Device and method for progressive roll bending composite forming of three-dimensional variable cross-section complex curved profiles

Abstract

The present invention discloses a device and method for the progressive roll-bending composite forming of three-dimensional variable-section complex curved profiles, including a multi-pass variable-section forming roller group for the progressive roll-bending of a plate, a guide mechanism and a bending die for the free bending forming of the plate. The present invention is based on the progressive roll-bending composite forming technology of three-dimensional variable-section complex curved profiles. Through the progressive roll-bending process of the plate, the plate is gradually formed into a variable-section profile at a small angle. Through the free bending process of the plate, different bending moments are applied to the variable-section profile in different directions, thereby realizing three-dimensional variable-section complex curved profiles with different bending directions and different bending radii. Based on the progressive roll-bending composite forming device for three-dimensional variable-section complex curved profiles, the continuous forming of the roller group and the motion trajectory design of the bending die can realize the integrated forming of the variable-section three-dimensional complex bending of the target component, which can effectively reduce processing costs and improve production efficiency, and is of great significance to the production of profile component forming.

Description

Technical Field

[0001] The present invention belongs to the technical field of progressive roll bending forming of three-dimensional variable-section complex profiles, and particularly relates to a device and method for multi-pass progressive roll bending comprehensive forming of variable-section complex profiles. Background Art

[0002] Lightweighting of profiles plays a crucial role in the aerospace industry. This can be achieved by using materials with higher specific strengths, and by replacing solid profiles with hollow profiles, which can meet production quality requirements.

[0003] Currently, traditional profile forming technologies include stamping, rolling, roll bending, and bending. These technologies have long production cycles and rely on manual adjustment, making continuous production impossible. The resulting profiles are monotonous, and complex profiles can only be formed by replacing molds. This high mold manufacturing cost severely restricts production efficiency. Progressive roll forming, as an emerging forming technology, primarily transforms a single sheet into a three-dimensional, complex, and variable-cross-section curved profile by applying various loads to the sheet using rollers. This technology utilizes rollers to perform multiple, continuous, and small-angle bends on the sheet, achieving smooth transitions between varying bend angles. The rollers can also be controlled to adjust their motion in three dimensions, enabling flexible, precise, and continuous forming. Key advantages of this technology include: real-time changes in sheet cross-section and bend radius without mold changes, reducing overall forming costs; the ability to freely bend components with a variety of cross-sections and complex shapes; and the precise forming of complex components with low cross-sectional distortion. This technology is a cold-bent one-piece forming technology that is energy-saving and environmentally friendly. It can meet the production needs of different fields, including three-dimensional variable-section complex curved profiles.

[0004] Currently, research on progressive roll bending technology is still immature, and the shape characteristics of products produced in a single pass are still limited. This invention is aimed at forming three-dimensional, complex curved profiles with variable cross-sections using multiple passes of progressive roll bending. This allows complex components with variable cross-sections to be produced without changing the mold, achieving integrated production and improving production efficiency. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention proposes a three-dimensional variable-section complex curved profile progressive roll bending composite forming device and method. It proposes first using a multi-pass roller group to perform progressive forming technology on the plate to achieve variable-section profile. This process is the progressive roll bending of the plate. Then, a single-pass roller is used to apply bending moments of different sizes and directions to the variable-section profile to achieve the overall forming of spatial curved components of various complex shapes. This process is the free bending forming of the plate.

[0006] The present invention adopts the following technical solutions:

