JP2008144866A - Pipe fitting, connection structure for pipe using the pipe fitting and connection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe fitting capable of performing connection with a counterpart side pipe while protecting it such that an O ring is not damaged. <P>SOLUTION: The pipe fitting is provided with a fitting body 2; a cap nut 3 thread-engaged with a male screw part 10; the O ring 5 for performing sealing between the fitting body 2 and the pipe 9; a removal stop mechanism 8 for performing removal stop of the fitting body 2 from the pipe 9; and a protection sleeve 6 attached to an inner periphery of the O ring 5 with a size capable of receiving the pipe 9 so as to cover the pipe 9 in the pressure-contact state and protecting the O ring. When the protection sleeve 6 is pushed to a depth side more than a position of the O ring 5 together with the pipe 9 internally inserted to the fitting body 2, the O ring 5 can be contacted with the pipe 9 for the first time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint and a pipe connection structure and connection method using the pipe joint, and particularly to a so-called bite type pipe joint for connecting to a thin-walled pipe and pipe connection using the pipe joint. The present invention relates to a structure and a connection method.

  So-called bite for the purpose of connecting thin pipes such as stainless steel pipes (eg, stainless steel pipes for general piping specified in JIS G3448 or stainless steel pipes for water supply specified in JWWA G15). A pipe joint of the type is proposed in Patent Documents 1 to 3 and the like.

In the techniques described in these Patent Documents 1 to 3, a joint main body into which the opposite pipe is inserted, a cap nut screwed into the joint main body, and the joint main body and the cap nut are interposed. In addition to the disc spring-shaped ring, the main element is a sealing member such as an O-ring that seals between the joint body and the pipe. And, as the cap nut is tightened, the disc spring-shaped ring is deformed, and the ring is bitten into the pipe, and a part of the pipe is plastically deformed to prevent the joint body and the pipe from coming off. Yes.
Japanese Patent No. 3404224 JP 2002-327876 A JP 9-166252 A

  However, in the techniques described in Patent Documents 1 to 3, a seal member such as an O-ring is arranged in advance on the inner peripheral surface of the joint body, and the seal member presses against the pipe at the moment when the pipe is inserted into the joint body. In order to obtain a predetermined sealing performance, the seal member protrudes from the inner peripheral surface of the joint body by a predetermined amount when the pipe is not inserted. Therefore, it is necessary to insert the pipe while expanding the seal member so as to get over the seal member at the time of inserting the pipe, which not only makes it difficult to insert the pipe into the joint body, but also requires a large force to insert the pipe.

  In addition, when the tube is inserted while expanding the seal member so as to get over the seal member, the tip of the tube and the seal member slide with a large force, for example, the seal member at the edge of the tip of the tube. There is a risk of scratching the surface, and there is a concern that the sealing performance and durability may deteriorate. In particular, when the cut pipe is inserted into the joint body, damage to the seal member becomes significant if the tip end face of the pipe is not sufficiently deburred.

  Furthermore, since the disc spring-shaped ring that controls the retaining is made to bite into the pipe to substantially plastically deform a part of the pipe, the flow path of the pipe is narrowed by this plastic deformation. It is not preferable.

  The present invention has been made by paying attention to such problems, and in particular, the sealing member is not damaged, and the tube has a strong retaining effect without narrowing the flow path of the tube by plastic deformation. The present invention provides a pipe joint that can be exhibited, and a pipe connection structure and connection method using the pipe joint.

  According to the first aspect of the present invention, a threaded portion is formed on the outer periphery of at least one end, a tubular joint body into which a mating tube is inserted at the one end, and a screw on the male thread. A cap nut, and an annular seal member such as an O-ring that controls the seal between the pipe and the joint body and the cap nut. And a retaining mechanism for retaining the joint body and the pipe by the screwing action by tightening the cap nut and a size capable of receiving the pipe so as to cover the inner periphery of the seal member. And a protective sleeve that is attached and protects the sealing member. In addition, the seal member can be brought into contact with the pipe for the first time when the protective sleeve is pushed into the back side with respect to the position of the seal member together with the pipe inserted in one end side of the joint body. Features.

