Automatic welding equipment and method for H-shaped flat finned tube

Abstract

The application relates to an automatic welding equipment and method for H-shaped flat fin tube, which comprises a support, a strip disc arranged on the support, a flat base tube conveying and fixing device, a resistance welding equipment, a fin negative mold and a negative mold driving device; the flat base tube conveying and fixing device comprises a loading roller way, a pressure roller, a driving roller and an unloading roller way arranged in sequence; the pressure roller is connected with a pressure roller driving device; the support is provided with a driving roller driving device; the driving roller is connected with the driving roller driving device through a transmission mechanism; the resistance welding equipment comprises a welding head, an electrode driving device and a welding transformer; the welding head is provided with a resistance welding electrode; the welding transformer is fixedly arranged on the support; the welding transformer is connected with the electrode driving device; and the electrode driving device drives the welding head to move; the application has the advantages of simple structure, automatic feeding, automatic forming and automatic welding of the flat elliptical fin tube, high automation degree and high efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-efficiency heat exchanger devices, and particularly relates to an H-shaped flat fin tube automatic welding equipment and method. BACKGROUND

[0002] The heat exchanger is one of the key equipment of the heat system and refrigeration equipment in the process industry such as chemical industry, energy and air separation. At present, the heat exchanger is evolving towards specialization and high efficiency, and it is extremely important to reduce the space occupied by the heat exchanger and save the production cost. Therefore, the heat transfer enhancement technology is of great significance to the heat exchanger. The high-efficiency finned tube can be applied in the heat exchanger to enhance the heat transfer effect. Most of the finned tubes need to be connected with the base pipe by welding during manufacturing.

[0003] The existing patent 1: RU2228241C1 "Method of connecting steel pipe with aluminum fin" proposes that first, an aluminum-zinc alloy (aluminum content 0.5% to 20%) is prepared on the surface of the steel pipe or the surface of the aluminum fin, then a cesium fluoroaluminate flux is applied to the contact surface of the steel pipe and the aluminum fin at room temperature, then the steel pipe and the aluminum fin are assembled and placed in a furnace for brazing, the brazing temperature is 370℃ to 470℃, and finally cooled at room temperature.

[0004] The disadvantage of this method is that the operation is relatively complex, and it is difficult to ensure the brazing penetration rate between the steel pipe and the fin during the subsequent brazing process. Moreover, a high temperature needs to be maintained during brazing, which increases the manufacturing cost.

[0005] The existing technology 2: DE19547133A1 "Method for welding spiral finned tube using induction heating" is used for spiral metal finned tube welding manufacturing, for example, a spiral strip of the same material is wound around a stainless steel pipe for welding. Pulse direct current is used for welding, and the current passes through the contact area of the circular base pipe and the spiral strip. There is a replaceable ferrite core inside the circular base pipe, which can concentrate the pulse direct current in the contact area of the pipe and the spiral strip. When the power is 50-100 kW, the frequency is 200-500 kHz, and the pulse voltage is 5-15 V, good welding effect can be obtained.

[0006] The disadvantage of this method is that it is only suitable for welding spiral fins on circular base pipes and cannot realize the welding of fins on elliptical pipes. This is because the welding electrode cannot be positioned and welded on the elliptical pipe during rotation. At the same time, the ferrite core needs to be removed from the pipe, making the device structure very complex.

[0007] In view of the above technical problems, improvement is needed. SUMMARY

[0008] The present application is to overcome the defects in the prior art, provide a kind of H type flat fin tube automatic welding equipment and method with simple and reasonable structure, ingenious design;For manufacturing heat exchanger element with higher heat exchange efficiency.Finned tube heat exchanger can be used in energy, construction, chemical industry and food industry etc.The proposed method can be used to produce by steel, aluminum and other alloy made of flat elliptical fin tube.

[0009] In order to achieve the above object, the technical scheme adopted by the present application is: an H type flat fin tube automatic welding equipment, comprising a support, a strip disc, a flat base pipe conveying and fixing device, a resistance welding device, a fin negative mold and a negative mold driving device arranged on the support;The flat base pipe conveying and fixing device comprises a loading roller, a pressure roller, a driving roller and an unloading roller arranged in sequence;Wherein, the pressure roller is connected with a pressure roller driving device;The driving roller is connected with the driving roller driving device through a transmission mechanism;The resistance welding device comprises a welding head, an electrode driving device and a welding transformer;The resistance welding electrode is arranged on the welding head, the welding transformer is fixed on the support, the welding transformer is connected with the electrode driving device, and the electrode driving device drives the welding head to move.

