Metal sandwich structure and method for manufacturing the same

Abstract

The present application relates to a kind of metal sandwich structure, including upper and lower panel and its metal sandwich layer being arranged between upper and lower panel;Metal sandwich layer is made of several parallelly arranged core plates, the upper and lower ends of each core plate are vertically connected with upper and lower panel respectively, and spacing is provided between adjacent core plates.In implementation, the internal metal sandwich layer between upper and lower panel and two panels, the outermost side of metal sandwich structure in length and width direction is open, the main part of metal sandwich layer between the four peripheral openings is longitudinally arranged core plate, and the core plate is hollow partition between metal core plate, and the upper and lower end surfaces of core plate are connected with the inner surface of panel by welding method;By changing the thickness of plate material, panel size, core plate height and core plate spacing, metal sandwich structure of multiple size specifications, different structural strength, which can meet the needs of various use scenarios, can be manufactured under the same structure form.

Description

Technical Field

[0001] This invention relates to the technical field of ship plate materials, specifically to a metal sandwich structure and its manufacturing method, and more particularly to a multi-specification high-strength all-metal sandwich structure for ship hull structures and its manufacturing method. Background Technology

[0002] In existing technologies, traditional marine stiffening plates typically employ a honeycomb-shaped metal sandwich structure. This type of honeycomb metal sandwich panel suffers from a relatively heavy structure, complex manufacturing process, and high production costs, while also exhibiting limitations in load-bearing capacity. Currently, lightweight design of ship structures is a key area requiring technological breakthroughs, thus rendering traditional metal sandwich panel structures unsuitable.

[0003] Therefore, there is an urgent need in the market for a new type of metal sandwich panel and a simpler manufacturing process. Summary of the Invention

[0004] The purpose of this invention is to provide an improved metal sandwich structure and its manufacturing method. Through structural improvement, the load-bearing capacity of the structure is effectively enhanced, and it has the advantages of high strength, good impact resistance and shock resistance. At the same time, the process is simple, and it can produce metal sandwich structures of various specifications, with a wide range of applications.

[0005] To achieve the above objectives, the technical solution of the present invention is: a metal sandwich structure, characterized in that: the metal sandwich structure includes upper and lower panels and a metal sandwich layer disposed between the upper and lower panels; the metal sandwich layer is composed of a number of parallel core plates, the upper and lower ends of each core plate being perpendicularly connected to the upper and lower panels respectively, and a gap being provided between adjacent core plates.

[0006] Preferably, the upper and lower panels and the core panel are all made of high-strength structural steel plates.

[0007] A method for manufacturing a metal sandwich structure, characterized by the following steps: a) cutting a high-strength structural steel plate into panel parts and core parts of specified dimensions using a laser cutting machine, then leveling the cut panel parts and core parts and eliminating the stress generated by cutting; b) grinding and cleaning the welding area of ​​the parts to be welded to remove impurities such as primer and oil; c) clamping the core plate with a core plate clamping module, hoisting the upper panel so that the panel is in close contact with the end face of the core plate, and then welding the core plate to the upper panel; d) repeating step c, welding the core plates to the upper panel in sequence; e) hoisting the lower panel, activating the panel depositing device so that the lower panel is in close contact with the end face of the core plate, and then performing laser penetration blind welding on the core plate and the lower panel in sequence; f) performing non-destructive testing, repairing and re-inspecting the detected welding defects, and completing the manufacturing of the metal sandwich structure.

[0008] Preferably, in step c, the core board is raised with a pad block until the upper end of the core board is about 3mm above the upper surface of the core board clamping module, and the core board clamping module is activated to make the core board tightly attached to the module reference plane, so that its straightness tolerance is less than or equal to 0.000033.

[0009] Further, in step c, the assembly baseline is marked on the upper and lower panels, the upper panel is hoisted and aligned with both ends of the core board, and the panel assembly baseline is aligned with the theoretical line of the core board. The panel clamping module is activated to make the panel and the end face of the core board fit tightly together, with an assembly gap of less than 0.0001mm. After the core board is welded to the upper panel, the weld is cooled to below 40℃ before subsequent assembly and welding operations are carried out.

[0010] Furthermore, in step d, the welded core board is leveled using either fire or mechanical methods to ensure that the flatness of the top panel is ≤1mm.

[0011] Further, in step d, the lower panel is hoisted so that its four sides are aligned with the upper panel, and the panel clamping device is activated to press down so that the lower panel is tightly attached to the end face of the core board, with an assembly gap of <0.0001mm.

