TWM664174U - Tube joint - Google Patents

Abstract

The present invention provides a pipe joint that can suppress fluid leakage even when the pipe body is inserted in the state where the joint body and the cover part are assembled. The pipe joint of the present invention comprises: a cylindrical metal joint body having a stepped surface at the inner bottom that abuts against the bottom end of the pipe body; and a cylindrical metal cover part that is assembled to the opening of the joint body by threaded fastening; and when the joint body and the cover part are assembled, an insertion space for inserting the pipe body is formed; the pipe joint further comprises ：The lock ring is arranged inside the aforementioned joint body and fixes the outer peripheral surface of the aforementioned tube body inserted before to limit the withdrawal of the tube body; and the sealing ring is arranged on the inner peripheral surface of the aforementioned cover component and contacts the outer peripheral surface of the aforementioned tube body inserted before and the peripheral surface of the aforementioned insertion space to prevent the fluid leaking from the gap between the bottom end of the aforementioned tube body and the aforementioned step difference surface from leaking to the outside of the aforementioned pipe joint.

Description

Pipe joints

The invention relates to a pipe joint, and more particularly to a pipe joint having a locking ring for limiting the withdrawal of an inserted pipe.

As such a pipe joint, the technology described in the following patent document 1 has been proposed. This pipe joint comprises: a cylindrical joint body having a stepped surface at the inner bottom that contacts the bottom end of the pipe body; and a cylindrical cover member that is assembled to the opening of the joint body by thread fastening. In this pipe joint, the pipe body is inserted in a state where the joint body and the cover member are assembled.

In addition, the pipe joint is provided with: a sealing ring for suppressing the fluid leaking from the gap between the bottom end of the inserted pipe body and the step surface from leaking to the outside of the pipe joint; and a locking ring for limiting the insertion of the pipe body.

The sealing ring is mounted on the sealing receiving portion formed on the inner peripheral surface of the joint body. The locking ring is mounted on the locking ring receiving portion formed on the inner peripheral surface of the cover member. The locking ring has a plurality of claws formed around the center hole of the annular plate.

According to the pipe joint constructed as described above, when inserting the pipe body, the claws of the lock ring are pressed by the outer peripheral surface of the pipe body and elastically expand the diameter, thereby inserting the pipe body until its bottom end abuts against the step surface. After the pipe body is inserted, if a force in the direction of pulling out is applied to the pipe body, the front end of the claws of the lock ring will bite the outer surface of the pipe body, thereby limiting the pulling out of the pipe body. [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2016-223544

[Technical problems that the new technology aims to solve]

As described above, in the structure of the pipe joint in which the pipe body is inserted after the joint body and the cover member are assembled, the following situation occurs: the fluid leaking from the gap between the bottom end of the inserted pipe body and the step surface leaks to the outside of the pipe joint through the gap between the joint body and the cover member.

Therefore, the purpose of this invention is to provide a pipe joint that can suppress fluid leakage even when the pipe body is inserted in a state where the joint body and the cover part are assembled. [Technical means]

The pipe joint of the invention comprises: a cylindrical metal joint body having a stepped surface at the inner bottom thereof abutting against the bottom end of the pipe body; and a cylindrical metal cover member assembled to the opening of the joint body by thread fastening; and when the joint body and the cover member are assembled, an insertion space for inserting the pipe body is formed, and the invention further comprises: The lock ring is arranged inside the aforementioned joint body and fixes the outer circumference of the inserted tube to limit the withdrawal of the tube; and the sealing ring is arranged on the inner circumference of the aforementioned cover component and contacts the outer circumference of the inserted tube and the circumference of the insertion space to suppress the fluid leaking from the gap between the bottom end of the tube and the step surface from leaking to the outside of the aforementioned pipe joint.

In the pipe joint of the present invention, the following structure can be adopted: when the aforementioned cover component is assembled to the aforementioned joint body, an outer side sealing ring is added to seal the gap between the inner peripheral surface of the opening part of the aforementioned joint body and the outer peripheral surface of the aforementioned cover component.

