JP5584378B1 - Pipe fitting - Google Patents

Abstract

To provide a pipe joint that exhibits a large pull-out resistance, is easy to manufacture, and can reduce costs.
A pipe gripping member 20 having a plurality of projecting pieces 21 is provided. The gripping member 20 has an inner protrusion 15 for pipe removal on the inner peripheral surface, and the outer peripheral surface is expanded outward. As the diameter tapered surface, there are a plurality of outer protrusions inclined outward. The outer protrusion of the gripping member 20 is locked to the inner protrusion of the drawing ring 24 inside the cap nut 2 to prevent the pipe from being pulled out.
[Selection] Figure 2

Description

  The present invention relates to a pipe joint.

Applicants have filed patent applications in the past for pipe joints such as those shown in FIG. 20, FIG. 21 and FIG. 22, mainly for connecting pipes made of plastic pipes. It has gained popularity all over the world (see Patent Document 1).
This pipe joint has a joint body 42 having an insertion tube portion 50, and the end portion of the plastic pipe 41 inserted while being fitted on the insertion tube portion 50 is tightened with a strong elastic tightening force. A fastening ring 43 with a slit 60 is provided. Then, in the state where the pipe is not inserted, a diameter-enlarging piece that is removably inserted into the slit 60 and held so as to expand the diameter of the clamping ring 43 against the strong elastic force of the clamping ring 43 ( Jump pin) 44.

  The diameter-expanded piece (jump pin) 44 and the tightening ring 43 are formed in advance in the subunit U as shown in FIGS. 21 and 22 (in the manufacturing factory) as shown in FIG. Assembled. When the pipe 41 is inserted from the direction of arrow A in FIG. 20, the tip of the pipe 41 comes into contact with the sensing inner diameter direction protrusion 44A of the diameter-enlarging piece 44, and the diameter-enlarging piece 44 is detached from the tightening ring 43. . Immediately due to this separation, a powerful tightening force in the diameter-reducing direction of the tightening ring 43 acts on the pipe 41, and the inner peripheral surface of the pipe 41 is pressed against the insertion tube portion 50 of the joint body 42, The pipe 41 cannot be pulled out by frictional force. In addition, the O-rings 45 and 45 can provide sealing performance.

Japanese Patent No. 3843288

  Although the pipe joints shown in FIGS. 20 to 22 described above are pipe joints having a stable and large pull-out force and high reliability, they have the following problems. (i) The tightening ring 43 is made of spring steel and has a structure that must exert a strong elastic tightening force. Therefore, as shown in FIG. 21 and FIG. (Ii) Before the sub unit U is assembled to the joint body 42 (as shown in FIG. 20), the diameter-expanded piece (jump pin) 44 is unexpectedly (Iii) The tightening ring 43 has a strong elastic force to the pipe 41 inserted with the enlarged diameter piece 44 detached. When tightened, it is required to generate a perfect circular shape and uniform clamping surface pressure over the entire 360 ° circumference. However, since such a uniform tightening surface pressure cannot be obtained, the width dimension of the spring steel must be changed from the slit 60 toward the circumferential direction, (Iv) In addition, in order to reduce the overall size of the joint, there is a restriction on the maximum width of the tightening ring 43. (V) The cost is high because the manufacturing is not easy as described above.

  Therefore, the present invention solves these problems (i) to (v), is easy to manufacture and can be reduced in cost, can exhibit a high pipe pull-out resistance, and can be used after pipe connection is completed. An object of the present invention is to provide a pipe joint that hardly moves in the pulling direction and always exhibits a stable and large pull-out force (prevention force).

  The present invention relates to a pipe joint comprising a joint body, a cap nut, and a pipe gripping member disposed inside the cap nut; the pipe gripping member contacts the end face of the pipe to be inserted. A closed annular base having a pipe contact portion that is in contact with and receiving a pressing force, and a plurality of cross-section arc-shaped protrusions extending outward from the closed annular base through a slit, and integrally having An internal protrusion for retaining that can bite into the outer peripheral surface of the pipe is formed on the inner peripheral surface side of the projecting piece, and the entire outer peripheral surface of the plurality of projecting pieces is formed as an outwardly enlarged taper surface. Molded integrally with plastic so as to have a plurality of locking outer protrusions on the outer peripheral surface side of the piece; and the outer side corresponding to the outer diameter-expanded taper surface of the entire outer peripheral surface of the plurality of the protruding pieces An aperture having an enlarged taper surface on the inner peripheral surface and an inner protrusion that can be engaged with the outer protrusion for locking. The ring, by fitted, a configuration in which is interposed between the ring and the inner surface and the pipe gripping member of the cap nut.

