JP2015152064A - Conversion joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a ring 18 to be prevented from being removed.SOLUTION: A conversion joint 10 connects a metallic pipe member (100) to a pipe member (102) made of synthetic resin. The conversion joint 10 comprises a joint main body 12 formed into a cylindrical shape by metal. One end part of the joint main body 12 is formed with a resin pipe connecting part 22. One end part of a resin pipe 16 is outwardly fitted to the resin pipe connecting part 22 and at the same time a fitted part between the resin pipe connecting part 22 and the resin pipe 16 is outwardly fitted with a metallic ring 18 for use in pushing the inner circumferential surface of one end part of the resin pipe 16 against the outer circumferential surface of the resin pipe connecting part 22. The ring 18 is formed with an expanded diameter part 36 of which inner diameter may become large as it faces to a deep side. In addition, the inner circumferential surface of the expanded diameter part 36 is formed with either one or plural salients 38.

Description

  The present invention relates to a conversion joint, and more particularly to a conversion joint that connects, for example, a metal pipe member and a synthetic resin pipe member.

  Non-Patent Document 1 discloses an example of a conventional conversion joint (dissimilar pipe joint) that connects a metal pipe member and a synthetic resin pipe member. As shown in FIG. 14, the conversion joint 1 disclosed in Non-Patent Document 1 is a union-type conversion joint, which is a joint body 2, a union nut 3 connected to a metal pipe member, and a synthetic resin. A resin pipe 4 connected to the pipe member. The joint body 2 is a metallic cylindrical body, and has a union flange 5 formed at one end and a resin pipe connection 6 formed at the other end. A union nut 3 is externally fitted to the joint body 2 on the union flange 5 side so as to be rotatable with respect to the joint body 2. On the other hand, one end of the resin tube 4 is fitted on the resin tube connection portion 6 of the joint body 2, and one end of the resin tube 4 is fitted on the fitting portion between the resin tube connection portion 6 and the resin tube 4. A ring 7 that presses the inner peripheral surface of the end portion against the outer peripheral surface of the resin pipe connecting portion 6 is externally fitted.

  Another example of a conventional conversion joint is disclosed in Patent Document 1. A conversion joint (a joint for soft synthetic resin pipes) disclosed in Patent Document 1 includes a metal connection socket, an extension socket coupled to the tip of the connection socket, and a ring (outer ring) for fastening a resin pipe fitted in the connection socket ). The connection socket is a metal cylindrical body and has a pipe connection portion formed at one end. Further, an enlarged diameter portion is formed on the inner side of the ring, and a plurality of anti-slip grooves are formed in an annular shape on the inner peripheral surface of the smaller diameter portion on the near side of the enlarged diameter portion.

Kubota C eye catalog No.D62-01 12.12.12.SZ “Polyethylene pipes for building equipment” P.10

Japanese Patent No. 3556115 [F16L 33/22, F16L 47/06]

  In the conversion joint of Non-Patent Document 1, when the resin pipe contracts at low temperatures or becomes thin due to aging, the tightening of the ring becomes loose, and the ring may be detached to the back side or the near side. .

  The conversion joint of Patent Document 1 has a structure in which resin pipes can be easily pulled out by simply arranging irregularities of the same height on the outer peripheral surface of the pipe connection portion of the connection socket. For this reason, in the conversion joint of Patent Document 1, it is attempted to ensure the tightening performance by increasing the axial length of the ring. However, if the ring is lengthened, the manufacturing cost increases. In addition, since a groove is formed on the inner peripheral surface of the small diameter portion on the near side of the enlarged diameter portion of the ring, when the ring is forcibly fitted to one end portion of the resin tube, the outer peripheral surface of the resin tube is damaged, It looks bad.

  Therefore, the main object of the present invention is to provide a novel conversion joint.

  Another object of the present invention is to provide a conversion joint that can appropriately prevent the ring from being detached.

  1st invention is a conversion joint which connects a metal pipe member and a synthetic resin pipe member, Comprising: The cylindrical joint main body which is formed with a metal and has a resin pipe connection part in one end part, A resin pipe whose end is externally fitted to the resin pipe connection part, a ring that is externally fitted to one end part of the resin pipe, and presses the inner peripheral surface of the one end part of the resin pipe against the outer peripheral surface of the resin pipe connection part, It is a conversion joint provided with the enlarged diameter part which is formed in a ring and an internal diameter becomes large as it goes to the back | inner side, and 1 or several convex part formed in the internal peripheral surface of an enlarged diameter part.

  In the first invention, the conversion joint is, for example, a union type conversion joint, and connects the metal pipe member and the synthetic resin pipe member. The conversion joint includes a joint body formed in a cylindrical shape with metal, and a resin pipe connection portion is formed at one end of the joint body. One end of the resin tube is fitted on the resin tube connecting portion, and the inner peripheral surface of the one end of the resin tube is connected to the resin tube connecting portion and the fitting portion of the resin tube. A metal ring that presses against the outer peripheral surface of the outer ring is fitted. The ring is formed with an enlarged diameter portion whose inner diameter increases toward the back side. In addition, one or more convex portions are formed on the inner peripheral surface of the enlarged diameter portion.