  In this case, as described in claim 2, when the protective sleeve is a bottomed annular ring having a flange portion on the back side, both the protection of the sealing member and the ease of extrusion of the protective sleeve are achieved. Is preferable.

  At the same time, as described in claim 3, it is preferable that the protective sleeve protects the sealing member in a pressure contact state with respect to the sealing member in order to prevent the protective sleeve from falling off.

  According to a fourth aspect of the present invention, the retaining mechanism is formed by using a disc spring interposed between the joint body and the cap nut as a main element, and the disc spring according to the screwing action of the cap nut. It is assumed that the edge portion of the disc spring bites into the pipe with elastic deformation.

  More specifically, as described in claim 5, the retaining mechanism includes a main disc spring having a convex shape toward the joint body side and a flat plate disposed on the anti-joint body side of the main disc spring. It is formed by superposing a washer and an auxiliary disc spring arranged opposite to the main disc spring on the anti-joint body side of the plain washer, and the auxiliary disc spring is screwed by the cap nut. When the auxiliary disc spring receives the pressing force associated with, the auxiliary disc spring presses the main disc spring via the flat washer, so that the edge portion on the small diameter side of the main disc spring bites into the pipe. .

  In this case, as described in claim 6, the main disc spring is formed as a substantially U-shaped cross section bent at an intermediate portion between the inner periphery and the outer periphery, and is flat with the end surface of the joint body. It is desirable that the edge portion of the smallest diameter bite into the pipe by being elastically deformed by being pressure-constrained with a washer so as to obtain a reliable retaining effect with a small screwing stroke of the cap nut. .

  Here, in order to make the above-mentioned retaining effect more reliable, as described in claim 7, the joint body is in contact with the cap nut at a screw advance limit position of the cap nut. It is desirable that a stopper surface for preventing screwing is formed and set so as to obtain a necessary amount of penetration into the pipe as a retaining mechanism in a state where the cap nut is in contact with the stopper surface.

  At the same time, in order to stabilize the relative positional relationship between the joint body and the pipe in the insertion direction, the inner periphery of the joint body is in contact with the distal end surface of the inserted pipe as described in claim 8. It is desirable that a position regulating surface for regulating the insertion position is formed.

  The invention according to claim 9 is taken as a pipe connection structure on the premise that the pipe joint according to claim 1 is used, and a mating pipe is inserted into the joint main body, By tightening the cap nut in the state where the protective sleeve is pushed into the back side from the position of the seal member together with the pipe, the gap between the joint body and the pipe is sealed by the seal member, and The joint body and the pipe are prevented from coming off.

  The invention described in claim 10 is a pipe connection method based on the premise that the pipe joint according to claim 1 is used, and the other pipe is inserted into the joint body. The cap nut is tightened in a state where the protective sleeve is pushed to the back side with respect to the position of the seal member together with the pipe, and the sealing function by the seal member and the retaining function by the retaining mechanism are held in the tightened state of the cap nut. It is characterized by being demonstrated.

  Therefore, in at least the inventions according to the first, ninth, and tenth aspects, since the seal member is covered and protected by the protective sleeve in the state of the pipe joint alone, the seal member is surely secured from contact with a tool or the like, for example. Can be protected.

  Also, when connecting the pipe, the protective sleeve is positioned on the inner peripheral side of the seal member at the stage where the pipe is inserted into the joint body until the tip of the pipe comes into contact with the protective sleeve. Are not in direct contact. When the tube is further pushed into the back side from that state, the protective sleeve that has been protecting the seal member until then is pushed out together with the tube, so that the tube and the seal member are in contact with each other for the first time. The protective sleeve pushed out together with the tube finishes its role at that time, while the seal member comes into pressure contact with the tube and exhibits its original sealing function.

  Subsequently, when the cap nut is tightened, the disc spring type retaining mechanism, for example, comes to perform its original function as the cap nut is screwed, and the joint body and the tube are firmly retained. Is done. In this case, if, for example, a disc spring, which is the main element of the retaining mechanism, is only bitten into the pipe and the pipe is not plastically deformed, the flow path of the pipe is not narrowed as in the prior art. .

