Method and device for forming curved surface of plate with thickness

Abstract

The present invention relates to the technical field of sheet metal forming, and solves the problem in the prior art of honeycomb aluminum sheet forming that it is impossible to separately control and process multiple sheets of different shapes at the same time. Specifically, a method and device for forming a curved surface of a sheet metal having thickness are disclosed, including a flat sheet forming area and a curved surface forming area; a flat sheet forming platform is provided in the flat sheet forming area, and a curved sheet forming base is provided in the curved surface forming area, and the curved sheet forming base includes a forming support base at the bottom and a curved sheet forming placement table provided on the upper surface of the forming support base; a multi-piece parallel heating plate group is provided on the bottom surface of the flat sheet forming platform, and the multi-piece parallel heating plate group is electrically connected to an electric control power supply; a coating pressure layer is provided on the flat sheet forming area and the curved surface forming area, and a suction port is provided on the flat sheet forming area. The present invention is used for forming sheets of thickness, and the curved sheet metal and the flat sheet metal can be formed simultaneously with the same set of equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of plate forming, in particular to a method and device for forming a curved surface of a plate having thickness. Background Art

[0002] Honeycomb aluminum panels are a thick composite material composed of two thin aluminum sheets and a honeycomb aluminum core. Due to their lightweight, high-strength, sound-insulating, and heat-insulating properties, they are widely used in architecture, aerospace, transportation, and other fields. Compression molding is the most common method for forming honeycomb aluminum panels. This involves pressing the bonded aluminum sheets and honeycomb core together to create a more solid and flat surface. The molding process requires precise control of temperature and pressure. Other molding methods include stamping and bending.

[0003] The high-precision processing and forming technology of honeycomb aluminum panels is quite difficult. In applications, they often need to be formed into various complex shapes, such as hyperboloids and curved surfaces. When using molds for press forming, the mold opening precision is very high, and a set of molds can only batch form plates of a single shape. It is impossible to form multiple shapes at the same time. The forming molds for concave and convex pressing are expensive and cannot produce workpieces with large size ranges. When forming using processes such as stamping and bending, in addition to the material's tendency to rebound, the heat generated during processing and the strong ductility of aluminum can easily lead to plastic deformation during processing beyond the required forming requirements, affecting processing precision and product quality. Therefore, the forming equipment and processes of honeycomb aluminum panels are expensive, difficult to process, and lack forming precision. The processing equipment and forming methods in the existing technology are difficult to avoid the above problems. Summary of the Invention

[0004] In order to solve the problem in the prior art of forming honeycomb aluminum panels that multiple panels of different shapes cannot be controlled and processed simultaneously, the present invention provides a method and device for forming a curved surface of a panel with thickness.

[0005] The technical solution adopted in the present invention is:

[0006] A device for forming a curved surface of a plate having thickness, comprising a flat surface forming area and a curved surface forming area, wherein the curved surface forming area is arranged in the flat surface forming area;

[0007] A flat plate forming platform is provided in the flat forming area, and a curved plate forming base is provided in the curved surface forming area. The curved plate forming base includes a forming support base at the bottom and a curved plate forming placement table provided on the upper surface of the forming support base for placing plates for bonding and curved surface forming.

[0008] The bottom surface of the flat plate forming platform is provided with a multi-piece parallel heating plate group for adjusting the temperature according to the plate forming requirements to heat and solidify the plate, and the multi-piece parallel heating plate group is electrically connected to an electric control power supply;

[0009] The flat surface forming area and the curved surface forming area are provided with a covering pressure layer for laminating and covering the plate and applying forming pressure to the plate. The flat surface forming area is provided with a suction port for connecting to a vacuum device.

[0010] Furthermore, a pressing frame mechanism is installed at a position around the edge of the flat panel forming platform, and the pressing frame mechanism includes a fixed pressing frame installed on the upper surface of the coated pressurizing layer and a pressing frame locking mechanism for fixing the fixed pressing frame to the flat panel forming platform. The pressing frame locking mechanism includes a locking member and a locking screw, one end of the locking member is connected to the fixed pressing frame, and the other end of the locking member is connected to the flat panel forming platform through the locking screw.

[0011] Furthermore, a pressure frame mounting groove for accommodating a fixed pressure frame is provided at the installation position of the pressure frame mechanism on the flat plate forming platform. The shape of the pressure frame mounting groove matches the fixed pressure frame, and the pressure frame mounting groove is concave. The coated pressurization layer is provided between the pressure frame mounting groove and the fixed pressure frame. A sealing strip for achieving gas sealing in the internal space of the coated pressurization layer is also connected between the bottom surface of the fixed pressure frame and the coated pressurization layer.

[0012] Furthermore, the multi-piece parallel heating plate group is evenly distributed on the bottom surface of the flat plate forming platform, and the curved plate forming base is equipped with a curved plate heat conduction mechanism;

[0013] The curved panel heat conduction mechanism includes a plurality of heat conduction bars arranged on a forming support base, and the heat conduction bars are connected to a multi-piece parallel heating plate group. The curved panel heat conduction mechanism also includes a curved surface heat conduction plate installed on a curved panel forming placement table, and the curved surface heat conduction plate is connected to the heat conduction bars. The curved surface heat conduction plates are evenly distributed on the curved panel forming placement table and have an embedded installation structure. The upper surface of the curved surface heat conduction plate and the upper surface of the curved panel forming placement table are located in the same curved surface.

[0014] Furthermore, the laminating and pressurizing layer includes a polyvinyl alcohol high-barrier composite film, a polyvinyl alcohol water-soluble liquid coating layer is provided on the side of the polyvinyl alcohol high-barrier composite film used for bonding with the plate, and a heat-conductive film layer is provided on the side of the polyvinyl alcohol high-barrier composite film facing away from the plate; the curved panel forming placement platform is composed of a metal panel, and the flat panel forming platform is composed of a glass panel.

[0015] Furthermore, a curved surface pressure regulating mechanism is provided at a position on the laminating and pressurizing layer corresponding to the curved surface forming area;

[0016] The curved surface pressure adjustment mechanism includes an auxiliary adjustment substrate and a piezoelectric chip mounted on the auxiliary adjustment substrate for changing the pressure by driving the auxiliary adjustment substrate to deform through the piezoelectric effect. The shape and size of the auxiliary adjustment substrate correspond to the shape and size of the surface of the curved panel forming and placing table. Pressure sensors are evenly arranged on the auxiliary adjustment substrate.

