Multi-degree-of-freedom flexible assembly equipment for special-shaped parts

Abstract

The invention relates to multi-degree-of-freedom flexible assembling equipment for special-shaped components, belongs to the technical field of flexible assembling, solves the problems of impact, jamming, wedge-caulking and the like in the assembling process of aerospace special-shaped components in the prior art, and comprises an assembling platform frame serving as a static platform, a plurality of spring flexible branch chains and a tool serving as a movable platform. The tool is installed on an assembly platform frame through spring flexible branch chains, and the assembly platform frame comprises a platform frame used as a supporting base of the multi-degree-of-freedom flexible assembly equipment; the hoisting unit is arranged on the platform frame, is connected to the spring flexible branch chain and is connected with the tool through the spring flexible branch chain; the middle supporting piece is arranged on the platform frame and used for fixing the special-shaped component to be assembled in advance; the spring flexible branch chain comprises a rope, a flexible branch chain adjuster used for adjusting the length of the rope, and a spring which are connected in series end to end.

Description

Technical Field

[0001] This invention belongs to the field of compliant assembly technology, and particularly relates to a multi-degree-of-freedom compliant assembly device for irregularly shaped parts. Background Technology

[0002] In the assembly process of aerospace irregularly shaped components, to ensure assembly accuracy and optimize the assembly path, guide grooves are often provided on the cylindrical parts of the aerospace irregularly shaped components, and sliders are installed on the outside of the components. During assembly, the aerospace irregularly shaped components experience assembly impact, jamming, and wedging under the contact force of the sliders. Due to product position errors, mechanical vibrations, and machining accuracy, assembly contact forces are generated during the assembly process. If these contact forces are not properly handled, assembly failure or product damage may occur. To smoothly assemble aerospace irregularly shaped components in an environment with assembly contact forces and avoid impact, jamming, and wedging during assembly, it is necessary to smooth out these contact forces. Since aerospace irregularly shaped components are usually large in size and heavy in weight, the smoothing assembly mechanism needs to have a certain load-bearing capacity and stability.

[0003] Currently, the conventional method for compliant assembly of irregularly shaped aerospace components involves manual assembly using hands and auxiliary support tools. This requires coordination among multiple people, which is difficult and labor-intensive. In addition, existing tandem compliant assembly mechanisms typically have low stiffness, weak load-bearing capacity, and are highly unstable at the ends, making them unsuitable for assembling large, irregularly shaped structures such as aerospace components.

[0004] Therefore, there is an urgent need in this field for a flexible assembly mechanism for aerospace irregular-shaped components that is flexible, meets the requirements of flexible degrees of freedom, is low in cost, has a large load-bearing capacity and good adjustability, and avoids assembly impact, jamming, wedging and other phenomena during the assembly process. Summary of the Invention

[0005] To address the aforementioned issues and achieve compliant assembly of irregularly shaped aerospace components, an embodiment of the present invention provides a multi-degree-of-freedom compliant assembly device for irregularly shaped components. This mechanism is a parallel mechanism with high load-bearing capacity and good stability, enabling six degrees of freedom flexibility for irregularly shaped aerospace components during assembly. During the assembly of slot blocks, flexibility avoids phenomena such as impact, jamming, and wedging, allowing irregularly shaped aerospace components to be assembled smoothly, and it also has strong versatility.

[0006] According to one embodiment of the present invention, a multi-degree-of-freedom compliant assembly device for irregularly shaped parts is provided, comprising: an assembly platform frame as a static platform, multiple spring flexible chains, and a tooling as a moving platform, the tooling being mounted to the assembly platform frame via the spring flexible chains.

[0007] The assembly platform frame includes: a platform frame, which serves as a support base for the multi-degree-of-freedom compliant assembly equipment; a hoisting unit, which is disposed on the platform frame and connected to the spring flexible chain and the tooling through the spring flexible chain; and an intermediate support member, which is disposed on the platform frame and used to pre-fix the irregularly shaped parts to be assembled.

[0008] The spring flexible branch includes: a rope, a flexible branch adjuster for adjusting the rope length, and a spring, which are connected to each other in a series connection.

[0009] The tooling includes: a front tooling, which engages with the front end of the irregularly shaped part to be assembled during use; a rear tooling, which engages with the rear end of the irregularly shaped part to be assembled during use; and a tooling adjustment rod, which connects the front tooling and the rear tooling.

[0010] Optionally, the hoisting unit further includes a safety device fixedly connected to its top, with the other end of the safety device connected to the tooling, and the length of the safety device is adjustable;

[0011] The flexible spring chain switches between two states by cooperating with the safety device:

[0012] Constraint state: Due to the tensioning of the safety device, the flexible spring chain is in a stress-free state, making the tooling connected to the flexible spring chain fully constrained in all six degrees of freedom;

[0013] Flexible state: Adjust the flexible branch adjuster to shorten the rope length, so that the spring flexible branch is taut and the safety is in a loose state, so that the tooling connected to the spring flexible branch has six degrees of freedom of flexibility.

[0014] Optionally, the assembly platform frame further includes a moving unit disposed on the platform frame, wherein the hoisting unit and the intermediate support are movably disposed on the platform frame by being mounted on the moving unit.

[0015] Optionally, the moving unit includes: a linear guide rail laid along the platform frame; a slider mounted on the linear guide rail and sliding thereon; and a sliding limiter mounted on the linear guide rail and fixed to the slider for limiting the sliding of the slider.