The pipe joint of the present invention can be constructed as follows: an auxiliary sealing ring is provided, which is arranged on the inner circumference of the aforementioned cover component and contacts the outer circumference of the aforementioned tube body inserted therein and the inner circumference of the aforementioned cover component, thereby sealing so that condensation generated on the outer circumference of the aforementioned tube body outside the pipe joint will not penetrate into the interior of the pipe joint.

The pipe joint of the present invention can be constructed as follows: the joint body and the cover member, when assembled, have abutment surfaces on the radially outer side of the insertion space that contact each other in the axial direction; at least a portion of the abutment surfaces serves as abutment sealing surfaces that abut and seal.

In the pipe joint of the present invention, the following structure can be adopted: an internal thread is formed on a part of the inner peripheral surface of the opening of the aforementioned joint body, and an external thread is formed on a part of the outer peripheral surface of the aforementioned cover member, and the aforementioned cover member is assembled to the opening of the aforementioned joint body by thread-tightening the aforementioned internal thread and the external thread; the aforementioned abutting sealing surface is arranged on the aforementioned step difference surface side and radially inward relative to the thread-tightening part of the aforementioned internal thread and the external thread. [Effect of the new type]

According to the pipe joint of the present invention, the sealing ring can be used to prevent the fluid from leaking from the outer circumference of the tube body and the circumference of the insertion space to the outside of the pipe joint; the abutting sealing surface can be used to prevent the fluid from leaking from the gap between the abutting surfaces of the joint body and the cover component to the outside of the pipe joint.

Below, with reference to Figures 1 to 5, a pipe joint of one embodiment of the present invention is described. The pipe joint 1 of this embodiment can be appropriately used to connect medical gas copper pipes, refrigerant copper pipes, etc., such as tube bodies 2A and 2B. In addition, it is known that such medical gases, refrigerants (including both gas and liquid), etc., are usually high pressure relative to the water pressure of tap water.

As shown in FIG1 , the pipe joint 1 of the first embodiment comprises: a joint body 3, a cover member 4, a plurality of sealing rings, and a plurality of locking rings 5. The pipe joint 1, in order to connect the connected pipe bodies 2A and 2B to each other, is formed into a pair of pipe joint parts 6A and 6B of a left-right symmetrical structure at the center position along the axial direction (long side direction) of the pipe bodies 2A and 2B and is integrally formed. Therefore, in the following description, the description of the structure of the pipe joint part 6A on one side relative to the center position also serves as the description of the structure of the other side.

Furthermore, the pipe joint portion 6A on one side and the pipe joint portion 6A on the other side have a joint body 3 that is symmetrical in structure and formed as one piece. However, in the following description, even if the joint body 3 is symmetrical in structure and formed as one piece, when the joint body 3 is referred to as the joint body 3 in the description of the structure of the pipe joint portion 6A on one side, it means the joint body 3 of the area occupied by the pipe joint portion 6A on one side.

The following is an explanation of the structure of the pipe joint portion 6A on one side. The pipe joint portion 6A includes: a joint body 3, a plurality of locking rings 5, a cover member 4, and a plurality of sealing rings. The joint body 3 is made of metal and is formed into a cylindrical shape having a body side insertion space 7 inside. The joint body 3 is integrally formed with: a body major diameter portion 8, which is the end side where the insertion of the pipe body 2A begins (hereinafter referred to as the "primary side" for convenience); and a body minor diameter portion 9, which is the bottom side where the insertion of the pipe body 2A is completed (hereinafter referred to as the "secondary side" for convenience). The body major diameter portion 8 is formed to have a larger diameter than the body minor diameter portion 9.

The inside of the main body major diameter portion 8 (primary side end portion) of the joint main body 3 is formed as an opening portion 10. An internal thread is formed in a region along the axial direction close to the secondary side of a part of the inner circumference of the main body major diameter portion 8. An annular main body side major diameter seal receiving recess 12 is formed on the inner circumference of the primary side end of the main body major diameter portion 8 for receiving a major diameter seal ring 11 as an outer side seal ring on the outer diameter side portion. The primary side end surface of the main body major diameter portion 8 is a main body side first contact surface 14 that contacts the cover side first contact surface 13 of the cover member 4.

