JP2007113724A - Pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe joint capable of increasing the degree of freedom in piping structure and connecting work by forming a structure allowing the insertion of a cap nut after machining to enlarge the end of a metal pipe. <P>SOLUTION: The pipe joint comprises a thin-walled stainless steel pipe 10 having an annular projecting part 13 on the end 12 side; a joint body 20 having an external thread 31 at the outer periphery of the end and inserting the end of the thin-walled stainless steel pipe 10 inside; the cap nut 40 formed with an inner diameter larger than the outer diameter of the annular projecting part 13 and having an internal thread 42 at the inner peripheral part so as to be screwed with the external thread 31 of a connection port 30; and an adapter ring 50 detachably arranged at the inner peripheral part of the cap nut 40 so as to be engaged with the annular projecting part 13, formed with an inner diameter smaller than the outer diameter of the annular projecting part 13, and formed combining a plurality of circular arc members 51, 52. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pipe joint that can easily and reliably connect a metal pipe such as a stainless steel pipe or a copper pipe used for water supply, hot water supply, cold / hot water pipes, etc. to a joint body at an installation site.

There is known an expanded pipe joint that can easily and reliably connect a thin stainless steel pipe having an annular protrusion formed on an end side thereof on site (see, for example, Patent Documents 1 to 3). As shown in FIG. 10, such a pipe-type pipe joint has an annular projecting portion in which a thin stainless steel pipe 100 connected to a joint body 200 (see FIG. 11) is bulged in the radial direction near the pipe end 101 by a dedicated tool. 102 is formed. Then, as shown in FIG. 11, the pipe end 101 of the thin-walled stainless steel pipe 100 is inserted into the joint main body 200, and a male screw (not shown) formed on the outer periphery of the end of the joint main body 200 is attached to the inner periphery of the cap nut 110. The formed female screw 111 is screwed in, and the annular projecting portion 102 of the thin stainless steel pipe 100 is clamped and fixed by the tapered portion (not shown) of the joint body 200, the cap nut 110 and the packing (not shown), and the packing is annular. It is brought into close contact with the inclined surface of the protruding portion 102 to prevent leakage of fluid flowing in the thin stainless steel tube 100. At the same time, the thin stainless steel pipe 100 is prevented from coming out.
No. 7-55424 JP-A-9-137784 Japanese Patent Laid-Open No. 10-318459

  The above-described pipe joint has the following problems. That is, since the inner diameter of the cap nut 110 is smaller than the outer diameter of the annular protruding portion 102, it is necessary to insert the cap nut 110 before performing the pipe expansion process. Moreover, since it is necessary to take the guide part of a dedicated tool to some extent, the joint pipe 120 into which the cap nut 110 is inserted is required to be long, and a large pipe space may be required. Further, a method of welding a short pipe expanded to narrow a piping space to a joint such as an elbow pipe 130 is also conceivable. However, if a resin ring is attached to the portion of the cap nut 110 that contacts the annular protrusion 102 to prevent co-rotation, or a lubricant such as Teflon (registered trademark) is coated or applied, There is a problem that the function of the joint cannot be exhibited, such as the resin ring and the lubricant are melted or peeled off due to heat. Further, there is a possibility that the connection cannot be made due to the deformation of the screw part due to the heat effect.

  Then, this invention aims at providing the pipe joint which can increase the freedom degree of piping structure and a connection operation | work by setting it as the structure which can insert a cap nut after expanding the end part of a metal pipe. .

  In order to solve the above problems and achieve the object, the pipe joint of the present invention is configured as follows.

  A metal tube having an annular protrusion formed on the end side on the end side, a tubular joint body having an external thread portion on the outer periphery of the end, and an end of the metal tube inserted therein, and an inner diameter thereof Is formed larger than the outer diameter of the annular projecting portion, and has a cap nut having an inner peripheral portion and a female screw portion that engages with the male screw portion of the joint body, and an inner peripheral portion of the cap nut. An adapter ring that is freely arranged, engages with the annular protrusion of the metal tube, has an inner diameter smaller than the outer diameter of the annular protrusion, and is configured by combining a plurality of arcuate members. It is characterized by having.