[0016] Optionally, the hoisting unit includes:

[0017] A front lifting frame is mounted on a slider on the linear guide rail at the front position of the assembly platform frame, is movably disposed on the assembly platform frame, and is used to cooperate with the front tooling;

[0018] The rear hoisting frame is mounted on a slider on the linear guide rail at the rear position of the assembly platform frame and is movably disposed on the assembly platform frame for cooperation with the rear tooling.

[0019] Multiple platform pull rings are fixedly connected to the base of the front lifting frame and the rear lifting frame, and are respectively connected to spring flexible branches to be connected to the front tooling and the rear tooling respectively via the spring flexible branches;

[0020] One end of the safety device is fixedly connected to the top of the front hoisting frame or the rear hoisting frame.

[0021] Optionally, the front lifting frame includes fixed pulleys fixedly installed at its top position and middle height; the rear lifting frame includes fixed pulleys fixedly installed at its top position and middle height; wherein, after assembly, one end of the spring flexible chain passes through the fixed pulley and is then connected to the tooling.

[0022] Optionally, the tooling further includes: a plurality of tooling lifting rings disposed on the front tooling and the rear tooling for connection with the spring flexible chain to connect the tooling to the assembly platform frame via the spring flexible chain; and adjusting screws disposed at the positions where the tooling adjusting rod is connected to the front tooling and the rear tooling, for adjusting and fastening the fit between the front and rear tooling and the irregular part to be assembled.

[0023] Optionally, one end of the spring flexible branch is connected to the platform pull ring on the assembly platform frame, and the other end is connected to the tooling lifting ring on the tooling. The spring flexible branches are distributed in parallel to form a flexible parallel mechanism with the assembly platform frame as the static platform and the tooling as the dynamic platform.

[0024] According to another embodiment of the present invention, a multi-degree-of-freedom compliant assembly device for irregularly shaped parts is provided. The device achieves six degrees of freedom flexibility through parallel spring flexible branches and includes: an assembly platform frame, tooling, and spring flexible branches. The assembly platform frame includes: a platform frame, a lifting unit mounted on the platform frame, an intermediate support, and a moving unit. The lifting unit and the intermediate support are mounted on the moving unit. The lifting unit includes a front lifting frame, a rear lifting frame, a telescopic top rod, a platform pull ring, and a safety device. The front lifting frame and the rear lifting frame are fixed in position by the sliding limiter. The telescopic top rod is mounted on the rear lifting frame. The platform pull ring and the safety device are both fixedly connected to the front lifting frame and the rear lifting frame. The moving unit includes a linear guide rail, a slider, and a sliding limiter used in conjunction with the slider. The slider and the sliding limiter are mounted on the linear guide rail.

[0025] The tooling includes: a front tooling, a rear tooling, a tooling adjusting rod, an adjusting screw, and a tooling lifting ring. The front tooling is installed at the front end of the aerospace irregular component, and the rear tooling is connected to the tail end of the aerospace irregular component. The front tooling and the rear tooling are connected by the tooling adjusting rod. The tail end of the aerospace irregular component to be assembled is pressed by the adjusting screw, so that the tooling and the aerospace irregular component are fixedly connected. One end of the tooling lifting ring is fixedly connected to the tooling, and the other end is connected to the spring flexible support chain.

[0026] The spring flexible branch includes: a rope, a flexible branch adjuster, and a spring. The rope, the flexible branch adjuster, and the spring can be connected end to end in any order to form each spring flexible branch.

[0027] Furthermore, the front hoisting frame is provided with several positions for installing the platform pull ring, for connecting the spring flexible support chain, and is provided with several safety devices to ensure that failure of the spring flexible support chain will not cause the aerospace irregular parts to be loosely fixed, impacted, or fall. The position of the platform pull ring on the front hoisting frame can be adjusted by sliding the slider on the linear guide rail, so that the mechanism is suitable for assembling aerospace irregular parts of different specifications and has scalability.

[0028] Furthermore, the rear hoisting frame is provided with several positions for installing the platform pull ring, for connecting the spring flexible support chain, and is provided with several safety devices to ensure that failure of the spring flexible support chain will not cause the aerospace irregular component to be loosely fixed, impacted, or fall. The position of the platform pull ring on the rear hoisting frame can be adjusted by sliding the slider on the linear guide rail, so that the mechanism is suitable for assembling aerospace irregular components of different specifications and has scalability. The telescopic top rod can provide force along the assembly direction during the assembly of aerospace irregular components.

[0029] Furthermore, the intermediate support serves to pre-fix the position of the aerospace irregularly shaped component. The intermediate support slides on the linear guide rail via the slider, making the mechanism suitable for assembling aerospace irregularly shaped components of different specifications and providing scalability.

[0030] Furthermore, by adjusting the adjusting screws on both sides of the tooling adjusting rod, a pre-tightening force is applied to the front tooling and the rear tooling along the tooling adjusting rod direction, thereby pressing the tail of the aerospace irregular component, so that the tooling and the aerospace irregular component form a fixed whole, and then the spring flexible support chain is connected through a number of tooling lifting rings fixed to the front tooling and the rear tooling.

[0031] Furthermore, one end of the spring flexible branch is connected to several platform pull rings on the assembly platform frame, and the other end is connected to several tooling lifting rings on the tooling. The spring flexible branches are distributed in parallel to form a flexible parallel mechanism with the assembly platform frame as the static platform and the tooling as the dynamic platform. The rigid force of fixing the aerospace irregular component is transitioned to a flexible force through the flexible branch adjuster, so that the aerospace irregular component has a six-degree-of-freedom compliance capability. The compliance capability in each direction can be adjusted by changing the stiffness of the spring or by changing the connection position of the two ends of several spring flexible branches.

