JP2008256012A - Joint for synthetic resin fluid pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a joint for a synthetic resin fluid pipe, preventing damage or turning up of a seal member even when the fluid pipe with its end obliquely cut is inserted. <P>SOLUTION: The joint into which the fluid pipe is inserted and which unremovably connects the fluid pipe includes: the annular seal member 23 mounted to an annular groove 22e formed in an inner cylinder 22 and brought in tight contact with the inner peripheral surface of the inserted fluid pipe; and a sleeve 27 which is movably mounted along the inner cylinder 22 on the peripheral surface of the inner cylinder 22, which is provided with an engagement portion formed on the peripheral surface and engaged with the fluid pipe, and which is push-pressed and moved along the inner cylinder 22 by the fluid pipe by inserting the fluid pipe to thereby crush the seal member 23 in a diameter contracting direction by the inner peripheral surface. A projecting portion 28 projecting further outward of the outside diameter of the sleeve 27 is provided between the end of the inner cylinder 22 and the sleeve 27. The fluid pipe gets over the projecting portion 28 to thereby avoid the contact of the fluid pipe with the end surface of the sleeve 27. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a joint in which a seal member provided on an inner cylinder of a joint body is in close contact with the inner peripheral surface of a fluid pipe to achieve reliable water stop, and in particular, a fluid pipe whose tip is cut obliquely is inserted. In this case, the present invention relates to a joint for a synthetic resin fluid pipe that can reliably prevent “breakage” and “turn-up” of the sealing member.

  Conventionally, a pipe body made of a synthetic resin such as cross-linked polyethylene or polybuden has been adopted as a water supply pipe for water supply or hot water supply. Various types of “joints” that realize easy connection of fluid pipes to headers (water separators) and the like have been proposed in the past. Recently, however, a circular cross-section that is fitted to the inner cylinder side has been proposed. There are various types of joints in which a “seal member” made of a resin O-ring is brought into close contact with the inner peripheral surface of a fluid pipe and the outer peripheral surface of the fluid pipe is pressed by an outer cylinder.

  However, in this type of joint, in order for the seal member to adhere to the inner peripheral surface of the fluid pipe, the end of the fluid pipe must pass over the seal member. Therefore, if there is no allowance, the end face of the fluid pipe presses the seal member from the side, so that the seal is broken or turned up and removed from the predetermined position. There is a problem that the water stop performance cannot be exhibited.

  As a technique capable of solving such a problem, a technique described in Patent Document 1 has been conventionally proposed. In the technique described in Patent Document 1, the guide ring (11) crushes and deforms the seal member (10), and the end surface of the connection pipe (22) can pass over the seal member (10). It is. According to the technique described in Patent Document 1, since the end surface of the connecting pipe (22) can pass over the seal member (10) without contacting the seal member (10), the seal member (10 ) Can be solved and problems caused by turning over.

  However, the water pipes as described above should be manufactured with a diameter according to a predetermined standard, but the diameters of the products that are actually marketed have errors for each manufacturer. Therefore, the guide ring (11) does not necessarily enter the inside of the connecting pipe (22) depending on the inner diameter of the water pipe (22) to be combined. Therefore, when the connection ring (22) is inserted into the pipe joint (A), if the guide ring (11) does not enter the inside of the connection pipe (22), the end face of the connection pipe (22) The guide ring (11) is pushed to the back of the pipe joint (A), and the end surface of the connecting pipe (22) is in direct contact with the seal member (10), and the seal member (10) is damaged or turned up. There is a problem that occurs.

  As a technique capable of solving such a problem, a technique described in Patent Document 2 has been conventionally proposed. In the technique described in Patent Document 2, as in the technique described in Patent Document 1, the sleeve (31) crushes and deforms the seal member (15), and the pipe (12 ), Which has a collar (32) that expands the inner diameter of the pipe (12) prior to the sleeve (31) entering the end of the pipe (12). It is. That is, according to the technique described in Patent Document 2, since the pipe (12) is inserted into the joint (11) and passes over the collar (32), the end surface of the pipe (12) and the sleeve (31) It is also conceivable that the sleeve (31) can be made to enter the inside of the pipe (12) while avoiding contact with the end face of).

