JP6515822B2 - Pipe fitting - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a pipe fitting used for water service, for example.

  As shown in FIG. 8, the pipe joint of Patent Document 1 includes a joint body 101 having a socket portion 101 a, a resin short pipe 102 inserted into and engaged with the socket portion 101 a, and the resin short pipe 102. A seal ring 103 for sealing between the outer peripheral surface of the housing 101 and the inner peripheral surface of the socket 101a, and an in-core 104 inserted and disposed inside the resin-made short tube 102.

  In the pipe joint, the inspection plug 110 is inserted into the joint body 101 and the resin short pipe 102 in order to perform a leak inspection of the seal ring 103. The inspection plug 110 can introduce an inspection fluid into the inside of the fitting, and allows the inspection fluid to reach the seal ring 103.

  The inspection plug 110 includes a first inspection seal ring 112 and a second inspection seal ring 113 in order to establish the inspection flow path 111 from the inspection plug 110 to the seal ring 103 inside the pipe joint. ing. The first inspection seal ring 112 seals between the inspection plug 110 and the inner peripheral surface of the in-core 104. The second test seal ring 113 seals between the test plug 110 and the non-insertion area where the resin short pipe 102 has not reached on the inner peripheral surface of the joint body 101.

Patent No. 4939826

  However, in the above-mentioned pipe joint, at the time of the leak inspection of the seal ring 103, the first end (end on the right side in the drawing) of the gap between the inner peripheral surface of the resin short pipe 102 and the outer peripheral surface of the in core 104 is for inspection. It is located in the atmosphere in the flow path 111. Further, the second end (end on the left side in the drawing) of the gap between the inner circumferential surface of the resin short tube 102 and the outer circumferential surface of the in-core 104 is located in a pressure atmosphere different from that in the inspection channel 111. Therefore, there is a problem that the leak inspection of the seal ring 103 can not be suitably performed because the gap can be a leak path of the test fluid.

  An object of the present invention is to provide a pipe joint capable of suitably performing a leak test.

Hereinafter, the means for solving the above-mentioned subject and its operation effect are described.
The piping joint for solving the above problems includes a first flow passage member having an outer cylindrical portion, a second flow passage member having an inner cylindrical portion inserted into the outer cylindrical portion and snap- engaged, and the inner cylindrical portion. A seal ring for a cylindrical portion that seals between an outer peripheral surface and an inner peripheral surface of the outer cylindrical portion, and an in- core inserted and disposed inside the inner cylindrical portion to strengthen the snap engagement . An inspection plug for introducing an inspection fluid for performing a leak inspection of the seal ring for the cylinder part can be inserted inside the inner cylinder part, and the inspection plug is for the cylinder part from the inspection plug In the piping joint including the inspection seal ring for establishing the inspection flow path to the seal ring, a step is provided on the inner peripheral surface of the inner cylindrical portion, and the step is bounded on the inner peripheral surface. The in-core is disposed on the side of the large diameter region The small-diameter region side with the step as a boundary in the inner peripheral surface, the inspection seal ring, characterized in that the test sealing surface forming a can abut annular is provided.

  According to the above configuration, at the time of the leak inspection of the seal ring for the cylindrical portion, the seal ring for inspection of the inspection plug is not the inner peripheral surface of the in-core but the inner peripheral surface (the seal surface for inspection) of the inner cylindrical portion. Since it is in direct contact, the gap between the outer peripheral surface of the in core and the inner peripheral surface of the second flow passage member is blocked from the inspection flow passage. Therefore, since the first end and the second end of the gap are both located in a pressure atmosphere different from that in the test channel, the gap can be prevented from becoming a leak path of the test fluid, and the cylinder Leak inspection of the seal ring for part can be suitably performed.

  Further, according to the above configuration, the in-core is disposed on the large diameter region side bordering the step on the inner circumferential surface of the inner cylindrical portion, and the inspection seal surface is formed on the small diameter region side bordering the step ing. Therefore, the setting of reducing the difference in diameter between the inner diameter of the in-core and the inner diameter of the seal surface for inspection on the inner side of the inner cylindrical portion becomes easy. And if it sets in this way, the change of the passage cross-sectional area of the fluid in the part corresponding to the above-mentioned diameter difference when fluid flows inside the inner cylinder part can be suppressed, and the smooth flow of the above-mentioned fluid is secured it can.