[0032] The multi-degree-of-freedom compliant assembly device for irregularly shaped parts provided according to an embodiment of the present invention has at least the following advantages over the prior art.

[0033] 1. The multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts provided according to the embodiments of the present invention uses springs as the key part of the flexible branches. The flexible branches are distributed in parallel to form a six-degree-of-freedom flexible parallel mechanism with the assembly platform frame as the static platform and the tooling as the dynamic platform. Compared with the traditional assembly method, it can achieve compliant assembly force in six degrees of freedom. The compliantness can be flexibly adjusted as needed. It can avoid phenomena such as impact, jamming, and wedging during the assembly process, and realize compliant assembly of aerospace irregularly shaped parts.

[0034] 2. The multi-degree-of-freedom compliant assembly equipment provided according to the embodiments of the present invention is a parallel mechanism, which greatly increases the load-bearing capacity and improves the stability compared with the serial mechanism of the prior art, and provides safer, smoother and more precise assembly of large equipment with large size, heavy weight and irregular shape, such as aerospace irregular parts.

[0035] 3. The combined use of the intermediate support, safety device, and flexible branch adjustment device of the multi-degree-of-freedom compliant assembly equipment provided by the embodiments of the present invention can transition the rigid force for fixing aerospace irregularly shaped components to a flexible force, reducing installation difficulty and improving equipment safety. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly introduced below. The features and advantages of the present invention can be more clearly understood by referring to the accompanying drawings. The accompanying drawings are schematic and should not be construed as limiting the present invention in any way. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 An overall isometric view of a multi-degree-of-freedom compliant assembly device for irregularly shaped parts, provided according to an embodiment of the present invention.

[0038] Figure 2 An isometric view of an assembly platform frame for a multi-degree-of-freedom compliant assembly device for irregularly shaped parts, provided according to an embodiment of the present invention.

[0039] Figure 3 An isometric view of a tooling for a multi-degree-of-freedom compliant assembly device for irregularly shaped parts, provided according to an embodiment of the present invention.

[0040] Figure 4 An isometric view of a spring flexible branch for a multi-degree-of-freedom compliant assembly device for irregularly shaped parts, provided according to an embodiment of the present invention.

[0041] Explanation of reference numerals in the attached figures:

[0042] 1-Platform frame; 2-Linear guide rail; 3-Slider; 4-Front lifting frame; 5-Sliding limiter; 6-Intermediate support; 7-Rear lifting frame; 71-High door frame; 72-Low door frame; 8-Telescopic top rod; 9-Platform pull ring; 10-Safety; 11-Front tooling; 12-Tooling adjusting rod; 13-Tooling lifting ring; 14-Rear tooling; 15-Adjusting screw; 16-Flexible branch chain adjuster; 17-Spring; 18-Rope; 19-Fixed pulley; 20-Tooling; 30-Spring flexible branch chain; 40-Assembly platform frame. Detailed Implementation

[0043] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0044] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0045] The following detailed description, with reference to the accompanying drawings, illustrates a multi-degree-of-freedom compliant assembly apparatus for irregularly shaped components according to an embodiment of the present invention. The multi-degree-of-freedom compliant assembly apparatus for irregularly shaped components provided by the embodiments of the present invention can be used for the assembly of irregularly shaped components of various sizes and can provide six-degree-of-freedom compliant assembly. The irregularly shaped components can be, for example, but not limited to, aerospace irregularly shaped components. In this embodiment, an aerospace irregularly shaped component is used as the structure to be assembled, and the multi-degree-of-freedom compliant assembly apparatus for assembling aerospace irregularly shaped components is used as an example for description. Figure 1 An overall isometric view of a multi-degree-of-freedom compliant assembly device for irregularly shaped parts, provided according to an embodiment of the present invention. Figure 2An isometric view of an assembly platform frame for a multi-degree-of-freedom compliant assembly device for irregularly shaped parts, provided according to an embodiment of the present invention. Figure 3 An isometric view of a tooling for a multi-degree-of-freedom compliant assembly device for irregularly shaped parts, provided according to an embodiment of the present invention. Figure 4 An isometric view of a spring flexible branch for a multi-degree-of-freedom compliant assembly device for irregularly shaped parts, provided according to an embodiment of the present invention.

[0046] like Figure 1-4 As shown, a multi-degree-of-freedom compliant assembly device for irregularly shaped parts, according to one embodiment of the present invention, achieves six degrees of freedom flexibility through parallel spring flexible branches. The multi-degree-of-freedom compliant assembly device includes: an assembly platform frame 40, a tooling 20, and a plurality of spring flexible branches 30 connected to the assembly platform frame and the tooling 20. The tooling 20 is mounted to the assembly platform frame 40 via the spring flexible branches 30.

[0047] refer to Figure 4 The spring-loaded flexible branch 30 includes a spring 17, a flexible branch adjuster 16, and a rope 18, and the spring 17, flexible branch adjuster 16, and rope 18 can be connected end-to-end in any order to form a straight line. The flexible branch adjuster 16 is used to adjust the length of the rope 18. Figure 4 In the illustrated embodiment, the assembly sequence of the spring flexible branch 30 is as follows: rope 18 is connected to flexible branch adjuster 16, and flexible branch adjuster 16 is connected to spring 17. Spring 17, flexible branch adjuster 16, and rope 18 can be detachably connected, for example, by hooks or loops, facilitating disassembly and installation. In other embodiments, this connection sequence can be changed as needed; for example, the order could be rope 18 connected to spring 17, and spring 17 linked to flexible branch connector 16. Optionally, in other embodiments, the number of flexible branch adjusters 16 included in each spring flexible branch 30 can be selected as needed; for example, two flexible branch adjusters 16 can be connected in series.