  However, when the cut end of the pipe (12) inserted into the joint described in Patent Document 2 is “oblique”, before the pipe (12) rides on the sleeve (31) completely, There arises a problem that the pipe (12) contacts the sleeve (31) and pushes the sleeve (31) toward the back of the joint (11). In detail, first, the sleeve (31) has a slight clearance between the sleeve (31) and the inner cylinder over the entire circumference so that the joint (11) can slide on the inner cylinder. (Gap) "exists. On the other hand, when the pipe (12) cut obliquely is pushed into the joint (11), there is a deviation in the timing of passing through the collar (32) regardless of the single cut end. Arise. Therefore, when the tip end side of the cut end portion of the pipe (12) rides on the sleeve (31), the sleeve (31) is pressed in one direction orthogonal to the axial center. ”Disappears, and the non-pressed side of the sleeve (31) protrudes beyond the collar (32). Therefore, the other side of the cut end of the pipe (12) cannot run on the sleeve (31), and the cut surface of the pipe (12) pushes the end surface of the sleeve (31). In this case, since a gap is generated between the pipe (12) and the sleeve (31), the seal member (15) protrudes from the gap and the seal member (15) is damaged.

Further, as shown in FIG. 11A, when the sleeve (31) is inserted into the pipe (12) cut obliquely, and the cut surface of the pipe (12) presses the sleeve (31). 11 (b), the pressing force of the pipe (12) is concentrated at one point on the contact surface of the sleeve (31), the sleeve (31) is inclined with respect to the axial direction, Could not move smoothly. Further, when the sleeve (31) in an inclined state presses the seal member (15), the seal member (15) is damaged or turned up. For this reason, even with the technique described in Patent Document 2, a complete solution to the problems involved in the conventional technique has not yet been achieved.
Japanese Patent No. 3600764 (FIGS. 1, 2, 3, 4) Japanese Patent Laid-Open No. 2001-295966 (Description / Column 0031, FIGS. 1, 3, and 4)

  In view of the above-described problems, the present invention is to immediately advance the inner diameter of the fluid pipe to be larger than the outer diameter of the sleeve in order to surely allow the sleeve to enter the inside of the fluid pipe. It has been devised to realize that the sleeve should be inserted into the fluid pipe. Therefore, the problem to be solved by the present invention is to provide a joint for a synthetic resin fluid pipe that can prevent a seal member from being broken or turned up even when a fluid pipe having a tip cut obliquely is inserted. It is to provide cheaply.

In order to solve the above-mentioned problems, the means taken by the present invention are as follows.
First, the joint 100 for a synthetic resin fluid pipe according to the first aspect of the present invention is a joint 100 of a synthetic resin fluid pipe having a connecting portion into which a fluid pipe is inserted and the fluid pipe is connected so as not to be removed. The joint body 21 having the inner cylinder 22 inserted into the end portion of the fluid pipe from the front end and the annular groove 22e formed in the inner cylinder 22 are attached to the inner peripheral surface of the inserted fluid pipe. A seal member 23, and an outer peripheral surface of the inner cylinder 22 movably mounted along the inner cylinder 22 and having an engaging portion 27c that engages with the fluid pipe on the outer peripheral face. By inserting the fluid pipe, A sleeve 27 that is pressed by the fluid pipe and moves along the inner cylinder 22 and crushes the seal member 23 in the diameter-reducing direction on the inner circumferential surface by this movement, and the tip of the inner cylinder 22 and the sleeve 27 In between, it projects outward from the outer diameter of the sleeve 27 That includes a projection 28, by overcoming the projecting portion 28 is the fluid tube, it is characterized in that the fluid tube to avoid contact with the front end surface of the sleeve 27.

  According to a second aspect of the present invention, in the joint 100 for a synthetic resin fluid pipe according to the first aspect, the sleeve 27 is arranged such that a tip end surface thereof is in contact with the protruding portion 28. Is.

  According to a third aspect of the present invention, in the joint 100 for a synthetic resin fluid pipe according to the second aspect, the protruding portion 28 has an extending portion 28 a that covers the outer periphery of the distal end portion of the sleeve 27. Is.

The effects obtained by adopting the above means are as follows.
First, the joint 100 according to the first aspect of the present invention moves along the inner cylinder 22 of the joint body 21 so that the seal member 23 fitted in the annular groove 22e formed in the inner cylinder 22 is reduced in the diameter direction. The sleeve 27 is provided with a protruding portion 28 that protrudes from the outer diameter of the sleeve 27 on the fluid pipe connecting end side of the sleeve 27. Therefore, the fluid pipe pushed into (inserted into) the joint 100 having the above-described configuration inevitably gets over the protrusion 28 before reaching the sleeve 27. Therefore, the cut end surface of the fluid pipe pushed into the joint 100 is corrected to a “perfect circle” by the protrusion 28 and has an inner diameter larger than the outer diameter of the sleeve 27 on the fluid pipe connection end side. “Expanded” over the entire circumference. When the fluid pipe is further pushed in, the sleeve 27 enters the inside of the fluid pipe, and comes into close contact with all the outer peripheral surfaces of the sleeve 27 so as to cover the fluid pipe. The sleeve 27 has an engaging portion 27c on the outer peripheral surface side. When the end of the fluid pipe comes into contact with the engaging portion 27c, the sleeve 27 stops entering. Then, as the fluid pipe is further pushed, the sleeve 27 is driven, and the seal member 23 is crushed by the inner peripheral surface of the sleeve 27 to reduce the diameter, and the fluid on the seal member 23 together with the sleeve 27 is fluidized. The end of the tube will pass. Therefore, according to the invention of this claim, since the cut end surface of the fluid pipe is “expanded” by the protruding portion 28, the sleeve 27 can be surely entered inside the fluid pipe. This is because it is possible to prevent “breakage” and “turn-up” of the seal member 23 caused by the cut end surface of the fluid pipe pressing the seal member 23.

