CN218030077U - Special screwed joint capable of being repeatedly disassembled and assembled and hermetically sealed - Google Patents

Abstract

The utility model discloses a but airtight special screwed joint of dismouting belongs to and bores completion threaded connection technical field for the instrument, and it includes external thread joint, female connection, vice seal structure, coupling mechanism and main seal structure, and under coupling mechanism's effect, vice seal structure and main seal structure realize sealed, and vice seal structure is located the coupling mechanism left side, and main seal structure is located the coupling mechanism right side. In the utility model, the thread is improved by the inclined ladder, and the thread has the characteristics of strong tensile capacity and easy buckling; the main sealing surface and the auxiliary sealing surface adopt a conical surface-to-conical surface structure form, so that the processing and the measurement are easy, the processing cost is low, and the quality controllability is high; the main and auxiliary double-sealing structure is adopted, so that the sealing reliability is good; the main seal adopts a self-tightening sealing form, the higher the pressure is, the better the sealing reliability is, the conformity with the field use requirement is high, the thread is positioned by adopting a positioning step, the screwing torque does not need to be controlled, the thread can be repeatedly used, and the use is convenient.

Description

Air-tight special screwed joint capable of being repeatedly disassembled and assembled

Technical Field

The utility model belongs to the technical field of bore threaded connection for the completion instrument, specifically be a but airtight special screwed joint of repeated dismouting.

Background

With the vigorous development of clean energy such as natural gas and the like, the application of the air sealing thread in a gas well is more and more extensive, particularly in an underground gas storage and a high-sulfur-content natural gas well, the requirement on the sealing performance of the threaded connection part of a pipe column joint is higher and higher, and the threaded connection part is the weakest link in the whole pipe column in sealing.

The sealing forms of the threaded joints commonly used at present mainly include the following two types: the first type is sealing by non-metallic seals, such as rubber O-rings, non-elastomeric sealed teflon gaskets, and the like. The second type is a metal thread seal joint. The non-metal sealing element has high processing and manufacturing realizable degree, but the service life of the non-metal sealing element cannot be effectively controlled, and particularly has the characteristics of poor reliability and easy failure under severe working conditions of underground high temperature, high pressure, high corrosion and the like, so that the existing requirements cannot be met. The metal thread sealing joint is usually in an API airtight threaded joint type, the thread conforms to API (american petroleum institute) standards, the thread requires strict control of make-up torque during tightening, the situation of sealing failure caused by insufficient make-up torque or excessive make-up torque in the field sometimes occurs, and the joint type is easy to be adhered to the ground, so that the joint type can be used only once. Meanwhile, the design concept of the existing well completion tool is gradually changed to large inner diameter and small outer diameter so as to meet the requirements of good running performance and large inner drift diameter. The API air-tight seal thread is mainly applied to connection of the upper end part and the lower end part of a tool and an oil sleeve due to the structural characteristics, but cannot be applied to connection of all parts in the tool, so that a proper air-tight seal threaded joint needs to be developed independently to meet the field use requirements.

US 7988205 B2 discloses a wedge-shaped threaded joint with a torque shoulder, which is provided with a metal sealing structure in a conical surface/conical surface form, wedge-shaped threads are processed on a male joint and a female joint, the thread width of the male joint is gradually increased from the front to the rear line, the thread width of the female joint is gradually decreased from the front to the rear, and both sides of the threads are in close contact after the joints are tightened to form a sealing effect; the defects are that the thread can not be processed by a forming cutter, the processing speed is very low, and the processing cost is high.

Patent CN 108952595A discloses an air-tight seal threaded joint, which adopts three seal structure forms, the seal structures adopt a conical surface-conical surface and a spherical surface-spherical surface seal form, and after the threads are screwed up, the seal surfaces are tightly attached to form a seal effect, so that the utility model has the advantages of more seal points and high reliability; the three-group sealing structure has the defects that the processing is complex, the requirements on the position degree and the profile degree of three groups of sealing surfaces are high, if deviation occurs, the three groups of sealing surfaces cannot simultaneously generate sealing effect, and negative effect can be generated.

Based on the above, there is a disadvantage 1: the thread can not be processed by a forming cutter, the processing speed is very low, and the processing cost is high; and (2) disadvantage: the machining is complex, the requirements on the position degree and the profile degree of the three groups of sealing surfaces are high, if deviation occurs, the three groups of sealing surfaces cannot simultaneously generate sealing effect, and negative effect can be generated; meanwhile, the auxiliary sealing technology is still based on certain defects, the inclined positioning shoulder is only used for supporting and sealing, gaps still easily occur, and the air sealing effect is poor due to long-term use, so that the problem is solved by a special threaded joint capable of repeatedly disassembling and assembling the air sealing.

