A water fire processing method for preventing the inner bottom from being concave in processing of K-shaped plate

Abstract

The water fire processing method for preventing the inner bottom from being concave in the processing of the K-shaped plate for ships comprises the following steps: preparing the matched tools for water fire bending; selecting the K-shaped plate to be processed, making the water fire processing scheme and marking the heating line; continuously heating and water tracking cooling; continuously strip heating at the marked line; strip heating on the K-shaped plate through independent lines, controlling the heating width, heating temperature, heating speed and water fire distance; turning over the K-shaped plate, heating from the two side wings to the middle of the bottom plate at the strip heating mark of the inner bottom plate and water tracking cooling; checking the longitudinal curvature forming condition, the bottom plate transverse flatness and the surface smoothness. The water fire processing method for preventing the inner bottom from being concave in the processing of the K-shaped plate for ships can effectively avoid the inner bottom concave and the muscle-like defects in the processing of the K-shaped plate for ships, can ensure the smoothness of the plate surface line, can quickly process and form, and can reduce the repeated correction time.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding, specifically to a water-fire processing method for machining K-shaped outer plates for ships to prevent indentation of the inner bottom. Background Technology

[0002] The K-shaped outer plating design is used in the bottom and midsection of the bow and stern of the hull. It features symmetrical bends on both sides and mostly has an outward curve. Typically, the K-shaped outer plating is a positioning plate used in the segmented construction and installation process, requiring high precision. Due to the special design of the K-shaped outer plating, a water-fire bending process is required to locally heat and cool the outer plating's side wings, bends, and bottom plate to shrink it. The shrinkage of the bottom heating zone causes the edges to yield and bend, achieving the desired shape.

[0003] In traditional water-fire processing, when heating the two sides and bottom of the K-shaped outer panel with ring strips, the shrinkage at the first heated sides and corners generates strong compressive stress inward. With the longitudinal fiber length balance disrupted, when the bottom is heated with lines, the compressive stress is released to the heated area, forming rib-like depressions. The greater the longitudinal curvature, the greater the additional deformation of the bottom panel depression, making subsequent corrections very difficult. This results in huge consumption of labor time and oxygen and fuel, leading to high processing costs. At the same time, extensive heating for corrections severely damages the substrate's primer, requiring additional processes such as sanding and repainting.

[0004] The existing technology (CN106251275A) discloses an automated processing method for forming an inverted triangle shape on a ship's sail-shaped outer plate. Its main technical features include the following steps: 1. Obtaining the position of the sail-shaped plate's central axis and extracting the heating starting point of the inverted triangle; 2. Determining the heating area of ​​the inverted triangle; 3. Calculating the velocity components of the heating gun in the x, y, and z directions, so that the heating gun head processes in a spiral manner. This inverted triangle heating method solves the problems of uneven heating of the plate surface, significant influence from the subjective experience of workers, and low efficiency associated with existing manual heating methods. It achieves fully automated heating production of water-fire bent plates, ensuring uniform heating of the plate surface, improving efficiency, and guaranteeing the quality of the fired water-fire bent plates, thus increasing production capacity. However, it is only suitable for ship sail-shaped outer plates, which are different from K-shaped outer plates. Generally, K-shaped outer plates are mostly designed for military applications and are relatively thin; therefore, this processing method is not applicable to K-shaped outer plates. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides a water and fire processing method for machining marine K-shaped outer plates to prevent indentation of the inner bottom. This method is used for machining the longitudinal outward curvature of special linear outer plates and is applicable to the machining of different types of K-shaped outer plates.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A method for machining marine K-shaped outer plating to prevent inboard bottom denting, wherein the K-shaped outer plating is an outer plating with a K-shaped line on the bottom of the hull and also has an outward curvature line, the method includes the following steps:

[0008] Step 1: Prepare the necessary tools for water and fire bending, including a heating gun, oxygen and gas pipeline, cooling water tap and water pipe. Connect the heating gun to the oxygen and gas pipeline and the cooling water tap to the water pipe.

