FIELD OF APPLICATION

[0001] The present invention relates to a fuel heating device applicable, for example, for cold starts, improvement of drivability, reduction in emissions of pollutant gases, inter alia other applications in automotive vehicles.

BACKGROUND OF THE INVENTION

[0002] Cold start systems are commonly utilised in the automotive market, in particular for vehicles utilising fuels of lower volatility, such as ethanol, methanol, or dual fuel technology. As is known by those skilled in the art, the satisfactory combustion of alcohol is temperature conditioned. In the past it was very common to observe drivers experiencing difficulty in starting the alcohol powered vehicles thereof on slightly colder days. The technology popularly known as 'little petrol tank' based on the additional injection of petrol to increase the volatility of the fuel mixture, present today in the majority of the flex fuel automobiles in Brazil, was an important advance rendering starts easier on colder days, nevertheless it still possesses diverse disadvantages, such as high emission of pollutant gases, increased safety risks, and leakage, in addition to the inconvenience that the user cannot neglect filling the ^x little tank' on cold days in order to provide cold starts of the vehicle.

[0003] In consequence, aware of this reality, companies and research workers have developed solutions of electric heaters for the fuel to be heated minimally above the flashpoint of the fuel in question and thus, even on cold days, achieve the provision of the ignition of the engine, eliminating the necessity of additional injection of petrol or of the popularly known 'little petrol tank for cold starts' . An example of heating technology utilised is the heater known as a ^x glow plug' . Flowing from applications in diesel vehicles, this type of heater takes the form of a metal rod positioned in the fuel gallery, heating fuel passing therethrough prior to being injected into the engine or the inlet manifold of the engine.

[0004] In spite of the development in terms of the ^x little petrol tank' , this heating technology employs a high temperature heater for rapid heating, producing risks of fuel boiling (should this occur, steam is injected instead of liquid fuel, leading to engine failures) , overheating, increase of internal pressures in the components, leakage and, in more extreme cases, even fire or melting of plastic parts. Other fuel heating technologies for cold starts have been created, however having geometric constructions and positionings differing from the glow plug, some, for example, incorporated into the fuel injector nozzle, all thereof until a given moment, and by virtue of having a small area of heat exchange with the fuel, operating at high temperatures, and furthermore also presenting the overheating and safety risks of the glow plug type heater.

[0005] To endeavour to avoid the risk of fuel overheating fuel heaters function together with a heating control unit, that is to say electronic ^x hardware' monitoring the heating of each heater, disconnecting the same in the case of overheating, working in a feedback monitoring network in real time. By virtue of the electronic monitoring hardware required the technology has become expensive, presenting complex implementation, requiring additional vehicular calibration time for adjustments to, and programming of, preheating times, in addition whereto it must be borne in mind that should an electronic component of the system 'burn out' or lose the connection thereof over years of use, this may lead to a tragedy by virtue of the high temperature which the heaters may attain in contact with fuels. [0006] In order to resolve the inconveniences and disadvantages brought about by this system of cold starts the applicant has developed a new system wherein the usual heaters are replaced by a heating element of the ^X PTC thermistor' type (thermistor having a positive temperature coefficient) in conjunction with a high efficiency heat exchanger. Such developments are divulged in the documents BR102015030039-5, BR102015024209-3 and BR102015028631-7. In this manner, by virtue of being disposed between the inlet and the outlet of the heating device, the fuel comes into contact with the heat exchanger which emits the heat received from the interior thereof by means of the thermistor. By means of this system the fuel is heated rapidly, utilising the low surface temperature PTC thermistor autocontrolled by the doping thereof with semiconductors, preventing the fuel exceeding a given temperature (selected in the doping and manufacturing process) and eliminating the problems brought about previously. It must be noted that, although other PTC type heaters do exist, such technologies having PTCs alone, without the use of high efficiency heat exchangers, also demand PTCs having a high surface temperature, this still maintaining the requirement for electronic temperature control hardware.

