Hydraulic tube expander for heat exchange tube

Abstract

The invention relates to a heat exchange tube hydraulic tube expander which comprises a core body, annular grooves are formed in the two ends of the core body respectively, sealing rings are sleeved with the annular grooves respectively, a blind hole is formed in one end of the core body and extends to the position between the two annular grooves, a water outlet communicated with the blind hole is formed in the core body, and the end, provided with the blind hole, of the core body is used for being connected with a hydraulic pump. The closed end of the core body is provided with a check ring, the core body is slidably sleeved with a sliding sleeve, the sliding sleeve is provided with a through hole matched with the water outlet, the end, provided with the blind hole, of the core body is in threaded connection with an adjusting nut, an annular groove is formed between the adjusting nut and the sliding sleeve, and an annular groove is formed between the sliding sleeve and the check ring; when the adjusting nut is rotated, the pressure of the sealing rings in the two annular grooves is adjusted at the same time, and the technical problem that the tube expander and the heat exchange tube are difficult to assemble and disassemble is solved.

Description

Technical Field

[0001] The invention belongs to the field of hydraulic tube expanding, and particularly relates to a hydraulic tube expander for heat exchange tubes. Background Art

[0002] A heat exchange tube self-sealing hydraulic tube expander usually has two deformable sealing rings. For example, the double-bowl type self-sealing hydraulic tube expander disclosed in the publication number CN2092383U. The two deformable sealing rings expand and deform under water pressure during operation and tightly abut against the inner wall of the heat exchange tube, thus realizing self-sealing. However, this structure has high requirements for the dimensional accuracy of the sealing rings. If the size is too large, it will be difficult for the tube expander to be inserted into the heat exchange tube; if the size is too small, the sealing effect will decline. Moreover, for such deformable sealing rings, after the tube expanding is completed and the pressure is released, there is a problem that they are stuck with the inner wall of the heat exchange tube and cannot be reset, resulting in difficulty in disassembling the tube expander.

[0003] Generally speaking, conventional tube expanders need to adjust the sealing rings before inserting them into the heat exchange tubes, making the outer diameter of the sealing rings larger than the inner diameter of the heat exchange tubes, and then forcibly inserting them into the heat exchange tubes. Such an operation method is time-consuming and laborious, with a large operation difficulty, and the sealing rings are easily worn, resulting in a decline in the sealing performance. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a hydraulic tube expander for heat exchange tubes to solve the technical problem of the large assembly and disassembly difficulty between the tube expander and the heat exchange tube.

[0005] To solve the above technical problem, the technical solution adopted by the present invention is: a hydraulic tube expander for heat exchange tubes, including a cylindrical core body. Annular grooves for accommodating sealing rings are respectively arranged at both ends of the core body, and sealing rings are respectively sleeved in the annular grooves. A blind hole extending axially is opened at one end of the core body, and the blind hole extends between the two annular grooves. At least one water outlet communicating with the blind hole is opened on the core body between the two annular grooves. The end of the core body where the blind hole is opened is used to connect a hydraulic pump. A retaining ring with an outer diameter larger than the outer diameter of the core body is arranged at the closed end of the core body. A sliding sleeve is slidably sleeved on the core body. A plurality of through holes cooperating with the water outlets are opened on the sliding sleeve. An adjusting nut is threadedly connected to the end of the core body where the blind hole is opened. An annular groove is formed between the adjusting nut and the sliding sleeve, and an annular groove is formed between the sliding sleeve and the retaining ring. When the adjusting nut is rotated, the pressure of the sealing rings in the two annular grooves is adjusted simultaneously.

[0006] As a preferred solution, at least one axially extending guiding groove is arranged on the inner wall of the sliding sleeve, and a guiding rail cooperating with the guiding groove is arranged on the outer wall of the core body. The length of the guiding rail is less than the length of the guiding groove. The guiding rail is located between the two annular grooves and the distance between the two annular grooves satisfies that the pressure adjustment of the sealing rings will not interfere with the guiding rail. The through holes correspond to the water outlets one by one, and the diameter of the through holes is larger than the diameter of the water outlets.

