Automatic welding device and process for air cooler tube plate and tube

Abstract

The invention relates to the technical field of air cooler welding, in particular to an automatic welding device and process for an air cooler tube plate and a tube. The tube plate robot is movably arranged on the base, a welding machine head is arranged on the tube plate robot, and the welding machine head is used for welding a tube plate and a tube; the visual positioning camera is fixed on the tube plate robot and is positioned beside the welding machine head; the pipe plate robot welding work depends on the cooperation of the robot and the visual positioning camera, the efficiency is greatly improved, the touch locating function is achieved, the arc height and the arc starting radius can be automatically adjusted according to the actual condition of each pipe, and therefore the welding seam consistency is good; meanwhile, moving, starting and stopping of a welding head of the tube plate robot welding workstation are controlled by equipment, manual intervention is almost not needed, and the technical problems that in the prior art, shielded metal arc welding is greatly influenced by human factors, and the manual participation degree of semi-automatic tube plate tungsten electrode argon arc welding is high are solved.

Description

Technical Field

[0001] The invention relates to the technical field of air cooler welding, and in particular to an automatic welding device and process for air cooler tube sheets and tubes. Background Art

[0002] An air cooler is a heat exchanger that uses air to cool hot fluids. It is mainly composed of tube bundles, brackets and fans. In the manufacturing process of air coolers, the welding of tube sheets and plates is a key step, which directly affects the sealing, strength and overall performance of the air cooler.

[0003] Arc welding is a common method for welding tube sheets and plates. For example, the invention patent document with the authorization announcement number CN114871532B discloses a method for manual deep hole welding of heat exchange tubes and tube sheets. This method mainly uses arc welding, which includes the following steps: Step 1, opening a groove: opening a groove on the tube hole of the tube sheet and the outer wall of the end of the heat exchange tube, and aligning the groove roots on the tube sheet and the heat exchange tube to form a deep hole welding groove; Step 2, performing arc welding: the electrode extends from the wire plug hole into the deep hole welding groove, and the arc extends from the wire plug hole to weld the electrode and the deep hole welding groove; wherein, the arc welding in step 2 is a multi-pass welding. The advantages of arc welding are simple equipment, low cost, strong applicability, and flexible and convenient operation, but it also has certain shortcomings: arc welding requires high operating skills of welders, the welding quality is greatly affected by human factors, and the weld formation is relatively rough.

[0004] Another welding method is the semi-automatic tube sheet tungsten inert gas arc welding method; the steps are as follows: the gun head of the semi-automatic tube sheet welding machine is manually hung on the gantry through a spring balancer. After the welding starts, the gun head is manually inserted into the pipe mouth to be welded. After the three legs of the gun head are in contact with the tube sheet surface, the expansion plug inserted into the pipe mouth is tightened with compressed air. At this time, the welding gun is positioned, the switch is manually pressed, and the gun head rotates counterclockwise to start welding. After the welding is completed, the switch is manually pressed to release the expansion plug, and then the manual gun head is removed and inserted into the next pipe mouth, and the operation is repeated until the entire tube sheet surface is welded. The disadvantage is that the efficiency is low, and the gun head needs to be manually moved, inserted and pulled out during welding, and the manual participation is relatively high. Summary of the invention

[0005] The present invention provides an automatic welding device for air cooler tube sheets and tubes, so as to solve the technical problems in the prior art that arc welding with electrodes is greatly affected by human factors and semi-automatic tube sheet tungsten inert gas arc welding has a high degree of human involvement; the present invention also provides an automatic welding process for air cooler tube sheets and tubes.

[0006] In order to solve the above problems, the automatic welding device for air cooler tube sheet and tube provided by the present invention adopts the following technical solutions:

[0007] An automatic welding device for air cooler tube sheet and tube, comprising:

[0008] Base;

[0009] A tube sheet robot is movably arranged on a base, and has a movable welding head, which is used to weld the tube sheet and the tube;

[0010] A visual positioning camera is fixed on the tube sheet robot and located beside the welding head. The visual positioning camera is used to locate the actual position of the tube sheet and the tube, so as to send a guidance signal to the tube sheet robot for adjusting the posture position of the welding head.

