JP2009097784A - Piping device, refrigeration cycle device equipped with the same, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piping device capable of preventing transmission of noise and reducing its mounting space. <P>SOLUTION: The piping device having a dual pipe structure carries out heat exchange between high-pressure coolant flowing through an outside flow passage 230 formed outside an inner pipe 220 inside an outer pipe 210 and low-pressure coolant flowing through an inside flow passage 240 formed inside the inner pipe 220. The piping device includes a spiral groove part 222 spirally formed on a pipe wall of the inner pipe 220, a spiral ridge part 223 partitioning the spiral groove part 222, a flow separating pipe 250 provided for a part of and inside the inner pipe 220 in the axial direction, supported by the spiral groove part 222, and forming a flow-separating area 255 for partially separating the inside flow passage 240, a main flow passage 251 formed inside the flow separating pipe 250 for circulating the low-pressure coolant, and a bypass flow passage 252 formed inside the ridge part 223 on the outside of the flow separating pipe 250 for circulating the low-pressure coolant in a path length different from that of the main flow passage 251. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a piping device, a refrigeration cycle device including the piping device, and a manufacturing method thereof.

  Patent Document 1 discloses a conventional refrigeration cycle apparatus mounted on a vehicle. This refrigeration cycle apparatus has a configuration in which a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular shape by a refrigerant pipe. A part of the high-pressure pipe between the condenser and the expansion valve through which the high-temperature and high-pressure refrigerant from the compressor flows and a part of the low-pressure pipe between the evaporator and the compressor through which the low-temperature and low-pressure refrigerant flows have a double pipe structure. Forming. In the double pipe portion, heat exchange is performed between the high-temperature and high-pressure refrigerant and the low-temperature and low-pressure refrigerant. As a result, the cooling performance of the refrigeration cycle apparatus is improved.

In this refrigeration cycle apparatus, the compressor and the condenser are disposed in the engine room, and the expansion valve and the evaporator are disposed in the vehicle interior. In general, in this case, a tank-like expansion silencer is interposed in the refrigerant pipe between the compressor and the double pipe section, that is, in the low-pressure pipe in the engine room upstream (chamber side) from the compressor. Is done. Thereby, it is possible to prevent the pulsation of the compressor from being transmitted to the vehicle interior via the refrigerant pipe and generating noise.
JP 2006-162241 A

  However, in the above configuration, since the silencer is interposed in the refrigerant pipe in the engine room, there arises a problem that the space for mounting the refrigerant pipe and the refrigeration cycle apparatus becomes large.

  The objective of this invention is providing the piping apparatus which can prevent transmission of a noise, and can reduce mounting space, the refrigerating cycle apparatus provided with the same, and its manufacturing method.

  In order to achieve the above object, the present invention employs the following technical means.

  The invention according to claim 1 includes an outer tube (210) and an inner tube (220) provided inside the outer tube (210), and is located inside the outer tube (210) and inside the inner tube (220). Between the first fluid that flows through the outer flow path (230) formed outside the inner flow path and the second fluid that flows through the inner flow path (240) formed inside the inner pipe (220). A pipe device having a double-pipe structure for exchanging, wherein a spiral groove portion (222) formed in a spiral shape on the tube wall of the inner tube (220) and protruding inside the inner tube (220), and an inner tube ( 220) and a spiral ridge portion (223) that protrudes outward and divides the spiral groove portion (222), and is provided inside the inner tube (220) and in a part of the axial direction of the inner tube (220). A diversion that is supported by the spiral groove (222) and forms a diversion region (255) that partially diverts the inner flow path (240). (250), a main flow path (251) that circulates the second fluid, formed inside the diverter pipe (250), and formed outside the diverter pipe (250) and inside the ridge (223). The bypass channel (252) bypasses the outer side of the main channel (251) in a spiral manner, partially diverts from the main channel (251), and distributes the second fluid with a path length different from that of the main channel (251). ).

  Accordingly, the sound wave propagating in the inner flow path (240) is divided into the main flow path (251) and the detour flow path (252) having different path lengths in the shunt region (255). For this reason, the phases of the sound waves propagating through both the flow paths (251, 252) can be shifted from each other, and the sound waves combined on the downstream side in the propagation direction of the shunt region (255) can be attenuated by the interference effect. Therefore, transmission of noise through the inner flow path (240) can be prevented. In addition, since it is possible to mute the inside of the piping device that performs heat exchange between fluids, it is not necessary to separately provide a silencer outside the piping device, and the mounting space can be reduced.

  In the invention according to claim 2, the spiral pitch (P2) of the peak portion (223) in the shunt region (255) is greater than the spiral pitch (P1) of the peak portion (223) other than the shunt region (255). It is characterized by narrowness.

  As a result, the length of the bypass flow path (252) can be increased with respect to the length of the shunt pipe (250), so that a predetermined path length difference is established between the bypass flow path (252) and the main flow path (251). The length of the shunt pipe (250) necessary for providing can be shortened. Therefore, since the diversion area | region (255) where heat exchange efficiency falls can be narrowed, the heat exchange performance of a piping apparatus improves.

  In the invention according to claim 3, the inclination angle (θ2) with respect to the tube axis of the spiral groove portion (222) in the flow dividing region (255) is inclined with respect to the tube axis of the spiral groove portion (222) other than the flow dividing region (255). It is characterized by being larger than the angle (θ1).