Further, a taper surface that shrinks outward is formed on the inner peripheral surface of the cap nut; an outer contraction taper surface that fits the taper surface of the cap nut is formed on the outer peripheral surface of the C-ring. Yes.
Moreover, the said ring is a C type | mold which has one place cut | disconnection in the circumference.
Alternatively, the ring integrally includes an inner end portion of the closed annular ring and a plurality of extending pieces having a cross-sectional arc shape extending outward from the inner end portion through a slit.
Further, the plurality of slits are composed of a plurality of narrow slits and one wide slit, and constitutes a part of the inner end of the closed ring, and the inner wall of the wide slit is connected to the ring. It was formed into a thin-walled piece that can be deformed when the drawing force is generated.
In addition, an elastic holding piece is integrally provided at the inner end of the ring to hold the position where the ring is moved minutely outward together with the pipe gripping member as the pipe is pulled out.
Further, the inclination angle of the tapered surface of the inner peripheral surface of the cap nut and the tapered surface of the outer peripheral surface of the ring is θ ₂ ; the outwardly enlarged taper surface of the inner peripheral surface of the ring, and a plurality of the protrusions When the gradient angle of the outwardly enlarged taper surface of the entire outer peripheral surface of the piece is θ ₁ ; θ ₁ <θ ₂ was set.

  According to the pipe joint according to the present invention, all the components can be made of plastic, and each component can be easily mass-produced and can be manufactured easily and inexpensively. The pipe joint and the pipe hardly move relatively in the axial direction (axial direction) and are strongly connected. In particular, it exerts a strong pull-out resistance against a plastic pipe or a composite pipe having a plastic outer peripheral layer.

It is sectional drawing of the pipe unconnected state which shows one Embodiment of this invention. It is sectional drawing of a pipe connection completion state. It is sectional drawing explaining the state which the pipe received the strong external force and carried out micro extraction. It is a side view which shows an example of a pipe holding member. It is a rear view of a pipe holding member. It is a front view of a pipe holding member. FIG. 6 is a YY sectional view of FIG. 5. It is a perspective view of a pipe holding member. It is a perspective view of a pipe holding member. It is explanatory drawing of the angle relationship of main components. It is a perspective view which shows an example of a ring. It is a perspective view of the other example of a ring. It is the perspective view which looked at the other example of the ring from another diagonal direction. It is a figure which shows the other example of a ring, Comprising: (A) is a front view, (B) is a side view. It is a perspective view which shows another example of a ring. It is the perspective view which looked at another example of a ring from another diagonal direction. It is a figure which shows another example of a ring, (A) is a front view, (B) is a side view. It is principal part expanded sectional explanatory drawing. It is principal part expanded sectional explanatory drawing. It is sectional drawing of the unconnected state which shows a prior art example. It is a front view which shows main parts. FIG. 22 is a sectional view taken along line BB in FIG.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
In the pipe unconnected state of FIG. 1 and the pipe connection completed state of FIG. 2, P is a pipe having at least an outer peripheral surface made of plastic, and as this pipe P, a plastic pipe (resin pipe), or A composite type resin pipe (composite pipe) having a metal layer such as aluminum inside is preferable.
Examples of the plastic used for the pipe P include cross-linked polyethylene. Reference numeral 1 denotes a joint body, and 2 denotes a cap nut.

The joint main body 1 includes an insertion cylinder portion 3 inserted into the end portion of the pipe P, a fixed cylinder portion 4 connected to the proximal end of the insertion cylinder portion 3, and a proximal end of the fixation cylinder portion 4. It is composed of a hexagonal protruding ridge portion 5, a male screw cylinder portion 6, and an outer envelope cylinder portion 7 with a male screw 7 </ b> A that is fixedly integrated with the fixing cylinder portion 4 in an outer fitting manner. Further, the joint body 1 has a hole 11 penetrating along the axis L _1, and the inner diameter of the hole 11 is set slightly small in the vicinity of the insertion tube portion 3.
Two concave circumferential grooves 8 and 8 are formed on the outer peripheral surface of the insertion cylinder portion 3, and an O-ring 9 is fitted into the concave circumferential groove 8 so as to be intimately sealed with the inner peripheral surface of the pipe P. (See FIG. 2).

A stepped portion (step surface portion) 13 is formed on the inner peripheral surface of the outer tube portion 7 at the same axial position as the stepped portion (step surface portion) 12 of the fixed tube portion 4 and the insertion tube portion 3. A space portion C having the attachment portions 12 and 13 as the bottom surface is formed between the inner peripheral surface of the screwed cap nut 2 and outer tube portion 7 and the outer peripheral surface of the insertion tube portion 3.
The cap nut 2 has, on its inner peripheral surface, a female screw 2A at the base end, a tapered surface 2B having a diameter reduced outward, and an inner flange portion 2C (forming an open end) from the inner side to the outer side. We have sequentially toward.
In the description of the present invention, “inward” and “outward” refer to “inward / outward in the axial direction” along the axis L ₁ unless otherwise specified. The direction in which the cap nut 2 is present when viewed from the center of gravity position is referred to as “outward”.

