CHECK VALVE FOR DIESEL ENGINE

摘要

A check valve for a diesel engine is provide to reduce a friction loss in an engine oil pump and to improve a fuel consumption ratio by relatively increasing oil injection amount in a low-rotation zone of the diesel engine and relatively decreasing the oil injection amount in a high-rotation zone of the diesel engine. A check valve for a diesel engine comprises a cylindrical pipe(10) having an oil inlet(20) and an oil outlet(30); a piston(40) slidably installed in the cylindrical pipe; and a spring(50) closing a passage communicating with the oil inlet and the oil outlet by pressing the piston toward the oil inlet. The spring is an asymmetric pressure spring having a relatively large change in the compression length of the spring in a zone where oil pressure is low and having a relatively small change in the compression length of the spring in a zone where oil pressure is high.