JP4882827B2 - Piping joint structure - Google Patents

Description

  The present invention relates to a joint structure for pipes that connect pipes to each other.

  As a conventional joint structure of this type, a structure as shown in FIG. 5 is known.

  FIG. 5 is a cross-sectional view of a conventional joint structure 200 for piping. In FIG. 5, a first pipe 10 having a substantially cylindrical shape and a second pipe 20 having a substantially cylindrical shape that are connected to each other are arranged coaxially so that the directions of the axes A thereof coincide with each other. The end of the first pipe 10 is provided with a first flange 12 having a substantially circular plate shape, and the end of the second pipe 20 is also provided with a second flange 22 having a substantially circular plate shape. And the end surface 11 of the 1st piping 10 containing the 1st flange 12 and the end surface 21 of the 2nd piping 20 containing the 2nd flange 22 are arrange | positioned facing each other.

  A plurality of, for example, six first bolt holes 16 are formed in the outer peripheral portion of the first flange 12 at substantially equal intervals in the circumferential direction, and a plurality of, for example, six outer peripheral portions of the second flange 22 are also formed at substantially equal intervals in the circumferential direction. For example, six second bolt holes 26 are formed. Here, the first bolt hole 16 and the second bolt hole 26 are arranged to face each other, and the bolt 30 is inserted into the first bolt hole 16 and the second bolt hole 26 and is tightened by the nut 32. Thereby, the end surface 11 of the first pipe 10 and the end surface 21 of the second pipe 20 are joined together. By joining together in this way, the flow path 40 is formed by both pipes.

  An annular groove 14 is formed on the end surface 11 of the first pipe 10. A rubber-like elastic O-ring 18 as an annular seal member is attached to the annular groove 14, and is compressed by being pressed by the end surface 21 of the other second pipe 20.

  The high pressure gas is supplied into the first pipe 10 and the second pipe 20 thus connected to each other, for example, from the first pipe 10 toward the second pipe 20.

  Patent Document 1 discloses that argon gas is sealed in an annular groove in which an O-ring is mounted, and the gas in the pipe is prevented from passing through the sealing material.

  Furthermore, in Patent Document 2, one flange provided at the end of one pipe and the other flange provided at the end of the other pipe are arranged to face each other, and an intermediate flange is arranged between the flanges. In addition, it is disclosed that an O-ring is disposed between the end face of the intermediate flange and the other end face of the flange facing the intermediate flange.

JP-A-7-68151 JP 2004-19832 A

  By the way, in the joint structure in which the O-ring 18 is attached to the annular groove 14 formed on the end face of the pipe and the pipes are joined together via the O-ring 18, when high-pressure gas is sealed in the pipe, FIG. As shown, a space 120 (hereinafter referred to as a space 120) between the pipe inner peripheral side of the annular groove 14 and the O-ring 18 through a gap 110 between the end face 11 of the first pipe 10 and the end face 21 of the second pipe 20. Leaked into the "inner peripheral space"). Further, the high-pressure gas reaches a space 122 between the O-ring 18 and the pipe outer peripheral side of the annular groove 14 (hereinafter referred to as “outer peripheral space”). As described above, when the pressure in the pipe decreases in a state where the high-pressure gas is accumulated in the outer peripheral space 122 of the annular groove 14, the pressure difference between the pressure in the outer peripheral space 122 and the pressure in the pipe causes a difference in FIG. As shown in FIG. 3, a pressure P applied to the inside of the pipe is applied to the O-ring 18, and a part of the O-ring 18 may protrude from the gap 110 between the end surface 11 and the end surface 21.

  The present invention provides a pipe joint structure in which an end face of a pipe and an end face of another member are connected via an annular seal member, and the annular seal member mounted in an annular groove formed on at least one of the end faces has both ends. It aims at preventing it from protruding into the gap between the surfaces.

A pipe joint structure according to the present invention is a pipe joint structure in which an end face of a pipe and an end face of another member are connected via an annular seal member made of a rubber-like elastic body , and the pipe is sealed. An annular groove on which the annular seal member is mounted is formed on at least one of an end surface of the pipe or an end surface of the other member, and at least one through groove reaching the outer peripheral surface of the pipe from the annular groove is an end surface of the pipe Alternatively, it is formed on at least one of the end faces of the other member, and the size of the through groove is determined by the pressure inside the pipe so that the annular seal member is connected to the through groove and the end face of the pipe or the end face of the pipe of the other member. is set so that the does not protrude into the gap, it characterized that you have.

  In one aspect of the joint structure for piping according to the present invention, the through groove is formed by laser processing.

  According to the present invention, at least one through groove extending from the annular groove to the outer peripheral surface of the pipe is formed on at least one of the end face of the pipe or the end face of the other member, so that the annular seal member is between the both end faces. It can be prevented from protruding into the gap.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment specifically showing the best mode for carrying out the invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a joint structure 100 according to this embodiment. Since the cross section of the joint structure 100 is the same as that of the conventional joint structure 200 described above, the same members as those of the joint structure 200 are denoted by the same reference numerals and description thereof is omitted.

    FIG. 2 is a view of the end surface 11 of the first pipe 10 as viewed from the direction of the arrow along the line BB in FIG. Hereinafter, the outer peripheral side end surface of the first pipe 10 is referred to as the “outer peripheral side seal surface” 11a, and the inner peripheral side end surface of the first pipe 10 is the second pipe. The seal surface in contact with the end surface is referred to as an “inner peripheral side seal surface” 11b.

