Control device for internal combustion engines
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2024-11-28
- Publication Date
- 2026-06-09
AI Technical Summary
【0006】 上記構成によれば、内燃機関の停止が指令されたとき、停止後の内燃機関の燃焼室で凝縮水の凍結が生じる可能性がある場合、吸気圧低下処理及びオイル噴射量増加処理が実行される。吸気圧低下処理では、内燃機関の吸気圧低下に伴って燃焼室内の圧力も低下する。そして、吸気圧低下処理及びオイル噴射量増加処理が終了した後、内燃機関が停止される。上記吸気圧低下処理による内燃機関の吸気圧の低下、及び、上記オイル噴射量増加処理によるオイルジェットからのオイル噴射量の増加により、意図的に燃焼室へのオイル上がりが生じさせられる。その結果、ピストンにおけるピストンリングを収容する溝内にオイルが充填されるため、そのオイルがピストンの溝内に入り込んだ凝縮水と混ざるようになる。このように溝内の凝縮水がオイルと混ざることにより、溝内の凝縮水の凝固点が下がるため、低外気温の環境下での機関停止中にピストンの溝内の凝縮水が凍結することを抑制できる。そして、ピストンの溝内での凝縮水の凍結によるピストンリングの機能不全を抑制できる。
Smart Images
Figure 2026093494000001_ABST
Abstract
Claims
1. Applicable to an internal combustion engine equipped with an oil jet that injects oil onto the back surface of a piston or the inner wall of a cylinder, the control device for an internal combustion engine includes a control unit that controls the intake pressure of the internal combustion engine and the amount of oil injected by the oil jet, and also stops the engine when a command to stop the internal combustion engine is issued, The control unit, when commanded to stop the internal combustion engine, performs an intake pressure reduction process to lower the intake pressure of the internal combustion engine and an oil injection amount increase process to increase the amount of oil injected by the oil jet, on the condition that there is a possibility of condensation freezing in the combustion chamber of the internal combustion engine after it has stopped, and stops the internal combustion engine after the intake pressure reduction process and the oil injection amount increase process have been completed.
2. The control device for an internal combustion engine according to claim 1, wherein when a command is given to stop the internal combustion engine, the control unit performs the intake pressure reduction process and the oil injection amount increase process based on the fact that the ambient temperature and the coolant temperature of the internal combustion engine are both below predetermined values and the cumulative value of the fuel injection amount since the start of the internal combustion engine is below a predetermined threshold, assuming that there is a possibility of condensation freezing in the combustion chamber of the internal combustion engine after it has stopped.
3. The control device for an internal combustion engine according to claim 1 or 2, wherein the intake pressure reduction process controls the throttle valve of the internal combustion engine to the closed side.
4. The aforementioned oil jet receives oil discharged from an electric oil pump and injects the oil. The control device for an internal combustion engine according to claim 1 or 2, wherein the oil injection amount increase process controls the electric oil pump so that the amount of oil discharged from the electric oil pump increases.
5. The aforementioned oil jet receives oil discharged from a mechanical oil pump driven by an internal combustion engine and injects the oil. The control device for an internal combustion engine according to claim 1 or 2, wherein the oil injection amount increase process controls the internal combustion engine so that the amount of oil discharged from the mechanical oil pump increases through an increase in the engine rotation speed.