阅读说明：本技术 胶圈密封扩口管材及组件、管材扩口方法及设备 (Rubber ring sealing flaring pipe, rubber ring sealing flaring assembly, pipe flaring method and equipment ) 是由 安宝宇 于 2019-11-15 设计创作，主要内容包括：本发明涉及一种胶圈密封扩口管材,所述管材的一端包括扩口端,其中：所述扩口端的内侧设置有至少两个密封胶圈,所述至少两个密封胶圈在扩口端的轴向方向上彼此间隔开且每一个密封胶圈所限定的平面垂直于所述轴向方向布置。本发明还涉及一种胶圈密封扩口管材组件,一种胶圈密封管材的扩口设备以及一种胶圈密封管材的扩口方法。(The invention relates to a rubber ring sealing flared tube, one end of the tube comprises a flared end, wherein: the inner side of the flared end is provided with at least two sealing rubber rings which are spaced from each other in the axial direction of the flared end, and the plane defined by each sealing rubber ring is arranged perpendicular to the axial direction. The invention also relates to a rubber ring seal flaring pipe component, a flaring device of the rubber ring seal flaring pipe and a flaring method of the rubber ring seal flaring pipe.)

1. A rubber-ring sealed flared tube, one end of the tube comprising a flared end, wherein:

the inner side of the flared end is provided with at least two sealing rubber rings which are spaced from each other in the axial direction of the flared end, and the plane defined by each sealing rubber ring is arranged perpendicular to the axial direction.

2. The flared tube of claim 1, wherein:

two sealing rubber rings are arranged on the inner side of the flared end.

3. The flared tube of claim 1, wherein:

the sealing rubber ring is a steel skeleton rubber ring; the pipe is made of high polymer materials.

4. The flared tube of claim 1, wherein:

the outer diameter of the flared tube is in the range of 50mm-1600 mm.

5. The flared tube of any one of claims 1-4, wherein:

at least one part of the flared tubing, which is positioned between two adjacent sealing rubber rings, has the same inner diameter as the other parts of the flared tubing.

6. A tubing assembly comprising:

a first tubing which is a rubber gasket seal flared tubing according to any one of claims 1-5; and

a second tubing having one end adapted for insertion into the flared end of the rubber gasket seal flared tubing and the at least two sealing rubber rings having an inner diameter designed to mate with the outer diameter of the one end of the second tubing to form a multi-layer rubber gasket seal.

7. The tubing assembly of claim 6, wherein:

the second tube is a rubber gasket seal flared tube according to any one of claims 1-5, the other end of the second tube being provided with the flared end.

8. A flaring device for a rubber-ring sealed tube, comprising:

the flaring die comprises a flaring die body and a first positioning device, wherein the flaring die body is in a cylindrical shape, the first positioning device comprises a plurality of positioning holes distributed along the circumferential direction of the die body, the positioning holes penetrate through the die body in the radial direction, and the positioning holes are arranged in groups in the circumferential direction; and

a second positioning device comprising a plurality of radial arms disposed within the mold body, the radial outer ends of the plurality of radial arms are respectively located in the plurality of locating holes, the plurality of radial arms have a first radial position and a second radial position, at the first radial position, the radially outer ends of the radial arms extend beyond the radially outer side of the die body and have a first extension height, in the second radial position, the radially outer end of the radial arm is located within the locating hole and is flush with the radially outer side of the die body, the second positioning device further comprises a radial arm drive adapted to drive the radial arm between a first radial position and a second radial position, wherein the radially outer end of the radial arm at the first radial position is adapted to block the sealing rubber ring from moving backwards along the axial direction of the flaring die.

9. The flaring device of claim 8, wherein:

the plurality of positioning holes comprises a set of positioning holes arranged along a first circumference;

the plurality of radial arms comprises a set of radial arms disposed in a radial plane;

the second positioning device further comprises a baffle plate, the baffle plate is sleeved outside the flaring die at the rear side of the positioning holes and is spaced from the positioning holes in the axial direction of the flaring die, the baffle plate is provided with a butting part and a driving part, the baffle plate is provided with a first axial position and a second axial position on the flaring die, the butting part is suitable for being butted with the sealing rubber ring to limit the position of the corresponding sealing rubber ring in the axial direction of the flaring die at the first axial position, and the butting part is suitable for being far away from the corresponding sealing rubber ring in the axial direction of the flaring die at the second axial position.