  The protective sleeve that originally protected the seal member and finished its function after the insertion of the pipe will remain in the joint body, but if it does not hinder the original function of the joint, There is no narrowing.

  According to the first, ninth, and tenth aspects of the invention, the seal member on the inner periphery of the joint body is protected in advance by the protective sleeve, and when the pipe is inserted into the joint body, the tip of the pipe, the seal member, Therefore, it is possible to prevent the seal member from being damaged, and to contribute to the improvement of the seal performance and the durability of the seal member.

  According to the second aspect of the present invention, since the protective sleeve has a bottomed annular shape, the sealing member can be protected with a large area, and the distal end portion of the opposite tube can be easily received. Thus, the protective sleeve can be reliably pushed out.

  According to the third aspect of the present invention, since the protective sleeve protects the sealing member in a pressure contact state with respect to the sealing member, it is possible to prevent the protective sleeve from falling off during the flow process or the conveying process of the pipe joint alone. it can.

  According to the fourth aspect of the present invention, the retaining mechanism is formed with the disc spring interposed between the joint body and the cap nut as the main element, and the edge portion of the disc spring is moved by the elastic deformation of the disc spring. Since the tube is made difficult to insert, the necessary and sufficient retaining effect can be obtained with a small number of parts.

  According to the fifth aspect of the present invention, the main disc spring, the flat washer and the auxiliary disc spring are arranged in an overlapping manner to form a retaining mechanism so that the edge portion on the small diameter side of the main disc spring is bitten into the pipe. Thus, there is an advantage that the main disc spring can be securely inserted into the pipe with a small screw stroke of the cap nut.

  According to the sixth aspect of the invention, the main disc spring is bent in a substantially U-shaped cross section, and the edge portion of the minimum diameter is bitten into the pipe. There is an advantage that the main disc spring can be securely inserted into the pipe by the stroke.

  According to the seventh aspect of the present invention, the joint body is formed with a stopper surface that abuts against the cap nut at the screw nut limit position, and the cap nut is prevented from coming off while the cap nut is in contact with the stopper surface. Since the amount of biting into the pipe necessary for the mechanism is obtained, there is no need to control the tightening of the cap nut, and no means for that is required, which increases the reliability of the joint and improves the connection. Excellent workability.

  According to the eighth aspect of the present invention, since the position regulating surface for regulating the insertion position is formed on the inner periphery of the joint main body so as to abut on the tip surface of the inserted tube, the insertion adjustment of the tube is managed. If it is not necessary, a means for that purpose is not necessary, and the reliability as a joint becomes high as described above, and the workability at the time of pipe connection is excellent.

  1 to 7 are views showing a more specific embodiment of the pipe joint according to the present invention. In particular, FIG. 1 is a perspective view of a straight pipe type pipe joint 1 as a single unit, and FIG. 2 is a front view thereof. FIG. 3 shows an enlarged whole sectional view.

  As shown in FIGS. 1 to 3, the pipe joint 1 is screwed into the tubular joint body 2 having a hexagonal large-diameter flange portion 2 a at the center in the longitudinal direction of the outer peripheral surface and the outer periphery of both ends of the joint body 2. The outer peripheral surface thus formed is a hexagonal cap nut 3, an O-ring 5 as a seal member mounted in advance on both ends of the inner peripheral surface 4 of the joint body 2, and an O-ring 5 mounted on the inner periphery of the O-ring 5. A protective sleeve 6 that protects the ring 5 and a three-ring retaining mechanism 8 that is interposed between the open end faces 7 at both ends of the joint body 2 and the cap nuts 3 are provided. As is clear from FIGS. 1 to 3, the maximum diameter of the joint body 2 is smaller than the maximum diameter of the cap nut 3.

  As shown in FIG. 5, the pipe joint 1 is formed by inserting pipes 9 having the same diameter from both sides of the joint body 2 in a so-called insertion form, and then tightening the cap nuts 3 on both sides. Thus, the O-ring 5 is used to prevent the detachment by the detachment prevention mechanism 8 while obtaining a predetermined sealing performance, thereby firmly connecting the tubes 9 and 9 together. Details of FIG. 5 will be described later.