[0007] The solution proposed by the foregoing documents is idealised for pressure injection conditions exceeding 20 bar. However, by virtue of the development in the technology of internal combustion engines, modern injection nozzles are designed to provide pressures of up to 500 bar, that is a say high pressures exist in direct fuel injection engines. In view of this reality, the fuel supply and heating system requires to acquire greater robustness.

[0008] The document US2010/078507 proposes a fuel supply and heating system provided with an injection nozzle comprising a device for heating fuel having longitudinal fins, having the objective of increasing the transfer of heat to the fuel flowing in the internal part of the said longitudinal fins. The solution proposed by US2010/078507, however, is of complex assembly and does not present means of withstanding high pressures, not being indicated for utilisation in a direct injection system.

[0009] The document US6109543 describes a system of preheating fuel comprising a fuel heating element constructed, preferentially, in a PTC material. Such heating element is located in the lower part of the injection nozzle, encompassing the needle valve. The upper part of the injection nozzle is overmoulded upon the lower part, forming the entire assembly of the injection nozzle. US6109543 additionally provides that the surface of the heating element may possess undulations and protuberances in order to maximise the exchange of heat between the said element and the fuel to be heated. The document US6109543 furthermore provides for the utilisation of plates creating turbulence in the fuel such as to increase the exchange of heat with the heating element.

[0010] The document US6109543, however, consists of a coupled construction of the heating component and the injector nozzle, preventing the replacement of solely one of these components, obliging the user to replace the entire injection assembly. Furthermore, the solution proposed by US6109543 does not include a system of insulation preventing heat loss to the external medium from the heating system, as disclosed by the present invention.

[0011] The document US2015/300300 discloses a system of preheating fuel provided with a heating body having an inlet and an outlet of fuel, the inlet connected to a fuel distribution rail and the outlet associated with an injection nozzle. The body of the heater contains, within the interior thereof, a heat dissipator transferring heat to the fuel, the heat being supplied by means of a PTC plate, such plate being associated with an electrical contact, the said electrical contact operating in contact with an electrical system. The system provides that the fuel be heated prior to entering into the injector nozzle and, consequently, prior to said fuel being inserted directly into the combustion chamber of the internal combustion engine.

[0012] The solution proposed by US2015/300300 nevertheless does not present a system of thermal insulation to prevent heat losses to the external medium, reducing the thermal performance of the assembly and unnecessarily heating the region adjacent to the same. Furthermore, the solution proposed by US2015/300300 does not present the robustness required to withstand the high pressures occurring in internal combustion engines having direct injection into the combustion chamber.

[0013] In this manner, the need clearly remains for a fuel heating assembly and injection system capable of providing an efficient heater, of simple installation and low cost of manufacture, in addition to being capable of operating under high injection pressures, in particular for engines comprising direct injection technology.

OBJECTS AND DESCRIPTION OF THE INVENTION

[0014] Consequently, an object of the invention is to provide a fuel heating device comprising means rendering possible that the heat exchanger may be made in a simpler manner, ensuring the passage of the fuel as a minimum along the entire extent of the heat exchanger for the efficient heating of the fuel.

[0015] Another object of the present invention is to ensure the reduction in the loss of the heat generated by the fuel heater to the medium external to the supply gallery . [0016] Furthermore, another of the objects of the present invention is to provide a fuel heating device capable of withstanding operation under high pressures of fuel supply.

[0017] One or more of the aforementioned objects of the present invention, inter alia others, are achieved by means of a fuel heating assembly comprising: at least one heating region 6, at least one heat exchanger 5 associated with the heating region 6, at least one thermal insulation element 3 encompassing the heat exchanger 5, at least one region of passage of fuel disposed between the surface of the heat exchanger 5 and the surface of the thermal insulation element 3, one fuel inlet region 7 and one fuel outlet region 8 fluidically communicant, and at least one region of engagement 13 capable of conferring association between the fuel heating assembly 2 and a body of gallery 1.

