JP2009085430A - Pipe fitting and refrigeration system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe fitting and a refrigeration cycle system using the same, which prevent pipe sealing performance and pipe holding mechanism from being impaired due to volume expansion force of ice because moisture in the air freezes in a non-airtight space formed between a fitting body and a coupling member. <P>SOLUTION: The pipe fitting has the fitting body 1 fixed to a device side to be connected of a connection pipe P2 to connect, and the coupling member 2 attached to a connection piping P2 and coupled with the fitting body 1. When the fitting body 1 and the coupling member 2 are connected, a non-airtight space S is formed between the fitting body 1 and the coupling member 2. A release port 5 communicating with the outside air is formed in the fitting body 1 or the coupling member 2. Since the ice growing in the space S is made to swell from the release port 5, increase of the force due to the volume expansion of ice is avoided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe joint and a refrigeration cycle apparatus using the pipe joint, and more particularly to a structure that prevents deterioration of pipe seal performance due to freezing of moisture in the air inside the pipe joint.

  There are various types of pipe joints used for fluid pipes that allow fluid to flow inside depending on the application. For example, in a refrigeration cycle apparatus such as an air conditioner in which a refrigerant flows in a fluid pipe, a flare-type pipe joint has been generally used in the past. The application pressure of the bite type pipe joint has been studied. Examples of such bite-type pipe joints include those described in Patent Document 1 and Patent Document 2. Moreover, patent document 3 can be hung up as a typical example of the flare type pipe joint generally used.

  FIG. 24 shows an example of a bite type pipe joint known from Patent Documents 1 and 2 and the like. As shown in FIG. 24, the bite type pipe joint generally includes a joint body 101, a coupling member 102, and a ferrule 103. The joint body 101 has a male screw 105 formed on the coupling member side, that is, on the outer periphery of the pipe connecting portion 104. The coupling member 102 is formed in a cap shape, and a female screw 106 that is screwed into the male screw 105 and a pressing surface 107 that presses the ferrule 103 against the end of the pipe connecting portion 104 are formed therein. In this example, the ferrule 103 includes a back ferrule 103a and a front ferrule 103b. Assembling this bite-in type pipe joint, first, the joint body side end of the ferrule 103 is opposed to the cam surface 108 formed at the end of the pipe connecting portion 104, and the coupling member side end of the ferrule 103 is The state is made to face the pressing surface 107 of the coupling member 102. Next, the female screw 106 of the coupling member 102 is screwed into the male screw 105 of the joint body 101. In this way, when the coupling member 102 is screwed into the joint body 101, the pressing surface 107 of the coupling member 102 presses the ferrule 103 against the cam surface 108 of the pipe connecting portion 104. As a result, the back ferrule 103a and the front ferrule 103b cooperate with each other to bite into the pipe 109 so as to prevent the pipe 109 from being detached and to obtain high sealing performance.

FIG. 25 shows a flare type pipe joint known from Patent Document 3. As shown in FIG. 25, the flare type pipe joint includes a joint body 201 and a coupling member (flare nut) 202. The joint body 201 includes a flare receiving surface 204 at the connecting end portion at the tip, and a male screw 206 is formed on the outer periphery of the large-diameter portion 205 on the rear side thereof. The coupling member 202 has a substantially cylindrical space inside, and is provided with a female screw 207 that is screwed into the male screw 206 on the inner peripheral surface of this space. Further, a flare pressure contact surface 209 for pressing the flare portion 208 formed at the connection end portion of the pipe 203 is formed on the inner surface where the coupling member 202 abuts. Then, the flare pressure contact surface 209 causes the flare 208 of the pipe 203 to be in pressure contact with the flare receiving surface 204, thereby connecting the joint body 101 and the pipe 203.
JP 2003-74769 A JP 2005-36947 A Japanese Patent Laid-Open No. 5-158771, FIG. 6, FIG.

  However, in the bite-in type pipe joint, the space portion 110 generated on the outer peripheral side of the ferrule 103 in a state where the coupling member 102 is fastened and the pipe 109 is connected is generated by the outside air intrusion passage 111 indicated by a broken line arrow in FIG. It is communicated with and is airtight. The outside air intrusion passage 111 here refers to a passage that communicates the space portion 110 with the outside air around the pipe joint through a threaded portion between the male screw 105 of the pipe connecting portion 104 and the female screw 106 of the coupling member 102. Further, in the bite type pipe joint after connection, the temperature of the pipe joint itself changes with the temperature change of the fluid such as the refrigerant. For this reason, when the temperature of the pipe joint is lowered, moisture in the air in the non-hermetic space 110 is condensed, and accordingly, moisture in the external air is passed through the above-described outside air intrusion passage 111. It will penetrate into the interior of the water, increasing the amount of moisture condensation. Further, when the temperature of the pipe joint becomes zero degrees or less due to a change in fluid temperature or a change in outside air temperature, condensed water or moisture in the air freezes in the space 110 or the like, and the amount of freezing increases with time. When the space 110 is filled with ice, the force due to the volume expansion of the ice begins to act on the members that form the ferrule 103 and the cam surface 108, and increases with time. As a result, these members are deformed by the force due to the volume expansion of ice, the pipe sealing performance and the pipe holding function are deteriorated, and there is a possibility that refrigerant leakage and pipe disconnection may occur.

  On the other hand, there is a similar problem in the flare type pipe joint shown in FIG. That is, the space 210 is formed on the tip side of the flare 208 inside the pipe joint. This space portion 210 is communicated with the outside air around the joint by the outside air intrusion passage 211 indicated by the broken-line arrow in FIG. 25, and is not airtight. Further, in the flare type pipe joint, the temperature of the pipe joint itself changes with the temperature change of the fluid such as the refrigerant used. Then, when the temperature of the pipe joint itself decreases, moisture in the air condenses in the space 210, and accordingly, moisture in the outside air further passes through the outside air intrusion passage 211 to the space 210. Penetration increases the amount of moisture condensation. Further, when the temperature of the pipe joint itself becomes zero degrees or less due to a change in the fluid temperature or a change in the outside air temperature, water condensed in the space part 210 or moisture in the air freezes, and the amount of freezing increases with time. Then, as shown in FIG. 26, the space portion 210 is filled with ice (shown as dots in this figure), and acts to push the flare portion 208 in the direction of the solid arrow A in FIG. As a result, the flare 208 and the end of the pipe 203 are deformed by the force due to the volume expansion of ice, and the pipe sealing performance and the pipe holding function may be deteriorated.

  The above description is given taking a pipe joint used in a refrigeration cycle apparatus such as an air conditioner as an example. However, the problem of freezing of water in the pipe joint is that the temperature in the pipe joint changes due to changes in the atmospheric temperature, etc. in fields other than refrigeration cycle devices such as air conditioners, and the moisture in the pipe joint Freezing may cause the pipe seal performance and pipe holding function to deteriorate.

