Expansion valve for refrigerating cycle

Abstract

An expansion valve for a refrigerating cycle, in which the body dimensions and the weight of the whole valve can be reduced and a reduction in cost can be achieved. An expansion valve of the invention comprising a temperature-sensing portion arranged in a refrigerant passage leading to an evaporator from a gas cooler or an internal heat exchanger in a vapor compression type refrigerating cycle and varied in internal pressure according to a refrigerant temperature at an outlet side of the gas cooler or on an outlet side of the internal heat exchanger, a valve member that mechanically interlocks with a change in internal pressure of the temperature-sensing portion to adjust an opening degree of a valve port, and a body that accommodates therein the valve member, and wherein the body is provided with a flow passage, through which a refrigerant reduced in pressure by the valve member is led to the evaporator while a refrigerant temperature at the outlet side of the gas cooler or on the outlet side of the internal heat exchanger is transmitted to the temperature-sensing portion. Also, that density, at which a refrigerant is charged in a temperature-sensing body, is set in the range of about 200 kg/m 3 to about 600 kg/m 3 . Further, a ratio of a temperature-sensing cylinder corresponding portion to the temperature-sensing body is made at least 60%.

1 . An expansion valve for a refrigerating cycle, arranged in a refrigerant passage leading from a gas cooler to an evaporator in a vapor compression type refrigerating cycle to adjust an opening degree of a valve port on the basis of a refrigerant temperature at an outlet side of the gas cooler to thereby control a refrigerant pressure at the outlet side of the gas cooler, the expansion valve comprising 
 a temperature-sensing portion, the inner pressure of which is varied according to the refrigerant temperature at the outlet side of the gas cooler,    a valve member that mechanically interlocks with a chance in internal pressure of the temperature-sensing portion to adjust an opening degree of the valve port, and    a body that accommodates therein the valve member, and    wherein the body is provided with a flow passage, through which a refrigerant reduced in pressure by the valve member is led to the evaporator while the refrigerant temperature at the outlet side of the gas cooler is transmitted to the temperature-sensing portion.    
   
   
       2 . The expansion valve for a refrigerating cycle according to  claim 1 , wherein the temperature-sensing portion comprises a diaphragm, and a lid and a lower support member, which interpose therebetween a peripheral edge of the diaphragm from upper and lower directions to define an enclosed space above the diaphragm, and transmission or a refrigerant temperature to the temperature-sensing portion is performed by a clearance, which is formed by the valve member and the lower support member to be communicated to the refrigerant passage.  
   
   
       3 . The expansion valve for a refrigerating cycle according to any one of  claim 1 , wherein the enclose, space of the temperature-sensing portion is charged with a refrigerant and provided with an adjustment spring, which biases the valve member in a valve closing direction.  
   
   
       4 . The expansion valve for a refrigerating cycle according to any one of  claim 1 , wherein the enclosed space of the temperature-sensing portion is charged with a mixed gas of a refrigerant and gases, which are lower in coefficient of thermal expansion than the refrigerant, and an adjustment spring, which biases the valve member in a valve closing direction, is omitted.  
   
   
       5 . The expansion valve for a refrigerating cycle according to any one of  claim 1 , further comprising a lid that covers a wall surface of the first enclosed space in contact with an outside air to provide an air layer between the wall surface and the outside air.  
   
   
       6 . The expansion valve for a refrigerating cycle according to any one of  claim 1 , wherein at least a part of the wall surface of the first enclosed space in contact with an outside air is covered by a thermal insulating material.  
   
