Back to results
US 2006/0052216 A1Published application
Variable valve system of internal combustion engine and control method thereof
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsHibiki Ueura, Naohide Fuwa
Life of this patent
Estimating the term…
Abstract
A valve characteristic changing mechanism is supplied with oil discharged from an electric oil pump in addition to oil discharged from a mechanical oil pump that is driven by an operation of an internal combustion engine. Driving of the electric oil pump is controlled such that a work rate of the electric oil pump increases as a temperature of the oil supplied to the valve characteristic changing mechanism increases, or as a viscosity of the oil is reduced.
Claims32
A variable valve system of an internal combustion engine, comprising:
- a mechanical oil pump which is driven by an operation of an internal combustion engine;
- a valve characteristic changing mechanism which is driven by a hydraulic pressure of oil discharged from the mechanical oil pump, thereby changing a valve characteristic of an engine valve;
- an electric oil pump which discharges oil for driving the valve characteristic changing mechanism;
- and
- a controller which controls the valve characteristic changing mechanism such that the valve characteristic of the engine valve is adjusted to a target characteristic that is set based on an engine operating state;
- wherein
- the controller drives the electric oil pump such that, as a temperature of the oil supplied to the valve characteristic changing mechanism increases, a hydraulic pressure of the oil discharged from the electric oil pump increases.
4 more elements
A variable valve system of an internal combustion engine, comprising:
- a mechanical oil pump which is driven by an operation of an internal combustion engine;
- a valve characteristic changing mechanism which is driven by a hydraulic pressure of oil discharged from the mechanical oil pump, thereby changing a valve characteristic of an engine valve;
- an electric oil pump which discharges oil for driving the valve characteristic changing mechanism;
- and
- a controller which controls the valve characteristic changing mechanism such that the valve characteristic of the engine valve is adjusted to a target characteristic that is set so as to be variable based on an engine operating state;
- wherein
- the controller drives the electric oil pump such that, as a viscosity of the oil supplied to the valve characteristic changing mechanism is reduced, a hydraulic pressure of the oil discharged from the electric oil pump increases.
4 more elements
A variable valve system of an internal combustion engine, comprising:
- a mechanical oil pump which is driven by an operation of an internal combustion engine;
- a valve characteristic changing mechanism which is driven by a hydraulic pressure of oil discharged from the mechanical oil pump, thereby changing a valve characteristic of an engine valve;
- an electric oil pump which discharges oil for driving the valve characteristic changing mechanism;
- and
- a controller which controls the valve characteristic changing mechanism such that the valve characteristic of the engine valve is adjusted to a target characteristic that is set based on an engine operating state;
- wherein
- the controller drives the electric oil pump such that, as a difference between the valve characteristic and the target characteristic increases, a hydraulic pressure of the oil discharged from the electric oil pump increases.
4 more elements
A variable valve system of an internal combustion engine, comprising:
- a mechanical oil pump which is driven by an operation of an internal combustion engine;
- a valve characteristic changing mechanism which is driven by a hydraulic pressure of oil discharged from the mechanical oil pump, thereby changing a valve characteristic of an engine valve;
- an electric oil pump which discharges oil for driving the valve characteristic changing mechanism;
- and
- a controller which controls the valve characteristic changing mechanism such that the valve characteristic of the engine valve is adjusted to a target characteristic that is set so as to be variable based on an engine operating state;
- wherein
- the controller drives the electric oil pump, such that, among driving regions of the valve characteristic changing mechanism, in a driving region in which a speed of change in the valve characteristic when the valve characteristic changing mechanism is driven is likely to be higher, a hydraulic pressure of the oil discharged from the electric oil pump is higher.
4 more elements
A control method for a variable valve system of an internal combustion engine, comprising the following steps of:
- providing a mechanical oil pump which is driven by an operation of an internal combustion engine;
- a valve characteristic changing mechanism which is driven by a hydraulic pressure of oil discharged from the mechanical oil pump, thereby changing a valve characteristic of an engine valve;
- and an electric oil pump which discharges oil for driving the valve characteristic changing mechanism;
- and
- driving the electric oil pump such that, as a temperature of the oil supplied to the valve characteristic changing mechanism increases, or as a viscosity of the oil supplied to the valve characteristic changing mechanism is reduced, a hydraulic pressure of the oil discharged from the electric oil pump increases.
2 more elements
A control method for a variable valve system of an internal combustion engine, comprising the following steps of:
- providing a mechanical oil pump which is driven by an operation of an internal combustion engine;
- a valve characteristic changing mechanism which is driven by a hydraulic pressure of oil discharged from the mechanical oil pump, thereby changing a valve characteristic of an engine valve;
- and an electric oil pump which discharges oil for driving the valve characteristic changing mechanism;
- and
- driving the electric oil pump such that, as a difference between the valve characteristic and a target characteristic that is set based on an engine operating state increases, a hydraulic pressure of the oil discharged from the electric oil pump increases.
2 more elements
A control method for a variable valve system of an internal combustion engine, comprising the following steps of:
- providing a mechanical oil pump which is driven by an operation of an internal combustion engine;
- a valve characteristic changing mechanism which is driven by a hydraulic pressure of oil discharged from the mechanical oil pump, thereby changing a valve characteristic of an engine valve;
- and an electric oil pump which discharges oil for driving the valve characteristic changing mechanism;
- and
- driving the electric oil pump such that, among driving regions of the valve characteristic changing mechanism, in a driving region in which a speed of change in the valve characteristic when the valve characteristic changing mechanism is driven is likely to be higher, a hydraulic pressure of the oil discharged from the electric oil pump is higher.
2 more elements
Dependencies are inferred from the claim text.