WO2018011906A1

WO2018011906A1 - Pipe joint

Info

Publication number: WO2018011906A1
Application number: PCT/JP2016/070660
Authority: WO
Inventors: 井上　智史; 秋生保田
Original assignee: 井上スダレ株式会社; 東尾メック株式会社
Priority date: 2016-07-13
Filing date: 2016-07-13
Publication date: 2018-01-18

Abstract

In order to provide a pipe joint that can be caused to sharply and reliably bite into the outer peripheral surface of a pipe, this pipe joint is provided with a joint body 1 furnished with a male screw, and cap nuts 3 threaded over male screws 2 of the joint body 1. The joint body 1 has cylindrical insertion groove parts 4 for insertion of to-be-connected pipes P, the insertion groove parts 4 opening axially outward. The insertion groove parts 4 are formed by inner cylinder parts 5, outer cylinder parts 6, and deep groove bottom parts 7. The outer cylinder parts 6 have sharp grooves S of which the cross-sections are pentagons having sharp triangular peaks toward the inner side of the pipe joint. When the male screws 2 of the joint body 1 and the cap nuts 3 are threaded together, the outer cylinder parts 6 integrated with the joint body 1 receive axial compression force from the cap nuts 3 while the inner surfaces P₂ of pipe distal ends P₁ are held by the inner cylinder parts 5 integrated with the joint body 1, bottom wall parts S₁ of the sharp grooves S undergo radially inward plastic deformation, and the pipes P inserted into the insertion groove parts 4 are bitten into from outer surfaces P₃ and secured in place.

Description

Pipe fitting

The present invention relates to a pipe joint.

Conventionally, flare joints are widely used as a type of pipe joint. In general, as shown in FIG. 14, a metal connected pipe 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 to the male thread 32 of the joint body 30. A flare end 37 formed by plastic working the end of 35 into a diameter-expanded taper is sandwiched to prevent the flare from being removed, and is sealed by its pressure contact force.

However, there was a drawback that the above flare processing hindered the work efficiency improvement at the piping work site. Therefore, various pipe joints have been proposed to avoid the problem. As shown in FIGS. 15 and 16, one of the inventors has a cylindrical compression deformation sleeve 41 having a U-shaped concave circumferential groove 40 on the outer peripheral surface, and is housed inside a cap nut 42. (See Patent Document 1).

However, there are disadvantages that the number of parts is large, a complicatedly shaped part (sleeve 41 for compression deformation) is required, and it takes time during assembly. Furthermore, since the

tapered contact surfaces

44 and 45 of the compression deformation sleeve 41 and the joint body 43 are configured to exert a sealing function by pressure-contact between metals, the mutual axial centers are eccentric or inclined by a minute angle. Then, there was a risk of fluid leakage from the

tapered contact surfaces

44 and 45. When the concave circumferential groove 40 is compressed by the screwing of the cap nut 42 and deformed from the state shown in FIGS. 17A and 17B as shown in FIG. Accordingly, there is a problem that the concave groove bottom 47 does not bite into the pipe 46 evenly by 360 °. That is, if the pipe 46 does not bite evenly by 360 °, there is a problem that fluid leaks and the pull-out force of the pipe 46 becomes insufficient.

Japanese Patent No. 5306553

The problem to be solved is that it has a large number of parts, requires complicatedly shaped parts, and takes time during assembly. Further, since the tapered contact surface between the compression deformation sleeve and the joint main body is displaced (according to the eccentricity or inclination of the shaft center), there is a risk of fluid leakage and the concave circumferential groove of the compression deformation sleeve. The bottom does not bite into the pipe evenly by 360 °, causing fluid leakage and insufficient resistance to pulling out of the connected pipe.

