A general design method for clamping in aircraft assembly

Abstract

A general design method for clamping in aircraft assembly, according to the technical requirements of aircraft assembly, the clamping structure is summarized as the reset precision slide rail structure of aircraft positioning connector and the skin shape positioning and riveting clamping structure; according to the accurate reset technical requirements, open the assembly design model in CATIA software, design the reset precision slide rail structure model of aircraft positioning connector and the skin shape positioning and riveting clamping structure system model, design the magnetic force model, and assemble the magnetic force model with the reset precision slide rail structure model of aircraft positioning connector and the skin shape positioning and riveting clamping structure system model to form the structure system model; then process planning and design are carried out on the basis of the assembly design model, the assembly simulation model is established according to the characteristics of the magnetic force reset structure, and the motion analysis is associated with the design assembly simulation model at the feature level to establish the accurate clamping system based on the process model.

Description

Technical Field

[0001] This invention relates to the field of aircraft assembly design technology, and in particular to a universal clamping design method for aircraft assembly. Background Technology

[0002] The accuracy of aircraft assembly affects not only the aircraft's aerodynamic performance and handling performance, but also its fatigue strength and service life. In digital assembly, to accommodate different aircraft models, hole-based positioning methods are widely used. However, the accuracy of hole positioning mechanisms is generally lower than that of surface positioning mechanisms, with a difference of nearly 10 times. Furthermore, the wear rate of holes is much higher than that of surfaces. Hole positioning mechanisms also restrict worker assembly efficiency and impact production capacity.

[0003] With the development of aircraft assembly technology, the requirements for aircraft assembly efficiency and accuracy are getting higher and higher. Flexible assembly and automated assembly are also constrained by outdated clamping methods. Therefore, innovation in clamping methods is the revolution in the development of digital aircraft assembly, and universal clamping design is an inevitable trend in the industry. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a universal clamping design method in aircraft assembly, so as to solve the problems in the background art mentioned above.

[0005] The technical problem solved by this invention is achieved by the following technical solution: A general design method for clamping in aircraft assembly, the specific steps of which are as follows: Step 1: Summarize typical clamping structures Based on the analysis of the aircraft assembly clamping structure according to the operating conditions, and according to the aircraft assembly technical requirements, the clamping structure is summarized into two typical cases: the precision slide rail structure for resetting aircraft positioning connectors and the skin shape positioning and riveting clamping structure. 1) Determine the working surface of the clamping structure Because the magnetic structure model needs to conform to the motion state according to the actual assembly technology requirements, the working surface of the magnetic structure must be in contact with the working surface of the moving structure, and it should not affect the motion trajectory of the corresponding moving parts. 2) Design typical reset structure forms Typical reset structures are divided into aircraft positioning connector reset precision slide rail structures and skin shape positioning and riveting clamping structures. Based on the self-weight of the moving parts in the typical reset structure and the friction force and friction coefficient in the direction of movement, the minimum required magnetic force is determined, and then the magnetic force model is optimized to meet the reset requirements of the moving parts. Step 2: Design the clamping structure system model 1) According to the technical requirements of precision reset, open the assembly design model in CATIA software, design the aircraft positioning connector reset precision slide rail structure model, add the basic structure, perform force analysis, determine the minimum required magnetic force, design the magnetic force model, and assemble the magnetic force model with the aircraft positioning connector reset precision slide rail structure model to form the aircraft positioning connector reset precision slide rail structure system model. 2) According to the requirements of precise resetting technology, open the assembly design model in CATIA software, design the skin shape positioning and riveting clamping structure system model, add the basic structure, perform force analysis, determine the minimum required magnetic force, design the magnetic force model, and perform assembly design with the skin shape positioning and riveting clamping structure system model to form the skin shape positioning and riveting clamping structure system model. 3) Based on the actual working conditions, confirm the movement path of the aircraft product, design a magnetic connection structure that meets both the stiffness requirements and the design requirements, and pre-design positioning components on the connection plate. Step 3: Establish a precision clamping system based on the process model Based on the assembly design model, process planning and design are carried out. According to the characteristics of the magnetic reset structure, a design assembly simulation model is established, the mechanical performance of the design assembly simulation model is analyzed, and then the motion analysis and the design assembly simulation model are correlated at the feature level. Collision detection is carried out to ensure the motion path of the motion mechanism, thereby establishing a precision clamping system based on the process model.

[0006] In this invention, in step 2), the basic structure includes a flat plate, a positioner, a support, and a precision slide rail.