  Thereby, since the space | interval of the spiral groove part (222) and peak part (223) in a shunt area | region (255) can be narrowed, the spiral pitch (P2) of the peak part (223) in a shunt area | region (255) is made into a shunt area | region. It becomes easy to make narrower than the helical pitch (P1) of the peak part (223) other than (255).

  The invention according to claim 4 is characterized in that the cross-sectional area (A2) of the bypass flow path (252) is equal to or larger than the cross-sectional area (A1) of the main flow path (251).

  Thereby, since the entrance area of the detour channel (252) can be increased with respect to the sound wave propagating through the inner channel (240), the sound wave easily propagates to the detour channel (252) side in the shunt region (255). Become. Therefore, since the intensity of the sound wave propagating through the bypass channel (252) and the intensity of the sound wave propagating through the main channel (251) can be brought close to each other, a high interference effect can be obtained.

  In the invention according to claim 5, at least one end portion (270a, 270b) of the flow dividing pipe (270) has a tapered portion (271, 272) formed so that the outer diameter becomes smaller toward the tip end side. It is characterized by having.

  Thereby, since the sound wave is guided to the outside of the flow dividing pipe (270) by the taper portion (272), the sound wave easily propagates to the detour channel (255) side in the flow dividing region (255). Moreover, by providing the taper portions (271, 272), the insertion property when the flow dividing pipe (270) is inserted into the inner pipe (220) is improved.

  The invention according to claim 6 is characterized in that at least one end (275a, 275b) of the flow dividing pipe (275) has a chamfered portion (276, 277) whose outer peripheral side is chamfered.

  Thereby, since the sound wave is guided to the outside of the flow dividing pipe (270) by the chamfered portion (277), the sound wave easily propagates to the detour channel (255) side in the flow dividing region (255). Further, by providing the chamfered portions (276, 277), the insertion property when inserting the flow dividing pipe (275) into the inner pipe (220) is improved.

  The invention described in claim 7 includes a compressor (101) that compresses the refrigerant, a condenser (102) that condenses the refrigerant compressed by the compressor (101), and a refrigerant condensed by the condenser (102). A decompression means (103) for decompressing and expanding; an evaporator (104) for evaporating the refrigerant decompressed by the decompression means (103) and returning it to the compressor (101); a compressor (101), a condenser (102), A refrigeration cycle apparatus having a refrigerant pipe (111, 112, 113) that sequentially connects the decompression means (103) and the evaporator (104) in an annular manner, and is part of the refrigerant pipe (111, 112, 113). The outer flow path (230) is provided between the condenser (102) and the decompression means (103) and constitutes a flow path through which the high-pressure refrigerant flows, and the inner flow path (240) , Evaporator (104) and compressor It is characterized in that it constitutes a channel through which low-pressure refrigerant is provided between the 101).

  Thereby, the sound produced by the pulsation of the compressor (101) can be silenced in the inner flow path (240) of the piping device. For this reason, since it is not always necessary to separately provide a silencer between the compressor (101) and the evaporator (104) of the refrigeration cycle apparatus, the space for mounting the refrigeration cycle apparatus can be reduced.

  According to the eighth aspect of the present invention, the inclination angle (θ3) with respect to the tube axis of the spiral groove portion (222) in the vicinity of the end portion (250b) on the compressor (101) side of the flow dividing tube (250) is the flow dividing region ( It is characterized in that it is smaller than the inclination angle (θ1) with respect to the tube axis of the spiral groove portion (222) other than 255).

  Thereby, since the inlet area of the detour channel (252) can be increased with respect to the sound wave propagating from the compressor (101) side, the sound wave easily propagates to the detour channel (252) side in the shunt region (255). Become. Therefore, since the intensity of the sound wave propagating through the bypass channel (252) and the intensity of the sound wave propagating through the main channel (251) can be brought close to each other, a high interference effect can be obtained.

  The invention according to claim 9 is characterized in that the flow dividing pipe (250) is arranged at the end of the inner flow path (240) on the compressor (101) side.

  Thereby, since the path length between the compressor (101) and the diversion area (255) can be shortened, it becomes easy to specify the wavelength of the sound wave propagating from the compressor (101) to the diversion area (255). . Therefore, it becomes easy to design the shunt pipe (250), the spiral groove part (222), and the peak part (223) so as to obtain a high silencing effect.

  As described in the tenth aspect of the present invention, the refrigeration cycle apparatus is particularly effective when mounted on a vehicle having a large mounting space.

  The invention according to claim 11 is provided with an outer tube (210) and an inner tube (220) provided inside the outer tube (210), inside the outer tube (210) and inside tube (220). Between the first fluid that flows through the outer flow path (230) formed outside the inner flow path and the second fluid that flows through the inner flow path (240) formed inside the inner pipe (220). A method of manufacturing a pipe device having a double pipe structure for exchanging, wherein a shunt pipe (250) having an outer diameter smaller than an inner diameter of an inner pipe (220) and shorter than an inner pipe (220) is changed to an inner pipe ( 220) and a spiral spiral groove (222) that protrudes inward and press-supports the shunt pipe (250) with the shunt pipe (250) inserted inside the inner pipe (220). A spiral ridge (223) that protrudes outward and divides the spiral groove (222) is formed on the tube wall of the inner tube (220). Thus, the main flow path (251) is formed inside the diversion pipe (250), and the outside of the main flow path (251) is spirally formed outside the diversion pipe (250) and inside the peak portion (223). A detour flow path (252) that detours the inner pipe (220) is formed, and the inner pipe (220) is inserted and fixed inside the outer pipe (210).

