| 摘要 |
PROBLEM TO BE SOLVED: To perform accurate control with weak electromagnetic force, by detecting the difference between the inner-crankcase pressure and the suction pressure with a piston, and by operating a valve member, which controls the refrigerant flow from the high-pressure compressor delivery side to a crankcase side, using this pressure difference. SOLUTION: An electromagnetic control valve 1-1 consists of a control valve part 1a and an electromagnetic proportional controlling part 1b. A valve body 17 is divided into an upper part 17a, an intermediate part 17b, and a lower part 17c, and a valve seat 17d is formed on the upper part 17a. In the lower part 17c of the valve body, a piston 12-1a which has a pore 12-1b in its upper part and a U-shaped cross section is placed on a lower-piston space 17g which communicates with a suction side of a compressor, so that the upper part of the piston faces a guide hole 17h of the inner-crankcase pressure Pc of the valve body. The piston 12-1a detects the pressure difference between Pc and the suction pressure Ps, and the pressure difference drives a valve which controls the flow from the high-pressure side (delivery pressure Pd) to a pressure control room (Pc). |
