Multi-fuel engine control with canister purge

• US 4,945,885 A
• Filed: 12/21/1989
• Issued: 08/07/1990
• Est. Priority Date: 06/16/1989
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Gonze, Eugene V., Brown, David B.
• Primary Examiner(s): Cross, E. Rollins
• Application Number:
  US07/453,166
• Time in Patent Office: 229 Days
• Field of Search: 123/520, 123/578, 123/478
• US Class Current: 123/520
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02D 19/0628 Determining the fuel pressure, temperature or flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02D 19/084 Blends of gasoline and alcohols, e.g. E85
• CPC Class Codes: F02D 19/087 with determination of densities, viscosities, composition, concentration or mixture ratios of fuels
• CPC Class Codes: F02D 2200/0606 Fuel temperature
• CPC Class Codes: F02D 2200/0611 Fuel type, fuel composition or fuel quality
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: F02D 41/0032 Controlling the purging of the canister as a function of the engine operating conditions
• CPC Class Codes: F02M 25/089 Layout of the fuel vapour installation
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A fuel control for a vehicle engine using a liquid mixture of two fuels includes a fuel vapor canister open to the fuel tank and canister purge apparatus effective to allow fuel vapors to be drawn from the canister to the engine at a controlled purge rate during engine operation. The canister purge apparatus is responsive to a fuel composition sensor to vary the purge rate as a function of the fuel composition. If the two fuels are gasoline and methanol, the canister purge rate is varied, in a predetermined range of fuel temperature, so as to provide a higher purge rate for mixtures of gasoline and methanol, in at least some proportions, than for either gasoline or methanol alone. The canister purge rate may further be varied in response to fuel temperature.

Claims

1. A fuel control for a vehicle engine having a fuel tank containing a liquid fuel mixture comprising first and second combustible fuels and having a volatility varying with the relative proportion of one of the first and second fuels, induction means effective to provide the liquid fuel mixture and air to the engine in a predetermined air/fuel ratio, a fuel composition sensor in the fuel conduit responsive to a physical parameter of the fuel mixture to generate a fuel composition signal indicative of the relative proportions of the first and second fuels in the fuel mixture, canister means in fluid communication with fuel vapor in the fuel tank and effective to store fuel vapor therefrom, and canister purge means for establishing fluid communication from the canister means to the induction means for removal of fuel vapor from the canister means to the engine at a controlled purge rate, the canister purge means being responsive to the fuel composition signal to vary the purge rate as a function of the fuel composition.

2. The fuel control of claim 1 in which the first and second fuels are gasoline and methanol and the canister purge means varies the purge rate in a predetermined range of fuel temperature so as to provide a higher purge rate for mixtures of gasoline and methanol, in at least some proportions, than for either gasoline or methanol alone.

3. The fuel control of claim 1 further comprising a temperature sensor effective to generate a signal indicative of fuel temperature, the canister purge means being further responsive thereto in varying the purge rate.

4. The fuel control of claim 3 in which the canister purge means increases the purge rate with increasing fuel temperature in a predetermined range of fuel temperatures.