Fuel gas feeding system

• US 20010032628A1
• Filed: 04/20/2001
• Published: 10/25/2001
• Est. Priority Date: 04/20/2000
• Status: Active Grant

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Akazaki, Shusuke, Goto, Hiroyuki, Yamazaki, Hideharu, Sakurai, Yoshihito
• Granted Patent: US 6,427,670 B2
• Time in Patent Office: Days
• US Class Current: 123/529
• CPC Class Codes: F02B 43/00 Engines characterised by operating on gaseous fuels; Plants including such engines engines characterised by the gas-air charge being ignited by compression ignition of an additional fuel F02B7/06; engines convertible from gas to other fuel consumption F02B69/04
• CPC Class Codes: F02D 19/022 to adjust the fuel pressure, temperature or composition
• CPC Class Codes: F02D 19/025 Failure diagnosis or prevention; Safety measures; Testing
• CPC Class Codes: F02D 19/027 Determining the fuel pressure, temperature or volume flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02D 2041/226 Fail safe control for fuel injection pump
• CPC Class Codes: F02D 41/0027 the fuel being gaseous non-electrical control F02D19/02
• CPC Class Codes: F02M 21/0215 Mixtures of gaseous fuels; Natural gas; Biogas; Mine gas; Landfill gas
• CPC Class Codes: F02M 21/0242 Shut-off valves; Check valves; Safety valves; Pressure relief valves
• CPC Class Codes: F02M 21/0278 Port fuel injectors for single or multipoint injection into the air intake system
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A first cutoff valve 24 and a second cutoff valve 41 are closed in a state in which an internal combustion engine 1 is stopped, and a reducing amount of a pressure P0 in a high pressure passageway 11 after the passage of a predetermined decision time T0 and a reducing amount of a pressure P2 in a low pressure passageway 12 after the passage of a predetermined decision time T2 are measured. When the reducing amount of the first pressure P0 is equal to or larger than a predetermined reducing amount ΔP0, it is decided that a leakage is generated in the high pressure passageway 11. When the reducing amount of the second pressure P2 is equal to or larger than a predetermined reducing amount ΔP2, it is decided that a leakage is generated in the low pressure passageway 12.

Claims

1. A fuel gas feeding system comprising:

a fuel gas feeding passageway for feeding a fuel gas to an internal combustion engine;

a plurality of cutoff valves provided in the middle of the fuel gas feeding passageway;

a pressure sensor for detecting a pressure in a portion partitioned by adjacent two of the cutoff valves in the fuel gas feeding passageway;

an engine stop detecting unit detecting stop of the engine; and

a failure detecting unit closing the two adjacent cutoff valves when the stop of the engine is detected, measuring a reducing amount of a pressure detected by the pressure sensor after a predetermined decision time passes, and deciding that a leakage is generated between the two adjacent cutoff valves when the reducing amount thus measured is equal to or larger than a predetermined reducing amount.

2. The fuel gas feeding system according to

claim 1

, wherein the fuel gas feeding passageway includes a high pressure passageway partitioned by a first cutoff valve and a second cutoff valve and having a comparatively high pressure of a fuel gas, and a low pressure passageway partitioned by the second cutoff valve and a third cutoff valve and having a comparatively low pressure of the fuel gas,

a pressure regulator is provided between the low pressure passageway and the second cutoff valve, and

the failure detecting unit sets the predetermined decision time required for deciding presence of a leakage in the low pressure passageway depending on a pressure in the high pressure passageway and a temperature of the fuel gas in the low pressure passageway.

3. The fuel gas feeding system according to

claim 2

, wherein the third cutoff valve is a fuel injection valve.

4. The fuel gas feeding system according to

claim 1

, further comprising:

an engine coolant temperature sensor detecting a cool ant temperature of the engine,

wherein, when the coolant temperature is lower than a predetermined coolant temperature, the processing of the failure detecting unit is stopped.