A double-layer copper tube and its laser welding device

Abstract

The present invention discloses a double-layer copper tube and its laser welding device, which relates to the technical field of laser welding of copper tubes. It includes an inner tube and an outer tube sleeved outside the inner tube. Connectors are installed at both ends of the outer tube, and the two connectors are interconnected; the outer surface of the inner tube is fixedly connected to the inner surface of the outer tube by welding. In the double-layer copper tube of the present invention, the inner tube is located inside the outer tube. The refrigerant in the inner tube can circulate, and the refrigerant in the outer tube can also circulate. During the circulation process, it passes through the radiator, which is beneficial to quickly dissipate heat, thereby improving the heat transfer effect of the overall copper tube. In addition, the inner tube and the outer tube in the present invention are fixedly connected by welding. In this way, during the later bending process of the double-layer copper tube, the inner tube and the outer tube will be bent synchronously, avoiding the phenomenon that the inner tube becomes flat under the action of the outer tube, and improving the bending effect of the inner tube.

Description

Technical Field

[0001] The present invention relates to the technical field of laser welding of copper tubes, and specifically to a double-layer copper tube and its laser welding device. Background Art

[0002] Copper tubes are important channels for the refrigerant to circulate in the air-conditioning system, ensuring the circulation of the refrigerant between the indoor unit and the outdoor unit, realizing the heat exchange, and thus achieving the effect of refrigeration or heating. High-quality copper tubes can maintain the stability of the system and improve the efficiency and durability of the air conditioner. In places with high requirements for the performance of the air-conditioning system such as hospitals, shopping malls, and hotels, double-layer copper tubes with better thermal conductivity are usually used.

[0003] For example, a double-layer refrigeration seamless copper tube disclosed in a Chinese utility model with the publication number CN209705453U includes a copper tube. A pipe hole is provided inside the copper tube, and a thread groove structure is provided on the inner wall of the pipe hole. An inner tube is provided in the inner cavity of the pipe hole, and the inner tube and the pipe hole can form a threaded rotary connection. A stopper is provided on one side of the inner tube, and the stopper is in a ring structure. Six first through holes are provided on the stopper, and a pipe hole is provided inside the first through holes. A connecting member is provided on the right side of the inner tube, and an insertion block is provided on the connecting member.

[0004] For the double-layer copper tubes in the prior art including the above patent, the refrigerant between the inner tube and the outer tube cannot circulate and cannot be fully heat-exchanged, which limits the overall thermal conductivity of the copper tube. Summary of the Invention

[0005] The purpose of the present invention is to provide a double-layer copper tube and its laser welding device to solve the above deficiencies in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A double-layer copper tube includes an inner tube and an outer tube sleeved outside the inner tube. Connectors are installed at both ends of the outer tube, and the two connectors are interconnected; the outer surface of the inner tube and the inner surface of the outer tube are fixedly connected by welding.

[0007] A laser welding device for welding the above double-layer copper tube includes a welding torch and a shaping seat for shaping the outer tube. The shaping seat is installed on a bottom plate. A supporting bracket for supporting the inner tube is fixedly installed on the bottom plate, and a limiting piece for limiting the outer tube is fixedly installed on the end surface of the shaping seat.

[0008] As a preferred technical solution of the present invention, a gantry is provided on the bottom plate. Two parallel tension shafts are installed on the gantry, and an abrasive belt is installed between the two tension shafts. The lower surface of the abrasive belt is in contact with the parts of the inner tube and the outer tube to be welded.

[0009] As a preferred technical solution of the present invention, an elastic telescopic rod is fixedly installed on the gantry. An adsorption box is fixedly installed at the end of the elastic telescopic rod. The bottom surface of the adsorption box is hollowed out and fits the upper surface of the grinding belt. A brush is provided on the bottom surface of the adsorption box.

[0010] As a preferred technical solution of the present invention, a driven gear is fixedly sleeved on the tensioning shaft. A driving shaft is fixedly installed on the gantry. A driving gear meshing with the driven gear is fixedly installed on the driving shaft. One end of the driving shaft is fixedly installed with an inclined disc. A rigid rod is fixedly installed on the side wall of the adsorption box. A ball rollingly cooperating with the surface of the disc is installed at one end of the rigid rod.

