JP2007218301A - Pipe joint, refrigerating device, heat pump type water heater and water supply pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe joint capable of preventing missing of a sleeve, and capable of securing sealing performance of a joining part while improving work efficiency in connection of a pipe, and a refrigerating device with the usage of the pipe joint. <P>SOLUTION: The sleeve 15 is integrally formed with respect to a nut 14 before joining of the pipe, and is cut and separated from the nut 14 by screwing of the nut 14 to a joint body. An outer peripheral surface 15g of the sleeve 15 is formed on an axial side compared to an extended surface P of the abutting surface 15c, and a rear end surface 15e to which pressing force from an inner side surface 14c is applied is formed on an inner peripheral side near an axis. Thereby, rotational torque by frictional force generated between the rear end surface 15e and the inner side surface 14c in biting of the sleeve 15 to a pipe is reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pipe joint for joining refrigerant pipes and the like, a refrigeration apparatus using the pipe joint, and the like.

  Conventionally, as a pipe joint used for joining a pipe that circulates fluid inside the refrigerant pipe of a refrigeration system, the pipe is joined to the joint hole of the joint body by inserting the pipe into the joint hole of the joint body and screwing the nut. Pipe fittings designed to do this are known. As such a pipe joint, as disclosed in Patent Document 1, when a nut is screwed into the joint body, a sleeve is interposed between the joint body and the nut, and the sleeve is bitten into the outer periphery of the pipe by screwing, so that the pipe and the joint Many so-called bite-in joints that join the main body to ensure the sealing performance of the joint are employed.

FIG. 9 shows the bite joint shown in Patent Document 1. This bite joint is composed of a joint body 101, a nut 102, and a sleeve 103 provided between the joint body 101 and the nut 102. When joining the pipe 104 to the joint body 101, the sleeve 103 is attached to the outer peripheral surface 104 a of the pipe 104, the tip 104 b of the pipe 104 is inserted into the joint hole 101 a of the joint body 101, and the threaded part 101 b of the joint body 101. Then, the threaded portion 102a of the nut 102 is screwed. Then, the rear end surface 103 a of the sleeve 103 receives a pressing force from the pressing surface 102 b of the nut 102, and the front end portion 103 b receives a pressing force from the tapered surface 101 c of the joint body 101. Therefore, the front end portion 103 b of the sleeve 103 bites into the outer peripheral surface 104 a of the pipe 104, and the pipe 104 is joined to the joint hole 101 a of the joint body 101. In this way, the bite joint is configured to join the pipe 104 and the joint main body 101 by biting the sleeve 103 into the pipe 104 to ensure the sealing performance of the joint portion.
Japanese Patent Laid-Open No. 2003-74768

  By the way, such a pipe joint is constituted by a joint body, a nut, and a sleeve, and thus there is a risk that the sleeve, which is a relatively small part, is lost before the pipes are joined. In addition, since a sleeve, which is a small component, is assembled when joining pipes, there is a problem that workability is poor. Also, since the sleeve is exposed to the portion that receives the pressing force and the portion that bites into the piping, when the sleeve is held as a spare part or when the sleeve is handled, the portion is easily damaged, There was a risk of adversely affecting the sealing performance of the joint.

  The present invention has been made in view of such circumstances, and the object thereof is to prevent the loss of the sleeve and to improve the workability at the time of connecting the pipe while ensuring the sealing performance of the joint portion. The object is to provide a pipe joint, a refrigeration apparatus using the pipe joint, and the like.

  The pipe joint according to the present invention includes a joint body in which a joint hole for joining pipes is formed on the inner periphery and a screw part is formed on the outer periphery, a nut screwed into the screw part, and the joint of the nut Before being screwed into the main body, the nut is provided integrally with the nut, and the nut is cut from the nut by screwing the nut into the joint body in a state where a pipe is inserted into the joint hole, and the nut A sleeve that receives the pressing force of the nut by screwing in, and bites into the outer periphery of the pipe, and when the sleeve bites into the pipe, the rotational torque due to the frictional force generated in the biting portion of the sleeve is caused by the pressing force. It is characterized by being made larger than the rotational torque by the frictional force generated between the sleeve and the nut.

  According to this configuration, the sleeve that bites into the outer periphery of the pipe by screwing the nut into the joint body is provided integrally with the nut before the nut is screwed into the joint body. For this reason, it is possible to prevent the sleeve from being lost until the pipes are joined, compared to the case where the sleeve is configured separately from the nut as in the prior art. There is no need to keep it as. Moreover, since it is not necessary to attach a sleeve when joining piping, workability | operativity at the time of connection of piping improves. Further, since the sleeve is provided integrally with the nut, it can be configured to prevent the sleeve biting portion from being exposed to the surface, and the biting portion or the like may be damaged when handling parts. Can be difficult. And since the sleeve is cut from the nut by screwing the nut into the joint body, the separated sleeve bites into the outer periphery of the pipe and joins the pipe to the joint hole of the joint body while ensuring the sealing performance of the joint. Can do.

  In addition, after the sleeve is cut from the nut by screwing in the nut, and when the sleeve bites into the outer periphery of the pipe by screwing in the nut, if the sleeve rotates together with the pressing force of the nut, the sleeve bite in The part may damage the piping and the joint body, which may reduce the sealing performance of the joint. For this reason, when the sleeve bites into the outer periphery of the pipe, it is necessary to slide the sleeve so that it does not rotate even if it receives the pressing force of the nut.