[0012] Furthermore, in step f, visual inspection is used to examine the weld seams of the metal sandwich structure; dye penetrant testing is used to perform non-destructive testing on the surface quality of the weld seams of the metal sandwich structure; and electromagnetic ultrasonic testing is used to perform non-destructive testing on the connection effectiveness of the welded joints of the metal sandwich structure.

[0013] Compared with the prior art, the technical solution of the present invention not only improves the overall technical solution, but also includes many improvements in details. Specifically, it has the following beneficial effects:

[0014] 1. The improved solution of the present invention includes a metal sandwich structure comprising upper and lower panels and a metal sandwich layer disposed between the upper and lower panels; the metal sandwich layer is composed of several parallel core plates, the upper and lower ends of each core plate being perpendicularly connected to the upper and lower panels respectively, and a gap being provided between adjacent core plates. The metal sandwich structure is designed to be lightweight as a whole, while its load-bearing capacity can be effectively improved, and it has the advantages of high strength, good impact resistance and impact resistance.

[0015] 2. In the preparation method of the present invention, by changing the thickness of the sheet, the size of the panel, the height of the core board and the spacing between the core boards, a high-strength metal sandwich structure with multiple sizes and different structural strengths under the same structural form can be manufactured to meet the needs of various application scenarios.

[0016] 3. The metal sandwich structure obtained by the preparation method of the present invention has increased structural bending stiffness due to the material distribution being far from the neutral axis, which solves problems such as weld formation, welding defects, and welding deformation, thereby improving production efficiency and product quality;

[0017] 4. The welding process of the present invention is a laser penetration blind welding, that is, after positioning the two ends of the two parts, high-power laser penetration welding is performed in an extremely narrow area of ​​3000mm in length and 3mm in width when weld seam tracking equipment cannot be used. Compared with the single beam method, the oblique double beam laser penetration welding can further increase the joint width of the core board and the panel welding joint, greatly improve the strength of the metal sandwich structure welding joint, and also strengthen the overall strength of the structure.

[0018] 5. The present invention has a simple structure and convenient manufacturing process. It is applicable to metal sandwich structures of different specifications, has a wide range of applications, and is easy to promote and utilize. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a structure according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the core board clamping module according to an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of a panel pressing module according to an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the structure after the first core board is welded to the upper panel in another embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram of the structure after the core board and the top panel are welded together in another embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram of the structure of the special platform for the metal sandwich structure of the present invention.

[0025] Figure 7 This is a schematic diagram illustrating the measurement of the metal sandwich structure according to the present invention.

[0026] Figure 8 This is a schematic diagram of the oblique dual-beam laser penetration welding of the metal sandwich structure according to the present invention.

[0027] Figure label:

[0028] 1. Top panel, 2. Bottom panel, 3. Core board, 4. Core board clamping module, 5. Panel pressing module, 6. Platform base, 7. Detection point, 8. Laser beam;

[0029] 41 Pad block, 42 ​​Core board clamping module transverse lead screw, 43 Transverse motor, 44 Clamping cylinder;

[0030] 51 Module pressure plate, 52 Downward pressure cylinder;

[0031] 61 Panel clamping module transverse guide rail. Detailed Implementation

[0032] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0033] This invention provides a metal sandwich structure, see details below. Figure 1 The difference between this and existing technologies lies in the following: the metal sandwich structure includes upper and lower panels and a metal sandwich layer disposed between the upper and lower panels; the metal sandwich layer is composed of several parallel core plates, the upper and lower ends of each core plate being perpendicularly connected to the upper and lower panels respectively, and there are gaps between adjacent core plates. The upper and lower panels and the core plates are all made of high-strength structural steel plates (such as A, B, D, and E grade plates, or AH, BH, DH, and EH grade marine high-strength steel) or other metal materials (such as titanium alloy plates, aluminum alloy plates, or stainless steel plates).

[0034] In practice, the upper and lower panels and the internal metal sandwich layer between the two panels have openings on the outermost sides in the length and width directions. The main body of the metal sandwich layer between the four openings consists of longitudinally arranged core plates, with hollow partitions between the metal core plates. The upper and lower end faces of the core plates are connected to the inner surface of the panels by welding. By changing the plate thickness, panel size, core plate height, and core plate spacing, metal sandwich structures with multiple sizes and different structural strengths under the same structural form can be manufactured to meet the needs of various application scenarios.

