JP2012189147A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint which allows coupling of pipes to be reliably confirmed even under such conditions that a visual confirmation on the coupling is impossible or difficult.SOLUTION: The pipe joint 10 includes: annular sealing members 31A, 31B mounted on an outer circumferential face of a pipe coupling sleeve 21; and a correction cylinder 40 which is locked as fitted outside the annular sealing members 31A, 31B, regulates expansion deformation of the annular sealing members 31A, 31B, and is pushed by a pipe P1 inserted into a pipe insertion region and moves deeper in the pipe insertion region 30. A detection window 29 is formed in a base end of an outer cylinder wall 27, the window which opens the pipe insertion region to the outside of the outer cylindrical wall 27. The correction cylinder 40 includes detection pieces 43, 43, which protrude outward from the detection window 29 when the correction cylinder 40 is moved deeper in the pipe insertion region.

Description

  The present invention relates to a pipe joint that can be connected by inserting a pipe into a pipe insertion region between a pipe coupling sleeve and an outer cylindrical wall surrounding the pipe coupling sleeve.

  As a conventional pipe joint of this type, a correction cylinder for preventing an O-ring attached to a pipe coupling sleeve from being detached from an O-ring groove when a pipe is inserted into the pipe insertion area is provided in the pipe insertion area. It is known that the straightened cylinder body is pushed by the pipe and moves toward the back side of the pipe insertion area. This pipe joint is provided with a window for confirming coupling on the outer cylinder wall, and the coupling state of the pipe can be visually confirmed by whether or not the straightened cylinder or the pipe itself can be seen from this window (for example, , See Patent Document 1).

Japanese Unexamined Patent Publication No. 2002-81587 (paragraph [0022], FIGS. 6 to 8)

  However, in the conventional pipe joint described above, there is a problem that it is impossible or difficult to confirm the connection when the connection work is performed in a dark place such as under the floor or attic, or in a narrow place where an operator cannot enter. there were.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pipe joint that can surely confirm the coupling even in a situation where it is impossible or difficult to visually confirm the coupling.

  In order to achieve the above object, a pipe joint according to the invention of claim 1 includes a pipe coupling sleeve extending from a base, a cylindrical outer cylinder wall surrounding the pipe coupling sleeve, a pipe coupling sleeve and an outer cylinder wall. A pipe retaining portion that is locked to a pipe inserted into a cylindrical pipe insertion region between the pipe, a ring sealing member that is mounted in an annular groove provided on the outer peripheral surface of the pipe coupling sleeve, and an annular seal In a pipe joint provided with a correction cylinder that moves by being pushed by a pipe inserted into a pipe insertion region on the outside of the member, a detection window formed on either the pipe coupling sleeve or the outer cylinder wall, and a correction cylinder And a detection piece that protrudes outward from the detection window when the correction cylinder moves to the inner side of the pipe insertion region.

  According to a second aspect of the present invention, in the pipe joint according to the first aspect, the correction cylinder is made of an elastic body, and is provided with a plurality of cuts extending from one end portion in the axial direction to the middle portion of the correction cylinder. Of these, the part sandwiched between adjacent cuts is used as a detection piece.

  According to a third aspect of the present invention, in the pipe joint according to the second aspect, a plurality of cuts are provided at predetermined intervals over the entire circumference of the correction cylinder, and a plurality of detection pieces are formed on the entire circumference of the correction cylinder. However, it has characteristics.

  According to a fourth aspect of the present invention, in the pipe joint according to any one of the first to third aspects, a plurality of detection windows are distributed in the circumferential direction of the pipe joint and project outward from the plurality of detection windows. It is characterized by providing a plurality of possible detection pieces.

  The invention of claim 5 is the pipe joint according to any one of claims 1 to 4, wherein the detection window is opened toward the side of the pipe joint, It is characterized in that a guide inclined portion that is inclined so as to gradually approach the detection window side toward the front in the pipe insertion direction is provided.

  According to a sixth aspect of the present invention, in the pipe joint according to the third aspect, the outer diameter of the base portion side of the pipe coupling sleeve is increased in a stepped manner from the outer diameter of the intermediate portion of the pipe coupling sleeve. The step surface between the base side and the intermediate part is a tapered surface, the outer cylinder wall is formed into a cylindrical shape with a uniform diameter, and a fixed part fixed to the base side of the pipe coupling sleeve is formed on the base side of the outer cylinder wall, It has a feature in that it has a plurality of detection windows arranged opposite to the tapered surface of the pipe coupling sleeve in the radial direction of the cylindrical wall and distributed in the circumferential direction of the outer cylindrical wall.

  According to a seventh aspect of the present invention, in the pipe joint according to any one of the first to sixth aspects, a plurality of annular grooves are provided on the outer peripheral surface of the pipe coupling sleeve, and an annular seal member is provided in each of the annular grooves. The correction cylinder is characterized in that it is locked in a state of being fitted to the outside of all the annular seal members.

  The invention according to claim 8 is the pipe joint according to any one of claims 1 to 7, wherein the one end side in the axial direction of the straightened cylinder has a smaller outer diameter and a smaller wall thickness than the other end side. While the thin tube portion is provided, on the other end side in the axial direction of the correction tube body, a thick tube portion having an outer diameter larger than that of the one end side and a large thickness is provided, and a plurality of the thin tube portions extending in the axial direction. And a portion between the adjacent cuts of the correction cylinder is used as a detection piece.

