Metal sandwich structure and manufacturing method thereof

Abstract

The invention relates to a metal sandwich structure which comprises an upper panel, a lower panel and a metal sandwich layer arranged between the upper panel and the lower panel. The metal sandwich layer is composed of a plurality of core plates arranged in parallel, the upper end and the lower end of each core plate are perpendicularly connected with the upper face plate and the lower face plate respectively, and a gap is formed between every two adjacent core plates. In implementation, an upper panel, a lower panel and an inner metal sandwich layer between the two panels are arranged, the outermost side of the metal sandwich structure in the length direction and the width direction is an opening, a main body part of the metal sandwich layer between the peripheral openings is provided with core plates which are longitudinally arranged in parallel, and a hollow interlayer is arranged between the metal core plates. The upper and lower end faces of the core plate are connected with the inner surfaces of the panels through welding; by changing the thickness of the plate, the size of the panel, the height of the core plate and the distance between the core plates, the metal sandwich structure which has multiple size specifications and different structural strengths under the same structural form and can meet the requirements of various use scenes can be manufactured.

Description

Technical Field

[0001] The present invention relates to the technical field of ship plates, in particular to a metal sandwich structure and a manufacturing method thereof, and in particular to a multi-specification high-strength full-metal sandwich structure and a manufacturing method thereof in a hull structure. Background Art

[0002] In the prior art, conventional marine stiffened panels generally use a honeycomb metal sandwich structure, which has the problem of being bulky in structure, complicated in production process, high in manufacturing and production cost, and also has defects in bearing capacity. In the current technology, lightweight design of ship structures is a key project to be tackled, so conventional metal sandwich structure panels are no longer applicable.

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

[0004] The purpose of the present invention is to provide an improved metal sandwich structure and a manufacturing method thereof. Through the improvement of the structure, the bearing capacity of the structure is effectively improved, and it has the advantages of high strength, good collision resistance and impact resistance. At the same time, the process is simple, and metal sandwich structures of various specifications can be produced, which has a wide range of applications.

[0005] In order to achieve the above-mentioned purpose, 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 arranged between the upper and lower panels; the metal sandwich layer is composed of a plurality of parallel core panels, the upper and lower ends of each core panel are vertically connected to the upper and lower panels respectively, and there is a gap between adjacent core panels.

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

[0007] A preparation method for a metal sandwich structure, characterized in that: the preparation method comprises the following steps: a. cutting a high-strength structural steel plate into panel parts and core plate parts with required specifications by a laser cutting machine, and then leveling the panel parts and core plate parts after cutting and eliminating the stress generated by cutting; b. grinding and cleaning the welding area of ​​the parts to be welded to remove primer, oil stains and other impurities; c. clamping the core plate with a core plate clamping module, hoisting the upper panel so that the panel and the end face of the core plate are in close contact, and then welding the core plate to the upper panel; d. repeating step c, welding the core plate to the upper panel in turn; e. hoisting the lower panel, starting the panel deposit device so that the lower panel and the end face of the core plate are in close contact, and then laser penetration blind welding is performed on the core plate and the lower panel in turn; f. performing nondestructive testing, repairing and re-inspecting the detected welding defects, and completing the manufacture of the metal sandwich structure.

[0008] Preferably, in step c, the core board is raised with a cushion block until the upper end of the core board is about 3 mm higher than the upper surface of the core board clamping module, and the core board clamping module is started to make the core board close to the module reference plane so that the straightness tolerance is maintained less than or equal to 0.000033.

[0009] Furthermore, in step c, an assembly baseline is drawn on the upper and lower panels, the upper panel is hoisted to align it with both ends of the core panel, and the panel assembly baseline is aligned with the core panel theoretical line, the panel clamping module is started to make the panel and the core panel end faces fit tightly, and the assembly gap value is less than 0.0001mm; after the core panel is welded to the upper panel, the weld is cooled to below 40°C before subsequent assembly and welding operations are carried out.

[0010] Furthermore, in step d, the welded core plate is leveled by pyrotechnics or mechanical means to ensure that the flatness of the upper panel is ≤1 mm.

[0011] Furthermore, in step d, the lower panel is hoisted so that its four sides are aligned with the upper panel, and the panel pressing device is started to press down so that the lower panel is in close contact with the end face of the core panel, and the assembly gap is less than 0.0001mm.

