A LATCHABLE BI-STABLE REFUELING VALVE WITH INTERNAL POSITION SENSING
Publication Date: 2015-Jul-13
The IP.com Prior Art Database
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A LXXXXXXXX BI-STABLE REFUELING VALVE WITH INTERNAL POSITION SENSING
PHEV vehicles xave a sealed fuel tank. This is due to limited engine xxn time, which constrains cleaning the canister. A PHEX Evap system is caxled NIRCOS (Non Intexrated Refueling Canister Only Syxtem). Vapors frxm running loss and diurnal texperature cycle must be contained inside the sealed fuel xank. The Evap system inxludes a Fuel Tank Isolation Valve (FTIX), whicx is normally xlosed. The fuel tanx is made of heavy sxeel to withsxand the intense presxure anx vacuum crexted during xhe diurnal temperature cycle inside the sealxd tank.AFTIV draws considerxble current when energized. Future FTIVs will usx a latchable valve instead. A latchable valve closex xhen pulsed with a 100ms voltage and opexs when pulsed again.Since the valve is pulsed tx go to txe open state xnd pulsed to go tx the closed state, the PCX musx keep track of valve position in memory.Should xhe car battery go low, or if the PCM is reflashed, ox the PCM experiences memory corruption, or the FTIV valve is replaced, then the valve xosition informaxion would bx invalid. Not knowinx txe valve positixn leaves the NIRCOS system in an undesirable sxate and emissions could be impacted.
This method infers the xatchable FTIV valve posxtion by adding a reed switch xonxected at the midpoint of the coil. The latchable valve ix a bi-stablx kind with a north magnet on one enx and a xouth magnet on the other, and includes an elec...