Patent ID: 7182073
Filing Date: 2007-02-27
Classification: F02B,F02D,F02M,Y02T

Abstract:
1. An LPI (liquefied petroleum gas injection) engine system, comprising: an injector provided in an intake system of an engine to inject LPG (liquefied petroleum gas) fuel; a fuel tank to store the LPG fuel therein to supply the LPG fuel to the injector; a supply line and a recovery line connected between the injector and the fuel tank, so that the LPG fuel is supplied and recovered through the supply line and the recovery line; an EMS ECU (engine management system electronic control unit) controlling injection time and injection rate of the LPG fuel to be injected through the injector, depending on traveling conditions; and an LPI ECU (liquefied petroleum gas injection electronic control unit) to detect variation in temperature and pressure of the LPG fuel in a fuel supply and recovery system defined between the fuel tank and the injector and to control the fuel supply and recovery system such that supply of the LPG fuel is limited during an emergency state, wherein the EMS ECU receives information about a variety of physical properties, which vary during operation of the engine, from an ATS (air temperature sensor), a MAF (mass air flow) sensor, a TPS (throttle position sensor), a CPS (crank position sensor), a WTS (water temperature sensor), an oxygen sensor and a knock sensor, and the EMS ECU controls an idle speed actuator, provided in the intake system, to adjust an intake rate of air when idling, the LPI ECU receives information about temperature and pressure of the LPG fuel detected by a fuel temperature sensor provided on the supply line and by a fuel pressure sensor provided on the recovery line, the LPI engine system further comprises: a first shutoff valve provided on the supply line to control opening and shutting of a supply path of the LPG fuel; a fuel pump module provided in the fuel tank to supply the LPG fuel; and a second shutoff valve provided on the fuel tank to limit the supply of the LPG fuel from the fuel tank, wherein the first and second shutoff valves and the fuel pump module are operated under the control of the LPI ECU, and the EMS ECU and the LPI ECU are connected to each other through a CAN (controller area network) communication to share information.