JP2008286259A - Pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe joint applicable to a metal-plastic composite pipe exhibiting strong pull-off resistance. <P>SOLUTION: The pipe joint comprises a joint body 2 having an insertion cylinder portion 3 to be inserted into an end 1a of a connected pipe 1, a clamp ring 5 with a slit 51 for fastening the end 1a of the pipe 1 externally fitted to the insertion cylinder portion 3 with resilient fastening force, and a diameter enlarged piece 6 removably held in the slit 51 so as to enlarge the diameter of the clamp ring 5 against the resilient force of the clamp ring 5. An encircling cylinder body 10 for encircling the insertion cylinder portion 3 and the clamp ring 5 has a tapered hole portion 35. When the clamp ring 5 tends to be pulled off together with the pipe end 1a, a C-shaped stop ring 20 is pressed against the tapered hole portion 35 of the encircling cylinder body 10 to shrink the diameter thereof. The stop ring 20 is moved toward the front end while abutting on the clamp ring 5 to shrink the diameter thereof. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe joint.

  Conventionally, a pipe joint for connecting a pipe for water supply or hot water supply has conventionally been developed by elastically coupling a joint body having an insertion tube portion inserted into the end portion of the pipe and an end portion of the pipe externally fitted into the insertion tube portion. Clamp ring with a slit for tightening with a specific tightening force, and releasably sandwiched in the slit so as to expand the diameter of the tightening ring against the elastic force of the clamp ring and when inserting a pipe The thing provided with the diameter expansion piece which detach | leaves is known (for example, refer patent document 1).

However, in the pipe joint of Patent Document 1, the applicable pipe is limited to a synthetic resin (plastic).
That is, the pipe to be connected is made of a synthetic resin such as cross-linked polyethylene or polybutene. If a concave groove is formed on the outer peripheral surface of the insertion tube portion, the inner surface of the pipe is deformed so as to conform to the concave groove. It was possible to withstand a large pulling force.
Further, in the pipe joint described in Patent Document 1, a Kikuza-shaped (petal-shaped) retaining ring in which a metal plate is punched is used. However, if the pipe to be connected is a synthetic resin (plastic), Kikuza It was also possible to increase the pull-out resistance by the plate-like teeth in the shape of petals (petal shape) biting into the outer peripheral surface of the pipe.

However, recently, metal / plastic composite pipes (also referred to as metal reinforced resin pipes) having a metal layer of Al or the like in a sandwich shape are being used as pipes for water supply and hot water supply.
In such a metal / plastic composite pipe, when the pipe end is tightened by the elastic force of the clamp ring, the pipe end may not be easily deformed in the direction of diameter reduction. If the inner peripheral surface of the pipe does not come into contact with a sufficient pressing force inward in the radial direction and some external force is applied, the pipe end may be pulled out together with the clamp ring.
In addition, the plate-shaped teeth of the above-mentioned sheet metal-made chrysanthemum (petal-shaped) retaining ring may bite deeply into the outer peripheral surface of the pipe end, destroying (breaking through) the inner metal layer, In the case of different kinds of metals, there is also a problem that they come into contact to cause contact corrosion of different metals (battery corrosion).
JP 2002-31822 A

The problem to be solved is that it is difficult to exert a stable and strong pulling force even for a metal / plastic composite tube, and there is a problem in durability due to contact corrosion of different metals.
The present invention solves such problems and can also be applied to metal / plastic composite pipes, and pipe connection work can be performed easily and quickly, exhibiting a strong pulling force and durability. Another object of the present invention is to provide a pipe joint that exhibits excellent sealing performance over a long period of time.

  Accordingly, the present invention provides a joint body having an insertion cylinder portion inserted into an end portion of a pipe to be connected, and a C-shape with a slit that elastically tightens the pipe end portion externally fitted to the insertion cylinder portion. A pipe joint provided with a cylindrical clamp ring and an enclosing cylinder that is attached to the joint body so as to surround the insertion cylinder and forms a pipe end insertion space, A taper hole that gradually decreases in diameter is formed, and when the clamp ring moves in the distal direction to be pulled out together with the elastically tightened pipe end, the clamp ring comes into contact with the clamp ring in the distal direction. A C-shaped stop ring made of a synthetic resin having a locking claw that is pressed to reduce the diameter by pressing against the tapered hole portion of the surrounding cylindrical body and bites into the outer peripheral surface of the pipe end portion is provided. .