  In addition, it is preferable that the said coupling for piping is comprised as follows. That is, the inspection seal surface is replaced with a first inspection seal surface, and a first inspection seal ring and a second inspection seal ring are provided as the inspection seal ring on the inspection plug, and the first inspection is performed. The first inspection seal ring can be in contact with the sealing surface, and the second inspection seal is in the non-insertion region where the inner cylindrical portion does not reach the inner peripheral surface of the first flow path member. A second inspection seal surface having an annular shape to which the ring can abut, and the second inspection seal surface and the first inspection seal surface are coaxially arranged and have the same inner diameter. I assume.

Sectional drawing which shows the structure of the coupling for piping. The front view which shows the slit of the outward claw part in a 2nd flow path member. Sectional drawing which shows the recess and temporary holding part of a 2nd flow path member. Sectional drawing which shows the temporary insertion state of in core with respect to the inner cylinder part of a 2nd flow path member. Sectional drawing which shows the mounting state of the coupling for piping with respect to the test | inspection plug at the time of a leak test | inspection. Sectional drawing which shows the recess of a 2nd flow-path member, and the other example of a temporary holding part. Sectional drawing which shows the recess of a 2nd flow-path member, and the other example of a temporary holding part. Sectional drawing which shows the conventional example of a pipe joint.

Hereinafter, one embodiment of a pipe fitting will be described with reference to FIGS. 1 to 5.
The piping joint 1 shown in FIG. 1 includes a cylindrical first flow path member 2 made of metal or resin, and a cylindrical second flow path member 3 made of resin engaged with the first flow path member 2. And an in-core 4 made of metal or hard resin for achieving long-term engagement of the second flow path member 3 with the first flow path member 2.

  An external thread 5 for connecting the pipe fitting 1 to a device such as a water faucet is formed on the outer peripheral surface of a portion near the one end (left end in FIG. 1) of the first flow path member 2. An outer cylindrical portion 6 for attaching the second flow path member 3 is provided at a portion near the other end (the right end in FIG. 1) in the first flow path member 2. Inside the center between both ends of the first flow path member 2, a stopper surface 7 orthogonal to the axis of the first flow path member 2 is formed. An inward claw portion 8 is formed on a portion near the right end of the first flow path member 2 on the inner peripheral surface of the outer cylinder portion 6 in the first flow path member 2, and the first class than the inward claw portion 8 An accommodating groove 10 in which the cylindrical portion seal ring 9 is accommodated is formed in a portion close to the inner side of the passage member 2.

  The inward claw portion 8 protrudes from the inner peripheral surface of the outer cylindrical portion 6 toward the axis of the first flow path member 2 and is formed in an annular shape extending in the circumferential direction of the inner peripheral surface of the outer cylindrical portion 6. A tapered surface 8 a whose diameter decreases toward the inner side of the first flow path member 2 is formed in a portion on the right end side of the first flow path member 2 in the inward claw portion 8. On the other hand, a vertical surface 8 b perpendicular to the axis of the first flow path member 2 is formed at a portion on the left end side of the first flow path member 2 in the inward claw portion 8.

  A portion near the one end (right end in FIG. 1) of the second flow path member 3 in the axial direction is a large diameter portion connectable to a water supply pipe or the like. A heating wire coil 13 is provided on the inner circumferential surface of the large diameter portion, and a pair of electrodes 14 connected to the heating wire coil 13 project outward from the outer circumferential surface of the large diameter portion. And by supplying electricity to the heating wire coil 13 in a state where the resin distribution pipe is inserted in the large diameter part, the contact part of the above distribution pipe and the large diameter part is melted and joined together ing. On the other hand, a portion near the other end (left end in FIG. 1) of the second flow path member 3 in the axial direction is formed smaller in diameter than the large diameter portion, and the outer cylindrical portion 6 in the first flow path member 2 It becomes the inner cylinder part 12 inserted inside of.