10. The flaring device of claim 9, wherein:

the abutting portion is an annular abutting portion and a radially outer wall surface of the annular abutting portion has a predetermined height higher than an outer side of the flaring die.

11. The flaring device of claim 10, wherein:

the baffle is a heating baffle.

12. The flaring device of claim 8, wherein:

the plurality of positioning holes comprise two groups of positioning holes which are respectively arranged along a first circumference and a second circumference which are spaced apart by a preset distance in the axial direction of the flaring die;

the plurality of radial arms includes two sets of radial arms disposed in two radial planes, respectively.

13. The flaring device of claim 8, further comprising:

the flaring fixture is used for clamping a pipe to be flared, the axial direction of the pipe to be flared is aligned with the axial direction of the flaring die,

wherein:

the flaring jig and the flaring die are adapted to move relative to each other in the axial direction of the flaring die.

14. The flaring device of claim 8, wherein:

the flaring die is provided with positioning grooves on the front side and the rear side of each group of positioning holes, and the sealing rubber ring is suitable for being arranged in the positioning grooves.

15. The flaring device of claim 8, wherein:

the flaring die also comprises a guide head connected with the die body and used for guiding the end of the tube to be flared to the die body.

16. The flaring device of claim 8, wherein:

the positioning holes arranged in groups are arranged at equal angular intervals in the circumferential direction.

17. The flaring device of any of claims 8-16, wherein:

the radial arm driving apparatus includes:

a drive shaft having an operating position and a withdrawn position in an axial direction; and

a driving cylinder connected to one end of the driving shaft, the driving cylinder having a first cylinder and a second cylinder connected to each other in an axial direction, a transition portion provided between the first cylinder and the second cylinder, the first cylinder having a first outer diameter, the second cylinder having a second outer diameter smaller than the first outer diameter, the driving cylinder being provided in the flare die coaxially with the flare die,

wherein:

the radial inner end or the part close to the radial inner end of the radial arm is provided with a pressing surface matched with the peripheral surface of the driving column body;

in the operating position of the drive shaft, the abutting surface of the radial arm abuts against the outer peripheral surface of the first column body, and in the retreating position of the drive shaft, the abutting surface of the radial arm abuts against the outer peripheral surface of the second column body.

18. The flaring device of claim 17, wherein:

the first cylinder and the second cylinder are both cylinders.

19. The flaring device of claim 17, wherein:

the outer side of the driving cylinder is provided with an axial guide groove extending through the first cylinder and the second cylinder, and the radial inner end of the radial arm is arranged in the axial guide groove.

20. The flaring device of claim 17, wherein:

the radial arm drive further comprises a spring body adapted to press the radial arm towards the drive cylinder.

21. The flaring device of claim 20, wherein:

the spring body is an annular spring, each group of radial arms is provided with a step part, and the annular spring is arranged on the step part and radially and inwardly extrudes the step part; or

The spring body comprises a plurality of compression springs which are respectively sleeved on the radial arms, step parts are arranged on the radial arms, and the compression springs are pressed between the inner wall of the flaring die and the step parts.

22. The flaring device of claim 17, wherein:

the other end of the drive shaft is located outside the flaring die and is driven.

23. The flaring device of any of claims 8-16, wherein:

the radial arm driving means includes pneumatic means or electric means for directly driving the radial arm to move in the radial direction.

24. The flaring device of any of claims 8-23, wherein:

the front end and the rear end of the die body are respectively provided with a front end wall and a rear end wall so as to limit a closed space in the die body, and the rear end wall is provided with a vacuumizing hole.