  In this respect, according to the same configuration, when the sleeve bites into the pipe, the rotational torque due to the frictional force generated at the biting portion of the sleeve is the rotational torque due to the frictional force generated between the sleeve and the nut due to the pressing force of the nut. To be bigger than. For this reason, when the nut is screwed and the sleeve is bitten into the pipe, the biting portion of the sleeve can be prevented from rotating, and the sleeve and the nut can be slid. Thereby, it can suppress that a piping and a coupling main body are damaged, and can ensure the sealing performance of a junction part. Also, when the sleeve bites into the pipe, it can be prevented that the biting portion of the sleeve rotates while contacting the outer periphery of the pipe, so that the tightening torque when screwing the nut can be reduced. The workability at the time of connection of can be improved.

  Further, the friction coefficient at the biting portion of the sleeve may be larger than the friction coefficient between the sleeve and the nut at the place where the pressing force is received. According to this configuration, since the friction coefficient at the biting portion of the sleeve is larger than the friction coefficient between the sleeve and the nut at the location where the pressing force of the nut is received, the rotational torque due to the frictional force generated at the biting portion of the sleeve is increased. Further, it is easy to configure so as to be larger than the rotational torque due to the frictional force generated between the sleeve and the nut due to the pressing force of the nut. For this reason, when the sleeve bites into the pipe, the sleeve biting portion can be prevented from rotating, and the sleeve and the nut can be easily slid.

  Further, the radius from the axial center of the biting portion of the sleeve may be larger than the radius from the axial center of the portion receiving the pressing force. According to this configuration, since the radius from the shaft center of the biting portion of the sleeve is larger than the radius from the shaft center of the location where the pressing force of the nut is received, the rotational torque due to the frictional force generated at the biting portion of the sleeve is It becomes easy to constitute so that it may become larger than the rotational torque by the frictional force which generate | occur | produces between a sleeve and a nut with the pressing force of a nut. For this reason, when the sleeve bites into the pipe, the sleeve biting portion can be prevented from rotating, and the sleeve and the nut can be easily slid.

  Further, the sleeve may be provided with the biting portion at a tip on one end side in the axial direction and a portion for receiving the pressing force on an end surface on the other end side. According to this configuration, the sleeve is provided with a biting portion at the tip on the one end side in the axial direction, and is provided with a portion for receiving the pressing force of the nut on the end surface on the other end side, so that the sleeve receives the pressing force with the biting portion. The distance from the location can be increased. For this reason, the amount of deformation by which the biting portion deforms toward the outer periphery of the pipe can be increased, the amount of biting into the pipe can be increased, and the sealing performance of the joint portion can be ensured.

  The sleeve has a conical contact surface on the outer periphery on the one end side that guides the biting portion into the pipe by contacting the joint main body, and has an outer diameter toward the other end side. The outer peripheral surface on the other end side may be formed closer to the axial center side than the extended surface of the contact surface.

  According to this configuration, the conical abutment surface that abuts on the joint body and guides the biting portion into the pipe so that the outer diameter increases from one end side to the other end side in the axial direction. When the outer peripheral surface of the other end side is formed on the axial center side with respect to the extended surface of the contact surface, the end surface on the other end side that receives the pressing force of the nut is formed on the inner peripheral side. Can do. For this reason, the radius from the axial center of the location which receives pressing force can be made small, and the rotational torque by the frictional force which generate | occur | produces between a sleeve and a nut by pressing force can be made small reliably. Thereby, when the sleeve bites into the pipe, it is possible to prevent the pipe and the joint body from being damaged, and to ensure the sealing performance of the joint portion.

  Further, the outer peripheral surface on the other end side is a conical surface, and the inclination angle of the conical surface with respect to the axial direction may be smaller than the inclination angle of the contact surface with respect to the axial direction. According to this configuration, the outer peripheral surface on the other end side is a conical surface, and the inclination angle of the conical surface with respect to the axial center direction is smaller than the inclination angle of the contact surface with respect to the axial center direction, so that the nut is pressed. The end surface on the other end side can be formed on the inner peripheral side. For this reason, the radius from the axial center of the location which receives pressing force can be made small, and the rotational torque by the frictional force which generate | occur | produces between a sleeve and a nut by pressing force can be made small reliably. Thereby, when the sleeve bites into the pipe, it is possible to prevent the pipe and the joint body from being damaged, and to ensure the sealing performance of the joint portion.

  The outer peripheral surface on the other end side may be a cylindrical surface. According to this configuration, since the outer peripheral surface on the other end side is a cylindrical surface, the end surface on the other end side that receives the pressing force of the nut can be formed on the inner peripheral side. For this reason, the radius from the axial center of the location which receives pressing force can be made smaller, and the rotational torque by the frictional force which generate | occur | produces between a sleeve and a nut by pressing force can be made smaller. Thereby, when the sleeve bites into the pipe, it is possible to prevent the pipe and the joint main body from being damaged, and to further ensure the sealing performance of the joint portion.

  The outer peripheral surface on the other end side may be a conical surface, and the conical surface may be formed so that the outer diameter increases toward the one end side. According to this configuration, the outer peripheral surface on the other end side is a conical surface, and this conical surface is formed so that the outer diameter increases toward the one end side, so that the end surface on the other end side that receives the pressing force of the nut Can be further formed on the inner peripheral side. For this reason, the radius from the axial center of the location that receives the pressing force can be further reduced, and the rotational torque due to the frictional force generated between the sleeve and the nut by the pressing force can be further reduced. Thereby, when the sleeve bites into the pipe, it is possible to prevent the pipe and the joint main body from being damaged, and to further ensure the sealing performance of the joint portion.

