CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority from Italian patent application no . 102020000031532 filed on December 18 , 2020 , the entire disclosure of which is incorporated herein by reference .

TECHNICAL SECTOR

The present invention relates to a heavy-duty vehicle comprising an improved aerodynamic system, in particular to a hydrogen-powered heavy-duty vehicle .

BACKGROUND OF THE INVENTION

There is a growing need to replace fossil energy sources for vehicle traction . This need is all the greater in heavy- duty and commercial vehicles , such as trucks , which have to meet high traction speci fications .

A well-known solution for replacing fossil energy sources is to use hydrogen drive systems such as fuel cells .

However, such fuel cells need to be constantly conditioned to prevent overheating . Therefore , it is known to provide additional heat exchangers that are normally located in an elevated position in the space behind the vehicle cabin, what is normally the space between the cabin and the trailer of a truck .

In this position, the heat exchangers receive the flow of air flowing over the top wall of the cabin in order to advantageously al low heat exchange with an air conditioning fluid flowing inside the heat exchanger .

However, this arrangement presents two problems .

Firstly, the arrangement of these heat exchangers increases the turbulence of the air flow behind the cab . This generates a resistant force , known as drag, to the motion of the vehicle .

In addition, the turbulent air leaving the heat exchanger, being heated, tends to recirculate around the heat exchanger, decreasing its thermodynamic efficiency .

There is therefore a need to provide for the installation of heat exchangers dedicated to the cooling circuit of a heavy-duty vehicle fuel cell , so that neither the thermal performance of the latter nor the overall aerodynamics of the vehicle suf fer .

The aim of the present invention is to meet the above requirements in an economical and optimised manner .

SUMMARY OF THE INVENTION

The aforementioned purpose is achieved by a vehicle equipped with an aerodynamic system as claimed in the attached independent claims .

Further preferred embodiments of the invention are made according to the dependent or related claims to the above- mentioned independent claims .

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment is described below for a better understanding of the present invention, provided by way of non-limiting example with reference to the accompanying drawings , wherein :

• figure 1 is a schematic side view illustrating a portion of a heavy-duty vehicle comprising an aerodynamic system according to a first embodiment of the invention;

• figure 2 is a perspective view illustrating a portion of a heavy-duty vehicle comprising an aerodynamic system according to a first embodiment of the invention;

• figure 3 is a schematic side view illustrating a portion of a heavy-duty vehicle comprising an aerodynamic system according to a second embodiment of the invention; and

• figure 4 is a perspective view illustrating a portion of a heavy-duty vehicle comprising an aerodynamic system according to a second embodiment of the invention . DETAILED DESCRIPTION OF THE INVENTION

In figure 1 , the number 1 refers overall to a heavy-duty vehicle , for example a truck, comprising a cabin 2 configured to tow a semi-trailer 3 .

Clearly the cabin 2 and the semi-trailer 3 can be any shape and are normally spaced out by a space 4 along a longitudinal axis A of the vehicle .

In more detail , the cabin 2 comprises a plurality of walls 2 ' defining a compartment for the driver and in particular a roof 2a and a rear wall 2b .

Preferably, between the cabin 2 and semi-trailer 3 , vehicle 1 may comprise , as is known, a side closure element 5 conspired to laterally delimit the space 4 and promote the aerodynamics of the vehicle .

The vehicle 1 is , at least partial ly, powered by hydrogen and therefore includes fuel cells , not illustrated, suitable for this purpose . Consequently, the vehicle 1 is provided with a conditioning system configured to maintain these cells at a predetermined operating temperature .

Advantageously, a portion of this conditioning system is placed in the space 5 , in particular at least one heat exchanger 7 and ventilation means 8 , advantageously carried by the cabin 2 , are housed in this space . In the example illustrated there are two heat exchangers 7 placed laterally in contact in a transverse direction with respect to the axis A and a plurality of electric fans as ventilation means 8 . As schematically illustrated, the ventilation means 8 are placed to the rear with respect to the at least one heat exchanger 7 along the direction of travel of the vehicle with respect to the axis A so as to promote the suction of an incoming air flow F ' after flowing over the roof 2a of the cabin and the expulsion of a superheated outgoing air flow F ' ' from the heat exchanger 7 .

According to the invention, referring to figures 1 and 2 , the vehicle 1 is provided with an aerodynamic system 10 housed in the space 4 and defining a space 11 in which the at least one heat exchanger 7 and the ventilation means 8 are housed, the aerodynamic system 10 is dimensioned so as to channel the flow F ' ' of air leaving the ventilation means 8 so that it is directed around the semi-trailer 3 , thus preventing the formation of vortices in the space 4 . In particular, this flow F ' ' is advantageously directed above semi-trailer 3 .

