Pipe joint

Abstract

To provide a pipe joint capable of preventing unintentional loosening of a nut after tightening, while allowing the nut to be intentionally loosened.SOLUTION: A pipe joint 20 comprises a tubular joint body, a nut 44, a movable engagement part 46, and a spacer 52. The movable engagement part 46 is disposed at a position adjacent to a base portion of a male screw of the joint body, as viewed from a tip end of the male screw. The movable engagement part 46 is disposed so as to enable movement of the joint body toward a central axis of a joint flow path forming part. The movable engagement part 46 engages with a nut-side engagement part of the nut 44. The spacer 52 can prevent movement of the movable engagement part 46 in a rearward direction of the movable engagement part 46, as viewed from a tip end of the male screw of the joint body. A projection engagement part 64 of the joint body engages with a separation-end projection part of the spacer 52 so as to prevent an increase in the width of a separated portion that can be opened and closed, in an occupying body 150 of the spacer 52.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a pipe joint. [Background technology]

[0002] Patent Document 1 discloses a pipe joint. This pipe joint connects steel pipes each having a bulged portion with an arc-shaped cross section formed on the outer periphery of its end. This pipe joint has a joint body, an O-ring mounting groove, an O-ring, an annular groove, a stopper ring, a fitting portion, and a nut. The joint body has an insertion portion into which the steel pipe is inserted. Male threads are formed on the outer periphery of both ends of the joint body. An O-ring mounting groove is provided on the inner periphery of the joint body. An O-ring is disposed in this O-ring mounting groove. The O-ring abuts against the bulged portion of the steel pipe. An annular groove is provided adjacent to the end of the male thread of the joint body. A stopper ring is disposed in the annular groove. The fitting portion faces the joint body across the bulged portion of the steel pipe and fits onto the steel pipe. The nut has a female thread and a notch. The female thread engages with the male thread of the joint body. The notch is provided on the inner peripheral surface of the female thread portion on the opening side of the fitting body. The notch engages with a stopper ring. The pipe fitting disclosed in Patent Document 1 can prevent seizure during tightening and can prevent the nut from loosening after tightening. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-256945 Summary of the Invention [Problem to be solved by the invention]

[0004] The pipe joint disclosed in Patent Document 1 has a problem in that once the nut is tightened, it cannot be loosened.

[0005] An object of the present invention is to provide a pipe joint that can prevent accidental loosening of a nut after tightening and also allows the nut to be intentionally loosened. [Means for solving the problem]

[0006] The pipe joint of the present invention will be described with reference to the drawings. Note that the reference numerals used in this section are intended to facilitate understanding of the invention, and are not intended to limit the scope of the invention to that shown in the drawings.

[0007] To achieve the above-mentioned object, according to one aspect of the present invention, a pipe fitting 20 includes a cylindrical fitting body 40 and a nut 44. The fitting body 40 has a fitting flow path forming portion 60 and a male thread 62. The fitting flow path forming portion 60 forms a flow path. The male thread 62 is disposed on the outer periphery of at least one end of the fitting flow path forming portion 60. The nut 44 has a female thread 102 and a pipe communication retaining portion 100. The female thread 102 meshes with the male thread 62 of the fitting body 40. The pipe communication retaining portion 100 is connected to the female thread 102. The pipe communication retaining portion 100 holds the pipe 200 so that the interior of the pipe 200 is in communication with the flow path of the fitting body 40. The nut 44 further has a nut-side engaging portion 104. The nut-side engagement portion 104 faces toward the root of the male thread 62 when the female thread 102 engages with the male thread 62 of the fitting body 40. The pipe fitting 20 further includes a movable engagement portion 46 and a spacer 52, 452. The movable engagement portion 46 is disposed at a position adjacent to the root of the male thread 62 when viewed from the tip of the male thread 62. The movable engagement portion 46 is disposed so as to be movable toward the central axis 180 of the fitting flow path forming portion 60. The movable engagement portion 46 engages with the nut-side engagement portion 104 when it has reached a predetermined position on the male thread 62. The spacer 52, 452 is disposed at the rear of at least a portion of the movable engagement portion 46 when viewed from the tip of the male thread 62. The spacer 52, 452 prevents the movable engagement portion 46 from moving in the rear direction of the movable engagement portion 46 when viewed from the tip of the male thread 62. The spacer 52, 452 has an occupying body 150, 460 and a separation end protrusion 152, 462. The occupying body 150, 460 is positioned at least partially behind the movable engagement portion 46 when viewed from the position of the tip of the male thread 62. The occupying body 150, 460 is annular, with a portion formed with a notch. The separation end protrusion 152, 462 protrudes from the end of the portion of the occupying body 150, 460 that is separated so as to be able to open and close. The joint body 40 further has a protruding engagement portion 64. The protruding engagement portion 64 engages with the separation end protrusion 152, 462 to prevent the width of the portion of the occupying body 150, 460 that is separated so as to be able to open and close from increasing.

