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公开(公告)号:US20220260025A1
公开(公告)日:2022-08-18
申请号:US17651139
申请日:2022-02-15
Applicant: C.R.F. Società Consortile per Azioni
Inventor: Raffaele RICCO , Sergio STUCCHI , Marcello GARGANO , Onofrio DE MICHELE , Chiara ALTAMURA
Abstract: An engine includes at least one cylinder, a first intake valve and a second intake valve associated with the cylinder, to control a flow of intake air from a first intake duct and a second intake duct, respectively. The two intake ducts communicate with a common intake manifold, so as to receive air at the same pressure. During the intake stage, in each cylinder operating cycle, initially an opening and closing movement of only the first intake valve is activated, while the second intake valve remains closed and, subsequently, an opening and closing movement of only said second intake valve is activated, while the first intake valve remains closed. In this way, the two air flows at the same pressure entering the cylinder give rise to a high turbulent kinetic energy, to the advantage of combustion efficiency and reduction of harmful exhaust emissions.
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公开(公告)号:US20250020072A1
公开(公告)日:2025-01-16
申请号:US18708390
申请日:2022-11-14
Applicant: C.R.F. SOCIETÀ CONSORTILE PER AZIONI
Inventor: Raffaele RICCO , Sergio STUCCHI , Marcello GARGANO , Onofrio DE MICHELE , Chiara ALTAMURA
Abstract: An internal-combustion engine has a plurality of cylinders each with two intake valves driven by respective pumping pistons operatively associated to cams of a camshaft, by respective hydraulic circuits. The hydraulic has its pressure chamber communicating with hydraulic actuators of the two intake valves, so that the two intake valves of each cylinder are controlled, via two different hydraulic circuits, by cams associated to two different cylinders. Each cam is configured to give rise to a cycle of opening and closing of each of the intake valves in an angular range of rotation of the crankshaft less than 180° such that, in each operating cycle of a cylinder, only the first intake valve initially opens and closes while the second intake valve remains closed, and then the second intake valve opens and closes while the first intake valve remains closed.
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公开(公告)号:US20170101903A1
公开(公告)日:2017-04-13
申请号:US15280577
申请日:2016-09-29
Applicant: C.R.F. Società Consortile per Azioni
Inventor: Sergio STUCCHI , Raffaele RICCO , Marcello GARGANO , Onofrio DE MICHELE , Carlo MAZZARELLA
CPC classification number: F01L1/25 , F01L9/025 , F01L2001/0537 , F01L2810/03 , F01L2810/04 , F02D13/0207
Abstract: A system for variable actuation of an engine valve of an internal-combustion engine includes a master piston and a slave piston, driven by the master piston. A control valve controls a communication of a volume of a pressurized fluid with a lower pressure environment, which is connected to a fluid accumulator, and an electronic control unit controls the electrically operated control valve. A device for dampening pressure oscillations is connected to the volume of pressurized fluid and includes an additional volume adapted for receiving fluid from the volume of pressurized fluid only when, following upon oscillations of the pressure in the volume of pressurized fluid, the pressure exceeds a maximum threshold value, which is higher than a mean pressure value that is set up in the volume of pressurized fluid when the master piston drives the slave piston in normal operating conditions.
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公开(公告)号:US20220243621A1
公开(公告)日:2022-08-04
申请号:US17621823
申请日:2020-08-06
Applicant: C.R.F. Società Consortile per Azioni
Inventor: Raffaele RICCO , Sergio STUCCHI , Carlo MAZZARELLA , Onofrio DE MICHELE
Abstract: An internal combustion engine includes an electro-hydraulic system for variable actuation of intake valves where each cylinder has two intake valves, associated with two intake conduits. A first conduit is generates within the cylinder a tumble motion of airflow introduced therein, when the intake valve associated thereto is at least partially opened. The second intake conduit generates within the cylinder a swirl motion of airflow introduced therein when the second intake valve is at least partially opened. A controller of controls one or more control valves to open only one of the intake valves of each cylinder in a condition of reduced engine operation, below a predetermined load and/or a predetermined speed of the engine, and to always open both intake valves in the remaining conditions of engine operation. The first intake valve is the only valve to be opened in the reduced engine operation condition.
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公开(公告)号:US20190162085A1
公开(公告)日:2019-05-30
申请号:US16110517
申请日:2018-08-23
Applicant: C.R.F. Società Consortile per Azioni
Inventor: Sergio STUCCHI , Marcello GARGANO , Raffaele RICCO , Onofrio DE MICHELE
Abstract: An actuating system of an engine valve comprises a movable member, for example, in the form of a master piston controlled by a cam of a camshaft. A slave piston is hydraulically controlled by the master piston by means of a volume of pressurized fluid, to open said engine valve against the action of a return spring. The system also comprises an auxiliary device for applying an additional force to the engine valve to keep the engine valve in a closed position. The auxiliary device is configured or controlled in such a way that the total force tending to keep the engine valve in its closed position varies during each rotation cycle of the cam. The total force is higher at least in one part of the rotation cycle of the cam wherein the engine valve must remain in its closed position, and is, instead, reduced at least in one part of the rotation cycle of the cam wherein the engine valve is not in its closed position.
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