  As a result, the flow dividing pipe (250) can be supported and fixed to the inner pipe (220) simultaneously with the formation of the spiral groove (222), so that the manufacturing process of the piping device can be simplified.

  In addition, the code | symbol in the bracket | parenthesis of each said means has shown an example of the corresponding relationship with the specific means as described in embodiment mentioned later.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. Drawing 1 is a mimetic diagram showing a schematic structure of a refrigerating cycle device provided with a piping device in this embodiment. As shown in FIG. 1, the piping device 200 and the refrigeration cycle device 100 are mounted on a vehicle using a water-cooled engine 10 as a driving source for traveling. The vehicle is partitioned by a dash panel 3 into an engine room 1 in which an engine 10 is mounted and a passenger compartment 2.

  The refrigeration cycle apparatus 100 has a configuration in which a compressor 101, a condenser (radiator) 102, an expansion valve 103, and an evaporator (heat absorber) 104 are sequentially connected in an annular manner via refrigerant pipes 111, 112, and 113. ing. Among these, the compressor 101 and the condenser 102 are disposed in the engine room 1, and the expansion valve 103 and the evaporator 104 are disposed in the vehicle compartment 2.

  An air conditioner (indoor unit) 120 is disposed in the passenger compartment 2. The air conditioner 120 includes an air conditioning case 121 and a blower 122, an evaporator 104, and a heater core 123 disposed in the air conditioning case 121. The blower 122 is configured to switch and introduce outside air or inside air to blow air into the passenger compartment 2 as conditioned air. The evaporator 104 is a heat exchanger for cooling that evaporates the refrigerant inside in accordance with the operation of the refrigeration cycle apparatus 100 and cools the conditioned air by latent heat of evaporation. The heater core 123 is a heat exchanger for heating that heats conditioned air using the cooling water of the engine 10 as a heating source.

  An air mix door 124 for adjusting the amount of conditioned air passing through the heater core 123 is provided on the upstream side of the air flow of the heater core 123. By adjusting the opening degree of the air mix door 124, the mixing ratio of the conditioned air cooled by the evaporator 104 and the conditioned air heated by the heater core 123 is varied. As a result, the temperature of the air blown into the passenger compartment 2 is adjusted.

  The compressor 101 of the refrigeration cycle apparatus 100 is a fluid device that compresses the refrigerant in the refrigeration cycle apparatus 100 to high temperature and high pressure. The compressor 101 is driven by the driving force of the engine 10, for example. The driving force of the engine 10 is transmitted to the pulley 13 fixed to the driving shaft of the compressor 101 via the crank pulley 11 and the driving belt 12. The pulley 13 is provided with an electromagnetic clutch (not shown) that connects and disconnects between the drive shaft of the compressor 101 and the pulley 13.

  The condenser 102 is connected to the discharge side of the compressor 101 and is a heat exchanger that condenses and liquefies the refrigerant compressed by the compressor 101 by heat exchange with the outside air flowing into the engine room 1. The condenser 102 and the compressor 101 are connected via a high-pressure refrigerant pipe 111.

  The expansion valve 103 is a decompression unit that decompresses and expands the refrigerant condensed in the condenser 102 to a low temperature and a low pressure. The expansion valve 103 is provided in the vicinity of the air conditioning case 121, for example, and is connected to the condenser 102 via a high-pressure refrigerant pipe 112. As the expansion valve 103, for example, a mechanical expansion valve whose valve opening is adjusted in accordance with the temperature and pressure of the refrigerant flowing out of the condenser 102 is used. The expansion valve 103 includes an electromagnetic actuator such as a motor that adjusts the valve opening, a sensor that detects the state of the high-pressure refrigerant and outputs an electrical signal, and a control device that controls the electromagnetic actuator in accordance with this signal. An electric expansion valve provided can also be used. In addition to the expansion valve 103, a throttle, an ejector, or the like can be used as the pressure reducing means.

  The evaporator 104 is a heat exchanger that evaporates the refrigerant decompressed by the expansion valve 103 and cools the conditioned air as described above. The refrigerant outlet side of the evaporator 104 is connected to the compressor 101 via a low-pressure refrigerant pipe 113.

  In the present embodiment, a double-pipe structure piping device 200 including an outer pipe 210 that constitutes at least a part of the high-pressure refrigerant pipe 112 and an inner pipe 220 that constitutes at least a part of the low-pressure refrigerant pipe 113 is provided. ing. In the double pipe portion of the piping device 200, heat exchange is performed between the high-temperature and high-pressure refrigerant (first fluid) flowing through the outer pipe 210 and the low-temperature and low-pressure refrigerant (second fluid) flowing through the inner pipe 220. As a result, the cooling performance of the refrigeration cycle apparatus 100 is improved.