[0017] A plurality of piezoelectric chips are provided, and the distribution density of the piezoelectric chips at the middle axis of the plate surface close to the auxiliary adjustment substrate is higher than the distribution density at the edge of the plate close to the auxiliary adjustment substrate;

[0018] The curved surface pressure regulating mechanism also includes a voltage regulating component electrically connected to the piezoelectric chip. Both the pressure sensing sensor and the voltage regulating component are connected to a power main control unit via a signal transmission component.

[0019] A method for forming a curved surface of a plate having thickness is performed using the above-mentioned curved surface forming device for a plate having thickness, comprising the following steps:

[0020] A. Perform arc pretreatment on the panel and bottom plate materials of the plate, roll the panel and bottom plate materials into an arc shape, and eliminate the internal stress in the panel and bottom plate materials;

[0021] B. Lay the bottom plate and the top plate of the plate after the arc pretreatment on the two sides of the plate core respectively, and evenly apply the adhesive material on the laminating surface to make the layers of materials bonded together to form a thick composite plate;

[0022] C. Placing the bonded sheet material on a curved panel forming placement table of a curved panel forming base of a sheet material curved surface forming device, so that the sheet material is attached to the forming surface of the curved panel forming placement table;

[0023] D. Covering the curved panel forming and placing table with a film-coated and pressurized layer, and fixing a press frame mechanism around the film-coated and pressurized layer around the curved panel forming and placing table to form an airtight structure inside;

[0024] E. Turn on the vacuum device connected to the suction port to extract the air in the space between the curved panel forming platform and the laminating and pressurizing layer to create a negative pressure environment. At the same time, turn on the electric control power supply of the multi-piece parallel heating plate group to heat the panel during the forming process and accelerate the curing process of the adhesive material.

[0025] F. After the negative pressure and heating process reaches the required time, stop vacuuming and heating, open the pressing frame mechanism and the laminating pressure layer, take out the plate on the curved plate forming table, and complete the curved surface forming process of the plate.

[0026] Furthermore, in step A, the front panel and the bottom panel after arcing are subjected to heat treatment to further eliminate stress, the heat treatment temperature is 150° C. to 250° C., the time is 5 minutes to 50 minutes, and the arcing speed is controlled to 5 to 10 meters per minute;

[0027] The pressure of the negative pressure formed by vacuuming in step E is controlled at -0.1 MPa to -0.05 MPa, the heating temperature is controlled at 80° C. to 150° C., and the heating time is controlled at 1 hour to 3 hours.

[0028] Furthermore, during the curved surface forming process of the plate, a curved surface pressure regulating mechanism is used to regulate the pressure of the curved surface forming of the plate. The specific regulation control method includes the following steps:

[0029] (1) Based on the plate shape, material properties, dimensional information of the plate, processing negative pressure, correlation between the voltage and deformation of the piezoelectric chip in the auxiliary regulating substrate, the ratio of the deformation of the piezoelectric chip to the auxiliary regulating substrate, and correlation between the deformation and pressure of the auxiliary regulating substrate, the pressure and duration required to be applied to multiple points on the force-bearing surface during the plate curved surface forming process are preset in the power main control unit;

[0030] (2) When covering and setting the laminating and pressurizing layer in step D, the auxiliary adjustment substrate of the curved surface pressure adjustment mechanism is aligned with the position of the plate to be processed, and the edge of the auxiliary adjustment substrate is fixed together with the edge of the plate to be processed;

[0031] (3) At the same time as the vacuum pumping device is turned on in step E, the curved surface pressure regulating mechanism is turned on, and the power main control unit sends a signal to increase the voltage to the voltage regulating component through the signal transmission component. After receiving the signal, the voltage regulating component linearly adjusts and increases the voltage of the piezoelectric chip in the auxiliary regulating substrate;

[0032] (4) When the pressure information of each position fed back by the pressure sensor through the signal transmission component reaches the value preset in step (1), the power main control unit sends a signal to the voltage regulating component through the signal transmission component to stop increasing the voltage, and the curved surface pressure regulating mechanism maintains the state of reaching the preset pressure until the preset time of step (1) is reached;

[0033] (5) After the preset time ends, the power main control unit sends a signal to reduce the voltage to the voltage regulating component through the signal transmission component. After receiving the signal, the voltage regulating component linearly adjusts and reduces the voltage of the piezoelectric chip in the auxiliary regulating substrate until the auxiliary regulating substrate returns to a state without deformation, completing the pressure control process.

[0034] Furthermore, when fixing the plate to be processed and the auxiliary adjustment substrate in step (2), the pressure impact value brought about by the fixing action at each point at the edge fixing portion is measured, and the measured pressure information is fed back to the preset pressure value in step (1), and the pressure impact value is compared with the preset pressure value to obtain a pressure correction coefficient, and the preset pressure value of the curved surface pressure adjustment mechanism at each point at the fixed portion is corrected by the pressure correction coefficient.

[0035] The beneficial effects of the present invention are:

[0036] The plate curved surface forming device of the present invention can simultaneously process flat plates and curved plates by setting up a flat forming area and a curved surface forming area. After the plate that needs curved surface forming is placed on the curved plate forming placement table of the curved surface forming substrate, it is covered by a coating and pressure layer, and then the vacuum equipment draws out air through the suction port to form negative pressure, so that the plate fits the preset shape of the curved plate forming placement table under the action of pressure. During the process, the plate is heated and cured by a multi-piece parallel heating plate group, which assists in higher plate forming efficiency. Compared with the device in the prior art that uses concave and convex dies for stamping and forming, this device can simultaneously form plates with multiple different forming requirements at one time, has strong versatility and high forming efficiency, and has the advantages of simple operation, simple structure, low cost and high forming precision. Moreover, it is processed and formed under the uniform pressure of the coating and pressure layer, and has the remarkable effect of uniform deformation and no rebound, which greatly improves the quality and efficiency of plate forming.

