Flame heating method for welding seam of thick plate winding drum

Abstract

The invention relates to a flame heating method for welding a welding seam of a thick plate winding drum in the technical field of crane manufacturing, which comprises the following steps of: 1, placing the winding drum on a welding equipment workbench, and adjusting the position of the winding drum to enable the welding seam to be positioned right above; secondly, according to the length of the winding drum, a plurality of flame guns are arranged on a top frame of flame heating equipment, and then the flame heating equipment is horizontally placed in an inner cavity of the winding drum in a centering mode; thirdly, the height of the top frame is adjusted through an adjusting device of the flame heating equipment, so that the distance between the inner top wall of the winding drum and a flame gun is a specific height; the multiple flame guns are arranged at specific transverse and longitudinal intervals, the top frame longitudinally reciprocates in the winding drum, a heat diffusion area is formed, it is ensured that the temperature distribution is more uniform in the preheating and post-heat treatment process of the winding drum weld joint area, and the heat dissipation efficiency is improved. And the welding quality problem caused by local overheating or insufficient heating can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of crane manufacturing, in particular to a flame heating method for welding a thick plate drum weld. Background Art

[0002] The drum is a key load-bearing component in lifting and transporting machinery. The welded drum has light weight, strong bearing capacity and obvious performance advantages. Therefore, most of the drums of current large-scale lifting and transporting equipment use welded drums.

[0003] The welding quality has a vital impact on the safety performance of lifting machinery and the service life of the equipment. For the welding of thick plate rolls in a low temperature environment, preheating is required during the welding process to ensure the welding quality.

[0004] At present, the commonly used heating methods for large welding coils during welding are flame heating and far infrared heating. The existing flame heating method is: a fixed frame is used to clamp the drying gun, the heating point is fixed, and the temperature of the heating area is uneven.

[0005] Therefore, we designed a flame heating method for welding thick plate roll welds. Summary of the invention

[0006] In order to overcome the deficiencies in the background technology, the present invention discloses a flame heating method for welding thick plate roll welds.

[0007] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme: A flame heating method for welding thick plate coil welds comprises the following steps: Step 1: Place the reel on the welding equipment workbench and adjust the reel position so that the weld is directly above; Step 2: According to the length of the roll, multiple flame guns are arranged on the top frame of the flame heating device with a horizontal spacing W of 160-180 mm and a vertical spacing L of 450-500 mm, and then the flame heating device is placed horizontally and centered in the inner cavity of the roll; Step 3: Adjust the height of the top frame through the adjustment device of the flame heating equipment so that the height H between the top wall of the roll and the flame gun is 145~155mm; Step 4: Ignite the flame gun and start the driving device of the flame heating device, and the driving device drives the top frame to move back and forth longitudinally within the moving stroke S, where S=LL / 10mm; Step 5: When the temperature of the welding area of ​​the workpiece reaches the specified preheating temperature T_1, the welding operation is started until it is completed, wherein during the welding process, the temperature of the welding area of ​​the workpiece is between the specified preheating temperature T_1 and the welding interlayer temperature T_2; Step 6: Adjust the gas flow rate of the flame gun so that the temperature of the welding area of ​​the workpiece quickly rises to the predetermined post-weld dehydrogenation heat treatment temperature T_3 and maintains it for a predetermined time t; Step 7: Turn off the flame gun and flame heating equipment, cover the weld area with asbestos cloth to keep it warm and cool it slowly to room temperature.

[0008] Preferably, the prescribed preheating temperature T_1 is 80-120°C.

[0009] Preferably, the predetermined post-weld dehydrogenation heat treatment temperature T_3 is 250-300°C.

[0010] Preferably, the predetermined time t=30+k(D-20) min, wherein k is a constant ranging from 1.8 to 2.2, and D is the wall thickness of the roll.

[0011] Preferably, the temperature of the welding area of ​​the workpiece in step five and step six is ​​monitored in real time by an infrared thermometer arranged on the top frame.