  Moreover, you may make it the outer peripheral surface of the said sleeve interpose at least 1 conical surface or a cylindrical surface between the outer peripheral surface of the said other end side, and the said contact surface. According to this configuration, since the outer peripheral surface of the sleeve has at least one conical surface or cylindrical surface interposed between the outer peripheral surface on the other end side and the contact surface, the outer peripheral surface of the sleeve is configured by a plurality of surfaces. The For this reason, in order to form the end surface of the other end side on the inner peripheral side, the outer peripheral surface of the sleeve can be formed in various modes in consideration of manufacturing convenience and the like.

  Further, the sleeve may bite into the outer periphery of the pipe by the contact surface contacting a conical guide surface formed on the joint body. According to this configuration, since the sleeve abuts the conical guide surface formed on the joint body so that the sleeve bites into the outer periphery of the pipe, the sleeve moves toward the outer periphery of the pipe as the nut moves in the screwing direction. It can comprise so that it may deform | transform gradually. For this reason, it can suppress that the tightening torque of a nut becomes excessive and it can be made to fasten a nut reliably and can make a sleeve bite into the outer periphery of piping reliably.

  Moreover, you may make it connect the piping through which the supercritical refrigerant | coolant used in a supercritical state distribute | circulates to a pipe joint. According to this configuration, even when the supercritical refrigerant used in the supercritical state flows in the pipe and a high pressure is applied to the joint between the pipe joint and the pipe, the pipe joint described above is in the joint with the pipe. Since the sealing property is ensured, the leakage of the refrigerant at the joint can be suitably suppressed.

  Moreover, you may make it connect the piping which a carbon dioxide refrigerant distribute | circulates to a pipe joint. According to this configuration, since the fluid flowing in the connected piping is a carbon dioxide refrigerant, the piping circuit using the above-described pipe joint can be configured in consideration of the global environment. In addition, even when carbon dioxide refrigerant is used in a supercritical state and high pressure is applied to the joint between the pipe joint and the pipe, the above pipe joint ensures the sealing performance at the joint with the pipe. Further, it is possible to suitably suppress the leakage of the refrigerant at the joint.

  Further, a pipe through which a hydrocarbon refrigerant flows may be connected to the pipe joint. According to this configuration, since the fluid flowing in the connected pipe is a hydrocarbon refrigerant such as propane or isobutane, the pipe circuit using the pipe joint can be configured in consideration of the global environment. Moreover, since said pipe joint is ensuring the sealing performance in a junction part with piping, it can suppress suitably that a hydrocarbon refrigerant with strong flammability leaks from a junction part.

  Moreover, the refrigeration apparatus according to the present invention is characterized in that the above-described pipe joint is used for a connection portion of a refrigerant pipe. According to this configuration, since the refrigeration apparatus uses the above-described pipe joint at the connection portion of the refrigerant pipe, the loss of the sleeve is prevented, and the workability at the time of pipe connection is improved, and the seal of the joint portion is provided. Thus, the refrigeration apparatus can be secured.

  Moreover, the heat pump type water heater according to the present invention is characterized in that the above-described pipe joint is used as a connection part of the refrigerant pipe. According to the same configuration, since the heat pump type hot water heater uses the above-described pipe joint at the connection portion of the refrigerant pipe, the loss of the sleeve is prevented, and the workability at the time of connecting the pipe is improved. It can be set as the heat pump type water heater which ensured the sealing performance.

  The water supply pipe according to the present invention is characterized in that the above-described pipe joint is used as a pipe connection part. According to this configuration, since the water supply pipe uses the above-mentioned pipe joint at the pipe connection part, the loss of the sleeve is prevented, the workability at the time of pipe connection is improved, and the sealing performance of the joint part The water supply pipe can be secured.

  According to the pipe joint according to the present invention, before the nut is screwed into the joint body, the sleeve is provided integrally with the nut, and the sleeve is cut from the nut by screwing the nut. Loss of the sleeve before connection can be prevented and workability at the time of pipe connection can be improved. In addition, when the nut is screwed in and the sleeve is bitten into the pipe, the sleeve bite is configured not to rotate, so that the pipe and the joint body are prevented from being damaged, and the sealing performance of the joint is ensured. Can do.

Hereinafter, with reference to FIGS. 1-5, one Embodiment of the pipe joint which actualized this invention is described.
FIG. 1 is a partial cross-sectional view showing a configuration of a pipe joint. The pipe joint 1 connects the pipes 11 and 12, a joint main body 13 into which the pipes 11 and 12 are inserted, a nut 14 that is screwed into the joint main body 13, and the joint main body 13 and the nut when the pipe is joined. 14 and a sleeve 15 interposed between them. The pipe 11 is fixed to the socket part 13a provided on one end side of the joint body 13 by brazing or the like, and the distal end part 12a of the pipe 12 joined to the joint body 13 is joined to the joint hole 13b provided on the other end side. Has been inserted. The pipe 12 inserted into the joint body 13 is joined to the joint body 13 by the front end 15a of the sleeve 15 biting into the outer peripheral surface 12b of the pipe 12 by screwing the nut 14 into the joint body 13. O represents the axes of the pipes 11 and 12, the joint body 13, the nut 14, and the sleeve 15.

  Here, the sleeve 15 that bites into the pipe 12 is formed integrally with the nut 14 through the connecting portion 15b before the nut 14 is screwed into the joint body 13, and the pipe 12 is inserted into the joint hole 13b. The nut 14 is cut and separated from the nut 14 by screwing the nut 14 into the joint body 13 in the state. Hereinafter, the detail of the pipe joint 1 comprised in this way is demonstrated.