In addition, the outer circumferential surface of the insertion tube portion is formed with a locking groove having a front end side surface 47a that is orthogonal to the axis and orthogonal to the shaft center, and the stop ring that bites into the outer circumferential surface of the pipe end portion. The axial position of the locking claw and the axial position of the locking groove are arranged so as to coincide with each other.
In addition, a single locking groove having a front end side surface that is orthogonal to the axis is formed on the outer peripheral surface of the insertion tube portion so as to be wide, and a plurality of the locking claws of the stop ring are formed. Provided so that the axial direction positions of the plurality of the locking claws of the stop ring that bite into the outer peripheral surface of the pipe end correspond to the width dimension of the wide locking groove. It is.

It is a pipe joint that can be applied to metal / plastic composite pipes (metal reinforced resin pipes) and can exhibit strong pull-out resistance, and it can be stably maintained over a long period of time. it can.
In particular, the clamp ring and the stop ring cooperate to exert a highly cooperative pull-out force.
Further, since the stop ring is made of a synthetic resin (insulating material), even if the latching claw bites in, no foreign metal contact corrosion occurs at all, and a stable and good connection state can be maintained for a longer period of time.
Of course, the pipe connection work can be done easily and quickly, and can be completed simply by inserting the pipe end.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
1 to 11, a pipe joint 50 according to the present invention includes, for example, a metal / plastic composite pipe (metal reinforced resin pipe) 1 in which cross-linked PE, Al, and cross-linked PE are laminated (see FIGS. 7 to 10). ) Is applicable. Reference numeral 2 denotes a joint body, which has an insertion cylinder portion 3 into which an end portion 1a of the pipe for connection 1 is inserted.

Reference numerals 4 and 4 denote two seal members (O-rings or the like) which are mounted (arranged) in the concave circumferential grooves 7 and 7 of the insertion tube portion 3 of the joint body 2 with a small interval. Reference numeral 5 denotes a C-shaped clamp ring (clamping ring) made of spring steel or the like, having a slit 51 at one circumference, and this clamp ring 5 is externally fitted to the insertion tube portion 3. 9a and 10 are elastically pressed (squeezed) with a strong surface pressure (throttle pressure) P.
6 is a diameter-expanding piece made of a highly rigid steel material, and can be detached from the slit 51 to expand the diameter of the clamp ring 5 against the elastic force of the clamp ring 5, in an initial state (conception with no pipe inserted) Then, as shown in FIG. 1, FIG. 4, and FIG. That is, the clamp ring 5 is in a diameter-expanded state by the diameter-expanding piece 6 so that the pipe end 1a can be inserted.

  Reference numeral 10 denotes an enclosing cylinder (cylindrical cover body) attached to the joint body 2 with the insertion cylinder portion 3 as an encircling shape. The enclosing cylinder (cylindrical cover body) 10 further accommodates the clamp ring 5. keeping. Specifically, the surrounding cylindrical body 10 includes a first cylindrical body 11 on the proximal end side and a second cylindrical body 12 on the distal end side. As shown in FIGS. 3 to 1, the first cylinder 11 and the second cylinder 12 are provided with a clamp ring 5 in a state of sandwiching the diameter-expanding piece 6 and a retaining ring (stop ring) 20 (described later). In order to be housed inside, they are integrally connected by screw connection 13 (see FIGS. 1 and 7), heat fusion or adhesion (see FIG. 6).

  The first cylindrical body 11 is preferably made of a transparent resin such as PA (polyamide, nylon), PES (polyethersulfone), or PC (polycarbonate), and the separation of the enlarged diameter piece 6 can be easily visually recognized from the outside. . The second cylinder 12 may be opaque and is made of the same synthetic resin, or a metal such as brass or a plastic composite material such as polyphenylsulfone (PPSU). When the first cylinder 11 and the second cylinder 12 are heat-sealed, the same or homogeneous resin is used. However, in the case of the screw connection 13, the combination of the respective materials is free.

Then, the clamp ring 5 will be described. A low trapezoidal shape (or a low triangular shape not shown) so that the central top portion 16 corresponds to the basic band portion ₁₅ of the uniform width dimension W15 and the slit 51 opposite to the slit 51 °. The bending reinforcement piece portions 17 are integrally provided continuously. That is, in a region opposite to the slit 51 by 180 °, along the one end edge (inner end edge) 18 of the basic band portion 15, the low trapezoidal (or low triangular shape) bending reinforcement piece 17 is pressed. It is integrally formed by plastic processing such as processing.
The low trapezoidal (or low triangular shape) bending reinforcement piece 17 preferably has a long base extending so as to occupy about 150 ° to 210 ° of 360 ° (entire circumference). In other words, in the unfolded state shown in FIG. 5, the bending reinforcing piece 17 is integrally connected to one end edge (one side) 18 over about 40% to 60% of the total length of the strip-shaped basic band 15 ( Form.