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved

In order to overcome prior art's above-mentioned defect, the utility model provides a but airtight special screwed joint of dismouting has solved the unable shaping cutter processing of screw thread, and process speed is very slow, and the processing cost is high, and it is complicated to connect, three sealed face position degrees of group and profile tolerance require highly, if produce the deviation, three sealed unable simultaneous production sealed effects of group, probably produce the negative effect, only rely on the location circular bead of slope to support simultaneously and seal, still easily appear the gap, long-time the use causes the not good problem of airtight effect.

An object of the utility model is to provide a but airtight special screwed joint of dismouting to it is big to solve among the prior art poor, the processing of sealing reliability and the detection degree of difficulty, and can't satisfy technical problem such as big internal diameter little external diameter requirement.

(II) technical scheme

In order to achieve the above object, the utility model provides a following technical scheme: a repeatedly detachable air-tight seal special threaded joint comprises an external threaded joint, an internal threaded joint, an auxiliary seal structure, a connecting mechanism and a main seal structure, wherein under the action of the connecting mechanism, the auxiliary seal structure and the main seal structure realize sealing, the auxiliary seal structure is positioned on the left side of the connecting mechanism, and the main seal structure is positioned on the right side of the connecting mechanism;

vice seal structure includes positioning mechanism and supporting mechanism, positioning mechanism sets up between external screw joint and interior screwed joint, and positioning mechanism's right side is fixed mutually with interior screwed joint's left side, and positioning mechanism designs for the round platform shape and left side diameter is greater than the right side diameter, supporting mechanism is fixed in external screw joint's right flank, positioning mechanism is located supporting mechanism's inboard.

As a further aspect of the present invention: the connecting mechanism adopts a threaded connection mode, and the threads are of a modified buttress straight thread structure.

As a further aspect of the present invention: the modified buttress external thread comprises an external thread guide surface and an external thread bearing surface, the external thread guide surface is connected with the crest through a secondary transition arc I, and the radius R3 of the modified buttress external thread is 0.45-0.55mm;

the external thread bearing surface is connected with the crest through a secondary transition circular arc II, and the radius R1 of the external thread bearing surface is 0.10-0.20mm;

the external thread guide surface and the external thread bearing surface are in transition connection with the tooth bottom through a secondary transition circular arc III, and the radius R2 of the external thread guide surface and the external thread bearing surface is 0.10-0.20mm;

the included angle alpha between the external thread guide surface and the vertical direction is 20-25 degrees, the included angle beta between the external thread bearing surface and the vertical direction is 1-5 degrees, and the tooth height h1 of the external thread is 1.05-1.10mm.

As a further aspect of the present invention: the external thread guide surface corresponds to the internal thread guide surface and is positioned on the internal thread joint, the internal thread guide surface is connected with the tooth bottom through a secondary transition arc V, and the radius of the internal thread guide surface is the same as R3;

the internal thread bearing surface is connected with the tooth bottom through a secondary transition arc IV, and the radius of the internal thread bearing surface is the same as that of the internal thread bearing surface R1;

the internal thread guide surface and the internal thread bearing surface are in transition connection with the crest through a secondary transition arc VI, and the radius of the internal thread guide surface and the radius of the internal thread bearing surface are the same as R2;

the included angle between the inner thread guide surface and the vertical direction is equal to alpha, the included angle between the inner thread bearing surface and the vertical direction is equal to beta, and the tooth height h2 of the inner thread is 1.05-1.10mm and is equal to h 1.

As a further aspect of the present invention: the main sealing structure is composed of an internal thread main sealing surface positioned inside the left side of the internal thread joint and an external conical surface at the right end of the external thread joint;

the main sealing surface of the internal thread is conical, the axis of the internal thread joint is collinear, the included angle theta 5 between the axis of the internal thread joint and the central axis in the horizontal direction is 14 degrees, and the length L4 in the horizontal direction is 11.00mm;

the outer sealing conical surface at the right end of the external thread joint is composed of three sections, namely a main sealing first conical surface positioned at the left side, a main sealing second conical surface positioned in the middle and a main sealing third conical surface positioned at the right side, and the axial lines of the three sections of conical surfaces are collinear and are collinear with the axial line of the external thread joint;

the length of the first conical surface of the main seal in the horizontal direction is 2.50mm, the length of the second conical surface of the main seal in the horizontal direction is 2.00mm, the length of the third conical surface of the main seal in the horizontal direction is 3.50mm, the included angle between the first conical surface of the main seal and the horizontal direction is theta, the included angle between the second conical surface of the main seal and the horizontal direction is theta 2, the included angle between the third conical surface of the main seal and the horizontal direction is theta 3, and the values of the included angles meet the condition that theta 1 is more than theta 2 and less than theta 3, and theta 2= theta 3-1, preferably theta 1=8 degrees, theta 2=14 degrees and theta 2=15 degrees;

a gap L5 needs to be reserved between the inner end face of the right side of the main sealing surface of the internal thread and the end face of the right side of the outer sealing conical surface, the distance L5 is 2-3mm, and a chamfer is arranged between the third conical face of the main sealing and the end face of the right side of the main sealing conical face.