  According to a ninth aspect of the present invention, in the pipe joint according to the eighth aspect, a plurality of annular grooves are provided on the outer peripheral surface of the pipe coupling sleeve, and an O-ring as an annular seal member is attached to each of the annular grooves, The meat tube portion is configured to at least surround a range from a position closer to the opening end of the pipe insertion region than a plurality of O-rings to a maximum outer diameter portion of the O-ring disposed farthest from the pipe insertion region. It has the characteristics where it was done.

  The invention of claim 10 is characterized in that, in the pipe joint according to any one of claims 1 to 9, the straightening cylinder is an insulator.

[Invention of Claim 1]
According to the first aspect of the present invention, when a pipe to be connected is inserted from the open end of the pipe insertion area, the correction cylinder is pushed by the pipe and moves to the back side of the pipe insertion area. The correction cylinder passes through the annular seal member in advance of the pipe, and pushes the annular seal member into the annular groove during the passage. As a result, the insertion tip of the pipe can be prevented from being damaged by hitting the annular seal member, or the annular seal member can be prevented from being turned up (disengaged from the annular groove), and the connection work between the pipe and the pipe coupling sleeve can be performed smoothly. it can.

  When the pipe is inserted to a predetermined insertion depth with respect to the pipe insertion region, the detection piece provided on the correction cylinder projects from the detection window to the outside of the outer cylinder wall. Thereby, even in a situation where it is impossible or difficult to visually confirm the coupling, it is possible to confirm the coupling of the pipe by confirming whether or not the detection piece has protruded by hand.

[Invention of claim 2]
According to the invention of claim 2, the detection piece can be formed relatively easily without increasing the number of parts only by providing a plurality of cuts in the correction cylinder formed of an elastic body. Moreover, when the pipe cut diagonally is inserted into the pipe insertion region, the correction cylinder can be elastically deformed flexibly according to the diagonal cut surface.

[Invention of claim 3]
According to the invention of claim 3, since the plurality of detection pieces are provided over the entire circumference of the correction cylinder, it is troublesome to position the detection piece and the detection window in advance when the correction cylinder is assembled. This eliminates the need to improve assembly workability.

[Invention of claim 4]
According to the invention of claim 4, since the detection pieces protrude from the plurality of detection windows, it becomes possible to more easily and surely confirm the connection by touch.

[Invention of claim 5]
According to the fifth aspect of the present invention, since the detection piece is guided to the detection window by the guide inclined portion at the back of the pipe insertion area, the detection piece can be smoothly projected from the detection window.

[Invention of claim 6]
According to the invention of claim 6, the plurality of detection pieces that are in contact with the taper surface at the back of the pipe insertion region are elastically deformed so as to expand along the taper surface. Protrudes from the detection window. By providing this tapered surface, the detection piece can be elastically deformed smoothly and protrude from the detection window.

[Invention of Claim 7]
According to the seventh aspect of the present invention, it is possible to prevent foreign matters from adhering to the plurality of annular seal members.

[Inventions of Claims 8 and 9]
According to the eighth aspect of the present invention, the thick deformation of the annular seal member can be reliably prevented by the thick cylindrical portion. Moreover, since the detection piece is formed in the thin tube portion, the detection piece can be flexibly deformed. Here, when the annular seal member is an O-ring and a plurality of the O-rings are provided, the thick-walled cylindrical portion is the most pipe from the position closer to the opening end of the pipe insertion region than the plurality of O-rings. It is preferable that at least the range up to the maximum outer diameter portion of the O-ring arranged on the back side of the insertion region is surrounded (invention of claim 9). By doing in this way, it becomes possible to prevent the expansion deformation of all the O-rings more reliably.

[Invention of Claim 10]
According to the invention of claim 10, for example, when a multilayer pipe in which the intermediate layer is made of metal and the innermost layer and the outermost layer are made of insulating resin is a pipe to be connected, it is exposed from the end face of the multilayer pipe. It is possible to insulate between the metal layer and the pipe joint by the straightening cylinder, and to prevent the occurrence of current corrosion.

The half sectional view of the pipe joint concerning a 1st embodiment of the present invention. Expanded cross section of pipe joint Cross-sectional view of one side of straightened cylinder One-side cross-sectional view of the pipe joint with the pipe inserted partway through the pipe insertion area One-side cross-sectional view of a pipe joint with the pipe inserted to the specified insertion depth The expanded sectional view of the pipe joint concerning a 2nd embodiment. Expanded sectional view of a pipe joint according to a modification One side sectional view of a pipe joint according to a modification Expanded sectional view of a pipe joint according to a modification Expanded sectional view of a pipe joint according to a modification

[First Embodiment]
Hereinafter, 1st Embodiment of the pipe joint 10 which concerns on this invention is described based on FIGS. As shown in FIG. 1, a pipe joint 10 includes a prismatic body 11 (hexagonal nut) serving as a base at an intermediate portion in the axial direction, and a screw coupling portion 12 and an insertion coupling portion in directions opposite to the prismatic body 11. 20 protrudes. The screw coupling portion 12 is formed with a thread groove on the outer peripheral surface of the cylindrical body, and can be screwed and connected to a pipe or a device (not shown).