[0037] The plate curved surface forming method of the present invention performs plate curved surface forming processing based on a plate curved surface forming device. Before the plates are bonded, the plate material is subjected to arc pretreatment to eliminate the internal stress of the material, effectively avoiding the generation of wrinkles, fractures and other defects on the plate surface during the deformation process due to the influence of the internal stress of the plate during the forming process. At the same time, it can also further prevent the plate from rebounding after forming. This method significantly improves the accuracy of plate curved surface forming, reduces the occurrence of defective products, and improves product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a three-dimensional perspective view of the overall structure of the plate curved surface forming device of the present invention;

[0039] Figure 2 for Figure 1 Schematic diagram of the explosion structure;

[0040] Figure 3 for Figure 1 The main view;

[0041] Figure 4 for Figure 1 Bottom perspective structure diagram;

[0042] Figure 5This is a schematic structural diagram of the heat conduction mechanism of the curved panel of the present invention;

[0043] Figure 6 Schematic diagram of the distribution structure of the auxiliary molding substrate, the piezoelectric wafer and the pressure sensing sensor of the present invention;

[0044] Figure 7 This is a control principle diagram of the curved surface pressure regulating mechanism of the present invention.

[0045] Reference numerals:

[0046] 1- plane forming area, 2- curved surface forming area, 3- plane panel forming platform, 4- curved panel forming substrate, 41- forming support base, 42- curved panel forming placement table, 5- multi-piece parallel heating plate group, 6- electric control power supply, 7- laminating pressurizing layer, 8- suction port, 9- pressing frame mechanism, 91- fixed pressing frame, 92- sealing strip, 10- curved panel heat conduction mechanism, 101- heat conduction strip, 102- curved surface heat conduction plate, 11- polyvinyl alcohol water-soluble liquid coating layer, 12- heat conduction film layer, 13- curved surface pressure adjustment mechanism, 131- auxiliary adjustment substrate, 132- piezoelectric chip, 133- pressure sensing sensor. DETAILED DESCRIPTION

[0047] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0048] The present invention provides a method and apparatus for forming a curved surface of a plate having a certain thickness, which is mainly applied to the field of plate forming technology, especially the curved surface forming of plates having a certain thickness, such as honeycomb aluminum plates. The plates formed and processed by the present invention have the characteristics of simple device operation, high forming precision, uniform deformation and no rebound. Specifically, the present invention can be implemented as follows:

[0049] Please refer to Figure 1-Figure 4, is a device for forming a curved surface of a plate with thickness according to the present invention. In order to solve the problem that the curved surface forming device of the plate in the prior art can only form a plate with a single curved surface shape, a plane forming area 1 and a curved surface forming area 2 are set, and the plate can be simultaneously formed and curved by the plane plate forming platform 3 and the curved plate forming base 4. Compared with the use of a set of concave and convex molds that can only process the plate into a fixed single shape, the present invention greatly enhances the versatility of the device, and only needs to set a plurality of curved plate forming bases 4 with different shapes to realize the curved surface forming of plates with multiple different curved surface forming requirements at the same time. The curved plate forming base 4 can also be set as a detachable and replaceable structure, which is convenient for processing plate objects with different requirements at any time; the curved plate forming base 4 specifically includes a forming support base 41 responsible for bottom support, and a curved plate forming placement table 42 responsible for providing placement space and providing forming shape. The curved plate forming placement table 42 can be partially set as a detachable structure, thereby achieving the effect of changing the forming shape at any time;

[0050] Based on the above forming area settings, in order to achieve better sheet forming effects, the present invention provides a coating pressure layer 7 to pressurize the sheets in the forming area during the forming process, and a suction port 8 connected to the vacuum equipment is provided between the coating pressure layer 7 and the forming area. During operation, the internal air is extracted through the suction port 8 to form a negative pressure space, so that the coating pressure layer 7 is firmly adsorbed on the forming area and the sheets therein under the action of negative pressure, and applies a uniformly distributed pressure to the sheets. For the sheets in the flat forming area 1, the auxiliary sheets are further quickly bonded to each other. For the sheets in the curved forming area 2, the sheets can be deformed in an orderly manner under the action of pressure and completely fit the surface shape of the curved panel forming placement table 42, so as to quickly obtain the desired formed shape without the need to use a concave and convex mold for stamping; preferably, an exhaust pipe connected to the suction port 8 is installed at the bottom of the flat forming area 1, and the pipe mouth of the exhaust pipe corresponds to the suction port 8, and is connected to the vacuum equipment to provide a gas channel to achieve a negative pressure environment.

[0051] In order to further improve the forming effect and processing efficiency on the basis of the pressurized forming processing of the plate by the laminating pressurizing layer 7, the present invention provides a multi-piece parallel heating plate group 5 for heating and curing the plate. The multi-piece parallel heating plate group 5 can switch the power supply of each part of the heating plate separately, so as to flexibly select the area that needs to be heated during processing. It is particularly suitable for honeycomb aluminum plates that require adhesive materials for bonding and require the adhesive materials to be quickly cured. The plate is heated under the pressure of the laminating pressurizing layer 7. Under the dual action of heating and pressurizing, the adhesive material will be more evenly distributed at the bonding position on the one hand, and quickly cured by heat on the other hand, accelerating the forming process, thereby achieving a simultaneous improvement in the forming effect and processing efficiency.

[0052] Please refer to Figure 1-Figure 2 In order to further improve the airtightness during the vacuuming process and ensure that the coated pressurizing layer 7 can have sufficient negative pressure to ensure that the plate is effectively formed under a certain pressure, the present invention provides a pressing frame mechanism 9. The pressing frame mechanism 9 is arranged at a position around the edge of the flat plate forming platform 3, and is used to fix the coated pressurizing layer 7 on the platform while improving the airtightness of the internal space during the vacuuming process, thereby improving the effect of negative pressure. In order to facilitate the disassembly and assembly of the pressing frame mechanism 9 and ensure the stability of the pressing frame mechanism 9 during operation, the pressing frame mechanism 9 is composed of a fixed pressing frame 91 and a pressing frame locking mechanism. The pressing frame locking mechanism firmly fixes the fixed pressing frame 91 to the platform through a locking member and a locking screw. Preferably, the locking member can be set to a C-shaped shape, and the upper end of the C-shaped shape is pressed above the fixed pressing frame 91, and the lower end of the C-shaped shape is threadedly connected to the locking screw, and one end of the screw is in contact with the bottom of the platform. The screw is rotated to press the locking member downward, and the fixed pressing frame 91 can be firmly fixed to the flat plate forming platform 3.

