Plastic sealed pipe fittings

Abstract

This invention proposes a resin-made sealed pipe fitting comprising a fitting body, an inner ring, and a nut. The inner ring has an insertion portion, and the fitting body has an insertion groove. The insertion portion is inserted into the insertion groove to form a sealed connection, and the nut is connected to the fitting body to ensure the insertion state of the insertion portion and the insertion groove. The nut is compressed against the inner ring, and in the free state, the thickness of the insertion portion changes linearly along the axial direction of the inner ring. In the inserted state, the insertion groove undergoes elastic deformation, and the rate of change of the insertion groove is smaller than the rate of change of the insertion portion in the free state. This invention has the following beneficial effects: 1. Since θ is greater than α, it not only ensures the sealing effect between the insertion portion and the insertion groove, but also reduces the frictional resistance that must be overcome when joining the insertion portion and the insertion groove. 2. The inner ring can be detached from the fitting body with relatively little force, and the compressibility of the inner ring does not decrease during rejoining, thus ensuring the reliability and durability of the seal.

Description

Technical Field

[0001] The present invention relates to a resin sealing pipe joint.

Background Art

[0002] Resin pipe joints used in manufacturing equipment in technical fields such as semiconductor manufacturing, medical / pharmaceutical manufacturing, food processing, and chemical industry are known. Such resin pipe joints are used to connect pipes for flowing fluids such as ultrapure water and chemical solutions to other pipes and fluid equipment and are joinable to the pipes.

[0003] Both US Patent No. 5743572A and Chinese Patent No. CN109642694B disclose the structure of such a joint, which mainly consists of a joint body, an inner ring, and a nut. As shown in FIG. 1, a groove portion b is formed in the joint body a, an insertion portion d is formed in the inner ring c, the insertion portion d is inserted into the groove portion b, the width D1 of the groove portion b does not change along the insertion direction, the wall thickness T0 of the insertion portion d does not change along the insertion direction, and T0 > D1.

[0004] During the use process, the applicant found that there are many deficiencies in such a structural method. 1. The insertion portion and groove portion are inserted horizontally, and there is significant resistance to insertion. During insertion, the frictional resistance that the inner ring must overcome is also large, requiring the inner ring insertion portion to be pushed in forcefully. This makes the contact surface prone to damage during the relative movement of insertion and removal, shortening the service life. Insertion and removal are very laborious, the insertion portion wears down during the relative movement of insertion and removal, and the more times it is inserted and removed the more wear occurs. The compression ratio of the inner ring decreases accordingly during the next installation, reducing the reliability of the seal. Moreover, the large frictional resistance results in a large tightening torque for the nut, making it laborious to tighten by hand. 2. After several years have passed since the inner ring was strongly pressed in, when attempting to remove the conduit from the joint, it pulls the conduit away from the joint body, causing the conduit and inner ring to separate. The inner ring has high frictional resistance and tends to remain attached to the joint body. When this occurs, when reattaching the removed conduit to the joint, it becomes necessary to remove the inner ring, which is still attached to the joint body, using tongs or similar tools. This not only damages the inner ring, but also weakens the seal between the detached inner ring and the conduit when reattaching them, reducing the airtightness between them and making it practically impossible to reattach the conduit and joint. [Overview of the project] [Means for solving the problem]