[0008] The movable engagement portion 46 is positioned adjacent to the base of the male thread 62 when viewed from the tip of the male thread 62. The movable engagement portion 46 engages with the nut-side engagement portion 104, which has reached a predetermined position on the male thread 62. In addition, the protruding engagement portion 64 engages with the separation end protrusion 152, 462 to prevent the width of the portion of the occupying body 150, 460 that is separated and can be opened and closed from expanding. This prevents accidental loosening of the nut 44 after tightening. Meanwhile, the movable engagement portion 46 is positioned so as to be movable toward the central axis 180 of the joint flow path forming portion 60. The spacer 52, 452 is positioned behind the movable engagement portion 46 when viewed from the tip of the male thread 62. The spacer 52, 452 prevents movement of the movable engagement portion 46 toward the back of the movable engagement portion 46 when viewed from the tip of the male thread 62. The occupying body 150, 460 of the spacer 52, 452 is annular, with a portion formed with a notch. This allows the occupying body 150, 460 to be removed from the fitting body 40. When the occupying body 150, 460 is removed from the fitting body 40, the movable engaging portion 46 becomes movable in the direction of the central axis 180 of the fitting flow-path forming portion 60. When the movable engaging portion 46 moves, the engagement between the movable engaging portion 46 and the nut-side engaging portion 104 is released. Because this engagement is released, it becomes possible to intentionally loosen the nut 44. As a result, a pipe fitting 20 is provided that can prevent accidental loosening of the nut 44 after tightening and also allows the nut 44 to be intentionally loosened.

[0009] Furthermore, it is desirable that the above-described protruding engagement portion 64 has a portion 80 protruding from the outer periphery of the joint flow-path forming portion 60 so as to form an axially penetrating portion 90 that penetrates in the direction of the central axis 180 of the joint flow-path forming portion 60. In this case, it is desirable that the separated end protruding portion 152 has a first protruding portion 160 and a second protruding portion 162. The first protruding portion 160 protrudes from one end of the portion of the occupying main body 150 that is separated so as to be able to open and close. The second protruding portion 162 protrudes from the other end of the portion of the occupying main body 150 that is separated so as to be able to open and close. In this case, it is desirable that both the first protruding portion 160 and the second protruding portion 162 are arranged to fit into the axially penetrating portion 90.

[0010] When both the first protrusion 160 and the second protrusion 162 are arranged to fit into the axial through-hole 90, the possibility of the portion of the occupying body 150 that is separated and can be opened and closed accidentally is reduced. Because this possibility is reduced, the possibility of the spacer 52 being accidentally removed is reduced. Because this possibility is reduced, the possibility of the movable engaging portion 46 and the nut-side engaging portion 104 being disengaged is reduced. As a result, accidental loosening of the nut 44 after tightening is prevented.

[0011] Alternatively, it is desirable that the one protrusion 160 and the other protrusion 162 are arranged to fit into a common axial through-portion 90 .

[0012] When the first protrusion 160 and the second protrusion 162 are fitted into the common axial through-hole 90, the width of the gap formed at the openably separated portion of the occupying body 150 is reduced. This reduced width reduces the possibility of the openably separated portion of the occupying body 150 accidentally opening. This reduced possibility prevents the nut 44 from accidentally loosening after tightening.

[0013] Alternatively, it is desirable that the above-described movable engagement portion 46 has a constraint-side engagement portion 120 and an anti-rotation protrusion 122. The constraint-side engagement portion 120 engages with the nut-side engagement portion 104 that has reached a predetermined position on the male thread 62. When the constraint-side engagement portion 120 is positioned adjacent to the base of the male thread 62 as viewed from the tip of the male thread 62, the anti-rotation protrusion 122 protrudes from the constraint-side engagement portion 120 toward the back of the constraint-side engagement portion 120 as viewed from the tip of the male thread 62. In this case, it is desirable that the anti-rotation protrusion 122 be positioned so that it fits into the axial through portion 90 while being sandwiched between the one protrusion 160 and the other protrusion 162.

[0014] When the anti-rotation projection 122 is positioned so as to be sandwiched between the one protrusion 160 and the other protrusion 162 and fitted into the axial through-portion 90, the possibility of the gap between the one protrusion 160 and the other protrusion 162 widening due to vibration or other accidental factors is reduced. Because this possibility is reduced, the possibility of the portion of the occupying body 150 that is separated so as to be able to open and close opening accidentally is also reduced. Because this possibility is reduced, the nut 44 is prevented from accidentally loosening after being tightened.

[0015] Furthermore, it is preferable that the protruding engagement portion 64 described above has a plurality of grooves 92, 92. The plurality of grooves 92, 92 are respectively positioned at positions where the spacer 452 is to be positioned when viewed from the position of the tip of the male thread 62. The plurality of grooves 92, 92 are all aligned along the circumferential direction of the joint body 40. In this case, it is preferable that the separation end protrusion 462 has a first inner circumferential protrusion 480 and a second inner circumferential protrusion 482. The first inner circumferential protrusion 480 protrudes from one of the inner circumferential surfaces of the occupying body 460 at a location where it contacts the notch. The second inner circumferential protrusion 482 protrudes from the other of the inner circumferential surfaces of the occupying body 460 at a location where it contacts the notch. In this case, it is preferable that the first inner circumferential protrusion 480 and the second inner circumferential protrusion 482 are positioned so as to fit one-to-one into the plurality of grooves 92, 92 of the joint body 40.

[0016] When the one inner peripheral protrusion 480 and the other inner peripheral protrusion 482 fit one-to-one into the multiple grooves 92, 92, the possibility of the spacer 452 coming off from the depth of the movable engagement portion 46 due to an accidentally occurring external force is further reduced.

[0017] Alternatively, it is desirable that the following angle be less than π radians. This angle is an angle 500 formed by an end 490 of the above-described plurality of grooves 92, 92 into which one inner peripheral protrusion 480 fits but which is far from the other inner peripheral protrusion 482, a portion 492 of the central axis of the male thread 62 that is surrounded by the plurality of grooves 92, 92, and an end 494 of the plurality of grooves 92, 92 into which the other inner peripheral protrusion 482 fits but which is far from the one inner peripheral protrusion 480.