[0053] Based on the structure of the above-mentioned pressing frame mechanism 9, the plate curved surface forming device of the present invention also provides a pressing frame installation groove at the installation position of the pressing frame mechanism 9 on the flat plate forming platform 3 to accommodate the installation of the fixed pressing frame 91. By matching the shape of the pressing frame installation groove with the fixed pressing frame 91, this structure can facilitate the installation operation of the pressing frame mechanism 9 while further improving the effect of the pressing frame mechanism 9 in enhancing the airtightness. During installation, the fixed pressing frame 91 is directly installed into the concave pressing frame installation groove and is locked therein by the pressing frame locking mechanism. Combined with the sealing effect of the sealing strip 92 set on the bottom surface of the fixed pressing frame 91, it can ensure that no air leakage or the like occurs during the vacuuming process, thereby improving the plate forming effect.

[0054] Please refer to Figure 4 、 Figure 5In order to improve the auxiliary forming effect of heating during the forming process, the present invention sets different structures for the distribution of the heating mechanisms of the flat plate forming platform 3 and the curved surface forming substrate. Specifically, the multi-piece parallel heating plate group 5 located at the flat plate forming platform 3 has heating plates evenly distributed throughout the area, so that the plate can be evenly heated during the flat forming process. On the curved plate forming substrate 4, since the multi-piece parallel heating plate group 5 is set on the bottom surface of the flat plate forming platform 3, it is a certain distance away from the curved surface forming position. In order to ensure the effective transfer of heat and improve the heating effect, the present invention sets a curved plate heat conduction mechanism 10 for auxiliary heat conduction, and the multi-piece parallel heating plate group 5 is evenly distributed throughout the area. The heat of the parallel heating plate group 5 is guided to the curved panel forming placement table 42; the curved panel heat conduction mechanism 10 includes a heat conduction bar 101 arranged on the forming support base 41, and the heat conduction bar 101 is connected to the heating plate to guide the heat to the curved surface heat conduction plate 102 connected above. The curved surface heat conduction plate 102 is arranged on the surface of the curved panel forming placement table 42 to provide heating for the curved surface forming of the plate. In order to avoid affecting the curved surface forming shape of the plate, the curved surface heat conduction plate 102 can be set as an embedded structure, which is located on the same curved surface as the upper surface of the curved panel forming placement table 42, so that the curved surface forming surface is smooth without transition gaps, thereby achieving the optimal curved surface forming effect.

[0055] As a preferred embodiment, in order to prevent components such as water vapor and oxygen from passing through the coating and pressurizing layer 7 during heating during the molding process and affecting the internal plate under heating conditions, the coating and pressurizing layer 7 of the present invention is preferably set to a polyvinyl alcohol high-barrier composite film, and a polyvinyl alcohol water-soluble liquid coating layer 11 is provided on the side of the polyvinyl alcohol high-barrier composite film used for bonding with the plate. On the one hand, the coating layer can make the surface of the film layer extremely smooth, which is conducive to curved surface bonding with the plate and can avoid affecting the surface texture of the plate during bonding. Compared with the use of cortical layers, cloth layers and other materials for covering and pressurizing, this material can also reduce the friction resistance during the bonding process and improve the tight bonding effect. In order to ensure that both sides of some plates with two panels (such as honeycomb aluminum plates) can be well heated and cured, a heat-conducting film layer 12 is also provided on the side of the polyvinyl alcohol high-barrier composite film facing away from the plate, so that the covered surface of the plate can also be fully heated, so that the molding effect of both sides of the plate is more uniform, avoiding the situation where the difference between the two sides is too large. The specific material selection of the heat-conducting film can be, for example, copper film, zinc oxide film and other materials. Copper has the characteristics of high thermal conductivity and good thermal conductivity. Zinc oxide film not only has good thermal conductivity, but also has the characteristics of high temperature resistance. The material itself can work effectively for a long time without being affected by heating; similarly, in order to ensure that the panel surface of the plate is not affected by the device during the molding process, the device of the present invention is configured such that the curved panel molding placement table 42 is composed of a metal panel, and the flat panel molding platform 3 is composed of a glass panel. Compared with using some wood materials or other materials with their own texture on the surface as a molding platform, the platform surface of the present invention is smoother and the bonding effect is better, and will not cause any impact on the surface texture of the plate.

[0056] Please refer to Figure 6 、 Figure 7 In order to solve the various defects that may occur in the forming of curved panels in the existing technology, such as deformation that does not meet expectations, plate wrinkles and breakage, excessive plate springback, etc., and to meet the needs of some high-precision plate forming requirements, the present invention sets a curved surface pressure adjustment mechanism 13 at the position corresponding to the curved surface forming area 2 on the coating and pressurizing layer 7, which is used to accurately and meticulously control the stress of each position of the plate during the curved surface forming process of the plate, so that the deformation of the plate during the curved surface forming process is more controllable, thereby meeting the needs of high-precision curved surface forming. In order to avoid negative pressure acting on the curved surface pressure adjustment mechanism 13 and affecting the control of the adjustment and increasing the difficulty of adjustment, it is preferred to set the curved surface pressure adjustment mechanism 13 above the coating and pressurizing layer 7, and the curved surface pressure adjustment mechanism 13 adjusts the pressure of the plate through the interval transmission of the coating and pressurizing layer 7. Specifically, the curved surface pressure adjustment mechanism 13 can be set as follows:

[0057] The curved surface pressure adjustment mechanism 13 includes an auxiliary adjustment substrate 131 and a piezoelectric chip 132 mounted on the auxiliary adjustment substrate 131 for changing the pressure by deforming the auxiliary adjustment substrate 131 through the piezoelectric effect. The piezoelectric material is a piezoelectric polycrystal (such as piezoelectric ceramics) with strong piezoelectricity and a high electromechanical coupling coefficient. According to the requirements of different parts of the curved surface forming of the plate, the piezoelectric chips 132 are arranged at specific positions of the curved plate. For example, the arrangement density is higher in stress concentration areas or areas where precise stress control is required, and lower in reverse. For example, a plurality of piezoelectric chips 132 are provided, and the distribution density of the piezoelectric chips 132 at the center axis of the plate surface near the auxiliary adjustment substrate 131 is higher than the distribution density at the plate edge near the auxiliary adjustment substrate 131. The piezoelectric chips 132 can be arranged by pasting, embedding, or integrating them into the auxiliary adjustment substrate 131. Preferably, the embedded or integrated method is used, so that the piezoelectric material and the auxiliary adjustment substrate 131 can be integrated to improve stability and durability.

