JP2002228062A - Pipe fittings - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When a metal tube is connected to a joint body in a sealed state by a nut, the metal tube can be prevented from rotating together with the nut, and can be screwed to the other side of the joint body. It is possible to prevent loosened nuts and the like and damage to the sealing material, thereby improving connection reliability. SOLUTION: An annular projecting portion 2 is formed by expanding a pipe at an end of a metal pipe, for example, a stainless steel pipe 1. The nut 12 provided with the sliding member 20 is fitted to the outside of the stainless steel tube 1. The female thread portion 16 of the nut 12 is screwed into the male thread portion 9 of the joint body 3, the annular projecting portion 2 of the stainless steel tube 1 is pressed via the sliding member 20, and the stainless steel tube 1 is advanced so as not to rotate together. The O-ring 8 accommodated in the accommodating recess 7 of the joint body 3 is pressed and compressed by the annular projection 2 of the stainless steel pipe 1 moving forward, and the stainless steel pipe 1 and the joint body 3 are connected in a sealed state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes a metal pipe such as a stainless steel pipe or a copper pipe used for water supply, hot water supply, cold and hot water pipes, etc. by utilizing an annular projecting portion formed by expanding the end of the pipe. The present invention relates to a pipe joint used for connection.

[0002]

2. Description of the Related Art Conventionally, this type of pipe joint has been disclosed in
Configurations such as those described in Japanese Patent Application Laid-Open No. 3-145089 and Japanese Patent Application Laid-Open No. 10-318459 are known. To briefly explain these conventional examples, an annular projecting portion having a mountain shape or an arc shape in cross section is formed by expanding a pipe at an end of a thin stainless steel pipe. An annular sealing material accommodating recess is formed inside the end of the joint body, and the sealing material is accommodated in the sealing material accommodating recess. Then, the end of the stainless steel pipe is inserted into the inside of the joint body, and the female screw part of the nut fitted to the stainless steel pipe is screwed into the male screw part formed on the outer periphery of the end of the joint body, inside the nut. The formed engagement portion presses the side of the annular projection of the stainless steel pipe away from the pipe end, and advances the stainless steel pipe. Along with this,
The inner surface of the sealing material is pressurized at the pipe end side of the annular projecting portion of the stainless steel pipe, and the sealing material is interposed in a compressed state between the sealing material receiving recess of the joint body and the annular projecting portion of the stainless steel tube, and It is configured to connect the steel pipes in a sealed state.

[0003]

However, in the structure of the prior art as described above, the side of the annular protruding portion of the stainless steel pipe with respect to the pipe end is pressed by the engaging surface of the nut to advance the stainless steel pipe. Since the female screw portion of the nut is screwed into the male screw portion of the joint body, the stainless steel pipe may rotate in the rotation direction of the nut due to frictional resistance between the nut and the annular projection of the stainless steel pipe. When this co-rotation occurs, the sealing material and the joint body that are compressed by the annular protrusion of the stainless steel pipe rotate integrally with the stainless steel pipe, and the stainless steel pipe is already connected to the other side of the joint body with a nut in the same manner as described above. In this case, the nut may be loosened with respect to the joint body, resulting in poor connection reliability. In addition, the sealing material may be damaged by frictional resistance with the annular projection of the stainless steel pipe,
Also in this respect, the reliability of the connection is poor.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. When connecting a metal pipe to a joint body by a nut in a sealed state, the object of the present invention is to prevent the metal pipe from rotating together with the nut. So that nuts and the like screwed to the other side of the joint main body can be prevented from being loosened and the seal material can be prevented from being damaged, so that the reliability of the connection can be improved. It is an object of the present invention to provide an improved pipe joint.

Another object of the present invention is to prevent the sliding member for preventing the nut and the metal pipe from rotating together from falling off the nut and further preventing the sliding member from being lost, thereby simplifying the connection work at the work site. It is an object of the present invention to provide a pipe joint which can be performed quickly and quickly.

