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 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:
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 hydraulically controlled actuator for actuation of an exhaust-side gas exchange valve of an internal combustion engine, containing a control piston that is displaceable within a cylinder and, with piston sides facing away from one another, delimits pressure chambers, of which the one pressure chamber impinges upon the gas exchange valve in the closing direction and the other pressure chamber impinges upon the gas exchange valve in the opening direction. In the actuator is provided at least one spring element, which can be brought into a preloaded state by the control piston moving in the closing direction of the gas exchange valve, and whose stored potential energy accelerates the gas exchange valve in the opening direction at least at the beginning of an opening phase, is provided. This results in a reduction in the energy expended in the context of valve actuation.
摘要:
An apparatus for controlling gas exchange valves of an internal combustion engine having hydraulic valve actuators each assigned to one gas exchange valve, with one adjusting piston acting on the gas exchange valve and two hydraulic work chambers defined by the adjusting piston the first work chamber acting on the gas exchange valve in the closing direction being constantly filled with fluid that is under pressure, and the second work chamber acting on the gas exchange valve in the opening direction can be filled with and relieved of fluid that is under pressure in alternation via a first and second electrical control valve. Two valve actuators are each triggered in alternation by the same first and the same second control valve, and the switchover of the control valves is performed during the closing state of the two gas exchange valves actuated by these valve actuators.
摘要:
A device for controlling an opening cross section in the combustion cylinder of an internal combustion engine is provided, the device having a gas exchange valve integrated into the combustion cylinder and having an actuator which drives the valve element to execute a closing stroke and an opening stroke. A valve brake which is active during a residual closing stroke of the valve element is provided for the purpose of reducing the impact velocity of the valve closure member of the valve element on the valve seat in the closing stroke of the valve element. The valve brake has a hydraulic damping element with a fluid displacement volume which flows out through a throttle cross section of a throttle opening, and a control unit for controlling the throttle cross section as a function of the viscosity of the displacement volume.
摘要:
An internal combustion engine having at least one combustion cylinder that includes a combustion chamber provided with gas-exchange valves, and an electrohydraulic valve control device having valve actuators that actuate the gas-exchange valves. To reduce manufacturing costs and/or the installation space required for the electrohydraulic valve control device, at least two synchronously controlled gas-exchange valves are connected using a coupling element to a common valve actuator, and the connection sites of the gas-exchange valves are flexibly formed on the coupling element.
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:
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).