| 摘要 |
In a fuel pump and method of operation, an infeed for low pressure fuel leads to a pumping chamber where in an intake phase low pressure fuel is drawn into the pumping chamber and in a pumping phase high pressure fuel is delivered to a common rail. An inlet metering valve and an inlet check valve are upstream of the pumping chamber, and a control system closes the metering valve when no fuel is to be pumped to the common rail. The inlet check valve is also opened while the inlet metering valve is closed and no fuel is to be pumped to the rail. The inlet metering valve can include a proportionally controlled piston that produces a variable quantity of feed fuel and is closable for the no-demand condition with a maximum travel that contacts and holds open the inlet check valve. |