25. A flaring method of a rubber ring sealing pipe comprises the following steps:

(1) -providing a flaring device according to any one of claims 8 to 24, wherein the set of radial arms is at a second radial position;

(2) placing two sealing rubber rings on a flaring die of the flaring device, wherein the two sealing rubber rings are positioned on two sides of a group of positioning holes in the axial direction;

(3) moving the radial arm from the second radial position to the first radial position;

(4) sleeving the softened pipe end of the straight pipe on the flaring die, wherein the softened pipe end extends beyond the two sealing rubber rings;

(5) moving the radial arm from a first radial position to a second radial position;

(6) so that the pipe end of the straight pipe is shaped; and

(7) the end of the straight tube is removed from the flaring die.

26. The method of claim 25, wherein:

the flaring device being a flaring device according to any one of claims 9-11;

step (2) or step (3) further comprises bringing the abutment portion of the shutter into a first axial position to abut against the sealing rubber ring located at the rear side of the set of positioning holes, and in step (4), the softened pipe end extends beyond the two sealing rubber rings to cover the abutment portion;

step (5) further comprises moving the abutment from the first axial position to the second axial position out of contact with the softened pipe end.

27. The method of claim 26, wherein:

the step (7) comprises urging the abutment in a direction from the second axial position towards the first axial position.

28. The method of claim 25, wherein:

the flaring device of claim 24;

and (6) vacuumizing the inner space of the die body, and cooling and shaping the pipe end.

Technical Field

The embodiment of the invention relates to the field of mechanical manufacturing, in particular to a rubber ring sealing pipe, a rubber ring sealing pipe assembly, a flaring method of the rubber ring sealing pipe and flaring equipment of the rubber ring sealing pipe.

Background

The rubber ring seal of the high polymer material pipeline mainly adopts common rubber ring flaring seal and steel skeleton rubber ring flaring seal (for example, the rubber ring is specified according to CJ/T493-2016). According to the comprehensive aspects of pressure bearing capacity, installation convenience and the like, the flaring performance of the steel skeleton rubber ring is optimal. The reason is that the whole steel sheet framework is embedded in the rubber ring with the medium and large calibers, and the steel sheet or steel wire framework is adopted for the small calibers, so that the rubber ring has the strongest service life and pressure bearing performance.

However, with the continuous extension of the working time of the pipeline, different fluid media are conveyed, and the sealing effect of the rubber ring is increasingly poor due to the difference of working environments (landfill conditions, ambient temperature, soil variability loosening displacement and the like), so that the leakage is inevitable. The normal service life of a single rubber ring is 50 years, and the service life of a high-quality polymer material pipeline can reach more than 100 years, so that the sealing performance of the rubber ring is required to be higher.

Disclosure of Invention

The invention is provided for improving the sealing performance of the pipe.

According to an aspect of an embodiment of the present invention, there is provided a rubber-ring sealed flared tube, one end of the tube comprising a flared end, wherein:

the inner side of the flared end is provided with at least two sealing rubber rings which are spaced from each other in the axial direction of the flared end, and the plane defined by each sealing rubber ring is arranged perpendicular to the axial direction.

The embodiment of the invention also relates to flaring equipment for the rubber ring sealing pipe, which comprises:

the flaring die comprises a flaring die body and a first positioning device, wherein the flaring die body is in a cylindrical shape, the first positioning device comprises a plurality of positioning holes distributed along the circumferential direction of the die body, the positioning holes penetrate through the die body in the radial direction, and the positioning holes are arranged in groups in the circumferential direction; and

a second positioning device comprising a plurality of radial arms disposed within the mold body, the radial outer ends of the plurality of radial arms are respectively located in the plurality of locating holes, the plurality of radial arms have a first radial position and a second radial position, at the first radial position, the radially outer ends of the radial arms extend beyond the radially outer side of the die body and have a first extension height, in the second radial position, the radially outer end of the radial arm is located within the locating hole and is flush with the radially outer side of the die body, the second positioning device further comprises a radial arm drive adapted to drive the radial arm between a first radial position and a second radial position, wherein the radially outer end of the radial arm at the first radial position is adapted to block the sealing rubber ring from moving backwards along the axial direction of the flaring die.