[0011] As a preferred technical solution of the present invention, a vertical pressure roller and a pressing roller are rotatably installed on the bottom plate. A driven bevel gear is fixedly installed on the pressing roller. A transmission shaft is rotatably installed on the gantry. A driving bevel gear meshing with the driven bevel gear is fixedly installed on the transmission shaft. Belt pulleys are fixedly installed on both the transmission shaft and the driving shaft, and a transmission belt is connected between the belt pulleys.

[0012] As a preferred technical solution of the present invention, a vertical shaft is installed on the adsorption box. A scraping strip fitting the inner wall of the adsorption box is fixedly installed at the bottom end of the vertical shaft.

[0013] As a preferred technical solution of the present invention, an adjusting gear is fixedly installed at the top end of the vertical shaft. An adjusting rack meshing with the adjusting gear is fixedly installed on the gantry.

[0014] In the above technical solution, a double-layer copper tube provided by the present invention has an inner tube located inside the outer tube. The refrigerant in the inner tube can circulate, and the refrigerant in the outer tube can also circulate. During the circulation process, it passes through a radiator, which is beneficial to quickly dissipate heat, thereby improving the heat transfer effect of the overall copper tube. In addition, the inner tube and the outer tube of the present invention are fixedly connected by welding. In this way, during the later bending process of the double-layer copper tube, the inner tube and the outer tube will be bent synchronously, avoiding the phenomenon that the inner tube becomes flat under the action of the outer tube, and improving the bending effect of the inner tube.

[0015] In the laser welding device of the present invention, through the mutual force between the shaping seat and the outer tube, the opened outer tube is contracted, and the seam of the outer tube is welded by a welding torch, so that the inner tube and the outer tube are connected together. During this process, the grinding belt grinds the connection part of the inner tube and the outer tube to remove the oxide layer, and the grinding belt will automatically adjust its own speed according to the actual conveying speed of the copper tube. When the conveying speed of the copper tube is fast, the grinding speed of the grinding belt also becomes faster accordingly. In addition, the debris on the grinding belt can be automatically adsorbed by the adsorption box, and the adsorption box reciprocates relative to the grinding belt, which can promote the debris to fall off. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0017] Figure 1 Structural schematic diagram of the double-layer copper tube in the embodiment of the present invention;

[0018] Figure 2 Cross-sectional view after welding of the inner tube and the outer tube in the embodiment of the present invention;

[0019] Figure 3 First three-dimensional structural schematic diagram of the laser welding device in the embodiment of the present invention;

[0020] Figure 4 Second three-dimensional structural schematic diagram of the laser welding device in the embodiment of the present invention;

[0021] Figure 5 For Figure 4 Enlarged schematic diagram at position A in

[0022] Figure 6 Internal structural schematic diagram of the adsorption box in the embodiment of the present invention.

[0023] Explanation of reference numerals:

[0024] 1. Inner tube; 2. Outer tube; 3. Joint; 4. Welding torch; 5. Shaping seat; 6. Base plate; 7. Bracket; 8. Limiting piece; 9. Gantry; 10. Tensioning shaft; 11. Grinding belt; 12. Elastic telescopic rod; 13. Adsorption box; 14. Driven gear; 15. Driving shaft; 16. Driving gear; 17. Disc; 18. Rigid rod; 19. Pressure roller; 20. Pressing roller; 21. Driven bevel gear; 22. Transmission shaft; 23. Driving bevel gear; 24. Belt pulley; 25. Transmission belt; 26. Vertical shaft; 27. Scraping strip; 28. Adjusting gear; 29. Adjusting rack. Detailed implementation manners

[0025] To enable those skilled in the art to better understand the technical solutions of the present invention, the following will further introduce the present invention in detail in conjunction with the drawings.

