JP2015048865A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact and inexpensive pipe joint that exerts high resistance to extraction of a pipe.SOLUTION: A claw piece part 5 for being locked by being engaged into an outer peripheral surface of an inserted pipe P to be connected is molded integrally with a joint body 10, at an inner peripheral end 12 of an opening of a hole part 11 of the joint body 10 subjected to insertion of the pipe P to be connected.

Description

  The present invention relates to a pipe joint.

Conventionally, a flare joint has been widely used as a kind of pipe joint (for example, see Patent Document 1).
Generally, as shown in FIG. 10, a metal connected pipe 35 is provided between the tapered surface 31 of the male threaded joint body 30 and the tapered surface 34 of the cap nut 33 screwed onto the male thread 32 of the joint body 30. The flare end portion 37 formed by plastic processing of the end portion of the wire in a diameter-expanded taper shape is sandwiched to prevent the flare end portion 37, and is sealed by the pressure contact force.

However, it requires skill to form the flare end 37 at the end of the connected pipe 35 by plastic working, and such flare processing hinders the work efficiency improvement at the piping work site. was there.
Various pipe joints have been proposed to avoid these problems. For example, the present applicant once proposed a pipe joint (a retaining ring) as shown in FIGS. 11 and 12 (see Patent Document 2).
That is, the taper surface 38 is formed on the inner peripheral surface of the cap nut 33 screwed to the male screw 32 of the joint body 30A, and the outer surfaces of the plurality of spring pieces 41 of the retaining ring 39 are used as the taper surfaces 41A. The diameter of the spring piece portion 41 is reduced by sliding contact with the surface 38, and the engaging claw portion 40 at the tip of the spring piece portion 41 is bitten into the outer peripheral surface of the pipe 35 to prevent the spring piece portion 41 from being pulled out.

Japanese Patent Laid-Open No. 2005-42858 JP 2011-12755 A

  However, the pipe joint shown in FIGS. 11 and 12 has the following problems. (Additional explanation will be described later with reference to FIG. 4.) (i) Unless the retaining ring 39 is a large part, it is difficult to always maintain a normal posture, and it accurately bites into the outer peripheral surface of the pipe 35. (Ii) The retaining ring 39 is locked when the pipe 35 is pulled out slightly in the direction of arrow C so that the taper surfaces 41A and 38 are in sliding contact and the spring piece 41 is deformed in the reduced diameter direction. Since the claw portion 40 is configured to bite into the outer peripheral surface of the pipe 35, a large space portion 42 is required inside the pipe joint, the pipe joint becomes large, and the pipe joint and the pipe 35 move relatively in the axial direction. (iii) The cap nut 33 must strongly press the retaining ring 39 with its tapered surface 38, and therefore the wall thickness near the tapered surface 38 must be extremely large. (iv) (V) The number of parts is large and the cost is high. (Vi) Large length (axial dimension).

  Therefore, the present invention solves these problems, and the whole is compact and has an extremely large number of parts (although it is a pipe joint that does not require the flaring of the end of the connected pipe described above). The purpose of the present invention is to provide a pipe joint that exhibits a large pipe pull-out force and can exhibit a large anti-pull-out force at all times without the pipe moving at all in the pull-out direction after completion of pipe connection. To do.

In the present invention, a claw piece portion that bites into and engages with the outer peripheral surface of the inserted pipe to be connected to the inner peripheral end of the opening of the joint body into which the connected pipe is inserted is integrated with the joint body. Molded.
In addition, an annular groove is formed on an end surface of the joint body where the hole is opened, and an inner peripheral wall of the groove is constituted by a plurality of the claw pieces arranged in the circumferential direction via minute slits. Furthermore, the outer peripheral wall of the concave groove is constituted by a short-cylinder wall with an external thread that has an external thread portion on which the cap nut is screwed, and a taper having an inner peripheral tapered surface that is pushed into the concave groove. A ring nut and a cap nut that pushes the taper ring into the concave groove and bites the claw piece into the outer peripheral surface of the pipe are provided.

According to the pipe joint according to the present invention, the number of parts can be reduced, and the claw piece can always maintain a stable posture (even if it is downsized), and the posture is stable even when biting into the pipe. With high accuracy, the pull-out resistance of the pipe is stable and large.
Furthermore, at the piping work site, loss of small parts does not occur, and piping connection can be made quickly and easily.