[0012] Preferably, the flame heating device comprises: A bottom frame, used to be placed horizontally in the inner cavity of the reel to be welded; An intermediate frame is longitudinally movably disposed on top of the bottom frame; A driving device, arranged on the bottom frame, for driving the middle frame to move back and forth; A sliding fit structure is provided between the bottom frame and the middle frame to ensure the stability and sliding performance of the middle frame; A top frame, which is located above the middle frame and can be adjusted in height by an adjustment device; Multiple flame guns are arranged at equal intervals on both sides of the top frame to heat the roll with flames; Infrared thermometer, mounted on the top frame, to monitor temperature.

[0013] Preferably, support cross bars are provided near both ends of the bottom surface of the bottom frame to accommodate coil welding operations of different diameters; The supporting cross bar comprises a fixed sleeve and a movable insert rod, wherein the movable insert rod is axially movably inserted in the fixed sleeve and is locked in position by a locking bolt.

[0014] Preferably, the driving device comprises a reduction motor installed on the bottom frame, a radial rotating rod arranged on the output shaft of the reduction motor, a rotating shaft and a bar frame arranged at the end of the radial rotating rod, the bar frame is correspondingly connected to the middle frame, and the inner cavity and the shaft body of the rotating shaft are movably matched, so that the reduction motor drives the radial rotating rod to rotate, thereby driving the rotating shaft to move along the circumference, so that the bar frame reciprocates or swings, and realizes the reciprocating movement of the middle frame; The strip frame is vertically arranged and fixedly connected to the middle frame. Alternatively, one end of the strip frame is correspondingly hinged to the bottom frame, and is movably connected to the middle frame via a movable shaft penetrating through its inner cavity.

[0015] Preferably, the adjusting device comprises a screw rod and a pressing nut, wherein the lower end of the screw rod is fixed to the middle frame and the upper end thereof passes through the top frame, and the pressing nut is located below the top frame and cooperates with the screw rod thread.

[0016] Preferably, the infrared thermometer is located in the middle of two flame guns adjacent to each other in the longitudinal direction.

[0017] Due to the adoption of the above-mentioned technical solution, the present invention has the following beneficial effects: 1. Multiple flame guns are arranged at specific horizontal and vertical intervals, and the top frame is moved back and forth longitudinally in the roll to form a heat diffusion zone, which ensures that the temperature distribution of the roll weld area is more uniform during preheating and post-heat treatment, helping to reduce welding quality problems caused by local overheating or insufficient heating; 2. Use infrared thermometer to monitor the temperature of the welding area of ​​the workpiece in real time, and adjust the gas flow of the flame gun according to the actual situation, so as to achieve accurate control of the temperature of the welding area of ​​the workpiece, ensure that the temperature conditions during the welding process meet the requirements, and improve the welding quality; 3. The setting of the supporting cross bar enables the flame heating equipment to be suitable for coil welding operations of different diameters and sizes, which not only increases the application range of the equipment, but also improves the flexibility and convenience of operation.

[0018] 4. The design of the sliding fit structure ensures the stability of the middle frame during movement. At the same time, the height of the top frame can be accurately adjusted through the adjustment device to meet the needs of different welding positions. These features work together to ensure the smooth and reliable operation of the flame heating equipment during the entire heating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the flame heating device in the present invention; Figure 2 This is a front view of the flame heating device of the present invention when in use; Figure 3 It is a partial assembly diagram of the bottom frame, the middle frame and the driving device in the present invention; Figure 4 for Figure 3 Right view of; Figure 5 It is a partial assembly schematic diagram of another structure of the bottom frame, the middle frame and the driving device in the present invention.

[0020] In the figure: 1. bottom frame; 2. supporting cross bar; 21. fixed sleeve; 22. movable plug rod; 23. locking bolt; 3. middle frame; 4. driving device; 41. reduction motor; 42. radial rotating rod; 43. rotating shaft; 44. bar frame; 45. movable shaft; 5. sliding fit structure; 51. linear slide; 52. roller; 6. top frame; 7. adjusting device; 71. screw; 72. top pressure nut; 8. flame gun; 9. infrared thermometer. DETAILED DESCRIPTION

[0021] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", etc. indicating directions or positional relationships, they only correspond to the drawings of the present application and are for the convenience of describing the present invention; it should be understood that if there are terms such as "end", "side", "end portion", "lateral", "lateral", "transverse", "longitudinal", etc. indicating directions or positional relationships, they only correspond to the length and width of the corresponding components, that is, the "end portion" indicates the head and tail areas in the length direction of the corresponding component, and the "side portion" indicates the head and tail areas in the width direction of the corresponding component; this is for the convenience of describing the present invention and is not to indicate or imply that the device or element referred to must have a specific direction.