[0058] To better adapt to the curved surface forming requirements of various sheet materials and to provide real-time pressure feedback during the forming process, the auxiliary adjustment substrate 131's surface shape and size correspond to the surface shape and size of the curved sheet forming platform 42. Pressure sensors 133 are evenly distributed across the auxiliary adjustment substrate 131. To ensure effective pressure-assisted adjustment, the material of the auxiliary adjustment substrate 131 should be as similar as possible to the material of the workpiece being processed, minimizing the performance gap between the two materials. For example, when processing curved honeycomb aluminum panels, the auxiliary adjustment substrate 131 should also be made of a material and performance similar to that of the aluminum panel to ensure effective pressure regulation.

[0059] To facilitate pressure control, the voltage is converted into deformation through the piezoelectric effect. The curved surface pressure adjustment mechanism 13 also includes a voltage adjustment component electrically connected to the piezoelectric chip 132. The voltage adjustment component is electrically connected to the electronic control power supply 6. The pressure sensing sensor 133 and the voltage adjustment component are both connected to the power main control unit through a signal transmission component.

[0060] Based on the above-mentioned curved surface pressure regulating mechanism 13, its working principle and working process are as follows:

[0061] The piezoelectric chip 132 can usually be installed in the concave part of the curved surface (that is, when the curved panel forming placement platform 42 is concave, the piezoelectric chip 132 is set in the concave part of the upper surface of the auxiliary adjustment substrate 131; when the curved panel forming placement platform 42 is convex, the piezoelectric chip 132 is set in the concave part of the lower surface of the auxiliary adjustment substrate 131). The voltage regulation component is connected to the electrodes of the piezoelectric chip 132. When the piezoelectric chip 132 is acted upon by a voltage signal, an electric field is generated on the piezoelectric chip 132. The piezoelectric chip 132 is deformed due to the inverse piezoelectric effect (electrical energy is converted into mechanical energy), thereby applying pressure to the plate to be processed that is bonded to the auxiliary adjustment substrate 131 to achieve pressure regulation. On the curved surface of the plate, the piezoelectric chip 132 is in the concave part and will be subjected to pressure, while the auxiliary adjustment substrate 131 connected to it is in the convex part and is subjected to tension. This structure enables the piezoelectric chip 132 to generate a large displacement and torque when subjected to voltage, thereby realizing an effective driving deformation function; electrodes are set on the piezoelectric chip 132 to apply voltage to it and detect the voltage or charge changes caused by the piezoelectric effect. The electrodes should be in close contact with the piezoelectric material to ensure good electrical conductivity. The electrodes can be connected to the power main control unit using wires or circuit boards to achieve remote control and monitoring. Dividing the piezoelectric chip 132 into multiple blocks can provide higher adjustment flexibility and local pressure control capabilities. By adjusting the voltage and polarity of different blocks of piezoelectric chips 132, precise control of the pressure in different areas can be achieved. This setting method is particularly suitable for sheet metal curved surface forming scenarios where fine adjustment of the pressure distribution is required.

[0062] Based on the above description, please refer to Figure 7 The pressure regulation implementation process of the curved surface pressure regulating mechanism 13 is as follows:

[0063] 1) Voltage input: Input the required voltage signal through the power main control unit and signal transmission components.

[0064] 2) Physical effect conversion: The voltage signal acts on the piezoelectric driver, and its physical effect (piezoelectric effect) is used to convert electrical energy into mechanical energy.

[0065] 3) Force output: The piezoelectric chip 132 deforms to generate force output, which acts on the auxiliary adjustment substrate 131. The auxiliary adjustment substrate 131 transmits the pressure to the plate to be processed.

[0066] 4) Pressure regulation: By adjusting the magnitude and polarity of the input voltage through the voltage regulation component, the magnitude and direction of the pressure can be continuously controlled, thereby achieving stepless regulation of the pressure. The pressure at each point (including around the piezoelectric chip 132) is monitored in real time through the pressure sensing sensor 133, and the pressure signal is fed back to the power main control unit through the signal transmission component until it is adjusted to the preset value.

[0067] The pressure sensing sensor 133 includes a plurality of pressure sensing sensors 133, which are evenly arranged at various positions on the auxiliary adjustment substrate 131. The pressure sensing sensor 133 can accurately measure the pressure changes at any position on the auxiliary adjustment substrate 131 and convert these changes into electrical signals for transmission. The models of the pressure sensing sensor 133 can be selected, for example: flexible film pressure sensors SF15-54, SF15-600, ZD10-100, etc., resistive pressure sensors Vishay TE series, etc.

[0068] The voltage regulating component receives electrical signals from the power main control unit, and adjusts the voltage applied to each part of the piezoelectric chip 132 on the auxiliary regulating substrate 131 according to these signals, and realizes precise regulation of pressure by changing the voltage. The voltage regulating component may include an adjustable power supply, a digital-to-analog converter and other components to realize the function of regulating voltage. The specific model selection can be made by technicians in this field based on existing mature technologies, and this solution can be implemented.

[0069] The main power control unit is responsible for processing data from the pressure sensor 133 and, based on the preset pressure distribution or change requirements, calculating the required voltage value. It then sends an adjustment signal to the voltage regulator assembly. Dynamic adjustments can also be made based on the real-time pressure state of the plate being processed to ensure precise pressure control. Control logic can be programmed into the main power control unit to adjust the voltage of the various piezoelectric chips 132 based on the desired pressure distribution. The specific control principles and processes of the main power control unit are as follows:

[0070] a. Input signal: The power main control unit receives input signals from external control signals or internal sensors. These signals represent parameters such as the required power size.

[0071] b. Input signal processing: The power main control unit analyzes and processes the input signal to determine the required output power parameters.

[0072] c. Power regulation: Based on the processed input signal, the power master control unit precisely controls the output power by sending execution signals to relevant power regulation components. This may include adjusting parameters such as voltage, current, and frequency to ensure that the output power matches the required parameters.

[0073] d. Output power monitoring: The power control unit can also be equipped with an output power monitoring function to monitor the parameters and waveform of the output power in real time. If the output power deviates from the predetermined parameters or waveform, the power control unit can make adjustments to ensure the stability and accuracy of the power output.

