RADIATOR AND PROCESS FOR MAKING SAID RADIATOR

Abstract

 The present invention relates to a radiator (1) comprising at least one collector (2; 2', 2") and at least one radiating element (3), having a first (4) and a second (5) end. Said at least one radiating element (3) being internally configured in order to have two conduits (7, 8) separated and in fluid connection between each other by means of at least a first opening (9). Said first conduit (7) having at least a second opening (10), and said second conduit (8) comprising at least a third opening (11). Said at least one collector (2; 2', 2") being configured in order to have two conduits (12, 13) separated among each other by at least a separation surface (19; 14), and provides at least a hole (6") on its external surface and at least a hole (6') in correspondence of the separation surface (19; 14) between said two conduits (12, 13), for each of said at least one radiating element (3).
The first end (4) of said at least one radiating element (3) is at least partially inserted in said at least one collector (2; 2', 2") through at least one of said respective holes (6'; 6") so that said at least one radiating element (3) is arranged substantially transversally in respect to said at least one collector (2; 2', 2"), so that said at least a second opening (10) of said first conduit (7) of said at least one radiating element (3) is in fluid connection with said second conduit (13) of said at least one collector (2; 2', 2"), and so that said at least a third opening (11) of said second conduit (8) of said at least one radiating element (3) is in fluid connection with said first conduit (12) of said at least one collector (2; 2', 2"). The present invention further relates to a process for making said radiator (1).

Description

[0001] The present invention relates to a radiator and to a rpocess for making said radiator.

[0002] In the following, the term radiator defines a heating body, usually comprising one or more radiant elements, capable of emitting heat by natural convection and radiation. In particular, reference will be made in the following to towel-heaters with cantilever radiant elements, although the technical teaching of the invention can be applied to other types of radiators.

[0003] As shown in figures 1 a and 1 b in the art there are known towel-heaters S having two vertical collectors C1 and C2 and a plurality of radiating elements R arranged transversally and projecting with respect to the vertical collectors C1, C2 and in fluid connection with the same. A heated heat carrier fluid, for example water, is made sliding in a first collector C1 and then sliding in a first radiant element R through a first inlet hole F1, crossing one radiating element R (as shown in the embodiment of figures 1b and 2b) or more radiating elements R, by suitable passages P between the radiating elements R (as shown in the embodiment of figures 1 a and 2a), and exiting through a second outlet hole F2 to exit from the second collector C2.

[0004] This type of known radiators are obtained from tubular metal of various shapes, mostly circular or elliptical for the collectors, and circular, elliptical or rectangular for radiating elements. Said tubular elements are subjected to cutting, drilling and closing of the ends operations to obtain the collectors and radiating elements, on the basis of the type of movement of the fluid carrier provided for the radiator (as explained in the above). The shape and size of the holes are generally such to make the following resistance pressure welding between collectors and radiating elements possible and effective. In particular, holes FC realised on manifolds C have a smaller diameter than holes FR realised on radiating elements R, and the following area is deformed outward (as shown in figures 3a - 3c).

[0005] Once prepared the collectors C and the radiating elements R, it is proceeded to the assembly of the radiator S by welding a radiating element R each time on the collectors C. The radiating element R is positioned on the same collectors C, it is pressed on collectors C themselves, and electric current is circulated. The heat developed by Joule effect in the contact areas melts the material of the two components C and R which are welded. Since the success rate of the welding depends proportionally from the maximum temperature reached in the joint, and this, in turn, depends on the density and the intensity of the current circulating in the contact zone between radiating element R and collector C, it is necessary that the shape of the holes FC of the collectors C and of the of the radiating elements R is such to minimize the contact surface and that surrounds the holes F in such a way that the weld is continuous, watertight and strong enough to withstand to the test pressure for the radiator.

[0006] For the same reasons, it is important that the positioning of the radiating element on the collector is very accurate, so that the contact surface between radiating element and collectors is uniform around the connection hole during the entire duration of welding.

[0007] A linear or angular displacement, even minimum, of the radiating element modifies the geometry of the contact zone, unbalancing the joint and irremediably compromising the welding. Besides the geometric control of the welding joint, it is necessary to precesely control even the welding parameters. The electric current flowing through the joint must be within optimal value range, range that is very tight. A too high value of current would cause the reaching of too high temperatures and the consequent plastic deformation of the material around the welding joint, and in some cases this could also cause the piercing of the workpiece. A too low value of current does not allow to reach the melting temperature in any point of the joint, which then would not be welded, or it ould seem to be welded without being welded.

