Device and method for assisting deformation elimination of single-edgefold invar strake

Abstract

The invention relates to the technical field of ship building, in particular to a device and method for assisting in eliminating deformation of a single-folded-edge invar strake, the device comprises a supporting frame, a connecting device used for clamping a clamping tongue is arranged on the lower portion of the supporting frame, an adjusting device is arranged at one end of the supporting frame, the connecting device is hinged to the supporting frame, and the adjusting device is connected with the supporting frame. A connecting block is arranged on the side face of the supporting frame, a connecting column is arranged on the side face of the connecting block, a connecting rod is detachably arranged on the connecting column, a plurality of crimping rods are arranged at the other end of the connecting rod, and when the single-folded-edge invar strake is formally welded, a segmented short welding and back welding process is adopted to assist in eliminating deformation. According to the device and the method, the angle between the connecting rod and the supporting frame can be changed, so that the crimping rod directly acts on the deformation position, through the synergistic effect of mechanical pre-pressing, uniform stress distribution and segmented back welding, the welding deformation of the thin plate is effectively controlled, and the quality and the dimensional precision of a welding seam are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shipbuilding, in particular to a device for assisting single-folded Invar plate in eliminating deformation and a method thereof. BACKGROUND

[0002] Invar steel is a nickel-iron alloy known for its extremely low coefficient of thermal expansion, which can maintain dimensional stability within a wide temperature range. However, its ultra-thin thickness (usually only 0.5-1.5 mm) makes it extremely sensitive to welding heat input. During welding, it is prone to deformation, warping, and even cracking due to temperature changes. In the application of LNG ship liquid cargo tanks, Invar steel needs to withstand the extremely low temperature environment of -163℃ of liquefied natural gas, so the requirement for welding quality is 100% defect-free. Otherwise, any small leakage may cause serious safety accidents.

[0003] In the LNG ship liquid cargo tank structure, Invar plates are connected to the composite beam of the insulation tank through single-folded edge design. However, due to the relatively long length of the Invar plate, local heat input during welding will cause thermal stress concentration in the folded edge area, thereby causing deformation problems such as arching and warping, making it difficult to achieve "zero gap" tight fit between them, which seriously affects the sealing performance.

[0004] Traditional welding methods usually rely on manual pressing. However, due to the poor rigidity and easy deformation of Invar steel thin plates, uneven external force application can easily lead to local stress concentration or secondary deformation. In Chinese patent document CN 113955046 A, a deformation control device and welding method suitable for LNG ship liquid cargo tank lap plates are disclosed. When fixing the connecting rod, the fixed ends at both ends need to be connected to the clasp. In terms of application scope, it is only applicable to positions where the clasp is present on both sides of the welding area, which can achieve the best use effect. However, in the welding of single-folded Invar plates, the place that needs to be welded is parallel to the extension direction of the clasp. If the technical solution in the disclosed document is used, the range of pressing is relatively limited, and the pressing position needs to be frequently moved during welding, which is cumbersome to operate, especially at the junction of the two inner walls, where there is only one clasp that needs to be welded. The existing technology cannot be used for pressing. If the pressing at the deformation site is not in place, it not only cannot meet the welding requirements and affect the welding quality, but also significantly increases the cost of later repair. SUMMARY

[0005] The present application aims to overcome the shortcomings of single-folded Invar plate arching deformation in the prior art, and provides a device for assisting single-folded Invar plate in eliminating deformation and a method thereof, which aims to eliminate the disadvantages of insufficient connection points during welding.

[0006] The application is realized by the technical scheme that the device for eliminating deformation of the single-folded edge Invar plate is used in the LNG ship liquid cargo tank structure, the Invar plate is connected with the composite beam of the insulation tank through the single-folded edge design, the edge of the Invar plate is provided with a clamping tongue, the device comprises a support frame, the lower part of the support frame is provided with a connecting device for clamping the clamping tongue, and the connecting device is hinged to the support frame; One end of the support frame is provided with an adjusting device, the adjusting device comprises an adjusting rod, the adjusting rod penetrates through the support frame, and the bottom of the adjusting rod is provided with a gasket; The side surface of the support frame is provided with a connecting block, the side surface of the connecting block is provided with a connecting column, the connecting column is detachably provided with a connecting rod, and the other end of the connecting rod is provided with a plurality of pressing rods.

