This patent application claims priority from Italian patent application no. 102022000024348 filed on Nov. 25, 2022, the entire disclosure of which is incorporated herein by reference.
The present invention relates to a car provided with an internal combustion engine.
The present invention is advantageously applied to a car provided with an internal combustion engine powered with hydrogen, to which the following discussion will explicitly refer without thereby losing generality.
Hydrogen does not exist in the natural state on the earth because it is combined in molecules with other atoms (for example, water or hydrocarbons) and therefore, in order to have hydrogen, it is necessary to produce it by means of reforming or electrolysis other consuming energy (consequently, hydrogen is not an energy source but an energy vector).
The environmental impact of a car provided with an internal combustion engine powered with hydrogen is much lower than the environmental impact of a similar car provided with an internal combustion engine powered with a fossil fuel, as an internal combustion engine powered with hydrogen does not generate greenhouse gas (CO2) and generates very little CO, HC and fine particulate matter (generated due to a minimum quantity of lubricating oil which is burned in the combustion chambers).
Hydrogen has a reduced density (having a very simple molecule composed of only two hydrogen atoms) and therefore, in order to be able to store a suitable quantity (mass) of hydrogen, it is necessary to utilize very voluminous hydrogen tanks also when the maximum storage pressure of hydrogen reaches 700 bars (which currently represent a market standard). Besides, the hydrogen tanks are to be arranged in a position which is suitably protected against impacts from all directions and the hydrogen tanks have to preferably have a spherical shape or a cylindrical shape so as to be able to be resistant to the high internal pressure of hydrogen; these constraints further complicate the positioning of the hydrogen tanks in a car.
Consequently, a car provided with an internal combustion engine powered with hydrogen is longer and heavier (autonomy being equal) than a similar car provided with an internal combustion engine powered with gasoline and thus results definitely penalized in the dynamic performance.
Documents DE10026458A1, DE725059C, GB428609A and US2021061255A1 describe an opposed-piston internal combustion engine.
The object of the present invention is to provide a car provided with an internal combustion engine powered with hydrogen which allows achieving a high performance (particularly in sports driving on track) without penalizing the autonomy.
According to the present invention, a car provided with an internal combustion engine powered with hydrogen is provided, in accordance with what is claimed by the appended claims.
The claims describe preferred embodiments of the present invention forming integral part of the present description.
The present invention will now be described with reference to the accompanying drawings, which illustrate some non-limiting example embodiments thereof, wherein:
In
According to what is illustrated in
Preferably, the electric machine 3 is reversible (i.e. it can operate both as electric motor absorbing electric energy and generating a mechanical torque, and as electric generator absorbing mechanical energy and generating electric energy); according to other embodiments not illustrated, the electric machine 3 is not provided (and therefore the car 1 is not hybrid).
According to what is illustrated in
According to what is illustrated in
According to what is illustrated in
According to a preferred embodiment, the internal combustion engine 5 is powered with hydrogen (or also another gaseous fuel). According to a different embodiment, the internal combustion engine 5 is powered with gasoline (or also another liquid fuel).
According to what is illustrated in
The internal combustion engine 5 is arranged in a central or rear position, i.e. the internal combustion engine is arranged behind the passenger compartment 9 and is located between the front wheels 2 and the rear wheels 4 (central arrangement as is illustrated in the accompanying figures) or is located beyond the rear wheels 4 (rear arrangement not illustrated). Furthermore, as is better illustrated in
As is better illustrated in
According to what is illustrated in
The two crankshafts 16 are connected to one another by means of a gear transmission 17 (better illustrated in
In the internal combustion engine 5 a head is not present, since a piston 13 acts as head for the other piston 13. Therefore, the engine block of the internal combustion engine 5 is only composed of the crankcase 15.
In the internal combustion engine 5 neither suction valves nor the exhaust valves are present, the function of which is carried out by suction ports 20 and exhaust ports 21 (illustrated in
According to what is illustrated in
In each cylinder 14 two diametrically opposed spark plugs 23 are provided which are arranged in the centre of the cylinder 14 and are cyclically activated for triggering the ignition of the mixture of air (comburent) and fuel present in the combustion chamber at the end of the compression phase; according to other embodiments not illustrated, the number and/or the arrangement of the spark plugs 23 are different.