[0007] A device for progressive roll-bending composite forming of three-dimensional variable-section complex curved profiles, including a multi-pass variable-section forming roller group for progressive roll-bending of plates, a guide mechanism and a bending die for free bending of plates. The roller group for variable-section forming controls the forming of the plate cross section by moving the rollers in the X-axis direction, controls the width of the plate cross section by moving the rollers in the Y-axis direction, and controls the smooth transition of the plate cross section by rotating the rollers in the Z-axis direction. It also uses rollers with multiple passes and different forming angles to make the plate cross section undergo continuous small angle changes and gradually form the plate, so that the plate is progressively formed into a variable-section profile along a planned route. During the forming process, it is necessary to ensure that the axis of the plate is always in a straight line. The guide mechanism clamps and fixes the variable-section profile, provides support for the profile, prevents the axis from offset, and connects the progressive roll-bending and free bending forming processes, transferring the variable-section profile to the bending die of the next device. The bending die includes two pairs of bending rollers, a spring mechanism, and a self-locking mechanism. The two pairs of bending rollers are arranged crosswise relative to each other, and the upper and lower bending rollers are bent. The bending roller is installed on the bending roller fixing frame, and the distance between the bending rollers is the height of the vertical plate of the variable-section profile. The side bending rollers can expand and contract according to the cross-sectional width of the plate. The spring mechanism is installed between the side bending rollers and the bending roller fixing frame. The tensile shaft is used as a support in the spring. When the cross-sectional width of the plate changes, the spring device is squeezed to achieve the change of the bending die cross-sectional area; the self-locking device includes a force sensor and an electromagnetic lock. The force sensor transmits the spring force to the electromagnetic lock in the form of an electrical signal. Once the spring forces on both sides of the spring mechanism are inconsistent, two different electrical signals will activate the electromagnetic lock. When the electromagnetic lock is activated, the side bending roller is self-locked; the bending die constantly changes its motion trajectory and posture, and the bending roller applies bending moments of different directions and sizes to the variable-section profile, realizing continuous bending of the profile in multiple sections and multiple directions, and finally forming a three-dimensional complex bent component.

[0008] The three-dimensional variable-section complex curved profile progressive roll-bending composite forming device is used to form a roller group with a variable section, which rotates around its own axis at a certain speed in the X-axis / Z-axis plane, moves horizontally along its own axis in the X-axis / Y-axis plane, and rotates around its own axis perpendicular to the X-axis / Y-axis plane. The plate is then passed through each roller in turn for multiple passes of continuous bending at small angles, thereby completing the variable-section forming of the target component and providing support and driving force for the profile forming process.

[0009] In the three-dimensional variable-section complex curved profile progressive roll-bending composite forming device, the variable-section profile is sent to the bending die through a guide mechanism. The spring mechanism in the bending die can enable the variable-section profile to pass through. The bending die used to form three-dimensional complex curved features performs continuous up and down, left and right linear motion in the Y-axis / Z-axis plane. The self-locking mechanism works as follows: once the bending die starts working in the Y-axis / Z-axis plane, the forces on both sides of the spring component are inconsistent. The force is transmitted to and activated by the electromagnetic lock through the sensor in the form of an electrical signal, causing the bending rollers on both sides of the spring to be locked. During the translation process, the bending rollers apply bending moments of different directions and sizes to the variable-section profile, thereby realizing the forming of different bending directions and different bending radii. Multi-segment and multi-directional free bending can complete the three-dimensional spatial configuration of the target component.

[0010] The device for progressive roller bending of complex, three-dimensional, variable-cross-section curved profiles utilizes friction between rollers and the sheet material to propel the sheet material forward along the X-axis. The number of forming rollers and their angle distribution are designed based on the cross-sectional shape of the profile, and the roller motion paths are designed based on the profile's variable cross-section path. After the sheet material passes through multiple, continuous progressive roller sets to form a variable-cross-section profile, a guide mechanism transfers the profile to a bending die, where a bending force is applied to the die to achieve the desired change in the YZ plane, ultimately forming the three-dimensional, variable-cross-section, complex curved profile.

[0011] According to the forming method of the three-dimensional variable cross-section complex curved profile progressive roll bending composite forming device, the steps include:

[0012] The first step is to extract the cross-sectional shape and bending angle of the final three-dimensional variable-section complex curved profile and extract the three-dimensional spatial configuration;

[0013] The second step is to design the roller parameters and roller motion trajectory according to the cross-sectional shape and bending angle, and design the bending die motion trajectory according to the three-dimensional spatial configuration;

[0014] The third step is to establish the eccentricity U of the bending die center from the coordinate origin, the distance A from the bending die center to the front end of the guide mechanism in the Z direction, the speed v of the tube billet feeding in the X direction, and t as the relationship between the time of feeding the tube billet in the X direction and the bending radius R through the three-dimensional space configuration;

[0015] The eccentricity and bending radius satisfy the relationship: U = R (1-COSθ), where The relationship between eccentricity and bending radius is obtained as follows:

[0016] Beneficial effects:

[0017] 1. The present invention is based on the technology of progressive roll bending composite forming of three-dimensional variable cross-section complex curved profiles. Through the process of progressive roll bending of the plate, the plate is gradually formed into a variable cross-section profile at a small angle. Through the process of free bending of the plate, different bending moments are applied to the variable cross-section profile in different directions, thus realizing three-dimensional variable cross-section complex curved profiles with different bending directions and bending radii.