[0048] In this embodiment, the rigid force used to fix the irregularly shaped aerospace component can be transitioned to a flexible force via the flexible branch adjuster 16. The number and position of the spring flexible branches 30 can be set as needed. Each spring flexible branch 30 is distributed in parallel between the assembly platform frame 40 and the tooling 20, forming a six-degree-of-freedom flexible parallel mechanism with the assembly platform frame 40 as the static platform and the tooling 20 as the dynamic platform. The parallel connection of the spring flexible branches 30 can be achieved by installing multiple spring flexible branches 30 in a manner that is approximately parallel to each other, including being approximately parallel to each other in the vertical direction or approximately parallel to each other in the horizontal direction. The rope 18 can be made of steel wire rope to provide load-bearing capacity for the heavy structure to be assembled. In one embodiment, the spring flexible branches 30 are arranged in a vertical 4-horizontal 4 layout, that is, two vertically installed spring flexible branches 30 and two horizontally installed spring flexible branches 30 are connected to the front of the tooling 20, and two vertically installed spring flexible branches 30 and two horizontally installed spring flexible branches 30 are connected to the rear of the tooling 20. The flexible spring-loaded branches 30 must meet this requirement: when no springs provide flexibility, each flexible spring-loaded branch 30 can constrain all six degrees of freedom of the tooling 20 (moving platform). After adding springs to each branch, the six degrees of freedom of the moving platform of the parallel mechanism can be made flexible. Springs 17 with different stiffnesses can be replaced according to the flexibility requirements of aerospace irregular component assembly, thereby achieving different degrees of flexibility.

[0049] See Figure 1 and Figure 2The hoisting unit may further include a safety device 10 fixedly connected to its top, with the other end of the safety device 10 connected to the tooling 20, and the length of the safety device 10 is adjustable. In optional embodiments, the safety device 10 may consist only of a rope, or it may include a rope and a flexible branch adjuster for adjusting the rope length. Optionally, in other embodiments, the number of flexible branch adjusters included in each safety device 10 can be selected as needed, for example, two flexible branch adjusters may be connected in series. The spring-loaded flexible branch 30, by cooperating with the safety device 10, allows the tooling 20 and the structure to be assembled to switch between a constrained state and a flexible state. In the constrained state: the safety device 10 is tensioned, and the flexible spring branch 30 is in a stress-free state, so that the tooling 20 and the structure to be assembled connected to the flexible spring branch 30 are fully constrained in six degrees of freedom. In the flexible state: the flexible branch adjuster 16 is adjusted to shorten the length of the rope 18, so that the spring 17 continuously extends, the rope tension continuously increases, and the flexible spring branch 30 is tensioned. When the tension of the rope 18 and the safety device 10 are balanced, the safety device 10 is in a loose tension state, so that the tooling 20 and the structure to be assembled connected to the flexible spring branch 30 have six degrees of freedom of flexibility. The multi-degree-of-freedom compliant assembly equipment provided by this embodiment increases the load-bearing capacity and stability compared to the serial mechanism, and compared with the traditional assembly method, it has the advantages of being able to achieve six degrees of freedom of assembly force compliance and adjustable compliance ability. It can use flexibility to avoid impact, jamming, and wedging phenomena during the assembly process, and realize the compliant assembly of aerospace irregular parts.

[0050] The spring flexible support chain 30 in the multi-degree-of-freedom compliant assembly equipment provided by the embodiments of the present invention uses springs as a flexible adjustment method, which has the advantages of large axial load-bearing capacity, good stability, easy design, good durability and low manufacturing cost; and springs of different stiffness can be replaced according to the flexibility requirements, and disassembly and installation are convenient when replacing springs; and in engineering applications, compared with methods such as flexible hinges, the spring flexible support chain 30 is more stable, reliable and convenient in use.

[0051] like Figure 2 As shown, the assembly platform frame 40 includes: a platform frame 1, a lifting unit, an intermediate support 6, and a movable unit mounted on the platform frame 1. The lifting unit and the intermediate support 6 are mounted on the movable unit, allowing the platform frame 1 to be moved and its position adjusted via the movable unit. The platform frame 1 can be a rectangular structure, providing a simple structure and stable support, and facilitating manufacturing and installation. (Reference) Figure 1 and 2 In this embodiment, when the multi-degree-of-freedom compliant assembly equipment is used to assemble aerospace irregular parts waiting to be assembled, the direction of the assembly platform frame 40 corresponding to the front end of the aerospace irregular part is the front part, and the direction corresponding to the rear end or tail of the aerospace irregular part is the rear part.

[0052] refer to Figure 2 In this embodiment, the hoisting unit may include a front hoisting frame 4, a rear hoisting frame 7, a telescopic top rod 8, a platform pull ring 9, and a safety device 10. The front hoisting frame 4 and the rear hoisting frame 7 are mounted on the moving unit, allowing them to move on the platform frame 1 and be fixed in place when adjusted to a suitable position. Position adjustment allows for flexible adaptation to aerospace irregularly shaped components of different specifications, while position fixation ensures stability during installation. The intermediate support 16 is disposed between the front hoisting frame 4 and the rear hoisting frame 7. The telescopic top rod 8 is mounted on the rear hoisting frame 7, preferably on the top of the rear hoisting frame 7, and provides force along the assembly direction during the assembly of aerospace irregularly shaped components. Platform pull ring 9 is fixedly connected to the base of the front lifting frame 4 and the rear lifting frame 7, and safety 10 is fixedly connected to the top of the front lifting frame 4 and the rear lifting frame 7. Platform pull ring 9 connects to the assembly platform frame 40 and tooling 20 by means of a spring flexible support chain 30. One end of safety 10 is connected to the safety connection of the assembly platform frame 40, and the other end is connected to the tooling lifting ring 13 on tooling 20, which mainly bears the weight. Telescopic top rod 8 can provide positioning for aerospace irregular parts when they are connected to tooling 20. Due to the uncertainty of assembly friction, when the assembly friction is large, the telescopic top rod 8 provides force in the assembly direction, which can make the flexibility of tooling 20 distributed in the non-assembly direction, making assembly easier.

