JP2019502226A - Magnetic induction furnace suitable for heated metal billets of non-ferrous metal materials - Google Patents

Abstract

A magnetic induction furnace (1) suitable for heating a solid or tubular metal billet (2) made of non-ferrous material to be extruded is a stationary stator (33) and moves in the stator (33) Heating in which there is at least one heating section (25) comprising at least one coaxial annular electric motor (250) with possible permanent magnet rotor (34) and an annular rotor (40) supporting a plurality of permanent magnets The annular rotor (40) is coaxial with the stator (33) and the rotor (34) of the coaxial annular electric motor (250) and has a plane (P) in which the furnace (1) exists (P). ) To define a section (27) having a vertical axis (W) and through the movement of the annular rotor (40) housed in the rotor (34) of the coaxial annular electric motor (250). It is suitable for accommodating at least one billet (2) suitable for being heated by the. The billet (2) is completely stationary when inserted into the compartment (27) and in this state remains in it during the entire heating operation. [Selection] Figure 2

Description

  The present invention relates to a magnetic induction furnace suitable for extruding at least one metal billet made of non-ferrous material, solid or tubular, according to the preamble of the main claim.

  For many years, the physical principle that a parasitic current that leads to heating of a metal body due to the Joule effect is generated by introducing an object or conductor metal body made of a ferromagnetic body, paramagnetic body, or diamagnetic body into a magnetic field. Known over. This physical principle has been used to heat metal billets for the purpose of making the metal billets more formable and thus malleable for later extrusion processes.

  WO2010 / 100082 describes a device for heating a metal (made) object by electromagnetic induction. Such a document describes the use of a stator suitable for moving at least one ring-shaped permanent magnet rotor, in which, for example, a cylindrical object is arranged. Several permanent magnet rotors (driven by a single stator or corresponding stator) that generate parasitic currents and thus heat the object in order to obtain the desired temperature distribution or profile along the surface of the object (cylindrical) Can be provided. This is to distinguish heating of this type of object so that it has a subsequent uniform extrusion. This type of object can be made of copper or aluminum.

  The above-mentioned PCT shows a vertical axis induction heating apparatus (hereinafter referred to as an induction furnace for convenience of explanation) for heating a billet disposed perpendicular to the plane supporting the apparatus or the furnace.

  However, in WO2010 / 100082, the billet may rotate about its axis and / or longitudinally along its axis during its heating. This is intended to obtain a uniform temperature distribution along the above-mentioned axis between the billet ends. This inevitably requires having suitable means to rotate or generate such an axial movement of the billet, thus complicating the manufacture of the furnace and increasing its cost. In addition, billet axial movement into or out of the furnace, or billets that may protrude from the furnace during movement, will result in continuous heating and subsequent cooling of the billet end (with considerable waste of energy). The center that is required and still immersed in the variable or rotating magnetic field of the furnace is hot and has a temperature higher than the temperature of the edges. This can adversely affect the extrusion process that the billet subsequently undergoes.

  In addition, the means for movably supporting the billets during operation are also subject to heating that can damage them over time.

  Finally, specifically due to the fact that the object is subjected to motion (rotational or axial) in the furnace during the heating process, it seems to have been made of several parts that are axially adjacent and continuous with each other Such objects must necessarily be machined to properly position them relative to each other without the possibility that the contact ends of such parts move relative to each other during their movement. Otherwise, the parts of the object that are subjected to heating (eg two or more consecutive billets) are more likely to collide with the walls of the compartment in which they are located, and are longitudinally not coaxial with each other. The wall is defined by a rotor having permanent magnets or includes filter means interposed between such rotor and the object.

  It is an object of the present invention to provide a magnetic induction furnace for heating a solid or tubular metal billet made of a non-ferrous material (e.g., aluminum) that undergoes improved extrusion over prior art furnaces. There is.

  In particular, it is an object of the present invention to provide a furnace of the above type which is simpler and therefore less expensive with respect to state-of-the-art furnaces.

  Another object is to provide a furnace that can heat the billet uniformly over the entire length at the desired temperature.