[0022] Embodiment 1, in combination with the attached Figure 1-5 A flame heating method for welding thick plate roll welds comprises the following steps: Step 1: Place the reel on the welding equipment workbench and adjust the reel position so that the weld is directly above.

[0023] Step 2: According to the length of the roll, multiple flame guns 8 are arranged on the top frame 6 of the flame heating device with a horizontal spacing W of 160-180 mm and a vertical spacing L of 450-500 mm, and then the flame heating device is placed horizontally and centered in the inner cavity of the roll; That is to say, the flame guns 8 have two rows and multiple columns, the distance between the flame guns 8 in two rows is 160-180 mm, and the distance between two flame guns 8 in adjacent columns in the same row is 450-500 mm; specifically, the number of flame guns 8 in each row is related to the length of the roll, so the number of flame guns 8 in each row is not specifically limited.

[0024] It should be noted that the flame heating device is placed horizontally and centered in the inner cavity of the roll, which can be understood as: the center of the flame heating device and the center of the roll are located on the same vertical line. At this time, the horizontal distance between the flame gun 8 and the weld is 80-90 mm.

[0025] In order to lower the height of the flame heating equipment, or to better adapt to rolls of different diameters, a supporting cross bar 2 that can be axially extended and retracted is laterally provided across the bottom of the flame heating equipment; by extending and retracting the supporting cross bar 2, rolls of different diameters can be used so that the bottom of the flame heating equipment is as close to the horizontal diameter of the roll as possible; that is to say, the height of the flame heating equipment in the inner cavity of the roll can be increased as much as possible.

[0026] Furthermore, the supporting cross bar 2 includes a fixed sleeve 21 installed on the bottom surface of the bottom frame 1, and movable insertion rods 22 are axially movably inserted at both ends of the fixed sleeve 21; wherein, a locking bolt 23 is screwed at the end of the fixed sleeve 21, and the movable insertion rod 22 is squeezed by the locking bolt 23 to lock the axial position of the movable insertion rod 22.

[0027] Step 3: Adjust the height of the top frame 6 by means of the adjusting device 7 of the flame heating device so that the height H between the top wall of the roll and the flame gun 8 is 145-155 mm; Furthermore, since the top frame 6 needs to move back and forth longitudinally, the flame heating device is also provided with an intermediate frame 3 vertically movably matched with the top frame 6, and the height of the top frame 6 is adjusted through the intermediate frame 3; Specifically, the middle frame 3 has an adjusting device 7 for adjusting the height of the top frame 6 .

[0028] In a possible implementation, the adjusting device 7 may be a jack.

[0029] In a possible implementation, the adjusting device 7 may be a screw rod 71 rotatably connected to the middle frame 3 at the lower end, and the shaft of the screw rod 71 passes through the top frame 6 and is threadedly engaged with the top frame 6 .

[0030] In a possible implementation, Figure 2 The adjusting device 7 can be a screw rod 71 whose lower end is fixedly connected to the middle frame 3 , the rod body of the screw rod 71 passes through the top frame 6 , and a top pressing nut 72 is provided at a position of the rod body of the screw rod 71 below the top frame 6 .

[0031] As required, at least three adjusting devices 7 are provided. When there are three adjusting devices 7 , they are distributed in a triangular shape to ensure the stability of the top frame 6 . When there are four adjusting devices 7 , they are distributed in a rectangular shape.

[0032] Step 4: Ignite the flame gun 8 and start the driving device 4 of the flame heating device. The driving device 4 drives the top frame 6 to move back and forth longitudinally within the moving stroke S, wherein S=LL / 10mm. With this arrangement, in the longitudinal direction, the area with L / 10mm between the two flame guns 8 is an area that is not directly heated by the flame gun 8, i.e., a heat diffusion zone. After the flame gun 8 moves to the extreme position, it is necessary to change the moving direction, so that the drum is heated longer at this position than at other positions, which easily leads to a temperature higher than the welding interlayer temperature T_2. The existence of the heat diffusion zone can absorb the heat at this position, thereby ensuring that the temperature of the workpiece welding area is balanced, and preventing the temperature at this position from being higher than the welding interlayer temperature T_2 and affecting the welding quality.

