JP2022175808A - Manufacturing method of pipe with joint - Google Patents

Abstract

To provide a manufacturing method of a pipe with a joint capable of reducing the number of processes in comparison with a conventional method, and further reducing an outer diameter of a cylindrical portion of the joint in comparison with the conventional method.SOLUTION: In a state that a front face of a flare portion (13) formed on an end portion of a pipe (3) is kept into contact with a seal face (11) formed inside of a cylindrical portion (6) of a joint (2), the cylindrical portion (6) of a part to which a collar member (4) is inserted, is caulked from a radial outer part of the cylindrical portion (6) while pressing an end face of the collar member (4) to a rear face of the flare portion (13).SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a pipe with a joint by connecting a pipe and a joint.

Patent Document 1 describes the following method for connecting a pipe and a joint. Insert the pipe into the tubular part of the fitting. A jig is inserted between the pipe body of the pipe and the tubular portion of the joint. A portion of the inner wall of the tubular portion is plastically deformed using this jig to fix the flared portion of the pipe to the inner surface of the tubular portion. After that, the jig is pulled out, and an elastic member (for example, a rubber tube) is arranged between the cylindrical portion and the pipe body. With the elastic member arranged, the cylindrical portion is caulked from the outside in the radial direction.

JP 2020-204391 A

The method described in Patent Literature 1 includes a step of plastically deforming a part of the inner wall of the cylindrical portion using a jig, and therefore has a large number of steps. Further, in order to plastically deform a portion of the inner wall of the tubular portion using a jig, it is necessary to firmly support the tubular portion from the side opposite to the side where the jig is inserted. Therefore, a shoulder portion for receiving the force from the jig is provided outside the cylindrical portion, which increases the outer diameter of the cylindrical portion.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a pipe with a joint that requires fewer steps than the conventional method and that can make the outer diameter of the tubular portion of the joint smaller than the conventional method.

A method for manufacturing a pipe with a joint disclosed in the present application is a method for manufacturing a pipe with a joint by connecting a pipe and a joint, wherein a flare portion having a larger outer diameter than a main body portion of the pipe is formed on the pipe. A step of forming a flared portion to be formed on the end portion, a step of forming a collar member to be fitted onto the main body portion of the pipe, a step of manufacturing a collar member, an end portion of the pipe on which the flared portion is formed, and the collar. a pipe collar inserting step of inserting the member into the tubular portion of the joint; and a crimping step of crimping the cylindrical portion of the portion into which the collar member is inserted from the radially outer side of the cylindrical portion while pressing the end surface of the collar member.

According to the manufacturing method described above, the number of steps can be reduced and the outer diameter of the cylindrical portion of the joint can be made smaller than before.

It is a side view of a pipe with a joint of a 1st embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 5 is a cross-sectional view for explaining a step of fitting a tubular collar member onto the pipe main body of the pipe; FIG. 5 is a cross-sectional view for explaining a step of inserting the end of the pipe and the collar member into the tubular portion of the joint; FIG. 4 is a cross-sectional view showing a state in which the end of the pipe and the collar member are inserted into the tubular portion of the joint; It is sectional drawing of the pipe with a joint of 2nd Embodiment. It is a figure equivalent to FIG. 5 about the pipe with a joint of 2nd Embodiment. FIG. 3 is a photograph showing a cross section of a pipe with a joint having the structure shown in FIGS. 1 and 2 that was actually manufactured. FIG.

A mode for carrying out the present invention will be described with reference to the drawings. In the following description, an embodiment in which a joint called an eye joint is used as the joint 2 connected to the pipe 3 is shown. The method for manufacturing a pipe with a joint according to the present invention is not limited to joints called eye joints, and can be applied to various joints.

As shown in FIGS. 1 and 2, the jointed pipe 1 includes a joint 2 , a pipe 3 , and a cylindrical collar member 4 . Note that the pipe with joint 1 is used for hydraulic piping and the like.

The joint 2 has an annular joint main body portion 5 and a cylindrical portion 6 (socket portion) protruding from a side surface of the joint main body portion 5 . A bolt or the like is inserted through the hole 5a of the joint main body 5. As shown in FIG. A hole 5b having a diameter smaller than that of the hole 5a is formed in the peripheral wall of the joint main body 5. As shown in FIG. The holes 5a and 5b are orthogonal and communicate with each other.

