IMPROVEMENT TO DEVICES FOR SUPPLYING FUEL UNDER HIGH PRESSURE BY TRANSFER PUMP

摘要

An improved apparatus for supplying fuel under high pressure by a transfer pump is provided to increase capacity of the transfer pump by increasing flow rate of fuel without increasing a volume of a fuel supply apparatus. An improved apparatus for supplying fuel under high pressure by a transfer pump includes two identical transfer pumps(3,4). The transfer pumps are operated by power supplied via a control unit for controlling fuel supply ratio. The transfer pumps are provided with two identical common rails(2). The control unit includes an external unit(5) having a control solenoid valve(52). A differential pressure valve(55) allows a low pressure supply stage(1) to be directly connected with the rail by shutting down the control solenoid valve when the high press supply system is broken. The control solenoid valve is integrally formed with a first transfer pump via a bypass.