JP2009063036A - Double piping joint device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To connect an internal heat exchanger having a double pipe structure to a front side circuit and a rear side circuit while maintaining the double pipe structure. <P>SOLUTION: The double piping joint device 11 has a joint part having a double pipe structure to be joined three ways. An end of a first joint part is connected to an other end of first double piping 41 connected to each of a compressor and a receiver. An end of a second joint part is connected to an other end of double piping 46 and second double piping 43 connected to a front side expansion valve 4. An end of a third joint part is connected to an other end of third double piping 49 connected to a rear side expansion valve 6. The first double piping 41, the double piping joint device 11, the double piping 46, the second double piping 43, and the third double piping 49 configure the internal heat exchanger along with piping. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a double pipe joint device, and more particularly, a refrigerant that flows through a double pipe functioning as an internal heat exchanger in a refrigeration cycle of an air conditioner for an automobile can be branched and merged while maintaining a double pipe structure. The present invention relates to a heavy pipe joint device.

  A vehicle having a large cabin capacity may be equipped with an automotive air conditioner that can independently air-condition the front and rear sides of the cabin. In such an automotive air conditioner, a front side expansion valve and front evaporator circuit that performs front side air conditioning control and a rear side expansion valve and rear side evaporator circuit that perform rear side air conditioning control are arranged in parallel. A refrigeration cycle arranged and configured is used. Here, as expansion valves used in the front side circuit and the rear side circuit, the temperature and pressure of the refrigerant at the outlet of each evaporator are sensed and evaporated so that the refrigerant at the outlet of the evaporator has a predetermined superheat degree. In many cases, a temperature-type expansion valve that controls the flow rate of the refrigerant supplied to the vessel is used.

  Further, in the refrigeration cycle, generally, an internal heat exchanger is provided that exchanges heat between the condensed high-temperature / high-pressure refrigerant directed to the expansion valve and the low-temperature / low-pressure refrigerant directed from the evaporator to the compressor. It is also known that the efficiency of the system can be improved. This is because the condensed refrigerant is further cooled by the internal heat exchanger to lower the enthalpy of the refrigerant at the inlet of the expansion valve and the evaporator, and the refrigerant that has left the evaporator is further superheated by the internal heat exchanger. This is because by increasing the enthalpy of the refrigerant at the suction port of the compressor, the difference in enthalpy increases and the coefficient of performance improves. As such an internal heat exchanger, a double pipe in which an inner pipe and an outer pipe are concentrically arranged is used, and a refrigerant flowing in the inner pipe and a refrigerant flowing in a space between the inner pipe and the outer pipe are used. Heat is exchanged between them.

By applying such an internal heat exchanger also in a refrigeration cycle having an expansion valve and an evaporator for the front and rear, respectively, the efficiency of the system can be improved in the same manner (for example, Patent Document 1). reference.). According to this Patent Document 1, it is provided with an internal heat exchanger having a double-pipe structure for exchanging heat between a condensed high-temperature / high-pressure refrigerant and an evaporated low-temperature / low-pressure refrigerant, The structure is branched into two independent pipes. One of the pipes branched on one end side of the internal heat exchanger is connected to a high-pressure heat exchanger, and the other pipe is connected to a suction port of the compressor. One pipe branched on the other end side of the internal heat exchanger is connected to a branch point to the front side expansion valve and the rear side expansion valve, and the other pipe is connected to the front side evaporator and the rear side evaporator. Connected to the junction. Furthermore, in the above-mentioned Patent Document 1, a first internal heat exchanger is provided between the high-pressure heat exchanger and the compressor and the circuits of the front side expansion valve and the front side evaporator, and the front side expansion valve and the front side are provided. A configuration in which a second internal heat exchanger is provided between the circuit of the evaporator and the circuits of the rear side expansion valve and the rear side evaporator is also shown.
JP 2007-71461 A (FIGS. 11 and 12)

However, since the conventional internal heat exchanger has its both ends branched into two independent pipes, there are problems that the number of branch joints increases and the piping becomes complicated.
The present invention has been made in view of such a point, and provides a double pipe joint device that can be connected to a front side circuit and a rear side circuit with a double pipe structure to constitute an internal heat exchanger. The purpose is to do.

  In the present invention, in order to solve the above-described problem, the first joint portion and the second joint portion having a double pipe structure provided at both ends in the axial direction, the first joint portion, and the second joint portion, respectively. Each of the inner pipes of the first joint part, the second joint part, and the third joint part. Are connected to each other inside, and a space between each outer pipe and the inner pipe is connected to each other inside to provide a double pipe joint device.