Further, the claw piece portion and the taper ring can be reduced in size (according to claim 2), and exhibit a sufficiently large pipe pulling force. Furthermore, since the cap nut has only to apply a force to push the taper ring, the inner flange portion can be made thinner. Also, there is no wasted space inside the pipe joint, making it possible to make it more compact (downsizing). In particular, the overall length (axial dimension) of the pipe joint can be made smaller than before.
Furthermore, the external force that pushes the claw piece into the outer peripheral surface of the pipe (pressing radially inward) is not limited to the conventional cap nut, but the peripheral wall of the cap nut (of the groove) It is generated by a total of three members, that is, the outer peripheral wall and the taper ring, and each member works together, so that there is no waste and the overall compactness can be achieved reasonably.

It is sectional drawing which shows one Embodiment of this invention. It is a figure which shows a cap nut fastening completion state, Comprising: (A) is sectional drawing corresponding to FIG. 1, (B) is an effect | action explanatory drawing. It is a figure which shows the principal part of a coupling main body, Comprising: (A) is the figure seen from the axial center direction (axial direction), (B) is principal part sectional drawing. It is a figure for demonstrating the advantage (an effect | action and effect) of this invention in the comparison with a prior art example. It is sectional drawing of the state before the cap nut fastening which shows other embodiment of this invention. It is sectional drawing of a cap nut fastening completion state. It is sectional drawing of the state before the cap nut fastening which shows another embodiment of this invention. It is sectional drawing of a cap nut fastening completion state. It is the perspective view which showed the various specific examples of the whole pipe joint. It is sectional drawing which shows one prior art example. It is principal part sectional drawing which shows another prior art example. It is a perspective view of the component of the principal part used for another prior art example.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
1 to 4, an embodiment of the present invention is shown, P is a pipe to be connected, 2 is a pipe joint according to the present invention, and FIG. 1 and FIG. However, as a whole, various pipe joints 2 such as an elbow type in FIG. 9A, a cheese type in FIG. 9B, a socket type in FIG. The other end of FIG. 2 can be freely configured to have another structure such as a taper screw or a flange.

The pipe joint 2 includes a joint body 10 and a cap nut 20. The joint body 10 has a male thread portion 3 on the outer peripheral surface of the end portion thereof, and the female thread portion 21 of the cap nut 20 is Screwed in and out freely.
In the hole 11 as the flow path of the joint body 10, an insertion portion 11A is formed to have a slightly larger inner diameter dimension (than the inner portion) in the same length as the planned insertion depth of the pipe P or slightly longer. ing. The inner peripheral end 12 of the hole 11 of the joint body 10 is engaged with the outer peripheral surface of the connected pipe P in the inserted state as the cap nut 20 is screwed (not to be pulled out). A plurality of claw pieces 5 to be molded are integrally formed with the joint body 10. For example, the joint body 10 integrally having the claw piece 5 can be manufactured by the lost wax method, and the material is preferably stainless steel or the like.

A specific shape will be described. As shown in FIGS. 3A and 3B, FIG. 1 and the like, an annular groove is formed on the end surface 13 (in the axial direction) where the hole 11 of the joint body 10 opens (in the axial direction). 14 is formed. That is, the groove 14 is formed in the end face 13 so as to open outward (axially outward) along the axis L ₁₁ of the hole 11.
The inner peripheral wall 15 of the annular groove 14 (see FIG. 3) is constituted by a plurality of claw piece portions 5 arranged in the circumferential direction via minute slits 16. In other words, when viewed from the direction of the axis L ₁₁ (see FIG. 3A), the claw piece 5 is a short arc shape, and the entire claw piece 5 has a thin cylindrical shape. An inner peripheral wall 15 of the groove 14 is formed by the entire plurality of claw pieces 5 having a thin cylindrical shape.

The outer peripheral wall 17 of the concave groove 14 is constituted by a short cylindrical wall 18 having a male screw portion 3 to which a cap nut 20 is screwed on the outer peripheral surface (with a male screw).
The groove bottom surface 19 of the annular groove 14, in FIGS. 1 to 4, located in the axis-orthogonal on a plane orthogonal to the axis L _11, by a predetermined small size from the end face 13 (e.g., 3 mm to 10 mm) joint Present inside the main body 10.
Further, non-clamping state (Fig. 1, Fig. 3) of the cap nut 20 in the outer peripheral surface of the inner peripheral wall 15 parallel to appear the axis L _11, parallel to the inner peripheral surface is also the axis L ₁₁ of the outer peripheral wall 17 appear. That is, the outer peripheral surface of the inner peripheral wall 15 and the inner peripheral surface of the outer peripheral wall 17 are formed as a cylindrical surface having the central axis L ₁₁ as the central axis, and the concave groove 14 is a longitudinal section in FIGS. 1 and 3B. The surface shape is rectangular.

