CN116251904A - Split ring structure and hydraulic expansion device - Google Patents

Abstract

The invention provides a split ring structure and a hydraulic expansion device. The split ring structure is used for being sleeved on the outer wall of the mandrel and located in the pipe, and comprises a split ring, wherein the split ring is provided with a first outer diameter and a second outer diameter, the first outer diameter is smaller than the second outer diameter, the split ring is used for being in sealing fit with the pipe at the second outer diameter, and a fit gap is formed between the split ring and the pipe at the first outer diameter. The split ring is of a reducing structure, and on the premise of ensuring that the split ring meets the sealing state, the probability of contact between the outer wall of the split ring and the inner wall of a pipe is reduced as much as possible by reducing the outer diameter of the split ring, so that the probability of scratching the inner wall of the pipe when the split ring is opened is reduced, and the quality of the pipe hole after expansion joint meets the expansion joint requirement.

Description

Split ring structure and hydraulic expansion device

Technical Field

The invention relates to the technical field of hydraulic expansion joint, in particular to a split ring structure and a hydraulic expansion device.

Background

A large number of tube-tube plates in the steam generator and heat exchanger products in the nuclear power petrochemical field are required to be subjected to hydraulic expansion, and the hydraulic expansion is a mechanical connection method for realizing tight connection of the tubes and the tube plates by plastic deformation and elastic deformation of the tube plates through hydraulic pressure. The hydraulic expansion joint can eliminate the gap between the pipe and the pipe plate, prevent the liquid from penetrating into the outer wall of the pipe to corrode, and avoid the failure of the welding seam caused by the alternating stress generated on the welding seam of the pipe and the pipe plate due to the vibration of the pipe bundle, and simultaneously increase the mechanical strength of the pipe-pipe plate connection.

The equipment used for expansion joint is hydraulic expansion equipment and an expansion gun, wherein the split ring is a key component of hydraulic expansion joint. The structural size of the split ring directly influences the quality of the expanded joint of the tube and the tube plate. For example, after the sealing welding of the tube and the tube plate of the steam generator product, the tube hole needs to be subjected to hydraulic expansion joint, the hydraulic expansion joint pressure is larger than or equal to 3100bar, the wall thickness of the tube is 1.35mm, the inner diameter phi of the tube hole is 12.3mm, the inner diameter phi of the tube hole after the sealing welding of the tube and the tube plate is 12.1mm, and the expansion joint difficulty is extremely high because the wall thickness of the tube is thicker, the diameter of the tube hole is small, the expansion joint length is 254mm, the expansion joint pressure is large, and the expansion joint length is long. Meanwhile, after expansion joint, the quality requirement on the inner wall of the pipe hole is higher, an endoscope is generally needed to be used for checking the inner surface of the expanded pipe after expansion joint, the inner wall surface of the pipe hole is required to be free of any defects such as cracks and scratches, and meanwhile, an illumination device (the illuminance is more than or equal to 500 lux) is adopted for checking that no circumferential scratches are allowed in a 40mm deep area from the pipe orifice. In the conventional split ring structure, because the inner diameter of the pipe is small, the expansion pressure is high, and when high-pressure liquid generates high-strength pressure through the center of the mandrel in the expansion test process, the split ring is opened at the longitudinal opening position, so that the opening end part of the split ring is in partial contact with the inner wall of the pipe, the inner wall is scratched, for example, circumferential and longitudinal scratches are generated on the inner surface of the pipe, and the expansion quality of the pipe-pipe plate is affected.

Disclosure of Invention

The invention aims to solve the problem that the existing split ring structure is easy to generate circumferential and longitudinal scratches on the inner surface of a pipe in the expansion joint process, so that the expansion joint quality is affected.

In order to solve at least one of the above problems, the present invention provides a split ring structure for being sleeved on an outer wall of a mandrel and located in a pipe, comprising a split ring, wherein the split ring has a first outer diameter and a second outer diameter, the first outer diameter is smaller than the second outer diameter, the split ring is used for being in sealing fit with the pipe at the second outer diameter, and a fit clearance is formed between the split ring and the pipe at the first outer diameter.

Preferably, the split ring comprises a first split ring part, a second split ring part and a transition structure for connecting the first split ring part and the second split ring part, wherein the outer diameter of the first split ring part is the first outer diameter, the outer diameter of the second split ring part is the second outer diameter, and the transition structure is a reducing structure.

Preferably, the first outer diameter is 11.3mm and the second outer diameter is 11.7mm.

Preferably, the inner diameter of the first split ring part is equal to the inner diameter of the second split ring part, and the wall thickness of the first split ring part is smaller than the wall thickness of the second split ring part.