The tubular portion 6 has a first tubular portion 7 on the side of the joint body portion 5 and a second tubular portion 8 on the side opposite to the side of the joint body portion 5 . A hole 9 extending in the axial direction is formed in the first tubular portion 7 . The hole 9 and the hole 5b of the joint main body portion 5 are formed integrally. The hole 9 and the hole 5b are continuous holes and serve as fluid flow paths.

A hole 10 extending in the axial direction is formed in the second tubular portion 8 . A hole 10 serves as a socket for the pipe 3, and is a hole into which the pipe 3 and the collar member 4 are inserted. Hole 10 has a larger diameter than hole 9 . The center of hole 10 and the center of hole 9 are the same, and hole 10 and hole 9 extend in the same axial direction. When the pipe 3 is inserted into the hole 10, the hole 9 and the pipe 3 communicate with each other. The hole 10 shown in FIGS. 1 and 2 is the hole after crimping, and the hole 10 before crimping is shown in FIGS. The diameter of the hole 10 before crimping is approximately the same as the outer diameter of the collar member 4 .

As shown in FIGS. 4 and 5 , an annular recess recessed toward the first tubular portion 7 is formed at the boundary portion (stepped portion) between the holes 10 and 9 . The surface of the recess on the hole center side is the seal surface 11 with which the flared portion 13 of the pipe 3 abuts. The sealing surface 11 has a tapered annular surface that tapers from the first cylindrical portion 7 side toward the second cylindrical portion 8 side, that is, tapers toward the side into which the pipe 3 is inserted. be done.

The pipe 3 has a tubular pipe body portion 12 and a flared portion 13 . A flared portion 13 is formed at the end of the pipe 3 . The outer diameter of the flared portion 13 is larger than the outer diameter of the pipe body portion 12 . The flared portion 13 has a ring shape that widens. The outer diameter of the flared portion 13 is approximately the same as the outer diameter of the collar member 4 .

For example, as shown in FIG. 3, the collar member 4 has a tapered surface 4a at its axial tip. The tapered surface 4a is an annular inclined surface that spreads toward the end. The tapered surface 4 a has a shape along the rear surface of the flared portion 13 of the pipe 3 . The rear surface of the flared portion 13 is the surface of the flared portion 13 on the pipe body portion 12 side in the axial direction of the pipe 3 . The front surface of the flared portion 13 is the opposite surface of the rear surface in the axial direction of the pipe 3 .

For example, as shown in FIG. 5 , the collar member 4 is manufactured to have a length such that a portion of the collar member 4 protrudes from the cylindrical portion 6 of the joint 2 . A collar member 4 having an inner diameter approximately equal to the outer diameter of the pipe body 12 is used.

In this embodiment, the collar member 4 is a metallic collar member, that is, a metallic collar. The material of the collar member 4 is, for example, iron (metal material). The material of the collar member 4 is not limited to iron, and may be a metal material other than iron, such as stainless steel, brass, or copper. The material of the joint 2 and the pipe 3 is also iron (metal material), for example. The material of the joint 2 and the pipe 3 is also not limited to iron, and may be a metal material other than iron, such as stainless steel, brass, or copper. Moreover, the collar member 4, the joint 2, and the pipe 3 may be plated or resin-coated.

The collar member 4 may be made of a material other than metal, such as rubber or resin.

A method for manufacturing the pipe with joint 1 will be described.

A flared portion 13 is formed at the end of the pipe 3 (a step of forming a flared portion) to prepare the pipe 3 as shown in the sectional view in FIG. In addition, a tubular collar member 4 is prepared by cutting a metallic tubular member (not shown) so that a part of it protrudes from the tubular portion 6 of the joint 2 (collar manufacturing process). At this time, the axial end surface of the collar member 4 is tapered to form a shape along the rear surface of the flared portion 13 of the pipe 3. is processed (color processing step). It should be noted that the end surface processing (tapering) of the collar member 4 is not essential.