[0018] If the angle 500 is less than π radians, when a force is applied to the notch of the occupying body 460 to widen it, the reaction force against the force can be increased. Because the reaction force can be increased, the possibility of the notch of the occupying body 460 widening can be reduced. When the possibility is reduced, unintentional loosening of the nut 44 is more effectively prevented. [Effects of the Invention]

[0019] According to the present invention, a pipe joint is provided which, when it includes a joint body and a nut connected thereto, prevents the nut from unintentionally loosening. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is an external view of a pipe joint according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view of a joint body according to a first embodiment of the present invention. [Figure 3] FIG. 1 is a side view of a joint body according to a first embodiment of the present invention. [Figure 4] 1 is an external view of a nut according to a first embodiment of the present invention. [Figure 5] FIG. 2 is a perspective view of a movable engagement portion according to the first embodiment of the present invention. [Figure 6] 1 is an external view of a spacer according to a first embodiment of the present invention. [Figure 7] 1 is a view showing an attachment state of a spacer according to a first embodiment of the present invention. [Figure 8] 3 is a view showing the inside of the joint body in a state where one end of the pipe abuts against the annular end wall portion of the entry direction correction tube in the first embodiment of the present invention. FIG. [Figure 9] 3 is a view showing the inside of the joint body in a state in which the sealing material is spread radially outward from the inner periphery thereof in the first embodiment of the present invention. FIG. [Figure 10] 4 is a view showing a state in which an engaging protrusion and an engaging recess are gradually approaching each other in the first embodiment of the present invention. FIG. [Figure 11]FIG. 10 is an external view of a spacer according to a second embodiment of the present invention. [Figure 12] FIG. 10 is a view showing a state in which a spacer according to a second embodiment of the present invention is arranged so as to fit one-to-one into a plurality of grooves of a joint body. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same components are designated by the same reference numerals. Their names and functions are the same. Therefore, detailed descriptions thereof will not be repeated.

[0022] First Embodiment [Pipe fitting configuration] Fig. 1 is an external view of a pipe fitting 20 according to this embodiment. In Fig. 1, two pipes 200, 200 are connected to the pipe fitting 20 according to this embodiment. In Fig. 1, the objects shown are shown with portions cut away. Below, the configuration of the pipe fitting 20 according to this embodiment will be described based on Fig. 1.

[0023] The pipe fitting 20 according to this embodiment is used to connect two pipes 200, 200 to each other. The pipe fitting 20 is connected to one end of one of the pair of pipes 200, 200 and the other end of the other. The pipe fitting 20 allows fluid flowing through one of the pair of pipes 200, 200 to pass to the other. The pipe 200 according to this embodiment has a pipe flow path forming portion 220, an engagement enlarged diameter portion 222, and a seal facing portion 224. The pipe flow path forming portion 220 forms a flow path. The engagement enlarged diameter portion 222 is formed closer to one end of the pipe 200 than the pipe flow path forming portion 220. The engagement enlarged diameter portion 222 forms a space communicating with the flow path formed by the pipe flow path forming portion 220. The engagement enlarged diameter portion 222 has a larger outer diameter than the pipe flow path forming portion 220. The seal facing portion 224 is formed closer to one end of the pipe 200 than the engagement enlarged diameter portion 222. The seal facing portion 224 forms a space, which will be described below. This space communicates with the flow path formed by the pipe flow path forming portion 220 and the space formed by the engagement enlarged diameter portion 222.

[0024] As shown in FIG. 1, the pipe fitting 20 of this embodiment comprises a cylindrical fitting body 40, a pair of annular sealing members 42, 42, a pair of nuts 44, 44, a pair of movable engaging portions 46, 46, a pair of entry direction correcting tubes 50, 50, and a pair of spacers 52, 52.

[0025] The joint body 40 is a member that forms the main body of the pipe joint 20. Both of the two pipes 200, 200 enter the joint body 40. One of the two pipes 200, 200 enters from one end of the joint body 40, and the other of the two pipes 200, 200 enters from the other end of the joint body 40.

[0026] The pair of seals 42, 42 are both disposed within the joint body 40. The pair of seals 42, 42 together seal between the outer peripheral surface of the pipe 200 and the inner peripheral surface of the joint body 40. One of the pair of seals 42, 42 seals between the inner peripheral surface of the joint body 40 and one of the two pipes 200, 200. The other of the pair of seals 42, 42 seals between the inner peripheral surface of the joint body 40 and the other of the two pipes 200, 200.

[0027] The pair of nuts 44, 44 are connected to one end and the other end of the joint body 40. One of the two tubes 200, 200 passes through one of the pair of nuts 44, 44, and the other of the two tubes 200, 200 passes through the other of the pair of nuts 44, 44.

[0028] One of the pair of movable engaging portions 46, 46 is disposed at a position adjacent to the base of one of the pair of male threads 62, 62 as viewed from the tip thereof. The other of the pair of movable engaging portions 46, 46 is disposed at a position adjacent to the base of the other of the pair of male threads 62, 62 as viewed from the tip thereof. The movable engaging portions 46, 46 are disposed so as to be movable in the direction of the central axis 180 of the joint flow path forming portion 60.

[0029] The pair of entry direction correction cylinders 50, 50 are both housed within the joint body 40. The entry direction correction cylinder 50 corrects the entry direction of the pipe 200 that is entering the joint body 40.