According to what is illustrated in
According to what is illustrated in
According to what is illustrated in
According to what is illustrated in
According to what is illustrated in
The gearbox 7 comprises one single output shaft 34 connected to the differential 8 which transmits the motion to the rear drive wheels 4; according to an alternative and equivalent embodiment, the dual-clutch gearbox 7 comprises two output shafts 34 both connected to the differential 8. From the differential 8 a pair of axle shafts 35 depart (schematically illustrated in
The gearbox 7 has seven forward gear ratios indicated by Roman numerals (first gear ratio I, second gear ratio II, third gear ratio III, fourth gear ratio IV, fifth gear ratio V, sixth gear ratio VI and seventh gear ratio VII) and a reverse gear (indicated by the letter R). Each input shaft 32 and the output shaft 34 are mechanically coupled to one another by means of a plurality of gears, each defines a respective gear ratio and comprises a primary toothed wheel 36 mounted on the input shaft 32 and a secondary toothed wheel 37 mounted on the output shaft 34. In order to allow the correct operation of the gearbox 7, all the odd gear ratios (first gear ratio I, third gear ratio III, fifth gear ratio V, seventh gear ratio VII) are coupled to a same input shaft 32, whereas all the even gear ratios (second gear ratio II, fourth gear ratio IV, and sixth gear ratio VI) are coupled to the other input shaft 32.
Each primary toothed wheel 36 is splined to a respective input shaft 32 for rotating always integral with the input shaft 32 and permanently meshes with the respective secondary toothed wheel 37; whereas, each secondary toothed wheel 37 is mounted idle on the output shaft 34. Furthermore, the gearbox 7 comprises four double synchronizers 38, each mounted coaxial to the output shaft 34, arranged between two secondary toothed wheels 37, and adapted to be actuated for alternatively engaging the two respective secondary toothed wheels 37 to the output shaft 34 (i.e. for alternatively making the two respective secondary toothed wheels 37 angularly integral with the output shaft 34). In other words, each synchronizer 38 can be shifted in a direction for engaging a secondary toothed wheel 37 with the output shaft 34, or can be shifted in the other direction for engaging the other secondary toothed wheel 37 with the output shaft 34.
According to a different embodiment not illustrated, the primary toothed wheels 36 are mounted idle on the respective input shafts 32, the synchronizers 38 are coupled to the primary toothed wheels 36, and the secondary toothed wheels 37 are splined to the output shaft 34 for always rotating integral with the output shaft 34.
The differential 8 receives the motion from the output shaft 34 of the gearbox 7 through an output toothed wheel 39 integral with the output shaft 34, is devoid of bevel gear (being the output shaft 34 already arranged transversely) and transmits the motion to the two rear drive wheels 4 by means of the two respective axle shafts 35. Preferably and according to what is illustrated in
In the embodiment illustrated in the accompanying figures, each clutch 31 is coaxial to the corresponding (longitudinally oriented) crankshaft 16 and is directly connected to an end of the corresponding crankshaft 16; consequently, between each clutch 31 and the corresponding (transversely oriented) input shaft 32 there is interposed a bevel gear 33. According to a different embodiment not illustrated, each clutch 31 is coaxial to the corresponding (transversely oriented) input shaft 32 and is directly connected to an end of the corresponding input shaft 32; consequently, between each clutch 31 and the corresponding (longitudinally oriented) crankshaft 16 there is interposed a bevel gear 33.
According to what is illustrated in
According to what is illustrated in
In the variation illustrated in
According to a different embodiment not illustrated, one single reversible electric machine is provided which carries out both the function of alternator (being made to operate as electric generator), and the function of starter motor (being made to operate as electric motor); the single reversible electric machine can be connected to a crankshaft 16 (in place of the alternator 40) or can be connected to the gear transmission 17 (in place of the starter motor 44).
According to what is illustrated in
According to what is illustrated in
According to a preferred embodiment, the removable panel 48 is at least partially transparent; in particular, the removable panel 48 centrally has a transparent window 49 (for example made of glass). The function of the transparent window 49 is essentially technical as it allows visibly inspecting the internal combustion engine 5 without having to remove the removable panel 48.
According to a preferred embodiment, the body 10 has no openable hood (arranged above the engine compartment 46) which allows access to the engine compartment 46; i.e. the access to the engine compartment 46 occurs only from below through the opening 47 as the upper part of the engine compartment 46 is permanently closed by fixed non-removable panels of the body 10. To such regard, it is important to observe that a top access to the engine compartment 46 would be anyway very difficult as it would require to remove the tanks 12.
