JP2009133417A - Pipe coupling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe coupling enabling removal of a fastening nut and a ferrule from an old pipe, and repeatedly usable by fitting and inserting the fastening unit and the ferrule to and into a new pipe. <P>SOLUTION: This pipe coupling is composed of a coupling body 1, the fastening nut 3 and the front-rear ferrules 5 and 6. A seal is performed by pressing the front side ferrule 5 in between an inner surface of a pipe receiving port 2 of the coupling body 1 and an outside surface of a pipe 4 by forwardly pushing the rear side ferrule 6 formed in a divided annular shape by fastening the pipe 4 inserted into the pipe receiving port 2 of the coupling body 1 by the fastening nut 3. The pipe 4 is held for preventing slipping-out by diametrically contracting the rear side ferrule 6, and holding of the pipe 4 is released by diametrically expanding and restoring the rear side ferrule 6 when loosening the fastening nut 3. Pipe holding force can be increased by arranging an annular projection strip 6e and an annular groove 6f on an inner peripheral surface of the rear side ferrule 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe joint used for a connection part of a fluid transfer pipe.

Conventionally, as shown in FIG. 4, a pipe 13 into which two ferrules 11 and 12 are inserted is inserted into a receiving port 15 of a joint body 14, and a tightening nut 16 is externally screwed into the receiving port 15 and tightened. Thus, the front ferrule 11 is press-fitted between the inner surface of the receiving port 15 and the outer surface of the pipe 13 to be hermetically sealed, and the rear ferrule 12 is placed between the inner surface of the front ferrule 11 and the outer surface of the pipe 13. There is known a pipe joint in which the pipe 13 is connected to the joint main body 14 by causing the pipe 13 to be wedged and preventing the pipe 13 from coming off (for example, see Patent Document 1).
Special table 2003-529032 gazette

In the pipe joint of Patent Document 1, the rear ferrule 12 is connected to the pipe 13 to prevent the pipe 13 from coming off even if the fastening nut 16 is loosened and the pipe 13 is removed from the joint body 14 when the pipe 13 is replaced. Therefore, the tightening nut 16 and the two ferrules 11 and 12 were removed from the old pipe 13 and inserted into the new pipe, and could not be used repeatedly.
Usually, the tightening nut 16 and the two ferrules 11 and 12 are sold as a set with the joint body 14, and only the tightening nut 16 and the two ferrules 11 and 12 are not sold separately. When replacing the pipe 13, it was necessary to purchase and replace the entire pipe joint including the joint body 14.

  An object of the present invention is to provide a pipe joint in which a tightening nut and a ferrule can be removed from an old pipe, and the tightening nut and the ferrule can be repeatedly inserted and inserted into a new pipe.

  In order to achieve the above object, the present invention includes a joint body, a fastening nut that is externally screwed into a pipe receiving port of the joint body, and a pipe that is externally fitted to the pipe receiving port, and In the pipe joint having the front and rear ferrules that are pushed toward the pipe receiving port by tightening the attached nut, the front and rear ferrules are composed of a front ferrule and a rear ferrule, and the front ferrule is entirely circular. The outer surface is a conical surface whose diameter increases from the front end toward the rear end, the inner surface is a cylindrical surface parallel to the axial direction, and the rear portion of this cylindrical surface is a conical surface whose diameter increases rearward. The rear ferrule has a split ring as a whole, an inner surface is a cylindrical surface parallel to the axial direction, and an outer surface is a conical surface whose diameter is reduced from the middle in the axial direction toward the front end. Rear fe And the front ferrule is pushed forward by tightening the tightening nut to press-fit the front ferrule between the pipe receiving inlet inner surface and the pipe outer surface of the joint body to perform a hermetic seal, and the rear ferrule itself is Since the outer surface is a conical surface that is reduced in diameter toward the front end in the middle of the axial direction, the conical surface at the rear end of the front ferrule receives a reduced diameter component to reduce the diameter, and holds the pipe to prevent it from coming off. When the tightening nut is loosened, the diameter is restored and the holding of the pipe is released.