[0018] 2. During the implementation of the present invention, the plate is driven forward along the X-axis direction by the friction between the plate and the roller. During the advancement, the plate is gradually formed by continuously changing the cross section at small angles by controlling the translation and rotation of the roller and multiple roller groups, and finally a variable cross-section profile is realized. The variable cross-section profile formed by roller bending is transferred to the bending die through a guide mechanism. The bending die applies bending moments of different directions and sizes to the variable cross-section profile during the translation process, thereby realizing the forming of different bending directions and different bending radii. Based on the three-dimensional variable cross-section complex bending profile progressive roller bending composite forming device, the variable cross-section three-dimensional complex bending integrated forming of the target component can be realized by utilizing the continuous forming of the roller group and the motion trajectory design of the bending die, which can effectively reduce processing costs and improve production efficiency, and is of great significance to the production of profile component forming. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 、 three Progressive roll bending composite forming device for complex curved profiles with variable cross-sections;

[0020] 1 roller set, 2 guide mechanism, 3 bending die;

[0021] Figure 2 , Schematic diagram of progressive roller bending roller assembly;

[0022] Figure 3 , schematic diagram of progressive roller bending of sheet metal;

[0023] Figure 4 , schematic diagram of the motion trajectory of the multi-pass forming roller group;

[0024] Figure 5 , Examples of sheet metal progressive roll bending to form variable cross-section profiles;

[0025] Figure 6 , Schematic diagram of the bending die for free bending of sheet metal; a. Dimensions of the bending die, b. Schematic diagram of the bending die structure;

[0026] 4 bending rollers, 5 spring mechanism;

[0027] Figure 7 , schematic diagram of target formed component; DETAILED DESCRIPTION

[0028] The present invention is described in detail below with reference to specific embodiments.

[0029] refer to Figure 1 The figure shows a three-dimensional variable cross-section complex curved profile progressive roll bending composite forming device, including a multi-pass variable cross-section forming roller set formed by progressive roll bending of the plate, a guide mechanism for the plate free bending forming, and a bending die. For details about the variable cross-section forming roller set for progressive roll bending of the plate, please refer to Figure 2 As shown, the plate cross-section forming control is achieved by the movement of the roller in the X-axis direction, the plate cross-section width control is achieved by the translation of the roller in the Y-axis direction, and the smooth transition control of the plate cross-section change is achieved by the rotation of the roller in the Z-axis direction. The plate cross-section is gradually formed by continuous small angle changes using multiple rollers. During the forming process, it is necessary to ensure that the axis of the plate is always in a straight line, so that the plate can be gradually formed into a variable cross-section profile according to the planned route. During the free bending process of the plate, the guide mechanism clamps and fixes the variable cross-section profile, provides support for the profile, prevents the axis from offset, and connects the transition from progressive roller bending to free bending, and transfers the variable cross-section profile to the bending die. As shown Figure 6 As shown, the bending die comprises two pairs of bending rollers, a spring mechanism, and a self-locking mechanism. The two pairs of bending rollers are arranged in a cross-section, with the upper and lower bending rollers mounted on a bending roller mounting frame. The spacing between the bending rollers is the height of the variable-section profile's vertical plate. The side bending rollers can expand and contract according to the plate's cross-sectional width. The spring mechanism is mounted between the side bending rollers and the bending roller mounting frame, supported by a tensile shaft. When the plate's cross-sectional width changes, the springs are compressed, causing the bending die's cross-sectional width to change. The self-locking mechanism includes a force sensor and an electromagnetic lock. The force sensor transmits the spring force in the spring mechanism to the electromagnetic lock in the form of an electrical signal. If the spring forces on both sides are inconsistent, two different electrical signals activate the electromagnetic lock, which activates the electromagnetic lock. By integrating the spring mechanism and self-locking mechanism into the bending die, the variable-section profile can pass through the die, with the die continuously changing its trajectory and posture. The bending rollers apply bending moments of varying directions and magnitudes to the variable-section profile, achieving continuous bending of the profile in multiple sections and directions, ultimately forming a three-dimensional, complex, variable-section curved member.