[0006]

In order to solve the above-mentioned problems, a pipe joint according to the present invention is formed by expanding a pipe at an end of a metal pipe, and gradually becomes larger in diameter from a pipe end to a separation side. Following the large diameter part, an annular projection with a gradually decreasing diameter,
A joint body having a male thread on the outer periphery of an end, a nut fitted on the periphery of the metal tube and having a female thread to be screwed into the male thread of the joint body, and advance integrally with the nut inside the nut; The female thread portion of the nut is screwed into the male thread portion of the joint main body, so that a side portion of the annular projection of the metal tube at a distance from the pipe end is pressed to advance the metal tube. A sliding member, and a sealing material interposed in a compressed state between at least the joint body and a pipe end side portion of the annular protrusion of the metal pipe as the metal pipe advances.

In order to solve the above-mentioned problem, another pipe joint of the present invention is characterized in that in the pipe joint, a male screw portion of the joint main body is fitted to a terminal end portion of the joint body, thereby preventing manual tightening of the nut, and And a stop ring hidden inside the tip of the nut when the nut is fully tightened by a tool.

In each of the pipe joints, the sliding member can be integrally provided with the nut by bonding, or the sliding member is fitted into a groove-like receiving recess of the nut and held by the nut. Alternatively, the sliding member may be provided integrally with the nut by fitting and bonding to the groove-shaped receiving recess of the nut.

[0009] The sliding member may be continuous in a continuous ring shape or may have a cut-off portion at one place. The sliding member is elastically deformed by an external force to reduce the diameter, and the diameter is increased by removing the external force. It is also possible to use a ring-shaped member that is restored.

[0010] In each of the pipe joints, the joint main body includes:
A sealing material accommodating recess is provided at an enlarged portion at the end, a sealing material is accommodated in the sealing material accommodating recess, and a female screw portion of the nut is screwed into a male screw portion of the joint body to form an inner side of the nut. By pressing the separation side of the annular projection of the metal tube relative to the tube end by the sliding member, the tube end side of the annular projection is pressed against the sealing material,
The joint body may be configured so as to apply pressure to a base end of the expanded portion.

According to the present invention configured as described above,
Insert the end of the metal tube into the joint body, screw the female thread of the nut fitted to the metal tube into the male thread of the joint body, and slide the metal tube through the sliding member provided inside the nut. The metal pipe is advanced by pressurizing the separation side portion with respect to the pipe end in the annular projection, and accompanying this, pressurizing the sealing material with at least the joint body and the pipe end side in the annular projection of the metal pipe,
The metal pipe and the joint body can be connected in a sealed state. As described above, when the metal pipe having the annular protrusion at the end is connected to the joint body in a sealed state by the nut, the metal pipe is advanced with respect to the joint body via the sliding member.
The metal tube can be prevented from rotating together with the nut.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described. 1 shows a pipe joint according to a first embodiment of the present invention, and is a cross-sectional view of a main part before connection, FIG. 2 is a cross-sectional view of the pipe joint, showing a main part in a state after connection, and FIG.
(A) and (b) are a front view and a right side view, respectively, showing a sliding member used for the pipe joint, and FIGS. 4 (a) and (b) are a front view, a right side view showing a stop ring used for the pipe joint, respectively. FIG.

In this embodiment, an example is shown in which a thin stainless steel pipe is used as a metal pipe and this stainless steel pipe is connected to a pipe joint. In FIGS. 1 and 2, one stainless steel pipe is connected to one side of a joint body. Indicates the state to connect to,
A state in which the other stainless steel pipe is connected to the other side of the joint body is not shown.

