JP6024014B2 - Manufacturing method of rotatable joint - Google Patents

Description

  The present invention provides a rotatable joint in which a metal pipe is rotatably connected to a metal fitting that is interposed between a metal pipe and a connection object such as a hose and connects the metal pipe and the connection object. Regarding the method.

  In recent years, flexible hoses made of highly flexible resin or the like have been used as part of water pipes. This flexible hose is used for piping work in a state where a metal pipe is connected to at least one end side in advance via a connection fitting.

  Patent Document 1 discloses a connection structure in which a hose and a metal pipe are integrated by connecting with a connection fitting. In this connection structure, with the insertion portion of the connection fitting inserted into the inner surface of the end portion of the metal pipe, a part of the end portion of the metal pipe is firmly attached to the ring-shaped groove formed on the outer peripheral surface of the insertion portion. The hose and the metal pipe are integrated by caulking.

JP 2004-36861 A

  However, in the connection structure of Patent Document 1, there is a problem that the metal pipe cannot be rotated with respect to the hose. During piping work, when connecting an L-shaped metal pipe connected to the other end of the hose with one end fixed to another metal pipe or the like, the metal pipe must not rotate with respect to the hose. In order to turn the L-shaped metal pipe into a direction suitable for connection with other metal pipes, the hose must be twisted, or one end of the hose that has been fixed first must be fixed again. The piping workability is poor.

  Therefore, it is conceivable to make the metal pipe rotatable relative to the connection object such as a hose by making the strength of caulking a part of the end of the metal pipe into the ring-shaped groove weaker than before. . However, simply reducing the strength of caulking has failed to make the metal pipe rotatable relative to the connection object while ensuring sufficient sealing performance.

  An object of the present invention is to provide a method for manufacturing a rotatable joint capable of improving piping workability by making a metal pipe rotatable with respect to a connection object while sufficiently securing a sealing property. That is.

In the manufacturing method of the rotatable joint according to the present invention, the metal pipe is rotatably connected to a connection fitting that is interposed between the metal pipe and the connection target and connects the metal pipe and the connection target. And a fitting step for fitting a seal ring into a ring-shaped groove formed on the outer periphery of the insertion portion to be inserted into the metal pipe of the connection fitting; and After inserting the end of the metal pipe into the end of the metal pipe and bringing the end of the metal pipe into contact with the flange provided on the connection object side of the insert, the ring-shaped groove of the insert A caulking step of caulking a part of the end of the metal pipe into an annular caulking groove formed on the outer periphery of the connection object side, and in the caulking step, the caulking groove in the width direction In Kicking the position of the connection object toward the located minimum outer diameter portion having an outer diameter of the smallest portion in the end portion of the metal pipe, and the outer diameter of the inner diameter of the prior SL minimum outer diameter is said caulking groove at least as much Do Ri, little contact with the outer peripheral surface of the inner peripheral surface of the end portion of the metal pipe is the caulking groove, and the metal on the flat surface between the ring-shaped groove and the caulking groove A part of the end portion of the metal pipe is caulked so that the inner peripheral surface of the end portion of the pipe hardly contacts .

  According to said structure, the minimum outer diameter part which is a site | part with the smallest outer diameter in the edge part of a metal pipe is located in the position near the connection target object in the width direction of a caulking groove, and the minimum outer diameter part By caulking a part of the end of the metal pipe into the caulking groove so that the inner diameter of the caulking groove is equal to or greater than the outer diameter of the caulking groove, the metal pipe can be prevented from almost contacting the insertion portion. . This reduces the resistance when trying to rotate the metal pipe relative to the insertion section, so that the metal pipe does not come out of the connection fitting, and the metal pipe rotates relative to the connection object. Can be possible. Therefore, piping workability can be improved.

