JP2009166510A - Refrigeration cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce leakage positions of high-pressure refrigerant which may leak from a connection part of a high-pressure pipe to the outside in a refrigeration cycle of a motor vehicle air conditioner. <P>SOLUTION: All of high-pressure pipe joints H1-H5 using sealing materials of high-pressure pipes 7, 11 and 12 which are located from a refrigerant outlet of a compressor 1 to a refrigerant inlet of an expansion valve 4 are disposed in low-pressure pipes 15, 16 and 17 located from a refrigerant outlet of an evaporator 5 to a refrigerant inlet of the compressor 1 to reduce the leakage positions of the high-pressure refrigerant, where the sealing parts by the sealing materials of the high-pressure pipe joints H1-H5 are directly exposed to atmosphere, to zero. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle, and more particularly, to a refrigeration cycle in which a location where a refrigerant leaks from a pipe joint using a sealing material for high-pressure piping to the atmosphere is reduced in an air conditioner for automobiles.

  In an automotive air conditioner, generally, a compressor, a condenser, and a receiver dryer are installed in an engine room, an evaporator is installed in a vehicle compartment, and an expansion valve is a partition wall or compartment that separates the vehicle compartment and the engine room. It is installed in the passenger compartment. In the refrigeration cycle, basically, a compressor, a condenser, a receiver dryer, an expansion valve, and an evaporator are piped so that the refrigerant flows in this order, and the refrigerant that has left the evaporator returns to the compressor ( For example, see Patent Document 1). Here, attention is paid to the joint portion of the pipe connecting the components of the refrigeration cycle.

  10A and 10B are diagrams for explaining a pipe joint part in a conventional refrigeration cycle, in which FIG. 10A shows a case where an expansion valve is arranged in a partition wall, and FIG. 10B shows that an expansion valve is arranged close to an evaporator. Shows the case. In FIG. 10, a thick solid line indicates a high-pressure pipe. In addition, the pipe joint is sealed from the atmosphere with a sealing material such as an O-ring. Among the parts that use the sealing material, the part where high pressure is applied is indicated by a solid line circle, Such a portion is indicated by a broken-line circle.

  First, in the refrigeration cycle shown in FIG. 10A, a compressor 101, a condenser 102, and a receiver dryer 103 are installed in an engine room, and an expansion valve 104 is formed by a partition wall 105 that partitions the vehicle compartment and the engine room. It is also installed as a pipe joint that relays the piping on the engine room side and the piping on the vehicle compartment side, and an evaporator 106 is installed in the vehicle compartment.

  Here, connecting portions of the respective high-pressure pipes from the refrigerant outlet of the compressor 101 to the refrigerant inlet of the expansion valve 104 via the condenser 102 and the receiver dryer 103 are sealed by O-rings. In addition, the low pressure piping that reciprocates between the expansion valve 104 and the evaporator 106 and the connection portion of the low pressure piping between the expansion valve 104 and the refrigerant inlet of the compressor 101 are also sealed by an O-ring. In the case of the temperature type expansion valve as shown in the figure, the expansion valve 104 includes an adjustment screw that adjusts the set value of the superheat degree of the refrigerant at the outlet of the evaporator 106 and a power element that detects the superheat degree. In addition, an O-ring that prevents leakage of the high-pressure refrigerant is used at the threaded portion of the adjustment screw, and an O-ring that prevents leakage of the low-pressure refrigerant is used at the mounting portion of the power element.

  Further, the refrigeration cycle shown in FIG. 10B shows an example in which the receiver dryer 103 is configured integrally with the condenser 102 (see, for example, Patent Document 2), and the expansion valve 104 is an evaporator 106. The example comprised integrally with is shown. In this refrigeration cycle, although the condenser 102 and the receiver dryer 103 are integrated, only a joint portion to which the receiver dryer 103 is attached is provided integrally with the condenser 102, and an O-ring seal is used. There is no change in the number of joints. In this refrigeration cycle, the number of seal points by the O-ring is increased by one at each of the high-pressure and low-pressure joints in the partition wall 105 as compared with the refrigeration cycle shown in FIG.

By the way, since the refrigerant | coolant currently used with the air conditioner for motor vehicles has a very large environmental load at the time of leaking to air | atmosphere, it is desired to suppress the refrigerant | coolant leak from a refrigerating cycle to air | atmosphere as much as possible. .
Japanese Patent Laying-Open No. 2003-302125 (FIG. 1) JP 2006-52938 A

  However, in the refrigeration cycle, the portion where the refrigerant may leak to the atmosphere is the seal portion by the O-ring. In particular, the seal portion at the connection portion of the high-pressure pipe is damaged to a slight extent. There is a problem that the sealing performance cannot be maintained in the case where there is dust or dust adheres, so that it must be strictly controlled.

