Hydraulic tube expander

Abstract

The utility model relates to a kind of heat exchange tube hydraulic tube expander, including core, annular groove is respectively provided at the both ends of core, annular groove is respectively sleeved with sealing ring, the blind hole is set in the one end of core, blind hole extends between two annular grooves, the water outlet that is communicated with blind hole is set in the core, the one end of core set blind hole is used to connect hydraulic pump, the closed end of core is provided with baffle ring, sliding sleeve pipe is slidably sleeved on the core, the through-hole that is cooperated with water outlet is set in sliding sleeve pipe, the one end of core set blind hole is screw-connected with an adjusting nut, adjusting nut and sliding sleeve pipe between form an annular groove, sliding sleeve pipe and baffle ring between form an annular groove, when rotating adjusting nut, the sealing ring in the pressure adjustment of two annular grooves is carried out simultaneously, solve the technical problem that tube expander and heat exchange tube assembly, disassembly difficult.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic tube expanders, specifically relating to a hydraulic tube expander for heat exchange tubes. Background Technology

[0002] Self-sealing hydraulic tube expanders for heat exchange tubes typically have two deformable sealing rings, such as the double-bowl type self-sealing hydraulic tube expander disclosed in CN2092383U. During operation, these two deformable sealing rings expand and deform under water pressure, pressing tightly against the inner wall of the heat exchange tube to achieve self-sealing. However, this structure requires high dimensional accuracy of the sealing rings; if the size is too large, the expander will be difficult to insert into the heat exchange tube, while if the size is too small, the sealing effect will decrease. Furthermore, after the tube expansion is completed and the pressure is released, these deformable sealing rings can become stuck to the inner wall of the heat exchange tube and cannot be reset, making disassembly of the expander difficult.

[0003] In general, conventional tube expanders require adjusting the sealing ring before inserting the heat exchange tube, ensuring that the outer diameter of the sealing ring is larger than the inner diameter of the heat exchange tube, before forcibly inserting the heat exchange tube. This operation is time-consuming, labor-intensive, and difficult to perform, and the sealing ring is easily worn, leading to a decrease in sealing performance. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a heat exchange tube hydraulic expander to solve the technical problem of the difficulty in assembling and disassembling the expander and the heat exchange tube.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: a heat exchanger tube hydraulic expander, comprising a cylindrical core, with annular grooves at both ends of the core for accommodating sealing rings, each sealing ring being fitted into one of the annular grooves; an axially extending blind hole at one end of the core extending between the two annular grooves; at least one outlet communicating with the blind hole on the core located between the two annular grooves; the end of the core with the blind hole for connecting to a hydraulic pump; a retaining ring with an outer diameter larger than the outer diameter of the core at the closed end of the core; a sliding sleeve slidably fitted onto the core, with several through holes cooperating with the outlet; an adjusting nut threadedly connected to the end of the core with the blind hole; an annular groove formed between the adjusting nut and the sliding sleeve, and another annular groove formed between the sliding sleeve and the retaining ring. Rotating the adjusting nut simultaneously adjusts the pressure of the sealing rings in the two annular grooves.

[0006] As a preferred embodiment, the inner wall of the sliding sleeve is provided with at least one axially extending guide groove, and the outer wall of the core is provided with a guide rail that cooperates with the guide groove. The length of the guide rail is less than the length of the guide groove. The guide rail is located between two annular grooves and the distance between the guide rail and the two annular grooves is sufficient to ensure that the pressure adjustment of the sealing ring will not interfere with the guide rail. The through hole corresponds one-to-one with the water outlet, and the diameter of the through hole is larger than the diameter of the water outlet.

[0007] As a preferred embodiment, 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 near 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.

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

[0009] As a preferred embodiment, two sealing rings are fitted inside any annular groove, and the two sealing rings are arranged sequentially along the axial direction of the core, with the sealing rings sealingly connected to the bottom of the annular groove.

[0010] As a preferred embodiment, three sealing rings are fitted inside any one of the annular grooves, and the three sealing rings are arranged in a triangular pattern. Any one of the sealing rings is a rubber-coated steel ring.