[0008] This assembly method is inherently subject to many dìawbvacks since the pressure exerted on the components during welding causes its deformation, which can sometimes be excessive. Furthermore, although potentially the welding is good under the mechanical aspect, it often happens that it is not airtight due to a difficult balancing of various factors such as the mechanical positioning, the welding current control, the just little difference from the tolerance of a hole, the excessive deformation of a component. It makes it necessary to further work the workpiece with greater costs and loss of efficiency.

[0009] During the assembly, the radiator is heated up to temperatures close to the melting point only in the connection zones between the collectors and the radiating element, while the rest of the radiator remains at room temperature. This generates tensions within the material responsible for the deformation of the components (collectors and radiating elements) and, consequently, of the whole radiator. It is therefore necessary to a further working step to recover the flatness of the radiator, generally, but not necessarily, by plastic deformation. Finally, the radiator is subjected to a pressure test and, if leaking occurs, it is repaired.

[0010] Therefore the crucial and critical step of the present process is the assembly of the collectors and radiating elements by pressure resistance welding, i.e. the main part of the manufacturing process of this type of radiators is today used in common manner.

[0011] Summarizing the known production process for manufacturing this type of radiator has several drawbacks and limitations. That is to say, the impossibility of having collectors and radiating elements that are not superimposed, limitations in the choice of the tubular sections by which collectors and radiating elements are realised, the need for extreme precision machining, the reduction of production capacity, the need to use machines subjected to variables difficult to control, such as the intensity of the welding current, the strict dimensional and geometric tolerances of the parts, the mutual positioning of the same, the coupling pressure.

[0012] Moreover, another method is presently known, for example, described in U.S. Patent n° 2,229,032, employed for smaller productions, in number of pieces. It is characterized by the welding method consisting in gentle manual brazing. It is generally carried out by a flame, by means of a torch, but it is a costly machining. It requires specialized staff knowing how to manually weld, since it is necessary to ensure that the components are maintained in the relative positions during welding, further, it is also necessary avoiding using the welding of components, their expansions causing the deformation of the final product. Furthermore, in case of very thin components, such as the radiating elements in the tubular section, it is not always possible to realise the welding grooves to allow passage of the filler material required for the welding operation. Therefore, the production times are very long and the obtained quality is not high. For this reason, this process is relegated to few handmade production.

[0013] Therefore, it is the object of the present invention that of obtaining a method for the production of radiators, preferably towel-heaters with cantilever radiating elements, overcomeing the problems of the prior art and allowing to freely choose any shape for the collectors, and radiating elements, any mutual positioning, with short times of the production process, low processing costs, an excellent quality and better performances.

[0014] It is therefore an object of the present invention a radiator comprising at least one collector and at least one radiating element, having a first and a second end, said at least one radiating element being internally configured in order to have two conduits separated and in fluid connection between each other by means of at least a first opening,said first conduit having at least a second opening, and said second conduit comprising at least a third opening, said at least one collector being configured in order to have two conduits separated among each other by at least a separation surface, said at least one collector providing at least a hole on its external surface and at least a hole in correspondence of the separation surface between said two conduits, for each of said at least one radiating element, said first end of said at least one radiating element being at least partially inserted in said at least one collector through at least one of said respective holes so that said at least one radiating element is arranged substantially transversally in respect to said at least one collector, so that said at least a second opening of said first conduit of said at least one radiating element is in fluid connection with said second conduit of said at least one collector, and so that said at least a third opening of said second conduit of said at least one radiating element is in fluid connection with said first conduit of said at least one collector.

[0015] Particularly, according to the invention, said radiator can comprise two collectors having an external surface, each collector comprising a respective conduit, wherein said conduits are separated between each other by means of the external surface of the respective collector.

[0016] Still according to the invention, said radiator can comprise a collector divided by a dividing wall in two separated conduits.

[0017] Always according to the invention, said radiator can comprise an external tubular element, corresponding with the external surface of said at least one radiating element, and an inner tubular element, arranged inside said external tubular element, in order to form said two conduits of said at least one radiating element, said inner tubular element has a length shorter than the length of the external tubular element and said at least a third opening of said second conduit of said at least one radiating element is obtained in the end openings of said inner tubular element and of said external tubular element in correspondence of the first end of said at least one radiating element.