  This invention is made | formed in view of such a point, and it aims at providing the refrigerating cycle which reduced the leak location of the refrigerant | coolant to the exterior from the connection part of a high voltage | pressure piping.

  In the present invention, in order to solve the above problems, a compressor, a condenser, a receiver dryer, and an expansion device are connected by high-pressure piping, and the expansion device, the evaporator, and the compressor are connected by low-pressure piping. In the cycle, all of the high-pressure pipe joints using the sealing material of the high-pressure pipe existing between the refrigerant outlet of the compressor and the refrigerant inlet of the expansion device are connected from the refrigerant outlet of the evaporator to the refrigerant inlet of the compressor. A refrigeration cycle is provided which is arranged in a low-pressure pipe existing between

  According to such a refrigeration cycle, the high-pressure refrigerant is not directly leaked into the atmosphere by arranging all the seal portions in the connection portion of the high-pressure pipe, which is a high-pressure leak site, in the low-pressure pipe.

  Further, in the present invention, in the refrigeration cycle configured by connecting a compressor, a condenser, a receiver dryer, and an expansion device with high-pressure piping, and connecting the expansion device, the evaporator, and the compressor with low-pressure piping, the receiver A high-pressure pipe joint that uses a high-pressure pipe sealant that exists between the refrigerant outlet of the dryer and the refrigerant inlet of the expansion device has a low pressure that exists between the refrigerant outlet of the evaporator and the refrigerant inlet of the compressor. A refrigeration cycle is provided that is disposed in a pipe.

  According to such a refrigeration cycle, the connection portion of the high-pressure pipe exposed from the receiver dryer to the expansion device is arranged in the low-pressure pipe so that the connection portion of the high-pressure pipe exposed to the atmosphere is condensed with the compressor. Only the connection part of the high-pressure pipe connecting between the two is connected, and the leakage part of the refrigerant to the outside can be greatly reduced.

  The refrigeration cycle of the present invention can completely eliminate or reduce the leaking part where the high-pressure refrigerant leaks directly to the atmosphere by arranging the joint of the high-pressure pipe using the sealing material in the low-pressure pipe. There is an advantage that you can.

  In addition, even if a refrigerant leaks at the joint portion of the high-pressure piping placed in the low-pressure piping, the leakage destination is in the low-pressure piping, and the leaked refrigerant is sucked into the compressor. Therefore, the reliability against external leakage to the atmosphere can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, taking as an example a case where the present invention is applied to an automotive air conditioner.
FIG. 1 is a schematic diagram showing a refrigeration cycle according to a first embodiment to which the present invention is applied.

  The refrigeration cycle includes a compressor 1, a condenser 2, a receiver dryer 3, an expansion valve 4 and an evaporator 5, and the compressor 1, the condenser 2 and the receiver dryer 3 are installed in an engine room partitioned by a partition wall 6. The expansion valve 4 and the evaporator 5 are installed in the passenger compartment.

  The refrigerant outlet of the compressor 1 is connected to one end of the high-pressure pipe 7 by a high-pressure pipe joint H1, and the other end of the high-pressure pipe 7 is connected to the inlet pipe 8 of the condenser 2 by a high-pressure pipe joint H2. . The condenser 2 is formed integrally with the main body of the receiver dryer 3, and at that time, an inlet pipe 8 of the condenser 2 and a refrigerant passage 9 that connects the refrigerant outlet of the condenser 2 and the refrigerant inlet of the receiver dryer 3 together. Joined by brazing. For this reason, there is no connection site by the O-ring seal from the inlet pipe 8 to the condenser 2, the refrigerant passage 9, and the main body of the receiver dryer 3.

  The receiver dryer 3 includes an outlet pipe 10 that feeds the accumulated liquid refrigerant, and the outlet pipe 10 is connected to one end of the high-pressure pipe 11 by a high-pressure pipe joint H3. The other end of the high-pressure pipe 11 is connected to one end of the high-pressure pipe 12 by a high-pressure pipe joint H4 at the penetrating position of the partition wall 6, and the other end is connected to the inlet pipe 13 of the expansion valve 4 by a high-pressure pipe joint H5. Has been. Here, each of the high-pressure pipe joints H1 to H5 indicates a connection site by an O-ring seal.