[0011] As a preferred embodiment, a gun head is connected to the open end of the core. The gun head is equipped with an insertion interface that mates with the open end of the core. A conduit is connected to the rear end of the insertion interface. The conduit extends out of the gun head to connect to a hydraulic pump. A solenoid valve is installed on the conduit. A pressure switch for controlling the solenoid valve is installed on the gun head. The conduit can withstand a high pressure greater than the hydraulic pressure required for tube expansion.

[0012] As a preferred embodiment, the open end of the core is provided with a light segment, on which an annular groove is provided. An adjusting nut is located between the light segment and the sealing ring. The light segment is adapted to the insertion interface. Multiple circumferentially 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 the locking pin part out of the pin hole. An electromagnet is provided on the bottom surface of each pin hole. Each electromagnet is connected to the power supply through the same unlocking switch. The unlocking switch is located on the gun head. The side of each locking pin facing out of the insertion interface is set as an inclined surface so that when the core is inserted, it can push each locking pin back into the pin hole.

[0013] As a preferred embodiment, a motor is installed inside the gun head. The motor is driven by a reduction gear set meshing with an external gear set on the outer wall of the adjusting nut. The reduction gear set is rotatably connected to the gun head. The motor is connected to the power supply 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 that extends out of the gun head.

[0014] As a preferred embodiment, the power source is a lithium battery fixedly installed inside the gun head, which supplies power to all electronic components inside the gun head.

[0015] The beneficial effects of this invention are as follows: This invention utilizes a sliding sleeve and an adjusting nut to simultaneously control the pressure adjustment of the sealing rings within the two annular grooves. By rotating the adjusting nut exposed at the end of the heat exchange tube, pressure is applied to the sealing rings already inserted into the heat exchange tube, causing them to expand radially outward and press tightly against the inner wall of the heat exchange tube, achieving a good seal. After expansion, the pressure on the sealing rings can be reduced by rotating the adjusting nut, causing the sealing rings to contract radially and separate from the inner wall of the heat exchange tube, facilitating the removal of the expander. This effectively solves the technical problem of the difficulty in assembling and disassembling the expander and heat exchange tube. Attached Figure Description

[0016] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, wherein:

[0017] Figure 1 This is a partial cross-sectional schematic diagram of a specific structure of the heat exchanger tube hydraulic expander described in a specific embodiment;

[0018] Figure 2 This is a schematic diagram of another sealing ring structure in a specific embodiment;

[0019] Figure 3 This is a schematic diagram of the connection between the core and the gun head in a specific embodiment;

[0020] Figures 1-3 Components: 1. Core; 2. Sealing ring; 3. Annular groove; 4. Blind hole; 5. 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 interface; 15. Guide tube; 16. Solenoid valve; 17. Pressure switch; 18. Optical section; 19. Slot; 20. Pin hole; 21. Locking pin; 22. Coil spring; 23. Electromagnet; 24. Unlocking switch; 25. Motor; 26. Reduction gear set; 27. External gear; 28. Forward / reverse switch; 29. ​​Protective cover; 30. Lithium battery. Detailed Implementation

[0021] The specific implementation scheme of this utility model will now be described in detail with reference to the accompanying drawings.

[0022] like Figure 1The heat exchanger tube hydraulic expander shown includes a cylindrical core 1. Both ends of the core 1 are provided with annular grooves 3 that can accommodate sealing rings 2. Sealing rings 2 are fitted into the annular grooves 3. One end of the core 1 has an axially extending blind hole 4 that extends between the two annular grooves 3. At least one outlet 5 communicating with the blind hole 4 is provided on the core 1 located between the two annular grooves 3. The end of the core 1 with the blind hole 4 is used to connect to a hydraulic pump. The closed end of the core 1 is provided with a retaining ring 6 whose outer diameter is larger than the outer diameter of the core 1. A sliding sleeve 7 is slidably fitted onto the core 1. The sliding sleeve 7 has several through holes 8 that mate with the outlet 5. An adjusting nut 9 is threadedly connected to the end of the core 1 with the blind hole 4. An annular groove 3 is formed between the adjusting nut 9 and the sliding sleeve 7, and also between the sliding sleeve 7 and the retaining ring 6. Since the movable sleeve 7 can slide back and forth along the circumference of the core 1, the pressure of the sealing rings 2 in the two annular grooves 3 can be adjusted simultaneously when the adjusting nut 9 is rotated.

