CN114515793B

CN114515793B - Tube expander

Info

Publication number: CN114515793B
Application number: CN202210081665.4A
Authority: CN
Inventors: 刘雄; 严伟杰; 饶纪平; 区章权
Original assignee: Foshan Huize Heat Exchanger Equipment Co ltd
Current assignee: Foshan Huize Heat Exchanger Equipment Co ltd
Priority date: 2022-01-24
Filing date: 2022-01-24
Publication date: 2024-03-26
Anticipated expiration: 2042-01-24
Also published as: CN114515793A

Abstract

The utility model relates to a technical field of tubular product processing equipment especially relates to a tube expander, which comprises a base, the frame includes the power seat, the flaring seat, and spacing seat, install the gib block on the power seat, the top of power seat is provided with the location drive assembly that is used for driving the gib block and do vertical direction upward movement, spacing seat middle part sliding connection has fin heat exchanger, fin heat exchanger is including installing frame and fin nest of tubes, the fin nest of tubes sets up in the middle part of installing frame, just lay between gib block and the installing frame, the middle part of flaring seat is provided with the transfer line, be provided with the driving piece that is used for driving the flaring seat to do vertical direction upward movement on the transfer line, be fixed with the bulging bar group on the flaring seat, just lay between bulging bar group and the fin nest of tubes, in order to improve the quality that the fin pipe expands the joint, this application provides a tube expander, skew phenomenon appears when can reduce the bulging bar.

Description

Tube expander

Technical Field

The application relates to the technical field of pipe processing equipment, in particular to a pipe expander.

Background

The fin heat exchanger is a heat exchange element for improving heat exchange efficiency, the common fin heat exchange tube comprises a mounting frame and a fin tube group, the fin tube group is arranged in the mounting frame, the arrangement of the fin tube group is used for increasing the outer surface area of the heat exchange tube so as to achieve the aim of improving heat exchange efficiency, in the processing process of the fin tube, the end diameter of the fin tube is usually enlarged by a tube expander, and according to different purposes, the tube expander can expand the end part and turn-ups the end part of the fin tube.

In the prior art, an operator needs to clamp the finned tube at one end of the frame, then an expanded tube driving assembly is arranged at one end, far away from the finned tube, of the frame, and the expanded tube driving assembly is used as a power source to drive an expanded rod to approach the finned tube, so that the expanded rod is expanded with the end part of the finned tube after being subjected to pressure, and further the expanded tube of the finned tube is completed.

However, in general, the geometric shape of the end of the expansion rod and the stroke of the expansion rod will directly affect the quality of the expansion joint of the finned tube, and because the expansion rod is long, the expansion rod is easy to deviate during tube expansion, and the quality of the expansion joint of the finned tube is low.

Disclosure of Invention

In order to improve the quality of the expansion joint of the finned tube, the application provides a tube expander, which can reduce the phenomenon of deflection when the expansion rod expands the tube.

The application provides a tube expander adopts following technical scheme:

the utility model provides a tube expander, includes the frame, the frame includes power seat, flaring seat and spacing seat, install the gib block on the power seat, the top of power seat is provided with and is used for the drive the gib block is the location drive assembly of vertical direction upward movement, spacing seat middle part sliding connection has fin heat exchanger, fin heat exchanger is including installing frame and fin nest of tubes, the fin nest of tubes sets up the middle part of installing frame, the gib block with just to laying between the installing frame, the middle part of flaring seat is provided with the transfer line, be provided with on the transfer line and be used for the drive the flaring seat is the driving piece of vertical direction upward movement, be fixed with the bulging bar group on the flaring seat, the bulging bar group with just to laying between the fin nest of tubes.