  The refrigerant outlet of the expansion valve 4 is connected to the refrigerant inlet of the evaporator 5 by a low-pressure pipe joint L1, and the refrigerant outlet is connected to a case 14 that accommodates the expansion valve 4 by a low-pressure pipe joint L2. The case 14 is connected to one end of the low-pressure pipe 15 by a low-pressure pipe joint L3, and the other end is connected to one end of the low-pressure pipe 16 by a low-pressure pipe joint L4 at a through position of the partition wall 6. The other end of the low-pressure pipe 16 is branched into two. One is connected to the main body of the receiver dryer 3 by a low-pressure pipe joint L5, and the other is connected to one end of the low-pressure pipe 17 by a low-pressure pipe joint L6. ing. The other end of the low-pressure pipe 17 is connected to the refrigerant inlet of the compressor 1 through a low-pressure pipe joint L7. Here, each of the low-pressure pipe joints L1-L7 indicates a connection site by an O-ring seal.

  In the above configuration, the high-pressure pipe joints H1-H5 sealed by the O-ring are all disposed in the low-pressure space surrounded by the case 14 and the low-pressure pipes 15, 16, and 17. For this reason, since the high-pressure piping joint H1-H5 is not directly exposed to the atmosphere, it does not become a leakage portion where the refrigerant may leak into the atmosphere. Even if refrigerant leakage occurs in the high-pressure pipe joints H1-H5, the leakage destination is in the case 14 and the low-pressure pipes 15, 16, and 17, so that the leaked refrigerant is recovered by the compressor. Will not leak into the atmosphere.

Next, a specific configuration of each high-pressure pipe joint H1-H5 will be described.
2 is a cross-sectional view showing an example of a pipe joint structure in the compressor, and FIG. 3 is a cross-sectional view taken along the line aa in FIG. In addition, the arrow in a figure has shown the flow direction of the refrigerant | coolant.

  The compressor 1 is provided with a discharge chamber 22 into which compressed refrigerant is discharged and a suction chamber 23 into which compressed refrigerant is sucked in a housing 21. In the housing 21, a refrigerant inlet 24 communicating with the suction chamber 23 is opened, and an outlet pipe 25 communicating with the discharge chamber 22 is concentrically disposed there. Thereby, the joint part of the compressor 1 is formed in the shape of a double pipe structure in which the high-pressure outlet pipe 25 is concentrically arranged in the low-pressure refrigerant inlet 24.

  The high pressure pipe 7 and the low pressure pipe 17 connected to the joint portion of the compressor 1 are subjected to end treatment so as to form a concentric double pipe structure so as to be fitted with the concentric double pipe structure on the compressor 1 side. It has been broken. Since the high-pressure pipe 7 and the low-pressure pipe 17 connect between the compressor 1 fixed to the engine block and the condenser 2 fixed to the vehicle chassis, the vibration of the engine is transmitted to the condenser 2. It is comprised with the flexible hose which has flexibility so that it may not. For this reason, the high-pressure pipe 7 and the low-pressure pipe 17 are provided with a metal member at a connection portion with the compressor 1. That is, the low-pressure pipe 17 is sandwiched between a metal pipe 26 inserted inside and a metal sleeve 27 fitted outside, and the metal sleeve 27 is caulked and fixed in an airtight manner. The part is joined to a joint member 28 fitted to the refrigerant inlet 24 of the compressor 1. As shown in FIG. 3, a cylindrical holding member 29 having struts 29a in three directions is inserted into the metal pipe 26 and fixed therein by an appropriate method. The high pressure pipe 7 is held near its end by the holding member 29, and a metal pipe 30 is inserted into the end. The end of the metal pipe 30 is flanged, and a sealing material 31 is provided between the flange and the end surface of the high-pressure pipe 7.

  The high-pressure pipe 7 whose end is treated in this way is directly fitted into the outlet pipe 25 of the compressor 1, and the low-pressure pipe 17 is fitted into the refrigerant inlet 24 of the compressor 1 by the joint member 28, and the bolt 32 is fixed to the housing 21 of the compressor 1. At this time, the high-pressure pipe 7 is sealed by the sealing material 31, and the low-pressure pipe 17 is sealed by the O-ring 33 provided on the joint member 28. For this reason, the joint portion between the compressor 1 and the high-pressure pipe 7 does not have a leakage portion where the high-pressure refrigerant leaks to the atmosphere.

4 is a cross-sectional view showing an example of a pipe joint structure in a receiver / dryer integrated condenser, and FIG. 5 is a cross-sectional view taken along the line bb of FIG.
The condenser 2 alternately arranges tubes 41 and corrugated fins (not shown) to form a plate-like heat exchanger core, and refrigerant is provided at both ends of the tubes 41 (only the left side is shown in the figure). The header 42 for branching and gathering is connected. The header 42 is partitioned by a partition plate 43, whereby the condenser 2 is configured in a form in which a plurality of independent heat exchangers are connected in series.