  The insertion coupling portion 20 has a double cylinder structure having a pipe coupling sleeve 21 protruding from the end face of the prismatic body 11 and an outer cylinder wall 27 surrounding the pipe coupling sleeve 21. In the present embodiment, the pipe coupling sleeve 21, the screw coupling portion 12, and the prismatic body 11 constitute a joint body 10A, and the internal flow path 10B passes through the axial center portion of the joint body 10A. The joint body 10A and the outer cylinder wall 27 are separate parts, and both the joint body 10A and the outer cylinder wall 27 are made of metal (for example, the joint body 10A is made of brass, and the outer cylinder wall 27 is made of aluminum).

  The pipe coupling sleeve 21 has a cylindrical shape, and includes a large-diameter cylindrical portion 22 protruding from the end face of the prismatic body 11 and a small-diameter cylindrical portion 23 having a small diameter in a stepped manner with respect to the large-diameter cylindrical portion 22. . The large-diameter cylindrical portion 22 corresponds to a “base side of the pipe coupling sleeve” in the present invention, and the small-diameter cylindrical portion 23 corresponds to “an intermediate portion of the pipe coupling sleeve” in the present invention.

  The outer cylinder wall 27 is a cylindrical body that is concentric and has a uniform diameter with the pipe coupling sleeve 21, and a base end portion thereof (corresponding to a “fixing portion” of the present invention) is fixed to the outer peripheral surface of the large-diameter cylindrical portion 22. It is fixed by (screwing, press fitting, welding or adhesive). A bottomed cylindrical pipe insertion region 30 is formed between the outer cylindrical wall 27 and the small-diameter cylindrical portion 23 of the pipe coupling sleeve 21, and a pipe P <b> 1 (to be connected) from the open end of the pipe insertion region 30. (See FIG. 4) can be inserted.

  The outer cylinder wall 27 is formed with a visual recognition window 28 for visually confirming the coupling state of the pipe coupling sleeve 21 and the pipe P1. The visual recognition window 28 is configured by a circular hole that penetrates the outer cylindrical wall 27, and a plurality (for example, three) of the visual recognition windows 28 are provided in the circumferential direction of the outer cylindrical wall 27.

  The radial width (internal / external diameter difference) of the pipe insertion region 30 is constant in the circumferential direction. Further, the radial width of the pipe insertion region 30 is slightly increased in the vicinity of the opening end of the pipe insertion region 30. Specifically, tapered portions 21 </ b> A and 27 </ b> A that are inclined toward the opening end of the pipe insertion region 30 are formed on the outer peripheral surface of the distal end portion of the pipe coupling sleeve 21 and the inner peripheral surface of the distal end portion of the outer cylindrical wall 27. ing. With this configuration, the insertion of the pipe P1 into the pipe insertion region 30 can be started smoothly. Further, even if the insertion tip of the pipe P1 is slightly deformed into an ellipse, it can be inserted as it is.

  A plurality of (for example, two) annular grooves 24, 24 are recessed in the middle of the small-diameter cylindrical portion 23 of the pipe coupling sleeve 21 with an interval in the axial direction. These annular grooves 24 and 24 have the same shape, and annular seal members 31A and 31B (in this embodiment, O-rings) are attached to the annular grooves 24 and 24, respectively. The annular seal members 31 </ b> A and 31 </ b> B are mounted in a state of protruding from the outer peripheral surface of the small diameter cylindrical portion 23 into the pipe insertion region 30. The annular seal members 31A and 31B are brought into close contact with the inner peripheral surface of the pipe P1 inserted into the pipe insertion region 30 (coupled to the pipe coupling sleeve 21), so that the space between the pipe P1 and the pipe coupling sleeve 21 is reached. (See FIG. 5). Note that the above-described viewing window 28 is formed further on the back side of the pipe insertion region 30 than the annular seal member 31B mounted on the back side of the pipe insertion region 30. Hereinafter, when the two annular seal members 31A and 31B are distinguished from each other, the opening end side of the pipe insertion region 30 is referred to as a “first annular seal member 31A”, and the rear side of the pipe insertion region 30 is This is referred to as “second annular seal member 31B”.

  Circumferential grooves 25 and 25 different from the annular grooves 24 and 24 are formed at both side positions of the pipe coupling sleeve 21 sandwiching the plurality of annular seal members 31A and 31B from the axial direction. Both the circumferential grooves 25 and 25 have the same shape, and retaining rings 32 </ b> A and 32 </ b> B (corresponding to the “pipe retaining portion” of the present invention) are fitted in the grooves. Each of the circumferential grooves 25, 25 is formed so that the groove is deepened toward the back side of the pipe insertion region 30, and the retaining rings 32A, 32B are fitted into the deepest deep groove portions 25A, 25A (see FIG. 2).