In more detail , the aerodynamic system 10 comprises a box shaped element 12 , advantageously carried by the cabin 2 and comprises a plurality of walls laterally delimiting the space 11 and axially defining a front opening 13 and a rear opening 14 . In particular, the front opening 13 is occupied, at least partially and preferably in its entirety, by the at least one heat exchanger 7 while the rear opening 14 is free .

In more detail , these openings 13 , 14 are essentially rectangular in shape . Preferably, both openings 13 , 14 are contained in planes whose perpendicular axis is inclined with respect to an axis vertical to the axis A. In greater detail , the openings 13 , 14 are contained in planes which are not parallel to each other .

Advantageously, the rear opening 14 is , at least partially, turned upwards so as to direct the flow F ' ' above the trailer 3 .

In particular, the shape of the box 12 is tapered between the front opening 13 and the rear opening 14 , decreasing in cross-sectional area, so as to allow the housing of a heat exchanger 7 of large surface area and at the same time accelerating the flow F ' ' of air exiting therefrom .

According to an alternative embodiment , illustrated in figures 3 and 4 , the aerodynamic system 10 is also configured to convey the air flow F ' passing around the cabin 2 , in particular above it , through the at least one heat exchanger 7 .

In such a case , the aerodynamic system 10 comprises an additional box element 15 , advantageously carried by the cabin 2 and defining an interior space 16 . In particular, the further box shaped element 15 comprises a plurality of walls laterally delimiting the space 16 and axially defining a front opening 17 and a rear opening 18 . In particular, the front opening 17 is free while the rear opening 18 faces the front opening 13 .

Advantageously, the two boxes 12 and 15 can be made as a single piece , so that the rear opening 18 and the front opening 13 coincide . Also with respect to the further box 15 , the openings 16 , 17 are substantially rectangular in shape and are contained in planes whose perpendicular axis is inclined with respect to an axi s vertical to the axis A. In more detail , they are also contained in planes which are not parallel to each other .

Advantageously, the front opening 17 is , at least partially, located above the roof 2a of the cabin 2 .

In particular, the shape of the box 15 is tapered between the front opening 17 and the rear opening 18 , increasing in cross-sectional area, so as to allow the housing of a heat exchanger 7 of large surface area and at the same time channelling the incoming flow F' without dispersion due to the formation of vortices.

In an alternative embodiment, which is not illustrated, the opening 14, and if provided, the opening 17, are defined in an end portion of the respective box shaped element 12, 15 so that this end portion is adjustable, in particular to vary the position and/or inclination of the respective opening 14 or 17, in order to cover different configurations of the cabin 2 and semi-trailer 3, i.e. having different geometries .

In particular, this adjustable end portion can be made in different ways, for example by means of a bellows portion or a telescopic portion and actuated by specific actuators, for example electromechanical or hydraulic. Advantageously the adjustment shall achieve the positioning of the opening 14 in such a way that it allows the flow F' ' to pass over the semi-trailer and, if present, the opening 17, to be positioned at the roof 2a of the cabin 2.

The operation of the embodiment of the vehicle provided with an aerodynamic system according to the above-described invention is as follows.

Referring to the embodiments 1 and 2, the flow of air F' flowing over the roof 2a of the cabin 2 impacts directly on the heat exchangers 7 and is forced by the suction of the ventilation means 8 to pass through the box 12 which directs it above the semi-trailer 3.

Referring to the embodiments 3 and 4, the flow of air F' flowing over the roof 2a of the cabin 2 is channelled to flow over the heat exchangers 7 and is forced by the suction of the ventilation means 8 to pass through the box 12 which directs it above the semi-trailer 3 .

From the foregoing, the advantages of a vehicle equipped with an aerodynamic system according to the invention are apparent .

Thanks to the aerodynamic system described, it is possible to reduce the aerodynamic drag by about 4 % and increase the ef ficiency of the heat exchangers 7 due to the lower temperature in the space 4 .

Again, in the version including the additional box, it is possible to channel the air flow to the exchangers , further increasing their ef ficiency .

In addition, the aerodynamic system described can be used and adj usted for any type and geometry of cabin 2 and trailer 3 .

Finally, it is clear that modi fications and variations can be made to the aerodynamic system according to the present invention which, however, do not depart from the scope of protection defined by the claims .

Clearly, there may be any number and type of heat exchangers and ventilation means . The same applies to the type and geometry of cabin and trailer .

Again, the tapered shape of the box or openings may be di f ferent .