JP5923579B2 - Resin pipe fittings - Google Patents

Description

  The present invention relates to a resin pipe joint.

  As a resin pipe joint used for tubes for fluids (for example, high-purity liquid, ultrapure water, or chemicals) handled in manufacturing processes in various technical fields such as semiconductor manufacturing, medical / pharmaceutical manufacturing, food processing, and chemical industry For example, a resin pipe joint described in Patent Document 1 is known.

  This type of resin pipe joint includes a joint body, an inner ring (sleeve), and a push ring (fastener). The fastener is made of a union nut or the like, and is configured so that a tube coupled to the resin pipe joint can be fastened to the joint body via the sleeve.

  The joint body has a body cylinder part, an outer cylinder part, and an inner cylinder part. The outer cylinder part is provided so as to protrude coaxially from the main body cylinder part in one axial direction. The inner cylinder part is disposed radially inward of the outer cylinder part, and the outer cylinder part is disposed outside the outer cylinder part so that a protruding end is positioned closer to the main body cylinder part than a protruding end of the outer cylinder part. It protrudes coaxially in the same direction as the tube portion.

  In the joint body, a groove portion that opens in one axial direction is surrounded by the body tube portion, the outer tube portion, and the inner tube portion.

  The sleeve includes a tubular fitting portion, a tubular connecting portion, a tubular insertion portion, and a tubular regulating portion. The fitting portion is configured to be detachably fitted to a radially inner side of the outer cylinder portion. The connecting portion is configured to project from the fitting portion in one axial direction and press fit into one end portion in the longitudinal direction of the tube.

  The said insertion part is coaxially projected from the said fitting part to the other axial direction, and is comprised so that it may be inserted in the groove part of the said coupling main body from the opening part. The restricting portion is disposed radially inward of the insertion portion, and the insertion portion is inserted from the fitting portion so that a protruding end is positioned closer to the fitting portion than a protruding end of the insertion portion. It protrudes in the same direction as the part.

  In the resin pipe joint, after the tube is connected to the sleeve, the insertion portion is press-fitted into the groove portion while the deformation movement of the inner cylinder portion is restricted by the restriction portion. The tube can be coupled to the resin pipe joint by connecting a sleeve to the joint body and then fastening the tube to the joint body using the fastener.

JP 2000-283372 A

  When connecting a tube to a conventional resin pipe joint, the connection between the sleeve and the joint main body is achieved by providing a groove in the groove portion of the joint main body in order to ensure a sealing property between the sleeve and the joint main body. The thickness of the insertion portion of the sleeve (the radial width) is set to a large value with respect to the width (radial width), and the insertion portion is strongly pressed into the groove portion.

  In this regard, as described above, the resin pipe joint and the tube are joined together by strong press-fitting, and after many years have passed in that state, the tube is inserted into the resin pipe by maintenance or facility layout change. When the tube is pulled away from the joint body in order to remove it from the joint, the sleeve remains in the joint body without the insertion part coming out of the groove, It was found that only the tube is easily detached from the joint body.

  When only the tube is detached from the joint body, the sleeve that is still connected to the joint body must be pulled out with pliers or the like when the removed tube is joined to the resin pipe joint again. In addition to this, there is a risk of damaging the sleeve, and when the sleeve and the tube separated in this way are recombined, the degree of adhesion between the two is weakened, and the sealing performance between the two may be reduced. Therefore, it becomes practically impossible to reconnect the tube to the resin pipe joint.

  Therefore, the resin pipe joint is caused by the sleeve separating from the tube and remaining in the joint body when the tube being coupled is removed for maintenance or facility layout change. It can be said that the removed tube may not be recombined.

  In addition, even if recombination of the tube to the resin pipe joint can be easily carried out, the long time use of the resin pipe joint causes years to pass since the first connection. It is considered that the time-dependent change of the resin pipe joint is progressing, and there is a possibility that sufficient sealing performance cannot be obtained between the sleeve and the joint body.

  The present invention has been made in view of such circumstances, and after the tube being joined is removed, the tube can be securely and easily joined again, and at the time of the first joining of the tube. It is an object of the present invention to provide a resin pipe joint that can maintain a good sealing property between the joint body and the sleeve regardless of whether it is recombined.