[0035] Example 1

[0036] In this embodiment, the metal sandwich structure includes upper and lower panels and a metal sandwich layer disposed between the upper and lower panels. The metal sandwich layer is composed of several parallel core plates, with the upper and lower ends of each core plate perpendicularly connected to the upper and lower panels, respectively, and a gap between adjacent core plates 3. The upper panel 1, lower panel 2, and core plates 3 are all made of high-strength structural steel plates. Specifically, the high-strength all-metal sandwich structure in this embodiment, due to the material distribution being far from the neutral axis, can increase the structural bending stiffness and has excellent properties such as high specific strength, vibration isolation and noise reduction, fire resistance and heat insulation, and good impact resistance.

[0037] The preparation method of the present invention includes the following steps: a) Cutting high-strength structural steel plates into panel parts and core board parts of required specifications using a laser cutting machine, and then leveling the cut panel parts and core board parts and eliminating the stress generated by cutting; b) Grinding and cleaning the welding area of ​​the parts to be welded to remove impurities such as primer and oil; c) Clamping the core board with a core board clamping module, hoisting the upper panel so that the panel is in close contact with the end face of the core board, and then welding the core board to the upper panel; d) Repeating step c, welding the core board to the upper panel in sequence; e) Hoisting the lower panel, activating the panel deposit device so that the lower panel is in close contact with the end face of the core board, and then performing laser penetration blind welding on the core board and the lower panel in sequence; f) Performing non-destructive testing, repairing and re-inspecting the detected welding defects, and completing the manufacturing of the metal sandwich structure.

[0038] Preferably, in step c, the core plate is raised using the pad block 41 until its upper end is approximately 3mm above the upper surface of the core plate clamping module 4. The core plate clamping module is then activated to ensure the core plate is tightly attached to the module's reference plane, maintaining a straightness tolerance of less than or equal to 0.000033. In step c, assembly baselines are marked on the upper and lower panels. The upper panel 1 is hoisted and aligned with both ends of the core plate 3, and the panel assembly baseline is aligned with the theoretical line of the core plate. The panel clamping module is then activated to ensure the panel is tightly attached to the end face of the core plate, with an assembly gap of less than 0.0001mm. After the core plate 3 is welded onto the upper panel 1, the weld is allowed to cool to below 40°C before subsequent assembly and welding operations are performed.

[0039] Specifically, in step d, the welded core board is leveled using either heat treatment or mechanical methods to ensure the flatness of the upper panel is ≤1mm. In step d, the lower panel is hoisted, its four sides are aligned with the upper panel, and the panel clamping device is activated to press down, making the lower panel tightly adhere to the end face of the core board, with an assembly gap of <0.0001mm.

[0040] In step e, laser penetration blind welding employs an oblique dual-beam welding method. (See [link to step e]) Figure 8 The laser beam was divided into two beams with a minimum diameter of 0.4 mm each. The beam centers were adjusted to a distance of 2.5 mm, intersecting and perpendicular to the weld direction, with a 40° beam angle evenly distributed on both sides of the weld centerline. The beam intersection point was located 3 mm below the focal plane. The welding speed was 1200 mm / min, the single laser power was 4.2 kW, and the total power of the two lasers was 8.4 kW. The shielding gas was pure argon with a flow rate of 25 L / min. During actual welding, the midpoint of the line connecting the centers of the two beams at the core plate ends must always be aligned with the centerline of the core plate thickness. That is, during the welding process, the center of the laser weld pool width coincides with the centerline of the core plate thickness to ensure that welding defects such as weld collapse or even weld penetration do not occur. At the same time, compared with the single-beam method, the use of oblique double-beam laser penetration welding can further increase the joint width of the core plate and the panel weld joint, significantly improve the strength of the weld joint of the metal sandwich structure, and also strengthen the overall strength of the structure.

[0041] In step f, visual inspection is used to examine the welds of the metal sandwich structure; dye penetrant testing is used to perform non-destructive testing on the surface quality of the welds of the metal sandwich structure; and electromagnetic ultrasonic testing is used to perform non-destructive testing on the connection effectiveness of the welded joints of the metal sandwich structure.

[0042] Specifically, the above steps are completed on a dedicated platform for metal sandwich structures (see...). Figure 6 The system includes a platform base 6, with symmetrically arranged panel clamping module transverse guide rails 61 on both sides. The panel clamping module 5 can slide along the panel clamping transverse guide rails. A core board clamping module 4 that cooperates with the panel clamping module is located in the middle of the platform base. A core board clamping module transverse lead screw 42 that cooperates with the core board clamping module is located on the platform base. A transverse motor 43 for driving the transverse lead screw is located at one end of the transverse lead screw. A pressing cylinder 52 for driving the panel clamping module to press down is located on the panel clamping module, and a clamping cylinder 44 for driving the core board clamping module to clamp is located on the core board clamping module.