Through adopting above-mentioned technical scheme, because just lay between deflector bar and the installing frame, under the effect of location drive assembly, can drive the deflector bar and do vertical decurrent motion, make the deflector bar easily support and press on the installing frame, and then can compress tightly the fin heat exchanger, the effect that skew phenomenon appears when can reaching the reduction expander tube and expand the pipe, in addition, under the effect of driving piece, the transfer line can rotate, make the flaring seat do vertical ascending motion, simultaneously, expander tube group also is vertical decurrent motion, can accomplish expander tube, the convenience of expander tube has been improved, and be favorable to guaranteeing the quality of fin tube expansion joint, after expander tube finishes, location drive assembly drive deflector bar is vertical upwards, make the deflector bar can conveniently separate with the fin heat exchanger, separation efficiency between fin heat exchanger and the spacing seat has been improved.

Preferably, the expansion rod group comprises a plurality of expansion rods, and the expansion rods comprise: a connecting rod mounted on the flare seat; a flanging lug fixed at one end of the connecting rod, which is close to the limiting seat; a flaring block fixed on the connecting rod and close to the top surface of the flanging lug; and a stop block arranged on the connecting rod near the top surface of the flaring block, wherein the diameter size of the stop block is larger than that of the flaring block.

Through adopting above-mentioned technical scheme, at the in-process that the expander tube expanded, the turn-ups lug offsets with the fin tube earlier, the turn-ups lug carries out the turn-ups to the fin tube, can provide the effect of direction for the tip expander tube of later stage to a certain extent, under the effect of pressure, the expander tube continues down movement, make the flaring piece peg graft completely in the middle part of fin tube, the diapire of stopping piece and the roof looks butt of fin tube, and then accomplish expander tube, the setting of stopping piece can carry out spacingly to the motion stroke of expander tube, the quality of fin tube expansion joint has been improved to a certain extent.

Preferably, an arc-shaped connection part is arranged between the flanging lug and the flaring block, and the arc-shaped connection part is in smooth transition with the flanging lug and the flaring block respectively.

By adopting the technical scheme, the arc-shaped connecting part is respectively in smooth transition with the flanging convex block and the flaring block, burrs on the transition section are reduced to scratch the finned tube, and the quality of the expanded joint of the finned tube is ensured.

Preferably, the positioning transmission assembly comprises: the locking column is fixed on the top surface of the power seat; a transmission shaft rotatably connected to the middle part of the locking column; a transmission gear installed at one end of the transmission shaft; the guide bar is arranged on one side, close to the transmission gear, of the rack, and the first driving motor is arranged on the side wall of the locking column, wherein the output end of the first driving motor is assembled with the transmission shaft, and the transmission gear is meshed with the rack.

Through adopting above-mentioned technical scheme, under first driving motor's effect, the transmission shaft can rotate, simultaneously, and drive gear also can rotate to, the drive rack rolls on the rack, drives the drive rack and drives the guide bar and carry out the ascending motion of vertical direction, promptly, can easily drive the guide bar and support and press on the fin heat exchanger, or easily separate guide bar, fin heat exchanger, improved the motion convenience and the efficiency of guide bar.

Preferably, the middle part of the guide bar is provided with a hollow groove in a penetrating way.

Through adopting above-mentioned technical scheme, through seting up the hollow tank at the middle part of gib block, can alleviate the whole weight of gib block, and then can easily drive gib block, and then can reduce first driving motor's power, saved manufacturing cost.

Preferably, an upper die holder is installed at the top of the power seat, a guide post is arranged between the upper die holder and the power seat, a lower die holder is arranged at the bottom of the limiting seat, a mounting post is arranged on the top surface of the lower die holder, and the guide post penetrates out of the power seat and is in sliding connection with the mounting post.

Through adopting above-mentioned technical scheme, through sliding connection guide post and erection column mutually, be favorable to guaranteeing that the relative motion between upper die base, power seat and the die holder can keep on same straight line, appear the skew phenomenon when being favorable to reducing the expander tube expansion, guaranteed the quality of fin tube expansion joint.

Preferably, the top wall of the upper die holder is provided with a second driving motor, the output end of the second driving motor is assembled with the transmission rod, one end of the transmission rod is in threaded connection with the flaring seat, and the other end of the transmission rod is in rotary connection with the upper die holder.