[0005] The object of this invention is to disclose a resin-made sealed pipe fitting, wherein the insertion portion is provided with an inclined angle θ, and θ is greater than the angle α of elastic deformation that occurs in the insertion groove portion during insertion, thereby not only guaranteeing a sealing effect between the insertion portion and the insertion groove portion, but also allowing the insertion portion to be inserted into the insertion groove portion more easily, reducing frictional resistance due to the restricting surface of the inner ring when joining the insertion portion and the insertion groove portion, the frictional resistance increases from small to large, the contact surface is less likely to be damaged, the service life of the fitting body and inner ring is extended, and the overall frictional resistance of the insertion portion and insertion groove portion is small, allowing the nut to be tightened with only a small torque. 2. The inner ring's insertion portion has a tapered cross-section, with the insertion tip having the maximum stroke and minimum compression, and the insertion end having the maximum compression and minimum stroke. When removing, the insertion end with the maximum compression is first detached from the insertion groove, allowing the inner ring to be detached from the joint body with relatively little force while maintaining the connection between the inner ring and the conduit. This reduces damage to the inner ring during each attachment and detachment process, improves the inner ring's service life, and relatively reduces labor with each attachment and detachment. Rejoining the conduit and joint is also more labor-saving, and the compression ratio of the inner ring does not decrease during rejoining, ensuring the reliability and durability of the seal.

[0006] To achieve the above objective, this application proposes a resin-made sealed pipe fitting comprising a fitting body, an inner ring, and a nut. The inner ring has an insertion portion, and the fitting body has an insertion groove. The insertion portion is inserted into the insertion groove to form a sealed connection, and the nut is connected to the fitting body to ensure the insertion state of the insertion portion and the insertion groove. The nut is compressed against the inner ring, and in the free state, the thickness of the insertion portion changes linearly along the axial direction of the inner ring. In the inserted state, the insertion groove undergoes elastic deformation, and the rate of change of the insertion groove is smaller than the rate of change of the insertion portion in the free state.

[0007] In some embodiments, when in a free state, the inner circumferential surface of the insertion portion forms an angle θ with the axis of the inner ring; when inserted, the insertion groove portion is elastically deformed, and the outer circumferential surface of the insertion groove portion forms an angle α with the axis of the inner ring, with the angle θ being greater than the angle α.

[0008] In some embodiments, 0 < θ < 15°.

[0009] In some embodiments, T2 > T1 ≥ D, where D is the width of the insertion groove, T1 is the thickness of the insertion tip of the insertion part, and T2 is the thickness of the insertion rear end of the insertion part.

[0010] In some embodiments, when inserted, the compression ratio of the insertion portion decreases along the insertion direction, the compression ratio of the insertion end of the insertion portion is 0 or greater, and the compression ratio of the insertion end of the insertion portion is 40% or less.

[0011] In some embodiments, when in the free state, the outer surface of the insertion portion and the axis of the inner ring form a certain angle.

[0012] In some embodiments, the joint body includes a cylindrical portion, on one side of the cylindrical portion an outer cylindrical portion and an inner cylindrical portion extending outward along the axial direction, the extending length of the outer cylindrical portion being greater than the extending length of the inner cylindrical portion, and the insertion groove portion being formed surrounded by the cylindrical portion, the outer cylindrical portion and the inner cylindrical portion.

[0013] In some embodiments, the system further includes a conduit, the inner ring is inserted into the conduit, and the inner ring is provided with a projection, the projection expanding the diameter of the conduit inlet to form a sealed connection.

[0014] In some embodiments, the conduit extends between the joint body and the inner ring, the nut is fitted into the conduit and screwed into the joint body, and the nut and the protrusion of the inner ring tightly fasten the conduit to form a sealed connection.

[0015] In some embodiments, the joint body and inner ring are made of a resin material. [Effects of the Invention]

[0016] The present invention has the following beneficial effects: 1. The insertion portion is provided with an inclined angle θ, and since θ is greater than the angle α of elastic deformation that occurs in the insertion groove during insertion, this not only ensures a sealing effect between the insertion portion and the insertion groove, but also allows the insertion portion to be inserted into the insertion groove more easily, reduces frictional resistance due to the restricting surface of the inner ring when joining the insertion portion and the insertion groove, the frictional resistance increases from small to large, the contact surface is less likely to be damaged, the service life of the joint body and inner ring is extended, and the overall frictional resistance of the insertion portion and insertion groove is small, allowing the nut to be tightened with only a small torque. 2. The inner ring's insertion portion has a tapered cross-section, with the insertion tip having the maximum stroke and minimum compression, and the insertion end having the maximum compression and minimum stroke. When removing, the insertion end with the maximum compression is first detached from the insertion groove, allowing the inner ring to be detached from the joint body with relatively little force while maintaining the connection between the inner ring and the conduit. This reduces damage to the inner ring during each attachment and detachment process, improves the inner ring's service life, and relatively reduces labor with each attachment and detachment. Rejoining the conduit and joint is also more labor-saving, and the compression ratio of the inner ring does not decrease during rejoining, ensuring the reliability and durability of the seal. [Brief explanation of the drawing]

