Induction heating device

Abstract

Device for connecting the heating head (14) in induction machines, the assembly / disassembly operation of which is simplified, capable of completely cooling all the components that the electric current generated by a power supply unit (12) passes through, by means of the flow of a heat transfer fluid (F) made to circulate by a cooling unit (13).

Description

FIELD OF THE INVENTION

[0001] Embodiments described here concern a heating device for induction heating machines, which is provided with a quick connector to connect the heating head to other components of the machine.

[0002] Such induction machines are used, for example, in the industrial or professional sector, or in general to heat localized parts of an electrically conductive material by means of electromagnetic induction, in processes such as melting, heat treatment, welding, brazing, drying, sealing, straightening, deformation and keying.BACKGROUND OF THE INVENTION

[0003] Different types of heating devices are known, suitable to heat metal elements, or also plastic materials, including electromagnetic induction heating devices, resistive heating devices or by burning a fuel and generating flames.

[0004] Thanks to their functional and structural characteristics, these electromagnetic induction heating devices are normally preferred over resistive heating devices or devices using flames.

[0005] In fact, the main advantages of induction heating are the speed, precision and repeatability of the heating process itself, energy efficiency, safety (due to the absence of open flames) and the better quality obtained in the finished product.

[0006] Here and hereafter reference will be made to electromagnetic induction heating machines, simply referred to as induction machines.

[0007] Known induction machines are normally provided with a heating device comprising a heating head, provided with, or connected to, an inductor, and an electric power supply unit that is configured to generate a high frequency alternating electric current, depending on the geometry and the type of material to be treated, and to supply it to the inductor.

[0008] The alternating electric current is used to generate a strong alternating magnetic field in the region of a ferrule connected to the heating head, which induces eddy currents in the electrically inductive material to be treated, located in proximity or in contact with the ferrule.

[0009] The eddy currents generate in the material to be treated a rise in temperature due to the Joule effect, functionally dependent on the power actually transmitted from the power supply unit to the ferrule.

[0010] Furthermore, known induction machines are normally provided with a cooling unit configured to dissipate and dispose of the heat produced by the electric components connected to the power supply unit, and in particular the heating head, that is the inductor, and / or the ferrule.

[0011] The characteristics of the electromagnetic field generated are correlated to the properties of the alternating current that passes through the inductor, so that, the greater the intensity of the magnetic field to be obtained, the greater the currents that must be fed, which can reach even thousands of amperes.

[0012] To prevent damage to the power cables, or to the components disposed around them, it is therefore necessary to cool the cables, keeping them immersed in a heat transfer fluid that flows between the respective delivery and return pipes.

[0013] One of the main problems relating to known induction machines is that the connection of the heating head, to which the ferrule is connected, with the electric power supply and hydraulic cooling circuits, has some not negligible critical issues.

[0014] Moreover, the possible replacement of the heating head, in the event of maintenance or to modify the field / sector of use of the heating machine, is very complex.

[0015] DE102010028057A1 discloses a known induction heating device comprising a heating head and a housing connected to the heating head by means of respective electric cables and pipes for a heat transfer liquid.

[0016] Normally connection devices are used in which the entrances of the power cables and of the heat transfer fluid are distinct and separate from each other and therefore the replacement of the heating head is slow and complex.

[0017] Fig. 1 schematically shows, delimited by the closed outline of the lines of dashes, a known heating device 110 of an induction machine 120, which comprises a heating head 114 and a connection device 111 which acts as an interface between the heating head 114 and respective electric power units 112 and hydraulic cooling units 113.

[0018] The heating head 114 comprises a ferrule 114a at one end.

[0019] The heating head 114 is connected to the power supply unit 112 by means of a pair of conductive electric cables 124, 125, and to the cooling unit 113 by means of respective delivery 115 and return 116 circuits in which a heat transfer fluid F flows.

[0020] The heating device 110 includes a junction block 117, which is provided with respective inlet and outlet apertures for power supply and hydraulic supply.

[0021] In particular, the junction block 117 is internally provided with a longitudinal conduit 121, which crosses it along its entire length, which is fluidically connected, along the delivery circuit 115, by means of a first delivery pipe 115a to the cooling unit 113, and by means of a second delivery pipe 115b to the heating head 114.

[0022] Furthermore, the junction block 117 is provided with two transverse conduits 123a, 123b which put the longitudinal conduit 121 in communication with the apertures for the entry / exit of the electric cables 124, 125.