According to this configuration, when the joint body and the pipe are connected, the front ferrule is press-fitted between the pipe receiving inner surface of the joint body and the outer surface of the joint by tightening the tightening nut, and the rear side is The diameter of the ferrule can be reduced to prevent the pipe from being pulled out. And when the tightening nut is loosened, the rear ferrule can be expanded and the holding of the pipe can be released, so the tightening nut and all ferrules can be removed (extracted) from the old pipe. Can be used repeatedly.
Further, according to the above configuration, the rear ferrule is pushed forward by tightening the tightening nut, and the front ferrule is press-fitted between the pipe inlet inner surface and the pipe outer surface of the joint body to perform a hermetic seal, The rear ferrule itself can be reduced in diameter to hold and hold the pipe, and when the tightening nut is loosened, the diameter can be restored and the holding of the pipe can be released.

The outer surface of the rear ferrule is a conical surface that is reduced in diameter from the middle in the axial direction toward the rear end. According to this configuration, the rear ferrule is pressed axially from both the front and rear by the front ferrule and the tightening nut by the tightening force of the tightening nut to generate the reduced diameter component force and firmly hold the pipe. And can be applied to high-pressure pipe joints.
The outer surface of the rear ferrule includes a conical surface that decreases in diameter from the middle in the axial direction toward the front end, and a conical surface that decreases in diameter from the middle in the axial direction toward the rear end at the front and rear with respect to the intermediate position in the axial direction. It may be either plane symmetric or non-plane symmetric.

Further, in the case where the conical surface whose diameter decreases from the middle of the outer surface of the rear ferrule toward the front end is a conical surface corresponding to the conical surface of the rear surface of the inner surface of the front ferrule, Contact between the conical surfaces of the ferrule can be used as surface contact to prevent mutual damage, improve durability, and enable repeated use.
Further, in the case where the surface that abuts the conical surface on the rear end side of the outer surface of the rear ferrule is a conical surface corresponding to the conical surface, the tightening nut is configured such that these contacts are surfaces of the conical surfaces. As a contact, damage to each other can be prevented, durability can be improved, and repeated use can be achieved.

The rear end of the rear ferrule may be a flat surface orthogonal to the axial direction. In this case, it is preferable that the tightening nut has a flat surface perpendicular to the axial direction that is in contact with the rear end of the rear ferrule. According to this configuration, the tightening force applied to the rear ferrule by the tightening nut can be transmitted 100% in the axial direction, and the front end of the front ferrule and the front end of the rear ferrule are tightly sealed to the pipe outer surface. And improvement of holding power can be expected.
Further, on the inner peripheral surface of the rear ferrule, an annular ridge is formed on the axial front end side, the rear end side, and the vicinity of the middle in the axial direction, and an annular groove is formed between these annular ridges. The rear ferrule can be held in contact with the outer surface of the pipe at three locations, axially front and rear, and in the middle, and the holding area of the pipe by the rear ferrule can be limited to the annular ridge surface. Since this can be non-contact, the holding force per unit area due to the reduced diameter component of the tightening force of the tightening nut can be improved. Can be definitely improved.

  ADVANTAGE OF THE INVENTION According to this invention, a clamp nut and a ferrule can be removed from old piping, and the pipe joint which inserted the clamping nut and ferrule in the new piping and was able to be used repeatedly can be provided.

Hereinafter, an embodiment of a pipe joint concerning the present invention is described based on a drawing.
As shown in FIGS. 1 to 2, the pipe joint of the present invention is inserted into a joint body 1, a tightening nut 3 that is externally screwed into a pipe inlet 2 of the joint body 1, and a pipe inlet 2. Ferrules 5 and 6 are provided that are fitted around the pipe 4 and are pushed and moved toward the pipe receiving port 2 by tightening the tightening nut 3.
A male screw 1 a is formed on the outer surface of the pipe receiving port 2 of the joint body 1, and a female screw 3 a is formed on the inner surface of the tightening nut 3 to be screwed with the male screw 1 a.