  In the invention according to claim 2, the end surface on the fluid pipe connection side of the sleeve 27 is in contact with the protruding portion 28 without a gap, so that the end surface of the sleeve 27 on the fluid pipe connection side is not exposed. Therefore, when the fluid pipe is pushed into the joint 100 according to the present claim, the fluid in the state where the diameter is expanded over the entire circumference by the projecting portion 28 on the end face of the sleeve 27 which is not exposed to the fluid pipe connection side. Since the end of the pipe approaches, the contact between the cut end face of the fluid pipe and the end face of the sleeve 27 on the fluid pipe connecting side can be reliably prevented.

  In the invention according to claim 3, the protruding portion 28 provided adjacent to the sleeve 27 has an extending portion 28 a that covers the fluid pipe connecting end portion of the sleeve 27. Therefore, in the joint 100 according to the present invention, since the fluid pipe connection end of the sleeve 27 is covered (protected) by the extension 28a, when the fluid pipe is pushed there, Contact between the cut end face of the pipe and the end face on the fluid pipe connecting side of the sleeve 27 can be prevented more reliably.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in FIGS. 1 to 8.

  A joint 100 for a synthetic resin fluid pipe shown in FIG. 1 is composed of an “outer cylinder 10”, a “joint body 21”, and an “inner cylinder 22”, and has a “connecting portion” that connects the fluid pipes in a non-removable manner. The outer cylinder 10 has a “cylindrical member 11”, an “engaging portion 12”, an “opening window 13”, and a “vertical rib”. 23 ”,“ retaining ring 24 ”,“ spacer 25 ”,“ fastener 26 ”,“ sleeve 27 ”, and“ projecting portion 28 ”. Hereinafter, each component will be described in order. The essential components in the present invention are “joint body 21”, “inner cylinder 22”, “seal member 23”, “sleeve 27”, and “projection 28”, and other components depend on the embodiment. It can be omitted arbitrarily.

  First, the configuration of the outer cylinder 10 will be described. First, the “cylindrical member 11” in the outer cylinder 10 has an inner diameter that allows the fluid pipe to be connected to be inserted. More specifically, when connecting a fluid pipe to this joint 100, while ensuring smooth insertion with respect to the outer cylinder 10, when the diameter of the fluid pipe is increased by passing water into the fluid pipe. Is preferably configured with an inner diameter that allows the outer peripheral surface of the fluid pipe and the inner peripheral surface of the outer cylinder 10 to be in close contact with each other. By adopting such a configuration, the outer cylinder 10 is gripped from the outside of the inserted fluid pipe, while the fluid pipe is engaged by a retaining ring 24 (described later) from the inside of the fluid pipe. Can be sandwiched from both sides (see FIG. 7). The cylindrical member 11 is not particularly limited in shape as long as it can perform the above function. However, when the cylindrical member 11 is formed in a “cylindrical shape”, it is preferable because it can be manufactured with a minimum amount of raw materials.