[0009] Step 2: Select the K-shaped outer plate that needs to be water-fire processed, place a template that matches the K-shaped outer plate, and draw a chalk line according to the longitudinal curvature scale lines of the templates at both ends of the K-shaped outer plate to check the longitudinal curvature workload. Based on the changes in the horizontal scale, estimate the water-fire processing workload, formulate a water-fire processing plan, and draw the corresponding heating lines.

[0010] Step 3: Oxygen fuel is delivered to the heating gun through the oxygen fuel pipeline. The oxygen fuel is adjusted to a neutral flame jet combustion by the heating gun for continuous heating. Cooling water is delivered to the cooling water tap through the water pipe for simultaneous water tracking cooling.

[0011] Step 4: Use a neutral flame to spirally heat the inner bottom plate of the K-shaped outer plate to form a strip heating zone, and continuously heat and cool with water. The strip heating zones are distributed without any breaks, and the strip heating zones are parallel but staggered in length.

[0012] Step 5: Heat the inner bottom plate of the K-shaped outer panel using individual linear heating elements. Adjust and control the width of the heating strips, heating temperature, heating speed, and water-fire distance based on the thickness of the K-shaped outer panel and the curvature of the template lines.

[0013] Step 6: Heat the outer side of the K-shaped outer panel with individual linear heating elements, controlling the width of the heating strip, heating temperature, heating speed, and water-fire distance according to the curvature of the template lines.

[0014] Step 7: Turn the K-shaped outer panel over so that the bottom is facing up. On the outer surface of the bottom panel, draw heating lines symmetrically from the sides to the bottom, starting from the neutral axis position of the two wings of the K-shaped outer panel, according to the original heating imprint. Repeat step 3 to perform continuous heating and water-tracking cooling.

[0015] Step 8: Use a template to check the longitudinal curvature forming and a ruler to check the horizontal flatness and surface finish of the base plate.

[0016] As a preferred technical solution, in step two, the water-fire processing method involves arranging transverse strip heating bands on the inner bottom plate to process the curved parts of the K-shaped outer plate and cooling them in a timely manner, controlling the width of the strip heating bands and the spacing between them, and controlling the length of the strip heating bands between the two corners.

[0017] As a preferred technical solution, in step three, when the heating gun is continuously heated, the oxygen-fuel gas is adjusted through the heating gun to form a neutral flame with a fixed flame core for jet combustion, thereby forming a heating source with a high temperature of 3050-3150℃ for water-fire processing.

[0018] As a preferred technical solution, the oxy-fuel mixture includes oxygen, propane, acetylene, and natural gas.

[0019] As a preferred technical solution, the flame outlet length of the heating gun is the same as the outlet length of the cooling water tap.

[0020] As a preferred technical solution, in step five, the width of the heating strip with a plate thickness of 7-10mm is controlled between 15-17mm, and the heating temperature is controlled at 600℃; the width of the heating strip with a plate thickness of 10-14mm is controlled between 17-20mm, and the heating temperature is controlled at 650℃.

[0021] As a preferred technical solution, in step seven, after all the preset heating lines on the inner bottom plate of the K-shaped outer plate have completed linear heating and water cooling, the K-shaped outer plate is flipped over and placed. The heating lines are drawn in a circular pattern from the center of the two wings to the preheating position at the bottom. The heating water on both sides is simultaneously heated and cooled. The heating time is 1.5 times longer at the corner. Then the heating is moved towards the center of the outer bottom plate, and the strip heating is carried out at a uniform speed, with heating and cooling carried out simultaneously.

[0022] As a preferred technical solution, in step eight, after all heating lines are completed, a template is used to check the longitudinal curvature and a ruler is used to check the flatness of the bottom. Any deviations are corrected locally until the template matches the rib line of each section of the K-shaped outer plate, ensuring that the outer surface of the K-shaped outer plate is smooth and glossy.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) The present invention provides a water-fire processing method for preventing indentation of the inner bottom of a marine K-shaped outer plate. The method utilizes linear continuous heated water cooling to effectively control the thermal expansion of the steel plate, causing radial contraction with the heating band as the origin. The uniform contraction of multiple heating bands causes the inner bottom plate to contract and tighten evenly, resisting the contraction stress of adjacent parts. Furthermore, because the bottom is pre-contracted, the fiber length is shortened. When the two wings of the K-shaped outer plate undergo water-fire contraction, the overall fiber length is kept as uniform as possible, preventing imbalance and effectively ensuring that the bottom plate will not deform or dent.