[0007] In this invention, in step 2), 1), the assembly design model is an MBD model. Based on the MBD model, process planning and design are carried out, motion paths are analyzed, the motion direction of the aircraft positioning connector reset precision slide rail structure is determined, and a corresponding thrust is applied to the MBD model. Then, the MBD model and process planning are associated at the feature level, thereby realizing the design of the aircraft positioning connector reset precision slide rail structure system model.

[0008] In this invention, in step 2), the basic structure includes a card plate, a surface contact base, and a pin.

[0009] In this invention, in step 2), the assembly design model is the MBD model. Based on the MBD model, process planning and design are carried out, motion paths are analyzed, the circumferential motion direction of the skin shape positioning and riveting clamping structure is determined, and a tangential force in the corresponding direction is applied to the MBD model. The MBD model and the process planning are associated at the feature level, thereby completing the design of a typical skin shape positioning and riveting clamping structure system model.

[0010] In this invention, in step 2), 3), the positioning element includes a screw and a pin hole.

[0011] In this invention, in step three, the assembly design model is an MBD model, and the mechanical properties of the designed assembly simulation model are analyzed. Then, the motion analysis is correlated with the designed assembly simulation model at the feature level. Beneficial effects

[0012] 1) The universal clamping design method for aircraft assembly provided by this invention can effectively improve the service life of aircraft assembly structures; 2) The universal clamping design method for aircraft assembly provided by this invention can effectively improve the positioning accuracy of aircraft assembly systems; 3) The precision slide rail structure for resetting aircraft positioning connectors provided by this invention can reduce the number of positioning components used in assembly, and avoid the situation where assembly tooling is messy, complicated, and inconvenient to use. 4) In this invention, process planning using the MBD model can avoid issues such as interference with the mold movement. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the precision slide rail structure for resetting the aircraft positioning connector in a preferred embodiment of the present invention.

[0014] Figure 2 This is a schematic diagram of the precision slide rail structure in a preferred embodiment of the present invention.

[0015] Figure 3 This is a schematic diagram of the motion module operation in a preferred embodiment of the present invention.

[0016] Figure 4 This is a schematic diagram of the magnetic support structure in a preferred embodiment of the present invention.

[0017] Figure 5 This is a cross-sectional view of the magnetic support in a preferred embodiment of the present invention.

[0018] Figure 6 This is a schematic diagram of commonly used motion simulation commands in a preferred embodiment of the present invention.

[0019] Figure 7 This is a schematic diagram of the skin shape positioning and riveting clamping structure in a preferred embodiment of the present invention.

[0020] Figure 8 This is a schematic diagram of the card plate in the open state in a preferred embodiment of the present invention.

[0021] Figure 9 This is a schematic diagram of the magnetic limiting seat for the card plate in a preferred embodiment of the present invention. Implementation