  FIG. 2 is a schematic diagram illustrating the configuration of the piping device 200. FIG. 3 is a cross-sectional view showing a configuration in the vicinity of the end portion on the compressor 101 side of the piping device 200 cut along a plane including the tube axis. FIG. 4 is a cross-sectional view showing a configuration of the piping device 200 cut along line IV-IV in FIG. 2 and 3, the flow direction of the high-pressure refrigerant is indicated by a white thick arrow, and the flow direction of the low-pressure refrigerant is indicated by a black thick arrow.

  As shown in FIGS. 2 to 4, the piping device 200 includes an outer tube 210 and an inner tube 220 that has an outer diameter smaller than the inner diameter of the outer tube 210 and is disposed so as to penetrate the inner side of the outer tube 210. It has a double pipe structure provided with. The outer tube 210 is formed of, for example, an aluminum φ22 mm tube (outer diameter 22 mm, inner diameter 19.6 mm). Both ends in the longitudinal direction of the outer tube 210 are combined with the inner tube 220 and then welded so that the entire circumference is contracted radially inward and airtight or liquid tight on the outer wall surface of the inner tube 220. Has been. Thereby, a space serving as an outer flow path 230 through which the high-pressure refrigerant flows is formed between the outer pipe 210 and the inner pipe 220. Inside the inner tube 220, an inner flow path 240 for circulating a low-pressure refrigerant is formed. The piping device 200 performs heat exchange between the high-pressure refrigerant flowing in the outer flow path 230 and the low-pressure refrigerant flowing in the inner flow path 240 in the heat exchange region 205 having a double pipe structure.

  The outer wall surfaces of both ends in the longitudinal direction of the outer pipe 210 are connected to the outside and the outer flow path 230, and one end of each of the aluminum liquid pipes 231 and 232 constituting a part of the high-pressure refrigerant pipe 112 is connected. ing. The other end of the liquid pipe 231 is connected to the condenser 102, and the other end of the liquid pipe 232 is connected to the expansion valve 103. Accordingly, the liquid pipe 231, the outer flow path 230, and the liquid pipe 232 allow the high-pressure refrigerant condensed by the condenser 102 to flow to the expansion valve 103.

  The inner tube 220 is formed of, for example, an aluminum 3/4 inch tube (outer diameter 19.1 mm, inner diameter 16.7 mm). One end side of the inner tube 220 is connected to the compressor 101, and the other end side is connected to the evaporator 104. The inner flow path 240 in the inner tube 220 allows the low-pressure refrigerant evaporated by the evaporator 104 to flow to the compressor 101 side. The tube diameters of the outer tube 210 and the inner tube 220 are secured to such an extent that the cross-sectional area of the outer flow channel 230 can flow the high-pressure refrigerant, and the outer diameter of the inner tube 220 is made as large as possible. Each is set so as to increase the surface area.

  On the tube wall of the inner tube 220 corresponding to the region where the outer flow path 230 is formed, a circumferential groove portion 221 and a spiral groove portion 222 that are both convex inward are provided. The circumferential groove portion 221 is provided at both ends of the outer tube 210 corresponding to the connection positions of the liquid pipes 231 and 232 and extends in the circumferential direction of the inner tube 220. Further, the spiral groove portion 222 is connected to both the circumferential groove portions 221 and extends in a spiral shape of one or more (for example, three) spirals between the both circumferential groove portions 221 in the longitudinal direction of the inner tube 220. By forming the circumferential groove 221 and the spiral groove 222, the outer flow path 230 is enlarged. The spiral groove portion 222 is partitioned by a spiral ridge portion 223 that maintains the outer diameter of the inner tube 220 before the formation of the spiral groove portion 222 and is convex to the outside of the inner tube 220.

  A part of the inner tube 220 in the axial direction is provided with a flow dividing region 255 for partially dividing the inner flow path 240. A circular branch pipe 250 is provided inside the inner pipe 220 in the branch area 255. The shunt tube 250 has an outer diameter that is substantially the same as the inner diameter of the inner tube 220 defined by the spiral groove portion 222, is inserted substantially coaxially with the inner tube 220, and is pressed against and supported by the tube inner wall side of the spiral groove portion 222. Yes. For example, the flow dividing pipe 250 is made of aluminum like the inner pipe 220 and the outer pipe 210 and has a relatively thin wall thickness. The shunt pipe 250 is provided at the end of the inner flow path 240 on the compressor 101 side.

  Inside the branch pipe 250, a main flow path 251 for allowing a part of the low-pressure refrigerant to flow in the branch area 255 is formed as shown by a solid thin arrow in FIG. The main flow path 251 extends substantially along the tube axes of the inner tube 220 and the diversion tube 250. The path length of the main flow path 251 is substantially equal to the length of the branch pipe 250.

  A bypass channel 252 that bypasses the outside of the main channel 251 in a spiral manner and partially diverts from the main channel 251 is formed in a space outside the shunt pipe 250 and inside the peak portion 223. As shown by the thin broken arrows in FIG. 3, the detour channel 252 circulates a part of the low-pressure refrigerant with a path length longer than that of the main channel 251 in the shunt region 255, and the main channel 251 on the downstream side of the shunt region 255. It is designed to merge with the low-pressure refrigerant that has circulated. For example, when three spiral grooves 222 are formed, three ridges 223 are formed, so that three bypass channels 252 are formed.

  Next, the manufacturing method of the piping apparatus in this embodiment is demonstrated.

