Fittings

Abstract

To provide a novel joint that can prevent the sealing member from falling off during the insertion of a resin pipe. [Solution] A pipe joint for connecting pipes, comprising: a cylindrical core inserted into the pipe; an O-ring disposed on the cylindrical core; a packing movable in the axial direction of the cylindrical core between a first position on the O-ring and a second position away from the first position; an annular clamp disposed on the packing at the first position; and an elastic member disposed on the cylindrical core that presses the packing toward the first position when the packing is in the second position.

Description

【Technical Field】 【0001】 The present disclosure relates to a joint connected to, for example, a pipe or a hose. 【Background Art】 【0002】 Patent Document 1 discloses a pipe joint for connecting a deformable conduit such as a pipe or a hose. This pipe joint includes a joint body inserted into the inside of the pipe, a seal member disposed on the joint body, a clamp ring, and a regulating sleeve covering the clamp ring. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2007-107680 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 In the operation of inserting a resin pipe into such a joint, the resin pipe may not be inserted to a predetermined position, and so-called trial insertion may occur, that is, the resin pipe is pulled out from the joint and inserted again. In such a case, it is desirable that the joint can prevent the seal member from falling off due to the movement of the resin pipe. 【0005】 The present disclosure provides a novel joint capable of preventing the seal member from falling off due to the insertion operation of the resin pipe. 【Means for Solving the Problems】 【0006】 The joint according to the present disclosure is a pipe joint for connecting pipes, comprising: a cylindrical core inserted into the pipe; an O-ring disposed on the cylindrical core; a packing movable in the axial direction of the cylindrical core between a first position on the O-ring and a second position away from the first position; an annular clamp disposed on the packing at the first position; and an elastic member disposed on the cylindrical core and pressing the packing toward the first position when the packing is located at the second position. [Effects of the Invention] 【0007】 This disclosure provides a novel joint capable of preventing the sealing member from falling off during the insertion of a resin pipe. [Brief explanation of the drawing] 【0008】 [Figure 1] Perspective view showing a joint according to the first embodiment of this disclosure [Figure 2] Exploded perspective view showing a joint according to the first embodiment of this disclosure [Figure 3] Cross-sectional perspective view showing a joint according to the first embodiment of this disclosure [Figure 4] Cross-sectional view illustrating the insertion process according to the first embodiment of this disclosure [Figure 5] Cross-sectional view illustrating the insertion process according to the first embodiment of this disclosure [Figure 6] Cross-sectional perspective view showing a joint according to a second embodiment of this disclosure. [Figure 7] Cross-sectional view showing a joint according to another embodiment of the present disclosure [Modes for carrying out the invention] 【0009】 Hereinafter, one embodiment of this disclosure will be described with reference to the drawings. 【0010】 <First Embodiment> As shown in Figure 1, the joint 1 comprises a cylindrical core 2, a union nut (an example of a cylindrical member in the first embodiment) 4, an O-ring 6, a packing 8, an elastic member 10, an annular clamp 12, and an annular cover 14. In this embodiment, the joint 1 is used, for example, in water supply and hot water piping, receiving a resin pipe (hose or tube) from the front opening 11 and a water heater, faucet, plumbing equipment, or water pipe from the rear. The resin pipe is, for example, a cross-linked polyethylene pipe, a polybutene pipe, or a polyethylene pipe. The water pipe is, for example, a resin pipe, a steel pipe, a copper pipe, or a stainless steel pipe. 【0011】 As shown in Figure 2, the cylindrical core 2 comprises a cylindrical portion 21 and a flange 22 connected to the rear end of the cylindrical portion 21. The cylindrical portion 21 has an outer diameter that allows it to be inserted into the resin pipe. The cylindrical portion 21 has an outer surface with a plurality of annular projections 21a for biting into the resin pipe and a clamping portion 21b for clamping the O-ring 6. The annular projections 21a in this embodiment include an inclined surface that is tilted with respect to the axial direction (direction along the central axis C) and a step connected to the inclined surface. The inclined surface moves further away from the axial center C as it extends towards the rear. The outer diameter of the clamping portion 21b is the same as or slightly smaller than the outer diameter of the annular projection 21a. The cylindrical core 2 is inserted into the resin pipe. In this embodiment, the front end of the cylindrical portion 21 is inserted into the resin pipe. 