  In the method for manufacturing a rotatable joint according to the present invention, a plurality of the ring-shaped grooves are formed on the outer periphery of the insertion portion, and in the fitting step, the seals fitted into the plurality of the ring-shaped grooves. The seal ring may be fitted into each of the plurality of ring-shaped grooves so that the outer diameters of the rings are equal. According to the above configuration, by forming a plurality of ring-shaped grooves into which the seal ring is fitted and providing a plurality of seal rings, sufficient sealing performance is ensured even when the metal pipe is hardly in contact with the insertion portion. can do. Also, by making the outer diameter of each seal ring fitted in each of the plurality of ring-shaped grooves equal, when the insertion part is inserted into the end of the metal pipe, or a part of the end of the metal pipe After the caulking is connected, the metal pipe is supported by the plurality of seal rings, so that the metal pipe is stabilized with respect to the insertion portion without wobbling in the direction inclined in the axial direction. Therefore, in a state where the metal pipe is stable with respect to the insertion portion, a part of the end portion of the metal pipe can be caulked into the caulking groove, and the caulking failure can be reduced. Even after a part of the end portion is caulked and connected, the metal pipe can be held in a stable state with respect to the insertion portion, and the metal pipe can be smoothly rotated.

  According to the method for manufacturing a rotatable joint of the present invention, the minimum outer diameter portion, which is the portion having the smallest outer diameter at the end of the metal pipe, is located at the position closer to the connection object in the width direction of the caulking groove, and The metal pipe cannot be removed from the connection fitting by caulking part of the end of the metal pipe into the caulking groove so that the inner diameter of the minimum outer diameter part is equal to or greater than the outer diameter of the caulking groove. Of course, since the metal pipe can be rotated with respect to the connection object, the piping workability can be improved.

It is a fragmentary sectional view showing a metal hose with a pipe. It is an enlarged view of the principal part A of a metal pipe hose. It is a figure which shows a crimping jig. It is a fragmentary sectional view which shows the conventional hose with a metal pipe. It is an enlarged view of the principal part B of the conventional metal hose with a pipe.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Configuration of hose with metal pipe)
The manufacturing method of the rotatable joint 1 by this embodiment is used when manufacturing the metal hose 10 with a pipe. As shown in FIG. 1, the metal pipe hose 10 is formed by connecting a hose (connection object) 11 and a metal pipe 12 with a connection fitting 13. The rotatable joint 1 has a connection structure in which a metal pipe 12 is rotatably connected to a connection fitting 13.

  The hose 11 is a general resin-made flexible resin composed of a laminated inner surface resin layer, a fiber reinforcement layer provided outside the inner surface resin layer, and an outer surface resin layer provided outside the fiber reinforcement layer. Such as a hose. The end of the hose 11 is fitted with the nipple part 20 and the socket part 21 of the connection fitting 13. In addition, the connection target object connected with the metal pipe 12 via the connection metal fitting 13 is not limited to the hose 11, and may be another metal pipe or the like.

  The metal pipe 12 has a main body portion 26 and an end portion 25 into which the insertion portion 22 of the connection fitting 13 is inserted. The metal pipe 12 is preferably made of copper or stainless steel from the viewpoint of easy forming during the caulking described later and corrosion resistance to chlorine contained in tap water. Further, the end 25 of the metal pipe 12 has a diameter larger than that of the main body 26. The reason is that the use of a standard-sized metal pipe suppresses an increase in cost, and the end portion 25 is expanded by a die to stabilize the radial dimension of the end portion 25. Because it can. In addition, by using a metal pipe having a diameter as small as possible, the handling of the metal pipe is facilitated, the piping workability is improved, and the weight of the product can be reduced.

  The connection fitting 13 has a nipple portion 20 inserted inside the end portion of the hose 11, a socket portion 21 fitted outside the end portion of the hose 11, and an end portion 25 inside the metal pipe 12. The insertion portion 22 is inserted along the inner surface of the portion 25. A ring-shaped caulking groove 24, a ring-shaped groove 23a, and a ring-shaped groove 23b are formed in this order on the outer peripheral surface of the insertion portion 22 from the side closer to the socket portion 21. O-rings (seal rings) 27 and 27 having the same dimensions are fitted into the two ring-shaped grooves 23a and 23b, respectively. In addition, as a seal ring fitted in the ring-shaped grooves 23a and 23b, a square ring having a square cross section may be used instead of the O-rings 27 and 27 having a circular cross section.

