A spark-ignited gas engine system comprises a combustion chamber defined by a piston, a head with a spark plug mechanism, and a cylinder having an associated intake valve and an associated exhaust valve, into which a mixture of combustible gas and air is entered via an intake manifold of the engine to drive a crankshaft. The system further comprises at least one turbocharger to compress the mixture. The system further comprises at least one camshaft, driven by the crankshaft via a gear assembly connected to the crankshaft, that comprises at least one cam that actuates the intake valve and the exhaust valve, at least one camphaser, coupled to the crankshaft via the gear assembly, and a controller to adjust a cam angle operation of the intake valve and the exhaust valve by adjusting the camphaser to a desired phase position to meet a target rotational phase of the camshaft.

To provide a controller and a control method, for an internal combustion engine, that can detect occurrence of knocking appropriately, even though the frequency distribution of the knock signal is distorted according to the occurrence state of knocking. The controller for the internal combustion engine calculates the background level by processing a low pass filter to the knock signal; and performs a low side frequency increase which makes a low side frequency, which is a cutoff frequency of the low pass filter in the case where the knock signal is smaller than an output value of the low pass filter, higher than a high side frequency, which is a cutoff frequency of the low pass filter in the case where the knock signal is larger than the output value of the low pass filter.

A valve mechanism includes a valve, a camshaft, an intermediate swing arm located between a cam and the valve, a lift regulating mechanism and a roller assembly. The cam drives the valve to move by means of the intermediate swing arm. The roller assembly is supported by the cam, an eccentric wheel of the lift regulating mechanism and an intermediate swing arm roller. A peripheral surface of the eccentric wheel includes a lift regulating section having a start point and an end point, a maximum lift point of the lift regulating section is located between the start point and the end point, and the lift regulating section is divided into a first section which is convex and a second section having at least a part thereof concave.

Disclosed is a method for determining the state of rotation of a camshaft of a vehicle engine, notable in that the method for determining the state of rotation of the camshaft determines that the state of rotation of the camshaft is in the process of stalling, corresponding to an intermediate state of rotation, when the time elapsed since the last detection of a camshaft wheel tooth-front by the sensor exceeds Tcam_cal, Tcam_cal being defined as the theoretical length of time needed for the camshaft wheel to cover an angular distance equal to the maximum angular distance separating two successive camshaft wheel tooth-fronts at a camshaft rotational speed corresponding to a predetermined low engine speed higher than the minimum engine speed tolerated by the engine.

A method for controlling intake and exhaust valves of an engine includes: controlling, by an intake continuous variable valve timing (CVVT) device, opening and closing timings of the intake valve; controlling, by an exhaust CVVT device, opening and closing timing of the exhaust valve; determining, by a controller, a target opening duration of the intake valve and target opening or target closing timings of the intake valve based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device, current opening and closing timings of the intake valve based on the target opening duration; and advancing or retarding, by the intake CVVD device, the current opening timing of the intake valve while simultaneously retarding or advancing the current closing timing of the intake valve by a predetermined value based on the target opening duration of the intake valve.

A method for controlling intake and exhaust valves of an engine may include: determining, by a controller, a target opening duration of the intake and exhaust valves based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device and by an exhaust CVVD device, current opening and closing timings of the intake valve and/or exhaust valve based on the target opening duration of the valves; and advancing or retarding, by the intake and/or exhaust CVVD devices, the current opening timing of the intake and exhaust valves while simultaneously retarding or advancing the current closing timing of the intake and exhaust valve by a predetermined value based on the target opening duration.

A controller for an internal combustion engine includes: a failure determination section which determines a failure state in a case where a relative rotation phase of an intake side valve opening and closing timing control mechanism does not change when controlling the mechanism after starting the driving of a starter motor and trying to change the relative rotation phase of the mechanism in a start control for starting an internal combustion engine. When the section determines a failure, the controller performs at least one of an intake air amount increase control in which an opening degree of a throttle valve is increased, an ignition timing advance angle control in which injection of fuel is performed at a timing earlier than a set timing and ignition is performed, and a multi-injection control in which the fuel is injected immediately before the ignition in addition to the fuel injection in an intake stroke.

A camshaft phaser includes a reservoir cover on a rear side, facing the cams, and a timing wheel on a front side. Fluid is routed from the oil control valve to the reservoir via radial channels defined between a rear cover and a thrust interface. Fluid may also be routed from a radial bearing to the reservoir via these channels. A spool in the oil control valve assembly has an internal passageway to route fluid from a front cavity to the radial channels.

A control method for a continuously variable valve lift mechanism includes: controlling a continuously variable valve lift mechanism to enter a limp mode when the continuously variable valve lift mechanism fails and disables an automatic valve lift changing function; driving and forcing the continuously variable valve lift mechanism to move to a maximum lift position; and triggering a self locking function to self lock the continuously variable valve lift mechanism at the maximum lift position when the continuously variable valve lift mechanism reaches the maximum lift position. A control system for a continuously variable valve lift mechanism, and a vehicle are also provided.

In a control device and a control method for a variable valve timing mechanism according to the present invention, the rotational phase of a camshaft is measured based on the cam angle signal and crank angle signal upon receiving each pulse of the cam angle signal, and the rotational phase change over time within a period of the cam angle signal is measured based on the motor angle signal. It is decided whether the cam angle signal and/or crank angle signal has a prescribed pulse pattern at a diagnostic timing that comes after the last pulse of the cam angle signal. When this decision result is positive, it is then decided whether the motor angle sensor operates normally or abnormally based on the rotational phase and the amount of rotational phase change that are measured when the last pulse of the cam angle signal is received before the diagnostic timing.