【0012】 The union nut 4 is arranged coaxially with the cylindrical core 2 and is rotatably connected to the cylindrical core 2 around a central axis C. In this embodiment, the union nut 4 can be directly connected to a faucet device inserted from the rear. The union nut 4 is made of, for example, brass, copper, carbon steel, stainless steel, or other metals. The union nut 4 has a first cylindrical portion 41 and a second cylindrical portion 42 connected to the rear end of the first cylindrical portion 41. As shown in Figure 3, the union nut 4 partially accommodates the cylindrical core 2. In this embodiment, the first cylindrical portion 41 accommodates the rear end of the cylindrical portion 21 and the flange 22 of the cylindrical core 2. The inner circumferential surface of the second cylindrical portion 42 has a female thread 42a that can be screwed onto, for example, a faucet device. 【0013】 The O-ring 6 is placed on the cylindrical core 2. In this embodiment, the O-ring 6 is placed on the outer circumferential surface of the cylindrical portion 21 of the cylindrical core 2 and is clamped by the clamping portion 21b. 【0014】 The packing 8 is positioned on the outer circumferential surface of the cylindrical core 2 and is movable in the axial direction. The front end of the packing 8 has a first inner diameter d1, and the rear end has a second inner diameter d2 that is smaller than the first inner diameter d1. In this embodiment, the first inner diameter d1 is the same as or slightly larger than the outer diameter of the O-ring 6 when attached to the cylindrical core 2, and the second inner diameter d2 is smaller than the outer diameter of the O-ring 6. As a result, the packing 8 is prevented from moving forward by the O-ring 6 on the outer circumferential surface of the cylindrical core 2 and can remain on the O-ring 6. Furthermore, the packing 8 can move relatively easily from front to rear, overcoming the annular projection 21a and clamping portion 21b formed on the cylindrical portion 21, whereas movement from rear to front is prevented by the step of the annular projection 21a on the cylindrical portion 21. 【0015】 The elastic member 10 is positioned on the outer circumferential surface of the cylindrical core 2. In this embodiment, the elastic member 10 is positioned between the packing 8 and the flange 22 of the cylindrical core 2 and deforms as the packing 8 moves. In this embodiment, the elastic member 10 is a compression coil spring. 【0016】 As shown in FIG. 2, the annular clamp 12 includes a clamp annular portion 121, a clamp engaging portion 122, a first gripping piece 123, a second gripping piece 124, and a clamping pin 125. The clamp annular portion 121 is formed of, for example, spring steel. The clamp engaging portion 122 is provided on the outer peripheral surface of the clamp annular portion 121 and engages with the annular cover 14. The clamp engaging portion 122 of the present embodiment is a through hole provided in the clamp annular portion 121, but is not limited thereto, and the clamp engaging portion 122 may be a recess provided on the outer surface of the clamp annular portion 121, or a claw or a protrusion protruding from the clamp annular portion 121. The first gripping piece 123 is connected to the first end of the clamp annular portion 121. The second gripping piece 124 is connected to the second end of the clamp annular portion 121 opposite to the first end. In the natural state, the first gripping piece 123 and the second gripping piece 124 are spaced apart from each other, and the clamp annular portion 121 is in a reduced diameter state. When the first gripping piece 123 and the second gripping piece 124 approach each other, the clamp annular portion 121 is in an enlarged diameter state. The clamping pin 125 sandwiches the first gripping piece 123 and the second gripping piece 124 and maintains them in a proximate state. The clamping pin 125 is detachable from the first gripping piece 123 and the second gripping piece 124. The first gripping piece 123 and the second gripping piece 124 protrude outside the annular cover 14 from the slit 143 of the annular cover 14. In the present embodiment, an operator can easily accommodate the annular clamp 12 in the annular cover 14 by sliding the first gripping piece 123 and the second gripping piece 124 into the slit 143 of the annular cover 14 from the second annular portion 141b side (rear) of the annular cover 14. 