JP2008138694A - Pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe joint by which a jointed pipe is prevented from coming off. <P>SOLUTION: The pipe joint is provided with a joint body 2 incorporating a seal member 4, a nut-like body 3, a movable member 5, and an elastic member 7. One end of the nut-like body 3 is fixed to the joint body 2, and a connection pipe 11 is inserted from the other end into the nut-like body 3. The movable member 5 is provided circumferentially with a plurality of come-off-stoppers 6 which are pushed by an expansion part 12 of the pipe 11 in the process of insertion operation of the connection pipe 11 having the expansion part 12 in the pipe end. The elastic member 7 is compressed in the insertion work. When the connection pipe 11 is inserted deep into the joint body 2, the movable member 5 is pushed back to the initial position by the restoring force of the elastic member 7, and as a result, the come-off-stoppers 6 is fit in the expansion part 12 in the pipe. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pipe joint for connecting a connecting pipe such as a thin steel pipe subjected to pipe end processing by a one-touch operation.

  As a pipe for water supply or hot water supply, a thin steel pipe excellent in corrosion resistance represented by a stainless steel pipe is frequently used. As a pipe joint for connecting this stainless steel pipe, conventionally, an end portion of a connection pipe is processed (pipe end processing) and the end portion is inserted into the pipe joint. For example, a pipe expansion method in which a tube end is expanded in the outer peripheral direction to form an arc-shaped protrusion has been put to practical use (see Patent Document 1). According to this pipe joint, after attaching a cap nut to the connection pipe, the end of the connection pipe is expanded with a dedicated tool (large power tool) to form a mountain-shaped (circular arc) protrusion, and this protrusion By inserting the tip of the part into the joint main body in which the O-ring is accommodated and then tightening the cap nut, the connecting pipe is advanced and the O-ring is compressed by the annular projecting part, so that the piping work is performed. According to this pipe expansion method, it is only necessary to screw the nut into the end of the connection pipe, so that there is an advantage that an easy and reliable connection can be made without skilled skills.

  Another method of forming a mountain-shaped protrusion at the end of the pipe is also practically used (see Patent Document 2). According to this pipe joint, by forming a mountain-shaped protrusion at the end of the connecting pipe, by screwing a nut into the joint body in which the outer peripheral male thread is formed and the packing is attached to the inner peripheral end, Piping is performed by sandwiching this protruding portion between the tapered surface of the nut and the packing. According to this method, it is only necessary to screw the nut into the end portion of the connection pipe, so that there is an advantage that an easy and reliable connection can be performed without skilled skills.

  On the other hand, the pipe joint of the type connected by a one-touch system using the connection pipe which does not give a pipe end process is also provided practically (refer patent document 3). In this pipe joint, an O-ring is fitted into two circumferential grooves provided on the inner surface of the large-diameter portion of the base body, a coil spring is fitted to the edge of the large-diameter portion, and a pressing member having a right-angled edge is fitted to the inner surface. An inner collar made of synthetic resin is disposed, and has a structure in which these are covered with a tapered outer collar. According to this pipe joint, when the connecting pipe is inserted from the tip of the inner collar, the pressing member is pushed to the tip side of the inner collar, but the outer surface of the pressing member is pressed by the tapered surface of the outer collar, Since the right-angled edge of each bites into the connecting pipe, the coupling between the pipe joint and the connecting pipe is maintained. When a pulling force acts on the connecting tube in this coupled state, the pressing member is pressed against the tapered portion side of the outer collar by the elastic force of the coil spring, and the edge of the pressing member presses the connecting tube by the tapered portion, Pulling of the connecting pipe is prevented. By pressing the tip of the inner collar inward from this coupled state, the pressing member is released from contact with the outer collar, and the connecting tube can be pulled out. In particular, the pressing member has a connection pipe drop prevention edge formed on its inward surface, so even if the connection pipe is a hard vinyl chloride pipe, this drop prevention edge bites into the connection pipe and has a function to prevent the connection pipe from coming off. It is supposed to have.