[0026] As Figure 1 And Figure 2As shown in the figure, this embodiment provides a double-layer copper tube, which includes an inner tube 1 and an outer tube 2 sleeved outside the inner tube 1. Connectors 3 are installed at both ends of the outer tube 2, and the two connectors 3 are interconnected; the outer surface of the inner tube 1 and the inner surface of the outer tube 2 are fixedly connected by welding. The refrigerant in the inner tube 1 and the refrigerant in the outer tube 2 are isolated from each other, and there are two radiators in the air-conditioning system, which dissipate heat from the refrigerant in the inner tube 1 and the refrigerant in the outer tube 2 respectively. In this way, during the operation of the air-conditioning system, the refrigerant in the inner tube 1 directly absorbs heat, and the refrigerant in the outer tube 2 absorbs the heat dissipated by the inner tube 1, thereby improving the overall heat dissipation effect of the air-conditioning system.

[0027] During the manufacturing process of the double-layer copper tube, it is necessary to bend the inner tube 1 and the outer tube 2 simultaneously. When an external force acts on the outer tube 2, the outer tube 2 is easily bent under the limiting action of the external mold. However, the inner tube 1 cannot directly contact the external mold, and the inner tube 1 often forms a flat bend under the action of the force during the bending process of the outer tube 2, which will undoubtedly affect the normal flow of the refrigerant in the inner tube 1 during use. In this embodiment, the inner tube 1 and the outer tube 2 are welded together, and when the outer tube 2 is bent, it will drive the inner tube 1 to bend synchronously with it, avoiding the inner tube 1 from forming a flat bend.

[0028] As Figure 3 As shown in the figure, this embodiment also provides a laser welding device for welding the inner tube 1 and the outer tube 2 in the above double-layer copper tube. Specifically, it includes a welding torch 4 and a shaping seat 5 for shaping the outer tube 2. A circular channel adapted to the outer tube 2 is horizontally opened on the shaping seat 5, and the shaping seat 5 is installed on the bottom plate 6; a supporting bracket 7 for supporting the inner tube 1 is fixedly installed on the bottom plate 6. The supporting bracket 7 is U-shaped and adapted to the outer surface of the inner tube 1, and a limiting piece 8 for limiting the outer tube 2 is fixedly installed on the end surface of the shaping seat 5.

[0029] Specifically, before welding, the cross-section of the outer tube 2 is U-shaped, and the operator can put the inner tube 1 into the outer tube 2 from the top opening of the outer tube 2; as the external feeding device pushes the inner tube 1 and the outer tube 2 synchronously, the outer tube 2 generates an interaction force with the shaping seat 5 during the feeding process and contracts into a cylindrical shape under the action of the shaping seat 5. There is a certain width of gap between the two sides of the contracted outer tube 2, and the outer surface of the inner tube 1 just seals this gap; in this way, when the welding torch 4 heats the gap between the two sides of the outer tube 2, the two sides of the outer tube 2 and the corresponding parts of the inner tube 1 and the gap will melt to form a molten pool, and the inner tube 1 and the outer tube 2 can be welded together. It should be noted that according to the different thicknesses of the inner tube 1 and the outer tube 2, different thicknesses of welding wires can be used for welding, or the method of welding without welding wire can also be used. After welding, the gap between the two sides of the outer tube 2 is blocked by the inner tube 1, so the refrigerant in the outer tube 2 will not leak.

[0030] As Figure 3 , Figure 4 and Figure 5 shown, a portal frame 9 is provided on the bottom plate 6, and two parallel tension shafts 10 are installed on the portal frame 9. The tension shafts 10 are in a horizontal state and perpendicular to the conveying direction of the inner tube 1 and the outer tube 2. A tensioned grinding belt 11 is installed between the two tension shafts 10. The lower surface of the grinding belt 11 is in contact with the parts of the inner tube 1 and the outer tube 2 to be welded. The grinding belt 11 grinds the parts of the inner tube 1 and the outer tube 2 to be welded before welding, removing the oxide layers on the surfaces of the inner tube 1 and the outer tube 2.