[0018] In particular, the fuel heating assembly of the present invention comprises the fluidic communication between the inlet 7 and the outlet 8 of fuel determined exclusively by means of the region of passage of fuel.

[0019] Furthermore, the fuel heating assembly comprises the thermal insulation element 3 provided with at least one guide recess 71, for fluidic communication between a fuel supply aperture and a first extremity 52 of the heat exchanger 5, and the thermal insulation element 3 provided with at least one fuel outlet aperture 81 disposed proximate to a second extremity 54 of the heat exchanger.

[0020] The objects of the present invention are additionally achieved by means of a fuel supply and heating system comprising a fuel heating assembly, as hereinbefore defined, wherein, in one embodiment, the heating system comprises an injection nozzle 4 supplied from a fuel outlet aperture 8 of the heating assembly 2.

[0021] Furthermore, the objects of the present invention are achieved through the fact that the injector nozzle is of the type utilised for direct fuel injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] These and other objectives, technical and functional improvements and advantages of the fuel heating assembly and fuel supply and heating system, objects of the present invention, will be apparent to those skilled in the art from the schematic figures appended illustrating a preferred, but not limitative, mode of embodiment of the present invention.

[0023] Figure 1 shows an exploded perspective view of a first embodiment of the fuel supply and heating system provided with a first embodiment of the fuel heating assembly of the present invention.

[0024] Figure 2 shows a detailed exploded view of a housing 9 of the embodiment of the fuel supply system and heating assembly illustrated in figure 1.

[0025] Figure 3 shows the fuel heating assembly depicted in figures 1 and 2.

[0026] Figure 4 shows an exploded view of the fuel heating assembly depicted in figure 3.

[0027] Figures 5A and 5B show orthogonally opposed longitudinal cross-sectional views of the fuel heating assembly depicted in figure 3.

[0028] Figure 6 shows a cross-sectional view of the fuel heating assembly illustrated in figures 1 to 4, duly associated with the housing 9 of the supply system depicted in figure 1.

[0029] Figure 7 shows a plan view of the fuel heating assembly of figure 3, presenting the supply terminals 64 and 65.

[0030] Figure 8 shows a plan view of the heating assembly, the protective cap 14 not being installed, of the body of the electrical connector 11 and of the component of engagement 10, indicating the earthing 641 of the terminal 64 against a wall 501 of the heat exchanger 5, and the contact structure 651 of the terminal 65. [0031] Figure 9 shows an exploded perspective view of a second embodiment of the fuel supply and heating system provided with a second embodiment of the fuel heating assembly of the present invention.

[0032] Figure 10 shows a detailed exploded view of a housing 9 of the embodiment of the fuel supply system and heating assembly depicted in figure 9.

[0033] Figure 11 shows the fuel heating assembly depicted in figures 9 and 10.

[0034] Figure 12 shows an exploded view of the fuel heating assembly depicted in figure 11.

[0035] Figures 13A and 13B show orthogonally opposed longitudinal cross-sectional views of the fuel heating assembly depicted in figure 11.

[0036] Figure 14 shows a cross-sectional view of the fuel heating assembly depicted in figures 9 to 12, duly associated with the housing 9 of the supply system depicted in figure 9.

[0037] Figure 15 shows an exploded perspective view of a third embodiment of the fuel supply and heating system provided with a third embodiment of the fuel heating assembly of the present invention.

[0038] Figure 16 shows a detailed exploded view of a housing 9 of the embodiment of the fuel supply system and heating assembly illustrated in figure 15.

[0039] Figure 17 shows the fuel heating assembly depicted in figures 15 and 16.

[0040] Figure 18 shows an exploded view of the fuel heating assembly depicted in figure 17.

[0041] Figures 19A and 19B show orthogonally opposed longitudinal cross-sectional views of the fuel heating assembly depicted in figure 17.

[0042] Figure 20 shows a cross-sectional view of the fuel heating assembly depicted in figures 15 to 18, duly associated with the housing 9 of the supply system depicted in figure 15.