  By forming the enlarged diameter portion in the ring in this way, the ring is fitted on the fitting portion between the resin tube connecting portion and the resin tube, and the inner peripheral surface of the ring and the outer peripheral surface of one end portion of the resin tube are When the crimped state is reached, the outer diameter of the one end portion of the resin tube increases along the inner diameter of the enlarged diameter portion toward the back side. For this reason, even when the resin tube contracts, the outer peripheral surface of the back side portion of the one end of the resin tube serves as a stopper, and the movement of the ring to the back side with respect to the resin tube is restricted. Further, by forming the convex portion on the inner peripheral surface of the enlarged diameter portion, the convex portion bites into the outer peripheral surface of the resin tube. For this reason, even when the resin tube contracts, the convex portion that bites into the resin tube serves as a stopper, and the movement of the ring relative to the resin tube, particularly the movement toward the near side, is restricted.

  In addition, by forming a convex portion on the inner peripheral surface of the enlarged diameter portion, the outer peripheral surface of the resin tube in the front side portion of the resin pipe connecting portion is less likely to contact the convex portion, so the front side portion of the resin pipe connecting portion The resin pipe outer peripheral surface is prevented from being damaged.

  According to the first invention, by forming the enlarged diameter portion in the ring, the outer peripheral surface of the one end portion of the resin tube serves as a stopper, and the movement of the ring to the back side can be restricted. Further, by forming the convex portion on the inner peripheral surface of the enlarged diameter portion, the convex portion bites into the outer peripheral surface of the resin tube, and the movement of the ring relative to the resin tube can be restricted. Therefore, even when the resin tube contracts due to temperature decrease or aging, it is possible to appropriately prevent the ring from being detached. Further, by forming the convex portion on the inner peripheral surface of the enlarged diameter portion, it is possible to prevent the resin tube outer peripheral surface from being damaged at the front side portion of the resin pipe connecting portion.

  A second invention is dependent on the first invention, and the ring includes a same-diameter portion having a flat inner peripheral surface in front of the enlarged-diameter portion.

  In the second invention, the ring is provided with the same-diameter portion on the near side of the enlarged-diameter portion. The inner peripheral surface of the same diameter portion is formed flat. In other words, the convex portions are formed only on the inner peripheral surface of the enlarged diameter portion, and no irregularities are formed on the inner peripheral surface of the same diameter portion. At this time, the inner diameter of the convex portion is made not to be smaller than the inner diameter of the same diameter portion.

  According to the second invention, it is possible to prevent the resin pipe outer peripheral surface from being damaged at the front side portion of the resin pipe connecting portion.

  A third invention is dependent on the first or second invention, and includes one or a plurality of protrusions formed on the outer peripheral surface of the resin pipe connecting portion, and the protrusion having the largest outer diameter among the protrusions is It is formed at a position facing the enlarged diameter portion.

  In 3rd invention, the 1 or several cyclic | annular protrusion part extended in the circumferential direction is formed in the outer peripheral surface of a resin pipe connection part. And the protrusion part with the largest outer diameter is formed in the position which opposes an enlarged diameter part among protrusion parts. Here, the protruding portion at the position opposite to the enlarged diameter portion has a wide setting range of the outer diameter, and the outer diameter of the protruding portion can be set large. That is, in the third aspect of the invention, the maximum height of the protrusion can be set large by forming an enlarged diameter portion on the ring and forming a protrusion with the maximum height at a position opposite to the enlarged diameter portion. . If the outer diameter of the protrusion is set to a large value, when the ring is fitted around the fitting part between the resin pipe connection part and the resin pipe, the inner peripheral surface of the resin pipe and the outer peripheral surface of the resin pipe connection part are crimped. In addition, since the protrusion of the resin tube connecting portion deeply penetrates into the resin tube, the resin tube is securely locked.

  Furthermore, the stress applied to one end portion of the resin tube is dispersed in the axial direction by forming the protrusion portion having the largest outer diameter at the inner periphery of the resin tube connection portion.

  According to the third invention, since the outer diameter of the protruding portion can be set large, the resin tube is securely locked, and the effect of preventing the resin tube from coming off from the resin tube connecting portion is enhanced. In addition, since the effect of preventing the resin pipe from coming off from the resin pipe connecting portion is high, the axial lengths of the ring and the resin pipe connecting portion can be shortened, and the manufacturing cost can be reduced. Furthermore, since the stress applied to one end portion of the resin tube can be averaged, the resin tube is prevented from being broken due to the stress concentration.

  The fourth invention is dependent on any one of the first to third inventions, and the distance between the inner peripheral surface of the ring and the outer peripheral surface of the resin pipe connecting portion is within an axial range where the enlarged diameter portion is formed. There is the smallest part.