  The header 42 has one end of an inlet pipe 8 to which the high-pressure pipe 7 from the compressor 1 is connected connected to the upper end side in the figure, and the refrigerant condensed in the condenser 2 is received in the receiver dryer on the lower end side in the figure. One end of the refrigerant passage 9 sent out to 3 is connected. The receiver dryer 3 has a bottomed cylindrical main body 44, and an opening end thereof is disposed upwardly opposite to the direction of gravity. The main body 44 has a hole 45 formed in the upper side surface in the figure, and a joint member 46 is connected to the hole 45. The joint member 46 has a double pipe structure at the end opposite to the hole 45, and an inlet pipe 47 that receives the high-pressure pipe 7 from the compressor 1 is disposed at the center. The inlet pipe 47 is connected to the other end of the inlet pipe 8 of the condenser 2. The other end of the refrigerant passage 9 constituting the refrigerant inlet of the receiver dryer 3 is connected to the main body 44 at a position below the hole 45 in the figure.

  The condenser 2, the main body 44 of the receiver dryer 3, the inlet pipe 8, the refrigerant passage 9, the joint member 46, and the inlet pipe 47 are integrally formed by brazing in the furnace. Thereby, there is no connection part which requires an O-ring seal between the refrigerant inlet of the condenser 2 and the refrigerant inlet of the receiver dryer 3. After brazing in the furnace, the desiccant 48, the outlet pipe 10 and the partition plate 49 are attached to the main body 44, and the receiver dryer 3 is completed. The partition plate 49 is installed in the main body 44 so as to partition the space between the hole 45 and the attachment position of the refrigerant passage 9 in a state where the outlet pipe 10 is attached in an airtight state.

  In the condenser 2 and the receiver dryer 3 configured as described above, the low pressure pipe 17 and the high pressure pipe 7 are connected to the joint member 46 and the inlet pipe 47 disposed therein in the same manner as the connection method of the compressor 1. It is connected by the method of. On the other hand, in the receiver dryer 3, the low-pressure pipe 16 and the high-pressure pipe 11 are connected to the open end of the main body 44 and the outlet pipe 10, respectively.

  The low-pressure pipe 16 and the high-pressure pipe 11 are constituted by a double pipe 50 as shown in FIG. The double pipe 50 includes an outer pipe 50a constituting the low-pressure pipe 16, an inner pipe 50b constituting the high-pressure pipe 11, and three columns 50c maintaining the concentricity thereof, and preferably formed integrally by hollow extrusion molding. Has been. The outer tube 50a is formed into a shape that can be connected to the main body 44 of the receiver dryer 3 by processing the end of the hollow extruded material, and the inlet pipe 51 is joined to the inner tube 50b.

  Such a double pipe 50 is fixed by a pipe clamp 52 by fitting the inlet pipe 51 with the outlet pipe 10 and fitting the outer pipe 50 a with the opening end of the main body 44 of the receiver dryer 3. At this time, the high-pressure fitting portion between the inlet pipe 51 and the outlet pipe 10 is sealed by the O-ring 53, and the low-pressure fitting portion between the outer pipe 50 a and the main body 44 is sealed by the O-ring 54.

  Thereby, the high pressure of the high pressure joint portion between the condenser 2 and the high pressure pipe 7 from the compressor 1 and the inlet pipe 51 joined to the outlet pipe 10 of the receiver dryer 3 and the inner pipe 50b of the double pipe 50. Since all of the joint portions are in the low-pressure refrigerant passage, they do not become leak sites where high-pressure refrigerant leaks to the atmosphere.

FIG. 6 is a cross-sectional view showing an example of a pipe joint structure in a partition wall.
In the partition wall 6 that partitions the engine room and the vehicle compartment, the double pipe 50 connected to the receiver dryer 3 and the double pipe 55 connected to the expansion valve 4 and its case 14 are connected. The double pipe 50 is cut and molded into the same shape as the end on the receiver dryer 3 side, and a connecting pipe 56 is joined to the inner pipe 50b. Similarly to the double pipe 50, the double pipe 55 is formed by processing the end of a hollow extruded material having an outer pipe 55a, an inner pipe 55b, and a column 55c, and connecting a connecting pipe 57 to the inner pipe 55b. Has been. The outer pipe 55 a of the double pipe 55 constitutes the low-pressure pipe 15 of FIG. 1, and the inner pipe 55 b constitutes the high-pressure pipe 12.