[0023] Each transverse conduit 123a, 123b is configured to receive inside it, by means of a cable gland element 122, a respective electric cable 124, 125, which, inside the junction block 117, are both disposed in the longitudinal conduit 121 and in a second delivery pipe 115b to the heating head 114.

[0024] The known solution in fig. 1 has the disadvantage that the portion of the electric cables 124a, 125a, which extends between the terminals 130, 131 of the power supply unit 112 and the junction block 117, remains uncovered and without cooling.

[0025] Since the electric cables 124, 125 passing inside the heating device are thinner and less insulated than those that connect the heating device 110 and the power supply unit 112 externally, they are more prone to overheating.

[0026] This overheating can lead to premature aging and damage of the electric cables and therefore, to a general malfunction of the induction machine, with an unexpected variation of its characteristic operating parameters (for example, current intensity and relative frequency).

[0027] Another disadvantage, due to the overheating of a part of the electric cables, concerns the risk, for an operator, of coming into contact with hot parts of the induction machine, compromising the safety of use of the induction machine itself.

[0028] Another disadvantage of known connection devices for the heating head concerns the complexity and laboriousness of assembling and disassembling the heating head, operations which must be entrusted to a specialized technician.

[0029] In fact, the connections of the electric power cables between the terminals of the power supply unit and the heating head must be carried out with extreme care, given the very high currents that easily damage the junctions that are not properly tightened.

[0030] Furthermore, if the assembly of the delivery and return pipes of the heat transfer fluid is not performed in a workmanlike manner, leaks of the heat transfer fluid itself may occur along the cooling circuit. These leaks can also occur in correspondence with the cable gland elements mounted on the junction block or on the containing body of the heating device. This can lead to the blocking of the machine, but also to breakdowns that have a chain effect on other components.

[0031] Another disadvantage that occurs during maintenance operations due to breakdowns, or replacement of the heating head in order to pass, for example, to a different application of the induction machine, concerns the need to keep the junction block in a fixed position, in order to correctly perform the assembly / disassembly of the components connected to it There is therefore a need to perfect a heating device and a device to connect the heating head which can overcome at least one of the disadvantages of the state of the art and which allow a rapid connection of the heating head in induction machines.

[0032] Furthermore, one purpose of the present invention is to provide a heating device that allows a simple and rapid replacement, without the intervention of specialized technicians, in the event of requirements due to breakdown, maintenance or change of the sector of use of the induction machine.

[0033] Another purpose is to provide a heating device that guarantees the correct cooling of the electric cables inside it, thus preventing possible overheating and power losses.

[0034] Another purpose of the present invention is to provide a connection device that allows to eliminate any possible losses of heat transfer fluid coming from the cooling unit, following the incorrect assembly / disassembly of the heating head.

[0035] Another purpose is to perfect a device to connect the heating head that is safe for an operator using the induction machine on which it is mounted, and that reduces the necessary maintenance interventions to a minimum.

[0036] Finally, yet another purpose of the present invention is to provide a connecting device for the heating head which is economical and at the same time guarantees high efficiency and durability over time.

[0037] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.SUMMARY OF THE INVENTION

[0038] The present invention is set forth and characterized in the independent claims 1 and 10. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea.

[0039] In accordance with the above purposes, this document provides an induction heating device provided with a heating head and a connection device suitable to function as an interface between the heating head and respective electrical and hydraulic circuits of an induction machine.

[0040] The connection device comprises a junction block configured to fluidically connect the heating head with a cooling unit and to electrically connect the heating head as above with a power supply unit, by means of a first and a second electric cable which act as input and output for the electric current.

[0041] The junction block comprises a first conduit and a second conduit, both associated with respective inlet and outlet apertures, and a transverse conduit which internally connects the first conduit and the second conduit to each other.

[0042] The first and second conduit are each configured to contain a heat transfer fluid and at least one segment of the electric cables.

[0043] According to some embodiments, the junction block is provided with common inlet and outlet apertures for the electrical circuit and the hydraulic circuit. Thanks to this conformation, the flow of the heat transfer fluid completely cools the electric cables that connect the power supply unit to the heating head, along their entire length inside the heating device.

[0044] According to some embodiments, a first electric cable is disposed passing through the first conduit between a first aperture and a second aperture associated therewith, and a second electric cable is disposed passing through the first conduit, the transverse conduit, and the second conduit, between the second aperture associated with the first conduit and a third aperture associated with the second conduit.