The rear surface of the inner surface of the tightening nut 3 is formed as an annular recess 3b that accommodates the front and rear ferrules 5 and 6. An annular flange 3c is formed on the rear of the annular recess 3b so as to protrude toward the inner diameter side. The inner surface of the portion 3 c is an insertion hole 3 d of the pipe 4.
An insertion hole 1b of the pipe 4 is formed on the inner surface of the pipe receiving part 2 of the joint body 1, and a positioning step 1c of the inserted pipe 4 is formed at the back of the insertion hole 1b. . Moreover, the entrance side of the insertion hole 1b is a conical surface 1d whose diameter increases from the back side toward the entrance side.
The front and rear ferrules 5 and 6 are composed of a front ferrule 5 and a rear ferrule 6. The front ferrule 5 has an annular shape as a whole, an outer surface is a conical surface 5a whose diameter increases from the front end toward the rear end, an inner surface is a cylindrical surface 5b parallel to the axial direction, and a rear portion of the cylindrical surface 5b is It is set as the conical surface 5c diameter-expanded toward back.

  Further, the rear ferrule 6 has a split ring shape as a whole, a cylindrical surface 6a whose inner surface is parallel to the axial direction, and conical surfaces 6b and 6c whose outer surfaces are reduced in diameter from the middle in the axial direction toward the front end and the rear end, respectively. It is said that. As shown in FIG. 2, the rear ferrule 6 is formed with a notch 6 d, and this notch 6 d has a minute gap (for example, about 0.5 to 0.1 mm) and is tightened by the tightening nut 3. The inner diameter in the previous natural state is slightly larger than the outer diameter of the pipe 4 to which it is applied. On the inner surface, annular ridges 6e are formed at both axial ends and in the center, and an annular groove 6f is formed therebetween.

The conical surfaces 6 b and 6 c on the outer surface of the rear ferrule 6 are conical surfaces corresponding to the conical surface 5 c on the rear surface of the inner surface of the front ferrule 5 and the front surface 3 e of the annular flange 3 c on the rear surface of the inner surface of the tightening nut 3.
The embodiment of the pipe joint of the present invention shown in FIGS. 1 and 2 has the above-described configuration. When the pipe 4 is connected to the joint body 1, as shown in FIGS. The end of the pipe 4 is inserted through the insertion hole 3d at the rear end. Thereafter, the rear ferrule 6 and the front ferrule 5 are sequentially inserted into the end of the pipe 4, and in this state, the end of the pipe 4 is inserted into the insertion hole 1 b of the pipe receiving port 2 of the joint body 1. In this case, the insertion depth of the pipe 4 is set until the end of the pipe 4 comes into contact with the positioning step portion 1c.

  Then, the tightening nut 3 is moved toward the pipe receiving port 2 of the joint body 1, and the female screw 3 a of the tightening nut 3 is screwed into the male screw 1 a of the pipe receiving port 2 of the joint body 1 and tightened. As a result, the front and rear ferrules 5 and 6 are accommodated in the annular recess 3b of the tightening nut 3, and then the rear ferrule 6 is moved to the joint body 1 side by the front surface 3e of the annular flange 3c of the tightening nut 3. It is pushed toward. As a result, the rear ferrule 6 press-fits the front ferrule 5 between the inner surface of the pipe receiving port 2 of the joint body 1 and the outer surface of the pipe 4 to perform a hermetic seal. This seal is achieved without rubber packing by the front ferrule 5 being press-fitted between the conical surface 1d on the inner surface of the pipe receiving port 2 of the joint body 1 and the outer surface of the pipe 4 so as to come into surface contact.

At the same time, the rear ferrule 6 itself has a split ring shape, and the conical surfaces 6 b and 6 c of the outer surface are the conical surfaces 5 c of the rear surface of the inner surface of the front ferrule 5 and the front surface of the annular flange 3 c of the inner surface of the tightening nut 3. By being in surface contact with 3e, the tightening force of the tightening nut 3 acts as a reduced diameter component force from both the front and rear sides. In 6e, the pipe 4 is firmly held to prevent it from coming off.
Then, when the tightening nut 3 is loosened, the rear ferrule 6 can be expanded in diameter, and the holding of the pipe 4 is released. Therefore, the rear ferrule 6 can be moved rearward to be separated from the front ferrule 5, and can be extracted together with the pipe 4 from the conical surface 1d of the pipe receiving port 2 of the joint body 1. Thereafter, the front and rear ferrules 5 and 6 and the tightening nut 3 can be removed from the pipe 4 and can be repeatedly used by being attached to other pipes.

