Gaseous fuel injection valve

A gaseous fuel injection valve configured to directly injecting gaseous fuel into a combustion chamber of an internal combustion engine, the gaseous fuel injection valve comprising:

• a main body formed in a cylindrical shape, the main body including a fuel passage and an injection hole, the fuel passage located inside the main body, the injection hole located at a tip end of the main body, wherein
• the main body includes a partition that divides the fuel passage into a first fuel passage and a second fuel passage, the first fuel passage being an upstream portion of the fuel passage, the second fuel passage being a downstream portion of the fuel passage, the partition having a communication hole through which the first fuel passage communicates with the second fuel passage,
• the main body includes a first valve, a second valve, and a seal member inside the main body, the first valve configured to open and close the communication hole from a side of the first fuel passage, the second valve configured to open and close the communication hole from a side of the second fuel passage, a seal member located between the first valve and the partition, the seal member configured to seal a region around an opening of the communication hole,
• the first valve is configured to be opened by a drive unit, and the second valve is configured to be opened in response to a pressure inside the communication hole exceeding a biasing force of a biasing member that is configured to urge the second valve toward a closed position,
• the main body includes an extended portion that extends toward the downstream portion from the partition,
• the main body includes a structure configured to cool the extended portion by causing the gaseous fuel, which has flowed out from the communication hole and undergone adiabatic expansion upon opening of the second valve, to impinge on the extended portion,
• the extended portion of the main body is a peripheral wall that extends from an outer periphery of the partition toward the downstream portion and forms the second fuel passage,
• the second valve includes:
• a cylindrical portion that is slidable with respect to an inner peripheral surface of the main body;
• and
• a guide portion configured to guide the gaseous fuel, which has flowed out from the communication hole and undergone adiabatic expansion, toward a radially outer side of the guide portion to impinge on the peripheral wall,
• the second fuel passage has a first portion at an upstream end and a second portion positioned downstream of the first portion,
• a passage diameter of the first portion differs from a passage diameter of the second portion,
• the first portion has an annular expanded space with a larger passage diameter than the second portion, the annular expanded space located at a radially outer side of the cylindrical portion,
• the guide portion of the second valve is configured to guide the gaseous fuel, which has flowed out from the communication hole and undergone adiabatic expansion, toward a radially outer side of the guide portion and introduce the gaseous fuel into the annular expanded space,
• the cylindrical portion has an opening through which the annular expanded space communicates with an inner space located at a radially inner side of the cylindrical portion.

A gaseous fuel injection valve configured to directly injecting gaseous fuel into a combustion chamber of an internal combustion engine, the gaseous fuel injection valve comprising:

• a main body formed in a cylindrical shape, the main body including a fuel passage and an injection hole, the fuel passage located inside the main body, the injection hole located at a tip end of the main body, wherein
• the main body includes a partition that divides the fuel passage into a first fuel passage and a second fuel passage, the first fuel passage being an upstream portion of the fuel passage, the second fuel passage being a downstream portion of the fuel passage, the partition having a communication hole through which the first fuel passage communicates with the second fuel passage,
• the main body includes a first valve, a second valve, and a seal member inside the main body, the first valve configured to open and close the communication hole from a side of the first fuel passage, the second valve configured to open and close the communication hole from a side of the second fuel passage, a seal member located between the first valve and the partition, the seal member configured to seal a region around an opening of the communication hole,
• the first valve is configured to be opened by a drive unit, and the second valve is configured to be opened in response to a pressure inside the communication hole exceeding a biasing force of a biasing member that is configured to urge the second valve toward a closed position,
• the main body includes an extended portion that extends toward the downstream portion from the partition,
• the main body includes a structure configured to cool the extended portion by causing the gaseous fuel, which has flowed out from the communication hole and undergone adiabatic expansion upon opening of the second valve, to impinge on the extended portion,
• the communication hole is configured to accommodate residual gas that remains downstream of the first vale during an interval between closure of the first valve and subsequent opening of the first valve such that a total volume of the communication hole matches a volume of the residual gas.