FR2532143A3 - MULTI-LAYER INDUCTION CYLINDRICAL COIL CONSISTED OF PARTIAL COILS, AND METHOD OF MANUFACTURING THE REEL - Google Patents

Abstract

MULTI-LAYER CYLINDRICAL INDUCTION COIL CONSTITUTED BY PARTIAL COILS, AND METHOD FOR MANUFACTURING THIS COIL. TO OBTAIN A COMPACT, EASY REPAIR, MULTI-LAYER INDUCTION CYLINDRICAL COIL, THIS COIL INCLUDES SEVERAL PARTIAL COILS SHAPED BY SEGMENTS2 WITH TWO SPIRALS3, 4 HAS SEVERAL LAYERS, AND WOUND IN OPPOSITE DIRECTIONS. THESE SPIRALS3, 4 ARE CONNECTED BY A TRANSITION ORGAN5 COMING OUT OF THE PLAN OF THE TWO SPIRALS. SEVERAL SEGMENTS2 CAN BE JUXTAPOSED ON A THERMAL INSULATION TUBE10. EACH SEGMENT3 FORM AN INDIVIDUAL COOLING CIRCUIT.

Description

CYLINDRICAL COIL OF INDUCTION WITH SEVERAL LAYERS CONSTITUTED

  BY PARTIAL COILS, AND METHOD OF MANUFACTURING THE SAME

COIL.

  The present invention relates to a cylindrical coil

  induction coil with several turns or layers, for heating or melting a metallic substance placed

in its internal space.

  Such an induction coil is known, for example, from the NO 4 report of Division I Ia of the VIIIth Congress of the International Union of Electrothermy, entitled "Theory of Multi-Layered Windings for Induction Heating and their Application". to a 1 MW, 50 Hz, Longitudinal Flux Billet Heater "and written by IG Harvey It is stated in this report that

  multi-layer induction coils make it possible to obtain

  improve efficiency compared to coils

  single-layer induction In this document from the literature

  specialized structure, it is not specified how the coil is specifically wound when the coil is

  layered, it results, in the presence of

  large section coils such as those to be

  used in induction coils of this kind

  problems relating to the realization of transition zones

  between the individual layers, since the conductors

  coils should be strongly bent in these

  These problems are particularly serious when

  that we use coil conductors inside

  each of which is a cooling channel.

  When using internally cooled conductors and winding up the coil in layers, in which case only one inlet connection and one coolant outlet connection are provided, technical difficulties are also encountered in certain circumstances. as the temperature of the coolant varies greatly as this fluid flows through the conductor, and different areas of the coil

  are cooled more or less strongly.

  In known induction coils, there is another problem when it is necessary to carry out repairs

  in the arrangement of the coils, for example when conductive

  Internally cooled coil coils exhibit leakage faults. When this is the case, in the arrangement

  known, it is necessary to completely remove the coil from the insulation tube.

  usually used thermal insulation and possibly

  completely replace this coil.

  The object of the invention is to propose an induction coil of the aforementioned type, which allows a compact winding and is easy to repair, even when using

  relatively strong section conductors

  also poses a method by which the induction coil

  can be manufactured without great complexity.

  In a multi-layer induction coil of the aforementioned type, this object is achieved by the fact that said coil comprises a plurality of partial coils formed as coil segments having two coil coils with multiple turns or layers; and

  in that the two spirals of a segment are wound

  in opposite directions, the turns or layers of

  internally these two spirals being connected by a

  transition organ moved obliquely out of the desider-

your spirals.

  Under these conditions, the coil segments formed by the two spirals constit Lrent respective sets

  compacts in which the coil conductor does not

  no kink in the accused In a refinement of the invention

  the two ends of each respective conductor of a segment are offset radially outwardly from the outer winding layers of the spirals of

  coil This allows a simple connection of the power cables

  electrical connection, as well as simple attachment of

  coolant cords in the case where the

  coil motor is made with internal cooling.

  With segments of this type it is possible to produce induction coils of virtually any length and it is even possible to simply align prefabricated partial coils with each other so that, despite mounting fast, we get a coil

  compact induction having a high percentage of copper.

  The percentage of copper provides an indication of the effective extent to which the copper conductor is filling the area of the coil section. The higher the percentage of copper approaches the value 1, the higher the

  power and the efficiency of the coil are improved.

