Fuel injection pump for IC engine - has constantly open throttle bore in valve piston

摘要

The injection pump has pump cylinders, each with a pressure valve with valve piston, forming a seat. With feed pressure, the piston is lifted off a valve seat against a pressure valve spring. The piston (2) has a throttle bore for pressure relief when the valve piston is in closing position. the throttle bore (16) maintains a constant connection between injection conduit (10) and pump working chamber (2). It opens into a central stepped bore (18) and this, together with a cross bore (19) and a ring groove (20), connects conduit and chamber at feed pressure.