  A further object is to provide a furnace of the above type that can heat several untreated billets (billets that have not undergone a specific surface treatment), arranged continuously along the axis of the furnace. is there.

  These and other objects that will be apparent to those skilled in the art are achieved by a furnace according to the main claim.

  For a better understanding of the present invention, the following drawings are attached as non-limiting examples.

FIG. 1 shows a perspective view of a first embodiment of the present invention in a first operating position. FIG. 2 is a view similar to that of FIG. 1, but at a different operating position of the furnace according to the invention. FIG. 3 is an enlarged view of a portion of the furnace of FIGS. 1 and 2. FIG. 4 is a perspective view of a modification of the furnace of FIG. FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. FIG. 6 is a perspective view of the components of the furnace of FIG. 4, ie its heating section. FIG. 7 shows an exploded view of some of the components of FIG. FIG. 8 shows a complete exploded view of the components of FIG. FIG. 9 shows a cross-sectional view taken along line 9-9 of FIG. FIG. 10 shows a perspective view of a further variant of the furnace of FIG. FIG. 11 is a top view in which some parts are omitted in order to clarify the modification of FIG. 12 shows a perspective view of the variation of FIG. 11 from another side. FIG. 13 shows a perspective view of the components of the furnace of FIG. FIG. 14 shows a perspective view of the application of a furnace according to the invention used together with a common gas furnace for heating the billet. FIG. 15 shows a perspective view of the application of FIG. 14 representing the furnace according to the invention in an exploded view. FIG. 16 shows a side view of the application of FIG. 14 with a furnace according to the invention in an exploded view.

  Referring to the above figures, a furnace according to the present invention is generally indicated at 1, which is an object 2 (non-limiting) having a cylindrical body 3 (solid or hollow or tubular) with juxtaposed ends 4 and 5. As an example, an aluminum alloy billet is suitable for heating using magnetic induction. Such a billet 2 is preferably arranged stably in the heating part 6 of such a furnace, such a heating part by means of magnetic induction of a radial rotating magnetic field and, for example, About 500 ° C. (for aluminum alloys) or higher (exemplary cases of other non-ferrous materials such as copper, bronze, brass, silver, etc.) to produce a parasitic current that causes heating to the desired temperature. Means suitable for producing with variable intensity around.

  Contrary to the longitudinal magnetic field normally generated in prior art magnetic induction furnaces, the generated radial rotating magnetic field allows more uniform and better heating than that obtained with prior art solutions. To. In particular, heating of the billet 2 can be obtained such that the temperature of the outer surface (surface) of the billet 2 is very slightly different from the internal temperature (core).

  The heating part 6 of the furnace 1 preferably has a base 11 and at least one screw 12 of a ball circulation (recirculating ball) or trapezoid type (or an equivalent moving actuator with axis Z), Associated with a fixing structure 10 including a pressing element 13 arranged at a distance from the base 11.

  The press element 13 is a heat-resistant (fireproof) material and is made of a material having a high coefficient of friction, which is preferably a billet obtained with one or more protrusions suitable for “contacting with the billet”. Having a surface for contact with.

  Advantageously, the end element 13A of the pressing element (or very element) can move in a floating manner relative to the vertical axis W of the pressing element 13 (ie swing about the axis W), and the billet The free end of the can be moved to adapt to the inclination that may be in contact with such an axis.

  The heating part 6 is suitable for holding the billet 2 during heating, and when the magnetic field for heating the billet is generated in such a heating part 6 by induction, the latter is not subjected to any movement. Thus, the latter is in an absolutely fixed and stationary position in part 2 during its heating.

  1 to 3 show a first embodiment of the furnace 1. It has a heating part 6 that is movable relative to the base 11 along a guide 15 (vertical and transverse to the heating part 66) connecting the castle 16 and the base arranged on the base 11, The part 6 is associated with a threading element (spiral) 600 attached to the screw 12, which in the castle 16 supports the pressing element 13 by the action of a kinematic unit 18 comprising a motor, transmission or gear motor. In cooperation with a service brake on a suitable gear (not shown) rotating at In the case of a power failure, the service brake is stopped, and the heating unit 6 slides along the guide 15 by the screw 12 moved by its weight to release the billet 2.