[0018] Furthermore, according to the invention, said at least one radiating element can comprise an external tubular element, corresponding with the external surface of said at least one radiating element, and an inner tubular element, arranged inside said external tubular element, in order to form said two conduits of said at least one radiating element, said inner tubular element has a length longer than the length of said external tubular element and said at least a second opening of said first conduit of said at least one radiating element is obtained in the end opening of said external tubular element in correspondence of the first end of said at least one radiating element and said at least one third opening of said second conduit of said at least one radiating element is obtained in the end opening of said inner tubular element in correspondence of the first end of said at least one radiating element.

[0019] Further, asccording to the invention, said at least one opening can be obtained in said inner tubular element.

[0020] Particularly, according to the invention, said first end of said at least one radiatinbg element can be tapered so as to facilitate coupling between said at least a radiationg element and said holes of said at least one collector.

[0021] Always according to the invention, said at least a second opening can be obtained on the external surface of said at least one radiating element.

[0022] Still according to the invention, said at least a third opening can be obtained on the external surface of said at least one radiating element.

[0023] Finally, according to the invention, said at least one radiating element can have an "L" shaped dividing wall able to form said two conduits hydraulically contiguous by means of said at least one first opening created between said wall and said surface of said at least one radiating element.

[0024] Further, it is an object of the present invention a process for making a radiator as described in the above providing the following steps:

a) inserting in said at least one collector said first end of said at least one radiating element through at least one of the respective holes of said at least one collector for assembling said radiator;

b) distributing a filler material, preferably copper, on the contact points between said at least one radiating element and said at least one collector;

c) fixing at least a radiating element to said at least one collector so that they are blocked between each other;

d) welding said radiator by means of brazing at a fusion temperature higher than the fusion temperature of said filler material;

e) cooling said radiator.

[0025] Particularly, according to the invention, said process can provide that said step c) occurs
through the expansion of said at least one radiating element inside said at least one collector, or
through interference couplings, or
by means of the manual or automatic affixing of welding points.

[0026] Still according to the invention, step c) can occur by deforming from the inside of said at least one collectorsaid first end of said at least one radiating element so as to lock it in position.

[0027] Always according to the invention, in order to make said radiator (1) during step a) the process can provide the following steps:

f1) coupling said inner tubular element of each of said at least one radiating element to a respective hole of a first collector forming a first semi-finished produc;

f2) coupling said external tubular element of each of said at least one radiating element to the respective hole of a second collector forming a second semi-finished product;

f3) coupling the two semi-finished products obtained by passing each inner tubular element through the holes obtained in said second collector (2"), so as to insert them inside the corresponding external tubular element.

[0028] Further, according to the invention, before said step a) it can provide the following steps:

g1) perforation of one sheet;

g2) bending one sheet for obtaining each of said at least one collector and/or for obtaining each of said at least one radiating element.

[0029] Preferably, according to the invention, step g2) can occur in order to fold said sheet for obtaining a radiating element or a collector having a butterfly shaped cross-section, wherein each conduit has a triangular shaped cross-section and the intersection line of the sheet in correspondence of the apexes of the triangles forms the separation wall between the two conduits.

[0030] Finally, according to the invention, step g2) can occur in order to fold said sheet so that a refolded border of the sheet forms the separation wall between the two conduits of the collector or of the radiating element.

[0031] The invention will be now described, for illustrative but not limitative purposes, with particular reference to the figures of the enclosed drawings, wherein:

figures 1 a and 1b show two front views of towel-heater with cantilevered radianyting elements in two embodiments of prior art;

figures 2a and 2b show two front views of a detail of the towel-heater respectively of figures 1a and 1b;

figure 3a shows a side section view of the collector assembly and of the radiant during the welding process of the prior art;

figure 3b shows a top sectional view of the assembly of figure 3a;

figure 3c shows a perspective view of the assembly of figure 3a;

figure 4 shows a perspective view of a radiator according to the invention in a first embodiment;

figure 5 shows a top view of the radiator of figure 4;

figure 6 shows a perspective exploded view of the radiator of figure 4;

figure 7a shows a radiating element side view of the radiator of figure 4;

figures 7b and 7c respectively show section views of the radiating element of figure 7a taken along plans VIIb and VIIc;

figures 8a and 8b respectively show front and plan section views of the radiator of figure 4;

figure 9 shows a top view of the radiator according to the invention in a second embodiment;

figures 10a and 10b show respectively front and plan views in section of the radiator of figure 9a;

figure 11 a shows a top view of the radiator according to the invention in a third embodiment;

figure 11b shows a perspective view of the collector of figure 11 a of the radiator;

figures 12a and 12b respectively show front and plan section views of the radiator of figure 11;

figure 13 shows a top view of the radiator according to the invention in a fourth embodiment;

figures 14a and 14b respectively show front and plan section views of the radiator of figure 13;