Further, the outer surface 17a of the reinforcing piece portion 17 of the annular ring C-shaped clamp ring 5 protrudes outward in the radial direction from the outer peripheral surface 15a of the basic band portion 15 (by plastic working or the like from the plate material). Is formed.
The diameter-enlarging piece 6 is sandwiched between corner portions R, R between the one end circle 18 of the basic band portion 15 and both end edges 8, 8 forming the slit 51. That is, the diameter-expanding piece 6 is made to correspond to the one end edge 18 side where the reinforcing piece portion 17 is disposed, and the diameter is expanded while maintaining a perfect circle.
Further, as shown in FIG. 5, the clamp ring 5 has a planar state in which the other end edge 19 of the basic band portion 15 is straight (straight). In other words, as shown in FIGS. 3 and 11, the clamp ring 5 has an annular C shape, and a reinforcing piece 17 protrudes from one end edge 18 of the clamp ring 5, and the other end edge 19 has a shaft end. It is an orthogonal planar shape orthogonal to the center L.

Next, the surrounding cylinder portion 10 is configured by connecting the first cylinder body 11 and the second cylinder body 12, and as shown in FIGS. 1 and 3, the base portion of the insertion cylinder portion 3 of the joint body 2. A base 23 of the first cylinder 11 is fitted in a shallow concave groove 22 on the outer peripheral surface of the short cylinder 21 provided continuously to the pipe, and is attached so as not to be pulled out from the joint body 1 in the axial direction. ing.
As shown in FIG. 1, FIG. 7, and FIG. 8, a pipe end insertion space 24 having an open end is formed in an annular shape between the surrounding cylinder 10 and the insertion cylinder 3. the inner peripheral surface 25 includes a diameter 27 in the inner diameter D ₂₇ for holding the base band portion 15 of the clamp ring 5, a large inside diameter D ₂₈ for holding the reinforcing piece 17 protruding in the radial outside outwardly a diameter 28, a distal end opening diameter portion 29 of the inner diameter D _29, and a preparative wear small diameter portion 26 of the inner diameter D _26, are provided. The large diameter portion 28 is disposed on the inner side (base end side) than the medium diameter portion 27.

That is, as shown in FIG. 6, the mounting small diameter portion 26, the large diameter portion 28, the medium diameter portion 27, and the distal opening small diameter portion 29 are sequentially arranged (formed) from the base portion toward the distal end. Then, set as _{D 28> D 27> D 29} > D 26. As shown in FIG. 6, the inner diameter D _{27 of the} medium diameter portion 27 is set slightly larger than the outer diameter d ₁ of the basic band portion 15 in the diameter expansion unit state of the clamp ring 5 sandwiching the diameter expansion piece 6. The medium diameter portion 27 corresponds to the outer peripheral surface of the substantially circular basic band portion 15 with a minute gap. Further, as shown by a two-dot chain line in the clamp ring 5 on the right side of FIG. 6, outside of the virtual circle N when a circle in contact with the reinforcing piece portion 17 (the central top portion 16 thereof) is drawn around the axis L. than the diameter d _2, the inner diameter D ₂₈ of the large diameter portion 28 is set slightly larger, with a minute gap, a virtual circle N corresponds to the large-diameter portion 28 (see FIG. 2 (B)).

By the way, the first cylinder 11 and the second cylinder 12 that are connected to each other by screw connection, heat fusion, or adhesion will be further described. First, the first cylinder 11 has a stepped portion 31. The mounting small-diameter portion 26 and the large-diameter portion 28 (having an opening at the tip) are partitioned and formed by a stepped portion 31 having a shape orthogonal to the axial center. Further, the mounting small-diameter portion 26 has a locking low ridge portion 32 and is engaged with the concave groove 22 on the outer periphery of the short cylindrical portion 21 of the joint body 2 in a rotatable and axially undrawable state. is doing.
The second cylinder 12 includes a fitting part 33 that is fitted (or screwed) to the tip of the first cylinder 11, a stepped part 34, the medium diameter part 27, and a reduced diameter tapered hole part. 35, a tip opening small diameter portion 29, and a pipe guiding chamfer 36. As can be seen from FIGS. 1 and 3, the distal end side of the basic band portion 15 of the clamp ring 5 is held in correspondence with the medium diameter portion 27 of the second cylinder 12. The outer peripheral surface has a tip diameter-reduced taper surface 37, and it can be said that the entire second cylinder 12 has a substantially tip-diameter tapered taper shape.