Therefore, a pipe joint according to the present invention is a pipe joint including a joint body with a male thread and a cap nut screwed to the male thread of the joint body. Has a cylindrical insertion groove portion that opens in the axial outer direction, the insertion groove portion is formed by an inner cylinder portion, an outer cylinder portion, and a rear groove bottom portion, and the outer cylinder portion is A sharp groove with a pentagonal cross section having a sharp triangular apex on the back side, and when the male screw of the joint body and the cap nut are screwed together, the pipe tip is formed at the inner cylinder part integral with the joint body The outer cylinder part integral with the joint body receives an axial compressive force from the cap nut, and the bottom wall part of the sharp groove is plastically deformed radially inward while Configured to cut out from the outer surface side of the pipe inserted in the insertion groove. Than is.

The cap nut has a seal groove on the inner circumferential surface on the outer side in the axial direction, the seal groove has a seal, and the inner diameter of the cap nut on the axial inner side is set to the male screw base end of the joint body. When setting the cap nut and the male screw of the joint body to be slightly smaller than the outer diameter of the outer peripheral surface near the side, the inner peripheral surface on the axially inner side of the cap nut is in contact with the outer peripheral surface. It is configured to ride in a pressure contact state and perform metal sealing.

Further, in a pipe joint including a joint body having two male threads and two cap nuts screwed to the male threads of the joint body, one of the pipes to be connected is inserted. The cap nut includes a compression deformation sleeve for preventing pull-out, and the pipe and the compression deformation sleeve can be detached from the joint body from a connected state of the pipe. The pipe connection portion into which the cap nut is screwed has a cylindrical insertion groove portion that opens in the axial direction for inserting the pipe to be connected, and the insertion groove portion includes an inner cylinder portion and an outer cylinder. The outer cylinder portion has a sharp groove with a pentagonal cross section having a sharp triangular apex on the back side, and the male screw of the joint body and the cap nut are screwed together. The inner end of the pipe at the inner cylinder part integral with the joint body. The outer cylinder part integral with the joint body receives an axial compressive force from the cap nut, and the bottom wall part of the sharp groove is plastically deformed radially inwardly. The pipe is inserted from the outer surface side of the pipe inserted into the groove and is prevented from being removed.

According to the pipe joint of the present invention, the bottom wall portion of the sharp groove is bitten into the outer peripheral surface of the pipe uniformly by 360 °, and relatively sharply, so that sufficient sealing performance and a large pipe pull-out force are obtained. Can demonstrate. In addition, the number of parts can be reduced, and accurate and quick pipe connection work can be realized.

It is sectional drawing which shows the state just before the pipe insertion of one Embodiment of this invention. It is sectional drawing of the untightened state which inserted the pipe. It is sectional drawing which shows a fastening completion state (connection completion). It is a principal part expanded sectional view for an effect | action description. It is a principal part expanded sectional view which shows the state in the middle of compression. It is a principal part expanded sectional view which shows the state after compression. It is a principal part expanded sectional view which shows a various modification. It is a principal part expanded sectional view. It is a principal part expanded sectional view. It is an external appearance perspective view which shows a modification. It is an external appearance perspective view which shows a modification. It is an external appearance perspective view which shows a modification. It is sectional drawing which shows other embodiment. It is sectional drawing which shows a prior art example. It is sectional drawing which shows the other prior art example of a pipe uninserted state. It is sectional drawing of the other conventional example of a connection completion state. It is explanatory drawing of the principal part of another prior art example.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
1, 2 and 3 show an embodiment of the present invention. FIG. 1 is a cross-sectional view showing a state immediately before the pipe P is inserted, and FIG. 2 is a cross-sectional view in an untightened state where the pipe P is inserted. FIG. 3 and FIG. 3 are sectional views showing a tightening (connection) completion state.

The pipe joint includes a metal joint body 1 with a male thread and a metal cap nut 3 that is screwed onto the male thread 2 of the joint body 1. The joint body 1 has a cylindrical insertion groove portion 4 that opens in the axial outward direction for inserting the pipe P to be connected. The insertion groove part 4 is formed by the inner cylinder part 5, the outer cylinder part 6, and the rear groove bottom part 7. The inner peripheral surface of the inner cylinder part 5 and the outer peripheral surface of the outer cylinder part 6 that form the inner surface of the insertion groove part 4 are formed with smooth surfaces (without irregularities).