[0053] like Figure 2 As shown, optionally, the front hoisting frame 4 can be configured as two side door frames installed at the front of the platform frame 1. Since in the assembly process of aerospace irregular components, the aerospace irregular components connected to the tooling 20 need to pass through the cylindrical components, the side door frame configuration can leave space for the cylindrical components. The rear hoisting frame 7 can be configured as a double door frame with high and low configuration installed at the rear of the platform frame 1. The slightly higher front door frame 71 provides space for the spring flexible support chain 30 to be hoisted to the rear tooling 14 and provides a safety installation position. The slightly lower rear door frame 72 is roughly at the same horizontal height as the rear tooling 14, which facilitates the provision of fixing points for the horizontally arranged spring flexible support chain 30. On the other hand, the lower door frame 72 can be equipped with a telescopic top rod 8 to provide force in the assembly direction for the aerospace irregular components.

[0054] refer to Figure 2The lifting unit may also include fixed pulleys. Specifically, the front lifting frame 4 includes fixed pulleys 19 fixedly installed at its top position and middle height; the rear lifting frame 7 includes fixed pulleys 19 fixedly installed at its top position and middle height; wherein, after assembly, one end of the rope 18 of the spring flexible chain 30 passes through the fixed pulley 19 and is then connected to the tooling 20. Optionally, the front lifting frame 4 may include fixed pulleys 19 fixedly installed at the top position and middle height of the front side door frame. The rear lifting frame 7 may also include fixed pulleys 19 fixed at the top of the high door frame 71 and the top of the low door frame 72, respectively serving as fixed pulleys 19 at the top position and middle height of the rear lifting frame 7. This arrangement allows one end of the rope 18 of the spring flexible chain to pass through the fixed pulley 19 and be connected to the tooling 20, thereby optimizing the spatial layout of the spring flexible chain 30 and reducing the height of the lifting points of the front lifting frame 4 and the rear lifting frame 7, reducing the size of the multi-degree-of-freedom compliant assembly equipment, and saving space.

[0055] In this embodiment, more platform pull rings 9 than are used can be provided at the base of the front lifting frame 4 and the rear lifting frame 7. In actual use, the position and number of spring flexible supports 30 to be installed are determined according to the external dimensions of the component to be assembled. The front lifting frame 4 and the rear lifting frame 7 are moved to a suitable position, and spring flexible supports 30 are connected to the corresponding positions and numbers of platform pull rings 9 to better match the component to be assembled. For example, when used for smaller aerospace irregularly shaped components, fewer platform pull rings 9 can be connected to the spring flexible supports 30; while when used for larger aerospace irregularly shaped components, more platform pull rings 9 can be connected to the spring flexible supports 30. Therefore, the multi-degree-of-freedom compliant assembly equipment including this lifting unit can adapt to aerospace irregularly shaped components of different dimensions by selecting and adjusting the number, distribution, and distance of the spring flexible supports 30, exhibiting good versatility. (Continue to refer to...) Figure 2 The moving unit may include a linear guide rail 2 mounted on the platform frame 1, multiple sliders 3 mounted to and sliding on the linear guide rail 2, and a sliding limiter 5 fixedly connected to the sliders 3 and restricting their movement. A front lifting frame 4, a rear lifting frame 7, and an intermediate support 6 are all movably mounted to the platform frame 1 by being fixed to the sliders 3. The sliding limiter 5 is fixedly connected to and mounted on the guide rail 2, and the front lifting frame 4 and rear lifting frame 7 are respectively fixedly mounted on the sliders 3 to move on the guide rail 2. The sliding limiter 5 restricts the movement of the front lifting frame 4 and rear lifting frame 7 and fixes them in the desired position.

[0056] refer to Figure 1In one optional embodiment, the vertical and horizontal arrangement of the spring flexible chain 30 can be specifically configured such that one end of the front vertically mounted spring flexible chain 30 is connected to the bottom of the front lifting frame 4 of the assembly platform, and the other end passes over the fixed pulley 19 at the top of the front lifting frame 4, thereby connecting to the tooling lifting rings 13 on both sides of the front tooling 11 of the tooling 20. One end of the rear vertically mounted spring flexible chain 30 is connected to the bottom of the rear lifting frame 7 on the assembly platform frame 40, and the other end passes over the fixed pulley 19 at the top of the middle high door frame 71 of the rear lifting frame 7, thereby connecting to the tooling lifting rings 13 on both sides of the rear tooling 14 of the tooling 20. One end of the front horizontally mounted spring flexible chain 30 is connected to the bottom of the front lifting frame 4 on the assembly platform frame 40, and the other end passes over the fixed pulleys 19 on both sides of the middle height outer side of the front lifting frame 4, thereby connecting to the tooling lifting rings 13 on both sides of the front tooling 11 of the tooling 20. Since the height of the fixed pulley 19 at the middle height is basically the same as the installation height of the tooling lifting ring 13, it can be considered as horizontal tension. One end of the horizontally installed spring flexible chain 30 at the rear is connected to the bottom of the rear lifting frame 7 on the assembly platform frame 40, and the other end passes around the fixed pulleys 19 on both sides of the low door frame 72 of the rear lifting frame 7, thereby connecting the tooling lifting rings 13 on both sides of the rear tooling 14 of the tooling 20. Since the height of the fixed pulley 19 is basically the same as the installation height of the tooling lifting ring 13, it can be considered as horizontal tension. The layout of the installed spring flexible chain 30 can be symmetrical.