  As shown in FIGS. 2 and 3, the inner peripheral surface 25 of the surrounding cylinder 10 is a protrusion for preventing the clamp ring 5 housed in the inner diameter of the large diameter portion 28 from falling down. Parts 38, 38. More specifically, in the second cylindrical body 12, the base end is connected to the stepped portion 31, and two ridges 38, 38 having mountain-shaped cross sections are formed in parallel with the axis L. Has been. The protrusions 38 and 38 are disposed with a mutual angle θ of 25 ° to 50 ° (see FIG. 2), and the one end circle 18 of the basic band portion 15 of the clamp ring 5 abuts on the tip surface 38a. . Moreover, as shown in FIGS. 1, 2, and 3, when assembled (when the clamp ring 5 is housed and assembled), it protrudes inward from one end edge 18 between the two protruding portions 38, 38. The sandwiched diameter-enlarging piece 6 is disposed. By assembling in this way, one end edge 18 to the basic band portion 15 of the clamp ring 5 comes into contact with the ridges 38, 38 (tip surfaces 38a, 38a thereof) in the vicinity of the slit 51 and is reinforced. The center top 16 of the piece 17 abuts against the stepped portion 31 so that the axial center of the clamp ring 5 coincides with the axial center of the joint body 2 in the space 24. Retained. In this way, the clamp ring 5 is held in the surrounding cylinder body 10 in a stable posture without falling down.

  The stop ring 20 will be described. It is a C-shaped overall shape having a cut at one place, and the material is preferably a hard synthetic resin such as PPSU. The stop ring 20 has a tapered surface 45 with a reduced diameter at the tip on the outer peripheral surface, and a plurality (two in the illustrated example) of locking claws 46, 46 on the inner peripheral surface. The locking claw 46 has a triangular mountain shape with the inner end edge facing inward of the pipe joint. That is, the cross-sectional shape of the locking claw 46 is set to a triangular mountain shape having an orthogonal inner end surface orthogonal to the axis L. The tapered surface 45 of the stop ring 20 is accommodated in the pipe end insertion space 24 so as to correspond to the tapered hole 35 of the surrounding cylinder 10 (the second cylinder 12). As shown in FIG. 3, the inclination angles α and β of the tapered surface 45 and the tapered hole portion 35 are set to 15 ° to 20 °, sufficiently larger than the conventional angles. Thereby, the axial direction dimension of the 2nd cylinder 12 and the width dimension of the stop ring 20 can be made small, and it contributes to the compactization of the axial direction dimension of a pipe joint.

Further, in the vicinity of the distal end of the insertion tube portion 3 of the joint body 2, locking concave grooves 47 and 47 having an axial center orthogonal surface are formed. A surface perpendicular to the axis of the locking groove 47 is disposed on the tip side. In other words, the locking groove 47 has a tip side surface 47a that is orthogonal to the axis. As a result, when an external force in the pulling direction of the pipe 1 is applied, the force that prevents the pipe 1 from being pulled out increases. As can be seen from FIG. 10, the locking grooves 47 and 47 correspond to the axial positions corresponding to the locking claws 46 and 46, respectively, with the stop ring 20 being squeezed. In other words, the axial position of the locking claw 46 of the stop ring 20 that bites into the outer peripheral surface of the pipe end 1a and the axial position of the locking groove 47 are arranged to coincide. did.
14 is an enlarged view of a main part of another embodiment, and the basic configuration is the same as that of FIG. 10, except that the locking groove 47 has a large width dimension W ₄₇ (wide width). Along with this, the axial direction positions of a plurality (two in FIG. 14) of the locking claws 46 are within the width dimension W ₄₇ of the wide locking groove 47. It is a point to correspond.