[0023] In this embodiment, a guide groove 10 extending axially is provided on the inner wall of the sliding sleeve 7, and a guide rail 11 that cooperates with the guide groove 10 is provided on the outer wall of the core 1. The length of the guide rail 11 is less than the length of the guide groove 10. The guide rail 11 is located between the two annular grooves 3 and the distance between the guide rail 11 and the two annular grooves 3 is such that the pressure adjustment of the sealing ring 2 will not interfere with the guide rail 11. The through hole 8 corresponds one-to-one with the water outlet 5, and the diameter of the through hole 8 is greater than the diameter of the water outlet 5.

[0024] The guide groove 10 and guide rail 11 are provided to eliminate the rotation of the sliding sleeve 7 relative to the core 1. This can prevent the through hole 8 from being misaligned with the outlet 5, thereby reducing the number of through holes 8 and improving the strength of the sliding sleeve 7.

[0025] 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 near the sealing ring 2 is used to abut against the sealing ring 2. The inner diameter of the extension tube 12 is larger than the outer diameter of the core 1.

[0026] The extension tube 12 can extend out of the threaded connection area of ​​the adjusting nut 9, pushing the sealing ring a greater distance toward the retaining ring 6. Users can adjust the distance between the two annular grooves 3 by simply replacing the adjusting nut 9 and sliding sleeve 7 with different lengths of extension tube 12, thereby adjusting the length of the expansion tube, making the operation simpler.

[0027] In this embodiment, the retaining ring 6 is integrally formed with the core 1. Of course, other connection methods are also possible, such as threaded connection with the core 1.

[0028] In this embodiment, two sealing rings 2 are fitted inside any one of the annular grooves 3. The two sealing rings 2 are arranged sequentially along the axial direction of the core 1, and the sealing rings 2 are sealed to the bottom of the annular groove 3.

[0029] As an improvement, such as Figure 2 As shown, three sealing rings 2 can be fitted into 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 pressed closer together, they push the rubber ring outward and expand it, increasing its outer diameter and making it tightly against the inner wall of the heat exchange tube. Because the three sealing rings 2 form a triangular structure, this sealing structure has a high pressure resistance and can resist the hydraulic pressure of tube expansion without leakage. After the adjusting nut 9 is loosened, it automatically contracts due to the mutual repulsion of the three sealing rings 2 and the retraction force of the middle rubber ring, separating from the inner wall of the heat exchange tube, so as to facilitate the removal of the tube expander.

[0030] like Figure 3 As shown, in this embodiment, a gun head 13 is also connected to the open end of the core 1. The gun head 13 is provided with a plug interface 14 that mates with the open end of the core 1. A conduit 15 is connected to the rear end of the plug interface 14. The conduit 15 extends out of the gun head 13 for connecting to a hydraulic pump or other high-pressure liquid supply device. A solenoid valve 16 is provided on the conduit 15. A pressure switch 17 for controlling the solenoid valve 16 is provided on the gun head 13. The high pressure that the conduit 15 can withstand is greater than the hydraulic pressure required for tube expansion.

[0031] The open end of the core 1 is provided with a light segment 18, the cross-section of which is polygonal to prevent the core 1 from rotating within the insertion interface 14. An annular groove 19 is provided on the light segment 18, and an adjusting nut 9 is located between the light segment 18 and the sealing ring 2. The light segment 18 is adapted to the insertion interface 14. Multiple circumferentially distributed pin holes 20 are provided 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 provided between the locking pin 21 and the bottom surface of the pin hole 20. 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 provided on the bottom surface of each pin hole 20. Each electromagnet 23 is connected to the power supply through the same unlocking switch 24. The unlocking switch 24 is provided on the gun head 13. The side of each locking pin 21 facing out of the insertion interface 14 is set with an inclined surface so that when the core 1 is inserted, it pushes each locking pin 21 back into the pin hole 20.