Japanese Patent Laid-Open No. 2002-228062 (pages 3 to 5, FIGS. 1 and 2) Japanese Utility Model Publication No. 63-145089 (pages 7 to 12, FIGS. 3 and 4) Japanese Patent Laid-Open No. 10-122460 (pages 3 to 5, FIG. 1)

  According to the pipe joint described in Patent Document 1 and Patent Document 2, even when the cap nut is tightened to the joint body with a predetermined torque or to a predetermined position, the water hammer pressure and the joint caused by the water hammer phenomenon are included. The cap nut may loosen due to runout of the entire piping. When the cap nut is loosened, the sealing surface pressure of the connecting pipe and the packing is lowered, and water leakage occurs from the lowered portion. Also, when the cap nut is tightened, a co-rotation phenomenon occurs in which the connecting tube rotates in the same direction as the cap nut due to the frictional force between the tapered surface formed on the inner surface of the cap nut and the ridges of the connecting tube. When connecting a joint to both ends of the pipe, if the cap nut is tightened to connect the joint to one end of the straight pipe and then the joint to the other end, the tightening force is transmitted to one end side, and this side cap nut May loosen. In addition, the use of a cap nut adds to its tightening man-hours, which increases the work man-hours.

According to the pipe joint described in Patent Document 3, the pressing member is locked by a soft touch by the reaction force of the connection pipe and the coil spring, and when a tensile force acts on the connection pipe by applying water pressure after construction, In this structure, the member is reduced in diameter along the tapered surface of the outer collar to exert a strong pull-out preventing force. Therefore, in order to connect the connecting pipe firmly, there are cases where the connecting pipe moves, for example, about several mm in the direction in which the connecting pipe comes out. When the connecting pipe moves in this way, in the pipe having a plurality of connecting portions, bending occurs to absorb the movement of the connecting pipe at each connecting portion, the axis of the connecting pipe does not match, and lack of self-supporting property There is a risk of piping.
In addition, it has excellent workability because the connection can be completed simply by inserting a connection pipe that has not been processed to prevent pull-out, but on the other hand, it is surely applied to the installer. There is a problem that it is a structure that makes it difficult to obtain confirmation of completion, and feels anxiety.

  Accordingly, an object of the present invention is to provide a pipe joint that solves the above-described problems, has excellent workability, and prevents the connection pipe from coming out.

  Another object of the present invention is to provide a pipe joint that eliminates the above-described problems, has excellent workability, prevents the connection pipe from coming out, and provides a pipe that is difficult to bend at the connection portion. is there.

  In order to achieve the above object, a pipe joint according to the present invention includes a joint body incorporating a seal member, a nut-like body in which one end side is fixed to the joint body and a connecting pipe is inserted from the other end side, A movable member that holds a plurality of retaining members that are pushed by the expanded portion in the process of inserting the connecting tube having an expanded portion in the circumferential direction, and an elastic member that is compressed by the insertion operation. It is characterized by.

  In the present invention, the elastic member is a compression coil spring having a truncated cone shape formed by winding a wire from one end to the other end so that the outer diameter increases. The movable member is inserted into the movable member. A plurality of holding pieces and a plurality of holding grooves are alternately arranged along the circumferential direction at an end of the holding piece, and a locking portion into which the retaining member is fitted is provided on at least one side surface of the holding piece. it can.

  In the present invention, the retaining member is formed in a mountain shape, and an edge portion can be provided on the inner peripheral surface thereof.

  In the present invention, a clamping ring can be attached to the outer peripheral surface of the retaining member.

  In the present invention, the elastic member may be omitted, and the seal member may also serve as the elastic member.

  In this invention, the said latching | locking part can be made into the shape which controls so that the relative movement direction with respect to the said movable member of the said retaining member may turn into a radial direction.

  In the present invention, the joint body can be a member integrated with the nut-shaped body.

  In the present invention, the movable member can be a C-shaped member.