  First, a branch pipe 250 having an outer diameter smaller than the inner diameter of the inner pipe 220 and a shorter length than the inner pipe 220 is inserted into the circular inner pipe 220. The inserted flow dividing pipe 250 is temporarily fixed at a position to be the flow dividing area 255 using, for example, an adhesive. Next, in a state where the flow dividing pipe 250 is inserted into a predetermined position in the inner pipe 220, the circulation groove part 221 and the spiral groove part 222 are formed in the pipe wall of the inner pipe 220.

  FIG. 5 is a diagram illustrating an example of a process for forming the circumferential groove 221 and the spiral groove 222. As shown in FIG. 5, a grooving tool 260 is used when forming the circumferential groove portion 221 and the spiral groove portion 222. The grooving tool 260 includes a disk-shaped block 261, a ball 262, and a bolt 263 that defines the position of the ball 262. The block 261 has an insertion hole 264 through which the inner tube 220 can be inserted at the center. The block 261 is provided with a plurality of radial holes extending radially from the inner wall surface of the insertion hole 264. Each radial hole accommodates a bolt 263 and a ball 262 attached to the tip of the bolt 263. The bolt 263 is screwed into the radial hole. The amount of protrusion of the ball 262 into the insertion hole 264 can be adjusted by rotating the bolt 263. The number of pairs of balls 262 and bolts 263 is equal to the number of spiral grooves 222 formed. In this embodiment, three pairs of balls 262 and bolts 263 are provided to form the three spiral groove portions 222.

  When forming the circumferential groove portion 221 and the spiral groove portion 222, the inner tube 220 is inserted into the insertion hole 264, and then both ends in the longitudinal direction of the inner tube 220 are fixed with a holder or the like (not shown). Then, the ball 262 is pressed to a position corresponding to the groove depth of the spiral groove 222 by the bolt 263. The groove depth of the spiral groove 222 is set to such an extent that the flow dividing pipe 250 inserted into the inner pipe 220 is pressed.

  In this state, by rotating the block 261 about the tube axis of the inner tube 220, a groove that protrudes inward is formed on the tube wall of the inner tube 220. If the block 261 is rotated without being moved, a circular groove 221 (not shown in FIG. 5) is formed, and if the block 261 is rotated while being moved in the longitudinal direction of the inner tube 220, a spiral groove 222 is formed. . At this time, the spiral pitch of the spiral groove 222 can be adjusted by adjusting the moving speed of the block 261.

  By forming the spiral groove 222 in the tube wall of the inner tube 220, the flow dividing tube 250 is pressure-supported by the inner tube 220. At this time, a ridge portion 223 in which the outer diameter of the inner tube 220 is substantially maintained is formed between the spiral groove portions 222 in a spiral shape. As a result, the main flow path 251 is formed inside the diversion pipe 250, and the detour flow path 252 that spirals around the outside of the main flow path 251 in a space outside the diversion pipe 250 and inside the peak portion 223. Is formed. Here, if the flow dividing tube 250 is inserted into a predetermined position in the inner tube 220 immediately before the spiral groove 222 is formed in the flow dividing region 255 of the inner tube 220, temporary fixing of the flow dividing tube 250 can be omitted.

  Thereafter, the inner tube 220 is inserted inside the outer tube 210 and fixed to the outer tube 210, and the outer tube 210 and the inner tube 220 are bent at a necessary portion according to the mounting space in the engine room 1 of the vehicle. After that, the piping device 200 of the present embodiment is manufactured.

  Next, the operation of the piping device and the refrigeration cycle device of the present embodiment will be described.

  When there is an air conditioning request from the passenger, for example, a cooling request, the electromagnetic clutch of the compressor 101 is connected. Thereby, the compressor 101 is driven by the engine 10, sucks the refrigerant from the evaporator 104 side, compresses it, and discharges it as a high-temperature high-pressure refrigerant to the condenser 102 side. The high-pressure refrigerant is cooled in the condenser 102 to be condensed and liquefied. The refrigerant here is almost in a liquid phase. The condensed and liquefied refrigerant flows into the expansion valve 103 through the high-pressure refrigerant pipe 112 including the outer flow path 230 of the pipe device 200. The refrigerant is decompressed and expanded by the expansion valve 103 and then evaporated by the evaporator 104. The refrigerant here is almost in a saturated gas state. In the evaporator 104, the conditioned air is cooled as the refrigerant evaporates. The saturated gas refrigerant evaporated in the evaporator 104 returns to the compressor 101 as a low-temperature low-pressure refrigerant through the low-pressure refrigerant pipe 113 including the inner flow path 240 (the main flow path 251 or the bypass flow path 252) of the piping device 200. .

  In the heat exchange region 205 of the piping device 200, heat exchange is performed between the high-pressure refrigerant passing through the outer flow path 230 and the low-pressure refrigerant passing through the inner flow path 240. As a result, the liquid-phase refrigerant that has flowed out of the condenser 102 is further subcooled by the piping device 200 and the temperature reduction is promoted. The saturated gas refrigerant flowing out of the evaporator 104 is further heated by the piping device 200 to become a gas refrigerant having a superheat degree.

