A two-degree-of-freedom compliant device for conforming complex curved surfaces

Abstract

This invention discloses a two-degree-of-freedom compliant device for conforming to complex curved surfaces, relating to the field of large-scale equipment manufacturing and assembly technology. It includes: a fixed platform of the compliant device connected to the ground or a statically determinate plane via a strong connection; a moving platform of the compliant device directly contacting the surface of the component through surface contact; compliant branches implemented as flexible hinges in the form of revolute pairs; rigid branches mainly distributed along the force transmission path; and loading branches located on both sides of the compliant device. When the loading sections on both sides of the loading branches are subjected to external force input, they drive the flexible hinges to deform and rotate, changing the configuration of the compliant branches and causing the moving platform of the compliant device to move and rotate. The moving platform of the compliant device changes the contact point position through the deformation of the compliant branches, thereby conforming to the surface of the component. This invention, through the deformability of the moving platform of the compliant device, can effectively conform to the surface of large, complex curved components and restore their designed state, without causing damage to the surface of the assembled parts during assembly.

Description

Technical Field

[0001] This invention relates to the field of large-scale equipment manufacturing and assembly technology, and in particular to a two-degree-of-freedom compliant device for conforming to complex curved surfaces. Background Technology

[0002] Large equipment such as ships and aircraft are characterized by their large size, heavy weight, and unique shapes, making them extremely difficult to manufacture. In actual production, they are typically first divided into several parts, called sections or sub-sections, according to function or process. These sections are then processed and manufactured separately at different locations, and finally, they are assembled together. The main task in assembling two sections is to fix one section and adjust the position and orientation of the other to match the mating surfaces, thus allowing for further processing and assembly. Due to the large weight of each section, specialized equipment is needed to support them during the docking process. However, in some typical manufacturing scenarios, such as the docking of aircraft fuselage sections, ultra-heavy sections, and circular pipes, the surfaces of the target large component sections are curved, possessing a certain curvature and angle. Furthermore, due to their own weight and internal loads, their surfaces deform, causing deformation of the mating surfaces as well, resulting in significant assembly difficulties.

[0003] Common support devices primarily operate on principles such as planar support and point support. These devices suffer from three main problems: First, ordinary support devices and assembly equipment have non-curved and non-flexible support surfaces, making them difficult to match with curved surfaces and easily damaging the surfaces of assembled components. Second, for heavy-duty assemblies, i.e., target sections weighing hundreds or even thousands of tons, commonly used hydraulic and electric drive components lack sufficient adjustment capabilities. Third, limited by adjustment capabilities, the devices cannot maintain the shape of deformed large component sections to correct them to their designed state, ultimately leading to unsatisfactory assembly precision. Due to these issues, the overall manufacturing of large component sections with complex curved surfaces still has significant room for improvement in terms of quality and efficiency, requiring specialized mechanisms, devices, and systems.

[0004] A compliant mechanism is a special type of mechanical structure that transmits and converts motion and force through its own flexible deformation, rather than a traditional kinematic pair. Its advantages lie in its small number of parts, the absence of lubrication and assembly requirements, and its high flexibility, making it widely used in industrial applications. In precision assembly, compliant mechanisms can reduce the number of parts, shorten assembly time, and simplify the manufacturing and assembly process. In the field of large-scale equipment manufacturing and assembly technology, as designed in this invention, the compliant mechanism can adjust the posture of the assembly section by adjusting the deformation of its own structure, rather than adjusting hydraulic cylinders, electric cylinders, etc., thus effectively completing manufacturing and assembly tasks.

[0005] In recent years, with the development of large component docking technology, some emerging technologies and equipment have emerged, such as dedicated assembly vehicles and assembly lifting mechanisms. However, these devices still have not solved the problems of limited end-effector control capabilities leading to inability to maintain shape, and poor compliance resulting in excessive local stress and damage to the surface of assembled components. For example, Chinese invention patent application CN201711270044.6, "Flexible Positioning Device for Automatic Docking Assembly of Large Thin-Walled Cylindrical Components," and Chinese invention patent application CN202410169838.7, "A Cooperative Attitude Adjustment Device for Compliant Docking of Ship Sections," have designed flexible positioning devices for automatic docking assembly for cylindrical section assembly and ship section assembly, respectively, improving docking efficiency and accuracy, but have not solved the three major problems not yet mentioned.

