# US 2014/0190444 A1 · Oil supply apparatus of internal combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190444 A1 - Document ID: US20140190444A1 - Status: Published application - Kind: A1 - Application number: 13/517,346 - Filed: 2011-08-10 - Published: 2014-07-10 - Earliest claimed: 2011-08-10 - Assignees: Toyota Jidosha Kabushiki Kaisha - Inventors: Yuta Inoue - Web page: https://patentgrep.com/patent/US20140190444A1 ## CPC - F01M 1/16: Controlling lubricant pressure or quantity (rendering machines or engines inoperative or idling on lubricant pressure failure F01M1/22) - F01M 11/12: concerning lubricant level - F01M 1/18: Indicating or safety devices (concerning lubricant level F01M11/06, F01M11/12) - F01M 2250/60: Operating parameters - F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING ## Abstract Disclosed is an oil supply apparatus which can be realized at a low cost, and can reliably detect the lowered level of the oil filled in the oil reservoir unit. The oil supply apparatus is provided with an oil pump which is set to have a plurality of switching discharge pressures at which the oil discharge pressures are changed for each target rotation speeds when the rotation speed of the internal combustion engine reaches the respective target rotation speed. The ECU is adapted to determine that the level of oil stored in the oil pan is lowered under the condition that the deviation between the target rotation speed of the engine set to correspond to the switching discharge pressure and the rotation speed of the engine actually detected when the discharge pressure reaches the switching discharge pressure is not less than the determination value. ## Claims ### Claim 1 An oil supply apparatus, comprising an oil supply passage that allows oil stored in an oil reservoir unit to be supplied to a plurality of lubrication sections of an internal combustion engine and recovers the oil into the oil reservoir unit, a pump unit that discharges the oil stored in the oil reservoir unit to the oil supply passage, the pump unit being controlled to have a plurality of different stages of oil discharge pressure varied in an increase amount of oil discharge pressure of the pump unit per the rotation speed of the internal combustion engine in response to the rotation speed area of the internal combustion engine, the pump unit having a plurality of switching discharge pressures each changed for each of a plurality of target rotation speeds when the rotation speeds of the internal combustion engine reach the plurality of target rotation speeds, respectively, and an abnormality determination unit being operative to set in advance the target rotation speed corresponding to an arbitrary switching discharge pressure selected from among the plurality of switching discharge pressures, and to determine that the level of oil stored in the oil reservoir unit is lowered under the condition that the deviation between the target rotation speed of the internal combustion engine set to correspond to the arbitrary switching discharge pressure and the actual rotation speed of the internal combustion engine actually detected when the oil discharge pressure reaches the arbitrary switching discharge pressure is not less than a determination value. ### Claim 2 (depends on 1) The oil supply apparatus as set forth in claim 1, which comprises a discharge pressure detection unit that detects the oil discharge pressure discharged from the pump unit, a rotation speed detection unit that detects the rotation speed of the internal combustion engine, and the abnormality determination unit being operative to determine that the level of oil stored in the oil reservoir unit is lowered in accordance with the detection information from the discharge pressure detection unit and the rotation speed detection unit under the condition that the deviation between the target rotation speed of the internal combustion engine set to correspond to the arbitrary switching discharge pressure and the actual rotation speed of the internal combustion engine actually detected when the oil discharge pressure reaches the arbitrary switching discharge pressure is not less than a determination value. ### Claim 3 (depends on 1) The oil supply apparatus as set forth in claim 1, which further comprises an abnormality alarming unit and the abnormality determination unit being operative to output an abnormality signal to the abnormality alarming unit under the condition that the deviation between the target rotation speed of the internal combustion engine set to correspond to the arbitrary switching discharge pressure and the actual rotation speed of the internal combustion engine actually detected when the oil discharge pressure reaches the arbitrary switching discharge pressure is not less than a determination value, and the abnormality alarming unit is operative to issue an alarm when receiving the abnormality signal from the abnormality determination unit. ### Claim 4 (depends on 1) The oil supply apparatus as set forth in claim 1, in which the abnormality determination unit is operative to estimate the variable amount of oil stored in the oil reservoir unit in accordance with the deviation. ### Claim 5 (depends on 1) The oil supply apparatus as set forth in claim 1 which further comprises an oil temperature detection unit that detects the temperature of oil discharged from the pump unit and the abnormality determination unit being operative to change the arbitrary switching discharge pressure in response to the target rotation speed of the internal combustion engine in accordance with the temperature of oil discharged from the pump unit. ### Claim 6 (depends on 5) The oil supply apparatus as set forth in claim 5, in which the abnormality determination unit is operative to calculate the arbitrary switching discharge pressure and the target rotation speed corresponding to the arbitrary switching discharge pressure in accordance with the detection information from the oil temperature detection unit, and to determine that the level of oil stored in the oil reservoir unit is lowered under the condition that the deviation between the target rotation speed of the internal combustion engine set to correspond to the arbitrary switching discharge pressure and the actual rotation speed of the internal combustion engine actually detected when the oil discharge pressure reaches the arbitrary switching discharge pressure is not less than a determination value.