[0007] As a preferred solution, an extension tube is connected to the end face of the adjusting nut facing the sealing ring. The annular end face of the extension tube close to the sealing ring is used to abut against the sealing ring, and the inner diameter of the extension tube is larger than the outer diameter of the core body.

[0008] As a preferred solution, the retaining ring is integrally formed with the core body or is threadedly connected to the core body.

[0009] As a preferred solution, two sealing rings are sleeved in any one of the annular grooves. The two sealing rings are arranged in sequence along the axial direction of the core body, and the sealing rings are hermetically connected to the bottom of the annular groove.

[0010] As a preferred solution, three sealing rings are sleeved in any one of the annular grooves. The three sealing rings are arranged in a triangular shape, and any one of the sealing rings is a rubber-coated steel ring.

[0011] As a preferred solution, a gun head is connected to the open end of the core body. An insertion interface matching the open end of the core body is provided on the gun head. A conduit is connected to the rear end of the insertion interface. The conduit extends out of the gun head for connecting to a hydraulic pump. An electromagnetic valve is provided on the conduit. A pressurizing switch for controlling the battery valve is provided on the gun head. The high pressure tolerance of the conduit is greater than the hydraulic pressure required for tube expansion.

[0012] As a preferred solution, a smooth section is provided at the open end of the core body. An annular card slot is provided on the smooth section. The adjusting nut is located between the smooth section and the sealing ring. The smooth section is adapted to the insertion interface. A plurality of circumferentially evenly distributed pin holes are provided on the inner wall of the insertion interface. A locking pin is slidably inserted into each pin hole. A coil spring is provided between the locking pin and the bottom surface of the pin hole. The elastic force of the coil spring pushes part of the locking pin out of the pin hole. An electromagnet is provided on the bottom surface of each pin hole. Each electromagnet is connected to a power source through the same unlocking switch. The unlocking switch is provided on the gun head. The side of the head of each locking pin facing outside the insertion interface is set as an inclined surface to facilitate the core body to push each locking pin back into the pin hole when inserted.

[0013] As a preferred solution, a motor is provided inside the gun head. The motor is meshed and driven with an external gear provided on the outer wall of the adjusting nut through a reduction gear set. The reduction gear set is rotatably connected to the gun head. The motor is connected to a power source through a forward and reverse switch. A protective cover extending towards the adjusting nut is provided at the front end of the gun head. The protective cover covers the part of the reduction gear set extending outside the gun head.

[0014] As a preferred solution, the power source is a lithium battery fixedly arranged inside the gun head. The lithium battery supplies power to all the electronic components inside the gun head.

[0015] The beneficial effects of the present invention are as follows: The present invention uses a sliding sleeve and an adjusting nut to simultaneously control the pressure adjustment of the sealing rings in two annular grooves. In this way, by rotating the adjusting nut exposed at the end of the heat exchange tube, the sealing ring inserted into the heat exchange tube can be pressurized, causing the sealing ring to expand radially outward and tightly abut against the inner wall of the heat exchange tube to achieve good sealing. After the tube expanding is completed, the pressure of the sealing ring can be reduced by rotating the adjusting nut, causing the sealing ring to contract radially and separate from the inner wall of the heat exchange tube, so as to facilitate the extraction of the tube expander. It effectively solves the technical problem of the difficult assembly and disassembly of the tube expander and the heat exchange tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following further elaborates on the specific embodiments of the present invention with reference to the drawings, where: Figure 1 is a semi-sectional schematic diagram of a specific structure of the heat exchange tube hydraulic tube expander described in the specific embodiment; Figure 2 is a schematic diagram of another sealing ring structure in the specific embodiment; Figure 3 is a schematic diagram of the connection structure between the core body and the gun head in the specific embodiment; Figures 1 to 3 In the figure: 1. Core body; 2. Sealing ring; 3. Annular groove; 4. Blind hole; 5. Water outlet; 6. Retaining ring; 7. Sliding sleeve; 8. Through hole; 9. Adjusting nut; 10. Guide groove; 11. Guide rail; 12. Extension tube; 13. Gun head; 14. Insertion port; 15. Conduit; 16. Electric valve; 17. Pressurizing switch; 18. Optical section; 19. Card slot; 20. Pin hole; 21. Lock pin; 22. Coil spring; 23. Electromagnet; 24. Unlocking switch; 25. Motor; 26. Reduction gear set; 27. External gear; 28. Forward and reverse switch; 29. Protective cover; 30. Lithium battery. SPECIFIC EMBODIMENTS