  FIG. 2 is a partial cross-sectional view of the joint body 13. The joint body 13 includes a socket portion 13 a to which the pipe 11 is fixed, a joint hole 13 b into which the pipe 12 is inserted, a male screw portion 13 c into which the nut 14 is screwed, and a sleeve 15 when the sleeve 15 bites into the pipe 12. 13d and the nut part 13e formed in the outer periphery.

  The socket portion 13a is formed in a columnar shape and has an inner diameter that is substantially equal to the outer diameter of the pipe 11 to be fixed. The joint hole 13b is formed in a columnar shape, and has an inner diameter substantially equal to the outer diameter of the pipe 12 to be inserted. The socket portion 13a and the joint hole 13b communicate with each other through the internal space 13f. The male screw portion 13c is formed on the outer peripheral side of the joint hole 13b and the internal space 13f in a screw shape to be screwed with the nut 14. 13 d of guide surfaces are located in the entrance side of the joint hole 13b, and are formed in the conical surface which has the same axial center as the axial center O, and an internal diameter becomes large toward an entrance side. By this conical surface, the sleeve 15 is guided while being pressed when the nut 14 is screwed, so that the sleeve 15 bites into the outer peripheral surface 12 b of the pipe 12. The nut portion 13e is provided so that the joint body 13 can be held when the nut 14 is screwed.

  FIG. 3 is a partial cross-sectional view of the nut 14. The nut 14 has a female screw portion 14 a that is screwed with the male screw portion 13 c of the joint body 13, and a holding hole 14 b that holds the outer periphery of the pipe 12, and the sleeve 15 is integrally formed. The female screw portion 14 a is formed on the inner peripheral surface on the insertion side to be screwed into the joint main body 13. The holding hole 14b is formed in a columnar shape and has an inner diameter that is substantially equal to the outer diameter of the pipe 12 to be held. The sleeve 15 is processed integrally with the nut 14 and is formed at a position opposite to the insertion side and on the inner diameter side with respect to the female screw portion 14a.

  The sleeve 15 is in contact with the front end portion 15 a that bites into the outer peripheral surface 12 b of the pipe 12 when the pipe 12 is connected, the connection portion 15 b of the nut 14 that is cut by screwing the nut 14, and the guide surface 13 d of the joint body 13. And a contact surface 15c for guiding the front end portion 15a so as to bite into the pipe 12. Further, the sleeve 15 has an inner peripheral surface 15d facing the pipe 12 and a rear end face 15e that receives a pressing force from the nut 14 when the front end portion 15a bites into the pipe 12.

  The front end portion 15 a is provided at the tip end of the nut 14 in the screwing direction, that is, the tip end on one end side in the axial direction of the sleeve 15. A front end 15f of the front end portion 15a is formed in a sharp edge shape so that the front end 15f surely bites into the outer peripheral surface 12b of the pipe 12. The connecting portion 15 b is provided on the outer periphery on the other end side in the axial direction of the sleeve 15. As shown in FIG. 3, the connecting portion 15 b is formed so as to be thin in the axial direction, and the sleeve 15 is configured to be easily cut from the nut 14.

  The contact surface 15c is located on the outer circumference on one end side in the axial direction of the sleeve 15, and has a conical surface having the same axis as the axis O and having an outer diameter increasing toward the other end. ing. The conical surface inclination angle β of the contact surface 15 c is formed to be smaller than the conical surface inclination angle α of the guide surface 13 d of the joint body 13. Thus, when the nut 14 is screwed, the front end portion 15a of the sleeve 15 is guided and deformed to the inner diameter side, and bites into the outer peripheral surface 12b of the pipe 12. Here, in order to smoothly guide the front end portion 15a of the sleeve 15, the inclination angle α of the guide surface 13d of the joint body 13 is preferably set to 15 ° or more and 30 ° or less, and is preferably 20 ° or more and 25 or less. It is more preferable that the angle be set at or below.

  The inner peripheral surface 15 d is formed in a columnar shape and has an inner diameter that is substantially equal to the outer diameter of the pipe 12. The rear end surface 15e is an end surface on the other end side in the axial direction of the sleeve 15, is formed substantially perpendicular to the axial center, and faces the inner side surface 14c of the holding hole 14b of the nut 14 substantially in parallel. ing. The rear end surface 15 e receives a pressing force from the inner side surface 14 c after the sleeve 15 is separated from the nut 14, and bites the front end portion 15 a into the outer peripheral surface 12 b of the pipe 12.

  Further, when the sleeve 15 is cut from the nut 14 by the screwing of the nut 14 and then bites into the outer peripheral surface 12b of the pipe 12 by the screwing of the nut 14, the sleeve 15 receives the pressing force of the nut 14 so as not to rotate together. It is configured. That is, when the sleeve 15 bites into the pipe 12, the rotational torque T1 due to the frictional force generated at the front end portion 15a that is the biting portion of the sleeve 15 is caused between the rear end surface 15e and the inner side surface 14c by the pressing force of the nut 14. The rotational torque T2 due to the generated frictional force is made larger. In this way, when the nut 14 is screwed and the sleeve 15 is bitten into the pipe 12, the front end portion 15a of the sleeve 15 is prevented from rotating, and the rear end surface 15e and the inner side surface 14c are configured to slide. be able to. For this reason, it can suppress that the outer peripheral surface 12b of the piping 12 and the guide surface 13d of the coupling main body 13 are damaged by rotation of the front-end part 15a, and can ensure the sealing performance of a junction part. Below, the structure which makes rotational torque T1 larger than rotational torque T2 is demonstrated.