[0033] Furthermore, the driving device 4 drives the middle frame 3 to move back and forth longitudinally, thereby driving the top frame 6 to move back and forth longitudinally.

[0034] Furthermore, in combination with Figure 3-5 The driving device 4 includes a reduction motor 41, and a radial rotating rod 42 is installed on the output shaft of the reduction motor 41. A rotating shaft 43 is provided at one end of the radial rotating rod 42. The rotating shaft 43 is matched with a bar frame 44, wherein the bar frame 44 is correspondingly connected to the middle frame 3. Specifically, the rotating shaft 43 is matched with the inner cavity of the bar frame 44, and more specifically, the rotating shaft 43 can move along the length direction of the bar frame 44. Specifically, the central axis direction of the output shaft of the reduction motor 41 is perpendicular to the moving direction of the middle frame 3. Preferably, the central axis direction of the output shaft of the reduction motor 41 is horizontal.

[0035] In a possible implementation, Figure 5 , the bar frame 44 is fixedly connected to the middle frame 3; that is, the operation of the reduction motor 41 can drive the radial rotating rod 42 to rotate, and then drive the rotating shaft 43 to move in a circle along the output shaft of the reduction motor 41, and then the rotating shaft 43 drives the bar frame 44 to move back and forth, thereby realizing the function of driving the middle frame 3 to move back and forth.

[0036] In another possible embodiment, Figure 3-4 , one end of the bar frame 44 is correspondingly connected and hinged to the bottom frame 1, and the middle frame 3 is provided with a movable shaft 45 inserted into the inner cavity of the bar frame 44, that is, the operation of the reduction motor 41 can drive the radial rotation rod 42 to rotate, and then drive the rotation shaft 43 to move in a circle along the output shaft of the reduction motor 41, and then the rotation drives the bar frame 44 to swing back and forth, and then drives the movable shaft 45 to move back and forth, realizing the function of driving the middle frame 3 to move back and forth. In this embodiment, the rotation center of the bar frame 44 and the output shaft of the reduction motor 41 are on the same vertical plane.

[0037] In order to reduce the length of the radial rotating rod 42 , the rotation center of the bar frame 44 and the movable axis 45 are respectively located on both sides of the rotating shaft 43 .

[0038] As needed, a sliding fit structure 5 is provided between the bottom of the middle frame 3 and the top of the bottom frame 1; further, the sliding fit structure 5 can be a slide rail pair in the prior art, or it can be a linear slide groove 51 provided on the top surface of the bottom frame 1 and a roller 52 provided on the bottom surface of the middle frame 3, wherein the roller 52 rolls in the groove cavity of the linear slide groove 51; wherein, at least two rollers 52 are provided on the bottom surface of the sliding fit structure 5 along its longitudinal direction.

[0039] Furthermore, in order to ensure the stability of the middle frame 3 , a sliding matching structure 5 is provided on both sides of the bottom frame 1 and the middle frame 3 .

[0040] Step 5: When the temperature of the welding area of ​​the workpiece reaches the specified preheating temperature T_1, the welding operation is started until it is completed, wherein during the welding process, the temperature of the welding area of ​​the workpiece is between the specified preheating temperature T_1 and the welding interlayer temperature T_2; In order to better control the temperature of the workpiece welding area, the infrared thermometer 9 arranged on the top frame 6 can be used to monitor the temperature of the workpiece welding area in real time, and the purpose of controlling the temperature of the workpiece welding area can be achieved by adjusting the gas flow of the flame gun 8.

[0041] As required, the infrared thermometer 9 is located in the middle of two flame guns 8 adjacent to each other in the longitudinal direction.

[0042] Furthermore, the preheating temperature T_1 is specified to be 80-120° C.; specifically, the preheating temperature T_1 is related to the ambient temperature, the thickness of the thick plate and the material of the thick plate, and is not specifically limited here.

[0043] In the example, when the ambient temperature is -5℃, the thick plate material is Q355C, the thick plate thickness is 25mm, and the specified preheating temperature is 80℃; when the ambient temperature is 10℃, the thick plate material is 35# steel, the thick plate thickness is 42mm, and the specified preheating temperature is 100℃; when the ambient temperature is 20℃, the thick plate material is Q690B, the thick plate thickness is 60mm, and the specified preheating temperature is 120℃.

