Abstract:
Methods and systems are provided for adjusting an oil pressure supplied to an engine and a variable cam timing (VCT) responsive to a condition of the VCT system. In one example, a method may include adjusting the oil pressure based on engine speed, engine load, and engine oil temperature, and responsive to a request to shift the VCT system during specific engine operating conditions, increasing the oil pressure to an upper threshold oil pressure for the duration of the shift.
Abstract:
Methods and systems are described for an engine with a cam torque actuated variable cam timing phaser. Phaser positioning control is improved by reducing inaccuracies resulting from inadvertent spool valve and/or phaser movement when the spool valve is commanded between regions. In addition, improved spool valve mapping is used to render phaser commands more consistent and robust.
Abstract:
A continuous variable valve lift engine may include determining whether an engine is in an idle state and an oil temperature of an engine is within a predetermined range, controlling, the engine in a predetermined control state when the engine is in the idle state and the oil temperature is within the predetermined range, and measuring, an error occurrence time when an error occurs in controlling the engine in the control state, and controlling the engine while switching the engine to a predetermined passive state when the error occurrence time is more than a preset time.
Abstract:
A method is provided for operating an engine assembly having a hydraulically actuated component. The method may include providing pressurized oil from a pressurized oil source to an oil passage in communication with the hydraulically actuated component and determining a first oil pressure measurement within the oil passage a first predetermined time after the providing. The method may further include preventing operation of the hydraulically actuated component when the first oil pressure measurement is below a first predetermined limit, isolating the oil passage from the pressurized oil source after the providing, and determining a second oil pressure measurement within the oil passage a second predetermined time after the isolating when the first oil pressure measurement is above the first predetermined limit. Operation of the hydraulically actuated component may be prevented when the second oil pressure measurement is above a second predetermined limit.
Abstract:
If a relative rotational phase between a first rotor drivably connected to a crankshaft and a second rotor drivably connected to a camshaft is not an intermediate lock phase when an engine is started, a fuel injection starting timing is delayed more than that of the time when the relative rotational phase is the intermediate lock phase. The delay time is determined according to the working oil temperature of a valve timing mechanism during the engine start or the same oil temperature at the previous stop time of the engine, for example. As a result, the start of the engine can be completed as soon as possible while retaining the startability of the internal combustion engine.
Abstract:
A fuel diluting quantity is estimated based on an alcohol concentration of the fuel. A response-deterioration determination value is corrected according to the estimated fuel diluting quantity. The response-deterioration determination value can be properly established even though the responsiveness of the variable valve timing controller is varied due to a variation in viscosity of the lubricant. Thereby, even when the responsiveness of the variable valve timing controller is varied (deteriorated) due to an increase in the fuel diluting quantity, it can be avoided that the computer determines that the variable valve timing controller has a defect.
Abstract:
The invention provides a control apparatus comprising a controller for determining a manipulated variable for manipulating a controlled object so that an output of the controlled object converges to a desired value and a modulator for modulating the manipulated variable by using one of a delta-sigma modulation algorithm, a sigma-delta modulation algorithm and a delta modulation algorithm to generate a modulated signal to be applied to the controlled object. The modulator generates the modulated signal so that a center value of an amplitude of the modulated signal follows a change of the manipulated variable. Thus, the modulated signal in which the manipulated variable is reflected without any loss can be generated even when the manipulated variable changes.
Abstract:
A valve opening/closing timing control apparatus and method can be used with a camshaft whose rotation is synchronized with opening/closing timing of an intake valve or an exhaust valve in an internal combustion engine; a relative rotation angle adjustment mechanism which transmits torque of a crankshaft in the internal combustion engine to the camshaft and which adjusts a relative rotation angle between the crankshaft and the camshaft; and a lock mechanism which depends on hydraulic fluid, and which mechanically locks or unlocks the relative rotation angle that is adjusted by the relative rotation angle adjustment mechanism. The apparatus and method determine the duration of a time period from a start of the internal combustion engine until a start of relative rotation angle adjustment, based upon an unlocking force of the hydraulic fluid that is applied to the lock mechanism when the lock mechanism is locked and the internal combustion engine is started.
Abstract:
A valve opening/closing timing control apparatus and method can be used with a camshaft whose rotation is synchronized with opening/closing timing of an intake valve or an exhaust valve in an internal combustion engine; a relative rotation angle adjustment mechanism which transmits torque of a crankshaft in the internal combustion engine to the camshaft and which adjusts a relative rotation angle between the crankshaft and the camshaft; and a lock mechanism which depends on hydraulic fluid, and which mechanically locks or unlocks the relative rotation angle that is adjusted by the relative rotation angle adjustment mechanism. The apparatus and method determine the duration of a time period from a start of the internal combustion engine until a start of relative rotation angle adjustment, based upon an unlocking force of the hydraulic fluid that is applied to the lock mechanism when the lock mechanism is locked and the internal combustion engine is started.
Abstract:
A preparation control for suppressing fluctuation of an output torque of the engine at the time of executing switching operation from the whole cylinder operation to the partial cylinder operation is executed when having made a switching request from the whole cylinder operation to the partial cylinder operation, the valve operation phase is fixed to a predetermined phase before executing the switching operation, and the cylinder deactivation mechanism is controlled so as to execute the switching operation at a target switching time which is prefixed by corresponding to the predetermined phase. The target switching time is previously set to a timing at which abnormal noises are not generated, by corresponding to the valve operation phase fixed to the predetermined phase.