Next, a modified embodiment of the present invention will be described with reference to FIGS. 3A to 3G show various cross-sectional shape examples of the rear ferrule 6.
First, FIGS. 3A to 3D show groups in which the outer surface of the rear ferrule 6 has an isosceles trapezoidal cross section that is plane-symmetric with respect to the intermediate position in the axial direction. A conical surface 6b whose diameter is reduced from the middle toward the front end and a conical surface 6c whose diameter is reduced from the middle in the axial direction toward the rear end are symmetrical with respect to the axially intermediate position. FIG. 3A shows a case where the inner peripheral surface is a flat surface parallel to the axial direction, and FIG. 3B shows the axial front end side, the rear end side, and the axially intermediate vicinity. An annular ridge 6e is formed at three locations on the inner peripheral surface, and an annular groove 6f is formed between these annular ridges 6e. 3 (C) and 3 (D) show that the axial width of the annular protrusion 6e is narrower and smaller than that of FIG. 3 (B), and the surface of the tightening pressure applied to the pipe 4 by the tightening nut 3 is shown. The pressure is increased to improve the holding force of the pipe 4. In addition, the cyclic | annular protrusion 3e of FIG.3 (C) is a case where a cross-sectional rectangle is made into a cross section, and the cyclic | annular protrusion 3e of FIG.

  Next, FIG. 3E shows a conical surface 6b in which the outer surface of the rear ferrule 6 is reduced in diameter from the middle in the axial direction (slightly forward from the axial intermediate position) to the front end, and the rear surface of the conical surface 6b. A cylindrical surface 6g parallel to the axial direction is formed from the end to the rear end surface of the rear ferrule 6, and the rear end of the cylindrical surface 6g is a flat surface 6h orthogonal to the axial direction. In this case, the front surface 3e of the annular flange 3c of the tightening nut 3 is preferably a flat surface orthogonal to the axial direction. In this case, the tightening force applied to the rear ferrule 6 by the tightening nut 3 can be transmitted at 100% in the axial direction, and the front end of the front ferrule 5 and the pipe 4 at the front end of the rear ferrule 6 can be transmitted. Improvement in tight sealability and holding power to the outer surface can be expected.

  3 (F) and 3 (G) show a group of the outer surface of the rear ferrule 6 having a non-isosceles trapezoidal cross section that is non-plane symmetrical with respect to the axial middle position. A conical surface 6b that decreases in diameter from the middle in the direction (axial intermediate position) toward the front end, and a conical surface 6c that decreases in diameter from the middle in the axial direction (slightly behind the axial intermediate position) toward the rear end. The former and the latter have different inclination angles so that they are non-plane symmetrical with respect to the axial middle position. In this case, the inclination angle of the conical surface 6b is smaller than the inclination angle of the conical surface 6c, and the axial length of the conical surface 6b is longer than the axial length of the conical surface 6c. As described above, when the front and rear conical surfaces 6 b and 6 c of the outer surface of the rear ferrule 6 are asymmetrical in the front and rear, the tightening force of the tightening nut 3 is reduced between the tightening nut 3 and the front ferrule 5. The ratio of conversion to the radial component force varies depending on the tilt angle. In particular, in the case of the embodiment shown in FIGS. 3F and 3G in which the inclination angle of the front conical surface 6b is smaller than the inclination angle of the rear conical surface 6c, the front end side and the rear end side of the rear ferrule 6 are used. When compared with the above, it is possible to increase the reduced diameter component force on the front end side than on the rear end side. 3 (F) shows a case where the inner surface of the rear ferrule 6 is a cylindrical surface 6a parallel to the axial direction, and FIG. 3 (G) shows both axial ends and an intermediate portion of the inner surface of the rear ferrule 6. The case is shown in which an annular protrusion 6e is formed and an annular groove 6f is formed therebetween.

  The embodiments and modified examples of the present invention are as described above. However, the present invention is not limited to these embodiments and modified examples, and can be implemented with various modifications. In addition, the outer periphery of the joint body 1 and the tightening nut 3 is formed with a rectangular portion for locking the wrench. The rectangular portion may be a hexagonal shape, but may be an octagonal shape. It may be a polygon. Further, the joint body 1, the tightening nut 3, the pipe 4 and the front and rear ferrules 5 and 6 can be all made of metal (for example, made of stainless steel or the like). It can also be applied to. Moreover, the pipe joint of this invention is divided and provided for every some size of the piping 4 applied.