Through adopting above-mentioned technical scheme, under the effect of second driving motor, the transfer line can rotate, and then drives the flaring seat and do the ascending motion of vertical direction, has improved the motion convenience of flaring seat.

Preferably, the fixing seat is installed on the top surface of the lower die holder, the limiting seat is arranged on one side, close to the lower die holder, of the fixing seat, sliding grooves are respectively formed in two opposite side walls of the fixing seat, the connecting sliding block is installed on the side wall of the mounting frame, and the connecting sliding block is in sliding connection with the sliding grooves in a matched mode.

Through adopting above-mentioned technical scheme, through carrying out sliding connection to connecting slider and spout, can accomplish the connection between fin heat exchanger and the fixing base, improved fin heat exchanger's installation stability, convenience.

Preferably, the middle part of the limiting seat is provided with a penetrating slot, the fin heat exchanger is in sliding connection with the penetrating slot, a shock absorption layer is arranged on the inner bottom wall of the limiting seat, and the bottom wall of the fin tube group is in butt joint with the shock absorption layer.

Through adopting above-mentioned technical scheme, the setting of buffer layer makes and is formed with the shock attenuation chamber between buffer layer and the spacing seat, is favorable to reducing the noise pollution when the expander rod expands the pipe, simultaneously, is favorable to reducing the fin tube and directly takes place the striking phenomenon with spacing seat inner bottom wall, has guaranteed the quality of fin tube expansion joint.

Preferably, the position of the input end of the limiting seat is provided with a wear-resistant gasket.

Through adopting above-mentioned technical scheme, wear-resisting packing ring has good wearability and impact resistance, through being provided with wear-resisting packing ring in the position department of spacing seat input, can reduce the friction between finned tube and the spacing seat, has improved the quality of finned tube expansion joint to a certain extent.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the guide strip and the mounting frame are arranged right away, under the action of the positioning transmission assembly, the guide strip can be driven to move vertically downwards, so that the guide strip can be easily pressed on the mounting frame, further the fin heat exchanger can be compressed, the effect of reducing the deflection phenomenon when the expansion rod expands the tube can be achieved, in addition, under the action of the driving piece, the transmission rod can rotate, the flaring seat can move vertically, meanwhile, the expansion rod group also moves vertically downwards, the expansion rod expands the tube, the convenience of expanding the tube of the expansion rod is improved, in addition, the quality of an expansion joint of the fin tube is guaranteed, after the expansion rod expands the tube, the positioning transmission assembly drives the guide strip to move vertically upwards, the guide strip can be conveniently separated from the fin heat exchanger, and the separation efficiency between the fin heat exchanger and the limiting seat is improved;

2. in the process of expanding the tube by the expansion rod, the flanging lug is propped against the fin tube, the flanging lug flanging the fin tube, the expansion rod can continue to move downwards under the action of pressure to a certain extent under the guiding effect provided by the end expansion tube at the later stage, the flaring block is completely inserted in the middle part of the fin tube, the bottom wall of the stop block is propped against the top wall of the fin tube, the expansion tube by the expansion rod is further completed, the movement stroke of the expansion rod can be limited by the stop block, and the quality of the expansion joint of the fin tube is improved to a certain extent.

Drawings

Fig. 1 is a schematic view showing a state when a tube is expanded by a tube expander in example 1.

Fig. 2 is a schematic diagram of the state after the tube expander expands in example 1.

Fig. 3 is a schematic diagram of the fit of the expander rod and the fin heat exchanger in example 1.

Fig. 4 is a full cross-sectional view of fig. 1.

Fig. 5 is a schematic diagram showing the fit of the expander rod and the fin heat exchanger in example 2.