[0030] One end of the joint body 40 passes through one of the pair of spacers 52, 52. One of the pair of spacers 52, 52 is positioned behind one of the pair of movable engagement portions 46, 46 when viewed from the position of the tip of one of the pair of male threads 62, 62. One of the pair of spacers 52, 52 prevents movement of one of the pair of movable engagement portions 46, 46 in the rearward direction when viewed from the position of the tip of one of the pair of male threads 62, 62. The other end of the joint body 40 passes through the other of the pair of spacers 52, 52. The other of the pair of spacers 52, 52 is positioned behind the other of the pair of movable engagement portions 46, 46 when viewed from the position of the tip of the other of the pair of male threads 62, 62. The other of the pair of spacers 52, 52 prevents movement of the other of the pair of movable engagement portions 46, 46 in the rearward direction when viewed from the position of the tip of the other of the pair of male threads 62, 62.

[0031] [Fitting body configuration] Fig. 2 is a perspective view of the joint body 40 according to this embodiment. Fig. 3 is a side view of the joint body 40 according to this embodiment. In Fig. 3, the illustrated objects are shown with portions thereof cut away. The configuration of the joint body 40 according to this embodiment will be described below with reference to Figs. 2 and 3.

[0032] The joint body 40 according to this embodiment has a joint flow path forming portion 60, a pair of male threads 62, 62, and a pair of protruding engagement portions 64, 64.

[0033] The joint flow path forming portion 60 forms a flow path. Water or other fluid passes through this flow path. The fluid flowing through this flow path and the fluid flowing through the two pipes 200, 200 are the same.

[0034] One of the pair of male threads 62, 62 is disposed on the outer periphery of one end of the joint flow path forming portion 60. The other of the pair of male threads 62, 62 is disposed on the outer periphery of the other end of the joint flow path forming portion 60.

[0035] In this embodiment, one of the pair of movable engagement portions 46, 46 described above is disposed at a position adjacent to the root of one of the pair of male threads 62, 62 when viewed from the tip of that male thread.

[0036] In this embodiment, the other of the pair of movable engagement portions 46, 46 described above is disposed at a position adjacent to the root of the other of the pair of male threads 62, 62 when viewed from the tip of that male thread.

[0037] One of the pair of protruding engagement portions 64, 64 is disposed at a position that is deep inside the male threads 62 when viewed from the tip of one of the pair of male threads 62, 62. The other of the pair of protruding engagement portions 64, 64 is disposed at a position that is deep inside the male threads 62 when viewed from the tip of the other of the pair of male threads 62, 62. The protruding engagement portions 64, 64 engage with a separation end protruding portion 152 of the spacer 52, which will be described later.

[0038] In this embodiment, the joint flow path forming portion 60 has a communication path forming portion 70, a pair of pipe end accommodating portions 72, 72, and a pair of sealing material accommodating portions 74, 74.

[0039] One of the pair of pipe end accommodating sections 72, 72 is arranged adjacent to one end of the communicating passage forming section 70. The other of the pair of pipe end accommodating sections 72, 72 is arranged adjacent to the other end of the communicating passage forming section 70. In other words, the pair of pipe end accommodating sections 72, 72 are arranged adjacent to each other with the communicating passage forming section 70 in between. One of the pair of pipe end accommodating sections 72, 72 accommodates one end of one of the pipes 200, 200. The other of the pair of pipe end accommodating sections 72, 72 accommodates the other end of the pipes 200, 200.

[0040] One of the pair of sealing material accommodating portions 74, 74 is positioned adjacent to one of the pair of pipe end accommodating portions 72, 72. One of the pair of sealing material accommodating portions 74, 74 accommodates one of the pair of sealing materials 42, 42. One end of one of the pair of pipes 200, 200 passes through one of the pair of sealing material accommodating portions 74, 74 and one of the pair of sealing materials 42, 42.

[0041] The other of the pair of sealing material accommodating portions 74, 74 is disposed adjacent to the other of the pair of pipe end accommodating portions 72, 72. The other of the pair of sealing material accommodating portions 74, 74 accommodates the other of the pair of sealing materials 42, 42. One end of the other of the pair of pipes 200, 200 passes through the other of the pair of sealing material accommodating portions 74, 74 and the other of the pair of sealing materials 42, 42.

[0042] In this embodiment, the central axis of the communicating passage forming portion 70, the central axis of the pair of pipe end accommodating portions 72, 72, and the central axis of the pair of sealing material accommodating portions 74, 74 all coincide with the central axis 180 of the joint flow path forming portion 60. Therefore, the central axis of the male thread 62, the central axis of the sealing material accommodating portion 74, and the central axis of the pipe end accommodating portion 72 are common.

[0043] In this embodiment, the protruding engagement portion 64 has an outer peripheral protruding portion 80 and an outer peripheral recessed portion 82 .

[0044] The outer peripheral protrusion 80 in this embodiment is an annular portion protruding from the outer periphery of the joint flow path forming portion 60. In this embodiment, the outer peripheral protrusion 80 has multiple axial through-portions 90, 90. The axial through-portions 90 are arranged on the outer periphery of the outer peripheral protrusion 80. The axial through-portions 90 are arranged so as to be exposed. The axial through-portions 90 are recessed. The axial through-portions 90 penetrate in the direction of the central axis 180 of the joint flow path forming portion 60.

[0045] The outer peripheral recess 82 according to this embodiment is disposed between the outer peripheral protrusion 80 and the male thread 62. As a result, the outer peripheral recess 82 of one of the pair of protruding engagement portions 64 is disposed at a position deep inside and adjacent to the male thread 62 when viewed from the tip of one of the pair of male threads 62. As a result, the outer peripheral recess 82 is disposed at a position where one of the pair of spacers 52 is disposed when viewed from the tip of one of the pair of male threads 62. Similarly, the outer peripheral recess 82 of the other of the pair of protruding engagement portions 64 is disposed at a position deep inside and adjacent to the male thread 62 when viewed from the tip of the other of the pair of male threads 62. As a result, the outer peripheral recess 82 is disposed at a position where the other of the pair of spacers 52 is disposed when viewed from the tip of the other of the pair of male threads 62.

