An oil passage switching valve suitable for a valve timing changing apparatus includes: a valve body, opening or closing an oil passage of operating oil; an urging spring, urging to position the valve body to a position corresponding to the retard position in a pause state; and a switching element, positioning the valve body to a position corresponding to the retard position when a state quantity of the operating oil is in a first range, and switching a position of the valve body in response to the state quantity (pressure or temperature) of the operating oil while resisting an urging force of the urging spring to position the valve body to a position corresponding to the advance position when the state quantity of the operating oil is in a second range greater than the first range.

The invention pertains to gas exchange in internal combustion engines using low to zero-emission fuels. The combustion engine has the ability to regulate the quantity of air/fuel mixture in the cylinder using one or more exhaust valve(s) (2) that can have adjustable opening times in order to control the gas exchange in the cylinder so that exhaust and alternatively also air can be expelled into the exhaust system. By reducing the quantity of air and thus the quantity of fuel for each cycle, that combined with reduced compression pressure means that engines can operate with a higher expansion ratio by leaving the exhaust valve(s) (2) open through a part of the compression stroke to reduce the amount of air to the combustion and reduce compression and then pressure rise before combustion. Air volume and gas exchange are regulated by compressor(s) (5) as well as opening and closing of exhaust valve(s) (2) with the exhaust valve control (4); alternatively, also intake valves for 4-stroke engines.

A novel latch seat for a switching rocker arm assembly used in variable valve actuation (VVA) systems for internal combustion engines. The seat is formed interactively in the assembled switching rocker arm using a novel fixture and press. The press interactively creates a curved dimple of the correct curvature, position and depth while measuring several lash dimensions. Since the latch seat is formed on the assembled rocker arm assembly, the latch seat depth is designed to account for the inaccuracies in the rocker arm assembly parts which create lash. Therefore all of the parts may be made with less precision since the latch seat is sized to compensate for the inaccuracies of all of the parts. The rocker arm assembly parts now may be manufactured to less stringent standards, but result in a rocker arm assembly with same accuracy of rocker arm assemblies manufactured to previous standards.

A method is disclosed for controlling an internal combustion engine having a first adjustable camshaft for the actuating of first valve elements of the internal combustion engine. An effect of an actuation at least of a first valve element by the first camshaft on this valve element is detected. An actual position of the first camshaft and/or of a crankshaft driving the latter is detected on the basis of this detecting of the effect. An adjustment of the first camshaft is calibrated on the basis of a first deviation between this detected actual position and a predetermined required position.

A system includes a valve actuation system, a pre-lubrication pump coupled to a lubrication circuit and configured to provide oil to the valve actuation system, a catalyst for receiving and treating exhaust gasses, and a controller. The controller is configured to identify an engine start request and determine whether the catalyst temperature is below a first threshold value. In response to determining that the catalyst temperature is below the first threshold value, the controller actuates the pre-lubrication pump to direct lubricant to the valve actuation system, controls the valve actuation system to deactivate at least one cylinder of an engine, and, subsequent to deactivating the at least one cylinder of the engine, cranks the engine.

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.

There is provided a variable valve timing system including: a variable valve device; an oil control valve configured to control a hydraulic pressure with respect to the variable valve device; an external pipe connecting a main gallery and the oil control valve; and a hydraulic pressure sensor configured to detect a hydraulic pressure in an oil path formed at the crankcase. The oil control valve is disposed on one side surface of the engine in the vehicle width direction. One end portion of the external pipe is connected to one side of the main gallery in the vehicle width direction. In a bottom view of a vehicle, the one end portion of the external pipe overlaps with the crankcase, and the hydraulic pressure sensor overlaps with the crankcase on one side of the one end portion of the external pipe in the vehicle width direction.

Various embodiments of the teachings herein include methods for operating a motor vehicle having combustion chambers. The methods may include: closing the combustion chambers of the motor vehicle towards the exhaust tract by bringing outlet valves of the combustion chambers into the closed state; checking whether the outlet valves of the combustion chambers of the motor vehicle are in a closed state by evaluating the pressure prevailing in an intake pipe of the motor vehicle; and in the event one or more of the outlet valves are not in a closed state, initiating countermeasures to comply with emissions protocols.

A system and associated methods for controlling valve motion in internal combustion engines provide a pulsing component for energizing a solenoid control valve in pulsatile fashion to cause a transient pressure change in a hydraulic network linking the control valve to a common, paired set of intake and exhaust main event deactivation mechanisms, which may be provided in respective valve bridges. The pressure change results in hydraulic deactivation of main event motion of the exhaust valve while avoiding deactivation of main intake event motion and thereby preserving intake main event valve motion, and supporting use of the intake main event motion for additional braking or other operations. The systems and methods are particularly suited for engine environments that employ cylinder deactivation (CDA) combined with high-power density (HPD) engine braking.

There is provided a variable valve timing system including: a variable valve device; an oil control valve configured to control a hydraulic pressure with respect to the variable valve device; an external pipe connecting a main gallery and the oil control valve; and a hydraulic pressure sensor configured to detect a hydraulic pressure in an oil path formed at the crankcase. The oil control valve is disposed on one side surface of the engine in the vehicle width direction. One end portion of the external pipe is connected to one side of the main gallery in the vehicle width direction. In a bottom view of a vehicle, the one end portion of the external pipe overlaps with the crankcase, and the hydraulic pressure sensor overlaps with the crankcase on one side of the one end portion of the external pipe in the vehicle width direction.