  In the induction coil according to the invention, the

  percentage of copper is very close to the value 1 at

less in the radial direction.

  Each individual partial coil has its own inlet and outlet connections for cooling fluid, respectively. The cooling is almost completely uniform in the axial direction of the coil,

  so that there is no overheating in any place.

  In addition to a relatively good power factor of the coil, the advantage is also obtained that this coil

  can be repaired very quickly, for example by replacing

  One or more partial coils The individual partial coils are very easily accessible and, because they have in particular a

  separate cooling, the induction coil according to the

  vention is characterized by a high reliability of

ment.

  In an improvement of the invention, a connection

  the outer coil of a spiral of a coil segment is electrically connected to the contiguous spiral connection of the neighboring segment Thanks to this interconnection, the segments

  individual coil coils are electrically connected in series.

  It is also conceivable to connect the corresponding ends of the outer winding layers with one another by means of a supply conductor, which makes it possible to

  to obtain a connection in parallel.

  An induction coil in which the conductors each comprise an internal cooling channel can

  to be cooled particularly well and uniformly

  me when each segment forms a cooling circuit

  separated and clean Thanks to the type of cooling,

  individual winding coils of adjacent coil segments

  cents can have substantially the same cooling temperature.

  In a method of manufacturing an induction coil

  With several turns or layers according to the invention, it is provided that, starting from the winding of smaller diameter, a spiral of a coil segment is wound in the direction

  hourly and that the other spiral is anti-clockwise

  schedule; that the inner ends of the bobbin

  not rolled out of the plane of the spirals; and that the inner ends are welded Since, during welding, the two coil spirals may be spaced apart from each other, they are pushed back one

  to each other after the welding operation, which gives them

  re a form ready for editing, under which they are very

closer to each other.

  According to another method of manufacturing an induction coil according to the invention, it is provided that, starting from the winding of smaller diameter, two-coil windings are wound in the same direction; and that the inner ends of the wound coil conductors are secured by welding, a coil spiral being shifted

180 from the other spiral.

  Depending on the winding device used, the second-mentioned method may be particularly well

  appropriate since all coil coils can

  wind in the same direction, for example in a clockwise direction. In a method according to the invention for producing a multi-turn or layer induction coil, in which

  the welding of both ends can be dispensed with

  coil conductors, it is expected that the conductors

  of length given, for the two spirals of a segment, wound in opposite directions, from the center

  of this conductor, to form two juxtaposed spirals.

  In this method, the conductor is for example placed by its center on a winding mandrel, after which the two ends of the conductor are wound in directions

opposed all around said mandrel.

  The invention will now be described in more detail by way of non-limiting example with reference to the accompanying drawings in which: FIG. 1 is a fragmentary lateral elevation of an induction coil comprising a partial coil and FIG. an end elevation of this induction coil.

  Figure 1 partially shows a cylindrical coil

  multi-turn induction die for heating a metal workpiece 1 to be machined into the internal space of the coil The induction coil portion illustrated in the drawing consists of a coil

  partial made in the form of a coil segment 2.

  This segment 2 consists of two coil 3 and coil 4

  in the opposite direction In the example of

  represented, a total number of eight

winding.

  The two turns or inner winding layers of the spirals 3 and 4 are in direct connection with a transition member 5 This member 5 extends obliquely relative to

in the plane of the two spirals 3 and 4.

  The upwardly extended ends of the outer coil layers are mutually offset, i.e. pulled outward from the plane of the drawing, or else

  pushed towards the interior of this plane.

  FIG. 2 The electrical connection of the partial coil is provided by connection terminals 6 and 7. In this embodiment, the conductors of the coil are in the form of a hollow conductor having a

  internal cooling channel at the ends of the

  the coils, sleeves 8 and 9 for connection to a water circulation system ensure the admission or

  the evacuation of water, respectively.

  An induction coil according to the invention consists of several segments 2 As shown by the lines

  in dotted lines in FIG. 1, these segments are very similar

  from each other They surround an insulation tube

  in which the workpiece 1 to be machined is guided to slide

  The individual partial coils may be offset from each other in such a way that the water circulation connections, as well as the connection terminals for the electrical connection are easily accessible, such as the indicate dashed lines in Figure 2 The importance of

  radially outward shift of the extremities

  external winding layers depends on the

  whose electrical connection and the connection to the

  Full circulation of the coolant should be carried out During assembly, the partial coils are first introduced into the furnace body Then the tube

  thermal insulation is slipped inside the coil.

