English to Polish Tech/Engineering Automotive / Cars & Trucks silnik

[0006] In XXX, in the name of Scuderi, a "split cycle" engine is described having a cylinder block with a compression cylinder and an expansion cylinder closed by a cylinder head in which one or more passageways (78) are provided, called "", closed at the respective ends by a compression-sided valve (84) and a combustion-sided valve (86).
Each crossover passageway defines a pressurized chamber (81), in which pressurized gas can be accumulated when both the compression-sided valves and combustion-sided valve are closed. In the passageways (78) the injection of petrol is provided by an injector (90) that injects petrol into the compressed air present in the cross-
over passageways. At least one spark-plug (92) is provided in the expansion cylinder for ignition of the mixture.

[0009] In XXX an engine is described of the same kind as described above that provides a crossover passageway having respective valves at the inlet and at the outlet openings. The duct comprises, furthermore, a
regenerator of the combustion gas for accumulating part of the heat of a cycle and exploiting it for a successive
cycle.

[0017] This way, before opening the transfer valve there are substantially only two chambers, one defined
by the compression cylinder and the other defined by the crossover passageway in combination with said expansion cylinder. Then, when opening said transfer valve, which is carried out at least 20° in advance with respect to the ETDC, there is not a substantial transfer of comburent fluid into said crossover passageway, since the pressure in the expansion cylinder is about equal to that compression cylinder. With the progress of the cycle, since the two cylinders communicate with each other via the crossover passageway, the pressure increases in a way identical everywhere, by the contemporaneous rising stroke of the two pistons, up to reaching the ETDC. Then, passed the ETDC, the compression piston continues to rise and the expansion piston starts to go down, causing a total transfer of said comburent fluid between the two cylinders through the crossover passageway. Simultaneously to the transfer, the injection is carried out and a subsequent combustion of all the fuel occurs. Since the transfer causes a high turbulence, the phenomena of evaporation and mixing between the fuel and the comburent fluid occur in a better way than in a conventional diesel engine. In particular, the evaporation is carried out in a quicker way and the mixture obtained is much more homogeneous. This way, a very effective combustion is obtained and a subsequent very low fraction of unburnt
particles is present in the exhaust gas, in particular carbonaceous dust.

[0022] This way, the compressed charge of fuel and comburent fluid is transferred into the combustion cylinder in the combustion phase through said crossover passageway, after opening the transfer valve. Therefore, the
crossover passageway has a pure transfer function and is not simply a pressurized storage reservoir of the comburent fluid.

[0023] Alternatively, said means for causing an open and close movement of said transfer valve opens said
transfer valve in advance with respect to closing said exhaust valve, so that in the expansion cylinder a wash-
ing out occurs with fresh comburent fluid of the exhaust gas occurs before closing said exhaust valve. Even in
this case, when closing the exhaust valve there is a congruent growth of the pressure in the two compression
and expansion cylinders, with possibility to reach a larger power.

[0024] Advantageously, said angular phase shift between the crankshaft angle of said compression piston
with respect to the crankshaft angle of said expansion piston is set between 10° and 45°, preferably between
20° and 30°, in particular of 25°. The angular phase shift between said compression piston and said expansion
piston has the aim to cause the transfer of the comburent fluid compressed by said compression cylinder to said
expansion cylinder.