[0032] The gun head 13 is also equipped with a motor 25. The motor 25 is driven by a reduction gear set 26 meshing with an external gear 27 set on the outer wall of the adjusting nut 9. The reduction gear set 26 is rotatably connected to the gun head 13. The motor 25 is connected to the power supply through a forward and reverse switch 28. The front end of the gun head 13 is provided with a protective cover 29 extending towards the adjusting nut 9. The protective cover 29 covers the part of the reduction gear set 26 that extends out of the gun head 13.

[0033] Users can control the forward and reverse rotation of motor 25 to drive the rotation of adjusting nut 9, thereby tightening or loosening the sealing ring.

[0034] The power source is a lithium battery 30 fixedly installed inside the gun head 13. The lithium battery 30 supplies power to all electronic components inside the gun head 13 to improve the ease of use of the gun head 13.

[0035] The working process of this utility model is as follows: Figure 1 When using the tube expander shown, the user first pre-tightens the adjusting nut 9 to keep the sealing rings 2 in both annular grooves 3 slightly tightened. At this time, the outer diameter of the sealing rings 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, and then further tightens the adjusting nut 9 to further compress the sealing rings 2 and expand them radially until the sealing rings 2 are tightly against the inner wall of the heat exchange tube. At this point, pulling out the tube expander will reveal that it cannot be moved. Connect the outlet of the hydraulic pump to the open end of the core 1 to supply liquid to the inside of the core 1. The high-pressure liquid enters the heat exchange tube through the blind hole 4, the outlet 5, and the through hole 8 to expand the heat exchange tube between the sealing rings 2. After the expansion is completed, control the hydraulic pump to run in reverse to extract the liquid from the heat exchange tube. Then loosen the adjusting nut 9. The pressure on the sealing rings 2 decreases, and they contract radially, separating from the inner wall of the heat exchange tube. The user then removes the tube expander.

[0036] like Figure 3 As shown, to improve ease of use, the rear end of the core 1 can be inserted into the nozzle 13. The rear end of the core 1 is sealed to the inner end of the insertion interface 14. Then, the user inserts the core 1 into the heat exchange tube and controls the motor 25 to rotate via the forward / reverse switch 28. The motor 25 drives the adjusting nut 9 to rotate via the reduction gear set 26 to tighten the adjusting nut, causing the sealing ring 2 to expand radially and abut against the inner wall of the heat exchange tube. Then, the user opens the solenoid valve 16 via the pressure switch 17, and the hydraulic pump supplies liquid to the blind hole 4 of the core 1 through the conduit 15, thereby expanding the heat exchange tube. After the tube is expanded, 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 via the forward / reverse switch 28, drives the adjusting nut 9 to rotate, loosens the sealing ring 2, and causes the sealing ring 2 to contract radially and separate from the heat exchange tube. The user then removes the core 1. When it is necessary to separate the core 1 and the gun head 13, press the unlock switch 24. Each electromagnet 23 will pull the locking pin 21 into the pin hole 20, causing the locking pin 21 to disengage from the slot 19, and then pull out the core 1.

[0037] When it is necessary to adjust the length of the expansion tube, the user can change the distance between the sealing rings 2 inside the two annular grooves 3 by replacing the sliding sleeve 7 with different lengths and the adjusting nut 9 with different lengths of extension tubes.

[0038] The above embodiments are merely illustrative of the principles and effects of the present invention, as well as some of the application examples, and are not intended to limit the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A heat exchanger tube hydraulic expander, comprising a cylindrical core (1), with annular grooves (3) at both ends of the core (1) for accommodating sealing rings (2), each annular groove (3) having a sealing ring (2) fitted inside the annular groove (3), and an axially extending blind hole (4) at one end of the core (1) extending between the two annular grooves (3). At least one outlet (5) communicating with the blind hole (4) is provided on the core (1) between the two annular grooves (3). The end of the core (1) with the blind hole (4) is used to connect to a hydraulic pump. The device is characterized in that... The closed end of the core (1) is provided with a retaining ring (6) with an outer diameter larger than that of the core (1). A sliding sleeve (7) is slidably sleeved on the core (1). Several through holes (8) that cooperate with the water outlet (5) are opened on the sliding sleeve (7). An adjusting nut (9) is threadedly connected to one end of the core (1) with a blind hole (4). An annular groove (3) is formed between the adjusting nut (9) and the sliding sleeve (7). 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 ring (2) in the two annular grooves (3) is adjusted at the same time.