A pipe gripping member 20 is disposed in the space C, and a throttle ring 24 assembled to the pipe gripping member 20 in an outer fitting manner is also provided in the space C. ing. In other words, the throttle ring 24 and the pipe gripping member 20 are disposed inside the cap nut 2.
The radially outer ring 24 has an outer diameter-reduced tapered surface 26 that fits with the tapered surface 2B of the cap nut 2 on the outer peripheral surface 25 thereof.
An example of the throttle ring 24 shown in FIG. 11 is a C-type with a single cut 28 in the circumference--C-ring ---- the pipe is not connected (FIG. 1) and the pipe is connected. In FIG. 2, the inner end surface 27 is in contact with the outer end surface 7 </ b> B of the outer packet cylinder portion 7. In addition, the ring 24 has an outer diameter-expanded tapered surface 29 on the inner peripheral surface, and the outer diameter-expanded tapered surface 29 has a plurality of (independent) inner protrusions 30 inclined inward. (See Figure 10 and Figure 11.)

Next, the pipe gripping member 20 will be described in detail with reference to FIGS. 4 to 9 and FIGS. The pipe gripping member 20 has a closed annular base portion 22 having a pipe contact portion 22A that receives the pushing force F when the end face 18 of the inserted pipe P abuts (as shown in FIGS. 1 to 2). In this example, the pipe contact portion 22A is constituted by three projecting pieces projecting radially inward. The projecting piece portion can be freely increased and decreased, and if desired, the pipe contact portion 22A may be formed as an inner flange shape (inner collar shape) over a circumference of 360 ° (not shown).
Further, the pipe gripping member 20 has a plurality of projecting pieces 21 (circular cross-sectional arc shape) extending outward from the closed annular base 22 through a plurality of axial slits S. The plurality of projecting pieces 21 and the closed ring base 22 are integrally formed of plastic. On the inner peripheral surface side of the projecting piece 21, there is a retaining inner protrusion 15 that can bite into the outer peripheral surface 14 of the pipe P.

  The entire outer peripheral surface 36 formed by the entirety of the plurality of protruding pieces 21 has an outward diameter-expanding taper shape. That is, the outwardly enlarged diameter tapered surface 16 is formed. In addition, a plurality of locking outer protrusions 17 are formed on the outer peripheral surface side of each protruding piece 21. As shown in FIG. 4 to FIG. 9, it is a shape that can be easily molded integrally with plastic. Although the number of the projecting pieces 21 is 9 in FIGS. 5 to 9, the number of the projecting pieces 21 can be increased or decreased freely within the range of 3 to 12. Further, each protruding piece 21 has a shape in which the thickness dimension increases at least from the axial direction intermediate portion to the outside.

Then, in correspondence with the outer diameter-expanded taper surface 16 of the entire outer peripheral surface 36 of the plurality of projecting pieces 21, a drawing ring having an outer diameter-expanded taper surface 29 on the inner peripheral surface (as shown in FIG. 10). 24 is fitted onto the pipe gripping member 20. That is, the ring 24 is assembled with being interposed between the inner surface of the cap nut 2 and the pipe gripping member 20.
Since the ring 24 has an independent inner ridge 30 that can be engaged with the outer ridge 17 for locking the pipe gripping member 20, the diameters of the parts are mutually reduced as shown in FIGS. 10, 1, and 2. A force in the direction (drawing force) is applied to the outer peripheral surface of the pipe P to exert a strong pull-out resistance. In addition, a tapered surface 2B that is reduced in diameter outward is formed on the inner peripheral surface of the cap nut 2, and an outer reduced diameter tapered surface that is fitted to the tapered surface 2B is provided on the outer peripheral surface 25 of the ring 24. Since 26 is formed, a stronger pull-out resistance can be exhibited.

Next, another embodiment shown in FIGS. 12 to 14 and another embodiment shown in FIGS. 15 to 17 will be described. The configuration of the diaphragm ring 24 is different from that of FIG. It has the following features.
That is, the ring 24 shown in FIGS. 12 to 17 has a closed annular inner end 51, and the cut of the C ring of FIG. 11 is connected, and there is no cut. The ring 24 shown in FIGS. 12 to 17 has a plurality of (pieces) of extended pieces 52 extended outward from the inner end 51 of the closed ring via the slit S _24. And have one. The stretched piece 52 has a circular cross section.