[0017] The following describes the specific implementation scheme of the present invention in detail with reference to the drawings.

[0018] As Figure 1The heat exchange tube hydraulic expansion tool shown in the figure includes a cylindrical core body 1. At both ends of the core body 1, there are annular grooves 3 that can accommodate sealing rings 2. Sealing rings 2 are respectively sleeved in the annular grooves 3. One end of the core body 1 is provided with an axially extending blind hole 4, and the blind hole 4 extends between the two annular grooves 3. At least one water outlet 5 communicating with the blind hole 4 is provided on the core body 1 between the two annular grooves 3. The end of the core body 1 where the blind hole 4 is opened is used to connect a hydraulic pump. A retaining ring 6 with an outer diameter larger than that of the core body 1 is provided at the closed end of the core body 1. A sliding sleeve 7 is slidably sleeved on the core body 1. A plurality of through holes 8 matching with the water outlet 5 are provided on the sliding sleeve 7. One end of the core body 1 where the blind hole 4 is opened is threadedly connected with an adjusting nut 9. An annular groove 3 is formed between the adjusting nut 9 and the sliding sleeve 7, and an annular groove 3 is formed between the sliding sleeve 7 and the retaining ring 6. Since the movable sleeve 7 can slide back and forth along the circumferential direction of the core body 1, when the adjusting nut 9 is rotated, the pressure of the sealing rings 2 in the two annular grooves 3 can be adjusted simultaneously.

[0019] In this embodiment, preferably, an axially extending guide groove 10 is provided on the inner wall of the sliding sleeve 7, and a guide rail 11 matching with the guide groove 10 is provided on the outer wall of the core body 1. The length of the guide rail 11 is less than that of the guide groove 10. The guide rail 11 is located between the two annular grooves 3, and the distance between the two annular grooves 3 satisfies that the pressure adjustment of the sealing ring 2 will not interfere with the guide rail 11. The through holes 8 correspond to the water outlets 5 one by one, and the diameter of the through holes 8 is larger than that of the water outlets 5.

[0020] The guide groove 10 and the guide rail 11 are provided to eliminate the rotation of the sliding sleeve 7 relative to the core body 1, which can avoid the misalignment of the through holes 8 and the water outlets 5, reduce the number of through holes 8 provided, and improve the strength of the sliding sleeve 7.

[0021] In this embodiment, an extension tube 12 is also connected to the end face of the adjusting nut 9 facing the sealing ring 2. The annular end face of the extension tube 12 close to the sealing ring 2 is used to abut against the sealing ring 2, and the inner diameter of the extension tube 12 is larger than the outer diameter of the core body 1.

[0022] The extension tube 12 can extend out of the threaded connection area of the adjusting nut 9, and the distance for pushing the sealing ring towards the retaining ring 6 is greater. As long as the user replaces the adjusting nut 9 and the sliding sleeve 7 with different lengths of extension tubes 12, the distance between the two annular grooves 3 can be adjusted, and further the expansion tube length can be adjusted, making the operation more convenient.

[0023] In this embodiment, the retaining ring 6 and the core body 1 are integrally formed. Of course, other connection methods can also be used, such as threaded connection with the core body 1.

[0024] In this embodiment, two sealing rings 2 are sleeved in any one of the annular grooves 3, and the two sealing rings 2 are arranged in sequence along the axial direction of the core body 1. The sealing ring 3 is hermetically connected to the bottom of the annular groove 3.