   
       7 . An expansion valve for a refrigerating cycle arranged in a refrigerant passage leading from an internal heat exchanger to an evaporator in a vapor compression type refrigerating cycle to adjust an opening degree of a valve port on the basis of a refrigerant temperature at an outlet side of the gas cooler to thereby control a refrigerant pressure at the outlet side of the gas cooler, the expansion valve comprising 
 a temperature-sensing portion, the inner pressure of which is varied according to the refrigerant temperature at the outlet side of the gas cooler,    a valve member that mechanically interlocks with a change in internal pressure of the temperature-sensing portion to adjust an opening degree of the valve port, and    a body that accommodates therein the valve member, and    wherein the body is provided with a first flow passage, through which a refrigerant flows to the internal heat exchanger, and a second flow passage, through which a refrigerant reduced in pressure by the valve member is led to the evaporator from the internal heat exchanger, while the refrigerant temperature at the outlet side of the gas cooler is transmitted to the temperature-sensing portion.    
   
   
       8 . The expansion valve for a refrigerating cycle according to  claim 7 , wherein the temperature-sensing portion comprises a diaphragm, and a lid and a lower support member, which interpose therebetween a peripheral edge of the diaphragm from upper and lower directions to define an enclosed space above the diaphragm, and transmission of a refrigerant temperature to the temperature-sensing portion is performed by a clearance, which is formed by the valve member and the lower support member to be communicated to the refrigerant passage.  
   
   
       9 . The expansion valve for a refrigerating cycle according to any one of  claim 7 , wherein the enclosed space of the temperature-sensing portion is charged with a refrigerant and provided with an adjustment spring, which biases the valve member in a valve closing direction.  
   
   
       10 . The expansion valve for a refrigerating cycle according to any one of  claim 7 , wherein the enclosed space of the temperature-sensing portion is charged with a mixed gas of a refrigerant and gases, which are lower in coefficient of thermal expansion than the refrigerant, and an adjustment spring, which biases the valve member in a valve closing direction, is omitted.  
   
   
       11 . The expansion valve for a refrigerating cycle according to any one of  claim 7 , further comprising a lid that covers a wall surface of the first enclosed space in contact with an outside air to provide an air layer between the wall surface and the outside air.  
   
   
       12 . The expansion valve for a refrigerating cycle according to any one of  claim 7 , wherein at least a part of the wall surface of the first enclosed space in contact with an outside air is covered by a thermal insulating material.  
   
   
       13 . An expansion valve for a refrigerating cycle arranged in a refrigerant passage leading from an internal heat exchanger to an evaporator in a vapor compression type refrigerating cycle to adjust an opening degree of a valve port on the basis of a refrigerant temperature at an outlet side of the internal heat exchanger to thereby control a refrigerant pressure at the outlet side of the internal heat exchanger, the expansion valve comprising 
 a temperature-sensing portion, inner pressure of which is varied according to the refrigerant temperature at the outlet side of the internal heat exchanger, a valve member that mechanically interlocks with a change in internal pressure of the temperature-sensing portion to adjust an opening degree of the valve port, and    a body that accommodates therein the valve member, and    wherein the body is provided with a flow passage, through which a refrigerant reduced in pressure by the valve member flows to the evaporator while the refrigerant temperature at the outlet side of the internal heat exchanger is transmitted to the temperature-sensing portion.    
   
   
       14 . The expansion valve for a refrigerating cycle according to  claim 13 , wherein the temperature-sensing portion comprises a diaphragm, and a lid and a lower support member, which interpose therebetween a peripheral edge of the diaphragm from upper and lower directions to define an enclosed space above the diaphragm, and transmission of a refrigerant temperature to the temperature-sensing portion is performed by a clearance, which is formed by the valve member and the lower support member to be communicated to the refrigerant passage.  
   
   
       15 . The expansion valve for a refrigerating cycle according to any one of  claim 13 , wherein the enclosed space of the temperature-sensing portion is charged with a refrigerant and provided with an adjustment spring, which biases the valve member in a valve closing direction.  
   
   
       16 . The expansion valve for a refrigerating cycle according to any one of  claim 13 , wherein the enclosed space of the temperature-sensing portion is charged with a mixed gas of a refrigerant and gases, which are lower in coefficient of thermal expansion than the refrigerant, and an adjustment spring, which biases the valve member in a valve closing direction, is omitted.  
   