【0017】 As shown in FIG. 3, the annular clamp 12 is coaxially arranged with the cylindrical core 2 and is arranged on the outer peripheral surface of the packing 8. The annular clamp 12 can selectively assume an enlarged diameter state and a reduced diameter state. The annular clamp 12 has an inner diameter larger than the outer diameter of the resin tube when in the enlarged diameter state and an inner diameter smaller than the outer diameter of the resin tube when in the reduced diameter state. 【0018】 The annular cover 14 is connected to the annular clamp 12 and houses a part of the cylindrical core 2. The annular cover 14 is formed of, for example, resin. The resin is, for example, polycarbonate, nylon, or acrylic. The annular cover 14 may be transparent or opaque. The transparent annular cover 14 is effective for an operator to check the insertion length of the resin tube during the operation of inserting the resin tube into the annular cover 14. 【0019】 The annular cover 14 has an inner diameter d3 that is smaller than the outer diameter of the resin tube. When a resin tube is inserted into the annular cover 14, the annular cover 14 elastically deforms and expands in diameter. As shown in FIG. 2, the annular cover 14 includes a cover annular portion 141, a cover engaging portion 142 for engaging with the annular clamp 12, and a slit 143. 【0020】 The cover annular portion 141 includes a first annular portion 141a and a second annular portion 141b. As shown in FIG. 3, the first annular portion 141a has an inner diameter d3 and houses the front end of the cylindrical core 2. The second annular portion 141b has an inner diameter larger than that of the first annular portion 141a and is disposed on the rear side of the first annular portion 141a. The second annular portion 141b houses the clamp annular portion 121 of the annular clamp 12. A connecting portion 141c, which is a surface extending in a direction intersecting the axial direction, is formed between the first annular portion 141a and the second annular portion 141b. The front end of the annular clamp 12 abuts against the connecting portion 141c in the present embodiment. Thereby, the cover annular portion 141 can restrict the forward movement of the annular clamp 12 and prevent the annular clamp 12 from falling off. 【0021】 Returning to Figure 2, the cover engaging portion 142 is provided on the inner circumferential surface of the cover annular portion 141 and engages with the clamp engaging portion 122 of the annular clamp 12. This prevents the cover engaging portion 142 from falling off the annular clamp 12 from the annular cover 14. Multiple cover engaging portions 142 may be provided at intervals, or there may be only one. In this embodiment, the cover engaging portion 142 is a plurality of claws protruding from the inner circumferential surface of the second annular portion 141b toward the axial center C. However, it is not limited to this, and the cover engaging portion 142 only needs to be able to engage with the clamp engaging portion 122. For example, if the clamp engaging portion 122 is a claw or projection, the cover engaging portion 142 may be a through hole or recess that receives the clamp engaging portion 122. 【0022】 The slit 143 is provided in the annular portion 141 of the cover and extends in the axial direction. As a result, the annular cover 14 has a C-shaped cross-section. The first gripping piece 123 and the second gripping piece 124 of the annular clamp 12 are inserted into the slit 143. This allows the slit 143 to suppress rotation of the annular clamp 12 around its axial center C. 【0023】 The annular clamp 12 and annular cover 14, connected in this expanded diameter state, accommodate a portion of the cylindrical core 2. In this embodiment, the annular clamp 12 and annular cover 14, which are connected in advance, are attached to the front end portion of the cylindrical core 2. However, the annular cover 14 may be connected to the annular clamp 12 after the annular clamp 12 has been attached to the cylindrical core 2. 【0024】 Next, using Figure 4, we will explain the insertion procedure for inserting the resin pipe into fitting 1. 【0025】 As shown in Figure 4(a), the joint 1 is prepared with the packing 8 in the first position C1. The O-ring 6 is clamped in the clamping portion 21b of the cylindrical core 2. 