  According to such a double pipe joint device, the first double pipe connected to the receiver and the compressor, the front side expansion valve, and the first and third joint parts having a double pipe structure, The second and third double pipes connected to the rear side expansion valve can be directly connected in a double pipe structure. As a result, it is possible to connect from the engine room to the front side expansion valve and the rear side expansion valve with a double pipe, and since there is no branching into two independent pipes on the way, the piping configuration can be simplified. it can.

  Since the double pipe joint device of the present invention has first to third joint portions each having a double pipe structure, the first double pipe connected to the receiver and the compressor is connected to the front side expansion valve. And the second and third double pipes connected to the rear side expansion valve can be directly connected in a double pipe structure, so that the pipes from the engine room to the front side expansion valve and the rear side expansion valve are each 1 The double piping of the book can simplify the piping configuration, and there is an advantage that the piping can also be configured to serve as an internal heat exchanger.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a system diagram showing a refrigeration cycle of an automotive air conditioner.
This refrigeration cycle is arranged in an engine room of a vehicle, and compresses a refrigerant 1, a condenser 2 that cools and condenses the compressed refrigerant, and separates the condensed refrigerant into gas and liquid. And a receiver 3 for sending out liquid refrigerant. A front side expansion valve 4 for adiabatically expanding the liquid refrigerant and a front side evaporator 5 for evaporating the expanded refrigerant are disposed on the front side of the vehicle interior, and the liquid refrigerant is insulated on the rear side of the vehicle interior. A rear side expansion valve 6 that expands and a rear side evaporator 7 that evaporates the expanded refrigerant are arranged. The receiver 3 is connected to the front side expansion valve 4 and the rear side expansion valve 6 by an internal heat exchanger 8 having a double pipe structure, and the low pressure outlet of the internal heat exchanger 8 is connected to the intake of the compressor 1. Connected to the mouth. Further, in the vicinity of the front-side evaporator 5 and the rear-side evaporator 7, blowers 9 and 10 are provided for allowing the air in the vehicle compartment to pass therethrough.

  The front side expansion valve 4 is configured so that the power element senses the temperature and pressure of the refrigerant at the outlet of the front side evaporator 5 so that the refrigerant at the outlet of the front side evaporator 5 has a predetermined superheat degree. 5 is a temperature type expansion valve that controls the flow rate of the refrigerant supplied to 5. The temperature type expansion valve includes a port that receives the high-pressure liquid refrigerant from the receiver 3 and a port that sends out the low-pressure refrigerant evaporated by the front-side evaporator 5 to the compressor 1. 4 is directly connected to the internal heat exchanger 8 having a double-pipe structure, with these ports having a double-pipe structure.

  The rear side expansion valve 6 is configured so that the power element senses the temperature and pressure of the refrigerant at the outlet of the rear side evaporator 7 so that the refrigerant at the outlet of the rear side evaporator 7 has a predetermined superheat degree. 7 is a temperature type expansion valve that controls the flow rate of the refrigerant supplied to 7. The rear side expansion valve 6 also has a double pipe structure with a port for receiving high pressure liquid refrigerant from the receiver 3 and a port for sending low pressure refrigerant evaporated by the rear side evaporator 7 to the compressor 1. It is directly connected to the internal heat exchanger 8 having a heavy pipe structure. The rear side expansion valve 6 is provided with an electromagnetic valve, and is closed when not energized, and allows flow control by a power element when energized.

  In the middle of the internal heat exchanger 8, a double pipe joint device 11 that can be branched and connected to a front side circuit and a rear side circuit with a double pipe structure is inserted. That is, the double pipe joint device 11 has a substantially T-shaped outer shape, and a joint portion of a double pipe structure that forms a joint on each of the three sides is formed. The other end of the double pipe whose one end is connected to the receiver 3 and the compressor 1 is connected to the first joint part, and the other end of the double pipe is connected to the front side expansion valve 4. The other end of the double pipe whose one end is connected to the rear side expansion valve 6 is connected to the third joint, and an internal heat exchanger is connected between the double pipe and the double pipe joint device 11. 8 and a part of connection piping of the refrigeration cycle.