[0006] In the assembly of thin sheet metal parts, some specialized conformal tooling is gradually being applied. For example, Chinese invention patent application CN202311803041.X, entitled "An Automatic Drilling and Riveting Conformal Tooling for Aircraft Super Panels," provides a simple conformal tooling that can quickly position and fix multiple single panels to improve assembly quality and efficiency. However, it is mainly aimed at thin sheet metal parts such as skin panels, and its application scope is limited.

[0007] In summary, the existing technology lacks a technology and device that can support large components with curved surfaces while maintaining the shape of the surface during elastic deformation. Currently, no descriptions or reports of technologies similar to this invention have been found, and no similar information has been collected domestically or internationally.

[0008] Therefore, those skilled in the art are dedicated to developing a two-degree-of-freedom compliant device for conforming complex curved surfaces. Summary of the Invention

[0009] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a device capable of bearing large components with curved surfaces and preserving the elastic deformation of the surface.

[0010] To achieve the above objectives, the present invention provides a two-degree-of-freedom compliant device for conforming to complex curved surfaces, characterized in that it comprises a fixed platform for the compliant device, a moving platform for the compliant device, compliant branches, rigid branches, and loading branches, wherein...

[0011] The compliant device is mounted on a fixed platform and is connected to the ground or the statically determinate plane in a strong connection manner.

[0012] The compliant device moving platform directly contacts the surface of the component through surface contact, and acts on the surface of the component that needs to maintain its shape;

[0013] The compliant branch is located within the compliant device and is implemented as a flexible hinge in the form of a revolute pair.

[0014] The rigid branches are located within the compliant device and are mainly distributed along the force transmission path.

[0015] The loading branches are located on both sides of the compliant device and are configured as the input source carriers for realizing the deformation of the compliant branches. When the loading sections on both sides of the loading branches are subjected to external force input, the flexible hinges are driven to deform and rotate, thereby driving the compliant branches to change their configuration and driving the movement and rotation of the compliant device's moving platform.

[0016] The fixed platform of the compliant device and the movable platform of the compliant device are connected by the compliant branch and the rigid branch. The movable platform of the compliant device changes the position of the contact point by deforming the compliant branch, thereby maintaining the shape of the component surface. The flexible hinge and the rigid branch are located in the same plane.

[0017] Furthermore, the compliant device fixed platform, the compliant device moving platform, the compliant branch, the rigid branch, and the loading branch are integrally molded and have the same material type and similar physical and chemical properties.

[0018] Furthermore, the material of the compliant device's fixed platform is a metallic material or a special material. The metallic material includes ordinary steel, high-strength steel, alloy steel, and aluminum alloy, and the special material includes resin material.

[0019] Furthermore, the compliant device's fixed platform is installed on the ground or the statically determinate plane by screwing or welding to ensure the overall rigidity of the device during operation.

[0020] Furthermore, the compliant device moving platform adopts a position control method to change the contact point position between the compliant device moving platform and the target component, thereby adjusting the spatial coordinates of key feature points on the surface of the target component, and thus preserving the shape of the target component surface.

[0021] Furthermore, the surface shape of the compliant device's moving platform is specifically designed according to the characteristics of the conforming object, and the surface shape includes a plane, a circular curve, an elliptical curve, and an upward-opening parabola.

[0022] Furthermore, the material of the compliant device moving platform is a metal material or a special material. The metal material includes ordinary steel, high-strength steel, alloy steel and aluminum alloy, and the special material includes resin material.

[0023] Furthermore, the flexible hinge includes a planar revolute joint and a planar prismatic joint, and the flexible hinge is connected to the compliant device fixed platform in an integral connection manner.

[0024] Furthermore, the compliant branch has the ability to move, and when a force is applied to the compliant branch, it will undergo elastic deformation, thereby changing the position of the center point of the compliant branch.

[0025] Furthermore, the rigid branch has a structural weight reduction and structural removal design, with the structural weight reduction and structural removal mainly distributed in the non-force transmission path, and the rigid branch has a large stiffness along the conformal adjustment direction.

[0026] In a preferred embodiment of the present invention, the present invention has the following advantages over the prior art:

[0027] 1. This invention utilizes the deformation capability of the compliant device's moving platform to effectively preserve the shape of large, complex curved surface components and restore them to their designed state, achieving the surface shape preservation capability of components in a fast, simple, and low-cost manner.

[0028] 2. This invention enables the docking operation to be compliant by having the compliant output end moving platform directly contact the target part, thereby reducing the risk of stress concentration on the surface of the assembled parts and avoiding surface damage.

[0029] 3. This invention adjusts the input end of the device manually or automatically, achieving support for heavy, large-sized, complex surface components in a low-cost, fast, and simple manner, which is of great significance for the promotion and application of compliant devices.