Preferably, the wall thickness of the first split ring is 1.3mm, and the wall thickness of the second split ring is 1.5mm.

Preferably, the split ring structure further comprises an inner sleeve, the inner sleeve is used for being sleeved on the outer wall of the mandrel, and the split ring is sleeved on the outer wall of the inner sleeve.

Preferably, the outer diameter of the inner sleeve is 9.5mm and the wall thickness of the inner sleeve is 0.36mm.

Preferably, a plurality of longitudinal openings are circumferentially distributed on the outer wall of the split ring, and the longitudinal openings longitudinally extend to one end of the split ring.

The split ring structure of the present invention has the advantages over the prior art:

the split ring is provided with two parts with different diameters and is of a reducing structure, wherein the part with larger diameter is used for being in sealing fit with a pipe so as to play a sealing role, a fit clearance is increased between the part with smaller diameter and the inner wall of the pipe, under high-strength pressure, the fit clearance is used for providing space for deformation of the split ring, so that the deformation resistance of the split ring is increased, the split ring is prevented from scratching the inner wall of the pipe in the hydraulic expansion process, and the probability that the outer wall of the split ring is contacted with the inner wall of the pipe is reduced as much as possible by reducing the outer diameter of the split ring on the premise that the split ring meets the sealing state, so that the probability of scratching the inner wall of the pipe when the split ring is opened is reduced, and the quality of the pipe hole after expansion meets the expansion requirement.

The invention also provides a hydraulic expansion device which is arranged in the pipe and comprises a mandrel and the split ring structure, wherein the split ring structure is sleeved on the outer wall of the mandrel.

Preferably, a central hole is formed in the mandrel along the axis, the central hole is used for allowing high-pressure liquid to enter, a radial hole penetrating through the mandrel is formed in the end portion of the central hole, and the radial hole is perpendicular to and communicated with the central hole.

The advantages of the expansion device of the present invention over the prior art are the same as those of the split ring structure over the prior art and are not described in detail herein.

Drawings

FIG. 1 is a schematic cross-sectional view of a first split ring of a medium diameter split ring structure according to a comparative example of the present invention;

FIG. 2 is a schematic cross-sectional view of a first inner sleeve of a medium diameter split ring structure according to a comparative example of the present invention;

FIG. 3 is a schematic perspective view of a split ring structure according to an embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of a split ring structure according to an embodiment of the present invention;

FIG. 5 is a schematic side view of a split ring structure according to an embodiment of the present invention;

FIG. 6 is a schematic view of a split ring structure according to an embodiment of the present invention;

FIG. 7 is a schematic cross-sectional view of a split ring in accordance with an embodiment of the present invention;

FIG. 8 is a schematic cross-sectional view of an inner sleeve according to an embodiment of the present invention;

fig. 9 is a schematic diagram of expansion principle in an embodiment of the present invention.

Reference numerals illustrate:

101-a first split ring; 102-a first inner sleeve; 103-a first longitudinal notch;

1-a split ring; 2-an inner sleeve; 3-a mandrel; 4-a sealing ring; a 5-adapter; 6-tube plate parent metal; 7-a tube; 8-gap between tube and tube sheet; 9-high pressure liquid; 10-longitudinal notch.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

Referring to fig. 3-9, a split ring structure according to an embodiment of the present invention is configured to be sleeved on an outer wall of a mandrel 3 and located in a pipe 7, and includes a split ring 1, where the split ring 1 has a first outer diameter and a second outer diameter, the first outer diameter is smaller than the second outer diameter, the split ring 1 is used for sealing engagement with the pipe 7 at the second outer diameter, and an engagement gap is provided between the split ring 1 and the pipe 7 at the first outer diameter.

The split ring 1 of this embodiment has two parts with different diameters, is the reducing structure, and wherein the part that the diameter is great is used for sealing cooperation with pipe 7 to play sealed effect, has increased the fit clearance between the part that the diameter is less and the pipe 7 inner wall, and under high strength pressure, this fit clearance is used for providing the space for split ring 1 warp, thereby increases split ring 1's anti deformability, avoids split ring 1 to fish tail pipe 7 inner wall in the hydraulic expansion joint in-process, thereby under the state of guaranteeing the seal, makes the tube hole quality after the expansion joint satisfy the expansion joint requirement.

