A method for processing and forming a ship hull bidirectional large-curvature outer plate

Abstract

The application discloses a method for processing and forming a ship body bidirectional large-curvature outer plate, and specifically comprises the following steps: S1, plate fixing, hoisting the plate to be processed to a fire platform; S2, oblique diagonal fire ring heating, after the plate is fixed, a heating fire ring is drawn on the plate reverse arc surface according to the direction of the plate transverse curvature, the heating fire ring is heated through a fire gun, and after heating, self-heating cooling is performed to generate transverse shrinkage deformation; S3, long-strip transverse heating forming, a plurality of transverse heating lines are drawn, and heating is performed along the transverse heating lines to complete transverse linear correction of the plate; and S4, water-fire bending plate longitudinal heating, local linear heating plastic forming is performed on the plate position with unqualified longitudinal curvature to complete longitudinal curvature adjustment of the plate. The plate is processed and formed through the oblique diagonal fire ring heating method, the long-strip heating method and the water-fire bending plate heating method, the plate processing with a transverse diagonal curvature greater than 500 mm is solved, and the plate processing forming rate is improved.

Description

Technical Field

[0001] This invention belongs to the field of shipbuilding technology, specifically relating to a method for processing and forming a double-curvature outer plate for a ship hull. Background Technology

[0002] Two-way large curvature outer plate is a relatively complex type of curved outer plate for ships. Its characteristics are that the diagonal curvature in the transverse direction is greater than 500mm, which is a positive or negative circular arc, while the longitudinal curvature is basically straight or has a small curvature. It belongs to the category of large curvature outer plates with small or even no longitudinal curvature, which is difficult to process and slow to form.

[0003] To achieve the required twist and curvature in the design, the processing methods for various linear hull plates are mainly divided into cold working mechanical forming, long strip heating forming, and hull pyrotechnic water-fire bending forming. For double-curvature hull plates, these processing methods have some drawbacks: (1) Cold working mechanical forming. This method uses external force to force the plate to deform and twist, but due to the limitations of mechanical equipment, complex linear plates cannot be processed to the required extent, and the large curvature of the plate cannot be reflected. Therefore, this method is only suitable for small curvature plates or simple bending plate processing, and large curvature hull plates cannot be pressed with a cold press. (2) Hull pyrotechnic long strip heating forming. However, it has obvious disadvantages for double-curvature hull plates. Because the heating line is long and the area to be heated is large, the longitudinal curvature will be affected while the transverse curvature of the plate is being formed, resulting in the need to correct the longitudinal curvature of the plate after forming. However, the transverse curvature that has been formed will spring back during the correction process, requiring repeated correction, resulting in slow plate forming speed and low efficiency, and causing uneven edges of the plate, affecting the appearance and structural strength of the plate. (3) Fire-water bending forming method for ship hulls. For outer plates with large bidirectional curvature, the two opposite corners of the outer plate need to be heated multiple times during the fire-water bending process to bend them. Then, water is used as a cooling medium to quickly cool the heated plate. After multiple heating and cooling cycles, the steel plate surface is affected by thermal expansion and contraction, resulting in uneven shrinkage and inconsistent thickness. The surface of the plate is severely carbonized, causing defects in the reinforcing bars, resulting in poor surface smoothness and poor linearity of the plate. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for processing and forming a double-sided large curvature outer plate of a ship hull. The method of this invention forms the plate by means of oblique diagonal fire ring heating, long strip heating and water-fire bending plate heating, which solves the problem of processing plates with a transverse diagonal curvature greater than 500mm and improves the plate forming rate.

[0005] To achieve the above-mentioned objectives, the technical solution provided by this invention patent is as follows:

[0006] A method for machining and forming a double-sided, high-curvature outer plate for a ship's hull, the method specifically includes the following steps:

[0007] S1, Fixing the board: Hoist the board to be processed to the firework platform. According to the line requirements of the board to be processed, raise the upturned diagonal of the board to be processed with wooden blocks, and press down the downturned diagonal of the board to be processed with weights and irons respectively.

[0008] S2, Diagonal heating rings: After the board is fixed, heating rings are drawn on the reverse arc surface of the board according to the direction of the lateral curvature of the board. The heating rings are evenly distributed on the board. After the heating rings are drawn, they are heated by a torch. After heating, they are self-cooled and produce lateral shrinkage deformation.

[0009] S3, long strip horizontal heating and forming, after the diagonal fire ring heating is completed, the processed board is inspected for line shape through the inspection sample box, the unqualified positions on the horizontal arc of the rib on the board are marked, and the marked points are connected to form multiple horizontal heating lines. Heating is carried out along the horizontal heating lines to complete the horizontal line shape correction of the board.

