Flexible roll bending forming device and method for integral ribbed panel

Abstract

The invention discloses a flexible roll bending forming device for a ribbed integral panel, which comprises a flexible upper roller and two rigid lower rollers, a rolling channel for a panel is formed between the flexible upper roller and the two rigid lower rollers, the flexible upper roller comprises a rigid transmission shaft and an elastic layer, and the rigid transmission shaft is coated with the elastic layer. The invention further discloses a flexible roll bending forming method of the integral ribbed panel. According to the flexible roll bending forming device and method for the integral wall plate with the ribs, the problems that in the prior art, in the bending process of the integral wall plate, the surface of a skin is concaved inwards, and buckling instability and deformation of the ribs exist are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of integral wall panel bending and forming, and in particular relates to a flexible rolling and bending forming device for an integral wall panel with ribs, and also relates to a flexible rolling and bending forming method for an integral wall panel with ribs. Background Art

[0002] Aluminum alloy ribbed integral wall panels are an important component of the aircraft's aerodynamic shape, and are also the main load-bearing components of wings, fuselages, etc. They have been widely used in aerospace and other fields due to their obvious weight reduction effects, good overall and local rigidity, high strength, and reduced assembly labor. The roll forming process has become the main process method for integral wall panel forming and manufacturing due to its wide adaptability and high flexibility. Roll forming can be specifically divided into rigid roll forming without fillers and rigid roll forming with auxiliary fillers. During rigid roll forming without fillers, the main defects of the integral wall panels are concave defects on the outer surface of the skin and buckling and instability deformation of the ribs. The reason is that during the rolling process, the rigid roller is in direct contact with the wall panel, and the contact area is on the rib surface, which will form stress concentration at the connection between the rib and the skin, while the stress in the central area of ​​the skin away from the rib is small, resulting in damage to the mechanical properties and geometric shape of the wall panel. Although the rigid rolling forming of auxiliary fillers can overcome the concave defects of the skin and the buckling and instability deformation of the ribs, the preparation of the fillers required for this process needs to be customized according to the specific type of ribs of the wall panel. The fillers need to be filled and cleaned before and after the rolling process. This process consumes a lot of manpower and is not conducive to mass production.

[0003] The Chinese patent with the authorization announcement number CN 114833254 B discloses an electromagnetic-assisted rolling forming method and its forming device, which applies a reverse bending force to the sheet through periodic electromagnetic pulse discharge, and resets the sheet under the elastic action of the elastic roller, so that local reverse bending and local bending can be performed alternately. The problem of large springback of thin-walled sheet with small curvature and difficult to control forming accuracy is solved. Due to the limitation of the discharge energy of the equipment, this method is only applicable to the forming of thin sheets with uniform thickness, and is not applicable to integral ribbed wall panels with complex structure and good rigidity. The Chinese patent with the authorization announcement number CN104439968 B discloses a large tank barrel section integral manufacturing method based on CNC mirror milling. This method solves the grid ribs and thin wall instability deformation defects during the rolling process of high-ribbed thin-walled sheet by filling the grid ribs with rubber pads after milling. However, the preparation of the filler required for this process needs to be customized according to the specific wall panel rib type, and the filler needs to be filled and cleaned before and after the rolling process, which is not conducive to mass production.

[0004] In summary, how to reduce the instability deformation defects of grid ribs and skins, improve the rolling forming accuracy, and solve the customization problem of the auxiliary filling process are the technical bottlenecks that need to be broken through in the rolling forming process of ribbed integral wall panels. Summary of the invention

[0005] The purpose of the present invention is to provide a flexible roll-bending forming device for an integral wall panel with ribs, which solves the problems of concave defects on the skin surface and buckling and unstable deformation of ribs in the bending process of the integral wall panel in the prior art.

[0006] Another object of the present invention is to provide a flexible roll-bending method for forming ribbed integral wall panels.

[0007] The first technical solution adopted by the present invention is to include a flexible upper roller and two rigid lower rollers, wherein a rolling channel for the plate is formed between the flexible upper roller and the two rigid lower rollers, and the flexible upper roller includes a rigid transmission shaft and an elastic layer, wherein the elastic layer is coated on the rigid transmission shaft.

[0008] The first technical solution of the present invention is also characterized in that: The rigid transmission shaft and the two rigid lower rollers are respectively connected with motors.

[0009] The flexible upper roller is also connected with a lifting device.

[0010] The two rigid lower rollers are located on the same level.

