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:
The invention relates to an electrohydraulic valve controller for controlling a gas exchange valve in internal combustion engines, having a hydraulically actuatable control valve including a control valve piston which can be acted upon, via electrically actuatable valves, by a hydraulic medium that is under pressure, and a hydraulically acting valve brake is assigned to the control valve piston. The valve brake (46) includes a temperature compensation for the hydraulic medium.
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 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:
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:
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 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:
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 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 sleevelike actuating piston of a valve actuator, has at least two shell-like key pieces, surrounding the shaft end and on whose radially outer circumferential surface there is a conically tapering portion, pointing away from a combustion chamber of the engine, and extending in complementary fashion to the cone angle of a radially inner conical portion of a conical fastening sleeve that includes the key pieces, and the conical fastening sleeve and the key pieces can be braced axially against one another. Protrusions and recesses engaging one another are provided on the radially inner circumferential surface of the key pieces and on the radially outer circumferential surface of the shaft end of the gas exchange valve. The conical fastening sleeve is formed by the actuating piston and the actuating piston and the key pieces have threaded portions that can be screwed into one another.