[0030] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0031] Figure 1 This is a side view schematic diagram of an embodiment of the present invention;

[0032] Figure 2 This is a perspective view of an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram illustrating the actual assembly of a large cylindrical part according to an embodiment of the present invention;

[0034] Figure 4 This is a side view of an embodiment of the present invention used in the actual assembly of a large cylindrical part;

[0035] Figure 5 This is a side view schematic diagram of another embodiment of the present invention;

[0036] Figure 6 This is a perspective view of another embodiment of the present invention.

[0037] The labels in the diagram are explained as follows:

[0038] 101-Compliant device fixed platform, 102-Compliant device moving platform, 103-Rigid branch, 104-Compliant branch, 105-Loading branch;

[0039] 301-Two-degree-of-freedom compliant device group, 302-Compliant device mounting base, 303-Large cylinder, 304-Horizontal loading direction wheel, 305-Vertical loading direction wheel;

[0040] 501-Compliant device fixed platform A, 502-Compliant device moving platform A, 503-Rigid branch A, 504-Compliant branch A, 505-Loading branch A. Detailed Implementation

[0041] The following description, with reference to the accompanying drawings, illustrates several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0042] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0043] like Figure 1 and Figure 2 As shown, existing orientation adjustment devices are limited by their adjustment capabilities and cannot maintain the shape of large deformed parts to their designed state, ultimately leading to insufficient assembly accuracy and low assembly efficiency. This invention provides a two-degree-of-freedom compliant device for maintaining the shape of complex curved surfaces. The device includes a compliant device fixed platform 101, a compliant device moving platform 102, a rigid branch 103, a compliant branch 104, and a loading branch 105.

[0044] The compliant device fixed platform 101 is installed on the ground or a statically determinate plane and is connected to the ground or statically determinate plane by a strong connection. The compliant device fixed platform 101 can be installed on the ground or statically determinate plane by screwing or welding to ensure the overall rigidity of the device during operation.

[0045] The material of the compliant device platform 101 can be metal or special materials. Metal materials include ordinary steel, high-strength steel, alloy steel and aluminum alloy, while special materials include resin materials.

[0046] The compliant device moving platform 102 directly contacts the surface of the component through surface contact, acting on the surface of the component that needs to be conformed. The compliant device moving platform 102 employs a position-based control method, changing the position of the contact point between the compliant device moving platform 102 and the target component, thereby adjusting the spatial coordinates of key feature points on the surface of the target component, and thus conforming to the surface of the target component. The surface shape of the compliant device moving platform 102 can be specifically designed according to the characteristics of the object to be conformed to, and the surface shape includes planes, circular curves, elliptical curves, and upward-opening parabolas, among other shapes.

[0047] The compliant device moving platform 102 can be made of metal or special materials. Metal materials include ordinary steel, high-strength steel, alloy steel and aluminum alloy, etc., while special materials include resin materials.

[0048] Rigid branches 103, located within the compliant device, are primarily distributed along the force transmission path. Rigid branches 103 incorporate structural weight reduction and removal designs, with these measures mainly distributed along non-force transmission paths. Rigid branches 103 exhibit significant stiffness along the conformal adjustment direction.

[0049] The compliant branch 104, located within the compliant device, is implemented as a flexible hinge in the form of a revolute joint. The revolute joints of the compliant branch 104 include planar revolute joints and planar prismatic joints, and these flexible hinges are connected to the fixed platform 101 of the compliant device in an integral connection.

[0050] The compliant branch 104 has the ability to move. When a force is applied to the compliant branch 104, it will undergo elastic deformation, thereby changing the position of the center point of the compliant branch 104.

[0051] Loading branches 105, located on both sides of the compliant device, are set as the input source carriers for realizing the deformation of the compliant branches 104. When the loading sections on both sides of the loading branches 105 are subjected to external force input, the flexible hinges are driven to deform and rotate, thereby driving the compliant branches 104 to change their configuration and driving the movement and rotation of the compliant device's moving platform.

[0052] In this embodiment of the invention, the compliant device fixed platform 101 and the compliant device moving platform 102 are connected by a compliant branch 104 and a rigid branch 103. The compliant device moving platform 102 changes the position of the contact point by deforming the compliant branch 104, thereby maintaining the shape of the component surface. The flexible hinge and the rigid branch 103 are located in the same plane.