[0043] Figure 21 shows an exploded perspective view of a forth embodiment of the fuel supply and heating system provided with a forth embodiment of the fuel heating assembly of the present invention.

[0044] Figure 22 shows a detailed exploded view of a housing 9 of the embodiment of the fuel supply system and heating assembly depicted in figure 21.

[0045] Figure 23 shows the fuel heating assembly depicted in figures 21 and 22.

[0046] Figure 24 shows an exploded view of the fuel heating assembly depicted in figure 23.

[0047] Figures 25A and 25B show orthogonally opposed longitudinal cross-sectional views of the fuel heating assembly depicted in figure 23.

[0048] Figure 26 shows a cross-sectional view of the fuel heating assembly depicted in figures 21 to 24, duly associated with the housing 9 of the supply system depicted in figure 21.

[0049] Figure 27 shows a second variation of the connector of the supply terminal of the heating assembly of the present invention, there being present solely one terminal 65, wherein the earthing is brought about by means of contact with the structure of the body of gallery 1.

[0050] Figure 28 shows an exploded perspective view of a fifth embodiment of the fuel supply and heating system provided with a fifth embodiment of the fuel heating assembly of the present invention.

[0051] Figure 29 shows a detailed exploded view of a housing 9 of the embodiment of the fuel supply system and heating assembly illustrated in figure 28.

[0052] Figure 30 shows the fuel heating assembly depicted in figures 28 and 29. [0053] Figure 31 shows an exploded view of the fuel heating assembly depicted in figure 30.

[0054] Figures 32A and 32B show orthogonally opposed longitudinal cross-sectional views of the fuel heating assembly depicted in figure 30.

[0055] Figure 33 shows a cross-sectional view of the fuel heating assembly illustrated in figures 28 to 31, duly associated with the housing 9 of the supply system depicted in figure 28.

[0056] Figure 34 shows a sixth embodiment of the heating assembly of the present invention wherein the association with the body of the gallery 1 is realised by means of a bolted flange.

[0057] Figure 35 shows a perspective view of the heating assembly depicted in figure 34.

[0058] Figure 36 shows an exploded perspective view of a seventh embodiment of the fuel supply and heating system provided with a seventh embodiment of the fuel heating assembly of the present invention.

[0059] Figure 37 shows a detailed exploded view of a housing 9 of the embodiment of the fuel supply system and heating assembly illustrated in figure 36.

[0060] Figure 38 shows the fuel heating assembly depicted in figures 36 and 37.

[0061] Figure 39 shows a cross-sectional view of the fuel heating assembly illustrated in figures 36 to 38, duly associated with the housing 9 of the supply system depicted in figure 36.

[0062] Figure 40 shows an exploded perspective view of an eighth embodiment of the fuel supply and heating system provided with an eighth embodiment of the fuel heating assembly of the present invention.

[0063] Figure 41 shows a detailed exploded view of a housing 9 of the embodiment of the fuel supply system and heating assembly depicted in figure 40. [0064] Figure 42 shows the fuel heating assembly depicted in figures 40 and 41.

[0065] Figure 43 shows an exploded view of the fuel heating assembly depicted in figure 42.

[0066] Figures 44A and 44B show orthogonally opposed longitudinal cross-sectional views of the fuel heating assembly depicted in figure 42.

[0067] Figure 45A shows a perspective view of a ninth embodiment of the fuel supply and heating system, wherein there is comprised an additional securing element (117) .

[0068] Figure 45B shows an exploded perspective view of the fuel supply and heating system depicted in figure 45A provided with a ninth embodiment of the fuel heating assembly of the present invention.

[0069] Figure 46 shows a detailed exploded view of a housing 9 of the embodiment of the fuel supply system and heating assembly depicted in figures 45A and 45B.

[0070] Figure 47 shows a cross-sectional view of the fuel heating assembly illustrated in figures 45A, 45B and 46, duly associated with the housing 9 of the supply system depicted in figure 45A.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0071] The invention is now described in relation to the appended figures. In the figures and in the description hereinafter similar parts are indicated using identical reference numbers. The figures are not necessarily to scale, that is say given characteristics of the invention may be shown at an exaggerated scale or in a schematic form and, having the objective of illustrating this description with greater clarity and concision, details of conventional elements may not be shown.