Reference numerals illustrate: 1. a base; 11. an upper die holder; 12. a guide post; 13. a power seat; 14. a flaring seat; 15. a limit seat; 16. a mounting column; 17. a lower die holder; 21. a guide bar; 211. a rack; 212. a hollow groove; 22. locking the column; 221. a transmission gear; 222. a first driving motor; 23. a limit bar; 231. a mating block; 24. a mating post; 241. a guide groove; 25. a fixed frame; 31. a second driving motor; 32. a transmission rod; 4. an expansion rod; 41. a connecting rod; 42. a flanging lug; 43. a flare block; 44. an arc-shaped connection part; 45. a stop block; 51. a fixed rod; 52. a flanging module; 61. a fixing seat; 611. a chute; 62. the connecting slide block; 63. inserting slots; 64. a shock absorbing layer; 65. a wear-resistant gasket; 7. a fin heat exchanger.

Detailed Description

In order to make the objects, technical solutions and advantageous effects of the present application more apparent, the present application will be described in further detail with reference to fig. 1 to 5 and examples.

The embodiment of the application discloses a tube expander.

Example 1:

referring to fig. 1 and 2, a tube expander comprises a machine base 1, wherein the machine base 1 comprises an upper die base 11 and a power base 13, specifically, the upper die base 11 and the power base 13 are arranged in a stacked manner from top to bottom, the upper die base 11 and the power base 13 are rectangular bases, guide posts 12 are fixed between the upper die base 11 and the power base 13, the four guide posts 12 are arranged at the positions of four corners of the upper die base 11 respectively, and one end of the guide post 12 far away from the upper die base 11 extends out of the power base 13.

Correspondingly, the bottom of the power seat 13 is provided with a lower die holder 17, in the embodiment of the application, the top surface of the lower die holder 17 is fixed with a mounting column 16, the mounting column 16 is a hollow circular column, four mounting columns 16 are arranged, the mounting column 16 and the guide column 12 are arranged right opposite to each other, the guide column 12 is inserted into the mounting column 16, and the guide column 12 and the mounting column 16 are in sliding connection, so that the relative movement among the upper die holder 11, the power seat 13 and the lower die holder 17 can be kept on the same straight line.

Referring to fig. 2, a guide bar 21 is disposed on a power seat 13, a hollow groove 212 is formed in the middle of the guide bar 21 in a penetrating manner, the hollow groove 212 is formed in the middle of the guide bar 21, the overall weight of the guide bar 21 can be reduced so as to drive the guide bar 21, the number of the guide bars 21 is determined according to the situation, in this embodiment, two guide bars 21 are slidably connected on the power seat 13, specifically, a locking column 22 is fixed between the power seat 13 and an upper die seat 11, the locking column 22 and the guide bar 21 are arranged in parallel, one end of the guide bar 21 far from the upper die seat 11 extends out of the power seat 13, a transmission shaft is rotatably connected in the middle of the locking column 22, a transmission gear 221 is fixed at one end of the transmission shaft, a first driving motor 222 is disposed at one side of the locking column 22 far from the transmission gear 221, a rack 211 is correspondingly fixed at one side of the guide bar 21 near the transmission gear 221, the rack 211 and the guide bar 21 are fixed in a welded manner, and the transmission gear 221 is meshed with the rack 211.

Under the action of the first driving motor 222, the driving shaft can rotate, so that the driving gear 221 fixed on the driving shaft also rotates, and the guide bar 21 moves in the vertical direction.

In order to further improve stability in the moving process of the guide bar 21, referring to fig. 2, two guide bars 21 are symmetrically arranged on the same long side of the power seat 13 along the central axis of the power seat 13, so that the guide bars 21 are respectively installed at two corners of the same long side of the power seat 13, correspondingly, two matching columns 24 are arranged on the other long side of the power seat 13, the two matching columns 24 are respectively fixed at two corners of the same long side of the power seat 13, and the matching columns 24 and the locking columns 22 are directly arranged.