[0053] In this embodiment, the compliant device fixed platform 101, the compliant device moving platform 102, the compliant branch 104, the rigid branch 103, and the loading branch 105 can be integrally molded and can have the same material type and similar physical and chemical properties.

[0054] Compared with the prior art, the two-degree-of-freedom compliant device for conforming complex curved surfaces provided in this embodiment of the invention has the following characteristics:

[0055] 1. Existing orientation adjustment devices are limited by their adjustment capabilities, making it impossible to maintain the shape of large, deformed parts and correct them to their designed state. This results in insufficient assembly accuracy and low assembly efficiency. This invention utilizes the elastic deformation of flexible components and the overall mechanism to transfer force, motion, and energy from the input end to the output end. The output end moving platform directly contacts the target part. By adjusting the flexible hinges in the device, the posture and shape of the output end moving platform are adjusted, thereby maintaining the shape of the target part. Through the compliant deformation capability of the moving platform, the device can effectively maintain the shape of large, complex curved surfaces of parts, restoring them to their designed state. This achieves the shape preservation capability of parts surfaces in a low-cost, fast, and simple manner.

[0056] 2. Existing support devices and assembly equipment typically have non-curved support surfaces that lack flexibility, making them difficult to match with curved surfaces and prone to damaging the surfaces of assembled components. This invention utilizes a compliant branch and flexible hinge structure, enabling the device to maintain flexibility when applying shape-keeping forces, thus preventing damage to the surfaces of assembled components. The compliant branch, implemented as a flexible hinge in the form of a revolute pair, allows for elastic deformation under load, maintaining a certain degree of flexibility while applying shape-keeping forces to the contact components. By controlling the force of the loading branch, the device ensures uniform stress distribution on the surface when adjusting the position and shape of components, reducing localized stress concentration and preventing surface damage. Furthermore, this invention achieves flexibility during the docking process through direct contact between the compliant output end moving platform and the target part, reducing the risk of stress concentration on the surface of the assembled components and thus preventing surface damage.

[0057] 3. For heavy-duty assembly, where the target section weighs hundreds or even thousands of tons, commonly used hydraulic and electric drive components lack sufficient adjustment capabilities. This invention uses a compliant mechanism to design a two-degree-of-freedom compliant device. It achieves motion and force transmission and conversion through the flexible deformation of the material itself, rather than by adjusting hydraulic or electric cylinders. Using ultra-high-pressure hydraulic cylinders and ultra-large electric cylinders for assembling and adjusting heavy-duty large components suffers from limited component response speed, complex servo system design, and an excessive number of control axes. This invention, by using a compliant device for adjustment, allows for an integrated design, effectively reducing the number of inputs and lowering the system control complexity. Adjusting the device's input end manually or automatically provides a low-cost, fast, and simple way to support heavy, large, and complex surface components, which is of great significance for the widespread application of compliant devices.

[0058] The present invention will now be described in detail with reference to preferred embodiments.

[0059] like Figures 1-2 As shown, a preferred embodiment of the present invention provides a two-degree-of-freedom compliant device for conforming to complex curved surfaces, comprising a fixed platform 101, a movable platform 102, rigid branches 103 and compliant branches 104 located within the compliant device, and a loading branch 105 located on the compliant device. The fixed platform 101 and the movable platform 102 are connected by the rigid branches 103 and compliant branches 104. The compliant branches 104 are implemented as flexible hinges in the form of revolute joints. The rigid branches 103 are distributed along the force transmission path, and each flexible hinge and rigid branch 103 is located in the same plane. At least four sets of rigid branches 103 and compliant branches 104 are provided, forming at least two sets of branches.

[0060] The compliant device moving platform 102 acts on the surface of the component that needs to be conformed by direct contact. The contact point position is changed by the deformation of the compliant branch 104, thereby conforming the surface of the component. The loading branch 105 is the input source carrier for the deformation of the compliant branch 104. It is located on both sides of the compliant device. When the loading ends on both sides are subjected to external force input, the flexible hinge is driven to deform and rotate, thereby driving the compliant branch 104 to change its configuration and driving the compliant device moving platform 102 to move and rotate.

[0061] like Figures 3-4 As shown, a preferred embodiment of the present invention is used in the actual assembly of large cylindrical parts, including a two-degree-of-freedom compliant device group 301, a compliant device mounting base 302, a large cylinder 303, a horizontal loading direction wheel 304, and a vertical loading direction wheel 305. Each two-degree-of-freedom compliant device is mounted on a mounting base, forming an attitude adjustment unit. During assembly and conformal maintenance, two rows of attitude adjustment units are arranged along the outer contact surface of the large cylinder 303. When conformal maintenance of the large cylinder 303 is required, the horizontal loading direction wheel 304 and the vertical loading direction wheel 305 are adjusted to drive the moving platform of each compliant device to adjust its position and posture, thereby conforming the surface of the large cylinder 303.