  In the present invention, a ring member having a locking piece that comes into contact with the inner peripheral surface can be attached to the end of the nut-shaped main body.

  According to the pipe joint of the present invention, when the connecting pipe is inserted, the expanded pipe portion comes into contact with the retaining member, the retaining member expands in the radial direction and rides on the expanded section while moving the movable member to the back side of the joint body. The elastic member is compressed. Next, when the retaining member rides on the expanded portion, the movable member is pushed back by receiving the restoring force of the elastic member, so that the retained member is pressed against the expanded portion, and the end of the connecting tube is in close contact with the sealing member. Therefore, a high pulling-in preventing force and a sealing performance can be obtained regardless of the one-touch operation in which the connecting pipe is simply inserted into the pipe joint.

  Further, by providing an edge portion that bites into the connecting pipe on the inner peripheral surface of the retaining member, the connecting pipe can be more reliably prevented from being pulled out.

  Furthermore, by attaching a ring member having a locking piece abutting on the inner peripheral surface to the end of the nut-like body, the axis of the connecting pipe and the axis of the joint body coincide with each other, and the self-supporting property of the pipe Can be improved.

  Hereinafter, first to seventh embodiments of the present invention will be described with reference to the accompanying drawings. In the second to seventh embodiments, the same parts as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[First Embodiment]
1 is a longitudinal sectional view of a pipe joint according to a first embodiment of the present invention, FIG. 2 is a perspective view thereof, FIG. 3 is a perspective view of a movable member, FIG. 4 is a perspective view of a retaining member, and FIG. FIG. 6 is a cross-sectional view showing a state in the middle of inserting the connecting pipe into the pipe joint of FIG. 1, and FIG. 7 is a cross-sectional view showing the state in which the connecting pipe is inserted all the way into the joint body. It is.

  As shown in FIG. 1, a pipe joint 1 includes a joint body 2 having both ends opened, a nut-like body 3 fixed to the outer periphery thereof, a seal member 4 attached to the inside of the joint body 2, and a nut-like shape. A movable member 5 incorporated in the main body 3, a retaining member 6 held by the movable member 5, and an elastic member 7 interposed between the end surface of the joint main body 2 and the movable member 5 are provided. The joint main body 2 has a male screw portion 21 for joining to a mating member (not shown) at one end portion on the outer peripheral side, and has a male screw portion 22 for fixing the nut-like main body 3 to the other end portion. . In the joint body 2, a circumferential groove 23 for receiving the distal end portion of the connection pipe (see FIG. 7) and a circumferential groove 24 for holding the seal member 4 are formed. The nut-shaped main body 3 has a female threaded portion 31 on the inner peripheral surface of the end portion on one end side and a tapered surface 32 that is inclined downward from the terminal end toward the other end portion. As the sealing member 4, for example, a rubber lip packing can be used, and as the elastic member 7, for example, a wire is wound so that the outer diameter increases from one end to the other end. A substantially frustoconical compression coil spring provided so that the small diameter side contacts the movable member 5 can be used.

  As shown in FIG. 3, the movable member 5 has an annular flange portion 51 having one end portion serving as a spring seat, and is cut into a rectangular shape with an arc-shaped holding piece 52 along the circumferential direction thereof. The held holding grooves 53 are alternately formed. Triangular locking portions 54 projecting into the holding groove 53 are formed on both side surfaces of each holding piece 52.

  As shown in FIG. 4, the retaining member 6 has a mountain-shaped portion 61 and a sandwiching portion 62 formed in the lower portion thereof, and in order for the locking portion 54 to be fitted to the side surface of the sandwiching portion 62, The width of the sandwiched portion 62 is narrower than the mountain-shaped portion 61. An inner peripheral surface 621 of the sandwiching portion 62 is formed in an arc shape so as to be fitted into the expanded portion of the connecting tube. As shown in FIG. 5, the retaining member 6 is inserted into the holding groove 53 of the movable member 5, and the step between the chevron portion 61 and the sandwiching portion 62 is locked to the locking portion 54. In a state of being sandwiched by 52, the pipe is assembled into the pipe joint so as not to fall off to the inner diameter side of the movable member 5. In the present embodiment, as described above, the locking portions 54 are formed on both side surfaces of each holding piece 52, but at least one of the holding pieces 52 unless the retaining member 6 falls off to the inner diameter side of the movable member 5. It should just be formed on the side surface.