[0057] The entire assembly platform frame 40 serves as the static platform of the multi-degree-of-freedom compliant assembly equipment. Multiple platform pull rings 9 on the front lifting frame 4 and the rear lifting frame 7 are connected to the spring flexible support chain 30. In conjunction with the rope 18 and the fixed pulley 19, an optimized layout is used. This layout reduces the height of the equipment, making the structure of the multi-degree-of-freedom compliant assembly equipment more compact. At this time, the fixed pulley 19 is the static platform hinge point of the multi-degree-of-freedom compliant assembly equipment.

[0058] In this embodiment, a safety device 10 can also be installed on the top of the front lifting frame 4 and the rear lifting frame 7. This safety device 10 is rigid and adjustable in length, and is used for rigid protection of the lifting unit and the tooling 20. One form of the safety device 10 may include: a lifting ring fixed to the top of the front lifting frame 4 and the rear lifting frame 7, one or more locking buckles, an adjustable-length rigging, and a lifting ring fixed to the tooling 20, forming an integral unit, the connection order of the components being interchangeable. This safety device is mainly used for rigid protection of the lifting frame and the tooling 20, preventing damage to the product caused by the tooling 20 falling as a whole with the aerospace irregularly shaped component after the accidental breakage of the rope of the spring flexible support chain 30. Furthermore, the rigid safety connection facilitates the initial positioning of the tooling 20. The weight of the tooling 20 and the aerospace-shaped component is gradually transferred from the safety device 10 to the various flexible branches via the flexible branch adjuster. After complete transfer, the tooling 20 exhibits six degrees of freedom of flexibility, the safety device is in a suspended state, and a certain amount of flexible space is left for the tooling 20. If the rope of the spring-loaded flexible branch 30 breaks unexpectedly, the safety device can immediately catch the entire tooling 20 and the aerospace-shaped component to prevent them from falling. A safety suspension point can be set next to the fixed pulley 19 through which the rope 18 of the spring-loaded flexible branch 30, which bears the weight of the aerospace-shaped component, passes. One end of the safety device 10 is fixed to this safety suspension point, and the other end of the safety device 10 is connected to the tooling lifting ring 13 connected to the rope 18 of the spring-loaded flexible branch 30.

[0059] Furthermore, a protective shell can be fitted over the rope 18 of the flexible spring support 30 to prevent product falls, rope injuries, and spring breakage due to chain breakage, effectively improving the safety of the equipment during installation and use. The distance between the front lifting frame 4 and the rear lifting frame 7 is adjusted by sliding the slider 3 on the linear guide 2, and the position of the slider 3 is fixed by the sliding limiter 5. This makes the multi-degree-of-freedom compliant assembly equipment suitable for assembling aerospace components with different external dimensions, offering good application scalability. In addition, the linear guide 2 has the advantages of high load-bearing capacity and low friction compared to other linear motion mechanisms. The sliding limiter 5 can be a manual clamp.

[0060] like Figure 3As shown, tooling 20 may include: a front tooling 11, a rear tooling 14, a tooling adjusting rod 12 connecting the front tooling 11 and the rear tooling 14, adjusting screws 15 disposed at the connection points between the front and rear parts of the adjusting rod 12 and the front and rear tooling 14, and multiple tooling lifting rings 13 fixedly disposed on the front and rear tooling 11. When installing aerospace irregularly shaped components, the front tooling 11 is assembled with the front end of the aerospace irregularly shaped component, and the rear tooling 14 is assembled with the rear end of the aerospace irregularly shaped component. The front tooling 11 and the rear tooling 14 are connected by the tooling adjusting rod 12, and the tail end of the aerospace irregularly shaped component is pressed together by the adjusting screws 15, thus securing the tooling 20 and the aerospace irregularly shaped component together. Each tooling lifting ring 13 is connected to a spring-loaded flexible support chain 30, thereby connecting to the assembly platform frame 40. The adjusting screw 15 at the rear of the tooling adjusting rod 12 is tightened after the rear tooling 14 is assembled with the tooling adjusting rod 12, thereby constraining the rear tooling 14 and solving the problem of the tail of the aerospace irregular component drooping. This makes the entire tooling 20 and the aerospace irregular component a stable whole, equivalent to the moving platform of the parallel mechanism. Several tooling lifting rings 13 are provided on the front tooling 11 and the rear tooling 14, serving as the hinge points of the moving platform of the parallel mechanism. They are connected to the spring flexible support chain 30, giving the moving platform, i.e., the aerospace irregular component, six degrees of freedom of flexibility. Each tooling lifting ring 13 on the tooling 20 corresponds to each platform pull ring 9 on the lifting unit via each spring flexible support chain 30. As an independent component, the tooling 20 is easy to replace and maintain. It can be replaced according to the tooling interface of different types of aerospace irregular components while ensuring the compliance effect, thereby further improving the versatility of this multi-degree-of-freedom compliant assembly equipment.