[0007] Further, the support frame is L-shaped, and the connecting device is arranged at the bottom of the support frame.

[0008] Further, the connecting device comprises a vertically arranged lifting plate, the top of the lifting plate is provided with a lifting rod, the lifting rod penetrates through the support frame, and the lifting rod is provided with an adjusting nut.

[0009] Further, the side surface of the lifting plate is provided with a limiting block, and the side surface of the support frame is provided with a sliding groove, and the limiting block is slidingly arranged in the sliding groove.

[0010] Further, the lower part of the lifting plate is provided with a connecting plate, the bottom of the connecting plate is hingedly provided with a fixed plate, the front end surface of the fixed plate is oppositely provided with a pressing plate, the upper parts of the fixed plate and the pressing plate are provided with connecting holes, the connecting holes are provided with a bolt, and the two ends of the bolt are provided with pressing blocks, and the pressing blocks are provided with pressing bolts.

[0011] Further, the abutting surfaces of the pressing blocks and the fixed plate and the pressing plate are inclined surfaces, and the thickness of the lower part of the pressing block is greater than that of the upper part.

[0012] Further, the connecting block is an L-shaped plate, the top of the connecting column is connected with the inner side surface of the connecting block, and the connecting column is provided with at least two.

[0013] Further, the end of the connecting rod is provided with a connecting hole, the connecting column is inserted into the connecting hole, the other end of the connecting rod is provided with an extension plate, the pressing rod is arranged at the end of the extension plate, and the bottom of the pressing rod faces the Invar plate.

[0014] Further, the end of the extension plate is provided with a plurality of pressing holes, the pressing rod is screwed with the pressing holes, and the bottom of the pressing rod is provided with a gasket.

[0015] A method for using a device for assisting single-folded edge yinwa column plate in eliminating deformation, the method comprising the following steps: Step one, according to the installation position of the yinwa column plate and the deformation of the yinwa column plate during welding, determine the position that needs to be pressed, select the appropriate length of the connecting rod according to the distance from the clamping tongue to the welding position, and rotate the pressing rod upward; Step two, insert one end of the connecting rod into the connecting column, and the upper surface of the connecting rod abuts against the connecting block; Step three, select the appropriate connecting point on the clamping tongue, determine the distance between the connecting device and the support frame by moving the up and down position of the lifting rod, clamp the fixed plate and the pressing plate on both sides of the clamping tongue, and then adjust the pressing bolt to make the fixed plate and the pressing plate stably connected on the clamping tongue; Step four, place a wooden block under the gasket of the adjusting rod to increase the contact area, and adjust the height of the adjusting rod so that the gasket at the bottom of the pressing rod can act on the upper surface of the deformation; Step five, place a wooden block or a copper block at the deformation, rotate the connecting rod left and right to determine the pressing position, make the bottom of the pressing rod act on the upper surface of the wooden block or the copper block, and then rotate the pressing rod downward to extrude the deformation flat, and in the case of a long deformation, use two sets of connecting rods and pressing rods to adjust the placement angle between the connecting rods to increase the acting area of the pressing position, and adjust the welding position flat.

[0016] The beneficial effects of the present application are: 1. By the synergistic effect of mechanical pre-pressing + stress distribution + segmented re-welding, the thin plate welding deformation is effectively controlled, and the welding quality and dimensional accuracy are ensured.

[0017] 2. According to the principle of lever, single-point support is adopted to connect the support frame and the clamping tongue, and during the welding process of the yinwa column plate, the deformation in a larger range can be pressed.

[0018] 3. The connection between the connecting device and the support frame is hinged, so that the connection between the support frame and the clamping tongue can rotate within a certain range, thereby reducing the stress on the clamping tongue when adjusting the pressing degree.

[0019] 4. The support frame is provided in an L-shaped structure, so that the bottom of the support frame can be better connected with the clamping tongue, and has a certain adjustment installation angle space, which can better cooperate with the connecting rod to achieve the pressing effect.

[0020] 5. The top of the connecting column is fixed with the connecting block, which ensures the stability of the connection during use and prevents the connection from being disconnected when adjusting the pressing degree, ensuring the safety in use.

[0021] 6. The connecting column is provided with at least two, and the included angle between the connecting column and the support frame can be freely adjusted according to the use site, increases the pressure application area on the deformation, reduces the operation steps, makes the compression rod closer to the deformation, and reduces the operation difficulty.