  The present invention has been made paying attention to such problems existing in the prior art. That is, according to the present invention, moisture in the air freezes in a non-airtight space formed between the joint body and the coupling member, and the pipe sealing performance and the pipe holding function are impaired by the volume expansion force of ice. It is an object of the present invention to provide a pipe joint that is free from refrigeration and a refrigeration cycle apparatus using the same.

A pipe joint according to the present invention solves the above-described problem, and is a pipe joint including a joint body and a coupling member that is externally connected to a connection pipe to be connected and joined to the joint body, The joint body or the coupling member is provided with an ice escape communicating hole communicating with the outside air with respect to a non-hermetic space formed between the joint body and the coupling member by connection. .

  Even if the non-hermetic space formed between the joint body and the coupling member is filled with ice due to condensation of moisture entering from the outside and freezing, Since it grows while bulging into the ice escape communicating hole, the force due to the volume expansion of ice does not increase. Therefore, the force acting on the members related to the seal mechanism and the pipe holding mechanism such as the ferrule and the flare portion does not increase, and the pipe sealing function and the pipe holding function are impaired by the force due to the volume expansion of the ice filling the space. The fear of being lost.

  The pipe joint is a bite-type pipe joint, and the ice escape communication hole communicates from the outer surface of the joint body to a non-airtight space formed on the distal end side of the coupling member. It may be formed in the joint body. If comprised in this way, the ice formed in a space part can be bulged through the communicating hole for ice escape formed in the coupling main body.

  Further, the pipe joint is a bite type pipe joint, and the ice escape communication hole is connected to the non-airtight space formed around the ferrule from the outer surface of the connection member. You may make it form in this. If comprised in this way, the ice formed in a space part can be bulged through the communicating hole for ice escape formed in the coupling member.

  The pipe joint is a flare-type pipe joint, and the ice escape communication hole communicates from the outer surface of the joint body to a non-airtight space formed on the tip side of the flare part. It may be formed in the joint body. With this configuration, since the ice escape communicating hole communicating with the outside air can be formed in the space where the ice accumulation and expansion force that presses the tip of the flare portion is generated, It can bulge through the escape communicating hole.

  The pipe joint is a flare-type pipe joint, and the ice escape communication hole communicates from the outer surface of the coupling member to a non-hermetic space formed on the tip side of the flare part. It may be formed on the coupling member. With this configuration, since the ice escape communicating hole communicating with the outside air can be formed in the space where the ice expansion and expansion force that presses the tip of the flare portion is generated, The expanding ice can be swelled through the ice escape communication hole. In particular, in the case of a structure in which the coupling member is fastened so as to cover the threaded portion of the joint body, the coupling member can easily communicate with the outside.

  The ice escape communicating hole is preferably set so that [volume of non-hermetic space (mm3)] / [hole cross-sectional area (mm2)] is 50 or less. When the ice escape communicating hole is formed in this way, even if only one ice escape communicating hole is formed, the ice formed in the non-airtight space between the joint body and the coupling member can be removed. It can be swelled outside without hindrance, and the pipe sealing function and the pipe holding function can be maintained.

  The ice escape communication hole is formed of a plurality of communication holes having a cross-sectional area that is at least larger than a cross-sectional area that may be water-sealed due to the surface tension of water. It is preferable that the escape communication hole is formed at a position equally divided in the circumferential direction. If comprised in this way, it will become possible to discharge | emit the condensed water to the space part between a coupling main body and a coupling member by one of the ice escape communicating holes. This alleviates ice growth.

  Moreover, the refrigeration apparatus according to the present invention uses the above pipe joint in a refrigerant circuit. Therefore, according to this refrigeration apparatus, even if the non-confidential space in the pipe joint is frozen and filled with ice, there is no fear that the function of the pipe joint is impaired by the force due to the volume expansion of the growing ice.

  According to the bite type pipe joint according to the present invention, even if ice grows so as to fill the inside of the non-confidential space formed between the joint body and the coupling member, the volume expansion of this ice is escaped by ice. It can be escaped through the communication hole. Accordingly, it is possible to eliminate the fear that a large force acts on the ferrule and the flare portion due to the volume expansion force of ice, and the pipe sealing function and the pipe holding function are impaired.

Embodiments of the present invention will be described below with reference to the drawings.
Note that, in the drawings of the embodiments, common elements are denoted by the same reference numerals, and descriptions thereof are omitted or simplified.

(Embodiment 1)
A pipe joint according to Embodiment 1 will be described with reference to FIGS. The pipe joint according to the first embodiment is a bite type pipe joint used in the refrigerant circuit of the refrigeration apparatus, and FIG. 1 is a partial cross-section in a state where the ferrule is in contact with the cam surface after the start of fastening of the bite type pipe joint. FIG. 2 is a partial cross-sectional view of the coupling member 2 in a state where the fastening is completed. 3 is a partial sectional view of the joint body, FIG. 4 relates to the joint body, is a right side view in FIG. 3, FIG. 5 is a partial sectional view of the coupling member, and FIG. 6 is an enlarged view around the ferrule. It is sectional drawing. FIG. 7 is a pipe connection process diagram of the bite-in type pipe joint.

  As shown in these drawings, the bite-in type pipe joint includes a joint body 1 attached to the connected side device of the connection pipe P2 to be connected, and a coupling member that is externally connected to the joint body 1 and is connected to the connection pipe P2. 2 and a ferrule 3 formed integrally with the coupling member 2. In the following description, when referring to the front-rear direction, the joint body 1 side, for example, the left side in FIG. 1, is the front side, and the coupling member 2 side, that is, the right side in FIG. This also applies to each embodiment described later.

  As shown in FIGS. 1 to 4, the joint body 1 is formed with a socket portion 11 having an insertion port 11 a into which an apparatus-side pipe P <b> 1 is inserted and brazed at an end portion on the side opposite to the coupling member. Then, on the side of the coupling member, a base portion 13 formed on the outer periphery with a nut portion 12 held by a general fastening tool when the coupling member 2 is fastened, and a female screw 14a as a threaded portion for screwing the coupling member 2 together. Is formed on the inner circumferential surface.

