PCV system for internal combustion engine
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsTakeshi Kitayama, Naoyuki Hayakawa
Life of this patent
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Abstract
A PCV system for an internal combustion engine that can suppress occurrence of preignition due to oil inflow into a cylinder is provided. A path switching valve is controlled so that blowby gas flows via a bypass passage, in a preig occurrence region. Thereby, path pressure loss increases, a PCV flow rate is decreased, and blowby gas can be passed through a separator with a high collection efficiency. As a result, an oil takeaway amount can be reduced, and occurrence of preignition due to cylinder oil inflow can be suppressed.
Claims7
A PCV system for an internal combustion engine, comprising:
- a PCV path that allows a crankcase of an internal combustion engine and an intake passage of the internal combustion engine to communicate with each other, and allows blowby gas in the crankcase to pass therethrough;
- a bypass passage that is connected in parallel to the PCV path;
- a valve that is provided between the PCV path and the bypass passage, and changes a flow path of the blowby gas between the PCV path and the bypass passage;
- a separator that is provided in the bypass passage;
- and
- control means that controls the valve so that the blowby gas can flow into the bypass passage when the internal combustion engine is operated in a predetermined load range,
- pressure detecting means that detects pressure in an inside of the crankcase,
- wherein the control means includes
- bypass control means that controls the valve so that the blowby gas can flow into the PCV path side when the pressure detected by the pressure detecting means is a predetermined value or more, in a case in which the valve is controlled so that the blowby gas flows to the bypass passage,
- wherein the control means includes enriching means that makes an air-fuel ratio of the internal combustion engine rich in a case of performing the control by the bypass control means.
A PCV system for an internal combustion engine, comprising:
- a PCV path that allows a crankcase of an internal combustion engine and an intake passage of the internal combustion engine to communicate with each other, and allows blowby gas in the crankcase to pass therethrough;
- a bypass passage that is connected in parallel to the PCV path;
- a valve that is provided between the PCV path and the bypass passage, and changes a flow path of the blowby gas between the PCV path and the bypass passage;
- a separator that is provided in the bypass passage;
- and
- a control unit that controls the valve so that the blowby gas can flow into the bypass passage when the internal combustion engine is operated in a predetermined load range,
- a pressure detecting unit that detects pressure in an inside of the crankcase,
- wherein the control unit includes
- a bypass control unit that controls the valve so that the blowby gas can flow into the PCV path side when the pressure detected by the pressure detecting unit is a predetermined value or more, in a case in which the valve is controlled so that the blowby gas flows to the bypass passage,
- wherein the control unit includes enriching unit that makes an air-fuel ratio of the internal combustion engine rich in a case of performing the control by the bypass control unit.
Dependencies are inferred from the claim text.