High pressure fuel pumps with mechanical pressure regulation

摘要

Methods are provided for operating a high pressure fuel pump to maintain one or more selectable, mechanically-regulated pressures. To reduce the cost and complexity associated with a fuel system that involves both port and direct fuel injection, a fuel and pump system is needed that removes complicated electronic control without degrading pump and engine performance. High pressure fuel pumps, associated systems, and methods are provided that involve adding one or more pressure relief valves and solenoid valves in order to maintain one or more discrete, substantially constant pressures of the high pressure fuel pumps and attached direct injection fuel rails.

主权项

1. A method, comprising:
during a first high pressure fuel pump operating mode, regulating a first fuel rail pressure via a first pressure relief valve; and during a second high pressure fuel pump operating mode, regulating a second fuel rail pressure via a second pressure relief valve that is in parallel with the first pressure relief valve and separated by a solenoid valve to direct fuel backflow to the first or second pressure relief valve, wherein a fuel rail pressure sensor is not provided on a direct injection fuel rail fluidly coupled to a high pressure fuel pump.