  Further, the joint body 1 has a shaft portion 15 that protrudes from the end surface of the base portion 13 on the side of the coupling member 2 into the female screw cylinder portion 14. And the annular space part 16 for inserting the protection cylinder part 23 of the coupling member 2 is formed in the outer peripheral side of the projecting shaft part 15, and it connects to the center part from the shaft part 15 to the base 13 at the time of piping connection. An insertion port 15a into which the pipe P2 is inserted is formed. Further, a step portion 17 is formed between the insertion port 11a and the insertion port 15a so as to protrude from the inner peripheral surfaces of the insertion ports 11a and 15a. The step portion 17 is configured such that the tip ends of the apparatus side pipe P1 and the connection pipe P2 inserted into the insertion ports 11a and 15a are brought into contact with the stepped surface of the step section 17 so that the tips of the apparatus side pipe P1 and the connection pipe P2 are connected. Is held at a predetermined position. The apparatus side pipe P1 and the connection pipe P2 have the same pipe diameter.

  A cam surface 18 is formed at the inlet of the insertion port 15a. The cam surface 18 is connected to the insertion port 15a on the front side, and is formed in a conical shape whose diameter increases toward the rear side (the coupling member 2 side). In addition, the inclination angle of the cam surface 18 with respect to the axial center of the pipe joint is formed larger than the tapered surface 32 of the tip portion of the ferrule 3 described later. Further, as shown in FIG. 4, the central portion 18 a of the cam surface 18 is formed at an inclination angle larger than the inclination angle of the other portion of the cam surface 18. This makes it easy to bite the tip of the ferrule 3 into the connection pipe P2.

  The female screw cylinder portion 14 is formed with one ice escape communicating hole 5 in the radial direction for communicating the annular space portion 16 and the ambient air around the female screw cylinder portion 14. The ice escape communication hole 5 is formed in such a state that the center side end portion thereof is half of the front end of the annular space portion 16.

  As shown in FIGS. 1, 2, 5, and 6, the coupling member 2 has a base portion 22 having a pipe through hole 21 through which the connection pipe P <b> 2 passes through the shaft center. Further, a protective cylinder portion 23 that protects the outer periphery of the ferrule 3 is formed. A male screw 22 a is formed on the outer periphery of the base portion 22 following the protective cylinder portion 23 as a screwing portion to be screwed with the joint body 1. Further, the rear portion of the base 22 is formed in a gripping portion 24 having a large outer shape so that it can be gripped by a fastening tool and having a hexagonal nut shape.

  In the coupling member 2 formed as described above, an annular ferrule 3 is formed in the protective cylinder portion 23 so as to protrude from the base portion 22 to the front side, that is, to the joint body 1 side. The hole in the axial center of the ferrule 3 is a through hole 31 that allows the connection pipe P2 to pass therethrough, and the diameter thereof is substantially the same as that of the pipe through hole 21 provided in the shaft center of the aforementioned insertion port 15a and base 22. . As can be seen from FIGS. 5 and 6, the ferrule 3 has an annular shape and is connected to the base portion 22 through the thin portion 4 extending in the radial direction at the rear end portion, and is integrally formed with the coupling member 2. Yes.

  When the ferrule 3 is viewed in an axial cross section, for example, as shown in FIG. 6, the rear portion is formed with a substantially constant thickness, and the outer peripheral surface is formed on the tapered surface 32 so that the front portion becomes thinner toward the tip. Has been. The inclination angle of the taper surface 32 is formed to be slightly smaller than the inclination angle of the cam surface 18 as described above. The rear end surface 33 of the ferrule 3 is formed so as to face the pressing surface 25 formed on the base portion 22 through a first notch that is recessed radially outward from the inner peripheral side. The first notch 34 has a pointed portion of the first notch 34, that is, an outer peripheral side portion formed in a substantially V shape, and an inner peripheral side portion of the first notch 34 has a plane whose front and rear surfaces are perpendicular to the axis. Is formed. Moreover, when it sees in more detail, the slight linear part 34a is formed in the tip part.

  On the other hand, the outer peripheral surface of the rear portion of the ferrule 3 and the front side of the thin portion 4 (that is, the front end side of the ferrule 3) are connected at a substantially right angle as seen in the axial cross section as shown in FIG. . Further, the right-angled corners are formed on the rear side of the rear end surface 33 extending from the ferrule 3 to the thin part 4 and on the front side from the cylindrical outer peripheral surface of the ferrule 3 to the plane on the front side of the thin part 4. An edge-shaped cut 41 is formed in a cross-sectional shape composed of a surface. Further, the cut portion 41 forms the thinnest wall portion 42 whose thickness is locally reduced. For this reason, when an axial force acts on the coupling member 2, stress concentration occurs in the thinnest portion 42.

  A second notch 35 is provided on the inner peripheral surface near the tip of the ferrule 3, and a third notch 36 is provided on the inner peripheral surface from the rear end side of the ferrule 3. The second notch 35 is for facilitating deformation of the tip side portion 3 a of the second notch 35. The second notch 35 is formed such that the cross-sectional shape in the axial direction is a right triangle, and the rear cut surface is perpendicular to the axial center. Further, the second notch 35 is inserted in a wedge shape between the connection pipe P2 and the insertion port 15a so that the connection pipe P2 is temporarily inserted in the stage where the coupling member 2 is manually tightened. It can be stopped. Further, the intersection of the rear notch surface and the inner peripheral surface of the second notch 35 forms an edge portion 3b, and this edge portion 3b bites into the connection pipe P2 at the tip of the ferrule 3. (See FIG. 7C).

  The third notch 36 is a trapezoid whose outer peripheral side is short and is substantially V-shaped, and is formed in the same shape as the pointed portion of the first notch 34 described above. That is, the first notch 34 has a shape in which both sides of the V-shape of the third notch 36 are formed so as to form a plane perpendicular to the axis. In addition, since the third notch 36 having a substantially V-shaped tip is formed, a thin wall is formed between the outer peripheral side of the third notch 36 (that is, the tip) and the outer peripheral surface of the rear portion of the ferrule 3. The annular thin portion 37 (see FIG. 6) is formed. By forming the third notch 36 and forming the annular thin portion 37 in this manner, the edge portion 3b on the front end side of the ferrule 3 is deformed so as to bite into the connection pipe P2, and the inner peripheral side of the rear end surface 33 The edge portion 3c forming the edge portion is deformed so as to bite into the connection pipe P2. Therefore, the entire ferrule 3 is deformed around the third notch 36 (see FIGS. 2 and 7C). As described above, in addition to the biting of the edge portion 3b at the tip, the edge portion 3c at the rear end is deformed so as to bite into the connection pipe P2. This is to prevent the transmitted vibration from being transmitted to the edge portion 3b and to maintain a high sealing function and piping holding function by the biting of the edge portion 3b at the tip.

  In the above configuration, the apparatus side pipe P1 and the connection pipe P2 are formed of copper pipes, and the joint body 1, the coupling member 2, and the ferrule 3 are formed of a brass material. These are optimal as materials for refrigeration equipment and are versatile.