  In the present embodiment, since the flow dividing tube 250 is provided in the flow dividing region 255, the heat exchange efficiency in the flow dividing region 255 is lowered. However, the temperature difference between the low-pressure refrigerant and the high-pressure refrigerant in the heat exchange region 205 is generally large at the inlet side end of the low-pressure refrigerant and is small at the outlet side end of the low-pressure refrigerant. Therefore, since heat exchange between the low-pressure refrigerant and the high-pressure refrigerant is mainly performed at the inlet side end of the low-pressure refrigerant, even if the heat exchange efficiency in the branch region 255 provided at the outlet-side end of the low-pressure refrigerant is reduced, The overall heat exchange performance of the piping device 200 is not significantly reduced.

  In this embodiment, since the inner tube 220 in which the inner channel 240 is formed is covered with the outer tube 210, the temperature of the low-pressure refrigerant passing through the inner channel 240 is increased by the radiant heat from the engine 10 or the like. Less likely For this reason, a decrease in cooling performance is prevented.

  Sound waves generated by the pulsation of the compressor 101 and traveling into the passenger compartment 2 propagate in the inner tube 220 in the direction opposite to the flow direction of the low-pressure refrigerant (rightward in FIG. 3). In the shunt region 255 of the inner tube 220, the sound wave propagation path is partially separated into the main flow path 251 and the bypass flow path 252. The sound wave propagated through the main flow path 251 and the sound wave propagated through the bypass flow path 252 are combined on the downstream side in the propagation direction (upstream side in the flow direction of the low-pressure refrigerant) with respect to the shunt region 255. Since the bypass channel 252 and the main channel 251 have different path lengths, a phase shift occurs between the sound wave propagated through the bypass channel 252 and the sound wave propagated through the main channel 251. Accordingly, since the combined sound waves weaken each other, the intensity of the sound transmitted to the inside of the passenger compartment 2 is reduced.

  The height of the silencing effect in the present embodiment largely depends on the relationship between the wavelength of the sound wave propagating through the shunt region 255 and the path length difference between the bypass channel 252 and the main channel 251. Therefore, the length and diameter of the shunt tube 250, the helical pitch of the spiral groove 222 and the peak portion 223, and the like are based on the wavelength range of sound generated in the compressor 101, the required silencing effect, heat exchange performance, and the like. It is determined.

  Here, if the difference between the intensity of the sound wave propagating through the bypass channel 252 and the intensity of the sound wave propagating through the main channel 251 is large, a high interference effect cannot be obtained. Therefore, when the cross-sectional area of the main flow path 251 is A1, the cross-sectional area of the bypass flow path 252 (the sum of the cross-sectional areas of the bypass flow paths 252 when a plurality of bypass flow paths 252 are formed) A2 is The cross-sectional area is preferably greater than A1. As a result, the sound wave inlet area (the outlet area of the low-pressure refrigerant) of the bypass flow path 252 increases and the sound waves easily propagate to the bypass flow path 252, so the intensity of the sound wave propagating through the bypass flow path 252 and the main flow path The intensity of the sound wave propagating through 251 can be made closer.

  In the present embodiment, since the branch pipe 250 is provided in the vicinity of the end of the inner pipe 220 on the compressor 101 side, the propagation path of the sound wave between the compressor 101 and the branch area 255 can be shortened. Therefore, since it becomes easy to specify the wavelength of the sound wave propagating through the shunt region 255, the length and the pipe diameter of the shunt pipe 250, the spiral pitch of the spiral groove 222 and the peak part 223, etc. are designed so as to obtain a high silencing effect. Easy to do. Further, since the sound wave propagating to most of the inner tube 220 has already been attenuated, resonance and the like occurring in the inner tube 220 can be suppressed.

  Moreover, in this embodiment, the sound produced by the pulsation of the compressor 101 is silenced in the piping device 200 that performs heat exchange between the low-pressure refrigerant and the high-pressure refrigerant. For this reason, it is not necessary to separately provide a silencer between the compressor 101 and the evaporator 104 of the refrigeration cycle apparatus 100. Therefore, transmission of noise into the passenger compartment 2 can be prevented and the space for mounting the refrigeration cycle apparatus 100 can be reduced.

  Furthermore, in this embodiment, since the flow dividing pipe 250 can be fixed to the inner pipe 220 at the same time when the spiral groove part 222 and the peak part 223 are formed, the manufacturing process of the piping device 200 is simplified.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view showing a main configuration of the piping device 201 in the present embodiment. As shown in FIG. 6, the piping device 201 is characterized in that the angle of inclination of the spiral groove 222 formed in the inner tube 220 with respect to the tube axis differs depending on the region.

  The inclination angle (maximum inclination angle) θ2 of the spiral groove portion 222 in the flow dividing region 255 where the flow dividing pipe 250 is formed is the inclination angle (maximum inclination angle) of the helical groove portion 222 in the regions upstream and downstream of the refrigerant flow from the flow dividing region 255. (Inclination angle) θ1 (θ2> θ1). Here, the inner diameter of the inner tube 220 defined by the spiral groove portion 222 and the outer diameter of the inner tube 220 defined by the peak portion 223 are substantially constant over the entire heat exchange region 205 (see FIG. 2). For this reason, the spiral pitch P2 of the spiral groove part 222 and the peak part 223 in the shunt area | region 255 is narrower than the spiral pitch P1 in another area | region (P2 <P1). Thereby, since the length of the detour channel 252 can be made longer than the length of the diversion tube 250, the diversion tube 250 necessary for providing a predetermined path length difference between the detour channel 252 and the main channel 251. Can be shortened. Therefore, since the diversion area | region 255 with low heat exchange efficiency can be narrowed, the heat exchange performance in the heat exchange area | region 205 of the piping apparatus 201 can be improved. Moreover, since the shunt pipe 250 can be reduced in size and weight, the piping device 201 can be reduced in size and weight.