  Here, for example, when air conditioning is performed only on the front side, the rear side expansion valve 6 is in a non-energized state and is closed, so that no refrigerant flows into the refrigerant flow path of the rear side circuit. In this state, when the compressor 1 and the front blower 9 are started, the high-temperature and high-pressure refrigerant compressed by the compressor 1 is condensed by the condenser 2 and stored in the receiver 3. The liquid refrigerant in the receiver 3 is supplied to the front side expansion valve 4 through the internal heat exchanger 8, where it is adiabatically expanded to become a low-temperature / low-pressure refrigerant. The refrigerant that has become a low-temperature and low-pressure refrigerant is sent to the front-side evaporator 5, where it is evaporated by heat exchange with the air in the vehicle compartment sent by the blower 9. The evaporated refrigerant is sent to the inlet of the compressor 1 through the front side expansion valve 4 and the internal heat exchanger 8.

  When the evaporated refrigerant passes through the front side expansion valve 4, the power element senses the temperature and pressure of the refrigerant that has left the front side evaporator 5, and the refrigerant at the outlet of the front side evaporator 5 has a predetermined overheat. The flow rate of the refrigerant sent to the front-side evaporator 5 is controlled so as to be at the same level. The internal heat exchanger 8 exchanges heat between the high-temperature refrigerant flowing from the receiver 3 toward the front side expansion valve 4 and the low-temperature refrigerant flowing from the front side expansion valve 4 toward the compressor 1. Thereby, the refrigerant sent to the front side expansion valve 4 is further cooled, and the refrigerant sent to the compressor 1 is further overheated, so that the enthalpy difference between the inlet of the front side expansion valve 4 and the inlet of the compressor 1 is increased. growing. As a result, since the coefficient of performance of the refrigeration cycle is improved, the load on the traveling engine that drives the compressor 1 can be reduced, and the efficiency of the automotive air conditioner can be improved.

  When rear-side air conditioning is performed, the rear-side expansion valve 6 is energized and the blower 10 is activated. As a result, the high-temperature / high-pressure liquid refrigerant branched by the double pipe joint device 11 of the internal heat exchanger 8 is supplied to the rear side expansion valve 6, where it is adiabatically expanded to become a low-temperature / low-pressure refrigerant. The low-temperature and low-pressure refrigerant is sent to the rear-side evaporator 7 where it is evaporated by heat exchange with the air in the vehicle compartment sent by the blower 10. The evaporated refrigerant enters the internal heat exchanger 8 through the rear side expansion valve 6 and merges with the refrigerant coming from the front side expansion valve 4 in the double pipe joint device 11, and the merged refrigerant becomes the compressor 1. Sent to the inlet.

  When the evaporated refrigerant passes through the rear side expansion valve 6, the power element senses the temperature and pressure of the refrigerant that has exited the rear side evaporator 7, and the refrigerant at the outlet of the rear side evaporator 7 has a predetermined superheat. The flow rate of the refrigerant sent to the rear-side evaporator 7 is controlled so as to reach the same level. The high temperature refrigerant flowing from the receiver 3 toward the rear side expansion valve 6 is heat-exchanged with the low temperature refrigerant flowing from the rear side expansion valve 6 toward the compressor 1 by the internal heat exchanger 8. As a result, the high-temperature refrigerant sent to the rear side expansion valve 6 is further cooled, and the low-temperature refrigerant sent to the compressor 1 is further heated, thereby improving the coefficient of performance of the refrigeration cycle.

  FIGS. 2A and 2B are diagrams showing materials before processing of the double pipe joint device, in which FIG. 2A shows a first hollow extruded material, and FIG. 2B shows a second hollow extruded material. 3A and 3B are diagrams showing a double pipe joint device, in which FIG. 3A is a plan view, FIG. 3B is a cross-sectional view taken along the line a-a in FIG. It is a front view.

  The double pipe joint device 11 is formed by processing the hollow extrusion moldings 12 and 13. The hollow extrusion moldings 12 and 13 have an outer shape in which a cylindrical portion 14 and a band-like portion 15 located on the side surface are integrally formed. In the case of the hollow extruded material 12 shown in FIG. 2A, the cylindrical portion 14 has two hollow portions 16 having a circular cross section in the circumferential direction except for the side where the belt-like portion 15 is provided. . In the case of the hollow extruded material 13 shown in FIG. 2B, in addition to the arc-shaped hollow portion 16, a hollow portion 17 having a circular cross section is disposed at the center of the cylindrical portion 14.

  The hollow extrusion moldings 12 and 13 having such an arc-shaped hollow portion 16 and a circular hollow portion 17 are formed into a length of, for example, several meters by extruding a base material from a mold, and are formed into an appropriate length. This is cut into the material of the double pipe joint device 11. The hollow extrusion molding materials 12 and 13 have the arc-shaped hollow portion 16, thereby enabling a significant reduction in material compared to the case of cutting a solid cylindrical member.

