Double-layer copper pipe and laser welding device thereof

Abstract

The invention discloses a double-layer copper pipe and a laser welding device thereof, and relates to the technical field of copper pipe laser welding, the double-layer copper pipe comprises an inner pipe and an outer pipe arranged outside the inner pipe in a sleeving manner, two ends of the outer pipe are provided with joints, and the two joints are communicated with each other; the outer surface of the inner pipe is fixedly connected with the inner surface of the outer pipe in a welding mode. According to the double-layer copper pipe, the inner pipe is located in the outer pipe, the condensing agent in the inner pipe can circularly flow, the condensing agent in the outer pipe can also circularly flow, heat can be quickly dissipated through the radiator in the circular flowing process, and therefore the overall heat transfer effect of the copper pipe is achieved. Besides, the inner pipe and the outer pipe are fixedly connected in a welding mode, in this way, in the later bending process of the double-layer copper pipe, the inner pipe and the outer pipe can be bent synchronously, the phenomenon that the inner pipe is flat under the acting force of the outer pipe is avoided, and the inner pipe bending effect is improved.

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 heat exchange, and thus achieving the effect of refrigeration or heating. High-quality copper tubes can maintain the stability of the system, improve the efficiency and durability of the air conditioner. Places with high requirements for the performance of the air-conditioning system, such as hospitals, shopping malls, and hotels, usually use double-layer copper tubes with better heat conduction performance.

[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 an annular structure. Six first through holes are provided on the stopper, and a pipe hole is provided inside the first through holes. A connector is provided on the right side of the inner tube, and an insertion block is provided on the connector.

[0004] In 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 heat conduction performance 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 solutions: 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 is fixedly connected to the inner surface of the outer tube 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 face 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; a slanted disc is fixedly installed at one end of the driving shaft. 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 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 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 interaction force between the shaping seat and the outer tube, the opened outer tube is contracted, and the joint 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 It is a schematic structural diagram of a double-layer copper tube in an embodiment of the present invention;

[0018] Figure 2 It is a cross-sectional view after welding the inner tube and the outer tube in an embodiment of the present invention;

[0019] Figure 3 It is a first three-dimensional structural diagram of a laser welding device in an embodiment of the present invention;

[0020] Figure 4 It is a second three-dimensional structural diagram of a laser welding device in an embodiment of the present invention;

[0021] Figure 5 For Figure 4 It is an enlarged schematic diagram of part A in

[0022] Figure 6 It is a schematic internal structure diagram of the adsorption box in an embodiment of the present invention.

[0023] Explanation of reference numerals:

[0024] 1. Inner tube; 2. Outer tube; 3. Connector; 4. Welding torch; 5. Shaping seat; 6. Base plate; 7. Support 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-bearing 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] In order 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. 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 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 to 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 shrinks into a cylindrical shape under the action of the shaping seat 5. The two side edges of the shrunk outer tube 2 do not fit together, but there is a gap with a certain width, 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 side edges of the outer tube 2, the two side edges 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, welding wires with different thicknesses can be used for welding, or the method of welding without welding wire can also be used. After welding, the gap between the two side edges 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 gantry 9 is provided on the bottom plate 6, and two parallel tension shafts 10 are installed on the gantry 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 gantry 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 is communicated with an external fan. 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 along 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 detachment 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 gantry 9. 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. A ball rolling in cooperation with 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. The driving gear 16 drives the driven gear 14 meshing with it to rotate, and the driven gear 14 drives the tension shaft 10 to rotate, thereby making the grinding belt 11 move. 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 back and forth. The faster the movement speed of the grinding belt 11, the faster the reciprocating translation speed of the adsorption box 13, 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 pressing roller 20 are rotatably mounted on the bottom plate 6. Rubber layers are covered on the surfaces of the pressure roller 19 and the pressing roller 20. The pressure roller 19 and the pressing 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 pressing roller 20 rotates, the outer tube 2 is driven to feed through the friction force between the pressing roller 20 and the outer tube 2, and the pressure roller 19 will rotate under the friction force of the outer tube 2; a driven bevel gear 21 is fixedly mounted on the pressing 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 pressing 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 As shown, a vertical shaft 26 is mounted on the adsorption box 13. 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 scraping strip 27 reciprocally rotates to scrape off 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. Undoubtedly, for those of ordinary skill in the art, without departing from the spirit and scope of the present invention, the described embodiments can be modified in various different ways. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A double-layer copper tube, comprising an inner tube (1) and an outer tube (2) sleeved outside the inner tube (1), characterized in that: Joints (3) are installed at both ends of the outer tube (2), and the two joints (3) are connected to each other; the outer surface of the inner tube (1) and the inner surface of the outer tube (2) are fixedly connected by welding.

2. A laser welding device for welding the double-layer copper tube according to claim 1, comprising a welding gun (4) and a shaping seat (5) for shaping the outer tube (2), the shaping seat (5) being mounted on a bottom plate (6), characterized in that: A support frame (7) for supporting the inner tube (1) is fixedly mounted on the bottom plate (6), and a limiting plate (8) for limiting the position of the outer tube (2) is fixedly mounted on the end surface of the shaping seat (5).

3. A laser welding device according to claim 2, characterized in that: A portal frame (9) is arranged on the bottom plate (6), and two 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 in contact with the parts of the inner tube (1) and the outer tube (2) to be welded.

4. A laser welding device according to claim 1, characterized in that: An elastic telescopic rod (12) is fixedly mounted on the door frame (9), an adsorption box (13) is fixedly mounted on the end of the elastic telescopic rod (12), the bottom surface of the adsorption box (13) is hollow and fits with the upper surface of the grinding belt (11), and bristles are arranged on the bottom surface of the adsorption box (13).

5. A laser welding device according to claim 4, characterized in that: A driven gear (14) is fixedly sleeved on the tensioning shaft (10), a driving shaft (15) is fixedly mounted on the door frame (9), and a driving gear (16) meshing with the driven gear (14) is fixedly mounted on the driving shaft (15); an inclined disc (17) is fixedly mounted on one end of the driving shaft (15), a rigid rod (18) is fixedly mounted on the side wall of the adsorption box (13), and a ball rolling with the surface of the disc (17) is mounted on one end of the rigid rod (18).

6. A laser welding device according to claim 5, characterized in that: A vertical pressure roller (19) and a pressure roller (20) are rotatably mounted on the bottom plate (6), and a driven bevel gear (21) is fixedly mounted on the pressure roller (20); a transmission shaft (22) is rotatably mounted on the portal frame (9), and a driving bevel gear (23) meshing with the driven bevel gear (21) is fixedly mounted on the transmission shaft (22); pulleys (24) are fixedly mounted on both the transmission shaft (22) and the driving shaft (15), and a transmission belt (25) is connected between the pulleys.

7. A laser welding device according to claim 6, characterized in that: A vertical shaft (26) is installed on the adsorption box (13), and a scraper strip (27) that fits the inner wall of the adsorption box (13) is fixedly installed on the bottom end of the vertical shaft (26).

8. A laser welding device according to claim 7, characterized in that: An adjusting gear (28) is fixedly mounted on the top of the vertical shaft (26), and an adjusting rack (29) meshing with the adjusting gear (28) is fixedly mounted on the door frame (9).

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