[0022] 7. The welding is carried out by adopting the sectional short welding and rewelding method, before the sectional rewelding method is welded, the equal division spot welding and the applied encryption spot welding uniformly distribute the stress received by the deformation weld to each place. The rewelding method effectively reduces the welding deformation, the short weld is reversely welded in sections, the heat concentration caused by continuous welding is avoided, the warping and deformation of the inconel steel can be significantly reduced, the penetration and forming are more easily controlled, and the problem of sensitivity of inconel steel welding to heat input is solved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present application; Figure 2 It is another angle schematic diagram of the structure of the present application; Figure 3 It is a front view schematic diagram of the structure of the present application; Figure 4 It is an enlarged schematic diagram of the structure at A of the present application; Figure 5 It is a position schematic diagram of the structure of the present application when two connecting rods are used; Figure 6 It is an enlarged schematic diagram of the structure at B of the present application; Figure 7 It is a schematic diagram of the structure state of the present application when used; 1, support frame; 101, adjusting rod; 102, gasket; 2, lifting rod; 201, adjusting nut; 202, lifting plate; 203, fixed plate; 204, pressing plate; 205, pressing block; 206, pressing bolt; 207, connecting plate; 208, rotating shaft; 209, bolt; 210, limiting block; 3, connecting block; 301, connecting column; 4, connecting rod; 401, extension plate; 402, compression rod; 5, clamping tongue. DETAILED DESCRIPTION

[0024] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "linkage" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0026] like Figures 1-5 As shown: This invention proposes a device and its method for eliminating deformation of a single-folded Invar plate, which mainly includes a support frame 1, a connecting device, an adjusting device, a connecting block 3, a connecting column 301, a connecting rod 4, and a pressing rod 402.

[0027] The support frame 1 is designed with an L-shaped structure. In practical implementation, a connecting device is provided on the short side of the L-shaped structure of the support frame 1, which connects to the latch 5 to form a stable connection point. The connecting device includes a lifting plate 202 that is slidably disposed on the inner side of the short side of the support frame 1. A lifting rod 2 is provided at the top of the lifting plate 202, and the lifting rod 2 extends upward through the support frame 1. The lifting rod 2 is a screw connected to the support frame 1 by threads. A sleeve is provided at the top of the lifting plate 202, and a bearing is provided inside the sleeve. The bottom end of the lifting rod 2 is placed in the bearing inside the sleeve, so that when the lifting rod 2 moves up and down, it can drive the lifting plate 202 to move up and down along the inner side of the short side of the support frame 1. A nut is screwed onto the upper part of the lifting rod 2. After the lifting plate 202 moves to a suitable position, the position of the lifting rod 2 is fixed by adjusting the nut 201, so that there is a suitable operating distance between the support frame 1 and the latch 5.

[0028] A limiting block 210 is provided at the contact point between the lifting plate 202 and the inner side of the support frame 1. The limiting block 210 is a strip-shaped block protruding from the surface of the lifting plate 202, and the strip-shaped block is arranged along the length direction of the lifting plate. A sliding groove is provided on the side of the support frame 1 to cooperate with the limiting block 210, and the limiting block 210 is slidably disposed inside the sliding groove. During the up and down movement of the lifting plate 202, the limiting block 210 moves inside the sliding groove, so that the lifting plate 202 moves up and down along the short side of the support frame 1. The limiting block and the sliding groove use a dovetail structure to cooperate, so that the limiting block can maintain a stable connection during the sliding process, ensuring the stability of the lifting process. At the same time, after the position of the lifting plate 202 is determined, the position of the support frame is kept stable, ensuring the reliability during use.