The invention according to claim 1
A main body cylinder portion in which a flow path for fluid is formed, an outer cylinder portion projecting coaxially from the main body cylinder portion in one axial direction thereof, and an inner side in the radial direction of the outer cylinder portion And an inner cylinder portion that is coaxially projected from the main body cylinder portion in the same direction as the outer cylinder portion so that the protruding end is positioned closer to the main body cylinder portion than the protruding end of the outer cylinder portion. A joint body that is formed by being surrounded by the body cylinder part, the outer cylinder part, and the inner cylinder part, and a groove part that opens in one axial direction;
A cylindrical fitting part that is detachably fitted to the radially inner side of the outer cylinder part, a cylinder that protrudes from the fitting part in one axial direction and is press-fitted into one longitudinal end of the tube A cylindrical connecting portion, a cylindrical insertion portion that is coaxially projected from the fitting portion to the other in the axial direction and is inserted into the groove portion from the opening portion, and a radially inner side of the insertion portion And a cylindrical restricting portion that protrudes in the same direction as the insertion portion from the fitting portion so that the protruding end is located closer to the fitting portion than the protruding end of the insertion portion. A sleeve configured to be connectable to or detachable from the joint body in a state of being coupled to the tube;
A resin pipe joint provided with a fastener capable of fastening the tube to the joint body via the sleeve,
The insertion portion has a radial width larger than a radial width of the groove portion, and the fitting portion is fitted on the radially inner side of the outer cylinder portion for connection of the sleeve to the joint body. When this is done, the press-fitting length into the groove is shorter than the depth in the axial direction of the groove, and the inner cylinder is pressed into the groove while being compressed and deformed inward in the radial direction. Configured,
When the insertion portion is press-fitted into the groove portion, the restricting portion is located radially inward of the inner cylinder portion, and is deformed inward in the radial direction of the inner cylinder portion pushed by the insertion portion. Configured to regulate movement,
The insertion portion is press-fitted into the groove portion in a state where the restriction portion restricts deformation movement of the inner cylinder portion, so that a gap between the inner peripheral surface of the insertion portion and the outer peripheral surface of the inner cylinder portion is established. A seal part to be sealed is formed,
The radial width of the insertion portion is D1, the radial width of the groove portion is D2, the press-fitting length of the insertion portion into the groove portion is L1, and the axial depth of the groove portion is L2. In this case, after completion of press-fitting of the insertion portion into the groove portion, the value of (D1-D2) / (L2-L1) is within the range of tan5 ° to tan15 ° in the cross section including the axial center of the insertion portion. It is what.

  According to this configuration, when the tube is coupled (re-coupled) to the resin pipe joint, the seal portion is formed to apply an appropriate surface pressure between the joint body and the sleeve connected to each other. The sealing portion exerts a sealing force in the radial direction to ensure excellent sealing performance between the joint main body and the sleeve.

  In addition, the sleeve can be securely detached from the joint body, and the tube can be detached from the resin pipe joint while being connected to the sleeve. The sleeve that is still connected to the tube can be easily reconnected to the joint body, and the tube can be reconnected to the resin pipe joint.

  Therefore, the tube removed from the resin pipe joint can be reliably and easily recombined during maintenance or facility layout change. Further, whether the resin pipe joint and the tube are coupled for the first time or when they are recombined, the sealing performance of the seal portion formed between the joint body and the sleeve is kept good. be able to.

The invention according to claim 2 is the resin pipe joint according to claim 1,
A first abutment surface is provided on the restriction portion of the sleeve,
A second abutting surface capable of abutting on the first abutting surface is provided on the inner cylinder portion of the joint body;
After the press-fitting of the insertion portion into the groove portion, the inner cylinder portion is sandwiched between the insertion portion and the restriction portion so that the first contact surface and the second contact surface are pressed against each other. Thus, a seal portion that seals between the first contact surface and the second contact surface is formed.

  According to this configuration, when the tube is coupled to the resin pipe joint, the radial direction between the insertion portion and the inner cylinder portion is between the joint body and the sleeve connected to each other. In addition to the sealing portion that applies the sealing force to the sealing portion, it is possible to form the additional sealing portion that applies the sealing force in the axial direction. Accordingly, it is possible to stably realize an excellent sealing property between the joint body and the sleeve.

The invention according to claim 3 is the resin pipe joint according to claim 1 or 2,
A cylindrical pressing portion that is externally fitted to the tube so as to be movable in the longitudinal direction of the fastener, and a cylindrical outer ring portion that can be screwed into the outer cylinder portion of the joint body from the outside in the radial direction. Have
In the connecting portion of the sleeve, a bulging portion is provided that bulges outward in the radial direction so as to expand a part of the tube when the connecting portion is press-fitted into the tube.
When the outer ring portion is screwed into the outer cylinder portion, the pressing portion presses the bulging portion toward the main body cylinder portion so that the insertion portion is press-fitted into the groove portion. It is what.

  According to this configuration, when the outer ring portion is screwed to the outer cylinder portion in order to fasten the tube to the joint body using the fastener, one end in the longitudinal direction of the tube into which the sleeve is press-fitted. It becomes possible to press the portion toward the bulging portion by the pressing portion and hold the tube in pressure contact with the bulging portion. Therefore, it is possible to prevent the tube coupled to the resin pipe joint from coming off.

The invention according to claim 4 is the resin pipe joint according to any one of claims 1 to 3,
The protruding end portion of the insertion portion is formed in a tapered shape so that its inner diameter increases from the fitting side toward the protruding end side.