In FIGS. 10 and 14, an arrow P ₂₀ indicates the pressure in the radial inward direction due to the stop ring 20. The pressure P ₂₀ is generated by pressure contact between the tapered hole portion 35 of the second cylinder 12 and the tapered surface 45 of the stop ring 20.
In short, this stop ring 20 is a C-shaped ring that acts as a so-called retaining ring, and as shown in FIG. 9, the clamp ring 5 bites into the pipe 1 with the throttle pressure P, which is sufficiently strong. Although the pipe 1 and the pipe joint are connected to each other, as shown in FIGS. 9 to 10 (or FIG. 14), the pipe 1 may be pulled out when a large external force is applied. However, the stop ring 20 prevents the pipe from being pulled out by the strong pressure P _{20 at} that time. In addition, the deformed inner surface of the pipe 1 bites into the locking concave groove 47 of the insertion tube portion 3, and the pipe can be further prevented from coming out.

By the way, as shown in FIG. 14, the reason why the common (single) locking groove 47 is made to correspond to the plurality of locking claws 46 and the operation and effect thereof will be described below.
That is, after the enforcement completed (see FIG. 9), if the pipe 1 is a get out, press the stop ring 20 the clamp ring 5 while moving in the direction of arrow Y ₅ together with the pipe 1, the stop ring 20 is tapered hole portion In response to the force in the direction of squeezing the pipe 1 from 35 (see arrow P ₂₀ ), a strong pressing force inward in the radial direction is applied to the outer peripheral surface of the pipe 1. However, in order to prevent the pipe 1 from slipping out as soon as possible at the stage where the enforcement is not completed, the tips of the locking claws 46, 46 of the stop ring 20 are sharp (as in FIG. 14). As a shape and a plurality of pieces, the pipe 1 is bitten.
If the number of the locking claws 46 is one, the volume for constricting the pipe 1 is insufficient, but the number of the locking claws 46 is two (a plurality) as shown in FIG. Can be secured.

Then, the pipe 1 by the presence of the metal layer 48 such as Al is small convex strip to be pressed, the readily hardly shrink-deformed (the inner peripheral surface as the locking claw 46, 46 arrow P ₂₀ in the radial direction within in Difficult to form). However, as shown in FIG. 14, by providing a common single locking groove 47 in the wide width dimension W ₄₇ , small protrusions can be easily formed on the inner peripheral surface. The small ridges on the inner surface of the pipe 1 are pushed into the pipe 47, so that the pipe can be prevented from coming off firmly at the tip side face 47a orthogonal to the axis. In addition, with such a configuration, the pipe retaining force (as shown in FIG. 14 or FIG. 10) is not limited to passing through the second cylindrical body 12 and the first cylindrical body 11 from the stop ring 20, but the insertion cylindrical portion 13 The pull-out force (tensile force) can also be dispersed via. As a result, the effect of increasing the durability of the first cylinder 11 and the second cylinder 12 made of synthetic resin is also exhibited.

  By using the stop ring 20 as a synthetic resin (insulating material), even if it is a metal plastic composite tube with a metal layer 48 of Al or the like laminated in a sandwich shape, contact corrosion of different metals (battery corrosion) occurs. Can be prevented. In addition, a small-diameter outer peripheral portion 52 having a step 51a is formed at the forefront of the insertion tube portion 3 of the pipe joint main body 2, and a shallow concave groove 52a is provided in the small-diameter outer peripheral portion 52.

Then, a guide ring 53 is fitted (externally fitted) to the small-diameter outer peripheral portion 52. When the pipe 1 is inserted by the guide ring 53 as shown in FIG. 7, the insertion tube portion 3 is connected to the pipe. During insertion and after insertion, for a long period of time-serves as centering. That is, the guide 1 is guided so that it can be inserted while the shaft center of the pipe 1 and the shaft center L of the joint body 2 (insertion tube portion 3) are aligned, and is centered for a long time after the connection is completed.
As a result, the sealing members 4 and 4 such as O-rings are uniformly compressed over 360 ° (entire circumference), and slidably contact (pressure contact) with the inner peripheral surface of the pipe 1 as shown in FIGS. Thereafter, (even if there is a minute gap between the inner peripheral surface of the pipe end portion 1a and the outer peripheral surface of the insertion cylinder portion 3, the seal member 4 is compressed at a uniform compression rate to 360 ° (over the entire circumference) over a long period of time. , 4 are compressed and good sealing properties (sealing performance) can be exhibited.