[0010] S4, water and fire bending plate longitudinal heating, inspect the longitudinal curvature of the plate after heating and forming, and perform local linear heating and shaping on the plate where the longitudinal curvature is not up to standard, to complete the longitudinal curvature adjustment of the plate and the outer plate processing and forming.

[0011] Furthermore, the pressure code is pistol-shaped. The short end of the pressure code is inserted into the hole of the pyrotechnic platform, and the long end of the pressure code is pressed against one corner of the floating plate. Multiple pressure codes are provided on one corner of the floating plate, and the other corner of the floating plate is pressed down by a pressure iron with a mass of 5T.

[0012] Furthermore, the diameter of the heating ring is four times the thickness of the plate. The heating ring is heated according to the linear direction of the plate, and the heating temperature of the heating ring by the torch is 850℃-900℃. The heating of the heating ring is specifically as follows: the heating ring is heated sequentially along the linear direction of the plate. After all the heating rings are heated, they are allowed to cool naturally. After natural cooling, the heating rings on the plate are reheated and allowed to cool naturally again, completing the diagonal heating of the heating rings, so that the plate completes the lateral shrinkage deformation.

[0013] Furthermore, the inspection sample box in S3 is a wooden mold with the same structure as the board after molding. The transverse arc shape of the ribs on the board is inspected by fitting the inspection sample box to the board, and the positions of the boards that fail the inspection are marked.

[0014] Furthermore, the elongated strip heating and forming specifically involves: using a neutral flame generated by an oxyacetylene mixture to heat along a marked transverse heating line and then naturally cooling it to complete the transverse elongated strip heating.

[0015] Furthermore, the inspection of the longitudinal curvature of the heated and formed sheet material specifically involves: attaching the heated and formed sheet material to an inspection sample box, marking the positions where the longitudinal curvature does not conform to the shape of the inspection sample box, and then subjecting the marked positions to localized linear heating.

[0016] Furthermore, the longitudinal heating of the water-fire bending plate specifically involves: using an oxyacetylene flame to rapidly heat the marked points where the longitudinal curvature of the plate is unqualified in a localized linear manner, and then cooling them with water to generate angular deformation and lateral shrinkage deformation, thereby causing localized plastic deformation of the plate.

[0017] Based on the above technical solution, the method for processing and forming a two-way large curvature outer plate of a ship hull, as disclosed in this patent, has achieved the following technical advantages through practical application:

[0018] 1. The present invention provides a method for forming a double-sided large curvature outer plate of a ship hull. The plate is formed by using a diagonal fire ring heating method, a long strip heating method, and a water-fire bending plate heating method. This method solves the problem of processing plates with a diagonal curvature greater than 500mm and improves the plate forming rate.

[0019] 2. This invention discloses a method for forming a double-sided, large-curvature outer plate for ship hulls. Compared with conventional processing methods, this method uses an oblique diagonal heating ring method to integrally form the plate. The plate is uniformly heated on the reverse arc surface, and pressure is applied using weights and pressure irons. Natural cooling is used instead of water cooling, allowing the plate to slowly transition from austenite to pearlite at high temperatures. This results in better yield strength on the plate surface, a smooth and even surface after forming, and no wavy defects on the longitudinal edges. Simultaneously, the weight of the pressure irons effectively accelerates the forming speed of the plate's curvature during heating, ensuring smooth curvature of the transverse ribs of the double-sided, large-curvature outer plate. The thermal expansion and contraction characteristics of the plate increase the shrinkage forming rate during processing, reducing the number of repeated heating cycles.

[0020] 3. The present invention provides a method for processing and forming a double-sided large curvature outer plate of a ship hull. It uses a long strip heating method, which has a small heating area and is suitable for local straightening of the plate. It utilizes the shrinkage force generated during the heating and cooling process of the plate to achieve the processing purpose. It reduces the time spent on repeatedly checking the line shape and correcting defects, and also allows the stress molecules generated in the heating area of ​​the outer plate to be evenly distributed within a sufficient time. It also reduces the number of times the double-sided large curvature outer plate is turned over during the production process, and improves the flatness and smoothness of the plate.

[0021] 4. The present invention provides a method for processing and forming a double-curvature outer plate for ship hulls. The method uses a water-fire bending heating method to heat the plate. During the longitudinal curvature correction of the plate, the already processed transverse curvature will not be affected. It is suitable for processing longitudinal curvature of plates with small curvature. After forming, the product surface is smooth, the plate edge is flat, and there are no obvious defects such as uneven steel bars or overall instability. Attached Figure Description

[0022] Figure 1 This is a flowchart of the outer plate processing and forming process in a method for processing and forming a double-sided large curvature outer plate of a ship hull according to the present invention.