The embodiment of the invention also relates to a flaring method of the rubber ring sealing pipe, which comprises the following steps:

(1) providing the flaring device described above wherein the set of radial arms is in a second radial position;

(2) placing two sealing rubber rings on a flaring die of the flaring device, wherein the two sealing rubber rings are positioned on two sides of a group of positioning holes in the axial direction;

(3) moving the radial arm from the second radial position to the first radial position;

(4) sleeving the softened pipe end of the straight pipe on the flaring die, wherein the softened pipe end extends beyond the two sealing rubber rings;

(5) moving the radial arm from a first radial position to a second radial position;

(6) so that the pipe end of the straight pipe is shaped; and

(7) the end of the straight tube is removed from the flaring die.

Drawings

These and other features and advantages of the various embodiments of the disclosed invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate like parts throughout, and in which:

FIG. 1 is a schematic view of a rubber gasket sealed flared tube according to an exemplary embodiment of the present invention;

FIG. 2 is a schematic view of a rubber gasket seal flaring apparatus for flaring a tube according to an exemplary embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a schematic diagram illustrating a bead seal tubing flaring operation;

FIG. 5 is a schematic view, partially in section, of a flaring die in accordance with an exemplary embodiment of the present invention;

FIG. 6 is a schematic view of a tubing assembly according to an exemplary embodiment of the present invention, showing a straight tube and flared tubing not yet connected;

fig. 7 is a schematic view illustrating an exemplary sealing effect of a pipe.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings. In the specification, the same or similar reference numerals denote the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention and should not be construed as limiting the invention.

The invention provides a multi-rubber-ring flaring multi-layer sealing technology, which is a remedy and a safety measure aiming at the leakage problem which can occur in the middle and large-caliber pipes, especially the high-pressure-bearing pipes after long-term use.

In the multilayer rubber ring sealing structure provided by the invention, the damage of various factors such as environment, landfill construction and the like to the inner rubber ring is reduced due to the protection of the outermost rubber ring, and the service life of the rubber ring can be effectively prolonged. In terms of the number of the rubber rings, more safe and durable choices can be made according to the conveying medium, the pressure grade, the service life requirement and the environmental condition of the pipeline.

The invention is especially suitable for the pipelines of high-pressure conveying high-molecular polymer materials with medium and large calibers (for example, the outer diameter of a flared pipe is in the range of 50mm-1600 mm), adopts two or more than two rubber rings to carry out multilayer sealing, and thus can meet the requirements of long service life of the pipelines, such as 100 years.

The invention also provides a flaring process of two or more steel skeleton rubber rings and a corresponding flaring die.

The present invention is described in detail below with reference to the accompanying drawings.

As shown in fig. 1, one end of the rubber gasket seal flared tube 10 includes a flared end 11 (left side in fig. 1), wherein: inside said flared end at least two sealing rubber rings 12 and 13 are provided (only two are shown in fig. 1, as can be appreciated by a person skilled in the art, more rubber rings may be provided). Also, as can be appreciated by those skilled in the art, as also shown in fig. 1, the at least two packing rubbers are spaced apart from each other in an axial direction X of the flared end and the plane defined by each packing rubber is arranged perpendicular to the axial direction X.

As shown in FIG. 1, at least a portion of the flared tube 10 between two adjacent sealing gaskets has the same inner diameter as the other portion of the flared tube.

FIG. 6 is a schematic illustration of a tube assembly according to an exemplary embodiment of the present invention, showing a straight tube 80 and flared tube 10 not yet connected. The flaring device for the rubber-ring sealed tube will now be described with reference to figures 2 to 5.

As can be seen from fig. 2-5, the body of the flaring die 20 of the flaring device is provided with a plurality of positioning holes 21 (corresponding to the positions where the later-mentioned radial arms 22 project out of the body, see for example fig. 3), which positioning holes 21 are arranged on the same circumference, and may also be equally spaced apart in the circumferential direction. The number of positioning holes may be 2, 3 or more. These positioning holes 21 penetrate the wall surface of the flaring die.

As shown in fig. 2-5, a drive cylinder 23 (in the form of a cylindrical wedge in fig. 2, 4, etc.) is provided in the flaring die 20. The cross-section of the driving cylinder 23 may be circular or may be in the shape of other regular polygons. The drive cylinder may be a solid body or, as shown, a cylindrical body.