  Such double pipes 50 and 55 are fixed by a pipe clamp 58 by fitting the connecting pipe 56 with the connecting pipe 57 and fitting the outer pipe 50a with the outer pipe 55a. At this time, the high-pressure fitting portion between the connection pipe 56 and the connection pipe 57 is sealed by the O-ring 59, and the low-pressure fitting portion between the outer pipe 50 a and the outer pipe 55 a is sealed by the O-ring 60. ing.

FIG. 7 is a cross-sectional view showing an example of a pipe joint structure in an expansion valve and an evaporator.
The double pipe 55 extending from the partition wall 6 is processed into the same shape as the connection side with the double pipe 50, and a connection pipe 61 is joined to the inner pipe 55b.

  The expansion valve 4 is a temperature type expansion valve that is directly connected to the evaporator 5, and has a double pipe connection structure in the connection portion with the evaporator 5 as well as the double pipe 55. Yes. Therefore, in the evaporator 5, the refrigerant inlet pipe 62 for introducing the refrigerant and the refrigerant outlet pipe 63 for leading the refrigerant have a double pipe structure, and the refrigerant inlet pipe so that the refrigerant outlet pipe 63 surrounds the refrigerant inlet pipe 62. 62 and substantially coaxial.

  The expansion valve 4 includes a body 64 having a shape in which cylinders intersect with each other in a T-shape, and each of the three end surfaces has a double tube structure. That is, at one end face of the body 64, the inner pipe is the low-pressure refrigerant outlet 65 of the expansion valve 4, and the outer pipe is the return low-pressure refrigerant inlet 66 of the expansion valve 4, and the refrigerant inlet formed integrally with the evaporator 5. The pipe 62 and the refrigerant outlet pipe 63 are connected to each other and sealed by O-rings 67 and 68, respectively. The end surface of the body 64 opposite to the side connected to the evaporator 5 is sealed by caulking the outer tube all around so as to lock the outer peripheral edge of the power element 69, and is sealed by an O-ring 70. It is sealed.

  The power element 69 includes an upper housing 71, a lower housing 72, a diaphragm 73, and a center disk 74. The space surrounded by the upper housing 71 and the diaphragm 73 constitutes a greenhouse, and is filled with a gas having the same or similar characteristics as the refrigerant of the refrigeration cycle. The lower housing 72 has its open ends bent alternately inward and outward in the circumferential direction, the outer bent portion is used to prevent the O-ring 70 from falling off, and the inner bent portion is used to prevent the center disk 74 from falling off. It is a stopper for.

  The portion extending upward from the center of the body 64 is a connecting portion with the double pipe 55, the inner pipe constituting the high-pressure refrigerant inlet 75, and the outer pipe returning to the low-pressure refrigerant outlet 76. It is composed. The high-pressure refrigerant inlet 75 and the return low-pressure refrigerant outlet 76 are fitted with a connecting pipe 61 and an outer pipe 55a joined to the inner pipe 55b of the double pipe 55, respectively, and are sealed by O-rings 77 and 78, respectively.

  The low-pressure refrigerant outlet 65 of the body 64 is formed with a central hole penetrating toward the power element 69, and a plurality of low-pressure refrigerant passages are formed in parallel around the central hole. In the center hole, a valve shaft guide 79 and a ring-shaped valve seat 80 are fitted and fixed to the body 64 by caulking. A valve body 81 is disposed so as to be able to contact and separate from the valve seat 80. The valve body 81 is formed integrally with a valve shaft 82 that extends in the axial direction via a valve seat 80 and a valve shaft guide 79. A cylindrical collar member 83 is fitted to the end of the valve shaft 82 opposite to the side on which the valve body 81 is formed, and on the valve body 81 side, an O for high pressure sealing is provided. A ring 84 is arranged. The collar member 83 is in contact with the center disk 74 of the power element 69 and transmits the displacement of the diaphragm 73 to the valve body 81. The collar member 83 has an outer diameter substantially equal to the inner diameter of the valve hole of the valve seat 80, thereby canceling the pressure of the refrigerant introduced into the high-pressure refrigerant inlet 75.

  The valve body 81 is biased in the valve closing direction by a spring 85, and the spring 85 is received by a spring receiving member 86 that is press-fitted into the low-pressure refrigerant outlet 65, and the spring receiving member 86 is connected to the inner pipe. The load of the spring 85 is adjusted by the amount of press-fitting.