[0043] Example 2

[0044] In this embodiment, the preparation method includes the following steps: a) Cutting high-strength structural steel plates into panel parts and core board parts according to specifications using a laser cutting machine, and then leveling the cut panel parts and core board parts and eliminating the stress generated by cutting; b) Grinding and cleaning the welding area of ​​the parts to be welded to remove impurities such as primer and oil; c) Clamping the core board with a core board clamping module, hoisting the upper panel so that the panel is in close contact with the end face of the core board, and then welding the core board to the upper panel; d) Repeating step c, welding the core board to the upper panel in sequence; e) Hoisting the lower panel, activating the panel deposit device so that the lower panel is in close contact with the end face of the core board, and then performing laser penetration blind welding on the core board and the lower panel in sequence; f) Performing non-destructive testing, repairing and re-inspecting the detected welding defects, and completing the manufacturing of the metal sandwich structure.

[0045] Specifically, high-strength structural steel plates are cut into core plates and panels of specified specifications using a laser cutting machine, and the surface roughness of the cut surface should meet Ra≤3.2; then the cut core plate and panel parts are leveled and the stress generated by cutting is eliminated, and the flatness of the large surface of the parts should be ≤0.5mm; then a stainless steel wire brush is used to grind and clean the area within 20mm around the weld of the parts to be welded, removing impurities such as primer and oil.

[0046] According to the core grid dimensions and theoretical line positions of the core board as required by the design drawings, mark the core board assembly baseline on the non-framework surfaces of the upper and lower panels; place the core board into... Figure 2The shown core plate clamping module 4 raises the core plate 3 to a height such that the upper end of the core plate is about 3 mm higher than the upper surface of the device using a suitable spacer 41 according to the height of the core plate. Start the core plate clamping module to make the core plate closely adhere to the reference plane of the module, and keep the straightness error ≤ 0.1 mm / 3000 mm. Lift and install the upper panel, align its two ends with those of the core plate, and align the panel assembly baseline with the two ends of the theoretical line of the core plate. Start the panel pressing module 5, as Figure 3 shown, the module pressing plate 51 presses down to make the inner surface of the upper panel closely adhere to the end face of the core plate, and the assembly gap < 0.05 mm. Use laser penetration welding to complete the welding of the T-joint between the upper panel and the core plate. After waiting for the weld seam to cool below 40 °C, loosen the panel pressing module to complete the welding of the first core plate (as Figure 4 shown); Assemble the second core plate and repeat the above steps until the weld seams between all core plates and the upper panel are completed; Flip the assembled single-sided comb-shaped structure over, and place and position it in the reverse state with the non-frame surface of the upper panel as the base surface (as Figure 1 shown).

[0047] Lift and install the lower panel, align its four sides with those of the upper panel, and start the panel pressing device to press down to make the lower panel closely adhere to the end face of the core plate, and the assembly gap < 0.05 mm. Use laser penetration welding to repeat the above steps to complete the welding of the T-joint between the inner surface of the lower panel and the core plate (as Figure 5 shown).

[0048] Figure 6 It is a special platform for metal sandwich structures, including a platform base 6. On both sides of the platform base, there are symmetrically arranged panel pressing module transverse guide rails 61. The panel pressing module 5 can slide along the panel pressing transverse guide rails. In the middle of the platform base, there is a core plate clamping module 4 that cooperates with the panel pressing module. On the platform base, there is a core plate clamping module transverse screw rod 42 that cooperates with the core plate clamping module. One end of the transverse screw rod is provided with a transverse motor 43 for driving the transverse screw rod. On the panel pressing module, there is a pressing cylinder 52 for driving the panel pressing module to press down. On the core plate clamping module, there is a clamping cylinder 44 for driving the core plate clamping module to clamp.

[0049] Use visual inspection to check the appearance of the weld seams of the metal sandwich structure; Use the coloring penetration method to perform non-destructive testing on the surface quality of the weld seams of the metal sandwich structure; Use the electromagnetic ultrasonic method to perform non-destructive testing on the connection effectiveness of the welded joints of the metal sandwich structure; Use a level to perform multi-point detection on the flatness of the upper and lower surfaces of the metal sandwich structure. The detection points 7 should be as Figure 7 shown, and it is qualified if the level bubbles are all in the middle area.