  The body 21 of the double pipe joint device 11 is formed by cutting the hollow extrusion molding materials 12 and 13 as described above into appropriate lengths and then performing precision cutting machining. First, with respect to the cut material of the body 21, the belt-like portion 15 is removed from both sides excluding the central portion in the longitudinal direction of the cylindrical portion 14, and the outer peripheral surface is cut so that the flange portions 22 and 23 are formed at both end edges. The annular grooves 24 and 25 are machined so that the arc-shaped hollow portions 16 are connected in the circumferential direction from both end faces of the cylindrical portion 14, and as shown in FIG. 26 and 27 are formed. At this time, in the case of a material having a hollow part 17 having a circular cross section at the center of the cylindrical part 14, inner pipes 28 and 29 concentric with the outer pipes 26 and 27 are formed at the same time. It becomes a double tube structure. In the case of a material without the hollow portion 17, the inner tubes 28 and 29 are formed by making a round hole in the central axis of the cylindrical portion 14.

  Further, the body 21 of the double pipe joint device 11 is machined on the belt-like portion 15 at the center in the longitudinal direction of the cylindrical portion 14 to form a double pipe whose axis is substantially orthogonal to the axis of the cylindrical portion 14. . That is, the band-shaped portion 15 is cut so that the columnar portion protrudes from the side surface of the columnar portion 14, and then the annular groove 30 is cut so as to communicate with the arcuate hollow portion 16, thereby FIG. As shown in (B) and (C), the outer tube 31 is formed. An inner tube 32 is formed by drilling a circular hole concentric with the outer tube 31 so as to communicate with the circular hollow portion 17, and becomes an end surface of a double tube structure.

  In this way, the double pipe joint device 11 has the first and second joint portions of the double pipe structure that form joints at both ends of the cylindrical portion 14, and is a side surface that is substantially orthogonal to the axis of the cylindrical portion 14. A body 21 having a third joint portion having a double pipe structure constituting the joint is formed, in which the inner pipes communicate with each other, and the space between the inner pipe and the outer pipe has an arc shape. They communicate with each other through the hollow portion 16.

FIG. 4 is a cross-sectional view showing the double pipe portion of the refrigeration cycle. In addition, the arrow in a figure has shown the flow direction of the refrigerant | coolant.
In the double pipe joint device 11, a first double pipe 41 is connected to the first joint portion. That is, one end side of the first double pipe 41 has a double pipe structure of an inner pipe and an outer pipe, and the inner pipe is fitted to the inner pipe 28 of the double pipe joint device 11. Sealed by the O-ring, the outer tube is fitted to the outer tube 26 of the double pipe joint device 11, sealed by the O-ring, and mechanically coupled by the pipe clamp 42. On the other end side of the first double pipe 41, the inner pipe and the outer pipe are branched, the inner pipe is connected to the receiver 3, and the outer pipe is connected to the suction port of the compressor 1.

  A second double pipe 43 is connected to the second joint portion of the double pipe joint device 11. One end side of the second double pipe 43 has a double pipe structure of an inner pipe and an outer pipe, and the inner pipe is fitted to the inner pipe 29 of the double pipe joint device 11 to form an O-ring. The outer pipe is fitted to the outer pipe 27 of the double pipe joint device 11, sealed by an O-ring, and mechanically coupled by a pipe clamp 44. The other end of the second double pipe 43 is connected to one end of a double pipe 46 extending from the vehicle compartment into the engine room via the partition wall 45, and the other end is connected to the front side expansion valve 4. The front side expansion valve 4 also has a high-pressure refrigerant inlet and a low-pressure refrigerant outlet formed in a double pipe structure, and can be connected to the double pipe 46 with a double pipe structure. Further, the front side expansion valve 4 can be connected to the front side evaporator 5 in a double tube structure.

  The third joint portion of the double pipe joint device 11 has a short length in the axial direction of the inner tube 32 and the outer tube 31, and the joint inner tube 47 and the outer tube 48 are welded to each. The joint inner pipe 47 and outer pipe 48 are connected to one end of a third double pipe 49 extending from the vehicle compartment into the engine room via a partition wall 45 and mechanically coupled by a pipe clamp 50. The other end of the third double pipe 49 is connected to the rear side expansion valve 6. The rear side expansion valve 6 also has a high-pressure refrigerant inlet and a low-pressure refrigerant outlet formed in a double pipe structure, and can be directly connected to the third double pipe 49 with a double pipe structure. Further, the rear side expansion valve 6 can be connected to the rear side evaporator 7 in a double pipe structure.