As shown in FIGS. 1 and 2, an annular protruding portion 2 is formed on a thin stainless steel pipe 1 by expanding the pipe at a position slightly inward from the end of the pipe. As an example, an annular rubber expanding member is inserted inside the end portion of the stainless steel pipe 1, and the expanding member is expanded in the outer peripheral direction, whereby the stainless steel pipe 1 is expanded at a uniform pressure.
By such a pipe expanding process, the annular projecting portion 2 is formed in an arc-shaped cross section in which the diameter gradually increases from the tube end side to the separation side, and gradually decreases after the large diameter portion.

The joint body 3 is made of a metal such as stainless steel, and the insertion part 4 at the end is formed in the annular projecting part 2 of the stainless steel pipe 1.
Of the insertion portion 4 is formed as a stopper portion 5 for restricting excessive insertion of the stainless steel tube 1.
A tapered inclining portion 6 having a taper shape gradually increasing in diameter toward the distal end is formed so that the tube end of the annular projecting portion 2 of the stainless steel tube 1 can be inserted into the forward inside of the tube. A seal material accommodating recess 7 is formed at a position of the opening 6 near the insertion portion 4. This housing recess 7
Is formed as an annular groove in the illustrated example, and an O-ring 8 serving as a sealing material is accommodated in an engaged state in which the O-ring 8 is prevented from being detached. The O-ring 8 is set such that the inner diameter of the O-ring 8 is larger than the outer diameter of the connected stainless steel pipe 1 before being expanded in the housing recess 7. A male screw portion 9 is formed on the outer peripheral surface of the end of the joint body 3. An annular housing groove 11 is formed in the joint body 3 adjacent to the end of the male screw portion 9 and the intermediate flange portion 10.

As the nut 12, a metal cap nut (union nut) such as stainless steel having a small diameter on the inside of the base, a middle diameter on the inside of the middle, and a large diameter on the inside of the tip.
Is used. An annular receiving recess 13 is formed inside the base of the nut 12, and the receiving recess 13 is open at the front and has a stepped portion 14 formed of an annular hole wall substantially parallel to the axis.
An engaging portion 15 projecting inward in a direction perpendicular to the step portion 14.
Are formed. A female screw portion 16 that can be screwed into the male screw portion 9 of the joint main body 3 is formed inside the intermediate portion of the nut 12, and a distal end portion of the nut 12 is formed as a jacket cylinder 17. A contact surface 18 and a pressing surface 19 are formed between the base portion and the intermediate portion of the nut 12 and between the intermediate portion and the distal end portion, each of which is a surface perpendicular to the axis.

The sliding member 20 is made of a low friction coefficient synthetic resin such as PTFE (polytetrafluoroethylene resin), PFA (perfluoroalkoxy resin), polyamide resin, polybutylene terephthalate resin, and the like. As shown, it is formed in a continuous ring shape as a whole, the outer peripheral surface is an annular surface substantially parallel to the axis, the rear end surface is a surface substantially perpendicular to the axis, and the inside is from the front end to the rear end side. The engagement surface 21 is formed in a tapered engagement surface 21 having a gradually decreasing diameter, and the rear side of the engagement surface 21 is formed to be a surface substantially parallel to the axis. The sliding member 20 is accommodated in the accommodating recess 13 of the nut 12, the outer peripheral surface is adhered to the step portion 14 with an adhesive 22, and the rear end surface is engaged with the engaging portion 15.
And is advanced integrally with the nut 12. The nut 12 and the sliding member 20 are fitted to the outer periphery of the stainless steel pipe 1 so as to be movable along the axial direction in a loose state.

The colored stop ring 23 is made of a polyacetal resin or the like. In particular, as is apparent from FIGS. A protruding portion 25 is integrally provided, and one portion of the ring-shaped portion 24 is separated by a separating portion 26, elastically deformed by an external force to expand the diameter, and restored by reducing the external force to reduce the diameter. It is supposed to be. The stop ring 23 has its ring-shaped portion 24 housed in the housing groove 11 of the joint body 3, and the protruding portion 25 is fitted to the male screw portion 9 at the outer periphery of the male screw portion 9 near the housing groove 11 with a gap. Have been combined.
At this time, since the stop ring 23 can be expanded by the separation portion 26 as described above, the ring-shaped portion 24 can easily pass through the male screw portion 9 and be easily housed in the housing groove 11.