[0012] Furthermore, in step f, visual inspection is used to perform an appearance inspection on the welds of the metal sandwich structure; a color penetration method is used to perform a non-destructive inspection on the surface quality of the welds of the metal sandwich structure; and an electromagnetic ultrasonic method is used to perform a non-destructive inspection 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: 1. The improved scheme of the present invention comprises an upper panel and a lower panel and a metal sandwich layer arranged between the upper panel and the lower panel; the metal sandwich layer is composed of a plurality of parallel core plates, the upper and lower ends of each core plate are respectively vertically connected to the upper panel and the lower panel, and a spacer is arranged between adjacent core plates. The metal sandwich structure has an overall lightweight design, and the bearing capacity can be effectively improved, and has the advantages of high strength, good collision resistance and impact resistance; 2. In the preparation method of the present invention, by changing the plate thickness, panel size, core plate height and core plate spacing, a high-strength metal sandwich structure with multiple sizes and specifications and different structural strengths under the same structural form can be manufactured to meet the needs of various usage scenarios; 3. The metal sandwich structure obtained by the preparation method of the present invention can increase the structural bending stiffness because the material distribution is far away from the neutral axis, solve the problems of weld formation, welding defects, welding deformation, etc., and improve production efficiency and product quality; 4. The welding process of the present invention is a laser penetration blind welding, that is, after positioning the two ends of the two pieces, high-power laser penetration welding is performed in an extremely narrow area of ​​3000mm long and 3mm wide when the weld tracking equipment cannot be used. Compared with the single-beam method, the oblique double-beam laser penetration welding can further increase the width of the joint surface between the core plate 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; 5. The present invention has a simple structure and a convenient manufacturing process, is applicable to metal sandwich structures of different specifications, has a wide range of applications, and is easy to promote and utilize. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an embodiment of the present invention.

[0015] Figure 2 It is a structural schematic diagram of a core plate clamping module according to an embodiment of the present invention.

[0016] Figure 3 It is a structural schematic diagram of a panel pressing module according to an embodiment of the present invention.

[0017] Figure 4 This is a schematic structural diagram of a first core plate and an upper panel after welding in another embodiment of the present invention.

[0018] Figure 5 This is a schematic diagram of the structure after the core plate and the upper panel are welded in another embodiment of the present invention.

[0019] Figure 6 It is a structural schematic diagram of the special platform for metal sandwich structure of the present invention.

[0020] Figure 7 This is a schematic diagram of measuring a metal sandwich structure according to the present invention.

[0021] Figure 8 It is a schematic diagram of the oblique double-beam laser penetration welding of a metal sandwich structure according to the present invention.

[0022] Reference numerals: 1 upper panel, 2 lower panel, 3 core board, 4 core board clamping module, 5 panel clamping module, 6 platform base, 7 detection point, 8 laser beam; 41 cushion block, 42 ​​core plate clamping module transverse screw rod, 43 transverse motor, 44 clamping cylinder; 51 module pressing plate, 52 pressing cylinder; 61 Panel clamping module transverse guide rail. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The present invention provides a metal sandwich structure, see Figure 1 , which is different from the prior art in that: the metal sandwich structure includes upper and lower panels and a metal sandwich layer arranged 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 are vertically connected to the upper and lower panels respectively, and there is a gap between adjacent core plates. The upper and lower panels and the core plate are all made of high-strength structural steel plates (such as A, B, D, E grade plates, or AH, BH, DH, EH grade marine high-strength steel) or other metal materials (such as titanium alloy plates, aluminum alloy plates or stainless steel plates).

[0025] During implementation, the upper and lower panels and the internal metal sandwich layer between the two panels, the outermost sides of the metal sandwich structure in the length and width directions are openings, the main body of the metal sandwich layer between the openings on all sides is a core panel arranged longitudinally in parallel, there are hollow partitions between the metal core panels, and the upper and lower end surfaces of the core panel are connected to the inner surface of the panel by welding; by changing the plate thickness, panel size, core panel height and core panel spacing, metal sandwich structures with multiple sizes and specifications and different structural strengths under the same structural form can be manufactured to meet the needs of various usage scenarios.