  According to this configuration, when the press-fitting of the insertion portion into the groove portion is started in order to connect the sleeve to the joint body, the insertion portion can be easily inserted into the groove portion from the protruding end portion.

  According to the present invention, after the tube being joined is removed, the tube can be securely and easily joined again, and the joint body and the sleeve can be joined at the first joining or rejoining of the tube. It is possible to provide a resin pipe joint capable of maintaining good sealing performance between the two.

It is sectional drawing of the resin pipe joint which concerns on one Embodiment of this invention. FIG. 2 is a partially enlarged view of FIG. 1. FIG. 3 is a partially enlarged view of FIG. 2. It is sectional drawing which shows the state which cancelled | released the connection of the coupling main body and sleeve in the resin pipe coupling of FIG. It is a figure which shows the experimental result of Experimental example 1. FIG. It is a figure which shows the experimental result of Experimental example 2. FIG. It is a figure which shows the experimental result of Experimental example 3. FIG. It is a figure which shows the experimental result of Experimental example 4. It is a figure which shows the experimental result of Experimental example 5. FIG. It is a figure which shows the experimental result of Experimental example 6. It is a figure which shows the experimental result of Experimental example 7. It is a figure which shows the experimental result of Experimental example 8. It is a figure which shows the experimental result of Experimental example 9. It is a figure which shows the experimental result of Experimental example 10.

  A preferred embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross-sectional view of a resin pipe joint 1 according to an embodiment of the present invention. FIG. 2 shows a partially enlarged view of FIG. FIG. 3 shows a partially enlarged view of FIG. FIG. 4 shows a state in which the connection between the joint body 3 and the sleeve 4 in the resin pipe joint 1 is released. In FIG. 1, the tube 2 is coupled to the resin pipe joint 1.

  As shown in FIGS. 1, 2, and 4, the resin pipe joint 1 is applied to a resin pipe joint to connect the tube 2 and another tube, or the tube 2 is a fluid device. It is installed at a tube connection position of a fluid device for connection to a valve (for example, a valve or a pump), and includes the joint body 3, the sleeve 4, and a fastener 5. In this embodiment, both the resin pipe joint 1 and the tube 2 are manufactured using a fluororesin.

  The joint body 3 includes a body tube portion 11, an outer tube portion 12, and an inner tube portion 13. In the present embodiment, the joint body 3 is specifically manufactured using PFA (perfluoroalkoxyalkane) or PTFE (polytetrafluoroethylene).

  The main body cylinder portion 11 has a flow path 14 for circulating a fluid such as a liquid inside the main body cylinder portion 11. In the present embodiment, the main body cylinder portion 11 is formed in a cylindrical shape. And the said flow path 14 is provided in the said main body cylinder part 11 so that the axial center direction may be extended.

  The outer cylinder portion 12 protrudes coaxially from one axial direction end of the main body cylindrical portion 11 to one axial direction. In the present embodiment, the outer cylinder portion 12 is formed in a cylindrical shape. A male screw 15 is provided on the outer peripheral surface of the outer tube portion 12 along the axial direction of the outer tube portion 12.

  The inner cylinder part 13 is disposed radially inward of the outer cylinder part 12. The inner cylinder part 13 is arranged so that the protruding end 16 is positioned closer to the main body cylinder part 11 than the protruding end 17 of the outer cylinder part 12 from the one axial end of the main body cylinder part 11 to the outer cylinder part. 12 projecting coaxially in the same direction.

  In the present embodiment, the inner cylinder part 13 is formed in a cylindrical shape having an inner diameter substantially the same as the inner diameter of the main body cylinder part 11 and having an outer diameter smaller than the inner diameter of the outer cylinder part 12. . A flow path 18 is provided in the inner cylinder portion 13 so as to extend in the axial direction, and is connected to the flow path 14.

  Further, the joint body 3 is provided with a groove portion 20 surrounded by the body tube portion 11, the outer tube portion 12, and the inner tube portion 13. In the present embodiment, the groove portion 20 is disposed so as to be sandwiched between the inner tube portion 13 and the other axial side (the root side) of the outer tube portion 12 facing the inner tube portion 13 with respect to the radial direction. ing.

  The groove portion 20 has an opening portion 21 in the vicinity of the protruding end 16 of the inner cylinder portion 13 and a closing portion 22 formed in a concave curved cross section on one end side in the axial direction of the main body cylinder portion 11. Thus, it is formed in an annular shape extending over the entire circumference of the outer peripheral surface of the inner cylinder portion 13.

  The groove width D2 of the groove portion 20 is set smaller than the depth L2. The groove width D2 of the groove portion 20 is a radial width between the inner peripheral surface of the outer cylindrical portion 12 and the outer peripheral surface of the inner cylindrical portion 13 (see FIG. 4). The depth L2 of the groove portion 20 is the axial width from the opening portion 21 of the groove portion 20 to the closing portion 22 (specifically, the change start portion 23 at which the groove width D2 starts to change) (FIG. 2). reference).