  The outer diameter of the inner cylindrical portion 12 is equal to or slightly smaller than the inner diameter of the outer cylindrical portion 6 in the first flow path member 2. On the outer peripheral surface of the inner cylindrical portion 12, an outward facing claw portion 16 snap-engaging with the inward facing claw portion 8 of the first flow passage member 2 is formed. A tapered surface 16 a whose diameter decreases toward the left end of the second flow path member 3 is formed at a portion on the left end side of the second flow path member 3 in the outward claw portion 16. On the other hand, a vertical surface 16 b orthogonal to the axis of the second flow passage member 3 is formed on the right end side portion of the second flow passage member 3 in the outward claw portion 16. Furthermore, a slit 22 extending in the axial direction of the second flow passage member 3 is formed between the tapered surface 16 a and the vertical surface 16 b in the outward facing claw portion 16.

  In addition, as shown in FIG. 2, although the slit 22 of this example is formed in one circumferential direction of the inner cylinder part 12 of the 2nd flow path member 3 in the outward claw part 16, in the circumferential direction You may form in multiple places along.

  As shown in FIG. 1, when the inner cylindrical portion 12 of the second flow path member 3 is attached to the inside of the outer cylindrical portion 6 of the first flow path member 2, that is, the outward claw portion 16 is an inward claw portion 8 When the snap engagement is performed, the vertical surface 16 b of the outward claw portion 16 faces the vertical surface 8 b of the inward claw portion 8 in the axial direction of the first flow passage member 2. Under this state, the small diameter portion of the inner cylindrical portion 12 is prevented from coming off the outer cylindrical portion 6 by the contact between the vertical surface 16 b of the outward claw 16 and the vertical surface 8 b of the inward claw 8. .

  When the small diameter portion of the inner cylindrical portion 12 is attached to the outer cylindrical portion 6, that is, the outward facing claw portion 16 snap-engages with the inward facing claw portion 8 and the vertical surface 16b and the vertical surface 8b face each other. At the same time, the second flow path member 3 can be displaced relative to the first flow path member 2 in the rotational direction about the axis. When the small diameter portion of the inner cylinder portion 12 is attached to the outer cylinder portion 6, the cylinder ring seal ring 9 seals the space between the outer cylinder portion 6 and the small diameter portion.

  A step 18 is provided on the inner peripheral surface of the inner cylindrical portion 12 of the second flow path member 3. On the inner peripheral surface of the inner cylindrical portion 12, a first inspection seal surface 19 having an annular shape is provided on the small diameter region side bordering the step 18. Further, in the non-insertion region where the inner cylindrical portion 12 does not reach on the inner peripheral surface of the first flow path member 2, an annular shape coaxial with the first inspection seal surface 19 and having the same inner diameter is provided. A second inspection seal surface 20 is provided. The first inspection seal surface 19 and the second inspection seal surface 20 are used when a leak inspection of the cylindrical portion seal ring 9 is performed. On the other hand, on the inner peripheral surface of the inner cylindrical portion 12 of the second flow passage member 3, the cylindrical in-core 4 is disposed on the large diameter region side bordering the step 18. At the right end of FIG. 1 in the in-core 4, a flange 17 is formed in contact with the boundary between the inner cylindrical portion 12 and the large diameter portion inside the second flow path member 3.

  The outer diameter of the portion other than the flange 17 in the in-core 4 is slightly larger than the inner diameter of the inner cylindrical portion 12. Then, when the above-mentioned portion of the in-core 4 is inserted inside the inner cylindrical portion 12, it is suppressed that the portion corresponding to the outward claw portion 16 in the inner cylindrical portion 12 is deformed in the diameter reducing direction and, accordingly, along with the deformation. It is suppressed that the snap engagement of the outward claw part 16 and the inward claw part 8 is cancelled | released. Therefore, by inserting the in-core 4 inside the inner cylindrical portion 12, the snap engagement between the outward claw 16 and the inward claw 8 becomes strong, and the snap engagement is maintained over a long period of time You will be able to

  As shown in FIG. 3, a plurality of recesses 21 extending in the circumferential direction are formed at the end portion on the large diameter portion side in the inner peripheral surface of the inner cylindrical portion 12, and A holding unit 23 is provided. The temporary holding portions 23 are provided at equal intervals in the circumferential direction at the end portion on the large diameter portion side of the inner peripheral surface of the inner cylindrical portion 12, and as shown in FIG. When inserted into the inside of the cylindrical portion 12, the incore 4 is held in contact with the outer peripheral surface of the end portion.