Reference numeral 7 denotes a (closed) closed annular taper ring having an inner peripheral tapered surface 8 and entering the concave groove 14 while being pressed by the inner flange portion 22 of the cap nut 20. Then, the engaging claw 5A at the tip (outer end) of the claw piece 5 is bitten into the outer peripheral surface of the pipe P (see FIGS. 2 and 4).
Sectional shape of the taper ring 7, in the embodiment of FIGS. 1-4, a parallel outer periphery 7A is a axis L _11, inner end surface 7B, the outer end surface 7C is the axis orthogonal plane. The inner peripheral taper surface 8 is a sloped surface that decreases outward, and the taper ring 7 is an annular body that acts as a wedge.
Reference numeral 23 denotes a sealing material such as an O-ring, which seals the pipe insertion portion 11A of the hole 11 and the outer peripheral surface of the pipe tip.

1 to 4, the axial direction dimension of the taper ring 7 is set larger than the depth dimension of the concave groove 14 by a small dimension (for example, 1 mm to 7 mm).
When the cap nut 20 is rotated with the work tool from the state of FIG. 1, the inner surface of the inner flange portion 22 of the cap nut 20 is pressed while being in sliding contact with the outer surface of the taper ring 7, and the taper ring 7 The circumferential taper surface 8 enters the concave groove 14 while pressing in the direction in which the locking claw 5A of the claw piece 5 is reduced in diameter (from FIG. 1), and the cap nut is tightened (completed) in FIG. Pipe connection work is completed quickly.

By the way, in FIG. 2 (B) and FIG. 4, the force (vector) which presses the nail | claw piece part 5 to radial inner direction (diameter-reduction direction) is demonstrated. In the present invention, a portion indicated by dots in FIG. 4A is a portion that presses the nail piece 5 and generates nail biting force (vector) Fp. That is, as will be apparent from the combination of FIG. 4 and FIG. 2B, the cylindrical portion 20A of the cap nut 20, the outer peripheral wall 17 of the joint body 10, and the diameter reduction direction of the taper ring 7 are shown. A total vector of the vectors F ₂₀ , F ₁₇ , and F ₇ acts on the claw piece portion 5 to strongly bite into the outer peripheral surface of the pipe P as a claw biting force (vector) Fp. Moreover, as indicated by an arrow G in FIG. 4, the joint end face 13 of the body 10 (the axis L ₁₁ direction) in a substantially inward location than the position, the claw diet write force shown with a dotted (vector) Fp There is a site of occurrence.
Specifically, in the embodiment shown in FIGS. 1 to 4, the nail biting force (Fp) is generated at the axial center position of the taper ring 7 having a short axial direction (thickness) dimension. It can be said that.

FIG. 4B is a cross-sectional (descriptive) view of the main part showing the operation and configuration of the conventional example of FIGS. 11 and 12 in order to compare the operation and effects of the present invention. In FIG. 4 (B), the part shown with dots is a part that presses the spring piece 41 and generates a force (vector) Fp that the claw 40 bites into the outer peripheral surface of the pipe P (35). . That is, the spring piece portion 41 in only the cap nut 33 is urged into the vector F _33, causes Tsumeshoku write power to the claw portion 40 (vector) Fp. Therefore, in order to give the vector F ₃₃ , the cap nut 33 needs a cap nut reduced diameter thick portion 43 having a large cross-sectional area on the outer side indicated by the arrow K.
Moreover, in FIGS. 4B and 11, the retaining ring 39 is pulled out in the direction of the arrow C by a predetermined dimension T, and the spring piece 41 is deformed in the reduced diameter direction so that the locking claw 40 is connected to the pipe 35. Therefore, a large space 42 is required between the tip of the joint body 30A and the inside of the cap nut 33, and the cap nut 33 must be enlarged.