[0061] In this embodiment, by using the intermediate support 6, safety device 10, flexible branch adjuster 16 and other components together, the rigid force of fixing the aerospace irregular component can be transferred to the flexible force formed by each spring 17, which reduces the installation difficulty and improves the safety of the equipment. At the same time, the spring flexible branch 30 is an independent component that is easy to replace and maintain.

[0062] The multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts provided according to the embodiments of the present invention can be used for six-degree-of-freedom assembly force compliance under large loads. By arranging each spring flexible branch 30 in parallel, it has the advantages of large load-bearing capacity, good stability, and high safety compared with a multi-joint six-degree-of-freedom serial mechanism.

[0063] In some embodiments, the front lifting frame 4 and the rear lifting frame 7 are equipped with several platform pull rings 9 for connecting the spring flexible support chain 30, and several safety devices 10 are provided to ensure that failure of the spring flexible support chain 30 will not lead to the aerospace irregular component being loosely fixed, impacted, or falling. By sliding the slider 3 on the linear guide rail 2, the positions of the front lifting frame 4 and the rear lifting frame 7, as well as the platform pull rings 9 mounted on the slider 3, can be adjusted, making the mechanism suitable for assembling aerospace irregular components of different specifications and providing scalability.

[0064] In some implementations, a telescopic top rod 8 mounted on top of the rear hoisting frame 7 can provide force along the assembly direction during the assembly of aerospace irregular components.

[0065] In some embodiments, the intermediate support 6 serves to pre-fix the position of the aerospace irregular component. The intermediate support 6 slides on the linear guide rail 2 via the slider 3, making the mechanism suitable for assembling aerospace irregular components of different specifications and having scalability.

[0066] In some embodiments, by adjusting the adjusting screws 15 on both sides of the tooling adjusting rod 12, a pre-tightening force along the direction of the tooling adjusting rod 12 is provided to the front tooling 11 and the rear tooling 14, thereby forming a fixed whole between the tooling 20 and the aerospace irregular part, and then connecting the spring flexible support chain 30 through a number of tooling lifting rings 13 fixed to the front tooling 11 and the rear tooling 14.

[0067] In some embodiments, one end of each spring flexible branch 30 is connected to the platform pull ring 9 on the assembly platform frame 40, and the other end is connected to the corresponding tooling lifting ring 13 on the tooling 20. The spring flexible branches 30 are distributed in parallel between the tooling 20 and the assembly platform frame 40, forming a flexible parallel mechanism with the assembly platform frame 40 as the static platform and the tooling 20 as the dynamic platform. The rigid force fixing the aerospace irregular component is transitioned to a flexible force through the flexible branch adjuster 16, giving the aerospace irregular component a six-degree-of-freedom compliance capability. In addition, the compliance capability in each direction can be adjusted by changing the stiffness of the spring 17 or by changing the connection position of the two ends of several spring flexible branches 30.

[0068] The following is an exemplary description of applying the multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts provided according to embodiments of the present invention to the assembly process of irregularly shaped aerospace parts.

[0069] First, based on the dimensions of the aerospace irregular component, slide and adjust the positions of the front lifting frame 4, the rear lifting frame 7, and the intermediate support 6 on the assembly platform frame 40; fix the aerospace irregular component to the intermediate support 6 on the assembly platform frame 40, pre-fixing the position of the aerospace irregular component; assemble the front end of the aerospace irregular component with the front tooling 11, assemble the rear end of the aerospace irregular component with the rear tooling 14, and adjust the adjusting screw 15 on the tooling adjusting rod 12 to press the tooling 20 and the aerospace irregular component together; connect the safety devices 10 installed on the front lifting frame 4 and the rear lifting frame 7 of the assembly platform frame 40 to the tooling 20, and adjust them to a suitable length and position.

[0070] Next, the safety device 10 on the assembly platform frame 40 is adjusted so that after the intermediate support 6 on the assembly platform frame 40 slides out, the aerospace irregular component assembled with the tooling 20 remains stationary in its original position due to the suspension of the safety device 10. The flexible branch adjuster 16 on the spring flexible branch 30 is adjusted so that the rope 18 is tightened and the spring 17 is stretched, so that the weight of the tooling 20 and the aerospace irregular component is gradually transferred from the safety device 10 to the spring flexible branch 30. After the transfer is complete, the safety device 10 is in a loosely stretched state. The flexible branch adjuster 16 on the remaining spring flexible branch 30 that does not bear the weight of the tooling 20 and the aerospace irregular component is adjusted to tighten the remaining rope. At this time, the aerospace irregular component installed on the tooling 20 has six degrees of freedom of flexibility relative to the assembly platform frame 40.

[0071] Next, during the contact assembly and docking process of the aerospace irregular-shaped components and cylindrical components, the cylindrical components of the aerospace irregular-shaped components are usually provided with guide grooves, and the outer surface of the aerospace irregular-shaped components can be provided with sliders. During assembly, the assembly platform frame 40 makes a rigid linear motion along the assembly axis of the aerospace irregular-shaped components (this rigid linear motion means that its motion path and attitude will not change due to external forces), driving the aerospace irregular-shaped components and cylindrical components into the assembly docking. Through each spring flexible branch 30, the aerospace irregular-shaped components fixed on the tooling 20 make flexible motion along the assembly axis (this flexible linear motion means that its motion path and attitude will change due to external forces), fine-tuning the attitude of the aerospace irregular-shaped components in various directions to better match the assembly docking angle and position. During the assembly and docking process, a contact force can be generated between the guide groove of the cylindrical component and the slider of the aerospace irregular component. This force is compliant by the six degrees of freedom of the tooling 20 relative to the assembly platform frame 40 in the multi-degree-of-freedom compliant assembly equipment for irregular components provided according to the embodiment of the present invention, avoiding assembly impact, jamming, wedging and other phenomena, so that the slider of the aerospace irregular component on the outer surface of the aerospace irregular component slides smoothly into place along the mating surface of the guide groove of the cylindrical component, and the aerospace irregular component and the cylindrical component are successfully assembled.