[0045] This prevents segments of the electrical connection cables, in particular the thinner ones, from remaining uncovered and without cooling, preventing a possible overheating of parts of the induction machine, and protecting the operator from possible injury risks, and also prevents possible power losses along the electrical circuit of the induction machine.

[0046] According to some embodiments, in the transverse conduit there is disposed a sealing element configured to allow the passage of the second cable through it, while preventing the passage of the heat transfer fluid, so as to guarantee a separation between the heat transfer fluid in the delivery circuit and in the return circuit.

[0047] According to some embodiments, the fluidic connection between the hydraulic cooling unit and the power supply unit and the junction block is achieved by using a pair of first connection elements and a pair of second connection elements, suitable to guarantee respective hydraulic and electrical couplings.

[0048] According to some embodiments, the first and second connection elements as above are configured to couple and connect fluidically and electrically to each other in a removable manner, without the aid of tools.

[0049] This achieves the advantage of assembling and disassembling the heating head, together with the connection device, from the electrical and hydraulic circuits of the induction machine in a rapid and quick manner, without the intervention of specialized technicians, since it is sufficient to disconnect the connection elements from each other, strictly after having turned off the power supply unit and intercepted the flow of the heat transfer fluid in correspondence with the cooling unit.

[0050] Advantageously, by using rapid attachments or couplings as first and second connection elements, possible losses of heat transfer fluid are prevented, which, on the other hand, can occur as a result of an incorrect assembly of the fluidic connections in the devices of the state of the art.

[0051] Thanks to the connection and disconnection simplicity, work times are considerably reduced and, moreover, it is not necessary for the operations to be carried out by specialized personnel, thus also reducing maintenance and labor costs.

[0052] Other embodiments concern an induction heating machine comprising a heating device connected to an electric power supply unit and to a hydraulic cooling unit respectively.

[0053] The present invention also concerns a method to instal / replace a heating device comprising a heating head in an induction machine, which provides to connect the heating head to a connection device by means of respective delivery and return conduits for the heat transfer fluid, and respective electric cables disposed inside the delivery conduit, wherein both the electric cables on the side of the heating head enter into the connection device in a same conduit, and on the opposite side, facing toward the outside of the heating device, each exit from a respective conduit, associated with an electric / hydraulic connector.

[0054] The method also provides to connect the heating device with the electric power supply unit and the cooling unit with respective connection conduits provided with a respective electric cable inside them, by means of rapid connectors, suitable to allow the connection of the respective electrical and hydraulic circuits.BRIEF DESCRIPTION OF THE DRAWINGS

[0055] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein: fig. 1 is a schematic section view of a device for connecting a heating head of the type known in the state of the art; fig. 2 is a schematic section view of a device for connecting a heating head, according to some embodiments described here; fig. 2a shows an enlargement of a detail of fig. 2 with the components disconnected from each other; figs. from 3 to 6 show different operating steps of connecting / replacing a heating head of an induction heating machine.

[0056] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.DESCRIPTION OF SOME EMBODIMENTS

[0057] We will now refer in detail to the possible embodiments of the invention, of which one or more examples are shown in the attached drawings. The examples are supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, one or more characteristics shown or described insomuch as they are part of one embodiment can be varied or adopted on, or in association with, other embodiments to produce further embodiments. It is understood that the present invention shall include all such modifications and variants.

[0058] Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.

[0059] The attached drawing 2 is used to describe some embodiments of an induction heating device 10 according to the invention (schematically delimited by the closed outline of the dashed lines) which can be used in an induction heating machine 20.

[0060] The heating device 10 comprises a heating head 14 and a connection device 11 that acts as an interface between the heating head 14 and the respective electric power supply unit 12 and the hydraulic cooling unit 13 of the induction machine 20, allowing them to be connected by means of respective electrical 18 and hydraulic circuits 19.

[0061] The heating head 14 comprises at one of its ends a ferrule 14a, which can possibly be removable.

[0062] The heating head 14 is connected to the electric power supply unit 12 by means of a pair of electric cables 24, 25 defining the electrical circuit 18, and to the cooling unit 113 by means of respective delivery 15 and return circuits 16 of the hydraulic circuit 18 in which a heat transfer fluid F flows.

[0063] The heating head 14 is configured to transfer the energy produced by the power supply unit 12 to a piece to be heated, made of electrically conductive material. In summary, the heating head 14 comprises, or is connected to, an inductor which is capable of generating a strong electromagnetic field in correspondence with the ferrule 14a.