  The sleeve 4 includes a fitting portion 25, a connecting portion 26, an insertion portion 27, and a restricting portion 28. The sleeve 4 is configured to be connectable to or detachable from the joint body 3 while being connected to the tube 2 by the connecting portion 26. In the present embodiment, the sleeve 4 is specifically manufactured using PFA.

  The fitting portion 25 has a cylindrical shape and is configured to be detachably fitted to the radially inner side of the outer cylinder portion 12 of the joint body 3. In the present embodiment, the fitting portion 25 has an outer diameter that is substantially the same as the inner diameter of the outer cylinder portion 12 and is substantially the same as the inner diameter of the inner cylinder portion 13 of the joint body 3 and the tube 2. It is formed in a cylindrical shape having an inner diameter.

  The connecting portion 26 has a cylindrical shape and is configured to project from the fitting portion 25 in one axial direction and be press-fitted into one longitudinal end portion of the tube 2. In the present embodiment, the connecting portion 26 is formed in a cylindrical shape having an inner diameter substantially the same as the inner diameter of the fitting portion 25 and the inner diameter of the tube 2.

  The connecting portion 26 has an outer diameter that is smaller than the outer diameter of the fitting portion 25 and larger than the inner diameter of the tube 2. And the said connection part 26 is fitted in the radial direction inner side of the said outer cylinder part 12 through the longitudinal direction one end part of this tube 2 in the state press-fit in the longitudinal direction one end part of the said tube 2 It is configured to be able to.

  The insertion portion 27 has a cylindrical shape, is coaxially projected from the fitting portion 25 in the other axial direction, and can be inserted into the groove portion 20 from the opening portion 21. ing. In the present embodiment, the insertion portion 27 is formed in a cylindrical shape having an outer diameter substantially the same as the outer diameter of the fitting portion 25 and having an inner diameter larger than the inner diameter of the fitting portion 25. Yes.

  The insertion part 27 has an outer diameter substantially the same as the inner diameter of the outer cylinder part 12 and an inner diameter smaller than the outer diameter of the inner cylinder part 13. That is, the insertion portion 27 has a thickness (radial width) D1 larger than the groove width D2 of the groove portion 20 (see FIG. 4). And the said insertion part 27 can be press-fit in the said groove part 20, pushing the outer peripheral side of the said inner cylinder part 13, and carrying out compression deformation.

  The insertion portion 27 has a press-fit length L1 that is shorter than the depth L2 of the groove portion 20 when press-fitted into the groove portion 20. Here, the press-fitting length L1 of the insertion portion 27 is the inner cylinder portion 13 of the inner peripheral surface of the insertion portion 27 in a state where the insertion of the insertion portion 27 into the groove portion 20 is completed. It is the axial direction width | variety of the part which touches the outer peripheral surface (refer FIG. 2).

  The restricting portion 28 has a cylindrical shape and is disposed radially inward of the insertion portion 27. The restricting portion 28 protrudes from the fitting portion 25 in the same direction as the insertion portion 27 so that the protruding end 29 is located closer to the fitting portion 25 than the protruding end 30 of the insertion portion 27. Has been.

  The restricting portion 28 is positioned radially inward of the inner cylindrical portion 13 when the insertion portion 27 is press-fitted into the groove portion 20 of the joint body 3 from the opening portion 21 toward the closing portion 22 side. The inner cylindrical portion 13 pushed by the insertion portion 27 is configured to be restricted from being deformed and moved inward in the radial direction (on the flow path 18 side).

  And the said insertion part 27 is press-fitted in the said groove part 20 in the state which the said control part 28 controls the deformation | transformation movement of the above-mentioned inner cylinder part 13, and the inner peripheral surface of the said insertion part 27 and the said inside A first seal portion 31 that seals between the outer peripheral surface of the tube portion 13 is formed.

  In the present embodiment, the restricting portion 28 is formed in a cylindrical shape having an inner diameter substantially the same as the inner diameter of the fitting portion 25. The restricting portion 28 is inserted so that the protruding end 16 side of the inner cylinder portion 13 can be sandwiched between one side (root side) in the axial direction of the inserting portion 27 facing the restricting portion 28. The outer diameter of the portion 27 is smaller than the inner diameter.

  Thus, when the insertion portion 27 is press-fitted into the groove portion 20, the restricting portion 28 is pushed by the insertion portion 27 to compress and deform the outer peripheral side of the main body cylindrical portion 11. The inner cylinder portion 13 that is to be deformed and moved inward in the radial direction from the end 16 side is supported by the protruding end 16 side so that the deformation movement of the inner cylinder portion 13 in the radially inward direction can be prevented. It has become.