  The movement of the heating unit 6 is obtained along the support column 21 in cooperation with the lower flat portion 20. Such struts support a fixed end plate 21A suitable for cooperating with the press element 13 to hold the billet in a fixed position during heating. This is facilitated by the contact of the surface of the press element 13 made of a material with a high coefficient of friction (for example of the type used for the production of brake pads) with the billet.

  Advantageously, such a plate 21A is also made of a refractory material and can oscillate in a floating manner to fit the surface of the billet 2 thereover.

  At least one of the plate 21A and the pressing element 13 includes means for measuring the temperature of the billet (e.g., means that operate in contact, such as a thermocouple or remotely, such as an optical pyrometer), The means can control the magnetic induction heating of the billet by detecting its temperature in the heating step. Such control is performed by a special unit for commanding and controlling various functions of the furnace not shown.

  It should be noted that billet heating is performed according to zones, and zone temperatures can be selected and evaluated (as described below).

  In any case, the temperature measurement is preferably performed for safety and control purposes, i.e., in fact, recognizing the properties of the material to be heated and the energy required to obtain this kind of heating. Thus, the ultimate temperature of the billet can be calculated without directly measuring.

  The control unit also cooperates with an element suitable for measuring the pressure exerted on the billet by the pressing element 13. Such a measuring element is advantageously a load cell, for example. Against the backdrop of pressure data detected by this type of load cell and temperature data detected by the temperature measuring means, the control unit is applied by the pressing element 13 as a function of the energy used for the heating produced by the heating part 6. Adjust pressure.

  Pressure measuring elements are also used for safety purposes to control the pressure applied to the billet in order to avoid deformation (to stretch when hot) and possible problems throughout the furnace.

  Such an element indirectly controls the extension of the heated billet, thereby avoiding further overpressure of the contacting machine parts or their deformation that may exceed the tolerance provided by the request. Used.

  Further, the heating unit 6 supports a side plate 22 that supports idler rollers or shoes 23 suitable for moving along the side guide 15 so as to guide the movement of the heating unit 6 to the castle (upper 16). Have

  The heating section 6 of the furnace 1 includes a heating section 25 (as in the embodiment) with a well-known (and described below) coaxial (or annular) brushless electric motor 250. Thus, each section 25 has a coaxial annular shape and is superposed and / or connected to other sections, and therefore suitable for functioning as a pedestal or compartment 27 when the billet 2 is subjected to magnetic induction heating. A central hole having a vertical axis W with respect to the plane P on which the furnace 1 exists is defined. As will be described later, each of the section 25 and the motor 250 is provided with a ring-shaped (annular) permanent magnet into which the billet 2 is inserted.

  In the illustrated example, the various heating sections 25 are axially superimposed on one another (eg, preferably 2, 4, 6, or 8), and each section has its annular motor 250. The whole is placed in the container 28 defined by the lower part 20 and also by the side plate 22 described above and on the other side of the heating part 6 different from the part where the plate 26 is located. Of the plate 22A. Accordingly, the container 28 is a solid polygon (as a function of the number of existing sections 25, as a function of the number of existing sections 25, with the upper surface 28A open and delimited by sections placed on top of the stack of sections 25 present in the container. (Cube).

  Such a container is movable as a whole along the guide 15 toward the castle 16. Therefore, the container is integrally joined to the column 21 A that is integrally joined to the base 11 and fixed to the plate 21 A. The arranged billet is received in the pedestal 27. Such movement is obtained by rotating the screw 12 by the kinematic unit 18 which is linked to the sliding of the threading element 600 and thus leads to the movement of the heating part 6 along the guide 15. Such movement, i.e., sliding of the heating section 6 relative to the base 11, is controlled by a linear transducer (and not shown) located in the castle 16.