  The joint body 2 is formed with male thread portions 11 that are screwed with the female thread portion 10 on the side of the cap nut 3 on both sides of the large diameter flange portion 2 a, and both end surfaces of the large diameter flange portion 2 are used as stopper surfaces 12. It faces the end face on the side of the cap nut 3, and the end surface on the side of the cap nut 3 comes into contact with the stopper surface 12 when the cap nut 3 is tightened to the limit. In other words, when the cap nut 3 is tightened and screwed, the end surface of the cap nut 3 abuts against the stopper surface 12 to prevent further screwing, so that the screw nut 3 has a screw advance limit position. Is to be decided. 1 to 3 illustrate a state in which the cap nut 3 is not in contact with the stopper surface 12.

  In addition, a circumferential groove 13 having a rectangular cross section for mounting the O-ring 5 is formed at both longitudinal ends of the inner peripheral surface 4 of the joint body 2, and at the central portion in the longitudinal direction of the inner peripheral surface 4. The inner flange portion 14 is formed to protrude.

  On the inner periphery of the O-ring 5 mounted in the circumferential groove 13, a bottomed annular protective sleeve having a flange portion 6 a (see FIG. 4A) on the back side in order to protect the O-ring 5. 6 is attached in a pressure contact state so as to conceal the O-ring 5. The inner diameter of the protective sleeve 6 is formed so as to be able to receive at least the tip of the opposite tube 9. The protective sleeve 6 is made of a thin plate. After the O-ring 5 is mounted, the protective sleeve 6 is set inside the O-ring 5 and then expanded in diameter with a predetermined jig. It is mounted so as to be elastically deformed, and at the same time, is self-held at that position while being in pressure contact with the O-ring 5.

  Further, both end surfaces of the inner flange portion 14 function as position restricting surfaces 14a for restricting the insertion position of the tube 9 with respect to the joint body 2 as shown in FIG. 5, and the distal end surface of the opposite tube 9 as will be described later. Is abutted against the position restricting surface 14 a together with the protective sleeve 6.

  Concave surfaces 15 that are one step lower are formed on the open end surfaces 7 at both ends of the joint body 2. The concave surface 15 is separated from the circumferential groove 13 by a partition flange 16 adjacent thereto, and receives a grip ring 18 forming a part of the retaining mechanism 8 by the concave surface 15 as will be described later. become.

  The diameter of the hole 17 on the side of the cap nut 3 and the inner diameter of the partition flange portion 16 can accept the outer diameter of the mating pipe 9 as well as the inner peripheral surface 4 of the joint body 2 and the inner diameter of the protective sleeve 6. It is formed in size. On the other hand, the inner diameter of the inner flange portion 14 is formed smaller than the outer diameter of the tube 9 due to its function.

  The retaining mechanism 8 interposed between the open end faces 7 at both ends of the joint main body 2 and the cap nut 3 includes a grip ring 18 as a main disc spring and a backup ring 19 as a plain washer in order from the joint main body 2. And an adjuster string 20 as an auxiliary disc spring are arranged in a superposed manner.

  The grip ring 18 is bent or curved in a substantially U-shaped cross section with the intermediate portion between the inner periphery and the outer periphery as a bent portion so as to protrude toward the concave surface 15 on the joint body 2 side, as shown in FIG. As shown in A), a small-diameter tapered cone-shaped convex portion 18 b is formed so as to protrude from the flat portion 18 a toward the concave surface 15, and the small-diameter convex portion 18 b side faces the concave surface 15. Yes. The backup ring 19 as a flat washer is a flat washer having a plate thickness larger than that of the grip ring 18 as the name suggests. The backup ring 19 is in close contact with the back surface of the flat portion 18a of the grip ring 18 so that the grip ring 18 is attached. I have a backup. Further, the adjuster string 20 as the auxiliary disc spring is also a disc spring shape having a smaller plate thickness than the backup ring 19 as the name suggests, and the concave surface 15 on the joint body 2 side is opposite to the grip ring 18. It is arrange | positioned so that it may become concave shape toward.