[0010] A method for H type flat fin tube automatic welding equipment, the specific steps are as follows:

[0011] Step 1: first, the flat base pipe is conveyed to the loading roller, and then the flat base pipe is fixed by driving the pressure roller through the pressure roller driving device;

[0012] Step 2: load two fin strips on two strip discs, and guide them to the assembly position on both sides of the flat base pipe through the guide;

[0013] Step 3: move the fin negative mold to the welding area on both sides of the flat base pipe by means of the negative mold driving device;

[0014] Step 4: move the welding head with resistance welding electrode to both sides of the flat base pipe by means of the electrode driving device, press the fin strip into the fin negative mold, form the required fin shape and contact with the flat base pipe;

[0015] Step 5: power on the resistance welding device, and the resistance welding electrode welds the fin strip and the flat base pipe under the action of the upsetting force;

[0016] Step 6: after resistance welding, the electrode driving device drives the welding head to retreat to the original position, and the fin negative mold is moved along the direction of the fin strip pressing edge by means of the negative mold driving device, and is moved out of the welding area;

[0017] Step 7: the driving roller moves the flat base pipe with a pair of welded fin strips forward by a fin spacing t under the action of the driving roller driving device;

[0018] Step 8: repeat the operation of steps 1-7, and complete the repeated forming and welding of the fin strip in the automatic mode to obtain the finished product H-shaped flat fin tube with the required length;

[0019] Step 9: unload the finished product H-shaped flat fin tube from the unloading roller, and complete the manufacturing.

[0020] As a preferred scheme of the present application, the die driving device, the electrode driving device and the pressure roller driving device are all pneumatic cylinders.

[0021] As a preferred scheme of the present application, the driving roller driving device is motor-driven.

[0022] As a preferred scheme of the present application, the resistance welding electrode is made of copper or bronze, and the working contact area is 10-100mm 2 .

[0023] As a preferred scheme of the present application, in step 4, a punch is arranged opposite to the resistance welding electrode to pre-press the fin strip, the punch is made of low-friction material, the preliminarily deformed fin strip is transported to the welding area after pre-pressing, and the fin strip is pressed into the die by the resistance welding electrode to form the required fin shape.

[0024] As a preferred scheme of the present application, in step 5, when the fin strip is welded with the flat base tube under the action of the upsetting force, the welding current is 2000-20000A, and the voltage is 5-20V; preferably, the voltage is 7V.

[0025] As a preferred scheme of the present application, in step 5, when the fin strip is welded with the flat base tube under the action of the upsetting force, the upsetting force is 500-5000N.

[0026] As a preferred scheme of the present application, the material of the fin strip and the flat base tube is carbon steel, stainless steel or aluminum alloy.

[0027] As a preferred scheme of the present application, the width of the fin strip is 50-200mm, and the thickness is 0.1-2mm.

[0028] As a preferred scheme of the present application, the wall thickness of the flat base tube is 1-5mm.

[0029] The present application has the following advantages:

[0030] 1. The present application has simple structure, and the H-shaped flat fin tube automatic welding equipment can realize automatic feeding, automatic forming and automatic welding of the flat elliptical fin tube, and has high automation degree and high efficiency.

[0031] 2. The H-shaped flat fin tube automatic welding equipment and method of the present application, the fin strip does not need to be processed into individual fins, saving process and cost;

[0032] 3. Compared with the brazing method of comparative technology 1, the resistance welding method of the present application does not need to preposition brazing filler metal and flux, saving process and cost. In addition, compared with the brazing method, the resistance welding method does not need to maintain high temperature for a long time, is more energy-saving, and improves process stability;

[0033] 4. The H-shaped flat fin tube automatic welding method of the present application, the fins are pressed onto the surface of the base pipe and resistance welded, increasing the contact welding area of the fins and the base pipe and improving the heat transfer efficiency;