[0030] The multi-pass variable cross-section forming roller set in the progressive roll bending of the plate is designed to design the roller set size and number according to the forming angle, and to design the roller set trajectory according to the variable cross-section plate, such as Figure 3 dotted line, Figure 4 Shown is the spatial trajectory of the roller group.

[0031] The free bending forming of the plate is based on the design of the motion trajectory of the bending die in the YZ plane according to the three-dimensional variable cross-section complex bending member.

[0032] A method for performing progressive roll bending of a three-dimensional variable cross-section complex curved profile using a progressive roll bending composite forming device for a three-dimensional variable cross-section complex curved profile comprises the following steps:

[0033] In the first step, geometric parameters are extracted from the cross-sectional shape and three-dimensional spatial configuration of the target profile component;

[0034] The second step is to determine the number of passes of the roller set, the distribution of the bending angle of each pass, the motion trajectory of the rollers in each pass and the design of the roller set according to the cross-sectional shape. Multi-pass progressive roll bending is used to form variable cross-sectional profiles such as Figure 5 As shown, the profile forming angle θ1 is 90°. The symmetrical cross section can be used to design a roller assembly with five passes. Similarly, the bending angles are assigned to each pass. The bending angles of each pass can be calculated to be 26°, 50°, 70°, 84°, and 90° based on the symmetrical cross section. The motion trajectory of the roller assembly is designed according to the shape of the variable cross section profile. The specific trajectory is shown in the figure. Figure 4 As shown in the figure, as the roller bends and feeds the plate, it continuously moves forward along the X-axis and is formed into a variable-section profile after passing through multiple progressive roller sets.

[0035] The third step is to design the motion trajectory of the bending die based on the three-dimensional spatial configuration of the target component, such as Figure 6 As shown, the bending die R1 = 25mm, R2 = 60mm, the bending radius of the bending section of the target component is R = 100mm, the bending angle θ2 is 90°, the minimum web width is 60mm, and the maximum web width is 160mm. When the web width changes, a spring device is used to transition. Once the bending die starts working, the electromagnetic lock is activated to lock the side bending rollers, and the bending die is used to apply bending moments of different directions and sizes to the variable-section profile. The bending angle and bending radius of the target component can be known from the extracted spatial structure. The motion trajectory of the bending die can be designed based on the relationship between the eccentricity U, the bending radius R and the bending angle θ2, that is, the relationship U = R-RCOSθ2. The eccentricity of the bending die on the Y / Z axis is obtained, and the motion trajectory of the bending die on the Y / Z plane can be obtained, as shown in Figure 7 The final target forming component.