As a further aspect of the present invention: the inner side of the right end of the external thread joint is provided with an elastic groove which is cylindrical, the length L7 of the external thread joint in the horizontal direction is 17.00-18.00mm, and the thickness L6 of the external thread joint is 4.50-4.60mm;

the inner part of the external thread joint is hollow, the diameter of the inner cavity at the left side of the external thread joint is L8, the diameter of the elastic groove at the right side of the external thread joint is L9, and the value of the diameter is L8 which is more than L9-1.00mm;

a grease containing cavity I is arranged between the main sealing mechanism and the connecting mechanism and used for storing redundant thread sealing grease;

the right side face of the external thread joint is fixed with the left side face of the conical surface embedded ring, the conical surface embedded ring is embedded into the conical surface embedded groove, and the conical surface embedded groove is formed in the right side of the inner wall of the internal thread joint.

As a further aspect of the present invention: the auxiliary sealing structure consists of an auxiliary sealing surface I, an auxiliary sealing surface II, an auxiliary transition arc I, an auxiliary transition arc II, a positioning mechanism and a supporting mechanism;

the auxiliary transition arc I is in tangent transition with the auxiliary sealing surface I, the auxiliary transition arc II is in tangent transition with the auxiliary sealing surface II, the auxiliary sealing surface I is in an inverted inner cone shape, the included angle theta 4 between the auxiliary transition arc I and the horizontal direction is 45 degrees or 30 degrees, the auxiliary sealing surface II is in an outer cone shape, the included angle theta 4 between the auxiliary transition arc II and the horizontal direction is 45 degrees or 30 degrees, and the horizontal inclination angle of the auxiliary transition arc I and the horizontal direction is equal to that of the auxiliary sealing surface I;

and a grease containing cavity II is arranged on the inner side of the auxiliary sealing structure and used for storing redundant thread sealing grease.

As a further aspect of the present invention: the positioning mechanism comprises an embedded ring, the right side face of the embedded ring is fixed with the left side face of the internal thread structure, the embedded ring is designed in an inclined mode, an included angle between the embedded ring and the horizontal direction is 20-30 degrees, the embedded ring is embedded into the embedded groove, the embedded groove is formed in the inner side of the external thread connector, a rubber pad is arranged at the bottom in the embedded groove and is in lap joint with the left side of the embedded ring, and a gasket is arranged on the outer ring of the inner wall of the embedded groove;

the outer wall of the embedding ring is provided with a first spherical sealing surface and a second spherical sealing surface, the first spherical sealing surface is positioned on the left side of the second spherical sealing surface, and the spherical crown height of the first spherical sealing surface is greater than that of the second spherical sealing surface.

As a further aspect of the present invention: the supporting mechanism comprises a supporting ring, the left side surface of the supporting ring is fixed with the right side of the external thread joint, the supporting ring is embedded into the rubber ring groove, five groups of sealing rubber rings are arranged on the inner ring and the outer ring of the supporting ring, the five groups of sealing rubber rings are embedded into the retaining grooves respectively, and the five groups of retaining grooves are arranged on the inner ring and the outer ring of the rubber ring groove respectively.

As a further aspect of the present invention: the axial interference magnitude of the sealing surface of the main sealing structure is 0.40-0.50mm, and the positioning shoulder I and the positioning shoulder II form an extrusion sealing surface.

(III) advantageous effects

Compared with the prior art, the beneficial effects of the utility model reside in that:

1. in the utility model, the thread is of an improved inclined ladder type, and the bearing surface has a positive angle (1-5 degrees); the positive angle of the guide surface is (20-25 degrees); the thread has the characteristics of strong tensile capacity and easy buckling; the main sealing surface and the auxiliary sealing surface adopt a conical surface-to-conical surface structure form, so that the processing and the measurement are easy, the processing cost is low, and the quality controllability is high; the main and auxiliary double-sealing structure is adopted, so that the sealing reliability is good; the main seal adopts a self-tightening sealing form, the higher the pressure is, the better the sealing reliability is, the conformity with the field use requirement is high, the thread is positioned by adopting a positioning step, the screwing torque does not need to be controlled, the thread can be repeatedly used, and the use is convenient.

