Patent ID: 7044089

Claim:
A cylinder head structure of an engine, in which there are provided two intake ports and two exhaust ports for each cylinder of a multi-cylinder engine and an engine cooling water is circulated in a cylinder head, comprising: a main water jacket to form part of a head-side water jacket provided in the cylinder head, the main water jacket being separated by an upper face of a bottom deck of the cylinder head forming a combustion chamber of the cylinder and extending from an engine front end portion to an engine rear end; an intake-side connecting hole and exhaust-side connecting hole to form part of the head-side water jacket, the intake-side and exhaust-side connecting holes being provided at a portion located between cylinders of the bottom deck of the cylinder head and at outer both sides in an engine width direction respectively so as to interconnect said main water jacket and a water jacket formed in a cylinder block; and a lateral rib provided at an upper face of the portion located between cylinders of bottom deck of the cylinder head so as to extend in the engine width direction, the lateral rib bifurcating at both ends thereof so as to get around said intake-side and exhaust-side connecting holes respectively, both ends of bifurcated portions of the lateral rib being respectively connected integrally with intake-port walls and exhaust-port walls of adjacent cylinders which respectively forms the intake ports and exhaust ports, a top portion of said lateral rib being configured so as to become taller gradually from a central portion thereof toward outside portions thereof in the engine width direction.