Control valve for variable displacement compressor

• Main Authors: KOWADA KAZUTAKA, SATO YOSHIE, MUTA SHUNJI, IRIE KAZUHIRO, KAWAMURA YUJI
• Format: Patent
• Language: English
• Published: 17.11.2005
• Edition: 7
• Subjects: BLASTING; HEATING; LIGHTING; MECHANICAL ENGINEERING; POSITIVE DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS; WEAPONS

In order to reduce the amount of refrigerant circulating within a variable displacement compressor to thereby improve compression efficiency, a control valve is configured to comprise a ball valve for controlling the flow rate of refrigerant flowing from a discharge chamber to a crankcase, a spool valve for controlling the flow rate of refrigerant flowing from the crankcase to a suction chamber, a diaphragm for sensing suction pressure, and a solenoid for setting the suction pressure, wherein the spool valve starts flow rate control after the ball valve is fully closed or nearly fully closed, and the ball valve starts flow rate control after the valve lift of the spool valve is minimized or nearly minimized. As a result, a region is almost eliminated in which the ball valve and the spool valve are both open simultaneously during switching of flow rate control between the ball valve and the spool valve, which makes it possible to minimize the flow rate of the refrigerant circulating within the compressor without contributing to a refrigerating operation, to thereby improve the efficiency of the compressor.