  In addition, by forming the recess 21 (FIG. 3) at the end on the large diameter side of the inner peripheral surface of the inner cylindrical portion 12, the end of the in-core 4 is temporarily inserted into the inner cylindrical portion 12. When the inner cylindrical portion 12 is inserted into the outer cylindrical portion 6 of the first flow path member 2, the inner cylindrical portion 12 is contracted in the diameter reducing direction so that the outward facing claw portion 16 engages with the inward facing claw portion 8. It becomes easy to produce the same deformation at the time of deformation. This is because when the inner cylindrical portion 12 tries to deform in the diameter reducing direction, the meat of the temporary holding portion 23 in contact with the outer peripheral surface of the end portion of the in-core 4 can be released into the recess 21. .

Next, a leak inspection of the cylindrical seal ring 9 in the pipe joint 1 will be described.
FIG. 5 shows an outline of an inspection apparatus which performs the above-mentioned leak inspection. In this inspection apparatus, an inspection plug 31 to which the assembled piping joint 1 can be attached is formed to protrude. Inside the test plug 31, a flow path 32 for flowing a test fluid (air, water, etc.) used for the leak test is formed. The flow path 32 is opened at the outer peripheral surface of the tip of the inspection plug 31. Then, in a state where the inspection plug 31 is inserted from the large diameter side of the second flow passage member 3 in the pipe joint 1 to the inside of the inner cylindrical portion 12, the opening of the flow passage 32 corresponds to the inner cylindrical portion 12. It comes to be positioned corresponding to the step 18.

  An accommodation groove 34 for accommodating the first inspection seal ring 33 is formed on the outer peripheral surface of the front end portion of the inspection plug 31 at the front end side (upper side in FIG. 5) than the opening of the flow passage 32. In addition, on the outer peripheral surface of the distal end portion of the inspection plug 31, an accommodation groove 36 in which the second inspection seal ring 35 is accommodated is formed in the proximal end side (the lower side in FIG. 5) than the opening of the flow path 32. It is done. Then, in a state in which the inspection plug 31 is inserted inside the inner cylindrical portion 12, while the first inspection seal ring 33 abuts on the first inspection seal surface 19 of the second flow path member 3, The second inspection seal ring 35 abuts on the second inspection seal surface 20 of the first flow passage member 2.

  When the first inspection seal ring 33 and the second inspection seal ring 35 of the inspection plug 31 abut on the first inspection seal surface 19 and the second inspection seal surface 20 respectively, the flow on the outer peripheral surface of the inspection plug 31 A test flow channel 37 is established between the opening of the passage 32 and the cylinder portion seal ring 9 and between the first flow channel member 2 and the second flow channel member 3 for flowing the test fluid. Then, when the test fluid flows into the test flow path 37 from the test plug 31 (flow path 32), the test fluid reaches the cylindrical seal ring 9 and the leak test is performed.

  In the leak inspection described above, if there is a leak of the test fluid at the seal ring 9 for the cylindrical portion, the test fluid that has leaked is for piping from between the outer peripheral surface of the inner cylindrical portion 12 and the inner peripheral surface of the outer cylindrical portion 6 It flows out of the joint 1. For this reason, by checking whether the test fluid flows out to the outside of the pipe joint 1, a test (leak test) is performed whether there is a leak of the test fluid at the tubular seal ring 9 or not. .

Next, the operation of the pipe joint 1 will be described.
As shown in FIG. 5, when the leak inspection of the cylinder part seal ring 9 is performed, the first inspection seal ring 33 of the inspection plug 31 is not the inner peripheral surface of the in-core 4 but the inner cylinder part 12. It abuts against the first inspection seal surface 19 which is the inner peripheral surface.