[0064] In particular, the heating head 14, or the ferrule 14a, can comprise, for example, a single-turn inductor or a solenoid, both made by means of a suitably shaped tube, made of electrically conductive material, electrically and fluidically connected to the respective electrical 18 and hydraulic circuits 19.

[0065] The cooling unit 13 is necessary to dispose and dissipate the heat generated by the components passed through by the high frequency alternating electric current, produced by the power supply unit 12. In fact, typically, the power supply unit 12 is configured to generate an alternating electric current having an intensity of even many thousands of Amperes, at a frequency comprised between less than 1kHz and over 1000kHz, in processes that require temperatures from a few degrees centigrade up to the melting temperature of the various metal pieces to be heated.

[0066] The cooling unit 13 is provided with means suitable to make a heat transfer fluid F flow toward / from the heating head 114, through the connection device 11, for example feed pumps, valves, or suchlike.

[0067] The connection device 11 comprises a junction block 17 provided with respective inlet and outlet apertures 31, 32, 33, 34 for the cables 24, 25 of the electrical circuit 18 and for the conduits 15, 16 of the hydraulic circuit 19.

[0068] According to some embodiments, the junction block 17 can be made of various synthetic or metal materials. According to one possible embodiment, the junction block 17 is made of aluminum alloy, which is a light and corrosion resistant material.

[0069] According to possible variants, the junction block 17 can also be made of plastic materials, since no particularly intense heat is generated in correspondence with it, and the cables are cooled by the fluid circulating inside it.

[0070] The heat transfer fluid F is made to circulate, in a closed circuit, starting from the cooling unit 13 toward the junction block 17 and up to the heating head 14, and then returns to the cooling unit 13 passing once again through the junction block 17.

[0071] The heat transfer fluid F can be any fluid whatsoever capable of exchanging heat, for example water, or oil, or a coolant liquid, or suchlike.

[0072] The junction block 17 is provided, internally, with a first conduit 21 that extends between a first aperture 31 and a second aperture 32, and with a second conduit 22 that extends respectively between a third aperture 33 and a fourth aperture 34.

[0073] The junction block 17 comprises a transverse conduit 23 which internally connects the first conduit 21 and the second conduit 22 to each other.

[0074] According to some embodiments, the first 21 and the second conduit 22 can extend in a longitudinal direction of the junction block 17, passing through it along its entire length.

[0075] According to a preferred but non-limiting embodiment, the longitudinal conduits 21, 22 are of the same length and are parallel to each other, with the respective apertures 31, 32 and 33, 34 facing opposite walls.

[0076] According to some embodiments, the transverse conduit 23 extends in an inclined direction with respect to the longitudinal axis, connecting to the respective first 21 and second conduit 22 in staggered positions along a longitudinal axis. This facilitates the insertion of an electric cable through it.

[0077] The first conduit 21 and the second conduit 22 are configured to house at least one segment of electric cable 24, 25 inside them and allow the flow of the heat transfer fluid F.

[0078] In particular, in correspondence with the apertures 32, 33 facing toward the cooling unit 13, in each of either the first conduit 21 or the second conduit 22 there are respectively housed the first electric cable 24 and the second electric cable 25, while in correspondence with the apertures 31, 34 facing toward the heating head 14, both cables 24, 25 are housed in a same conduit 21 and disposed in correspondence with a same aperture 31.

[0079] Inside the junction block 17, the first electric cable 24 is disposed in the first conduit 21 between the first aperture 31 and the second aperture 32, while the second electric cable 25 is disposed passing through the first conduit 21, the transverse conduit 23, the second conduit 22, between the first aperture 31 and the third aperture 33.

[0080] According to a preferred embodiment, the connection device 11 comprises a sealing element 28 disposed inside the transverse conduit 23.

[0081] In accordance with possible embodiments, the sealing element 28 can be any suitably shaped perforated packing whatsoever, made of compressible material (for example, rubber), which ensures the hermetic seal of the transverse conduit 23.

[0082] Consequently, the sealing element 25 keeps the delivery and return flows of the heat transfer fluid F separated, optimizing the heat exchange between the heat transfer fluid F and the components electrically connected to the power supply unit 12.

[0083] In particular, the delivery circuit 15 is connected to the first conduit 21, so as to cool both the cables 24, 25 toward the heating head 14, while the return circuit 16 is connected to the second conduit 22.

