The present disclosure relates to engine having electronically controlled piston cooling jets, and more particularly to electronically controlled piston cooling jets that may be selectively operated based on engine operating conditions and an electronic control module to control the piston cooling jets.
Many modern diesel engines contain piston cooling jets that spray engine oil on an underside of a piston to provide cooling to the piston. Engine oil, sometimes also referred to as engine lubrication oil or engine lube oil, is continuously fed from an oil rail, or oil gallery to engine parts needing lubrication. For example, it is typically necessary to lubricate parts such as crank shaft and connecting rod bearings, turbochargers, and, in some engines, piston cooling jets. An oil system as described above requires a large oil pump in order to provide the required oil flow rates. Additionally, minimum engine oil pressure recommended for turbochargers from various turbocharger manufacturers are often set at about twenty pounds per square inch (20 psi), a level that may not be met when engine oil is at operating temperature and the engine is operating at low engine speeds, or if the engine is operating at lower engine speeds and the engine components are worn.
According to one embodiment, an engine oil system for an internal combustion engine comprises an electronic control module, an engine oil sump, an engine oil pump, an engine oil gallery, an engine oil pressure sensor, a solenoid control valve, and at least one oil receiving component. The engine oil pump is disposed in fluid communication with the engine oil sump. The engine oil gallery is disposed in fluid communication with at least one engine bearing and a turbocharger. The engine oil pressure sensor is disposed in fluid communication with the oil gallery. The oil pressure sensor generates an output signal that is transmitted to the electronic control module. The solenoid control valve is disposed in fluid communication with the engine oil gallery and electronic communication with the electronic control module. The solenoid control valve is moveable between at least an open position and a closed position in response to at least an output signal received from the electronic control module. The at least one oil receiving component is disposed in fluid communication with the engine oil gallery.
According to another embodiment, an electronically controllable piston cooling jet system for an internal combustion engine having an electronic control module and at least one piston is provided. The piston cooling jet system comprises at least one piston cooling jet, a pressure sensor, and a solenoid control valve. The piston cooling jet provides oil to the at least one piston. The pressure sensor is in fluid communication with an oil supply to the at least one piston cooling jet. The pressure sensor generates an output signal indicative of fluid pressure within the oil supply. The solenoid control valve has an open position and a closed position. The electronic control module operatively controls the solenoid control valve to the open position and the closed position based upon the output of the oil pressure sensor.
According to one process, a method of controlling an electronically controllable oil receiving subsystem of an engine is provided. The engine has an electronic control module, at least one piston, an oil pressure sensor, a solenoid control valve moveable between at least an open position and a closed position, and at least one oil receiving component. One aspect of the method generates an output signal of the oil pressure sensor indicative of engine oil pressure. The output of the oil pressure sensor is transmitted to the electronic control module. The oil pressure indicated by the output signal of the oil pressure sensor is compared to at least a first predetermined value stored in a memory of the electronic control module. An actuation signal transmits to the solenoid control valve contains at least an instruction to position the solenoid control valve in the open position when the output signal of the oil pressure sensor is indicative of an oil pressure greater than the at least a first predetermined value stored in the memory of the electronic control module. Oil flow is provided to the at least one oil receiving component when the solenoid control valve is in the open position.
The engine oil system 10 additionally has an oil filter 18 that removes certain contaminates within the engine oil to prevent damage to the engine. Filtered engine oil is provided to an oil gallery 20. The engine oil gallery 20 has a pressure regulating valve 22 adapted to prevent engine oil pressure from exceeding a predefined threshold. Excessively high engine oil pressure may cause damage to the engine, therefore, the pressure regulating valve allows some oil within the oil gallery 20 to be returned to the engine oil sump 12, thus, reducing the oil pressure within the engine oil gallery 20. The engine oil gallery 20 is adapted to deliver oil to engine bearings and other engine components 24 that require engine oil. The engine bearings and other engine components 24 that require engine oil are in fluid communication with the engine oil sump 12, such that engine oil drains from the engine bearings and other engine components 24 to the engine oil sump 12.
The engine oil gallery 20 additionally provides engine oil to the turbocharger 26. The turbocharger 26 typically receives engine oil from the oil gallery 20 via an oil supply line (not shown) and is not directly connected to the engine oil gallery 20. The engine oil provides lubrication to at least one bearing within the turbocharger 26. Oil that is provided to the turbocharger 26 also drains back to the engine oil sump 12, typically via an oil return line (not shown).
As shown in
For example, when the pressure sensor 34 and the ECM 32 detect oil pressure below a first oil pressure threshold stored in a memory of the ECM 32, the ECM 32 causes the solenoid control valve 28 to close, stopping the flow of oil to the oil receiving components 30, such as piston cooling jets.
Similarly, when the pressure sensor 34 and the ECM 32 detect oil pressure above a second oil pressure threshold stored in a memory of the ECM 32, the ECM 32 causes the solenoid control valve 28 to open, allowing oil to flow to the oil receiving components 30 such as piston cooling jets. The first threshold and the second threshold may be generally equal, or the first threshold may be a lower oil pressure than the second threshold oil pressure. Therefore, certain operating conditions may exist when the engine oil pressure is above the first threshold oil pressure while the solenoid control valve 28 remains closed, and no oil flows to the oil receiving components.
Therefore, the use of a solenoid control valve 28 to control oil flow to the oil receiving components 30, such as piston cooling jets or other non-lubricating oil receiving components, may be used to help ensure that minimum oil pressure required for the turbocharger 26 may be maintained even in operating conditions historically known to produce low oil pressure, such as low engine speeds while the engine oil is warm.
In addition to increasing the oil pressure, the use of a solenoid control valve 28 to control oil flow to the oil receiving components 30, such as piston cooling jets, may also allow a lower volume oil pump 14 to be used. A lower volume oil pump may be used as engine oil will not flow through the solenoid control valve 28 to the oil receiving components 30 if oil pressure falls below the first oil pressure threshold, therefore, a lower volume pump may be utilized to achieve minimum oil pressure required for normal engine operation. The use of a lower volume oil pump 14 may also reduce a parasitic load on the engine from the oil pump 14, thus, increasing the fuel economy of the engine.
The solenoid control valve 28 to control oil flow to oil receiving components 30 may additionally be utilized to enhance oil warm up from cold starts. For instance, the ECM 32 may cause the solenoid control valve 28 to open when the engine is first started such that the oil flowing through the oil receiving components 30, such as piston cooling jets, is heated by the pistons, reducing the time required for the engine oil to reach normal operating temperatures.
Additionally, the engine oil system 10 may increase the oil change interval for the engine oil by decreasing work to the oil by using the solenoid control valve 28 to control the flow of oil to oil receiving components 30. Increased oil change intervals allow a vehicle having an engine with the engine oil system 10 to be in use for longer periods of time between servicing, potentially increasing the productivity of the vehicle.
While specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying Claims.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US10/31131 | 4/15/2010 | WO | 00 | 4/2/2013 |