  The retaining rings 32 </ b> A and 32 </ b> B are made of, for example, a metal split ring having a C shape in plan view. The inner circumferential edges of the retaining rings 32A and 32B are locked to the circumferential grooves 25 and 25, and the outer circumferential edge projects from the outer circumferential surface of the pipe coupling sleeve 21 into the pipe insertion region 30, and the outer circumferential edge has an acute edge. Portions 32E and 32E are formed. The retaining rings 32 </ b> A and 32 </ b> B are fan-shaped in cross section, and an arcuate surface 32 </ b> R is formed on the opening end side of the pipe insertion region 30 to allow passage of the correction cylinder 40 and the pipe P <b> 1. An edge portion 32E is formed on the back side to prohibit extraction of the pipe P1 (see FIG. 2). When the pipe P1 to be connected is inserted into the pipe insertion region 30, the retaining rings 32A and 32B are elastically deformed so as to reduce the diameter, and the edge portions 32E and 32E abut against the inner peripheral surface of the pipe P1 due to the elastic force ( Or bite in). Hereinafter, when distinguishing the two retaining rings 32A and 32B, the opening end side of the pipe insertion region 30 is referred to as a “first retaining ring 32A” and the inner side is referred to as a “second retaining ring 32B”.

  Of the inner peripheral surface of the outer cylindrical wall 27, a retaining edge portion 27 </ b> E is provided over the entire circumference at a position facing the circumferential groove 25 (first retaining ring 32 </ b> A) formed on the opening end side of the pipe insertion region 30. Are integrally formed. The retaining edge portion 27 </ b> E slightly protrudes inside the pipe insertion region 30 and abuts (or bites) the outer peripheral surface of the pipe P <b> 1 inserted into the pipe insertion region 30.

  In the pipe insertion region 30, a correction cylinder 40 for assisting the insertion of the pipe P1 is assembled. The correction cylinder 40 is pushed by the pipe P1 inserted into the pipe insertion region 30 and moves in the pipe insertion region 30 toward the back, and the annular seal members 31A and 31B precede the insertion tip of the pipe P1. When passing, the annular seal members 31A and 31B are deformed so as to be pushed into the annular grooves 24 and 24, thereby preventing contact between the insertion tip of the pipe P1 and the annular seal members 31A and 31B.

  The correction cylinder 40 is made of an elastic body (in this embodiment, rubber) that is equal to or harder than the annular seal members 31A and 31B. This prevents the annular seal members 31A and 31B from being expanded and deformed as described above, and when the obliquely cut pipe P1 is inserted into the pipe insertion region 30, the correction cylinder is adapted according to the oblique cut surface. This is for flexibly deforming the body 40. The straightening cylinder 40 may be made of a thermoplastic elastomer or an elastic foam.

  As shown in FIG. 3, the correction cylinder 40 has a cylindrical shape with a large dimension in the radial direction with respect to the axial direction. As shown in FIG. 2, the correction cylinder 40 is mounted so as to cover both the two annular seal members 31 </ b> A and 31 </ b> B in an unused state before the pipe P <b> 1 is inserted into the pipe insertion region 30. Yes. Specifically, the correction cylinder 40 is configured so that the second annular seal member 31B and the second retaining member are disposed from the intermediate position between the first retaining ring 32A and the first annular seal member 31A in the pipe coupling sleeve 21. The range up to an intermediate position with the ring 32B is surrounded. The straightening cylinder 40 is prevented from falling off the pipe insertion region 30 by the first retaining ring 32A.

  An annular closed space 44 is formed between the inner peripheral surface of the straightening cylinder 40 and the outer peripheral surface of the pipe coupling sleeve 21, and two annular seal members 31 </ b> A and 31 </ b> B are accommodated in the closed space 44. More specifically, the inner diameter of the large-diameter portion 40A formed at the intermediate portion in the axial direction on the inner peripheral surface of the straightening cylinder 40 is determined by the annular seal members 31A and 31B (O-rings) mounted in the annular grooves 24 and 24. ) Is the same as or slightly larger than the maximum outer diameter. On the other hand, the inner diameters of the small diameter portions 40B and 40B formed at both end portions in the axial direction of the inner peripheral surface of the correction cylinder 40 are larger than the maximum outer diameter portions of the annular seal members 31A and 31B (O-rings). It becomes small and is in contact with the outer peripheral surface of the pipe coupling sleeve 21. Thus, in the unused state, the correction cylinder 40 covers the entire two annular seal members 31A and 31B so that the annular seal members 31A and 31B are not exposed. (Dust etc.) can be reliably prevented from adhering to the annular seal members 31A and 31B. Further, since the correction cylinder 40 does not apply a load to the annular seal members 31A and 31B in the unused state, it can be stored for a long time in a state where the correction cylinder 40 is assembled (the state shown in FIG. 1). In addition, the internal diameter of the small diameter parts 40B and 40B in the correction | amendment cylinder 40 is equal to or smaller than the internal diameter of the pipe P1 which is a connection object.

  In the straightened cylinder 40, between the small diameter portion 40B and the large diameter portion 40A on the opening end side of the pipe insertion region 30, a tapered portion 40C that gradually increases in diameter from the small diameter portion 40B toward the large diameter portion 40A. Is provided. By providing the tapered portion 40C, when the correction cylinder 40 passes through the annular seal members 31A and 31B, it is possible to easily get over without turning the annular seal members 31A and 31B. In the present embodiment, the first annular seal member 31A and the first retaining ring 32A can restrict the movement of the correction cylinder 40 in the axial direction when not in use.

