| 摘要 |
PROBLEM TO BE SOLVED: To properly insert a pin in a lock mechanism into a hole in an internal combustion engine stop step and to properly pull the pin which is inserted into the hole, out of the hole when starting a valve timing variable mechanism.SOLUTION: When a hydraulic pressure within the hydraulic chamber of a valve timing variable mechanism 16 required for canceling torque acting on an intake camshaft 12 because of opening and closing of an intake valve 11 is defined as "depressing pressure", a spring constant of a spring biasing the pin of a lock mechanism to a hole side is set as follows. Namely, the spring constant is set such that the unlock pressure (minimum value of the hydraulic pressure in the hydraulic chamber capable of pulling the pin out of the hole) becomes higher than the maximum value of the depressing pressure while the angle of action of a cam to the intake valve 11 is defined as a base value. Further, when starting the valve timing varying mechanism 16, the angle of action of the cam is made greater than the base value so that the maximum value of the depressing pressure becomes higher than the unlock pressure. |