  More specifically, such a linear transducer is associated with the press element 13, and after loading the billet into the furnace 1 which brings such element 13 into contact with the billet, such element 13 It is possible to measure the exact length of the billet by the first movement of the billet. This takes advantage of the fact that the plate 21A is fixed and determines the reference plane.

  Through this measurement (fully automatic), the control unit controls the lift of the heating unit 6 by rotating the screw 12 so that the movement of the heating unit 6 covers the actual length of the billet. Due to the fact that such a length is derived from a previous billet cutting process that does not always allow a fixed and unambiguous measurement of the billet, it is not constant (although it is nominally established) Absent.

  In addition, for the measurement of the actual length of the billet, the pick-up arm that moves the billet from the furnace to the forging machine can avoid its imbalance during its movement or it can exist along the path of travel In order to be able to overcome sexual obstacles, it is possible to always locate and grasp the optimum position.

  Thus, the billet 2 can access the pedestal 27 from the surface 28A, which pedestal begins at such a surface and ends at the lower flat 20 described above.

  With reference to FIGS. 6-9, each heating section 25 includes an outer containment housing 30 having an annular shape and has a central hole 31. A corresponding ring-shaped (annular) electric motor 250 is placed in such a hole. The motor 250 includes a stator 33 and an inner rotor that includes a permanent magnet 34. The stator 33 is electrically supplied via a connector 36 protruding from the containment housing 30. In the containment housing 30, there is a cooling circuit (a type of cooling circuit with water, glycol or other fluid) provided around the stator 33 via a pipe connected to a connection 38 present in the housing 30. ) Exists.

  An annular rotor 40 (or a calibrator magnetic body that also functions as a cylindrical spacer in the illustrated embodiment) is disposed in the motor 250, and the annular rotor 40 has an annular cylindrical shape having an axial hole. Defined by at least one annular body 41 including a member 41A and supporting a plurality of fixed permanent magnets 43, the arrangement of which is conveniently used as a channel for cooling the magnets and A base 44 applied to the annular body 41 is defined. On the bearing member 47 interposed between the permanent magnet rotor 34 and the hollow portion 48 provided inside the annular body 41 in the vicinity of the juxtaposed ends thereof, the main body 40 (or as a whole, that is, An “annular magnetic rotor” is provided in view of this type of body 40 having an annular body 41, a member 41A and a magnet 43).

  Given that the billet 2 has different diameters, the member 41A can have different embodiments with different axial holes, thus defining differently shaped pedestals 27 for different billets. Further, as shown, such a rotor 40 may be formed to mold a simple ring that supports a magnet 43 on a suitable pedestal of its annular body 41.

  Advantageously, the magnet has a “roof-like” shape (not a parallelogram or cubic block), and the magnetic flow is a corresponding support ring 41A made of a magnetically permeable material (and each section). The fact of completely enclosing the closed end cover 49B) makes it possible to have a high magnetic performance. Furthermore, because of such a roof tile-like shape, the aforementioned magnetic flow is convenient to direct to the part to be heated (billet 2) and thus measures high penetration into the billet. .

  As described above, each section 25 has an end cover for closing the bearing 49B and a corresponding end magnetic flange that closes the magnetic field of the magnet (suitable to maintain it in the group of magnets 43). 49A and a flange for supporting the bearing portion 49C.

  Preferably, the magnet 43 is covered toward the pedestal 27 by an aluminum cylinder (not shown) having the same height as the magnet group 43. Such a cylinder is covered by a layer (not shown) made of an infrared radiation reflective material suitable for breaking it towards the billet located on the pedestal 27 to protect the magnet 43 from excessive heating. To do.

  This also contributes to improving the heating of the billet 2.

  In the embodiment of FIGS. 1-3 (non-limiting), the rotor protrudes from the containment housing 30 and they rotate freely on pins 51 fixed to corners 51A of such housing. The rotation is guided by the grooved disk 50. All grooved disks 50 have cavities 54 that cooperate with flanges or collars 55 that project radially from the corresponding rotor.