Next, a pipe connection method using the bite type pipe joint configured as described above will be described with reference to FIGS. 1, 2, and 7.
Prior to connecting the connection pipe P2 to the joint body 1, the joint body 1 is attached to the apparatus-side pipe P1. This attachment operation is inserted until the tip end of the apparatus-side pipe P1 contacts the stepped portion 17, and then the brazing material is poured from the inlet side end of the insertion port 11a and brazed.

  Next, the connection pipe P2 is connected by the bite-in type pipe joint by inserting the connection pipe P2 into the pipe through hole 21 of the coupling member 2 and mounting the coupling member 2 on the connection pipe P2. And the front-end | tip part of the connection piping P2 is inserted in the insertion port 15a through the through-hole 31 of the ferrule 3, and the coupling member 2 is screwed together with the coupling main body 1 in the state which contact | abutted the front-end | tip to the step part 17. FIG. 1 shows a state in which the tip side portion 3a of the ferrule 3 is in contact with the cam surface 18 in this manner.

  When the coupling member 2 is further tightened by hand from this state, the tip side portion 3a of the ferrule 3 is pushed between the connection pipe P2 and the insertion port 15a, and the connection pipe P2 is temporarily fixed. This state is shown in FIG.

  After that, since the tapered surface 32 of the rear portion of the second notch 35 in the ferrule 3 comes into contact with the cam surface 18, a large rotational torque is required. Therefore, in the subsequent process from this stage, the coupling member 2 is fastened to the joint body 1 using a fastening tool. As in the case of the conventional example, the coupling member 2 is tightened with this tightening while the front end portion of the ferrule 3 is pressed against the cam surface 18, whereby a forward force in the axial direction acts on the thin portion 4. At this time, stress concentration occurs at the intersection of the outer peripheral surface of the ferrule 3 and the front surface of the thin portion 4, that is, the thinnest portion 42 having a cut 41 (see FIG. 7A). The thin portion 4 is cut, and the outer peripheral end of the rear end surface 33 comes into contact with the pressing surface 25 (see FIG. 7B).

  The ferrule 3 is separated from the coupling member 2 as described above, and the outer peripheral side end of the rear end surface 33 is pressed by the pressing surface 25. Moreover, the ferrule 3 acts similarly to the independent ferrule 3 thereafter. That is, the ferrule 3 is formed on an inclined surface in which the axial center side of the pressing surface 25 expands rearward when the coupling member 2 is further tightened from the state where the outer peripheral side end portion of the rear end surface 33 is pressed by the pressing surface 25. Therefore, the front and rear portions around the third notch 36 are easily bent toward the axial center. Therefore, the ferrule 3 is inclined so that the edge portion 3b bites into the connection pipe P2 around the third notch 36 at the front portion of the third notch 36, and at the rear portion of the third notch 36, the third notch 36 The edge portion 3c on the inner peripheral side of the rear end surface 33 is inclined so as to bite into the connection pipe P2 with reference to 36 (see FIG. 7C).

  Further, the ferrule 3 is deformed so that the rear portion thereof is inclined with respect to the third notch 36 as described above, and the edge portion 3c bites in, and when this biting amount becomes an appropriate value, the front surface forming the third notch 36 is The shape of the third notch 36 is set so that the rear surface is in contact with the substantially entire surface. The shape is as described above, and is substantially V-shaped as the shape of the tip of the first notch 34 as shown in an enlarged view in FIG. It is a trapezoid in which a short straight line portion is formed at the tip of each. As a result, in the ferrule 3 according to the first embodiment, after the front surface and the rear surface forming the third notch 36 abut on substantially the entire surface, the inclination around the third notch 36 is restricted, and the edge portion It is set so that excessive bite of 3c does not occur.

  Thus, when the biting of the edge portion 3b at the front end portion of the ferrule 3 and the biting of the edge portion 3c at the rear end portion of the ferrule 3 reach a predetermined amount, the rotational torque for tightening the coupling member 2 reaches a predetermined value. Thus, the fastening of the coupling member 2 is completed and the connection of the connection pipe P2 is completed (see FIG. 2).

  Next, in the pipe joint in which the connection pipe is connected to P2 in this way, processing of ice generated in the space in the pipe joint when a low-temperature fluid of zero degrees or less flows in the connection pipe P2 will be described.

  In the state where the connection of the connection pipe P <b> 2 is completed as described above, a space in which the space around the ferrule 3 and a part of the annular space 16 left at the tip of the protective cylinder 23 are combined. The part S is formed between the joint body 1 and the coupling member 2 (see, for example, FIG. 2). Note that the space S formed between the joint body 1 and the coupling member 2 in this way is, as shown in FIG. 8, even if the ice escape communication hole 5 is not formed, the female screw 14a. And the male screw 22a are external air intrusion passages R and are not airtight. For this reason, when the space S is cooled and moisture in the air in the space S is condensed, the moisture is replenished through the outside air intrusion passage R accordingly. For this reason, when the space part S is cooled below 0 degree | times, ice is produced | generated and it has set | placed on the condition where the quantity of ice increases with the passage of time.

  On the other hand, in the case of the present embodiment, the space portion S is communicated with the outside air not only by the outside air intrusion passage R but also by the ice escape communication hole 5, so that when the air in the space portion S is cooled and condensed, Water is supplied to the space S not only from the outside air intrusion passage R but also from the ice escape communication hole 5. Accordingly, when the space portion S is cooled for a long time, the volume of ice generated in the space portion increases, and the space portion S is eventually filled with ice. This can be said to be the same as before. However, in the case of the present embodiment, the space portion S is filled with ice, so that the ice bulges into the ice escape communication hole 5 so that the force due to the volume expansion of the ice does not increase.

  The ice escape communication hole 5 in the present embodiment is formed so as to communicate with the annular space portion 16 remaining at the tip of the protective cylinder 23, and the tip of the ice escape communication hole 5 is half Is formed on the base 13. Therefore, it is not necessary to provide a large space at the tip of the protective cylinder 23, and consideration is given to obtaining a compact pipe joint.

In addition, the ice escape communicating hole 5 can be used to push out the ice filling the space without any trouble, based on the knowledge obtained from the experimental results [volume of the non-hermetic space (mm ³ )] / The “hole cross-sectional area (mm ² )” is set to be 50 or less.

  In the present embodiment, since the ice escape communication hole 5 set as described above is formed in the joint body 1, the ice generated in the space S fills the ice when the space S is filled. It bulges into the escape communication hole 5. As a result, the force due to the volume expansion of ice does not increase, and a large force does not act on the shaft portion 15 on which the ferrule 3 and the cam surface 18 are formed at the tip. Therefore, in the bite type pipe joint according to this embodiment, the pipe sealing function and the pipe holding function are not deteriorated.