The female thread 16 is screwed into the male thread 9 of the joint body 3 in a state where the nut 12 is fitted to the stainless steel pipe 1, so that the stainless steel pipe is inclined by the inclined engaging surface 21 of the sliding member 20. The stainless steel pipe 1 can be advanced by pressurizing the side of the annular projection 2 away from the pipe end. Along with this, the tube end side of the annular projecting portion 2 of the stainless steel tube 1 is pressed against the O-ring 8 to press the O-ring 8 against the bottom side of the housing recess 7, and the O-ring 8 is The joint body 3 and the stainless steel pipe 1 at the bottom and the pipe end side of the annular projection 2
Can be compressed in the direction of inclination with respect to the axis of.

When the nut 12 is tightened into the joint body 3, in the case of manual tightening, the pressing surface 19 is brought into contact with the projection 25 of the stop ring 23 from the projection 25.
Are not deformed, that is, the nut 12 and the sliding member 2
0, the stainless steel tube 1 cannot be advanced,
In the case of final fastening by a tool, the projection 25 of the stop ring 23 can be deformed by the pressing surface 19, that is, the stainless steel pipe 1 can be advanced as described above by the nut 12 and the sliding member 20. Is set. This deformed projection 25 is
Is concealed inside the outer cylinder 17 of the first embodiment. Further, the stainless steel tube 1 is advanced by the nut 12 and the sliding member 20 as described above, and the base of the annular projecting portion 2 at the tube end side in the continuous state in which the O-ring 8 is compressed is the same as the insertion portion 4 of the joint body 3. The abutment portion 18 of the nut 12 abuts on the distal end surface of the joint main body 3 while being pressed against a corner portion of the joint portion 3 with the expanded portion 6.

In the above configuration, the connection operation between the stainless steel pipe 1 and the joint body 3 will be described below. First, as shown in FIG. 1, one or two nuts 12 and a sliding member 20 are fitted into a stainless steel pipe 1,
At one end or both ends of the stainless steel pipe 1,
The tube is expanded slightly wider than the end of the tube so as to expand the diameter of the tube as described above, thereby forming an annular projecting portion 2 having an arc-shaped cross section. Next, the tip of the annular projecting portion 2 of the stainless steel pipe 1 is inserted into the insertion portion 4 of the joint body 3. Next, the nut 12 fitted to the stainless steel pipe 1 is manually turned together with the sliding member 20 to screw the female screw portion 16 of the nut 12 into the male screw portion 9 of the joint main body 3. The pressing surface 19 located is brought into contact with the distal end surface of the projection 25 of the stop ring 23.

Next, the nut 12 is tightened together with the sliding member 20 using a tool as shown in FIG. 2, and the protrusion 25 of the stop ring 23 is pressed and crushed by the pressing surface 19 of the nut 12 so as to be crushed. The stainless steel pipe 1 is advanced by pressing the side of the annular projection 2 of the stainless steel pipe 1 away from the pipe end by the engagement surface 21 of the stainless steel pipe 1. As the stainless steel pipe 1 advances, the O-ring 8 is pressed against the bottom of the accommodation recess 7 at the pipe end side of the annular projection 2 of the stainless steel pipe 1, and the base of the annular projection 2 on the pipe end side is joined. It presses against the corner 27 of the main body 3. Here, the sum of the frictional resistance to the O-ring 8 and the frictional resistance to the corner 27 of the tube end side portion of the annular protrusion 2 is determined by the engagement surface 21 of the sliding member 20 and the separation side portion of the annular protrusion 2 to the tube end. When the nut 12 is rotated together with the sliding member 20 to fasten the nut 12 to the joint body 3, the stainless steel pipe 1
Can be prevented from rotating together.

