A valve drive for an internal combustion engine, including a gas exchange valve; a first mechanically driven drive mechanism; and a second drive mechanism connected to the gas exchange valve to move same. The first and second drive mechanisms connected via a hydraulic coupling device that has a pressure chamber, which can be relieved of pressure via a valve device and is designed to couple the drive mechanisms by hydraulic pressure and to decouple same in a pressure-relieved state. The valve device has two switch valves fluidically connected to the pressure chamber in parallel and via which the pressure chamber is relieved of pressure in the open state of at least one of the switch valves. The valve drive has a controller that actuates the switch valves in a delayed manner to provide a variable valve stroke of the gas exchange valve during a stroke movement.

A valve drive for an internal combustion engine, including a gas exchange valve; a first mechanically driven drive mechanism; and a second drive mechanism connected to the gas exchange valve to move same. The first and second drive mechanisms connected via a hydraulic coupling device that has a pressure chamber, which can be relieved of pressure via a valve device and is designed to couple the drive mechanisms by hydraulic pressure and to decouple same in a pressure-relieved state. The valve device has two switch valves fluidically connected to the pressure chamber in parallel and via which the pressure chamber is relieved of pressure in the open state of at least one of the switch valves. The valve drive has a controller that actuates the switch valves in a delayed manner to provide a variable valve stroke of the gas exchange valve during a stroke movement.

Systems and methods for internal exhaust gas recirculation (iEGR) in internal combustion engines may utilize secondary intake valve lift events during an exhaust valve main event in lost motion valve actuation systems. The secondary intake valve lift event may occur at the beginning or end of the exhaust valve main event. Favorable intake valve lift profiles are obtained with the use of a reset component, which may perform a hydraulic reset on the lost motion component in order to ensure that the intake valve secondary lift event occurs optimally near the beginning of an exhaust valve main event. The reset component may be triggered using motion from an exhaust valvetrain, for example, by a triggering component such as a reset pad, on an exhaust rocker. The reset component may also be triggered on the basis of the intake rocker arm position, in which case a reset pad that is fixed to the engine head or fixed relative to the intake rocker motion may be used.

Systems and methods for internal exhaust gas recirculation (iEGR) in internal combustion engines may utilize secondary intake valve lift events during an exhaust valve main event in lost motion valve actuation systems. The secondary intake valve lift event may occur at the beginning or end of the exhaust valve main event. Favorable intake valve lift profiles are obtained with the use of a reset component, which may perform a hydraulic reset on the lost motion component in order to ensure that the intake valve secondary lift event occurs optimally near the beginning of an exhaust valve main event. The reset component may be triggered using motion from an exhaust valvetrain, for example, by a triggering component such as a reset pad, on an exhaust rocker. The reset component may also be triggered on the basis of the intake rocker arm position, in which case a reset pad that is fixed to the engine head or fixed relative to the intake rocker motion may be used.

A cam phasing mechanism (1) for a cam assembly (100) of an internal combustion engine, the cam assembly (100) comprising a camshaft (120) and an actuator (130) for opening a valve (505) at a reference position of rotation of the camshaft (120), the cam phasing mechanism (1) comprising: a force transfer member (2a) for interposition between the camshaft (120) and the actuator (130) of the cam assembly (100) for transferring force between the camshaft (120) and the actuator (130); and an adjuster (2b) for selectively moving the force transfer member (2a) to adjust the reference position of rotation of the camshaft (120).

A hydraulics unit for an internal combustion engine with a hydraulically variable gas exchange valve gear, is provided that includes a hydraulic housing having a pressure chamber, a pressure relief chamber and a venting duct. The venting duct is connected, on a hydraulic housing inner side, to the pressure relief chamber via a restriction and opens on a hydraulic housing outer side. The venting duct has a siphon with a downward first duct section and an upward second duct section, respectively in the direction of gravity and in the venting direction. When a gas exchange valve is closed, a lowermost section of the siphon is below a boundary of a pressure chamber defined by a slave piston.

The present invention discloses a hydraulic valve mechanism with variable valve opening times and an internal combustion engine, which can effectively implement a single-opening working mode, a two-opening working mode or a multi-opening working mode of a valve in the same working cycle, and can implement a rapid and stable switchover among various working modes according to working condition requirements of the internal combustion engine. A main structure thereof includes a housing, a valve cam including a main protrusion and at least one auxiliary protrusion, a hydraulic rotary valve having a hydraulic switch valve function, a hydraulic drive component, a valve drive component, and the like. Oil passages of the hydraulic drive component, the hydraulic rotary valve, and the valve drive component are in communication.

An intake valve device capable of implementing two-stage switching of a gas distribution phase and a diesel engine. The intake valve device comprises a cam (1), a tappet guide rod component (2), a rocker arm (3), a variable valve bridge (7), and an intake valve (12) connected in sequence, and further comprises an intake valve drive piston (5), the intake valve drive piston (5) being capable of abutting against the rocker arm (3), a piston cavity accommodating the intake valve drive piston (5) is provided in the variable valve bridge (7), wherein communication between the high-pressure end of the piston cavity and a main oil path (10) can be established or broken by means of a high-pressure oil path (8), while the low-pressure end of the piston cavity is communicated with the main oil path (10) by means of a low-pressure oil path (11), and in order to ensure the formation of the pressure in the piston cavity to ensure that there is sufficient pressure to open the intake valve (12), an one-way valve (7) communicating from the low-pressure end to the high-pressure end is formed in the piston cavity. The cam (1) is a multi-lift cam having high and low cam molded lines, and can meet the requirements for the gas distribution phase under two working conditions, thereby achieving optimal engine performance and emission target. Moreover, the provided intake valve drive piston (5) and hydraulic oil path implement switching of the lifts of the cam (1).

A variable valve lift (VVL) system for an internal combustion engine is provided that utilizes hydraulic fluid supply pressure feedback to provide noise free operation. The VVL system includes a high pressure pump, a solenoid valve, a pressure translating device, a one-way valve, and a hydraulic fluid pressure sensor. The high pressure pump is fluidly connected to the solenoid valve and pressure translating device by at least one fluid gallery that forms a high pressure chamber. The solenoid valve selectively fluidly connects the high pressure chamber to a middle pressure chamber formed by at least one fluid gallery that fluidly connects the one-way valve to the solenoid valve. The hydraulic fluid pressure sensor is arranged to detect a hydraulic fluid supply pressure of the one-way valve and provides feedback to an electronic controller that determines a proper fluid intake opening timing of the solenoid valve.

A variable valve lift (VVL) system for an internal combustion engine is provided that utilizes hydraulic fluid supply pressure feedback to provide noise free operation. The VVL system includes a high pressure pump, a solenoid valve, a pressure translating device, a one-way valve, and a hydraulic fluid pressure sensor. The high pressure pump is fluidly connected to the solenoid valve and pressure translating device by at least one fluid gallery that forms a high pressure chamber. The solenoid valve selectively fluidly connects the high pressure chamber to a middle pressure chamber formed by at least one fluid gallery that fluidly connects the one-way valve to the solenoid valve. The hydraulic fluid pressure sensor is arranged to detect a hydraulic fluid supply pressure of the one-way valve and provides feedback to an electronic controller that determines a proper fluid intake opening timing of the solenoid valve.