Next, as shown in FIG. 3, the collar member 4 is fitted onto the pipe body 12 of the pipe 3 from the side where the flared portion 13 is not formed. The collar member 4 is fitted onto the pipe main body 12 from the side of the tapered surface 4a. After that, as shown in FIG. 4, the end portion of the pipe 3 on which the flared portion 13 is formed and the collar member 4 externally inserted into the pipe body portion 12 are separately manufactured and prepared as the second joint 2. It is inserted into the cylindrical portion 8 (pipe collar insertion step).

When the pipe collar inserting process is carried out, the three members, ie, the joint 2, the pipe 3, and the collar member 4, are brought into the state shown in FIG. The front surface of the flared portion 13 of the pipe 3 abuts against the sealing surface 11 formed inside the tubular portion 6 of the joint 2 , and the tapered surface 4 a of the collar member 4 abuts against the rear surface of the flared portion 13 .

In addition, in a state in which the collar member 4 is externally inserted into the pipe body portion 12 of the pipe 3, that is, in a state in which the collar member 4 is set on the end portion of the pipe 3, the end portion of the pipe 3 and the collar member 4 are connected to the joint. It is not always necessary to insert it into the second cylindrical portion 8 of 2. After inserting the end portion of the pipe 3 alone into the second tubular portion 8 of the joint 2, the collar member 4 is fitted over the pipe body portion 12, and the collar member 4 is inserted into the second tubular portion 8. good too.

Next, while the front surface of the flared portion 13 of the pipe 3 is in contact with the seal surface 11 formed inside the cylindrical portion 6 of the joint 2, the tapered surface 4a of the collar member 4 is pressed against the rear surface of the flared portion 13. Then, the second cylindrical portion 8 of the joint 2 into which the collar member 4 is inserted is crimped from the radially outer side of the cylindrical portion 6 (crimping step). Arrows in FIG. 2 indicate the crimping direction of the second tubular portion 8 . For crimping, 8-way crimping, which crimps the crimped portion from all eight directions, or hexagonal crimping, which crimps from six directions, or the like is used. The second cylindrical portion 8 may be crimped from a plurality of radially outward directions of the cylindrical portion 6 without being limited to the eight-way crimping or the hexagonal crimping.

A method of pressing the tapered surface 4a of the collar member 4 against the rear surface of the flared portion 13 is, for example, as follows. A coil spring (not shown) is fitted around the pipe main body 12 and axially pushes the collar member 4 into the second cylindrical portion 8 . Alternatively, an air cylinder or the like is used to axially push the collar member 4 into the second tubular portion 8 . The force pushing the collar member 4 axially into the second tubular portion 8 is not significant (it is not necessary). Therefore, the force that axially pushes the collar member 4 into the second cylindrical portion 8 can be received by supporting the joint main body 5 against some jig.

When the second tubular portion 8 of the joint 2 into which the collar member 4 is inserted is crimped from the radially outer side of the tubular portion 6, the collar member 4 is attached to the second tubular portion 8 and the pipe body. Along with the portion 12 , a portion is slightly recessed radially inward (plastically deformed). Further, the collar member 4 slightly extends (plastically deforms) in its axial direction. Since the collar member 4 is sandwiched between the second cylindrical portion 8 and the pipe main body portion 12, it easily extends in the axial direction.

When plastic deformation extending in the axial direction occurs in the collar member 4 , the end surface (the tapered surface 4 a in this embodiment) of the collar member 4 strongly presses the rear surface of the flared portion 13 of the pipe 3 . As a result, the front surface of the flared portion 13 is strongly pressed against the sealing surface 11 formed inside the cylindrical portion 6, and the sealing performance between the joint 2 and the pipe 3 is ensured. In addition, a portion of the second cylindrical portion 8 located on the rear side of the flared portion 13 is slightly recessed radially inward by caulking from the radially outer side, and the outer peripheral surface of the pipe body portion 12 is provided with a collar. As the member 4 is pressed, the second cylindrical portion 8 is pressed against the outer peripheral surface of the collar member 4 . As a result, the front surface of the flared portion 13 is maintained in a state of being strongly pressed against the seal surface 11, and the pipe 3 will not come off from the joint 2 unless a very large tensile force acts. FIG. 8 is a photograph of the actually manufactured pipe with joint 1 having the structure shown in FIGS. The manufactured pipe with joint 1 was cut in half in the axial direction and photographed. As can be seen from FIG. 8, the front surface of the flared portion 13 of the pipe 3 is reliably pressed against the seal surface 11 inside the joint 2, and this state is maintained.