  The construction procedure of piping by the pipe joint 1 will be described with reference to FIGS. First, as shown in FIG. 6, after all parts including the nut-shaped main body 3 are assembled in the joint main body 2, a connecting pipe in which a pipe expanding portion 12 having an arc-shaped cross section is formed at the pipe end from the right side of the figure. 11 (for example, SUS304 steel pipe) is inserted. In the insertion process of the connecting pipe, when the distal end of the connecting pipe 11 is inserted partway into the inner surface of the seal member 4, the retaining member 6 is pushed to the left side of the drawing by the pipe expanding portion 12. The end surface 611 of the chevron 61 (see FIG. 4) abuts on the flange 51 of the movable member 5 and compresses the elastic member 7.

  Next, as shown in FIG. 7, when the insertion operation is continued until the tip of the connection pipe 11 abuts against the joint body 2, the pipe expansion portion 12 fits into the inner peripheral surface 621 (see FIG. 4) of the retaining member 6, and the connection work Ends. As shown in FIG. 7, the elastic member 7 returns to the original state in the state where the connection work is completed, so that the restoring force is transmitted to the retaining member 6 via the flange portion 51 of the movable member 5. Due to this restoring force, the retaining member 6 is pushed to the right side of the drawing, and the inner peripheral surface 621 appears in close contact with the expanded portion 12, so that even if a withdrawal force acts on the connecting pipe 11, the pipe joint Never get out of one. That is, according to the present embodiment, the connection work can be performed by a substantial one-touch operation such as inserting the connection pipe to the back of the pipe joint. In addition, according to the present embodiment, since the lip packing is used as the seal member 4, even when the connecting pipe is inserted with the pipe axis being inclined, the packing is in close contact with the connecting pipe. The packing surface pressure is ensured and high sealing performance can be maintained.

  According to the pipe joint according to the present embodiment, the pipe cutting process, the pipe end chamfering process for removing the burr at the pipe end, the nut attaching process for attaching the nut-shaped main body to the connecting pipe, the pipe expanding process, and the insertion for inserting the connecting pipe Piping can be done in five processes, such as the process, so the piping process can be reduced compared to the conventional pipe expansion method (the main tightening process for tightening the nut and the indicator confirmation process for confirming the amount of tightening of the nut can be omitted), and The piping man-hours can be greatly reduced. Furthermore, since the expanded pipe part 12 is provided in the edge part of the connecting pipe 11, and it is a structure which connects the connecting pipe 11 by a part of the retaining member 6 getting over the expanded pipe part 12 and mechanically locking, construction The movement of the connecting pipe 11 in the axial direction when a water pressure is applied later and a pulling force is applied to the connecting pipe 11 can be made much smaller than that of the conventional one-touch joint.

[Second Embodiment]
FIG. 8 is a perspective view of another example of the retaining member, and FIG. 9 is a cross-sectional view showing a state where the connecting pipe is inserted to the back of the joint body.

  This embodiment has the same configuration as that of the first embodiment except that the retaining member shown in FIG. 8 is used. The retaining member 6 has a plurality of (for example, four) edge portions 622 formed on the inner peripheral surface of the sandwiching portion 62 formed inside the chevron 61. By using the retaining member 6, as shown in FIG. 9, when the connecting pipe 11 is inserted to the back of the joint body 2, the edge portion 622 of the retaining member 6 is locked to the outer peripheral surface of the connecting pipe 11. Thus, it is possible to further improve the pull-out preventing force of the connecting pipe.

