CONTROL VALVE FOR VARIABLE DISPLACEMENT COMPRESSOR

PROBLEM TO BE SOLVED: To provide a control valve for the duty ratio control of a variable displacement compressor having improved property near a valve closing position. SOLUTION: A valve portion 10 for controlling the opening/closing of a passage between a port 14 for discharge pressure Pd and a port 15 for pressure Pc is formed by a spool valve. A valve element 18 and a shaft 23 held by a body 13 are integrated with each other and formed with the same outer diameter. Thus, centerless polishing work can be applied to the integrated part to improve the tolerance of the outer diameters and the accuracy of surface roughness. A valve hole 17 and a hole holding the shaft 23 are also formed with the same inner diameter and mirror finished with vanishing work to improve the tolerance of the inner diameters and the accuracy of surface roughness, resulting in a reduction in the internal leakage of refrigerant during closing the valve. With the valve portion 10 formed by the spool valve, there is no collision/rebound of the valve element 18 due to the duty ratio control which causes the worsening of the property near the valve closing position. COPYRIGHT: (C)2005,JPO&NCIPI