  The embodiment of the present invention of FIGS. 1 to 3 provides that the heating part 6 is movable along the guide 15 in order to heat the billet. Actually, in the initial use process of the present invention, the heating unit 6 is placed on the base 11. While maintaining this configuration, the billet 2 is disposed between the press element 13 and the plate 21A (by a common handling device (not shown) outside the furnace 1), and the press element 13 is disposed between the plate 21A. This kind of billet is activated to close.

  Advantageously, the pressing element 13 is defined by a hydraulic, pneumatic or hydraulic actuator with a movable plunge 13A suitable for pressing the billet 2 against the plate 21A. This also makes it possible to counter any possible rotational reaction of the billet when the magnetic rotor 40 housed in the station 25 is actuated, and the rotation is contained in the stator 33 of the motor 250 described above. It is generated by a rotating magnetic field generated by the movement of the rotor 34. Such rotation can be avoided, reduced or countered by alternating the direction of rotation of the rotor 34 of the motor 250 of the adjacent continuous heating section 25 from clockwise to counterclockwise rotation.

  In this manner, the heating unit 6 is lifted toward the castle 16 by the rotation of the screw 12 until the entire billet 2 is covered, that is, until it completely enters the pedestal 27. Therefore, it should be noted that the entire section 25 stacked in the housing 30 covers the entire length of the billet 2.

  Once the motor described above is activated, the magnetic field generated by the annular rotor 40 preferably penetrates in the radial direction of the billet, thereby generating a parasitic current that heats the billet due to the Joule effect. Such heating is controlled in a manner known per se, for example using a thermocouple associated with the pressing element 13 and the plate 21A. Advantageously, other thermocouples can be placed between the various heating sections 25 so that the temperature can be measured along the billet as well as the two heads or ends. This allows for better monitoring or control of the temperature trend, ie the heating of the billet along the axis of the entire billet.

  After such an operation (process), the motor 25 is stopped and the heating unit 6 is returned to the base 11. The billet thus heated (held by the element 13 on the plate 21A) is removed from the furnace 1 (for example by a handling device) and passed to this extruder via this or another handling device (not shown). It is inserted directly. In fact, because of the specific shape of the furnace, it has a small lateral dimension (slightly greater than 1 or 2 meters per side on the plane P), placed on the side of the extruder, and heated billet Quick loading into the extruder is possible.

  Assuming that the billet 2 does not move during heating, there is no need for a more or less complex mechanism suitable for supporting the billet during such a process. The billet can simply be placed on the plate 21A associated with the heating section 6 of the furnace 1 (this is actually the part that functions as the latter “furnace”), preferably pressed against the plate 21A by the pressing element 13 It is done.

  The motor 250 used is a ring-shaped coaxial type as described above, and is advantageously a three-phase synchronous type with a large number of poles and windings necessary to optimize torque and have the necessary power. It is preferable that Such a motor has a high performance of about 95%. They are "sensorless", i.e. they do not have a transducer for setting the position of the rotor and the rotational speed of the motor. Against the background of the algorithm, the aforementioned control unit of the furnace is responsible for synchronizing all the motors 250 of the heating section 6 and for accurately changing the rotational speed as a function of the temperature distribution requirements desired for the billet and possibly the conical temperature. provide.

  Each of the magnetic rotors 40 has a number of poles that are not bound to a specific value, and in any case this number will be even or odd and will be greater than two.

  The magnetic induction furnace has a high performance of about 95%. In fact, since they are permanent magnets, the magnets used (neodymium iron boron, NdFeB) are part of the energy supplied to the core (core) of the electromagnetic induction furnace with heat (of the energy supplied) (Up to 50%) No magnetizing current is required as generated in the core of the electromagnetic induction furnace to dissipate.

  4 and 5, the heating unit 6 of the furnace 1 is fixed to the base 11, and a movable support (movable support) 61 for the billet 2 is close to the bottom of the base 11. A well or compartment 60 (obtained in the plane P on which such a base is located) is provided. Such a support is associated with an actuator 62 (for example, a screw 63 driven by an electric motor 64) housed in such a compartment 60.