In some embodiments, a plurality of longitudinal slits 10 are circumferentially distributed on the outer wall of the split ring 1, and the longitudinal slits 10 extend to one end of the split ring 1 in the longitudinal direction. As shown in fig. 3 and 5, the outer wall of the split ring 1 is provided with longitudinal slits 10 penetrating through the end, and a plurality of longitudinal slits 10 are uniformly distributed along the circumferential direction. The end part of the split ring 1 can be opened at the position of the longitudinal notch 10 under the action of high pressure, so that the sealing effect of the split ring 1 is exerted.

In some embodiments, the split ring 1 includes a first split ring portion, a second split ring portion, and a transition structure connecting the first split ring portion and the second split ring portion, where the outer diameter of the first split ring portion is the first outer diameter, the outer diameter of the second split ring portion is the second outer diameter, and the transition structure is a reducing structure.

In this embodiment, the split ring 1 is formed by a first split ring portion, a transition structure and a second split ring portion, so that the whole split ring 1 is of a reducing structure, and by reducing the outer diameter of the first split ring portion, a fit gap for resisting deformation is formed between the outer wall of the split ring 1 and the inner wall of the pipe 7, the deformation space of the split ring 1 under high-strength pressure is increased, and the split ring 1 is prevented from scratching the inner wall of the pipe 7 when being deformed under high-strength pressure.

In some embodiments, the first outer diameter is 11.3mm and the second outer diameter is 11.7mm. The diameter of the transition structure is gradually changed from 11.3mm to 11.7mm, so that transition connection between the two split ring parts is realized.

In some embodiments, the first split ring portion has an inner diameter equal to an inner diameter of the second split ring portion, and the first split ring portion has a wall thickness less than a wall thickness of the second split ring portion.

In this embodiment, the inner diameter of the entire split ring 1 is unchanged, because the outer diameter of the first split ring portion is smaller than the outer diameter of the second split ring portion, the wall thickness of the first split ring portion is smaller than the wall thickness of the second split ring portion, and the second split ring portion needs to be in sealing fit with the inner wall of the pipe 7 to achieve a sealing effect, so that the rigidity of the split ring 1 is increased by increasing the wall thickness of the second split ring portion, and under the condition of receiving the same cutting and cutting force, the cutting or cutting deformation generated by the split ring 1 is smaller, and in the processing process of the split ring 1, the deformation caused by the processing can be reduced; at the same time, the wall thickness is increased, so that the strength of the split ring 1 can be improved, and the deformation resistance of the split ring structure is further increased.

In some embodiments, the second split ring portion is located at an end of the split ring 1, and the wall thickness of the second split ring portion is 1.3mm.

In the embodiment, the wall thickness of the end part of the split ring 1 is increased to 1.3mm, and the wall thickness of the split ring 1 is increased, so that the strength of the split ring 1 is improved, and the deformation resistance of the variable-diameter split ring structure is improved. Meanwhile, the wall thickness of the end part of the split ring 1 is increased, and the deformation caused by processing is reduced in the processing process of the opening position of the end part of the split ring 1.

In some embodiments, the device further comprises an inner sleeve 2, the inner sleeve 2 is used for being sleeved on the outer wall of the mandrel 3, and the split ring 1 is sleeved on the outer wall of the inner sleeve 2. The inner sleeve 2 is arranged inside the split ring 1 and plays a supporting role on the split ring 1 so as to improve the strength of the whole split ring structure.

As shown in fig. 8, a circle of boss is arranged on the outer wall of the end part of the inner sleeve 2, and a notch matched with the boss is arranged on the inner wall of the end part of the split ring 1, so that the split ring 1 is connected with the inner sleeve 2 through the limiting function of the boss and the notch. Preferably, the matching surface of the boss and the notch is set as an inclined surface.

For ease of comparison, a comparative example is provided, with fig. 1 and 2 showing schematic diagrams of a medium diameter split ring structure comprising a first split ring 101 and a first inner sleeve 102 in the comparative example, with fig. 1 showing schematic cross-sectional views of the first split ring 101 with dimensions, and fig. 2 showing schematic cross-sectional views of the first inner sleeve with dimensions. As shown in fig. 1, the first split ring 101 has a cylindrical structure, an outer diameter of 12mm, a length of 25mm, and 6 first longitudinal slits 103 uniformly distributed in the circumferential direction of the opening portion, and as shown in fig. 2, the outer diameter of the first inner sleeve 102 is 10mm, and the wall thickness is 0.6mm.

The working principle of hydraulic expansion joint is that a hydraulic expander injects high-pressure water into an expansion gun mandrel 3, the high-pressure water is used for sealing through an O-shaped ring and a split ring 1, the inner diameter of a tube bundle is enlarged to be attached to a tube plate tube hole by means of the pressure of the high-pressure water, a gap 8 between a tube and the tube plate is eliminated, the corrosion problem of in-service operation is reduced, when the hydraulic pressure is increased, the O-shaped ring deforms and simultaneously presses a support ring and the split ring 1, so that the split ring 1 and the support ring deform together, the transition of the termination size of the hydraulic expansion joint is realized, and the stress concentration point of a final expansion point is reduced.

