摘要:
A vapor management system (10) includes a sense tube (47) disposed in a fuel tank (12). A differential pressure sensor (17) has one side connected to the sense tube and another side connected to a vapor cavity so that the pressure sensor can measure a differential pressure (DP) between a volume of the vapor cavity and a volume of the sense tube containing liquid fuel. A temperature sensor (26) is in the vapor cavity. A processor 1) receives DP and T measurements at certain time intervals to determine the temperature at time zero (T0), the differential pressure at time zero (DP0), the temperature at a certain time (Tt), and the differential pressure at a certain time (DPt), and 2) when (Tt−T0) is greater than a certain value, compares DPt to a certain differential pressure value.
摘要:
A vapor management system (10) includes a fuel tank (12), a canister (14), a pressure control valve (16) between the tank and canister and defining a high pressure side (34) and a low pressure side (32), a vacuum source (18), a purge valve (19) between the canister and vacuum source, a leak detection valve (20) connected with the canister and including a processor (30). A pressure sensor (24) and a temperature sensor (26) are disposed in a fuel vapor cavity of the fuel tank, with signals from the sensors being received by the processor. Based on an absolute temperature measured by the temperature sensor, the processor compares a predicted pressure in the fuel tank to the measured absolute pressure, and identifies a leak on the high pressure side if the predicted pressure is outside a tolerance range, while maintaining pressure in the fuel tank.
摘要:
A vapor management system (10) includes a sense tube (47) disposed in a fuel tank (12). A differential pressure sensor (17) has one side connected to the sense tube and another side connected to a vapor cavity so that the pressure sensor can measure a differential pressure (DP) between a volume of the vapor cavity and a volume of the sense tube containing liquid fuel. A temperature sensor (26) is in the vapor cavity. A processor 1) receives DP and T measurements at certain time intervals to determine the temperature at time zero (T0), the differential pressure at time zero (DP0), the temperature at a certain time (Tt), and the differential pressure at a certain time (DPt), and 2) when (Tt-T0) is greater than a certain value, compares DPt to a certain differential pressure value.
摘要:
A purge valve is provided for a vehicle. The purge valve 10 includes a body 12 to be coupled to an intake manifold 40 of the vehicle and to a canister 33. The body has an orifice 20 for communicating vapor from the canister 33 with airflow in the intake manifold 40. A valve 18 is movable between a first position closing the orifice 20 and a second position opening the orifice. A shape memory alloy (SMA) structure 31 is associated with the valve such that when electric current is provided to the SMA structure 31 to heat the SMA structure above a transformation temperature thereof, the SMA structure transforms from an original shape to a second shape, thereby causing the valve 18 to move from the first position to the second position, and when the current is removed from the SMA structure, the SMA structure returns to the original shape, thereby permitting the valve 18 to return to the first position.
摘要:
An integrated pressure management system manages pressure and detects leaks in a fuel system. The integrated pressure management system also performs a leak diagnostic for the head space in a fuel tank, a canister that collects volatile fuel vapors from the head space, a purge valve, and all associated.
摘要:
An integrated pressure management system manages pressure and detects leaks in a fuel system. The integrated pressure management system also performs a leak diagnostic for the headspace in a fuel tank, a canister that collects volatile fuel vapors from the headspace, a purge valve, and all associated hoses and connections.
摘要:
An integrated pressure management system manages pressure and detects leaks in a fuel system. The integrated pressure management system also performs a leak diagnostic for the headspace in a fuel tank, a canister that collects volatile fuel vapors from the headspace, a purge valve, and all associated hoses and connections.
摘要:
An integrated pressure management system manages pressure and detects leaks in a fuel system. The integrated pressure management system also performs a leak diagnostic for the headspace in a fuel tank, a canister that collects volatile fuel vapors from the headspace, a purge valve, and all associated hoses and connections.
摘要:
An integrated pressure management system manages pressure and detects leaks in a fuel system. The integrated pressure management system also performs a leak diagnostic for the headspace in a fuel tank, a canister that collects volatile fuel vapors from the headspace, a purge valve, and all associated hoses and connections.
摘要:
A leak detection monitor (22; 222) for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle. One embodiment (22) utilizes engine intake system vacuum to vent the evaporative emission space to atmosphere when the engine is running; another (222), an electromagnet actuator (270, 280). Venting ceases when the engine is shut off. Changes in vapor pressure in the evaporative emission space are monitored over time by electric devices (74; 282) after the engine has been shut off to distinguish between a gross leak, a small leak smaller than a gross leak, and a leak that is at most smaller than a small leak.