  In such a case, inoperatively, the support 61 is located near the base 11, in other words, near the base 11 of the lower part 20 of the furnace 6 as opposed to the embodiment of FIGS. A center hole 66 coaxial with the pedestal 27 for billets is provided. When the billet 2 needs to be heated, such a support (referred to as the axis Z) is lifted up to the upper surface 28A of the container 28 of the heating unit 6 via the actuator 62 on the base 27. On such a support 61, the billet 2 pressed against the support of the press element 13 is arranged.

  At this point, both the press element 13 and the actuator 62 move together along the axes Z and W of the pedestal 27 and the billet is inserted into the heating unit 6 and is blocked and held in the fixed pedestal. After heating the billet (obtained using the heating section 25), such movement is repeated in reverse, and the heated billet is removed from the pedestal 27 for removal from the furnace.

  Because of the present invention, several billets 2 (not necessarily regular shapes) arranged along the axes Z and W are subjected to heating without the need for surface treatment of the head, and the complete It enables alignment (adjustment) and maintenance of such alignment during the heating operation.

  Figures 10 to 13 show a further variant of the invention. In such figures, portions corresponding to those of the previously described drawings are indicated using the same reference numerals.

  In the variant in question, the furnace structure is horizontal axis in the sense that the heating part 6 is movable parallel to the horizontal plane P on which the furnace is located. The figure shows that two groups of heating parts 6 operate in parallel or alternately with each other (when one heating part is heated, the other heating part is loaded with a billet 2 to be heated or already heated. 1 shows furnace 1 from which billets are removed.

  The furnace 1 comprises a base 11 having an end upright 110 that supports a pressing element 13 (similar to that of FIG. 1 already described) driven by a hydraulic, pneumatic or hydraulic linear actuator. . Each press element has an actuator 130 and a movable plunger 13A (having a barrel 131 suitable for cooperating with the billet 2 at its end). In the embodiment shown in the drawing in question, the furnace 1 has a pair of coaxially movable juxtaposed plungers 13A arranged at least on the same longitudinal axis M along the furnace 1.

  In a preferred embodiment, the furnace heating section 6, which includes two portions 66 A and 66 B associated with a carriage 140 that is movable along a guide 145 present on the base 11, moves along the axis M described above. Such movement is obtained by electromechanical, hydraulic, pneumatic or hydraulic actuators known per se (such as screw-type and connected motors). Portions 66A and 66B include at least one heating section 25 with a coaxial motor 250 that is slidable for an internal compartment or pedestal 27 along a corresponding plunger 13A.

  Thus, according to the variant in question, the billet 2 can be moved, for example, along the overhead guide 311 and has its own means for actuating the movement, for example a small overhead crane or carriage 310 handling device. It may be carried by 300. The handling device can transport the billet 2 (moved along the overhead guide 311 by the carriage 310) on the axis M when the juxtaposed piston 13A is positioned to separate the body 131. A movable gripping member 313, such as a clamp, associated with a vertical moving member (e.g., support arm or pulley, overhead crane) 314. Advantageously, one or more movable saddles associated with the base 11 support the billet along such an axis M.

  When the billets are in such positions, the plungers are moved closer to their barrels 131 to secure the billets therebetween. At this point all saddles have been pulled back (after functioning) and the billet is held only by the press element 13. Obviously, in this step, all heating parts or parts thereof are proximal to the upright member 110.

  Thereby, such a heating part is moved along the base 11 in order to “roll” the billet 2 received in the pedestal 27.

  In the example of the drawings, the two heating parts 66A and 66B surround the billet and they are secured together using a side plate 370 associated with the outer containment housing 30 of such a heating section 25. . After heating, such heating portions 66A and 66B separate, each slide rises from the base, and element 13 releases a billet that can be removed.

  In accordance with the present invention, various embodiments provide a compact furnace with a low mass and low installation and maintenance costs. This is due to the suitability of the pedestal 24 for the various dimensions of the billet with the interchangeability of the member 41A that supports the magnet 43 (along with the members defining the pedestals of the various sections).

