Method and apparatus for fuel injection-spark ignition system for an internal combustion engine

• US 4,066,046 A
• Filed: 09/08/1976
• Issued: 01/03/1978
• Est. Priority Date: 07/29/1974
• Status: Expired due to Term

• Current Assignee: Roy E. Mcalister
• Original Assignee: Roy E. Mcalister
• Inventors: McAlister, Roy E.
• Primary Examiner(s): Lazarus, Ronald H.
• Assistant Examiner(s): Argenbright, Tony M.
• Application Number:
  US05/721,505
• Time in Patent Office: 482 Days
• Field of Search: 123/32 ST, 123/32 SA, 123/32 SP, 123/143 B, 123/191 S, 123/191 SP, 123/32 AE, 123/32 EA, 123/32 SJ
• US Class Current: 123/295
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02B 17/005 having direct injection in the combustion chamber
• CPC Class Codes: F02F 2007/0092 Transparent materials
• CPC Class Codes: F02M 57/06 the devices being sparking plugs
• CPC Class Codes: F02P 5/045 combined with electronic control of other engine functions, e.g. fuel injection in general F02D37/02
• CPC Class Codes: F02P 5/142 dependent on a combination of several specific conditions F02P5/075, F02P5/106 takes precedence
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

Method and apparatus for providing improved combustion in an internal combustion engine by spark-ignition of fuel that is directly injected into cylinders to present a stratified fuel-air mixture at time of ignition. Reduced mixing of the fuel and air prior to ignition and thus greater stratification permits improved control of the combustion process to increase power and reduce pollutant emissions.

Claims

1. A method of operating an internal combustion engine having a chamber defined by positive displacement elements which are relatively movable through successive cycles of operation wherein the volume of said chamber increases and decreases between maximum and minimum values having a ratio within the range of a conventional spark ignition engine and a pair of spaced electrodes defining an electrical discharge path within said chamber when at a minimum value thereof, said method comprising the steps of:

introducing during each cycle of operation into said chamber a charge of oxidizing gas substantially free of combustible fuel,

compressing during each cycle of operation said oxidizing gas substantially to a volume near said minimum value by the decreasing relative movement of said positive displacement elements,

injecting during each cycle of power operation a combustible fuel as a high pressure jet directly into the oxidizing gas within said chamber at a predetermined time during the compression thereof prior to said positive displacement elements decreasing said chamber to said minimum value in a direction toward one of said electrodes and away from the other electrode so that there is established before the completion of said fuel injection within the chamber space containing said discharge path an interface between the oxidizing gas contacting said other electrode and the injected fuel moving away from said other electrode which presents a range of fuel-oxidizing gas mixture ratios which inherently includes ignitable mixture ratios and mixture ratios both too-fuel-rich and too-fuel-lean to ignite,

causing during each cycle of power operation an electrical current to discharge between said electrodes within said chamber space along said path while said injection is taking place so as to ignite the mixture of oxidizing gas and fuel therein having an ignitable mixture ratio and to establish a flame front which continues by virtue of the continued injection of fuel and the mixture thereof with oxidizing gas within the chamber under the dynamic fluid conditions occasioned by the injected fuel momentum and the relative movement of the positive displacement elements defining the chamber so that substantially the entire charge of injected fuel is burned within an envelope of oxidizing gas in contact with the surfaces of said positive displacement elements defining said chamber,

continuously sensing the speed of rotation of said engine and the position of a speed control mechanism for said engine, and

utilizing the sensed engine speed and speed control mechanism position to determine the time said injection is initiated and the timer period of its continuation so as to optimize the BMEP characteristics of the engine.

2. A method as defined in claim 1 wherein a higher sensed speed and a higher speed control mechanism position are utilized to initiate said injection at an earlier time and to continue said injection for a longer time period.

3. A method as defined in claim 2 wherein the time period within which said injection is continued does not extend beyond the time during each cycle when said positive displacement elements reach said minimum value.

4. A method as defined in claim 2 wherein the time period within which said injection is continued extends beyond the time during each cycle when said positive displacement elements reach said minimum value.

5. A method as defined in claim 1 wherein the engine speed is sensed by the rotational movement of a member driven by a shaft connected to rotate at a speed proportional to the speed of said engine and wherein the position of said speed control mechanism is sensed by an axial movement of said member with respect to said shaft.