[0011] The second technical solution adopted by the present invention is a flexible roll-bending forming method of a ribbed integral wall panel, and the specific steps are as follows: S1, taking the milled integral wall panel as the part to be bent, and determining the initial relative position relationship between the integral wall panel and the rigid lower roller according to the flexible rolling bending principle; S2, determining the hardness of the flexible upper roller and the flexible rolling bending process parameters of the entire wall panel; S3, performing a rolling forming test on the integral wall panel after milling according to the flexible rolling bending process parameters of the integral wall panel, obtaining the mechanical property parameters of the bent integral wall panel, and completing the rolling forming.

[0012] The second technical solution of the present invention is also characterized in that: The initial relative position relationship between the integral wall panel and the rigid lower roller is determined in S1 as follows: the integral wall panel is placed between two rigid lower rollers that remain fixed, so that the integral wall panel is in contact with the two rigid lower rollers at the same time.

[0013] The process parameters of the integral wall panel flexible rolling bending in S2 include the downward pressure and the rotation speed of the flexible upper roller.

[0014] S3 is specifically: A1, initial state: the integral wall panel is placed between two rigid lower rollers so that it contacts the two rigid lower rollers at the same time; A2, downward bending process: the flexible upper roller is pressed downward to bend and deform the entire wall panel; A3, continuous rolling process; the flexible upper roller is driven by a motor to rotate the elastic layer in the circumferential direction, and the friction between the elastic layer and the integral wall panel causes the two supporting rigid lower rollers to rotate synchronously, driving the integral wall panel to feed forward, achieving continuous bending, and continuous local plastic deformation promotes the final formation of the integral wall panel; A4, the rolling process is terminated and the wall panel enters the springback stage; with continuous feeding, the rolling process is terminated, and the entire wall panel enters the springback stage after no loading, and after the stress is released, it is in the final bending state.

[0015] The axial width of the flexible upper roller and the two rigid lower rollers is greater than the overall wall panel width.

[0016] The beneficial effects of the present invention are: (1) The flexible roll-bending forming device and method of the ribbed integral wall panel provided by the present invention utilizes a compressible elastic layer to replace the traditional rigid roller, which can reduce the defects of the concave defect on the outer surface of the skin and the buckling and instability deformation of the ribs. The test shows that the maximum stress value of the integral wall panel in the final bending state is significantly reduced, and the stress uniformity during the rolling process is improved. In this method, the flexible roller can effectively reduce the surface damage of the integral wall panel to be processed during the rolling process.

[0017] (2) The flexible rolling forming device and method of the ribbed integral wall panel provided by the present invention have good processing continuity and ensure the consistency of the forming curvature of the bending section. The flexible roller of the present invention can determine the hardness of the elastic layer according to the groove depth of the integral wall panel. It only needs to adjust the rolling process parameters and replace the elastic layer with different material hardness or hardness gradient, and the process has strong versatility. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 It is a structural schematic diagram of a flexible roll-bending forming device for a ribbed integral wall panel of the present invention; Figure 2 It is a design flow chart of the flexible roll-bending forming device of the ribbed integral wall panel of the present invention; Figure 3 It is a schematic flow chart of the flexible roll-bending forming method of the ribbed integral wall panel of the present invention; Figure 4 is a schematic structural diagram of an integral wall panel to be rolled in Embodiment 3 of the present invention; Figure 5 is a stress cloud diagram of the test results in Example 3 of the present invention; Figure 6 is a stress curve diagram of the test results in Example 3 of the present invention; Figure 7 is a stress cloud diagram of the test results in Example 4 of the present invention; Figure 8 is a stress curve diagram of the test results in Example 4 of the present invention; Fig. 9is a schematic structural diagram of an integral wall panel to be rolled in Embodiment 5 of the present invention; Fig.10 It is a schematic diagram of a flexible wheel with a stepped hardness distribution in Example 6 of the present invention.

[0018] In the figure, 1. flexible upper roller, 2. rigid lower roller, 3. rigid transmission shaft, 4. elastic layer, 5. integral wall panel. DETAILED DESCRIPTION

[0019] The present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0020] Example 1 The present invention provides a flexible rolling forming device for a ribbed integral wall panel, such as Figure 1 As shown, it includes a flexible upper roller 1 and two rigid lower rollers 2, a rolling channel for the plate is formed between the flexible upper roller 1 and the two rigid lower rollers 2, and the two rigid lower rollers 2 are located on the same horizontal line; the flexible upper roller 1 includes a rigid transmission shaft 3 and an elastic layer 4, and the elastic layer 4 is coated on the rigid transmission shaft 3; the rigid transmission shaft 3 and the two rigid lower rollers 2 are respectively connected to motors; the flexible upper roller 1 is also connected to a lifting device.