The power seat 13 is close to the position department sliding connection who cooperates post 24 has spacing 23, in this application embodiment, the shape size of spacing 23 is unanimous with the shape size of gib block 21, arrange mutually parallel between spacing 23 and the gib block 21, the outer wall welding of spacing 23 has cooperation piece 231, the guide slot 241 has been seted up to one side that cooperates post 24 to be close to cooperation piece 231, the extending direction of guide slot 241 is unanimous with the extending direction of cooperation post 24, looks adaptation sliding connection between cooperation piece 231 and the guide slot 241, in addition, be provided with fixed frame 25 at the top of power seat 13, fixed frame 25 carries out bolted connection with gib block 21 respectively, spacing 23, namely, make gib block 21, spacing 23 and fixed frame 25 mutually fixed.

When the first driving motor 222 drives the guide bar 21 to move in the vertical direction, under the cooperation of the fixing frame 25, the cooperation block 231 can slide on the guide groove 241, so as to drive the limit bar 23 to move in the vertical direction, which is beneficial to reducing the offset phenomenon of the guide bar 21 and the limit bar 23 in the moving process.

The machine base 1 further comprises a flaring seat 14, referring to fig. 2 and 3, the flaring seat 14 is arranged at the bottom of the power seat 13, a transmission rod 32 is arranged between the flaring seat 14 and the upper die seat 11, in the embodiment of the application, the transmission rod 32 is a ball screw, one end of the transmission rod 32 is in threaded connection with the flaring seat 14, the other end of the transmission rod 32 is in rotational connection with the upper die seat 11, a second driving motor 31 is arranged at the position, close to the transmission rod 32, of the upper die seat 11, the output end of the second driving motor 31 is assembled with the transmission rod 32, and the transmission rod 32 can rotate under the driving of the second driving motor 31, so that the flaring seat 14 can move in the vertical direction.

In addition, be provided with the expander group on flaring seat 14, expander group is including a plurality of expander 4, and parallel layout is between a plurality of expander 4, carries out fixed connection between expander 4 and the flaring seat 14, and when the motion in vertical direction was done to second driving motor 31 drive flaring seat 14, the motion in vertical direction also can be done simultaneously to a plurality of expander 4.

In this embodiment, the expansion rod 4 includes a connecting rod 41, a flanging lug 42, a flaring block 43, and a stop block 45, referring to fig. 3, the connecting rod 41, the flanging lug 42, the flaring block 43, and the stop block 45 are integrally formed, the connecting rod 41 is a round rod body, the connecting rod 41 is fixed on the flaring seat 14, one end of the connecting rod 41 far away from the lower die holder 17 is slidably connected with the power seat 13, the cross section of the flanging lug 42 is triangular, the flanging lug 42 is disposed at one end of the connecting rod 41 near the limiting seat 15, the small end of the flanging lug 42 is disposed at the extreme end of the connecting rod 41, the flaring block 43 is a round block, the flaring block 43 is fixed on the top surface of the connecting rod 41 near the flanging lug 42, the stop block 45 is also a round block, the diameter of the stop block 45 is larger than the diameter of the flaring block 43, an arc-shaped connection part 44 is formed between the flanging lug 42 and the flaring block 43, and the arc-shaped connection part 44 is in smooth transition with the flanging lug 42 and the flaring block 43 respectively.

Referring to fig. 4, a limiting seat 15 is provided at the top of a lower die holder 17, a fin heat exchanger 7 is slidably connected in the middle of the limiting seat 15, the fin heat exchanger 7 comprises a mounting frame and a fin tube set, the fin tube set is arranged in the middle of the mounting frame, the fin tube set comprises a plurality of fin tubes, in the embodiment of the application, the number of fin rods is consistent with that of expansion rods 4, the expansion rods 4 and the fin tubes are directly arranged one by one, a guide strip 21 is directly arranged opposite to the top surface of one side of the mounting frame, and a limiting strip 23 is directly arranged opposite to the top surface of the other side of the mounting frame.