   
       17 . Am expansion valve for a refrigerating cycle arranged in a refrigerant passage leading to an evaporator from a gas cooler through an internal heat exchanger in a vapor compression type refrigerating cycle to adjust an opening degree of a valve port on the basis of a refrigerant temperature at an outlet side of the gas cooler or a refrigerant temperature at an outlet side of the internal heat exchanger to thereby control a refrigerant pressure at the outlet side of the internal heat exchanger, the expansion valve comprising 
 a temperature-sensing portion charged with a refrigerant and varied in inner pressure according to the refrigerant temperature at the outlet side of the gas cooler or the refrigerant temperature at the outlet side of the internal heat exchanger, and    a valve member that mechanically interlocks with a change in internal pressure of the temperature-sensing portion to adjust an opening degree of the valve port, and    wherein the density, at which a refrigerant is charged in the temperature-sensing portion, is 200 to 600 kg/m 3  in a valve closed state.    
   
   
       18 . The expansion valve for a refrigerating cycle according to  claim 17 , wherein the density, at which a refrigerant is charged in the temperature-sensing portion, is 200 to 450 kg/m 3  in a valve closed state.  
   
   
       19 . The expansion valve for a refrigerating cycle according to  claim 17 , wherein the valve member is opened when high pressure at the outlet side of the gas cooler or at the outlet side of the internal heat exchanger becomes higher, by a predetermined magnitude, than inner pressure in the temperature-sensing portion.  
   
   
       20 . The expansion valve for a refrigerating cycle according to  claim 19 , wherein a load corresponding to the predetermined magnitude is given by an elastic member, or a non-condensed gas charged in the temperature-sensing portion together with a refrigerant, or the elastic member and the non-condensed gas.  
   
   
       21 . The expansion valve for a refrigerating cycle according to  claim 20 , wherein the elastic member comprises any one of a coil spring, a diaphragm, and a bellows, or an optional combination thereof.  
   
   
       22 . The expansion valve for a refrigerating cycle according to  claim 17 , wherein when a refrigerant temperature at the outlet side of the gas cooler is 50° C. or higher, the internal heat exchanger heats a refrigerant sucked into a compressor so that superheat becomes 10° C. or higher.  
   
   
       23 . An expansion valve for a refrigerating cycle that uses a refrigerant in a supercritical state, the expansion valve comprising a temperature-sensing portion having 
 a first enclosed space provided above a diaphragm and charged with a refrigerant, and    a second enclosed space provided to be communicated to the first enclosed space, and    wherein a refrigerant on an outlet side of a gas cooler, or a refrigerant on an outlet side of an internal heat exchanger is introduced below the diaphragm to apply high pressure below the diaphragm, a refrigerant temperature at the outlet side of the gas cooler, or a refrigerant temperature at the outlet side of the internal heat exchanger is transmitted to a refrigerant charged in the temperature-sensing portion, and the valve is opened and closed by that displacement of the diaphragm, which is caused by a pressure difference between above and below the diaphragm.    
   
   
       24 . The expansion valve for a refrigerating cycle according to  claim 23 , wherein the second enclosed space is provided inside a valve member fixed to the diaphragm.  
   
   
       25 . The expansion valve for a refrigerating cycle according to  claim 23 , wherein the sum of a half of a volume of the first enclosed space and a volume of the second enclosed space amounts to 60% or more of the sum of a volume of the first enclosed space and the second enclosed space.  
   
   
       26 . The expansion valve for a refrigerating cycle according to any one of  claim 23 , further comprising a lid that covers a wall surface of the first enclosed space in contact with an outside air to provide an air layer between the wall surface and the outside air.  
   
   
       27 . The expansion valve for a refrigerating cycle according to any one of  claim 23 , wherein at least a part of the wall surface of the first enclosed space in contact with an outside air is covered by a thermal insulating material.