A sharp groove S having a pentagonal cross section with a sharp triangular apex 8 (see FIG. 4) on the back side of the outer cylinder portion 6—this is a building-type groove S with a double-flow roof, or an isosceles triangle and a rectangle. An internal cylinder integrated with the joint body 1 when the male screw 2 and the cap nut 3 of the joint body 1 are screwed together, which is a pentagonal groove S having a cross-sectional pentagonal shape and can be paraphrased. While receiving the inner surface P ₂ of the pipe tip P ₁ at the portion 5, the outer cylinder portion 6 integral with the joint body 1 receives the axial compressive force F (see FIGS. 5 and 6) from the cap nut 3. The bottom wall portion S ₁ of the sharp groove S is plastically deformed in the radial inward direction and bites in from the outer surface P ₃ side of the pipe P inserted into the insertion groove portion 4 so as to prevent it from being removed.

When the compression force F is received from the uncompressed state of FIG. 4 (according to the screwing of the cap nut 3), as shown in FIG. 5, the bottom wall portion S ₁ is evenly distributed over the entire 360 ° circumference. Immediately plastically deforms radially inward. Thereafter, as shown in FIG. 6, a mountain-shaped closed annular bite S ₂ that is close to a triangle is formed in the radial inward direction.

As described above, it is considered that “the bottom wall portion S ₁ is uniformly plastically deformed over the entire 360 ° circumference” for the following reason.
(i) The axial center of the outer cylindrical part 6 that causes plastic deformation, the axial center of the cylindrical insertion groove part 4, the axial center of the pipe P to be connected (inserted into the insertion groove part 4), the pipe P The axial center of the inner cylinder portion 5 that holds the inner surface P ₂ always coincides with the axial center L ₁ of the joint body 1, and the bottom wall portion S ₁ is plastically deformed in such a state that it always coincides. To go.
(ii) That is, in FIGS. 15 and 16 of the conventional example, since the sleeve 41 is separate from the joint body 43, the axis of the sleeve 41 is eccentric with respect to the axis of the joint body 43. However, in the present invention, such eccentricity and inclination do not occur, and the outer cylinder portion 6 itself always keeps its axis aligned with the axis 1 of the joint body 1, This is because the bottom wall S ₁ undergoes plastic deformation.

As shown in FIG. 7, the ratio of each dimension can be freely changed in the shape of the sharp groove S. That is, FIG. 7A shows a case where (axial direction length dimension L) :( rectangular depth dimension H ₁ ) :( isosceles triangle height dimension H ₂ ) = 2: 1: 1. Show. FIG. 7B shows a case where the ratio of the length dimension L in the axial direction is set smaller than that in FIG. FIG. 7C shows a case where the ratio of the rectangular depth dimension H ₁ is set smaller than that in FIG. 7A—that is, H ₁ <H _{2 —} . FIG. 7D shows a case where the ratio of the axial length dimension L and the ratio of the rectangular depth dimension H ₁ are set smaller than those in FIG. 7A.

As shown in FIGS. 1 to 3, the cap nut 3 has a seal groove 10 on the outer circumferential inner surface 9 in the axial direction and a seal 11 in the seal groove 10. If this seal 11 does not exist, when inserting the pipe P as shown in FIG. 1 to FIG. By providing the nut 3, the insertion depth of the pipe P can be maintained stably and accurately, and further, the effect of being able to center the pipe P with respect to the cap nut 3 is exhibited. . As shown in FIGS. 8 and 9, the inner diameter D ₁ (on the smooth inner peripheral surface 13 provided axially inward from the female screw 20) on the axial inner side of the cap nut 3 is set to the male screw base of the joint body 1. When setting the cap nut 3 and the male screw 2 of the joint body 1 to be slightly smaller than the outer diameter D ₂ of the outer peripheral surface 12 near the end side (for example, 0.1 mm to 0.3 mm smaller), the cap nut 3 The inner peripheral surface 13 on the inner side in the axial direction rides on the outer peripheral surface 12 in a pressure contact state, and performs metal sealing by contact between the metal and the metal.