figure 15 shows a top view of the radiator according to the invention in a fifth embodiment;

figure 16 shows a perspective view of the collector of the radiator of figure 15;

figure 17a shows a side view of a variant of the radiating element of the radiator according to the invention;

figures 17b and 17c respectively show section views of the radiating element of figure 17a taken along plans XVIIB and XVIIc;

figure 18a shows a top view of the radiator according to the invention in a sixth embodiment;

figure 18b shows a perspective view of the collector of figure 18a of the radiator;

figures 19a and 19b respectively show front and plan section views of the radiator of figure 18a;

figure 20a shows a front sectional view of the radiator according to the invention in a seventh embodiment;

figure 20b shows a top sectional view of the radiator of figure 20a;

figures 21 a and 21 b show front and plan section views of the radiator of figure 20a during a first stage of assembly;

figures 22a and 22b show front and plan section views of the radiator of figure 20a during a second stage of assembly;

figure 23a shows a side view of a further variant of the radiating element of the radiator according to the invention;

figures 23b and 23c respectively show section views of the radiant element of figure 23a along the plans XXIIIb and XXIIIc;

figure 24a shows a side view of a further variant of the radiating element of the radiator according to the invention;

figures 24b and 24c respectively show section views of the radiant element of figure 24a taken along plans XXIVb and XXIVc;

figures 25a - 25h show top views of the radiator according to the invention in further embodiments;

figure 26a shows a top view of the collectror of figure 16;

figure 26b shows a top view of a cut and perforated sheet for obtaining the collector of figure 16;

figure 26c shows a perspective view of the collector offigure 16 obtained by folding the sheet of figure 26b;

figure 27a shows a top view of a radiator according to the invention in an eighth embodiment;

figure 27b shows a front view of the radiator of figure 27a;

figures 27c and 27d show a partial perspective view of the radiator of figure 27a assembled and exploded;

figures 27e - 27f respectively show section views from above and from the front of the radiator of figure 27a;

figure 28a shows a top view of a radiator according to the invention in a ninth embodiment;

figure 28b shows a front view of the radiator of figure 28a; and

figures 28c and 28b show a partial perspective view of the radiator of figure 27a assembled and exploded.

[0032] Observing figures 4 - 9, reference is made to the radiator according to the invention, indicated by the reference number 1.

[0033] Said radiator 1 comprises two collectors 2 ' and 2 ", specifically arranged vertically, and a plurality of radiating elements 3 arranged transversely with respect to said collectors 2', 2", particularly arranged horizontally. In the specific embodiment, the radiating elements 3 are inclined by an angle equal to 90° with respect to said collectors 2', 2", in other embodiments said angle can be different from 90°.

[0034] Said radiating elements 3 have a first end 4 coupled with said collectors 2', 2 , so as to obtain a camntilever towel-heaters radiator 1.

[0035] In other embodiments further collectors can be provided on the second ends 5 of the radiating elements 3, without departing from the scope of the present invention.

[0036] Each collector 2', 2" has an inner conduct 12, 13 separated from the conduit 13, 12 of the other collector 2", 2' by means of the outer surface 19 of each collector 2', 2". In the present embodiment said collectors 2', 2" have the outer surfaces 19 adjacent, in other embodiments, as shown in figures 28a - 28d, said collectors 2', 2" can be spaced each other.

[0037] Moreover, each collector 2', 2" has a plurality of holes 6', 6", wherein each hole 6' or pair of holes 6" of each collector 2', 2" is adapted to house the first end 4 of a respective radiating element 3.

[0038] The shape and size of the holes 6', 6" is substantially identical to the section of the first end 4 of the radiating elements 3 so as to allow to the radiant element 3 to enter the respective hole 6', 6" of each collector 2', 2".

[0039] In the specific embodiment, the holes 6', 6" and the first end section 4 of the radiating elements 3 is circular. However, in other embodiments it may be rectangular (as shown in figures 17a - 17c and 24a - 24c) or of other geometric shapes.

[0040] As shown in particular in Figures 7a - 7c, each radiating element 3 is internally configured so as to have at least two ducts 7, 8 and separated in fluid connection with each other by means of at least a first opening 9. Furthermore, the first conduit 7 presents at least a second opening 10 formed on the tubular surface 17 of the radiating element 3, and the second conduit 8 comprises at least a third opening 11 formed at the first end 4 of the radiating element 3.