  Here, the outer diameter of the insertion portion 22 is within a range where it is not difficult to insert it into the inner surface of the end portion 25 of the metal pipe 12 in a state where the O-rings 27 and 27 are fitted in the ring-shaped grooves 23a and 23b from the viewpoint of sealing performance. It is preferable to make the gap between the outer surface of the insertion portion 22 and the inner surface of the end portion 25 as small as possible, as close as possible to the inner diameter of the end portion 25.

  Further, the two ring-shaped grooves 23a and 23b are respectively formed on the flat surface having the same diameter on the outer peripheral surface of the insertion portion 22, and have the same depth. Therefore, if the O-rings 27 and 27 having the same dimensions are fitted in the two ring-shaped grooves 23a and 23b, the outer diameters of the two O-rings 27 and 27 are equal. Thus, when the insertion portion 22 is inserted into the end portion 25 of the metal pipe 12, or after a part of the end portion 25 of the metal pipe 12 is caulked and connected as will be described later, the two O-rings 27, 27, the metal pipe 12 can be stably supported.

  The two ring-shaped grooves 23a and 23b may have different depths as long as the outer diameters of the two seal rings fitted in the two ring-shaped grooves 23a and 23b are equal to each other. In addition, a seal ring having a different dimension may be used in combination. That is, even if the depth of the ring-shaped groove 23a is deeper than the depth of the ring-shaped groove 23b, the outer diameter of a seal ring such as an O-ring 27 or a square ring fitted in the ring-shaped groove 23a is If the outer diameter of the seal ring fitted in 23b is the same, when the insertion portion 22 is inserted into the end portion 25 of the metal pipe 12, or as described later, a part of the end portion 25 of the metal pipe 12 is removed. After caulking and connecting, the metal pipe 12 can be stably supported by the two seal rings.

  The caulking groove 24 is formed wider than the two ring-shaped grooves 23a and 23b. A part of the end portion 25 of the metal pipe 12 is caulked in the caulking groove 24.

(Manufacturing method of metal pipe hose)
Next, the manufacturing method of the metal pipe hose 10 using the manufacturing method of the rotatable joint 1 of this embodiment is demonstrated. First, as shown in FIG. 1, after inserting the end portion of the hose 11 into the gap between the nipple portion 20 and the socket portion 21 of the connection fitting 13, the socket portion 21 is caulked from the outer periphery. Thereby, the nipple part 20 and the socket part 21 are fitted with the end part of the hose 11. Next, an O-ring 27 having the same dimensions is fitted into each of the two ring-shaped grooves 23 a and 23 b formed on the outer peripheral surface of the insertion portion 22 of the connection fitting 13. Next, after inserting the insertion portion 22 into the end portion 25 of the metal pipe 12, a part of the end portion 25 of the metal pipe 12 is caulked into the caulking groove 24 formed on the outer peripheral surface of the insertion portion 22. Thereby, the insertion portion 22 is fitted to the end portion 25 of the metal pipe 12. In this way, the hose 11 and the metal pipe 12 are connected via the connection fitting 13.

  Here, when inserting the insertion portion 22 into the end portion 25 of the metal pipe 12, as shown in FIG. 2 which is an enlarged view of the main part A of the metal pipe hose 10, the end of the metal pipe 12 is inserted. The tip 25 a of the portion 25 is brought into contact with the flange portion 22 a of the insertion portion 22 that forms the side wall of the caulking groove 24 on the socket portion 21 side. As a result, the metal pipe 12 is positioned with respect to the connection fitting 13. In FIG. 2, a gap s described later is formed between the tip 25a of the end portion 25 and the flange portion 22a.