[Third Embodiment]
FIG. 10 is a cross-sectional view showing a state where the connecting pipe is inserted to the back of the joint body.

  This embodiment is different from the second embodiment in that an O-ring inscribed in the connection pipe 11 is used as the seal member 4 and a compression coil spring wound in a cylindrical shape is used as the elastic member 7. . Further, in the present embodiment, the joint body 2 and the nut-shaped body 3 are coupled by fitting a part of the fixing ring 8 fitted in the inner circumferential groove 33 of the nut-shaped body 3 into the outer circumferential groove 26 of the joint body 2. This is also different from the second embodiment. According to the present embodiment, since the O-ring that seals the inner diameter side of the end of the connecting pipe 11 is used as the seal member 4, the seal member 4 and the elastic member 7 (compression coil spring) are pivoted as shown in FIG. It can provide so that the position of a direction may become the same position or a close position. As a result, the straight pipe portion 13 at the pipe end can be shortened. For example, even when the length of the straight pipe portion 13 at the pipe end is 1 to 5 mm, good sealing performance can be ensured.

[Fourth Embodiment]
11 is a longitudinal sectional view of a pipe joint according to a fourth embodiment of the present invention, FIG. 12 is a perspective view of a movable member equipped with a retaining member, FIG. 13 is an enlarged perspective view of a portion B in FIG. FIG. 15 is a cross-sectional view showing a state in the middle of inserting the connecting pipe into the pipe joint of FIG. 11, and FIG.

  In this embodiment, the seal member (O-ring) 4 is brought into close contact with the outer peripheral surface of the connecting pipe 11, the elastic member 7 is omitted, and the third embodiment is used except that the retaining member and the movable member shown in FIG. 12 are used. The configuration is the same as that of In the pipe joint 1 shown in FIG. 11, an O-ring that is a seal member 4 is built in the joint body 2, and the movable member 5 is provided so that the seal member 4 and the cylindrical portion 57 of the movable member 5 are adjacent to each other. Yes. As shown in FIGS. 12 and 13, the retaining member 6 is formed with two outer peripheral grooves 63 on the outer periphery thereof along the circumferential direction, for example, and a tightening ring 9 is attached thereto. Further, a guide groove 55 having a width that allows the retaining member 6 to move is formed in the flange portion 51 of the movable member 5.

  According to the present embodiment, when the connection pipe 11 is inserted into the joint body 2, as shown in FIG. 14, when the tip of the connection pipe 11 is inserted partway along the inner surface of the elastic member 5, the retaining member 6 is a pipe expanding portion 12 that is pushed toward the back side of the joint body 2, and the outer peripheral surface on the right side of the retaining member 6 is formed on the nut-shaped body 3 along the guide groove 55 formed in the flange portion 51 of the movable member 5. It moves along the tapered surface 32 (ascends obliquely) and passes through its tip. When the insertion is further continued and the connecting pipe 11 is inserted into the joint body 2, the outer peripheral surface of the connecting pipe 11 is in close contact with the inner peripheral surface of the seal member 4, and the seal member 4 is a cylinder of the movable member 5. The portion 57 is elastically compressed. The diameter-enhanced retaining member 6 is pushed back by the restoring force of the sealing member 4 and the restoring force of the tightening ring 9 to reduce the diameter, and the edge portion formed on the inner peripheral surface of the retaining member 6 is pressed against the outer periphery of the expanded portion. . Therefore, even if a pulling force acts on the connecting pipe 11, it is more reliably prevented from coming out of the pipe joint.

[Fifth Embodiment]
16 is a front view of a pipe joint according to a fifth embodiment of the present invention, FIG. 17 is a sectional view taken along the line CC of FIG. 16, FIG. 18 is a perspective view of a movable member, and FIG. 19 is a perspective view of a retaining member. 20 is a perspective view of the movable member equipped with the retaining member, FIG. 21 is a cross-sectional view showing a state in the middle of inserting the connection pipe into the pipe joint of FIG. 16, and FIG. It is sectional drawing which shows a state.