  Furthermore, certain embodiments of the heating unit 6 and the electric motor 250 and the relative magnet roller 40 provide a magnetic streamline frequency that is significantly lower than that required in an induction furnace. For this reason, they (magnetic flow) penetrate deeper into the billet and obtain a more uniform heating.

  This therefore makes it possible to obtain a very high general performance of the furnace, which is higher than 80-85%.

  Furthermore, the present invention makes it possible to obtain a furnace that allows uneven heating of the billet between one end and the other end. This technique (or temperature cone) is required to obtain a uniform temperature during extrusion. This possibility of heating the billet in different ways along its axis makes it possible to Derived from the use of the heating unit 6 having a motor, the faster the rotation of the magnetic rotor 40 coaxial with the electric motor 250, the higher the temperature reached by the billet section arranged in such a motor is preset. Higher in time units.

  Obviously, such a temperature distribution is undesirable, but if any section of the billet wants to have a different temperature relative to the other sections, what is needed is to adjust the rotational speed of the electric motor And includes a motor 40 provided with such a section for the purpose of obtaining a desired temperature.

  FIGS. 14-16 show a specific application of the furnace 1 according to the invention to a general gas furnace 400. In such figures, portions corresponding to those previously described are indicated using the same reference numerals.

  According to the present invention, a guide 440 suitable for supporting the furnace 1 is arranged on one side 400A of the furnace 400. More particularly, the furnace 1 comprises a main part 401 having a guide element 443 slidable on a guide 440 and clamping means 445 suitable for securing a billet (not shown) at the furnace outlet. . Such a means 445 is clamped and comprises an actuator 446 suitable for acting on a return member 447 hinged to the main part 401, for example a hydraulic actuator, and is hinged to the first half clamp 449. Acting on the rod 448. The other second half clamp 450 is integrally joined to the return member 447 and is hinged to the corresponding pins 451 and 452 rising from the flat surface 455 of the main part 401, similarly to the first half clamp 449. .

  The bracket 463 that supports at least one heating section 25 of the furnace 1 (only one of which is shown in the figure in question) is removed from the upper 460 and lower 461 sides of the main part 401. Such a section is closed by another main part 402 provided with clamping means as described above, which is indicated by the same reference numerals in the figure and will not be described further.

  Finally, walls 403 and 404 are provided. The first wall (403) is arranged between the main part 401 and the heating part 25, and the second wall (404) is arranged in the front, that is, in the empty wall of the furnace 1. They serve as spacers and guards, respectively.

  The furnace 1 applied to the gas furnace 400 makes it possible to heat the end of the billet already heated by the furnace 400 at a temperature different from the temperature of the gas furnace, so that the conical shape of the billet Allows heating (ie, creates a conical temperature trend therein).

  In use, the billet exiting the furnace is securely fixed by the half clamps 449 and 450 of the clamping means 445 of the main parts 401 and 402, while the section 25 is heating it according to the method described with respect to the previous figure. It is held stationary.

  Conversely, if it is necessary to further heat the billet or generate a conical temperature, the furnace 1 moves on one side of the outlet opening of the billet of the furnace 400 (eg, via a drive means not shown). can do.

  Various embodiments of the invention have been described.

  However, many other variations may be provided in light of the foregoing description and are considered to be within the protection scope of the present invention as defined by the following claims.