  Further, when caulking a part of the end portion 25 of the metal pipe 12 into the caulking groove 24, a caulking jig 41 shown in FIG. 3 is used. The caulking jig 41 has eight claw members 41a to 41h each having arcuate tips each having a length obtained by dividing the circumference of a circle indicated by a dotted line into eight equal parts. A portion 25b of the end 25 is moved by positioning the portion 25b of the end 25 at the center position of the claw members 41a to 41h and moving the claw members 41a to 41h toward the center of the circle indicated by the dotted line. Is caulked into the caulking groove 24 from a direction of approximately 360 degrees.

  Here, a conventional metal pipe hose 50 is shown in FIG. The configuration of the metal pipe hose 50 is substantially the same as that of the metal pipe hose 10 of the present embodiment, but there are some differences such as one ring-shaped groove 23 into which the O-ring 27 is fitted. There is.

  As shown in FIG. 5 which is an enlarged view of the main part B of the metal pipe hose 50, in the conventional method of manufacturing the metal pipe hose 50, as shown by the arrows, the ring in the width direction of the caulking groove 24 is shown. The minimum outer diameter portion 25f, which is the smallest outer diameter portion of the end portion 25 of the metal pipe 12, is located near the groove 23, and the inner diameter of the minimum outer diameter portion 25f is the outer diameter of the caulking groove 24. In other words, the part 25b of the end 25 of the metal pipe 12 is made to contact the inner peripheral surface 25c of the part 25b of the end 25 and the outer peripheral surface of the caulking groove 24 completely. It is caulked in the caulking groove 24. Specifically, the position of the minimum outer diameter portion 25f closer to the ring-shaped groove 23 in the width direction of the caulking groove 24 is determined by the caulking jig 41 positioned closer to the ring-shaped groove 23 than the center of the caulking groove 24 in the width direction. In addition, a part 25b of the end portion 25 is firmly caulked into the caulking groove 24 so that the inner peripheral surface 25c and the outer peripheral surface of the caulking groove 24 are in close contact with each other. A portion 25 b of the end portion 25 is caulked in the caulking groove 24, whereby a minimum outer diameter portion 25 f is formed at the end portion 25 of the metal pipe 12. In the conventional configuration, the groove width of the caulking groove 24 (the dimension in the width direction from the end face of the flange portion 22a to the corner portion 22c of the insertion portion 22) is 4.5 mm, and the conventional method for manufacturing the hose 50 with a metal pipe Then, a part 25b of the end portion 25 is caulked aiming at a position 2.4 mm from the end face of the flange portion 22a, that is, a position closer to the ring-shaped groove 23 than the center in the width direction of the caulking groove 24. The minimum outer diameter portion 25f thus formed is located at a position in the range of 2.3 to 2.8 mm from the end surface of the flange portion 22a. That is, the minimum outer diameter portion 25f is located at a position exceeding 1/2 of the groove width of the caulking groove 24 from the end surface of the flange portion 22a. As a result, the inner peripheral surface 25c of the part 25b of the end portion 25 is in wide close contact with the outer peripheral surface of the caulking groove 24 along the axial direction. Further, the inner peripheral surface 25e of the end portion 25 facing the corner portion 22c of the insertion portion 22 is not easily inserted into the corner portion 22c, and most of the inner peripheral surface 25d of the end portion 25 facing the flat surface 22b of the insertion portion 22 is largely It contacts the flat surface 22b. Furthermore, the tip 25a of the end portion 25 is in contact with the flange portion 22a. Therefore, even if the metal pipe 12 is rotated with respect to the insertion portion 22, a large resistance force is generated between the metal pipe 12 and the insertion portion 22. Therefore, in the conventional hose 50 with a metal pipe, the metal pipe 12 does not rotate with respect to the connection fitting 13 (and thus the hose 11).