[0029] The lower part of the lifting plate 202 is connected with a connecting plate 208, the connecting plate 207 is connected with the lifting plate 202 through bolts, which is convenient for the maintenance and replacement of the connecting device in the later period. The bottom of the connecting plate 207 is provided with a rotating shaft 208 along the width direction of the lifting plate 202, the connecting plate is hinged with the fixed plate 203 arranged at the lower part through the rotating shaft 208, and the fixed plate 203 can rotate towards the direction close to the support frame 1. The front end surface of the fixed plate 203 is oppositely provided with a pressing plate 204, and the upper parts of the fixed plate 203 and the pressing plate 204 are provided with connecting holes, the inside of the connecting holes is provided with a latch 209, the pressing plate 204 can move along the latch 209 to change the distance between the fixed plate 203 and the pressing plate 204. In use, the fixed plate 203 and the pressing plate 204 are clamped on both sides of the clamping tongue 5, and the both ends of the latch 209 are provided with pressing blocks 205 downward, the lower parts of the pressing blocks 205 act on the outer surfaces of the fixed plate 203 and the pressing plate 204 respectively, and the pressing blocks 205 are provided with pressing bolts 206, the bottom of the pressing bolt 206 acts on the pressing plate 204. The pressing plate 204 and the fixed plate 203 are placed at both ends of the clamping tongue 5, and a rubber pad can be placed between the fixed plate 203 and the pressing plate 204 to reduce the deformation amount of the clamping tongue 5 after being subjected to pressure. By tightening the pressing bolt 206, the latch 209 pulls the pressing plate 204 and the fixed plate 203 to the middle position, and then the clamping tongue 5 is clamped firmly between the pressing plate 204 and the fixed plate 203.

[0030] The abutting surfaces of the pressing block 205 and the fixed plate 203 and the pressing plate 204 are provided as inclined surfaces, when the pressing bolt 206 is tightened (as shown in Figure 4 The bottom of the pressing bolt 206 acts on the pressing plate 204, the pressing block 205 on one side of the fixed plate 203 generates an acting force on the fixed plate 203, and the inclined surface is arranged to make the lower part of the fixed plate 203 bear the pressure first, thereby increasing the fastening when the clamping tongue is pressed tightly, clamping the clamping tongue 5, and ensuring the fixation of the position of the support frame 1. By adjusting the tightness of the pressing bolt 206, the connection and separation of the support frame 1 and the clamping tongue 5 can be realized. When the installation position of the invar plate is inclined and it is inconvenient to adjust after the support frame 1 is connected with the clamping tongue 5, the distance between the fixed plate 203, the pressing plate 204 and the clamping tongue 5 can be adjusted through the lifting rod 2. The support frame 1 is installed at the end of the adjusting rod 101, which has a better adjustment range and improves the use effect. In use, after the clamping tongue 5 is clamped by the pressing plate 204 and the top plate 203, the support frame 1 can rotate in a vertical plane perpendicular to the invar plate within a certain range with the connection point of the clamping tongue 5 as the center. During the rotation of the support frame 1, the clamping tongue 5 will not be subjected to stress when the support frame 1 rotates because the connecting device is hinged with the support frame 1. Compared with the prior art, the stress on the clamping tongue 5 can be reduced when adjusting the pressing degree of the invar plate welding part, the secondary damage is prevented, and the use effect is improved.

[0031] The long side of the support frame 1 is provided with an adjusting device at one end, wherein the adjusting device comprises an adjusting rod 101 and a gasket 102, the adjusting rod 101 is arranged in parallel with the short side of the support frame 1 and penetrates the support frame 1, the adjusting rod 101 is a screw rod and is connected with the support frame 1 through threads, and the length of the adjusting rod 101 at the lower part of the support frame 1 can be adjusted by rotating the adjusting rod 101. The gasket 102 is a rubber pad, and the gasket 102 is arranged at the bottom of the adjusting rod 101. In use, in order to reduce the pressure on the Invar plate, a wooden board can also be placed below the gasket 102 to increase the contact area and prevent the Invar plate from being damaged due to extrusion, thereby ensuring the use effect. When the length of the adjusting rod 101 is adjusted, since the other end of the support frame 1 is connected with the clamping tongue 5, the included angle between the end of the long side of the support frame 1 and the Invar plate also changes. Correspondingly, when the included angle between the support frame 1 and the Invar plate increases, the included angle between the connecting rod 4 arranged at the other end of the support frame 1 and the Invar plate decreases (as shown in FIG. 9). Figure 3 By controlling the length of the adjusting rod 101 between the support frame 1 and the Invar plate, the pressing effect on the welding joint can be better adjusted by the connecting rod 4 in use, so as to adapt to the pressing requirements of different deformation positions and improve the application range of the device.