The front end surface 16 of the outer cylinder portion 6 of the joint body 1 and the pressing surface 17 of the cap nut 3 that presses the front end surface 16 are orthogonal to the axial center. The sharp groove S can be compressed and deformed by pressing the distal end surface 16 of the outer cylinder portion 6 with the pressing surface 17 of the cap nut 3 uniformly and efficiently 360 °.
This will be described more specifically. If the tip surface 16 and the pressing surface 17 are inclined surfaces (tapered surfaces), the tip edge of the outer cylinder portion 6 is moved (in addition to the compression deformation of the sharp groove S) as the cap nut 3 is screwed. This will cause a diameter-reducing deformation that presses in the radial inward direction. In order to cause such reduced diameter deformation, an extra rotational torque must be applied to the cap nut 3, which makes it difficult to rotate the cap nut. In other words, since the distal end surface 16 and the pressing surface 17 are orthogonal to the axis L1, the rotational torque to be applied can be intensively used for compressive deformation of the sharp groove S.

The outer diameter D ₆ and the male screw of the joint body 1 2 of the outer cylindrical portion 6 of the root diameter D ₆ 'is Hitoshini. (Refer to FIG. 1 and FIG. 2) When the cap nut 3 is tightened, it is guided to the outer tube portion 6 and can be tightened smoothly.

The width A of the cap nut 3 is set to be not less than 1.3 times and not more than twice the nominal diameter E of the screw. When the width across flats A is within this range, the cap nut 3 can be prevented from escaping when the cap nut 3 is tightened and the cap nut 3 receives a force from the outer tube portion 6. If the width across flats A is less than 1.3 times the nominal diameter E of the screw, when the cap nut 3 is tightened and the cap nut 3 receives a force from the outer tube portion 6, it will escape and deform, and the sharp groove S will be evenly 360 °. can not bite into the bottom wall portion S ₁ of the pipe P, there is a risk that fluid leaks. When the width A of the two surfaces exceeds twice the nominal diameter E of the screw, the cap nut 3 becomes unnecessarily large, so that it cannot be made compact and difficult to handle.

10 to 12 show a modification. That is, as shown in FIGS. 1 to 3, at both ends in the axial center direction, in addition to socket-type fittings having connection mechanisms such as a cap nut 3, an outer cylindrical portion 6, and an insertion groove portion 4, elbow-type fittings ( FIG. 10) and a T-shaped pipe joint (FIG. 11) may be used. Furthermore, as shown in FIG. 12, one of the pipe connection ports 18 of the socket-type pipe joint may be a tapered cylinder 19 with a male thread.

FIG. 13 shows another embodiment. In a pipe joint provided with a joint body 1 having two male screws 2 and two cap nuts 3 screwed to each male screw 2 of the joint body 1, a pipe P to be connected is inserted. One of the cap nuts 3 is provided with a compression deformation sleeve 15 for preventing withdrawal, and the pipe P and the compression deformation sleeve 15 can be detached from the joint body 1 from the connected (completed) state of the pipe P. To do. That is, the pipe P and the compression deformation sleeve 15 (and the cap nut 3 and the seal 11) can be integrally separated from the joint body 1 from the connection completion state.