  The fastener 5 is configured to be able to fasten the tube 2 to the joint body 3 via the sleeve 4. As the fastener 5, a union nut is used in the present embodiment. The details of the fastener 5 will be described later.

  With such a configuration, the tube 2 can be coupled to the resin pipe joint 1 by performing the following coupling operation. That is, in the coupling operation, first, the sleeve 4 is coupled to the tube 2 by press-fitting the coupling portion 26 into one longitudinal end portion of the tube 2.

  Then, by pressing the insertion portion 27 into the groove portion 20, the sleeve 4 that has been connected to the tube 2 is connected to the joint so that the flow path 32 of the tube 2 communicates with the flow paths 14 and 18. Connect to the main body 3. Finally, the tube 2 is fastened to the joint body 3 using the fastener 5.

  In the present embodiment, when the tube 2 is coupled to the resin pipe joint 1 as described above, the depth of the groove 20 when the insertion portion 27 is press-fitted into the groove 20. Since the press-fitting length L1 of the insertion part 27 is shorter than L2, as shown in FIG. 2, the closing part of the groove part 20 located on the opposite side of the opening part 21 of the groove part 20 in the axial direction. A space 33 is formed between 22 and the protruding end 30 of the insertion portion 27.

  As described above, the radial width of the insertion part 27 is D1, the radial width of the groove part 20 is D2, the press-fitting length of the insertion part 27 into the groove part 20 is L1, and the groove part When the depth of 20 is L2, in the cross section including the axial center of the insertion portion 27 after the press-fitting of the insertion portion 27 into the groove portion 20, (D1-D2) / (L2-L1) The value (that is, the value of S2 / S1 in FIG. 3) is set to be in the range of tan 5 ° to tan 15 °.

  The insertion portion 27 is preferably press-fitted into the groove portion 20 so that the insertion ratio L1 / L2 of the insertion portion 27 with respect to the groove portion 20 is 20% or more, preferably 30% or more.

  With the above configuration, when the tube 2 is coupled (re-coupled) to the resin pipe joint 1, an appropriate surface pressure is applied between the joint body 3 and the sleeve 4 connected to each other. The first seal portion 31 is formed, and a sealing force is applied in the radial direction by the first seal portion 31, so that excellent sealing performance can be ensured between the joint body 3 and the sleeve 4.

  In addition, the sleeve 4 can be securely detached from the joint body 3, and the tube 2 can be detached from the resin pipe joint 1 while being connected to the tube 2. The sleeve 4 that is still connected to the tube 2 can be easily reconnected to the joint body 3, and the tube 2 can be reconnected to the resin pipe joint 1.

  Therefore, it is possible to reliably and easily recombine the tube 2 removed from the resin pipe joint 1 during maintenance or facility layout change. Further, the first seal portion 31 formed between the joint body 3 and the sleeve 4, whether the resin pipe joint 1 and the tube 2 are coupled for the first time or when they are recombined. It is possible to maintain good sealing performance.

  This effect was clarified by carrying out the following Experimental Examples 1 to 10.

  In Experimental Example 1, a plurality of first resin pipe joints, in Experimental Example 2, a plurality of second resin pipe joints, in Experimental Example 3, a plurality of third resin pipe joints, and in Experimental Example 4, a plurality of fourth resin pipe joints. In Experimental Example 5, a plurality of fifth resin pipe joints were prepared as resin pipe joints. Each of these resin pipe joints includes a joint body and a sleeve made of PFA.

  In each experimental example, the plurality of resin pipe joints have substantially the same configuration as that of the resin pipe joint 1 according to the above-described embodiment, and (D1-D2) / (L2- Different values of L1) were selected and used within the range of tan1 ° to tan20 °.

  In Experimental Examples 1 to 5, the insertion rate of the insertion portion with respect to the groove portion was different for each experimental example. For convenience of experiment, the insertion rate is 90% in Experimental Example 1, 80% in Experimental Example 2, 60% in Experimental Example 3, 40% in Experimental Example 4, and 30% in Experimental Example 5. .

  In addition, a leakage test was performed on each of the resin pipe joints (test bodies) in Experimental Examples 1 to 5. In addition, in this resinous pipe joint to be used, this leak test is performed on the contact portion between the inner cylinder portion 13 and the insertion portion 27 so that the second seal portion 43 described later does not function in FIG. It was carried out after adding a groove part that allows fluid to freely flow between the flow path 18 side and the space 39.

  In each of the test specimens, whether or not fluid leakage occurs in the first seal portion when the joint body and the sleeve are connected for the first time (whether or not leakage occurs at the first connection), and This is for checking whether or not fluid leakage occurs in the first seal portion when the joint body and the sleeve are reconnected (whether or not leakage occurs during reconnection).