[0011] The beneficial effects of the automatic welding device for air cooler tube sheet and tube provided by the present invention are:

[0012] 1) Improve efficiency: The tube sheet robot welding work relies on the cooperation of the robot and the visual positioning camera. The fastest speed can reach 55 seconds per tube mouth, and one worker can operate 3-4 tube sheet robot welding workstations at the same time, which greatly improves the welding efficiency and reduces labor costs;

[0013] 2) Stable welding quality: The parameters of the tube-to-sheet robot welding are controlled by servo motors and sensors, which can be adjusted quantitatively. It also has a touch-finding function, which can automatically adjust the arc height and arc radius according to the actual situation of each tube, so that the weld consistency is better;

[0014] 3) Low degree of manual intervention: The movement and start and stop of the welding head of the tube sheet robot welding workstation are all controlled by the equipment, and almost no manual intervention is required;

[0015] In summary, the present invention improves and upgrades the existing welding process, and effectively solves the technical problems in the prior art that arc welding with electrodes is greatly affected by human factors and that the manual participation of semi-automatic tube sheet tungsten inert gas arc welding is high.

[0016] In order to solve the above problems, the automatic welding process of air cooler tube sheet and tube provided by the present invention adopts the following technical solutions:

[0017] An automatic welding process for air cooler tube sheet and tube comprises the following steps:

[0018] S1. Grinding and cleaning: Grind and clean the tube sheet and fin tube to remove the rust and grease layer on the surface;

[0019] S2. Pipe penetration: insert the cleaned finned tube into the processing hole of the tube sheet, and the finned tube is arranged on the tube sheet surface. The outer side of the processing hole of the tube sheet is chamfered, and then the tube sheet and the finned tube are tack welded without filling wire by manual tungsten inert gas arc welding. The tack welding is performed at the 3 o'clock position in the clockwise direction, and the finned tube penetration and tack welding work of the entire tube sheet surface are completed in sequence;

[0020] S3. Positioning and placement: placing the tube sheet surface of the air cooler to be welded after the tube threading is completed on one side of the base of the tube sheet robot, so that the entire tube sheet surface is within the operating range of the tube sheet robot;

[0021] S4. Establishing a user coordinate system: operating the tube sheet robot and the tube sheet surface to establish a user coordinate system, so that the welding head of the tube sheet robot is arranged perpendicular to the tube sheet surface;

[0022] S5. Calibration parameters: set the workpiece calibration parameters of the tube sheet robot according to the needs. The workpiece calibration parameters include the tube orifice diameter, the allowable diameter deviation range, the minimum spacing between the tube orifices, and the tube orifice extension distance;

[0023] S6. Coordinate transformation: Select any two nozzles on the tube sheet surface for workpiece calibration, so that the welding head of the tube sheet robot can accurately identify the actual position of each nozzle through the camera, and transform the deviation between the actual position of each nozzle and the theoretical position in the CAD drawing into the coordinate value of the robot movement through the software, so that the robot can accurately move to the actual position of the nozzle for welding;

[0024] S7, welding simulation: select any pipe mouth, after the visual positioning camera recognizes the pipe mouth, the welding head finds the position by touch, performs simulated welding, and observes whether there is a large position deviation between the rotation center of the welding head and the center of the fin tube. If the deviation is large, adjust the position;

[0025] S8. Actual welding: Perform pipe opening welding operation, select the tube sheet robot to weld each pipe opening in turn, and the welding head welds the pipe openings in sequence under the guidance of the visual positioning camera.

[0026] The beneficial effects are: with the help of the tube sheet robot, there is no need to manually move the gun head, insert and pull out the expansion plug during welding, which reduces the degree of manual participation. The tube sheet robot welding work relies on the robot and the visual positioning camera to work together. The fastest speed can reach 55 seconds per pipe mouth, and one worker can operate 3-4 tube sheet robot welding workstations at the same time, greatly improving welding efficiency and reducing labor costs; the parameters of the tube sheet robot welding work are controlled by servo motors and sensors, which can be adjusted quantitatively, and have a touch positioning function, which can automatically adjust the arc height and arc starting radius according to the actual situation of each tube, so that the weld consistency is better.