(effect)
The second cylindrical portion 8 of the joint 2 into which the collar member 4 is inserted is moved to the diameter of the cylindrical portion 6 without particularly pressing the end surface of the collar member 4 against the rear surface of the flared portion 13 of the pipe 3 . It is possible to extend (plastically deform) the collar member 4 in its axial direction even if it is caulked from the direction outside. However, in this case, the collar member 4 may move in the direction of coming out of the second tubular portion 8 . Therefore, it is difficult for the front surface of the flared portion 13 to be strongly pressed against the sealing surface 11 , and it is difficult to ensure the sealing performance between the joint 2 and the pipe 3 .

On the other hand, in the manufacturing method described above, the end surface of the collar member 4 (in this embodiment, the tapered surface 4a) is pressed against the rear surface of the flared portion 13 of the pipe 3, and the joint where the collar member 4 is inserted is inserted. 2 is crimped from the radially outer side of the tubular portion 6 . The crimping takes a short time, and the force acting on the outer peripheral surface of the second tubular portion 8 is like an impact force. Therefore, by crimping the second cylindrical portion 8 from the radially outer side while pressing the end face of the collar member 4 against the rear surface of the flared portion 13, the collar member 4 moves in the direction of coming out of the second cylindrical portion 8. can be prevented, and the front surface of the flared portion 13 can be in a state of being strongly pressed against the seal surface 11.例文帳に追加

Further, in the manufacturing method described above, there is no step of plastically deforming a part of the inner wall of the cylindrical portion 6 using a jig as in Patent Document 1 (Japanese Patent Application Laid-Open No. 2020-204391). Therefore, there is no process of extracting the jig from the cylindrical portion 6 . Therefore, according to the manufacturing method described above, the number of steps can be reduced as compared with the conventional method. In addition, since it is not necessary to provide the cylindrical portion 6 with a shoulder portion for receiving the force from the jig as in Patent Document 1, the outer diameter of the cylindrical portion 6 can be reduced accordingly.

Further, in the above-described manufacturing method, in the pipe collar insertion step, after the collar member 4 is fitted onto the pipe main body 12, the end of the pipe 3 on which the flared portion 13 is formed and the collar member 4 are It is inserted into the second cylindrical portion 8 (cylindrical portion 6) of the joint 2. According to this, after inserting the end of the pipe 3 alone into the second tubular portion 8 (tubular portion 6) of the joint 2, the collar member 4 is inserted into the second tubular portion 8 (tubular portion 6). Insertion of the pipe 3 and the collar member 4 into the tubular portion 6 becomes easier than in the case of doing so.

Further, by processing the end surface of the collar member 4 into a shape (tapered surface 4a in this embodiment) along the rear surface of the flared portion 13, the contact area between the end surface of the collar member 4 and the rear surface of the flared portion 13 is increased. As a result, the pressing of the flared portion 13 against the sealing surface 11 by caulking becomes more reliable. Also, the end portion of the collar member 4 and the flare portion 13 are integrated.

In addition, by manufacturing the collar member 4 in such a length that a portion of the collar member 4 protrudes from the tubular portion 6 of the joint 2, the collar member 4 is attached to the rear surface of the flared portion 13 when performing the caulking process. It becomes easier to press the end face.

Moreover, in this embodiment, a metal collar is used as the collar member 4 . With this configuration, the front surface of the flared portion 13 can be pressed against the seal surface 11 more strongly than when the collar member 4 made of rubber or resin is used.

FIG. 6 is a cross-sectional view of the pipe with joint 201 of the second embodiment. FIG. 7 is a cross-sectional view showing the state of the joint-equipped pipe 201 before the crimping process. Regarding the pipe with a joint 201 of the second embodiment, the members constituting the pipe with a joint 1 of the first embodiment, the members similar to each part, and the members constituting the pipe with a joint 1 of the first embodiment, each part are given the same reference numerals.

