Methods of Flexible Fuel Engine Conversions

• US 20080091334A1
• Filed: 12/11/2007
• Published: 04/17/2008
• Est. Priority Date: 04/25/2005
• Status: Active Grant

• Current Assignee: Rochester Products Corporation
• Original Assignee: Rochester Products Corporation
• Inventors: Carlson, Grant, Heise, Karl
• Granted Patent: US 7,607,422 B2
• Time in Patent Office: Days
• US Class Current: 701/105
• CPC Class Codes: F02D 19/066 Retrofit of secondary fuel supply systems; Conversion of engines to operate on multiple fuels
• CPC Class Codes: F02D 19/087 with determination of densities, viscosities, composition, concentration or mixture ratios of fuels
• CPC Class Codes: F02D 2200/0611 Fuel type, fuel composition or fuel quality
• CPC Class Codes: F02D 2400/11 After-sales modification devices designed to be used to modify an engine afterwards
• 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 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue
• CPC Class Codes: F02P 5/1518 using two or more central computing units, e.g. interpolation
• CPC Class Codes: F02P 5/1527 with means allowing burning of two or more fuels, e.g. super or normal, premium or regular
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Methods and apparatus are disclosed for converting and optimizing the fuel system of an internal combustion engine in a pre-existing (used) vehicle to be fuel flexible and thus to operate on a mixture of fuels (like ethanol and gasoline) from a single fuel tank. The conversion includes adding a fuel composition sensor installed in the fuel line and/or adding an exhaust gas oxygen sensor installed in the engine'"'"'s exhaust in addition to adding an electronic control unit with at least one fuel injector driver circuit for controlling an output signal to at least one fuel injector for controlling the air to fuel ratio of the engine. The electronic control unit can control both engine ignition timing and the air to fuel ratio of the engine based upon the composition of fuel mixture in the fuel tank. The electronic control unit can also control other aspects of engine operation like intake manifold boost for those engines that have turbo or superchargers.

Claims

1. An apparatus for converting the fuel system of an engine to operate on a mixture of fuels where one such fuel is an alternate fuel, the apparatus comprising:

a fuel composition sensor for detecting the percentage or ratio of said alternate fuel in the fuel mixture being supplied to said engine;

at least one fuel injector driver circuit for controlling an output signal to at least one fuel injector for varying or metering the amount of fuel delivered to said engine; and

an electronic control unit for controlling the air to fuel ratio of said engine, for receiving as an input said percentage or ratio of said alternative fuel from said fuel composition sensor, and for changing said fuel injector driver circuit'"'"'s output signal to control said fuel injector in order to vary the amount of fuel metered into said engine in order to maintain the correct air to fuel ratio needed for proper engine combustion.

2. The apparatus in claim 1, further including an ignition control circuit for controlling the ignition timing of the engine based upon the said percentage or ratio of said alternative fuel.

3. The apparatus according to claim 2, wherein at least one ignition timing signal is received by the said ignition control circuit from the engine'"'"'s distributor.

4. The apparatus according to claim 3 wherein said ignition timing signal received by the said ignition control circuit is then delayed or advanced by said ignition control circuit before being sent back to the said engine'"'"'s distributor.

5. The said ignition control circuit according to claim 2 is located in the said electronic control unit.

6. The apparatus in claim 1, wherein the said fuel injectors are fed by a fuel pump that is fed by the said carburetor'"'"'s fuel pump.