  As shown in FIG. 2, the correction cylinder 40 is divided into a thick cylinder 41 and a thin cylinder 42 at an intermediate portion in the axial direction. The thick cylindrical portion 41 has a relatively large outer diameter and a large thickness, whereas the thin cylindrical portion 42 has a relatively small outer diameter and a small thickness. And the thick cylinder part 41 is arrange | positioned in the opening end side of the pipe insertion area | region 30, and the thin cylinder part 42 is arrange | positioned in the back | inner side of the pipe insertion area | region 30. FIG.

  The outer diameter of the thick tube portion 41 is the same as or slightly smaller than the inner diameter of the outer tube wall 27. That is, the thick-walled cylinder portion 41 is in contact with the inner peripheral surface of the outer cylinder wall 27 or close to it with a slight gap. By adopting such a configuration, it is possible to suppress the expansion deformation of the thick-walled cylinder portion 41 when the thick-walled cylinder portion 41 gets over the annular seal members 31A and 31B, and hence the expansion deformation of the annular seal members 31A and 31B. . Note that the outer diameter of the thick-walled cylinder portion 41 is substantially equal to the outer diameter of the pipe P1 to be connected.

  Here, in the unused state shown in FIG. 2, the thick cylindrical portion 41 is connected to the first annular seal member 31 </ b> A and the second annular seal member 31 </ b> A from the position closer to the opening end of the pipe insertion region 30 than the first annular seal member 31 </ b> A. The range up to an intermediate position with the annular seal member 31B is surrounded. Further, the thin-walled cylinder portion 42 has a range from an intermediate position between the first annular seal member 31A and the second annular seal member 31B to a position on the back side of the pipe insertion region 30 from the second annular seal member 31B. Besieged.

  As shown in FIG. 3, the thin tube portion 42 extends from a position near the inner peripheral surface of the thick tube portion 41 at one end. A plurality of detection pieces 43, 43 are formed in the thin cylindrical portion 42 in the circumferential direction. That is, a plurality of cuts extending from one axial end portion to the middle portion of the correction cylinder 40 are formed at regular intervals over the entire circumference of the correction cylinder 40, and a portion sandwiched between adjacent cuts is formed. These are detection pieces 43 and 43, respectively. These detection pieces 43, 43 are in the form of strips having the same width, the base ends of which are connected to the thick tube portion 41.

  As shown in FIG. 1, a detection window 29 is formed through the outer cylinder wall 27 in addition to the viewing window 28. The detection window 29 is formed so as to penetrate through the base end portion of the outer cylinder wall 27 (more specifically, slightly distal end side from the fixing portion with the pipe coupling sleeve 21), and the innermost wall of the pipe insertion region 30 is formed in the outer cylinder wall. 27 is opened radially outward. The detection window 29 has, for example, a horizontally long rectangular shape, and a plurality (for example, three) of detection windows 29 are provided at intervals in the circumferential direction of the outer cylinder wall 27.

  A guide inclined portion 26 is formed at the bottom of the pipe insertion region 30. That is, of the outer peripheral surface of the pipe coupling sleeve 21, the stepped surface between the large diameter cylindrical portion 22 and the small diameter cylindrical portion 23 increases in diameter toward the large diameter cylindrical portion 22 from the small diameter cylindrical portion 23. The tapered surface is a guide inclined portion 26. The plurality of detection windows 29 and 29 are formed at positions facing the guide inclined portion 26 (tapered surface) in the radial direction of the outer cylindrical wall 27.

  The configuration of the pipe joint 10 of the present embodiment is as described above, and the operation of the present embodiment will be described below. When the pipe P1 is coupled to the insertion coupling portion 20 of the pipe joint 10, the insertion tip portion of the pipe P1 is inserted from the opening end of the pipe insertion region 30. Immediately after the insertion, the insertion tip of the pipe P1 is brought into sliding contact with the arc surface 32R of the first retaining ring 32A so as to reduce the diameter of the first retaining ring 32A and abut against the correction cylinder 40. When the pipe P1 is further pushed in from here, as shown in the change from FIG. 1 to FIG. 4, the correction cylinder 40 is pushed toward the back side of the pipe insertion region 30 by being pushed by the pipe P1. The straightening cylinder 40 has a first annular shape preceding the pipe P1 while pushing the first annular seal member 31A into the annular groove 24 by the inner peripheral surface (tapered portion 40C and small diameter portion 40B on the opening end side). Passing through the seal member 31A, the second annular seal member 31B passes through the second annular seal member 31B prior to the pipe P1 while pushing the second annular seal member 31B into the annular groove 24 in the same manner. Since the correction cylinder 40 pushes the annular seal members 31A and 31B into the annular grooves 24 and 24 prior to the insertion tip of the pipe P1, the annular seal members 31A and 31B are damaged by the inner peripheral edge of the insertion tip of the pipe P1. Or the annular seal members 31A, 31B can be prevented from being turned over (disengaged from the annular grooves 24, 24) by being pushed by the pipe P1, and the connection work between the pipe P1 and the pipe connection sleeve 21 can be performed smoothly. it can.

  When the correction cylinder 40 passes through the second annular seal member 31B, it comes into sliding contact with the arc surface of the second retaining ring 32B to reduce the diameter of the second retaining ring 32B and further toward the back side.