[0021] The lifting device is used to control the flexible upper roller 1 to move up and down in the vertical direction. The height and inclination angle of the flexible upper roller 1 can be controlled by electric, hydraulic, mechanical and other means, so as to achieve the up and down adjustment of the flexible upper roller 1 during the rolling process. When the flexible upper roller 1 descends, the gap between the flexible upper roller 1 and the workpiece becomes smaller, and the rolling pressure increases, thereby causing the workpiece to deform. Conversely, when the flexible upper roller 1 rises, the gap between the flexible upper roller 1 and the workpiece becomes larger, and the rolling pressure decreases, thereby reducing the deformation of the workpiece. By moving the flexible upper roller 1 up and down, the rolling pressure and the degree of rolling deformation during the rolling process can be controlled to obtain the expected rolling effect.

[0022] Example 2 This embodiment provides a design method for a flexible roll-bending forming device for a ribbed integral wall panel, such as Figure 2 As shown, the specific implementation steps are as follows: The first step is to establish a model, in which a flexible roll-bending forming device model is established; the flexible upper roller 1 and the rigid lower roller 2 are modeled and given geometric dimensions, and the material is selected to obtain a flexible roll-bending forming device model.

[0023] Specifically: The geometric dimensions of the flexible upper roller 1 are , material selection: elastic layer 4 is polyurethane rubber, rigid transmission shaft 3 is Q235A. The geometric dimensions of rigid lower roller 3 are: : The material selected is: Q235A. The axial width of all rollers is greater than the width of the overall wall plate 5; this is to avoid uneven force on the edge due to axial deformation of the polyurethane rubber at the edge of the elastic roller after compression deformation.

[0024] The second step is to determine the assembly relationship between the integral wall panel 5 and the flexible roll-bending forming device; including determining the initial height of the flexible upper roller 1 from the contact horizontal line of the integral wall panel 5, determining the center distance of the rigid lower roller 2; determining the initial relative position relationship between the integral wall panel 5 and the rigid lower roller 2; Specifically: the two rigid lower rollers 2 are at the same horizontal position. The initial height of the flexible upper roller 1 from the wall panel contact horizontal line is determined to be 17 mm, and the center distance between the two rigid lower rollers 2 is 90 mm; the initial state of the integral wall panel 5 is determined to be placed on the rigid lower roller 2.

[0025] The third step is to ensure that the flexible upper roller 1 can be controlled to move up and down in the vertical direction and actively rotate in the circumferential direction, and the rigid lower roller 2 can be controlled to move left and right in the horizontal direction and passively rotate in the circumferential direction.

[0026] Specifically: horizontal control can realize the adjustment of the center distance of the rigid lower rollers 2, and the center distance of the two rigid lower rollers 2 is adjusted to 90 mm. After the adjustment, the two rigid lower rollers 2 are fixed to prevent the two rigid lower rollers 2 from moving left and right after the integral wall panel 5 is compressed.

[0027] The fourth step is to obtain a flexible rolling device model using the above-mentioned integral wall panel flexible rolling forming device design method.

[0028] Example 3 This embodiment provides a flexible rolling forming method for a ribbed integral wall panel, using the flexible rolling forming device for the ribbed integral wall panel provided in the above embodiment, such as Figure 3 As shown, the specific steps are: S1, taking the milled grid integral wall panel as the part to be bent, and determining the initial relative position relationship between the integral wall panel 5 and the rigid lower roller 2 according to the rolling bending principle; Specifically, the integral wall panel 5 is placed between two rigid lower rollers 2 that remain fixed, so that it contacts the rigid lower rollers 2. The integral wall panel to be rolled after milling has a structural size such as Figure 4 The integral wall panel 5 is made of 7050-T7451 aluminum alloy.

[0029] S2, determine the flexible rolling and bending process parameters of the whole wall panel; including the hardness of the flexible upper roller 1 and the rolling and bending process parameters, the rolling and bending process parameters include the downward pressure and the rotation speed of the flexible upper roller 1.

[0030] Specifically: the elastic layer 4 material is polyurethane rubber with a hardness of 95A, the downward pressure is preliminarily determined to be 17 mm, and the rotation speed of the flexible upper roller 1 is 4 rad / s.