  In the expansion valve 4 having the above configuration, the liquid refrigerant supplied through the inner pipe 55b of the double pipe 55 and the connection pipe 61 is introduced into the high-pressure refrigerant inlet 75, and between the valve seat 80 and the valve body 81. Flows out to the low-pressure refrigerant outlet 65 through the gap. At this time, the refrigerant is adiabatically expanded to become a low-temperature / low-pressure gas-liquid mixed refrigerant, and is introduced into the evaporator 5 through the refrigerant inlet pipe 62. In the evaporator 5, the introduced refrigerant is evaporated by heat exchange with the air in the passenger compartment, flows out from the refrigerant outlet pipe 63, and is introduced into the expansion valve 4 from the return low-pressure refrigerant inlet 66. The evaporated refrigerant returns through the low-pressure refrigerant passage formed in the body 64 and flows out to the low-pressure refrigerant outlet 76. Since the return low-pressure refrigerant outlet 76 communicates with the space surrounded by the diaphragm 73 and the lower housing 72 of the power element 69, the temperature and pressure of the refrigerant returned from the evaporator 5 are detected by the power element 69. The Since the pressure in the temperature sensitive room rises and falls according to the detected temperature and pressure of the refrigerant, the diaphragm 73 is displaced in the opening / closing direction of the valve body 81 according to the temperature and pressure. The displacement is transmitted to the collar member 83 via the center disk 74 and further transmitted to the valve body 81 via the valve shaft 82. As a result, the lift of the valve body 81 changes, and the flow rate of the refrigerant supplied to the evaporator 5 is controlled. That is, the expansion valve 4 senses the temperature and pressure of the refrigerant exiting the evaporator 5 and controls the flow rate of the refrigerant supplied to the evaporator 5 so that the refrigerant maintains a predetermined degree of superheat. Become.

  Also in this expansion valve 4, the high-pressure fitting portion between the connection pipe 61 joined to the double pipe 55 and the high-pressure refrigerant inlet 75 is in the low-pressure refrigerant return passage formed in the body 64. High-pressure refrigerant does not leak into the atmosphere.

  In this embodiment, an example in which a temperature-type expansion valve is used as the expansion valve 4 has been described. However, an electronic expansion valve in which the opening degree of the expansion valve can be controlled by an external signal can be similarly applied. it can.

  FIG. 8 is a schematic diagram showing a refrigeration cycle according to a second embodiment to which the present invention is applied. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The refrigerant outlet of the compressor 1 is connected to one end of the high-pressure pipe 7 by a high-pressure pipe joint H1, and the other end of the high-pressure pipe 7 is connected to the condenser 2 by a high-pressure pipe joint H2. The condenser 2 is integrally formed with the main body of the receiver dryer 3 by brazing, and an O-ring seal is provided from the high-pressure pipe joint H2 of the condenser 2 to the condenser 2, the refrigerant passage 9, and the main body of the receiver dryer 3. Connection by is unnecessary.

  The outlet pipe 10 of the receiver dryer 3 is connected to one end of the high-pressure pipe 11 by a high-pressure pipe joint H3, and the other end is connected to one end of the high-pressure pipe 12 by a high-pressure pipe joint H4. The other end of the high pressure pipe 12 is connected to the inlet pipe 13 of the expansion valve 4 by a high pressure pipe joint H5.

  The refrigerant outlet of the expansion valve 4 is connected to the refrigerant inlet of the evaporator 5 by a low-pressure pipe joint L1, and the refrigerant outlet is connected to a case 14 that accommodates the expansion valve 4 by a low-pressure pipe joint L2. The case 14 is connected to one end of the low-pressure pipe 15 by a low-pressure pipe joint L3, and the other end is connected to one end of the low-pressure pipe 16 by a low-pressure pipe joint L4. The other end of the low-pressure pipe 16 is branched into two. One is connected to the main body of the receiver dryer 3 by a low-pressure pipe joint L5, and the other is connected to one end of the low-pressure pipe 17 by a low-pressure pipe joint L6. Has been. The other end of the low-pressure pipe 17 is connected to the refrigerant inlet of the compressor 1 through a low-pressure pipe joint L7.

  Here, among the high-pressure pipe joints H1-H5 sealed by the O-ring, the high-pressure pipe joint H3-H5 is arranged in a low-pressure space surrounded by the case 14 and the low-pressure pipes 15 and 16, and The leaking part of the high-pressure pipe 7 that is directly exposed to is only the high-pressure pipe joint H1-H2. For this reason, in the prior art shown in FIG. 10, the number of leaked parts of the high-pressure pipe by the O-ring seal that was 7 or 8 can be reduced to two places of the high-pressure pipe joints H1-H2.

