| 摘要 |
<p>PURPOSE:To prevent the occurrence of overcooling in exhaust gas and overheating in a catalyzer, by installing a low temperature service exhaust manifold and a high temperature service exhaust manifold provided with a liquid-cooled type cooling unit, and selecting the manifold that makes exhaust flow according to heating value of the exhaust gas. CONSTITUTION:An exhaust manifold is branched off to a low temperature service exhaust manifold 3a and a high temperature service exhaust manifold 3b, and a liquid-cooled type cooling unit 9 is installed in the high temperature service manifold 3b. IN addition, cutoff valves 4a and 4b are installed in these manifolds 3a and 3b, and a catalytic converter 8 is set up at the downstream side of these valves. And, and engine speed Ne and suction air quantity Q are detected, and the heating value is more than the specified value, the cutoff valve 4a is closed and the valve 4b is opened instead, making the exhaust flow into the high temperature service manifold 3b, cooling the cooling unit, thus overheating in the catalytic converter 8 is prevented from occurring.</p> |