As shown in fig. 2, 4-5, there is a change in the diameter of the drive cylinder. For example, the diameter of the middle column portion is larger, while the diameters of the column portions on both sides are smaller.

As shown in fig. 2-5, the flaring die 20 is further provided with radial arms 22 (in fig. 2, 4-5, embodied as positioning blocks movable in a radial direction), the radial arms 22 having a radial outer end and a radial inner end. The radially outer end of the radial arm 22 (the upper end of the upper radial arm in fig. 2) extends into the positioning hole 21, and as shown in fig. 2, when the radially inner end of the radial arm 22 (the lower end of the upper radial arm in fig. 2) abuts against the outer peripheral surface of the cylinder portion of the drive cylinder 23 with a larger diameter, the radially outer end of the radial arm extends beyond the outer peripheral surface of the flaring die body so as to function as a stopper for the rubber ring 14 from moving rightward in fig. 2.

Referring to fig. 4, when the radially inner end of the radial arm 22 (the lower end of the upper radial arm in fig. 4) abuts against the outer peripheral surface of the cylindrical portion of the drive cylinder 23 having a smaller diameter, the radially outer end of the radial arm 22 (the upper end of the upper radial arm in fig. 4) is flush with the outer peripheral surface of the flare die body.

The change in radial position of the radial arm 22 can be achieved by moving the drive shaft 24 back and forth in the axial direction in fig. 2, 4-5. Drive shaft 24 may be electrically or pneumatically driven.

As shown in fig. 2-3 and 5, an annular spring 25 is further provided in the flaring die, and each set of radial arms 22 is provided with a step 221 (see fig. 5), on which the annular spring 25 is provided and presses the step radially inward. However, other ways of pressing the step portion toward the driving cylinder by the spring may also be adopted, for example, a plurality of compression springs may be respectively sleeved on the radial arms, and the radial arms are provided with step portions, and the compression springs are pressed between the inner wall of the flaring die and the step portions.

In order to facilitate the stabilization of the radially inner ends of the radial arms, although not shown, the outside of the driving cylinder 23 may be further provided with axial guide grooves extending from the small-diameter cylinder portion to the large-diameter cylinder portion, the radially inner ends of the radial arms being disposed in the axial guide grooves, and the axial guide grooves may guide the movement of the radially inner ends of the radial arms.

As shown in fig. 5, the flaring die 20 is provided with positioning grooves 26 at the front and rear sides of each set of positioning holes, and the sealing rubber ring is suitable for being placed in the positioning grooves.

Although not shown, the plurality of positioning holes may include two sets of positioning holes arranged along first and second circumferences spaced apart by a predetermined distance in an axial direction of the flaring die, respectively. The predetermined distance here is at least sufficient to allow a rubber ring to be placed between the first circumference and the second circumference.

As shown in FIG. 2, the flaring die 20 further includes a guide head 27 associated with the die body for guiding the end of the tube to be flared onto the die body. The guide head may not be provided.

As shown in fig. 2 and 4, the flaring die 20 is also provided with a baffle 28. As shown in fig. 2 and 4, the baffle 28 is sleeved outside the flaring die at the rear side of the plurality of positioning holes so as to be spaced apart from the plurality of positioning holes in the axial direction of the flaring die, the baffle 28 has an abutting portion 281 (exemplified as a horizontal portion in the drawing) and a driving portion 282 (exemplified as a vertical portion in the drawing), and the baffle 28 has a first axial position and a second axial position on the flaring die, in the first axial position (see, for example, fig. 2), the abutting portion 281 is adapted to abut against the seal rubber ring 13 to define the position of the corresponding seal rubber ring 13 in the axial direction of the flaring die, and in the second axial position (see, for example, fig. 4), the abutting portion 281 is adapted to be away from the corresponding seal rubber ring 13 in the axial direction of the flaring die.