  The pipe joint 1 shown in FIG. 16 has the same configuration as that of the first embodiment except that the movable member shown in FIG. 18 and the retaining member shown in FIG. 19 are used.

  In the present embodiment, the movable member 5 shown in FIG. 18 has an annular flange portion 51 (see FIG. 17) whose one end is a spring seat, similar to that shown in FIG. Arc-shaped holding pieces 52 and holding grooves 53 cut into a rectangular shape are alternately formed along the direction. However, the movable member 5 is different from that shown in FIG. 3 in that pentagonal locking portions 54 protruding into the holding grooves 53 are formed on both side surfaces of each holding piece 52. Further, the retaining member 6 shown in FIG. 19 is different from that shown in FIG. 4 in that a restriction groove 613 having a shape in which the engaging portion 54 of the movable member 5 fits is formed on both side surfaces of the chevron 61.

  After setting the movable member 5 holding the above-described retaining member 6 to the pipe joint 1 (see FIG. 17), when the connection pipe 11 is inserted into the pipe joint 1, the tip of the connection pipe 11 reaches the middle of the inner surface of the seal member 4. When being inserted, the retaining member 6 is lifted upward by the tube expanding portion 12, and its end surface 611 (see FIG. 19) abuts on the flange portion 51 of the movable member 5 to compress the elastic member 7 (see FIG. 21). ). Next, when the insertion operation is continued until the tip of the connection pipe 11 comes into contact with the joint body 2, the pipe expansion portion 12 fits into the inner peripheral surface 612 (see FIG. 19) of the retaining member 6 and the connection work is completed (see FIG. 22). ). In the present embodiment, the relative movement direction of the retaining member 6 with respect to the movable member 5 is regulated so that the regulation groove 613 is in the radial direction by contacting the end surface 541 of the locking portion 54 of the movable member 5. The retaining member 6 moves along the tapered surface 32 of the nut-shaped main body 3. Therefore, a state in which the inner peripheral surface of the retaining member 6 is in close contact with the expanded portion 12 of the connecting pipe 11 appears over substantially the entire length.

[Sixth Embodiment]
23 is a cross-sectional view of a pipe joint according to a sixth embodiment of the present invention, FIG. 24 is a perspective view of the pipe joint (however, the connecting pipe is omitted), and FIG. 25 is a ring incorporated in the pipe joint of FIG. It is a perspective view which shows a member.

  This embodiment has the same configuration as that of the second embodiment except that the ring member 10 shown in FIG. 25 is inserted into the end of the pipe joint. The ring member 10 is an arc-shaped member obtained by dividing an annular member into a plurality of parts (for example, divided into two parts). The ring member 10 extends from a base 101 and an inner diameter side end surface thereof, and a locking piece 102 having a thick tip is formed. Have. According to this pipe joint 1, the ring member 10 is inserted into the connecting pipe insertion side (nut-shaped main body), and the tip end portion (thick part) of the locking piece 102 is formed at the end of the joint main body 2. Further, by fitting into the inner circumferential groove 34 (see FIG. 23), the axis of the connecting pipe always coincides with the axis of the joint body, and the self-supporting property of the pipe can be improved. In the present embodiment, the ring member 10 is inserted into the nut-shaped main body after the construction is completed and is inserted into the nut-like main body, so that the ring member 10 is a plurality of divided arc-shaped members. By allowing the connecting pipe 11 to pass before forming the expanded portion 12 of the pipe 11, a single cylindrical member can be obtained.

[Seventh Embodiment]
FIG. 26 is a longitudinal sectional view of a pipe joint according to a seventh embodiment of the present invention, FIG. 27 is a perspective view of a movable member, and FIG. 28 is a cross section showing a state in the middle of inserting a connecting pipe into the pipe joint of FIG. FIG. 29 is a cross-sectional view showing a state where the connecting pipe is inserted all the way into the joint body.

