CYLINDER HEAD STRUCTURE IN MULTI-CYLINDER ENGINE.

摘要

A COOLECTING EXHAUST PORT (18) PROVIDED IN A CYLINDER HEAD (12) IS COMPRISED OF EXHAUST PORT SECTIONS (46) EXTENDING FROM EXHAUST VALVE BORES (35) IN CYLINDERS (14), AND AN EXHAUST COLLECTING SECTION (47) IN WHICH THE EXHAUST PORT SECTIONS (46) ARE COLLECTED. THE CYLINDER HEAD (12) INCLUDES A PROTRUSION (49) PROJECTING IN AN ARCH SHAPE OUTSIDE A SIDE WALL (111) OF A CYLINDER BLOCK (11). THE EXHAUST COLLECTING SECTION (47) OF THE COLLECTING EXHAUST PORT (18) DIRECTLY FACES AN INNER SURFACE OF A SIDE WALL (121) OF THE PROTRUSION (49). WATER JACKETS (J2 AND J3) FOR COOLING THE PROTRUSION (49) ARE PROVIDED IN UPPER AND LOWER SURFACES OF THE PROTRUSION (49) HAVING THE COLLECTING EXHAUST PORT (18) DEFINED THEREIN. THE WATER JACKETS (J2 AND J3) ARE NOT PROVIDED BETWEEN THE SIDE WALL (121) OF THE PROTRUSION (49) AND THE EXHAUST COLLECTING SECTION (47). THUS, THE COMPACT CYLINDER HEAD (12) HAVING THE COLLECTING EXHAUST PORT (18) INTEGRALLY PROVIDED THEREIN CAN BE FORMED, WHILE AVOIDING THE COMPLICATION OF THE STRUCTURE OF A CORE.