[0027] Furthermore, in step S2, the finned tube extends out of the tube sheet surface by 7-8 mm, and a chamfer of 2±0.5 mm is formed on the outer side of the tube sheet processing hole.

[0028] Furthermore, in step S3, the tube sheet surface after the tube threading is completed is located within a range of 1-1.5 m directly in front of the base where the robot is located.

[0029] Furthermore, in step S5, the diameter of the pipe orifice is 28 mm, the allowable diameter deviation range is ±0.4 mm, the minimum spacing between the pipe orifices is 35.4 mm, and the pipe orifice extension distance is 7 mm.

[0030] Furthermore, in step S7, after the welding head touches and locates, it is rotated along the fin tube according to the set arc starting radius and arc starting height to observe whether there is a large position deviation between the rotation center of the welding head and the center of the fin tube 1.

[0031] Furthermore, the arc starting radius is R2.65mm, and the arc starting height is H1.7mm.

[0032] Further, in step S7, if the deviation is large, the position is adjusted by the "X" and "Y" values ​​of the tube sheet robot vision parameters so that the rotation center of the welding head coincides with the center of the fin tube.

[0033] The beneficial effect is that when deviations occur, the position of the welding head can be adjusted by adjusting parameters to ensure the welding effect.

[0034] Furthermore, in step S8, when performing pipe nozzle welding, first select the welding parameter interface, divide the entire pipe nozzle welding into multiple intervals, set the parameters, and then select the tube sheet robot to weld each pipe nozzle in turn, and the welding head welds the pipe nozzles in sequence under the guidance of the visual positioning camera.

[0035] Furthermore, the entire pipe mouth welding is divided into 5 intervals, namely 0-90°, 90-180°, 180-270°, 270-355°, and 355-370°. Parameters including peak current, peak time, base current, base time, peak wire feeding speed, base wire feeding speed, rotation speed, and arc height can be set for each interval to complete the parameter setting.

[0036] The beneficial effects of the automatic welding process for air cooler tube sheets and tubes provided by the present invention are:

[0037] 1) Improve efficiency: The tube sheet robot welding work relies on the cooperation of the robot and the visual positioning camera. The fastest speed can reach 55 seconds per tube mouth, and one worker can operate 3-4 tube sheet robot welding workstations at the same time, which greatly improves the welding efficiency and reduces labor costs;

[0038] 2) Stable welding quality: The parameters of the tube-to-sheet robot welding are controlled by servo motors and sensors, which can be adjusted quantitatively. It also has a touch-finding function, which can automatically adjust the arc height and arc radius according to the actual situation of each tube, so that the weld consistency is better;

[0039] 3) Low degree of manual intervention: The movement and start and stop of the welding head of the tube sheet robot welding workstation are all controlled by the equipment, and almost no manual intervention is required;

[0040] In summary, the present invention improves and upgrades the existing welding process, and effectively solves the technical problems in the prior art that arc welding with electrodes is greatly affected by human factors and that the manual participation of semi-automatic tube sheet tungsten inert gas arc welding is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0042] Figure 1 Schematic diagram of the coordination between the fin tube and the tube sheet;

[0043] Figure 2 A schematic diagram of the automatic welding device for air cooler tube sheet and tube provided by the present invention when in use;

[0044] Figure 3 A schematic diagram of the automatic welding device for air cooler tube sheet and tube provided by the present invention;

[0045] Figure 4 The present invention provides a flowchart of the automatic welding process for air cooler tube sheets and tubes.