[0074] As a preferred implementation, a digital power controller can be selected as the main power control unit. The specific model can be selected and used based on existing mature technologies. This component uses digital circuits and microprocessors for power regulation and control, and has the advantages of high precision, high flexibility, and programmability. It is suitable for application scenarios that require complex power regulation and control.

[0075] The curved surface pressure regulating mechanism 13 of the present invention can accurately control and adjust the pressure at each point, and can continuously and smoothly adjust the pressure acting at any position on the plate to be processed without obvious jumps or mutations. This stepless adjustment method enables the curved surface pressure regulating mechanism 13 to more accurately control the pressure state of the curved plate, thereby meeting a wider range of application needs.

[0076] A method for forming a curved surface of a plate having thickness according to the present invention is performed using the above-mentioned curved surface forming device for a plate having thickness, and comprises the following steps:

[0077] A. Perform arc pretreatment on the panel and bottom plate materials of the plate, roll the panel and bottom plate materials into an arc shape, and eliminate the internal stress in the panel and bottom plate materials;

[0078] Preferably, in step A, the panel and bottom plate after arcing are heat treated to further eliminate stress, the heat treatment temperature is 150° C. to 250° C., such as 150° C., 180° C., 200° C., 220° C. or 250° C., the time is 5 minutes to 50 minutes, such as 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes or 50 minutes, and the arcing speed is controlled to 5 to 10 meters per minute, such as 5 meters, 6 meters, 7 meters, 8 meters, 9 meters, 10 meters per minute;

[0079] B. Lay the bottom plate and the top plate of the plate after the arc pretreatment on the two sides of the plate core respectively, and evenly apply the adhesive material on the laminating surface to make the layers of materials bonded together to form a thick composite plate;

[0080] C. Place the bonded sheet material on the curved panel forming platform 42 of the curved panel forming base 4 of the sheet material curved surface forming device, so that the sheet material is attached to the forming surface of the curved panel forming platform 42;

[0081] D. Cover the curved panel forming and placing table 42 with a film-coated and pressurized layer 7, and fix a press frame mechanism 9 around the film-coated and pressurized layer 7 around the curved panel forming and placing table 42 to form an airtight structure inside;

[0082] E. Turn on the vacuum device connected to the suction port 8 to extract the air from the space between the curved panel forming and placement platform 42 and the laminating and pressurizing layer 7 to create a negative pressure environment. At the same time, turn on the electronically controlled power supply 6 of the multi-piece parallel heating plate group 5 to heat the panel during the forming process and accelerate the curing process of the adhesive material.

[0083] Preferably, the pressure of the negative pressure formed by vacuuming in step E is controlled at -0.1 MPa to -0.05 MPa, such as -0.1 MPa, -0.08 MPa, -0.06 MPa or -0.05 MPa, the heating temperature is controlled at 80°C to 150°C, such as 80°C, 100°C, 120°C, 130°C or 150°C, and the heating time is controlled at 1 hour to 3 hours, such as 1 hour, 1.5 hours, 2 hours, 2.5 hours or 3 hours.

[0084] F. After the negative pressure and heating process reaches the required time, stop vacuuming and heating, open the pressing frame mechanism 9 and the laminating and pressurizing layer 7, take out the plate on the curved plate forming placement table 42, and complete the plate curved surface forming process.

[0085] Preferably, in order to achieve a better plate surface forming effect and improve the forming accuracy, the present invention adopts a curved surface pressure regulating mechanism 13 to adjust the pressure of the curved surface forming of the plate during the plate surface forming process. Figure 7 The specific pressure regulation control method is described through the following two embodiments:

[0086] Example 1

[0087] This embodiment is an implementation method for forming a curved plate surface when the surface of the curved plate forming placement table 42 is concave. The specific method is as follows:

[0088] (1) The pressure and duration required to be applied to multiple points on the force-bearing surface of the plate during the curved surface forming process are preset in the power main control unit according to the various parameters required for the plate curved surface forming process. For example, for the plate shape, the pressure is calculated based on the curvature, deflection and other information of the plate required for the forming process; for the material properties of the plate, such as the individual properties of the panel, base plate and core material of the honeycomb aluminum plate and the properties of the overall plate after composite, the pressure is calculated; for the dimensional information of the plate, including the length, width and thickness of the plate, all need to be included in the calculation; the above data can be obtained according to the existing material mechanics related analysis and calculation methods, which will not be repeated here;

[0089] The magnitude of the processing negative pressure can be obtained by measuring the magnitude of the negative pressure that can be generated by the actual equipment, so as to be incorporated into the calculation of the pressure regulation. The correlation between the voltage and deformation of the piezoelectric chip 132 in the auxiliary regulating substrate 131, the deformation ratio of the piezoelectric chip 132 to the auxiliary regulating substrate 131, and the correlation between the deformation and pressure of the auxiliary regulating substrate 131 are the key to the pressure regulation control method of this embodiment. Before processing, the relationship between the pressure, deformation and voltage regulation of the auxiliary regulating substrate 131 and the piezoelectric chip 132 can be measured by specific experiments. Based on the correlation of the experimentally measured mutual data, a parameter function relationship can be established, and this can be used as a basis to realize the conversion from voltage regulation to pressure regulation.

[0090] It should be noted that when the surface of the curved panel forming placement table 42 is concave, the deformation direction of the plate is based on edge support, and the area around the center of the deformation is concave. The reaction force to the auxiliary adjustment substrate 131 is the largest at the center of the deformation, and gradually diffuses and decreases toward the surrounding area. The pressure distribution factor should be considered when presetting the pressure adjustment at each position; the piezoelectric chip 132 can be set on the inner concave surface of the auxiliary adjustment substrate 131 to obtain a better stress state. In this embodiment, it is set on the upper surface.

[0091] (2) When covering and setting the laminating pressure layer 7 in step D, the auxiliary adjustment substrate 131 of the curved surface pressure adjustment mechanism 13 is fitted to the position of the plate to be processed, and the edge of the auxiliary adjustment substrate 131 is fixed together with the edge of the plate to be processed; as a preferred method, when fixing the plate to be processed and the auxiliary adjustment substrate 131, the pressure influence value brought by the fixing action at each point at the edge fixed portion is measured, and the measured pressure information is fed back to the preset pressure value in step (1), and the pressure influence value is compared with the preset pressure value to obtain a pressure correction coefficient, and the preset pressure value of the curved surface pressure adjustment mechanism 13 at each point at the fixed portion is corrected by the pressure correction coefficient.

