| 主权项 |
1. An expansion valve, which is applied to a vapor compression refrigeration cycle, wherein the expansion valve depressurizes and expands a high pressure refrigerant, and the expansion valve outputs a low pressure refrigerant, which is depressurized and expanded by the expansion valve, toward a refrigerant inlet of an evaporator, the expansion valve comprising:
a body portion that forms:
a high pressure refrigerant passage that conducts the high pressure refrigerant;a throttle passage that is provided in the high pressure refrigerant passage, wherein the throttle passage depressurizes and expands the high pressure refrigerant; anda low pressure refrigerant passage that conducts the low pressure refrigerant, which is outputted from the evaporator; a valve element that adjusts an opening degree of the throttle passage; an element portion that is placed outside of the body portion and includes a pressure-operated member, wherein the pressure-operated member is displaceable in response to a pressure difference between:
an internal pressure of a sealed space of the element portion, in which a temperature sensitive medium is sealed, wherein a pressure of the temperature sensitive medium is changeable in response to a temperature; anda pressure of the low pressure refrigerant that flows in the low pressure refrigerant passage; and a temperature sensitive rod that is placed such that at least a portion of the temperature sensitive rod is located in the low pressure refrigerant passage, wherein the temperature sensitive rod conducts displacement of the pressure-operated member to the valve element and conducts a temperature of the low pressure refrigerant, which flows through the low pressure refrigerant passage, to the temperature sensitive medium, wherein: the temperature sensitive rod includes a blind hole, which opens to the sealed space and extends in an inside of the temperature sensitive rod in an axial direction of the temperature sensitive rod; the temperature sensitive medium is a mixture gas, which is a mixture of a refrigerant and an inert gas, wherein the inert gas is different from the refrigerant; and a mixing ratio of the inert gas in the temperature sensitive medium is set based on a ratio of an equivalent diameter of the blind hole, which is measured in a direction perpendicular to the axial direction of the temperature sensitive rod, relative to a depth of the blind hole, which is measured in the axial direction of the temperature sensitive rod, in such a manner that a time constant of heat conduction from the temperature sensitive rod to the temperature sensitive medium is kept within a predetermined time constant range. |
