| 摘要 |
PURPOSE:To reduce the size of a driving means and to drive a cam so that a minimum lift amount is produced during the starting through location of a position detecting means for the starting, by a method wherein a cam, adapted to a lift amount of a valve, is driven through the medium of an elastic member. CONSTITUTION:A lift control cam 20 is rotated through the medium of a control shaft 23 and an elastic member 24 by means of a step motor 26 according to the operating state of an engine, and is adapted to change a fulcrum position allowing a lever to make contact with the back of a locker arm and control lift characteristics of suction and exhaust valves. Contacts 28 and 29, which detect a position during the starting, are located onto the control shaft 23. The step motor 26 is driven until a cam surface, providing a minimum lift amount, is brought into contact with the lever, and after lift during the starting is set in all valves, a starter motor is started. This causes torque, by means of which the control cam 20 is rotated, to be accumulated in the elastic member 24, and causes the control cam 20 to be rotated during non-lift. |