  According to the present invention, it is possible to increase the degree of freedom of the piping structure and connection work by adopting a structure in which the cap nut can be inserted after the end portion of the metal tube is expanded.

  FIG. 1 is a side view showing a pipe joint 1 according to an embodiment of the present invention with a part cut away. In the figure, K indicates a thin stainless steel pipe.

  The pipe joint 1 includes a thin stainless steel pipe (metal pipe) 10 and an elbow-type joint body 11. On the end 12 side of the thin stainless steel tube 10, an annular protrusion 13 is formed which has a larger diameter than the outer diameter of the thin stainless steel tube 10 by tube expansion.

  The joint body 20 includes three cylindrical connection ports 30, a cap nut 40 that is screwed into a male screw 31 (described later) of the connection port 30, an adapter ring 50 and a resin ring 60 disposed inside the cap nut 40. And.

  A male screw 31 is formed on the outer periphery of the connection port 30. Further, the fitting portion 32 into which the end portion 12 of the thin stainless steel tube 10 is fitted, the annular groove 33, and the annular protruding portion 13 of the thin stainless steel tube 10 are engaged from the proximal end side to the distal end side on the inner peripheral side. A tapered portion 34 is formed, and an O-ring 35 is attached to the annular groove 33. The axial length of the fitting portion 32 is formed slightly longer than the length from the annular protruding portion 13 to the end portion 12 of the thin stainless steel pipe 10.

  As shown in FIG. 2, the cap nut 40 is formed in a cylindrical shape, and is fitted with an opening 41, a female screw 42 formed with a female screw, and an adapter ring 50, which will be described later, from the right side in FIG. 2. The joint part 43 and the collar part 44 with which the adapter ring 50 engages are provided. Note that the inner diameter of the flange portion 44 is formed to be larger than the annular protrusion 13 of the thin stainless steel tube 10.

  As shown in FIG. 4, the adapter ring 50 includes arc-shaped arc members 51 and 52 that are divided into two in the circumferential direction. Further, as shown in FIGS. 2 and 3, these arc members 51 and 52 are first portions 51 a and 52 a that are fitted to the fitting portion 43 from the right side in the drawing, and the outer diameter thereof is the inner diameter of the flange portion 44. 2nd part 51b and 52b slightly smaller than this.

  As shown in FIGS. 3 and 5, the resin ring 60 has a ring shape with a part cut, and is formed so as to be fitted to the inner peripheral portions of the first portions 51 a and 52 a of the adapter ring 50. . The inner diameter is formed so as to engage with the annular protrusion 13 (see FIG. 9). The resin ring 60 has a function of preventing the thin stainless steel tube 10 from rotating together when the cap nut 40 is tightened. Instead of the resin ring 60, a lubricant such as Teflon may be applied to the inner peripheral portion of the adapter ring 50.

  In the pipe joint 1 configured as described above, the thin stainless steel pipe 10 and the joint body 20 are connected as shown in FIGS. In addition, the pipe expansion process which forms the cyclic | annular protrusion part 13 in the thin-walled stainless steel pipe 10 previously using a special tool etc. is performed. First, as shown in FIG. 6, the cap nut 40 is inserted into the thin-walled stainless steel pipe 10. At this time, since the inner diameter of the flange portion 44 of the cap nut 40 is larger than the outer diameter of the annular protruding portion 13 of the thin stainless steel pipe 10, the flange portion 44 is not caught.

  Next, as shown in FIG. 7, the arc members 51 and 52 are arranged in the fitting portion 43 of the cap nut 40 to form the adapter ring 50. Although the inner diameters of the arc members 51 and 52 are smaller than the outer diameter of the annular protrusion 13, the arc members 51 and 52 are arc-shaped and can be set in the fitting portion 43 regardless of the outer diameter of the annular protrusion 13. .