The opening 10 is a cylindrical large-diameter space into which the secondary side region of the cover member 4 is inserted. On the secondary side of this opening 10, a main body side insertion space 7 is formed in a continuous manner. The inner bottom of the main body side insertion space 7 of the joint body 3 is a reduced diameter, and an annular step surface 16 is formed to abut against the bottom end surface 15 of the inserted pipe body 2A. The step surface 16 is a side surface of one side of a step wall 17, and is arranged in a plane orthogonal to the axial direction; the aforementioned step wall 17 is formed in a reduced diameter manner at the center position along the axial direction of the joint body 3 of the pipe joint 1.

The connector body 3 has a lock ring receiving portion 18. The lock ring receiving portion 18 is disposed between the body large diameter portion 8 and the body small diameter portion 9. The lock ring receiving portion 18 is formed at an end position on the side of the opening portion 10 in the body side insertion space 7. The lock ring receiving portion 18 is formed to be larger than the diameter of the body side insertion space 7 and smaller than the diameter of the opening portion 10. The diameter of the lock ring receiving portion 18 is set to be slightly larger than the outer diameter of the lock ring 5, so that the lock ring 5 can be received in the lock ring receiving portion 18. The length along the axial direction of the lock ring receiving portion 18 is set to be able to accommodate a plurality of (here, two) lock rings 5.

The end surface of the lock ring receiving portion 18 on the step surface 16 side is a fixing surface 19 that prevents the lock ring 5 from moving to the secondary side. The fixing surface 19 is arranged on the primary side opposite to the step surface 16 and is formed in an annular shape. The fixing surface 19 is arranged in a plane orthogonal to the axial direction.

Here, the structure of the lock ring 5 is described. The multiple lock rings 5 have the same structure, so the description of the structure of one of the lock rings 5 is also used as the description of the other lock rings 5.

The lock ring 5 is made of metal. As shown in FIG. 1 and FIG. 2 (a) and (b), the lock ring 5 has: an annular flange 20 along the axial direction, an annular claw holding portion 21 formed by bending from the end of the flange 20 toward the center side, and a plurality of claws 22 formed by bending on the inner circumference of the claw holding portion 21.

In particular, each claw 22 is arranged at equal intervals on the inner peripheral surface of the claw holding portion 21 in the circumferential direction, and is bent so as to be inclined toward the insertion direction (secondary side) of the tube body 2A. The outer diameter line of the claw 22 is formed in an arc shape. The claw 22 is formed so that the diameter of the imaginary circle C (two-point chain line on the drawing) connecting the front ends of the claws 22 is slightly smaller than the outer diameter of the tube body 2A. This lock ring 5 is arranged so as to contact the lock ring receiving portion 18 in the axial direction.

The lock ring receiving portion 18 (body side insertion space 7) and the opening portion 10 form a ring-shaped body side second contact surface 23 that is orthogonal to the axial direction and parallel to the step surface 16 and the fixing surface 19. The body side second contact surface 23 is a surface that contacts the cover side second contact surface 24 of the cover member 4 and is one side of a metal contact seal surface that constitutes an example of a contact sealing surface. Therefore, the body side second contact surface 23 is processed into a smooth surface. The body side second contact surface 23 is arranged on the step surface 16 side relative to the internal thread and radially inward.

Next, the structure of the cover member 4 is described. The cover member 4 is assembled to the opening portion 10 of the joint body 3 by threaded fastening. The cover member 4 is made of metal. The cover member 4 is formed into a cylindrical shape with the inner portion serving as the cover side insertion space 25. The cover side insertion space 25 is connected to the body side insertion space 7 when the cover member 4 is assembled to the joint body 3. The cover member 4 comprises: a reduced portion 28 having an auxiliary seal receiving portion 27 for mounting an auxiliary seal ring 26; a cover large diameter portion 29 integrally formed on the secondary side of the reduced portion 28; and a cover small diameter portion 30 integrally formed on the secondary side of the cover large diameter portion 29.

The outer circumference of the contraction portion 28 is contracted to one side and thereby formed into a cone shape. An auxiliary seal receiving portion 27 for mounting an auxiliary seal ring 26 is formed on the inner circumference of the contraction portion 28. The auxiliary seal ring 26 contacts the outer circumference of the tube body 2A, thereby assisting in preventing condensation generated on the outer circumference of the tube body 2A outside the pipe joint 1 from penetrating into the inside of the pipe joint 1.