[0041] In the present embodiment, the third opening 11 coincides with the lateral opening of the first end 4 of the radiating element 3. In other embodiments, as shown in figures 27a - 27f, both ends 4 and 5 of the radiating element 3 are closed and the third opening 11 is formed at the outer surface or outer tubular element 17 of the radiating element 3.

[0042] The two conducts 7 and 8 are separated each other by means of a dividing wall, in the specific embodiment an inner tubular element 15 arranged inside and concentrically to the tubular element 17 outside the radiating element 17, so as to realise the two conducts 7 and 8.

[0043] In particular, both ends of the tubular elements 15 and 17 in correspondence of the second end 5 of the radiating element 3 are closed. The first conduit 7 is closed at both ends by using the end of the inner tubular element 15, outwardly flared so as to connect with the inner surface of the outer tubular 17.

[0044] In other embodiments, said inner tubular element 15 can have one or both ends outwardly flared so as to connect with the inner surface of said outer tubular element 17.

[0045] Therefore, once that each radiating element 3 is coupled, more in particular inserted, in the respective holes 6', 6" of each collector 2', 2", the second opening 10 of the first conduct 7 is in fluid connection with the second collector 2" and the third opening 11 of the second conduct 8 is in fluid connection with the first collector 2'.

[0046] Therefore the first end 4 of the radiating elements 3 are at least partially inserted inside said conducts 12 and 13 of said collectors 2', 2".

[0047] The radiator 1 thus obtained allows to generate a circuit whose path allows the heat transfer fluid, in particular water, to enter into each radiating element 3 by one of the two collectors ', 2" (the one connected to the outlet from the main network), to cross the radiating element 3 for its entire length in one of the two conducts 7, 8, and then return to the second of the two conducts 8, 7 to exit from the radiating element 3 from the opening 10, 11 which connects to the second connector 2" , 2' (the one that leads to the return to the main network) as also shown in the embodiment of figures 18 - 19.

[0048] The holes for the entry and exit of water in the radiating element can have any size, compatibly with the dimensions of the radiating element. This surely improves the circulation of water through the radiating element and then through the radiator, and thus the performance of the radiator.

[0049] The radiating elements 3 are closed, but not necessarily, by means of plugs 16 in correspondence of the second end 5 while the first end 4, which is aimed to mechanically enter in the collectors 2', 2" may be tapered or not, as shown in the embodiment of figures 18a-18b and 19a-19b, wherein the first end 4 of the radiating elements 3 is slightly tapered so as to have a descending section to facilitate insertion of the radiating elements 3 into the holes 6' and 6" of the collectors 2' and 2". When the radiator 1 has been assembled, the first ends 4 are deformed from the inside of the collector 2', 2" with an automatic machine so as to lock them in position.

[0050] The assembly phase of the radiator 1 is distinct from the welding step. The assembly is realized through the inclusion of all radiating elements 3 in the collectors 2, and the radiator 1 is prepared by the use of precision supports. This activity can be simply carried out either by an operator with the aid of jigs, or through the use of common automatic machinery. Once positioned all the components, it is necessary to fix radiating elements 3 to the collectors 2 in order to obtain a higher quality of the welding process. This operation can be performed, for example, through the expansion of the radiating element within the collector, rather than by interference couplings, or still by means of the manual or automatic small welding points.

[0051] In the case of the embodiment of the radiator 1 according to the invention, shown in figures 20a - 20b, in which the radiator 1 design involves the use of two collectors 2', 2" and two distinct tubular elements 15 and 17 to realise the radiating element 3, it is possible using a different method for assembling an alternative to the previously described system.

[0052] In the specific embodiment, the inner tubular element 15 presents only one end, in correspondence of the second end 5 of the radiating element 2, flared outwardly and the other end open and of longer with respect to the outer tubular element 17.

[0053] It provides a first stage of assembly, shown in figures 21 a and 21 b, in which a first inner tubular element 15 forming the second conduct 8 of the radiating element 3 is coupled either mechanically or via other coupling methods, to the respective photo 6' of the first collector 2', and a second outer tubular element 17, greater than the inner tubular element 15, is coupled to the respective hole 6" of the second collector 2". This step is repeated for all components of the radiating elements 3.

[0054] Subsequently, they are coupled the two, or more, semi-finished products 22 and 23 thus obtained, by passing the inner tubular element 15 through the hole 6" of the second collector 2", so that they fit within the outer tubular element 17 and generate the corresponding hydraulic circuit inside to the radiating elements 3, and then the total of the radiator 1.