  Immediately after passing through the second retaining ring 32B, the correction cylinder 40 has a plurality of detection pieces 43, 43 that hit the conical guide inclined portion 26 formed in the bottom of the pipe insertion region 30, and the guide inclination thereof. The detection pieces 43 and 43 are elastically deformed so as to expand radially by the guidance of the portion 26.

  Then, as shown in FIG. 5, when the pipe P <b> 1 is inserted to a specified insertion depth, any of the plurality of detection pieces 43, 43 passes through the detection windows 29, 29 of the outer cylinder wall 27. It protrudes outside the outer cylinder wall 27. Here, since the detection pieces 43 and 43 are formed in the thin-walled cylindrical portion 42 in the correction cylinder 40, the detection pieces 43 and 43 can be easily elastically deformed. Further, by providing the conical guide inclined portion 26, the detection pieces 43, 43 can be smoothly projected from the detection windows 29, 29. Here, since there is no detection window 29, the other detection pieces 43 and 43 that cannot protrude from the detection window 29 are crushed at the innermost part of the pipe insertion region 30 to be bent or compressed.

  The pair of retaining rings 32A and 32B are elastically deformed so as to be reduced in diameter by being pushed by the inner peripheral surface of the pipe P1, and the edge portions 32E and 32E abut against the inner peripheral surface of the pipe P1 by the elastic force thereof. (Or bite in). Further, the pair of annular seal members 31A and 31B are in close contact with the inner peripheral surface of the pipe P1, and seal the fitting portion between the pipe coupling sleeve 21 and the pipe P1.

  Here, as shown in FIG. 5, when the pipe P1 coupled to the pipe joint 10 is pulled out from the pipe coupling sleeve 21, the retaining rings 32A and 32B move from the deep groove portion 25A of the circumferential grooves 25 and 25 to the shallow groove portion 25B. As a result, the diameter of the pipe P1 is increased and the inner peripheral surface of the pipe P1 is further bitten. As a result, it is possible to strongly inhibit the pipe P1 from coming off.

  Now, it is possible to visually confirm the connection of the pipe P1 in the same manner as a conventional pipe joint. That is, the pipe joint 10 of the present embodiment is provided with the visual recognition window 28, and if the visual recognition window 28 is completely blocked by the outer surface of the pipe P1, it can be determined that the coupling state is appropriate. If the viewing window 28 is not completely closed by the outer surface of the pipe P1, it can be determined that the connection is incomplete.

  Furthermore, the pipe joint 10 according to the present embodiment can be confirmed by touch even when it is impossible or difficult to visually confirm the connection from the visual window 28. That is, if the pipe P1 is inserted to a specified insertion depth, the detection pieces 43 and 43 protrude from the detection windows 29 and 29 as shown in FIG. Therefore, when the pipe joint 10 is touched from the outside, if the detection pieces 43 and 43 can be touched, it can be determined that the coupling state is appropriate, and if the detection pieces 43 and 43 cannot be touched, the detection pieces 43 and 43 are incomplete. It can be determined that this is a simple combination.

  As described above, according to this embodiment, whether or not the detection pieces 43 and 43 protrude from the detection windows 29 and 29 can be confirmed by touch even when it is impossible or difficult to visually confirm the connection. Thus, the connection confirmation of the pipe P1 can be performed.

  Further, since the plurality of detection pieces 43, 43 are formed over the entire circumference of the correction cylinder 40, when the pipe P1 is inserted to a predetermined insertion depth, any one of the plurality of detection pieces 43, 43 is detected. It always projects from the detection windows 29 and 29. Therefore, when assembling the straightened cylinder 40 to the pipe insertion region 30, the trouble of previously positioning the detection pieces 43, 43 and the detection windows 29, 29 is saved, and the assembling workability is improved.

  Further, since the first retaining ring 32A and the retaining edge portion 27E are provided at a position closer to the opening end of the pipe insertion region 30 than the plurality of annular seal members 31A and 31B, for example, as shown in FIG. When the pipe P1 is to be pulled out after the correction cylinder 40 has been pushed halfway by the pipe P1, the pipe P1 can be prohibited from being pulled out by the retaining ring 32A and the retaining edge portion 27E. That is, since the insertion and removal of the pipe P1 after the correction cylinder 40 has moved from the unused position can be prohibited, it is possible to prevent the annular seal portions 31A and 31B from being turned up due to the reinsertion of the pipe P1. .

  Further, in a proper coupling state, a part of the detection pieces 43, 43 protrudes from the detection windows 29, 29, and the other detection pieces 43, 43 are bent or compressed at the innermost part of the pipe insertion region 30, When the detection pieces 43 and 43 are provided without changing the axial length of the straightening cylinder 40 from the conventional product, the space occupied by the straightening cylinder 40 in the innermost part of the pipe insertion region 30 can be reduced. Accordingly, the insertion depth of the pipe P1 can be made deeper and the axial length of the pipe joint 10 can be shortened.

  Even when the axial length of the straightened cylinder 40 is extended from that of the conventional product and the detection pieces 43 and 43 are formed in the extension portion, the extension portion protrudes outward from the detection windows 29 and 29, or the pipe insertion region. Since the bending deformation or the compression deformation is performed at the innermost portion of the pipe 30, it is possible to suppress the expansion of the space occupied by the correction cylinder 40 at the innermost portion of the pipe insertion region 30.