By screwing the female thread 16 of the nut 12 into the male thread 9 of the joint body 3 until the contact surface 18 of the nut 12 comes into contact with the distal end face of the joint body 3 in this manner, the stainless steel pipe 1 The O-ring 8 is compressed in the inclined direction with respect to the axis of the joint main body 3 and the stainless steel pipe 1 at the pipe end side of the annular projection 2 and the bottom of the accommodation recess 7, so that the joint main body 3 and the stainless steel pipe 1 are completely connected. It is possible to prevent leakage of the fluid flowing inside the stainless steel pipe 1 by connecting to a proper sealing state. When the stainless steel pipe 1 and the joint body 3 are connected in this manner, the O-ring 8 is strongly pressed on substantially two surfaces on the bottom of the housing recess 7 and the pipe end side of the annular projection 2, so that the O-ring 8 The compression set is small and the resilience can be sufficiently provided. Therefore, the seal between the stainless steel pipe 1 and the joint body 3 can be semi-permanently secured, and the sealing property is extremely excellent.

In the connection work between the stainless steel pipe 1 and the joint body 3, the nut 12 is securely tightened, and whether or not the nut 12 is connected is determined by the parallel projection 25 of the colored stop ring 23. As shown in FIG. 2, the nut 12 is crushed by the pressing surface 19 of the nut 12 and concealed by
Can be surely tightened, and it can be confirmed that the connection has been securely performed.

Even if the stainless steel pipe 1 that has not been expanded into the joint body 3 is piped by carelessness of the operator, the inner circumference of the O-ring 8 and the outer circumference of the unexpanded stainless steel pipe 1 as described above. Since there is a gap between the pipes (see FIG. 1), a water leak occurs at the time of a water pressure test after pipe installation, so that repair can be immediately performed by repair work.

After the pipe is installed, a water pressure (pneumatic) test is performed to check the seal of the connection between the stainless steel pipe 1 and the joint body 3. When the pipe is connected in a completely sealed state as described above, Does not leak water (air),
When there is a defect such as forgetting to tighten the nut 12, FIG.
Since water (air) leaks to the outside through a gap between the inner peripheral surface of the O-ring 8 and the outer peripheral surface of the stainless steel pipe 1 as shown in (1), defective pipe connection can be found, and complete pipe connection can be performed.

In the first embodiment, since the sliding member 20 is integrally provided in the receiving recess 13 of the nut 12 by bonding, when the stainless steel pipe 1 is inserted through the nut 12, the sliding member 20 is 12 can be prevented from being lost by dropping, and therefore, the piping work can be performed smoothly and quickly.

Next, a second embodiment of the present invention will be described. FIG. 5 shows a pipe joint according to a second embodiment of the present invention, and is a cross-sectional view of main parts in a state before connection. FIG. 6 shows the pipe joint, and is a cross-sectional view of main parts in a state after connection. 3A and 3B are a front view and a right side view, respectively, showing a sliding member used for the pipe joint.

The present embodiment differs from the first embodiment in the configuration in which the sliding member 20 is provided integrally with the nut 12, and is the same in other configurations. The description is omitted by attaching the reference numerals, and different configurations will be mainly described.

In this embodiment, as shown in FIGS. 5 to 7, an accommodation recess 28 formed of an annular groove is formed inside the base of the nut 12. On the other hand, the sliding member 29
It is made of a synthetic resin having a low friction coefficient and is formed in a ring shape as a whole, but has a cut-off portion 30 at one place, and is elastically deformed by an external force to reduce the diameter, and the diameter is increased by removing the external force. Is restored as follows.
The sliding member 29 is formed so that its outer peripheral surface, front end surface, and rear end surface can conform to the shape of the accommodating recess 28, and has a tapered shape such that the inside gradually decreases in diameter from the front end to the rear end. The engaging surface 31 is formed so that the rear side of the engaging surface 31 is substantially parallel to the axis. The diameter of the sliding member 29 is reduced by elastic deformation due to external force, and the sliding member 29 is inserted into the housing recess 28 of the nut 12 from the lower protruding portion side on the front side thereof, and the housing recess 2 is removed by removing the external force.
It is expanded in 8 and held so as not to come off.