  Here, if the first inspection seal ring 33 is in contact with the inner circumferential surface of the in-core 4, the outer circumferential surface of the in-core 4 and the inner circumferential surface of the second flow passage member 3 (inner cylindrical portion 12) The first end (upper end in FIG. 5) of the gap is located in the atmosphere of the same pressure as that in the test channel 37. At this time, the second end (the end on the lower side in FIG. 5) of the gap between the outer peripheral surface of the in-core 4 and the inner peripheral surface of the second flow passage member 3 is in an atmosphere of pressure different from that in the inspection flow passage 37 Located in Therefore, the gap between the outer peripheral surface of the in-core 4 and the inner peripheral surface of the second flow path member 3 can be a leak path of the test fluid from the inside of the test flow path 37. Then, when a leak of the fluid for inspection from the leak path occurs, there is a possibility that the leak inspection of the seal ring 9 for the tubular portion can not be suitably performed.

  However, as described above, the first inspection seal ring 33 is in contact with the first inspection seal surface 19 that is the inner peripheral surface of the inner cylindrical portion 12. Therefore, the gap between the outer peripheral surface of the in-core 4 and the inner peripheral surface of the second flow passage member 3 is blocked from the inspection flow passage 37 by the first inspection seal ring 33. Therefore, since the first end and the second end of the gap are both located in the atmosphere at a pressure different from that in the test channel 37, the gap is a leak of the test fluid from the test channel 37. It is possible to prevent the route.

According to the present embodiment described above, the following effects can be obtained.
(1) At the time of the leak inspection of the seal ring 9 for the cylindrical portion, the gap between the outer peripheral surface of the in-core 4 and the inner peripheral surface of the second flow passage member 3 becomes a leak path of the test fluid from the test flow passage 37 Can be prevented. Then, by preventing the leak of the test fluid from the leak path, the leak test of the seal ring 9 for the tubular portion in the pipe joint 1 can be suitably performed.

  (2) On the inner circumferential surface of the inner cylindrical portion 12, the in-core 4 is disposed on the large diameter region side bordering the step 18, and on the small diameter region side bordering the step 18, the first inspection seal surface 19 is formed. For this reason, in the inner side of the inner cylindrical portion 12, setting (for example, setting “0”) to reduce the difference in diameter between the inner diameter of the in-core 4 and the inner diameter of the first inspection seal surface 19 is facilitated. And if it sets in this way, the change of the passage cross-sectional area of the fluid in the part corresponding to the above-mentioned diameter difference when the fluid flows inside the inner cylinder part 12 (in core 4) can be suppressed. Smooth flow can be secured.

  (3) At the time of assembly of the pipe fitting 1, insert the inner cylindrical portion 12 of the second flow path member 3 inside the outer cylindrical portion 6 of the first flow path member 2 and When the direction claw portion 16 is snap-engaged, the outward claw portion 16 is pushed in the direction of reducing the diameter of the inner cylindrical portion 12, so that the outward claw portion 16 is crushed at that time and the inner cylindrical portion 12 There is a possibility of blocking between the cylindrical portion 6. In this case, even if leak of the test fluid occurs in the seal ring 9 for the cylinder portion during the leak test, the leaked test fluid is blocked by the crushed outward claw portion 16 and is outside the pipe joint 1 It does not flow out. Therefore, even if a leak of the test fluid occurs in the cylinder part seal ring 9, a problem arises that it can not be confirmed. However, since the outward claw portion 16 is provided with the slit 22, even if the outward claw portion 16 is crushed as described above, the inspection fluid leaked by the cylindrical portion seal ring 9 is used as the slit 22. It will flow out to the exterior of the pipe joint 1, and the occurrence of the above problem can be suppressed.

  (4) The in core 4 is formed with the flange 17 in contact with the boundary between the inner cylindrical portion 12 and the large diameter portion inside the second flow path member 3. The need to be pushed in will be suppressed through the contact. Therefore, it is possible to avoid that the tip of the in-core 4 is pressed against the step 18 and the destruction of the step 18 caused by the in-core 4 being unnecessarily pushed into the inner cylindrical portion 12.

  (5) Further, since the flange 17 is provided at the end of the in-core 4, the end surface of the in-core 4 can be enlarged by the amount of the flange 17. Therefore, by pressing the end face of the in-core 4 to push the in-core 4 into the inner cylindrical portion 12, the pressing can be stably performed so that the in-core 4 is not inclined with respect to the pushing direction. Can be stabilized.