[0072] During assembly, the moving platform of the six-degree-of-freedom parallel attitude adjustment platform (another mechanical system) drives the assembly platform frame 40 of this invention to perform six-degree-of-freedom motion. Simultaneously, the assembly platform frame drives the tooling 20 to perform six-degree-of-freedom motion via flexible spring chains. At this time, the assembly platform frame 40 performs rigid motion, while the tooling 20 performs flexible motion, thereby avoiding jamming of irregularly shaped aerospace components during assembly.

[0073] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-degree-of-freedom compliant assembly device for irregularly shaped parts, characterized in that, include: The assembly platform frame (40) serves as a static platform, with multiple spring-loaded flexible chains (30), and the tooling (20) serves as a dynamic platform, which is mounted to the assembly platform frame (40) via the spring-loaded flexible chains (30). The assembly platform frame (40) includes: Platform frame (1) serves as a support base for the multi-degree-of-freedom compliant assembly equipment; The hoisting unit is mounted on the platform frame (1) and connected to the spring flexible support chain (30) and the tooling (20) via the spring flexible support chain (30). An intermediate support member (6) is provided on the platform frame (1) for pre-fixing irregularly shaped parts to be assembled; The spring flexible branch (30) includes: A rope (18), a flexible branch regulator (16) for adjusting the length of the rope (18), and a spring (17) are connected to each other in a series connection. The tooling (20) includes: The front tooling (11) mates with the front end of the irregularly shaped part to be assembled during use. The post-tooling (14) mates with the rear end of the irregularly shaped part to be assembled during use. Tooling adjustment rod (12) connects the front tooling (11) and the rear tooling (14).

2. The multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts according to claim 1, characterized in that, The hoisting unit also includes a safety device (10) fixedly connected to its top, and the other end of the safety device (10) is connected to the tooling (20), and the length of the safety device (10) is adjustable; The spring-loaded flexible branch (30) switches between two states by cooperating with the safety device (10): Constraint state: The spring flexible branch (30) is in a state of no force due to the tension of the safety (10), so that the tooling (20) connected to the spring flexible branch (30) is constrained in all six degrees of freedom; Flexible state: Adjust the flexible branch regulator (16) to shorten the length of the rope (18), so that the spring flexible branch (30) is tensioned and the safety (10) is in a loose state, so that the tooling (20) connected to the spring flexible branch (30) has six degrees of freedom of flexibility.

3. The multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts according to claim 2, characterized in that, The assembly platform frame (40) also includes: A mobile unit is disposed on the platform frame (1), and the hoisting unit and the intermediate support (6) are movably disposed on the platform frame (1) by being mounted on the mobile unit.

4. The multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts according to claim 3, characterized in that, The mobile unit includes: Linear guide rails (2) are laid along the platform frame (1). The slider (3) is mounted on the linear guide (2) and slides on it. A sliding limiter (5) is mounted on the linear guide (2) and fixed to the slider (3) to limit the sliding of the slider (3).

5. The multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts according to claim 4, characterized in that, The hoisting unit includes: The front hoisting frame (4) is mounted on the slider (3) on the linear guide rail (2) at the front position of the assembly platform frame (40), is movably mounted on the assembly platform frame (40), and is used to cooperate with the front tooling (11). The rear hoisting frame (7) is mounted on the slider (3) on the linear guide rail (2) at the rear position of the assembly platform frame (40) and is movably mounted on the assembly platform frame (40) for cooperation with the rear tooling (14). Multiple platform pull rings (9) are fixedly connected to the base of the front lifting frame (4) and the rear lifting frame (7), and are respectively connected to the spring flexible branch (30) to be connected to the front tooling (11) and the rear tooling (14) via the spring flexible branch (30); One end of the safety device (10) is fixedly connected to the top of the front hoisting frame (4) or the rear hoisting frame (7).

6. The multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts according to claim 5, characterized in that: The front lifting frame (4) includes fixed pulleys (19) fixedly installed at its top position and middle height; The rear lifting frame (7) includes fixed pulleys (19) that are fixedly installed at its top position and at its middle height; In the assembly process, one end of the spring flexible branch (30) passes through the fixed pulley (19) and is then connected to the tooling (20).

7. The multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts according to claim 6, characterized in that, The tooling (20) also includes: Multiple tooling lifting rings (13) are provided on the front tooling (11) and the rear tooling (14) for connection with the spring flexible chain (30) to connect the tooling (20) to the assembly platform frame (40) via the spring flexible chain (30); Adjusting screws (15) are located at the positions where the tooling adjusting rod (12) is connected to the front tooling (11) and the tooling adjusting rod (12) is connected to the rear tooling (14). The adjusting screws (15) are used to adjust and tighten the fit between the front tooling (11) and the rear tooling (14) and the irregular part to be assembled.

8. The multi-degree-of-freedom compliant assembly equipment for irregularly shaped parts according to claim 7, characterized in that, One end of the spring flexible branch (30) is connected to the platform pull ring (9) on the assembly platform frame (40), and the other end is connected to the tooling lifting ring (13) on the tooling (20). The spring flexible branches (30) are distributed in parallel to form a flexible parallel mechanism with the assembly platform frame (40) as the static platform and the tooling (20) as the dynamic platform.

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