  In 4th invention, the part where the distance of the inner peripheral surface of a ring and the outer peripheral surface of a resin pipe connection part becomes the smallest was provided in the axial direction range in which an enlarged diameter part is formed. That is, by forming the enlarged diameter portion, the height of the protrusion is increased to the extent that the distance between the outer peripheral surface of the resin pipe connecting portion and the inner peripheral surface of the ring is increased, so that the enlarged diameter portion is formed. The minimum distance is within the axial range.

  According to the fourth aspect of the invention, the stress applied to one end of the resin tube can be dispersed, so that the resin tube can be prevented from being broken due to the stress concentration. Further, since the protrusion height of the protrusion is increased, the resin tube is securely locked, and the effect of preventing the resin tube from coming off from the resin tube connection portion can be obtained.

  According to this invention, by forming the enlarged diameter portion in the ring, the outer peripheral surface of the one end portion of the resin tube serves as a stopper, and the movement of the ring to the back side can be restricted. Further, by forming the convex portion on the inner peripheral surface of the enlarged diameter portion, the convex portion bites into the outer peripheral surface of the resin tube, and the movement of the ring relative to the resin tube can be restricted. Therefore, even when the resin tube contracts due to temperature decrease or aging, it is possible to appropriately prevent the ring from being detached. Further, by forming the convex portion on the inner peripheral surface of the enlarged diameter portion, it is possible to prevent the resin tube outer peripheral surface from being damaged at the front side portion of the resin pipe connecting portion.

  The above object, other objects, features, and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

It is an illustration figure which shows the external appearance of one Example of the conversion coupling of this invention. It is an illustration figure which shows the use condition of the conversion coupling of FIG. It is sectional drawing of the conversion coupling of FIG. It is a principal part enlarged view of FIG. (A) is sectional drawing of the coupling main body with which the conversion coupling of FIG. 1 is provided. (B) is sectional drawing of the ring with which the conversion coupling of FIG. 1 is provided. It is an illustration figure which shows a mode that the conversion coupling of FIG. 1 is assembled. It is sectional drawing which shows the other Example of the conversion coupling of this invention. It is a principal part enlarged view of FIG. It is sectional drawing which shows the further another Example of the conversion coupling of this invention. It is a principal part enlarged view of FIG. It is a principal part enlarged view of sectional drawing which shows the further another Example of the conversion coupling of this invention. It is a principal part enlarged view of sectional drawing which shows the further another Example of the conversion coupling of this invention. It is sectional drawing which shows the further another Example of the conversion coupling of this invention. It is sectional drawing which shows an example of the conventional conversion coupling (heterogeneous pipe coupling).

  1 and 2, a conversion joint 10 according to an embodiment of the present invention is a union-type conversion joint (dissimilar pipe joint) that connects a metal pipe member 100 and a synthetic resin pipe member 102. And includes a joint body 12, a union nut 14, a resin pipe 16, a ring 18, and the like. For example, the conversion joint 10 is used for connecting a pipe 102a formed of a synthetic resin such as polyethylene to a pipe member 100 such as a valve or a water meter formed of a metal such as a copper alloy in a pipe for water supply. Used. In addition, the resin pipe 16 and the pipe 102a of the conversion joint 10 are appropriately connected by using an electric fusion joint 102b which is an example of the synthetic resin pipe member 102. The nominal diameter of the conversion joint 10 is, for example, 20-100 mm, and its axial length is, for example, 50-400 mm.

  As shown in FIG. 3 to FIG. 5, the joint body 12 of the conversion joint 10 is a cylindrical body formed of a metal such as a copper alloy, and has an annular projecting outward at one end thereof. A union flange 20 is formed. A resin pipe connecting portion 22 is formed at the other end of the joint body 12.

  As can be clearly seen from FIG. 5A, the resin pipe connection portion 22 is formed in a short cylinder shape whose outer peripheral surface is smaller in diameter than the center portion of the joint body 12, and is connected to the center portion of the joint body 12 and the resin pipe. A stepped portion 24 is formed at a portion corresponding to the boundary with the portion 22. An introduction portion 26 is formed at the tip of the resin pipe connection portion 22. The outer peripheral surface of the introduction portion 26 is formed in a tapered shape that reduces the diameter in two steps toward the front side so that the pipe end of the resin pipe 16 can be easily received and the occurrence of stress concentration in the introduction portion 26 can be suppressed. The Moreover, the part of the outer peripheral surface back side of the introducing | transducing part 26 is chamfered and formed in a curved surface shape.

  One or more annular protrusions 30 extending in the circumferential direction are formed on the outer peripheral surface of the resin pipe connection portion 22. In this embodiment, three protrusions 30 arranged in the axial direction are formed. The protrusion 30 has a substantially trapezoidal cross section, and the side surface on the near side is a tapered surface that decreases in diameter toward the near side, and the side surface on the far side is a substantially vertical surface. As a result, the resin tube 16 can be easily fitted onto the resin tube connection portion 22 and the resin tube 16 can be easily locked by the protrusions 30, thereby preventing the resin tube 16 from coming off the resin tube connection portion 22. .

