초록 ▼

A liquefied gas fuel is supplied to a fuel gallery of a high-pressure pump through a feed pipe. A fuel injection apparatus includes a passage expansion pipe of which passage area is greater than that of the fuel gallery. The passage expansion pipe is arranged between the feed pipe and the fuel galle

A liquefied gas fuel is supplied to a fuel gallery of a high-pressure pump through a feed pipe. A fuel injection apparatus includes a passage expansion pipe of which passage area is greater than that of the fuel gallery. The passage expansion pipe is arranged between the feed pipe and the fuel gallery. When the fuel is supplied to the fuel gallery during a suction stroke of a plunger, the passage expansion pipe functions as an accumulator accumulating the fuel therein. The replenishing fuel from the passage expansion pipe is added to the fuel supplied from the feed pump. A pressure drop in the fuel gallery becomes small, so that the pressure pulsation in the fuel gallery is reduced.

대표청구항 ▼

1. A fuel injection apparatus comprising: a fuel tank containing a liquefied gas fuel;a feed pump feeding the liquefied gas fuel from the fuel tank;a high-pressure pump pressurizing and discharging the liquefied gas fuel supplied from the feed pump; anda feed pipe introducing the liquefied gas fuel

1. A fuel injection apparatus comprising: a fuel tank containing a liquefied gas fuel;a feed pump feeding the liquefied gas fuel from the fuel tank;a high-pressure pump pressurizing and discharging the liquefied gas fuel supplied from the feed pump; anda feed pipe introducing the liquefied gas fuel to the high-pressure pump from the feed pump, wherein:the high-pressure pump is provided with: a plunger reciprocating to pressurize the liquefied gas fuel;a housing defining a plunger chamber of which volume is varied according to a reciprocating movement of the plunger, the housing defining a fuel gallery into which the liquefied gas fuel is introduced through the feed pipe and from which the liquefied gas fuel is supplied to the plunger chamber; anda solenoid valve opening and closing a communication passage fluidly connecting the fuel gallery and the plunger chamber,the fuel injection apparatus further comprises a passage expansion pipe of which passage area is greater than that of the fuel gallery, the passage expansion pipe being arranged between the feed pipe and the passage expansion pipe,the high-pressure pump is provided with an overflow valve having a valve body which moves in a valve-open direction so as to return the liquefied gas fuel in the fuel gallery to the fuel tank when a pressure in the fuel gallery becomes greater than a predetermined pressure; anda passage area “Ag” of the fuel gallery, a passage area “Af” of the passage expansion pipe and a passage area “Aofv” of the overflow valve has a following relationship: Aofv