Then, in the embodiment shown in FIGS. 12 to 14, a plurality of slits S ₂₄ are a plurality of narrow slits S _N, and, from one wide slit S _W, is constructed. Further, some of閉円endocyclic end 51, are formed with a rear wall 53 of the wide slit S _W, the inner wall portion 53, when the diaphragm force generation of the ring 24,閉円The inner end of the ring is formed in a deformable thin piece so that the diameter thereof is reduced. That is, the thin-walled back wall 53 is bent and deformed into a small dogleg shape or a small U-shape. The functional thin piece of meat-like inner wall portion 53, as shown by arrows 54 and 55 in FIG. 13 (A), the located shift the axial opposite directions in wide slit S _W, to prevent so-called torsional deformation have.

Then, Te is at the another embodiment shown in FIGS. 15 to 17, the slit S ₂₄ has only narrow slits S _N, are a plurality of arranged at equal pitches in the circumferential direction. In this way, the plurality of extending pieces 52 having a circular arc cross section are equally arranged with the same shape and the same dimensions.
The ring 24 having the shape (configuration) as shown in FIGS. 12 to 14 and FIGS. 15 to 17 is similar to the C-shaped ring 24 illustrated in FIG. As shown, the pipe gripping member 20 is assembled in an outer fitting manner and is provided in the inner space C of the cap nut 2. A plurality of extending pieces 52 form an outwardly reduced diameter tapered surface 26 and is fitted to the tapered surface 2 </ b> B of the cap nut 2. Further, the outer diameter-expanded tapered surface 29 is formed as a whole with the inner surfaces of the plurality of extending pieces 52. Further, the inner protrusion 30 is configured by the entire inner surface of the plurality of extending pieces 52. That is, in FIG. 11, the independent inner ridge 30 is continuous over approximately 360 °, but in FIGS. 12 to 17, the same independent inner ridge is formed as a whole while being divided by the slit S ₂₄ .

12 to 17, a plurality of extending pieces 52 extending outward from the closed annular inner end 51 through the closed annular inner end 51 and a plurality of axial slits S ₂₄ will be described. Is formed integrally with plastic, and each of the stretched pieces 52 can be elastically deformed (oscillated) in the radial direction independently, and with respect to the outer ridge 17 located in the radial inward position, Even if the ridges 30 of the extended piece 52 are not sufficiently engaged with each other, the remaining extended piece 52 (independently deforming radially inward) against the outer ridge 17 (on the inner surface) ) The ridges 30 are securely engaged (engaged).
The plurality of extending pieces 52 as a whole form an outer diameter-expanded tapered surface 29 on the inner peripheral surface, and the ridge (which forms an independent annular ridge 30 that is not helical) is It is formed corresponding to the outer diameter-expanded tapered surface 29.
Further, an outer diameter-reduced tapered surface 26 is formed on the outer peripheral surface of the plurality of extending pieces 52 as a whole.

In FIGS. 12 to 14, the inner wall portion 53 of the wide slit S _W is under use state of FIG. 3, although variant, the inner wall portion 56 corresponding to the (rest of the) narrow slits S _N (somewhat meat It is not necessary to deform (as thickness) (however, it may be slightly deformable). On the other hand, all the slits S _{24 in} the case of FIGS. 15 to 17 are narrow slits _SN , but the wall 56 is formed to have a small thickness so as to be deformed (under the use state of FIG. 3). Thus, it is desirable to enable the diameter reduction of the inner end 51 of the closed ring.
12 to 17 exemplify the case where the number of stretched pieces 52 is nine. This can be increased or decreased freely within the range of 3 to 12. Further, as shown in FIG. 10, the longitudinal cross-sectional shape of each stretched piece 52 is a shape in which the thickness dimension decreases from the middle to the outside in the axial direction.

  By the way, there may be a case where a large pulling force (unexpected) exceeding the normal pulling force is applied to the pipe P. At that time, as shown in FIGS. Move to a small dimension. When this is called minute pull-out movement, the inner end 37 of the ring 24 holds the position where the ring 24 is minutely moved outward together with the pipe gripping member 20 along with the minute pull-out movement of the pipe P. Thus, a plurality of elastic holding pieces 38 for preventing the return to the direction opposite to the arrow Z--inward-- are integrally provided (FIGS. 1 to 3 and FIG. 10). , FIG. 11, FIG. 12 to FIG. 17, FIG. 18, FIG. 19).

11 and 12 to 17 exemplify the three elastic holding pieces 38, but it is also possible to use two or four or more. Moreover, the elastic holding piece 38 has an arc shape substantially equal to the inner diameter dimension of the transverse cross-section ring 24, and the wall thickness is large at the proximal end, and gradually decreases from the intermediate section to the distal end. Thin and uniform. Thereby, even if the elastic holding piece 38 is small, it exerts a large elastic force.
And the notch part 39 is formed in the corner | angular part of the outer end surface 7B and inner peripheral surface of the outer envelope cylinder part 7. FIG. As shown in FIGS. 18 and 19, the cutout portion 39 has a two-step shape including a first stepped portion 39A and a second stepped portion 39B. In other words, the notch 39 has a back side (inward) small-diameter portion 39C and an external large-diameter portion 39D. The first stepped portion 39A forms the small-diameter portion 39C, and A large diameter portion 39D is formed by the two-stepped portion 39B.