【0026】 The packing 8 covers part or all of the O-ring 6. The packing 8 is movable between a first position C1 (see Figure 4(a)) and a second position C2 (see Figure 4(b)) which is axially separated from the first position C1. As shown in Figure 4(a), in the first position C1, the packing 8 is located outside the union nut 4 and on the O-ring 6. As shown in Figure 4(b), in the second position C2, the packing 8 has moved rearward from the first position C1 and is located inside the union nut 4. 【0027】 As shown in Figures 4(a) and 4(b), when the packing 8 is in the first position C1, the elastic member 10 is in an uncompressed or slightly compressed state. In the joint 1 of this embodiment, when the packing 8 is in the first position C1, a portion of the elastic member 10 is exposed to the outside from the front end of the union nut 4, making it visible to the worker. This allows the worker to confirm that the packing 8 of the joint 1 is in the first position C1. 【0028】 Next, the resin pipe P1 is inserted into the joint 1 from the front. 【0029】 The inner diameter d3 of the annular cover 14 (see Figure 3) is smaller than the outer diameter of the resin pipe P1. Therefore, the annular cover 14 elastically deforms and expands in diameter as the resin pipe P1 is inserted. As shown in Figure 4(b), the resin pipe P1 is inserted while being sandwiched between the inner circumferential surface of the annular cover 14 and the outer circumferential surface of the cylindrical core 2. At this time, the annular cover 14, which has been elastically deformed by the resin pipe P1, presses down on the resin pipe P1 together with the cylindrical core 2. Furthermore, as the annular cover 14 expands in diameter, the cover engagement portion 142 is displaced in a direction away from the axis center C and engages with the clamp engagement portion 122 of the annular clamp 12. The engagement of the cover engagement portion 142 with the clamp engagement portion 122 prevents the annular clamp 12 from moving relative to the annular cover 14. In addition, the compression of the annular cover 14 relative to the resin pipe P1 makes it difficult for the annular cover 14 and the annular clamp 12 engaged with it to move on the resin pipe P1. This prevents the expanded annular clamp 12 from sliding down along the resin pipe P1 (see Figure 2 for details). 【0030】 The resin pipe P1 is inserted into the joint 1 while pressing the packing 8 toward the second position C2. As the packing 8 moves axially along the cylindrical portion 21 of the cylindrical core 2 from the first position C1 toward the second position C2, the elastic member 10 is compressed between the packing 8 and the flange 22. In this embodiment, the elastic member 10 is compressed and elastically deformed between the rear end of the packing 8 and the flange 22. When the packing 8 is in the second position C2, the elastic member 10 is in a compressed state and presses the packing 8 toward the first position C1. 【0031】 The packing 8 moves along the insertion direction while being pressed against the tip of the resin pipe P1, and moves to the outside of the annular clamp 12. At this time, as the packing 8 moves, the annular clamp 12 is unloaded, so the annular clamp 12 itself becomes movable relative to the resin pipe P1. On the other hand, the annular cover 14, which is elastically deformed and expanded in diameter by the resin pipe P1, holds the resin pipe P1, so the annular clamp 12 connected to the annular cover 14 can also maintain its position relative to the resin pipe P1. 【0032】 Furthermore, the annular cover 14, whose diameter is expanded by the resin pipe P1, and the annular clamp 12 connected to the annular cover 14 move in the insertion direction together with the resin pipe P1. The O-ring 6 is positioned between the outer circumferential surface of the cylindrical core 2 and the inner circumferential surface of the resin pipe P1. The packing 8 is pressed against the tip of the resin pipe P1 and moves further in the insertion direction, thereby compressing the elastic member 10. The resin pipe P1 is inserted until the packing 8 is in the second position C2 within the union nut 4. 【0033】 Finally, by removing the clamping pin 125 of the annular clamp 12 and reducing the diameter of the annular clamp 12, the resin pipe P1 is tightened and the O-ring 6 is compressed. As a result, the O-ring 6 seals the space between the cylindrical core 2 and the resin pipe P1. 【0034】 The procedure for inserting the resin pipe P1 into the fitting 1 has been described above. However, in the actual insertion process, there are cases where, for some reason, the resin pipe P1 is moved in the opposite direction to the insertion direction (pulling out) during insertion, and then the resin pipe P1 is reinserted. The state of the fitting 1 when such insertion and removal of the resin pipe P1 (so-called hesitant insertion) occurs is described below. 