  On the other hand, as shown in FIG. 2, in the manufacturing method of the rotatable joint 1 of this embodiment used for manufacturing the metal pipe hose 10, as shown by the arrows, the socket portion 21 in the width direction of the caulking groove 24 is shown. The minimum outer diameter portion (the portion having the smallest outer diameter at the end portion 25 of the metal pipe 12) 25f is located at a position closer to it, and the inner diameter of the minimum outer diameter portion 25f is equal to or greater than the outer diameter of the caulking groove 24. In other words, the portion 25b of the end portion 25 of the metal pipe 12 is caulked in the caulking groove 24 so that the inner peripheral surface 25c of the portion 25b of the end portion 25 and the outer peripheral surface of the caulking groove 24 are not completely in contact with each other. Squeezed. Specifically, the minimum outer diameter portion 25f is positioned closer to the socket portion 21 in the width direction of the caulking groove 24 by the caulking jig 41 positioned closer to the socket portion 21 than the center of the caulking groove 24 in the width direction. In addition, the end portion 25 is formed so that the inner diameter of the minimum outer diameter portion 25f is equal to or larger than the outer diameter of the caulking groove 24 (so that the inner peripheral surface 25c and the outer peripheral surface of the caulking groove 24 are hardly in contact). A portion 25 b is caulked in the caulking groove 24. A portion 25 b of the end portion 25 is caulked in the caulking groove 24, whereby a minimum outer diameter portion 25 f is formed at the end portion 25 of the metal pipe 12. In the present embodiment, the groove width of the caulking groove 24 is 4.5 mm as in the conventional embodiment, and in the manufacturing method of the rotatable joint 1 of the present embodiment, the position is 2.0 mm from the end face of the flange portion 22a, that is, The portion 25b of the end portion 25 is caulked by aiming at the position closer to the socket portion 21 than the center of the caulking groove 24 in the width direction. The minimum outer diameter portion 25f thus formed is located at a position in the range of 1.5 to 2.25 mm from the end face of the flange portion 22a. That is, the minimum outer diameter portion 25f is located at a position equal to or less than 1/2 of the groove width of the caulking groove 24 from the end surface of the flange portion 22a. As a result, the inner peripheral surface 25 c of the part 25 b of the end portion 25 hardly contacts the outer peripheral surface of the caulking groove 24. Further, the inner peripheral surface 25e of the end portion 25 facing the corner portion 22c of the insertion portion 22 hardly penetrates into the corner portion 22c, and the inner peripheral surface 25d of the end portion 25 facing the flat surface 22b of the insertion portion 22 is flat. Almost no contact with the surface 22b. Further, due to plastic deformation of the metal pipe 12, a gap s is generated between the tip 25 a of the end portion 25 and the flange portion 22 a of the insertion portion 22 over substantially the entire circumference of the end portion 25. Therefore, the resistance force generated between the metal pipe 12 and the insertion portion 22 when the metal pipe 12 is rotated with respect to the insertion portion 22 is reduced. Therefore, in the metal pipe hose 10, the metal pipe 12 rotates with respect to the connection fitting 13 (and thus the hose 11).

  Since the inner peripheral surface 25 c of the part 25 b of the end portion 25 hardly contacts the outer peripheral surface of the caulking groove 24, a part of the inner peripheral surface 25 c may be in contact with the outer peripheral surface of the caulking groove 24. . That is, at least a part of the inner diameter of the minimum outer diameter portion 25 f may be the same as the outer diameter of the caulking groove 24. Further, since the inner peripheral surface 25e of the end portion 25 hardly penetrates into the corner portion 22c, a part of the inner peripheral surface 25e may be recessed into the corner portion 22c, or the inner peripheral surface 25d of the end portion 25 may be reduced. Since the flat surface 22b of the insertion part 22 is hardly contacted, a part of the inner peripheral surface 25d may be in contact with the flat surface 22b. Furthermore, since the gap s is generated over substantially the entire circumference in the circumferential direction of the end portion 25, there may be a portion where the gap s does not occur.