  In the state of FIGS. 1 and 2, as shown in FIG. 18, the inner end 37 abuts the outer end surface 7B of the outer tube 7 and the elastic holding piece 38 is radially inward (from the free state). In a state of being elastically deformed, the small diameter portion 39C is invaded. Thereafter, when an excessive pulling force is applied in the arrow Z direction, as shown in FIGS. 3 and 19, the gripping member 20 and the ring 24 together with the pipe P cause a slight pull-out movement in the Z direction. 19, the elastic holding piece 38 is restored in the direction of the arrow Y by its elastic force, fitted into the large diameter portion 39D of the notch 39, and the inner end of the elastic holding piece 38 is the second. Corresponds to (contacts) the stepped portion 39B. Therefore, even if an external force in the direction opposite to the arrow Z (arrow X direction) is applied to the pipe P after that, the state shown in FIGS. 3 and 19 is surely made stronger, that is, the ring 24 is stronger than FIG. As a result, the pipe gripping member 20 can hold the outer peripheral surface of the pipe P more strongly.

Considering the case where the elastic holding piece 38 and the notch 39 described above of the present invention do not exist, when an excessive external force in the direction of the arrow Z acts on the pipe P, it becomes from FIG. 2 to FIG. When the pipe P is made of plastic, the biting concave portion of the inner protrusion 15 for retaining is permanently deformed by a very small amount due to a creep phenomenon.
Thereafter, when an inward force (in the direction of the arrow X) acts on the pipe P, the state is restored from the state shown in FIG. 3 to FIG. 2, and the ring 24 also moves inward (in the direction of the arrow X) to move the ring 24 and the tapered surface 2B. The pressure contact force at the gradient pressure contact portion is reduced, and the locking force (pull-out resistance) between the locking protrusion 15 and the outer peripheral surface of the pipe P is reduced, which may cause the pipe to be pulled out.
In the present invention, such a possibility of pulling out the pipe is prevented by the elastic holding piece 38 or the like (in any of FIGS. 11, 12 to 14, and 15 to 17). In addition, the shape of the notch 39 is not limited to the illustrated embodiment, and the inner end of the elastic holding piece 38 is connected to the outer end face of the outer envelope cylinder 7 under the state of FIGS. It is also free to configure so as to contact 7B.

10 and 1, the gradient angle between the tapered surface 2B of the inner peripheral surface of the cap nut 2 and the tapered surface 26 of the outer peripheral surface 25 of the ring 24 is θ ₂ ; When the inclination angle of the outer diameter-expanded taper surface 16 of the entire outer peripheral surface formed by the outer diameter-expanded taper surface 29 of the peripheral surface and the plurality of projecting pieces 21 of the pipe gripping member 20 is θ ₁ ; Θ ₁ <θ ₂ was set.
For example, 3 ° ≦ θ ₁ ≦ 7 ° and 8 ° ≦ θ ₂ ≦ 12 °. In particular, by setting 4 ° ≦ θ ₁ ≦ 6 °, the pipe gripping member 20 can be pushed lightly even if the pipe pushing force F (see FIG. 2) of the operator is small, and tightening in the radial inward direction. The force increases, and a strong pull-out force can be obtained, and the pipe connection work can be done easily and quickly.
As the above-mentioned pipe pushing force F, a worker's normal force of about 15 kg to 25 kg is sufficient. In the pipe gripping member 20, the outer diameter-expanding tapered surface 16 may be formed over the entire length in the axial direction of the projecting piece 21, but as shown in the figure, It is desirable to form it only in the portion where it is disposed and to make the others cylindrical (straight).