Since the bite type pipe joint according to the first embodiment is configured as described above, the following effects can be obtained.
(1) The non-hermetic space S formed between the joint body 1 and the coupling member 2 is filled with ice as moisture entering from outside condenses and freezes. Even so, the ice bulges out from the ice escape communication hole 5. For this reason, the force by the volume expansion of ice does not become large. Therefore, the force acting on the member related to the seal mechanism and the pipe holding mechanism such as the ferrule 3 and the shaft portion 15 that forms the cam surface 18 at the tip does not increase, and the pipe sealing function and the pipe holding function may be impaired. Absent.

  (2) The ice escape communication hole 5 is formed in the joint body 1 so as to communicate from the outer surface of the joint body 1 to the non-hermetic space S formed on the distal end side of the coupling member 2. Therefore, the ice escape communication hole 5 can be formed in the joint body 1 without being obstructed by the coupling member 2, and the ice formed in the space S is bulged through the ice escape communication hole 5. be able to.

(3) The ice escape communication hole 5 is set so that [the volume of the non-hermetic space (mm ³ )] / [hole cross-sectional area (mm ² )] is 50 or less. Therefore, even if only one ice escape communication hole 5 is formed, the ice that can be formed into the non-airtight space S between the joint body 1 and the coupling member 2 can be moved out of the space S without trouble. It can be bulged, and a pipe sealing function and a pipe holding function can be maintained.

  (4) Since the refrigeration apparatus according to the present embodiment uses the pipe joint configured as described above for the refrigerant circuit, the inside of the non-confidential space S in the pipe joint is frozen and iced. Even if it is filled, there is no risk of impairing the function of the pipe joint due to the force caused by the volume expansion of the growing ice.

  (5) The ice escape communication hole 5 is formed so as to communicate with the annular space portion 16 remaining at the distal end portion of the protective cylinder portion 23, and is formed so that half of the distal end portion covers the base portion 13. Therefore, it is not necessary to provide a large space at the tip of the protective cylinder 23, and a compact pipe joint can be obtained.

(Embodiment 2)
Next, the second embodiment will be described with reference to FIGS. The second embodiment is different from the first embodiment in that the position of the ice escape communication hole 5 is changed, and the ice escape communication hole 5 is not provided in the joint body 1. In this embodiment, the ice escape communication hole 5 is a through hole parallel to the axis of the pipe joint so as to penetrate from the side surface of the coupling member 2 on the side opposite to the joint body to the peripheral portion of the ferrule 3 of the space S. As shown in FIG. 10, two ice escape communication holes 5 are provided. As in the case where one ice escape communicating hole 5 is provided as described above, the large volume of the [volume of the non-hermetic space (mm ³ )] / [hole cross-sectional area (mm ² )] is 50 or less. Although it does not need to be an area, at least a hole larger than the hole closed by the surface tension of water is required.

  Since the pipe joint according to the second embodiment is configured as described above, the ice formed in the space can be bulged through the ice escape communication hole 5 formed in the coupling member. In the case of a structure in which a male thread is formed in the joint body 1 and the female thread of the coupling member 2 is screwed to the male thread, the ice escape communicating with the coupling member 2 as in the second embodiment. Providing holes may be effective.

  In this embodiment, since two ice escape communication holes 5 are formed, the dew condensation water stored in the space S is up to half of the space S. Therefore, the amount of ice generated is reduced.

(Embodiment 3)
Next, Embodiment 3 will be described with reference to FIGS. In the third embodiment, the pipe joint is a flared pipe joint, and an ice escape communicating hole is provided in the joint body, and the pipe joint cannot be easily loosened after the pipe connection is completed. This will be specifically described below. 11 is a partial cross-sectional view in a state immediately before completion of connection of the connection pipe, and FIG. 12 is a partial cross-sectional view in a state of completion of connection of the connection pipe. FIG. 13 is a right side view of FIG. 12 excluding the gripping portion. FIG. 14 shows a dedicated tool for loosening the screwing of the remaining portion of the coupling member after the connection of the connection pipe is completed.

  The flare type pipe joint according to the third embodiment includes a joint main body 1 attached to the connected side device of the connection pipe P2 and a coupling member 2 that is externally connected to the joint main body 1 by being connected to the connection pipe P2. .

  As shown in FIGS. 11 and 12, the joint body 1 has substantially the same configuration as that of the first embodiment, and the socket portion 11 having the insertion port 11a and the nut portion 12 are formed on the outer periphery. A base portion 13 and a female screw cylinder portion 14 having an internal thread 14 a formed on the inner peripheral surface, and a shaft portion 15 projecting from the base portion 13 into the female screw cylinder portion 14 are provided. In addition, a smaller annular space 16 is formed around the shaft portion 15 than in the case of the first embodiment. In addition, a communication hole 15b is formed in the central portion from the shaft portion 15 to the base portion 13 so that the insertion port 11a communicates with the distal end side of the shaft portion 15, and a flare receiving surface 19 is formed at the distal end of the shaft portion 15. Has been.

  On the other hand, the coupling member 2 has a tubular connecting portion 53 formed at the center by a radial disk-shaped slit 52, and a pipe connecting portion 54 is formed on the joint body side via the tubular connecting portion 53, and the anti-joint body side. A grip portion 55 is formed on the surface. The pipe connecting portion 54 is formed with a male screw 54a threadedly engaged with the female screw 14a of the joint main body 1 on the outer periphery, a pipe through hole 21 for connecting pipe penetration being formed at the center, and a joint main body of the pipe through hole 21. A tapered flare pressure contact surface 56 is formed at the side end. Further, the gripping portion 55 has a nut-shaped hexagonal shape so that it can be gripped by a general tool when the coupling member 2 is screwed to the joint body 1. The tubular connecting portion 53 is cut when the rotational torque for tightening the grip portion 55 reaches a predetermined value immediately before the coupling member 2 is completely tightened to complete the coupling member 2 and complete the connection of the connection pipe P2. Is configured to do.

  An engagement hole 57 for engaging the engagement protrusion 61 of the dedicated tool 60 is formed on the side surface of the pipe connection portion 54 on the side opposite to the joint body. Six engagement hole portions 57 are formed at an equal pitch on a predetermined circumference. In order to form the engagement hole portion 57, the gripping portion 55 is formed with a processing hole 58 at a position corresponding to the engagement hole portion 57.