Fig. 6 shows a schematic view of the split ring structure in this embodiment, fig. 7 is a schematic cross-sectional view of the split ring 1, and fig. 8 is a schematic cross-sectional view of the inner sleeve 2. The split ring 1 adopts a cylinder reducing structure, the outer diameter of the split ring 1 is 11.3mm and 11.7mm respectively to form a reducing structure, the deformation resistance of the split ring 1 is increased under the condition of ensuring sealing, the length of the split ring 1 is 25mm, 6 longitudinal openings are uniformly distributed in the circumferential direction of the opening part of the tail part of the split ring 1, the outer diameter of an inner sleeve 2 of the split ring 1 is 9.5mm, and the wall thickness of the inner sleeve 2 is 0.36mm.

It can be seen that, compared with the first split ring 101 of the conventional equal diameter split ring in the comparative example, the split ring 1 of the present embodiment is changed from a constant diameter structure with a diameter of 12mm to a variable diameter structure with a diameter of 11.3mm at one end and a diameter of 11.7mm at the other end, and the second split ring portion with a diameter of 11.7mm is in sealing engagement with the inner wall of the pipe 7 to ensure sealing, while the first split ring portion with a diameter of 11.3mm is reduced in outer diameter as much as possible to minimize the probability of contact with the inner wall of the pipe 7, thereby reducing the probability of damage to the inner wall of the pipe 7. That is, in this embodiment, on the premise of ensuring the sealing of the hydraulic expansion joint pipe 7, a fit clearance of 0.3mm is increased between the split ring 1 and the pipe 7, and the deformation space of the split ring 1 under high-strength pressure is increased. As shown in fig. 6, the diameter of the second split ring part on the split ring 1 is 11.7mm, and the length is 4.3mm, namely, at least the split ring is ensured to be in sealing fit with the inner wall of the pipe by 4.3mm, so as to meet the sealing requirement, and the diameters of the rest lengths of the split ring can be properly reduced, so that the gap between the split ring and the inner wall of the pipe is increased, and the probability of contact with the inner wall of the pipe is reduced.

It can also be seen by comparison that the wall thickness of the split ring 1 in this embodiment is increased as a whole, specifically, the wall thickness of the first split ring portion is increased from 1mm to 1.3mm, the wall thickness of the second split ring portion is increased from 1mm to 1.5mm, the wall thickness of the split ring 1 is increased by 0.3mm, the wall thickness of the end portion at the position of the split ring is increased by 0.5mm, the thickness of the split ring 1 is increased, the strength of the split ring 1 is increased, and the deformation resistance of the split ring structure is increased. Meanwhile, the wall thickness of the end part of the split ring 1 is increased, and the deformation generated in the processing process is reduced.

It can also be seen by comparison that the diameter of the inner sleeve 2 of the embodiment is reduced from 10mm to 9.5mm, the wall thickness is reduced from 0.6mm to 0.36mm, the thickness of the split ring 1 is increased by reducing the outer diameter of the split ring 1, the size of the inner sleeve 2 is reduced, the inner wall of the pipe hole is prevented from being scratched by the split ring 1 in the hydraulic expansion process, and the quality of the pipe hole after chapping meets the expansion requirement.

In the embodiment, the sealing device of the high-pressure hydraulic expansion rod is optimized by redesigning the structure of the hydraulic expansion rod split ring which is a key component of the hydraulic expansion gun. The size and the size of the designed split ring can strictly control the size of the hydraulic expanded joint pipe hole and the quality of the inner wall, ensure that the length of the hydraulic expanded joint is controlled within 0.5mm, and the inner wall of the expanded joint pipe hole is smooth without any scratch and damage. Through the optimal design to the hydraulic expansion rod split ring, hydraulic expansion joint operation precision and expansion joint quality are ensured.

The embodiment of the invention also provides a hydraulic expansion device which is arranged in the pipe 7 and comprises the mandrel 3 and the split ring structure, wherein the split ring structure is sleeved on the outer wall of the mandrel 3.