In the case where a pipe end to be flared is fitted over the abutting portion 281, the abutting portion 281 is an annular abutting portion and a radially outer wall surface of the annular abutting portion has a predetermined height higher than an outer side of the flaring die, where the predetermined height is a height that allows the pipe end to be flared, and is generally not higher than a height of the rubber ring.

The stop 28 may function to locate the rubber band and to withdraw the tube end from the flaring die after the tube end to be flared is set.

In a further embodiment, the baffle 28 may also have a heating effect.

In fig. 4, the flaring device further comprises a flaring jig 29. The flaring clamp 29 is used to clamp the tube to be flared with its axial direction aligned with the axial direction of the flaring die (in fig. 4, the axes of both are aligned), the flaring clamp and the flaring die being adapted to move relative to each other in the axial direction of the flaring die.

For the driving of the radial arms, it is not limited to the way mentioned above and shown in the drawings, but it is also possible to provide special pneumatic or electric components for directly driving the radial arms to move in the radial direction. In this case, a spring may be provided to retract the radial arm toward the inside to return, or the return may be achieved via a pneumatic or electric component.

Furthermore, during the evacuation operation mentioned below, the inner wall of the pipe end to be flared will abut the outer wall of the flaring die, which also makes it possible to effect a resetting of the radial arms.

The flaring method of the rubber gasket seal tube will be described with reference to fig. 2 and 4.

First, as shown in fig. 2, two seal rubber rings 12, 13 are placed on a flaring die 20 of the flaring device, the two seal rubber rings being located on both sides of a set of positioning holes 21 in the axial direction.

Next, the radial arm 22 is caused to move from the second radial position to the first radial position, and the abutment portion 281 of the shutter 28 is caused to be in the first axial position to abut against the seal rubber ring on the rear side of the set of positioning holes, so that the two rubber rings 12 and 13 are blocked by the radially outer end of the radial arm 22 and by the abutment portion 281, respectively, in the left-to-right direction in fig. 2.

Again, the softened tube end of the straight tube 80 is sleeved onto the flare 20 and extends beyond the two sealing rubber rings (as shown in fig. 4), although not shown, to cover the abutment.

Thereafter, the radial arms 22 are moved from the first radial position to the second radial position and the abutment 281 is moved from the first axial position to the second axial position out of contact with the softened pipe end.

Then, the inner space of the die body is vacuumized, and the tube end is cooled and shaped. The cooling may be spray cooling or other cooling means.

Finally, the tube end is pushed by the abutment 281 of the flapper 28 to be removed from the flaring die.

It should be noted that, in the present invention, two rubber rings are provided as an example, but the present invention is not limited to this, and a plurality of rubber rings may be provided.

In the present invention, "front" or "front side" means, for example, in fig. 2 and 4, a left side or a left side direction of the flaring die, and "rear" or "rear side" means, for example, in fig. 2 and 4, a right side or a right side direction of the flaring die.

Based on the above, the invention provides the following technical scheme:

1. a rubber-ring sealed flared tube, one end of the tube comprising a flared end, wherein:

the inner side of the flared end is provided with at least two sealing rubber rings which are spaced from each other in the axial direction of the flared end, and the plane defined by each sealing rubber ring is arranged perpendicular to the axial direction.

2. The flared tube of claim 1, wherein:

two sealing rubber rings are arranged on the inner side of the flared end.

3. The flared tube of claim 1, wherein:

the sealing rubber ring is a steel skeleton rubber ring; the pipe is made of high polymer materials.

4. The flared tube of claim 1, wherein:

the caliber of the flaring pipe is within the range of 50mm-1600 mm.

5. The flared tube of any one of claims 1-4, wherein:

at least one part of the flared tubing, which is positioned between two adjacent sealing rubber rings, has the same inner diameter as the other parts of the flared tubing.

6. A tubing assembly comprising:

a first tubing, the first tubing being a rubber gasket seal flared tubing according to any one of claims 1-5; and

a second tubing having one end adapted for insertion into the flared end of the rubber gasket seal flared tubing and the at least two sealing rubber rings having an inner diameter designed to mate with the outer diameter of the one end of the second tubing to form a multi-layer rubber gasket seal.