[0031] S3, performing a rolling forming test on the integral wall panel after milling using the integral wall panel flexible rolling forming device to obtain mechanical property parameters of the bent integral wall panel 5.

[0032] Specifically: The rolling forming test process can be divided into four stages: Stage 1: Initial state, the integral wall panel 5 is placed between two rigid lower rollers 2 that remain fixed, so that it contacts the two lower rollers at the same time; Stage 2: Downward pressure bending process; the flexible upper roller 1 is controlled to press down, and the downward pressure is 17mm, so that the integral wall panel 5 undergoes bending deformation with a certain curvature; Stage 3: Continuous rolling process; the flexible upper roller 1 is driven by a motor to rotate the elastic layer 4 circumferentially, and the roller speed is 4rad / s. The friction between the elastic layer 4 of the flexible upper roller 1 and the integral wall panel 5 causes the two supporting rigid lower rollers 2 to rotate synchronously, driving the integral wall panel 5 to feed forward, thereby achieving continuous bending, and continuous local plastic deformation promotes the final forming of the integral wall panel. Stage 4: The rolling process terminates and the wall panel enters the rebound stage; with continuous feeding, the rolling process terminates, and the integral wall panel 5 enters the rebound stage after no loading, and after the stress is released, it is in the final bending state.

[0033] Test results: Figure 5 and Figure 6 Shown is the test result diagram in Example 3 of the present invention, which describes the corresponding stress cloud diagram and curve diagram using the flexible rolling forming method of the present invention and the traditional rigid rolling forming method. In the figure, the maximum stress of the integral wall panel ribs processed by the rigid rolling forming method is 418Mpa, and the stress changes greatly at the beginning and end of the rolling. The integral wall panel processed by the flexible rolling forming method of the present invention has a maximum rib stress of 261Mpa, and the stress changes uniformly throughout the rolling process. Using the method of the present invention, the maximum stress of the ribs is reduced by 37%. 10 positions of the rolling process are evenly taken, and the figure reflects the different stress uniformity under the two methods.

[0034] The integral wall panel roll forming device designed in Example 2 of the present invention reduces the stress of the ribs by establishing a flexible roller covered with polyurethane rubber, thereby reducing the inner concave defect of the outer surface of the skin and the buckling and instability deformation of the ribs. In this method, the flexible roller can effectively reduce the surface damage of the integral wall panel to be processed during the roll forming process, thereby effectively improving the roll forming yield of the integral wall panel.

[0035] The roll-bending forming device for the integral wall panel provided in the embodiment of the present invention can execute the roll-bending forming method for the integral wall panel provided in any embodiment of the present invention, and has the above-mentioned beneficial effects.

[0036] Example 4 This embodiment provides a rolling bending test of the integral wall panel 5 under different flexible roller hardnesses. It is based on the embodiment 2, and only the hardness of the flexible upper roller 1 in the embodiment 2 is changed. The rest of the rolling bending forming device and method are consistent with the embodiments 2 and 3. The results obtained through the test are as follows: Figure 7 and Figure 8 It is a diagram of the test results in Example 2 of the present invention.

[0037] like Figure 7 and Figure 8 As shown, the corresponding stress cloud diagrams and curve diagrams are obtained by using the flexible rolling forming method of the present invention and the traditional rigid rolling forming method. In the figure, the maximum stress of the ribs of the integral wall panel processed by the rigid rolling forming method is 384Mpa, and the stress changes greatly at the beginning and end of the rolling. The integral wall panel 5 processed by the flexible rolling forming method of the present invention has a maximum stress of 246Mpa in the ribs, and the stress changes evenly during the entire rolling process. When the method of the present invention is used, the maximum stress of the ribs is reduced by 35%. 10 positions of the rolling process are evenly taken, reflecting the different stress uniformity under the two methods.

[0038] The integral wall panel rolling bending device designed by embodiments 1 and 2 of the present invention, and the flexible rolling bending forming device established by establishing flexible rollers covered with polyurethane rubber of different hardness, can also reduce the stress of the integral wall panel ribs and improve the uneven stress of the ribs before and after the rolling process, thereby reducing the concave defects on the outer surface of the skin and the defects of the ribs buckling, instability and deformation.

[0039] Example 5 This embodiment provides an orthogonal grid integral wall panel arranged obliquely, the structure of which is as follows Fig. 9 As shown. The flexible rolling device designed in Example 2 can be used to roll the obliquely arranged orthogonal grid integral wall panel described in this embodiment. This method is not only applicable to the integral wall panel with regularly staggered ribs described in this article, but can also be applied to the rolling forming method of the integral wall panel without regular ribs.