[0025] (2) The water and fire processing method for preventing the inner bottom of the K-shaped outer plate of the ship is made by using a cooling water tap and a heating gun together. The processing of the parts can be completed by a single person. The operation is flexible and does not require other mechanical facilities or auxiliary tooling. The work efficiency is high and the processing cost is low.

[0026] (3) The water and fire processing method for preventing the inner bottom of the K-shaped outer plate of the ship is highly applicable and can be flexibly applied to different ship types and different K-shaped outer plate curvatures. This processing method is also applicable to the correction of welding deformation of U-shaped parts.

[0027] (4) The water-fire processing method for preventing inner bottom depression in the K-shaped outer plate of the present invention is an improved water-fire processing technology evolved from the traditional water-fire bending plate processing technology. It can improve the working efficiency by more than 35%, prevent the generation of rib-like and wave-like defects, and ensure the smoothness and gloss of the outer plate. It has been successfully applied to the processing of various types of ships. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the heating gun structure in a water-fire processing method for preventing indentation of the inner bottom in the machining of K-shaped outer plates for ships according to the present invention;

[0029] Figure 2 This is a schematic diagram of the connection between the cooling water tap and the water pipe in a water and fire processing method for preventing the inner bottom from sinking in a K-shaped outer plate of a ship according to the present invention.

[0030] Figure 3 This is a schematic diagram illustrating the template placement process in a water and fire processing method for preventing insole denting in marine K-shaped outer plates according to the present invention.

[0031] Figure 4 This is a schematic diagram illustrating the operation of drawing pre-set heating lines on the K-shaped outer plate in a water and fire processing method for preventing insole dents in marine K-shaped outer plates according to the present invention.

[0032] Figure 5 This is a schematic diagram illustrating the operation of drawing a ring-shaped heating line after the K-shaped outer plate is flipped over in a water and fire processing method for preventing the inner bottom from sinking in a marine K-shaped outer plate according to the present invention.

[0033] In the diagram: 1. K-shaped outer panel; 2. Heating gun; 3. Cooling water tap; 31. Valve; 4. Oxygen and gas pipeline; 5. Template; 6. Water pipe. Detailed Implementation

[0034] The technical solution of the present invention will be further described below with reference to specific embodiments:

[0035] A method for machining a marine K-shaped outer plating 1 to prevent indentation of the inner bottom, wherein the K-shaped outer plating 1 is an outer plating with a K-shaped line on the bottom of the hull and also has an outward curvature line, the method includes the following steps:

[0036] Step 1, as follows Figure 1 As shown, the tools for water-fire bending are prepared, including a heating gun 2, an oxygen / gas pipeline 4, a cooling water tap 3, and a water pipe 6. The heating gun 2 is connected to the oxygen / gas pipeline 4, and the cooling water tap 3 is connected to the water pipe 6. Figure 2 As shown, the cooling water tap 3 is a special tap used to deliver cooling water. A valve 31 is provided on the water pipe 6 near the cooling water tap 3. The weight of the cooling water tap 3 is less than the weight of the heating gun 2 so that the weight of the two is similar during operation and the grip is comfortable.

[0037] Step 2, select the K-shaped outer panel 1 that requires water and fire processing, such as... Figure 3 As shown, place the template 5, which matches the K-shaped outer plate 1, upright according to the marked rib positions. Using the longitudinal curvature scale lines at both ends of the template 5 (bow and stern of the K-shaped outer plate 1), pull a chalk line to check the longitudinal curvature workload. Based on the changes in the scale line, estimate the water-fire machining workload and formulate a water-fire machining plan. Specifically, for the areas on the K-shaped outer plate 1 requiring curvature machining, arrange transverse strip heating bands on the inner bottom plate and cool them promptly. Control the width of the heating bands and the spacing between them. The length of the heating bands should be controlled between the two corners. Figure 4 As shown, pre-set heating lines are drawn at the bottom of the K-shaped outer plate 1 according to the required water and fire processing curvature;

