Methods and systems are provided for providing secondary air to an exhaust system during catalyst warm-up. In one example, a method may include, responsive to a cold start of an engine: operating the engine with a number of unfired cylinders and a remaining number of fired cylinders each engine cycle, and adjusting exhaust mixing by adjusting an exhaust valve parameter of at least one unfired cylinder of the number of unfired cylinders. In this way, the unfired cylinders may provide the secondary air as well as increased mixing of the secondary air with burned exhaust gas from fired cylinders, thus increasing exotherm production in the exhaust system to increase a temperature of the catalyst.

The disclosure relates to a valve train for an internal combustion engine and to an internal combustion engine. The valve train has an inlet valve actuation mechanism for the periodic actuation of an inlet valve of the internal combustion engine. The valve train also has a delay element, which is in contact with the inlet valve actuation mechanism and which has a hydraulic chamber for delaying a closing movement of the inlet valve by means of a hydraulic medium. The valve train has a hydraulic feed for feeding the hydraulic medium into the hydraulic chamber, the hydraulic feed having a control shaft, and the control shaft being mechanically driven by the internal combustion engine. The control shaft has an axially extended cavity for the hydraulic medium, and at least one opening for intermittently feeding the hydraulic medium from the cavity to the hydraulic chamber.

A slide cam system includes a camshaft comprising a carrier shaft with slide cam elements that each comprise a slotted switching member having a switching groove. The slide cam elements are displaceable axially relative to the carrier shaft by an actuator pin. A displacement element is arranged parallel with a longitudinal axis of the carrier shaft, and the displacement element is axially displaceable in a direction of the longitudinal axis. The displacement element has a first coupling pin arranged in a region of the first slide cam element and a second coupling pin arranged in a region of the second slide cam element. The coupling pins cooperate with a slotted switching member of the associated slide cam element such that as a result of the displacement element a movement initiated by the actuator pin of the first slide cam element can be transmitted to the second slide cam element.

A system for controlling actuation of an engine valve comprises a pivot and a torsion spring having first and second legs operatively connected to the pivot. A lever arm is adjustably affixed to and extending away from the pivot, and is further rotatable about a pivot axis of the pivot between a retracted position and an extended position and vice versa relative to a motion conveying component. Furthermore, a housing is provided having a pivot bore formed therein with the pivot rotatably disposed in the pivot bore. The housing further comprises a first and second openings intersecting with the pivot bore such that the first and second legs extend out of the first opening and the lever arm extends out of the second opening. When a first force is applied by the motion conveying component to the lever arm, such first force maintains the lever arm in the extended position.

A compact, modular, lost motion variable valve actuation assembly includes a dry start hydraulic circuit to enable quick priming of a lost motion master-slave circuit from a dry start reservoir to the master piston chamber during engine start. Motion of the master piston on engine startup may draw in fluid from the dry start hydraulic circuit. The dry start components may be integrated into a compact modular rocker shaft pedestal package suitable for retrofit on existing engine head assemblies. The master piston may include a push tube interface that includes a deep push tube cavity and lubrication capabilities in the master piston that provides for improved wear, stability, easy installation and alignment. The slave piston may be provided with a valve catch to reduce valve closing velocity during cycles involving lost-motion.

A method of predicting vehicle engine torque using an artificial neural network is provided. A data-based artificial neural network model is applied to more accurately calculate torque and reduce development costs for calibration and logics.

A fully variable valve train with a rotary plunger for an internal combustion engine. A motor actuates a high-pressure oil injection pump; when a timing driven electromagnetic valve connected to an oil inlet is opened, high-pressure oil enters a hydraulic cylinder; and when the force applied to a plunger by the hydraulic oil is larger than the force of a valve returning spring, the plunger is pushed to move down, so that a valve is opened. When the valve is required to be return, the timing driven electromagnetic valve connected to the oil inlet is closed, and the timing driven electromagnetic valve connected to the oil inlet is opened; the valve moves up under the action of the valve spring, pushing the plunger to move up and thereby discharging the low-pressure oil out of the hydraulic cylinder, then the plunger and the valve return to the initial positions.

A method of two-step variable valve lift (VVL) malfunction avoidance learning control may include: in a two-step VVL system which is operated with a main lift and a secondary lift, verifying, by an electronic control unit (ECU), an operation avoidance area based on locking of a lock pin of a cam follower ; performing VVL operation learning, in which a failure of occurrence of the second lift is determined on the basis of a locking failure of the cam follower due to an initially set value of the operation avoidance area; and reflecting the operation avoidance area to the two-step VVL system with a corrected set value which is obtained through the VVL operation learning.

A continuous variable valve duration apparatus includes a cam unit, a cam formed on the cam unit, a camshaft inserted into the cam, a guide bracket, a guide shaft mounted on the guide bracket and disposed perpendicular to the camshaft, wherein a guide screw thread is formed on the guide shaft, a wheel housing disposed within the guide bracket, an inner wheel rotatably inserted into the wheel housing and movable perpendicular to the camshaft, a worm wheel disposed within the wheel housing, wherein an inner screw thread configured to engage with the guide screw thread is formed inside the worm wheel and an outer screw thread is formed on the worm wheel, a control shaft, a control worm formed on the control shaft, and a wheel elastic portion mounted to the wheel housing.

A compact, modular, lost motion variable valve actuation assembly includes a dry start hydraulic circuit to enable quick priming of a lost motion master-slave circuit from a dry start reservoir to the master piston chamber during engine start. Motion of the master piston on engine startup may draw in fluid from the dry start hydraulic circuit. The dry start components may be integrated into a compact modular rocker shaft pedestal package suitable for retrofit on existing engine head assemblies. The master piston may include a push tube interface that includes a deep push tube cavity and lubrication capabilities in the master piston that provides for improved wear, stability, easy installation and alignment. The slave piston may be provided with a valve catch to reduce valve closing velocity during cycles involving lost-motion.