[0055] Regardless of the assembly system and from the blocking technique chosen, in this step it is not required any hydraulic seal of the radiating collector joints, which need only be strong enough to hold the collectors and radiating elements blocked during the subsequent welding step by means of strong brazing, so that they are not permitted reciprocal displacements, neither by heating the pieces.

[0056] The replacement of the pressure resistance weld with the strong brazing is particularly advantageous because of its versatility in terms of variety of sealable, and therefore realizable, shapes, the decrease of the costs and of the times and the increase of reliability and quality.

[0057] Strong brazing, unlike the resistance welding, requires no special shapes of welding joints, and certainly not set any limits to the shapes and reciprocal arrangements of the components to be welded, i.e. collectors and radiating elements. Let's then add that with the brazing it is possible to tight weld and with good mechanical resistance joints than with other welding systems (including manual soldering) would not be accessible by welding tools such septa within tubular elements to divide them into separate ducts hydraulically or deformed sheet metal ducts to create any form.

[0058] The brazing of the strong type is carried out by automated methods (for example in an furnace under protected atmosphere, immersion, induction).

[0059] Preferably according to the invention, it is used the strong automatic brazing process in the furnace. In particular, the furnace is of the continuous type, fed by a conveyor belt moving at constant speed components from the entrance, through the hot zone, the cooling, until the exit.

[0060] This type of furnace requires very little manual labor and is therefore suitable for large-scale productions.

[0061] Specifically, during the strong brazing process, a filler material, for example copper, is distributed by capillarity within joints or points of contact between collectors 2', 2"and radiating elements 3, but also, if present, in the welding joints comprised of edges of one or more partitions and the tubular element within which it has been, or has been incorporated to divide it into two or more distinct hydraulic conduits 7, 8, but also in the weld joints made by the contact edges of a sheet deformed in such a way as to constitute one or more hydraulic conduits 7, 8, which might function as collectors rather than radiating elements.

[0062] Thanks to the previous step in which the elements are secured each other, when the assembled radiator 1 is welded by means of strong brazing, which provides for the automatic handling of the radiator for passage inside the brazing furnace, it is possible to move, heat, solder and cool the radiator 1 preventing that its components, collectors and radiating elements, move each other.

[0063] Once cooled the piece, the hydraulic and structural strength of welded joints is ensured by the filler material solidified within them. This welding process is inherently very efficient, easily automated and almost free from defects.

[0064] During strong brasing, temperatures are reaced higher than the melting temperature of the filler material, usually, but not necessarily copper (beyond 500°C), but maximum temperature that can be reached is always lower than the melting temperature of the material by which colletors and radiating elements are made up, usually but not necessarily stainless. Lower heating to which the radiator is subjected diminishes stresses of the material. Further, heating of radiator is less localised, and thus more uniform, with respect to the concentrated heating of resistance welding. This minimizes, if not even prevents as for oven brazing, differential heating and coinsequently buckling of the poiece due to the above cause.

[0065] Despite this improvement, also in the improved process according to the patent it is present a step ofaimed to retrieve the flatness of the radiator after brazing. But in this case the deformation will be due to the residual stress of the material of which collectors and radiating elements are made that emerge during the radiator cooling subsequent to brazing. Obviously the extent of this type of deformation is less than the deformation caused by the strong thermal differential that is generated during the resistance welding, with consequent lower corrective action in the phase of recovery of the flatness.

[0066] Finally, the radiator is tested under pressure and, if it is leaking, is repaired. Also in this last stepo, the new improved process greatly reduces leakages, and consequent repair, given the greater reliability of brazing compared with resistance welding.

[0067] This allows the improvement of the entire process according to various aspects such as the greater variety of shapes tha can be used for the collectors and radiating element, the possibility of creating conducts starting from deformed metal sheets at will, the possibility to divide a conduit into two or more separate conducts, the simplification of the drilling step, the simplification of the step of mechanical assembly, the simplification of the step of recovery of the flatness, the lowest number of leakings when testing and minor repairs.

[0068] Indeed, in further embodiments, the collectors 2', 2", can have different shapes with respect to the circular shape, such as quadrangular or polygonal as shown in figures 9 - 10 and in figures 25a - 25d. This shows the versatility of the shapes that can be obtained with the radiator according to the invention.

[0069] Furthermore, as is shown in figures 11 - 12 in a third embodiment of the radiator 1 according to the invention, the radiator 1 may comprise a single collector 2 vertically divided by a dividing divider 14 into two separate con ducts 12 13 having the same function of the first 2' and of the second 2" collector of the previously described embodiment.

[0070] Therefore also the dividing divider 14 has a plurality of holes 6 in number equal to the number of holes 6" formed in the collector 2 for the insertion of a radiating element 3 in each pair of holes 6', 6".