Hereinafter, additional description will be given with respect to the illustrated embodiment (although some explanations overlap).
In the space C inside the pipe joint, the pipe gripping member 20 and the ring 24 are assembled inside and outside in the radial direction as shown in FIGS. In the pipe gripping member 20, the inner protrusion 15 for retaining the inner surface of the projecting piece 21, such as a badminton blade, spaced from the closed annular base 22 by a plurality of sheets, is preferably A plurality of independent ridges formed on the virtual inner peripheral surface including the projecting pieces 21 are arcuately divided by the slits S. It is desirable that the ridge 15 has an inhomogeneous triangular shape (in cross section) inclined inward. Furthermore, it is desirable that the locking outer ridge 17 on the outer surface of the projecting piece 21 has an unequal triangular shape that is inclined outward (transverse section). The inner protrusion 30 of the ring 24 has an inhomogeneous triangular shape that is inclined inward (cross section). As is clear from FIGS. 1 to 3, the size of the unequal triangular triangle in the cross section of the inner protrusion 15 for retaining is made larger, and the outer outer protrusion 17 and the inner protrusion 30 are made smaller. To do. That is, in order to bite into the outer peripheral surface of the pipe P and to exert a strong pulling resistance, the cross section of the inner protrusion 15 for retaining is made large, and the outer protrusion 17 and the inner protrusion 30 are engaged with each other ( It is desirable to make the cross-section small to make the crossover at the time of engagement) smooth, and to cross over a small jagged unequal triangular mountain. (Note that in FIGS. 10 and 11, the inner protrusion 30 and the outer protrusion 17 are drawn large, but it is preferable that the inner protrusion 30 and the outer protrusion 17 be sufficiently smaller than this drawing.)

The inserted pipe P comes into contact with the pipe contact portion 22A projecting radially inward from the closed annular base portion 22, and the pipe gripping member 20 is dragged by the pushing force F as shown in FIG. The outer protrusion 17 has passed over the small inner protrusion 30 (described above), and the state shown in FIGS. 1 to 2 is obtained. Since the slits S are separated into a plurality of (sheets) projecting pieces 21 and the projecting pieces 21 are easily elastically deformed inward and outward at the inner end portion, the inserted pipe P is eccentric, Even when it is not a true circle, it can be inserted smoothly and flexibly, and the outer protrusion 17 can be smoothly passed over the inner protrusion 30.
Further, the locking outer ridge 17 is inclined outward, the independent inner ridge 30 is inclined inward, and both are formed small (as a small cross-sectional area triangle). When the operator grips the pipe P with his / her hand to give the pushing force F, the pipe gripping member 20 and the pipe P can be inserted lightly together, and the protrusion 21 is prevented by elastic deformation in the radial inward direction. The inner ridge 15 bites into the plastic outer surface of the pipe P and exhibits a strong pull-out resistance. As shown in FIGS. 1 and 2, the ring 24 (in principle) is in pressure contact with the tapered surface 2B of the cap nut 2 and is in pressure contact with the outer end surface 7B of the outer tube portion 7. It remains stationary (fixed). That is, when a normal pulling force is applied to the pipe P, the pipe joint of the present invention has the advantage that the pipe P does not move at all in a stationary state (fixed) in the connection completion state of FIG.

However, depending on the case, it is assumed that an excessive pulling force acts on the pipe P when an earthquake occurs or some accident occurs. When such an excessive pulling force is applied, the pipe P, the pipe gripping member 20 and the ring 24 are integrated with each other by the interlocking of the protrusions 15, 17 and 30 in the direction of arrow Z (outward) in FIG. 11, the ring 24 having the cut 28 shown in FIG. 11 is squeezed while the tapered surface 26 strongly presses against the tapered surface 2 </ b> B of the cap nut 2. The interlocking force increases rapidly, and the pipe P is securely held (gripped) and cannot be pulled out any further. In particular, as described with reference to FIG. 10, since θ ₂ > θ ₁ is set, if the ring 24 moves slightly outward, the above-mentioned mutual locking force increases, and strong pipe pull-out resistance Demonstrate power.

  The structure and shape of the pipe joint according to the present invention (except for the O-rings 9 and 9) can be made of plastic and have a structure and shape, and as shown in FIG. The strong elastic clamping force (elastic force) described with reference to FIGS. 21 and 22 does not act between the components, and the operator can perform the assembly work very easily. Moreover, there is no danger of one of the parts popping out.

By the way, the shape of the joint body 1 (excluding the outer tube 7) of the embodiment of the present invention shown in FIGS. 1, 2 and 3 is exactly the same as that of the joint body 42 shown in FIG. Therefore, there is an advantage that the injection mold can be shared as it is.
The pipe P applied to the present invention may be a whole plastic pipe or a composite plastic pipe having a metal reinforcing layer inside.

  Next, in the piping work site, the tip surface 18 of the pipe P may be cut obliquely (not in a shape orthogonal to the axial center). Considering the case where the pipe gripping member 20 shown in FIGS. 5 to 9 is a C-shaped ring (C-ring), the tip surface 18 that is obliquely cut is directly connected to the C-ring having the cut. Assuming the case where the C-ring is pushed in contact with each other, the mutual position in the axial direction of both ends of the C-ring breaks slightly shifts inward and outward --- twisting --- The outer ridge 17 of the C ring is deformed in a slightly spiraling direction and cannot be accurately locked to the independent inner ridge 30 of the ring 24. As described above, if the both protrusions 17 and 30 are not accurately locked, when the pipe pulling force is applied, slipping occurs between the both protrusions 17 and 30 (both tapered surfaces 16 and 29). A problem that the pull-out force decreases is predicted.