[0046] In this embodiment, the outer peripheral recess 82 has a plurality of grooves 92, 92. These grooves 92, 92 are respectively arranged at positions where the spacer 52 would be disposed when viewed from the position of the tip of the male thread 62. All of these grooves 92, 92 are aligned along the circumferential direction of the joint body 40.

[0047] [Nut configuration] 4 is an external view of the nut 44 according to this embodiment. The configuration of the nut 44 according to this embodiment will be described below with reference to FIG.

[0048] The nut 44 according to this embodiment has a pipe communication holding portion 100, a female thread 102, a nut side engaging portion 104, eight nut outer peripheral recesses 106, and a covering portion .

[0049] The pipe communication holding portion 100 holds the pipe 200 so that the inside of the pipe 200 is in communication with the inside of the joint body 40. In this embodiment, the pipe communication holding portion 100 houses the engagement enlarged diameter portion 222 of the pipe 200.

[0050] The female thread 102 is connected to the pipe communication holding portion 100. The female thread 102 connects the pipe communication holding portion 100 to the joint body 40. In the present embodiment, the female thread 102 of one of the pair of nuts 44, 44 engages with one of the pair of male threads 62, 62 of the joint body 40. The female thread 102 of the other of the pair of nuts 44, 44 engages with the other of the pair of male threads 62, 62 of the joint body 40. As a result, the pipe communication holding portion 100 holds the pipe 200 so that the interior of the pipe 200 is in communication with the interior of the joint body 40.

[0051] When the female thread 102 meshes with the male thread 62 of the joint body 40, the nut side engaging portion 104 faces toward the root of the male thread 62. When the nut side engaging portion 104 reaches the root of the male thread 62, it engages with the movable engaging portion 46. In the present embodiment, the nut side engaging portion 104 has a large number of engaging recesses 110. These engaging recesses 110 are positioned to face engaging protrusions 144 (described below) of the movable engaging portion 46 when the female thread 102 meshes with the male thread 62 of the joint body 40. Each of the engaging recesses 110 is recessed.

[0052] In this embodiment, the nut outer periphery recess 106 is disposed on the outer periphery of the pipe communication holding part 100. The nut outer periphery recess 106 forms a groove.

[0053] In the present embodiment, the covering portion 108 is disposed at a location that faces the root of the male thread 62 when the female thread 102 meshes with the male thread 62 of the fitting body 40. The covering portion 108 is disposed so as to surround the central axis of the female thread 102 and, therefore, the central axis 182 of the pipe communication holding portion 100. Furthermore, in the present embodiment, the covering portion 108 is disposed outside the engagement recess 110 when viewed from the position of the central axis of the female thread 102 and, therefore, the central axis 182 of the pipe communication holding portion 100.

[0054] [Configuration of the movable engagement part] 5 is a perspective view of the movable engagement portion 46 according to this embodiment. The configuration of the movable engagement portion 46 according to this embodiment will be described below with reference to FIG.

[0055] In this embodiment, the movable engagement portion 46 has a restraining side engagement portion 120 and a rotation prevention protrusion 122 .

[0056] The restraining side engaging portion 120 engages with the nut side engaging portion 104 that has reached a predetermined location in the vicinity of the base of the male thread 62 .

[0057] The anti-rotation protrusion 122 protrudes from the restraining side engagement portion 120. When the restraining side engagement portion 120 is positioned adjacent to the root of the male thread 62 as viewed from the tip of the male thread 62, the anti-rotation protrusion 122 is positioned so as to extend toward the back of the restraining side engagement portion 120 as viewed from the tip of the male thread 62. The anti-rotation protrusion 122 fits into one of the multiple axial through-portions 90 described above. When the anti-rotation protrusion 122 fits into the axial through-portion 90 that penetrates the joint flow-channel forming portion 60 toward the central axis 180, it prevents the movable engagement portion 46 from shifting in the circumferential direction around the central axis 180. As described above, in this embodiment, the central axes of the pair of male threads 62, 62 both coincide with the central axis 180 of the joint flow-channel forming portion 60. This prevents the movable engagement portion 46 from shifting in the circumferential direction around the central axis of the male thread 62. As a result, the movable engaging portion 46 is positioned in a state where its rotation around the central axis 180 of the joint flow-path forming portion 60 of the joint main body 40 is restricted. Furthermore, by fitting the anti-rotation protrusion 122 into any of the above-described multiple axial through-portions 90, the movable engaging portion 46 can move inward when viewed from the tip of the male thread 62.

[0058] The restraining side engaging portion 120 according to this embodiment has a housing space forming portion 140, an index portion 142, and a plurality of engaging protrusions 144, 144.

[0059] The joint body 40 passes through the accommodation space forming portion 140. In this embodiment, the accommodation space forming portion 140 forms a plurality of accommodation spaces therein. The accommodation spaces are arranged to extend along the central axis of the male thread 62 when the joint body 40 passes through the accommodation space forming portion 140. The accommodation spaces open in the direction of the tip of the male thread 62.

[0060] The indicator portion 142 is connected to the accommodation space forming portion 140. The indicator portion 142 is intended to be disposed closer to the male thread 62 than the accommodation space forming portion 140. The indicator portion 142 is disposed on the rear side of the surface of the restraint side engaging portion 120 on which the rotation prevention protrusion 122 is disposed.

