METHOD TO MITIGATE REVERSE OIL FLOW TO THE COMBUSTION CHAMBER VIA HYBRID CYLINDER CUTOUT FOR INTERNAL COMBUSTION ENGINES

Abstract

This disclosure generally relates to a method for oil mitigation in the cooling and lubrication of piston(s) for electronic fuel injected internal combustion engines, incorporating cylinder cutout technology. This concept leverages the engine fuel injection table and determines which cylinder(s) or bank of cylinders are to be cutout and specifically, reduces the pulse width of the fuel injected into those cylinder(s) to an idle condition, whereby reducing the reverse oiling and wet stacking effect, prevalent in traditional cylinder cutout technology.

Claims

1. A method of mitigating lubricating oil from entering the combustion chamber, in a fuel-injected, spark-ignited, compression-ignited, internal combustion engine, having at least two cylinders comprising cylinder cutout, the method comprising the steps of: sensing an operator demand requesting the engine be placed in cylinder cutout; and monitoring engine speed while waiting for the engine to exceed an idle speed; and communicating a list of cylinders targeted to be cutout, to a routine that sets the said cylinder(s) to an idle state, whereby said idle state keeps the said cylinder(s) warm, without terminating combustion; and waiting in a loop during the idle state until the operator requests normal engine operation, whereby allowing traditional valve operation, helping prevent reverse oil flow to the combustion chamber.

2. A method according to claim 1 wherein the engine is using a crankcase pressure-fed, oil spray and splash, piston cooling and lubricating system.

3. A method according to claim 1 wherein the engine is using an oil flow nozzle, piston cooling and lubricating system.

4. A method according to claim 1 wherein the engine powers a commercial vehicle.

5. A method according to claim 1 wherein the engine powers an off-highway vehicle.

6. A method according to claim 1 wherein the engine powers a railway locomotive.

7. A method according to claim 1 wherein the engine powers a military vehicle.

8. A method according to claim 1 wherein the engine powers a marine vehicle.

9. A method according to claim 1 wherein the engine powers an automotive vehicle.

10. A method according to claim 1 wherein the engine powers a generator set.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 depicts a schematic illustration embodying the present invention.

[0012] FIG. 2 is a flowchart illustrating the HCCO strategy for use with the present invention.

DETAILED DESCRIPTION

[0013] The embodiment described in the present invention is by way of illustration only and should not be construed in any way, to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any type of suitably arranged device or system. The drawings may not necessarily be to scale and certain features illustrated in a schematic form. As used in the specification and claims, for the purpose of describing and defining the disclosure, the term “substantially” and “moderately” represents the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. As used herein, the term module, or block, refers to an application specific integrated circuit (ASIC), a processor that is shared, dedicated, or part of a group and memory that executes firmware, software, combinational logic circuits that perform the functionality of this invention. OEM is a standard industry term that stands for original equipment manufacturer. ECM refers to an engine control module. HCCO protocol requires use on an engine initially designed with programmed cylinder cutout architecture.

[0014] FIG. 1 includes a compression-ignition and/or a spark-ignition, 2-cylinder configuration engine 10 that comprises a typical oil lubricating, fixed or variable displacement pump 12, used to pressure-feed cooling oil 14 from the oil sump 16, through engine components (not illustrated) and within the crankcase 18 cavity to the piston undersides(s) 20, 22. Splashed and sprayed oil 14 is illustrated, dripping off the piston underside(s) 20, 22 to the oil sump 16. The pressure-fed oil is commonly routed through drilled crankshaft holes, directed, and splashed to the piston underside (not illustrated). Another method is to route the oil through a piston cooling flow nozzle assembly (not illustrated). Pistons move up and down within the cylinder(s) 24, 26, whereby fuel injected through fuel injector(s) 32, 34 into the combustion chamber(s) 28, 30, wherein chamber 28 illustrates substantial combustion activity, referred to as a “working-cylinder”. Combustion chamber 30, in contrast, exhibits minimal combustion activity, termed “idle-cylinder” in the present invention. A minimum quantity of injected fuel into the idle-cylinder shall prevent the piston from “motoring” in the cylinder cavity; therefore, never terminating combustion. As an analogy, an idle-cylinder may be thought of as a pilot light on an older gas furnace.

[0015] A conventional ECM 40, with attached engine sensors 42 comprises a CPU 44, System Clock 46, Memory 48(includes RAM, EEPROM, FLASH), memory look-up tables, including BOI 50, DEMAND TORQUE 52, TORQUE/RPM/BOI 54, FUEL INJECTION MODULE 56, Fuel Injector Driver 58 to fire fuel injector(s) 32, 34. ENGINE CONTROL ROUTINES 60, wherein CCO block 62 makes a determination (as an example) of whether a single cylinder or bank of cylinders is to transition to a cutout state and communicates to HCCO block 64 of the present invention. HCCO module 64 sets cylinder 26 to an idle or “no-load” state. An idle fuel state precludes the cylinder from cooling off on long distance vehicle trips and losing its ability to burn off accumulated particulate matter, as defined by “wet-stacking”. HCCO block 64 is additionally responsible for returning the idle-cylinder to a working-cylinder state 28 upon determination by CCO module 62, to transition to all working-cylinder(s). A requirement for the idle-cylinder 26 to transition back to a working cylinder 24 is to operate above an idle speed.

[0016] Turning to FIG. 2, block 70 defines the entry point for the software control routine illustrated in FIG. 1, HCCO module 64. An initial condition for HCCO module 64 is determined at decision block 72. If the engine is operating at an above idle rpm, the “YES” path shall be taken to block 76; however, if the engine is not above idle, the “NO” path shall be taken to block 74. Block 74 is responsible for raising the engine rpm moderately above an idle condition. CCO and HCCO methodologies recover the power lost in the cutout cylinder(s) with added fuel injected to the remaining working cylinders and commonly referred to as “pumping loss”.

[0017] Block 76 reads a list of cylinders to be cutout, as illustrated in CCO module 62 of FIG. 1. CCO module 62 may execute the cutout of one cylinder or a plurality of cylinders, whereby an entire “left bank” or “right bank” may be cutout. The OEM engine architecture and CCO methodology dictates the how and the number of cylinders to be cutout.

[0018] Block 78 receives the cutout list of cylinders and performs a HCCO, whereby each targeted cylinder is lowered to an idle rpm and specifically, the said cylinder is not totally cutout. Each hybrid cylinder will have minimal combustion as illustrated by combustion chamber 30 from FIG. 1. An idle condition will maintain combustion and not require the cylinder to be in continual intervals of cutout and recharge.

[0019] Decision Block 80 receives an instruction whether to continue operating the engine in a HCCO mode, or not. If “YES”, the path to Decision Block 82 is taken, whereas if “NO”, a loop-back to continue HYBRID CCO is taken.

[0020] Return Block 82 directs the flow of program control back to Block 60 of FIG. 1, whereby normal engine operation is dictated by the vehicle operator engine control.