The fixed seat 61 is installed to the top surface of die holder 17, and spacing seat 15 sets up in the one side that the fixed seat 61 is close to die holder 17, and the parallel arrangement between spacing seat 15 and the die holder 17, and spout 611 has been seted up respectively to the opposite lateral wall of fixed seat 61, and spout 611 sets up on the minor face inside wall of fixed seat 61, and correspondingly, connecting slider 62 is installed to the lateral wall of installing the frame, looks adaptation sliding connection between connecting slider 62 and the spout 611.

The middle part of spacing seat 15 has been seted up and has been worn slot 63, sliding connection between fin heat exchanger 7 and the interlude groove 63, be provided with buffer layer 64 on the inner bottom wall of spacing seat 15, the diapire of fin nest of tubes and buffer layer 64 looks butt, wherein, buffer layer 64 includes the shock attenuation board and buffer spring, the cross-section size of shock attenuation board matches with the cross-section size of interlude groove 63, buffer spring's one end is assembled with the inner bottom wall of spacing seat 15, the other end is assembled with the diapire of shock attenuation board, be formed with the shock attenuation chamber between messenger's shock attenuation board and the spacing seat 15, be favorable to reducing the noise pollution when expanding tube of telescopic link 4, simultaneously, be favorable to reducing the fin pipe and take place the striking phenomenon with the inner bottom wall of spacing seat 15 directly, in addition, be provided with wear-resisting washer 65 in the position department of spacing seat 15 input, wear-resisting washer 65 is the rubber washer, fix mutually through the mode of glue bonding between wear-resisting washer 65 and the spacing seat 15, can protect the fin nest of tubes to a certain extent.

The implementation principle of the tube expander in the embodiment of the application is as follows:

the worker first slides the fin heat exchanger 7 into the fixed seat 61, that is, slides the connecting slider 62 with the chute 611, slides the bottom of the fin heat exchanger 7 with the limit seat 15, and then slides and inserts the guide post 12 into the mounting post 16.

Under the effect of first driving motor 222, the transmission shaft can rotate, makes fixed epaxial drive gear 221 also rotate, and under the cooperation effect of fixed frame 25, guide bar 21, spacing 23 are vertical downward motion simultaneously, and cooperation piece 231 slides with guide slot 241 mutually, and then makes guide bar 21, spacing 23 support simultaneously and presses on the top surface of installing the frame, accomplishes the location to fin heat exchanger 7.

Under the drive of the second driving motor 31, the transmission rod 32 can rotate, and the flaring seat 14 drives the expansion rod 4 to vertically and downwards move at the same time, so that the expansion rod 4 is inserted in the middle of the finned tube, the bottom of the finned tube is propped against the top surface of the damping plate, and the expansion of the finned tube is completed.

Example 2:

this embodiment differs from embodiment 1 in that the structure of the expansion rod 4 is different.

Referring to fig. 4 and 5, the expansion rod 4 includes a fixing rod 51 and a flanging module 52, in this embodiment, the fixing rod 51 is a circular rod body, the flanging module 52 is a triangular block, an integral molding is formed between the fixing rod 51 and the flanging module 52, a connection part between the fixing rod 51 and the flanging module 52 is smooth, when the end of a finned tube needs to be flanged, the fixing rod 51 is installed on the flaring seat 14, the small end of the flanging module 52 is right opposite to the middle of the finned tube, under the driving of the second driving motor 31, the transmission rod 32 can rotate, the flaring seat 14 drives the expansion rod 4 to do vertical downward movement at the same time, so that the expansion rod 4 is inserted in the middle of the finned tube, the bottom of the finned tube is propped against the top surface of the damping plate, and the end flanging of the finned tube is completed.