[0017] [Figure 1] This diagram shows the structure of the insertion part and insertion groove part of the conventional technology. [Figure 2] This figure shows the structure of the resin-made sealed pipe fitting of the present invention. [Figure 3] This is an enlarged view of the symbol A in Figure 2. [Figure 4] This diagram shows the structure of the insertion section and insertion groove section. [Modes for carrying out the invention]

[0018] The present invention will be described in detail below based on the embodiments shown in the drawings, but these embodiments are not limitations to the present invention, and any functional, method, or structural equivalent transformation or substitution performed by those skilled in the art based on these embodiments falls within the scope of the present invention.

[0019] As shown in FIGS. 2 to 4, it is a resin sealed pipe joint, comprising a joint body 1, an inner ring 2, and a nut 3. The joint body 1 and the inner ring 2 are made of a resin material, and the joint body 1 and the inner ring 2 are deformable.

[0020] An insertion portion 21 is formed on the inner ring 2, an insertion groove portion 10 is formed on the joint body 1, and the insertion portion 21 is inserted into the insertion groove portion 10 to form a sealed connection, serving as a first sealing portion 51.

[0021] In the free state, the thickness of the insertion portion 21 linearly changes in diameter along the axial direction of the inner ring 2. In the inserted state, the insertion groove portion 10 elastically deform, and the diameter change rate of the insertion groove portion 10 is smaller than the diameter change rate of the insertion portion 21 in the free state. Specifically, in this embodiment, in the free state, that is, when the insertion portion 21 and the insertion groove portion 10 are not inserted, the inner peripheral surface of the insertion portion 21 forms an angle θ with the axis of the inner ring 2, where 0 < θ < 15°. In this embodiment, θ = 15°. By providing the inclined angle θ on the insertion portion 21, it can be inserted into the insertion groove portion 10 more easily, and a sealing surface is formed when the insertion portion 21 is inserted into the insertion groove portion 10.

[0022] The insertion portion 21 is provided with an inclined angle θ. When the insertion portion and the insertion groove portion are joined, the frictional resistance by the restricting surface of the inner ring is reduced. The frictional resistance is small and then becomes large, the contact surface is not easily damaged, the sealing effect between the joint body 1 and the inner ring 2 is more sustainable, the service life of the joint body 1 and the inner ring 2 is prolonged, the overall frictional resistance of the insertion portion and the insertion groove portion is small, and the nut can be tightened by applying only a small torque, saving time and labor.

[0023] In the inserted state, like the compressed portion 211 in FIG. 2, the insertion portion 21 is compressed. As the pressure is applied, the compression amount of the insertion portion 21 increases. At the same time, the insertion groove portion 10 elastically deform, and the outer peripheral surface of the insertion groove portion 10 forms an angle α with the axis of the inner ring 2. The angle θ is larger than the angle α, ensuring the sealing effect between the insertion portion 21 and the insertion groove portion 10.

[0024] T2 > T1 ≥ D, where D is the width of the insertion groove 10, T1 is the thickness of the insertion tip of the insertion part 21, and T2 is the thickness of the insertion rear end of the insertion part 21. In the inserted state, the compression rate of the insertion part 21 decreases along the insertion direction, the compression rate of the insertion tip of the insertion part 21 is 0 or more, and the compression rate of the insertion rear end of the insertion part 21 is 40% or less.