  Next, specific configurations of the high-pressure pipe joint H3 and the low-pressure pipe joint L5-L6 will be described, but the other connections of the high-pressure pipe 7 and the low-pressure pipe 17 are the same as the conventional ones, and the high-pressure pipe joint H3- Since the configurations of H5 and the low-pressure pipe joints L1-L4 are the same as those described in the refrigeration cycle according to the first embodiment, they will not be described in detail.

  FIG. 9 is a cross-sectional view showing an example of a pipe joint structure in a receiver / dryer integrated condenser. In FIG. 9, the same components as those shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the condenser 2, a joint member 87 is brazed to a refrigerant inlet formed in the header 42, and the high pressure pipe 7 from the compressor 1 is connected to the joint member 87. A joint member 88 is brazed to the hole 45 formed in the main body 44 of the receiver dryer 3, and the low pressure pipe 17 to the compressor 1 is connected to the joint member 88. In this example, the main body 44 of the receiver dryer 3 joined integrally with the condenser 2 is not a deep-drawn bottomed cylindrical shape, but a closing member 44a is brazed to one end of a cylindrical pipe. Is formed.

  In the receiver dryer 3 configured as described above, the open end of the main body 44 and the outlet pipe 10 are respectively connected to an inlet pipe 51 joined to the low pressure pipe 16 and the high pressure pipe 11 of the double pipe 50, It is fixed by a pipe clamp 52. At this time, the high-pressure fitting portion between the inlet pipe 51 and the outlet pipe 10 is sealed by the O-ring 53, and the low-pressure fitting portion between the outer pipe 50 a and the main body 44 is sealed by the O-ring 54. Thereby, since the high-pressure joint portion between the condenser 2 and the high-pressure pipe 7 from the compressor 1 is in the low-pressure refrigerant passage, the high-pressure refrigerant does not become a leakage portion that leaks to the atmosphere.

It is the schematic which shows the refrigerating cycle which concerns on 1st Embodiment to which this invention is applied. It is sectional drawing which shows an example of the piping joint structure in a compressor. FIG. 3 is a cross-sectional view taken along the line aa in FIG. 2. It is sectional drawing which shows an example of the piping joint structure in a receiver dryer integrated type condenser. It is bb arrow sectional drawing of FIG. It is sectional drawing which shows an example of the piping joint structure in a partition. It is sectional drawing which shows an example of the piping joint structure in an expansion valve and an evaporator. It is the schematic which shows the refrigerating cycle which concerns on 2nd Embodiment to which this invention is applied. It is sectional drawing which shows an example of the piping joint structure in a receiver dryer integrated type condenser. It is a figure explaining the piping joint site | part in the conventional refrigeration cycle, Comprising: (A) shows the case where an expansion valve is arrange | positioned at a partition, (B) shows the case where an expansion valve is arrange | positioned close to an evaporator ing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Receiver dryer 4 Expansion valve 5 Evaporator 6 Bulkhead 7 High pressure piping 8 Inlet piping 9 Refrigerant passage 10 Outlet piping 11, 12 High pressure piping 13 Inlet piping 14 Cases 15, 16, 17 Low pressure piping 21 Housing 22 Discharge Chamber 23 Suction chamber 24 Refrigerant inlet 25 Outlet piping 26 Metal pipe 27 Metal sleeve 28 Joint member 29 Holding member 29a Strut 30 Metal pipe 31 Sealing material 32 Bolt 33 O-ring 41 Tube 42 Header 43 Partition plate 44 Main body 44a Closing member 45 Hole 46 Joint member 47 Inlet pipe 48 Desiccant 49 Partition plate 50 Double pipe 50a Outer pipe 50b Inner pipe 50c Post 51 Inlet pipe 52 Pipe clamp 53 O ring 54 O ring 55 Double pipe 55a Outer pipe 55b Inner pipe 55c Post 56, 57 Connection piping 58 Pipe clamp 59, 60 O-ring 61 Connection pipe 62 Refrigerant inlet pipe 63 Refrigerant outlet pipe 64 Body 65 Low-pressure refrigerant outlet 66 Return low-pressure refrigerant inlet 67, 68 O-ring 69 Power element 70 O-ring 71 Upper housing 72 Lower housing 73 Diaphragm 74 Center disk 75 High-pressure refrigerant inlet 76 Return low-pressure refrigerant outlet 77, 78 O-ring 79 Valve shaft guide 80 Valve seat 81 Valve body 82 Valve shaft 83 Collar member 84 O-ring 85 Spring 86 Spring receiving member 87, 88 Joint member H1-H5 High pressure Piping Fitting L1-L7 Low Pressure Piping Fitting