  On the outer periphery of the sleeve 15, a plurality of surfaces are formed from the contact surface 15 c to the other end side. As shown in FIG. 3, the outer peripheral surface 15g formed on the most other end side is formed on the axial center side with respect to the extended surface P of the conical contact surface 15c. For this reason, the rear end surface 15e that receives the pressing force from the inner side surface 14c is formed on the inner peripheral side close to the axis, so that the radius R1 from the axis of the rear end surface 15e is reduced. Note that the rear end surface 15e and the inner side surface 14c are tapered surfaces that are slightly reduced in thickness toward the axial center for the convenience of manufacturing. Therefore, strictly speaking, the portion of the rear end surface 15e that receives the pressing force is the rear end surface. It will be located in the outermost peripheral side of 15e. For this reason, the radius from the axial center of the rear end surface described below indicates the distance between the outer peripheral side of the rear end surface and the axial center.

  Here, FIG. 4 shows the shape of the sleeve 115 when the outer peripheral surface 15g is not provided on the sleeve and the contact surface 15c is extended to form the outer periphery of the sleeve. The sleeve 115 is integrally formed with the nut 114 through the connecting portion 115b. The sleeve 115 has an abutment surface 115 c that abuts against the guide surface 13 d of the joint body 13 and guides the front end portion 115 a into the pipe 12. The contact surface 115c is provided on the outer periphery of the sleeve 115, and is formed in a conical surface whose outer diameter increases from one end side to the other end side in the axial direction. The inclination angle of the conical surface of the contact surface 115 c is formed at the same angle as the inclination angle β of the contact surface 15 c of the sleeve 15. In such a sleeve 115, since the radius R2 from the axial center of the rear end face 115e is increased, the rotational torque T2 is increased. Therefore, in the present embodiment, as shown in FIG. 3, the sleeve 15 is configured such that the radius R1 from the axial center of the rear end face 15e is small, and the rotational torque T2 is relatively small.

  Further, the friction coefficient between the outer peripheral surface 12b and the guide surface 13d and the front end portion 15a is set to be larger than the friction coefficient between the rear end surface 15e and the inner side surface 14c. Thereby, the rotational torque T1 is made relatively large with respect to the rotational torque T2.

  Next, a pipe connection method for joining the pipe 12 to the joint body 13 using the pipe joint 1 will be described. FIG. 5 is a cross-sectional view showing the operation around the sleeve 15 of the pipe joint 1. When joining the pipe 12 to the joint body 13, first, the pipe 12 is passed through the holding hole 14 b of the nut 14, and the distal end portion 12 a of the pipe 12 is inserted into the joint hole 13 b of the joint body 13. Then, while holding the nut portion 13e of the joint body 13, the female thread portion 14a of the nut 14 is screwed into the male thread portion 13c of the joint body 13 as shown in FIG.

  As the nut 14 is screwed in, the guide surface 13d of the joint body 13 comes into contact with the front end portion 15a of the sleeve 15, and the pressing force increases as the nut 14 is screwed. Thereby, in the connection part 15b of the sleeve 15, the shear force added to the screwing direction of the nut 14 becomes large, and the connection part 15b of the sleeve 15 is cut. Then, as shown in FIG. 5B, the nut 14 and the sleeve 15 are separated.

  When the nut 14 is continuously screwed in, the guide surface 13d of the joint body 13 comes into contact with the front end portion 15a of the sleeve 15, and the inner side surface 14c of the nut 14 comes into contact with the rear end surface 15e of the sleeve 15. As the nut 14 is screwed, the rear end surface 15 e of the sleeve 15 receives a pressing force and a rotational force from the inner side surface 14 c of the nut 14. At this time, the rotational torque T1 due to the frictional force generated at the front end portion 15a of the sleeve 15 becomes larger than the rotational torque T2 due to the frictional force generated between the rear end surface 15e and the inner side surface 14c due to the pressing force of the nut 14. Thus, the front end portion 15a does not rotate, but slides between the rear end surface 15e and the inner side surface 14c. Then, the abutment surface 15c of the sleeve 15 is guided to the inner peripheral side while abutting against the guide surface 13d of the joint body 13, whereby the front end portion 15a of the sleeve 15 is connected to the pipe 12 as shown in FIG. It bites into the outer peripheral surface 12b of.

  Thus, the pipe joint 1 joins the pipe 12 to the joint main body 13 by causing the front end portion 15a of the sleeve 15 to bite into the outer peripheral surface 12b of the pipe 12. At this time, the gap between the front end portion 15 a of the sleeve 15 and the outer peripheral surface 12 b of the pipe 12 is sealed by the biting of the front end portion 15 a of the sleeve 15. Further, when the contact surface 15 c of the sleeve 15 and the guide surface 13 d of the joint body 13 are in close contact, the space between the contact surface 15 c of the sleeve 15 and the guide surface 13 d of the joint body 13 is sealed. By sealing these places, the sealing performance between the pipe 12 and the joint body 13 is ensured.

According to the above embodiment, the following effects can be obtained.
(1) In the above embodiment, the sleeve 15 that bites into the outer peripheral surface 12 b of the pipe 12 is formed integrally with the nut 14 before the nut 14 is screwed into the joint body 13. For this reason, it is possible to prevent the sleeve 15 from being lost before the pipe 12 is joined, as compared with the case where the sleeve 15 is configured separately from the nut 14. There is no need to store them as parts. Further, since the sleeve 15 is formed integrally with the nut 14, there is no work for assembling the sleeve 15 when the pipe 12 is joined to the joint body 13, and workability at the time of connecting the pipe 12 is improved. The sleeve 15 is cut from the nut 14 by screwing the nut 14 into the joint body 13 and bites into the outer peripheral surface 12b of the pipe 12, so that the sleeve 15 can be easily cut, and the sealing performance of the joint portion The pipe 12 can be joined to the joint hole 13b of the joint body 13 while ensuring the above.

