Abstract: A valve operating system for a multicylinder engine opens and closes a pair of valves provided on each of cylinders by means of a pair of rocker arms operated by a cam provided on a camshaft supported on a cam holder. When viewed in a direction of a cylinder axis, the pair of rocker arms of at least one of the cylinders are inclined in opposite directions to each other with respect to a direction orthogonal to a camshaft axis. Therefore, thrust loads acting on the camshaft from the pair of rocker arms are counteracted individually for each of the cylinders, thereby enabling the thrust load to be reduced and axial movement of the camshaft to be prevented.

Abstract: A valve operating system for a multicylinder engine opens and closes a pair of valves provided on each of cylinders by means of a pair of rocker arms operated by a cam provided on a camshaft supported on a cam holder. When viewed in a direction of a cylinder axis, the pair of rocker aims of at least one of the cylinders are inclined in opposite directions to each other with respect to a direction orthogonal to a camshaft axis. Therefore, thrust loads acting on the camshaft from the pair of rocker al is are counteracted individually for each of the cylinders, thereby enabling the thrust load to be reduced and axial movement of the camshaft to be prevented.

Abstract: The present invention discloses an apparatus and a method for automatically designing a jig comprising at least one part. In this apparatus and method, the kind of a jig and the kind of a workpiece to be worked on are first specified, a basic linkage mode which basically shows a linkage between the parts of the specified jig is then searched for, and structural models of the parts forming the jig are successively generated by using at a starting point data with respect to a position of the workpiece to be worked on by the jig on the basis of the basic linkage model searched for.