[0032] The outer side of the short side of the support frame 1 is provided with a connecting block 3, which is an L-shaped angle iron, and the connecting block 3 is welded and fixed with the support frame 1, and the opening surface of the connecting block 3 is arranged downward. The inner side of the connecting block 3 is provided with at least two connecting columns 301 vertically downward, the top of the connecting column 301 is fixed with the inner side of the connecting block 3, and the connecting column 301 is detachably inserted with a connecting rod 4, and the length of the connecting rod 4 can be selected according to the on-site use demand. The end of the connecting rod 4 is provided with a connecting hole, and the connecting hole is inserted and matched with the connecting column 301. In use, the connecting rod 4 is inserted upward from the lower part of the connecting column 301, and then the support frame is clamped on the clamping tongue 5 through the fixed plate 203 and the pressing plate 204, at this time the connecting rod 4 can be rotated at a certain angle above the yinwa column plate. The crimping rod 402 at the other end of the connecting rod 4 is placed in the place where pressure is needed in advance, the length of the adjusting rod 101 is adjusted, so that the crimping rod 402 is slightly stressed, and the effect that the connecting rod 4 does not fall off from the connecting column 301 is achieved. Then rotate the connecting rod 4, adjust the crimping rod 4 to act directly on the accurate pressure position. When the connecting position of the support frame 1 and the clamping tongue 5 is inconvenient to adjust, the adjustment of the pressure position can also be realized by changing the rotation angle of the connecting rod 4, which reduces the operation steps of frequently adjusting the clamping position according to the welding condition in the prior art, and improves the welding efficiency. When the position of the clamping tongue 5 and the position of the welding pressure do not correspond, the effect of pressure is realized by changing the angle between the support frame 1 and the connecting rod 4. Especially when the welding position is between the angles of multiple inner wall surfaces, by replacing the longer connecting rod 4, even if the distance between the clamping tongue 5 and the pressure position is far or the positions do not correspond, as long as it is within the fan-shaped area formed by the rotation of the connecting rod 4, by increasing the angle between the support frame 1 and the yinwa column plate, the pressure effect on the welding position can be achieved through the connecting rod 4 and the crimping rod 402, which meets the pressure crimping demand that the position of the clamping tongue 5 and the position of the deformation do not correspond, and only one clamping tongue 5 can complete a great improvement in the application range.

[0033] The other end of the connecting rod 4 is provided with an extension plate 401 extending to both sides of the connecting rod 4, which increases the pressure range during use. A plurality of crimping holes are provided on the extension plate 401, and a crimping rod 402 is connected in the crimping hole by screwing. Rotating the crimping rod 402 can adjust the length of the crimping rod 402 below the extension plate 401. By adjusting the length of the extension plate 401, the degree of pressure is controlled, and the control effect on the deformation of the Invar plate is further adjusted. The bottom of the crimping rod 402 is also provided with a gasket 102. In use, the crimping rod 402 moves downward, and a wood block or a copper block is placed below the gasket 102 to increase the action area during crimping, so as to protect the surface of the Invar plate from being damaged, and make the welding position more flat and convenient for welding. When the deformation distance is long, two connecting rods 4 can be used on the same support frame 1 to increase the action area during crimping, reduce repeated operations, and improve the welding efficiency. When the welding position is at the junction, by changing the angle between the connecting rod 4 and the support frame 1, only one clamping tongue 5 is used for connection, so that the crimping rod 402 can directly act on the deformation position, reducing the difficulty of manual operation and improving the welding effect.

[0034] In the manufacture of LNG ship liquid cargo tank, the method for eliminating the deformation of single-folded Invar plate during welding process is provided to make the welding seam flat after the welding of single-folded Invar plate is completed, and quality problems caused by welding deformation are avoided. The single-folded Invar plate is a structure form of Invar steel in the liquid cargo tank.