2. The utility model discloses in, mutually support through between positioning mechanism and the bearing structure, location circular bead I is close to each other with location circular bead II, make the becket embedding glue the inslot, make the sealed ring imbed respectively and keep off groove and glue the annular in, setting through multiunit sealed ring and fender groove, further increase its connection gas tightness, the embedding ring sets up first spherical sealing face and second spherical sealing face for slope design and outer lane simultaneously, first spherical sealing face is located second spherical sealing face left side, and the spherical crown height of first spherical sealing face is greater than the spherical crown height of second spherical sealing face, seal through first spherical sealing face and second spherical sealing face, produce deformation in the embedded groove in the external thread joint is hugged closely to first spherical sealing face, current second spherical sealing face does not produce deformation, and the contact pressure who bears is greater than second spherical sealing face, when this special thread joint bears too big load and causes first spherical yielding and when losing sealing ability, thereby this special thread joint of second spherical sealing face then keeps in the elastic deformation scope and has guaranteed this special thread joint can not take place to leak, through the mutually support mutually supporting of first spherical thread, this sealed reliability of this sealed greatly with this sealed face.

Drawings

Fig. 1 is an assembled sectional view of the male and female screw connectors according to the present invention;

FIG. 2 is a schematic view of the male connector of the present invention;

fig. 3 is the inner thread joint of the present invention;

FIG. 4 is a schematic view of a partial structure of the connection mechanism of the present invention;

FIG. 5 is a schematic structural view of a section of the connecting mechanism of the present invention;

fig. 6 is a partial schematic view of the main sealing structure of the present invention;

fig. 7 is a schematic sectional view of the external thread joint of the present invention;

in the figure: 1. an externally threaded nipple; 2. an internal thread joint; 3. a secondary sealing structure; 4. a connecting mechanism; 5. a primary seal structure; 301. a secondary sealing surface I; 302. a secondary transition arc I; 303. a fat containing cavity II; 304. positioning a shoulder I; 305. positioning a shoulder II; 306. a secondary sealing surface II; 307. a secondary transition arc II; 308. a positioning mechanism; 3081. an insert ring; 3082. a first spherical sealing surface; 3083. a second spherical sealing surface; 3084. a rubber pad; 3085. a groove is embedded; 309. a support mechanism; 3091. a branch ring; 3092. sealing the rubber ring; 3093. a rubber ring groove; 3094. a baffle groove; 401. a secondary transition arc I; 402. an external thread guide surface; 403. a secondary transition arc II; 404. an external thread bearing surface; 405. a second transition arc III; 406. an internal thread bearing surface; 407. a secondary transition arc IV; 408. a secondary transition arc V; 409. an internal thread guide surface; 410. a secondary transition arc VI; 501. a primary seal first conical surface; 502. a primary seal second conical surface; 503. a primary seal third conical surface; 504. chamfering; 505. an internal threaded primary seal face; 506. a fat containing cavity I; 507. an elastic groove; 508. a conical surface embedding ring; 509. and a conical surface caulking groove.

Detailed Description

The technical solution of the present patent will be described in further detail with reference to the following embodiments.

As shown in fig. 1-7, the utility model provides a technical solution: the utility model provides a but airtight special screwed joint of dismouting, includes external screwed joint 1, internal thread joint 2, vice seal structure 3, coupling mechanism 4 and main seal structure 5, and under coupling mechanism 4's effect, vice seal structure 3 and main seal structure 5 realize sealed, and vice seal structure 3 is located coupling mechanism 4 left side, and main seal structure 5 is located coupling mechanism 4 right side.

The auxiliary sealing structure 3 comprises a positioning mechanism 308 and a supporting mechanism 309, the positioning mechanism 308 is arranged between the external thread joint 1 and the internal thread joint 2, the right side of the positioning mechanism 308 is fixed with the left side of the internal thread joint 2, the positioning mechanism 308 is designed in a circular truncated cone shape, the diameter of the left side of the positioning mechanism 308 is larger than that of the right side of the internal thread joint 2, the supporting mechanism 309 is fixed on the right side surface of the external thread joint 1, and the positioning mechanism 308 is located on the inner side of the supporting mechanism 309.

Specifically, as shown in fig. 1, 2, 4 and 5, the connection mechanism 4 adopts a threaded connection form, and the threads are a modified buttress straight thread structure.

The modified buttress external thread comprises an external thread guide surface 402 and an external thread bearing surface 404, wherein the external thread guide surface 402 is connected with the crest through a secondary transition circular arc I401, and the radius R3 of the external thread guide surface is 0.45-0.55mm.