[0025] As an improved solution, as Figure 2 shown, three sealing rings 2 can be sleeved in any annular groove 3. The three sealing rings 2 are arranged in a triangular shape. The two outer sealing rings 2 are rubber-coated steel rings, and the middle sealing ring 2 is a rubber ring. The inner diameter of the rubber ring is slightly larger than that of the rubber-coated steel ring. When the two rubber-coated steel rings are squeezed and approached towards each other, the rubber ring is extruded and expanded outwards, so that the outer diameter of the rubber ring is enlarged and tightly abuts against the inner wall of the heat exchange tube. Since the three sealing rings 2 form a triangular structure, such a sealing structure has a large pressure-bearing capacity and can resist the hydraulic pressure of tube expansion without leakage. After the adjusting nut 9 is loosened, it automatically contracts due to the repulsive force between the three sealing rings 2 and the retraction force of the middle rubber ring, and separates from the inner wall of the heat exchange tube, so as to facilitate the removal of the tube expander.

[0026] As Figure 3 shown, in this embodiment, a gun head 13 is further connected to the open end of the core body 1. An insertion interface 14 matching the open end of the core body 1 is arranged on the gun head 13. A conduit 15 is connected to the rear end of the insertion interface 14. The conduit 15 extends out of the gun head 13 for connecting a hydraulic pump or other high-pressure liquid supply device. An electromagnetic valve 16 is arranged on the conduit 15. A pressurizing switch 17 for controlling the battery valve 16 is arranged on the gun head 13. The pressure resistance of the conduit 15 is greater than the hydraulic pressure required for tube expansion.

[0027] A light section 18 is arranged at the open end of the core body 1. The cross section of the light section 18 is polygonal to prevent the core body 1 from rotating in the insertion interface 14. An annular groove 19 is formed on the light section 18. The adjusting nut 9 is located between the light section 18 and the sealing ring 2. The light section 18 is adapted to the insertion interface 14. A plurality of pin holes 20 evenly distributed in the circumferential direction are formed on the inner wall of the insertion interface 14. A locking pin 21 is slidably inserted into each pin hole 20. A coil spring 22 is arranged between the locking pin 22 and the bottom surface of the pin hole 21. The elastic force of the coil spring 22 pushes part of the locking pin 21 out of the pin hole 20. An electromagnet 23 is arranged on the bottom surface of each pin hole 20. Each electromagnet 23 is connected to a power supply through the same unlocking switch 24. The unlocking switch 24 is arranged on the gun head 13. The head of each locking pin 21 is provided with an inclined surface towards the outside of the insertion interface 14 to facilitate the core body 1 to push each locking pin 21 to retract into the pin hole 20 when inserted.

[0028] A motor 25 is further arranged in the gun head 13. The motor 25 is in meshing transmission with an external gear 27 arranged on the outer wall of the adjusting nut 9 through a reduction gear set 26. The reduction gear set 26 is rotatably connected to the gun head 13. The motor 25 is connected to a power supply through a forward and reverse switch 28. A protective cover 29 extending towards the adjusting nut 9 is arranged at the front end of the gun head 13. The protective cover 29 covers the part of the reduction gear set 26 extending out of the gun head 13.

[0029] The user can drive the rotation of the adjusting nut 9 by controlling the forward and reverse rotation of the motor 25 to tighten or loosen the sealing ring.

[0030] The power supply is a lithium battery 30 fixedly arranged inside the gun head 13. The lithium battery 30 supplies power to all the electronic components inside the gun head 13 to improve the convenience of use of the gun head 13.

