CYLINDER HEAD HAVING EGR GAS COOLING STRUCTURE, AND METHOD FOR MANUFACTURING SAME

摘要

It has been difficult to manufacturing a cylinder head having an EGR gas cooling structure which has high cooling performance and can be easily configured. A cylinder head having an EGR gas cooling structure is configured in such a manner that a gas passage which guides to the air intake port side a part of the exhaust gas discharged from the exhaust port is disposed within the cylinder head water jacket to cool the exhaust gas flowing through the gas passage. The gas passage comprises a cooling section which makes contact with the coolant within the cylinder head water jacket, and also comprises a hollow pipe which has high-strength sections located at side portions of the cooling section and having higher strength than the cooling section. The high-strength sections of the gas passage are molded within and surrounded by the cylinder head.