  Further, when the intermediate layer is made of a metal (for example, aluminum) and the multilayer pipe in which the innermost layer and the outermost layer are made of an insulating resin (for example, cross-linked polyethylene) is the pipe P1 to be connected, the correction cylinder 40 Is made of an insulator, it is possible to insulate between the metal layer exposed from the end face of the pipe P1 and the pipe joint 10 in the coupled state with the pipe P1, and thus prevent the occurrence of electrical corrosion. Can do.

[Second Embodiment]
In the first embodiment, the retaining rings 32A and 32B are mounted on the outer peripheral surface of the pipe coupling sleeve 21, but in the present embodiment, the first ring is mounted on the inner peripheral surface of the outer cylindrical wall 27. Different from the embodiment. That is, as shown in FIG. 6, the circumferential grooves 25, 25 are recessed and formed on both sides of the inner peripheral surface of the outer cylindrical wall 27 with the annular seal members 31 </ b> A, 31 </ b> B interposed therebetween. The outer peripheral edges of 32A and 32B are fitted. Edge portions 32E and 32E are formed on the inner peripheral edges of the retaining rings 32A and 32B, and the edge portions 32E and 32E protrude from the inner peripheral surface of the outer cylindrical wall 27 to the inside of the pipe insertion region 30. When the pipe P1 is inserted into the pipe insertion region 30, the retaining rings 32A and 32B are elastically deformed so as to expand in diameter, and the edge portions 32E and 32E abut against the outer peripheral surface of the pipe P1 by its elastic force. As a result, it is possible to strongly inhibit the pipe P1 from coming off. Also according to the present embodiment, the same effects as those of the first embodiment can be obtained.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

  (1) In the above-described embodiment, cuts extending in the axial direction are formed in the thin cylindrical portion 42 of the correction cylinder 40 at regular intervals over the entire circumference, and the portions sandwiched between adjacent cuts are detected pieces 43. However, one detection piece 43 or a plurality of detection pieces 43 may be provided at intervals in the circumferential direction of the correction cylinder 40.

  (2) In the above embodiment, the correction cylinder 40 is made of an elastic body and the detection piece 43 is elastically deformable. However, the detection piece 43 is plastically deformed by using the correction cylinder 40 made of metal or resin. It is good also as a possible structure.

  (3) In the above-described embodiment, the visual recognition window 28 for visually confirming the coupling state between the pipe P1 and the pipe joint 10 is formed. However, the visual recognition window 28 is not essential and may be configured without the visual recognition window 28. Good.

  (4) In the above embodiment, as the “pipe retaining portion” of the present invention, the retaining rings 32A and 32B, which are separate parts from the pipe coupling sleeve 21, are provided. For example, as in the retaining edge portion 27E, the pipe coupling An annular edge portion that protrudes inside the pipe insertion region 30 may be integrally formed on the outer peripheral surface of the sleeve 21.

  (5) In the above embodiment, in the unused state, the tip end of the detection piece 43 is located on the deeper side of the pipe insertion region 30 than the second annular seal member 31B, but at least the second annular seal member 31B. It is only necessary to reach the maximum outer diameter portion.

  (6) In the said embodiment, although the front-end | tip part arrange | positioned in the back | inner side of the pipe insertion area | region 30 among the correction | amendment cylinders 40 had made the shape bent inside, as a structure which eliminated the bending of this front-end | tip part Also good.

  (7) In the above embodiment, in the unused state, the thick-walled cylinder portion 41 of the correction cylinder body 40 has a first annular shape from a position closer to the opening end of the pipe insertion region 30 than the first annular seal member 31A. As shown in FIG. 7, the opening of the pipe insertion region 30 is more open than the first annular seal member 31 </ b> A, although the range up to the intermediate position between the seal member 31 </ b> A and the second annular seal member 31 </ b> B is included. It is good also as a structure which surrounds at least the range from the position of an end side to the largest outer diameter part of the 2nd annular seal member 31B. In this way, the expansion deformation of all the annular seal members 31A and 31B can be reliably prevented.

  (8) In the above embodiment, the detection piece 43 that cannot be protruded from the detection window 29 is bent or compressed at the innermost part of the pipe insertion region 30, but as shown in FIG. A pocket 35 for receiving the non-protrudable detection piece 43 may be formed at the proximal end portion of the pipe coupling sleeve 21.

  (9) In the above embodiment, the detection window 29 is formed at the base end portion of the outer cylindrical wall 27 so that the detection piece 43 protrudes to the side. The detection piece 43 may be formed in the base end portion so as to protrude in the axial direction. For example, as shown in FIG. 9, a fixed flange wall 21H projecting sideways is formed at the proximal end portion of the pipe coupling sleeve 21, and the proximal end of the outer cylinder wall 27 is formed on the outer peripheral surface of the fixed flange wall 21H. When the portion is fixed integrally, a detection window 29 that penetrates the fixed flange wall 21H in the axial direction of the pipe coupling sleeve 21 is formed, and the detection piece 43 can protrude from the detection window 29. Also good.

