RU2417861C2 - Flat inductor for magnetic pulse compaction of artciles from nanosized powders - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to powder metallurgy. Proposed flat inductor consists of inductor spiral representing Archimedes spiral, casing, interturn insulation and current leads to connect inductor to power supply. Zero and potential current leads are made up of rods with cylindrical bulge provided with groove receiving inductor bus that features double thickness and depth equal to bus height. Grooves in cylindrical bulge form transition from current lead to spiral turn made along tangential line in current lead/bus contact zone. Inductor bus permanently connected with current leads features double thickness, smoothly reducing to single thickness at the distance of, at least, current lead cylindrical section diametre.

EFFECT: longer life at discharge high powers.

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Description

The invention relates to devices for compacting powders in the field of powder metallurgy, in particular to devices for magnetic pulse pressing of products from nanosized powder materials.

Known methods of induction magnetic pulse pressing of powder materials, which are based on the excitation of electromechanical forces in a conductive body that transfers these forces to the pressed material. An inductor for magnetic pulse pressing of powder products, consisting of an inductor spiral made in an Archimedes spiral, a casing, current leads, which connect the inductor to a power source (V. Mironov, Pulse compaction of powders. // Riga: Zinatne, can be considered as an analogue. , 1980, 196 p.).

The disadvantage of this analogue is the lack of insulation of the inductor coil, which leads to inter-turn breakdown of the coil and a short life of the inductor.

The closest analogue of the device, the prototype, the authors consider the typical design of the inductor for flat stamping (V. A. Golenkov, AM Dmitriev and others. "Special technological processes and equipment for pressure treatment", ISBN 5-217-03247-2. - M .: Engineering, 2004, 464 pp.), Consisting of a spiral inductor, a casing, current leads, insulation. A distinctive feature of the prototype, in comparison with the analogue presented above, is the presence of coil insulation of the inductor coil in the form of coil winding of the inductor coil with tape insulation and filling of the inter-turn space of the coil of the inductor with an epoxy compound.

The disadvantage of the design of the prototype is the contact zone of the current leads, with the coil of the inductor. The uneven distribution of current in the contact area of the current lead / inductor coil leads to the destruction of the contact zone at high discharge energies for several tens of pulses.

An object of the invention is the design of current leads, providing an increase in the life of the inductor at high discharge energies.

The problem is solved due to the fact that the current leads are functionally divided into potential (located in the center of the spiral) and zero (located at the end of the peripheral coil of the spiral).

Potential and zero current leads are rods of materials with high electrical conductivity. At one end of the current leads there are structural elements for connecting the inductor to the power source, at the other there are structural elements in which the ends of the coil of the inductor are attached using an integral connection.

On figa shows a bottom view, on figb - side view of the structural element of the zero current lead is a cylindrical thickening 1, along the diameter of which a groove 2 is made for the inductor bus double thickness and a depth equal to the height of the bus, with a sample of the symmetrical axis of the groove forming the transition to the outer coil of the spiral tangentially in the contact area of the current lead / bus.

On figa shows a bottom view, on figb is a side view of the structural element of the potential current lead, which is a cylindrical thickening 1, the continuation of which is a half-cylinder 3, the height exceeding the height of the inductor bus, in which the groove 2 is made in the form of a half-turn for double bus thickness and depth equal to its height so that a uniformly expanding half-turn 4 is formed along the groove along the groove, forming a tangential transition to the internal coil of the spiral in the current lead / bus zone.

The inductor bus has a double thickness in the contact zone and gradually decreases to a single thickness at a distance of not less than the diameter of the cylindrical part of the current leads.

The inductor spiral is fastened in the grooves of the current leads by an integral connection.

These design of current leads and busbars of the inductor ensure a smooth flow of current at the junction of the current lead / bus and provide an increase in the life of the inductor at high discharge energies.

The following inductor design is proposed.

A flat inductor is wound in a spiral by Archimedes with a bus, which can be used as standard strips of materials with high electrical conductivity. The inductor bus has a double thickness in the contact zone and gradually decreases to a single thickness at a distance of not less than the diameter of the cylindrical part of the corresponding current leads, which is achieved by soldering to it high-temperature, well-conducting solder pieces of standard strips selected as the bus, providing the proposed geometry.

One end of the busbar with an integral connection (soldering with a high-temperature well-conducting solder) is fixed in a potential current lead. The second end of the bus is mounted in a similar way in the zero current lead. The bus section between the current leads is wrapped with tape insulation. An inductor bus is formed into an Archimedes spiral around a potential current lead and placed in a casing in which it is filled with an epoxy compound.

Manufacturing example

A flat inductor was manufactured for magnetic-pulse pressing of products from nanosized powders: the inductor spiral was made of a 2.5 × 11 mm ² copper busbar, the current leads were made of brass, the ends of the spiral were fixed by silver soldering in the current leads, 16 turns of the inductor spiral were insulated from each other with a layer of fiberglass 0.5 mm thick and rigidly fixed in the bandage by impregnation with a polyester compound. Inductors of this design, when pressed with an ultimate design force of 850 kN (energy of a current source of 30 kJ), have a resource of at least 5000 pulses.

Claims (1)

Flat inductor for magnetic pulse pressing of products from nanoscale powders, containing an inductor spiral made in the form of an Archimedean spiral, a casing, inter-turn insulation, current leads, at one end of which are structural elements for connecting the inductor to a power source, characterized in that the zero current lead is made in the form of a rod with a cylindrical thickening, along the diameter of which a groove is made for the inductor tire of double thickness and a depth equal to the height of the tire, with a sample of the symmetrical axis of the groove, which initiates the transition to the external spiral coil tangentially in the contact area of the current lead / bus, and the potential current lead with a cylindrical thickening, the continuation of which is a half cylinder, the height of which exceeds the height of the inductor bus, in which a groove is made in the form of a half-turn for the bus double the thickness and depth equal to its height so that along the groove a uniformly expanding half-turn is formed by sampling, forming a tangential transition to the internal coil of the spiral in the current lead / bus zone, and the inductor bus, inseparably connected to the current lead mi, has a double thickness in the contact zone and gradually decreases to a single thickness at a distance of not less than the diameter of the cylindrical part of the current leads.

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