[0035] The specific use method of the device is as follows, Step one, first analyze the site situation of the welding and installation of the single-folded Invar plate in the LNG ship liquid cargo tank, select a connecting rod 4 with appropriate length according to the distance from the clamping tongue 5 on the bulkhead to the welding position, and rotate the crimping rod 402 upward to provide installation space for subsequent installation; Step two, insert the end of the connecting rod 4 provided with a connecting hole into the connecting column 301, ensure that the upper surface of the connecting rod 4 is in close contact with the connecting block 3, so that the crimping position is closer to the fixed point of the clamping tongue 5, ensure the action effect during compression, and reduce the welding difficulty; Step four, select a suitable connection position on the clamping tongue 5 near the welding position, adjust the distance between the connecting device and the support frame 1 by moving the up-down position of the lifting rod 2, so that the fixed plate 203 and the pressing plate 204 can be accurately clamped on both sides of the clamping tongue 5. By adjusting the compression bolt 206, the fixed plate 203 and the pressing plate 204 are stably connected on the clamping tongue 5 and maintain appropriate height, which provides operation space for the adjusting rod 101 on the support frame 1 and the crimping rod 402 on the connecting rod 4, and provides stable support for subsequent pressure application; Step five, place copper or wood blocks under the gasket 102 of the adjusting rod 101 to increase the contact area and improve the uniformity of the pressure, adjust the height of the adjusting rod 101 so that the gasket 102 at the bottom of the crimping rod 402 can accurately act on the deformed part, place wood or copper blocks as auxiliary support at the deformed part, determine the best pressure position by rotating the connecting rod 4 left and right, act the gasket 102 at the bottom of the crimping rod 402 on the upper surface of the wood or copper block, and then rotate the crimping rod 402 downward to apply pressure to the deformed part, extrude it flat, adjust it to the best welding position, and facilitate subsequent welding. Step six, for a deformed part with a longer length, two groups of connecting rods 4 and crimping rods 402 can be used for cooperative operation (as shown in Figure 5 and Figure 7 ), by adjusting the placement angle between the connecting rods 4, increasing the action area of the pressure, ensuring that the entire welding part can be uniformly and fully pressed, so as to realize the flat adjustment of the welding part; Step seven, according to the above operation, after the device is pre-fixed, all the crimping rods 402 as small spider legs and the adjusting rods 101 as large spider legs are locked in turn, and the arched deformed part is crimped flat. When welding formally, the segmented short welding and rewelding process is adopted, the heat input of each welding is strictly controlled, and the copper block is removed after the weld is completely cooled. Through the synergistic effect of mechanical pre-pressing + stress distribution + segmented rewelding, the thin plate welding deformation is effectively controlled, and the weld quality and size accuracy are guaranteed.

[0036] When the device of the application is used to assist in eliminating the deformation of the single-folded edge yinwa column plate, the support frame 1 is clamped at the nearest clamping tongue 5, so that the support frame 1 can be adjusted in a certain range, and the connecting rod 4 can better act on the deformed part. When the length of the crimping rod 402 is not enough to completely press down the deformed part, the supporting length of the adjusting rod 101 is adjusted, the lever principle is used, the connecting rod 4 is assisted to reduce the included angle between the yinwa column plate, and the crimping rod 402 is used in cooperation, which can better assist the crimping rod 402 to act on the deformed part and completely flatten the arched part. Even if the support frame 1 and the connecting rod 4 are arranged at an included angle, they can be used in cooperation to meet different use environments, improve welding efficiency, and ensure use effect. Cooperating with a specific welding method effectively solves the deformation problem of the single-folded edge yinwa column plate caused by heat stress concentration during welding, reduces the welding difficulty of the deformed part which is not easy to press tightly, improves the welding quality and sealing performance, and reduces the later repair cost.

[0037] When the single-folded edge corrugated plate is found to be deformed due to the pre-welding, a wood block or a copper block is pressed at the position of the arch deformation of the plate, and the pressing rods 402 are rotated. The pressing rods 402 are provided in plurality, and the adjusting rod 101 is provided in one and is located opposite to the pressing rods 402, so that the wood block or the copper block just presses the arch of the plate. Then, the point welding is performed step by step, the deformation is shared to the whole welding seam to be repaired, and the welding area is encrypted according to the WPS requirement. After the point welding is completed, all the pressing rods 402 are then tightened, and finally the adjusting rod 101 is tightened, so that the whole tooling reaches a balanced state. The copper block is used for pressing, which can well play a heat absorption effect and is diffused to the whole copper block, so as to avoid the heat concentration to cause the warping and deformation. The two surfaces of the copper block in contact with the corrugated plate are smooth and flat, the heat transfer is more smooth, and the heat dissipation is faster. When the copper block is removed after welding, the welding seam must be cooled, and the essence is to avoid the copper block from being removed too early, and the stress is affected by thermal expansion and cold shrinkage to cause the corrugated plate to warp and deform.