The difference between the jointed pipe 1 of the first embodiment and the jointed pipe 201 of the second embodiment is the structure around the flared portion of the pipe 3 .

The outer diameter of the flared portion 14 of the pipe 3 that constitutes the jointed pipe 201 of the second embodiment is larger than the outer diameter of the pipe body portion 12 . The flare portion 14 has a tapered ring shape. The outer diameter of the flared portion 14 is approximately the same as the outer diameter of the collar member 4 .

The sealing surface 15 formed at the boundary portion (stepped portion) between the hole 10 and the hole 9 in the cylindrical portion 6 is aligned with the shape of the front surface of the flared portion 14 and extends from the first cylindrical portion 7 side to the second cylindrical portion. It is a tapered annular surface that widens toward the side of the shaped portion 8, that is, that widens toward the side into which the pipe 3 is inserted. The flared portion 14 of the pipe 3 contacts the seal surface 15 .

The end surface 4b of the collar member 4 that contacts the rear surface of the flared portion 14 of the pipe 3 has its inner corners chamfered over the entire circumference so as to follow the rear surface of the flared portion 14 of the pipe 3. As in the case of the first embodiment, it is not essential to process the end surface of the collar member 4 . In the second embodiment, the R chamfering process is not essential.

A method for manufacturing the pipe with a joint 201 of the second embodiment is the same as the method for manufacturing the pipe with a joint 1 according to the first embodiment, so the description thereof will be omitted.

The present invention is not limited to the above embodiments, and elements of the above embodiments can be appropriately combined or various modifications can be made to the above embodiments without departing from the scope of the invention.

For example, the above embodiment can be modified as follows.

The collar member 4 does not have to be formed in such a length that a portion of the collar member 4 protrudes from the cylindrical portion 6 of the joint 2 . That is, the collar member 4 may be formed to have a length such that the end surface of the tubular portion 6 and the collar end surface thereof are flush with each other when inserted into the tubular portion 6. It may be formed to have a length such that the two tubular portions 8) can be entirely accommodated.

1, 201: pipe with joint 2: joint 3: pipe 4: collar member 4a: tapered surface (end surface)
4b: End surface 6: Cylindrical portions 11, 15: Seal surface 12: Pipe body portions 13, 14: Flare portion

Claims (5)

A method for manufacturing a pipe with a joint by connecting a pipe and a joint,
a flare portion forming step of forming a flare portion having an outer diameter larger than that of the pipe main body portion of the pipe at the end portion of the pipe;
a collar manufacturing process for manufacturing a cylindrical collar member to be fitted onto the pipe main body;
a pipe collar inserting step of inserting the end portion of the pipe on which the flared portion is formed and the collar member into the cylindrical portion of the joint;
With the front surface of the flared portion in contact with the sealing surface formed inside the cylindrical portion, the end surface of the collar member is pressed against the rear surface of the flared portion, and the portion where the collar member is inserted is pressed. a crimping step of crimping the cylindrical portion from the radially outer side of the cylindrical portion;
comprising a
A method for manufacturing a pipe with a fitting. In the method for manufacturing a pipe with a fitting according to claim 1,
In the pipe collar inserting step, after the collar member is fitted onto the pipe main body, the end of the pipe on which the flared portion is formed and the collar member are inserted into the tubular portion of the joint. insert,
A method for manufacturing a pipe with a fitting. In the method for manufacturing a pipe with a fitting according to claim 1 or 2,
A collar processing step performed before the pipe collar inserting step, further comprising a collar processing step of processing the end surface of the collar member into a shape along the rear surface of the flared portion.
A method for manufacturing a pipe with a fitting. In the method for manufacturing a pipe with a joint according to any one of claims 1 to 3,
In the collar manufacturing step, the collar member is manufactured to a length such that a portion of the collar member protrudes from the tubular portion of the joint.
A method for manufacturing a pipe with a fitting. In the method for manufacturing a pipe with a fitting according to any one of claims 1 to 4,
wherein the collar member is a metallic collar;
A method for manufacturing a pipe with a fitting.

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