  Further, the outer diameter of the protrusion 30 is formed so as to be larger toward the back side, and the protrusion 30 having the largest outer diameter among the three protrusions 30 is an enlarged diameter portion formed on the ring 18 described later. 36 is formed at a position facing 36. Here, the projecting portion 30 arranged at a position facing the enlarged diameter portion 36, that is, a position where the diameter of the inner peripheral surface of the ring 18 is increased, has a wide setting range of the outer diameter. For this reason, the protrusion part 30 of the opposing position of the enlarged diameter part 36 can set the protrusion height large. Then, by setting the protruding height of the protruding portion 30 to be large, the protruding portion 30 greatly bites into the inner peripheral surface of the resin tube 16, so that the resin tube 16 is reliably prevented from coming off from the resin tube connecting portion 22. Further, by forming the high protrusion 30 on the back side portion of the outer peripheral surface of the resin pipe connection portion 22, it is possible to reduce the stress applied to the resin pipe 16 in the front side portion of the resin pipe connection portion 22. That is, the stress applied to one end of the resin tube 16 can be dispersed and averaged in the axial direction.

  Further, a portion where the distance between the inner peripheral surface of the ring 18 and the outer peripheral surface of the resin pipe connecting portion 22 is the smallest is provided at a position opposite to the enlarged diameter portion 36, that is, at the back side portion of the resin pipe connecting portion 22. . That is, the outer diameter (projection height) of the protrusion 30 is increased more than the distance between the outer peripheral surface of the resin pipe connecting portion 22 and the inner peripheral surface of the ring 18 by forming the enlarged diameter portion 36. Thus, a portion having a minimum distance comes within an axial range in which the enlarged diameter portion 36 is formed. In this embodiment, the distance between the inner peripheral surface of the ring 18 and the outer peripheral surface of the resin pipe connecting portion 22 is the minimum distance at the axial position where the apex of the highest protrusion 30 of the three protrusions 30 is present. Is set. Thus, the effect of stress averaging can be enhanced by providing a portion having a minimum distance in the back side portion of the resin pipe connecting portion 22. Further, by increasing the protruding height of the protrusion 30, the effect of preventing the resin tube 16 from being pulled out increases.

  In addition, the outer peripheral part of the resin pipe connection part 22, ie, the introducing | transducing part 26, the protrusion part 30, etc., is good to form by cutting.

  As shown in FIG. 3, a union nut 14 is externally fitted to the joint body 12 on the union flange portion 20 side so as to be rotatable with respect to the joint body 12. The union nut 14 is a hexagonal cylindrical cap nut formed of a metal such as a copper alloy. On the inner peripheral surface of the union nut 14, an internal thread portion 32 that engages with the external thread portion of the metal pipe member 100 is formed. It is formed. Further, an annular locking portion 34 projecting inward is formed at one end portion of the union nut 14, and the locking portion 34 is locked to the union flange portion 20.

  Further, as shown in FIGS. 3 and 4, one end of the resin tube 16 is fitted on the resin tube connection portion 22, and the fitting portion between the resin tube connection portion 22 and the resin tube 16 is fitted on the resin tube connection portion 22. The ring 18 is externally fitted. The resin pipe 16 is a short pipe formed of a synthetic resin such as polyethylene, and is used as a connection portion with a synthetic resin pipe member 102 (see FIG. 2). The inner diameter of the resin pipe 16 is set to be the same as or smaller than the outer diameter of the resin pipe connecting portion 22 of the joint body 12, and when one end of the resin pipe 16 is externally fitted to the resin pipe connecting portion 22, the resin pipe The resin pipe connecting portion 22 is forcibly inserted into the inside 16.

  The ring 18 is a member that prevents the resin tube 16 from being detached by tightening one end portion of the resin tube 16 from the outside and pressing the inner peripheral surface of the resin tube 16 against the outer peripheral surface of the resin tube connecting portion 22. As shown in FIG. 5 (B), the ring 18 is formed in a short cylindrical shape by a metal such as stainless steel or copper, and is formed on the front side of the enlarged diameter portion 36 and the enlarged diameter portion 36 formed on the back side thereof. The same diameter part 40 is included. The enlarged diameter portion 36 is formed so that the inner diameter becomes larger toward the back side. One or more circumferential convex portions 38 extending in the circumferential direction are provided on the inner peripheral surface of the enlarged diameter portion 36. In this embodiment, two convex portions 38 arranged in the axial direction are formed. The convex portion 38 has a substantially trapezoidal cross section, and the side surface on the back side is a tapered surface that increases in diameter toward the back side, and the side surface on the near side is a substantially vertical surface. The tip portions of the two convex portions 38 are inclined surfaces whose inner diameter increases toward the back side, and the inner diameter of the tip portion of the back convex portion 38 is larger than the inner diameter of the tip portion of the front convex portion 38. Is set.