  Then, as will be described later, by inserting the tube 9 on the mating side into the joint body 2 and tightening the cap nut 3, the three rings 18, 19, and 20 forming the retaining mechanism 8 are The grip ring 18 is elastically deformed by pressing, and the edge portion 38 (see FIG. 7) having the minimum diameter is inserted into the tube 9 so as to exert a retaining function. That is, in the pipe joint 1 according to the present embodiment, as described above, the grip ring 18 is sufficiently inserted into the mating pipe 9 by tightening until the end face of each cap nut 3 comes into contact with the stopper face 12. In this state, it is set so that the expected retaining effect is exhibited for the first time.

  The joint constituent elements including the joint body 2 and the cap nut 3 as well as the protective sleeve 6 and the rings 18, 19, 20 are made of a non-ferrous metal material such as stainless steel or brass or a resin material. In this case, it is desirable that the grip ring 18 is made of a material having a hardness that is at least greater than that of the tube 9 so that the grip ring 18 is not easily inserted into the grip ring 18.

  Next, a procedure for connecting the pipes 9 and 9 using the pipe joint 1 configured as described above will be described in detail with reference to FIGS.

  4 shows an enlarged view of the procedure for inserting (connecting) the pipe 9 from the right side to the pipe joint 1 of FIG. 3, and FIG. 5 shows the pipe inserted from the right side of the pipe joint 1 of FIG. The state in the middle of inserting the pipe | tube 9 from the left side is shown with respect to the pipe joint 1 of the same figure after having connected 9.

  First, as shown in FIG. 3, both the cap nuts 3 do not abut against the stopper surface 12, and each cap nut 3 leaves a predetermined amount of tightening stroke (screwing stroke) α. As shown in (A) of FIG. 1, the opposite tube 9 is inserted into the joint body 2.

  As described above, in the state in which the tightening stroke α of the cap nut 3 remains, the three rings 18, 19, and 20 forming the retaining mechanism 8 are not yet clamped, and slightly each of them. Since it has a degree of freedom of movement, as shown in FIG. 4 (B) and the left half of FIG. 5, these rings 18, 19, and 20 smoothly insert the opposite tube 9 into it. The tip end surface of the tube 9 is seated on the flange portion 6 a of the protective sleeve 6. In this state, the O-ring 5 still does not contact the tube 9. Further, as shown in FIG. 4B, the inner diameter of the protective sleeve 6 is formed to be slightly larger than the inner diameter of the partition flange portion 16 in advance, so that the front end surface of the tube 9 is not seated on the flange portion 6a. The protective sleeve 6 is not pushed out.

  When the tube 9 is still pushed into the back side from the state of FIG. 4B, the protective sleeve 6 comes out of the O-ring 5 together with the tube 9, and as shown in FIG. The tube 9 is inserted deeply until it sits together with the protective sleeve 6 on the position regulating surface 14a which is the end surface of the inner flange portion 14. At the moment when the protective sleeve 6 pushed by the tube 9 comes out of the O-ring 5 together with the tube 9, the outer peripheral surface of the tube 9 is released for the first time when the O-ring 5 is released from the restraint by the protective sleeve 6 and is elastically restored. In this state, the original function due to the pressure contact of the O-ring 5 is exhibited. At this time, even when the O-ring 5 slides on the outer peripheral surface of the tube 9 in the process of inserting the tube 9 after the protective sleeve 6 comes out of the O-ring 5, the edge is sharp as in the conventional case. Alternatively, since the tip of the tube 9 possibly attached with the “burr” and the O-ring 5 do not slide with a large force, the O-ring 5 can be prevented from being damaged or broken. Further, since it is not necessary for the tip of the tube 9 to get over the O-ring 5 as in the prior art, the force required to insert the tube 9 can be significantly smaller than in the prior art. The protective sleeve 6 ends its role when it comes out of the O-ring 5 and is seated on the position restricting surface 14a.

