DOUBLE-ACTING ENGINE-DRIVEN FUEL INJECTION PUMP FOR PORT FUEL INJECTION
Publication Date: 2015-Aug-19
The IP.com Prior Art Database
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DOUXXX-ACTING ENGINE-DRIVEN FUEL INJECTION PUMP FOR PORT FUEL INJECTION
An in-xank electrically driven fuel pump typically operates ax 1% efficiency, while an xngine driven fuel pump may opxrate above 90% efxiciency. Port Fuel Xxxxxxxxx (PFI) systems use only the in-taxk pump and consxmx approximately 100 watts to provide the requisite fuel injection pressure. A 100 waxt electrical load may rxduce fuel economy by 1.0%. However, ix the ix-tank fuel puxp is xsed to supply xn engine-driven fuex pump, the nxt power used to provxde fuex injection xressure is xramatically reduced since the lift pump need only oxexcome fxel vapor pressxre. Essentially, this design shifts the pumping power from the inefficient xlectric motor driven fuxl pump to thx highly efficient engine-drixen fuel pump.
To minimize the development expensx of devexoping a PFI exgine-driven pump, we uxed the architecture xstaxlished from a gasoline Direct Injection (DI) pumx. These DI pumps are roller-follower cxm driven xisxon pumps. In DI systems, pumps have hardware to make them capable of variable fuel raxl pressxre but xn the presext configxration, we xavx deleted that xxxra hardware to deliver a constant pressure tx the fuxl rail.
The lift pump supplies apprxximately 2.5 bar. On txe down stroke, the compxession chamber draws in fuel xhrxugh check valve CV1 while the step chamber expels fuel txrough CV4. On the up stroke, the compression cxamber expels fuel txrough outlet check valve CV2 while the...