  Next, the “engagement portion 12” in the outer cylinder 10 is provided at the end of the cylindrical member 11, and engages the outer cylinder 10 with the joint body 21 in a freely rotatable manner. Therefore, it is necessary to make the structure (shape / dimension) into a shape that can be engaged with an engaged portion 22d (described later) provided in the joint body 21. More specifically, if the engaged portion 22d formed of a single groove formed on the outer peripheral surface of the joint body 21 is configured, the annular protrusion 12a or one or more that can be engaged with the groove is formed. It is conceivable that the projection 12a is projected on the inner peripheral surface of the outer cylinder 10. The technical idea according to the present invention is not limited to such a structure. If the expanded fluid pipe does not hinder the rotation of the outer cylinder 10, a protrusion is provided on the joint body 21 side and the outer cylinder 10 side is provided. A structure may be adopted in which grooves are provided to engage with each other. Furthermore, in the present invention, the “outer cylinder 10” includes the “cylindrical member 11” and the “engaging portion 12” made of a single metal material (for example, “brass”, preferably “bronze”, the same applies hereinafter) or In addition to the case where they are integrally formed of a synthetic resin material (for example, a synthetic resin generally referred to as “engineering plastic” or “super engineering plastic”; hereinafter the same), “cylindrical member 11” and “engaging portion 12”. May be formed of different materials and assembled into a single unit. Specifically, it is preferable that the cylindrical member 11 facing the seal member 23 and the retaining ring 24 is made of a metal material and the engaging portion 12 is made of a synthetic resin material, and these are integrally assembled. By forming the cylindrical member 11 from a metal material, it is possible to reliably suppress the expanded diameter fluid pipe, and by forming the engaging portion 12 from a synthetic resin material, easy fitting to the joint body 21 is possible. This is because the rotation of the outer cylinder 10 can be lightened because the friction against the joint body 21 is reduced. It is also conceivable that the outer cylinder 10 formed of a synthetic resin material is covered with a metal cylinder to compensate for the mechanical strength of the outer cylinder 10.

  In addition, the “opening window 13” in the outer cylinder 10 is provided in the vicinity of the connection portion of the outer cylinder 10 with the joint body 21 so that the insertion position of the fluid pipe with respect to the joint 100 can be visually confirmed. . In the present invention, the shape of the “open window 13” is not particularly limited as long as the insertion position of the fluid pipe with respect to the joint 100 can be visually confirmed. Note that, as described above, in the present invention, the outer cylinder 10 can be partially or entirely made of synthetic resin, and therefore the portion where the opening window 13 is arranged is made of synthetic resin. In addition, the shape of the opening window 13 can be variously configured. Specifically, in the case where the thickness around the opening window 13 is formed into a tapered shape, the finger of the operator who installs the joint 100 can enter the opening window 13 so that it is effective. It is. This is because, depending on the installation location of the joint 100, the opening window 13 may not be visually confirmed. In this case, an operator causes his / her finger to enter the opening window 13 to This is because reliable insertion can be confirmed by “scrubbing”. Furthermore, it is also possible to implement the visual confirmation by the operator by configuring the opening window 13 portion with a transparent synthetic resin. In addition, when the whole outer cylinder 10 is comprised with a synthetic resin, although the thickness of the said outer cylinder 10 needs to be thickened a little compared with the case where it comprises with a metal, the said coupling 100 is provided cheaply. It becomes possible to do.

  Next, the configuration of the “joint body 21” will be described. First, the joint main body 21 has an inner cylinder 22 (described below) and connects to a connected device such as a “header (water separator)” or a “water heater”. In the present invention, the “joint body 21” is not particularly limited, and should be arbitrarily changed according to the structure (shape / dimension) of the connection portion of various devices to be connected. Specifically, it is conceivable to form a screwed portion that can be screwed into the connection port of the connected device to realize a reliable connection with the connected device. In addition, when the said joint main body 21 is integrally formed with the said to-be-connected apparatus, it is not necessary to provide the said screwing part.

  Next, the “inner cylinder 22” configured together with the joint body 21 is inserted by entering inward from the end of the fluid pipe. More specifically, the inner cylinder 22 is integrally formed with the joint main body 21 or the inner cylinder 22 is screwed into a screw hole opening provided in the joint main body 21. A sealing member 23 (described later), a retaining ring 24 (described later), and a fastener 26 (described later) are disposed on the outer peripheral surface of the “inner cylinder 22”. In addition, when the configuration including the outer cylinder 10 is adopted, a “connection port” for allowing the fluid pipe to enter between the outer peripheral surface of the inner cylinder 22 and the inner peripheral surface of the outer cylinder 10 is configured. It becomes.

  In addition, the “seal member 23” in the joint body 21 has an annular shape, and is mounted on the “annular groove 22e” formed on the outer peripheral surface of the inner cylinder 22, and is connected to the inner peripheral surface of the fluid pipe to be connected. It closely adheres to prevent water leakage from the end opening of the fluid pipe. More specifically, it is conceivable that an O-ring made of synthetic rubber or natural rubber is fitted into an annular groove 22e formed on the outer peripheral surface of the inner cylinder 22. The number of the sealing members 23 may be one as long as water leakage from the fluid pipe end opening can be prevented, but it is preferable to provide two or more if it is intended to prevent water leakage more reliably. . Further, in the present invention, the “annular groove 22 e” in which the seal member 23 is arranged is formed directly on the peripheral surface of the inner cylinder 22 in the joint body 21, and also on the peripheral surface of the inner cylinder 22. It is also possible to form the annular groove 22e by screwing the member or by inserting a spacer-like (or washer-like) member.