  The inner peripheral surface of the same diameter portion 40 is a flat surface, and no irregularities are formed. That is, the convex portion 38 is formed only on the inner peripheral surface of the enlarged diameter portion 36. Further, the inner diameter of the convex portion 38 is made not to be smaller than the inner diameter of the same-diameter portion 40.

  The inner diameter of the ring 18 is set to be smaller than the outer diameter of one end of the resin pipe 16 in the state of being externally fitted to the resin pipe connecting portion 22, and when the ring 18 is externally fitted to the one end of the resin pipe 16. The one end of the resin tube 16 is forced into the ring 18. The inner diameter of the ring 18 is larger than the outer diameter of the central portion of the joint body 12, and when the ring 18 is externally fitted to one end of the resin pipe 16, the ring 18 and the stepped portion 24 of the joint body 12 are Does not touch.

  In this way, by forming the enlarged diameter portion 36 in the ring 18, the ring 18 is externally fitted to the fitting portion between the resin pipe connecting portion 22 and the resin pipe 16, and the inner peripheral surface of the ring 18 and the resin pipe 16 are When the outer peripheral surface of the one end is in a pressure-bonded state, the outer diameter of the one end of the resin tube 22 increases along the inner diameter of the enlarged diameter portion 36 toward the back side. For this reason, the outer peripheral surface of the back side part of the one end part of the resin pipe 16 becomes a stopper, and the movement to the back side of the ring 18 with respect to the resin pipe 16 is regulated. Further, by forming the convex portion 38 on the inner peripheral surface of the enlarged diameter portion 36, the convex portion 38 bites into the outer peripheral surface of the resin tube 16. For this reason, the convex part 38 which bites into the resin tube 16 serves as a stopper, and the movement of the ring 18 relative to the resin tube 16, particularly the movement toward the front side, is restricted.

  In addition, as described above, the protrusion height of the protrusion 30 of the resin pipe connecting portion 22 is set to be large at the position opposite to the enlarged diameter portion 36, so that the outer peripheral surface of the resin pipe 16 is the inner peripheral surface of the ring 18. The protrusion 38 formed on the ring 18 surely bites into the outer peripheral surface of the resin tube 16 and the effect of restricting the movement of the ring 18 is enhanced.

  Then, with reference to FIG. 6, the method of assembling each member 12,14,16,18 and manufacturing the conversion coupling 10 is demonstrated. First, as shown in FIG. 6A, a union nut 14 is externally fitted to the joint body 12. Specifically, the joint body 12 is inserted into the union nut 14 from the resin pipe connection part 22 side, and the union nut 14 is left as it is until the union flange part 20 and the locking part 34 abut. Move. The union nut 14 fitted on the joint body 12 can move in the axial direction on the outer peripheral surface of the joint body 12 and can rotate in the circumferential direction.

  Next, as shown in FIG. 6B, one end of the resin pipe 16 is externally fitted to the resin pipe connection portion 22 of the joint body 12. Specifically, the resin pipe 16 is pushed in along the tapered surface of the introduction part 26 of the resin pipe connection part 22, and the resin pipe connection part 22 is forced into the resin pipe 16 as it is. That is, the resin tube 16 is pushed in until the one end portion of the resin tube 16 abuts on the stepped portion 24 of the joint body 12 while the diameter of the resin tube 16 is expanded by the resin tube connection portion 22. At this time, since a restoring force for returning to the original diameter is generated at one end portion of the resin tube 16 whose diameter has been expanded by forced insertion of the resin tube connection portion 22, the inner peripheral surface of the resin tube 16 has a protrusion 30. Close contact with.

  Thereafter, as shown in FIG. 6C, the ring 18 is externally fitted to one end portion of the resin tube 16, that is, the fitting portion between the resin tube 16 and the resin tube connecting portion 22. Specifically, one end portion of the resin pipe 16 connected to the resin pipe connection portion 22 is inserted from the back side of the ring 18. Then, the one end of the resin tube 16 is forcibly inserted into the ring 18 as it is. That is, while pressing one end portion of the resin tube 16 from the outside by the ring 18, the ring 18 is pushed in until the back end surface of the ring 18 comes to the position of the back end surface of the resin tube 16. At this time, as described above, the convex portion 38 is formed only in the diameter-expanded portion, and the inner diameter of the convex portion 38 is set larger than the inner diameter of the same-diameter portion 40, so that the front side of the resin pipe connecting portion 22. The outer peripheral surface of the resin tube 16 at the side portion is unlikely to contact the convex portion 38. For this reason, damage to the outer peripheral surface of the resin pipe 16 at the front side portion of the resin pipe connecting portion 22 is prevented. Further, when the ring 18 is externally fitted to the fitting portion between the resin tube 16 and the resin tube connecting portion 22, and the inner peripheral surface of the resin tube 16 and the outer peripheral surface of the resin tube connecting portion 22 are in a crimped state, the resin tube The protrusion 30 bites into the inner peripheral surface of 16. Thereby, the water stop performance between the resin pipe 16 and the resin pipe connecting portion 22 is ensured and the resin pipe 16 is prevented from being detached from the resin pipe connecting portion 22. Further, the inner peripheral surface of the ring 18 and the outer peripheral surface of one end portion of the resin tube 16 are in a pressure-bonded state, and the outer diameter of the one end portion of the resin tube 16 is the back side along the inner diameter of the expanded diameter portion 36. The convex portion 38 formed on the enlarged diameter portion 36 bites into the outer peripheral surface of the resin tube 16. This restricts the movement of the ring.