[0092] (3) Simultaneously with the vacuum pumping device being turned on in step E, the curved surface pressure regulating mechanism 13 is turned on. The power main control unit sends a voltage-increasing signal to the voltage regulating component via the signal transmission component. After receiving the signal, the voltage regulating component linearly adjusts and increases the voltage of the piezoelectric chip 132 in the auxiliary regulating substrate 131. The parameters of the voltage regulating component can be set according to a predetermined voltage range. For example, the output voltage range of the adjustable power supply and the output range of the digital-to-analog converter can be adjusted.

[0093] (4) When the pressure information of each position fed back by the pressure sensing sensor 133 through the signal transmission component reaches the preset value of step (1), the power main control unit sends a signal to the voltage regulating component through the signal transmission component to stop increasing the voltage, and the curved surface pressure regulating mechanism 13 maintains the state of reaching the preset pressure until the preset time of step (1) is reached; it should be noted that in this process, the laminating pressure layer 7 also continuously applies pressure to the plate, and the start and end time of the pressure regulation and the start and end time of the negative pressure application can be set separately according to the plate forming requirements. For plate forming with higher requirements for precision, the pressure regulation duration can be extended. Preferably, in order to avoid the installation position of the pressure sensing sensor 133 from conflicting with the piezoelectric chip 132, and also in order to better set the distribution points of the pressure sensing sensor 133 and monitor as many points as possible, the pressure sensing sensor 133 can be set on the back side of the piezoelectric chip 132 on the auxiliary molding substrate, that is, the lower surface in this embodiment. This method can enable the pressure at the corresponding installation point of the piezoelectric chip 132 to be monitored, thereby making the pressure feedback data more accurate. Specifically, the pressure state of the piezoelectric chip 132 located on the other side can be obtained based on the material stress state relationship analysis in the thickness direction of the auxiliary molding substrate.

[0094] (5) After the preset time ends, the power main control unit sends a signal to reduce the voltage to the voltage regulating component through the signal transmission component. After receiving the signal, the voltage regulating component linearly adjusts and reduces the voltage of the piezoelectric chip 132 in the auxiliary regulating substrate 131 until the auxiliary regulating substrate 131 returns to a state without deformation, completing the pressure regulation control process.

[0095] Example 2

[0096] Compared to Example 1, this embodiment is an implementation scheme for forming a curved surface of a plate when the surface of the curved plate forming placement platform 42 is convex. The difference from Example 1 is that when the surface of the curved plate forming placement platform 42 is convex, the plate deformation direction is based on the support of the plate deformation center point, and the surrounding area near the edge of the plate deforms downward. The reaction force on the auxiliary adjustment substrate 131 at the center point of its deformation is the smallest, and it diffuses and increases in sequence to the surrounding area. Compared to the pressure regulation control in Example 1, the change in pressure distribution should be considered when presetting the pressure regulation at each position, thereby changing the distribution and direction of the pressure regulation amount of the auxiliary adjustment substrate 131 and the piezoelectric chip 132 at each position to ensure the effect of the curved surface forming of the plate. The piezoelectric chip 132 can be set on the inner concave surface of the auxiliary adjustment substrate 131 to obtain a better stress state. In this embodiment, it is set on the lower surface.

[0097] Preferably, the pressure sensing sensor 133 can be set on the back side of the piezoelectric chip 132 on the auxiliary molding substrate, that is, the upper surface in this embodiment, so that the pressure at the corresponding installation point of the piezoelectric chip 132 can also be monitored, thereby making the pressure feedback data more accurate.

[0098] The above-described embodiments merely represent specific implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A device for forming a curved surface of a plate having thickness, characterized in that: It includes a plane forming area and a curved forming area, wherein the curved forming area is arranged in the plane forming area; A flat plate forming platform is provided in the flat forming area, and a curved plate forming base is provided in the curved surface forming area. The curved plate forming base includes a forming support base at the bottom and a curved plate forming placement table provided on the upper surface of the forming support base for placing plates for bonding and curved surface forming. The bottom surface of the flat plate forming platform is provided with a multi-piece parallel heating plate group for adjusting the temperature according to the plate forming requirements to heat and solidify the plate, and the multi-piece parallel heating plate group is electrically connected to an electric control power supply; The flat forming area and the curved forming area are provided with a film pressure layer for laminating the covering plate and applying forming pressure to the plate, and the flat forming area is provided with a suction port for connecting to a vacuum device; A curved surface pressure regulating mechanism is provided at a position on the laminating and pressurizing layer corresponding to the curved surface forming area; The curved surface pressure adjustment mechanism includes an auxiliary adjustment substrate and a piezoelectric chip mounted on the auxiliary adjustment substrate for changing the pressure by driving the auxiliary adjustment substrate to deform through the piezoelectric effect. The shape and size of the auxiliary adjustment substrate correspond to the shape and size of the surface of the curved panel forming and placing table. Pressure sensors are evenly arranged on the auxiliary adjustment substrate. There are multiple piezoelectric chips, and the distribution density of the piezoelectric chips near the middle axis of the auxiliary regulating substrate is higher than the distribution density near the edge of the auxiliary regulating substrate; The curved surface pressure regulating mechanism further comprises a voltage regulating component electrically connected to the piezoelectric chip, and the pressure sensing sensor and the voltage regulating component are both connected to a power main control unit via a signal transmission component; The curved surface pressure regulating mechanism is arranged on the laminating and pressurizing layer, and the curved surface pressure regulating mechanism regulates the pressure of the plate through the interval transmission of the laminating and pressurizing layer.

2. The device for forming a curved surface of a plate having thickness according to claim 1, characterized in that: A pressing frame mechanism is installed at a position around the edge of the flat panel forming platform. The pressing frame mechanism includes a fixed pressing frame installed on the upper surface of the coated pressurizing layer and a pressing frame locking mechanism for fixing the fixed pressing frame to the flat panel forming platform. The pressing frame locking mechanism includes a locking member and a locking screw. One end of the locking member is connected to the fixed pressing frame, and the other end of the locking member is connected to the flat panel forming platform through the locking screw.