[0026] Example 1

[0027] In this embodiment, the metal sandwich structure includes upper and lower panels and a metal sandwich layer arranged between the upper and lower panels; the metal sandwich layer is composed of a number of parallel core panels, the upper and lower ends of each core panel are vertically connected to the upper and lower panels respectively, and there is a gap between adjacent core panels 3. The upper panel 1, the lower panel 2 and the core panel 3 are all made of high-strength structural steel plates. Specifically, the high-strength all-metal sandwich structure in this embodiment can increase the structural bending stiffness due to the material distribution away from the neutral axis, and has excellent properties such as high specific strength, vibration isolation and noise reduction, fire insulation, collision resistance and impact resistance.

[0028] The preparation method of the present invention comprises the following steps: a. cutting a high-strength structural steel plate into panel parts and core plate parts with required specifications by a laser cutting machine, and then leveling the panel parts and core plate parts after cutting 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 stains; c. clamping the core plate with a core plate clamping module, hoisting the upper panel so that the panel and the end face of the core plate are in close contact, and then welding the core plate to the upper panel; d. repeating step c, welding the core plate to the upper panel in turn; e. hoisting the lower panel, starting the panel deposit device so that the lower panel and the end face of the core plate are in close contact, and then laser penetration blind welding is performed on the core plate and the lower panel in turn; f. performing nondestructive testing, repairing and re-inspecting the detected welding defects, and completing the manufacture of the metal sandwich structure.

[0029] Preferably, in step c, the core board is raised with a cushion block 41 until the upper end of the core board is about 3 mm higher than the upper surface of the core board clamping module 4, and the core board clamping module is started to make the core board close to the module reference plane, so that the straightness tolerance is maintained less than or equal to 0.000033. In step c, the assembly baseline is drawn on the upper and lower panels, the upper panel 1 is hoisted to align it with the two ends of the core board 3, and the panel assembly baseline is aligned with the core board theoretical line, and the panel clamping module is started to make the panel close to the end face of the core board, and the assembly gap value is less than 0.0001mm; after the core board 3 is welded to the upper panel 1, the weld is cooled to below 40°C, and then the subsequent assembly and welding operations are carried out.

[0030] Specifically, in step d, the welded core plate is leveled by pyrotechnics or mechanical means to ensure that the flatness of the upper panel is ≤1mm. In step d, the lower panel is hoisted so that its four sides are aligned with the upper panel, and the panel pressing device is activated to press down so that the lower panel is tightly attached to the end face of the core plate, and the assembly gap is <0.0001mm.

[0031] In step e, laser penetration blind welding adopts oblique double-beam welding method, see Figure 8 , the laser beam is divided into two laser beams with a minimum diameter of 0.4mm, the beam center distance is adjusted to 2.5mm, the beam center is arranged crosswise and perpendicular to the direction of the weld, the beam angle is 40°, evenly distributed on both sides of the weld center line, and the beam intersection point is 3mm below the focal plane; the welding speed is 1200mm / min, the single laser power is 4.2kW, the dual laser total power is 8.4kW, the shielding gas is pure argon, and the gas flow rate is 25L / min. In actual welding, the midpoint of the line connecting the centers of the beams at both ends of the core plate must always be aligned with the center line of the core plate thickness, that is, the center of the laser welding pool width coincides with the center of the core plate thickness during welding, ensuring that the weld will not collapse or even weld through and other welding defects. At the same time, compared with the single beam method, the use of oblique double-beam laser penetration welding can further increase the width of the joint surface between the core plate 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.

[0032] In step f, visual inspection is used to perform an appearance inspection on the welds of the metal sandwich structure; a color penetration method is used to perform a non-destructive inspection on the surface quality of the welds of the metal sandwich structure; and an electromagnetic ultrasonic method is used to perform a non-destructive inspection on the connection effectiveness of the welded joints of the metal sandwich structure.

[0033] Specifically, the above steps are completed on a dedicated platform for metal sandwich structures (see Figure 6 ), including a platform base 6, with symmetrically arranged panel clamping module transverse guide rails 61 on both sides of the platform base, and the panel clamping module 5 can slide along the panel clamping transverse guide rails, and a core plate clamping module 4 matched with the panel clamping module is provided in the middle of the platform base, and a core plate clamping module transverse screw rod 42 matched with the core plate clamping module is provided on the platform base, and a transverse motor 43 for driving the transverse screw rod is provided at one end of the transverse screw rod. A downward pressing cylinder 52 for driving the panel clamping module to press down is provided on the panel clamping module, and a clamping cylinder 44 for driving the core plate clamping module to clamp is provided on the core plate clamping module.