7. The tubing assembly of claim 6, wherein:

the second pipe is the rubber ring seal flaring pipe according to any one of 1-5, and the other end of the second pipe is provided with the flaring end.

8. A flaring device for a rubber-ring sealed tube, comprising:

the flaring die comprises a flaring die body and a first positioning device, wherein the flaring die body is in a cylindrical shape, the first positioning device comprises a plurality of positioning holes distributed along the circumferential direction of the die body, the positioning holes penetrate through the die body in the radial direction, and the positioning holes are arranged in groups in the circumferential direction; and

a second positioning device comprising a plurality of radial arms disposed within the mold body, the radial outer ends of the plurality of radial arms are respectively located in the plurality of locating holes, the plurality of radial arms have a first radial position and a second radial position, at the first radial position, the radially outer ends of the radial arms extend beyond the radially outer side of the die body and have a first extension height, in the second radial position, the radially outer end of the radial arm is located within the locating hole and is flush with the radially outer side of the die body, the second positioning device further comprises a radial arm drive adapted to drive the radial arm between a first radial position and a second radial position, wherein the radially outer end of the radial arm at the first radial position is adapted to block the sealing rubber ring from moving backwards along the axial direction of the flaring die.

9. The flaring device of claim 8, wherein:

the plurality of positioning holes comprises a set of positioning holes arranged along a first circumference;

the plurality of radial arms comprises a set of radial arms disposed in a radial plane;

the second positioning device further comprises a baffle plate, the baffle plate is sleeved outside the flaring die at the rear side of the positioning holes and is spaced from the positioning holes in the axial direction of the flaring die, the baffle plate is provided with a butting part and a driving part, the baffle plate is provided with a first axial position and a second axial position on the flaring die, the butting part is suitable for being butted with the sealing rubber ring to limit the position of the corresponding sealing rubber ring in the axial direction of the flaring die at the first axial position, and the butting part is suitable for being far away from the corresponding sealing rubber ring in the axial direction of the flaring die at the second axial position.

10. The flaring device of claim 9, wherein:

the abutting portion is an annular abutting portion and a radially outer wall surface of the annular abutting portion has a predetermined height higher than an outer side of the flaring die.

11. The flaring device of claim 10, wherein:

the baffle is a heating baffle.

12. The flaring device of claim 8, wherein:

the plurality of positioning holes comprise two groups of positioning holes which are respectively arranged along a first circumference and a second circumference which are spaced apart by a preset distance in the axial direction of the flaring die;

the plurality of radial arms includes two sets of radial arms disposed in two radial planes, respectively.

13. The flaring device of claim 8, further comprising:

the flaring fixture is used for clamping a pipe to be flared, the axial direction of the pipe to be flared is aligned with the axial direction of the flaring die,

wherein:

the flaring jig and the flaring die are adapted to move relative to each other in the axial direction of the flaring die.

14. The flaring device of claim 8, wherein:

the flaring die is provided with positioning grooves on the front side and the rear side of each group of positioning holes, and the sealing rubber ring is suitable for being arranged in the positioning grooves.

15. The flaring device of claim 8, wherein:

the flaring die also comprises a guide head connected with the die body and used for guiding the end of the tube to be flared to the die body.

16. The flaring device of claim 8, wherein:

the positioning holes arranged in groups are arranged at equal angular intervals in the circumferential direction.

17. The flaring device of any one of claims 8-16, wherein:

the radial arm driving apparatus includes:

a drive shaft having an operating position and a withdrawn position in an axial direction; and

a driving cylinder connected to one end of the driving shaft, the driving cylinder having a first cylinder and a second cylinder connected to each other in an axial direction, a transition portion provided between the first cylinder and the second cylinder, the first cylinder having a first outer diameter, the second cylinder having a second outer diameter smaller than the first outer diameter, the driving cylinder being provided in the flare die coaxially with the flare die,

wherein:

the radial inner end or the part close to the radial inner end of the radial arm is provided with a pressing surface matched with the peripheral surface of the driving column body;

in the operating position of the drive shaft, the abutting surface of the radial arm abuts against the outer peripheral surface of the first column body, and in the retreating position of the drive shaft, the abutting surface of the radial arm abuts against the outer peripheral surface of the second column body.