[0022] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0023] A general design method for clamping in aircraft assembly, the specific steps of which are as follows: Step 1: Summarize typical clamping structures Based on the analysis of the aircraft assembly clamping structure according to the operating conditions, and according to the aircraft assembly technical requirements, the clamping structure is summarized into two typical cases: the precision slide rail structure for resetting aircraft positioning connectors and the skin shape positioning and riveting clamping structure. 1) Determine the working surface of the clamping structure Because the magnetic structure model needs to conform to the motion state according to the actual assembly technology requirements, the working surface of the magnetic structure must be in contact with the working surface of the moving structure, and it should not affect the motion trajectory of the corresponding moving parts. 2) Design typical reset structure forms Typical reset structures are divided into aircraft positioning connector reset precision slide rail structures and skin shape positioning and riveting clamping structures. Based on the self-weight of the moving parts in the typical reset structure and the friction force and friction coefficient in the direction of movement, the minimum required magnetic force is determined, and then the magnetic force model is optimized to meet the reset requirements of the moving parts. Step 2: Design the clamping structure system model 1) Based on the requirements of precise reset technology, open the assembly design model in CATIA software, design the aircraft positioning connector reset precision slide rail structure model, add basic structures such as plate, positioner, support, and precision slide rail, perform force analysis, determine the minimum required magnetic force, design the magnetic force model, and assemble the magnetic force model with the aircraft positioning connector reset precision slide rail structure model to form the aircraft positioning connector reset precision slide rail structure system model. like Figure 1 The typical motion positioning structure of the aircraft connector shown includes a base plate 1, a connector locator 2, a handle 3, a precision slide rail 4, a support 5, a magnetic base 6, a magnetic switch 7, a positioning pin 8, a magnetic connection support 9, a cylindrical pin 10, a bolt 11, and an aircraft connector 12. Due to the openness of the aircraft connector 12 and the requirements for removing aircraft components from the assembly, the connector locator 2 must be able to be retracted after use and accurately reset upon reuse. Therefore, the model of the aircraft positioning connector reset precision slide rail structure system is as follows: Figure 1 As shown, the working surface of the magnetic reset structure should first be the support plane that connects with the precision slide rail, and it should not affect the movement of the mechanism. Therefore, the precision slide rail structure is designed as follows: Figure 2 As shown, the usage status is as follows Figure 1 As shown, the magnetic switch is in the closed state. When not in use, the magnetic switch 7 can be opened, and the handle 3 can be moved to the non-working position, as shown. Figure 2The image shows the non-working state; Upon investigation, the coefficient of friction of the precision guide rail was found to be μ. Analysis using CATIA software confirmed this. Figure 3 The mass of the motion module is m, and the gravity it experiences is G=mg. Therefore, the frictional force is F=μ×Fn. A safety factor is selected as needed. P is the connection and positioning surface of the aircraft component. From this, the minimum magnetic force required for the corresponding magnetic support can be determined. The design of the corresponding magnetic support is as follows: Figure 4 As shown; The magnetic support needs to meet the requirements for precise resetting; therefore, pin holes and bolt holes are designed to meet the needs of precise positioning. Figure 5 The diagram shows a cross-sectional view of the magnetic support. The magnetic support structure consists of a permanent magnet material 21, a magnetic switch 22, a steel plate plane 23, a base plate 24, a positioning pin 25 (not shown in the figure, represented by the center line), and a bolt 26 (not shown in the figure, represented by the center line). When the magnetic switch 22 is open, the magnetic support is activated; when the magnetic switch is closed, the magnetic force is deactivated, thus satisfying the reset requirements of the moving parts. After determining the typical precision slide rail accurate reset structure model, process planning and design are carried out based on the MBD model, and motion path is analyzed. Figure 6 This is a commonly used motion simulation command. It determines the linear motion direction of the precision slide rail, applies a corresponding thrust to the MBD model, and associates the MBD model with the process planning at the feature level. This facilitates the process design of the MBD model, thereby realizing the design of the precision slide rail structure system model for aircraft positioning connector resetting. 2) Based on the requirements of precise resetting technology, open the assembly design model in CATIA software, design the skin shape positioning and riveting clamping structure system model, add basic structures such as clamping plates, surface contact bases, and pins, perform force analysis, determine the minimum required magnetic force, design the magnetic force model, and assemble the magnetic force model with the skin shape positioning and riveting clamping structure system model to form the skin shape positioning and riveting clamping structure system model. like Figure 7 The diagram shows a typical skin shape positioning and riveting clamping structure, including a frame 71, a clamping plate 72, a support 73, a pin 74, a magnetic limit seat 75, a magnetic switch 76, a magnetic connection support 77, and an aircraft skin 78. The clamping plate 72 is used to ensure the shape of the aircraft skin. To meet the requirements for removing the aircraft skin 78 from the rack, the clamping plate 72 must be able to be opened after use and accurately reset for reuse. In use, the clamping plate is in the closed state, at which time the magnetic switch 76 is closed. When the clamping plate 72 is not in use, the magnetic switch 76 can be opened, and the clamping plate 72 can be moved in a circular motion along the pin 74 at the support 73, finally suspending itself on the tooling. The clamping plate 72 in the open state is as follows. Figure 8 As shown; First, it is determined that the working surface of the card plate reset structure should be a plane perpendicular to the magnetic limit seat, and should not affect the circumferential motion of the card plate. Therefore, a typical card plate reset structure is as follows: Figure 8 As shown; Using CATIA software, the mass of the pallet is m, and the gravity it experiences is G=mg. A safety factor is selected as needed, thus determining the minimum clamping force required. The corresponding magnetic limit seat design for the pallet is as follows: Figure 9 As shown; like Figure 9 The magnetic limit seat is shown. It consists of permanent magnet material, magnetic switch, steel plate, base plate, positioning pin, and bolts. When the magnetic switch is turned on, the magnetic limit seat is activated; when the magnetic switch is turned off, the magnetic force is deactivated, thus meeting the reset requirements of the moving parts. After determining the typical skin shape positioning and riveting clamping structure model, process planning and design are carried out based on the MBD model. The motion path is analyzed, the circumferential motion direction of the skin shape positioning and riveting clamping structure is determined, and the corresponding tangential force is applied to the MBD model. The MBD model and process planning are associated at the feature level, which facilitates the process design of the MBD model, thereby realizing the design of the skin shape positioning and riveting clamping structure system model. 3) Based on the actual working conditions, confirm the motion path of the aircraft product, design a magnetic connection structure that meets both the stiffness requirements and the design requirements, and pre-design screws and pin holes on the connection plate. Step 3: Establish a precision clamping system based on the process model Based on the MBD model, process planning and design are carried out. According to the characteristics of the magnetic reset structure, an MBD assembly simulation model is established, the mechanical performance of the model is analyzed, and then the motion analysis and MBD assembly simulation model are correlated at the feature level. Collision detection is performed to ensure the motion path of the motion mechanism, thereby establishing a precision clamping system based on the process model.