The cover large diameter portion 29 is a portion held by a tool; the cover component 4 is held by a tool and rotated to be screwed into the connector body 3.

The small diameter cover portion 30 is formed to have a smaller diameter than the large diameter cover portion 29. The large diameter cover portion 29 and the small diameter cover portion 30 are formed integrally via the first cover side contact surface 13. The first cover side contact surface 13 is located in a plane orthogonal to the axial direction and is formed in an annular shape. An annular cover side large diameter seal receiving recess 31 is formed near the primary side end of the outer peripheral surface of the small diameter cover portion 30 (i.e., near the first cover side contact surface 13) for receiving the large diameter seal ring 11 in the inner diameter side portion. An outer thread that is threadedly engaged with the inner thread is formed on the outer peripheral surface of the small diameter cover portion 30 at a secondary side opposite to the large diameter seal accommodating recess 31 on the cover side.

The secondary side end surface 32 of the small diameter portion of the cover small diameter portion 30 is formed into an annular surface. The secondary side end surface 32 of the small diameter portion is set to be longer in the radial direction than the second contact surface 23 of the body side. The secondary side end surface 32 of the small diameter portion has a second contact surface 24 of the cover side that contacts the second contact surface 23 of the body side in the axial direction, and a pressing surface 33 of the primary side surface of the claw holding portion 21 that can contact the lock ring 5 on the primary side. An annular recess (symbol omitted) is formed between the second contact surface 24 of the cover side and the pressing surface 33.

The second contact surface 24 on the cover side is the other side of the metal contact sealing surface. Therefore, the second contact surface 24 on the cover side is processed into a smooth surface. The second contact surface 24 on the cover side is arranged on the side of the step surface 16 relative to the external thread and on the radial inner side. The radial outer side and the radial inner side of the second contact surface 24 on the cover side are chamfered.

On the inner circumferential surface of the cover member 4, the receiving recesses 34 of the small-diameter sealing ring 35 are arranged at intervals in the axial direction, and a small-diameter sealing ring 35 is installed in each receiving recess 34. The receiving recesses 34 (small-diameter sealing ring 35) arranged on the secondary side and the secondary side end surface 32 of the small-diameter part are arranged at intervals in the axial direction.

In the pipe joint 1 of this embodiment, the pipe joint part 6A constituted as a pair of symmetrical and integrally formed structures. In the pipe joint 1, the lock ring 5 is arranged in the axial direction and mounted on the lock ring receiving part 18 of the joint body 3. In the cover member 4, the small diameter seal ring 35 is mounted on the receiving recess 34; the auxiliary seal ring 26 is mounted on the auxiliary seal receiving part 27; and the large diameter seal ring 11 is mounted on the inner diameter side portion of the large diameter seal receiving recess 31 on the cover side. In this way, when each component is installed on the connector body 3 and the cover component 4, the small-diameter cover portion 30 of the cover component 4 is inserted into the opening portion 10 of the connector body 3, and assembled by tightening the threads of the external thread and the internal thread. In this way, the connector body 3 and the cover component 4 become one body, and the body side insertion space 7 and the cover side insertion space 25 are connected to form an insertion space for the tube body 2A.

When the cover member 4 is assembled to the opening 10 of the joint body 3 by tightening the threads of the external thread and the internal thread, the large diameter portion 29 of the cover is held with a tool to rotate the cover member 4, thereby locking the cover member 4 to the joint body 3. In this way, the outer diameter side portion of the large diameter sealing ring 11 will be accommodated in the large diameter sealing accommodation recess 12 on the body side.

In addition, the large diameter seal ring 11 is held and compressed between the outer circumference of the cover side large diameter seal receiving recess 31 and the inner circumference of the body side large diameter seal receiving recess 12. Thus, the thread fastening portion 36 of the threaded engagement portion of the external thread and the internal thread seals the gap between the inner circumference of the body large diameter portion 8 and the outer circumference of the cover small diameter portion 30 on the axially outer side. The outer side in the axial direction refers to the primary side (the inflow side of the fluid flowing through the tube body 2A) in the pipe joint 6A on one side, and the secondary side (the outflow side of the fluid flowing through the tube body 2A) in the pipe joint 6A on the other side, which is a bilaterally symmetrical structure with the pipe joint 6A on one side.