[0071] Even in this case, the section of the collector 2 may be of different geometric shapes, as shown in figures 25e - 25h.

[0072] Still, both the collector 2 that the radiating element 3 of the radiator 1 according to the invention can be obtained by bending a metal sheet, previously perforated.

[0073] For example, the radiator 1 of figures 13 - 14 comprises a collector 2 obtained by bending and drilling a single sheet, so as to have a throttle section, wherein each conduit 12 and 13 of the collector 2 has a triangular section and in correspondence of the apexes of the intersection line of the sheet in correspondence of the triangles form the separation divider 14 between the two conducts 12 and 13.

[0074] Or, as shown in figures 15 - 16 and 26a - 26c, the sheet 20 may be folded along fold lines 21 so as to form a collector 2 in which a sheet metal flap folded form of the separation wall 14 between the two conducts 12 and 13 of the collector 2. for example may have a quadrangular section in which the separation divider 14 is equivalent to a diagonal of the quadrilateral.

[0075] The same procedure can be used to realise the radiating elements 3, as shown by way of example in figures 17a - 17c, in which the radiating element 3 is obtained by bending and drilling a single sheet to form two conducts 7 and 8 in fluid connection by means of at least one opening 9 formed in the separation wall 15 between the two conducts 7 and 8. Subsequently, closure element or plug 16 is placed in correspondence of the second end 5 of the radiating element 3.

[0076] In figures 23a - 23c and 24a - 24c there are shown other variants of the radiating elements 3 of the radiator 1 according to the invention, in which, beyond the section of the radiating elements quadrangular, circular or of other polygonal shape, show how the internal circuit of the radiating element 2 for the sliding of the heat transfer fluid can be realized.

[0077] In particular, said radiating elements 3 may present a dividing surface 18 obtained by the insertion in the tubular 17 of a bent plate 18, into the radiating element 3 capable of forming two conducts 7 and 8 contiguous hydraulically by means of an opening created by an opening 9 between the septum 18 and the walls of the radiant element 3 and the plug 16 placed in correspondence of the second end 5 of the radiating element 3.

[0078] The dividing surface 18 is "L" shaped so as to prevent the fluid to exit through the third opening 11, but the inlet hrough the second opening 10 passing through the first conduit 7, the first opening 9 and the second conduit 8 to exit through the third opening 11.

[0079] In other embodiments of such a circuit construction it can be reversed, without departing from the scope of the present invention.

[0080] In the foregoing preferred embodiments have been described and other variants of the present invention have been suggested, but it is to be understood that those skilled in the art can make modifications and changes, without departing from the scope as defined by the enclosed claims.

Claims

1. Radiator (1) comprising at least one collector (2; 2', 2") and at least one radiating element (3), having a first (4) and a second (5) end,
said at least one radiating element (3) being internally configured in order to have two conduits (7, 8) separated and in fluid connection between each other by means of at least a first opening (9),
said first conduit (7) having at least a second opening (10), and said second conduit (8) comprising at least a third opening (11),
said at least one collector (2; 2', 2") being configured in order to have two conduits (12, 13) separated among each other by at least a separation surface (19; 14),
said at least one collector (2; 2', 2") providing at least a hole (6") on its external surface and at least a hole (6') in correspondence of the separation surface (19; 14) between said two conduits (12, 13), for each of said at least one radiating element (3),
said first end (4) of said at least one radiating element (3) being at least partially inserted in said at least one collector (2; 2', 2") through at least one of said respective holes (6'; 6") so that said at least one radiating element (3) is arranged substantially transversally in respect to said at least one collector (2; 2', 2"), so that said at least a second opening (10) of said first conduit (7) of said at least one radiating element (3) is in fluid connection with said second conduit (13) of said at least one collector (2; 2', 2"), and so that said at least a third opening (11) of said second conduit (8) of said at least one radiating element (3) is in fluid connection with said first conduit (12) of said at least one collector (2; 2', 2").

2. Radiator (1) according to the previous claim, characterized in comprising two collectors (2', 2") having an external surface (19), each collector (2'; 2") comprising a respective conduit (12; 13), wherein said conduits (12, 13) are separated between each other by means of the external surface (19) of the respective collector (2', 2").

3. Radiator (1) according to claim 1, characterized in comprising a collector (2) divided by a dividing wall 14) in two separated conduits (12, 13).

