Apparatus for controlling timings of exhaust valves and method thereof
AssigneeUnisia Jecs Corporation
InventorsNaoki Tomisawa, Seizi Suga
Life of this patent
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Abstract
The timing for opening the exhaust valve is advanced by an angle that varies depending upon the load exerted on an engine and the rotational speed of the engine at the cold starting of the engine during a predetermined period of time after the complete combustion. The heat of combustion is positively discharged into an exhaust system and, hence, an oxygen sensor and a catalytic converter disposed in the exhaust system of the engine are activated more quickly.
Claims8
An apparatus for controlling timings of exhaust valves comprising:
- a variable valve timing mechanism for varying timings for opening and closing exhaust valves.
- a complete combustion detection means for detecting the complete combustion state of an engine based on whether or not a rotational speed of the engine becomes equal to or greater than a predetermined rotational speed.
- a cranking detection means for detecting the cranking state of the engine and
- a valve timing control means for controlling said variable valve timing mechanism in order to advance, by a predetermined angle, the timing for opening the exhaust valve for a predetermined period of time after a time after the lapse of a predetermined delay time from when the completer combustion state of the engine is detected.
(NEW) A method of controlling timings of exhaust valves comprising the steps of
- detecting a complete combustion state of an engine based on whether or not a rotational speed of the engine becomes equal to or greater than a predetermined rotational speed;
- detecting the cranking state of the engine;
- and
- controlling timings for opening and closing exhaust valves in order to advance by a predetermined angle, the timing for opening the exhaust valve for a predetermined period of time after a time after the lapse of a predetermined delay time from when the complete combustion state of the engine is detected.
(NEW) The method for controlling timings of exhaust valves according to claim, wherein said step of controlling includes varying said predetermined period of time for advancing the timing for opening the exhaust valve depending on a temperature of the engine detected in the engine cranking state.
Dependencies are inferred from the claim text.