  (2) In the above embodiment, when the sleeve 15 bites into the pipe 12, the rotational torque T1 due to the frictional force generated at the front end portion 15a of the sleeve 15 is caused by the pressing force of the nut 14 between the rear end surface 15e and the inner side surface 14c. It is comprised so that it may become larger than the rotational torque T2 by the frictional force generate | occur | produced between. For this reason, when the sleeve 15 bites into the pipe 12, it is possible to prevent the front end portion 15a of the sleeve 15 from rotating and to slide between the rear end surface 15e and the inner side surface 14c. Thereby, since it can suppress that the outer peripheral surface 12b of the piping 12 and the guide surface 13d of the coupling main body 13 are damaged by rotation of the front-end part 15a, the sealing performance of a junction part is securable.

  (3) In the above embodiment, the outer peripheral surface 15g formed on the other end side in the axial direction of the sleeve 15 is formed on the axial center side with respect to the extended surface P of the conical contact surface 15c. The rear end surface 15e that receives the pressing force from the inner side surface 14c is formed on the inner peripheral side close to the axis, and the radius R1 from the axis of the rear end surface 15e is reduced. For this reason, the rotational torque T2 can be reduced, and the rotational torque T1 can be easily configured to be larger than the rotational torque T2. Therefore, when the sleeve 15 bites into the pipe 12, the front end portion 15a of the sleeve 15 rotates. It is easy to configure so that the gap between the rear end surface 15e and the inner side surface 14c is slid. Thereby, it can suppress that the piping 12 and the coupling main body 13 are damaged, and can ensure the sealing performance of a junction part.

  (4) In the above embodiment, the friction coefficient between the outer peripheral surface 12b and the guide surface 13d and the front end portion 15a is set to be larger than the friction coefficient between the rear end surface 15e and the inner side surface 14c. Therefore, it is easy to configure the rotational torque T1 to be larger than the rotational torque T2. For this reason, when the sleeve 15 bites into the pipe 12, the front end portion 15a of the sleeve 15 can be prevented from rotating, and the rear end surface 15e and the inner side surface 14c can be configured to slide. Thereby, it can suppress that the piping 12 and the coupling main body 13 are damaged, and can ensure the sealing performance of a junction part.

  (5) In the above embodiment, when the sleeve 15 bites into the pipe 12, the sleeve 15 can be prevented from rotating, so that the front end portion 15 a rotates while contacting the outer peripheral surface 12 b of the pipe 12. Can be prevented. For this reason, the tightening torque when screwing the nut 14 can be reduced, and workability at the time of connecting the pipe 12 can be improved.

  (6) In the above-described embodiment, the sleeve 15 is provided with the front end portion 15a that is a biting portion at the tip on one end side in the axial direction, and the rear end surface 15e that receives the pressing force of the nut 14 on the end surface on the other end side. Since it is provided, the distance between the front end portion 15a and the rear end surface 15e can be increased. For this reason, the amount of deformation of the front end portion 15a toward the outer peripheral surface 12b of the pipe 12 can be increased, the amount of biting of the sleeve 15 into the pipe 12 is increased, and the sealing performance of the joint portion is ensured. Can do.

  (7) In the above embodiment, the conical guide surface 13d formed on the joint body 13 abuts on the conical abutment surface 15c formed on the sleeve 15 so that the sleeve 15 bites into the pipe 12. The front end 15a of the sleeve 15 can be configured to be gradually deformed as the nut 14 is screwed. For this reason, it can suppress that the screwing torque of the nut 14 becomes excessive, can make it fasten the nut 14, and can make the sleeve 15 bite into the piping 12 reliably.

In addition, you may change the said embodiment as follows.
-In above-mentioned embodiment, although the pipe joint 1 was comprised so that the sleeve 15 might be integrally processed with respect to the nut 14, so that the sleeve 15 may be joined with respect to the nut 14 by methods, such as adhesion | attachment and a fitting. It may be configured.

  In the above embodiment, the contact surface 15c of the sleeve 15 is formed in a conical surface having an outer diameter that increases from one end side to the other end side in the axial direction. For example, it may be formed on a cylindrical surface.

  In the above embodiment, the sleeve 15 is configured such that the radius R1 from the axis of the rear end surface 15e is reduced in order to reduce the rotational torque T2, but from the axis of the front end 15a that is a biting portion. The sleeve 15 may be configured to be larger than the radius R1 from the axis of the rear end face 15e. This makes it easy to configure the rotational torque T1 to be greater than the rotational torque T2, so that the front end portion 15a of the sleeve 15 is prevented from rotating and the rear end surface 15e and the inner side surface 14c slide. It becomes easy to constitute. For this reason, it can suppress that the piping 12 and the coupling main body 13 are damaged, and can ensure the sealing performance of a junction part.