Further, the closed annular guide ring 53 has a large-diameter lip 54 and a small-diameter lip 55, so that dissolved oxygen and chlorine in the water deteriorate into the seal member 4 when the water supply / hot water supply is used (after completion of the pipe connection). It can prevent adverse effects such as promotion. Further, the insertion guide ring 53 has a guide taper portion 59 that is reduced in diameter toward the distal end on the outermost peripheral surface thereof.
The small-diameter lip 55 is larger (slightly) than the inner diameter of the pipe end 1a in the free state, and lightly contacts the inner peripheral surface of the pipe end 1a in the connected state. The large-diameter lip 54 is (sufficiently) larger (free state) than the inner diameter of the pipe end 1a, and on the other hand, in the connected state of FIGS. . The lips 54 and 55 can be freely increased (not shown).
The guide ring 53 is sufficiently harder than the inner sealing materials 4 and 4 and desirably has a rubber hardness HA 90 or higher. Further, as shown in FIGS. 9 and 10, the tensile yield elongation is high, and it has a flexibility that does not break even if it is bent at 90 °. For example, a resin such as PP, PE, PPE, and PVDF is used.

  In this way, the insertion guide ring 53 prevents the liquid from entering the seal member 4 and the centering function for matching the axial center of the pipe end portion 1a with the axial center of the insertion tube portion 3. The secondary seal function is also used.

In FIG. 1, the joint body 2 has a male screw portion 56, but in the present invention, in addition to this, a type having a plurality of insertion tube portions 3 (therefore, the right side of FIG. 1). It can be applied to various types such as elbow type, etc.
Further, as shown in FIGS. 2 and 4, the slit 51 corresponds between the two protruding portions 38, 38 by the sandwiched enlarged diameter piece 6, and the one end edge 18 of the uniform width dimension W ₁₅ is surely secured. The clamp ring 5 can be held in the normal position without falling down, and the end portion 1a of the pipe 1 can be smoothly inserted.

  4 and 5, the slit 51 is formed in a zigzag shape, and under the state of FIG. 9 or 10, the liquid (water) passes through the inner peripheral surface of the end 1 a of the pipe 1 and the seal member 4. It is possible to effectively prevent leakage (running) in the axial direction (at the circumferential position corresponding to the slit 51). Specifically, one end in the longitudinal direction of the basic band portion 15 is a convex shape having a projecting piece 57 in the center, and the other end is formed in a concave shape having a concave portion 58 in the center. Note that FIG. 11 is a diagram drawn by omitting (simplifying) such protrusions 57 and recesses 58.

  As can be seen from FIGS. 4, 1, and 3, the resting piece 17 of the clamp ring 5 is plastically deformed outward in the radial direction while maintaining the same thickness as the basic band portion 15. Therefore, the inner surface 17b of the reinforcing piece 17 is always separated from the pipe end 1a by a very small size, and as shown in FIG. 9 or FIG. Only the portion 15 is strongly pressed (pressed), and the surface pressure (throttle pressure) P maintains a high value.

In FIG. 5, the following relational expression is established between the width dimension W 15 of the basic band portion 15 and the maximum width dimension W _h at the central top portion 16.
1.4 × W ₁₅ ≦ Wh ≦ 1.8 × W ₁₅

  As shown in FIG. 7, when the pipe end 1a is inserted into the insertion space 24 from the open end of the main pipe joint, the pipe inner circumferential surface is guided and guided (guided) by the guide ring 53 while being centered. The seal members 4 and 4 are inserted as shown in FIG. 8 while elastically compressing the seal members 4 and 4 uniformly around the circumference, and the tip end surface of the pipe collides with the enlarged diameter piece 6. As shown in FIG. The clamp ring 5 is detached from the slit 51, and the diameter of the clamp ring 5 is reduced by its own elastic force. Fixed in shape.

Thereafter, when a large external force is applied, the pipe end portion 1a is to be pulled out together with the clamp ring 5 as shown in FIGS. The other end edge 19 presses against the inner end surface of the stop ring 20 (with a uniform surface pressure) to move the stop ring 20 to the right (to the opening end side) in the figure, and the tapered hole portion 35 and the tapered surface 45 at throttling action by sliding contact, while biting engagement claw 46, 46 of the stop ring 20 at high pressure P ₂₀ is the outer peripheral surface of the pipe end portion 1a, to deform the pipe end 1a as shown in FIG. 10 Thus, together with the locking recesses 47, 47, a strong pulling force can be used to prevent the removal.