  Subsequently, the resin ring 60 is disposed inside the adapter ring 50. The inner diameter of the resin ring 60 is also smaller than that of the annular protrusion 13, but is flexible and partially cut, so that the adapter ring is independent of the outer diameter of the annular protrusion 13. 50 can be set inside.

  Next, as shown in FIG. 8, the end 12 side of the thin stainless steel pipe 10 is inserted into the connection port 30 of the joint body 20. Then, by tightening the cap nut 40, when the male screw 31 and the female screw 42 are screwed together, the annular protruding portion 13 is pressed by the flange portion 44, the adapter ring 50, and the resin ring 60, and proceeds to the joint body 20 side. . At this time, the annular protrusion 13 advances to a position where it comes into contact with the O-ring 35 and is in a sealed state.

  Thus, according to the pipe joint 1 which concerns on this Embodiment, even if it is a case where the cyclic | annular protrusion part 13 is previously formed in the thin stainless steel pipe 10, the cap nut 40 can be set. Therefore, the length of the joint pipe can be shortened, and the piping space can be reduced. Further, when the expanded short pipe is welded to a joint such as an elbow, it can be performed without the cap nut 40, so that the resin ring and the lubricant are not melted or peeled off due to the heat of welding, and the joint is required. The function can be fully exhibited. Further, it is possible to prevent the connection from being lost due to the deformation of the screw portion due to the heat effect.

  In the example described above, an elbow-shaped thin stainless steel pipe is shown, but it is needless to say that the present invention can be applied to other shapes of thin stainless steel pipes such as a straight pipe. Moreover, although the thin stainless steel pipe was used as the metal pipe, a metal pipe and a pipe joint having a shape in which an annular protrusion is formed in advance may be cast. Manufacturing cost can be reduced by manufacturing a metal tube by casting.

  As described above, according to the pipe joint 1 according to the present embodiment, it is possible to increase the degree of freedom of the piping structure and connection work.

  It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the present invention.

The side view which fractures | ruptures and shows a part of pipe joint which concerns on one embodiment of this invention. The side view which cuts and shows the cap nut integrated in the pipe joint partially. The exploded assembly figure which cuts and shows the cap nut partially. The front view which shows the adapter ring integrated in the cap nut. The front view which shows the sliding ring integrated in the same bag nut. The side view which cuts off the attachment procedure which attaches the same cap nut to a pipe joint, and shows it partially. The side view which cuts off the attachment procedure which attaches the same cap nut to a pipe joint, and shows it partially. The side view which cuts off the attachment procedure which attaches the same cap nut to a pipe joint, and shows it partially. The side view which shows the state in which the cap nut was attached to the pipe joint, partially cut away. The side view which shows an example of a pipe joint. The side view which cuts and shows the same pipe joint partially.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Pipe joint, 10 ... Thin-walled stainless steel pipe, 12 ... End part, 13 ... Annular protrusion, 20 ... Joint main body, 30 ... Connection port, 40 ... Cap nut, 50 ... Adapter ring, 51, 52 ... Arc member, 60 ... resin ring.

Claims (3)

A metal tube having a large-diameter annular protrusion on the end side;
A tubular joint main body having a male screw part on the outer periphery of the end part and into which the end of the metal tube is inserted,
A cap nut having an inner diameter formed larger than the outer diameter of the annular projecting portion and having an internal thread portion screwed into an external thread portion of the joint body on the inner peripheral portion;
A plurality of arcuate members that are detachably disposed on the inner periphery of the cap nut, engage with the annular protrusion of the metal tube, have an inner diameter smaller than the outer diameter of the annular protrusion, and A pipe joint comprising an adapter ring configured in combination.   The pipe joint according to claim 1, further comprising a resin ring disposed on an inner peripheral side of the adapter ring and cut at least at one place.   The pipe joint according to claim 1, wherein a lubricant is provided on an inner peripheral side of the adapter ring.

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