[0061] The engaging protrusion 144 is accommodated in one of the multiple accommodation spaces formed by the accommodation space forming portion 140. A portion of one engaging protrusion 144 is accommodated in one accommodation space. Another portion of the engaging protrusion 144 protrudes outside the accommodation space forming portion 140. The engaging protrusion 144 protrudes along the central axis of the accommodation space forming portion 140. The accommodation space forming portion 140 is arranged so that its central axis is aligned with the central axis 180 of the joint flow path forming portion 60 of the joint main body 40. In this embodiment, the central axis of the male thread 62 coincides with the central axis 180 of the joint flow path forming portion 60. As a result, the engaging protrusion 144 protrudes from the accommodation space forming portion 140 along the central axis of the male thread 62. The engaging protrusion 144 is arranged so as to face toward the tip of the male thread 62. As described above, the nut-side engaging portion 104 faces the root direction of the male thread 62 when the female thread 102 meshes with the male thread 62. As a result, in the case of this embodiment, the engaging recess 110 of the nut-side engaging portion 104 of the nut 44 faces the engaging protrusions 144, 144 of the movable engaging portion 46 when the female thread 102 of the nut 44 meshes with the male thread 62 of the joint body 40 described above. Note that in the case of this embodiment, the engaging protrusion 144 is located inside the index portion 142 when viewed from the position of the central axis of the male thread 62.

[0062] [Spacer configuration] Fig. 6 is an external view of the spacer 52 according to this embodiment. Fig. 7 is a view showing the installation state of the spacer 52 according to this embodiment. The configuration of the spacer 52 according to this embodiment will be described with reference to Figs. 6 and 7. The spacer 52 according to this embodiment has an occupying main body 150 and a separation end protrusion 152.

[0063] The occupying body 150 is positioned between the outer peripheral protrusion 80 and the accommodation space forming portion 140 so as to be in close contact with the accommodation space forming portion 140. As a result, the occupying body 150 is positioned at least partially behind the movable engagement portion 46 when viewed from the position of the tip of the male thread 62. The occupying body 150 has a ring shape with a portion separated so as to be able to open and close freely. In this embodiment, the occupying body 150 is positioned between the outer peripheral protrusion 80 and the accommodation space forming portion 140. By positioning the occupying body 150 there, movement of the accommodation space forming portion 140 in a direction toward the outer peripheral protrusion 80 is prevented. As a result, once the engaging protrusion 144 engages with the engaging recess 110, the engagement is difficult to release. Because the engagement is difficult to release, the connection between the fitting body 40 and the nut 44 is also difficult to release.

[0064] The separation end protrusion 152 protrudes from the end of the portion of the occupying body 150 that is separated so as to be openable and closable. In this embodiment, the separation end protrusion 152 has a first protrusion 160 and an second protrusion 162. The first protrusion 160 protrudes from one end of the portion of the occupying body 150 that is separated so as to be openable and closable. The second protrusion 162 protrudes from the other end of the portion of the occupying body 150 that is separated so as to be openable and closable. The first protrusion 160 and the second protrusion 162 protrude from the occupying body 150 in a direction along the central axis 184 of the occupying body 150. As shown in FIG. 7 , in this embodiment, the first protrusion 160 and the second protrusion 162 of the spacer 52 fit into a gap formed between the axial through-portion 90 and the anti-rotation protrusion 122. This prevents the spacer 52 from falling off due to vibration or other accidental factors. In this embodiment, when the first protrusion 160 and the second protrusion 162 are pulled up from the gap formed between the axially penetrating portion 90 and the anti-rotation projection 122, the occupying body 150 of the spacer 52 can be easily removed. When the occupying body 150 is removed, the accommodation space forming portion 140 can easily move in a direction approaching the outer peripheral protrusion 80. When the accommodation space forming portion 140 can easily move, the engagement between the engaging protrusion 144 and the engaging recess 110 can be easily released. This also makes it easy to release the connection between the fitting body 40 and the nut 44.

[0065] [How to connect pipe fittings] The method for connecting the pair of pipes 200, 200 and the pipe joint 20 according to this embodiment is as follows: First, an operator passes the nut 44 through a commercially available steel pipe.

[0066] Once the steel pipe has passed through the nut 44, the worker uses a well-known method to expand the portion of the steel pipe that has already passed through the nut 44. This forms the expanded diameter engaging portion 222 and the seal facing portion 224 according to this embodiment. As a result, one of the pair of pipes 200, 200 according to this embodiment is completed.

[0067] Next, the worker inserts the tip portion of the pipe 200 that has passed through the nut 44 into one end of the joint flow path forming portion 60. The end of the pipe 200 that has entered the joint flow path forming portion 60 passes through one of the pair of sealing material accommodating portions 74, 74 and enters one of the pair of pipe end accommodating portions 72, 72.

[0068] The end of the pipe 200 that has entered one of the pair of pipe end accommodating sections 72, 72 hits one of the pair of entry direction correction tubes 50, 50. Figure 8 is a diagram showing the interior of the fitting body 40 in this state. As the end of the pipe 200 continues to advance, the entry direction correction tube 50 is pushed into the pipe end accommodating section 72.

[0069] As the entry direction correcting tube 50 is pushed into the pipe end accommodating portion 72, one end of the pipe 200 penetrates the sealing material 42. As the one end of the pipe 200 advances through the fitting body 40, the one end of the pipe 200 expands the sealing material 42 from its inner periphery outward in the radial direction. Figure 9 is a diagram showing the interior of the fitting body 40 in a state in which the sealing material 42 has expanded from its inner periphery outward in the radial direction. As is clear from Figure 9, as the one end of the pipe 200 penetrates the sealing material 42 and expands it from its inner periphery outward in the radial direction, the sealing material 42 is pressed against the inner circumferential surface of the sealing material accommodating portion 74.