[0025] In the free state, the outer peripheral surface 212 of the insertion part 21 and the axis of the inner ring 2 form a certain angle. In the inserted state, the outer peripheral surface 212 of the insertion part 21 is bonded to the inner peripheral surface 101 of the insertion groove 10, the outer peripheral surface 212 of the insertion part 21 is extruded, the insertion groove 10 is elastically deformed, and the inner peripheral surface 101 of the insertion groove 10 and the axis of the inner ring 2 form a certain angle.

[0026] The stroke of the insertion tip of the insertion part 21 is the largest and the compression amount is the smallest. The compression amount of the insertion rear end of the insertion part 21 is the largest and the stroke is the smallest. When removing, in order to first disengage the insertion rear end with the largest compression amount from the insertion groove 10, while maintaining the connection state between the inner ring 2 and the conduit 4, with a relatively small force, the inner ring 2 can be disengaged from the joint body 1, reducing the damage to the inner ring 2 during each attachment and detachment process, improving the service life of the inner ring 2, relatively saving labor for each attachment and detachment, making the reconnection of the conduit 4 and the joint more labor-saving, and when reconnecting, there is no wear on both the inner ring 2 and the joint body 1, the compression rate of the inner ring 2 does not decrease, and the sealing reliability and durability can be guaranteed.

[0027] When removing, the inner ring 2 and the conduit 4 do not disengage, the conduit 4 does not deform, and the sealing effects of the second sealing part 52 and the third sealing part 53 during reconnection are also guaranteed. Therefore, the sealing performance between the joint body 1 and the inner ring 2 can be ensured well both during the first connection of the resin-made sealing pipe joint and the conduit and during reconnection.

[0028] The joint body 1 includes a cylindrical portion 11, and an outer cylindrical portion 12 and an inner cylindrical portion 13 are formed on one side of the cylindrical portion 11, extending outward along the axial direction. The inner cylindrical portion 13 and the outer cylindrical portion 12 are arranged substantially inward and outward in the longitudinal direction. The extending length of the outer cylindrical portion 12 is greater than the extending length of the inner cylindrical portion 13, and the insertion groove portion 10 is formed by being surrounded by the cylindrical portion 11, the outer cylindrical portion 12, and the inner cylindrical portion 13.

[0029] The assembly further includes a conduit 4, the inner ring 2 is inserted into the conduit 4, and the inner ring 2 is provided with a projection 22, the projection 22 expands the diameter of the inlet of the conduit 4 to form a sealed connection, which forms a second sealed portion 52. The conduit 4 extends between the joint body 1 and the inner ring 2, and the nut 3 and the projection of the inner ring 2 tightly fasten the conduit 4 to form a sealed connection, which forms a third sealed portion 53.

[0030] The nut 3 is fitted onto the conduit 4 and screwed onto the joint body 1. Specifically, the nut 3 is fastened to the outer cylindrical portion 12 of the joint body 1 via an internal thread, and together with the inner ring 2, fastens the conduit 4 to the joint body 1. By connecting the nut 3 to the joint body 1, the insertion state of the insertion portion 21 and the insertion groove portion 10 is ensured, and the nut 3 is in a crimped state against the inner ring 2.

[0031] Because the frictional resistance that the restricting surface of the inner ring 2 must overcome when the insertion portion 21 and the insertion groove portion 10 are small, the nut 3 can form a sealing portion that applies appropriate surface pressure between the interconnected joint body 1 and the inner ring 2 with only a small torque applied. This sealing portion then applies a sealing force in the radial direction, causing the insertion portion 21 and the insertion groove portion 10 to be in close contact, further ensuring excellent sealing between the joint body 1 and the inner ring 2, and thus ensuring the sealing effect of the first sealing portion 51.