6. A method as defined in claim 5 wherein the engine speed sensed and the speed control mechanism position sensed are utilized as aforesaid by maintaining a supply of said combustible fuel under pressure, providing valve means which is normally closed to prevent communication of the combustible fuel supply with said chamber and movable in response to the establishment of an electrical current in association therewith into an open position establishing communication of the combustible fuel supply with said chamber, establishing an electrical current in association with said valve means the initiation and duration of which is a function of the axial position and speed of rotation of said member.

7. A method as defined in claim 6 wherein said electrical current is established by contacting a conductive map area on the periphery of said member with pick-up electrical brush means.

8. A method as defined in claim 6 wherein said electrical current is established by contacting a variable resistance member extending radially inwardly from the periphery of said member with pick-up electrical brush means.

9. A method as defined in claim 6 wherein said electrical current is established by transmitting light through a window in the periphery of said member and converting the transmitted light into said electrical current.

10. An internal combustion engine comprising:

positive displacement elements defining a chamber, said elements being relatively movable through successive cycles of operation wherein the volume of said chamber increases and decreases between maximum and minimum values having a ratio within the range of a conventional spark ignition engine,

a pair of spaced electrodes defining an electrical discharge path within said chamber when at a minimum value thereof,

means for introducing during each cycle of operation into said chamber a charge of oxidizing gas substantially free of combustible fuel so that during each cycle of operation said oxidizing gas will be compressed substantially to a volume near said minimum value by the decreasing relative movement of said positive displacement elements,

means or injecting during each cycle of power operation a combustible fuel as a high pressure jet directly into the oxidizing gas within said chamber at a predetermined time during the compression thereof prior to said positive displacement elements decreasing said chamber to said minimum value in a direction toward one of said electrodes and away from the other electrode so that there is established before the completion of said fuel injection within the chamber space containing said discharge path an interface between the oxidizing gas contacting said other electrode and the injected fuel moving away from said other electrode which presents a range of fuel-oxidizing gas mixture ratios which inherently includes ignitable mixture ratios and mixture ratios both too-fuel-rich and too-fuel-lean to ignite,

means for causing during each cycle of power operation an electrical current to discharge between said electrodes within said chamber space along said path while said injection is taking place so as to ignite the mixture of oxidizing gas and fuel therein having an ignitable mixture ratio and to establish a flame front which continues by virtue of the continued injection of fuel and the mixture thereof with oxidizing gas within the chamber under the dynamic fluid conditions occasioned by the injected fuel momentum and the relative movement of the positive displacement elements defining the chamber so that substantially the entire charge of injected fuel is burned within an envelope of oxidizing gas in contact with the surfaces of said positive displacement elements defining said chamber,

a speed control mechanism for said engine,

means for continuously sensing the speed of rotation of said engine and the position of said speed control mechanism, and

means for utilizing the sensed engine speed and speed control mechanism position to determine the time said injection is initiated and the time period of its continuation so as to optimize the BMEP characteristics of the engine.

11. Apparatus as defined in claim 10 wherein said last mentioned means is operable such that a higher sensed speed and a higher speed control mechanism position are utilized to initiate said injection at an earlier time and to continue said injection for a longer time period.

12. Apparatus as defined in claim 11 wherein the time period within which said injection is continued does not extend beyond the time during each cycle when said positive displacement elements reach said minimum value.

13. Apparatus as defined in claim 11 wherein the time period within which said injection is continued extends beyond the time during each cycle when said positive displacement elements reach said minimum value.

14. Apparatus as defined in claim 10 wherein said engine speed sensing means comprises a member driven by a shaft connected to rotate at a speed proportional to the speed of said engine and wherein said speed control mechanism position sensing means comprises means for sensing an axial movement of said member with respect to said shaft.

15. Apparatus as defined in claim 14 wherein the engine speed sensed and the speed control mechanism position sensed are utilized as aforesaid by means maintaining a supply of said combustible fuel under pressure, valve means normally closed to prevent communication of the combustible fuel supply with said chamber and movable in response to the establishment of an electrical current in association therewith into an open position establishing communication of the combustible fuel supply with said chamber, and means for establishing an electrical current in association with said valve means the initiation and duration of which is a function of the axial position and speed of rotation of said member.

16. Apparatus as defined in claim 15 wherein said electrical current establishing means includes a conductive map area on the periphery of said member and pick-up electrical brush means operable associated therewith.

17. Apparatus as defined in claim 15 wherein said electrical current establishing means includes a variable resistance member extending radially inwardly from the periphery of said member and pick-up electrical brush means operably associated therewith.

18. Apparatus as defined in claim 15 wherein said electrical current establishing means includes means for transmitting light through a window in the periphery of said member and means for converting the transmitted light into said electrical current.