  As shown in FIG. 4D, the cap nut 3 is tightened until the distal end surface of the tube 9 is seated on the position regulating surface 14 a together with the protective sleeve 6 until it comes into contact with the stopper surface 12. Along with the screwing action based on the tightening of the cap nut 3, the three rings forming the retaining mechanism 8, that is, the grip ring 18, the backup ring 19 and the adjust ring 20, are pressed against each other. Finally, the edge portion 38 (see FIG. 7) of the minimum diameter of the grip ring 18 facing the concave surface 15 on the joint body 2 side is inserted into the outer periphery of the opposite tube 9 and self-holds the state. As a result, the pipe 9 is instantly prevented from coming off. The state where the retaining is applied is shown in the right half of FIG.

  In the present embodiment, it is only necessary to tighten the cap nut 3 by a slight tightening stroke (screwing stroke) α necessary for elastically deforming the grip ring 18. Can be handled with a general-purpose spanner or adjustable wrench.

  2 and 6, the maximum diameter of the joint body 2 is formed smaller than the maximum diameter of the cap nut 3, and a step is positively provided between them. As shown in FIG. 6, even when the spanner S1 for the joint body 2 and the spanner S2 for the cap nut 3 are used in combination, the position of the spanner S1 for the joint body 2 is restricted at the end faces of both cap nuts 3. The spanners S1 for the joint body 2 are not moved and detached in the longitudinal direction of the pipe joint 1.

  Here, the process in which the grip ring 18 is difficult to fit into the counterpart tube 9 will be described in more detail with reference to FIG. 7. As shown in FIGS. 3 to 5, the grip ring 18 forming the retaining mechanism 8 is provided. Even when the cap nut 3 is not squeezed by tightening, the back side of the flat portion 18a of the grip ring 18 is backed up by the backup ring 19, so that the grip ring 18 self-holds the posture of FIG. ing. When the cap nut 3 is screwed by tightening the cap nut 3, the grip ring 18 is pressed through the adjust ring 20 and the backup ring 19, and the three members are connected between the joint body 2 and the cap nut 3. It comes to be pressed.

  In FIG. 7, reference symbol P <b> 1 indicates a state in which the edge portion 28 at the tip of the convex portion 18 b of the grip ring 18 indicated by a thick solid line contacts the concave surface 15 (the height of the grip ring 18 at this time is h <b> 1. P2 indicates a pipe connection completion state in which the edge portion 28 at the tip of the convex portion 18b of the grip ring 18 indicated by a thick broken line is in contact with the concave surface 15 and the flat portion 18a is in contact with the open end surface 7. (The height of the grip ring 18 at this time is h2), and symbol P3 indicates a state in which the grip ring 18 indicated by a thin broken line is at a position intermediate between the two states.

  When the grip ring 18 is pressed, the edge portion 28 at the tip of the convex portion 18a first comes into contact with the concave surface 15, and a force in the F direction is further applied by the backup ring 19, so that the height of the grip ring 18 is increased. The grip ring 18 is elastically deformed as if the entire grip ring 18 is expanded so that the height is reduced from h1 to h2, and the edge portion 28 gradually moves from the E1 position to the E3 position through the E2 position. One edge portion 38 on the smallest inner diameter side gradually moves from the e1 position to the e3 position through the e2 position, and finally the flat portion 18a of the grip ring 18 is the opening end face as shown in FIG. 7, the edge portion 38 is inserted into the tube 9 at the e3 position so as to be prevented from coming off, and the connection work between the pipe joint 1 and the tube 9 is completed.

  Here, depending on processing errors of the joint body 2, the grip ring 18, the backup ring 20, or the like, the flat portion 18 a of the grip ring 18 may not be in close contact with the opening end surface 7 in a state where the retaining is completed. The 38 is inserted into the tube 9 reliably.

  In the state where the retaining is completed as described above, the end surface of the cap nut 3 comes into contact with the stopper surface 12 at the same time as the edge portion 38 bites in at the e3 position as described above, and the cap nut 3 beyond that. Tightening (screwing) is prevented. Then, the state of the right half part of FIG. 5 is self-held. The connection procedure of the pipe 9 is exactly the same for the other pipe 9 on the left side of FIG.

