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EVAP LEAK DIAGNOSTICS USING ACCUMULATOR BOTTLE

IP.com Disclosure Number: IPCOM000241983D
Publication Date: 2015-Jun-11
Document File: 1 page(s) / 256K

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The IP.com Prior Art Database

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EVAP LEAK DIAGNOSTICS USING ACCUMULATOR BOTTLE

Vehicles sold in North Ameriaca are required to perform Evap leak detection as part of OBDII requirements. Green states required to monitor for 0.02" leaks as part of the Clean Air Act Section 177. (CAA) IN MY2017, all states have to perform 0.02" leak tests. A method used in the prior art consists of evacuating liquid fuel into a bladder. According to the Ideal Gas Law, PV=nRT, when the vapor dome expands as a result of removing liquid fuel, a vacuum generates inside the vapor dome if system is sealed. If system has a leak in it, vacuum does not develop. Once diagnostics are over, liquid needs to drain back into the tank. The prior art method used a pressurized bottle with internal bladder apparatus. Fuel was stored inside the bladder temporarily and the pressurized bottle put fuel back into the fuel tank once the leak detection is finished. Without the pressurized bottle, the fuel may become trapped inside the bladder and prevent any future leak detection execution (disable method).Over time, the pressurized bottle may lose pressure itself and this is problematic.

Method

This new method replaces the pressurized bottle/bladder with a fixed reservoir.The same technique is used to fill up the reservoir and analyze for leak vs no leak. Specifically, the fuel pump and additional valves are used to evacuate fuel inside the reservoir. However, a different method is used to empty the reservoir.The same fuel pump that w...