【0035】 Figure 5(a) shows the joint 1 when the insertion of the resin pipe P1 is interrupted while the packing 8 is positioned between the first position C1 (see Figure 4(a)) and the second position C2 (see Figure 4(b)). As shown in Figure 5(a), the elastic member 10 is pressed by the packing 8 and undergoes elastic deformation, and also presses in the opposite direction to the insertion direction (black arrow in Figure 5(a)) in an attempt to push the packing 8 back to the first position C1. 【0036】 Furthermore, the O-ring 6 is sandwiched between the outer circumferential surface of the cylindrical core 2 and the inner circumferential surface of the resin pipe P1, and is held by the clamping portion 21b of the cylindrical core 2 and retained on the outer circumferential surface of the cylindrical core 2. 【0037】 Furthermore, the annular cover 14 is enlarged in diameter relative to the resin pipe P1, and the cover engagement portion 142 engages with the clamp engagement portion 122 of the annular clamp 12 (see Figure 2 for both). As a result, the annular cover 14 maintains its position relative to the resin pipe P1, and the movement of the annular clamp 12 connected to the annular cover 14 relative to the resin pipe P1 is also suppressed. 【0038】 As shown in Figure 5(b), as the resin pipe P1 is withdrawn from the joint 1, the packing 8 is pressed by the elastic member 10 and moves to the first position C1, following the movement of the resin pipe P1 in the withdrawal direction (opposite to the insertion direction). Finally, the packing 8 enters the expanded annular clamp 12, covers the O-ring 6, and reaches the first position C1. As a result, the O-ring 6 is sandwiched between the packing 8 and the cylindrical core 2 instead of the resin pipe P1, and is held on the outer circumferential surface of the cylindrical core 2 by being sandwiched by the clamping portion 21b of the cylindrical core 2. When the packing 8 returns to the first position C1, the elastic member 10 becomes uncompressed, and the packing 8 is sandwiched between the outer circumferential surface of the cylindrical core 2 and the inner circumferential surface of the annular clamp 12, and is held in the first position C1. 【0039】 Furthermore, if the resin pipe P1 is withdrawn, it is pulled out of the joint 1, leaving the packing 8 inside the annular clamp 12. The O-ring 6 is held between the cylindrical core 2 and the packing 8 by the clamping portion 21b of the cylindrical core 2 and is held on the cylindrical core 2. In addition, the annular clamp 12 expands in diameter by accommodating the packing 8, suppressing its movement relative to the cylindrical core 2, and also suppressing the movement of the annular cover 14 connected to the annular clamp 12 relative to the cylindrical core 2. As a result, the joint 1 returns to the state before the resin pipe P1 was inserted, and the resin pipe P1 can be inserted again (see Figure 4(a)). 【0040】 Thus, even if the insertion of the resin pipe P1 is interrupted midway, or if an attempt is made to pull out the resin pipe P1 that has been partially inserted, the O-ring 6 will be sandwiched between either the packing 8 or the resin pipe P1 and the cylindrical core 2. As a result, the joint 1 can hold the O-ring 6 on the outer surface of the cylindrical core 2 by sandwiching it between the clamping portion 21b of the cylindrical core 2, regardless of the movement of the resin pipe P1 in the insertion or withdrawal direction. Furthermore, when the packing 8 moves out of the annular clamp 12, the annular cover 14 expands in diameter and elastically deforms to engage with the annular clamp 12, thereby suppressing the movement of the annular clamp 12 relative to the cylindrical core 2. For this reason, even if the resin pipe P1 is repeatedly inserted and pulled out, the joint 1 can prevent the movement of the annular clamp 12 relative to the annular cover 14 by the engagement of the cover engaging portion 142 with the clamp engaging portion 122. In addition, the compression of the annular cover 14 on the resin pipe P1 makes it difficult for the annular cover 14 and the annular clamp 12 engaged with it to move along the resin pipe P1. As a result, the joint 1 can prevent the expanded annular clamp 12 from sliding down along the resin pipe P1. Consequently, the O-ring 6 and the annular clamp 12 can be prevented from falling off during the insertion of the resin pipe P1, improving work efficiency. 【0041】 <Second Embodiment> Next, a second embodiment of the present disclosure will be described with reference to Figure 6. In the following description, a configuration different from the first embodiment will be described, and redundant explanations will be omitted. In this embodiment, a resin pipe with a larger diameter than the joint 1 of the first embodiment is inserted into the joint 101. 