| 摘要 |
PURPOSE: To provide an accurate switching point of a control valve by forming the cam track of a cam into a predetermined continuous shape, the cam being adapted for controlling the control valve, for imparting the accurate switching points between the first to third switching positions of the control valve. CONSTITUTION: An internal combustion engine, in which an exhaust gas return valve 5 operated by a pneumatic servo motor 7 having a working chamber 8 intervenes in an exhaust gas return conduit 4 through which part of exhaust gas in an exhaust manifold 2 flows back to an air feed duct 3, includes a control valve 13 for controlling the pressure supplied to the working chamber 8, the control valve 13 being associated with the adjusting lever 16 of a fuel injection pump 15 which controls injection quantity; i.e., the adjusting lever 16 is connected to the operating member 22 of the control valve 13 via a control cam 20. The control cam 20 is shaped to describe an upgrade or downgrade cam track and formed so that the control valve 13 occupies three switching positions in sequence with the operation of shifting the adjusting lever 16 from a no-load operating position to a full-load operating position. |
