Reciprocating engine with a variable compression ratio mechanism
AssigneeNissan Motor Co., Ltd.
InventorsRyosuke Hiyoshi, Kenshi Ushijima, Yoshiteru Yasuda, Katsuya Moteki
Life of this patent
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Abstract
A reciprocating engine with a variable compression ratio mechanism is disclosed. A lubrication system of the engine is improved by controlling an oil pressure according to a compression ratio setting. The lubrication system includes various combinations of control valves and oil passages. The oil relief passage is opened at a high compression ratio setting applied to a low engine load range and is otherwise closed at a low compression ratio setting applied to a high engine load range.
Claims22
A reciprocating engine comprising:
- a variable compression ratio mechanism for regulating an engine compression ratio according to an engine load;
- a main oil passage;
- an oil pressure source hydraulically connected to the main oil passage for supplying pressurized lubricating oil to the main oil passage;
- an oil supply passage hydraulically connecting the main oil passage to a lubricated element;
- and
- an oil pressure control device for controlling an oil pressure in the main oil passage according to the engine compression ratio.
A reciprocating engine comprising:
- a variable compression ratio mechanism for regulating an engine compression ratio;
- a main oil passage;
- an oil pressure source hydraulically connected to the main oil passage for supplying pressurized lubricating oil to the main oil passage;
- an oil supply passage hydraulically connecting the main oil passage to a lubricated element;
- and
- an oil pressure control device for controlling an oil pressure in the main oil passage according to an engine load which is a parameter used to determine the engine compression ratio.
A reciprocating engine comprising:
- a variable compression ratio mechanism for regulating an engine compression ratio according to an engine load;
- a main oil passage;
- an oil pressure source hydraulically connected to the main oil passage for supplying pressurized lubricating oil to the main oil passage;
- oil supply means for supplying lubricating oil from the oil pressure source via the main oil passage to a lubricated element;
- and
- oil pressure control means for controlling an oil pressure in the main oil passage according to the engine compression ratio.
A reciprocating engine comprising:
- a variable compression ratio mechanism for regulating an engine compression ratio;
- a main oil passage;
- an oil pressure source hydraulically connected to the main oil passage for supplying pressurized lubricating oil to the main oil passage;
- oil supply means for supplying lubricating oil from the oil pressure source via the main oil passage to a lubricated element;
- and
- oil pressure control means for controlling an oil pressure in the main oil passage according to an engine load which is a parameter used to determine the engine compression ratio.
A method of regulating an oil pressure in a main oil passage of a reciprocating engine including at least a variable compression ratio mechanism for regulating an engine compression ratio, a main oil passage, an oil pressure source hydraulically connected to the main oil passage for supplying pressurized lubricating oil to the main oil passage, an oil supply passage hydraulically connecting the main oil passage to a lubricated element, and an oil pressure control device for controlling an oil pressure in the main oil passage, the method comprising:
- determining whether the engine compression ratio is high or low relative to a predetermined value;
- operating the oil pressure control device for keeping the pressure in the main oil passage when the engine compression ratio is low;
- and
- operating the oil pressure control device for lowering the pressure in the main oil passage when the engine compression ratio is high.
Dependencies are inferred from the claim text.