The external thread bearing surface 404 is connected with the crest through a secondary transition circular arc II 403, and the radius R1 of the external thread bearing surface is 0.10-0.20mm.

The external thread guide surface 402 and the external thread bearing surface 404 are in transition connection with the tooth root through a secondary transition circular arc III 405, and the radius R2 of the transition connection is 0.10-0.20mm.

The included angle alpha between the external thread guide surface 402 and the vertical direction is 20-25 degrees to improve the thread connection performance, the included angle beta between the external thread bearing surface 404 and the vertical direction is 1-5 degrees to improve the tensile strength of the thread and avoid leakage caused by the fact that the interference of the sealing surface is reduced under the action of axial pulling load, and the tooth height h1 of the external thread is 1.05-1.10mm.

The external thread guide surface 402 corresponds to the internal thread guide surface 409 and is positioned on the internal thread joint 2, the internal thread guide surface 409 is connected with the tooth bottom through a secondary transition arc V408, the damage caused by stress concentration of the root part of the thread is avoided, and the radius of the internal thread guide surface is the same as that of the internal thread guide surface R3.

The internal thread bearing surface 406 is connected with the tooth bottom through a secondary transition arc IV 407, so that the damage caused by stress concentration of the thread root is avoided, and the radius of the internal thread bearing surface is the same as that of R1.

The internal thread guide surface 409 and the internal thread bearing surface 406 are in transition connection with the crest through a secondary transition circular arc VI 410, and the radius of the internal thread guide surface and the radius of the internal thread bearing surface are the same as R2.

The included angle between the internal thread guide surface 409 and the vertical direction is equal to alpha, the included angle between the internal thread bearing surface 406 and the vertical direction is equal to beta, and the internal thread tooth height h2 is 1.05-1.10mm and is equal to h1, so that the tooth height is minimized on the premise that the tensile strength of the thread is met, the effective residual wall thickness of the joint is prevented from being reduced, and the overall tensile strength of the joint is reduced.

The primary seal structure 5 is composed of a female primary seal surface 505 located inside the left side of the female adapter 2 and an outer tapered surface at the right end of the male adapter 1.

The internal thread main sealing surface 505 is conical, the axial lines of the internal thread joints 2 are collinear, the included angle theta 5 between the axial lines and the horizontal central axis is 14 degrees, and the length L4 in the horizontal direction is 11.00mm.

Specifically, as shown in fig. 1, fig. 2, fig. 6, and fig. 7, the external sealing conical surface at the right end of the external thread joint 1 is composed of three sections, namely, a main sealing first conical surface 501 at the left side, a main sealing second conical surface 502 at the middle, and a main sealing third conical surface 503 at the right side, and the axial lines of the three sections of conical surfaces are collinear and collinear with the axial line of the external thread joint 1.

The length of the first main seal conical surface 501 in the horizontal direction is 2.50mm, the length of the second main seal conical surface 502 in the horizontal direction is 2.00mm, the length of the third main seal conical surface 503 in the horizontal direction is 3.50mm, the included angle between the first main seal conical surface 501 and the horizontal direction is theta, the included angle between the second main seal conical surface 502 and the horizontal direction is theta 2, the included angle between the third main seal conical surface 503 and the horizontal direction is theta 3, and the value of the included angle satisfies the condition that theta 1 is greater than theta 2 and is greater than theta 3, theta 2= theta 3-1, preferably theta 1=8, theta 2=14 and theta 2= 15.

A gap L5 needs to be reserved between the inner end surface on the right side of the internal thread main sealing surface 505 and the end surface on the right side of the external sealing conical surface, the L5 is 2-3mm, so that the main sealing conical surface can deform freely, the axial interference magnitude is guaranteed, a chamfer 504 is arranged between the main sealing third conical surface 503 and the end surface on the right side of the main sealing third conical surface, and the damage to the internal thread main sealing surface 505 caused by sharp corners during assembly is avoided.

An elastic groove 507 is arranged on the inner side of the right end of the male adapter 1 and is cylindrical, the length L7 of the elastic groove in the horizontal direction is 17.00-18.00mm, the thickness L6 of the elastic groove is 4.50-4.60mm, the elastic groove 507 enables the first conical surface 501 of the main seal, the second conical surface 502 of the main seal and the third conical surface 503 of the main seal to generate elastic bending deformation rather than plastic deformation under the given axial interference so as to achieve the set initial seal specific pressure, and in the working process, internal high-pressure fluid extrudes the inner wall of the elastic groove 507 to enable the second conical surface 502 of the main seal surface to be attached to the main seal surface 505505 of the internal thread more tightly, so that the contact pressure is further improved, and the self-tight seal effect is achieved.