[0038] In the specific implementation of the present application, the welding is performed by using the rewelding method, the deformed arch is first pressed flat downward, then the welding seam at the pressing position is equally divided and point welded, the long deformation is shared into multiple short deformations, then the point welding is encrypted, the connecting points are increased, and finally the rewelding is performed in sections to completely weld the deformation. The rewelding method decomposes the long welding seam into multiple short welding passes by using the reverse segmental welding process, so that each welding pass can be independently cooled, thereby effectively avoiding the heat accumulation effect in continuous welding. This process control mode significantly reduces the heat affected zone range by 40%-50%, and at the same time reduces the welding peak temperature by about 15%-20%, thereby realizing the precise control of the welding heat input. The rewelding method offsets the shrinkage stress of adjacent welding passes by using the reverse segmental welding process, thereby significantly improving the welding deformation problem. After using this method, the overall deformation can be reduced by 60%-70%, the workpiece flatness can be accurately controlled within ±0.3mm, and in particular, the flatness of the folded edge area is obviously improved. At the same time, the welding residual stress is also effectively reduced by 35%-45%, and the improvement of this stress state not only improves the dimensional stability of the workpiece, but also provides better mechanical performance guarantee for subsequent processing and use.

[0039] The rewelding method significantly improves the overall quality of the corrugated plate welding seam by accurately controlling the heat input and segmental cooling. This method effectively reduces the grain coarsening degree of the welding heat affected zone, greatly reduces the micro-crack occurrence rate, and also reduces common welding defects such as pores. The welding seam formed by using the rewelding process has excellent low-temperature performance, and the sealing completely meets the stringent use requirements of the LNG ship in the extreme low-temperature environment of-163℃. The heat input is more evenly distributed during the welding process, and the phenomenon of heat stress concentration in traditional welding is effectively improved.

[0040] The welding deformation is effectively reduced by the back welding method, the short welding seam is segmented and inversely welded, the heat concentration caused by continuous welding is avoided, the warping and deformation of the invar steel are significantly reduced, the back welding method is more easy to control the penetration and forming, and the problem of the welding sensitivity of the invar steel to heat input is solved. The precise control of heat in the welding process significantly improves the process stability, the controllability of the whole welding process is greatly enhanced, a safer working environment is created for the operators, and the quality risk caused by process fluctuation is reduced. The improvement of the safety not only guarantees the safety of the operators, but also provides a reliable guarantee for continuous and stable production.

[0041] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the foregoing embodiments of the present application are described in detail, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement, within the spirit and principles of the present application, any modification, equivalent replacement, improvement, etc., should be included in the protection scope of the present application.

Claims

1. A device for eliminating deformation of an auxiliary single-fold Invar plate in an LNG carrier cargo tank structure, wherein the Invar plate is connected to an insulating box composite beam via a single-fold design, and a latch is provided on the tank wall near the single-fold Invar plate, characterized in that: The device includes a support frame (1), and the lower part of the support frame (1) is provided with a connecting device for clamping the latch (5), and the connecting device is hinged to the support frame (1). An adjustment device is provided at one end of the support frame (1). The adjustment device includes an adjustment rod (101), which passes through the support frame (1). A pad (102) is provided at the bottom of the adjustment rod (101). The support frame (1) has a connecting block (3) on its side, and a connecting column (301) is provided on the side of the connecting block (3). The connecting column (301) is detachably provided with a connecting rod (4), and the other end of the connecting rod (4) is provided with multiple crimping rods (402).

2. The device for eliminating deformation of an auxiliary single-folded Invar plate according to claim 1, characterized in that: The support frame (1) is L-shaped, and the connecting device is located at the bottom of the support frame (1).

3. The device for eliminating deformation of an auxiliary single-folded Invar plate according to claim 1, characterized in that: The connecting device includes a vertically arranged lifting plate (202), a lifting rod (2) is provided on the top of the lifting plate (202), the lifting rod (2) passes through the support frame (1), and an adjusting nut (201) is provided on the lifting rod (2).

4. The device for eliminating deformation of an auxiliary single-folded Invar plate according to claim 3, characterized in that: The lifting plate (202) is provided with a limiting block (210) on its side, and the support frame (1) is provided with a sliding groove on its side. The limiting block (210) is slidably disposed inside the sliding groove.