  In the leak test, the colored permeate is sealed in the flow paths (flow paths in the joint body and the sleeve) of each test specimen, and 1.4 MPa of nitrogen gas is added to the sealed permeate, and the joint body Penetration of the osmotic fluid from the channel through the groove (the groove) to the first seal portion (whether or not a part of the osmotic fluid moves beyond the first seal portion) Was confirmed visually.

  In addition, since reconnection of the joint body and the sleeve (that is, attachment / detachment of the tube) is generally performed after a lapse of time from the time of initial connection, leakage at the time of reconnection in the test body is performed. The occurrence of the occurrence of the occurrence of the above-mentioned joint is performed by repeating heating (150 ° C., 1 hour) and cooling (temperature 25 ° C., 6 hours) 10 times alternately for the joint body and the sleeve used at the time of the first connection. This was confirmed after causing a change in restoring characteristics (creep deformation) due to internal stress or the like in the main body and the sleeve.

  In Experimental Example 6, a plurality of sixth resin pipe joints, in Experimental Example 7, a plurality of seventh resin pipe joints, in Experimental Example 8, a plurality of eighth resin pipe joints, and in Experimental Example 9, a plurality of ninth resin pipe joints. In the experiment example 10, a plurality of tenth resin pipe joints were prepared as resin pipe joints. Each of these resin pipe joints includes a joint body made of PTFE and a sleeve made of PFA.

  In each experimental example, the plurality of resin pipe joints have substantially the same configuration as that of the resin pipe joint 1 according to the above-described embodiment, and (D1-D2) / (L2- Different values of L1) were selected and used within the range of tan1 ° to tan20 °.

  Moreover, in Experimental Example 6 to Experimental Example 10, the insertion rate of the insertion portion with respect to the groove portion was different for each experimental example. For convenience of experiment, the insertion rate is 90% in Experimental Example 6, 80% in Experimental Example 7, 60% in Experimental Example 8, 40% in Experimental Example 9, and 30% in Experimental Example 10. .

  In addition, the same leak test as in Experimental Examples 1 to 5 was performed for each of the resin pipe joints (test bodies) in Experimental Examples 6 to 10.

  Further, each of the resin pipe joints (test bodies) in Experimental Examples 1 to 10 was repeatedly subjected to a bonding performance confirmation test.

  Whether the tube can be reliably and easily re-bonded to the test body after removing the tube being bonded from each test body of each of Experimental Examples 1 to 10 in the repeated bonding performance confirmation test, Specifically, it is for confirming whether or not the sleeve may remain in the joint body without being removed from the groove when the tube is detached (whether or not there is a possibility of remaining of the sleeve).

  5 to 14 show the experimental results of the leakage test and the repeated bonding performance confirmation test for Experimental Examples 1 to 10, respectively. From FIG. 5 to FIG. 14, in any of Experimental Examples 1 to 10, the test body in which the value of (D1−D2) / (L2−L1) is set to be in the range of tan5 ° to tan15 ° It has been found that there is no leakage at the time of initial connection and no leakage at the time of reconnection, and there is no fear of the sleeve remaining. That is, the above-mentioned operational effects could be confirmed.

  As shown in FIGS. 2 and 4, in the present embodiment, a first contact surface 41 is provided on the restriction portion 28 of the sleeve 4. Specifically, the restricting portion 28 is formed in a tapered shape whose outer diameter gradually decreases from one side (the base side) in the axial direction toward the other side (the protruding end 29 side). The first contact surface 41 is disposed on the radially outer side of the restricting portion 28 as a tapered surface. More specifically, the first contact surface 41 is formed on the outer peripheral surface of the restricting portion 28.

  A second abutment surface 42 that can abut on the first abutment surface 41 is provided on the inner cylinder portion 13 of the joint body 3. Specifically, the protruding end 16 side of the inner cylinder part 13 is formed in a tapered shape whose inner diameter gradually increases from the other axial side (the base side) toward one side (the protruding end 16 side). . The second contact surface 42 is disposed on the radially inner side on the protruding end 16 side of the inner cylindrical portion 13 as a tapered surface. More specifically, the second contact surface 42 is formed on the inner peripheral surface of the inner cylinder portion 13 on the protruding end 16 side.

  As shown in FIGS. 1 and 2, after the insertion portion 27 is press-fitted into the groove portion 20, the first contact surface 41 and the second contact surface 42 are press-contacted. The cylindrical part 13 is sandwiched between the insertion part 27 and the restricting part 28, and the second seal part 43 that seals between the first abutment surface 41 and the second abutment surface 42 is provided. It is comprised so that it may be formed.

  With this configuration, when the tube 2 is coupled to the resin pipe joint 1, the first sealing force is applied in the radial direction between the joint body 3 and the sleeve 4 connected to each other. In addition to the seal portion 31, the second seal portion 43 that applies a sealing force in the axial direction can be formed. Therefore, it is possible to stably realize an excellent sealing property between the joint body 3 and the sleeve 4.