  In the present invention, since the above-mentioned obliquely cut distal end surface 18 abuts the closed annular base portion 22 having the pipe contact portion 22A, the base portion 22 maintains the axial orthogonal plane posture, The strip 17 and the independent inner projection 30 are accurately locked to each other. Further, by having the plurality of protrusions 21, the pipe gripping member 20 can be smoothly reduced in diameter while maintaining a normal posture, and the protrusions 15 bite into the outer peripheral surface 14 of the pipe P evenly by 360 °.

As described above, the present invention is a pipe joint comprising a joint body 1, a cap nut 2, and a pipe gripping member 20 disposed inside the cap nut 2; Is extended outward from the closed annular base 22 through the slit S, and a closed annular base 22 having a pipe contact portion 22A that receives the pushing force F when the end face 18 of the inserted pipe P abuts. And a plurality of arc-shaped projecting pieces 21 having a cross-sectional arc shape, and a retaining inner protrusion 15 that can bite into the pipe outer peripheral surface 14 is formed on the inner peripheral surface side of the projecting piece 21, and The entire outer peripheral surface 36 of the plurality of projecting pieces 21 is formed as an outward-diameter taper surface 16, and is integrally molded with plastic so that there are a plurality of locking outer protrusions 17 on the outer peripheral surface side of the projecting piece 21. Moreover, an outer diameter-expanded taper surface 29 corresponding to the outer diameter-expanded taper surface 16 of the entire outer peripheral surface 36 of the plurality of projecting pieces 21 is used as the inner peripheral surface. In addition, a squeezing ring 24 having an inner ridge 30 that can be engaged with the locking outer ridge 17 is externally fitted, and the ring 24 is connected to the inner surface of the cap nut 2 and the pipe gripping member 20. Therefore, the problems (i) to (v) described in the conventional examples (FIGS. 20 to 22) can be solved, and the manufacturing is easy, and the danger in manufacturing Can be eliminated, and downsizing and cost reduction can be achieved. In particular, the pipe pull-out resistance is also great, and the pipe P does not move in the pull-out direction (outward) after the completion of the pipe connection, and exhibits a large pull-out resistance.
In particular, the pipe gripping member 20 is an integral molding of plastic and can be easily assembled into the space in the cap nut 2. Further, the pipe gripping member 20 does not twist when retracted inward, and the plurality of protruding pieces 21 are uniformly reduced in diameter and deformed with the outer protrusion 17 of the outer diameter-expanding tapered surface 16. The inner ridges 30 of the ring 24 are securely locked to each other, and the inner ridges 15 are evenly bited into the outer peripheral surface of the pipe P evenly.

Further, a taper surface 2B that is reduced outwardly is formed on the inner peripheral surface of the cap nut 2; an outer diameter-reduced taper that is fitted to the taper surface 2B of the cap nut 2 is formed on the outer peripheral surface 25 of the ring 24. Since the surface 26 is formed, when an excessive pulling force is applied to the pipe P in the event of an earthquake or an accident, the pipe P can be prevented from being pulled out with a strong pulling force.
Further, since the ring 24 is a C type having a single cut 28 on the circumference, there is an advantage that a simple mold can be used and it is easy to manufacture.
Further, the ring 24, the閉円ring inner end 51, and a plurality of cross-sectional arc-shaped draw piece 52 extends outwardly from the inner end portion 51 through the slit S _24, integrated Since each of the extending pieces 52 elastically swings independently, it is easy to accurately engage (engage) the outer protrusion 17 of the pipe gripping member 20. That is, even if the axial centers of the drawing ring 24 and the pipe gripping member 20 are inclined at a minute angle with each other, and the protrusion 30 and the outer protrusion 17 do not mesh with each other in some of the extending pieces 52, the remaining Since the extended piece 52 can engage with each other, it is possible to effectively prevent an accident in which the pipe gripping member 20 and the pipe P are slipped off (slip off).

Further, a plurality of the slits S ₂₄ are a plurality of narrow slits S _N and, consists one wide slit S _W, constitutes part of the閉円endocyclic end 51, the wide slit S _W of the inner wall portion 53, so it formed in the deformable thin piece shape upon squeezing force generation of the ring 24, when the C-shaped ring of the rear wall 53 of the wide slit S _W is omitted if, overall In some cases, twisting deformation may occur, and it is assumed that the ridge 30 does not mesh with the outer ridge 17 with high accuracy, whereas the inner end 51 of the closed ring is continuous by the thin-walled back wall 53. The twisting deformation can be prevented. In addition, the thin-walled back wall portion 53 is deformed, so that the entire ring 24 can be reliably elastically reduced in diameter.
In addition, an elastic holding piece portion 38 is integrally formed at the inner end of the ring 24 to hold the position where the ring 24 is moved minutely outward together with the pipe gripping member 20 as the pipe P is slightly pulled out. Because it is provided, excessive pulling force acts on the pipe P, and once the position where the pipe P, the gripping member 20 and the ring 24 have moved slightly is maintained as it is, the strong pulling resistance is maintained as it is. Can keep.