  Here, in the present embodiment, the strength of caulking the part 25b of the end portion 25 of the metal pipe 12 into the caulking groove 24 by using the caulking jig 41 is made weaker than that of the conventional metal pipe 12. The inner diameter of the minimum outer diameter portion 25 f at the end portion 25 is equal to or greater than the outer diameter of the caulking groove 24. If the inner diameter of the minimum outer diameter portion 25f is equal to the outer diameter of the caulking groove 24, the inner peripheral surface 25c of the part 25b of the end portion 25 is in contact with the outer peripheral surface of the caulking groove 24. If the inner diameter of the minimum outer diameter portion 25 f is larger than the outer diameter of the caulking groove 24, the inner peripheral surface 25 c of the part 25 b of the end portion 25 is not in contact with the outer peripheral surface of the caulking groove 24.

  Thus, in the manufacturing method of the rotatable joint 1 of this embodiment, it is a site | part with the smallest outer diameter in the edge part 25 of the metal pipe 12 in the position near the socket part 21 in the width direction of the caulking groove 24. A portion 25b of the end portion 25 of the metal pipe 12 is formed in the caulking groove 24 so that the minimum outer diameter portion 25f is located and the inner diameter of the minimum outer diameter portion 25f is equal to or larger than the outer diameter of the caulking groove 24. By caulking, the metal pipe 12 is hardly brought into contact with the insertion portion 22. As a result, the resistance when the metal pipe 12 is rotated with respect to the insertion portion 22 is reduced, so that the metal pipe 12 does not come out of the connection fitting 13 and the metal pipe 12 does not come out of the connection fitting 13. 13 (and eventually the hose 11) is rotatable.

  Moreover, in the conventional metal pipe hose 50, since the metal pipe 12 and the connection fitting 13 are firmly fitted, a single O-ring 27 can ensure sufficient sealing performance. On the other hand, in the metal pipe hose 10 using the manufacturing method of the rotatable joint 1 of the present embodiment in which the metal pipe 12 hardly contacts the insertion portion 22, the ring-shaped groove 23a into which the O-ring 27 is fitted. 23b and two O-rings 27 are provided, so that the sealing performance is sufficiently ensured even when the metal pipe 12 is hardly in contact with the insertion portion 22.

  Further, by using two O-rings 27 of the same size, the outer diameters of the two O-rings 27 and 27 fitted in the two ring-shaped grooves 23a and 23b are made equal, so that the insertion portion 22 is Since the metal pipe 12 is supported by the two O-rings 27 and 27 after being inserted into the end portion 25 of the metal pipe 12 or after a part of the end portion 25 of the metal pipe 12 is caulked and connected, The metal pipe 12 is stable with respect to the insertion portion 22 without wobbling in a direction inclined in the axial direction. Therefore, a part of the end portion 25 of the metal pipe 12 can be caulked into the caulking groove 24 in a state where the metal pipe 12 is stable with respect to the insertion portion 22, and the caulking failure is reduced, and the metal Even after caulking and connecting a part of the end portion 25 of the pipe 12, the metal pipe 12 can be held stably with respect to the insertion portion 22, and the metal pipe 12 can be smoothly rotated. be able to.

  In the present embodiment, the number of the ring-shaped grooves into which the O-ring 27 is fitted is two. However, the present invention is not limited to this and may be two or more.

(effect)
As described above, according to the method of manufacturing the rotatable joint 1 according to this embodiment, the outer diameter of the end portion 25 of the metal pipe 12 is the largest at the position near the socket portion 21 in the width direction of the caulking groove 24. A part 25b of the end 25 of the metal pipe 12 is placed so that the smallest outer diameter 25f, which is a small part, is located and the inner diameter of the smallest outer diameter 25f is equal to or greater than the outer diameter of the caulking groove 24. By caulking into the caulking groove 24, the metal pipe 12 can be made to hardly contact the insertion portion 22. As a result, the resistance when the metal pipe 12 is rotated with respect to the insertion portion 22 is reduced, so that the metal pipe 12 is not pulled out of the connection fitting 13 and the metal pipe 12 is hose ( The object to be connected) 11 can be made rotatable. Therefore, piping workability can be improved.

