Direct acting solenoid valve and four-way switching valve equipped with it as a pilot valve

摘要

While being able to reduce noise effectively, without requiring lowering frequency of a compressor greatly from heating operation at the time of a change to defrosting operation. According to the voltage appied by the electromagnetic coil of the direct-acting electromagnetic valve, the first piston and the second piston are located at the absorption position and the non-abosrption position, the first valve core is located at one end position communicated with the end and the other end position communicated with the port, the second valve core is located at the opening position of the opening port and the closing position of the closing port. When the defrosting turning to the warming turning and warming turning to the defrosting turning are performed, the second valve core is located at the opening position, and the pressure of the main valve chamber reduces the presetting voltage.