In the present embodiment, the pipe joint 1 uses the joint body 2 in which the nut-shaped body is integrated and the tapered surface 27 corresponding to the tapered surface 32 is formed on the inner diameter side, and the movable member shown in FIG. 27 is used. Other than that, the configuration is the same as that of the first embodiment. In this Embodiment, since the coupling main body 2 with which the nut-shaped main body was integrated is used, the number of parts of the pipe coupling 1 can be reduced. Further, the movable member 5 is a C-shaped member in which a groove 56 is formed in one ring shape, and is elastically deformable in the radial direction, so that the diameter of the movable member 5 is reduced in the radial direction to open the end of the joint body 2 (see FIG. 26 to the inside of the joint body 2.
Since the movable member 5 in the present embodiment includes the kerf 56, the diameter of the movable member 5 is reduced when the movable member 5 is biased toward the tapered surface 28 by the elastic member 7 in a state where the movable member 5 is attached to the joint body 2. However, the movable member 5 only needs to have such rigidity that the movable member 5 is not deformed until the movable member 5 is pulled out of the joint body 2 by the force in the reduced diameter direction. Further, a member that prevents the diameter reduction may be fitted into the kerf 56.

  In this invention, the main member which comprises the pipe joint 1 can be formed with the following material, for example. Since the joint body 2 requires corrosion resistance and rigidity, it can be formed by a precision casting technique using, for example, an SCS material or a bronze material. Since the nut-like body 3 also needs corrosion resistance and rigidity, for example, it is formed by a precision casting technique using an SCS material, or a plastic working technique such as hot forging, cold forging or press molding using austenitic stainless steel. Can be formed.

  The seal member 4 can be formed of an olefin rubber, and is preferably formed of EPDM, which is a terpolymer of ethylene, propylene, and a diene monomer for crosslinking, which is particularly excellent in heat resistance. It can also be formed of FKM (fluororubber) having excellent chemical resistance. The movable member 5 can be formed of a general-purpose engineering plastic such as polyolefin (for example, crosslinked PE) or a special engineering plastic such as PPS (polyphenylene sulfide) having excellent heat resistance. The retaining member 6 is preferably formed of a material harder than the connecting pipe, for example, martensitic stainless steel (SUS420) when the connecting pipe is austenitic stainless steel (SUS304). When a compression coil spring is used as the elastic member 7, this member can be formed of austenitic stainless steel (SUS304).

  In the above embodiment, the retaining member 6 has been described with respect to the angle-shaped pipe joint that covers the expanded portion 12 of the connecting tube 11. However, the present invention is not limited to this, and the retaining member 6 is at least partially. Any shape that climbs over the largest diameter portion of the expanded pipe portion 12 and engages with it is acceptable. In the above embodiment, the male screw adapter joint in which the male thread for connection is formed on one side of the joint body has been described. However, the present invention is not limited to this, and other structures (for example, elbow joints) Of course, it can be applied to pipe joints.