In addition, the said embodiment can also be changed as follows, for example.
The upper and lower sides of the pipe joint 1 may be reversed from that in FIG. That is, the joint 1 for piping is attached to the inspection plug 31 in a state in which the first flow path member 2 is down. Then, under the mounted state, the first inspection seal ring 33 and the second inspection seal ring 35 of the inspection plug 31 are the first inspection seal surface 19 and the second inspection seal surface 20 of the pipe joint 1. The positions of the first inspection seal ring 33 and the second inspection seal ring 35 are changed so as to abut on the front side. Furthermore, the position of the opening of the flow path 32 is also changed so that the opening of the flow path 32 is located between the first inspection seal ring 33 and the second inspection seal ring 35 after the position change.

  As shown in FIG. 6, the temporary holding portion 23 is annularly extended over the entire circumferential direction at the end on the large diameter portion side of the inner peripheral surface of the inner cylindrical portion 12, and the recess 21 is the inner cylindrical portion The inner circumferential surface of the inner circumferential surface 12 of the inner circumferential surface 12 of the inner circumferential surface 12 may extend in an annular shape over the entire circumferential direction.

  As shown in FIG. 7, the recess 21 is annularly extended over the entire circumferential direction at the end on the large diameter portion side of the inner peripheral surface of the inner cylindrical portion 12, and the temporary holding portion 23 is the recess It may be provided so as to be dotted at predetermined intervals in the circumferential direction in the inside 21.

  The in-core 4 does not necessarily have to be provided with the flange 17, and the flange 17 can be omitted. Further, in this case, the length of the in-core can be shortened to a length corresponding to the seal ring 9 for the cylindrical portion and the outward claw portion 16, and in such a case, the in-core can be made compact. You can also.

  The step 18 may restrict insertion of the in-core 4 by coming into contact with the in-core 4 inserted inside the inner cylindrical portion 12. In this case, the in-core 4 is in contact with the step 18, and the position of the first flow path member 2 (inner cylinder 12) in the axial direction is determined. Therefore, when the in-core in which the above-mentioned flange is omitted is used, the position of the in-core 4 when brought into contact with the step 18 is adjusted to a desired position, for example, by appropriately adjusting the position of the step 18 in the axial direction. It becomes easy to set the position corresponding to the cylindrical seal ring 9 and the outward claw portion 16.

  DESCRIPTION OF SYMBOLS 1 ... Fitting for piping, 2 ... 1st flow path member, 3 ... 2nd flow path member, 4 ... in core, 5 ... male screw, 6 ... outer cylinder part, 7 ... stopper surface, 8 ... inward claw part, 8a ... taper Surface 8b: Vertical surface 9: Seal ring for cylindrical portion 10: Housing groove 12: Inner cylindrical portion 13: Heating coil coil 14: Electrode 16: Outward claw portion 16a: Tapered surface 16b: Vertical surface, 17 flange, 18 step difference, 19 first seal surface for inspection, 20 second seal surface for inspection, 21 recess, 22 slit, 23 temporary holding portion, 31 inspection plug, 32 ... flow path, 33 ... seal ring for first inspection, 34 ... accommodation groove, 35 ... seal ring for second inspection, 36 ... accommodation groove, 37 ... flow path for inspection.

Claims (1)

A first flow passage member having an outer cylindrical portion, a second flow passage member having an inner cylindrical portion inserted into the outer cylindrical portion and snap- engaged, an outer peripheral surface of the inner cylindrical portion and an inner circumference of the outer cylindrical portion A seal ring for sealing the space between the inner surface and the inner surface, and an in- core inserted and disposed inside the inner cylindrical portion to strengthen the snap engagement ; It is possible to insert an inspection plug for introducing an inspection fluid for performing a leak inspection of the cylinder part seal ring, and the inspection plug establishes an inspection flow path from the inspection plug to the cylinder part seal ring In a pipe joint provided with an inspection seal ring for
A step is provided on the inner circumferential surface of the inner cylindrical portion, and the in-core is disposed on the inner circumferential surface on the large diameter region side bordering the step on the inner circumferential surface, and the step is bounded on the inner circumferential surface An inspection seal surface having an annular shape to which the inspection seal ring can be abutted is provided on the small diameter region side.

Images