A control device controls an internal combustion engine including: an elastic wave sensor arranged and configured to output a signal responsive to the strength of an acoustic emission wave produced at a sliding portion; and a variable oil pump. The control device is configured to execute an oil pressure control such that the oil pressure approaches a target oil pressure according to an engine operating condition. This oil pressure control includes a first pressure-increase processing executed where an AE correlation value correlated with the strength or occurrence frequency of the acoustic emission wave detected by the elastic wave sensor is greater than a first threshold value. The first pressure-increase processing increases the target oil pressure associated with a first engine operating condition present when the AE correlation value becomes greater than the first threshold value, as compared to when the AE correlation value is not greater than that.

Methods and systems are provided for diagnosing the functioning of a variable displacement oil pump. In one example, a method may include commanding a change in displacement of the variable displacement oil pump during a vehicle keyed-off condition and diagnosing a degradation of the oil pump based on a corresponding change in an estimated crankcase pressure.

A system for controlling a variable oil pump is provided. The system includes a variable oil pump that varies a discharge pressure of oil and an actuator that is operated to vary the discharge pressure of the oil of the variable oil pump. A controller turns the actuator on or off based a relationship between an outdoor temperature and a cooling water temperature of an engine.

Methods and systems are provided for indicating degradation of a variable displacement oil pump. In one example, an engine method comprises indicating degradation of the oil pump based on a fuel usage change of the engine, responsive to a commanded change in displacement of the variable oil pump. In response to an indicated degradation, engine wear may be avoided and fuel economy may be improved by adjusting engine operation.

A variable capacity pump includes a control ring moveable within a pump chamber to alter the volumetric capacity of the pump. First and second control chambers individually receive pressurized fluid to create forces to bias the control ring in a predetermined direction. A return spring urges the control ring toward a maximum volumetric capacity pump position. The control ring connects and disconnects the second control chamber from a source of pressurized fluid based on a position of the control ring. Forces from the control chambers and the spring act in combination with one another or against one another and against the spring force to establish first and second equilibrium pressures based on a pressurized or vented condition of the second control chamber.

A variable displacement vane pump has a control slide displaceable within its housing and a first control chamber and a second control chamber for receiving pressurized lubricant. A thermally adjustable control valve is provided in the housing for adjusting pump displacement based on a temperature of the lubricant. In addition to fluid communication channels in the control chambers, at least one vent port is provided in the second chamber. The control valve is configured to control pressure and fluid communication between the chambers along with the control slide. The control valve can help reduce pump displacement at lower temperatures and low engine speeds. At lower temperatures, the second control chamber can be pressurized by the first control chamber. At higher temperatures, the second control chamber can be vented through the control valve and/or the vent port, despite the position of the control slide.

An oil supply device for an engine is provided with an oil pump of a variable capacity type; a plurality of hydraulically operated devices connected to the pump via an oil path; a pump control unit which changes the capacity of the pump to control a discharge amount of oil; and a hydraulic pressure detecting unit which detects a hydraulic pressure of the oil path. The plurality of the hydraulically operated devices include a metal bearing, and the pump control unit sets a highest requested hydraulic pressure among requested hydraulic pressures of the hydraulically operated devices as a target hydraulic pressure for each of the operating conditions of the engine, and changes the capacity of the pump in such a manner that the hydraulic pressure detected by the hydraulic pressure detecting unit coincides with the target hydraulic pressure for controlling the discharge amount.

A method for diagnosing a failure of a solenoid valve of a piston cooling device is provided. The method includes varying a pressure in a variable proportional control oil pump when an opening command or a closing command of the solenoid valve is sent to inject oil from the piston cooling device. Additionally, a variation of an oil pressure in an oil flow path of the piston cooling device is monitoring according to a variation of the pressure in the variable proportional control oil pump and whether a failure occurs at the solenoid valve of the piston cooling device is then determined.

An oil pump device includes an oil pump (10) and an electrically operated control valve (20). The valve adjusts hydraulic pressures to be applied to a decrease-side control pressure chamber (15A) for causing a pump casing (14) to swing in the discharge amount decrease direction and an increase-side control pressure chamber (15B) for causing the pump casing to swing in the discharge amount increase direction so as to hold the pump casing at a predetermined approximately intermediate position between the maximum swing position in the discharge amount decrease direction and the maximum swing position in the discharge amount increase direction by balancing the urging forces of a decrease-side return spring (16) for urging the pump casing in the discharge amount decrease direction and an increase-side return spring (17) for urging the pump casing in the discharge amount increase direction when supply of current to the valve is stopped.

A hydraulic control apparatus is provided including: an electromagnetic valve that has an input port communicating with a supply destination unit of oil and a control port that is switched between communication and disconnection by resultant force of a hydraulic pressure of the supply destination unit and electromagnetic force; a variable displacement pump which has a suction port communicating with a supply source of the oil, an ejection port communicating with the supply destination unit, and a control chamber communicating with the control port and rotates in accordance with drive of the supply destination unit, in which an amount of the oil ejected to the supply destination unit through the ejection port changes in accordance with a pressure in the control chamber; and a control unit that controls a value of a necessary current that is caused to flow through the electromagnetic valve.