  As shown in FIG. 1, in the present embodiment, the fastener 5 includes a pressing portion 46 and an outer ring portion 47. Specifically, the fastener is a union nut as described above, and is manufactured using PFA.

  The said press part 46 is a cylindrical thing, and is comprised so that the said tube 2 may be moved so that the movement to the longitudinal direction is possible. In the present embodiment, the pressing portion 46 is formed in a cylindrical shape having an inner diameter that is substantially the same as or slightly larger than the outer diameter of the tube 2.

  The outer ring portion 47 is configured to be able to be screwed into the outer tube portion 12 of the joint body 3 from the outside in the radial direction. In the present embodiment, the outer ring portion 47 is formed in a cylindrical shape having an inner diameter larger than the inner diameter of the pressing portion 46. The outer ring portion 47 protrudes coaxially from the radially outer portion of the pressing portion 46 to the other axial direction.

  The outer ring portion 47 has an inner diameter that is substantially the same as the outer diameter of the outer cylinder portion 12 so as to surround the outer cylinder portion 12. On the inner peripheral surface of the outer ring portion 47, a female screw 48 corresponding to the male screw 15 of the outer cylinder portion 12 is provided along the axial direction of the outer ring portion 47. Thus, the outer ring portion 47 can be screwed with the outer cylinder portion 12.

  In the present embodiment, a bulging portion 50 is provided at the connecting portion 26 of the sleeve 4. The bulging portion 50 bulges outward in the radial direction so as to expand a part of the longitudinal end portion of the tube 2 when the connecting portion 26 is press-fitted into the longitudinal end portion of the tube 2. The shape can be made to be.

  Then, when the outer ring portion 47 of the fastener 5 is screwed into the outer cylinder portion 12, the insertion portion 27 of the sleeve 4 is press-fitted into the groove portion 20 of the joint body 3. The pressing part 46 presses the bulging part 50 of the sleeve 4 toward the main body cylinder part 11.

  Specifically, the bulging portion 50 is formed in a convex curved section. The bulging portion 50 is disposed closer to one side in the axial direction of the connecting portion 26, and extends over the entire outer peripheral surface of the connecting portion 26. The bulging portion 50 is configured to form an enlarged region at one end in the longitudinal direction of the tube 2 when the connecting portion 26 is press-fitted into the tube 2.

  A third abutting surface 53 that can abut on a corner portion 52 located on the radially inner side of the pressing portion 46 and on the other side in the axial direction is formed in the enlarged diameter region of the tube 2. The third abutting surface 53 is disposed on one side in the longitudinal direction of the connecting portion 26 in the enlarged diameter region of the tube 2, and the outer diameter of the tube 2 is gradually reduced from the other side in the longitudinal direction toward the one side. It is formed in a tapered shape.

  With such a configuration, when the outer ring portion 47 of the fastener 5 is screwed to the outer cylinder portion 12 in order to fasten the tube 2 to the joint body 3, the tube 2 into which the sleeve 4 is press-fitted. The third abutting surface 53 is pressed toward the bulging portion 50 by the pressing portion 46 (the corner portion 52) of the fastener 5, and the tube 2 is held in pressure contact with the bulging portion 50. It becomes possible to do. Therefore, it is possible to prevent the tube 2 connected to the resin pipe joint 1 from coming off.

  Further, in the present embodiment, as shown in FIG. 1, a fourth contact surface 54 is formed in the expanded region of the tube 2 in addition to the third contact surface 53. The fourth contact surface 54 is disposed on the other side in the longitudinal direction of the connecting portion 26 in the enlarged diameter region of the tube 2, and the outer diameter of the tube 2 gradually decreases from one side in the longitudinal direction to the other side. It is formed in a tapered shape.

  The outer cylinder portion 12 of the joint body 3 is provided with a fifth contact surface 55 that can contact the fourth contact surface 54. The fifth contact surface 55 is disposed radially inward in the vicinity of the protruding end 17 of the outer cylinder portion 12. The fifth contact surface 55 is formed in a taper shape in which the inner diameter of the outer cylinder portion 12 gradually increases from the other side (base side) in the axial direction toward one side (the projecting end 17 side). .

  With such a configuration, when the outer ring portion 47 is screwed to the outer cylinder portion 12 in order to fasten the tube 2 to the joint body 3, the fourth portion of the tube 2 into which the connecting portion 26 is press-fitted. The contact surface 54 is pressed by the pressing portion 46 toward the fifth contact surface 55 via the sleeve 4 to form a third seal portion 56 between the tube 2 and the outer cylinder portion 12. It becomes possible. Therefore, excellent sealing performance can be ensured between the tube 2 and the joint body 3.