[0038] Step 3: The operator holds the heating gun 2 in one hand and continuously heats the pre-set heating wire in a spiral motion. The heating gun 2 uses oxy-fuel mixture of oxygen and gas as energy. The gas includes propane, acetylene and natural gas. The oxy-fuel mixture is delivered to the heating gun 2 through the oxy-fuel pipeline 4. The heating gun 2 is then adjusted to a neutral flame with a fixed flame core for jet combustion, forming a heating source with a high temperature of 3050-3150℃ for water-fire processing. The operator holds the cooling water tap 3 in the other hand and delivers cooling water through the water pipe 6 to the cooling water tap 3 for simultaneous water tracking cooling. The width of the heating band is equal, and the heating speed, heating temperature and water-fire distance are equal. The flame outlet length of the heating gun 2 is the same as the outlet length of the cooling water tap 3.

[0039] Step 4: Use a neutral flame to create a spiral heating strip on the inner bottom plate of the K-shaped outer plate 1, and perform continuous heating and water-following cooling. When the spiral heating zone is heated to a visible dark red, move it forward continuously. The heating speed is uniform, the width of the heating strip is consistent, and the heating strip is arranged laterally, starting from the two corners. The greater the longitudinal curvature, the smaller the interval between the heating strips, and vice versa. The width of the heating strip is controlled between 15-20mm. The longitudinal curvature is controlled by the number of heating strips. When there are many heating strips, the lengths are staggered.

[0040] Step 5: The inner bottom plate of the K-shaped outer plate 1 is heated by individual lines. The width of the heating strip, the heating temperature, the heating speed and the water-fire distance are adjusted and controlled according to the plate thickness. Generally, for a plate thickness of 7-10mm, the width of the heating strip is controlled between 15-17mm and the heating temperature is controlled at 600℃. For a plate thickness of 10-14mm, the width of the heating strip is controlled between 17-20mm and the heating temperature is controlled at 650℃.

[0041] Step 6: Heat the outer side of the K-shaped outer panel 1 with individual linear heating elements, controlling the width of the heating strip, heating temperature, heating speed, and water-fire distance according to the curvature of the template 5.

[0042] Step 7: After all the preset heating lines on the inner bottom plate of the K-shaped outer panel 1 have completed the linear heating and cooling process, as follows... Figure 5 As shown, flip the K-shaped outer plate 1 over so that the bottom is facing up and draw a ring-shaped heating line. Two people use the same power heating gun 2 to heat the K-shaped outer plate 1 from the center axis of the wings on both sides. After passing the corner, stop for 1.5 times the heating time, and then move towards the center of the outer bottom plate to heat. Perform strip heating at a uniform speed and simultaneously perform water tracking cooling. The heating method is basically the same as the operation in steps four, five and six.

[0043] Step 8: After all heating lines are completed, use template 5 to check the longitudinal curvature and use a ruler to check the flatness of the bottom. Make local corrections for any deviations until template 5 matches the rib line of each section of the K-shaped outer plate 1, ensuring that the outer surface of the K-shaped outer plate 1 is smooth and glossy.