[0072] For the purposes of the present invention, as fuel heating assembly 2 there is to be understood a component responsible for providing the heating of the fuel pumped from the tank of the vehicle prior to this entering the injection nozzle.

[0073] Consequently, for the purposes of the present invention, the fuel heating assembly 2 comprises at least a heating region 6 wherein a source of heat is capable of controlledly heating the fuel and at least one heat exchanger 5 associated with the heating region 6.

[0074] In the heating region, in a preferential but non- limitative manner, a plate assembly of a thermistor element 62 is employed and this may additionally comprise associated thermoconductive sheets between the said thermistor element 62 and a surface of heat exchanger 5 such as to optimise and render uniform the exchange of heat between the thermistor element 62 and the heat exchanger 5.

[0075] The association of the heating region 6 with the heat exchanger 5 has, as objective thereof, to transfer the heat transferred onto one of the surfaces of the heat exchanger 5 onto another surface of the heat exchanger 5 in contact with the fuel to be heated, such region being defined as a region of passage of fuel.

[0076] Additionally, a thermal insulation element 3 encompasses the heat exchanger 5, having the objective of minimising the loss of heat generated in the heating region 6 to the external medium, increasing the energy performance of the assembly and, furthermore, having the objective of limiting and restricting the region of passage of fuel in respect of the surface of the heat exchanger 5, restricting in this manner the same to have optimised contact with the heated surface of the heat exchanger 5 and, thus, ensuring the effective heating of the fuel with the minimum energy possible .

[0077] Consequently, one region of passage of fuel arises between a surface of the heat exchanger 5 and a surface of a thermal insulation element 3, that is to say the thermal insulation element 3 encompasses the heat exchanger of the heating component of the present invention.

[0078] The thermal heating element 3 is, furthermore, installed in manner juxtaposed to an aperture 9 of the gallery 1 such as to prevent the passage of fuel between the thermal insulation element 3 and the aperture 9, and to ensure that all the fuel entering into the gallery 1 and attaining the injector nozzle 4 flows through the region of passage of fuel and, consequently, is heated when the heating region 6 is operating.

[0079] The said region of passage of fuel is also delimited by a fuel inlet region 7 and a fuel outlet region 8, these being fluidically communicant between one another, that is to say the fuel egressing from a supply gallery 1 and restricted to an injector nozzle 4 is constrained in an obligatory manner to pass solely through the region of passage of fuel.

[0080] The fuel inlet region 7 is aligned with a fuel supply aperture 16 of the gallery 1, forming at least one guide recess 71 for fluidic communication between the fuel supply aperture 16 and a first extremity 52 of the heat exchanger 5, and the thermal insulation element 3 is provided with at least one fuel outlet aperture 81 disposed proximate to a second extremity of the heat exchanger 54, the first extremity 52 and the second extremity 54 being opposed to one another such that the fuel admitted by the fuel heating assembly 2 of the present invention flows obligatorily along the entire length of the surface of the heat exchanger, with a view to optimisation of the heating of the fuel.

[0081] Associated with this constructional characteristic, in one embodiment of the present invention the thermal insulation element 3 comprises a radial recess 31 disposed at the level of the aperture 16 of supply of fuel from the gallery 1 when installed in the aperture 9 of the gallery 1. Such radial recess 31 extends from the level of the fuel supply aperture 16 as far as a first extremity 52 of the heat exchanger 5, and the extremity opposite to the disposition of the radial recess 31 is installed in a juxtaposed manner to the aperture 9 of the gallery 1. Such geometry directs the fuel admitted by the supply aperture 16 as far as a first extremity 52 of the heat exchanger 5.

[0082] At the extremity whereat the radial recess 31 is disposed the thermal insulation element 3 comprises, in addition, a plurality of apertures 32 capable of permitting the passage of fuel.