The compression deformation sleeve 15 has a cylindrical insertion groove portion 4 ′ that opens in the axial direction for inserting the pipe P to be connected, and the insertion groove portion 4 ′ has an outer cylinder portion 5 ′ and an outer cylinder portion 5 ′. It is formed by the cylinder part 6 'and the back groove bottom part 7'. The outer cylinder portion 6 'has a sharp groove S' having a pentagonal cross section having a sharp triangular apex portion 8 'on the back side. Other configurations are the same as those of the above-described embodiment.

In the present invention, the design can be changed, and for example, three sharp grooves S may be formed in the outer cylinder portion 6.

As described above, the present invention provides a pipe joint including a joint body 1 with a male thread and a cap nut 3 that is screwed onto the male thread 2 of the joint body 1. It has a cylindrical insertion groove 4 that opens in the axial direction for inserting the pipe P to be connected. The insertion groove 4 includes an inner cylinder 5, an outer cylinder 6, and a back groove bottom 7. When the outer cylinder portion 6 has a sharp groove S with a pentagonal cross section having a sharp triangular apex 8 on the back side, and the male screw 2 of the joint body 1 and the cap nut 3 are screwed together Further, while the inner cylinder portion 5 integral with the joint body 1 receives the inner surface P ₂ of the pipe tip P ₁ , the outer cylinder portion 6 integral with the joint body 1 extends in the axial direction from the cap nut 3. in response to the compressive force F, the bottom wall portion S ₁ of the sharp groove S is plastically deformed in the radial inward direction, and is inserted into the insertion groove 4 And then, is retaining fit bite from an outer surface P ₃ side of type P, it exhibits the Chodai effects as follows. That is,
(i) The number of parts is small, it is easy to manufacture, and the structure is simple.
(ii) The axis center of the cylindrical insertion groove portion 4 naturally coincides with the axis L ₁ of the joint body 1, and therefore the axis center of the pipe P to be inserted also coincides with the bottom wall of the sharp groove S. The part S ₁ can bite 360 ° uniformly with respect to the pipe outer peripheral surface P ₃ , and can exhibit a stable and high sealing performance and a pull-out resistance of the pipe P.
(iii) A sharp groove S having a pentagonal cross section having a sharp triangular apex 8 bites into the pipe outer peripheral surface P ₃ sharply (as a triangular mountain shape), can further improve the sealing performance, and has a greater pulling resistance. Can demonstrate.
(iv) Compared to the rotational torque of the cap nut 42 of FIGS. 15 to 17 of the conventional example, the rotational torque of the cap nut 3 of the present invention can be remarkably small, and the sharp groove S is shown in FIGS. The bottom wall portion S ₁ becomes a triangular mountain shape so that it deeply and securely bites into the outer surface P _{3 of the} pipe P. That is, as shown in FIG. 17C, the conventional concave circumferential groove 40 has a U shape and the concave circumferential groove bottom 47 is round, and it is difficult to bite into the outer circumferential surface of the pipe due to the projecting deformation in the radial inward direction. The outer peripheral surface of the conventional sleeve 41 has a small protruding portion radially outward at the opening corner portion of the concave circumferential groove 40, and is strongly pressed against the inner peripheral surface of the cap nut 42. The present invention solves the problem that the rotational torque for rotating the nut 42 with the work tool increases.
(v) Further, as described in (iv) above, the outer peripheral surface of the conventional sleeve 41 (see FIGS. 15, 16, and 17) is the sleeve compression deformation at the opening corner of the concave circumferential groove 40. At this time, a small protruding portion is generated in the radially outward direction, and is strongly pressed against the inner peripheral surface of the cap nut 42, so that the inner sleeve 41 and the pipe 46 also rotate with the rotation of the cap nut 42 by the work tool. Further, the twisting of the pipe may occur, adversely affecting other parts of the piping, and the tapered contact surfaces 44 and 45 may slip each other, thereby destroying the sealing function by the metal touch. In the present invention, such a problem is solved, and the twist of the pipe P does not occur at all.
(vi) When the connecting pipe 46 is thin, in the conventional example, the pipe P is deformed 48 radially inward as shown in FIG. There remains a problem that the sealing performance by the plastic deformation portion in the radial direction of the circumferential groove bottom portion 47 is hindered and the pull-out resistance of the pipe is also reduced. However, in the present invention, the inner cylindrical portion 5 of the insertion groove portion 4 is configured to receive the inner surface P ₂ of the pipe tip P ₁ , so that even if the pipe P is thin, it is shown in FIG. As described above, it is possible to prevent the inner surface P ₂ of the pipe tip P ₁ from “escape” in the radial inward direction, exhibit high sealing performance, and have a strong pull-out force of the pipe.
(vii) In the conventional example (FIGS. 15 and 16), the tapered contact surfaces 44 and 45 are so-called metal touches, and there is a possibility of fluid leakage. Since there is no touch site, the risk of fluid leakage could be eliminated. In addition, since the outer cylinder portion 6 itself has a structure that undergoes plastic deformation under the axial compression force of the cap nut 3, it has a stable posture from the beginning to the end of the plastic deformation (completion of connection). The bottom wall portion S ₁ of S undergoes plastic deformation with high accuracy in the radial inward direction, and deeply bites into the outer surface P _{3 of the} pipe P to prevent it from being removed. Moreover, the inner cylinder section 5 always responsible from the inner surface P ₂ of the pipe P, the above bite to be a more reliable.