  As described above, according to the present embodiment, the grip ring 18 having a generally U-shaped cross section forming the retaining mechanism 8 is elastically deformed so that the edge portion 38 is not easily inserted into the counterpart tube 9. Since the stopper is applied, the screwing stroke of the cap nut 3 for preventing the stopper is extremely small.

  Further, when cleaning the inside of the pipe joint 1, etc., it can be easily disassembled by loosening the cap nut 3, and each of the rings 18, 19, By exchanging 20, at least the joint body 2 and the cap nut 3 can be reused. In this case, once disassembled, the protective sleeve 6 may or may not be used.

  As described above, the protective sleeve 6 that originally protected the O-ring 5 and finished its function after the insertion of the pipe 9 is left in the joint body 2. There is no hindrance to the function and the flow path is not narrowed.

  FIG. 8 shows a second embodiment of the pipe joint according to the present invention, and shows a cross-sectional view of the main part thereof. In addition, the same code | symbol is attached | subjected to the part which is common in FIG.

  In the second embodiment, the protective sleeve 26 disposed on the inner periphery of the O-ring 5 is formed in a tapered shape that tapers toward the back side of the joint body 2, and becomes the counterpart side. When the tube 9 is inserted, the inner diameter thereof is set so that the tip of the tube 9 comes into contact with a substantially intermediate position in the longitudinal direction on the inner peripheral surface of the protective sleeve 26.

  Therefore, since the function of the protective sleeve 26 is the same as that of the first embodiment also in the second embodiment, the O-ring 5 can be protected by the protective sleeve 26 when the tube 9 is inserted. .

  FIGS. 9 and 10 and FIGS. 11 and 12 show third and fourth embodiments of the pipe joint according to the present invention. In FIGS. 9 and 10, the first embodiment mainly includes the protective sleeve 6 and the retaining mechanism 8. The structure of the pipe joint 1 of the embodiment is applied to a pipe joint 41 in which the joint body 42 forms a so-called T-shape. In FIGS. 11 and 12, the structure of the pipe joint of the first embodiment is used. Is applied to a pipe joint 51 called a bend in which the joint body 52 has a predetermined curvature.

  FIG. 13 is a view showing a fifth embodiment of the pipe joint according to the present invention.

  In the fifth embodiment, when connecting the pipes 9 and 9 with the screw-in type T-shaped pipe joint 61 using a taper screw, the protective sleeve 6 and the disconnection between the T-type pipe joint 61 and the pipe 9 are connected. The pipe joint 71 of the first embodiment having the stop mechanism 8 as a main element is interposed. That is, the relationship between the joint main body 72 and the cap nut 3 in the pipe joint 71 is the same as that of the first embodiment, but the other end of the joint main body 72 is a taper screw serving as a connecting portion with the T-shaped pipe joint 61. A male screw portion 73 is formed.

  In these third to fifth embodiments, it goes without saying that the same operational effects as those of the first embodiment described above can be obtained.

The figure which shows 1st Embodiment of the pipe joint which concerns on this invention, and is a perspective view in a pipe joint single-piece | unit. Front explanatory drawing of FIG. The expanded sectional view of FIG. It is a figure for demonstrating the behavior of the principal part at the time of inserting and connecting a pipe | tube with respect to the pipe joint of FIG. 3, (A) is a principal part expanded sectional view at the time of the insertion start of the other pipe | tube, (B) Is an enlarged cross-sectional view of the main part when the pipe is seated on the protective sleeve, (C) is an enlarged cross-sectional view of the main part when the pipe is seated on the position regulating surface together with the protective sleeve, and (D) is when the stopper is applied. FIG. Explanatory drawing for demonstrating the behavior at the time of inserting and connecting a pipe | tube from right and left with respect to the pipe joint of FIG. Explanatory drawing when the spanner which is a tool is performed to the pipe joint of FIG. FIG. 5 is an enlarged explanatory view for explaining the behavior of the grip ring alone in FIG. 4. The figure which shows 2nd Embodiment of the pipe joint which concerns on this invention, The principal part expanded sectional view. The figure which shows 3rd Embodiment of the pipe joint which concerns on this invention, and is a front view at the time of applying to a T-shaped pipe joint. FIG. 10 is a perspective view of the T-shaped pipe joint illustrated in FIG. 9. The figure which shows 4th Embodiment of the pipe joint which concerns on this invention, and is a front view at the time of applying to a bend. FIG. 12 is a perspective view of the T-shaped pipe joint illustrated in FIG. 11. The figure which shows 5th Embodiment of the pipe joint which concerns on this invention, and is sectional drawing in the case of using together with a screw-in type T-shaped pipe joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pipe joint 2 ... Joint main body 3 ... Cap nut 5 ... O-ring as a sealing member 6 ... Protection sleeve 6a ... Flange part 8 ... Detachment mechanism 9 ... Pipe 10 ... Male thread part 11 ... Female thread part 18 ... Main plate Grip ring as a spring 19 ... Backup ring as a plain washer 20 ... Adjuster string as auxiliary disc spring 26 ... Protective sleeve 38a ... Edge