  As described above, the conversion joint 10 has a simple structure in which the resin pipe 16 and the ring 18 are forcibly inserted into the resin pipe connection portion 22 of the joint body 12 after the union nut 14 is externally fitted to the joint body 12. Therefore, it is not necessary to perform a caulking operation of the ring 18 and the manufacturing can be easily performed.

  According to this embodiment, by forming the enlarged diameter portion 36 in the ring 18, the outer peripheral surface of the back end portion of the one end portion of the resin tube 16 serves as a stopper, and the movement of the ring 18 to the back side is restricted. Can do. Further, by forming the convex portion 38 on the inner peripheral surface of the enlarged diameter portion 36, the convex portion 38 bites into the outer peripheral surface of the resin tube 16, and the movement of the ring 18 relative to the resin tube 16, particularly the movement toward the near side, is restricted. can do. For this reason, even when the resin tube 16 contracts, the detachment of the ring 18 can be appropriately prevented.

  Furthermore, by forming the convex portion 38 on the inner peripheral surface of the enlarged diameter portion 36, when the resin tube 16 is forcibly inserted into the ring 18, the outer peripheral surface of the resin tube 16 in the front side portion of the resin tube connecting portion 22 is formed. Damage can be prevented.

  Further, by forming the enlarged diameter portion 36 in the ring 18 and forming the projection portion 30 having the maximum height at a position opposed to the enlarged diameter portion 36, the maximum height of the projection portion 30 can be set large. By setting the protruding height of the protruding portion 30 to be large, the resin tube 16 is reliably locked. And since the prevention effect of the resin tube 16 coming off from the resin tube connection portion 22 is high, the axial length of the ring and the resin tube connection portion 22 can be shortened, and the manufacturing cost can be reduced.

  Furthermore, since the stress applied to one end of the resin tube 16 can be averaged, the resin tube 16 can be prevented from being broken due to stress concentration.

  Subsequently, a conversion joint 10 according to another embodiment of the present invention will be described with reference to FIGS. The embodiment shown in FIG. 7 is different from the above-described embodiment in that it includes a stepped portion 42 formed on the inner side surface of the innermost protrusion 30. Since the other configurations are the same, the same reference numerals are used for overlapping portions, and the description thereof is omitted or simplified.

  Referring to FIGS. 7 and 8, a conversion joint 10 according to an embodiment of the present invention has a union flange 20 formed at one end and a resin pipe connection 22 formed at the other end. A metal joint body 12 is provided. Further, a union nut 14 is externally fitted to the joint body 12 on the side of the union flange portion 20 so as to be rotatable with respect to the joint body 12. On the other hand, one end portion of the resin tube 16 is fitted on the resin tube connection portion 22 of the joint body 12, and one end of the resin tube 16 is fitted on the fitting portion between the resin tube connection portion 22 and the resin tube 16. A ring 18 that presses the inner peripheral surface of the end portion against the outer peripheral surface of the resin pipe connecting portion 22 is externally fitted.

  One or more annular protrusions 30 extending in the circumferential direction are formed on the outer peripheral surface of the resin pipe connection portion 22. In this embodiment, three protrusions 30 arranged in the axial direction are formed. The protrusion 30 has a substantially trapezoidal cross section, and the side surface on the near side is a tapered surface that decreases in diameter toward the near side, and the side surface on the far side is a substantially vertical surface.

  Further, a stepped portion 42 having a substantially rectangular cross section is formed on the inner side surface of the innermost protrusion 30. When the protruding portion 30 is raised, the resin of the resin tube 16 does not easily enter the base portion on the back side. However, by providing the stepped portion 42 on the back side surface of the protruding portion 30 in advance, the back side of the protruding portion 30 is provided. The resin of the resin tube 16 also wraps around the side surface without any gap, and the crimping performance between the inner peripheral surface of the resin tube 16 and the outer peripheral surface of the resin tube connecting portion 22 is enhanced. Thereby, the water stop performance between the resin pipe 16 and the resin pipe connecting portion 22 and the effect of preventing the resin pipe 16 from coming off from the resin pipe connecting portion 22 are obtained.

  Further, by forming such a staircase portion 42, a tightening force at the back side portion of the ring 18 is ensured, and the separation of the ring 18 to the back side can be reliably prevented.

  In the embodiment shown in FIG. 7, as in the embodiment shown in FIG. 3, even when the resin tube 16 contracts, the ring 18 can be appropriately prevented from being detached.

