CONTROL DEVICE OF GAS INJECTION VALVE

摘要

PURPOSE:To perform highly accurate injection quantity control of less than minimum injection quantity by providing a pressure control means reducing fuel gas supplying pressure by correlating to fuel request quantity of less than a predetermined value in an injection quantity control device of a gas injection valve. CONSTITUTION:A pressure control device 14 including a pressure regulating valve 30 is interposed on a supply system of fuel gas pressurized to a predetermined pressure by a compressor and supplied, and the pressure regulating valve 30 is controlled by a pressure control circuit 32. The pressure control circuit 32 is constituted so that it compares fuel request quantity signal QG output from a governor and a lower limit injection quantity Qmin previously determined based on gas injection quantity control characteristic of a fuel injection valve 22, and that when QG<Qmin, objective supply pressure PGO of fuel gas is determined based on a function previously set and that the deviation with the pressure PG is output to the pressure regulating valve 30 as a control signal DELTAPG. And a control rack bar 18 of an injection pump 16 is slid to be adjusted by the fuel request quantity signal QG to control fuel quantity.