  Further, the “prevention ring 24” in the joint main body 21 is an annular member that is externally inserted on the inner peripheral surface of the inner cylinder 22, and has a plurality of claws 24a that bite into the inner peripheral surface of the fluid pipe, In order to prevent the tube from being pulled out from the connection port, the fastener 26 can be rotated in the circumferential direction around the inner tube 22 along with the fluid tube in a state where the claw 24a bites into the inner surface of the fluid tube. (To be described later). That is, since the retaining ring 24 is an annular member without a slit portion (separation portion) having a plurality of claws 24a radially, when the fluid pipe is compressed after being connected, the diameter can be uniformly reduced. Therefore, the load can be uniformly engaged with the inner peripheral surface of the fluid pipe without locally concentrating the load on the inner peripheral surface of the fluid pipe.

  Further, since the retaining ring 24 is an annular member having no slit portion (separating portion), the slit portion is not distorted when the fluid pipe is inserted. As a result, it is possible to reliably avoid a load (burden) from being locally applied to the fluid pipe. The number of the retaining rings 24 may be one as long as the fluid pipe can be prevented from being pulled out, but it is preferable to provide two or more when the fluid pipe is more reliably prevented from being pulled out. . In this case, it is more preferable that a spacer 25 is interposed between the retaining rings 24 so that a space is provided at a position where the “nail 24a” engages on the inner peripheral surface of the fluid pipe so that the load is not concentrated on the fluid pipe. It is.

  Further, when the retaining ring 24 is disposed on the circumferential surface of the inner cylinder 22 so as to be inserted closer to the fluid pipe connecting end than the seal member 23, the retaining ring 24 is exposed to internal pressure in the fluid pipe. It becomes. Therefore, when water is circulated through the inserted fluid pipe, the retaining ring is engaged with the inner peripheral surface of the fluid pipe whose diameter is expanded by the internal pressure, and the fluid pipe is connected to the inner cylinder of the joint body. Therefore, even a fluid pipe having an internal pressure can be freely rotated together with the outer cylinder. In that case, it is particularly preferable that the retaining ring 24 is made of stainless steel having both “strong elasticity” and “not easily oxidized”.

  The “fastener 26” in the joint body 21 is engaged (or formed) on the fluid pipe connecting end side of the retaining ring 24 on the circumferential surface of the inner cylinder 22, and the retaining ring 24 is rotatably fixed. To do. That is, in the present invention, the retaining ring 24 is made of an annular member having no slit portion (separating portion), which is inserted from the end portion of the joint main body 21, so that the position is maintained.

  More specifically, as shown in FIG. 4, an outer surface screw is formed at the end of the inner cylinder 22 on the fluid pipe connection side, and an inner surface screw that can be screwed to the outer surface screw is formed in the fastener 26. Alternatively, as shown in FIG. 8, an inner surface screw is formed on the inner peripheral surface of the end portion of the inner cylinder 22 on the fluid pipe connection side, and an outer surface screw that can be screwed to the inner surface screw is formed on the fastener 26. Thus, it is preferable to screw them together. By adopting such a configuration, since the annular retaining ring 24 can be inserted from the threaded end portion of the inner cylinder 22 with the fastener 26, the joint 100 can be easily assembled. Further, when a synthetic resin spacer (or washer) is interposed between the retaining ring 24 and the fastener 26, the friction received by the retaining ring 24 can be reduced. This is effective because the rotation of the retaining ring 24 can be lightened.

  A “sleeve 27” in the joint body 21 is attached to the outer peripheral surface of the inner cylinder 22 so as to be movable along the inner cylinder 22, and is pressed against the fluid pipe by insertion of the fluid pipe along the inner cylinder 22. By moving, the seal member 23 is crushed in the diameter reducing direction on the inner peripheral surface side. Such “squeezing” suppresses occurrence of “breakage” and “turn-up” of the seal member 23 due to contact with the end face of the fluid pipe. The sleeve 27 includes an “engaging portion 27 c” on the outer peripheral surface thereof. Therefore, when the fluid pipe is pushed into the depth of the joint, the cut end surface of the fluid pipe comes into contact with the engaging portion 27c. By further pushing the fluid pipe there, the sleeve 27 is also driven and moved to the back of the joint.