[0034] 5. For fin strip with large thickness (1-2 mm), the device of the present application can also be configured with a punch placed opposite the resistance welding electrode for pre-pressing the fin strip. The punch material is selected from low-friction coefficient materials such as nylon 6. After pre-pressing, the initially deformed fin strip is transported to the welding area and pressed into the negative mold by the resistance welding electrode to form the required fin shape. The punch can effectively reduce the difficulty of strip pressing, improve production efficiency, and improve the quality of the manufactured H-shaped flat fin tube;

[0035] 6. Compared with comparative technology 2, the H-shaped flat fin tube automatic welding method of the present application is suitable for manufacturing round pipe spiral fins. The device and method of the present application are suitable for efficient manufacturing of flat elliptical fin tubes. Compared with round pipe spiral fins, flat elliptical fin tubes have higher heat transfer efficiency;

[0036] 7. When aluminum material is used as the fin strip, the device and method of the present application are easier to operate, and the fin tube has higher thermal efficiency, which is 1.5-2 times that of the same structure steel fin tube. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a top view of the H-shaped flat fin tube automatic welding equipment of the embodiment of the present application;

[0038] Figure 2 is a top view of the electrode part of the H-shaped flat fin tube automatic welding equipment of the embodiment of the present application;

[0039] Figure 3 is a side view of the H-shaped flat fin tube automatic welding equipment of the embodiment of the present application;

[0040] Figure 4 is a schematic view of the structure of the H-shaped flat fin tube of the embodiment of the present application.

[0041] The attached figures are labeled as follows: 1. Strip reel; 2. Finned strip; 3. Flat base tube conveying and fixing device; 4. Flat base tube; 5. Resistance welding equipment; 6. Finned female mold; 7. Female mold driving device; 8. Welding head; 9. Electrode driving device; 10. Resistance welding electrode; 11. Welding transformer; 12. Loading roller conveyor; 13. Transmission mechanism; 14. Pressure roller; 15. Pressure roller driving device; 16. Drive roller; 17. Drive roller driving device; 18. Unloading roller conveyor; 20. Support. Detailed Implementation

[0042] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0043] Example 1:

[0044] like Figures 1-3 As shown, an automated welding equipment for H-type flat finned tubes includes a support 20, a strip tray 1, a flat base tube conveying and fixing device 3, a resistance welding device 5, a finned die 6, and a die driving device 7 arranged on the support 20. The flat base tube conveying and fixing device 3 includes a loading roller 12, a pressure roller 14, a driving roller 16, and an unloading roller 18 arranged in sequence. The pressure roller 14 is connected to a pressure roller driving device 15. A driving roller driving device 17 is installed on the support 20, and the driving roller 16 and the driving roller driving device 17 are connected by a transmission mechanism 13. The resistance welding device 5 includes a welding head 8, an electrode driving device 9, and a welding transformer 11. The welding head 8 is provided with a resistance welding electrode 10, and the welding transformer 11 is fixed on the support 20. The welding transformer 11 is connected to the electrode driving device 9, and the electrode driving device 9 drives the welding head 8 to move. The automated welding equipment for H-type flat finned tubes of the present invention can realize automatic feeding, automatic forming, and automatic welding of flat elliptical finned tubes, with a high degree of automation and high efficiency.

[0045] A method for automated assembly and welding of H-type flat finned tubes, comprising the following specific steps:

[0046] Step 1: First, the flat base tube 4 with a wall thickness of 3mm made of aluminum alloy is transported to the loading roller conveyor 12, and then the pressure roller 14 is driven by the pressure roller drive device 15 to fix the flat base tube 4.

[0047] Step 2: Load two rolls of finned strip 2 made of aluminum alloy, each 100mm wide and 0.5mm thick, onto two strip reels 1, and guide them to the assembly positions on both sides of the flat base tube 4 using guides.