The gradient angle between the tapered surface 2B of the inner peripheral surface of the cap nut 2 and the tapered surface 26 of the outer peripheral surface 25 of the ring 24 is θ ₂ ; When the gradient angle of the outer diameter-expanded tapered surface 16 of the entire outer peripheral surface of the plurality of protruding pieces 21 is θ ₁ ; since θ ₁ <θ ₂ is set, the operator manually puts the pipe P inside If it is pushed inward, it can be inserted and inserted in the pipe joint with a relatively small force. On the other hand, when a large pulling force acts on the pipe P due to an earthquake or an accident after the connection is completed, a strong pulling force is generated by the large gradient angle θ ₂ .

1 Joint body 2 Cap nut 2B Tapered surface
14 Outer surface
15 Inner protrusion for retaining
16 Outward expansion taper surface
17 External protrusion
18 (front) end face
20 Pipe gripping member
21 Projection
22 End of closed ring
22A Pipe contact (projection piece)
24 Diaphragm ring
25 Outer surface
26 Tapered surface
28 cuts
30 Independent ridges
36 Outer surface
38 Elastic holding piece
51 End of closed ring
52 Stretched piece
53 Back wall F Pushing force P Pipe S, S ₂₄ slit S _N narrow slit S _W wide slit θ ₁ , θ ₂ Gradient angle

Claims (7)

In a pipe joint comprising a joint body (1), a cap nut (2), and a pipe gripping member (20) disposed inside the cap nut (2),
The pipe gripping member (20) includes a closed annular base (22) having a pipe contact portion (22A) that receives the pushing force (F) by abutting the end face (18) of the inserted pipe (P). And a plurality of cross-section arc-shaped projecting pieces (21) extending outward from the closed annular base (22) through the slit (S), and an outer peripheral surface of the pipe (14) The inner protrusion (15) for retaining that can be caught in the inner surface is formed on the inner peripheral surface side of the protruding piece (21), and the entire outer peripheral surface (36) of the plurality of protruding pieces (21) is outward. As the enlarged diameter tapered surface (16), integrally molded with plastic so as to have a plurality of locking outer protrusions (17) on the outer peripheral surface side of the protruding piece (21),
In addition, the inner peripheral surface has an outer diameter-expanded taper surface (29) corresponding to the outer diameter-expanded taper surface (16) of the entire outer peripheral surface (36) of the plurality of projecting pieces (21), and The squeezing ring (24) having the inner ridge (30) freely engageable with the locking outer ridge (17) is externally fitted, and the ring (24) is attached to the inner surface of the cap nut (2). And a pipe gripping member (20). A tapered surface (2B) is formed on the inner peripheral surface of the cap nut (2), the diameter of which decreases outward,
The pipe according to claim 1, wherein an outer peripheral surface (25) of the ring (24) is formed with an outer diameter-reduced tapered surface (26) that fits into the tapered surface (2B) of the cap nut (2). Fittings.   The pipe joint according to claim 1 or 2, wherein the ring (24) is a C type having a cut (28) at one place on the circumference. Said ring (24) is閉円ring inner end (51), a slit (S ₂₄₎ a plurality of cross-sectional arc-shaped draw piece that is stretched outwardly from the inner end (51) via the The pipe joint of Claim 1 or 2 which has (52) integrally. The plurality of slits (S ₂₄ ) includes a plurality of narrow slits (S _N ) and one wide slit (S _W ), and constitutes a part of the inner end (51) of the closed ring. The pipe joint according to claim 4, wherein the inner wall (53) of the wide slit (S _W ) is formed into a thin piece that can be deformed when the ring (24) generates a drawing force.   The inner end of the ring (24) is elastically held to hold the position where the ring (24) has moved minutely outward together with the pipe gripping member (20) as the pipe (P) is pulled out. The pipe joint according to claim 1 or 2, wherein the piece (38) is provided integrally. The gradient angle between the tapered surface (2B) of the inner peripheral surface of the cap nut (2) and the tapered surface (26) of the outer peripheral surface (25) of the ring (24) is (θ ₂ ),
The gradient angle of the outer diameter-expanded taper surface (29) of the inner peripheral surface of the ring (24) and the outer diameter-expanded taper surface (16) of the entire outer peripheral surface of the plurality of protruding pieces (21) is (θ ₁ )
The pipe joint according to claim ₂ , wherein θ ₁ <θ ₂ is set.

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