  In addition, since the staircase portion 42 is formed, it is possible to improve the crimping performance between the inner peripheral surface of the resin tube 16 and the outer peripheral surface of the resin tube connecting portion 22. Thereby, the water stop performance between the resin pipe 16 and the resin pipe connecting portion 22 and the effect of preventing the resin pipe 16 from coming off from the resin pipe connecting portion 22 are obtained.

  Further, the formation of the staircase portion 42 ensures a tightening force at the back side portion of the ring 18 and can reliably prevent the ring 18 from being detached to the back side.

  In the embodiment shown in FIG. 7, the one-step staircase portion 42 having a substantially rectangular cross section is formed on the back side surface of the innermost protrusion 30. It is not limited to. Further, in this embodiment, the staircase portion 42 is formed only on the back side surface of the innermost protrusion 30. However, the position and number of the staircase portions 42 are not limited to this. For example, the staircase portion 42 may be formed on the back side surface of each protrusion 30. In this case, the resin of the resin tube 16 wraps around the back side surface of each protrusion 30 without a gap, and the crimping performance between the inner peripheral surface of the resin tube 16 and the outer peripheral surface of the resin tube connecting portion 22 is further enhanced.

  Next, with reference to FIGS. 9 and 10, a conversion joint 10 which is still another embodiment of the present invention will be described. The embodiment shown in FIG. 9 is different from the above-described embodiment in that it includes an inclined portion 44 formed at the inner periphery of the resin pipe connecting portion 22. Since other configurations are the same, the same reference numerals are used for overlapping portions, and the description thereof is omitted or simplified.

  Referring to FIGS. 9 and 10, conversion joint 10 according to one embodiment of the present invention has a union flange portion 20 formed at one end portion and a resin pipe connection portion 22 formed at the other end portion. A metal joint body 12 is provided. One end portion of the resin tube 16 is fitted on the resin tube connection portion 22 of the joint body 12, and one end portion of the resin tube 16 is fitted on a fitting portion between the resin tube connection portion 22 and the resin tube 16. A ring 18 that presses the inner circumferential surface of the resin tube against the outer circumferential surface of the resin pipe connecting portion 22 is fitted.

  One or more protrusions 30 extending in the circumferential direction are formed on the outer peripheral surface of the resin pipe connection portion 22. In this embodiment, two protrusions 30 arranged in the axial direction are formed.

  An inclined portion 44 whose outer diameter increases toward the back side is formed at the back of the outer peripheral surface of the resin pipe connecting portion 22. The inclined portion 44 is formed by making the base portion of the resin pipe connecting portion 22 thick. The rear protrusion 30 is formed on the inclined portion 44. By forming the inclined portion 44 at the back of the outer peripheral surface of the resin pipe connecting portion 22, when the ring 18 is externally fitted to the fitting portion between the resin pipe connecting portion 22 and the resin pipe 16, the resin pipe 16 is crimped by the ring 18. The force to be increased gradually increases toward the back side of the ring 18, and the tightening force at the back side portion of the ring 18 is ensured. This more reliably prevents the ring 18 from being detached to the back side.

  In addition, by providing the inclined portion 44 at the back of the outer peripheral surface of the resin pipe connecting portion 22, the resin of the resin tube 16 wraps around the outer peripheral surface of the resin pipe connecting portion 22 without a gap, and the inner periphery of the resin pipe 16. The pressure bonding performance between the surface and the outer peripheral surface of the resin pipe connecting portion 22 is enhanced. Thereby, the water stop performance between the resin pipe 16 and the resin pipe connecting portion 22 and the effect of preventing the resin pipe 16 from coming off from the resin pipe connecting portion 22 are obtained.

  In the embodiment shown in FIG. 9, as in the embodiment shown in FIG. 3, even when the resin tube 16 contracts, the ring 18 can be appropriately prevented from being detached.

  Further, since the inclined portion 44 is formed, a tightening force at the back side portion of the ring 18 is ensured, and the release of the ring 18 to the back side can be reliably prevented.

  Furthermore, by forming the inclined portion 44, the pressure bonding performance between the inner peripheral surface of the resin tube 16 and the outer peripheral surface of the resin tube connecting portion 22 can be enhanced. Thereby, the water stop performance between the resin pipe 16 and the resin pipe connecting portion 22 and the effect of preventing the resin pipe 16 from coming off from the resin pipe connecting portion 22 are obtained.

  In the embodiment shown in FIG. 9, the inclined portion 44 is formed only on the outer peripheral surface of the resin pipe connecting portion 22, but the range in which the inclined portion 44 is formed is not limited to this. For example, the inclined portion 44 may be formed from the innermost portion of the resin pipe connecting portion 22 to the inner side surface of the introducing portion 26.

