A valve opening and closing timing control apparatus includes: a driving side rotor synchronously rotating with a crankshaft of an engine; a driven side rotor disposed at a coaxial core with a rotary shaft core of the driving side rotor and integrally rotating with a camshaft for a valve opening and closing; a connecting bolt disposed at the coaxial core with the rotary shaft core to connect the driven side rotor to the camshaft, and on which an advance angle port and a retard angle port are formed on an outer peripheral surface; and a spool disposed in a spool chamber of the inside of the connecting bolt, and controlling the feeding and discharging of working fluid to the advance angle port or the retard angle port from a pump port formed on the connecting bolt.

A method according to the invention for controlling an internal combustion engine having a camshaft whose phase with respect to a crankshaft can be adjusted by means of an electric adjustment device, and a control device comprises the steps S1 to S3, wherein in step S1 a stop request is output from the control device to the electric adjustment device. Subsequently, in step S2 a manipulated variable in the form of a pulse duty factor is output from the electric adjustment device, wherein the pulse duty factor counteracts a camshaft torque. In step S3, the direction of rotation of the camshaft is monitored, wherein in step S4, when a reversal of the direction of rotation of the camshaft is detected, an intensity level of this reversal of the direction of rotation is calculated by determining a rotational speed gradient. Furthermore, in a step S5 the pulse duty factor is corrected as a function of the rotational speed gradient in such a way that the influence of the reversal of the direction of rotation on the position of the camshaft is compensated.

A control device is configured, if, although the control device has caused a cam switching device to perform a first cam switching operation for switching the profiles of all the valve-driving cams of a plurality of cylinders from a first profile to a second profile, the profiles of all the valve-driving cams of the plurality of cylinders do not coincide with the second profile, to cause the cam switching device to perform a second cam switching operation for switching the profile of the valve-driving cam for at least one or more normal cylinders that are one or more cylinders at which the switching of profiles to the second profile has succeeded.

A method, control system, and variable valve timing system are provided for controlling an actuator that can be switched into an on state and an off state with pulse width modulation. The systems and method include controls configured to determine an actual system parameter on a first time schedule and a desired system parameter on a second time schedule. On a third time schedule, a position error difference between the actual system parameter and the desired system parameter is determined. The third time schedule is configured to begin and to determine the position error difference each time that the actual system parameter is determined and each time that the desired system parameter is determined. A desired duty cycle is determined, and a duty cycle command is sent to a pulse width modulation output unit.

Various embodiments of the teachings herein include a method for controlling a cam using an ECU (electronic control unit) comprising: learning a holding region in which linearity is not ensured by increasing or decreasing a PWM signal while the cam maintains a holding state; based on the results of the learning, generating a final PWM signal; and transmitting the final PWM signal to an oil control valve. The final PWM signal comprises a sum of a minimum PWM signal for the cam to leave the holding region and a control PWM signal for the cam to reach a desired position.

Methods and systems are provided for a phase control apparatus in a variable cam timing (VCT) system of an engine, the phase control apparatus having a locking pin coupled to a rotor vane and engageable with a locking pin recess in the phase control apparatus cover plate. In one example, a method for assembling the phase control apparatus may include positioning respective retarded side surfaces of the rotor vane and the housing in face-sharing contact while positioning respective retarded side surfaces of the locking pin and the locking pin recess in face-sharing contact and maintaining a backlash gap between only the advanced side surfaces of the locking pin the locking pin recess.

A multiple variable valve lift apparatus may include a moving cam formed in a hollow cylindrical shape into which a camshaft is inserted. In particular, the moving cam rotates together with the camshaft, moves in an axial direction of the camshaft, and includes a cam guide protrusion and a plurality of cams realizing different valve lift with each other. Moreover, the apparatus includes: an operating unit selectively guiding the cam guide protrusion; a controller controlling the operating unit; a valve opening/closing unit contacting with any one cam of the cams; and at least two pins disposed at the operating unit so as to guide the cam guide protrusion. The cam guide protrusion includes an inserted portion being selectively inserted between the pins and a shift portion.

Methods and systems are provided for controlling a variable camshaft timing system. In one example, a method may include actuating a camshaft phaser with a camshaft duty cycle determined based on a sampled camshaft position and an estimated camshaft position, the estimated camshaft position determined based on a previously determined camshaft duty cycle.

A control device has two modes as control modes of an electric power supply to an electromagnetic solenoid, which are used when a first determining unit determines that a difference between a sensed value of a phase and a target value of the phase exceeds a permissible range. One of the modes is a special mode that is used when a second determining unit determines that the sensed value of the phase reaches a threshold value. Another one of the modes is a normal mode that is used when the second determining unit determines that the sensed value of the phase does not reach the threshold value. In the special mode, the control device controls supply of the electric power to the electromagnetic solenoid in such a manner that an opening degree of an advancing port is larger than the opening degree of the advancing port in the normal mode.

A method of phasing the opening and closing of internal combustion engine intake and exhaust valves relative to the rotation of the crankshaft is based upon changes in engine speed, engine load and ambient relative humidity. During certain conditions of higher humidity, in order to maintain good combustion stability and thus overall engine operation, it is necessary to reduce intake and exhaust valve overlap by adjusting the phase of the intake and exhaust camshafts. This is achieved by utilizing a set of cam position reference values and constraints based upon engine speed, engine load and humidity that are contained in lookup tables that adjust and limit cam position and valve overlap. Generally speaking, in order to maintain optimum engine performance, intake and exhaust valve overlap is reduced with higher ambient humidity and vice versa.