[0031] The working process of the present invention is as follows: When the tube expander shown in Figure 1 is in use, the user first pre-tightens the adjusting nut 9 so that the sealing rings 2 in the two annular grooves 3 are both kept in a gently clamped state. At this time, the outer diameter of the sealing ring 2 is still smaller than the inner diameter of the heat exchange tube. The user inserts the tube expander into the heat exchange tube from one end of the heat exchange tube, and then further tightens the adjusting nut 9 so that the sealing ring 2 is further extruded and radially expanded until the sealing ring 2 abuts tightly against the inner wall of the heat exchange tube. At this time, when the tube expander is pulled, it can be found that the tube expander cannot be moved. Connect the liquid outlet end of the hydraulic pump to the open end of the core body 1, supply liquid to the inside of the core body 1, and the high-pressure liquid enters the heat exchange tube through the blind hole 4, the water outlet 5, and the through hole 8 to expand the heat exchange tube between the sealing rings 2. After the tube expansion is completed, control the hydraulic pump to run in reverse to draw out the liquid in the heat exchange tube, then loosen the adjusting nut 9, the pressure on the sealing ring 2 is reduced, and it radially contracts and separates from the inner wall of the heat exchange tube, and then the user withdraws the tube expander.

[0032] As Figure 3 shown, in order to improve the convenience of use, the rear end of the core body 1 can be plugged into the gun head 13, and the rear end of the core body 1 is hermetically connected to the inner end of the insertion port 14. Then the user inserts the core body 1 into the heat exchange tube, controls the rotation of the motor 25 through the forward and reverse switch 28, and the motor 25 drives the adjusting nut 9 to rotate through the reduction gear set 26 to tighten the adjusting nut so that the sealing ring 2 radially expands and abuts against the inner wall of the heat exchange tube. Then the user opens the solenoid valve 16 through the pressure switch 17, and the hydraulic pump supplies liquid to the blind hole 4 of the core body 1 through the conduit 15, thereby expanding the heat exchange tube. After the tube expansion is completed, the user first controls the hydraulic pump to work in reverse to draw back the liquid, then closes the solenoid valve 16, controls the motor 25 to reverse through the forward and reverse switch 28, drives the adjusting nut 9 to turn over, loosens the sealing ring 2, the sealing ring 2 radially contracts and separates from the heat exchange tube, and the user withdraws the core body 1. When it is necessary to separate the core body 1 and the gun head 13, press the unlocking switch 24, and each electromagnet 23 will suck the locking pin 21 into the pin hole 20 so that the locking pin 21 disengages from the card slot 19, and then the core body 1 is pulled out.

[0033] When it is necessary to adjust the tube expansion length, the user can replace the sliding sleeve 7 with different lengths and the adjusting nut 9 with an extension tube of different lengths to change the distance between the sealing rings 2 in the two annular grooves 3.

[0034] The above embodiments merely illustrate the principles and effects of the present invention and some of the applied embodiments, rather than limiting the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention.

Claims

1. Hydraulic tube expander for heat exchange tubes, comprising a cylindrical core body (1), annular grooves (3) capable of accommodating sealing rings (2) are respectively arranged at both ends of the core body (1), the sealing rings (2) are respectively sleeved in the annular grooves (3), a blind hole (4) extending axially is formed at one end of the core body (1), the blind hole (4) extends between the two annular grooves (3), at least one water outlet (5) communicating with the blind hole (4) is formed on the core body (1) between the two annular grooves (3), one end of the core body (1) where the blind hole (4) is formed is used for connecting a hydraulic pump, and it is characterized in that, A retaining ring (6) with an outer diameter larger than that of the core body (1) is provided at the closed end of the core body (1). A sliding sleeve (7) is slidably sleeved on the core body (1). A plurality of through holes (8) adapted to the water outlet (5) are formed in the sliding sleeve (7). One end of the core body (1) where the blind hole (4) is formed is threadedly connected with an adjusting nut (9). An annular groove (3) is formed between the adjusting nut (9) and the sliding sleeve (7), and an annular groove (3) is formed between the sliding sleeve (7) and the retaining ring (6). When the adjusting nut (9) is rotated, the pressure of the sealing rings (2) in the two annular grooves (3) is adjusted simultaneously.