Claims (10)

A cylindrical joint body in which a threaded portion is formed at least at one end outer periphery, and a tube serving as a mating side is inserted into the one end side;
A cap nut to be screwed onto the male thread part,
An annular seal member that is attached to the inner periphery of the joint body and manages the seal with the pipe;
A retaining mechanism that is interposed between the joint body and the cap nut, and that prevents the joint body and the pipe from coming off with its screwing action by tightening the cap nut;
A protective sleeve that is mounted to cover the inner periphery of the seal member with a size that can receive the tube, and protects the seal member;
With
A tube characterized in that the seal member can come into contact with the tube only when the protective sleeve is pushed into the inner side from the position of the seal member together with the tube inserted into one end of the joint body. Fittings.   The pipe joint according to claim 1, wherein the protective sleeve is a bottomed annular ring having a flange portion on the back side.   The pipe joint according to claim 1 or 2, wherein the protective sleeve protects the seal member in a pressure contact state with the seal member.   The retainer mechanism is formed with a disc spring interposed between the joint body and the cap nut as a main element, and the disc spring has an elastic deformation caused by the screwing action of the cap nut. The pipe joint according to any one of claims 1 to 3, wherein the pipe is inserted into the pipe. The retaining mechanism includes a main disc spring having a convex shape toward the joint body side, a flat washer disposed on the anti-joint body side of the main disc spring, and the main plate on the anti-joint body side of the flat washer. It is formed by superposing the auxiliary disc springs arranged in the opposite direction to the springs,
When the auxiliary disc spring receives a pressing force associated with the screwing action of the cap nut, the auxiliary disc spring presses the main disc spring through the flat washer, so that the edge portion on the small diameter side of the main disc spring is placed on the pipe. The pipe joint according to claim 4, wherein the pipe joint is bitten.   The main disc spring is formed as a substantially U-shaped section bent at an intermediate portion between the inner periphery and the outer periphery, and is elastically deformed by being restrained by pressure between the end face of the joint body and a flat washer. The pipe joint according to claim 5, wherein an edge portion having the minimum diameter bites into the pipe.   The joint body is provided with a stopper surface that abuts against the cap nut at the screw nut limit position to prevent further screwing. The stopper nut comes off when the cap nut contacts the stopper surface. The pipe joint according to any one of claims 4 to 6, wherein the pipe joint is set so as to obtain an amount of biting into the pipe necessary as a stop mechanism.   The position restriction surface which contacts the tip end surface of the inserted pipe and restricts the insertion position is formed on the inner periphery of the joint body. Pipe fittings. A pipe connection structure using the pipe joint according to claim 1,
Insert the pipe on the mating side into the joint body, and tighten the cap nut with the protective sleeve pushed into the back side of the seal member together with the pipe, so that the gap between the joint body and the pipe is sealed. A pipe connection structure, wherein the pipe main body is sealed with a member and the joint body and the pipe are prevented from coming off by the retaining mechanism. A pipe connection method using the pipe joint according to claim 1,
Insert the tube on the other side into the fitting body, tighten the cap nut with the tube and the protective sleeve pushed into the back side from the position of the seal member,
A pipe connecting method characterized by exhibiting a sealing function by a sealing member and a retaining function by a retaining mechanism when the cap nut is tightened.

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