【0042】 As shown in Figure 6, the joint 101 further comprises a spacer 16 (an example of a cylindrical member in the second embodiment). The spacer 16 is cylindrical in shape and is arranged coaxially with the cylindrical core 2. The spacer 16 is placed on the cylindrical core 2 and accommodates a portion of the cylindrical portion 21. In the axial direction, the spacer 16 is positioned between the annular clamp 12 and the union nut 4, with the front end of the spacer 16 in contact with the rear end of the annular clamp 12 and the rear end of the spacer 16 in contact with the outer surface of the first cylindrical portion 41 of the union nut 4. 【0043】 The packing 8 is movable between a first position C1 located on the O-ring 6 and inside the annular clamp 12, and a second position C2 located inside the spacer 16. When the packing 8 is in the first position C1, the elastic member 10 is in an uncompressed state. When the packing 8 is in the second position C2, the elastic member 10 is compressed and presses the packing 8 toward the first position C1. 【0044】 As described above, the joint 1,101 relating to this disclosure can achieve the following effects. 【0045】 The joint 1 (101) is a pipe joint for connecting pipes (resin pipes), and comprises a cylindrical core 2 inserted into the pipe, an O-ring 6 disposed on the cylindrical core 2, a packing 8 movable in the axial direction of the cylindrical core 2 between a first position C1 on the O-ring 6 and a second position C2 away from the first position C1, an annular clamp 12 disposed on the packing 8 at the first position C1, and an elastic member 10 disposed on the cylindrical core 2 that presses the packing 8 toward the first position C1 when the packing 8 is located at the second position C2. 【0046】 With this type of joint 1(101), when the packing 8 is in the first position C1, the O-ring 6 is held on the cylindrical core 2, sandwiched between the packing 8 and the cylindrical core 2. When the resin pipe is inserted into the joint 1(101) and the packing 8 moves from the first position C1 to the second position C2, the O-ring 6 is held on the cylindrical core 2, sandwiched between the inner circumferential surface of the resin pipe that pushed out the packing 8 and the cylindrical core 2. Furthermore, when the resin pipe moves in the withdrawal direction opposite to the insertion direction, the packing 8 is pressed by the elastic member 10 and moves toward the first position C1. As a result, the O-ring 6 is sandwiched between the packing 8, which has moved to the first position C1, and the cylindrical core 2. Thus, even when the resin pipe is inserted or removed, the O-ring 6 is sandwiched between either the packing 8 or the inner circumferential surface of the resin pipe and the cylindrical core 2, suppressing axial movement and holding it on the cylindrical core 2. As a result, the joint 1 can prevent the O-ring 6 from moving or falling out of the cylindrical core 2. 【0047】 Furthermore, the joint 1(101) further comprises an annular cover 14 connected to the annular clamp 12, the inner diameter of the annular cover 14 being smaller than the outer diameter of the pipe, and the annular cover 14 expanding in diameter due to elastic deformation when the pipe is inserted. 【0048】 This allows the annular cover 14 to compress and hold the resin pipe, thereby preventing the annular clamp 12 from moving or falling off the resin pipe. 【0049】 Furthermore, the annular cover 14 has a C-shaped cross-section. This allows the annular cover 14 to increase the deformation allowance when a resin pipe is inserted inside and expands in diameter, making it possible to accept resin pipes with different outer diameters. 【0050】 Furthermore, the annular cover 14 includes a cover annular portion 141 and a cover engaging portion 142 provided on the inner circumferential surface of the cover annular portion 141, and the annular clamp 12 includes a clamp annular portion 121 and a clamp engaging portion 122 provided on the outer circumferential surface of the clamp annular portion 121 that engages with the cover engaging portion 142. 【0051】 As a result, the cover engagement portion 142 and the clamp engagement portion 122 can connect the annular cover 14 and the annular clamp 12, suppressing the movement of the annular clamp 12 as the resin pipe moves. When the annular cover 14 expands in diameter, the cover engagement portion 142 provided on the inner circumferential surface of the annular cover 14 moves toward the annular clamp 12, bringing the cover engagement portion 142 and the clamp engagement portion 122 closer together. This further suppresses the movement of the annular clamp 12, preventing the annular clamp 12 from falling off. 