[0023] Figure 2 This is a diagram of the plate fixing structure in a method for processing and forming a double-curvature outer plate of a ship hull according to the present invention.

[0024] Figure 3 This is a structural diagram of the transverse heating line in a method for processing and forming a double-curvature outer plate of a ship hull according to the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific examples shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0026] like Figure 1-3 The present invention pertains to a method for processing and forming a bidirectional large curvature outer plate for a ship hull, and the method specifically includes the following steps:

[0027] S1, Fixing the board: Hoist the board to be processed to the firework platform. According to the line requirements of the board to be processed, raise the upturned diagonal of the board to be processed with wooden blocks, and press down the downturned diagonal of the board to be processed with weights and irons respectively.

[0028] S2, Diagonal heating rings: After the board is fixed, heating rings are drawn on the reverse arc surface of the board according to the direction of the lateral curvature of the board. The heating rings are evenly distributed on the board. After the heating rings are drawn, they are heated by a torch. After heating, they are self-cooled and produce lateral shrinkage deformation.

[0029] S3, long strip horizontal heating and forming, after the diagonal fire ring heating is completed, the processed board is inspected for line shape through the inspection sample box, the unqualified positions on the horizontal arc of the rib on the board are marked, and the marked points are connected to form multiple horizontal heating lines. Heating is carried out along the horizontal heating lines to complete the horizontal line shape correction of the board.

[0030] S4, water and fire bending plate longitudinal heating, inspect the longitudinal curvature of the plate after heating and forming, and perform local linear heating and shaping on the plate where the longitudinal curvature is not up to standard, to complete the longitudinal curvature adjustment of the plate and the outer plate processing and forming.

[0031] The pressure code is pistol-shaped. The short end of the pressure code is inserted into the hole of the pyrotechnic platform, and the long end of the pressure code is pressed against one corner of the floating plate. Multiple pressure codes are set on one corner of the floating plate, and the other corner of the floating plate is pressed down by a pressure iron with a mass of 5T.

[0032] The diameter of the heating ring is four times the thickness of the plate. The heating ring is heated according to the linear direction of the plate. The heating temperature of the heating ring by the torch is 850℃-900℃. The heating of the heating ring is as follows: the heating ring is heated sequentially along the linear direction of the plate. After all the heating rings are heated, they are allowed to cool naturally. After natural cooling, the heating rings on the plate are reheated and allowed to cool naturally again to complete the diagonal heating of the heating rings, so that the plate can complete the lateral shrinkage deformation.

[0033] Compared to traditional processing methods, the oblique diagonal heating method for integral forming of sheet metal involves uniform heating of the reverse arc surface of the part, with pressure applied using weights and squeegees. Natural cooling is used instead of water cooling, allowing the sheet metal to slowly transition from austenite (good plasticity but lower strength) to pearlite (higher strength, moderate hardness, and good plasticity and toughness) at high temperatures. This results in better yield strength on the sheet surface, a smooth and evenly thickened finish after forming, and no wavy defects on the longitudinal edges. The weight of the squeegees effectively accelerates the curvature forming speed during heating, ensuring smooth transverse rib curvature of the double-sided large-curvature outer plate. The thermal expansion and contraction properties of the sheet metal also increase the shrinkage forming rate during processing, reducing the number of reheating cycles.

[0034] The inspection sample box in S3 is a wooden mold with the same structure as the board after it is formed. The transverse arc shape of the ribs on the board is inspected by fitting the inspection sample box to the board. The positions of the boards that fail the inspection are marked.

[0035] The process of heating and forming the long strip involves using a neutral flame generated by an oxyacetylene mixture to heat the strip along a marked transverse heating line and then allowing it to cool naturally, thus completing the transverse heating of the long strip.

[0036] The advantage of the strip heating method lies in its small heating area, allowing for single or double strip localized correction of the affected areas of the board, achieving the same correction effect as the circular heating method. Therefore, this method is suitable for localized correction of boards, utilizing the shrinkage force generated during the heating and cooling process to achieve the processing objective. This operation not only reduces the time spent on repeatedly checking alignment and correcting defects but also ensures that the stress molecules generated in the heated area of ​​the outer panel are evenly distributed within a sufficient time. It reduces the number of times large-curvature outer panels need to be flipped during production (as boards often require processing on both sides, necessitating flipping, which not only poses safety hazards but also easily causes board deformation), while still meeting the required flatness and smoothness.

