Fuel metering unit for injection system has valve with flat characteristic for idling/low load, steep characteristic for partial/full load; transition between characteristics can be differentiated

摘要

The unit has a high pressure pump driven depending on engine speed and a regulating valve actuated by an electromagnet and with a valve piston in a valve housing with control openings shaped and configured to produce at least two control ranges, one with a flat characteristic for idling and low load and one with a steep characteristic for partial and full load. The transition between the flat and steep characteristics can be differentiated. The unit has a high pressure pump driven depending on engine speed to produce the required fuel pressure and throughput in each engine operating state and a regulating valve actuated by an electromagnet and with a valve piston in a valve housing with control openings (32,34,35) shaped and configured to produce at least two control ranges, one with a flat characteristic for idling and low load and one with a steep characteristic for partial and full load. The transition between the flat and steep characteristics can be differentiated.