Further, the cap nut 3 has a seal groove 10 on the inner peripheral surface 9 on the outer side in the axial direction, the seal groove 10 has a seal 11, and an inner diameter D ₁ on the axial inner side of the cap nut 3 is When the joint nut 1 is set slightly smaller than the outer diameter D ₂ of the outer peripheral surface 12 in the vicinity of the male screw base end side and the cap nut 3 and the male screw 2 of the joint body 1 are screwed together, the cap nut Since the inner peripheral surface 13 on the inner side in the axial direction 3 rides on the outer peripheral surface 12 in a pressure contact state and is metal-sealed, fluid leakage can be prevented more reliably and air can enter from the outside. Condensation can be prevented, and invasion of corrosive gas can be prevented.

In addition, in a pipe joint including a joint body 1 having two male screws 2 and two cap nuts 3 screwed to each male screw 2 of the joint body 1, a pipe to be connected One of the cap nuts 3 into which P is inserted is provided with a compression deformation sleeve 15 for preventing pull-out, and the pipe P and the compression deformation sleeve 15 can be detached from the joint body 1 from the connected state of the pipe P. The coupling body 1 has a cylindrical insertion groove portion 4 that opens in the axial direction for inserting the pipe P to be connected into the pipe connection portion to which the other cap nut 3 is screwed. The insertion groove part 4 is formed by an inner cylinder part 5, an outer cylinder part 6 and a back groove bottom part 7, and the outer cylinder part 6 has a pentagonal cross section having a sharp triangular apex 8 on the back side. When having a sharp groove S and screwing the male screw 2 of the joint body 1 and the cap nut 3 together The outer cylindrical portion 6 integral with the joint main body 1 extends in the axial direction from the cap nut 3 while receiving the inner surface P ₂ of the pipe tip P _{1 with} the inner cylindrical portion 5 integral with the joint main body 1. In response to the compressive force F, the bottom wall portion S ₁ of the sharp groove S is plastically deformed radially inward, and bites in from the outer surface P ₃ side of the pipe P inserted into the insertion groove portion 4 to prevent it. Since it is configured as described above, the above-described operational effects (i) to (vii) can be exhibited.

Further, when it is necessary to separate the pipe P in the pipe connection completed state (in the case of transfer, exchange, etc.), the cap nut 3 on the side of the compressible deformation sleeve 15 which is separable is screwed out to compress and deform. The sleeve 15 can be easily removed from the joint body 1.