[0036] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A three-dimensional variable cross-section complex curved profile progressive roll bending composite forming device, characterized in that: It includes a multi-pass variable-section forming roller group for progressive roll bending of plates, a guide mechanism and a bending die for free bending forming of plates; the multi-pass variable-section forming roller group controls the plate section forming by the movement of the roller in the X-axis direction, controls the plate section width by the translation of the roller in the Y-axis direction, and controls the smooth transition of the plate section change by the rotation of the roller in the Z-axis direction, and utilizes rollers with different forming angles in multiple passes to make the plate section undergo continuous small angle changes and gradually form, so that the plate is progressively formed into a variable-section profile along a planned route, and during the forming process, it is necessary to ensure that the plate axis is always in a straight line; the guide mechanism clamps and fixes the variable-section profile, provides support for the variable-section profile, prevents the axis from offset, and connects the progressive roll bending and free bending forming, and transfers the variable-section profile to the bending die of the next device; the bending die includes two pairs of bending rollers, a spring mechanism and a self-locking mechanism , two pairs of bending rollers are arranged opposite each other and crosswise, the upper and lower bending rollers are installed on the bending roller fixing frame, the distance between the upper and lower bending rollers is the height of the variable-section profile vertical plate, the side bending rollers can expand and contract according to the cross-sectional width of the variable-section profile, the spring mechanism is installed between the side bending rollers and the bending roller fixing frame, the spring mechanism is supported by the tensile shaft, when the cross-sectional width of the variable-section profile changes, the spring mechanism is squeezed to realize the change of the bending die cross-section; the self-locking mechanism includes a force sensor and an electromagnetic lock, the force sensor transmits the spring force to the electromagnetic lock in the form of an electrical signal, once the spring forces on both sides of the spring mechanism are inconsistent, two different electrical signals will activate the electromagnetic lock, when the electromagnetic lock is activated, the side bending rollers are self-locked; the bending die constantly changes its motion trajectory and posture, and the two pairs of bending rollers apply bending moments of different directions and sizes to the variable-section profile, thereby realizing multi-segment and multi-direction continuous bending of the variable-section profile, and finally forming a three-dimensional variable-section complex bent profile.

2. The device for progressive roll bending of three-dimensional variable cross-section complex curved profiles according to claim 1, characterized in that: The roller group used for forming variable cross-sections rotates at a certain speed around their respective axes in the X-axis / Z-axis plane, moves horizontally along their respective axes in the X-axis / Y-axis plane, and rotates perpendicular to their respective axes in the X-axis / Y-axis plane. The sheet metal is sequentially bent through each roller for multiple passes with small angles to complete the variable cross-section forming of the profile, while providing support and driving force for the profile forming process.

3. The device for progressive roll bending of three-dimensional variable cross-section complex curved profiles according to claim 1, characterized in that: The variable-section profile is sent to the bending die through a guide mechanism. The spring mechanism in the bending die can enable the variable-section profile to pass through. The bending die used to form three-dimensional complex bending features performs continuous up and down, left and right linear motion in the Y-axis / Z-axis plane.

4. The device for progressive roll bending of three-dimensional variable cross-section complex curved profiles according to claim 1, characterized in that: The self-locking mechanism, once the bending die starts to work in the Y-axis / Z-axis plane, the forces on both sides of the spring mechanism are inconsistent, and an electrical signal is transmitted to and activated by the force sensor to lock the bending rollers on both sides of the spring mechanism. During the translation process, the bending roller applies bending moments of different directions and sizes to the variable-section profile, thereby realizing the forming of different bending directions and different bending radii. Multi-segment and multi-directional free bending can complete the three-dimensional spatial configuration of the profile.

5. The device for progressive roll bending composite forming of three-dimensional variable cross-section complex curved profiles according to claim 1, characterized in that: The friction between the roller and the plate is used to drive the plate forward along the X-axis direction. The number of forming roller groups and the forming angle distribution are designed according to the cross-sectional shape of the profile, and the movement trajectory of the forming roller is designed according to the variable cross-sectional path of the profile. After the plate passes through multiple passes of the variable cross-sectional forming roller group to form a variable cross-sectional profile, the variable cross-sectional profile is immediately transferred to the bending die through the guide mechanism. The bending die applies a bending force to it to meet the change requirements of the YZ plane, and finally forms a three-dimensional variable cross-sectional complex bent profile.

6. The forming method of the device according to any one of claims 1 to 5, characterized in that: The following steps are involved: The first step is to extract the cross-sectional shape and bending angle of the final three-dimensional variable-section complex curved profile and extract the three-dimensional spatial configuration; The second step is to design the roller parameters and roller motion trajectory according to the cross-sectional shape and bending angle, and design the bending die motion trajectory according to the three-dimensional spatial configuration; The third step is to analyze the forming process parameters. Through the three-dimensional spatial configuration, the relationship between the eccentricity U of the bending die center from the coordinate origin, the distance A from the bending die center to the front end of the guide mechanism in the Z direction, the speed v of the profile feeding along the X direction, the time t of the profile feeding along the X direction and the bending radius R is established; The eccentricity U and the bending radius R satisfy the relationship: ,in , the relationship between eccentricity and bending radius is obtained as follows: .

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