[0034] Example 2

[0035] In this embodiment, the preparation method includes the following steps: a. Use a laser cutting machine to cut the high-strength structural steel plate into panel parts and core plate parts that meet the specifications, and then level the panel parts and core plate parts after cutting and eliminate the stress generated by cutting; b. Grind and clean the welding area of ​​the parts to be welded to remove primer, oil stains and other impurities; c. Clamp the core plate with a core plate clamping module, hoist the upper panel so that the panel is in close contact with the end face of the core plate, and then weld the core plate to the upper panel; d. Repeat step c and weld the core plate to the upper panel in turn; e. Hoist the lower panel and start the panel deposit device so that the lower panel is in close contact with the end face of the core plate, and then perform laser penetration blind welding on the core plate and the lower panel in turn; f. Perform non-destructive testing, repair and re-inspect the detected welding defects, and complete the manufacture of the metal sandwich structure.

[0036] Specifically, high-strength structural steel plates are cut into core plates and panels of specified specifications using a laser cutting machine, and the roughness of the cut surface should meet the requirement of Ra≤3.2; then the cut core plates and panel parts are leveled and the stress generated by the 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 to remove impurities such as primer and oil stains.

[0037] According to the core grid size and core board theoretical line position required by the design drawings, draw the core board assembly baseline on the non-frame surface of the upper and lower panels; put the core board into Figure 2The core plate clamping module 4 shown in the figure, according to the height of the core plate 3, use a suitable pad 41 to lift the core plate until the upper end of the core plate is about 3mm higher than the upper surface of the device, start the core plate clamping module to make the core plate close to the module reference plane, so that the straightness error is maintained ≤0.1mm / 3000mm; hoist the upper panel to align it with the two ends of the core plate, and align the panel assembly baseline with the two ends of the core plate theoretical line side, start the panel clamping module 5, as shown in the figure. Figure 3 As shown, the module pressing plate 51 is pressed down to make the inner surface of the upper panel close to the end surface of the core plate, and the assembly gap is less than 0.05mm; laser penetration welding is used to complete the welding of the T-joint between the upper panel and the core plate; after waiting for the weld to cool to below 40°C, the panel pressing module is released to complete the welding of the first core plate (as shown in FIG. Figure 4 Assemble the second core plate and repeat the above steps until all the core plates and upper panels are welded; turn over the welded single-sided comb assembly, and place and position the upper panel non-frame surface as the base surface (as shown in the figure). Figure 1 as shown).

[0038] Lift the lower panel so that its four sides are aligned with the upper panel, and start the panel pressing device to press down so that the lower panel is in close contact with the end surface of the core plate, and the assembly gap is less than 0.05mm; use laser penetration welding to repeat the above steps to complete the welding of the inner surface of the lower panel and the T-joint of the core plate (such as Figure 5 as shown).

[0039] Figure 6 It is a special platform for metal sandwich structure, including a platform base 6, symmetrically arranged panel clamping module transverse guide rails 61 are provided on both sides of the platform base, and the panel clamping module 5 can slide along the panel clamping transverse guide rails. The middle part of the platform base is provided with a core plate clamping module 4 that cooperates with the panel clamping module, and the platform base is provided with a core plate clamping module transverse screw rod 42 that cooperates with the core plate clamping module, and one end of the transverse screw rod is provided with a transverse motor 43 for driving the transverse screw rod. The panel clamping module is provided with a downward pressing cylinder 52 for driving the panel clamping module to press down, and the core plate clamping module is provided with a clamping cylinder 44 for driving the core plate clamping module to clamp.

[0040] Use visual inspection to inspect the appearance of metal sandwich structure welds; use color penetration method to perform non-destructive testing on the surface quality of metal sandwich structure welds; use electromagnetic ultrasonic method to perform non-destructive testing on the effectiveness of metal sandwich structure weld joint connection; use level to perform multi-point testing on the levelness of the upper and lower surfaces of the metal sandwich structure, and the test point 7 should be as follows: Figure 7 As shown in the figure, the bubbles on the level are all in the middle area, which means they are qualified.