  Moreover, in this embodiment, as shown in FIG.2, FIG.3, FIG.4, as for the protrusion end part 58 of the said insertion part 27, the internal diameter is the said protrusion end from the said fitting part 25 side (root side). It is formed in a tapered shape so as to increase toward the 30 side. Here, a chamfering process is performed on the radially inner side of the protruding end portion 58 of the insertion portion 27 to provide a tapered chamfered portion 59.

  With such a configuration, when the insertion of the insertion portion 27 into the groove portion 20 is started in order to connect the sleeve 4 to the joint body 3, the insertion portion 27 is moved from the protruding end portion 58 to the groove portion. 20 becomes easy to insert.

DESCRIPTION OF SYMBOLS 1 Resin pipe joint 2 Tube 3 Joint main body 4 Sleeve 5 Fastener 11 Main body cylinder part 12 Outer cylinder part 13 Inner cylinder part 20 Groove part 25 Fitting part 26 Connection part 27 Insertion part 28 Restriction part 31 1st seal part 41 1st 1 abutment surface 42 2nd abutment surface 43 second seal portion 46 pressing portion 47 outer ring portion 50 bulging portion 58 protruding end portion of insertion portion

Claims (4)

A main body cylinder portion in which a flow path for fluid is formed, an outer cylinder portion projecting coaxially from the main body cylinder portion in one axial direction thereof, and an inner side in the radial direction of the outer cylinder portion And an inner cylinder portion that is coaxially projected from the main body cylinder portion in the same direction as the outer cylinder portion so that the protruding end is positioned closer to the main body cylinder portion than the protruding end of the outer cylinder portion. A joint body that is formed by being surrounded by the body cylinder part, the outer cylinder part, and the inner cylinder part, and a groove part that opens in one axial direction;
A cylindrical fitting part that is detachably fitted to the radially inner side of the outer cylinder part, a cylinder that protrudes from the fitting part in one axial direction and is press-fitted into one longitudinal end of the tube A cylindrical connecting portion, a cylindrical insertion portion that is coaxially projected from the fitting portion to the other in the axial direction and is inserted into the groove portion from the opening portion, and a radially inner side of the insertion portion And a cylindrical restricting portion that protrudes in the same direction as the insertion portion from the fitting portion so that the protruding end is located closer to the fitting portion than the protruding end of the insertion portion. A sleeve configured to be connectable to or detachable from the joint body in a state of being coupled to the tube;
A resin pipe joint provided with a fastener capable of fastening the tube to the joint body via the sleeve,
The insertion portion has a radial width larger than a radial width of the groove portion, and the fitting portion is fitted on the radially inner side of the outer cylinder portion for connection of the sleeve to the joint body. When this is done, the press-fitting length into the groove is shorter than the depth in the axial direction of the groove, and the inner cylinder is pressed into the groove while being compressed and deformed inward in the radial direction. Configured,
When the insertion portion is press-fitted into the groove portion, the restricting portion is located radially inward of the inner cylinder portion, and is deformed inward in the radial direction of the inner cylinder portion pushed by the insertion portion. Configured to regulate movement,
The insertion portion is press-fitted into the groove portion in a state where the restriction portion restricts deformation movement of the inner cylinder portion, so that a gap between the inner peripheral surface of the insertion portion and the outer peripheral surface of the inner cylinder portion is established. A seal part to be sealed is formed,
The radial width of the insertion portion is D1, the radial width of the groove portion is D2, the press-fitting length of the insertion portion into the groove portion is L1, and the axial depth of the groove portion is L2. In this case, after completion of press-fitting of the insertion portion into the groove portion, the value of (D1-D2) / (L2-L1) is within the range of tan5 ° to tan15 ° in the cross section including the axial center of the insertion portion. Resin pipe joints characterized in that. A first abutment surface is provided on the restriction portion of the sleeve,
A second abutting surface capable of abutting on the first abutting surface is provided on the inner cylinder portion of the joint body;
After the press-fitting of the insertion portion into the groove portion, the inner cylinder portion is sandwiched between the insertion portion and the restriction portion so that the first contact surface and the second contact surface are pressed against each other. The resin pipe joint according to claim 1, wherein a seal portion that seals between the first contact surface and the second contact surface is formed. A cylindrical pressing portion that is externally fitted to the tube so as to be movable in the longitudinal direction of the fastener, and a cylindrical outer ring portion that can be screwed into the outer cylinder portion of the joint body from the outside in the radial direction. Have
In the connecting portion of the sleeve, a bulging portion is provided that bulges outward in the radial direction so as to expand a part of the tube when the connecting portion is press-fitted into the tube.
When the outer ring portion is screwed into the outer cylinder portion, the pressing portion presses the bulging portion toward the main body cylinder portion so that the insertion portion is press-fitted into the groove portion. The resin pipe joint according to claim 1 or 2, wherein the resin pipe joint is provided.   The protruding end portion of the insertion portion is formed in a tapered shape so that its inner diameter increases from the fitting side toward the protruding end side. The resin pipe joint according to claim 1.

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