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Internal combustion engine provided with a plurality of cylinders divided into a first group and a second group; a control unit for deactivating all the cylinders of the second group; a first exhaust conduit and a second exhaust conduit, which are reciprocally connected at an intersection and which

Internal combustion engine provided with a plurality of cylinders divided into a first group and a second group; a control unit for deactivating all the cylinders of the second group; a first exhaust conduit and a second exhaust conduit, which are reciprocally connected at an intersection and which are respectively connected to cylinders of the first group and to cylinders of the second group; a catalyzer, which is arranged along the first exhaust conduit upstream of the intersection and is provided with first sensors for detecting the exhaust gases; and a second catalyzer, which is arranged downstream of the intersection and is provided with second sensors for detecting the exhaust gas composition.

대표청구항 ▼

1. An internal combustion engine comprising: a plurality of cylinders divided into a first group and into a second group;a control unit to deactivate all cylinders of the second group;a first intake conduit and a second intake conduit, which are connected respectively to the cylinders of the first g

1. An internal combustion engine comprising: a plurality of cylinders divided into a first group and into a second group;a control unit to deactivate all cylinders of the second group;a first intake conduit and a second intake conduit, which are connected respectively to the cylinders of the first group and to the cylinders of the second group and are controlled respectively by a first throttle valve and by a second throttle valve;at least one first exhaust conduit and at least one second exhaust conduit, which are connected respectively to the cylinders of the first group and to the cylinders of the second group;an intersection at which the first exhaust conduit and the second exhaust conduit are reciprocally connected;at least one catalyzer, which is arranged along the first exhaust conduit upstream of the intersection and is provided with first sensors to detect the composition of exhaust gases at the first catalyzer itself; andat least one second catalyzer, which is arranged downstream of the intersection and is provided with second sensors to detect the composition of exhaust gases a the second catalyzer itself;wherein the intersection between the first exhaust conduit and the second exhaust conduit comprises an intersection conduit, which is regulated by an intersection valve. 2. An engine according to claim 1, wherein each cylinder comprises at least one suction valve to regulate the flow of air introduced from the intake conduit, at least one exhaust valve to regulate the flow of air output towards the exhaust conduit, and an injector to inject fuel within the cylinder itself; to deactivate all the cylinders of the second group the control unit cuts off fuel supply to the cylinders of the second group by acting on the injectors without intervening in any way on the actuation of the suction and exhaust valves, which continue to be operated. 3. An engine according to claim 2, wherein all cylinders of the second group are deactivated, the control unit keeping the second throttle valve in a partially open position. 4. An engine according to claim 2, wherein when all the cylinders of the second group are deactivated, the control unit determines the temperature within the second catalyzer and keeps the throttle valve in a partially open position only if the temperature within the second catalyzer is higher than a threshold. 5. An, engine according to claim 1, wherein a recirculation conduit is provided, the conduit is regulated by a recirculation valve and puts into communication the first exhaust conduit with the second feeding conduit. 6. An engine according to claim 5, wherein the recirculation conduit is inserted in the second feeding conduit downstream of the second throttle valve and is inserted in the first exhaust conduit downstream of the first catalyzer. 7. An engine according to claim 1, wherein when all the cylinders of the engine are active the electronic control unit uses the signals from the first sensors to control combustion within the cylinders of the first group and uses the difference between the signals from the second sensors and the signals from the first sensors to control combustion within the cylinders of the second group; when all the cylinders of the second group are deactivated, the electronic control unit uses only the signals from the first sensors to control combustion within the cylinders of the first group. 8. An engine according to claim 1, wherein at least one pre-catalyzer is provided, which is arranged along the first exhaust conduit upstream of the first catalyzer, and at least one second pre-catalyzer, which is arranged along the second exhaust conduit upstream of the second catalyzer and upstream of the intersection. 9. An engine according to claim 8, wherein the first sensors are arranged one upstream of the first pre-catalyzer and one downstream of the first catalyzer; the second sensors are arranged one upstream of the second pre-catalyzer and one downstream of the second catalyzer. 10. An engine according to claim 1, wherein each exhaust conduit comprises one single exhaust manifold communicating with all the cylinders associated to the exhaust conduit itself. 11. An engine according to claim 10, wherein the cylinders are divided into a first row coinciding with the first group of cylinders and in a second row coinciding with the second group of cylinders. 12. An engine according to claim 10, wherein in the intersection the first exhaust conduit and the second exhaust conduit join to form a common exhaust conduit, along which is arranged the second catalyzer is arranged. 13. An engine according to claim 12, wherein the nominal capacity of the second catalyzer is double that of the first catalyzer. 14. An engine according to claim 12, wherein the first exhaust conduit comprises a bypass conduit, which is arranged in parallel to the first catalyzer and whose input is regulated by a bypass valve. 15. An engine according to claim 14, wherein when all the cylinders are activate, the control unit determines the temperature within the first catalyzer and keeps the bypass valve in an open position only if the temperature within the first catalyzer is higher than a threshold. 16. An engine according to claim 1, wherein the second catalyzer is arranged along the second exhaust conduit downstream of the intersection; along the first exhaust conduit and downstream of the intersection is arranged an intersection valve adapted to close the first exhaust conduit itself. 17. An engine according to claim 16, wherein along the intersection conduit a third catalyzer is arranged. 18. An engine according to claim 17, wherein the third catalyzer is without sensors. 19. An engine according to claim 16, wherein the nominal capacity of the second catalyzer is the same as that of the first catalyzer. 20. An engine according to claim 1, wherein all the cylinders are divided into a first row and a second row and the cylinders of each group of cylinders are arranged on both the first row and the second row; each exhaust conduit receiving exhaust gases from the cylinders arranged on both rows and comprising two exhaust manifolds, each of which is associated to one of the rows; each exhaust conduit is split to comprise to half exhaust conduits, each of which is connected to one of the exhaust manifolds. 21. An engine according to claim 20, wherein each half exhaust conduit of the first exhaust conduit comprises a first catalyzer provided with first sensors for detecting the composition of exhaust gases upstream and downstream of the first catalyzer itself. 22. An engine according to claim 21, wherein the two half exhaust conduits of the first exhaust conduit are joined at the intersection. 23. An engine according to claim 21, wherein the two half exhaust conduits of the first exhaust conduit are joined upstream of the intersection. 24. An engine according to claim 22, wherein in the intersection the first exhaust conduit and the second exhaust conduit join to form a common exhaust conduit, along which the second catalyzer is arranged. 25. An engine according to claim 24, wherein the nominal capacity of the second catalyzer is double that of each first catalyzer. 26. An engine according to claim 21, wherein each half exhaust conduit of the first exhaust conduit joins with a second half exhaust conduit of the second exhaust conduit at an intersection, upstream of which the two half exhaust conduits join to form a common exhaust conduit, along which is arranged a second catalyzer. 27. An engine according to claim 26, wherein the nominal capacity of each second catalyzer is double that of each first catalyzer. 28. An engine according to claim 21, wherein the two half exhaust conduits of the first exhaust conduit join upstream of the first catalyzer; the two half exhaust conduits of the second exhaust conduit join upstream of the intersection.