Variable valve operating system for internal combustion engine

A variable valve operating system for an internal combustion engine comprising:

• a variable valve-lift and working-angle control mechanism that changes at least one of a valve lift and a working angle of each of engine valves;
• at least two variable valve timing control mechanisms that change valve timings independently of each other;
• and
• a control unit configured to be electronically connected to the variable valve-lift and working-angle control mechanism and the variable valve timing control mechanisms for responding a failure in one of the variable valve timing control mechanisms for failsafe purposes;
• the control unit comprising:
• a first failsafe section capable of executing a first failsafe operating mode in which at least one of the valve lift and the working angle of each of engine valves is increasingly compensated for by the variable valve-lift and working-angle control mechanism, when the one variable valve timing control mechanism is failed.

A variable valve operating system for an internal combustion engine with at least two cylinder banks comprising:

• a variable valve-lift and working-angle control mechanism that changes at least one of a valve lift and a working angle of each of engine valves arranged in each of the cylinder banks;
• at least two variable valve timing control mechanisms provided for each of the cylinder banks, for changing a valve timing of each of the engine valves arranged in one bank of the cylinder banks and a valve timing of each of the engine valves arranged in the other bank independently of each other;
• and
• a control unit configured to be electronically connected to the variable valve-lift and working-angle control mechanism and the variable valve timing control mechanisms for responding a failure in one of the variable valve timing control mechanisms for failsafe purposes;
• the control unit comprising:
• malfunction detection means for determining whether one of the variable valve timing control mechanisms is failed;
• and
• failsafe means for executing a failsafe operating mode in which at least one of the valve lift and the working angle of each of engine valves is increasingly compensated for by the variable valve-lift and working-angle control mechanism, when the one variable valve timing control mechanism is failed.