摘要:
A cylinder-piston drive, e.g., an hydraulically controlled actuator for actuating a gas-exchange valve of an internal combustion engine, has an operating piston that is displaceable inside a cylinder and delimits pressure chambers by piston sides facing away from one another. The operating piston has a multipart design and is made up of at least two partial pistons that are placed inside one another, are displaceable relative to each other and strike against one another at stop faces. One pressure chamber is delimited by all, and the other pressure chamber is delimited by only a part, of the partial pistons and the sliding paths of the partial pistons not delimiting the other pressure chamber may be reduced compared to the overall sliding path of the operating piston. At least one stop face, arranged on the cylinder, may be provided against which a stop face of one of the partial pistons strikes after traveling the reduced sliding path. At least some of the stop faces associated with each other may be designed as conical surfaces that in each case form a conical seat when struck. In this manner, the leakage volume flow may be reduced by the operating piston.
摘要:
A cylinder head for a combustion cylinder of an internal combustion engine is provided, which has at least one inlet opening and at least one outlet opening, as well as gas exchange valves which are operable by electrohydraulic valve actuators, some of which gas exchange valves function as inlet valves to control the at least one inlet opening, and some of which gas exchange valves function as outlet valves to control the at least one outlet opening. For the purpose of producing a compact, complete module which, as a separate component, may be tested for reliability and may be installed into the engine block of the internal combustion engine without additional preassembly effort, the cylinder head is provided with at least one high pressure line for supplying fluid under high pressure and at least one recycling line for recycling fluid, which have coupling openings for the hydraulic coupling of the valve actuators, and also means for fastening the valve actuators are provided.
摘要:
A connection between a shaft end of a gas exchange valve of an internal combustion engine and a final control element of a valve actuator, with at least two shell-shaped wedge-shaped pieces, surrounding the shaft end and braced on the final control element, whose radially outer circumferential surface extends conically and which are surrounded by at least one conical clamping sleeve whose radially inner circumferential surface extends complimentary to the cone angle of the wedge-shaped pieces, wherein on the radially inner circumferential surface of the wedge-shaped pieces and on the radially outer circumferential surface of the shaft end of the gas exchange valve, protrusions and recesses that mesh with one another are provided. To enable rotary motions of the shaft end relative to the wedge-shaped pieces, the latter adjoin one another without gaps in the circumferential direction, forming an encompassing wedge-shaped sleeve, whose inside diameter is slightly larger than the outside diameter of the shaft end of the gas exchange valve, and that the protrusions and recesses mesh with one another with slight play.
摘要:
An hydraulically controlled actuator for activating a valve, especially for activating a gas-exchange valve in a combustion cylinder of an internal combustion engine, which includes two fluid-filled pressure chambers having controllable chamber volumes and a movable operating piston which delimits the pressure chambers by piston sides facing away from one another, the operating piston acting upon the valve and having an effective closing area acted upon by fluid pressure in the pressure chambers to close the valve and an effective opening area acted upon by the fluid pressure to open the valve. To influence the kinematics of the opening and closing movement of the valve, the operating piston is such that the surface area of at least one of the two effective areas changes along the sliding path of the operating piston.
摘要:
A hydraulic actuator for gas exchange valves of internal combustion engines is disclosed, in which the lifting of the gas exchange valve from the valve seat is effected with great force. The opening motion of the gas exchange valve then ensues at reduced force. Upon closure of the gas exchange valve, the gas exchange valve is braked before striking the valve seat, so that operation of the gas exchange valve with little wear and little noise can be achieved.
摘要:
A method and a device for operating an internal combustion engine having a plurality of cylinders are described, each cylinder having at least one intake valve and one exhaust valve having fully variable valve control, a fuel feed to at least one first cylinder of the plurality of cylinders being deactivated, a first quantity of fresh air being drawn in by opening the at least one intake valve of the at least one first cylinder in a first downward movement of the piston of the at least one first cylinder, and a second quantity of fresh air being ejected by opening the at least one exhaust valve with a first upward movement of the piston of the at least one first cylinder.
摘要:
A control system and a control method for an internal combustion engine have a cylinder including an intake valve and an exhaust valve with a fully variable valve-gear assembly. An engine control unit determines setpoint values with regard to a fresh gas charge, an internal residual gas charge, a torque reduction, an EGR control strategy, and a charging strategy. In addition, a transmission device is provided which transmits setpoint values determined by the engine control unit to a valve control unit in synchronization with the crankshaft angle. The valve control unit controls the fully variable valve-gear assembly of the intake and exhaust valve of the cylinder of the internal combustion engine on the basis of the setpoint values determined by the engine control unit.
摘要:
In a method and a circuit system for operating a solenoid valve, particularly for actuating an electrohydraulic gas-exchange valve control, an injection valve, or an intake or exhaust valve of an internal combustion engine, to permit the simplest possible driving of the solenoid valve, the solenoid valve is acted upon in a controlled manner in a cycle including three phases, in which in a pull-up phase, the solenoid valve is connected for a predefined time duration to a first voltage of predetermined magnitude for generating a pull-up current, in a holding phase is connected to a second voltage of predetermined magnitude for generating a holding current, and in a de-energize phase is separated from both voltages.
摘要:
The invention relates to a device of the build-up of pressure in supply systems (6, 11, 20, and 23) to components (19, 36) on internal combustion engines (2). The invention includes directly couples lubricant systems and pressure-generating systems (3, 8), an electric fuel pump (34), as well as a control apparatus for determining lubricant pressures. A supply module (12, 34) is provided with an independent drive (16) and supplies lubricant in the lubricant oil circuit (24) or to selected lubricating position, or fuel into a fuel supply (36). The supply module (12, 34) can optionally include a pressure converter (30).
摘要:
A method for controlling the opening of at least one intake valve of a combustion chamber in a periodically working piston engine, at least one intake valve of the combustion chamber being opened during a first partial period of a working period of the piston engine for charging the combustion chamber; and at least one intake valve of the combustion chamber being opened during a second partial period of the working period, wherein the second partial period begins after the combustion of the combustion chamber charge and has no overlap with the first partial period.