  In the present embodiment, the first pipe 10 and the second pipe 20 constituting the joint structure 100 are both metal pipes, and the bolts 30 are inserted into the first bolt holes 16 and the second bolt holes 26 and the nuts 32 are inserted. The end surface 11 and the end surface 21 are directly pressed to form a so-called metal seal between metal surfaces. In this way, when the pipes are tightened with the nut 32, the outer peripheral side seal surface 11a is closer to the tightening portion of the nut 32 than the inner peripheral side seal surface 11b, and therefore the tightening torque by the nut 32 is large. That is, the outer peripheral seal surface 11a has higher sealing performance than the inner peripheral seal surface 11b. Therefore, when high-pressure gas is sealed in the flow path 40 inside the pipe, the high-pressure gas accumulated in the outer peripheral space 122 formed by the O-ring 18 and the outer peripheral side of the annular groove 14 is removed from the outer peripheral seal surface 11a. It is hard to leak outside the pipe. Therefore, when the pressure in the pipe decreases, the inner peripheral seal surface 11b and the end face 21 of the second pipe are caused by a pressure difference between the pressure in the outer peripheral space 122 and the pressure in the pipe (in the flow path 40). A part of the O-ring 18 may protrude from the gap.

  Therefore, in this embodiment, as shown in FIG. 2, the outer periphery in the radial direction of the first pipe 10 from the outer peripheral side wall 14 a of the annular groove 14 to the outer peripheral seal surface 11 a which is the outer peripheral end face of the first pipe 10. A through groove 19 reaching the surface 10b is formed. By forming the through groove 19, the high-pressure gas accumulated in the outer peripheral space 122 is discharged to the outside of the first pipe 10. Therefore, even when the pressure in the pipe decreases, a pressure difference between the pressure in the outer peripheral space 122 and the pressure in the pipe is less likely to occur. Therefore, even when the pressure in the pipe decreases, it becomes difficult for the pressure P to the inside of the pipe to be applied to the O-ring 18, preventing a part of the O-ring 18 from protruding into the gap 110 between the end face 11 and the end face 21. be able to.

  Here, if the through groove 19 is a very large groove, when high-pressure gas is sealed in the pipe, the pressure from the inside of the pipe causes a part of the O-ring 18 to pass through the through groove 19 and the second pipe 20. There is a risk of protruding into the gap with the end surface 21. Therefore, the size of the through groove 19 may be determined based on an experiment or the like in advance according to the pressure inside the pipe at the time of high-pressure gas filling, the material and hardness of the O-ring 18, for example, the depth of the through groove 19. May be about 10 μm.

  3A, a plurality of through grooves 19 may be formed on the outer peripheral side seal surface 11a, or a plurality of through grooves 19 may be formed radially around the axis A as shown in FIG. 3B.

  The through groove 19 may be formed on the end surface 11 of the first pipe 10 by, for example, laser processing. For example, from the viewpoint of ease of laser processing, laser processing may be performed by scanning the laser in a straight line in the radial direction with respect to the end surface 11 of the first pipe, as shown in FIG. 3C. Here, when the laser beam is simply scanned in the radial direction, a groove is also formed on the inner peripheral seal surface 11b. However, as described above, the depth of the groove is set such that the O-ring does not protrude. Therefore, even if a groove is formed on the inner peripheral seal surface 11b, there is no significant problem.

  Moreover, the technique shown in this embodiment is applicable also in the case of another joint structure. For example, as shown in FIG. 4, the technique shown in the above embodiment can also be applied when a circular flange 50 is arranged as another member on the end face of the first pipe 10 to seal the pipe. In addition, as disclosed in Patent Document 2, the technique shown in the above embodiment can also be applied when an intermediate flange is disposed as another member between the pipes and the pipes are sealed.

  Moreover, said embodiment demonstrated the example which forms a through groove in the end surface of piping by the side where an annular groove is formed. However, since the gas accumulated in the outer peripheral space only needs to be discharged to the outside of the pipe, a through groove may be formed on the end face of the pipe on the side where the annular groove is not formed. Moreover, you may form a through groove in the both end surfaces of both piping, respectively.

It is sectional drawing of the joint structure of piping concerning this embodiment. It is a figure at the time of seeing the end surface of 1st piping from the arrow direction along the BB line in FIG. It is a figure for demonstrating the penetration groove | channel formed in the end surface of 1st piping. It is a figure for demonstrating the penetration groove | channel formed in the end surface of 1st piping. It is a figure for demonstrating the penetration groove | channel formed in the end surface of 1st piping. It is sectional drawing of the joint structure of piping which concerns on the modification of this embodiment. It is sectional drawing of the joint structure of the conventional piping. It is a figure for demonstrating the case where a part of O-ring protrudes in the clearance gap between the end surfaces which contact | connect through an O-ring. It is a figure for demonstrating the case where a part of O-ring protrudes in the clearance gap between the end surfaces which contact | connect through an O-ring.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 1st piping, 11 end surface, 11a Outer peripheral side sealing surface, 11b Inner peripheral sealing surface, 14 Annular groove, 18 O-ring, 19 Through groove, 20 Second piping, 21 End surface, 30 Bolt, 32 Nut, 40 Flow path , 100 joint structure, 110 gap, 120 inner space, 122 outer space.

Claims (2)

A pipe joint structure for connecting an end face of a pipe and an end face of another member via an annular seal member made of a rubber-like elastic body , and sealing the pipe,
An annular groove in which the annular seal member is mounted is formed on at least one of an end face of the pipe or an end face of the other member;
At least one through groove reaching from the annular groove to the outer peripheral surface of the pipe is formed on at least one of an end face of the pipe or an end face of the other member ;
The size of the through groove, that you have been set so that the annular sealing member by the pressure inside the pipe does not protrude into the gap between the end surface of the pipe end face or the other member of the pipe and the through-groove Characteristic piping joint structure. In the pipe joint structure according to claim 1,
The joint structure for piping, wherein the through groove is formed by laser processing.

Images