The action described below is performed on the pipe joint part 6A on one side. As described above, the joint body 3 and the cover part 4 are assembled as the pipe joint 1, and the pipe body 2A is inserted from the cover side insertion space 25 of the pipe joint 1 into the body side insertion space 7 (from the primary side to the secondary side). If the pipe body 2A is inserted into the cover side insertion space 25, the auxiliary sealing ring 26 is elastically compressed between the outer circumference of the pipe body 2A and the outer circumference of the auxiliary sealing receiving part 27. If the pipe body 2A is further inserted, the small diameter sealing ring 35 is compressed between the outer circumference of the pipe body 2A and the outer circumference of the receiving recess 34.

The receiving recess 34 arranged on the secondary side and the secondary side end surface 32 of the small diameter portion are arranged at intervals in the axial direction, so if the tube body 2A is further inserted, the front end side portion of the tube body 2A will be guided to the inner circumference between the receiving recess 34 in the small diameter portion 30 of the cover and the secondary side end surface 32 of the small diameter portion, and reach the lock ring 5.

In the lock ring 5, the claw 22 is elastically pressed radially outward by the outer peripheral surface of the tube body 2A, thereby allowing the tube body 2A to be inserted, so that the tube body 2A can be inserted into the insertion space (body side insertion space 7) until the bottom end surface 15 of the tube body 2A abuts the step surface 16. After the tube body 2A is inserted, if a force in the extraction direction is applied to the tube body 2A, the front end of the claw 22 will bite the outer surface of the tube body 2A, thereby preventing the tube body 2A from being pulled out. In addition, the compression surface 33 abuts the primary side surface of the claw holding portion 21, thereby preventing the lock ring 5 from moving to the primary side.

The pipe connector 1 of this embodiment can limit the removal by inserting the pipe body 2A to a specified length in the assembly of the connector body 3 and the cover part 4. Such a pipe connector 1 is also called a one-touch connector. In addition, the pipe connector part 6A on the other side is also inserted into the pipe body 2A in the same manner as the pipe connector part 6A on one side.

In the pipe joint 1 of this embodiment, when the pipe body 2A is inserted into the insertion space, the auxiliary sealing ring 26 and the small diameter sealing ring 35 are compressed between the outer circumference of the pipe body 2A and the circumference of the insertion space and are compressed in the radial direction.

When the tube body 2A is inserted into the insertion space of the pipe joint 1, the fluid is supplied to the tube body 2A and flows. When the fluid leaks from the gap between the bottom end surface 15 of the tube body 2A and the step surface 16 of the joint body 3, the auxiliary sealing ring 26 and the small diameter sealing ring 35 that are in contact with and compressed by the outer peripheral surface of the tube body 2A and the peripheral surface of the insertion space can suppress the fluid from leaking from the outer peripheral surface of the tube body 2A and the peripheral surface of the insertion space to the outside of the pipe joint 1.

In the pipe joint 1 of this embodiment, the small-diameter sealing ring 35 is arranged on the primary side relative to the lock ring 5. That is, when the pipe body 2A is inserted into the pipe joint 1, the portion of the outer circumference of the pipe body 2A that contacts the small-diameter sealing ring 35 will not have scratches caused by contact with the claws 22 of the lock ring 5. Therefore, the gap between the inner side of the cover member 4 and the outer circumference of the pipe body 2A is reliably sealed by the small-diameter sealing ring 35.

In addition, the pipe joint 1 in this embodiment is a joint body 3 and a cover part 4, two different parts, are assembled with each other in the axial direction. At this time, the first contact surface 13 on the cover side and the first contact surface 14 on the body side are in contact with each other in the axial direction. In addition, the second contact surface 24 on the cover side and the second contact surface 23 on the body side are in contact with each other in the axial direction. Moreover, the second contact surface 24 on the cover side and the second contact surface 23 on the body side constitute a metal contact sealing surface as a contact sealing surface.