DESCRIPTION OF SYMBOLS 1 Joint body 2 Male screw 3 Cap nut 4 Insertion groove part 5 Inner cylinder part 6 Outer cylinder part 7 Back groove bottom part 8 Triangle top part 9 Axial direction outer side inner peripheral surface 10 Seal groove 11 Seal 12 (Near male screw base end side) ) Outer surface 13 Inner surface 14 Pipe insertion port 15 Compression deformation sleeve D ₁ Inner diameter D ₂ Outer diameter F Compression force P (For connected) Pipe P ₁ Pipe tip P ₂ Inner surface P ₃ Outer surface (Pipe outer surface)
S Sharp groove (Building-type groove with double-flow roof, 5-sided groove)
S ₁ bottom wall

Claims

In a pipe joint comprising a male threaded joint body (1) and a cap nut (3) screwed onto the male thread (2) of the joint body (1),
The joint body (1) has a cylindrical insertion groove (4) that opens in the axial outward direction for inserting the pipe (P) to be connected, and the insertion groove (4) Formed by the inner cylinder part (5), the outer cylinder part (6) and the back groove bottom part (7),
The outer cylinder portion (6) has a sharp groove (S) having a pentagonal cross section with a sharp triangular apex (8) on the back side, the male screw (2) of the joint body (1) and the cap nut When the screw (3) is screwed, the joint main body (P 2 ) is supported by the inner cylinder portion (5) integral with the joint main body (1) while the inner surface (P 2 ) of the pipe tip (P 1 ) is supported. 1) and the outer cylindrical portion of the integral (6) is subjected to a compressive force in the axial direction (F) from the cap nut (3), the bottom wall of the sharp groove (S) (S 1) is radial in direction A pipe joint characterized in that it is plastically deformed and bites in from the outer surface (P 3 ) side of the pipe (P) inserted in the insertion groove (4) to prevent it from being pulled out.
The cap nut (3) has a seal groove (10) on the inner circumferential surface (9) on the outer side in the axial direction, and has a seal (11) in the seal groove (10).
The inner diameter (D 1 ) on the axial inner side of the cap nut (3) is set slightly smaller than the outer diameter (D 2 ) of the outer peripheral surface (12) in the vicinity of the male screw base end of the joint body (1). When the cap nut (3) and the male screw (2) of the joint body (1) are screwed together, the inner peripheral surface (13) on the inner side in the axial direction of the cap nut (3) is the outer periphery. The pipe joint according to claim 1, wherein the pipe joint is configured to ride on the surface (12) in a pressure contact state and to perform a metal seal.
A pipe joint comprising: a joint body (1) having two male threads (2); and two cap nuts (3) screwed to each male thread (2) of the joint body (1) In
One of the cap nuts (3) into which the pipe (P) to be connected is inserted is provided with a compression deformation sleeve (15) for preventing pull-out, and the pipe (P) is connected to the pipe (P) from the connected state. The compression deformation sleeve (15) is configured to be removable from the joint body (1), and the joint body (1) is connected to a pipe connection portion to which the other cap nut (3) is screwed. A cylindrical insertion groove (4) that opens in the axial direction for inserting the pipe (P), and the insertion groove (4) includes an inner cylinder (5) and an outer cylinder ( 6) and the back groove bottom (7),
The outer cylinder portion (6) has a sharp groove (S) having a pentagonal cross section with a sharp triangular apex (8) on the back side, the male screw (2) of the joint body (1) and the cap nut When the screw (3) is screwed, the joint main body (P 2 ) is supported by the inner cylinder portion (5) integral with the joint main body (1) while the inner surface (P 2 ) of the pipe tip (P 1 ) is supported. 1) and the outer cylindrical portion of the integral (6) is subjected to a compressive force in the axial direction (F) from the cap nut (3), the bottom wall of the sharp groove (S) (S 1) is radial in direction A pipe joint characterized in that it is plastically deformed and bites in from the outer surface (P 3 ) side of the pipe (P) inserted in the insertion groove (4) to prevent it from being pulled out.