  In addition, by forming a plurality of ring-shaped grooves 23 a and 23 b into which the O-ring 27 is fitted and providing a plurality of O-rings 27, the sealing performance is sufficient even when the metal pipe 12 is hardly in contact with the insertion portion 22. Can be secured. Further, when the outer diameters of the O-rings 27 and 27 fitted in each of the plurality of ring-shaped grooves 23a and 23b are made equal, when the insertion portion 22 is inserted into the end portion 25 of the metal pipe 12, After caulking and connecting a part of the end portion 25 of the metal pipe 12, the metal pipe 12 is supported by a plurality of O-rings 27 and 27, so that the metal pipe 12 is staggered in an axially inclined direction. And stable with respect to the insertion portion 22. Therefore, a part of the end portion 25 of the metal pipe 12 can be caulked into the caulking groove 24 in a state where the metal pipe 12 is stable with respect to the insertion portion 22, and caulking defects can be reduced. Even after caulking and connecting a part of the end portion 25 of the metal pipe 12, the metal pipe 12 can be held in a stable state with respect to the insertion portion 22, and the metal pipe 12 can be smoothly moved. Can be rotated.

(Modification of this embodiment)
The embodiment of the present invention has been described above, but only specific examples are illustrated, and the present invention is not particularly limited, and the specific configuration and the like can be appropriately changed in design. Further, the actions and effects described in the embodiments of the invention only list the most preferable actions and effects resulting from the present invention, and the actions and effects according to the present invention are described in the embodiments of the present invention. It is not limited to what was done.

  For example, in the manufacture of the metal pipe hose 10, the connection fitting 13 and the hose 11 are first connected, and then the connection fitting 13 and the metal pipe 12 are connected. May be. That is, after the connection fitting 13 and the metal pipe 12 are first connected, the connection fitting 13 and the hose 11 may be connected.

1 Rotating joint 10 Hose with metal pipe 11 Hose (object to be connected)
12 Metal pipe 13 Connection fitting 20 Nipple part 21 Socket part 22 Insertion part 22a Flange part 22b Flat surface 22c Corner part 23a, 23b Ring-shaped groove 24 Caulking groove 25 End part 25a Tip 25b Part 25c, 25d, 25e Inner peripheral surface 25f Minimum outer diameter part 26 Body part 27 O-ring (seal ring)
41 Caulking jig 41a to 41h Claw member 50 Metal pipe hose s Gap

Claims (2)

A method of manufacturing a rotatable joint in which the metal pipe is rotatably connected to a connection fitting that is interposed between a metal pipe and a connection object and connects the metal pipe and the connection object. ,
A fitting step of fitting a seal ring into a ring-shaped groove formed on the outer periphery of the insertion portion inserted into the metal pipe of the connection fitting;
After inserting the insertion portion into the end portion of the metal pipe and bringing the end of the metal pipe into contact with a flange portion provided closer to the connection object than the insertion portion, A caulking step of caulking a part of an end of the metal pipe into a ring-shaped caulking groove formed on an outer periphery on the connection object side with respect to the ring-shaped groove;
Have
In the caulking step, the position of the object to be connected close in the width direction of the caulking groove, the minimum outer diameter section outer diameter of the smallest portion is located at the end of the metal pipe, before SL minimum outer diameter Ri inner diameter of the part is Do, or better than, the outer diameter of the caulking groove, the inner peripheral surface of the end portion of the metal pipe is hardly in contact with the outer peripheral surface of the caulking groove, and wherein said ring-shaped groove caulking A method for manufacturing a rotatable joint, characterized in that a part of the end of the metal pipe is caulked so that the inner peripheral surface of the end of the metal pipe is hardly in contact with a flat surface between the grooves. . A plurality of the ring-shaped grooves are formed on the outer periphery of the insertion portion,
In the fitting step, the seal ring is fitted into each of the plurality of ring-shaped grooves so that the outer diameters of the seal rings fitted into the plurality of ring-shaped grooves are equal to each other. The method for manufacturing a rotatable joint according to claim 1.

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