  As described above, the first and second double pipes 41 and 43 connected to the double pipe joint device 11, and the third double pipe 49 connected via the joint inner pipe 47 and the outer pipe 48 The double pipe 46 connected to the second double pipe 43 constitutes the internal heat exchanger 8. The internal heat exchanger 8 also serves as a pipe between the first double pipe 41 and the front-side expansion valve 4 and the rear-side expansion valve 6. Since there is no need for a branch joint that branches each end of the heavy pipe into two independent pipes, the pipe of the refrigeration cycle can be greatly simplified.

  In addition, in the double pipe joint apparatus 11 according to this embodiment, the body 21 is formed by machining a hollow extrusion molding material, and has a joint portion having a double pipe structure on such three sides. As the double pipe joint device 11, the body 21 can be formed also by a die casting method. In this case, the third joint portion is preferably formed to have the same axial length as the other first and second joint portions.

  In the above embodiment, the first double pipe 41, the second double pipe 43, the double pipe 46, the third double pipe 49, and the double pipe joint that constitute the internal heat exchanger 8 are used. In the apparatus 11, a high-pressure refrigerant flows through the inner pipe, and a low-pressure refrigerant flows through the refrigerant passage between the inner pipe and the outer pipe. However, the low-pressure refrigerant flows through the inner pipe, A high-pressure refrigerant may be allowed to flow in the refrigerant passage between the two.

It is a system diagram which shows the refrigerating cycle of the air conditioner for motor vehicles. It is a figure which shows the material before a process of a double pipe joint apparatus, Comprising: (A) shows the 1st hollow extrusion molding material, (B) has shown the 2nd hollow extrusion molding material. It is a figure which shows a double piping joint apparatus, Comprising: (A) is a top view, (B) is a sectional view taken on the line aa of (A), (C) is a left side view, (D) is a front view. is there. It is sectional drawing which shows the double pipe part of a refrigerating cycle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Receiver 4 Front side expansion valve 5 Front side evaporator 6 Rear side expansion valve 7 Rear side evaporator 8 Internal heat exchanger 9,10 Blower 11 Double piping joint apparatus 12, 13 Hollow extrusion molding material 14 cylindrical part 15 belt-like part 16, 17 hollow part 21 body 22, 23 flange part 24, 25 annular groove 26, 27 outer pipe 28, 29 inner pipe 30 annular groove 31 outer pipe 32 inner pipe 41 first double pipe 42 pipe Clamp 43 Second double pipe 44 Pipe clamp 45 Bulkhead 46 Double pipe 47 Inner pipe 48 Outer pipe 49 Third double pipe 50 Pipe clamp

Claims (5)

  Provided in a direction substantially perpendicular to the first joint portion and the second joint portion of the double pipe structure provided at both ends in the axial direction, and the axes of the first joint portion and the second joint portion, respectively. A third joint portion having a double pipe structure, and the respective inner pipes of the first joint portion, the second joint portion, and the third joint portion communicate with each other inside, and The double pipe joint device characterized in that the space between the outer pipe and the inner pipe communicates with each other inside.   The body of the first joint part, the second joint part, and the third joint part is made of a hollow extruded material having a plurality of passages in the axial direction, and both ends of the hollow extruded material are machined. A double pipe structure is formed by machining to form the first joint part and the second joint part, and a double pipe structure is formed by machining in a direction substantially perpendicular to the axis of the hollow extruded material. The double pipe joint device according to claim 1, wherein the third joint portion is configured.   The said channel | path comprises the refrigerant | coolant channel | path which mutually connects the space between the said outer tube and the said inner tube of a said 1st coupling part and a said 2nd coupling part. Double pipe fitting device.   3. The double pipe joint device according to claim 2, wherein one of the passages constitutes a refrigerant passage that allows the inner pipes of the first joint portion and the second joint portion to communicate with each other. . A refrigeration cycle having a front side expansion valve and a front side evaporator for performing front side air conditioning control, a rear side expansion valve and a rear side evaporator for performing rear side air conditioning control, and an internal heat exchanger having a double pipe structure In
Provided in a direction substantially perpendicular to the first joint portion and the second joint portion of the double pipe structure provided at both ends in the axial direction, and the axes of the first joint portion and the second joint portion, respectively. A double pipe joint device having a third joint part of a double pipe structure;
The double pipe joint device connects the first double pipe on the engine room side to the second double pipe to the front side expansion valve and the third double pipe to the rear side expansion valve. A refrigeration cycle comprising a heat exchanger.

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