| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable valve timing device capable of starting a control mode to be used proprietarily in starting at the proper timing and suppressing the exhaustion of unburnt HC certainly. SOLUTION: At the time of cold starting, the cold start mode is conducted in which an exhaust valve is advanced in the phase angle when a certain starting time T1 has elapsed after complete combustion-(2) in the attached diagram, whereby the exhaust gas during combustion is left for post-combustion so as to raise the temperature of a catalyst, and with a lower temperature of cooling water, the starting time T1 is set to a larger value so that the start timing in the cold start mode is delayed. Thereby inconvenience likely when the start of the cold start mode is premature can be prevented, for example emission of unburnt HC, disconnection of the post-combustion, etc. |