[0044] This embodiment is merely a further explanation of the present invention and is not intended to limit the present invention. Those skilled in the art can make non-inventive modifications to this embodiment as needed after reading this specification, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for machining a K-shaped outer plating for preventing inboard bottom dents, wherein the K-shaped outer plating is an outer plating with a K-shaped line on the bottom of the hull, and the K-shaped outer plating also has an outward curvature line, characterized in that... The method includes the following steps: Step 1: Prepare the supporting tools for water and fire bending plate processing, including a heating gun, oxygen and gas pipeline, cooling water tap and water pipe. The heating gun is connected to the oxygen and gas pipeline, and the cooling water tap is connected to the water pipe. Step 2: Select the K-shaped outer plate that needs water-fire processing, place a template that matches the K-shaped outer plate, and draw a chalk line according to the longitudinal curvature scale lines at the bow and stern ends of the template to check the longitudinal curvature workload. Based on the changes in the horizontal scale, estimate the water-fire processing workload, formulate a water-fire processing plan, and draw the corresponding heating lines. The water-fire processing plan is to arrange transverse strip heating bands on the inner bottom plate to process the curvature of the K-shaped outer plate and cool them in time. Control the width of the strip heating bands and the spacing between the strip heating bands, and control the length of the strip heating bands between the two corners. Step 3: Oxygen fuel is delivered to the heating gun through the oxygen fuel pipeline. The oxygen fuel is adjusted to a neutral flame jet combustion by the heating gun for continuous heating. Cooling water is delivered to the cooling water tap through the water pipe for simultaneous water tracking cooling. Step 4: Use a neutral flame to spirally heat the inner bottom plate of the K-shaped outer plate to form a strip heating band, and continuously heat and cool with water. The strip heating bands are distributed without breaks and are parallel but staggered in length. Step 5: Individual linear heating strips are applied to the inner bottom plate of the K-shaped outer panel. The width of the heating strips, heating temperature, heating speed, and water-fire distance are adjusted and controlled according to the thickness of the K-shaped outer panel and the curvature of the template lines. Step 6: The outer side of the K-shaped outer plate is heated by individual linear heating elements. The width of the heating strip, the heating temperature, the heating speed, and the water-fire distance are controlled according to the curvature of the template line. Step 7: Turn the K-shaped outer plate over so that the bottom is facing up. On the outer surface of the bottom plate, draw heating lines symmetrically from the side to the bottom along the neutral axis of the two wings of the K-shaped outer plate, following the original heating imprint. Repeat step 3 to perform continuous heating and water-tracking cooling. Step 8: Use the template to check the longitudinal curvature forming condition and use a ruler to check the transverse flatness and surface finish of the base plate.

2. The method for water and fire processing to prevent indentation of the inner bottom in marine K-shaped outer plate according to claim 1, characterized in that, In step three, when the heating gun is continuously heated, the oxygen-fuel gas is adjusted through the heating gun to form a neutral flame with a fixed flame core for jet combustion, forming a heating source with a high temperature of 3050-3150℃ for water-fire processing.

3. The method for water and fire processing to prevent indentation of the inner bottom in marine K-shaped outer plate according to claim 2, characterized in that, The oxy-fuel mixture includes oxygen, propane, acetylene, and natural gas.

4. The method for water and fire processing to prevent indentation of the inner bottom in marine K-shaped outer plate according to claim 1, characterized in that, In step three, the flame outlet length of the heating gun is the same as the outlet length of the cooling water tap.

5. A water-and-fire processing method for preventing indentation of the inner bottom in marine K-shaped outer plate according to claim 1, characterized in that, In step five, the width of the heating strip for 7-10mm thick plates is controlled between 15-17mm, and the heating temperature is controlled at 600℃; the width of the heating strip for 10-14mm thick plates is controlled between 17-20mm, and the heating temperature is controlled at 650℃.

6. The method for water and fire processing to prevent indentation of the inner bottom in marine K-shaped outer plate according to claim 1, characterized in that, In step seven, after all the preset heating lines on the inner bottom plate of the K-shaped outer plate have completed linear heating and cooling, the K-shaped outer plate is flipped over and placed. The heating lines are drawn in a circular pattern from the center of the two wings to the preheating position at the bottom. The heating water on both sides is simultaneously heated and cooled. The heating time is 1.5 times longer at the corner. Then the heating is moved towards the center of the outer bottom plate, and the linear heating is carried out at a uniform speed, with heating and cooling carried out simultaneously.

7. A water-and-fire processing method for preventing indentation of the inner bottom in marine K-shaped outer plate according to claim 1, characterized in that, In step eight, after all heating lines are completed, the template is used to check the longitudinal curvature and the bottom flatness is checked with a ruler. Any deviations are corrected locally until the template matches the rib line of each section of the K-shaped outer plate, ensuring that the outer surface of the K-shaped outer plate is smooth and glossy.

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