Claims (11)

In a refrigeration cycle configured by connecting a compressor, a condenser, a receiver dryer and an expansion device with high-pressure piping, and connecting the expansion device, an evaporator and the compressor with low-pressure piping,
All of the high-pressure pipe joints using the sealing material of the high-pressure pipe existing between the refrigerant outlet of the compressor and the refrigerant inlet of the expansion device are between the refrigerant outlet of the evaporator and the refrigerant inlet of the compressor. The refrigeration cycle is arranged in a low-pressure pipe existing in the factory.   The compressor high-pressure refrigerant outlet is concentrically disposed in a low-pressure refrigerant inlet, the condenser high-pressure refrigerant inlet is concentrically disposed in a joint member communicating with a low-pressure pipe from the evaporator, and the compression The refrigerant inlet of the compressor and the joint member are connected by a flexible low pressure hose, and the flexible high pressure hose disposed in the low pressure hose is connected to the refrigerant outlet of the compressor and the refrigerant of the condenser. The refrigeration cycle according to claim 1, wherein the refrigeration cycle is connected to the inlet.   The refrigeration cycle according to claim 2, wherein the high-pressure refrigerant passage connecting the refrigerant outlet of the condenser and the refrigerant inlet of the receiver dryer is joined by welding.   The receiver dryer is arranged airtightly through a partition plate arranged airtight so as to partition a space in which the condensed refrigerant is stored in a bottomed cylindrical main body, and through the partition plate. A low-pressure passage of the joint member is welded to the main body between the partition plate and the open end of the main body, and the open end of the main body and the outlet pipe are concentric double pipes. The refrigeration cycle according to claim 2, wherein the refrigeration cycle has a structure, and an outer pipe and an inner pipe of the double pipe are respectively connected to the open end of the main body and the outlet pipe of the double pipe structure.   The expansion device is accommodated in a case formed to communicate with a refrigerant outlet of the evaporator, a refrigerant inlet is connected to the inner pipe of the double pipe in the case, and a refrigerant outlet is 5. The refrigeration cycle according to claim 4, wherein the refrigeration cycle is connected to a refrigerant inlet of the evaporator that opens into a case, and the case is connected to the outer pipe of the double pipe.   The double pipe includes a first double pipe on the receiver dryer side and a second double pipe on the expansion device side, and the first double pipe and the second double pipe include two The refrigeration cycle according to claim 5, wherein the refrigeration cycle is connected to each other in a state of a double pipe structure. In a refrigeration cycle configured by connecting a compressor, a condenser, a receiver dryer, and an expansion device with high-pressure piping, and connecting the expansion device, the evaporator, and the compressor with low-pressure piping,
A high-pressure pipe joint using a sealing material for a high-pressure pipe existing between the refrigerant outlet of the receiver dryer and the refrigerant inlet of the expansion device exists between the refrigerant outlet of the evaporator and the refrigerant inlet of the compressor. A refrigeration cycle that is arranged in a low-pressure pipe.   The refrigeration cycle according to claim 7, wherein a high-pressure refrigerant passage connecting the refrigerant outlet of the condenser and the refrigerant inlet of the receiver dryer is joined by welding.   The receiver dryer has a bottomed cylindrical shape, and an open end defines a main body that forms a joint of a low-pressure pipe from the evaporator, and a space in which the condensed refrigerant is stored in the main body. A partition plate arranged in an airtight manner, an outlet pipe passing through the partition plate and arranged in an airtight manner to form a refrigerant outlet, and the main body between the partition plate and the open end are joined by welding. And a joint member to which a low-pressure pipe to the compressor is connected, and the opening end of the main body and the outlet pipe have a concentric double pipe structure, and the opening end of the double pipe structure and The refrigeration cycle according to claim 7, wherein an outer pipe and an inner pipe of a double pipe are respectively connected to the outlet pipe.   The expansion device is accommodated in a case formed to communicate with a refrigerant outlet of the evaporator, a refrigerant inlet is connected to the inner pipe of the double pipe in the case, and a refrigerant outlet is The refrigeration cycle according to claim 9, wherein the refrigeration cycle is connected to a refrigerant inlet of the evaporator that opens into a case, and the case is connected to the outer pipe of the double pipe.   The double pipe includes a first double pipe on the receiver dryer side and a second double pipe on the expansion device side, and the first double pipe and the second double pipe include two The refrigeration cycle according to claim 10, which are connected to each other in a state of a double pipe structure.

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