[0031] As Figure 4 and Figure 5 shown, an elastic telescopic rod 12 is fixedly installed on the portal frame 9. The elastic telescopic rod 12 is parallel to the tension shaft 10. An adsorption box 13 is fixedly installed at the end of the elastic telescopic rod 12. The upper part of the adsorption box 13 communicates with an external fan, and the fan sucks air from the adsorption box 13. The bottom surface of the adsorption box 13 is hollowed out and is in contact with the upper surface of the grinding belt 11. Brush hairs are provided on the bottom surface of the adsorption box 13. During the working process, the bottom surface of the adsorption box 13 is in contact with the upper surface of the grinding belt 11 and adsorbs the grinding debris adhered to the grinding belt 11; at the same time, the adsorption box 13 reciprocates horizontally under the action of an external force in the direction perpendicular to the conveying direction of the inner tube 1 and the outer tube 2, generating a relative movement perpendicular to each other with the grinding belt 11, thereby promoting the falling off of the debris adhered to the grinding belt 11.

[0032] As Figure 3 , Figure 4 and Figure 5 shown, a driven gear 14 is fixedly sleeved on the tension shaft 10, a driving shaft 15 is fixedly installed on the portal frame 9, and a driving gear 16 meshing with the driven gear 14 is fixedly installed on the driving shaft 15; one end of the driving shaft 15 is fixedly installed with an inclined disc 17, a rigid rod 18 is fixedly installed on the side wall of the adsorption box 13, and a ball rolling on the surface of the disc 17 is installed at one end of the rigid rod 18. The elastic telescopic rod 12 is always in a compressed state, so there is an interaction force between the ball at the end of the rigid rod 18 and the surface of the disc 17. When the driving shaft 15 rotates driven by an external motor, it will drive the driving gear 16 to rotate, and the driving gear 16 will drive the driven gear 14 meshing with it to rotate, and the driven gear 14 will drive the tension shaft 10 to rotate, so that the grinding belt 11 moves. When the driving shaft 15 rotates, it will also drive the disc 17 to rotate. During the rotation of the disc 17, it cooperates with the elastic telescopic rod 12 to push the adsorption box 13 and the rigid rod 18 horizontally in a reciprocating manner; the faster the grinding belt 11 moves, the faster the adsorption box 13 reciprocates horizontally, ensuring the adsorption effect on the debris on the grinding belt 11.

[0033] As Figure 3 and Figure 4As shown, a vertical pressure roller 19 and a pressure-applying roller 20 are rotatably mounted on the bottom plate 6. Rubber layers are covered on the surfaces of both the pressure roller 19 and the pressure-applying roller 20. The pressure roller 19 and the pressure-applying roller 20 are respectively located on both sides of the outer tube 2 and are in contact with the outer wall of the outer tube 2 and there is a mutual extrusion force. When the pressure-applying roller 20 rotates, the outer tube 2 is driven to feed through the frictional force between the pressure-applying roller 20 and the outer tube 2, and the pressure roller 19 will rotate under the action of the frictional force of the outer tube 2; a driven bevel gear 21 is fixedly mounted on the pressure-applying roller 20; a transmission shaft 22 is rotatably mounted on the gantry 9, and a driving bevel gear 23 meshing with the driven bevel gear 21 is fixedly mounted on the transmission shaft 22; belt wheels 24 are fixedly mounted on both the transmission shaft 22 and the driving shaft 15, and a transmission belt 25 is connected between the belt wheels.

[0034] Specifically, when the driving shaft 15 rotates, the transmission shaft 22 and the driving bevel gear 23 are driven to rotate through the belt wheels 24 and the transmission belt 25, the driving bevel gear 23 drives the driven bevel gear 21 meshing with it to rotate, and the driven bevel gear 21 drives the pressure-applying roller 20 to rotate; thus, in this embodiment, only one external driving source is used to realize the driving of the grinding belt 11 to move and the feeding and conveying of the outer tube 2, and when the outer tube 2 is conveyed faster, the moving speed of the grinding belt 11 is also correspondingly faster, ensuring the grinding effect.