[0083] Furthermore, the fuel heating assembly 2 comprises at least a region of engagement 13 capable of conferring association between the fuel heating assembly 2 and a body of gallery 1, such region of engagement 13 being defined by any constructional arrangement capable of conferring rigidity upon the association between the fuel heating assembly 2 and the aperture 9 of the body of gallery 1 sufficient to withstand pressures of up to 500 bar, rendering possible the application of the fuel heating assembly and supply system of the present invention in association with injector nozzles of the direct injection type .

[0084] The region of engagement 13 between the fuel heating assembly 2 and the body of gallery 1 may be defined in diverse manners, always provided that the aforedefined operational conditions are satisfied. Non-limitative variations of the present invention define such region of engagement 13 as being obtained by a threaded union to a housing 9 of the gallery 1, a threaded union of a component of engagement 10 associated with the fuel heating assembly 2 by means of the overmoulding of the body of the electrical connector 11, a threaded union of a threaded portion 53 of the heat exchanger 5 with the housing 9 of the gallery 1, a flange 107 between the fuel heating assembly 2 and a body of gallery 1, the direct overmoulding of the body of the electrical connector 11 upon the housing 9 of the gallery 1, inter alia other and equivalent manners, or the combination of the same.

[0085] In an alternative embodiment of the present invention the component of engagement 10 is composed of thermoplastic material. In order to render this embodiment viable a different profile of thread, or a greater length of the same, may be utilised to confer sufficient engagement rigidity to withstand the operating pressures.

[0086] In the embodiment wherein the region of engagement 13 arises by means of a flange 107 between the fuel heating assembly 2 and a body of gallery 1, a flange 107 is incorporated into the fuel heating assembly 2 associateable with a support surface 111 disposed upon gallery 1 such that the engagement between the fuel heating assembly 2 and the gallery 2 arises by means of screwing up a plurality of bolts 222 installed peripherally to flange 107.

[0087] The fuel heating assembly 2, in one constructive variant, comprises furthermore an additional securing element 117 to confer sufficient rigidity to ensure safe operation of the heating element 2 for operation under the high working pressure.

[0088] Such additional securing element 117 may be defined by the association between a flanged disc 147 and a base 157.

[0089] In one embodiment, the flanged disc 147 is provided with a first aperture 127 for the passage of the body of the electrical connector 11, a first pressure region 187 of the heating assembly 2 capable of providing support and exerting pressure upon the heating assembly 2 against the aperture 9 of the gallery 1 and comprising, furthermore, radial apertures 137 for the passage of securing bolts 200.

[0090] In this same embodiment, the base 157 is provided with a second aperture 167 for installation upon the structure of the gallery 1, a second pressure region 197 capable of providing support and exerting pressure upon the gallery 1 in the direction of the flanged disc, and radial apertures 177 for the passage of securing bolts 200.

[0091] In this manner, the additional securing element 117 confers additional engagement of the heating assembly 2 with the gallery 1 by means of the joint support of the first pressure region 187 upon the heating assembly 2 and of the second pressure region 197 upon the structure of gallery 1, the base 157 and the flanged disc 147 being brought against one another by means of the torque applied to the radially disposed securing bolts 200.

[0092] In one embodiment of the present invention the fuel heating assembly 2 comprises an aperture 51 in the heat exchanger 5 for the installation of a heating element defined by a thermistor element 62, such that at least one electrical supply terminal 64, 65 of the said thermistor element 62 is in a through manner installed through the said aperture 51, rendering possible the connection of wires/harnesses in a body of electrical connector 11. Furthermore, a protective cap 14 is installed upon the aperture 51 provided with apertures for passing through the electrical supply terminal 64, 65.

[0093] In one embodiment of the present invention the fuel heating assembly 2 comprises solely one positive terminal 65, the negative terminal being achieved by means of earthing in gallery 1. Such construction permits reduction in expense in the preparation of wires and harnesses and presents the advantage of utilising the earthing of the gallery 1 itself.