Therefore, the gap between the joint body 3 and the cover member 4 is securely sealed by the metal contact sealing surface at the radially inner position relative to the threaded fastening portion 36 and the radially outer position of the insertion space. Therefore, even if the fluid leaks from the gap between the bottom end surface 15 of the tube body 2A and the step surface 16 of the joint body 3, the fluid can be prevented from leaking from the gap between the joint body 3 and the cover member 4 to the outside of the pipe joint 1. Moreover, even if the fluid leaks from the metal contact sealing surface, the leakage can be prevented by the large diameter sealing ring 11.

The pipe joint 1 of the present invention is not limited to the above-mentioned embodiments. FIG. 3 shows the pipe joint 1 of the second embodiment of the present invention. The second embodiment of the pipe joint 1 has a different structure from the first embodiment of the pipe joint 1, which is a metal contact sealing surface. In the first embodiment of the pipe joint 1, the metal contact sealing surface is constituted by the second contact surface 24 on the cover side and the second contact surface 23 on the body side.

The metal contact sealing surface in the second embodiment is composed of the first contact surface 13 on the cover side and the first contact surface 14 on the body side. The first contact surface 13 on the cover side and the first contact surface 14 on the body side are formed as smooth surfaces, and the radial outer side and radial inner side of the first contact surface 14 on the body side are chamfered. The metal contact sealing surface in the second embodiment is composed of the first contact surface 13 on the cover side and the first contact surface 14 on the body side, and is therefore arranged at the radial inner side position relative to the threaded fastening portion 36 and the radial outer side position of the insertion space.

The large diameter sealing ring 11 is arranged at the same position as the first embodiment. The large diameter sealing ring 11 is clamped and compressed between the outer peripheral surface of the large diameter sealing receiving recess 31 on the cover side and the inner peripheral surface of the large diameter sealing receiving recess 12 on the body side. In this way, the thread tightening portion 36 of the threaded portion of the external thread and the internal thread seals the gap between the inner peripheral surface of the main body large diameter portion 8 and the outer peripheral surface of the small diameter portion 30 of the cover on the outer side of the axial direction.

In the second embodiment of the pipe joint 1, the fluid leaking from the gap between the bottom end surface 15 of the tube body 2A and the step surface 16 of the joint body 3 is suppressed from leaking to the outside by the large-diameter sealing ring 11. Even if the fluid moves from the large-diameter sealing ring 11 to the outside, the metal contact sealing surface formed by the first contact surface 13 on the cover side and the first contact surface 14 on the body side can still suppress the fluid from leaking from the gap between the joint body 3 and the cover member 4 to the outside of the pipe joint 1. Other functions and effects are the same as those of the first embodiment, so they are not repeated.

FIG. 4 shows a pipe joint 1 of the third embodiment. In the pipe joint 1 of the third embodiment, the metal contact sealing surface is a tapered surface with a small diameter toward the secondary side. The outer periphery of the secondary side end of the small diameter cover portion 30 of the cover member 4 forms a tapered cover surface 40 with a small diameter toward the secondary side; the interface between the body small diameter portion 9 of the joint body 3 and the lock ring receiving portion 18 forms a body tapered surface 41 with a small diameter toward the secondary side. The cover tapered surface 40 and the body tapered surface 41 are formed as smooth surfaces.

At this time, the metal contact sealing surface is arranged at the radially inner position relative to the threaded fastening portion 36 and the radially outer position of the insertion space, and the gap between the joint body 3 and the cover part 4 is reliably sealed by the metal contact sealing surface.

FIG5 shows a fourth embodiment of the pipe joint 1. In the first embodiment, the second contact surface 23 on the body side is an annular plane perpendicular to the axial direction and parallel to the step surface 16 and the fixing surface 19; and the second contact surface 24 on the cover side has a cross-sectional shape in which the radial outer side and the radial inner side of the smooth surface are chamfered. In contrast, in the fourth embodiment, the second contact surface 23 on the body side has a cross-sectional shape in which the radial outer side and the radial inner side of the smooth surface are chamfered. In addition, the radial outer side of the pressing surface 33 forms an annular smooth surface that is orthogonal to the axial direction and parallel to the step surface 16 and the fixing surface 19, and forms the second contact surface 24 on the cover side. Moreover, the second contact surface 23 on the body side and the second contact surface 24 on the cover side form a metal contact sealing surface.