[0046] Description of reference numerals:

[0047] 1. Fin tube; 2. Tube sheet; 3. Air cooler; 4. Tube sheet surface; 5. Base; 6. Tube sheet robot; 7. Welding head; 8. Chamfering; 9. Visual positioning camera. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0049] It should be noted that the technical concept of the present invention is to use the tube sheet robot 6, the visual positioning camera 9 and the new process designed for the welding joint to achieve three beneficial effects: 1) Improve efficiency: The welding work of the tube sheet robot 6 relies on the cooperation of the robot and the visual positioning camera 9, and the fastest speed can reach 55s per pipe mouth, and 3-4 tube sheet robot 6 welding workstations can be operated by one worker at the same time, which greatly improves the welding efficiency and reduces the labor cost; 2) Stable welding quality: The parameters of the tube sheet robot 6 welding work are controlled by the servo motor and the sensor, which can be adjusted quantitatively, and have a touch positioning function, which can automatically adjust the arc height and arc starting radius according to the actual situation of each tube, so that the weld consistency is better; 3) Low degree of manual intervention: The movement and start and stop of the welding head 7 of the tube sheet robot 6 welding workstation are all controlled by the equipment, and almost no manual intervention is required; to solve the technical problems in the prior art that the arc welding of the welding rod is greatly affected by human factors and the manual participation of the semi-automatic tube sheet tungsten inert gas arc welding is high.

[0050] After introducing the basic principle of the present invention, various non-limiting embodiments of the present invention are described in detail below. The number of any element in the drawings is for illustration and not for limitation, and any naming is only for distinction and does not have any limiting meaning.

[0051] The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0052] Embodiments of the automatic welding device for air cooler tube sheet and tube provided by the present invention:

[0053] like Figures 1 to 3 As shown, the automatic welding device for air cooler tube sheet and tube comprises a base 5, on which a tube sheet robot 6 is movably arranged, and the tube sheet robot 6 has a movable welding head 7, which is used to weld the tube sheet 2 and the tube.

[0054] Based on the above structure, there is also a visual positioning camera 9, which is fixed on the tube sheet robot 6 and located next to the welding head 7. The visual positioning camera 9 is used to locate the actual position of the tube sheet 2 and the tube, so as to send a guidance signal to the tube sheet robot 6 for adjusting the posture position of the welding head 7.

[0055] Embodiment of the automatic welding process for air cooler tube sheet and tube provided by the present invention:

[0056] An automatic welding process for air cooler tube sheet and tube comprises the following steps:

[0057] S1. Grinding and cleaning: Grind and clean the tube sheet 2 and the fin tube 1 to remove the rust and grease layer on the surface. The fin tube 1 is the tube mentioned in the title.

[0058] S2, tube insertion: insert the cleaned fin tube 1 into the processing hole of the tube sheet 2, the fin tube 1 extends out of the tube sheet surface 4, and a chamfer 8 is provided on the outer side of the processing hole of the tube sheet 2, and then the tube sheet 2 and the fin tube 1 are tack welded without filling wire by manual tungsten inert gas arc welding, and the tack welding is performed at the 3 o'clock position in the clockwise direction, and the fin tube 1 and tack welding work of the entire tube sheet surface 4 are completed in sequence;

[0059] S3, positioning and placing: placing the tube sheet surface 4 of the air cooler 3 to be welded after the tube threading is completed on one side of the base 5 where the tube sheet robot 6 is located, so that the entire tube sheet surface 4 is within the operating range of the tube sheet robot 6;

[0060] S4, establishing a user coordinate system: operating the tube sheet robot 6 and the tube sheet surface 4 to establish a user coordinate system, so that the welding head 7 of the tube sheet robot 6 is arranged perpendicular to the tube sheet surface 4;

[0061] S5, calibration parameters: setting the workpiece calibration parameters of the tube sheet robot 6 as needed, the workpiece calibration parameters including the tube orifice diameter, the allowable diameter deviation range, the minimum spacing between the tube orifices, and the tube orifice extension distance;

[0062] S6, coordinate conversion: select any two nozzles on the tube sheet surface 4 for workpiece calibration, so that the welding head 7 of the tube sheet robot 6 can accurately identify the actual position of each nozzle through the camera, and convert the deviation between the actual position of each nozzle and the theoretical position in the CAD drawing into the coordinate value of the robot movement through the software, so that the robot can accurately move to the actual position of the nozzle for welding;

[0063] S7, welding simulation: select any pipe opening, and after the visual positioning camera 9 recognizes the pipe opening, the welding head 7 performs simulated welding by touching and finding the position, and observes whether there is a large position deviation between the rotation center of the welding head 7 and the center of the fin tube 1. If the deviation is large, adjust the position;

[0064] S8, actual welding: perform pipe opening welding operation, select the tube sheet robot 6 to weld each pipe opening in turn, and the welding head 7 welds the pipe openings in sequence under the guidance of the visual positioning camera 9.