4A and 4B, when compared with the projection of the small dimension L _{20 in} the present invention from the end face 13 of the joint body 10, 30A (see FIG. 4A), it is conventional. example FIG. 4 (B) the large dimension L ₃₃ minutes protrudes, the difference [Delta] L ₁ is said to significantly greater.
In other words, in FIG. 4 (B) showing the conventional example, a large cap nut reduced diameter thick portion 43 exists in the direction of the arrow K, whereas in FIG. 4 (A) of the present invention, the cap nut 20 There is only a small thickness (in the direction of the arrow K) of the thickness of the inner flange portion 22 and the non-intruding portion of the taper ring 7, and the difference ΔL ₁ is made compact by the present invention, and FIG. ) (B) (C) As a whole, it can be seen that the contribution of the downsizing is significant.
4A and 4B, the pipe insertion portion 11A can be reduced by the axial dimension ΔL _{2 in the} present invention. That is, in FIG. 4 (B), nail biting is not started until the pipe P (35) is slightly pulled out in the direction of the arrow (C), whereas in the present invention (FIG. 4 (A)), the cap nut Claw biting is completed at the same time as tightening (screwing) of 20 is completed, and there is no pipe pull-out movement.

Next, another embodiment of the present invention shown in FIGS. 5 and 6 will be described. The same reference numerals as those in the embodiment of FIGS. 1 to 4 described above have the same configuration, and therefore, the configuration and operation that are mainly different will be described below.
First, in the embodiment shown in FIGS. 5 and 6, a counterbore 24 is formed on the inner surface of the inner flange portion 22 of the cap nut 20, and the inner peripheral surface portion 24A and the outer peripheral corner portion 25 of the taper ring 7 are formed. In order to prevent the taper ring 7 from being dropped or lost during assembly work or connection work, it is possible to work as a unit with the cap nut 20 in addition. In order to generate the vector Fp described with reference to B) and FIG. 4, it is assisted by the inner flange portion 22 of the cap nut 20 as shown in FIG. 6B.

6B, in addition to the vectors F ₇ , F ₁₇ , and F ₂₀ shown in FIG. 2B, the counterbore inner peripheral surface portion 24 A of the inner surface of the inner flange portion 22, and the outer periphery of the taper ring 7 The vector F ₂₂ is given to the taper ring 7 at the fitting portion with the corner 25, and finally added to the nail biting force (vector) Fp. As a result, a stronger vector Fp is obtained, and the posture of the taper ring 7 is always more stable.
Further, in the joint body 10, a radial through hole 26 is formed slightly inward of the joint body from the male screw portion 3, and the outer end portion of the through hole 26 has a large diameter so that a spherical body or the like is formed. The plug 27 of elastic material is inserted. Then, the cylindrical portion 20A of the cap nut 20 is extended inward to form a stopper pressing tube portion 28, and the stopper 27 closes the through hole 26 when the cap nut is completely tightened (see FIG. 6). And
When the pipe connection work is completed, water or the like is generally fed into the pipe at a predetermined pressure, and an initial pressure resistance test is performed. This is made up of such a through hole 26, a plug 27, and a plug retainer tube portion 28 (cap nut A connection completion confirmation means S for checking whether or not 20 is completely tightened.

Next, another embodiment of the present invention shown in FIGS. 7 and 8 will be described. The same reference numerals as those in FIGS. 1 to 4 are the same as those in FIG.
In the embodiment shown in FIGS. 7 and 8, the spot facings 24 are formed deeper on the inner surface of the inner collar portion 22 of the cap nut 20 than in the case of FIGS. 5 and 6. The inner peripheral surface portion 24A and the outer peripheral surface near the outer end of the taper ring 7 are fitted (fitted) to improve ease of assembling work and prevent the taper ring 7 from falling or lost. As in the case already described in B), the size of the nail biting force (vector) Fp is further increased by the portion of the inner collar portion 22 of the cap nut 20.

Then, as shown in FIG. 7, a gasket (sheet packing) 29 is fitted in the inner part of the annular groove 14, and the inner end face 7B of the taper ring 7 is in a state where the cap nut is tightened as shown in FIG. The gasket 29 is pressed to seal the back of the groove 14 and prevent liquid leakage through the outer peripheral surface of the taper ring 7.
Further, a square-shaped cross-sectional seal groove 44 is formed in the outer peripheral corner of the taper ring 7 in a notch shape, and a sealing material 45 such as an O-ring is attached to the seal groove 44, and the outer peripheral surface of the pipe P And the inner peripheral surface of the taper ring 7 are sealed. Therefore, the sealing material 23 does not have to be provided at the position shown in FIGS. 7 and 8, if an operation of insufficient tightening of the cap nut 20 is performed, if a liquid of a predetermined pressure is sent in the initial leakage inspection, the sheet packing 29 is used. Since the liquid leaks via the outer peripheral surface of the taper ring 7, it is possible to immediately find a defective piping operation.