[0050] Use a tape measure to measure the external dimensions of the metal sandwich structure. The detection items are length, width, and height. Among them, the length needs to be measured for the two long sides on both sides, the width needs to be measured for the two short sides at both ends, and the height needs to be measured according to Figure 7The six points shown are measured. The length error should be ≤5mm / 3000mm, the width error should be ≤2mm / 1500mm, and the height error should be ≤2mm / 500mm. The metal sandwich structure is measured using a total station and compared with the theoretical model. The maximum error of the overall dimensions should be ≤5mm.

[0051] Detected welding defects should be repaired and re-inspected using appropriate welding methods and process parameters to complete the manufacturing of the metal sandwich structure. The metal core plate is obtained by laser cutting of a flat raw material plate. The upper and lower metal panels are also obtained by laser cutting of a flat raw material plate.

[0052] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for manufacturing a metal sandwich structure, the metal sandwich structure comprising upper and lower panels and a metal sandwich layer disposed between the upper and lower panels; the metal sandwich layer is composed of a plurality of parallel core plates, the upper and lower ends of each core plate being perpendicularly connected to the upper and lower panels respectively, and a gap being provided between adjacent core plates; the upper and lower panels and the core plates are all made of high-strength structural steel plates, characterized in that: The preparation method comprises the following steps: a, cutting high-strength structural steel plates into panel parts and core plate parts with a laser cutting machine, and then flattening the panel parts and the core plate parts after cutting and eliminating the stress generated during cutting; b, polishing and cleaning the welding area of the parts to be welded to remove the primer, oil stains and impurities; c, clamping the core plate with a core plate clamping module, hoisting the upper panel, and then tightly attaching the upper panel to the end surface of the core plate, and then welding the core plate on the upper panel; d, repeating the step c, and sequentially welding the core plates on the upper panel; e, hoisting the lower panel, starting the panel pressing device, and then tightly attaching the lower panel to the end surface of the core plate, and then sequentially performing laser penetration blind welding on the core plate and the lower panel, wherein the laser penetration blind welding adopts an oblique double-beam welding method, the laser beam is divided into two laser beams with a minimum diameter of 0.4 mm, the center distance of the laser beams is adjusted to 2.5 mm, the laser beams are arranged in cross and perpendicular to the weld joint, the laser beam angle is 40° and is uniformly distributed on both sides of the weld center line, and the intersection point of the laser beams is located 3 mm below the focal plane; f, performing nondestructive testing, repairing and re-inspecting the detected welding defects, and completing the manufacturing of the metal sandwich structure.

2. A method of making a metal sandwich structure according to claim 1, characterized in that: In the step c, the core plate is lifted by the spacer to be 3 mm higher than the upper end of the core plate clamping module, the core plate clamping module is started to tightly attach the core plate to the reference plane of the module, and the straightness tolerance is less than or equal to 0.000033.

3. The method of claim 1, wherein: In the step c, the assembly base line is drawn on the upper and lower panels, the upper panel is hoisted to be aligned with the two ends of the core plate, the panel assembly base line is aligned with the theoretical line of the core plate, the panel pressing module is started to tightly attach the panel to the end surface of the core plate, and the assembly gap value is less than 0.0001 mm; after the core plate is welded on the upper panel, the welding seam is cooled to below 40 DEG C, and then subsequent assembly and welding operations are performed.

4. The method of claim 1, wherein: In the step d, the completed core plate is flattened by using a pyrotechnic or mechanical method, and the flatness of the upper panel is ensured to be less than or equal to 1 mm.

5. The method of claim 1, wherein: In the step d, the lower panel is hoisted to be aligned with the four edges of the upper panel, and the panel pressing device is started to press down, so that the lower panel is tightly attached to the end surface of the core plate, and the assembly gap is less than 0.0001 mm.

6. The method of claim 1, wherein: In the step e, the welding speed is 1200 mm / min, the single laser power is 4.2 kW, the total power of the double laser is 8.4 kW, the protective gas is pure argon, and the gas flow is 25 L / min.

7. The method of claim 1, wherein: In the step f, visual inspection is used to perform appearance inspection on the welding seam of the metal sandwich structure, the coloring penetration method is used to perform nondestructive testing on the surface quality of the welding seam of the metal sandwich structure, and the electromagnetic ultrasonic method is used to perform nondestructive testing on the connection effectiveness of the welding joint of the metal sandwich structure.

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