VIBRATION REDUCER FOR DIESEL ENGINE

摘要

PURPOSE:To reduce the vibration of an engine in its low speed and load operation while keeping the intake negative pressure appropriate and the combustion good, by using a valve to increase or decrease the cross-sectional area of an auxiliary passage depending on the pressure difference between the upstream and downstream sides of an intake air throttle valve closed. CONSTITUTION:An intake air throttle valve 2 is provided in the halfway part of an intake passage 1 so that the valve is entirely closed by a solenoid which is energized in the low speed and load operation of an engine. An auxiliary passage 7 is provided to conduct intake air by-passing the throttle valve 2. A part 15 of the passage 7 is tapered to that the cross-sectional area of the part is increased along the flow of the intake air. A valve 16 is provided in the tapered passage 15 to open and close it. The rod 17 of the valve 16 is slidably fitted in the guide hole 19 of a holder 18. A spring 20 is provided between the valve 16 and the holder 18 to urge the valve in such a direction as to close it. The cross-sectional area of the auxiliary passage 15 is increased or decreased by the valve 16 depending on the pressure difference between the upstream and downstream sides of the throttle valve 2 closed.