The pipe joint formed as described above is connected to the connection pipe as follows.
First, as in the case of the first embodiment, the joint body 1 is attached to the apparatus-side pipe P1. And then. The connecting pipe P2 is inserted into the pipe through-hole 21 of the connecting member 2, and the connecting member 2 is externally attached to the connecting pipe P2. Next, the tip of the connection pipe P2 is flared to form a flare portion 59. Then, the coupling member 2 is tightened while pressing the flare portion 59 against the flare receiving surface 19. At this time, the coupling member 2 is fastened while holding the outer surface of the grip portion 55 with a general tool. Thus, when the state just before the completion of the fastening of the coupling member 2 is reached, the flare portion 59 is pressed against the flare receiving surface 19 by the flare pressure contact surface 56 as shown in FIG. Further, when the gripping portion 55 is further gripped and the coupling member 2 is tightened, the rotational torque is increased to a predetermined level, whereby the tubular connecting portion 53 is cut and the gripping portion 55 is separated from the pipe connection portion 54. In this way, the connection of the connection pipe P2 is completed.

  In addition, when the connection of the connection pipe P2 is removed and the pipe is started again after the pipe connection is made in this way, a general manufacturer cannot use a general tool, so a specialized manufacturer who owns a special tool will undertake this. A dedicated tool 60 as a special tool used in this embodiment has a handle 63 attached to a semi-cylindrical base 62 as shown in FIG. The inner peripheral radius of the semicircular hole 64 of the base portion 62 is slightly larger than the connection pipe P2. Further, four columnar engaging projections 61 that can be engaged with any four of the six engaging hole portions 57 are formed on the side surface of the base portion 62 as engaging portions.

  The pipe connection portion 54 of the coupling member 2 screwed into the joint body 1 engages the engagement protrusion 61 of the dedicated tool 60 with the engagement hole 57 on the side surface, and the handle 63 of the dedicated tool 60. When the base portion 62 is rotated by applying a force to the joint member 2, the remaining portion of the coupling member 2 can be loosened. Therefore, it is possible to remove the connection pipe P2 that has been connected with the joint body 1 left, and to connect the connection pipe P2 again to the joint body 1 using the new coupling member 2.

  Next, in the pipe joint to which the connection pipe is connected in this way, the processing of ice generated in the space in the pipe joint when a low-temperature fluid of zero degrees or less flows in the connection pipe P2 will be described.

  In the state where the connection of the connection pipe P2 is completed as described above, for example, as shown in FIG. 12, the space portion S formed between the joint body 1 and the coupling member 2 is a space portion at the tip of the flare portion 59. And the portion of the annular space portion 16 on the outer periphery of the shaft portion 15 are formed in combination. The space S formed between the joint body 1 and the coupling member 2 in this way can enter the outside air into the threaded portion between the female screw 14a and the male screw 54a, as in the first embodiment. It has become. In the case of the present embodiment, the space portion S is formed by integrating a part of the annular space portion 16 at the tip of the pipe connecting portion 54. The ice escape communication hole 5 communicates with the outside air. Therefore, the air in the space S is cooled and condensed. When the moisture in the air in the space S decreases, the water is replenished to the space S in balance with the outside air. Moreover, when the space part S is cooled for a long time, the quantity of the water produced | generated in the space part S will increase, and the volume of ice will increase. However, in the case of the present embodiment, the ice is swelled into the ice escape communication hole 5 so that the force due to the volume expansion of the ice does not increase even if the space S is filled with ice.

  In addition, the ice escape communication hole 5 is based on the knowledge obtained from the experimental results in order to be able to push out the ice filling the space S without hindrance [volume of the non-hermetic space (mm3)]. / [Hole cross-sectional area (mm2)] is set to be 50 or less.

  In the present embodiment, since the ice escape communication hole 5 set as described above is formed in the joint body 1, the ice generated in the space S fills the ice when the space S is filled. It bulges into the escape communication hole 5. As a result, the force due to the volume expansion of ice does not increase, and the flare portion 59 and the flare receiving surface 19 do not act on the shaft portion 15 formed at the tip. Therefore, in the bite type pipe joint according to this embodiment, the pipe sealing function and the pipe holding function are not deteriorated.

Since the bite type pipe joint according to Embodiment 3 is configured as described above, the following effects can be achieved.
(1) Even if ice grows in the non-hermetic space S formed between the joint body 1 and the coupling member 2, the ice is swelled from the ice escape communication hole 5. For this reason, the force by the volume expansion of ice does not become large. Accordingly, the force acting on the seal mechanism such as the flare portion 59 and the shaft portion 15 that forms the flare receiving surface 19 at the tip and the member related to the pipe holding mechanism is not increased, and the pipe sealing function and the pipe holding function are impaired. There is no fear.

  (2) Since the ice escape communicating hole 5 communicating with the outside air is formed in the space portion S where the accumulation and expansion force of the ice that presses the tip of the flare 59 is generated, It is possible to escape through the communication hole 5.

(3) In addition, the same effects as the effects (3) and (4) in the first embodiment can be obtained.
(Embodiment 4)
Next, the fourth embodiment will be described with reference to FIGS. 15 and 16. The fourth embodiment is an example in which an ice escape communicating hole is provided in a coupling member in a flared pipe joint having a different structure. 15 is a partial cross-sectional view in a state before the flare nut is fastened, and FIG. 16 is a partial cross-sectional view of a main part in a state in which the fastening is completed. In addition, the same code | symbol is attached | subjected to the same component as Embodiment 3, and the description is abbreviate | omitted or simplified.

  The flare type pipe joint according to the fourth embodiment includes a joint main body 1 attached to the connected side device of the connection pipe P2, and a coupling member 2 that is externally connected to the joint main body 1 by being connected to the connection pipe P2. .

  As shown in FIGS. 15 and 16, the joint body 1 includes a socket portion 11 having an insertion port 11 a and a base portion 13 having a nut portion 12 formed on the outer periphery, as in the third embodiment. And the axial part 15 by which the external thread 15c was formed in the outer periphery is protruded in the coupling member side of the base part 13. As shown in FIG. In this embodiment, the female screw cylinder as in the third embodiment is not formed. Further, a flare receiving surface 19 is formed at the tip of the shaft portion 15 as in the case of the third embodiment. The shaft portion 15 is provided with an insertion port 11a at the shaft center portion. A communication hole 15b is formed to communicate with the tip.

  As shown in FIG. 15, the coupling member 2 has a cap nut shape including a base portion 71 formed of a substantially tapered wall body and a female screw cylinder portion 72 formed at the front portion of the base portion 71. A pipe through hole 21 through which the connection pipe P <b> 2 passes is formed at the center of the base 71, and a flare pressure contact surface 56 is formed on the front side of the base 71. Further, the outer periphery of the female screw cylindrical portion 72 has a hexagonal nut-like outer shape, and a female screw 72a that is screwed into the male screw 15c of the joint body 1 is formed on the inner peripheral surface. Further, an ice escape communication hole 5 is formed immediately before the flare pressure contact surface 56 of the female screw cylinder 72.