Claims (18)

  A magnetic induction furnace (1) suitable for heating a solid or tubular metal billet (2) made of a non-ferrous material subjected to extrusion molding, comprising a fixed stator (33) and a stator (33) There is at least one heating section (25) including at least one coaxial annular electric motor (250) having a permanent magnet rotor (34) movable at a plurality of, and an annular rotor (40) supporting a plurality of permanent magnets The annular rotor (40) is coaxial with the stator (33) and the rotor (34) of the coaxial annular electric motor (250), and a plane on which the furnace (1) exists. Defining a section (27) having a vertical axis (W) relative to (P), and through movement of the annular rotor (40) housed in the rotor (34) of the coaxial annular electric motor (250), Suitable for containing at least one billet (2) suitable to be heated by air induction, said billet (2) being completely stationary when inserted into said compartment (27) In this state, the furnace (1), which remains in it during the entire heating operation.   The heating part (6) relates to a fixing structure (10) comprising a base part (11) and at least one pressing element (13) separated from the heating part (6), The furnace according to claim 1, characterized in that it holds the billet (2) closed between.   The furnace according to claim 2, wherein the heating part (6) is movable with respect to the fixed structure (10).   There is a guide (15) perpendicular to the plane (P) connecting the base (11) to the castle (16) that supports the pressing element (13), and the heating part ( 6) move to move the castle (16), actuator means (12, 18) associated with such a basket (16) and the heating part (6) along the guide (15). 4. Furnace according to claim 3, characterized in that it is provided with guiding means (600) associated with the suitable heating section (6).   The actuator means (12) is a screw driven in a controlled manner by an electric motor (18), and a threading element (600) as the guiding means associated with the heating part (6) is on the screw. The furnace according to claim 4, wherein the furnace moves.   There is a horizontal guide (145) associated with the base (11) in which the heating unit (6) moves in parallel, and the movement occurs parallel to the plane (P) where the base exists. The furnace according to claim 3.   The furnace according to claim 6, wherein a plurality of horizontal guides (145) for moving the plurality of heating sections (6) are provided.   Each heating part (6) includes an autonomous part (66A, 66B) movable on the same axis (M) along the horizontal guide (145), which part is a billet (2) for heating. The furnace according to claim 6, wherein the furnaces are spaced apart from each other and accessible to each other for the purpose of containing the steel.   The pressing element (13) includes a movable member (13A) movable with respect to a fixed plate (21A) integrally joined to a support column on which the heating unit (6) moves, and the heating unit (6) The furnace according to claim 2, wherein during the heating, the billet moves between the plate and the movable member (13A) so as to maintain a closed state.   Two press elements (13) arranged in a juxtaposed position with respect to the base (11) are provided, one of the press elements being on the base for holding the billet during heating The furnace according to claim 2, characterized in that it is at least movable and is arranged parallel to a plane (P) in which the base is present.   The heating unit (6) is static with respect to the fixed structure (10), and is provided with moving means for moving the billet (2) into the compartment (27). 27) is suitable for introducing the billet (2) into the heating part for its heating when the billet is closed, the moving means accepting the billet (2) for heating or 3. Furnace according to claim 2, characterized in that it is suitable for approaching a pressing element (13) for the purpose of receiving a billet (2) for removal from (1).   The moving means comprises a support (61) movable within the compartment (27) and an actuator means (62) arranged below the furnace heating part (6) for operating such movement. The furnace according to claim 11.   13. A furnace according to claim 12, wherein the actuator means is hydraulic, pneumatic, hydraulic, or mechanical with motion generated by an electric motor.   13. Furnace according to claim 12, characterized in that the actuator means are arranged in a compartment (60) which lies under a plane (P) in which the heating part (6) of the furnace is present.   An annular rotor (40) is selected from a plurality of rotors (40) such that the radial dimension of the compartment (27) suitable for accommodating the billet (2) in the radial direction is uniform, the annular rotor The furnace according to claim 1, characterized in that (40) supports a plurality of fixed permanent magnets (43), preferably in the form of roof tiles.   2. A furnace as claimed in claim 1, characterized in that it is provided with temperature detection means suitable for measuring the temperature of one or more areas of the billet.   A distance measuring means is provided between the pressing element (13) and the fixed plate (21A) and is suitable for detecting the actual dimensions of the billet (2) in the length direction. Item 10. The furnace according to Item 9.   A control unit suitable for controlling the relative movement of the heating unit (6) with respect to the billet (2) and the rotational speed of each of the coaxial motors (250) according to temperature measurement and / or execution distance is provided. A furnace according to claims 16 and 17, characterized in that

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