The foregoing is a preferred embodiment of the present application, which is merely illustrative of the present application and not intended to limit the scope of the present application in any way, so long as the present application is not limited thereto: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims

1. The utility model provides a tube expander, includes frame (1), its characterized in that, frame (1) includes power seat (13), flaring seat (14) and spacing seat (15), power seat (13), flaring seat (14) and spacing seat (15) set gradually from the top down, install guide bar (21) on power seat (13), the top of power seat (13) is provided with and is used for driving guide bar (21) carries out the location transmission subassembly of motion on the vertical direction, the middle part sliding connection of spacing seat (15) has fin heat exchanger (7), fin heat exchanger (7) are including installing frame and fin nest of tubes, fin nest of tubes sets up the middle part of installing frame, guide bar (21) with just lay between the installing frame, guide bar (21) are supported and are pressed the top surface of installing frame, are used for carrying out the location to fin heat exchanger (7), the middle part rotation of flaring seat (14) is connected with transfer line (32), be provided with on frame (1) guide bar (21) carries out the vertical direction motion, output end and the fin (14) are arranged with the fin nest of tubes on the vertical direction of tubes, the fin heat exchanger (14) is directly over with the driving rod (14) is arranged on the vertical direction of motion, the transmission rod (32) is used for driving the expansion rod group to vertically move downwards in the rotating process.

2. A tube expander as claimed in claim 1, wherein said expander group comprises a plurality of expander rods (4), said expander rods (4) comprising: a connecting rod (41) mounted on the flare seat (14); a flanging lug (42) fixed at one end of the connecting rod (41) close to the limit seat (15); a flaring block (43) which is fixed on the connecting rod (41) and is close to the top surface of the flanging lug (42); and a stop block (45) arranged on the connecting rod (41) near the top surface of the flaring block (43), wherein the diameter size of the stop block (45) is larger than the diameter size of the flaring block (43).

3. A tube expander as claimed in claim 2, wherein an arc-shaped engagement portion (44) is provided between the flanging lug (42) and the flaring block (43), and the arc-shaped engagement portion (44) is in smooth transition with the flanging lug (42) and the flaring block (43) respectively.

4. A tube expander as claimed in claim 1, wherein the positioning drive assembly comprises: a locking column (22) fixed on the top surface of the power seat (13); a transmission shaft rotatably connected to the middle part of the locking column (22); a transmission gear (221) installed at one end of the transmission shaft; the guide bar (21) is arranged on one side, close to the transmission gear (221), of the rack (211), and a first driving motor (222) is arranged on the side wall of the locking column (22), wherein the output end of the first driving motor (222) is assembled with the transmission shaft, and the transmission gear (221) is meshed with the rack (211).

5. A tube expander as claimed in claim 4, wherein the middle part of the guide bar (21) is provided with a hollow slot (212) therethrough.

6. The tube expander according to claim 1, wherein an upper die holder (11) is mounted at the top of the power seat (13), a guide column (12) is arranged between the upper die holder (11) and the power seat (13), a lower die holder (17) is arranged at the bottom of the limiting seat (15), a mounting column (16) is arranged on the top surface of the lower die holder (17), and a part of the guide column (12) penetrating out of the power seat (13) is in sliding connection with the mounting column (16).

7. A tube expander as claimed in claim 6, wherein the top wall of the upper die holder (11) is provided with a second driving motor (31), the output end of the second driving motor (31) is assembled with the transmission rod (32), one end of the transmission rod (32) is in threaded connection with the flaring seat (14), and the other end is in rotational connection with the upper die holder (11).

8. The tube expander as claimed in claim 6, wherein a fixing seat (61) is mounted on the top surface of the lower die holder (17), the limiting seat (15) is disposed on one side of the fixing seat (61) close to the lower die holder (17), sliding grooves (611) are respectively formed in two opposite side walls of the fixing seat (61), a connecting sliding block (62) is mounted on the side wall of the mounting frame, and the connecting sliding block (62) is in sliding connection with the sliding grooves (611) in a matched mode.

9. The tube expander according to claim 1, wherein a through slot (63) is formed in the middle of the limiting seat (15), the fin heat exchanger (7) is slidably connected with the through slot (63), a shock absorption layer (64) is arranged on the inner bottom wall of the limiting seat (15), and the bottom wall of the fin tube set is abutted against the shock absorption layer (64).

10. A tube expander as claimed in claim 9, wherein the limit seat (15) is provided with a wear washer (65) at the location of the input end.