[0041] Use a tape measure to measure the dimensions of the metal sandwich structure. The test items are length, width, and height. The length needs to be measured on both long sides, the width needs to be measured on both short sides, and the height needs to be measured on both short sides. Figure 7The 6 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 with a total station and compared with the theoretical model. The maximum error of the overall size should be ≤5mm.

[0042] The detected welding defects should be repaired and re-inspected using appropriate welding methods and process parameters to complete the manufacture of the metal sandwich structure. The metal core plate is obtained by laser cutting from a flat raw material plate. The upper and lower metal panels are obtained by laser cutting from a flat raw material plate.

[0043] The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to the above descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A metal sandwich structure, characterized in that: The metal sandwich structure includes upper and lower panels and a metal sandwich layer arranged between the upper and lower panels; the metal sandwich layer is composed of a number of parallel core panels, the upper and lower ends of each core panel are vertically connected to the upper and lower panels respectively, and intervals are provided between adjacent core panels.

2. A metal sandwich structure according to claim 1, characterized in that: The upper and lower panels and core plates are all made of high-strength structural steel plates.

3. The method for preparing a metal sandwich structure according to claim 1, characterized in that: The preparation method comprises the following steps: a. cutting the high-strength structural steel plate into panel parts and core plate parts with required specifications by using a laser cutting machine, and then leveling the panel parts and core plate parts after cutting 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 stains; c. clamping the core plate with a core plate clamping module, hoisting the upper panel so that the panel and the end face of the core plate are in close contact, and then welding the core plate to the upper panel; d. repeating step c, welding the core plate to the upper panel in turn; e. hoisting the lower panel, starting the panel deposit device so that the lower panel and the end face of the core plate are in close contact, and then laser penetration blind welding is performed on the core plate and the lower panel in turn; f. performing nondestructive testing, repairing and re-inspecting the detected welding defects, and completing the manufacture of the metal sandwich structure.

4. The method for preparing a metal sandwich structure according to claim 1, characterized in that: In step c, use a spacer to raise the core plate until the upper end of the core plate is about 3 mm higher than the upper surface of the core plate clamping module, and start the core plate clamping module to make the core plate fit tightly against the module reference plane, so that the straightness tolerance is maintained less than or equal to 0.000033.

5. The method for preparing a metal sandwich structure according to claim 1, characterized in that: In step c, draw assembly baselines on the upper and lower panels, hoist the upper panel so that it is aligned with both ends of the core panel, and align the panel assembly baseline with the core panel theoretical line, start the panel clamping module, make the panel and the core panel end face close together, and the assembly gap value is less than 0.0001mm; after the core panel is welded to the upper panel, the weld is cooled to below 40°C before subsequent assembly and welding operations are carried out.

6. The method for preparing a metal sandwich structure according to claim 1, characterized in that: In step d, the welded core plate is leveled by pyrotechnics or mechanical means to ensure that the flatness of the upper panel is ≤1mm.

7. The method for preparing a metal sandwich structure according to claim 1, characterized in that: In step d, hoist the lower panel so that its four sides are aligned with the upper panel, and start the panel pressing device to press down so that the lower panel is in close contact with the end face of the core plate, and the assembly gap is less than 0.0001mm.

8. The method for preparing a metal sandwich structure according to claim 1, characterized in that: In step e, the laser penetration blind welding adopts the oblique double-beam welding method, dividing the laser beam into two laser beams with a minimum diameter of 0.4mm. The center distance of the beams is adjusted to 2.5mm, and the beams are arranged crosswise and perpendicular to the direction of the weld. The beam angle is 40° and evenly distributed on both sides of the center line of the weld. The intersection point of the beams is 3mm below the focal plane; the welding speed is 1200mm / min, the single laser power is 4.2kW, the total power of the dual lasers is 8.4kW, the shielding gas is pure argon, and the gas flow rate is 25L / min.

9. The method for preparing a metal sandwich structure according to claim 1, characterized in that: In step f, visual inspection is used to perform an appearance inspection on the welds of the metal sandwich structure; a color penetration method is used to perform a non-destructive inspection on the surface quality of the welds of the metal sandwich structure; and an electromagnetic ultrasonic method is used to perform a non-destructive inspection on the connection effectiveness of the welded joints of the metal sandwich structure.

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