[0032] The series of detailed descriptions above are merely specific descriptions of possible embodiments of the present application and are not intended to limit the scope of protection of the present application. Equivalent embodiments or modifications that do not deviate from the spirit of the present application should be included within the scope of protection of the present application.

[0033] Furthermore, although this specification describes embodiments, each embodiment does not necessarily contain only one independent technical solution. This descriptive form of this specification is simply for clarity, and those skilled in the art should understand that the specification should be considered as a whole, and that the technical solutions of each embodiment can be appropriately combined to form other embodiments that will be understood by those skilled in the art. [Explanation of Symbols]

[0034] 1. Joint body; 2. Inner ring; 3. Nut; 4. Conduit; 21. Insertion part; 10. Insertion groove; 51. First sealing part; 52. Second sealing part; 53. Third sealing part; 210. Inner circumferential surface of insertion part; 212. Outer circumferential surface of insertion part; 100. Outer circumferential surface of insertion groove; 101. Inner circumferential surface of insertion groove; 211. Compressed part; 22. Projection; 11. Cylinder part; 12. Outer cylinder part; 13. Inner cylinder part.

Claims

1. The joint comprises a body, an inner ring, and a nut. The inner ring has an insertion portion, and the body has an insertion groove. The insertion portion is inserted into the insertion groove to form a sealed connection, and the nut is connected to the body, thereby ensuring the insertion state of the insertion portion and the insertion groove, and the nut is crimped against the inner ring. A resin-made sealed pipe fitting characterized in that, when in a free state, the thickness of the insertion portion changes linearly along the axial direction of the inner ring, and when in an inserted state, the insertion groove portion undergoes elastic deformation, and the rate of change of the insertion groove portion is smaller than the rate of change of the insertion portion in a free state.

2. The resin sealing pipe fitting according to claim 1, characterized in that, when in a free state, the inner circumferential surface of the insertion portion forms an angle θ with the axis of the inner ring, and when in an inserted state, the insertion groove portion is elastically deformed, the outer circumferential surface of the insertion groove portion forms an angle α with the axis of the inner ring, and the angle θ is greater than the angle α.

3. The resin-made sealed pipe fitting according to claim 2, characterized in that 0 < θ < 15°.

4. The resin sealed pipe fitting according to claim 3, characterized in that T2 > T1 ≥ D, where D is the width of the insertion groove, T1 is the thickness of the insertion tip of the insertion part, and T2 is the thickness of the insertion rear end of the insertion part.

5. The resin-made sealed pipe fitting according to claim 4, characterized in that, when inserted, the compression ratio of the insertion portion decreases along the insertion direction, the compression ratio of the insertion tip of the insertion portion is 0 or more, and the compression ratio of the insertion rear end of the insertion portion is 40% or less.

6. The resin-made sealed pipe fitting according to claim 5, characterized in that when in a free state, the outer surface of the insertion portion and the axis of the inner ring form a certain angle.

7. The resin sealing pipe fitting according to claim 1, characterized in that the fitting body includes a cylindrical portion, an outer cylindrical portion and an inner cylindrical portion are formed on one side of the cylindrical portion, the extending length of the outer cylindrical portion is greater than the extending length of the inner cylindrical portion, and the insertion groove portion is formed surrounded by the cylindrical portion, the outer cylindrical portion and the inner cylindrical portion.

8. The resin sealed pipe fitting according to claim 1, further comprising a conduit, wherein the inner ring is inserted into the conduit, the inner ring is provided with a projection, and the projection expands the diameter of the conduit inlet to form a sealed connection.

9. The resin sealed pipe fitting according to claim 8, characterized in that the conduit extends between the fitting body and the inner ring, the nut is fitted into the conduit and screwed into the fitting body, and the conduit is tightly tightened by the nut and the protrusion of the inner ring to form a sealed connection.

10. The resin-made sealed pipe fitting according to claim 1, characterized in that the fitting body and inner ring are made of resin material.

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