The pipe joint configured in this manner is connected to a connection pipe as in the case of the third embodiment.
That is, the joint body 1 is attached to the apparatus-side pipe P1, the coupling member 2 is sheathed on the connection pipe P2, and a flare portion 59 at the tip of the connection pipe P2 is formed. Then, when the coupling member 2 is tightened while pressing the flare 59 against the flare receiving surface 19 and a predetermined rotational torque is reached, the fastening of the coupling member 2 is completed as shown in FIG. 16, and the pipe connection of the connection pipe P2 is completed. Is completed.

  In the case of this embodiment, the coupling member 2 is tightened and relaxed by being held by a general tool in the same manner as the conventional one. Therefore, the work for redoing the piping has no place in place of the conventional one, and the coupling member 2 may be loosened.

  Further, in this embodiment, the processing of ice generated in the space in the pipe joint when a low-temperature fluid of zero degrees or less flows in the connection pipe P2 is substantially the same as in the case of the third embodiment. is there. That is, the space portion S (see FIG. 16) formed between the joint body 1 and the coupling member 2 is formed on the tip side of the flare portion 59. The space portion S includes the ice escape communication hole 5 and the male screw. It is in a state of communication with the outside air mainly through the ice escape communication hole 5 through the screwed portion between the 15c and the female screw 72a. Accordingly, when the space S is cooled, moisture in the air is condensed and liquefied, and accordingly, moisture is replenished from the outside air. Further, when the liquefied water is frozen and the space S is filled with ice, the ice grows so as to swell out of the ice escape communication hole 5, so that the force due to the volume expansion of ice increases. There is nothing. Therefore, even in the bite type pipe joint according to this embodiment, the pipe sealing function and the pipe holding function are not deteriorated.

  Since the present embodiment is formed as described above, the same effects as (1) and (2) in the third embodiment and (3) and (4) in the first embodiment can be achieved. . In the case of this embodiment, since the non-hermetic space S formed on the front end side of the flare portion 59 is formed on the coupling member 2 so as to communicate with the outer surface of the coupling member 2. The ice that expands in volume is easily released through the ice escape communication hole 5. In particular, in the case of the structure as in the present embodiment in which the coupling member 2 is fastened so as to cover the threaded portion of the joint body 1, there is an effect that the coupling member 2 can easily communicate with the outside. .

(Modification)
(1) In the first embodiment, as shown in FIG. 17, the ice escape communication hole may be formed on the flat surface portion instead of the apex portion of the internal thread cylinder portion 14 forming a hexagonal nut shape. Further, as shown in FIGS. 18 and 19, the hole may be inclined instead of the hole toward the axis. FIGS. 17 and 18 are drawings corresponding to FIG. 4 and show the differences in the ice escape communication holes 5.

  (2) Further, as in the modification shown in FIGS. 18 and 19, it is preferable that the number of ice escape communication holes 5 be arranged uniformly on a predetermined circumference. This number is two in FIGS. 18 and 19, but it may be larger. As described above, when the ice escape communication holes 5 are distributed and arranged at equal intervals on the predetermined circumference, the moisture condensed and liquefied in the space S passes through at least one ice escape communication hole 5 into the space. An amount up to half of the part S is discharged. Therefore, since the air portion is formed in the space portion S, the force due to the volume expansion of ice does not increase, and the force that causes the force due to the volume expansion of ice to act on each portion can be reduced.

  (3) The position of the ice escape communication hole 5 in the fourth embodiment may be formed in the tapered wall portion of the coupling member 2 as shown in FIG. Thus, the position of the ice escape communication hole 5 may be changed within a range not impairing the function of the pipe joint.

  (4) In the third embodiment, if the engagement hole 57 is changed to a hole that penetrates the threaded portion, the through hole becomes parallel to the axis as in the second embodiment, and the outside and the space S are communicated. It is also possible to substitute the penetrating hole for the ice escape communicating hole 5.

  (5) In the bite type pipe joint of Embodiments 1 and 2, the ferrule 3 may be formed separately from the coupling member as shown in FIG. In this case, the ferrule 3 may be composed of one member, or may be composed of a plurality of members as shown in FIG.

  (6) Further, in the case where the ferrule is formed separately from the joint body and the coupling member and is composed of one member, the stage of the parts before assembling the ferrule formed separately Then, it may be temporarily fixed to the coupling member and integrated. This example will be specifically described below with reference to the drawings.

  FIG. 21 is a state diagram at the start of tightening of the bite type pipe joint according to this modification. FIG. 22 is a state diagram in which the ferrule is temporarily held on the coupling member in the bite type pipe joint. FIG. 6 is a state diagram when the pipe connection of the bite type pipe joint is completed. Note that, in these drawings, portions common to the first embodiment are denoted by common reference numerals, and description thereof is omitted or simplified.

As shown in FIG. 21, the bite type pipe joint includes a joint body 1, a coupling member 2, and a ferrule 3.
The joint body 1 is formed so that the axial dimension of the annular space portion 16 is shortened because the protective cylinder portion 23 as in the first embodiment is not formed on the coupling member 2.

  As shown in FIG. 22, the ferrule 3 is not integrally formed in the coupling member 2. Further, the coupling member 2 is formed in a hexagonal nut shape so that the base portion 22 in the first embodiment can be gripped by a fastening tool and a portion provided with a male screw 22a that is screwed to the joint body 1 on the outer periphery. The grip portion 24 is divided into two, and both are connected via a tubular connecting portion 26. This tubular connecting portion 26 is cut when the pipe connection is completed, similarly to the tubular connecting portion 53 in the third embodiment. Further, as in the third embodiment, the coupling member 2 is a dedicated tool (not shown) so that the portion provided with the male screw 22a screwed into the joint body 1 of the base portion 22 can be loosened after the pipe connection is completed. Four engagement hole portions 27 for inserting the cylindrical engagement protrusions are formed at equal intervals on the same circumference. Further, in order to make it possible to process the engagement hole portion 27 from the side surface of the grip portion 24, four processing holes 28 are formed at positions corresponding to the engagement hole portion 27 in the grip portion 24. The dedicated tool that can be used in this modified example is not described with reference to the drawings, but is similar to the dedicated tool 60 in the third embodiment described above, and the number of cylindrical engagement protrusions is four. In addition to the number, the dimensions of each part may be appropriately changed.

  The coupling member 2 is formed with a temporary holding mechanism for temporarily holding the ferrule 3 before assembling. As a temporary holding mechanism formed on the coupling member side, a large-diameter portion 29a is formed in front of the pressing surface 25, and further, a radially inward annular protrusion 29b is formed in front of the pressing surface 25.