  Specifically, a “small-diameter portion 27 a” having a cylindrical shape with an outer diameter smaller than the inner diameter of the fluid pipe inserted into the joint body 21 and expanded by a protrusion 28 (described later); A configuration having a “large-diameter portion 27b” having a tapered shape that gradually expands to an outer diameter larger than the inner diameter is preferable (see FIG. 2). When such a configuration is employed, the outer peripheral surface of the “large diameter portion 27b” serves as the “engaging portion 27c”. According to such a configuration, even if the end of the fluid pipe is cut obliquely or distorted, the sleeve 27 can be surely entered into the fluid pipe, and FIG. As shown in FIG. 5, the engaging portion 27c (large diameter portion 27b) is pressed all around the cut end surface. Accordingly, the pressing force of the fluid pipe is dispersed over the entire circumference of the engaging portion 27c (large diameter portion 27b) in the sleeve 27, so that the sleeve 27 can be surely moved straight in the axial direction. Therefore, it is possible to prevent the occurrence of “damage / turn-up of the seal member accompanying the inclination of the sleeve” (see FIG. 11) as in the prior art. In this case, the sleeve 27 can be configured to have a partially tapered shape by forming a flat plate made of stainless steel into a cylindrical shape and expanding the diameter by pressing from one opening of the cylindrical member.

  However, even if the fluid pipe is once inserted, the sleeve 27 may also be retracted following the fluid pipe if the fluid pipe is retracted in the removal direction for some reason. When the sleeve 27 is retracted, the fluid pipe connecting end portion of the sleeve 27 may damage the seal member 23. In order to eliminate this possibility, it is necessary that the sleeve 27 does not move backward once it has entered the depth of the joint. For this purpose, it is conceivable to adopt a configuration in which the distal end portion of the sleeve 27 and the inner peripheral surface of the outer cylinder 10 can be engaged with each other. Specifically, as shown in FIG. 9, a flat portion 27 d formed by bending a distal end portion of the sleeve 27 on the back side of the joint outward is formed, while the outer peripheral surface of the outer cylinder 10 is formed. A rib 10a that continuously protrudes in the insertion direction of the fluid pipe is formed at the insertion limit portion of the fluid pipe in the cylinder, and the flat portion 27d of the sleeve 27 is moved to the inner peripheral surface of the outer cylinder 10 by the inserted fluid pipe. It is preferable to employ a configuration that engages with the rib 10a. By adopting such a configuration, the sleeve 27 can be prevented from retreating, and hence contact with the seal member 23 can also be avoided.

  The “projection 28” in the joint body 21 is provided adjacent to the fluid pipe connection end of the sleeve 27, and is larger than the outer diameter of the sleeve 27 between the tip of the inner cylinder 22 and the sleeve 27. If the fluid pipe passes over this, the inner diameter of the fluid pipe is expanded to avoid contact between the end face of the fluid pipe and the front end face of the sleeve 27. It is something to squeeze. More specifically, as shown in FIG. 2, when a configuration having “small diameter portion 27 a” and “large diameter portion 27 b” is adopted for the sleeve 27, the outer diameter of the small diameter portion 27 a in the sleeve 27 is adopted. The inner diameter of the fluid pipe inserted into the joint 100 is made larger than the outer diameter of the small-diameter portion 27a of the sleeve 27. That is, when the end of the fluid pipe inserted into the joint body 21 gets over the protrusion 28 before reaching the sleeve 27, the inner diameter of the end of the fluid pipe is expanded, and the sleeve is placed in the fluid pipe. This makes it possible to smoothly enter the 27 small-diameter portions 27a. Further, when the sleeve 27 is pressed against the fluid pipe connection side by the seal member 23, the end surface on the small diameter portion 27 a side of the sleeve 27 is always in contact with the protruding portion 28. Further, as shown in FIG. 8D, the protruding portion 28 may form an extending portion 28 a that covers the end portion of the sleeve 27 on the small diameter portion 27 a side. By adopting such a configuration, the fluid pipe connection end portion of the sleeve 27 is covered (protected) by the extension portion 28a, so that even if the fluid pipe cut “obliquely” is pushed into the joint, The cut end surface of the fluid pipe does not contact the end face of the sleeve 27 on the fluid pipe connection side. Therefore, since no gap is generated between the fluid pipe and the sleeve 27, the seal member 23 does not protrude from the gap. The projecting portion 28 is made of synthetic resin and may be interposed between the sleeve 27 and the retaining ring 24. However, the present invention is not particularly limited to this configuration. It may be formed integrally with the tube 22.

Among the embodiments described above, a preferred embodiment will be described below.
1 to 8 show a joint 100 according to a first embodiment. 1 is an exploded perspective view of a joint 100 according to the present embodiment, FIG. 3 is a side view of the joint 100 according to the present embodiment, and FIGS. 4 to 7 are cross-sectional views of the joint 100 according to the present embodiment. It is.