3. The device for forming a curved surface of a plate having thickness according to claim 2, characterized in that: A press frame mounting groove for accommodating a fixed press frame is provided at the installation position of the press frame mechanism on the flat plate forming platform. The shape of the press frame mounting groove matches the fixed press frame, and the press frame mounting groove is concave. The coated pressurization layer is provided between the press frame mounting groove and the fixed press frame. A sealing strip for achieving gas sealing in the internal space of the coated pressurization layer is also connected between the bottom surface of the fixed press frame and the coated pressurization layer.

4. The device for forming a curved surface of a plate having thickness according to claim 1, characterized in that: The multi-piece parallel heating plate group is evenly distributed on the bottom surface of the flat plate forming platform, and the curved plate forming base is equipped with a curved plate heat conduction mechanism; The curved panel heat conduction mechanism includes a plurality of heat conduction bars arranged on a forming support base, and the heat conduction bars are connected to a multi-piece parallel heating plate group. The curved panel heat conduction mechanism also includes a curved surface heat conduction plate installed on a curved panel forming placement table, and the curved surface heat conduction plate is connected to the heat conduction bars. The curved surface heat conduction plates are evenly distributed on the curved panel forming placement table and have an embedded installation structure. The upper surface of the curved surface heat conduction plate and the upper surface of the curved panel forming placement table are located in the same curved surface.

5. The device for forming a curved surface of a plate having thickness according to claim 1, characterized in that: The laminating and pressurizing layer includes a polyvinyl alcohol high-barrier composite film, a polyvinyl alcohol water-soluble liquid coating layer is provided on the side of the polyvinyl alcohol high-barrier composite film used for bonding with the plate, and a heat-conducting film layer is provided on the side of the polyvinyl alcohol high-barrier composite film facing away from the plate; the curved panel forming placement platform is composed of a metal panel, and the flat panel forming platform is composed of a glass panel.

6. A method for forming a curved surface of a plate having thickness, using the device for forming a curved surface of a plate having thickness according to any one of claims 1 to 5, characterized in that: The steps include: A. Perform arc pretreatment on the panel and bottom plate materials of the plate, roll the panel and bottom plate materials into an arc shape, and eliminate the internal stress in the panel and bottom plate materials; B. Lay the bottom plate and the top plate of the plate after the arc pretreatment on the two sides of the plate core respectively, and evenly apply the adhesive material on the laminating surface to make the layers of materials bonded together to form a thick composite plate; C. Placing the bonded sheet material on a curved panel forming placement table of a curved panel forming base of a sheet material curved surface forming device, so that the sheet material is attached to the forming surface of the curved panel forming placement table; D. Covering the curved panel forming and placing table with a film-coated and pressurized layer, and fixing a press frame mechanism around the film-coated and pressurized layer around the curved panel forming and placing table to form an airtight structure inside; E. Turn on the vacuum device connected to the suction port to extract the air in the space between the curved panel forming platform and the laminating and pressurizing layer to create a negative pressure environment. At the same time, turn on the electric control power supply of the multi-piece parallel heating plate group to heat the panel during the forming process and accelerate the curing process of the adhesive material. F. After the negative pressure and heating process reaches the required time, stop vacuuming and heating, open the pressing frame mechanism and the laminating pressure layer, take out the plate on the curved plate forming table, and complete the curved surface forming process of the plate.

7. A method for forming a curved surface of a plate having thickness according to claim 6, characterized in that: In step A, the panel and base plate after arcing are subjected to heat treatment to further eliminate stress, the heat treatment temperature is 150°C to 250°C, the time is 5 minutes to 50 minutes, and the arcing speed is controlled to 5 to 10 meters per minute; In the step E, the pressure of the vacuum forming negative pressure is controlled at -0.1 MPa to -0.05 MPa, the heating temperature is controlled at 80° C. to 150° C., and the heating time is controlled at 1 hour to 3 hours.

8. The method for forming a curved surface of a plate having thickness according to claim 6, characterized in that: During the curved surface forming process of the plate, a curved surface pressure regulating mechanism is used to regulate the curved surface forming pressure of the plate. The specific regulation control method includes the following steps: (1) Based on the plate shape, material properties, dimensional information of the plate, processing negative pressure, correlation between the voltage and deformation of the piezoelectric chip in the auxiliary regulating substrate, deformation ratio of the piezoelectric chip to the auxiliary regulating substrate, and correlation between deformation and pressure of the auxiliary regulating substrate, the pressure and duration required to be applied at multiple points on the force-bearing surface during plate curved surface forming are preset in the power main control unit; (2) When covering and setting the laminating and pressurizing layer in step D, the auxiliary adjustment substrate of the curved surface pressure adjustment mechanism is aligned with the position of the plate to be processed, and the edge of the auxiliary adjustment substrate is fixed together with the edge of the plate to be processed; (3) At the same time as the vacuum equipment is turned on in step E, the curved surface pressure regulating mechanism is turned on, and the power main control unit sends a signal to increase the voltage to the voltage regulating component through the signal transmission component. After receiving the signal, the voltage regulating component linearly adjusts and increases the voltage of the piezoelectric chip in the auxiliary regulating substrate; (4) When the pressure information of each position fed back by the pressure sensor through the signal transmission component reaches the value preset in step (1), the power main control unit sends a signal to the voltage regulating component through the signal transmission component to stop increasing the voltage, and the curved surface pressure regulating mechanism maintains the state of reaching the preset pressure until the preset time of step (1) is reached; (5) After the preset time ends, the power main control unit sends a signal to reduce the voltage to the voltage regulating component through the signal transmission component. After receiving the signal, the voltage regulating component linearly adjusts and reduces the voltage of the piezoelectric chip in the auxiliary regulating substrate until the auxiliary regulating substrate returns to a state without deformation, completing the pressure control process.

9. The method for forming a curved surface of a plate having thickness according to claim 8, characterized in that: When fixing the plate to be processed and the auxiliary adjustment substrate in step (2), the pressure influence value brought about by the fixing action at each point at the edge fixing portion is measured, and the measured pressure information is fed back to the preset pressure value in step (1), and the pressure influence value is compared with the preset pressure value to obtain a pressure correction coefficient, and the preset pressure value of the curved surface pressure adjustment mechanism at each point at the fixed portion is corrected by the pressure correction coefficient.

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