According to a preferred embodiment, the removable panel 48 is directly fixed to the chassis 76 by means of a plurality of screws 50 (preferably quarter-turn screws 50). The rear aerodynamic diffuser 45 faces the road surface, is arranged behind the removable panel 48, and borders with the removable panel 48. Namely, the rear aerodynamic diffuser 45 starts where the removable panel 48 ends. Also the aerodynamic diffuser 45 is removable for allowing a simpler access to the gearbox 7.
The embodiments described herein can be combined with one another without departing from the scope of protection of the present invention.
The above-described car 1 has numerous advantages.
Firstly, the above-described car 1 allows simultaneously combining a large hydrogen storage capacity (being thus able to offer a satisfactory autonomy) with a very high dynamic performance thanks to a wheelbase, an overall weight, and a weight distribution which are optimal. These results are obtained thanks to the particular conformation and arrangement of the internal combustion engine 5 and of the drive system 6 which allow creating a substantial free space for housing the hydrogen tanks 12 without penalizing the dynamic performance of the car 1. In fact, the internal combustion engine 5 and the drive system 6 are completely located in a central position (i.e. between the front wheels 2 and the rear wheels 4) and are arranged very low; consequently, the centre of gravity of the car 1 is perfectly central and is arranged low enabling obtaining an optimal dynamic behaviour of the car 1. To such regard, it is important to note that the tanks 12 are arranged above, but despite being very bulky they have, on the whole, a reduced weight (also when they are full).
The above-described car 1 allows providing a rear aerodynamic extractor (diffuser) having extremely large dimensions thus allowing the generation of a very high aerodynamic load without any penalization of the drag. Namely, in the above-described car 1, the aerodynamic diffuser 45 has a very large dimension (it thus allows generating a high aerodynamic load for a modest increase in the drag) even if the internal combustion engine 5 is placed in a central/rear position (thus having an optimal mass distribution between the front axle and the rear axle) and, simultaneously, the wheelbase is relatively short (i.e. the car 1 has an extremely performing dynamic behaviour).
In the above-described car 1, also thanks to the particular conformation of the dual-clutch gearbox 7 which is transversely arranged immediately behind the internal combustion engine 5, it is possible to obtain a particularly favourable (i.e. compact despite being very functional) location of all the elements of the powertrain system for minimizing the wheelbase length (i.e. the distance between the front axle and the rear axle).
In the above-described car 1, the accessibility to all the zones of the internal combustion engine 5 is optimal and complete; this result is obtained thanks to the accessibility from the bottom which, once lifted the car 1, always allows an operator to arrange himself/herself exactly under the component on which to intervene. Namely, the accessibility from the bottom to the internal combustion engine 5 makes the maintenance easy and simple, as the operators are not limited by the shape of the car 1 but can easily move in all the zones of the internal combustion engine 5 being the car 1 lifted.
In the above-described car 1, the fact that the removable panel is at least partially transparent constitutes, besides an undoubtful technical advantage as explained in the foregoing, an aesthetic innovation and makes the removable panel also an aesthetic element; it is important to note that thanks to the aerodynamic diffuser 45 of great dimensions, it is relatively easy to see through the transparent wall of the removable panel at least part of the internal combustion engine 5 without having to exceedingly bend.
In the above-described car 1, the body 10 results particularly rigid and resistant thanks to the complete absence of an opening for the access to the engine compartment 46 (and normally closed by a hood). In this manner, the rigidity being equal, it is possible to reduce the overall mass of the body 10. Furthermore, the absence of an opening for the access to the engine compartment 46 also makes the body 10 completely continuous (i.e. without interruptions) thus reducing the drag coefficient. The possibility to eliminate through the body 10 an opening for accessing the engine compartment 46 is given by the fact that the internal combustion engine 5 is very thin and is arranged in substantial contact with the bottom 11 of the car. Therefore, all the main components of the internal combustion engine 5 are located in the lower part of the engine compartment 46 and are easily accessible from the bottom 11 through the opening 47 closed by the removable panel 48.
Number | Date | Country | Kind |
---|---|---|---|
102022000024348 | Nov 2022 | IT | national |