[0040] The rolling device for the integral wall panels implemented in this embodiment expands the applicable processing scenarios by providing obliquely arranged orthogonal grid integral wall panels, but is not limited to the integral wall panels established in this embodiment.

[0041] Example 6 This embodiment provides flexible rollers with different gradient hardness, such as Fig.10As shown, the flexible roller is reflected in that the inner and outer sides of the elastic layer have different hardnesses, and the hardness increases from the outer layer to the inner layer of the elastic layer. The flexible rollers of the flexible rolling bending devices designed in Embodiments 1 and 2 are replaced with flexible rollers with a hardness gradient, which can be used to implement the rolling forming method of the integral wall panel with ribs with a high aspect ratio that is not described in the embodiments of the present invention. The material with a lower hardness of the outer layer can increase the deformation of the elastic layer and achieve a better deformation filling effect.

Claims

1. A flexible roll-bending device for a ribbed integral wall panel, characterized in that: The invention comprises a flexible upper roller (1) and two rigid lower rollers (2), wherein a rolling channel for a plate is formed between the flexible upper roller (1) and the two rigid lower rollers (2), and the flexible upper roller (1) comprises a rigid transmission shaft (3) and an elastic layer (4), wherein the elastic layer (4) is coated on the rigid transmission shaft (3).

2. The flexible roll-bending forming device for ribbed integral wall panels according to claim 1, characterized in that: The rigid transmission shaft (3) and the two rigid lower rollers (2) are respectively connected to motors.

3. The flexible roll-bending forming device for ribbed integral wall panels according to claim 1, characterized in that: The flexible upper roller (1) is also connected to a lifting device.

4. The flexible roll-bending forming device for ribbed integral wall panels according to claim 1, characterized in that: The two rigid lower rollers (2) are located on the same horizontal line.

5. A flexible rolling forming method for a ribbed integral wall panel, characterized in that: The flexible roll-bending forming device for the ribbed integral wall panel according to any one of claims 1 to 4 is used, and the specific steps are as follows: S1, taking the milled integral wall panel (5) as a part to be bent, and determining the initial relative position relationship between the integral wall panel (5) and the rigid lower roller (2) according to the flexible rolling bending principle; S2, determining the hardness of the flexible upper roller (1) and the flexible rolling bending process parameters of the integral wall panel (5); S3, performing a rolling forming test on the integral wall panel (5) after the milling process according to the flexible rolling process parameters of the integral wall panel (5), obtaining the mechanical property parameters of the bent integral wall panel (5), and completing the rolling forming.

6. The flexible roll-bending forming method of the ribbed integral wall panel according to claim 5, characterized in that: The step of determining the initial relative position relationship between the integral wall panel (5) and the rigid lower roller (2) in S1 is specifically as follows: placing the integral wall panel (5) between two rigid lower rollers (2) that remain fixed, so that the integral wall panel (5) is in contact with the two rigid lower rollers (2) at the same time.

7. The flexible roll-bending forming method of the ribbed integral wall panel according to claim 5, characterized in that: The process parameters for the flexible rolling bending of the integral wall panel (5) described in S2 include the amount of downward pressure and the rotation speed of the flexible upper roller (1).

8. The flexible roll-bending forming method of the ribbed integral wall panel according to claim 5, characterized in that: S3 is specifically: A1, initial state: the integral wall panel (5) is placed between two rigid lower rollers (1) so that it is in contact with the two rigid lower rollers (2) at the same time; A2, downward pressing and bending process: the flexible upper roller (1) is pressed downward to cause the whole wall panel (5) to bend and deform; A3, continuous rolling bending process; the flexible upper roller (1) is driven by a motor to rotate the elastic layer in the circumferential direction, and the friction between the elastic layer (4) and the integral wall panel (5) causes the two supporting rigid lower rollers (2) to rotate synchronously, driving the integral wall panel (5) to feed forward, thereby achieving continuous bending, and continuous local plastic deformation promotes the final forming of the integral wall panel; A4, the rolling process is terminated and the wall panel enters the springback stage; with continuous feeding, the rolling process is terminated, and the entire wall panel (5) enters the springback stage after being unloaded, and after the stress is released, it is in the final bending state.

9. The flexible roll-bending forming method of the ribbed integral wall panel according to claim 5, characterized in that: The axial width of the flexible upper roller (1) and the two rigid lower rollers (2) is greater than the width of the entire wall panel (5).

Images