When the nut 12 and the sliding member 29 are loosely fitted to the stainless steel tube 1, the female thread 16 of the nut 12 is screwed into the male thread 9 of the joint main body 3, whereby the sliding member 29 is engaged. Inclined surface 3 at
1, the stainless steel pipe 1 is advanced by pressing the side of the annular projection 12 of the stainless steel pipe 1 away from the pipe end, and the joint body 3 and the stainless steel pipe 1 are sealed in the same manner as in the first embodiment. Can be connected.

Also in this embodiment, the frictional resistance of the annular projecting portion 2 to the O-ring 8 on the tube end side and the corner 27
By setting the sum of the frictional resistance of the nut 12 and the frictional surface between the engagement surface 31 of the sliding member 29 and the separation side of the annular projection 2 with respect to the pipe end, the nut 12 is rotated and the nut 12 is rotated. When the steel pipe 12 is fastened to the joint body 3, the stainless steel pipe 1 can be prevented from rotating together. In particular, the sliding member 29 can be rotated with respect to the nut 12 by housing the sliding member 29 in the housing recess 28 formed of an annular groove in the nut 12 and holding it on the nut 12 as in the present embodiment. , Stainless steel pipe 1
The nut 1 is located on the side of the annular projecting portion 2 which is separated from the pipe end.
The frictional resistance when pressing the joint body 3 via the sliding member 29 when tightening the joint body 3 can be further reduced.

In the first embodiment, the sliding member 20 can be configured to have a cut-off portion at one place, as in the second embodiment. Further, in each of the first and second embodiments, the sliding member 20,
28 may be formed in a split type such as a split type. Also,
The sliding member 29 according to the second embodiment is housed in the housing recess 28 formed of an annular groove, and is bonded to the nut 12.
Can also be provided integrally. Further, the sliding member 29 can be formed in an annular shape without being divided. In this case, for example, if one of the walls forming the housing recess 28 is screwed to the nut 12, the sliding member 29 can be formed. Can be easily accommodated in the accommodation recess 28. In addition, the first
The sliding member 20 in the embodiment may be simply accommodated without being bonded to the accommodation recess 13. Further, the frictional resistance between the pipe end side portion of the annular projecting portion 2 of the stainless steel tube 1 and the sealing material is set to be larger than the frictional resistance between the sliding side members 20 and 28 and the separation side portion of the annular projecting portion 2 with respect to the tube end. By doing so, the pipe end side portion of the annular projecting portion 2 does not have to be pressed against the corner portion 27 of the joint body 3. Further, the sealing material such as the O-ring 8 is housed in a housing recess whose tip side is open, and this sealing material can be pressed not only by the annular projecting portion 2 of the stainless steel pipe 1 but also by the contact surface 18 of the nut 12. it can. In addition, the present invention can be variously changed in design without departing from the basic technical idea.

[0034]

As described above, according to the present invention, the end of the metal pipe is inserted into the joint body, and the female thread of the nut fitted to the metal pipe is screwed into the male thread of the joint body. , The metal pipe is advanced by pressurizing the side of the annular projection of the metal pipe away from the pipe end via a sliding member provided inside the nut, and accordingly, at least the joint body and the annular projection of the metal pipe The sealing material is pressurized with the pipe end side of the above, and the metal pipe and the joint body can be connected in a sealed state. As described above, when the metal pipe having the annular protrusion at the end is connected to the joint body in a sealed state by the nut, the metal pipe is advanced with respect to the joint body via the sliding member.
The metal tube can be prevented from rotating together with the nut. Therefore, it is possible to prevent a nut or the like screwed to the other side of the joint main body from being loosened or to prevent damage to the sealing material, thereby improving connection reliability.