[0024] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A universal clamping design method for aircraft assembly, characterized in that, The specific steps are as follows: Step 1: Summarize typical clamping structures Based on the analysis of the aircraft assembly clamping structure according to the operating conditions, and according to the aircraft assembly technical requirements, the clamping structure is summarized into the precision slide rail structure for resetting aircraft positioning connectors and the skin shape positioning and riveting clamping structure. Step 2: Design the clamping structure system model 1) According to the technical requirements of precision reset, open the assembly design model in CATIA software, design the aircraft positioning connector reset precision slide rail structure model, add the basic structure, perform force analysis, determine the minimum required magnetic force, design the magnetic force model, and assemble the magnetic force model with the aircraft positioning connector reset precision slide rail structure model to form the aircraft positioning connector reset precision slide rail structure system model. 2) According to the requirements of precise resetting technology, open the assembly design model in CATIA software, design the skin shape positioning and riveting clamping structure system model, add the basic structure, perform force analysis, determine the minimum required magnetic force, design the magnetic force model, and perform assembly design with the skin shape positioning and riveting clamping structure system model to form the skin shape positioning and riveting clamping structure system model. 3) Based on the actual working conditions, confirm the movement path of the aircraft product, design a magnetic connection structure that meets both the stiffness requirements and the design requirements, and pre-design positioning components on the connection plate. Step 3: Establish a precision clamping system based on the process model Based on the assembly design model, process planning and design are carried out. According to the characteristics of the magnetic reset structure, a design assembly simulation model is established, the mechanical performance of the design assembly simulation model is analyzed, and then the motion analysis and the design assembly simulation model are correlated at the feature level. Collision detection is performed to ensure the motion path of the motion mechanism, thereby establishing a precision clamping system based on the process model.

2. The universal clamping design method for aircraft assembly according to claim 1, characterized in that, In step one), the typical clamping structures are summarized as follows: 1) Determine the working surface of the clamping structure Because the magnetic structure model needs to conform to the motion state according to the actual assembly technology requirements, the working surface of the magnetic structure must be in contact with the working surface of the moving structure, and it should not affect the motion trajectory of the corresponding moving parts. 2) Design typical reset structure forms Typical reset structures are divided into precision slide rail structures for aircraft positioning connectors and skin shape positioning and riveting clamping structures. Based on the self-weight of the moving parts in the typical reset structure and the friction force and friction coefficient in the direction of movement, the minimum required magnetic force is determined, and then the magnetic force model is optimized to meet the reset requirements of the moving parts.

3. The universal clamping design method for aircraft assembly according to claim 1, characterized in that, In step 2), the basic structure includes a flat plate, a positioner, a support, and a precision slide rail.

4. The universal clamping design method for aircraft assembly according to claim 1, characterized in that, In step 2), 1), the assembly design model is the MBD model. Based on the MBD model, process planning and design are carried out, motion paths are analyzed, the motion direction of the aircraft positioning connector reset precision slide rail structure is determined, and a corresponding thrust is applied to the MBD model. Then, the MBD model and process planning are associated at the feature level, thereby realizing the design of the aircraft positioning connector reset precision slide rail structure system model.

5. The universal clamping design method for aircraft assembly according to claim 1, characterized in that, In step 2), the basic structure includes a card plate, a surface contact base, and a pin.

6. The universal clamping design method for aircraft assembly according to claim 1, characterized in that, In step 2), the assembly design model is the MBD model. Based on the MBD model, process planning and design are carried out, motion paths are analyzed, the circumferential motion direction of the skin shape positioning and riveting clamping structure is determined, and tangential force in the corresponding direction is applied to the MBD model. The MBD model and process planning are associated at the feature level, thereby completing the design of a typical skin shape positioning and riveting clamping structure system model.

7. The universal clamping design method for aircraft assembly according to claim 1, characterized in that, In step 2), 3), the positioning components include screws and pin holes.

8. The universal clamping design method for aircraft assembly according to claim 1, characterized in that, In step three, the assembly design model is an MBD model, and the mechanical performance of the design assembly simulation model is analyzed. Then, the motion analysis is associated with the design assembly simulation model at the feature level.

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