  Further, in each of the above-described embodiments, two or three protrusions 30 arranged in the axial direction are formed on the resin pipe connection part 22, but, for example, four protrusions 30 are formed as shown in FIG. May be. In this embodiment, four annular projections 30 arranged in the axial direction are formed, and two of the rear projections 30 are formed at positions opposed to the enlarged diameter portion 36. Further, the innermost projection 30 has a narrow axial width. At this time, since the resin of the resin tube 16 does not easily wrap around the inner side surface of the innermost protrusion 30, the groove between the innermost protrusion 30 and the stepped portion 24 should be shallow. preferable. In this embodiment, the two projecting portions 30 are formed at positions opposite to the enlarged diameter portion so that the outer diameters of the two projecting portions 30 can be set large. By increasing the projecting height of the two projecting portions 30, the projecting portion 30 is easily caught on the resin tube 16, and the resin tube 16 is more reliably locked.

  In addition, the shape of the protrusion part 30 formed in the resin pipe connection part 22, a protrusion height, the number, etc. are not limited to what is disclosed by each above-mentioned Example. Instead of the annular projecting portion 30, for example, the projecting portions may be formed in a rounded pattern, or a plurality of projecting portions may be randomly formed.

  Further, in each of the above-described embodiments, the tip portions of the two convex portions 38 formed on the diameter-expanded portion 36 of the ring 18 are inclined surfaces whose inner diameter increases toward the back side, and the inner diameter of the back-side convex portion 38. Is set to be larger than the inner diameter of the convex portion 38 on the near side, but as shown in FIG. 12, the tip portion of the convex portion 38 may be a horizontal plane, and the inner diameter of the convex portion 38 on the far side is set to the convex portion on the near side. You may set to the magnitude | size below the internal diameter of 38. In this case, since the protruding height of the convex portion 38 can be set larger, the convex portion 38 bites into the outer peripheral surface of the resin tube 16 and the effect of restricting the movement of the ring 18 is enhanced.

  Note that the shape, height, number, and the like of the convex portions 38 formed on the diameter-expanded portion 36 of the ring 18 are not limited to those disclosed in the above-described embodiments.

  Further, in each of the above-described embodiments, the distance between the inner peripheral surface of the ring 18 and the outer peripheral surface of the resin pipe connecting portion 22 at the axial position where the apex of the protruding portion 30 formed at the opposed position of the enlarged diameter portion 36 is present. However, the portion having the minimum distance may not necessarily be within the axial range in which the enlarged diameter portion 36 is formed. For example, the distance between the inner peripheral surface of the ring 18 and the outer peripheral surface of the resin pipe connecting portion 22 is minimized at the axial position where the apex of the protrusion 30 formed at the position opposite to the same diameter portion 40 is present. Also good. Furthermore, the portion where the distance between the inner peripheral surface of the ring 18 and the outer peripheral surface of the resin pipe connecting portion 22 is the minimum is not necessarily the axial position where the apex of the protrusion 30 and the apex of the convex portion 38 face each other. Good. For example, it may be set so that it is shifted from the apex of the projecting portion 30 and has a minimum distance at the axial position where the side surface of the projecting portion 30 and the apex of the convex portion 38 face each other.

  Furthermore, in each of the above-described embodiments, a union-type conversion joint is illustrated as an example of the conversion joint 10. However, as shown in FIG. 13, the conversion joint 10 has a connection portion with a metal pipe member 100. It may be a male screw type conversion joint integrally formed with the main body 12, or another type of conversion joint such as a female screw type. That is, the shape (configuration) of the end of the joint body 12 on the side connected to the metal pipe member 100 can be changed as appropriate.

  It should be noted that the specific numerical values such as the dimensions given above are merely examples, and can be appropriately changed according to necessity such as product specifications.

DESCRIPTION OF SYMBOLS 10 ... Conversion joint 12 ... Joint main body 16 ... Resin pipe 18 ... Ring 22 ... Resin pipe connection part 30 ... Protrusion part 36 ... Expanded part 38 ... Convex part 40 ... Same diameter part 100 ... Metal pipe member 102 ... Synthetic resin Pipe members

Claims (4)

A conversion joint for connecting a metal pipe member and a synthetic resin pipe member,
A tubular joint body formed of metal and having a resin pipe connecting portion at one end,
A resin pipe whose one end is externally fitted to the resin pipe connecting portion;
A ring that is externally fitted to one end of the resin pipe and presses the inner peripheral surface of the one end of the resin pipe against the outer peripheral surface of the resin pipe connecting portion;
An enlarged diameter portion formed on the ring and having an inner diameter that increases toward the back side, and
A conversion joint comprising one or more convex portions formed on the inner peripheral surface of the enlarged diameter portion.   2. The conversion joint according to claim 1, wherein the ring includes a same-diameter portion having a flat inner peripheral surface on the near side from the enlarged-diameter portion. Comprising one or a plurality of protrusions formed on the outer peripheral surface of the resin pipe connecting portion;
The conversion joint according to claim 1, wherein a protrusion having the largest outer diameter among the protrusions is formed at a position facing the enlarged diameter portion.   4. The part according to claim 1, wherein there is a portion where the distance between the inner peripheral surface of the ring and the outer peripheral surface of the resin pipe connecting portion is the smallest within an axial range in which the enlarged diameter portion is formed. Conversion fittings.

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