2. The hydraulic tube expander for heat exchange tubes according to claim 1, wherein At least one axially extending guiding groove (10) is provided on the inner wall of the sliding sleeve (7). A guiding rail (11) adapted to the guiding groove (10) is provided on the outer wall of the core body (1). The length of the guiding rail (11) is smaller than that of the guiding groove (10). The guiding rail (11) is located between the two annular grooves (3), and the distance between the guiding rail (11) and the two annular grooves (3) is such that the pressure adjustment of the sealing ring (2) will not interfere with the guiding rail (11). The through holes (8) correspond to the water outlets (5) one by one, and the diameter of the through holes (8) is larger than that of the water outlets (5).

3. The hydraulic tube expander for heat exchange tubes according to claim 1, characterized in that, One end face of the adjusting nut (9) facing the sealing ring (2) is connected with an extension pipe (12). The annular end face of the extension pipe (12) close to the sealing ring (2) is used to abut against the sealing ring (2), and the inner diameter of the extension pipe (12) is larger than the outer diameter of the core body (1).

4. The hydraulic tube expander for heat exchange tubes according to claim 1, wherein, The retaining ring (6) is integrally formed with the core body (1) or is threadedly connected with the core body (1).

5. The hydraulic tube expander for heat exchange tubes according to claim 1, characterized in that, Two sealing rings (2) are sleeved in any one of the annular grooves (3). The two sealing rings (2) are arranged in sequence along the axial direction of the core body (1), and the sealing ring (3) is hermetically connected with the bottom of the annular groove (3).

6. The hydraulic tube expander for heat exchange tubes according to claim 1, wherein Three sealing rings (2) are sleeved in any one of the annular grooves (3). The three sealing rings (2) are arranged in a triangular shape. Any one of the sealing rings (2) is a rubber-coated steel ring.

7. The hydraulic tube expander for heat exchange tubes according to claim 1, wherein A gun head (13) is connected to the open end of the core body (1). An insertion interface (14) adapted to the open end of the core body (1) is provided on the gun head (13). A conduit (15) is connected to the rear end of the insertion interface (14). The conduit (15) extends out of the gun head (13) for connecting to a hydraulic pump. An electromagnetic valve (16) is provided on the conduit (15). A pressurizing switch (17) for controlling the battery valve (16) is provided on the gun head (13). The pressure resistance of the conduit (15) is greater than the hydraulic pressure required for tube expansion.

8. The hydraulic tube expander for heat exchange tubes according to claim 7, characterized in that, An open end of the core body (1) is provided with a light section (18), and an annular slot (19) is formed in the light section (18). The adjusting nut (9) is located between the light section (18) and the sealing ring (2). The light section (18) is adapted to the insertion interface (14). A plurality of circumferentially evenly distributed pin holes (20) are formed in the inner wall of the insertion interface (14). A locking pin (21) is slidably inserted into each pin hole (20). A coil spring (22) is arranged between the locking pin (22) and the bottom surface of the pin hole (21). The elastic force of the coil spring (22) pushes part of the locking pin (21) out of the pin hole (20). An electromagnet (23) is arranged on the inner bottom surface of each pin hole (20). Each electromagnet (23) is connected to a power supply through the same unlocking switch (24). The unlocking switch (24) is arranged on the gun head (13). One side of the head of each locking pin (21) facing outside the insertion interface (14) is arranged as an inclined surface, so as to facilitate the core body (1) to push each locking pin (21) to retract into the pin hole (20) when inserted.

9. The hydraulic tube expander for heat exchange tubes according to claim 7, wherein A motor (25) is arranged in the gun head (13). The motor (25) is in meshing transmission with an external gear (27) arranged on the outer wall of the adjusting nut (9) through a reduction gear set (26). The reduction gear set (26) is rotatably connected to the gun head (13). The motor (25) is connected to a power supply through a forward and reverse switch (28). A protective cover (29) extending towards the adjusting nut (9) is arranged at the front end of the gun head (13). The protective cover (29) covers the part of the reduction gear set (26) extending outside the gun head (13).

10. The hydraulic tube expander for heat exchange tubes according to claim 7, characterized in that, The power supply is a lithium battery (30) fixedly arranged inside the gun head (13). The lithium battery (30) supplies power to all the electronic components in the gun head (13).

Images