[0048] Step 3: Using the female mold driving device 7, move the fin female mold 6 to the welding area on both sides of the flat base tube 4;

[0049] Step 4: With the help of electrode driving device 9, the welding head 8 with resistance welding electrode 10 is moved to both sides of the flat base pipe 4, the fin strip 2 is pressed into the fin negative mold 6 to form the required fin shape and contact with the flat base pipe 4;

[0050] Step 5: The resistance welding device 5 is powered on, and the resistance welding electrode 10 is welded to the fin strip 2 and the flat base pipe 4 under the action of the top forging force, the top forging force is 2000N, the welding current is 8000A, and the voltage is 7V;

[0051] Step 6: After the resistance welding is completed, the electrode driving device 9 drives the welding head 8 to retreat to the original position, and the fin negative mold 6 is moved along the direction of the fin strip 2 profiled edge by the negative mold driving device 7, and is moved away from the welding area;

[0052] Step 7: The driving roller 16 moves the flat base pipe 4 with a pair of welded fin strips 2 forward by a fin spacing t under the action of the driving roller driving device 17;

[0053] Step 8: Repeat steps 1-7 to complete the repeated forming and welding of the fin strip 2 in an automatic mode to obtain a finished product H-shaped flat finned pipe of a required length;

[0054] Step 9: The finished product H-shaped flat finned pipe is unloaded from the unloading roller 18 to complete the manufacturing. The manufactured H-shaped flat finned pipe is as shown in Figure 4 .

[0055] In this embodiment, the materials of the fin strip 2 and the flat base pipe 4 can also be carbon steel or stainless steel; the width of the fin strip 2 is 50-200mm, and the thickness is 0.1-2mm; the wall thickness of the flat base pipe 4 is 1-5mm; the resistance welding electrode 10 can also be made of bronze; the working contact area of the resistance welding electrode 10 is 10-100mm 2 ; when the fin strip 2 is welded to the flat base pipe 4 under the action of the top forging force, the top forging force is 500-5000N, the welding current is 2000-20000A, and the voltage is 5-20V.

[0056] The negative mold driving device 7, the electrode driving device 9 and the pressure roller driving device 15 are all driven by pneumatic cylinders, and the driving roller driving device 17 is driven by a motor, which improves the overall automation degree.

[0057] By using the H-shaped flat finned pipe automatic welding equipment and method, the fin strip does not need to be processed into a single fin, which saves the process and saves the cost; at the same time, the fin is pressed onto the surface of the base pipe from the whole strip and resistance welded, which increases the contact welding area of the fin and the base pipe and improves the heat transfer efficiency.

[0058] Example 2:

[0059] On the basis of the automatic welding equipment for H-shaped flat finned tube described in Embodiment 1, a punch is arranged in pairs with the resistance welding electrode 10 for pre-pressing the fin strip 2, the punch material is selected from low friction coefficient materials such as nylon 6, after pre-pressing, the initially deformed fin strip 2 is transported to the welding area, and the fin strip 2 is pressed into the negative mold 6 by the resistance welding electrode 10 to form the required fin shape. The punch described in this embodiment is suitable for pre-pressing and forming of relatively thick fin strip with a thickness of 1-2 mm, which reduces the difficulty of strip pressing, improves production efficiency, and improves the quality of manufactured H-shaped flat finned tube.

[0060] The other contents of this embodiment can refer to Embodiment 1.

[0061] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application; therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

[0062] Although the terms such as strip disc 1, fin strip 2, flat base tube conveying and fixing device 3, flat base tube 4, resistance welding equipment 5, fin negative mold 6, negative mold driving device 7, welding head 8, electrode driving device 9, resistance welding electrode 10, welding transformer 11, loading roller 12, transmission mechanism 13, pressure roller 14, pressure roller driving device 15, driving roller 16, driving roller driving device 17, unloading roller 18, support 20, etc. are used more frequently in this paper, but the possibility of using other terms is not excluded; the use of these terms is only for more convenient description and explanation of the essence of the present application; any kind of additional limitation is contrary to the spirit of the present application.