[0065] With the help of the tube sheet robot 6, it is no longer necessary to manually move the gun head, insert and remove the expansion plug during welding, which reduces the degree of manual participation. The welding work of the tube sheet robot 6 relies on the cooperation of the robot and the visual positioning camera 9. The fastest speed can reach 55 seconds per pipe mouth, and 3-4 tube sheet robot 6 welding workstations can be operated by one worker at the same time, which greatly improves welding efficiency and reduces labor costs; the parameters of the tube sheet robot 6 welding work are controlled by servo motors and sensors, which can be adjusted quantitatively, and have a touch positioning function, which can automatically adjust the arc height and arc starting radius according to the actual situation of each tube, so that the weld consistency is better.

[0066] Specifically, in step S2, the finned tube 1 extends 7-8 mm from the tube sheet surface, and a 2±0.5 mm chamfer 8 is formed on the outer side of the tube sheet processing hole. In step S3, the tube sheet surface 4 after the tube is threaded is located within 1-1.5 m in front of the base 5 where the robot is located.

[0067] In step S5, the diameter of the pipe opening is 28 mm, the allowable diameter deviation range is ±0.4 mm, the minimum spacing between the pipe openings is 35.4 mm, and the pipe opening extension distance is 7 mm.

[0068] In step S7, after the welding head 7 touches and locates, it rotates along the fin tube 1 according to the set arc starting radius and arc starting height to observe whether there is a large position deviation between the rotation center of the welding head 7 and the center of the fin tube 11. Specifically, the arc starting radius is R2.65mm and the arc starting height is H1.7mm.

[0069] In addition, in step S7, if the deviation is large, the position is adjusted by the "X" and "Y" values ​​of the visual parameters of the tube sheet robot 6 so that the rotation center of the welding head 7 coincides with the center of the fin tube 1. When a deviation occurs, the position of the welding head 7 can also be adjusted by adjusting the parameters to ensure the welding effect.

[0070] It is best to have, in step S8, when performing pipe nozzle welding, first select the welding parameter interface, divide the entire pipe nozzle welding into multiple intervals, set the parameters, and then select the tube sheet robot 6 to weld each pipe nozzle in turn, and the welding head 7 welds the pipe nozzles in sequence under the guidance of the visual positioning camera 9.

[0071] Specifically, the entire pipe mouth welding is divided into 5 intervals, namely 0-90°, 90-180°, 180-270°, 270-355°, and 355-370°. Parameters including peak current, peak time, base current, base time, peak wire feeding speed, base wire feeding speed, rotation speed, and arc height can be set for each interval to complete the parameter setting.

[0072] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "width", "horizontal", "top", "bottom", "inside", "outside" and the like, which indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings of this specification, and are only for the purpose of facilitating the explanation of the scheme of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or elements involved must have the specific orientation, be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of the present invention.

[0073] In addition, in the description of this specification, “plurality” means at least two, for example, two, three or more, etc., unless otherwise clearly and specifically defined.

Claims

1. An automatic welding device for air cooler tube sheet and tube, characterized in that: include: Base; A tube sheet robot is movably arranged on a base, and has a movable welding head, which is used to weld the tube sheet and the tube; A visual positioning camera is fixed on the tube sheet robot and located beside the welding head. The visual positioning camera is used to locate the actual position of the tube sheet and the tube, so as to send a guidance signal to the tube sheet robot for adjusting the posture position of the welding head.