Incidentally, FIG. 12 shows a conventional clamp ring 40. Since the width dimension W ₄₀ is uniform (as described above), the rigidity in the vicinity of the slit 41 is too large, and the slit vicinity areas 42 and 42 are not elastically deformed. On the contrary, the bending moment acts intensively (largely) in the slit opposite region 43 to cause plastic deformation, and the inner surface shape of the clamp ring 40 deviates from a true circle as shown in FIG. Thus, there has been a problem that it becomes difficult to insert the pipe end portion thereafter, and the pressure P for squeezing the pipe end portion in the radial direction after the diameter-expanded piece is detached from the slit 41 becomes uneven.

Figure 13 shows a comparative example, in order to solve such a problem, as it is the outer diameter (inner diameter) dimensions of a free state of Figure 12, clamp the width W _60, increased by the slit opposite region 63 It is a ring 60 and can prevent plastic deformation of the slit opposite region 63, but there is little deformation of the slit vicinity regions 62 and 62 in the vicinity of the slit 61, and the roundness of the expanded state is not sufficient, and The pressure P at which the diameter-expanding piece is released and presses the end of the pipe is not yet uniform.
On the other hand, in the present invention, as shown in FIG. 11, the outer peripheral surface 17a of the bending reinforcement piece 17 protrudes outward in the radial direction from the outer peripheral surface 15a of the basic band portion 15, so that the strength against the bending moment is increased. The rigidity of the reinforcing piece 17 is sufficiently increased. As shown in FIG. 11 (D), the inner surface of the reinforcing piece 17 is enlarged in a perfect circle, and the pipe end 1a can be inserted smoothly. In addition, the elastic diameter expansion deformation is equalized over the entire circumference, the diameter expansion piece 6 is detached, and the pipe end 1a is pressed with the pressure P as shown in FIG. 9 (or FIG. 10). Tighten with uniform pressure almost equal over the entire circumference. In other words, as shown in FIG. 11D, the elastic deformation is dispersed so as to be uniform over the entire circumference, and the elastic deformation is urged from the entire circumference in the direction of diameter reduction with the uniform pressure P. Thereby, the sealing performance (sealability) of the seal member 4 is improved.

The present invention is not limited to the illustrated embodiment, and the design can be changed freely. For example, the shape of the clamp ring 5, the shape of the diameter-expanded piece 6, the mutual arrangement position, and the like can be freely changed.
As described above, the present invention includes the joint body 2 having the insertion cylinder portion 3 inserted into the end portion 1a of the pipe 1 to be connected and the pipe end portion 1a externally fitted to the insertion cylinder portion 3. A C-shaped clamp ring 5 with a slit 51 that is elastically tightened, and an enclosing cylinder 10 that is attached to the joint body 2 so as to form the pipe end insertion space 24 with the insertion cylinder 3 surrounded. The pipe end 1a is a pipe joint provided with a tapered hole 35 that gradually decreases in diameter at the distal end side and the clamp ring 5 is elastically tightened. When it is moved in the distal direction that is pulled out together, it comes into contact with the clamp ring 5 and is pressed in the distal direction, and is pressed against the tapered hole portion 35 of the surrounding cylindrical body 10 to reduce its diameter. C-shaped strike made of synthetic resin with locking claw 46 that bites into the outer peripheral surface Since the pull ring 20 is provided, when a strong pulling force that cannot be withstood by the clamp ring 5 is applied, the stop ring 20 gives a strong resistance to the pulling force, and the pipe end 1a and the pipe joint. Always secure (maintain) the connection state with. In particular, it can be said to be a very suitable pipe joint for a metal / plastic composite pipe (metal reinforced resin pipe) that is difficult to deform. Further, even if it is used for a metal / plastic composite pipe having a metal layer such as Al in the middle, no different metal contact corrosion occurs.

  In addition, a locking concave groove 47 having a distal end side surface 47a orthogonal to the axis is formed on the outer peripheral surface of the insertion tube portion 3, and the stop that bites into the outer peripheral surface of the pipe end portion 1a. Since the axial position of the locking claw 46 of the ring 20 and the axial position of the locking groove 47 are arranged so as to coincide with each other (as shown in FIG. 10), the locking claw 46 46, the inner surface of the pipe end 1a deformed inward in the radial direction enters into the locking grooves 47, 47, and exhibits a stronger pull-out resistance. Then, the intruded inner surface of the pipe end portion 1a is strongly locked by the orthogonal plane-shaped tip side surface 47a, thereby providing a stronger pull-out resistance.