2. The heat exchanger tube hydraulic expander according to claim 1, characterized in that, The inner wall of the sliding sleeve (7) is provided with at least one axially extending guide groove (10), and the outer wall of the core (1) is provided with a guide rail (11) that cooperates with the guide groove (10). The length of the guide rail (11) is less than the length of the guide groove (10). The guide rail (11) is located between the two annular grooves (3) and the distance between the guide rail (11) and the two annular grooves (3) is such that the pressure adjustment of the sealing ring (2) will not interfere with the guide rail (11). The through hole (8) corresponds one-to-one with the water outlet (5). The diameter of the through hole (8) is greater than the diameter of the water outlet (5).

3. The heat exchanger tube hydraulic expander according to claim 1, characterized in that, An extension tube (12) is connected to one end face of the adjusting nut (9) facing the sealing ring (2). The annular end face of the extension tube (12) near the sealing ring (2) is used to abut against the sealing ring (2). The inner diameter of the extension tube (12) is larger than the outer diameter of the core (1).

4. The heat exchanger tube hydraulic expander according to claim 1, characterized in that, The retaining ring (6) is integrally formed with the core (1) or threadedly connected to the core (1).

5. The heat exchanger tube hydraulic expander according to claim 1, characterized in that, Two sealing rings (2) are fitted inside any annular groove (3). The two sealing rings (2) are arranged sequentially along the axial direction of the core (1). The sealing rings (2) are sealed to the bottom of the annular groove (3).

6. The heat exchanger tube hydraulic expander according to claim 1, characterized in that, Three sealing rings (2) are fitted inside any annular groove (3). The three sealing rings (2) are arranged in a triangular shape. Any sealing ring (2) is a rubber-coated steel ring.

7. The heat exchanger tube hydraulic expander according to claim 1, characterized in that, The core (1) has a gun head (13) connected to its open end. The gun head (13) has a plug (14) that matches the open end of the core (1). The rear end of the plug (14) is connected to a conduit (15). The conduit (15) extends out of the gun head (13) to connect to a hydraulic pump. The conduit (15) has a solenoid valve (16) and the gun head (13) has a pressure switch (17) for controlling the solenoid valve (16). The conduit (15) can withstand higher pressure than the hydraulic pressure required for tube expansion.

8. The heat exchanger tube hydraulic expander according to claim 7, characterized in that, The core (1) has an open end with a light section (18), and an annular groove (19) is provided on the light section (18). An 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). Multiple circumferentially distributed pin holes (20) are provided on the inner wall of the insertion interface (14). A locking pin (21) is slidably inserted into each pin hole (20). A coil spring (21) is provided between the locking pin (21) and the bottom surface of the pin hole (20). 2) The elastic force of the coil spring (22) pushes the locking pin (21) part out of the pin hole (20). An electromagnet (23) is provided on the bottom surface of each pin hole (20). Each electromagnet (23) is connected to the power supply through the same unlocking switch (24). The unlocking switch (24) is set on the gun head (13). The head of each locking pin (21) is set as an inclined surface on the side facing the insertion interface (14) so ​​that when the core (1) is inserted, it pushes each locking pin (21) back into the pin hole (20).

9. The heat exchanger tube hydraulic expander according to claim 7, characterized in that, The gun head (13) is equipped with a motor (25). The motor (25) is driven by a reduction gear set (26) meshing with an external gear (27) set on the outer wall of the adjusting nut (9). The reduction gear set (26) is rotatably connected to the gun head (13). The motor (25) is connected to the power supply through a forward and reverse switch (28). The front end of the gun head (13) is provided with a protective cover (29) extending towards the adjusting nut (9). The protective cover (29) covers the part of the reduction gear set (26) that extends out of the gun head (13).

10. The heat exchanger tube hydraulic expander according to claim 8, characterized in that, The power source is a lithium battery (30) fixedly installed inside the gun head (13), which supplies power to all electronic components inside the gun head (13).

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