  In the above embodiment, a plurality of surfaces are formed on the outer periphery of the sleeve 15, but the outer peripheral surface 15g on the other end side in the axial direction is on the axial center side with respect to the extended surface P of the conical contact surface 15c. The sleeve 15 may have other shapes as long as it is formed in the shape. FIG. 6 shows an example in which the outer peripheral surface on the other end side of the sleeve is formed on the axial center side with respect to the extended surface P of the contact surface. 6A is an example in which the outer peripheral surface 31g of the sleeve 31 is formed as a conical surface having an inclination angle smaller than the inclination angle of the contact surface 31c, and FIG. 6B is an outer peripheral surface of the sleeve 32. FIG. 6C shows an example in which the outer peripheral surface 33g of the sleeve 33 is formed in a conical surface whose outer diameter increases toward the contact surface 33c side (one end side). It is. As described above, even when the outer periphery of the sleeve 15 is configured by two surfaces of the contact surfaces 31c, 32c, and 33c and the outer peripheral surfaces 31g, 32g, and 33g, the shape of the contact surfaces 31c, 32c, and 33c is maintained. The rear end surfaces 31e, 32e, 33e can be formed on the inner peripheral side close to the axis. For this reason, the radii R3, R4, R5 from the axial center of the rear end faces 31e, 32e, 33e can be reduced to reduce the rotational torque T2. Further, as in the above-described embodiment, at least one conical surface or cylindrical surface may be interposed between the outer peripheral surface on the other end side in the axial direction and the contact surface. FIG. 6D shows an example in which a conical surface 34i having an inclination angle smaller than that of the contact surface 34c is interposed between the outer peripheral surface 34g and the contact surface 34c. Thus, even if the outer periphery of the sleeve 34 is constituted by a plurality of surfaces, the rear end surface 34e can be formed on the inner peripheral side close to the axial center while maintaining the shape of the contact surface 34c. The rotational torque T2 can be reduced by reducing the radius R6 from the shaft center. As described above, in order to form the rear end surface of the sleeve on the inner peripheral side, the outer periphery of the sleeve can be formed in various modes in consideration of manufacturing convenience and the like.

  In the above embodiment, the front end portion 15 a provided at the tip of the sleeve 15 bites into the outer peripheral surface 12 b of the pipe 12 when the pipe 12 is joined, but the portion other than the tip of the sleeve 15 is the outer peripheral surface of the pipe 12. You may make it bite into 12b.

  -In the said embodiment, although it does not specifically limit about the kind of the fluid which flows through the inside of the piping 12, It seems to connect the piping through which the supercritical refrigerant | coolant used in a supercritical state distribute | circulates by the pipe joint 1 of the said embodiment. It may be. In this way, even when the supercritical refrigerant used in the supercritical state flows in the pipe and a high pressure is applied to the joint between the pipe joint and the pipe, the pipe joint 1 is in the joint with the pipe. Since the sealing property is ensured, the leakage of the refrigerant at the joint can be suitably suppressed.

  -Moreover, you may make it connect the piping through which a carbon dioxide refrigerant distribute | circulates by the pipe joint 1 of the said embodiment. If it does in this way, since the fluid which flows through the connected piping is a carbon dioxide refrigerant, the piping circuit using said pipe joint 1 can be set as the structure which considered the global environment. In addition, even when carbon dioxide refrigerant is used in a supercritical state and high pressure is applied to the joint between the pipe joint and the pipe, the pipe joint 1 has a sealing property at the joint with the pipe. Therefore, it is possible to suitably suppress the leakage of the refrigerant at the joint.

  -Moreover, you may make it connect the piping through which a hydrocarbon refrigerant distribute | circulates by the pipe joint 1 of the said embodiment. If it does in this way, since the fluid which flows through the connected piping is hydrocarbon refrigerants, such as propane and isobutane, the piping circuit using the above-mentioned pipe joint 1 can be made into the composition which considered the global environment. Moreover, since said pipe joint 1 has the sealing performance in a junction part with piping, it can suppress suitably that a hydrocarbon refrigerant with strong flammability leaks from a junction part.

  In the above embodiment, the pipe joint 1 connects the pipe 11 and the pipe 12, but the configuration of these pipe joints 1 is the same as the indoor unit 42 and the outdoor unit 43 of the air conditioner 41 as shown in FIG. May be applied to the connecting portions 45 and 46 of the refrigerant pipe 44 that communicates with each other. In this way, since the air conditioner 41 uses the pipe joint 1 having the above-described effects, the sleeve is prevented from being lost, and the workability at the time of connecting the refrigerant pipe 44 is improved. It can be set as the air conditioner 41 which ensured the sealing performance. The configuration of the pipe joint 1 can also be applied to a connection portion of a shut-off valve as disposed in the connection portion 46, or can be applied to a connection portion of a refrigerant pipe in a refrigeration apparatus other than the air conditioner 41. You can also. In such a shut-off valve and refrigeration apparatus, the same effect as when the pipe joint 1 is applied to the connection portions 45 and 46 of the air conditioner 41 can be obtained.