  As shown in FIG. 1 or FIG. 3, the joint 100 according to the present embodiment includes an outer cylinder 10 including a cylindrical member 11, an engaging portion 12, and an opening window 13, a screwed portion 21, an inner cylinder 22, and a seal member. 23, a retaining ring 24, a spacer 25, a fastener 26, a sleeve 27, and a joint body 21 including a projecting portion 28 are integrally assembled.

  First, in the present embodiment, the outer cylinder 10 is provided with a portion facing the seal member 23 and the retaining ring 24 so as to be rotatable in the circumferential direction with respect to the joint body 21 via the engaging portion 12. The outer cylinder 10 is formed of most of the cylindrical member 11 with bronze, and the portion having the opening window 13 and the engaging portion 12 (that is, the joint end portion with the joint body 21) is a super engineering plastic. It is formed of a kind of polyphenylene sulfide (PPS), and these parts are assembled together. The form shown in FIG. 1 and the form shown in FIG. 3 differ in the shape of the joint end portion of the “outer cylinder 10” with the joint body 21, but these are only differences in design. Specifically, in the form shown in FIG. 1, three "opening windows 13" are formed on the circumference, and three "engagement protrusions 12a" are formed on the inner peripheral surface. It is made by projecting. On the other hand, in the form shown in FIG. 3, the “opening window 13” is formed on the circumference in two large and small portions (for convenience, four places), and the annular “engagement protrusion 12a” is formed on the inner peripheral surface. Is formed by protruding one place.

  The “screw-in part” corresponding to the joint body 21 and the “inner cylinder 22” are integrally formed of bronze. In order to easily connect the screwed portion 21 to a device (not shown) such as a header (water separator), a “hex nut” is formed in the immediate vicinity of the screwed portion 21. The inner cylinder 22 includes a “large diameter portion 22a”, a “medium diameter portion 22b”, and a “small diameter portion 22c”. A straight groove is formed on the outer peripheral surface of the large diameter portion 22a to form an “engaged portion 22d”. “A seal member 23” can be arranged by forming a double annular groove 22e on the outer peripheral surface of the medium diameter portion 22b, and a thread groove is formed at the end of the small diameter portion 22c to obtain “sleeve 27”. The "projection 28", the "prevention ring 24", and the "spacer 25" are inserted, and the "fastener 26" can be screwed together. In the present embodiment, the outer diameter of the “annular groove 22e” portion in the medium diameter portion 22b and the outer diameter of the small diameter portion 22c are substantially the same.

  Further, in this embodiment, the seal member 23 is composed of an O-ring having a circular cross section formed of synthetic rubber, and is disposed in two annular grooves 22e formed in the middle diameter portion of the inner cylinder 22, respectively. Is. Of these two O-rings, a sleeve 27 is inserted and arranged so as to cover the outer periphery of the O-ring on the connection end side. The sleeve 27 is composed of a tapered tubular member 11 formed of stainless steel. A protruding portion 28 is provided adjacent to the small diameter portion 27 a side of the sleeve 27. The protruding portion 28 includes an extending portion 28a, and the end portion on the small diameter portion 27a side of the sleeve 27 is covered with the extending portion 28a. The projecting portion 28 is made of synthetic resin, and reduces the rotational resistance of the retaining ring 24 provided adjacent to the connecting end portion side of the projecting portion 28. The retaining ring 24 is composed of an annular member (without a separating portion), and has a plurality of “claws 24a” that can engage with the inner peripheral surface of the fluid pipe P radially on the outer periphery of the annular member. The claw 24a is erected obliquely in the insertion direction of the fluid pipe P to be connected. After the fluid pipe P is inserted, the claw 24a bites into the inner peripheral surface of the fluid pipe P so as not to be removed. It becomes. Two retaining rings 24 are arranged with a spacer 25 in between, and a thread groove formed at the end of the small-diameter portion 22c so that the retaining ring 24 on the connecting end side of the two retaining rings 24 is not detached. The fasteners 26 are screwed together. By screwing the fastener 26, the sleeve 27, the protruding portion 28, the retaining ring 24, and the spacer 25 are inserted into the inner tube 22 of the joint main body 21 and maintained in an integrated state.

Subsequently, the usage state of the joint 100 according to the present embodiment will be described with reference to FIGS. 4 to 7.
First, FIG. 4 shows a cross section taken along line AA of the joint 100 shown in FIG. 3 and shows a state where the fluid pipe P has not yet been inserted. Next, FIG. 5 is a diagram illustrating a state in which the insertion of the fluid pipe P into the joint 100 illustrated in FIG. FIG. 6 shows a state where the insertion of the fluid pipe P into the joint 100 shown in FIG. 5 is completed, and is a state where water is not yet circulated in the fluid pipe P. FIG. 7 shows a state in which water is circulated through the fluid pipe P inserted through the joint 100 shown in FIG. 6, internal pressure is generated in the fluid pipe P, and the diameter of the fluid pipe P is expanded in the joint 100. Is.