As shown in fig. 9, the hydraulic expansion device mainly comprises an adapter 5, a split ring, a sealing ring 4, a supporting ring, a mandrel 3 and the like, wherein the mandrel 3 is in threaded connection with the adapter 5, and the sealing ring 4 is preferably an O-shaped ring. The working principle of the tube bundle hydraulic expansion joint is that the hydraulic tube expander injects high-pressure water into the mandrel 3 of the hydraulic expansion device, the inner diameter of the tube bundle is enlarged to be attached to the tube plate tube hole by means of the pressure of the high-pressure water, the gap 8 between the tube and the tube plate is eliminated, the corrosion problem of in-service operation is reduced, when the hydraulic pressure is increased, the O-shaped ring deforms, the supporting ring and the split ring 1 are pressed, the split ring 1 and the supporting ring deform together, the transition of the termination size of the hydraulic expansion joint is realized, and the stress concentration point of a final expansion point is reduced.

In some embodiments, a central hole is arranged in the mandrel 3 along the axis, the central hole is used for allowing high-pressure liquid 9 to enter, and a radial hole penetrating through the mandrel 3 is arranged at the end of the central hole, and the radial hole is perpendicular to and communicated with the central hole.

In this embodiment, a central hole through which high-pressure liquid 9 is introduced and a radial hole communicated with the central hole are provided in the mandrel 3, the high-pressure liquid 9 is sprayed between the outer wall of the mandrel 3 and the inner wall of the pipe 7 through the central hole and the radial hole, the end of the split ring 1 is opened at the longitudinal opening position under the action of high pressure, and the split ring and the sealing ring 4 together seal the pipe hole. The high-strength pressure generated by the high-pressure liquid 9 causes the tube 7 to generate plastic deformation, the tube plate base metal 6 generates elastic deformation, after a period of time, the high-strength pressure is removed, the elastic deformation of the tube plate base metal 6 can be restored to the original state, but the plastic deformation of the tube 7 still keeps the state of the enlarged diameter and cannot be restored to the original state, so that the tube 7 is tightly connected with the tube plate.

In summary, in this embodiment, by changing the split ring 1 into a reducing structure, increasing the wall thickness, reducing the outer diameter of the split ring 1, increasing the deformation resistance of the split ring 1 under high-strength pressure, avoiding the split ring 1 from scratching the inner wall of the pipe hole in the hydraulic expansion joint process, and ensuring the quality of the pipe hole after expansion joint to meet the expansion joint requirement in the state of ensuring the sealing.

Although the present disclosure is described above, the scope of protection of the present disclosure is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the scope of the invention.

Claims (10)

1. The utility model provides a split ring structure, its characterized in that is used for the cover to locate dabber (3) outer wall, and is located pipe (7), including split ring (1), split ring (1) have first external diameter and second external diameter, first external diameter is less than the second external diameter, split ring (1) are in second external diameter department be used for with pipe (7) sealing fit, split ring (1) are in first external diameter department with have the fit clearance between pipe (7).

2. The split ring structure according to claim 1, wherein the split ring (1) comprises a first split ring portion, a second split ring portion, and a transition structure connecting the first split ring portion and the second split ring portion, the first split ring portion having an outer diameter of the first outer diameter, the second split ring portion having an outer diameter of the second outer diameter, the transition structure being a reducing structure.

3. The split ring structure of claim 2, wherein said first outer diameter is 11.3mm and said second outer diameter is 11.7mm.

4. A split ring structure according to claim 3, wherein the inner diameter of the first split ring portion is equal to the inner diameter of the second split ring portion, the wall thickness of the first split ring portion being less than the wall thickness of the second split ring portion.

5. The split ring structure of claim 4, wherein said first split ring has a wall thickness of 1.3mm and said second split ring portion has a wall thickness of 1.5mm.

6. The split ring structure according to claim 5, further comprising an inner sleeve (2), wherein the inner sleeve (2) is configured to be sleeved on an outer wall of the mandrel (3), and wherein the split ring (1) is sleeved on an outer wall of the inner sleeve (2).

7. The split ring structure according to claim 6, wherein the outer diameter of the inner sleeve (2) is 9.5mm and the wall thickness of the inner sleeve (2) is 0.36mm.

8. The split ring structure according to claim 7, wherein a plurality of longitudinal slits (10) are circumferentially distributed on the outer wall of the split ring (1), and the longitudinal slits (10) extend longitudinally to one end of the split ring (1).

9. A hydraulic expansion device, characterized in that it is intended to be placed inside a tube (7), comprising a mandrel (3) and a split ring structure according to any one of claims 1-8, said split ring structure being placed around the outer wall of said mandrel (3).

10. Hydraulic expansion device according to claim 9, characterized in that a central hole is provided in the mandrel (3) along the axis for the entry of high-pressure liquid (9), the end of which is provided with a radial hole through the mandrel (3), which is perpendicular to and communicates with the central hole.

Images