| 摘要 |
<p>In a four-way switching valve a pressure-regulating chamber 9 is selectively connected to a low-pressure chamber d or a high-pressure chamber a by a three-way solenoid valve 17. Another pressure-regulating chamber 8 communicates with a chamber b by a tube 16. When the three-way solenoid valve 17 connects the pressure-regulating chamber 9 t the low-pressure chamber d, ports A, B communicate while ports B, D are separated. Pressure increase in chamber b increases the pressure in pressure-regulating chamber 8. A plug 2 urged by a piston 3 separates ports A and C and connects ports C and D. When three-way solenoid valve 17 connects pressure-regulating chamber 9 to high-pressure chamber a, a plug 4 urged by a piston 5 separates ports A and B and connects ports B and D. Reduced pressure in chamber b reduces the pressure in the pressure-regulating chamber 8. The plug 2 urged by high pressure connects ports A and C, and separates ports C and D. Those superimposed valve functions avoid refrigerant leakages when controlling the pressures in the pressure-regulating chambers 8 and 9. <IMAGE></p> |