  In the present embodiment, the inclination angle (maximum inclination angle) θ3 of the spiral groove 222 in the vicinity of the refrigerant outlet side end 250b on the compressor 101 side in the branch pipe 250 is the inclination angle of the spiral groove 222 in the flow dividing region 255. It is smaller than θ2 (θ3 <θ2), and is smaller than the inclination angle θ1 of the spiral groove 222 on the upstream side of the refrigerant flow from the flow dividing region 255 (θ3 <θ1). For this reason, the helical pitch P3 of the spiral groove part 222 and the peak part 223 near the refrigerant outlet side end part 250b is wider than the spiral pitch P2 of the spiral groove part 222 and the peak part 223 in the flow dividing region 255 (P3> P2). In addition, the spiral pitch P1 of the spiral groove portion 222 and the peak portion 223 on the upstream side of the refrigerant flow from the shunt region 255 becomes wider (P3> P1). Accordingly, the sound wave inlet area (the outlet area of the low-pressure refrigerant) of the bypass flow path 252 can be increased, so that the sound wave easily propagates to the bypass flow path 252 side. Therefore, the intensity of the sound wave propagating through the bypass channel 252 (indicated by the arrow b in the figure) and the intensity of the sound wave propagating through the main channel 251 (indicated by the arrow a in the figure) can be made close to each other. Is obtained.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a cross-sectional view showing the configuration of the branch pipe 270 of the piping device in the present embodiment. As shown in FIG. 7, the refrigerant inlet side end 270a and the refrigerant outlet side end 270b of the branch pipe 270 are formed with tapered portions 271 and 272, respectively, so that the outer diameter becomes smaller toward the tip side. Yes. Thereby, the sound wave propagating from the compressor 101 side to the flow dividing region 255 is guided to the outside of the flow dividing tube 270 by the tapered portion 272 formed at the refrigerant outlet side end portion 270 b of the flow dividing tube 270. For this reason, the sound wave easily propagates to the bypass channel 255 side in the shunt region 255.

  Further, since the taper portions 271 and 272 are formed at the refrigerant inlet side end portion 270a and the refrigerant outlet side end portion 270b of the flow dividing pipe 270, the insertion property when the flow dividing pipe 270 is inserted into the inner pipe 220 is improved. .

  Further, since the tapered portion 271 is formed at the refrigerant inlet side end portion 270a of the diversion pipe 270, the low-pressure refrigerant flowing into the diversion area 255 is guided to the outside of the diversion pipe 270 and easily flows into the bypass flow path 252. The effect of becoming is also obtained.

  FIG. 8 is a cross-sectional view showing a modification of the configuration of the shunt tube of the present embodiment. As shown in FIG. 8, chamfered portions 276 and 277 whose outer peripheral sides are chamfered, for example, are formed at the refrigerant inlet side end portion 275 a and the refrigerant outlet side end portion 275 b of the diversion pipe 275. Also according to this modification, the sound wave propagating to the flow dividing region 255 can be guided to the bypass flow channel 252 and the insertion property when the flow dividing tube 275 is inserted into the inner tube 220 is improved. Further, even if the chamfered portions 276 and 277 are formed by C chamfering instead of R chamfering, the same effect can be obtained.

(Other embodiments)
In the above embodiment, the flow dividing pipe 250 is fixed to the inner pipe 220 by pressure contact. However, the flow dividing pipe 250 may be fixed to the inner pipe 220 by bonding or other joining methods.

  Moreover, in the said embodiment, although the shunt pipe 250 was made from aluminum, you may form with other materials, such as stainless steel and resin.

  Further, in the above-described embodiment, the spiral groove portion 222 and the peak portion 223 are formed after the branch pipe 250 is inserted into the inner tube 220. However, the branch pipe 250 is formed in the inner tube 220 after the spiral groove portion 222 and the peak portion 223 are formed. May be inserted. For example, in this case, if the inner diameter of the inner pipe 220 defined by the spiral groove 222 is slightly smaller than the outer diameter of the flow dividing pipe 250 and the flow dividing pipe 250 is press-fitted into the inner pipe 220, the flow dividing pipe 250 Fixing is easy.

It is a schematic diagram which shows schematic structure of the refrigerating-cycle apparatus in 1st Embodiment. It is a schematic diagram which shows the structure of the piping apparatus in 1st Embodiment. It is sectional drawing which shows the principal part structure of the piping apparatus cut | disconnected in the surface containing a pipe axis. It is sectional drawing which shows the principal part structure of the piping apparatus cut | disconnected by the IV-IV line of FIG. It is a figure which shows an example of the formation process of a circumference groove part and a spiral groove part. It is sectional drawing which shows the principal part structure of the piping apparatus in 2nd Embodiment. It is sectional drawing which shows the structure of the shunt pipe of the piping apparatus in 3rd Embodiment. It is sectional drawing which shows the modification of a structure of the shunt pipe of the piping apparatus in 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Refrigeration cycle apparatus 101 Compressor 102 Condenser 103 Decompression means 104 Evaporator 111, 112 High pressure refrigerant piping 113 Low pressure refrigerant piping 200, 201 Piping apparatus 210 Outer pipe 220 Inner pipe 222 Spiral groove part 223 Peak part 230 Outer flow path 240 Inner flow Channels 250, 270, 275 Diverging pipe 251 Main channel 252 Detour channel 255 Diverging region 271, 272 Taper 276, 277 Chamfer