4. Radiator (1) according to any one of the previous claims, characterized in that said at least one radiating element (3) comprises an external tubular element (17), corresponding with the external surface of said at least one radiating element (3), and an inner tubular element (15), arranged inside said external tubular element (17), in order to form said two conduits (7, 8) of said at least one radiating element (3), in that said inner tubular element (15) has a length shorter than the length of the external tubular element (17) and in that said at least a third opening (11) of said second conduit (8) of said at least one radiating element (3) is obtained in the end openings of said inner tubular element (15) and of said external tubular element (17) in correspondence of the first end (4) of said at least one radiating element (3).

5. Radiator (1) according to any one of the claims 1 - 3, characterized in that said at least one radiating element (3) comprises an external tubular element (17), corresponding with the external surface of said at least one radiating element (3), and an inner tubular element (15), arranged inside said external tubular element (17), in order to form said two conduits (7, 8) of said at least one radiating element (3), in that said inner tubular element (15) has a length longer than the length of said external tubular element (17) and in that said at least a second opening (10) of said first conduit (7) of said at least one radiating element (3) is obtained in the end opening of said external tubular element (17) in correspondence of the first end (4) of said at least one radiating element (3) and in that said at least one third opening (11) of said second conduit (8) of said at least one radiating element (3) is obtained in the end opening of said inner tubular element (15) in correspondence of the first end (4) of said at least one radiating element (3).

6. Radiator (1) according to any one of the preceding claims, characterized in that said at least one second opening (10) is obtained in the outer surface (17) of said at least one radiating element (3).

7. Radiator (1) according to any one of the previous claims, characterized in that at least a third opening is obtained in the outer surface (17) of said at least one radiating element (3).

8. Radiator (1) according to any one of the claims 1 - 3 and 6 - 7, characterized in that said at least one radiating element (3) has an "L" shaped dividing wall (18) able to form said two conduits (7, 8) hydraulically contiguous by means of said at least one first opening (9) created between said wall (18) and said surface (17) of said at least one radiating element (3).

9. Process for making a radiator (1) according to any one of the claims 1 - 8 characterized in providing the following steps:

a) inserting in said at least one collector (2; 2', 2") said first end (4) of said at least one radiating element (3) through at least one of the respective holes (6', 6") of said at least one collector (2; 2', 2") for assembling said radiator (1);

b) distributing a filler material, preferably copper, on the contact points between said at least one radiating element (3) and said at least one collector (2; 2', 2");

c) fixing at least a radiating element (3) to said at least one collector (2; 2', 2") so that they blocked between each other;

d) welding said radiator (1) by means of brazing at a fusion temperature higher than the fusion temperature of said filler material;

e) cooling said radiator (1).

10. Process according to claim 9, characterized in that said step c) occurs
through the expansion of said at least one radiating element (3) inside said at least one collector (2; 2', 2"), or
through interference couplings, or
by means of the manual or automatic affixing of welding points.

11. Process according to the previous claim, characterized in that step c) occurs by deforming from the inside of said at least one collector (2; 2', 2") said first end (4) of said at least one radiating element (3) so as to lock it in position.

12. Process according to one of the preceding claims 9 - 11, characterized in that in order to make said radiator (1), according to claim 5 when depending from claim 2, during said step a) it provides the following steps:

f1) coupling said inner tubular element (15) of each of said at least one radiating element (3) to a respective hole (6') of a first collector (2') forming a first semi-finished product (22);

f2) coupling said external tubular element (17) of each of said at least one radiating element (3) to the respective hole (6") of a second collector (2") forming a second semi-finished product (23);

f3) coupling the two semi-finished products (22, 23) obtained by passing each inner tubular element (15) through the holes (6") obtained in said second collector (2"), so as to insert them inside the corresponding external tubular element (17).

13. Process according to any one of the claims 9 - 12, characterized in that before said step a) it provides the following steps:

g1) perforation of one sheet (20);

g2) bending one sheet (20) for obtaining each of said at least one collector (2; 2', 2") and/or for obtaining each of said at least one radiating element (3).

14. Process according to the previous claim, characterized in that step g2) occurs in order to fold said sheet (20) for obtaining a radiating element or a collector (2) having a butterfly shaped cross-section, wherein each conduit (12, 13) has a triangular shaped cross-section and the intersection line of the sheet in correspondence of the apexes of the triangles forms the separation wall (14) between the two conduits (12, 13).

15. Process according to claim 13, characterized in that step g2) occurs in order to fold said sheet (20) so that a refolded border of the sheet (20) forms the separation wall (14, 15) between the two conduits (12, 13; 7, 8) of the collector (2) or of the radiating element (3).

Drawing