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US 6,598,569 B2Granted
Variable valve timing device of internal combustion engine
AssigneeNissan Motor Co., Ltd.
InventorsShinichi Takemura, Takanobu Sugiyama
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AssigneeNissan Motor Co., Ltd.
InventorsShinichi Takemura, Takanobu Sugiyama
Estimating the term…
To an internal combustion engine having intake and exhaust valves, there is applied a variable valve timing device. The timing device comprises a first mechanism which varies a working angle of the intake valve within a first given range from a minimum working angle to a maximum working angle; a second mechanism which varies an operation phase of the exhaust valve within a second given range from a most retarded phase to a most advanced phase; and a control unit which controls both the first and second mechanisms in accordance with an operation condition of the engine. The control unit is configured to carry out, when the engine is under an idle operation range, controlling the first mechanism to cause the intake valve to assume the minimum working angle, and controlling the second mechanism to cause the exhaust valve to assume the most advanced phase, and when the intake valve assumes the minimum working angle, controlling the first mechanism to set the open timing of the intake valve to a first point retarded relative to the top dead center (TDC), and when the exhaust valve assumes the most advanced phase, controlling the second mechanism to set the close timing of the exhaust valve to a second point retarded relative to the top dead center (TDC).
A variable valve timing device of an internal combustion engine having intake and exhaust valves, comprising:
A variable valve timing device of an internal combustion engine having intake and exhaust valves, comprising:
In an internal combustion engine having a first mechanism which varies a working angle of an intake valve of the engine within a range from a minimum working angle to a maximum working angle, and a second mechanism which varies an operation phase of the exhaust valve within a range from a most retarded phase to a most advanced phase,
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
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Term ended 17 Jan 2022 (estimated)
1. Field of Invention
The present invention relates in general to control devices for controlling internal combustion engines, and more particularly to valve control devices of a timing-variable type that, for achieving desired operation of the engine throughout entire operation range, controls the timing of intake and/or exhaust valves in accordance with operation condition of the engine. More specifically, the present invention is concerned with improvement of such variable valve control devices, by which the working angle and the operation phase of intake and/or exhaust valves are varied or controlled in accordance with the engine operation condition.
2. Description of Prior Art
FIG. 1 is a schematic view of a variable valve timing device of an internal combustion engine, according to the present invention;
FIG. 2 is an enlarged sectional view of the variable valve timing device taken along the line II—II of FIG. 1, showing an intake valve working angle varying mechanism;
FIG. 3 is an enlarged top view of the variable valve timing device, showing the intake valve working angle varying mechanism;
In the following, a variable valve timing device according to the present invention will be described in detail with reference to the accompanying drawings. For ease of understanding, various dimensional terms such as, upper, lower, right, left, upward, downward, etc., are used in the description. However, such terms are to be understood with respect to only a drawing or drawings in which the corresponding part or portion is shown.
Referring to FIGS. 1 to 11, there is shown a variable valve timing device of an internal combustion engine, which is an embodiment of the present invention. In the illustrated embodiment, the engine to which the valve timing device of the invention is practically applied has two intake valves and two exhaust valves for each cylinder.
As is seen from FIG. 1, the variable valve timing device of the invention comprises an intake valve working angle varying mechanism 1 (or first mechanism) which varies or controls the working angle of each intake valve 12 within a first given range from a minimum working angle to a maximum working angle, an exhaust valve operation phase varying mechanism 2 (or second mechanism) which varies or controls the operation phase of each exhaust valve (not shown) within a second given range from a most retarded phase to a most advanced phase and a control unit 3 which controls the above-mentioned first and second mechanisms 1 and 2 in accordance with an operation condition of the engine. The engine operation condition is estimated by processing information signals issued from various sensors such as an intake valve position sensor 58, an exhaust valve position sensor 59 and the like. The control unit 3 comprises a micro-computer including generally CPU, RAM, ROM and input and output interfaces.