[0035] As Figure 4 、 Figure 5 and Figure 6 shown, a vertical shaft 26 is mounted on the adsorption box 13, and a scraping strip 27 that fits against the inner wall of the adsorption box 13 is fixedly mounted at the bottom end of the vertical shaft 26. The inside of the adsorption box 13 is a cylindrical shape that penetrates up and down; a regulating gear 28 is fixedly mounted at the top end of the vertical shaft 26, and a regulating rack 29 meshing with the regulating gear 28 is fixedly mounted on the gantry 9. Specifically, when the adsorption box 13 reciprocates horizontally, the vertical shaft 26 and the regulating gear 28 also reciprocate horizontally. Since the regulating rack 29 is fixed, the regulating gear 28 meshing with it will reciprocally rotate, thereby driving the vertical shaft 26 and the scraping strip 27 to reciprocally rotate; the reciprocally rotating scraping strip 27 scrapes the debris adhering to the inner wall of the adsorption box 13 during the movement following the airflow.

[0036] Only some exemplary embodiments of the present invention have been described by way of illustration above. Without doubt, for those of ordinary skill in the art, various different ways can be used to modify the described embodiments without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the protection scope of the claims of the present invention.

Claims

1. A laser welding device for welding a double-layer copper tube. The double-layer copper tube includes an inner tube (1) and an outer tube (2) sleeved outside the inner tube (1). Joints (3) are installed at both ends of the outer tube (2), and the two joints (3) are interconnected; the outer surface of the inner tube (1) is fixedly connected to the inner surface of the outer tube (2) by welding; the laser welding device includes a welding torch (4) and a shaping seat (5) for shaping the outer tube (2). The shaping seat (5) is installed on a bottom plate (6), and is characterized in that, A support bracket (7) for supporting the inner tube (1) is fixedly installed on the bottom plate (6), and a limiting piece (8) for limiting the outer tube (2) is fixedly installed on the end face of the shaping seat (5); A portal frame (9) is arranged on the bottom plate (6), two parallel tensioning shafts (10) are installed on the portal frame (9), a grinding belt (11) is installed between the two tensioning shafts (10), and the lower surface of the grinding belt (11) is attached to the parts of the inner tube (1) and the outer tube (2) to be welded; An elastic telescopic rod (12) is fixedly installed on the portal frame (9), an adsorption box (13) is fixedly installed at the end of the elastic telescopic rod (12), the bottom surface of the adsorption box (13) is hollowed out and attached to the upper surface of the grinding belt (11), and brush hairs are arranged on the bottom surface of the adsorption box (13); A driven gear (14) is fixedly sleeved on the tensioning shaft (10), a driving shaft (15) is fixedly installed on the portal frame (9), and a driving gear (16) meshing with the driven gear (14) is fixedly installed on the driving shaft (15); One end of the driving shaft (15) is fixedly installed with an inclined disc (17), a rigid rod (18) is fixedly installed on the side wall of the adsorption box (13), and a ball rolling on the surface of the disc (17) is installed at one end of the rigid rod (18); A vertical pressure roller (19) and a pressing roller (20) are rotatably installed on the bottom plate (6), and a driven bevel gear (21) is fixedly installed on the pressing roller (20); A transmission shaft (22) is rotatably installed on the portal frame (9), and a driving bevel gear (23) meshing with the driven bevel gear (21) is fixedly installed on the transmission shaft (22); Belt wheels (24) are fixedly installed on both the transmission shaft (22) and the driving shaft (15), and a transmission belt (25) is connected between the belt wheels.

2. The laser welding device according to claim 1, characterized in that, A vertical shaft (26) is installed on the adsorption box (13), and a scraping strip (27) attached to the inner wall of the adsorption box (13) is fixedly installed at the bottom end of the vertical shaft (26).

3. The laser welding device according to claim 2, wherein, An adjusting gear (28) is fixedly installed at the top end of the vertical shaft (26), and an adjusting rack (29) meshing with the adjusting gear (28) is fixedly installed on the portal frame (9).

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