At this time, the metal contact sealing surface is arranged at the radially inner position relative to the threaded fastening portion 36 and the radially outer position of the insertion space, and the gap between the joint body 3 and the cover part 4 is reliably sealed by the metal contact sealing surface.

FIG6 shows a fifth embodiment of the pipe joint 1. The fifth embodiment of the pipe joint 1 is constructed as follows: the body tapered surface 41 of the pipe joint 1 of the third embodiment is used as a smooth surface, and the body side second sealing surface is used as a metal contact sealing surface. At this time, the inclination of the body tapered surface 41 is set to a specified inclination angle relative to the axial direction (for example, 45° relative to the axial direction). In addition, the secondary side end surface 32 of the small diameter portion of the cover member 4 is an annular smooth surface that is orthogonal to the axial direction and parallel to the step surface 16 and the fixing surface 19. Furthermore, the corner 40a of the continuous portion between the secondary side end surface 32 of the small diameter portion 30 of the cover and the outer peripheral surface of the small diameter portion 30 of the cover is used as a metal contact sealing surface.

In the pipe joints 1 of the first to fourth embodiments, the metal contact sealing surface is formed into a plane in advance. In contrast, the pipe joint 1 of the fifth embodiment locks the cover member 4 to the joint body 3, thereby pressing the corner 40a of the cover small diameter portion 30 to the plane body cone 41, and making the body cone 41 and the corner 40a abut against each other in a planar manner, thereby forming a metal contact sealing surface.

At this time, the metal contact sealing surface is arranged at the radially inner position relative to the threaded fastening portion 36 and the radially outer position of the insertion space, and the gap between the joint body 3 and the cover part 4 is reliably sealed by the metal contact sealing surface.

As another embodiment, for example, in all embodiments, the large-diameter sealing ring 11 can also be omitted. In this case, the body-side large-diameter sealing receiving recess 12 is not formed in the connector body 3; and the cover part 4 is not formed with a cover-side large-diameter sealing receiving recess 31.

In this structure, for example, in the pipe joint 1 of the first embodiment, the second contact surface 24 on the cover side and the second contact surface 23 on the body side contact in the axial direction to form a metal contact sealing surface. Even if the fluid leaks from the gap between the bottom end surface 15 of the tube body 2A and the step surface 16 of the joint body 3, the fluid can still be prevented from leaking from the gap between the joint body 3 and the cover member 4 to the outside of the pipe joint 1.

In the second embodiment, the first contact surface on the cover side and the first contact surface on the body side are contacted in the axial direction to form a metal contact sealing surface; in the first, third, fourth and fifth embodiments, the second contact surface on the cover side and the second contact surface on the body side are contacted in the axial direction to form a metal contact sealing surface. However, for example, the pipe joint 1 of the first, third, fourth and fifth embodiments may also be a pipe joint 1 having a structure in which the first contact surface on the cover side and the first contact surface on the body side are contacted in the axial direction to form a metal contact sealing surface as shown in the second embodiment.

In the above-mentioned embodiments, the pipe joint 1 is illustrated as being integrally formed with a pair of pipe joint portions 6A. However, as long as at least one of the pipe joint portions is the pipe joint portion 6A of the present invention, the other pipe joint portion may not be the pipe joint portion 6A of the present invention.

In the above-mentioned embodiments, as an example of the abutting sealing surface, the metal contact sealing surface of the abutting surfaces of the parts made of metal materials is listed. However, as long as the gap between the joint body 3 and the cover part 4 is surely sealed by the abutting sealing surface, it is not limited to the abutting surfaces of the parts made of metal materials, and can also be the abutting surface of resin materials, or the abutting structure of resin materials and metal materials.

Furthermore, the auxiliary sealing ring 26 is not necessarily required. It is not required when connecting the pipe bodies 2A and 2B that will not produce condensation. In this case, the auxiliary sealing receiving portion 27 is also not required. In addition, the pipe bodies 2A and 2B connected by the pipe joint 1 are not limited to metal, but can also be a composite pipe body of metal and resin.