The internal part of the male adapter 1 is hollow, the diameter of the inner cavity on the left side is L8, the diameter of the elastic groove 507 on the right side is L9, and the values of the diameters meet the condition that L8 is larger than L9-1.00mm, so that the main sealing surface 505 of the internal thread can generate elastic bending deformation under the given axial interference, and the set initial sealing specific pressure is reached.

Be equipped with between main sealing mechanism and coupling mechanism 4 and hold fat chamber I506, hold fat chamber I506 and be used for saving unnecessary thread sealing fat, connect the back of fastening, unnecessary thread sealing fat on the sealed face of main sealing structure 5 can get into and hold fat chamber I506, avoids influencing the contact pressure of main sealed face because of thread sealing fat pressure is too high, also can play the effect of supplementary seal simultaneously.

The right side of the male adapter 1 is fixed to the left side of the tapered insert ring 508, the tapered insert ring 508 is inserted into the tapered insert groove 509, and the tapered insert groove 509 is formed on the right side of the inner wall of the female adapter 2.

The auxiliary sealing structure 3 is composed of an auxiliary sealing surface I301, an auxiliary sealing surface II 306, an auxiliary transition arc I302, an auxiliary transition arc II 307, a positioning mechanism 308 and a supporting mechanism 309.

The tangent transition of vice transition circular arc I302 and vice sealed face I301, avoid producing the stress concentration phenomenon, vice transition circular arc II 307 is tangent transition with vice sealed face II 306, avoid producing the stress concentration phenomenon, can avoid damaging vice sealed face I301 in the assembling process simultaneously, vice sealed face I301 is the interior toper of falling, it is 45 or 30 with horizontal direction contained angle theta 4, vice sealed face II 306 is the external cone, it is 45 or 30 with horizontal direction contained angle theta 4, equal with I301 horizontal inclination of vice sealed face, this seal structure has higher reliability.

The inboard of 3 of vice seal structure is equipped with holds fat chamber II 303, holds II 303 of fat chamber and is used for saving unnecessary thread sealing fat, connects the back of fastening, and unnecessary thread sealing fat can get into on the sealed face of vice seal structure 3 holds II 303 of fat chamber, avoids influencing the contact pressure of vice sealed face because of thread sealing fat pressure is too high, also can play supplementary sealed effect simultaneously.

Specifically, as shown in fig. 1, fig. 2 and fig. 3, the positioning mechanism 308 includes an embedding ring 3081, the right side of the embedding ring 3081 is fixed to the left side of the internal thread structure, the embedding ring 3081 is designed to be inclined, and has an included angle of 20 ° to 30 ° with the horizontal direction, the embedding ring 3081 is embedded in the embedding groove 3085, the embedding groove 3085 is disposed on the inner side of the external thread joint 1, a rubber pad 3084 is disposed at the bottom inside the embedding groove 3085, the rubber pad 3084 is overlapped with the left side of the embedding ring 3081, and a gasket is disposed on the outer ring of the inner wall of the embedding groove 3085.

The outer wall of the insert ring 3081 is provided with a first spherical sealing surface 3082 and a second spherical sealing surface 3083, the first spherical sealing surface 3082 is positioned on the left side of the second spherical sealing surface 3083, and the spherical cap height of the first spherical sealing surface 3082 is greater than the spherical cap height of the second spherical sealing surface 3083.

The supporting mechanism 309 comprises a supporting ring 3091, the left side surface of the supporting ring 3091 is fixed to the right side of the male connector 1, the supporting ring 3091 is embedded into a rubber ring groove 3093, five groups of sealing rubber rings 3092 are arranged on the inner ring and the outer ring of the supporting ring 3091, the five groups of sealing rubber rings 3092 are embedded into a blocking groove 3094 respectively, and the five groups of blocking grooves 3094 are arranged on the inner ring and the outer ring of the rubber ring groove 3093 respectively.