5. The device for eliminating deformation of an auxiliary single-folded Invar plate according to claim 3 or 4, characterized in that: The lower part of the lifting plate (202) is provided with a connecting plate (207), and the bottom of the connecting plate (207) is hinged with a fixed plate (203). The front end face of the fixed plate (203) is provided with a pressure plate (204). The upper part of the fixed plate (203) and the pressure plate (204) are provided with connecting holes. The inside of the connecting holes is provided with a pin (209). Both ends of the pin (209) are provided with pressure blocks (205). The pressure blocks (205) are provided with clamping bolts (206).

6. The device for eliminating deformation of an auxiliary single-folded Invar plate according to claim 5, characterized in that: The contact surface between the pressure block (205) and the fixed plate (203) and the pressure plate (204) is set as an inclined surface, and the thickness of the lower part of the pressure block (205) is greater than the thickness of the upper part.

7. The device for eliminating deformation of an auxiliary single-folded Invar plate according to claim 1, characterized in that: The connecting block (3) is an L-shaped plate, and the top of the connecting column (301) is connected to the inner side of the connecting block (3). There are at least two connecting columns (301).

8. The device for eliminating deformation of an auxiliary single-folded Invar plate according to claim 7, characterized in that: The end of the connecting rod (4) is provided with a connecting hole, the connecting post (301) is inserted into the connecting hole, the other end of the connecting rod (4) is provided with an extension plate (401), the pressing rod (402) is provided at the end of the extension plate (401), and the bottom of the pressing rod (402) faces the Invar plate.

9. The device for eliminating deformation of an auxiliary single-folded Invar plate according to claim 8, characterized in that: The end of the extension plate (401) is provided with a plurality of crimping holes, the crimping rod (402) is screwed to the crimping holes, and the bottom of the crimping rod (402) is provided with a gasket (102).

10. A method for eliminating welding deformation of single-folded Invar plates, characterized in that: The apparatus for eliminating deformation using an auxiliary single-fold Invar plate as described in any one of claims 1-9 comprises the following steps: Step 1: Based on the installation position of the Invar plate and the deformation of the Invar plate weld during the welding process, determine the position where pressure needs to be applied, select a suitable length of connecting rod (4) based on the distance from the latch (5) to the weld, and rotate the pressing rod (402) upwards; Step 2: Insert one end of the connecting rod (4) into the connecting post (301), and make the upper surface of the connecting rod (4) abut against the connecting block (3); Step 3: Select a suitable connection point on the latch (5), determine the distance between the connecting device and the support frame (1) by moving the lifting rod (2) up and down, and clamp the fixed plate (203) and the pressure plate (204) on both sides of the latch (5). Then adjust the clamping bolt (206) so that the fixed plate (203) and the pressure plate (204) are firmly connected on the latch (5). Step 4: Place a wooden block under the pad (102) of the adjusting rod (101) to increase the contact area and adjust the height of the adjusting rod (101) so that the pad (102) at the bottom of the pressing rod (402) can act on the area above the deformation. Step 5: Place a wooden or copper block at the deformed part of the single-fold Invar plate, rotate the connecting rod (4) left and right to determine the pressure position, apply the bottom of the pressing rod (402) to the upper surface of the wooden or copper block, and then rotate the pressing rod (402) downward to press the deformed part of the single-fold Invar plate flat. If the deformed part of the single-fold Invar plate is long, use two sets of connecting rods (4) and pressing rods (402), adjust the placement angle between the connecting rods (4) to increase the area of ​​pressure, and adjust the weld to be flat. Step six: After pressing the deformed area flat according to step five, use a segmented short welding and back-welding method during welding, strictly control the heat input of each welding segment, and remove the copper or wooden block after the weld has completely cooled.

11. A method for eliminating welding deformation of a single-folded Invar plate according to claim 10, characterized in that: After the pressure rod (402) presses the deformed part of the flat plate arch, it is then gradually and evenly spot welded to distribute the deformation to the entire weld seam to be repaired, and then the area to be welded is densely spot welded according to WPS requirements.

12. The method for eliminating welding deformation of a single-folded Invar plate according to claim 11, characterized in that: After spot welding, tighten all the crimping rods (402) and then tighten the adjusting rod (101) to bring the whole device to a balanced state. Welding is carried out by segmented short welding and back welding. After welding, wait for the weld to cool completely before removing the crimping rods (402) and copper blocks.

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