[0094] The said thermistor element 62 may present different geometries always provided that it ensures the transfer of heat by means of one wall of the heat exchanger 5 in a uniform manner. Inter alia geometries of the thermistor element known in the state of the art there are listed: plates being planar (as depicted in figures 31 to 35) or semicircular (as depicted in figures 4 to 6, 12 to 14, 24 to 26 and 43) . Furthermore, the thermistor element in one constructional variant of the present invention comprises a tubular geometry having a closed cross-section (such as depicted in figures 18 to 20) .

[0095] For any of the aforedefined constructional variants of the thermistor element an installation/guide structure 61 is employed having as objective thereof to ensure the correct installation of the thermistor element 62 and, moreover, the associated installation of the thermistor element 62 with the contact structure 651, this acting as source of electrical supply for the generation of heat of the thermistor element and, moreover, pressing the thermistor element 62 against the wall of the heat exchanger 5 for a more effective exchange through the medium of thermal conduction.

[0096] In conditions wherein the pressure from the thermistor element 62 does not effectively provide the thermal exchange between the thermistor element 62 and the heat exchanger 5 or, moreover, in conditions wherein it is desired to increase the thermal exchange between these two components, a thermoconductive sheet 63 is employed between the thermistor element 62 and the surface of the heat exchanger 5.

[0097] In one embodiment of the present invention the body of the electrical connector 11 is installed in an overmoulded manner, encompassing the extremity of the heat exchanger disposed proximate to the aperture 51, and the protective cap 14. Such form of association has as objective to confer increased rigidity upon the heating assembly 2.

[0098] In one embodiment of the present invention, as illustrated in figure 26, one extremity 511 of the heat exchanger 5 is bent such as to form a fold to accept the overmoulded material and ensure rigidity in the assembly between the heat exchanger 5 and the body of the electrical connector 11.

[0099] The overmoulding of the body of the electrical connector 11 may be realised by means of any thermoplastic injection process of the state of the art and has as determinant constructional characteristic the fact of ensuring that the overmoulded material encompasses at least part of the protective cap 14 and/or of the heat exchanger element 5.

[0100] In particular, in one embodiment of the present invention, the protective cap 14 is provided with apertures 141 capable of permitting the encompassing by the overmoulded material from the body of the electrical connector 11 with a view to ensuring greater rigidity in the securing between the components.

[0101] In one embodiment of the present invention, the region of passage of fuel is defined by a helicoidal channel disposed along the surface of the heat exchanger 5, such helicoidal channel being defined by a helicoidal finned surface impressed upon the surface of heat exchanger of the heat exchanger element 5. Such geometry having the fuel inlet at a first extremity 52 of the heat exchanger (commencement of the helicoidal channel) and the fuel outlet proximate to the second extremity 54 of the heat exchanger (end of the helicoidal channel) , this associated with installation of the heat exchanger 5 juxtaposed to the thermal insulation element 3, ensures that the fuel flows exclusively along the finned surface, the region of passage of fuel being defined as the peripheral path around the heat exchanger 5 defined by the helicoidal grooves, ensuring effective heat exchange and superior energy performance .

[0102] Finally, in one constructional variant of the fuel heating assembly 2 of the present invention, a sealing ring 15 is installed around the fuel heating assembly 2 to prevent the leakage of fuel, in particular due to the high pressure of pumping the same.

[0103] Another object of the present invention consists in a fuel supply and heating system comprising a fuel heating assembly as aforedefined, in particular comprising an injector nozzle 4 supplied from a fuel outlet aperture 8 of the heating assembly 2.

[0104] In a preferential embodiment, the fuel supply and heating system of the present invention makes use of an injector nozzle 4 of the type utilised for direct fuel inj ection .

[0105] It is clear, as the those skilled in the art will well understand, that numerous modifications and variations of the invention are possible in the light of the foregoing teachings, without departing from the scope of protection thereof as delimited by the claims appended.