Claims

1. An automated welding equipment for H-type flat finned tubes, characterized in that: Includes a support (20); a strip tray (1) arranged on the support (20); a flat base tube conveying and fixing device (3); a resistance welding equipment (5); a finned female mold (6); and a female mold driving device (7). The flat tube conveying and fixing device (3) includes a loading roller (12), a pressure roller (14), a drive roller (16) and an unloading roller (18) arranged in sequence; wherein, a pressure roller drive device (15) is connected to the pressure roller (14); a drive roller drive device (17) is installed on the bracket (20), and the drive roller (16) and the drive roller drive device (17) are connected by a transmission mechanism (13); The resistance welding equipment (5) includes a welding head (8), an electrode driving device (9), and a welding transformer (11); the welding head (8) is provided with a resistance welding electrode (10), the welding transformer (11) is fixed on the support (20), the welding transformer (11) is connected to the electrode driving device (9), and the electrode driving device (9) drives the welding head (8) to move.

2. The automated welding equipment for H-type flat finned tubes according to claim 1, characterized in that: The female mold driving device (7), electrode driving device (9), and pressure roller driving device (15) are all pneumatic cylinders.

3. The automated welding equipment for H-type flat finned tubes according to claim 1, characterized in that: The drive roller drive device (17) is driven by a motor.

4. The automated welding equipment for H-type flat finned tubes according to claim 1, characterized in that: The resistance welding electrode (10) is made of copper, and its working contact area is 10-100 mm². 2 .

5. A method of using an automated welding equipment for H-type flat finned tubes as described in any one of claims 1 to 4, characterized in that, The specific steps are as follows: Step 1: First, the flat base tube (4) is transported to the loading roller conveyor (12), and then the pressure roller (14) is driven by the pressure roller drive device (15) to fix the flat base tube (4); Step 2: Load the two rolls of finned strip (2) onto two strip reels (1) and guide them to the assembly positions on both sides of the flat base tube (4) using guides; Step 3: Using the female mold driving device (7), move the fin female mold (6) to the welding area on both sides of the flat base tube (4); Step 4: Using the electrode driving device (9), move the welding head (8) with the resistance welding electrode (10) to both sides of the flat base tube (4), press the fin strip (2) into the fin female mold (6) to form the required fin shape and contact the flat base tube (4). Step 5: The resistance welding equipment (5) is powered on, and the resistance welding electrode (10) welds the finned strip (2) to the flat base tube (4) under the action of upsetting force; Step 6: After resistance welding is completed, the electrode driving device (9) drives the welding head (8) to retract to the original position, and the fin female mold (6) is moved along the pressing and folding direction of the fin strip (2) by the female mold driving device (7) and moved out of the welding area; Step 7: The drive roller (16) moves the flat base tube (4) with a pair of finned strips (2) welded together forward by a fin spacing t under the action of the drive roller drive device (17); Step 8: Repeat steps 1 to 7 to complete the repeated forming and welding of the fin strip (2) in automatic mode to obtain the finished H-shaped flat fin tube of the required length; Step 9: Unload the finished H-shaped flat finned tube from the unloading roller conveyor (18) to complete the manufacturing process.

6. The method of using the automated welding equipment for H-type flat finned tubes according to claim 5, characterized in that: In step 4, a punch is set up to be placed in conjunction with the resistance welding electrode (10) for pre-pressing the fin strip (2). The punch material is a low friction coefficient material. After pre-pressing, the initially deformed fin strip (2) is transported to the welding area, and the resistance welding electrode (10) presses the fin strip (2) into the fin female mold (6) to form the required fin shape.

7. The method of using the automated welding equipment for H-type flat finned tubes according to claim 5, characterized in that: In step 5, when the resistance welding electrode (10) welds the finned strip (2) to the flat base tube (4) under the action of upsetting force, the welding current is 2000~20000A and the voltage is 5~20V.

8. The method of using the automated welding equipment for H-type flat finned tubes according to claim 5, characterized in that: In step 5, when the resistance welding electrode (10) welds the finned strip (2) to the flat base tube (4) under the action of upsetting force, the upsetting force is 500~5000N.

9. The method of using the automated welding equipment for H-type flat finned tubes according to claim 7, characterized in that: The finned strip (2) and the flat base tube (4) are made of carbon steel, stainless steel or aluminum alloy.

10. The method of using the automated welding equipment for H-type flat finned tubes according to claim 7, characterized in that: The finned strip (2) has a width of 50-200 mm and a thickness of 0.1-2 mm.

11. The method of using the automated welding equipment for H-type flat finned tubes according to claim 7, characterized in that: The wall thickness of the flat base tube (4) is 1 to 5 mm.

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