2. An automatic welding process for air cooler tube sheet and tube, characterized in that: The steps include: S1. Grinding and cleaning: Grind and clean the tube sheet and fin tube to remove the rust and grease layer on the surface; S2. Pipe penetration: insert the cleaned finned tube into the processing hole of the tube sheet, and the finned tube is arranged on the tube sheet surface. The outer side of the processing hole of the tube sheet is chamfered, and then the tube sheet and the finned tube are tack welded without filling wire by manual tungsten inert gas arc welding. The tack welding is performed at the 3 o'clock position in the clockwise direction, and the finned tube penetration and tack welding work of the entire tube sheet surface are completed in sequence; S3. Positioning and placement: placing the tube sheet surface of the air cooler to be welded after the tube threading is completed on one side of the base of the tube sheet robot, so that the entire tube sheet surface is within the operating range of the tube sheet robot; S4. Establishing a user coordinate system: operating the tube sheet robot and the tube sheet surface to establish a user coordinate system, so that the welding head of the tube sheet robot is arranged perpendicular to the tube sheet surface; S5. Calibration parameters: set the workpiece calibration parameters of the tube sheet robot according to the needs. The workpiece calibration parameters include the tube orifice diameter, the allowable diameter deviation range, the minimum spacing between the tube orifices, and the tube orifice extension distance; S6. Coordinate transformation: Select any two nozzles on the tube sheet surface for workpiece calibration, so that the welding head of the tube sheet robot can accurately identify the actual position of each nozzle through the camera, and transform the deviation between the actual position of each nozzle and the theoretical position in the CAD drawing into the coordinate value of the robot movement through the software, so that the robot can accurately move to the actual position of the nozzle for welding; S7, welding simulation: select any pipe mouth, after the visual positioning camera recognizes the pipe mouth, the welding head finds the position by touch, performs simulated welding, and observes whether there is a large position deviation between the rotation center of the welding head and the center of the fin tube. If the deviation is large, adjust the position; S8, actual welding: perform pipe opening welding operation, select the tube sheet robot to weld each pipe opening in turn, and the welding head welds the pipe openings in sequence under the guidance of the visual positioning camera; In step S7, if the deviation is large, the position is adjusted by the "X" and "Y" values ​​of the tube sheet robot vision parameters so that the rotation center of the welding head coincides with the center of the fin tube; In step S8, when the pipe nozzle welding is performed, the welding parameter interface is first selected, the entire pipe nozzle welding is divided into multiple intervals, and the parameters are set. Then, the tube sheet robot is selected to weld each pipe nozzle in turn, and the welding head welds the pipe nozzles in sequence under the guidance of the visual positioning camera; The entire pipe mouth welding is divided into 5 intervals, namely 0-90°, 90-180°, 180-270°, 270-355°, and 355-370°. Parameters including peak current, peak time, base current, base time, peak wire feeding speed, base wire feeding speed, rotation speed, and arc height can be set for each interval to complete the parameter setting.

3. The automatic welding process for air cooler tube sheet and tube according to claim 2 is characterized in that: In step S2, the finned tube extends 7-8 mm beyond the tube sheet surface, and a chamfer of 2±0.5 mm is formed on the outer side of the tube sheet processing hole.

4. The automatic welding process for air cooler tube sheet and tube according to claim 3 is characterized in that: In step S3, the tube plate surface after the tube threading is completed is located within a range of 1-1.5 m in front of the base where the robot is located.

5. The automatic welding process for air cooler tube sheet and tube according to claim 4 is characterized in that: In step S5, the diameter of the pipe opening is 28 mm, the allowable diameter deviation range is ±0.4 mm, the minimum spacing between the pipe openings is 35.4 mm, and the pipe opening extension distance is 7 mm.

6. The automatic welding process for air cooler tube sheet and tube according to claim 5 is characterized in that: In step S7, after the welding head touches and locates, it is rotated along the fin tube according to the set arc starting radius and arc starting height to observe whether there is a large position deviation between the rotation center of the welding head and the center of the fin tube 1.

7. The automatic welding process for air cooler tube sheet and tube according to claim 6 is characterized in that: The arc starting radius is R2.65mm and the arc starting height is H1.7mm.

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