In addition, a single locking recess groove 47 having a distal end side surface 47a orthogonal to the axis is formed on the outer peripheral surface of the insertion cylinder portion 3 and the locking ring of the stop ring 20 is fixed. A plurality of claws 46 are provided, and the axial position of the plurality of locking claws 46 of the stop ring 20 biting into the outer peripheral surface of the pipe end 1a is the width dimension of the wide locking groove 47. Since it is configured to correspond to W ₄₇ , when applied to a metal / plastic composite pipe (metal reinforced resin pipe) having a metal layer 48 such as Al, it deforms radially inward and is small on the inner peripheral surface of the pipe 1 Easy to form ridges--that is, easy to enter into the wide locking groove 47 as small ridges--and a plurality of locking claws 46 makes it easy to form small ridges with sufficient volume It can be formed to have a strong pulling force.

It is a longitudinal cross-sectional view which shows one Embodiment of this invention. It is principal part sectional drawing of a component. It is sectional explanatory drawing of a decomposition | disassembly state. It is a perspective view of an example of a clamp ring. It is a plane expansion state figure of a clamp ring. It is principal part structure explanatory drawing. It is a principal part expanded sectional view which shows a pipe insertion state. It is a principal part expanded sectional view which shows the state just before completion of pipe insertion. It is a principal part expanded sectional view which shows a connection completion state. It is a principal part expanded sectional view which shows the state which the extraction force acted. It is a figure for demonstrating the clamp ring which concerns on this invention, Comprising: (A) is a front view, (B) is a side view, (C) is a perspective view, (D) is a front view of a diameter-expanded state. It is a figure for demonstrating the conventional clamp ring, Comprising: (A) is a front view, (B) is a side view, (C) is a perspective view, (D) is a front view of a diameter-expanded state. It is a figure for demonstrating the clamp ring of a comparative example, Comprising: (A) is a front view, (B) is a side view, (C) is a perspective view, (D) is a front view of a diameter-expanded state. It is a principal part expanded sectional view of other embodiment which shows the state which the extraction force acted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pipe 1a End part 2 Joint body 3 Insertion cylinder part 4 Seal member 5 Clamp ring 6 Expanded piece 7 Concave groove 8 End edge
10 Enclosing cylinder
15 Basic band
15a outer peripheral surface
17 Reinforcement piece
17a exterior
18 One edge
19 Other edge
20 Stop ring
24 Pipe end insertion space
25 Inner surface
27 Medium diameter part
28 Large diameter part
29 Tip opening small diameter part
35 Taper hole
38 Ridge
46 Locking claw
47 Locking groove
47a Tip side
51 slit
52 Small diameter outer periphery
53 Guide ring
54 Large diameter lip
55 Small diameter lip
59 Guide taper part R Corner part W ₁₅ Uniform width dimension

Claims (3)

A joint body (2) having an insertion cylinder part (3) to be inserted into the end part (1a) of the pipe (1) to be connected, and the pipe end part (1a) externally fitted to the insertion cylinder part (3) C-shaped clamp ring (5) with a slit (51) for elastically tightening), and the pipe end insertion space ( 24) an enclosing cylinder (10) forming a pipe joint,
The pipe end (1a) is formed with a tapered hole (35) that gradually decreases in diameter at the front end side of the surrounding cylinder (10), and the clamp ring (5) is elastically tightened. When it is moved in the distal direction that is pulled out together with the clamp ring (5), it is pressed in the distal direction, pressed against the tapered hole (35) of the surrounding cylinder (10), and reduced in diameter, A pipe joint comprising a synthetic resin C-shaped stop ring (20) having a locking claw (46) that bites into the outer peripheral surface of the pipe end (1a).   On the outer peripheral surface of the insertion tube portion (3), a locking groove (47) having a distal end side surface (47a) orthogonal to the axis is formed, and the outer peripheral surface of the pipe end portion (1a). The axial direction position of the said locking claw (46) of the said stop ring (20) which entrapped in and the axial direction position of the said locking groove (47) are arrange | positioned so that it may correspond. The described pipe joint. On the outer peripheral surface of the insertion tube portion (3), a single locking concave groove (47) having a distal end side surface (47a) orthogonal to the axis is formed wide, and the stop ring ( A plurality of the locking claws (46) of 20) are provided, and the axial direction of the plurality of the locking claws (46) of the stop ring (20) biting into the outer peripheral surface of the pipe end (1a) The pipe joint according to claim 1, wherein the position corresponds to the width dimension (W ₄₇ ) of the wide locking groove (47).

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