It is a vertical side view of the pipe joint which concerns on this invention. It is a vertical side view of the disassembled state of the pipe joint of FIG. (A)-(G) are sectional drawings which show the modification of the cross-sectional shape of a rear side ferrule. It is a vertical side view of the conventional pipe joint.

Explanation of symbols

1 Joint body 2 Piping receptacle 3 Clamping nut 4 Piping 5 Front ferrule 6 Rear ferrule

Claims (9)

The joint body (1), the tightening nut (3) externally screwed into the pipe receiving port (2) of the joint body (1), and the pipe (4) inserted into the pipe receiving port (2) In a pipe joint provided with a ferrule (5-6) before and after being fitted and being pushed and moved toward the pipe receiving port (2) by tightening the tightening nut (3),
The front and rear ferrules (5 to 6) include a front ferrule (5) and a rear ferrule (6).
The front ferrule (5) is generally annular, the outer surface is a conical surface (5a) whose diameter increases from the front end toward the rear end, and the inner surface is a cylindrical surface (5b) parallel to the axial direction. The rear portion of the cylindrical surface (5b) is a conical surface (5c) whose diameter increases toward the rear,
The rear ferrule (6) has a generally annular shape, an inner surface is a cylindrical surface (6a) parallel to the axial direction, and an outer surface is a conical surface (6b) whose diameter is reduced from the middle in the axial direction toward the front end. As well as
The rear ferrule (6) is pushed forward by the tightening of the tightening nut (3) so that the front ferrule (5) is connected to the pipe receiving port (2) inner surface and the pipe (4) outer surface of the joint body (1). The rear ferrule (6) itself is press-fitted in between to perform a hermetic seal.
Since the outer surface is a conical surface (6b) whose diameter is reduced from the middle in the axial direction toward the front end, the conical surface (5c) at the rear end of the front ferrule (5) receives a reduced diameter component to reduce the diameter. The pipe joint is configured to hold the pipe (4) so that the diameter of the pipe (4) is restored when the tightening nut (3) is loosened to release the pipe (4).   2. The pipe joint according to claim 1, wherein an outer surface of the rear ferrule (6) is a conical surface (6 c) whose diameter is reduced from the middle in the axial direction toward the rear end.   The outer surface of the rear ferrule (6) has a conical surface (6b) whose diameter is reduced from the middle in the axial direction toward the front end and a conical surface (6c) whose diameter is reduced from the middle in the axial direction toward the rear end in the axial direction. The pipe joint according to claim 2, wherein the pipe joint is plane-symmetric with respect to an intermediate position.   The outer surface of the rear ferrule (6) has a conical surface (6b) whose diameter is reduced from the middle in the axial direction toward the front end and a conical surface (6c) whose diameter is reduced from the middle in the axial direction toward the rear end in the axial direction. The pipe joint according to claim 2, wherein the pipe joint is non-plane symmetrical with respect to an intermediate position.   The conical surface (6b) whose diameter decreases from the middle of the outer surface of the rear ferrule (6) toward the front end is a conical surface corresponding to the conical surface (5c) at the rear of the inner surface of the front ferrule (5). The pipe joint according to any one of claims 1 to 4, wherein the pipe joint is provided.   The tightening nut (3) has a front surface (3e) that contacts the conical surface (6c) on the rear end side of the outer surface of the rear ferrule (6) as a conical surface corresponding to the conical surface (6c). The pipe joint according to any one of claims 2 to 5, wherein the pipe joint is provided.   The pipe joint according to claim 1, wherein the rear end of the rear ferrule (6) is a flat surface (6h) orthogonal to the axial direction.   The tightening nut (3) is characterized in that the front surface (3e) contacting the flat surface (6h) at the rear end of the rear ferrule (6) is a flat surface perpendicular to the axial direction. The pipe joint according to claim 7.   On the inner peripheral surface of the rear ferrule (6), annular ridges (6e) are formed on the axial front end side, the rear end side, and in the vicinity of the middle in the axial direction, and between these annular ridges (6e). An annular groove (6f) is formed in the pipe joint according to any one of claims 1 to 8.

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