Further, the sliding member is provided integrally with the nut,
Alternatively, by holding the metal tube so that it can be prevented from being detached, the sliding member can be prevented from dropping and losing when the metal tube is inserted into the nut, and therefore, the connection operation can be performed smoothly and quickly.

[Brief description of the drawings]

FIG. 1 shows a pipe joint according to a first embodiment of the present invention,
It is a principal part sectional view in the state before connection.

FIG. 2 is a sectional view of a main part of the pipe joint in a state after connection.

3 (a) and 3 (b) are a front view and a right side view, respectively, showing a sliding member used for the pipe joint.

FIGS. 4A and 4B are a front view and a right side view showing a stop ring used in the pipe joint, respectively.

FIG. 5 shows a pipe joint according to a second embodiment of the present invention,
It is a principal part sectional view in the state before connection.

FIG. 6 is a sectional view of a main part of the pipe joint in a state after connection.

FIGS. 7 (a) and 7 (b) are a front view and a right side view showing a sliding member used for the pipe joint, respectively.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stainless steel pipe (metal pipe) 2 Annular protrusion 3 Joint main body 8 O-ring (seal material) 12 Nut 13 Housing recess 20 Sliding member 21 Engaging surface 23 Stop ring 28 Housing recess 29 Sliding member 31 Engaging surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Maki Akatsuka, 2-5-13, Sanno, Ota-ku, Tokyo Inside Bencan Corporation (72) Satoshi Saito 2-5-13-, Sanno, Ota-ku, Tokyo Stock Company F-term (reference) in the company Bencan 3H014 DA01

Claims (8)

[Claims] 1. An annular projection formed at the end of a metal tube by expanding the pipe, gradually increasing in diameter from the tube end side to the separation side, gradually decreasing in diameter following the large diameter portion, and an outer periphery of the end portion. A nut having an internal thread portion, a nut having an internal thread portion fitted on the outer periphery of the metal pipe and screwing into the external thread portion of the joint body, and being able to advance integrally with the nut inside the nut. Is provided, by screwing the female screw part of this nut to the male screw part of the joint body,
A sliding member that presses a side portion of the annular projection of the metal tube away from the pipe end to advance the metal tube; and a tube at least in the joint body and the annular projection of the metal tube with the advancement of the metal tube. A pipe joint comprising: a sealing member interposed in a compressed state with the end side portion. 2. A fitting which is fitted to a terminal end portion of a male screw portion of a joint body, prevents a nut from being manually tightened, and has a projecting portion which is deformed when the nut is fully tightened by a tool. 2. The pipe joint according to claim 1, further comprising a stop ring concealed inside the tip of the nut when tightening. 3. The pipe joint according to claim 1, wherein the sliding member is provided integrally with the nut by bonding. 4. The pipe joint according to claim 1, wherein the sliding member is fitted into the groove-shaped receiving recess of the nut and held by the nut. 5. The pipe joint according to claim 1, wherein the sliding member is fitted into and adhered to the groove-shaped receiving recess of the nut and provided integrally with the nut. 6. The pipe joint according to claim 1, wherein the sliding member is formed in a continuous ring shape. 7. The sliding member has a separation portion at one place,
The pipe joint according to any one of claims 1 to 5, wherein the pipe joint is formed in a ring shape that is elastically deformed by an external force to reduce the diameter and is restored to an enlarged diameter by removing the external force. 8. The joint body has a seal material accommodating recess in an enlarged portion at an end portion, the seal material is accommodated in the seal material accommodating recess, and a female screw portion of a nut is provided in a male screw portion of the joint body. By pressing the separated side portion of the annular projection of the metal tube with respect to the tube end by the sliding member inside the nut being screwed, the tube end side portion of the annular projection is pressed against the sealing material, The pipe joint according to any one of claims 1 to 6, wherein a pressure is applied to a base end of the expanded portion of the joint body.