[0044] It should be noted that the welding interlayer temperature T_2 is 230°C.

[0045] In this step, in order to prevent the temperature of the workpiece welding area from being lower than the specified preheating temperature T_1 or higher than the welding interlayer temperature T_2, it is necessary to adjust the gas flow of the flame gun 8. The specific adjustment method is: when the temperature of the workpiece welding area is in an ascending state and the temperature of the workpiece welding area is higher than T_2-(T_2- T_1) / 5°C, reduce the gas flow of the flame gun 8 to achieve the purpose of lowering the temperature of the workpiece welding area; when the temperature of the workpiece welding area is in a descending state and the temperature of the workpiece welding area is lower than T_1+(T_2- T_1) / 5°C, increase the gas flow of the flame gun 8 to achieve the purpose of raising the temperature of the workpiece welding area.

[0046] For ease of understanding, take the ambient temperature of -5°C, the thick plate material is Q355C, and the thick plate thickness is 25mm as an example. When the temperature of the workpiece welding area is in the process of rising, the temperature of the workpiece welding area is higher than 200°C, the gas flow of the flame gun 8 is reduced. When the temperature of the workpiece welding area is in the process of falling, the temperature of the workpiece welding area is lower than 110°C, the gas flow of the flame gun 8 is increased.

[0047] Step 6: Adjust the gas flow of the flame gun 8 so that the temperature of the workpiece welding area quickly rises to the predetermined post-weld dehydrogenation heat treatment temperature T_3 and maintains it for a predetermined time t; as required, the predetermined post-weld dehydrogenation heat treatment temperature T_3 is 250~300℃.

[0048] Furthermore, the predetermined time t=30+k(D-20)min, wherein k is a constant ranging from 1.8 to 2.2, and D is the wall thickness of the roll.

[0049] In order to better control the temperature of the workpiece welding area, the infrared thermometer 9 arranged on the top frame 6 can be used to monitor the temperature of the workpiece welding area in real time, and the purpose of controlling the temperature of the workpiece welding area can be achieved by adjusting the gas flow of the flame gun 8.

[0050] The specific method of adjusting the gas flow rate of the flame gun 8 is: when the temperature of the workpiece welding area is in an ascending state, the temperature of the workpiece welding area is higher than T_3 upper limit - (T_3 upper limit - T_3 lower limit) / 5°C, that is, when the temperature of the workpiece welding area is higher than 290°C, reduce the gas flow rate of the flame gun 8 to achieve the purpose of lowering the temperature of the workpiece welding area; when the temperature of the workpiece welding area is in a descending state, the temperature of the workpiece welding area is lower than T_3 lower limit + (T_3 upper limit - T_3 lower limit) / 5°C, that is, when the temperature of the workpiece welding area is lower than 260°C, increase the gas flow rate of the flame gun 8 to achieve the purpose of raising the temperature of the workpiece welding area.

[0051] Step 7: Turn off the flame gun 8 and the flame heating device, cover the weld area with asbestos cloth to keep it warm and slowly cool it down to room temperature; The flame heating device further comprises a bottom frame 1 , and two supporting cross bars 2 are arranged at two ends of the bottom of the bottom frame 1 .

[0052] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and it is intended that all changes that fall within the meaning and scope of equivalent elements are included in the present invention.

Claims

1. A flame heating method for welding thick plate coil welds, characterized in that: The following steps are involved: Step 1: Place the reel on the welding equipment workbench and adjust the reel position so that the weld is directly above; Step 2: according to the length of the roll, a plurality of flame guns (8) are arranged on the top frame (6) of the flame heating device in a manner such that the horizontal spacing W is 160-180 mm and the vertical spacing L is 450-500 mm, and then the flame heating device is horizontally and centrally placed in the inner cavity of the roll; Step 3: adjusting the height of the top frame (6) by means of the adjusting device (7) of the flame heating device so that the height H between the top wall of the roll and the flame gun (8) is 145-155 mm; Step 4: Ignite the flame gun (8) and start the driving device (4) of the flame heating device, the driving device (4) drives the top frame (6) to move back and forth longitudinally within a moving stroke S, where S=LL / 10mm; Step 5: When the temperature of the welding area of ​​the workpiece reaches the specified preheating temperature T_1, the welding operation is started until it is completed, wherein during the welding process, the temperature of the welding area of ​​the workpiece is between the specified preheating temperature T_1 and the welding interlayer temperature T_2; Step 6: Adjust the gas flow rate of the flame gun (8) so that the temperature of the welding area of ​​the workpiece rises rapidly to a predetermined post-weld dehydrogenation heat treatment temperature T_3 and is maintained for a predetermined time t; Step 7: Turn off the flame gun (8) and the flame heating equipment, cover the weld area with asbestos cloth to keep it warm and slowly cool it to room temperature.