18. The flaring device of claim 17, wherein:

the first cylinder and the second cylinder are both cylinders.

19. The flaring device of claim 17, wherein:

the outer side of the driving cylinder is provided with an axial guide groove extending through the first cylinder and the second cylinder, and the radial inner end of the radial arm is arranged in the axial guide groove.

20. The flaring device of claim 17, wherein:

the radial arm drive further comprises a spring body adapted to press the radial arm towards the drive cylinder.

21. The flaring device of claim 20, wherein:

the spring body is an annular spring, each group of radial arms is provided with a step part, and the annular spring is arranged on the step part and radially and inwardly extrudes the step part; or

The spring body comprises a plurality of compression springs which are respectively sleeved on the radial arms, step parts are arranged on the radial arms, and the compression springs are pressed between the inner wall of the flaring die and the step parts.

22. The flaring device of claim 17, wherein:

the other end of the drive shaft is located outside the flaring die and is driven.

23. The flaring device of any one of claims 8-16, wherein:

the radial arm driving means includes pneumatic means or electric means for directly driving the radial arm to move in the radial direction.

24. The flaring device of any one of claims 8-23, wherein:

the front end and the rear end of the die body are respectively provided with a front end wall and a rear end wall so as to limit a closed space in the die body, and the rear end wall is provided with a vacuumizing hole.

25. A flaring method of a rubber ring sealing pipe comprises the following steps:

(1) providing a flaring device according to any one of claims 8-24, wherein the set of radial arms is at a second radial position;

(2) placing two sealing rubber rings on a flaring die of the flaring device, wherein the two sealing rubber rings are positioned on two sides of a group of positioning holes in the axial direction;

(3) moving the radial arm from the second radial position to the first radial position;

(4) sleeving the softened pipe end of the straight pipe on the flaring die, wherein the softened pipe end extends beyond the two sealing rubber rings;

(5) moving the radial arm from a first radial position to a second radial position;

(6) so that the pipe end of the straight pipe is shaped; and

(7) the end of the straight tube is removed from the flaring die.

26. The method of claim 25, wherein:

the flaring device is the flaring device according to any one of the claims 9-11;

step (2) or step (3) further comprises bringing the abutment portion of the shutter into a first axial position to abut against the sealing rubber ring located at the rear side of the set of positioning holes, and in step (4), the softened pipe end extends beyond the two sealing rubber rings to cover the abutment portion;

step (5) further comprises moving the abutment from the first axial position to the second axial position out of contact with the softened pipe end.

27. The method of 26, wherein:

the step (7) comprises urging the abutment in a direction from the second axial position towards the first axial position.

28. The method of claim 25, wherein:

the flaring device is the flaring device according to 24;

and (6) vacuumizing the inner space of the die body, and cooling and shaping the pipe end.

Fig. 7 is a schematic diagram illustrating the sealing effect of the pipeline, specifically, a pressure curve diagram of a static hydraulic sealing test of sealing the pipe with a double-rubber-ring flaring and sealing the pipe at 3.36 times of nominal pressure and maintaining the pressure for 1 hour. In fig. 7, the two vertical axes are pressure and temperature, respectively, and the horizontal axis is time. From the results shown in fig. 7, it can be seen that the seal was leak-free and the sample was not deformed.

In the invention, two or more steel skeleton rubber rings are reasonably arranged at the flaring end of the pipeline, so that the problem of pipeline leakage caused by the sealing failure of a single rubber ring can be solved.

Based on the flaring method and the flaring equipment provided by the invention, the flaring of the multi-rubber-ring sealing pipe can be simply realized.

It is to be noted that, in the present invention, the radial arm is taken as an example, and in the drawings, the radial arm is also in the form of an arm, but in the present invention, it is within the scope of the present invention, regardless of the form of the so-called "arm" of the radial arm, as long as the variation of the radial position of the radially outer end of the radial arm within the positioning hole can be achieved, for example, the radial arm also includes a short protrusion or block extending into the positioning hole.

Although embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.