which is folded into a square in the case of a magnetic device for magnetizing a flat magnet or, in the case of a magnetic device for magnetizing a cylindrical magnet, wrapped in a toroidal roll.

According to variant II, the body 8 is composed of isolated concentric tubes which are folded into squares in the case of a magnetic magnet magnetizing device, or rolled into a toroidal shape in the case of a magnetic magnet magnetizing device. The conduction paths have a rectangular cross section when the body 8 is folded into a quad and a cross section in the form of a circle when the body 8 has a cylindrical shape.

The number of half pairs that the body 8 can have according to the invention is expressed by the equation: p = 1 + N, where N is the set of natural numbers.

The multi-pole magnetic device according to the invention enables the generation of a high-intensity magnetic field, with a magnetic field strength of the order of 2500 kA / m on very narrow surfaces at the circumference in the case of a cylindrical magnet or at the surface of a flat magnet. Such high strength is required for the magnetization of rare earth magnetic materials, as shown in Figures 6 and 1.

Claims (8)

PATENT APPLICATIONS A multipolar magnet device for producing multipolar permanent magnets with symmetrical and alternating opposite poles, wherein permanent magnets are made of highly coercive materials such as solid magnetic ferrites and rare earth based materials, characterized in that they are mounted on a support (1) a supporting column (2) and a supporting column (3) between which is a support (4) of a mandrel (5) on which a magnet is mounted, magnetized, so that in the vertical axis of the mandrel (5) there is also an axis of the magnetic head (6) which is located in the middle of the mechanical shield (7) so that the columns (2 and 3) pass through the cylindrical openings (7a) on the side portions of the shield (7), the cylindrical opening (14a) of the cooling plate (14) to be a magnetic shield (7) with an integrated magnetic head (6) movable along the pillar (2 and 3) so that the mechanical shield (7) is made of electrically non-conductive and non-magnetic material of adequate mechanical strength to which the magnetic head (6) relies in the radial direction to cool it thorn (15) clamped in cool a support plate (14) having a longitudinal, ventilation pipe (16) so that the cooling mandrel (15) has a narrower tube (15a) in the inner cylindrical portion (15a), which is inclined obliquely at the bottom to have a cylindrical portion (15a) ) a longitudinal tube (15c) that joins the tube (16) of the cooling plate (14). 2. The multipole magnet device according to claim 1, characterized in that the multipole magnet head (6) is made of a solid cylindrical body (8) of well electrically conductive material, which is hollow in the middle so that the body (8) is geometrically shaped, that the notches (9) begin at the top of the body (8) and end at about 8/9 of the height of the body (8), that the notches (9) divide the body (8) vertically into circular sections which are perpendicular to the vertical axis, that the first notch (10) divides the body (8) along the vertical side and is located between the first and last notches (9), on which the connecting clips (12 and 13) are located, so that the notches (11) begin at the bottom and end at about 8/9 of the height of the body (8) so that the notches (11) divide the body (8) into circular sections from the bottom up, so that after the notch (10) the notches (9 and 11) alternately follow the circumference of the body (8). Multipole magnet device according to claims 1 and 2, characterized in that the cylindrical body (8) of the multipolar magnet head (6) is made of well electrically conductive and insulated tape rolled into a toroidal roll. Multipole magnet device according to claims 1 and 2, characterized in that the cylindrical body (8) of the multipolar magnet head (6) is made of a well electrically conductive and insulated strip which is folded into a square. Multipole magnet device according to claims 1 and 2, characterized in that the cylindrical body (8) of the multipolar magnet head (6) is made of insulated concentric tubes. Multifunctional magnet device according to claims 1 to 5, characterized in that the notches in the cylindrical body 8 of the multifunctional magnet head (6) are made by a wire or immersion erosion process and that the recesses in the notches are filled with synthetic glass-reinforced resin fibers or Kevlar® fibers. Multipole magnet device according to claims 1 to 5, characterized in that the multipolar magnet head (6) is fabricated by a material withdrawal method and that the notches in the notches are filled with synthetic resin, glass fiber reinforced or Kevlar® fibers . Multifunctional magnet device according to claim 1, characterized in that during the magnetization process and especially thereafter, coolant is supplied through the coolant tube (15b), which is passed through the cooling plate tube (15c) and tube (16). (14) Discharges into the cooling system.