  Further, FIG. 8 shows a process in which the small diameter portion 27a of the sleeve 27 in the joint 100 according to the present embodiment enters the inside of the inserted fluid pipe P. 8A is an enlarged view of a part of FIG. 4, and FIG. 8C is an enlarged view of a part of FIG. 8 (b) shows the way from the state shown in FIG. 8 (a) to FIG. 8 (c), and the inserted fluid pipe P gets over the protruding portion 28, and the fluid is shown in FIG. The state where the inner diameter of the pipe P is expanded is shown. FIG. 8D shows a cross section in a state where the sleeve 27 is in contact with the protruding portion 28, and the extended portion 28 a provided on the protruding portion 28 is the end of the sleeve 27 on the small diameter portion 27 a side. The state which covered the part is shown.

1 is an exploded perspective view of a joint 100 according to Embodiment 1. FIG. It is a figure which expands and shows the sleeve 27 and the protrusion part 28 in FIG. It is a side view of the coupling 100 shown in FIG. It is the sectional view on the AA line of the coupling 100 shown in FIG. FIG. 5 is a diagram showing a state in which insertion of the fluid pipe P into the joint 100 shown in FIG. It is a figure which shows the state which the insertion of the fluid pipe | tube P with respect to the coupling 100 shown in FIG. 5 was completed. FIG. 7 is a view showing a state in which water is circulated in the fluid pipe P inserted through the joint 100 shown in FIG. 6, an internal pressure is generated in the fluid pipe P, and the diameter of the fluid pipe P is expanded in the joint 100. (A) A part of FIG. 4 is enlarged. (B) The way from c to c is shown. (B) It shows the way from the state shown in the a to the later c. (C) A part of FIG. 5 is enlarged. (D) A cross section in a state where the sleeve 27 is in contact with the protruding portion 28 is shown. FIG. 5 is an enlarged view of the joint 100 shown in FIG. 4, and shows a state in which a flat portion 27 d of a sleeve 27 is bitten into a rib 10 a erected on the inner peripheral surface of the outer cylinder 10. FIG. 5 is a diagram showing a state in which insertion of a fluid pipe P having an oblique cut end surface is started with respect to the joint 100 shown in FIG. It is a figure which shows the state which inserted the pipe with respect to the coupling which concerns on a prior art in steps.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Outer cylinder 11 Cylindrical member 12 Engagement part 12a Engagement protrusion 13 Opening window 21 Joint body 22 Inner cylinder 22a Large diameter part 22b Medium diameter part 22c Small diameter part 22d Engagement part 22e Groove 23 Seal member 24 Stop ring 24a Claw 25 Spacer 26 Fastener 27 Sleeve 27a Small-diameter portion 27b Large-diameter portion 27c Engagement portion 27d Flat portion 28 Projection portion 28a Extension portion 29 O-ring 100 Joint P Fluid pipe

Claims (3)

A joint of a synthetic resin fluid pipe provided with a connection part into which the fluid pipe is inserted and the fluid pipe is connected so as not to be removed.
A joint body having an inner cylinder inserted from the tip into the end of the fluid pipe;
An annular seal member mounted in an annular groove formed in the inner cylinder and intimately contacting the inner peripheral surface of the inserted fluid pipe;
An outer cylinder is mounted on the outer circumferential surface of the inner cylinder so as to be movable along the inner cylinder. The outer cylinder has an engaging portion that engages with the fluid pipe, and the inner pipe is pressed by the fluid pipe by insertion of the fluid pipe. And a sleeve that squeezes the seal member in the diameter-reducing direction on the inner peripheral surface by this movement,
Between the front end of the inner cylinder and the sleeve, there is provided a projecting portion that projects outward from the outer diameter of the sleeve, and the fluid tube passes over the projecting portion, so that the fluid tube becomes the front end surface of the sleeve. A joint for a synthetic resin fluid pipe characterized by avoiding contact with the fluid. In the joint for a synthetic resin fluid pipe according to claim 1,
The joint for a synthetic resin fluid pipe, wherein the sleeve has a tip end surface disposed in contact with the protruding portion. In the joint for a synthetic resin fluid pipe according to claim 2,
The joint for a synthetic resin fluid pipe, wherein the protruding portion has an extending portion that covers an outer periphery of a distal end portion of the sleeve.

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