摘要:
Disclosed is a simple, easy-to-produce, and reliable connection between a shaft of a gas exchange valve and an actuator. This connection is detachable and, as a result, can be connected and disconnected multiple times. It is also possible to dispose the coupling piece on the shaft of the gas exchange valve and provide circumferential grooves on the control element of the actuator.
摘要:
A device for controlling gas exchange valves of an internal combustion engine, which has hydraulic valve positioners, each having a positioning piston acting on the gas exchange valve and two hydraulic working chambers, delimited by the positioning piston, of which the first working chamber, for closing the gas exchange valve, is continuously filled under fluid pressure and the second working chamber, for opening the gas exchange valve, is alternately filled and emptied with pressurized fluid via a first and second electrical control valve. To reduce the number of control valves, which may be necessary, for a valve pair, the filling of the second working chamber of the second valve positioner is performed via the second working chamber of the first valve positioner, which is connected to the first control valve, after a predetermined stroke of the positioning piston of the first valve positioner to open the assigned gas exchange valve.
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 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.
摘要:
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. The second working chamber of the other valve actuator is filled with fluid with the aid of a switchover valve and the fluid pressure in the second working chamber of the one valve actuator.
摘要:
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. The second working chamber of the other valve actuator is filled with fluid with the aid of a switchover valve and the fluid pressure in the second working chamber of the one valve actuator.
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:
Disclosed is a simple, easy-to-produce, and reliable connection between a shaft of a gas exchange valve and an actuator. This connection is detachable and, as a result, can be connected and disconnected multiple times. It is also possible to dispose the coupling piece on the shaft of the gas exchange valve and provide circumferential grooves on the control element of the actuator 5.
摘要:
The present invention relates to a connection between a shaft end of a gas exchange valve of an internal combustion engine and a sleeve-shaped actuating element of a valve actuator, which is guided in an axially movable manner within a pressure region, which is able to be pressurized with a pressure medium, of the valve actuator and at least partially surrounds the shaft end. The present invention provides for the connection to be situated outside of the pressure region and in the region of an opening, which is formed on the side of the valve actuator away from the combustion chamber, and is, for example, coaxial to the shaft end.
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.