[0084] According to one possible embodiment, the connection device 11 comprises connectors 26, 27 connected to the junction block 17 in correspondence with the second aperture 32 and the third aperture 33 respectively, suitable to allow the connection of the junction block 17 with respective delivery 15 and return circuits 16 of the hydraulic circuit 19.

[0085] According to a preferred embodiment, the connection between the junction block 11 and the cooling unit 13 is made by means of respective first delivery and return pipes 35, 36.

[0086] According to some embodiments, the junction block 17 is directly connected to the heating head 14.

[0087] According to possible variants, the junction block 17 is connected to the heating head 14 with respective second delivery and return pipes 37, 38.

[0088] According to a preferred embodiment, the pipes 35, 36, 37, 38 can be tubular elements which can be flexible and deformable, made of rubber and / or plastic material and / or steel braid and resistant to high temperatures. Advantageously, the deformability of the pipes 35, 36, 37, 38 allows an operator to maneuver the heating head 14 in a functional and versatile manner as the type of use varies.

[0089] According to one possible variant, the pipes 35, 36, 37, 38 can be segments of rigid pipes, which follow a determinate path, made of plastic material or metal material, resistant to high temperatures.

[0090] According to some embodiments, the first pipes 35, 36 are each connected to the junction block 17 in correspondence with the connectors 26, 27.

[0091] According to some embodiments, the connection device 11 comprises first connection elements 39 of the rapid type, each suitable to couple to a mating second connection element 40 provided on respective third delivery 41 and return pipes 42 connected to the cooling unit 13.

[0092] The first and second connection elements 39, 40 can be of the type suitable to allow a rapid reciprocal coupling / uncoupling, preventing unwanted leakages of the heat transfer liquid F.

[0093] In order to obtain a rapid and simple change of the heating head 14 in the induction heating machine 20, each first connection element 39 and second connection element 40 pair is configured to achieve the fluidic connection between the cooling unit 13 and the junction block 17.

[0094] The first connection elements 39 can be connected directly to the connectors 26, 27, or to the first pipes 35, 36, in correspondence with the end facing toward the cooling unit 13.

[0095] According to some embodiments, for example described with reference to figs. 2 and 2a, the first connection element 39 is made of at least partly conductive material and an electrical connection is made between each of the first 24 and second cables 25 and the respective first connection element 39. This connection can be made on an internal side of the connection element 39, for example by means of a welding zone 47 of the cable 24, 25, or also by means of a connection with a terminal provided on an internal side of the connection element 39.

[0096] Furthermore, the second connection elements 40 are configured to electrically connect to the power supply unit 12 by means of respective electric cables 43, 44. These electric cables 43, 44 can have a greater section than the electric cables 24, 25 disposed in the heating device 10.

[0097] According to some embodiments, each of the connection elements 39, 40 is configured to guarantee both an electrical coupling and also a hydraulic coupling, thus allowing both the supply of electrical energy in the cables 24, 25, and also the feed of the heat transfer fluid F.

[0098] The electrical connections can be made by means of the connection of the electric cables 43, 44 coming from the power supply unit 12 to a terminal belonging to the second connection element 40, or directly to the casing of the second connection elements 40.

[0099] According to some embodiments, for example described with reference to figs. 2 and 2a, the second connection element 40 is made of at least partly conductive material and an electrical connection is made between each of the first 43 and second cables 44 and the respective second connection element 40. This connection can be made on an external side of the connection element 40, for example by means of a welding zone 48 of the cable 43, 44, or also by means of a connection with a terminal provided on an external side of the connection element 40.

[0100] These connection elements 39, 40 are preferably configured to couple and connect fluidically and electrically to each other in a removable manner, without the aid of tools (fig. 2a).

[0101] According to a preferred embodiment, the first connection element 39 and the corresponding second connection element 40 are, respectively, the male element 45 and the female element 46, or vice versa, of a rapid coupling attachment.

[0102] The conductive material with which the connection devices 39, 40 are made acts as an electrical circuit, allowing the current to pass between the external cables 43, 44 and the internal cables 24, 25.

[0103] Some embodiments described here also concern a method to replace a heating device 10 in an induction heating machine 20, wherein the method provides to: electrically connect the heating head 14 of the heating device 10 to a connection device 11 by inserting respective electric cables 24, 25 in a junction block 17 through a first aperture 31 and making them exit from a respective second 32 and third aperture 33; hydraulically connect the heating head 14 with the first 31 and the fourth aperture 34 of the junction block 17 by means of respective delivery 37 and return pipes 38; connect the second aperture 32 and the third aperture 33 by means of respective electrical 18 and hydraulic circuits 19, respectively to the electric power supply unit 12 and to the hydraulic cooling unit 13.