The axial interference magnitude of the sealing surface of the main sealing structure 5 is 0.40-0.50mm, under the interference magnitude, the main sealing structure 5 can realize sealing and does not generate plastic deformation, so that the characteristic of repeated disassembly and use is realized, the positioning shoulder I304 and the positioning shoulder II 305 form an extrusion sealing surface, the contact stress distribution of the sealing surface and the strength of the sealing surface structure are ensured, the upper buckling torque does not need to be controlled, the operation is very convenient, and the reliability is high.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

Claims (10)

1. The utility model provides a but airtight special screwed joint of dismouting, includes external thread joint (1), internal thread joint (2), vice seal structure (3), coupling mechanism (4) and main seal structure (5), its characterized in that: under the action of the connecting mechanism (4), the auxiliary sealing structure (3) and the main sealing structure (5) realize sealing, the auxiliary sealing structure (3) is positioned on the left side of the connecting mechanism (4), and the main sealing structure (5) is positioned on the right side of the connecting mechanism (4);

vice seal structure (3) are including positioning mechanism (308) and supporting mechanism (309), positioning mechanism (308) set up between external thread joint (1) and female connection (2), and the right side of positioning mechanism (308) is fixed mutually with the left side of female connection (2), and positioning mechanism (308) are round platform shape design and left side diameter is greater than the right side diameter, supporting mechanism (309) are fixed in the right flank of external thread joint (1), positioning mechanism (308) are located the inboard of supporting mechanism (309).

2. The special threaded joint capable of being repeatedly disassembled and assembled and hermetically sealed according to claim 1, is characterized in that: the connecting mechanism (4) adopts a threaded connection mode, and the threads are of a modified buttress straight thread structure.

3. The special threaded joint capable of being repeatedly disassembled and assembled and hermetically sealed according to claim 2, is characterized in that: the modified buttress external thread comprises an external thread guide surface (402) and an external thread bearing surface (404), the external thread guide surface (402) is connected with the crest through a secondary transition circular arc I (401), and the radius R3 of the modified buttress external thread is 0.45-0.55mm;

the external thread bearing surface (404) is connected with the crest through a secondary transition arc II (403), and the radius R1 of the external thread bearing surface is 0.10-0.20mm;

the external thread guide surface (402) and the external thread bearing surface (404) are in transition connection with the tooth bottom through a secondary transition arc III (405), and the radius R2 of the external thread guide surface and the external thread bearing surface is 0.10-0.20mm;

an included angle alpha between the external thread guide surface (402) and the vertical direction is 20-25 degrees, an included angle beta between the external thread bearing surface (404) and the vertical direction is 1-5 degrees, and the tooth height h1 of the external thread is 1.05-1.10mm.

4. The special threaded joint capable of being repeatedly disassembled and assembled and hermetically sealed according to claim 3, is characterized in that: the external thread guide surface (402) corresponds to the internal thread guide surface (409) and is positioned on the internal thread joint (2), the internal thread guide surface (409) is connected with the tooth bottom through a secondary transition arc V (408), and the radius of the internal thread guide surface is the same as that of the internal thread guide surface R3;

the internal thread bearing surface (406) is connected with the tooth bottom through a secondary transition arc IV (407), and the radius of the internal thread bearing surface is the same as that of the tooth bottom R1;

the internal thread guide surface (409) and the internal thread bearing surface (406) are in transition connection with the crest through a secondary transition arc VI (410), and the radius of the internal thread guide surface and the radius of the internal thread bearing surface are the same as R2;

the included angle between the inner thread guide surface (409) and the vertical direction is equal to alpha, the included angle between the inner thread bearing surface (406) and the vertical direction is equal to beta, and the tooth height h2 of the inner thread is 1.05-1.10mm and is equal to h 1.

5. The special threaded joint capable of being repeatedly disassembled and assembled and hermetically sealed according to claim 1, is characterized in that: the main sealing structure (5) is composed of an internal thread main sealing surface (505) positioned inside the left side of the internal thread joint (2) and an external conical surface at the right end of the external thread joint (1);

the main sealing surface (505) of the internal thread is conical, the axial lines of the internal thread joints (2) on the axial lines are collinear, the included angle theta 5 between the axial lines and the central axis in the horizontal direction is 14 degrees, and the length L4 in the horizontal direction is 11.00mm;

the external sealing conical surface at the right end of the external thread joint (1) is composed of three sections, namely a main sealing first conical surface (501) positioned at the left side, a main sealing second conical surface (502) positioned in the middle and a main sealing third conical surface (503) positioned at the right side, and the axial lines of the three sections of conical surfaces are collinear and are collinear with the axial line of the external thread joint (1);

the length of a first main seal conical surface (501) in the horizontal direction is 2.50mm, the length of a second main seal conical surface (502) in the horizontal direction is 2.00mm, the length of a third main seal conical surface (503) in the horizontal direction is 3.50mm, the included angle between the first main seal conical surface (501) and the horizontal direction is theta, the included angle between the second main seal conical surface (502) and the horizontal direction is theta 2, the included angle between the third main seal conical surface (503) and the horizontal direction is theta 3, the value of the included angle satisfies the condition that theta 1 is larger than theta 2 and smaller than theta 3, theta 2= theta 3-1, and theta 1=8, theta 2=14 and theta 2=15 degrees are taken;

a gap L5 needs to be reserved between the inner end face of the right side of the internal thread main sealing face (505) and the end face of the right side of the external sealing conical face, the L5 is 2-3mm, and a chamfer (504) is arranged between the third conical face (503) of the main sealing and the end face of the right side of the main sealing face.