[0070] Once one end of the pipe 200 has advanced sufficiently through the joint flow passage forming portion 60 , the operator engages the internal threads 102 of the nut 44 with the external threads 62 disposed on one end of the joint flow passage forming portion 60 .

[0071] As the worker continues to screw the female thread 102 of the nut 44 into the male thread 62 of the joint body 40, the engaging recess 110 facing each engaging protrusion 144 changes sequentially. Accordingly, the distance between the engaging protrusion 144 and the engaging recess 110 facing it gradually decreases. Figure 10 is a diagram showing the state in which the engaging protrusion 144 and the engaging recess 110 are gradually decreasing in size.

[0072] Thereafter, the engaging protrusion 144 fits into a certain engaging recess 110. As a result, one of the pair of pipes 200, 200 is connected to the pipe fitting 20 according to this embodiment. This also results in the engaging enlarged diameter portion 222 being engaged with the interior of the pipe fitting 20. The seal opposing portion 224 is disposed within the fitting body 40.

[0073] Next, the worker similarly connects the other of the pair of pipes 200, 200 to the pipe joint 20. When this connection is complete, the connection between the pair of pipes 200, 200 and the pipe joint 20 according to this embodiment is complete.

[0074] [Explanation of Effects According to This Embodiment] As described above, the pipe joint 20 according to this embodiment not only prevents the nut 44 from accidentally loosening after it has been tightened, but also makes it possible to intentionally loosen the nut 44.

[0075] Second Embodiment [Pipe fitting configuration] Fig. 11 is an external view of a spacer 452 according to this embodiment. The pipe joint according to this embodiment includes a pair of spacers 452, 452 shown in Fig. 11 instead of the pair of spacers 52, 52 according to the first embodiment.

[0076] As shown in FIG. 11, the spacer 452 according to this embodiment includes an occupying body 460, a separation end protrusion 462, and a protrusion engagement portion 464.

[0077] The occupying body 460 is disposed between the outer peripheral protrusion 80 and the accommodation space forming portion 140 so as to be in close contact with the accommodation space forming portion 140. As a result, the occupying body 460 is disposed at the rear of at least a portion of the movable engagement portion 46 when viewed from the position of the tip of the male screw 62. The occupying body 460 has a ring-like shape with a portion separated so as to be able to open and close freely.

[0078] The separation end protrusion 462 according to this embodiment protrudes from the end of the portion of the inner circumferential surface of the occupying body 460 that is separated so as to be openable and closable. The separation end protrusion 462 is arranged to fit into the outer peripheral recess 82 of the joint body 40.

[0079] The protrusion engagement portion 464 protrudes from one end of the occupying body 460 at the point where it contacts the notch, along the extension direction of the occupying body 460. The protrusion engagement portion 464 engages with the anti-rotation protrusion 122 when the occupying body 460 is disposed between the outer peripheral protrusion 80 and the storage space forming portion 140.

[0080] In this embodiment, the separation end protrusion 462 has one inner peripheral protrusion 480 and another inner peripheral protrusion 482. The one inner peripheral protrusion 480 protrudes from one side of the inner peripheral surface of the occupying body 460 at a location where it contacts the cutout. The other inner peripheral protrusion 482 protrudes from the other side of the inner peripheral surface of the occupying body 460 at a location where it contacts the cutout.

[0081] 12 is a diagram showing a situation in which a spacer 452 according to this embodiment is arranged so as to fit one-to-one into a plurality of grooves 92, 92 of a joint body 40. As shown in Fig. 12, in this embodiment, a first inner circumferential protrusion 480 fits into one of the plurality of grooves 92, 92. A second inner circumferential protrusion 482 fits into a groove 92 other than the groove 92. As a result, the first inner circumferential protrusion 480 and the second inner circumferential protrusion 482 are arranged so as to fit one-to-one into a plurality of grooves 92, 92 of the joint body 40.

[0082] In this embodiment, the following angle is less than π radians: the angle 500 is formed by an end 490 of the plurality of grooves 92, 92 into which the one inner circumferential protrusion 480 fits but which is far from the other inner circumferential protrusion 482, a portion 492 of the central axis of the male thread 62 that is surrounded by the plurality of grooves 92, 92, and an end 494 of the plurality of grooves 92, 92 into which the other inner circumferential protrusion 482 fits but which is far from the one inner circumferential protrusion 480.

[0083] The one inner peripheral protrusion 480 and the other inner peripheral protrusion 482 are arranged to fit one-to-one into the multiple grooves 92, 92 of the joint body 40. As a result, a spacer 452 is arranged between the outer peripheral protrusion 80 and the accommodation space forming portion 140. By placing the spacer 452 there, movement of the accommodation space forming portion 140 in a direction approaching the outer peripheral protrusion 80 is prevented. As a result, once the engaging protrusion 144 engages with the engaging recess 110, the engagement is difficult to release. Because the engagement is difficult to release, the connection between the joint body 40 and the nut 44 is also difficult to release.

[0084] On the other hand, when the spacer 452 is removed, the accommodation space forming portion 140 can easily move in a direction approaching the outer peripheral protrusion 80. When the accommodation space forming portion 140 can easily move, the engagement between the engaging protrusion 144 and the engaging recess 110 can easily be released. This also makes it easy to release the connection between the joint body 40 and the nut 44.

[0085] Other points are the same as those of the pipe joint 20 according to the first embodiment, and therefore detailed description thereof will not be repeated here.