[0062] like Figures 5-6 As shown, this is another embodiment of the present invention, which is another two-degree-of-freedom compliant device for conforming complex curved surfaces, including a compliant device fixed platform A501, a compliant device moving platform A502, a rigid branch A503 and a compliant branch A504 located within the compliant device, and a loading branch A505 located on the compliant device.

[0063] The two-degree-of-freedom compliant device for conforming complex curved surfaces provided in this invention has the following specific advantages:

[0064] 1. Technological advantages

[0065] 1) It can preserve the shape of large, deformed component sections;

[0066] 2) It can be matched with curved surfaces, and will not damage the surface of the assembled parts during assembly;

[0067] 3) It can be applied to assembly scenarios where the weight reaches hundreds or even thousands of tons.

[0068] 2. Performance Indicators

[0069] 1) The load-bearing capacity of a single two-degree-of-freedom compliant device can reach 10T-50T or more;

[0070] 2) It can be applied to large-scale assembly scenarios with weights ranging from 100T to 2000T.

[0071] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A two-degree-of-freedom compliant device for conforming to complex curved surfaces, characterized in that, This includes a compliant device fixed platform, a compliant device moving platform, a compliant branch, a rigid branch, and a loading branch, among which, The compliant device is mounted on a fixed platform and is connected to the ground or the statically determinate plane in a strong connection manner. The compliant device moving platform directly contacts the surface of the component through surface contact, and acts on the surface of the component that needs to maintain its shape; The compliant branch is located within the compliant device and is implemented as a flexible hinge in the form of a revolute pair. The rigid branches are located within the compliant device and are mainly distributed along the force transmission path. The loading branches are located on both sides of the compliant device and are configured as the input source carriers for realizing the deformation of the compliant branches. When the loading sections on both sides of the loading branches are subjected to external force input, the flexible hinges are driven to deform and rotate, thereby driving the compliant branches to change their configuration and driving the movement and rotation of the compliant device's moving platform. The fixed platform of the compliant device and the movable platform of the compliant device are connected by the compliant branch and the rigid branch. The movable platform of the compliant device changes the position of the contact point by deforming the compliant branch, thereby maintaining the shape of the component surface. The flexible hinge and the rigid branch are located in the same plane.

2. The apparatus as claimed in claim 1, characterized in that, The compliant device fixed platform, the compliant device moving platform, the compliant branch, the rigid branch, and the loading branch are integrally molded and have the same material type and similar physical and chemical properties.

3. The apparatus as described in claim 2, characterized in that, The compliant device's fixed platform is made of metallic or special materials. The metallic materials include ordinary steel, high-strength steel, alloy steel, and aluminum alloy, while the special materials include resin materials.

4. The apparatus as described in claim 3, characterized in that, The compliant device is mounted on the ground or the statically fixed plane by screwing or welding to ensure the overall rigidity of the device during operation.

5. The apparatus as described in claim 4, characterized in that, The compliant motion platform adopts a position control method to change the contact point position between the compliant motion platform and the target component, thereby adjusting the spatial coordinates of key feature points on the surface of the target component, and thus preserving the shape of the target component surface.

6. The apparatus as claimed in claim 5, characterized in that, The surface shape of the compliant device's moving platform is designed specifically for the characteristics of the conforming object. The surface shape includes a plane, a circular curve, an elliptical curve, and an upward-opening parabola.

7. The apparatus as claimed in claim 6, characterized in that, The compliant device's motion platform is made of metallic or special materials. The metallic materials include ordinary steel, high-strength steel, alloy steel, and aluminum alloy, while the special materials include resin materials.

8. The apparatus as claimed in claim 7, characterized in that, The flexible hinge includes planar revolute joints and planar prismatic joints, and the flexible hinge is connected to the fixed platform of the compliant device in an integral connection.

9. The apparatus as claimed in claim 8, characterized in that, The compliant branch has the ability to move. When a force is applied to the compliant branch, it will undergo elastic deformation, thereby changing the position of the center point of the compliant branch.

10. The apparatus as claimed in claim 9, characterized in that, The rigid branch has a structural weight reduction and structural removal design, which are distributed in the non-force transmission path. The rigid branch has a large stiffness along the conformal adjustment direction.

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