6. The special screwed joint capable of being repeatedly disassembled and assembled and hermetically sealed according to claim 5, is characterized in that: an elastic groove (507) is formed in the inner side of the right end of the external thread joint (1) and is cylindrical, the length L7 of the external thread joint in the horizontal direction is 17.00-18.00mm, and the thickness L6 of the external thread joint is 4.50-4.60mm;

the inner part of the external thread joint (1) is hollow, the diameter of the inner cavity at the left side is L8, the diameter of the elastic groove (507) at the right side is L9, and the value of L8 is more than L9-1.00mm;

a grease containing cavity I (506) is arranged between the main sealing mechanism and the connecting mechanism (4), and the grease containing cavity I (506) is used for storing redundant thread sealing grease;

the right side surface of the external thread joint (1) is fixed with the left side surface of the conical surface embedded ring (508), the conical surface embedded ring (508) is embedded into the conical surface embedded groove (509), and the conical surface embedded groove (509) is formed in the right side of the inner wall of the internal thread joint (2).

7. The special screwed joint capable of being repeatedly disassembled and assembled and hermetically sealed according to claim 1, is characterized in that: the auxiliary sealing structure (3) is composed of an auxiliary sealing surface I (301), an auxiliary sealing surface II (306), an auxiliary transition arc I (302), an auxiliary transition arc II (307), a positioning mechanism (308) and a supporting mechanism (309);

the auxiliary transition arc I (302) is in tangential transition with the auxiliary sealing surface I (301), the auxiliary transition arc II (307) is in tangential transition with the auxiliary sealing surface II (306), the auxiliary sealing surface I (301) is in an inverted inner cone shape, the included angle theta 4 between the auxiliary sealing surface I (301) and the horizontal direction is 45 degrees or 30 degrees, the auxiliary sealing surface II (306) is in an outer cone shape, the included angle theta 4 between the auxiliary sealing surface I (301) and the horizontal direction is 45 degrees or 30 degrees, and the horizontal inclination angle of the auxiliary sealing surface II (306) is equal to that of the auxiliary sealing surface I (301);

and a grease containing cavity II (303) is arranged on the inner side of the auxiliary sealing structure (3), and the grease containing cavity II (303) is used for storing redundant thread sealing grease.

8. The special threaded joint capable of being repeatedly disassembled and assembled and hermetically sealed according to claim 7, is characterized in that: the positioning mechanism (308) comprises an embedding ring (3081), the right side face of the embedding ring (3081) is fixed with the left side face of the internal thread structure, the embedding ring (3081) is designed to be inclined, an included angle between the embedding ring (3081) and the horizontal direction is 20-30 degrees, the embedding ring (3081) is embedded in the embedding groove (3085), the embedding groove (3085) is arranged on the inner side of the external thread connector (1), a rubber pad (3084) is arranged at the bottom in the embedding groove (3085), the rubber pad (3084) is in lap joint with the left side of the embedding ring (3081), and a gasket is arranged on the outer ring of the inner wall of the embedding groove (3085);

the outer wall of embedding ring (3081) is equipped with first spherical sealing face (3082) and second spherical sealing face (3083), first spherical sealing face (3082) are located second spherical sealing face (3083) left side, and the spherical crown height of first spherical sealing face (3082) is greater than the spherical crown height of second spherical sealing face (3083).

9. The special threaded joint capable of being repeatedly disassembled and assembled and hermetically sealed according to claim 1, is characterized in that: supporting mechanism (309) is including brace ring (3091), the left surface of brace ring (3091) is fixed mutually with the right side of external screwed joint (1), in brace ring (3091) embedding glue ring groove (3093), the inner circle and the outer lane of brace ring (3091) all are provided with five groups of sealed gluey rings (3092), and five groups of sealed gluey rings (3092) imbed respectively and keep off in groove (3094), and five groups keep off the inner circle and the outer lane that groove (3094) set up respectively and glue ring groove (3093).

10. The special threaded joint capable of being repeatedly disassembled and assembled and hermetically sealed according to claim 1, is characterized in that: the axial interference of the sealing surface of the main sealing structure (5) is 0.40-0.50mm, and the positioning shoulder I (304) and the positioning shoulder II (305) form an extrusion sealing surface.

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