[0086] [How to connect pipe fittings] The method of connecting the pair of pipes 200, 200 according to this embodiment to the pipe joint according to this embodiment is the same as that of the pipe joint 20 according to the first embodiment, and therefore detailed description thereof will not be repeated here.

[0087] [Explanation of Effects According to This Embodiment] As described above, the pipe joint according to this embodiment not only prevents the nut 44 from accidentally loosening after it has been tightened, but also makes it possible to intentionally loosen the nut 44.

[0088] [Variations] The embodiments disclosed herein are examples in all respects. The scope of the present invention is not limited to the above-described embodiments. Of course, various design modifications may be made to the above-described embodiments without departing from the spirit of the present invention.

[0089] For example, there are no particular limitations on the specific form in which the protruding engagement portion 64 engages with the separation end protruding portions 152, 462. Therefore, the protruding engagement portion 64 does not need to have the outer peripheral recess 82. [Explanation of symbols]

[0090] 20...Pipe fitting 40...Joint body 42...Sealing material 44...Nut 46...Movable engagement part 50…Entry direction correction tube 52,452...Spacer 60...Joint flow path forming portion 62...Male thread 64...Protruding engagement part 70…Communication path forming part 72...Pipe end housing 74...Sealing material storage section 80…Outer peripheral protrusion 82...Outer periphery recess 90...Axial penetration part 92...Groove 100...Pipe communication holding part 102...Female thread 104...Nut side engagement portion 106...Nut outer periphery recess 108...Covering part 110...engagement recess 120…Restriction side engagement part 122...Rotation prevention protrusion 140...accommodation space forming portion 142...Indicator section 144…Engagement convex portion 150,460…Occupied body 152,462...Separation end protrusion 160...One side protrusion 162...Other protrusion 180,182,184…center axis 200…tube 220...Pipe flow path forming part 222...Enlarged diameter part for engagement 224... Seal facing part 464...Protrusion engaging part 480...One inner peripheral protrusion 482...Other inner peripheral protrusion

Claims

1. a cylindrical joint body having a joint flow path forming portion that forms a flow path and a male thread disposed on an outer periphery of at least one end of the joint flow path forming portion; a nut having a female thread that engages with the male thread of the fitting body and a pipe communication holding portion that is connected to the female thread and holds the pipe so that the inside of the pipe is in communication with the flow path of the fitting body, The nut further has a nut-side engaging portion that faces a root direction of the male thread when the female thread engages with the male thread of the joint body, The pipe joint is a movable engaging portion that is disposed at a position adjacent to the root of the male thread as viewed from the tip of the male thread so as to be movable in the central axial direction of the joint flow path forming portion, and that engages with the nut side engaging portion that has reached a predetermined position on the male thread; a spacer that is disposed at the rear of at least a portion of the movable engagement portion as viewed from the position of the tip of the male screw and that prevents movement of the movable engagement portion in a direction toward the rear of the movable engagement portion as viewed from the position of the tip of the male screw, The spacer is an annular occupying body that is disposed at the rear of at least a portion of the movable engagement portion as viewed from the position of the tip of the male screw and that has a cutout; a separation end protrusion protruding from an end of the portion of the occupying body that is separated so as to be openable and closable; A pipe fitting characterized in that the fitting body further has a protruding engagement portion that engages with the separation end protrusion to prevent the width of the portion of the occupying body that is separated so as to be able to be opened and closed from increasing.

2. the protruding engagement portion has a portion protruding from an outer periphery of the joint flow-path forming portion so as to form an axial through-portion that penetrates the joint flow-path forming portion in a central axial direction, The separation end protrusion is a one-side protrusion protruding from one end of the portion of the occupying body that is separated so as to be openable and closable; and a second protrusion protruding from the other end of the portion of the occupying body that is separated so as to be openable and closable. The pipe joint according to claim 1, wherein both the one protruding portion and the other protruding portion are arranged to fit into the axial through-portion.

3. The pipe joint according to claim 2, wherein the one protruding portion and the other protruding portion are arranged to fit into the common axial through-portion.

4. The movable engagement portion is a restraining side engaging portion that engages with the nut side engaging portion that has reached a predetermined position on the male thread; a rotation preventing protrusion that protrudes from the restraining side engaging portion toward the back of the restraining side engaging portion as viewed from the tip of the male screw when the restraining side engaging portion is disposed at a position adjacent to the root of the male screw as viewed from the tip of the male screw, 4. The pipe joint according to claim 3, wherein the anti-rotation projection is arranged to be fitted into the axially through-portion while being sandwiched between the one protruding portion and the other protruding portion.

5. the protruding engagement portions are arranged at positions where the spacers are arranged when viewed from the position of the tip of the male thread, and each of the protruding engagement portions has a plurality of grooves aligned along the circumferential direction of the joint body, The separation end protrusion is a one-side inner peripheral protrusion protruding from one side of an inner peripheral surface of the occupying body at a location that contacts the notch; and a second inner peripheral protrusion protruding from the second inner peripheral surface of the occupying body at a location that contacts the notch, 2. The pipe joint according to claim 1, wherein the one inner peripheral protrusion and the other inner peripheral protrusion are arranged to fit one-to-one into the plurality of grooves of the joint body.

6. 6. The pipe fitting according to claim 5, characterized in that an angle formed by an end of the plurality of grooves into which the one inner circumferential protrusion fits that is farther from the other inner circumferential protrusion, a portion of the central axis of the male thread that is surrounded by the plurality of grooves, and an end of the plurality of grooves into which the other inner circumferential protrusion fits that is farther from the one inner circumferential protrusion is less than π radians.

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