  (10) Further, the portion where the detection window 29 is formed is limited to either the pipe coupling sleeve 21 or the base end portion of the outer cylindrical wall 27 as in the first embodiment and the modification (9). Instead, it may be formed at a portion where the base end portions of the pipe coupling sleeve 21 and the outer cylindrical wall 27 communicate with each other. For example, as shown in FIG. 10, a fixed flange wall 27H projects inward from the base end portion of the outer cylindrical wall 27, and the fixed flange wall 27H and the fixed flange wall 21H of the pipe connecting sleeve 21 are overlapped to form a pipe connection. In the case where the sleeve 21 and the outer cylinder wall 27 are integrally fixed, the detection piece 43 may protrude from the detection window 29 that penetrates both the fixed flange walls 21H and 27H.

  (11) In the above embodiment, the outer cylindrical wall 27 is fixed to the large-diameter cylindrical portion 22 that is the base end portion (base portion side portion) of the pipe coupling sleeve 21, but the base portion where the pipe coupling sleeve 21 extends ( In the above embodiment, the outer cylinder wall 27 may be fixed to the prismatic body 11), and the detection window may be formed at the base.

10 Pipe joint 11 Rectangular column (base)
21 Pipe connection sleeve 22 Large diameter cylindrical portion 23 Small diameter cylindrical portion 24 Annular groove 26 Guide inclined portion (tapered surface)
27 Outer cylinder wall 27E Stop edge (pipe stop)
29 Detection window 30 Pipe insertion region 31A, 31B Annular seal member 32A, 32B Stop ring (pipe stop part)
40 Straightening cylinder 41 Thick cylinder part 42 Thin cylinder part 43 Detection piece
P1 pipe

Claims (10)

A pipe coupling sleeve extending from the base, and
A cylindrical outer cylinder wall surrounding the pipe coupling sleeve;
A pipe retaining portion that is locked to a pipe inserted into a cylindrical pipe insertion region between the pipe coupling sleeve and the outer cylindrical wall to prevent the pipe from being detached;
An annular seal member mounted in an annular groove provided on the outer peripheral surface of the pipe coupling sleeve;
In the pipe joint provided with the correction cylinder that moves by being pushed by the pipe inserted into the pipe insertion region outside the annular seal member,
A detection window formed on either the pipe coupling sleeve or the outer cylinder wall;
A pipe joint, comprising: a detection piece provided on the correction cylinder and protruding outward from the detection window when the correction cylinder moves to the back side of the pipe insertion region.   The correction cylinder is made of an elastic body, and is provided with a plurality of cuts extending from one axial end portion to an intermediate portion of the correction cylinder, and a portion of the correction cylinder sandwiched by the adjacent cuts is The pipe joint according to claim 1, wherein the pipe joint is a detection piece.   3. The pipe joint according to claim 2, wherein the plurality of cuts are provided at predetermined intervals along the entire circumference of the straightening cylinder, and the plurality of detection pieces are formed on the whole circumference of the straightening cylinder. .   The detection window according to any one of claims 1 to 3, wherein a plurality of the detection windows are arranged in a distributed manner in a circumferential direction of the pipe joint, and a plurality of detection pieces that can protrude outward from the plurality of detection windows are provided. A pipe joint according to claim. The detection window is opened toward the side of the pipe joint,
5. The guide inclined portion that is inclined to gradually approach the detection window side toward the front in the insertion direction of the pipe is provided at the back of the pipe insertion region. The pipe joint according to any one of claims. The outer diameter of the pipe coupling sleeve on the base side is increased in a stepped manner from the outer diameter of the intermediate part of the pipe coupling sleeve, and the step surface between the base side and the intermediate part of the pipe coupling sleeve is tapered. age,
The outer cylinder wall is formed into a cylindrical shape having a uniform diameter, and a fixed portion fixed to the base side of the pipe connection sleeve on the base side of the outer cylinder wall, and the pipe connection in the radial direction of the outer cylinder wall 4. The pipe joint according to claim 3, further comprising a plurality of the detection windows arranged to be distributed in a circumferential direction of the outer cylinder wall so as to face the tapered surface of the sleeve. A plurality of the annular grooves are provided on the outer peripheral surface of the pipe coupling sleeve, and the annular seal members are respectively attached to the annular grooves,
The pipe joint according to any one of claims 1 to 6, wherein the straightening cylinder is locked in a state of being fitted to the outside of all the annular seal members. The one end side in the axial direction of the correction cylinder is provided with a thin-walled cylinder portion having a smaller outer diameter and smaller wall thickness than the other end side, whereas the other end side in the axial direction of the correction cylinder is from one end side. A thick cylindrical portion having a large outer diameter and a large thickness is provided,
A plurality of cuts extending in the axial direction are formed in the thin-walled cylindrical portion, and a portion sandwiched between the adjacent cuts in the correction cylinder is used as the detection piece. The pipe joint according to any one of claims. A plurality of the annular grooves are provided on the outer peripheral surface of the pipe coupling sleeve, and an O-ring as the annular seal member is attached to each of the annular grooves,
The thick-walled cylinder portion ranges from a position closer to the opening end of the pipe insertion region than the plurality of O-rings to a maximum outer diameter portion of the O-ring arranged farthest from the pipe insertion region. The pipe joint according to claim 8, wherein the pipe joint is configured to surround at least.   The pipe joint according to any one of claims 1 to 9, wherein the straightening cylinder is an insulator.

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