[0037] The process of inspecting the longitudinal curvature of the heated and formed sheet material involves: fitting the heated and formed sheet material into an inspection sample box, marking the locations where the longitudinal curvature does not conform to the shape of the inspection sample box, and then subjecting the marked locations to localized linear heating.

[0038] The longitudinal heating of the water-fire bending plate specifically involves using an oxyacetylene flame to rapidly heat the marked points where the longitudinal curvature of the plate is substandard, and then cooling them with water to induce angular deformation and lateral shrinkage deformation, thereby causing localized plastic deformation of the plate.

[0039] The water-fire bending heating method for plates offers advantages such as high production efficiency, good forming quality, and simple operation. It does not affect the already processed transverse curvature during the longitudinal curvature correction of the plate. Therefore, this method is suitable for processing longitudinal curvature of plates with small curvatures. The resulting product has a smooth surface, smooth edges, and no obvious defects such as uneven reinforcement or overall instability.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for processing and forming a double-sided, large-curvature outer plate for a ship's hull, characterized in that, The method specifically includes the following steps: S1, Fixing the board: Hoist the board to be processed to the firework platform. According to the line requirements of the board to be processed, raise the upturned diagonal of the board to be processed with wooden blocks, and press down the downturned diagonal of the board to be processed with weights and irons respectively. The pressure code is pistol-shaped. The short end of the pressure code is inserted into the hole of the pyrotechnic platform, and the long end of the pressure code is pressed on one corner of the floating plate. Multiple pressure codes are set on one corner of the floating plate. The other corner of the floating plate is pressed down by a pressure iron with a mass of 5T. S2, Diagonal heating rings: After the board is fixed, heating rings are drawn on the reverse arc surface of the board according to the direction of the lateral curvature of the board. The heating rings are evenly distributed on the board. After the heating rings are drawn, they are heated by a torch. After heating, they are self-cooled and produce lateral shrinkage deformation. The diameter of the heating ring is four times the thickness of the plate. The heating ring is heated according to the linear direction of the plate. The heating temperature of the heating ring by the torch is 850℃-900℃. The heating of the heating ring is as follows: the heating ring is heated sequentially along the linear direction of the plate. After all the heating rings are heated, they are allowed to cool naturally. After natural cooling, the heating rings on the plate are reheated and allowed to cool naturally again to complete the diagonal heating of the heating rings, so that the plate can complete the lateral shrinkage deformation. S3, long strip horizontal heating and forming, after the diagonal fire ring heating is completed, the processed board is inspected for line shape through the inspection sample box. The unqualified positions on the horizontal arc of the rib on the board are marked, and the marked points are connected to form multiple horizontal heating lines. Heating is carried out along the horizontal heating lines to complete the horizontal line shape correction of the board. S4, water and fire bending plate longitudinal heating, inspect the longitudinal curvature of the plate after heating and forming, and perform local linear heating and shaping on the plate where the longitudinal curvature is not up to standard, to complete the longitudinal curvature adjustment of the plate and the outer plate processing and forming.

2. The method for processing and forming a double-sided large curvature outer plate for a ship hull according to claim 1, characterized in that, The inspection sample box in S3 is a wooden mold with the same structure as the board after it is formed. The transverse arc shape of the ribs on the board is inspected by fitting the inspection sample box to the board. The positions of the boards that fail the inspection are marked.

3. The method for processing and forming a double-sided large curvature outer plate for a ship hull according to claim 2, characterized in that, The transverse heating and forming of the long strip is specifically achieved by using a neutral flame generated by an oxyacetylene mixture to heat the strip along a marked transverse heating line and then allowing it to cool naturally, thus completing the transverse heating of the long strip.

4. The method for processing and forming a double-sided large curvature outer plate for a ship hull according to claim 1, characterized in that, The process of inspecting the longitudinal curvature of the heated and formed sheet material involves: fitting the heated and formed sheet material into an inspection sample box, marking the locations where the longitudinal curvature does not conform to the shape of the inspection sample box, and then subjecting the marked locations to localized linear heating.

5. The method for processing and forming a double-sided large curvature outer plate for a ship hull according to claim 4, characterized in that, The longitudinal heating of the water-fire bending plate specifically involves using an oxyacetylene flame to rapidly heat the marked points where the longitudinal curvature of the plate is substandard, and then cooling them with water to induce angular deformation and lateral shrinkage deformation, thereby causing localized plastic deformation of the plate.

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