1: Pipe joint

2A, 2B: Tube body

3: Connector body

4: Cover parts

5: Lock ring

6A, 6B: Pipe joint

7: Insertion space on the body side

8: Main body diameter

9: Small diameter of the body

10: Opening

11: Large diameter sealing ring

12: Large diameter sealing receiving recess on the side of the body

13: First contact surface on the cover side

14: First contact surface on the body side

15: Bottom end face

16: Step difference surface

17: Step wall

18: Lock ring storage unit

19: Fixed surface

20: flange

21: Claw holding part

22: Claws

23: Second contact surface on the body side

24: Second contact surface on the cover side

25: Cover side insertion space

26: Auxiliary sealing ring

27: Auxiliary sealing storage unit

28: Reduction

29: Cover the large diameter

30: Cover the small path

31: Large diameter sealing receiving recess on the cover side

32: Secondary side end face of small diameter part

33: Pressed noodles

34: Accommodation recess

35: Small diameter sealing ring

36: Fastening part

[Figure 1] Partial cross-sectional side view of the pipe joint of the first embodiment of this invention.

〔Figure 2〕Single-body diagram of the same lock ring, (a) is the side view, (b) is the front view.

[Figure 3] Partial cross-sectional side view of the pipe joint of the second embodiment of this invention.

[Figure 4] Partial cross-sectional side view of the pipe joint of the third embodiment of this invention.

[Figure 5] Partial cross-sectional side view of the pipe joint of the fourth embodiment of this invention.

[Figure 6] Partial cross-sectional side view of the fifth embodiment of the pipe joint of this invention.

1: Pipe joint

2A, 2B: Tube body

3: Connector body

4: Cover parts

5: Lock ring

6A, 6B: Pipe joint

7: Insertion space on the body side

8: Main body diameter

9: Small diameter of the body

10: Opening

11: Large diameter sealing ring

12: Large diameter sealing receiving recess on the side of the body

13: First contact surface on the cover side

14: First contact surface on the body side

15: Bottom end face

16: Step difference surface

17: Step wall

18: Lock ring storage unit

19: Fixed surface

20: flange

21: Claw holding part

23: Second contact surface on the body side

24: Second contact surface on the cover side

25: Cover side insertion space

26: Auxiliary sealing ring

27: Auxiliary sealing storage unit

28: Reduction

29: Cover the large diameter

30: Cover the small path

31: Large diameter sealing receiving recess on the cover side

32: Secondary side end face of small diameter part

33: Pressed noodles

34: Accommodation recess

35: Small diameter sealing ring

36: Fastening part

Claims (5)

A pipe joint, which comprises: A cylindrical metal joint body, which has a stepped surface at the inner bottom that abuts against the bottom end of a tube body; and A cylindrical metal cover member, which is assembled to the opening of the joint body by threaded fastening; and When the joint body and the cover member are assembled, an insertion space for inserting the tube body is formed; The pipe joint further comprises: A lock ring, which is arranged inside the joint body and fixes the outer peripheral surface of the inserted tube body to restrict the removal of the tube body; and The sealing ring is arranged on the inner circumference of the cover component and contacts the outer circumference of the inserted tube and the circumference of the insertion space to prevent the fluid leaking from the gap between the bottom end of the tube and the step surface from leaking to the outside of the pipe joint. A pipe joint as described in claim 1, wherein, when the cover member is assembled to the joint body, an outer sealing ring is installed to seal the gap between the inner circumference of the opening portion of the joint body and the outer circumference of the cover member. A pipe joint as described in claim 1 or 2, wherein an auxiliary sealing ring is provided, which is arranged on the inner circumference of the cover component and contacts the outer circumference of the inserted tube body and the inner circumference of the cover component, thereby sealing so that condensation generated on the outer circumference of the pipe joint outside the tube body will not penetrate into the interior of the pipe joint. The pipe joint as described in claim 1, wherein the joint body and the cover member, when assembled, have abutment surfaces on the radially outer side of the insertion space that contact each other in the axial direction; At least a portion of the abutment surface serves as an abutment sealing surface for abutment and sealing. A pipe joint as described in claim 4, wherein an internal thread is formed on a portion of the inner circumference of the opening of the joint body, and an external thread is formed on a portion of the outer circumference of the cover member, and the cover member is assembled to the opening of the joint body by thread-tightening the internal thread and the external thread; The abutting sealing surface is arranged on the step difference surface side and radially inward of the thread-tightening portion of the internal thread and the external thread.