It is sectional drawing of the pipe joint concerning the 1st Embodiment of this invention. It is a perspective view of a pipe joint concerning a 1st embodiment of the present invention. The movable member integrated in the pipe joint of FIG. 1 is shown, (a) is a perspective view, (b) is the perspective view which expanded the A section of (a). It is a perspective view of a retaining member. It is a perspective view of the movable member in which the retaining member was set. It is sectional drawing which shows the state in the middle of a connection pipe being inserted in the pipe joint of FIG. It is sectional drawing which shows the state by which the connection pipe was inserted in the pipe joint of FIG. It is a perspective view which shows the other example of a securing member. It is sectional drawing which shows the state by which the connection pipe was inserted to the back by the pipe joint concerning the 2nd Embodiment of this invention. It is sectional drawing which shows the state by which the connection pipe was inserted to the back by the pipe joint concerning the 3rd Embodiment of this invention. It is sectional drawing of the pipe joint concerning the 4th Embodiment of this invention. It is a perspective view which shows the movable member integrated in the pipe joint of FIG. It is the perspective view which expanded the B section of FIG. It is sectional drawing which shows the state in the middle of a connection pipe being inserted in the pipe joint of FIG. It is sectional drawing which shows the state by which the connection pipe was inserted in the pipe joint of FIG. It is a front view of the pipe joint concerning the 5th Embodiment of this invention. It is CC sectional view taken on the line of FIG. The movable member integrated in the pipe joint of FIG. 16 is shown, (a) is a perspective view, (b) is the perspective view which expanded the D section of (a). The retaining member is shown, (a) is a perspective view, (b) is a perspective view of (a) seen from the E direction. It is a perspective view of the movable member in which the retaining member was set. It is sectional drawing which shows the state in the middle of a connection pipe being inserted in the pipe joint of FIG. It is sectional drawing which shows the state by which the connection pipe was inserted in the pipe joint of FIG. It is sectional drawing of the pipe joint concerning the 6th Embodiment of this invention. It is a perspective view of the pipe joint concerning the 6th Embodiment of this invention. It is a perspective view which shows the ring member integrated in the pipe joint of FIG. It is sectional drawing of the pipe joint concerning the 7th Embodiment of this invention. It is a perspective view which shows the holding member integrated in the pipe joint of FIG. It is sectional drawing which shows the state in the middle of a connection pipe being inserted in the pipe joint of FIG. It is sectional drawing which shows the state by which the connection pipe was inserted in the pipe joint of FIG.

Explanation of symbols

1: Pipe fitting,
2: Joint body, 21, 22: Male thread portion, 23, 24, 25: Circumferential groove, 26: Outer peripheral groove, 27: Tapered surface 3: Nut-shaped main body, 31: Female thread portion, 32: Tapered surface, 33 : Inner circumferential groove, 34: locking groove 4: seal member,
5: movable member, 51: flange portion, 52: holding piece, 53: holding groove, 54: locking portion, 541: end face, 55: guide groove, 56: cut groove, 57: cylindrical portion 6: retaining member, 61 : Chevron part, 611: end face, 612: inner peripheral face, 613: regulating groove, 62: clamping part, 621: inner peripheral face, 622: edge part, 63: outer peripheral groove 7: elastic member,
8: fixing ring,
9: Tightening ring,
10: Ring member, 101: Base part, 102: Locking piece 11: Connection pipe, 12: Expanded pipe part, 13: Straight pipe part

Claims (9)

In the course of the insertion operation of the joint body including the seal member, the nut-like body having one end side fixed to the joint body and the connection pipe inserted from the other end side, and the connection pipe having the pipe expansion portion at the pipe end. A pipe joint comprising: a movable member that holds a plurality of retaining members pushed by a pipe expanding portion along a circumferential direction; and an elastic member that is compressed by the insertion operation. The elastic member is a compression coil spring having a truncated cone shape formed by winding a wire from one end to the other end so that the outer diameter increases, and the movable member is on the side where the connection pipe is inserted. A plurality of holding pieces and a plurality of holding grooves are alternately arranged along the circumferential direction at an end portion, and has an engaging portion into which the retaining member is fitted on at least one side surface of the holding piece. Item 1. The pipe joint according to Item 1. The pipe joint according to claim 1, wherein the retaining member is formed in a mountain shape and has an edge portion on an inner peripheral surface thereof. The pipe joint according to any one of claims 1 to 3, wherein a tightening ring is mounted on the outer peripheral surface of the retaining member. The pipe joint according to claim 1, wherein the seal member also serves as the elastic member. The pipe joint according to any one of claims 2 to 5, wherein the locking portion has a shape that regulates the relative movement direction of the retaining member with respect to the movable member to be a radial direction. The pipe joint according to any one of claims 1 to 6, wherein the joint body is a member in which the nut-like body is integrated. The pipe joint according to claim 1, wherein the movable member is a C-shaped member. The pipe joint according to any one of claims 1 to 8, wherein a ring member having a locking piece that comes into contact with an inner peripheral surface thereof is attached to an end of the nut-shaped main body.

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