  As a variant, as thermal insulation, a ceramic mass

  can be introduced into the rigidly incorporated

  is lying. To form an electrical connection in series, the connection terminals of two spirals close to segments

  different are connected to each other.

  In parallel, corresponding spirals of the individual segments are connected to each other.

  According to a method of manufacturing a segment 2 of

  In accordance with FIG. 1, a coil of coil is first wound on a winding mandrel whose outer diameter is slightly larger than the outer diameter of the heat insulation tube 10, so that turns or individual winding layers a, b

  h are very close to each other Then, the former

  tremity of the winding layer has the innermost is substantially pushed or pulled out of the plane formed by the spiral, for example being pushed to the interior of the

  plan of the drawing according to FIG.

  outside of a spiral coil

  rolled in the opposite direction is then welded to this end.

  mity shifted outward, so that the two spirals of the coil are then connected to each other

by the transition member 5.

  This process is used when both spirals

  must be joined by welding to form a seg-

  coil, without any of these spirals having to be

  pulled out of the winding mandrel before the seg-

  coil has reached its final completion position

  nal. However, instead of winding the one-e coil spirals in the opposite direction, the two spirals can also be wound in the same direction, one of the spirals then being shifted by 1800 before the ends of said spiral are secured by welding. In a process in which it is not necessary to weld the ends of the innermost winding layer, it is intended to place a coil conductor of given length by center sop tangentially on a mandrel. winding, to wind then, one after the other or simultaneously, the two halves in opposite directions When applying this method, it should be taken care, before winding-up or during the winding of the layers located at inside, that the future transition organ is appropriately oriented obliquely to the axis

of the coil.

  Once the coil segments are completed, several

  segments of this type can be placed on an iso-

  thermal insulation, electrically interconnected and connected

  dice to flexible hoses for circulation of

  chilling Electrical insulation of the coil conductors is ensured by layers of insulating tape

  wound on the outer face of the coil conductor.

  It goes without saying that many modifications can

  can be made to the described coil and process and

  shown without departing from the scope of the invention.

Claims (7)

  1 cylindrical induction coil with several turns   or layers for heating or melting a sub-   metal stance placed in its internal space, coil characterized in that it comprises a plurality of partial coils made in the form of segments (2) of bobbin having two spirals (3, 4) coil with several turns or layers; and in that the two spirals (3.4) of a segment are wound in opposite directions, the   turns or internal winding layers of these two spira-   the (3, 4) being connected by a transition member (5) offset obliquely out of the plane of said spirals   Induction coil according to claim 1, characterized   by the fact that the ends of the winding layers   external coils (3,4) are shifted radially outward.   Induction coil according to claim 2, characterized   terized by the fact that an external connection of a spiral   a coil segment is electrically connected to the connection   adjacent spiral of the neighboring segment.   4 Induction coil according to any one of   Claims 1 to 3, wherein the drivers   each of them can be a cooling can, characterized   in that each segment (2) forms a feedback circuit clean and distinct coldness.   A method of manufacturing a multi-turn or layer induction coil according to any one of   claims 1 to 4, characterized by the fact that,   the winding of the smaller diameter winding, a spiral of one coil segment is wound clockwise, the other spiral being wound in the counter-clockwise direction by the fact that the inner ends of the coil conductors   coiled coil are released, for example pushed or   outward, from the plane of the spirals; and speak   that the inner ends are welded.   Process for manufacturing a multi-turn or layer induction coil according to any one of   Claims 1 to 4, characterized in that from   of the winding of smaller diameter, two coil spirals are wound in the same direction; and by the fact   that the inner ends of the coil coil conductors   are secured by welding, a spiral coil   being offset by 180 from the other perpendicular spiral at the axis of the spirals.   7 Process for manufacturing a multi-turn or layer induction coil according to any one of   claims 1 to 4, characterized in that for   the two spirals of a segment, the length conductor   data is wound in opposite directions, from the center   be of this conductor, to form two juxtaposed coil spirals.