【0052】 Furthermore, the device further includes a cylindrical member 4(16) arranged coaxially with the cylindrical core 2 and partially housing the cylindrical core 2, wherein the first position C1 is located outside the cylindrical member 4(16) and the second position C2 is located inside the cylindrical member 4(16). 【0053】 As a result, the packing 8 is sandwiched between the annular clamp 12 and the cylindrical core 2 at the first position C1, and between the cylindrical member 4(16) and the cylindrical core 2 at the second position C2. Therefore, the joint 1 can prevent the packing 8 from separating from the outer surface of the cylindrical core 2 and falling off as it moves between the first position C1 and the second position C2. 【0054】 Although embodiments have been described above, this disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. In particular, the various modifications described herein can be combined as needed. 【0055】 As shown in Figure 7, the joint 1 may further include a packing 18 and a screw plug 19. The packing 18 is arranged coaxially with the cylindrical core 2 and housed within the union nut 4. The packing 18 in this embodiment is a non-asbestos packing, is arranged within the second cylindrical portion 42 of the union nut 4, and is positioned in contact with the rear end of the flange 22 of the cylindrical core 2. The screw plug 19 is arranged coaxially with the cylindrical core 2 together with the packing 18 and housed within the union nut 4. The screw plug 19 is fixed to the rear end of the union nut 4 and is removed during installation to connect the joint 1 to a plumbing fixture or the like. In this embodiment, the screw plug 19 is located within the second cylindrical portion 42 of the union nut 4, on the opposite side of the cylindrical core 2, with the packing 18 in between. The screw plug 19 has a main body portion 191 housed within the union nut 4 and a flange portion 192 that extends from the end of the main body portion 191 opposite to the packing 18. The main body 191 brings the packing 18 into contact with the rear end of the cylindrical core 2 and houses it within the union nut 4, while also protecting the female thread 42a formed on the inner circumference of the union nut 4. As a result, the screw plug 19 prevents the packing 18 from falling out of the union nut 4, for example, when transporting the joint 1, and also protects the female thread 42a of the union nut 4. The packing 18 and screw plug 19 are similarly applicable to the joint 101 of the second embodiment. [Explanation of Symbols] 【0056】 1,101: Fitting 2: Cylindrical core 4,16: Cylindrical member 6: O-ring 8: Packing 10: Elastic member 12: Annular clamp 14: Annular cover 142: Cover engagement part 122: Clamp engagement part C1: 1st position C2: 2nd position

Claims

[Claim 1] A pipe fitting for connecting pipes, A cylindrical core inserted into the aforementioned pipe, An O-ring is placed on the cylindrical core, A packing that is movable in the axial direction of the cylindrical core between a first position on the O-ring and a second position away from the first position, An annular clamp positioned on the packing at the first position, An elastic member disposed on the cylindrical core, which presses the packing toward the first position when the packing is in the second position, A fitting equipped with a joint. [Claim 2] The annular clamp is further equipped with an annular cover connected to the annular clamp, The inner diameter of the annular cover is smaller than the outer diameter of the pipe. The annular cover expands in diameter by elastic deformation when the tube is inserted. The fitting according to claim 1. [Claim 3] The annular cover has a C-shaped cross-section. The joint according to claim 2. [Claim 4] The annular cover includes a cover annular portion and a cover engaging portion provided on the inner circumferential surface of the cover annular portion. The annular clamp includes a clamp annular portion and a clamp engaging portion provided on the outer circumferential surface of the clamp annular portion, which engages with the cover engaging portion. The joint according to claim 2. [Claim 5] The system further comprises a cylindrical member arranged coaxially with the cylindrical core and partially housing the cylindrical core, The first position is located outside the cylindrical member, The second position is located within the cylindrical member, A joint according to any one of claims 1 to 4.

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