2. The flame heating method for welding thick plate drum weld according to claim 1 is characterized in that: The prescribed preheating temperature T_1 is 80~120°C.

3. The flame heating method for welding thick plate drum weld according to claim 1, characterized in that: The predetermined post-weld dehydrogenation heat treatment temperature T_3 is 250~300°C.

4. The flame heating method for welding thick plate drum weld according to claim 1 is characterized in that: The predetermined time t=30+k(D-20)min, wherein k is a constant of 1.8-2.2, and D is the wall thickness of the roll.

5. The flame heating method for welding thick plate drum weld according to claim 1, characterized in that: The temperature of the welding area of ​​the workpiece in step five and step six is ​​monitored in real time by an infrared thermometer (9) arranged on the top frame (6).

6. The flame heating method for welding thick plate drum weld according to claim 1, characterized in that: The flame heating device comprises: A bottom frame (1) is used to be placed horizontally in the inner cavity of the reel to be welded; An intermediate frame (3) is disposed on the top of the bottom frame (1) in a longitudinally movable manner; A driving device (4) is provided on the bottom frame (1) and is used to drive the middle frame (3) to move back and forth; A sliding matching structure (5) is provided between the bottom frame (1) and the middle frame (3) and is used to ensure the stability and sliding performance of the middle frame (3); A top frame (6) located above the middle frame (3) and having a height adjustable by an adjustment device (7); A plurality of flame guns (8) are arranged at equal intervals on both sides of the top frame (6) for performing flame heating on the roll; An infrared thermometer (9) is mounted on the top frame (6) to monitor the temperature.

7. The flame heating method for welding thick plate drum weld according to claim 6, characterized in that: The bottom surface of the bottom frame (1) is provided with supporting cross bars (2) near both ends to accommodate welding operations of coils with different diameters; The supporting crossbar (2) comprises a fixed sleeve (21) and a movable insertion rod (22); the movable insertion rod (22) is axially movably inserted into the fixed sleeve (21) and is locked in position by a locking bolt (23).

8. The flame heating method for welding thick plate drum weld according to claim 6, characterized in that: The driving device (4) comprises a reduction motor (41) mounted on the bottom frame (1), a radial rotating rod (42) arranged on the output shaft of the reduction motor (41), a rotating shaft (43) arranged at the end of the radial rotating rod (42), and a strip frame (44); the strip frame (44) is correspondingly connected to the middle frame (3), and the inner cavity and the shaft body of the rotating shaft (43) are movably matched, so that the reduction motor (41) drives the radial rotating rod (42) to rotate, thereby driving the rotating shaft (43) to move in a circle, so that the strip frame (44) reciprocates or swings, thereby realizing the reciprocating movement of the middle frame (3); The strip frame (44) is arranged vertically and fixedly connected to the middle frame (3). Alternatively, one end of the strip frame (44) is hinged to the bottom frame (1) and is movably connected to the middle frame (3) via a movable shaft (45) that passes through its inner cavity.

9. The flame heating method for welding thick plate drum weld according to claim 6, characterized in that: The adjusting device (7) comprises a screw rod (71) and a pressing nut (72); the lower end of the screw rod (71) is fixedly connected to the middle frame (3) and the upper end passes through the top frame (6); the pressing nut (72) is located below the top frame (6) and is threadably matched with the screw rod (71).

10. The flame heating method for welding thick plate drum weld according to claim 6, characterized in that: The infrared thermometer (9) is located in the middle of two flame guns (8) adjacent to each other in the longitudinal direction.

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