By the way, as pipe P which can apply the pipe joint which concerns on this invention, hard pipe materials, such as stainless steel, can be mentioned, However, Even if it is various other materials, it is applicable. The joint body 10 is preferably manufactured by the lost wax method from the viewpoints of cost, ease of manufacture, and quality, and the material is preferably stainless steel. When the joint body 10 is manufactured by the lost wax method, the annular groove 14 can exhibit sufficient performance and quality without being subjected to machining. Further, it is desirable that the inner peripheral surface portion of the claw piece portion 5 (or a part of the locking claw 5A) is formed by machining such as grinding.
The application of the present invention is not limited, but is most suitable for use in piping for supplying hot water.

As described in detail above, the present invention engages the outer peripheral surface of the inserted pipe P into the opening inner peripheral edge 12 of the hole 11 of the joint body 10 into which the pipe P is inserted. Since the claw piece portion 5 to be stopped is integrally formed with the joint body 10, the claw piece portion 5 bites in while maintaining a stable posture at all times even with a small size. Therefore, the pipe pull-out resistance is strong and stable. Further, since the claw piece portion 5 has a small size, the tip (locking claw) moves only in the radial direction and hardly moves in the axial direction when the pipe P is deformed in the radial inward direction. It does not move to the axis L ₁₁ direction. Therefore, in piping work, the pipe length dimension can be determined easily and accurately according to the site.
Moreover, the flaring of the conventional pipe end portion can be omitted, the dimension of the axial direction (axis L ₁₁ direction) is short, compact, yet exerts a powerful scratch抜力.

  Further, in the present invention, an annular groove 14 is formed in the end surface 13 where the hole 11 of the joint body 10 opens, and the inner peripheral wall 15 of the groove 14 is circumferentially arranged through the minute slit 16. It is constituted by a plurality of the claw piece portions 5 arranged side by side, and the outer peripheral wall 17 of the concave groove 14 is further constituted by a short cylindrical wall 18 with an external thread having an external thread portion 3 to which a cap nut is screwed. In addition, the taper ring 7 having the inner peripheral tapered surface 8 pushed into the concave groove 14 and the taper ring 7 are pushed into the concave groove 14 so that the claw piece 5 is bitten into the outer peripheral surface of the pipe P. Since the configuration includes the cap nut 20, as described with reference to FIGS. 2B and 4, even if the cap nut 20 is extremely small, the outer peripheral wall 17 and the taper ring 7 of the joint body 10 are formed in the bag. In cooperation with the nut 20, a sufficient vector Fp can be applied to the claw 5A. That is, even if the whole is compact, a strong nail biting force Fp can be exhibited. Since the taper ring 7 is pushed into the concave groove 14 as a wedge, the claw 5A of the claw piece portion 5 can hold the biting state firmly and stably on the outer peripheral surface of the pipe P.

3 Male thread part 5 Claw piece part 7 Tapered ring 8 Inner circumference taper surface
10 Fitting body
11 hole
12 Opening edge
13 End face
14 Annular groove
15 Inner wall
16 Micro slit
18 short cylinder wall
20 Cap nut P Connected pipe

Claims (2)

  The joint pipe (P) is inserted into the inner peripheral end (12) of the opening (11) of the joint body (10) and is inserted into the outer peripheral surface of the connected pipe (P). A pipe joint characterized in that a claw piece (5) to be molded is integrally formed with the joint body (10). An annular groove (14) is formed in the end surface (13) where the hole (11) of the joint body (10) opens, and the inner peripheral wall (15) of the groove (14) has a micro slit (16 ), And the outer peripheral wall (17) of the concave groove (14) is a male screw part (3) for screwing a cap nut. It is constituted by an externally threaded short cylinder wall (18) having an outer peripheral surface,
And the taper ring (7) which has an inner peripheral taper surface (8) pushed into the said concave groove (14), and this taper ring (7) is pushed into the said concave groove (14), and the said nail | claw piece part ( The pipe joint according to claim 1, further comprising a cap nut (20) for allowing 5) to bite into the outer peripheral surface of the pipe (P).

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