  -Moreover, you may apply the structure of the pipe joint 1 of the said embodiment to the connection part of piping of a heat pump type water heater. FIG. 8 is a schematic view showing a connection state of piping of a heat pump type hot water heater. FIG. 8 (a) shows a schematic diagram of a heat pump type water heater 51 composed of one tank. The heat pump type hot water heater 51 includes a heat pump unit 61 that draws heat from outside air, and a hot water storage unit 71 that supplies hot water using the heat pumped by the heat pump unit 61. The heat pump unit 61 is composed of a refrigeration cycle apparatus having an expansion valve 62, an air heat exchanger 63, a compressor 64, and a water heat exchanger 65, and the refrigerant circulates in a refrigerant pipe 66 connecting the devices. In the hot water storage unit 71, the water supplied to the tank 73 via the water supply pipe 72 circulates between the tank 73 and the water heat exchanger 65 by the pump 74, and the hot water heat-exchanged by the water heat exchanger 65 is supplied. The hot water is supplied from the tank 73 through the water supply pipe 75. FIG. 8B shows a schematic diagram of a heat pump type water heater 52 composed of two tanks. The heat pump type hot water heater 52 has the same configuration as the heat pump type hot water heater 51, but the tank of the hot water storage unit 81 is configured by connecting a first tank 82 and a second tank 83 in series. The hot water stored in the first tank 82 and the second tank 83 is circulated by the pump 85 between the follow-up heat exchanger 84 and sent from the bathtub 86 through the water supply pipe 87 by the pump 88. A warming function is added such that the warm water is heated by exchanging heat with the chasing heat exchanger 84 and returned to the bathtub 86 via the water supply pipe 89. In such heat pump hot water heaters 51, 52, for example, the pipe joints 1, 2 can be used for the connection part 67 provided in the refrigerant pipe 66 and the connection part 76 provided in the water supply pipes 72, 75. In addition, in the heat pump hot water heater 52, the pipe joints 1 and 2 can be used for the connection portions 90 provided in the water supply pipes 87 and 89 in addition to this. In this case, since the heat pump type hot water heaters 51 and 52 use the pipe joints 1 and 2 having the above-described effects, the loss of the sleeve is prevented and the workability at the time of connecting the pipes is improved, and the joint portion of the pipes The heat pump type hot water heaters 51 and 52 can be ensured. In addition, you may make it provide said connection part 67,76,90 in another position by arrangement | positioning of the apparatus and unit which comprise a heat pump type water heater. In this manner, the pipe joints 1 and 2 can be applied not only to the connection portion of the refrigerant pipe but also to the connection portion of the water supply pipe through which water flows.

The fragmentary sectional view which shows the structure of the pipe joint which concerns on this invention. The fragmentary sectional view of the joint main part concerning the present invention. The fragmentary sectional view of the nut concerning the present invention. The fragmentary sectional view of the nut in a comparative example. (A) is sectional drawing before a sleeve is cut | disconnected, (b) is sectional drawing after a sleeve is cut | disconnected, (c) is sectional drawing when a sleeve bites into piping. (A), (b), (c), (d) is sectional drawing which shows the shape of the sleeve in another example of this invention. Schematic which shows the connection state of the refrigerant | coolant piping between the indoor unit and outdoor unit of an air conditioner. (A) is schematic which shows the connection state of piping of a heat pump type hot water heater, (b) is the schematic which shows the connection state of piping of the heat pump type hot water heater in another example. Sectional drawing which shows the structure of the pipe joint which concerns on a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Pipe joint, 11, 12 ... Piping, 13 ... Joint main body, 14 ... Nut, 15, 31, 32, 33, 34 ... Sleeve, 41 ... Air conditioner, 51, 52 ... Heat pump type hot water heater.

Claims (16)

A joint body in which a joint hole for joining pipes is formed on the inner periphery, and a thread portion is formed on the outer periphery;
A nut screwed into the threaded portion;
Before the nut is screwed into the joint body, the nut is provided integrally with the nut, and is cut from the nut by screwing the nut into the joint body in a state where a pipe is inserted into the joint hole. A sleeve that receives the pressing force of the nut by further screwing of the nut and bites into the outer periphery of the pipe,
When the sleeve bites into the pipe, the rotational torque due to the frictional force generated at the biting portion of the sleeve is larger than the rotational torque due to the frictional force generated between the sleeve and the nut due to the pressing force. A pipe joint characterized by In the pipe joint according to claim 1,
The pipe joint according to claim 1, wherein a friction coefficient at a biting portion of the sleeve is larger than a friction coefficient between the sleeve and the nut at a place where the pressing force is received. In the pipe joint according to claim 1 or 2,
The pipe joint according to claim 1, wherein a radius from the axial center of the biting portion of the sleeve is larger than a radius from the axial center of the portion receiving the pressing force. In the pipe joint according to any one of claims 1 to 3,
The pipe joint, wherein the sleeve is provided with the biting portion at a tip on one end side in the axial direction, and a portion for receiving the pressing force is provided on an end surface on the other end side. In the pipe joint according to claim 4,
The sleeve has a conical contact surface on the outer periphery on the one end side that guides the biting portion into the pipe by contacting the joint body, and the outer diameter increases toward the other end side. And the outer peripheral surface on the other end side is formed on the axial center side with respect to the extended surface of the contact surface. In the pipe joint according to claim 5,
The outer peripheral surface on the other end side is a conical surface, and the inclination angle of the conical surface with respect to the axial direction is smaller than the inclination angle of the contact surface with respect to the axial direction. In the pipe joint according to claim 5,
The outer peripheral surface on the other end side is a cylindrical surface. In the pipe joint according to claim 5,
The outer peripheral surface on the other end side is a conical surface, and the conical surface is formed so that an outer diameter increases toward the one end side. In the pipe joint according to any one of claims 6 to 8,
An outer peripheral surface of the sleeve is formed by interposing at least one conical surface or a cylindrical surface between the outer peripheral surface on the other end side and the contact surface. In the pipe joint according to any one of claims 5 to 9,
The pipe joint according to claim 1, wherein the sleeve bites into an outer periphery of the pipe by abutting a conical guide surface formed on the joint body.   The pipe joint according to any one of claims 1 to 10, wherein a pipe through which a supercritical refrigerant used in a supercritical state flows is connected.   The pipe joint according to any one of claims 1 to 10, wherein a pipe through which a carbon dioxide refrigerant flows is connected.   The pipe joint according to any one of claims 1 to 10, wherein a pipe through which a hydrocarbon refrigerant flows is connected.   A refrigeration apparatus using the pipe joint according to any one of claims 1 to 13 for a connection part of a refrigerant pipe.   A heat pump type hot water heater using the pipe joint according to any one of claims 1 to 13 as a connection part of a refrigerant pipe.   A water supply pipe, wherein the pipe joint according to any one of claims 1 to 10 is used as a connection part of the pipe.

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