Abstract: An apparatus for controlling gas exchange valves includes at least one valve positioner, associated with a gas exchange valve, and a pressure supply device which supplies the valve positioner with a fluid under high pressure. The valve positioner encompasses a working cylinder having a positioning piston, coupled to the gas exchange valve, which delimits an upper pressure space for opening the valve and a lower pressure space for closing the valve, and encompasses a control valve controlling the hydraulic pressure in the pressure spaces. In order to reduce the manufacturing costs and electrical energy demand of the apparatus, the upper pressure space is connected directly, and the lower pressure space via a restrictor throttle, to the pressure supply device; and the control valve is connected to the lower pressure space and to a relief line. Depending on the switch position, the control valve additionally connects the lower pressure space to the relief line or blocks it off from the relief line.

Abstract: 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.

Abstract: An internal combustion engine includes a hydraulic system with a hydraulic pump. A lubricant system for moving parts of the engine is also provided, which includes a lubricant pump. To enable making the engine smaller, it is proposed that the hydraulic pump is connected to the lubricant system in such a way that it can be lubricated by the lubricant.

Abstract: An hydraulic valve actuator for actuating a gas-exchange valve in a combustion cylinder of an internal combustion engine has an operating piston delimiting two pressure chambers, of which the lower pressure chamber acting in the valve-closing direction is permanently charged with fluid pressure via which an intake and return line can be charged by, or relieved of, fluid pressure. To brake the gas-exchange valve in the final phase of the closing procedure to reduce the set-down speed, the return line of the upper pressure chamber is split between two discharge openings, which are connected to one another and arranged in the housing with axial clearance, the upper discharge opening being coupled to a restrictor and the lower discharge opening being displaceable relative to the operating piston and disposed in its displacement path such that it may be closed thereby at a defined distance, prior to reaching its upper limit position.

Abstract: A gas exchange valve device for an internal combustion engine is provided with a hydraulic apparatus which includes a fluid circuit and at least one pressure reservoir connected to the fluid circuit and containing piston prestressed by a device, and also includes a controllable actuating device. A gas exchange valve is also provided, whose valve element is acted on by the actuating device. In order to achieve a simpler design of the gas exchange valve device the pressure reservoir is disposed so that in an approximately unpressurized state of the pressure reservoir, its piston at least indirectly locks the valve element of the gas exchange valve in an essentially closed position.

Abstract: A device for controlling gas-exchange valves of an internal combustion engine is provided, which device has hydraulic valve actuators each allocated to one gas-exchange valve. Each valve actuator has an actuating piston acting on the gas-exchange valve, and two hydraulic working chambers delimited by the actuating piston, of which the first working chamber acting upon the gas-exchange valve in the closing direction is constantly filled with fluid under pressure, and the second working chamber acting upon the gas-exchange valve in the opening direction is able to be alternately filled with fluid under pressure and relieved via two electric control valves. For the purpose of cost reduction, provided for each valve-actuator pair is a single first electric control valve that is acted upon with the fluid pressure on the intake side, and is connected on the outlet side to the second working chamber of one valve actuator.

Abstract: 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.

Abstract: A pressure-supply device for an electrohydraulic valve control of gas-exchange valves in internal combustion engines which has a fluid reservoir, a fluid output for the connection of the valve control, and a high-pressure pump which removes fluid from the fluid reservoir and delivers it under high pressure to the fluid output. To attain high pump efficiency and high system dynamics, the high-pressure pump is constructed as constant-displacement pump having a pump inlet and a pump outlet, and the pump outlet is connectible by a switchover valve alternately to the fluid output and, accompanied by blocking of the fluid output, to the fluid reservoir.

Abstract: A method for cylinder-charge control is described as implementing an internal recirculation of residual gas in the cylinder, through controlling the closing times of at least one exhaust valve of the respective cylinder and by opening at least one intake valve in the vicinity of top dead center of the piston, along with intermittent discharge of residual gas in front of the at least one intake valve. Within one charge-exchange process in the cylinder, in at least two phases that are offset in time from one another, at least one intake valve is opened. This method optimizes the engine operation in the warm-up phase from the standpoint of consumption, pollutant emission and running smoothness.

Abstract: 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.

Abstract: A filter is indicated for use in a flowing, viscous medium, particularly in the delivery flow of a pump delivering hydraulic oil for an electrohydraulic valve control, that has a filter housing (11) including an inlet and outlet (12, 13), and a filter element (15) arranged in the filter housing (11) between the inlet and outlet (12, 13).

Abstract: 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.

Abstract: A pressure reservoir is used to exert pressure on a hydraulic system with which, a gas exchange valve, for instance, of an internal combustion engine can be actuated. The pressure reservoir includes a housing and a piston that is prestressed in operation by a device. To enable making the pressure reservoir as small as possible, it is proposed that the device which prestresses the piston of the pressure reservoir has a characteristic force-travel curve, in one range of motion of the piston, that has a slope which differs from the slope in a different range of motion of the piston.

Abstract: 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.

Abstract: 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.

Abstract: A device is proposed for controlling gas-exchange valves, at least one of which is assigned as intake valve (11) and at least one of which as discharge valve (12) to a combustion chamber of an internal combustion engine. The internal combustion engine includes electrohydraulic valve actuators (18) assigned in each case to a gas-exchange valve for its actuation, and a pressure-supply reservoir (26) having a high-pressure pump and a pressure-storage unit, which supplies the valve-actuators (18) with a fluid at high pressure. To reduce the energy consumed by the control device, the pressure-storage unit has two separate high-pressure reservoirs (31, 32), one of which is connected to the valve actuator (18) for the at least one intake valve (11) and the other to the valve actuator (18) for the at least one discharge valve (12).

Abstract: A connection between two shaft ends situated coaxially one behind the other, of a gas exchange valve of an internal combustion engine and a piston rod of a valve actuator is provided, where at least one coupling member at least partially surrounds the shaft ends. The coupling member is radially compressed with respect to the two shaft ends by at least one compressing member to produce static friction locking between each shaft end and the coupling member that transfers the actuating motion of valve actuator to gas exchange valve in a slip-free manner. As a result, the fatigue strength of the connection may be increased and its assembly and disassembly may be simplified.

Abstract: An apparatus for controlling gas exchange valves is described, having at least one valve positioner (16), associated with a gas exchange valve (10), and a pressure supply device (25) which supplies the valve positioner (16) with a fluid under high pressure. The valve positioner (16) encompasses a working cylinder (17) having a positioning piston (21), coupled to the gas exchange valve (10), which delimits an upper pressure space (22) for valve closure and a lower pressure space (23) for valve opening, and encompasses a control valve (19) controlling the hydraulic pressure in the pressure spaces (22, 23). In order to reduce the manufacturing costs and electrical energy demand of the apparatus, the upper pressure space (22) is connected directly, and the lower pressure space (23) via a restrictor throttle (18), to the pressure supply device (25); and the control valve (19) is connected to the lower pressure space (23) and to a relief line (27).

Abstract: 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.

Abstract: A device is described for controlling gas exchange valves of an internal combustion engine, which has hydraulic valve positioners (17, 18), each having a positioning piston (26) acting on the gas exchange valve (12, 13) and two hydraulic working chambers (27, 28), delimited by the positioning piston (26), of which the first working chamber (27), for closing the gas exchange valve (12, 13), is continuously under fluid pressure and the second working chamber (28), for opening the gas exchange valve (10), may be alternately filled and emptied with pressurized fluid via a first and second electrical control valve (34, 35).