[0104] It is clear that modifications and / or additions of parts may be made to the heating device 10, to the induction heating machine 20 and to the method to connect the heating head as described heretofore, without departing from the field and scope of the present invention as defined by the claims.

[0105] In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.

Claims

1. Induction heating device comprising a heating head (14), and a connection device (11), electrically and hydraulically connected to said heating head (14) by means of respective electric cables (24, 25) and delivery (37) and return pipes (38) for a heat transfer fluid (F), and configured to connect said heating head (14) to the respective electrical (18) and hydraulic circuits (19) of an induction machine (20), characterized in that said connection device (11) comprises a junction block (17) comprising a first conduit (21) which extends between a first aperture (31) and a second aperture (32), a second conduit (22) which extends between a third aperture (33) and a fourth aperture (34), and a transverse conduit (23) which internally connects said conduits (21, 22) with each other, wherein said conduits (21, 22, 23) are configured to each house at least one segment of said electric cables (24, 25) and to be connected to respective delivery (15) and return conduits (16) of said hydraulic circuit (19) and allow the flow of the heat transfer fluid (F) through them in contact with said electric cables (24, 25).

2. Heating device as in claim 1, characterized in that a first electric cable (24) is disposed through in said first conduit (21) from said first aperture (31) to said second aperture (32), and a second electric cable (25) is disposed passing through said first conduit (21), said transverse conduit (23), said second conduit (22), between said first aperture (31) associated with the first conduit (21) and a third aperture (33) associated with the second conduit (22).

3. Heating device as in claim 1 or 2, characterized in that it comprises a sealing element (28), disposed in said transverse conduit (23), and configured to allow the passage of said second electric cable (25), ensuring the hermetic seal of said transverse conduit (23) and the separation of the delivery and return heat transfer fluid (F) in the first conduit (21) and in the second conduit (22).

4. Heating device as in any claim hereinbefore, characterized in that said transverse conduit (23) extends in a direction inclined with respect to the longitudinal axis, connecting to the respective first conduit (21) and second conduit (22) in offset positions along said longitudinal axis.

5. Heating device as in any claim hereinbefore, characterized in that said first conduit (21) and second conduit (22) develop parallel to each other in a longitudinal direction and the respective apertures (31, 32; 33, 34) are aligned with each other on opposite sides of the junction block (17).

6. Heating device as in any claim hereinbefore, characterized in that said connection device (11) comprises first connection elements (39) of the rapid type, each suitable to couple with a mating second connection element (40) and guarantee both an electrical coupling and also a hydraulic coupling with said electrical (18) and hydraulic circuits (19).

7. Heating device as in claim 6, characterized in that said connection device (11) comprises connectors (26, 27) connected to the junction block (17) in correspondence with the first aperture (31) and the third aperture (33) respectively, suitable to allow the connection with respective first delivery and return pipes (35, 36).

8. Induction heating machine, comprising an electric power supply unit (12), a hydraulic cooling unit (13), and a heating device (10) as in any claim hereinbefore, respectively connected to said junction block with respective electrical (18) and hydraulic circuits (19) in correspondence with said second (32) and third aperture (33).

9. Heating machine as in claim 8, characterized in that said connection device (11) comprises delivery and return pipes (35, 36) provided, in correspondence with the end opposite the junction block (17), with a respective first connection element (39) and said cooling unit (13) is connected to respective delivery (41) and return pipes (42) each provided with a second connection element (39) connected by means of a respective electric cable (43, 44) to said power supply unit (12), wherein said connection elements (39, 40) are configured to couple and connect fluidically and electrically with each other.

10. Method to replace a heating device (10) in an induction heating machine (20) as in claim 8 or 9, wherein the method provides to: - electrically connect a heating head (14) of said heating device (10) to a connection device (11) by inserting respective electric cables (24, 25) in a junction block (17) through a first aperture (31) and making them exit from a respective second aperture (32) and third aperture (33); - hydraulically connect said heating head (14) with the first aperture (31) and a fourth aperture (34) of said junction block (17) by means of respective delivery (37) and return pipes (38); - connect the second aperture (32) and third aperture (33), by means of respective delivery (15) and return conduits (16) to a hydraulic circuit (19) of a hydraulic cooling unit (13), and by means of respective electric cables (43, 44) to an electrical circuit (18) of an electric power supply unit (12).

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