  The ferrule 3 is provided with a temporary holding mechanism at the rear end, but the front thereof is basically the same as that of the first embodiment. As a temporary holding mechanism for the ferrule 3, a radially outwardly protruding annular protrusion 38 is formed at the rear end portion of the ferrule 3. The protrusion 38 has an outer diameter slightly larger than the inner diameter of the protrusion 29b of the coupling member 2 described above, is formed smaller than the inner diameter of the large diameter section 29a, and further has a dimension in the axial direction of the large diameter section 29a. Is formed smaller than the axial dimension of the large diameter portion 29a.

  The ferrule 3 configured in this manner presses the projecting portion 38 at the rear end against the projecting portion 29b of the coupling member 2, so that the projecting portion 38 is press-fitted into the large-diameter portion 29a as shown in FIG. As long as it is not pulled strongly, the protrusion 38 is held in the large-diameter portion 29 a and the ferrule 3 is temporarily held by the coupling member 2.

  The coupling member 2 on which the ferrule 3 is temporarily held is sheathed on the connection pipe P2 while the ferrule 3 is temporarily held, and the coupling member 2 is tightened by hand-turning so that the tip of the ferrule 3 contacts the cam surface 18. When this is in a fastening start state, the coupling member 2 is continuously tightened by hand at first, and the distal end side portion 3a is pushed between the connection pipe P2 and the insertion port 15a as described above. Stop is done. Moreover, it fastens similarly to the case of Embodiment 1 by fastening the coupling member 2 using a fastening tool after that (refer FIG. 23). In this modification, the ice escape communication hole 5 operates in the same manner as in the first embodiment.

  (7) In each embodiment, the joint main body 1 is attached by being brazed to the pipe P1 on the connected device side, but a male screw for pipe is formed in the socket portion 11 and screwed into the device on the connected device side. May be attached. Moreover, when using for connection of piping, you may make it attach to one piping.

  The pipe joint according to the present invention is used as a pipe joint such as a flare-type pipe joint or a bite-type pipe joint. These pipe joints are used for pipe joints of refrigerant pipes that use copper pipes in refrigeration apparatuses such as air conditioners and heat pump hot water supply apparatuses.

It is a fragmentary sectional view of the bite type pipe joint which concerns on Embodiment 1 of this invention, Comprising: The state which the ferrule contact | abutted to the cam surface after the fastening start is shown. It is a fragmentary sectional view of the same bite type pipe joint, Comprising: The state of fastening completion is shown. It is a fragmentary sectional view of the joint main part in the bite type pipe joint. FIG. 4 is a right side view in FIG. 3 relating to a joint body in the bite type pipe joint. It is a fragmentary sectional view of the connecting member in the bite type pipe joint. It is an expanded sectional view around the ferrule in the bite type pipe joint. It is a pipe connection process figure around a ferrule in the same bite type pipe joint, (a) is a state figure where piping was temporarily fixed by the tip side end part of a ferrule, and (b) after a ferrule was separated (C) is a state diagram of completion of fastening. It is a reference example figure concerning the embodiment. It is a fragmentary sectional view of the bite type pipe joint which concerns on Embodiment 2, Comprising: The state of fastening completion is shown. It is the side view seen from the anti-joint body side of the bite type pipe joint. It is a fragmentary sectional view of the flare type pipe joint concerning Embodiment 3 of the present invention, and shows the state just before completion of conclusion. It is a fragmentary sectional view of the flare type pipe joint, Comprising: The state of fastening completion is shown. It is a right view of the screwing state part in the state of fastening completion of the flare type pipe joint. It is an external appearance perspective view of the exclusive jig | tool used for the same embodiment. It is a fragmentary sectional view of the flare type pipe joint concerning Embodiment 4 of the present invention, and shows the state before fastening. It is a fragmentary sectional view of the same bite type pipe joint, Comprising: The state of fastening completion is shown. FIG. 6 is a right side view of the same bite type pipe joint according to a modification of the first embodiment. FIG. 10 is a right side view of the bite type pipe joint according to another modification of the first embodiment. It is a fragmentary sectional view of the joint main part in the modification. FIG. 10 is a partial cross-sectional view of a bite type pipe joint according to a modification of the fourth embodiment. It is a fragmentary sectional view of the bite type pipe joint concerning modification (6), and is a state figure at the time of a fastening start. In the same bite type pipe joint, it is a state diagram in which a ferrule is temporarily held by a coupling member. It is a fragmentary sectional view of the bite type pipe joint, and is a state diagram at the time of completion of fastening. It is a fragmentary sectional view of the bite type pipe joint concerning a conventional example, and shows the state of completion of fastening. It is a fragmentary sectional view of the flare type pipe joint concerning other conventional examples, and shows the state of conclusion completion. It is a fragmentary sectional view of the flare type pipe joint, Comprising: It is a frozen state explanatory view of internal space.

Explanation of symbols

  S: space part, P2: connection pipe, 1 ... joint body, 2 ... coupling member, 5 ... communication hole for ice escape, 3 ... ferrule, 59 ... flare part.

Claims (8)

A pipe joint comprising a joint body and a coupling member that is externally connected to the connection pipe to be connected and joined to the joint body,
The joint body or the coupling member is provided with an ice escape communicating hole that communicates a non-hermetic space formed between the joint body and the coupling member by connection between the joint body and the coupling member. Pipe fittings.   The pipe joint is a bite type pipe joint, and the ice escape communication hole is connected to the non-airtight space formed on the distal end side of the coupling member from the outer surface of the joint body. The pipe joint according to claim 1, wherein the pipe joint is formed on the main body.   The pipe joint is a bite-type pipe joint, and the ice escape communicating hole is formed in the coupling member so as to communicate from the outer surface of the coupling member to a non-airtight space formed around the ferrule. The pipe joint according to claim 1, wherein the pipe joint is provided.   The pipe joint is a flare-type pipe joint, and the ice escape communication hole is connected to the non-airtight space formed at the front end side of the flare part so as to communicate from the outer surface of the joint body. The pipe joint according to claim 1, wherein the pipe joint is formed on the main body.   The pipe joint is a flare-type pipe joint, and the ice escape communication hole is coupled so as to communicate from the outer surface of the coupling member to a non-hermetic space formed on the tip side of the flare section. The pipe joint according to claim 1, wherein the pipe joint is formed on a member. The ice escape communicating hole is set so that [volume of non-hermetic space (mm ³ )] / [hole cross-sectional area (mm ² )] is 50 or less. The pipe joint according to any one of?   The ice escape communication hole is formed of a plurality of communication holes having a cross-sectional area that is at least larger than a cross-sectional area that may be blocked by the surface tension of water, and the plurality of ice escape holes. The communication hole according to any one of claims 1 to 6, wherein the communication hole is formed at a position equally divided in a circumferential direction.   A refrigeration apparatus using the bite type pipe joint according to any one of claims 1 to 7 in a refrigerant circuit.

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