Adaptive individual-cylinder thermal state control using piston cooling for a GDCI engine

Patent metadata

Field	Value
Publication number	US-8997698-B1
Application number	US-201314096119-A
Country	US
Kind code	B1
Filing date	Dec 4, 2013
Priority date	Dec 4, 2013
Publication date	Apr 7, 2015
Grant date	Apr 7, 2015

Abstract

A system for a multi-cylinder compression ignition engine includes a plurality of nozzles, at least one nozzle per cylinder, with each nozzle configured to spray oil onto the bottom side of a piston of the engine to cool that piston. Independent control of the oil spray from the nozzles is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the oil spray onto the piston in that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder engine, including determining a combustion parameter for combustion taking place in in a cylinder of the engine and controlling an oil spray targeted onto the bottom of a piston disposed in that cylinder is also presented.

First claim

We claim:

1. A control system for a multi-cylinder compression ignition engine, said engine defining a plurality of cylinders and having a plurality of pistons, each cylinder having a piston reciprocally movable in the cylinder, each piston having a top side and a bottom side, the top side of the piston partially defining a combustion chamber having an air intake port and an exhaust port, the system comprising:
an oil path supplying oil to the engine;
a nozzle means comprising a plurality of nozzles, each of the plurality of nozzles connected to said oil path and configured to spray oil onto the bottom side of one piston of the plurality of pistons;
a valve means configured to control the flow of oil from the oil path to the nozzle means;
a sensor means for sensing and/or calculating a combustion parameter for combustion occurring in each individual cylinder of the plurality of cylinders; and
a controller means configured to calculate a desired oil flow from each nozzle of the plurality of nozzles based on the combustion parameter for combustion occurring in the cylinder containing the piston onto which the nozzle is configured to spray oil, said controller means further configured to control said valve means to adjust the flow rate from each nozzle of the plurality of nozzles based on the calculated desired oil flow from the nozzle.

2. The control system of claim 1 , further comprising an oil pump configured to supply pressurized oil from the oil path to the valve means.

3. The control system of claim 2 , further comprising an oil sensing means configured to measure the temperature and/or pressure of the pressurized oil supplied by the oil pump.

4. The control system of claim 2 , wherein the oil pump is controllable by the controller means.

5. The control system of claim 4 , wherein the oil pressure from the oil pump is continuously variable.

6. The control system of claim 4 , wherein the oil pump is controllable to provide pressurized oil at two different non-zero pressure levels.

7. The control system of claim 1 , wherein each nozzle is targeted so as to provide oil spray so as to provide optimal piston cooling over the bottom side of its corresponding piston.

8. The control system of claim 1 , wherein the oil spray flow to each piston is controlled such that all cylinders operate with similar combustion phasing and burn characteristics.

9. The control system of claim 1 , wherein the combustion parameter is selected from the group consisting of combustion chamber temperature, combustion chamber pressure, crank angle corresponding to start of combustion (SOC), crank angle corresponding to 50% heat release (CA50), heat release rate, maximum rate of pressure rise (MPRR), location of peak pressure (LPP), ignition dwell, ignition delay, combustion noise level, and combinations of one or more of these parameters.

10. The control system of claim 1 , wherein the controller means includes a learning section that determines and retains in memory a learned valve control parameter for the valve means based on the combustion parameter.

11. The control system of claim 10 wherein the learning section modifies the learned valve control parameter over time.

12. A method for influencing combustion in a multi-cylinder compression ignition engine, the method comprising the steps of:
determining a combustion parameter for combustion taking place in a cylinder of the engine; and
controlling an oil spray targeted onto the bottom of a piston disposed in the cylinder, the control of the oil spray based on the sensed combustion parameter, wherein the engine includes means for determining the combustion parameter for combustion taking place in each individual cylinder of the engine, and the engine additionally comprises means for independently controlling the oil spray to each piston in the engine.

13. The method of claim 12 , further comprising the step of controlling an oil pump configured to delivery oil to the means for independently controlling the oil spray to each piston in the engine.

14. A method for influencing combustion in a multi-cylinder compression ignition engine, the method comprising the steps of:
determining a combustion parameter for combustion taking place in a cylinder of the engine; and
controlling through a valve means an oil spray targeted onto the bottom of a piston disposed in the cylinder, the control of the oil spray based on the sensed combustion parameter, additionally comprising the steps of determining and retaining in memory a learned valve control parameter for the valve means based on the combustion parameter.

15. The method of claim 14 additionally comprising the step of modifying the learned valve control parameter over time.

Assignees

• Delphi Tech Inc

Inventors

• Roth Gregory T
• Husted Harry L
• Sellnau Mark C

Classifications

• F01P7/14 Primary

  the coolant being liquid · CPC title

• F01P3/08 Primary

  Cooling of piston exterior only, e.g. by jets · CPC title

• F01P2023/08

  Microprocessor; Microcomputer · CPC title