Claims (11)

An outer tube (210) and an inner tube (220) provided on the inner side of the outer tube (210) are provided, and are formed inside the outer tube (210) and outside the inner tube (220). Double that exchanges heat between the first fluid that flows through the outer flow path (230) and the second fluid that flows through the inner flow path (240) formed inside the inner pipe (220). A piping device having a pipe structure,
A spiral groove portion (222) formed in a spiral shape on the tube wall of the inner tube (220) and projecting inside the inner tube (220);
A spiral ridge (223) that protrudes outward from the inner tube (220) and defines the spiral groove (222);
Inside the inner pipe (220), provided in a part of the inner pipe (220) in the axial direction and supported by the spiral groove (222), the inner flow path (240) is partially branched. A diversion tube (250) forming a diversion region (255);
A main flow path (251) that is formed inside the diversion pipe (250) and allows the second fluid to flow therethrough;
It is formed outside the diversion pipe (250) and inside the ridge (223), and partially diverts from the main flow path (251) by bypassing the outside of the main flow path (251) in a spiral shape. And a bypass channel (252) for circulating the second fluid with a path length different from that of the main channel (251).   The spiral pitch (P2) of the peak part (223) in the branch region (255) is narrower than the spiral pitch (P1) of the peak part (223) other than the branch region (255). The piping device according to claim 1.   The inclination angle (θ2) of the spiral groove portion (222) with respect to the tube axis in the diversion region (255) is greater than the inclination angle (θ1) of the spiral groove portion (222) with respect to the tube axis in the region other than the diversion region (255). The piping device according to claim 2, wherein the piping device is also large.   The piping device according to any one of claims 1 to 3, wherein a cross-sectional area (A2) of the bypass flow path (252) is equal to or greater than a cross-sectional area (A1) of the main flow path (251). .   The at least one end (270a, 270b) of the flow dividing pipe (270) has a tapered portion (271, 272) formed so that the outer diameter becomes smaller toward the tip end side. Item 5. The piping device according to any one of Items 1 to 4.   The at least one end (275a, 275b) of the flow dividing pipe (275) has a chamfered portion (276, 277) whose outer peripheral side is chamfered. The piping apparatus according to the item. A compressor (101) that compresses the refrigerant, a condenser (102) that condenses the refrigerant compressed by the compressor (101), and a decompression means (103) that decompresses and expands the refrigerant condensed by the condenser (102) ), An evaporator (104) for evaporating the refrigerant decompressed by the decompression means (103) and returning it to the compressor (101), the compressor (101), the condenser (102), and the decompression means (103) and a refrigerant pipe (111, 112, 113) sequentially connecting the evaporator (104) in an annular shape,
The piping device according to any one of claims 1 to 7 is used as a part of the refrigerant piping (111, 112, 113),
The outer flow path (230) is provided between the condenser (102) and the decompression means (103) to constitute a flow path through which a high-pressure refrigerant flows.
The refrigeration cycle apparatus, wherein the inner flow path (240) is provided between the evaporator (104) and the compressor (101) and forms a flow path through which a low-pressure refrigerant flows.   The inclination angle (θ3) with respect to the tube axis of the spiral groove portion (222) in the vicinity of the end portion (250b) on the compressor (101) side of the diversion tube (250) is set to be other than the diversion region (255). The piping apparatus according to claim 7, wherein the helical groove (222) is smaller than an inclination angle (θ1) with respect to a pipe axis.   The refrigeration cycle apparatus according to claim 7 or 8, wherein the branch pipe (250) is disposed at an end of the inner flow path (240) on the compressor (101) side.   The refrigeration cycle apparatus according to any one of claims 7 to 9, wherein the refrigeration cycle apparatus is mounted on a vehicle. An outer tube (210) and an inner tube (220) provided on the inner side of the outer tube (210) are formed inside the outer tube (210) and outside the inner tube (220). Double that exchanges heat between the first fluid that flows through the outer flow path (230) and the second fluid that flows through the inner flow path (240) formed inside the inner pipe (220). A method of manufacturing a piping device having a pipe structure,
A shunt pipe (250) having an outer diameter smaller than the inner diameter of the inner pipe (220) and shorter than the inner pipe (220) is inserted inside the inner pipe (220);
In a state where the flow dividing pipe (250) is inserted inside the inner pipe (220), a spiral spiral groove portion (222) which protrudes inward and press-supports the flow distribution pipe (250) is protruded and protrudes outward. A spiral ridge (223) defining a spiral groove (222) is formed on the tube wall of the inner tube (220) to form a main channel (251) inside the flow dividing tube (250). Forming a bypass channel (252) that spirals around the outside of the main channel (251) outside the shunt pipe (250) and inside the peak (223);
A method of manufacturing a piping device, wherein the inner pipe (220) is inserted and fixed inside the outer pipe (210).

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