A clamping and positioning method for composite material hatch

Abstract

A method for clamping and positioning a composite material door comprises: a theoretical model and an allowable clamping force of the composite material door is known; a plurality of outer shape clamping plates and a plurality of matching clamping clamping plates are provided on a positioning fixture; the composite material door is clamped and positioned between the outer shape clamping plates and the clamping clamping plates; the entire composite material door body is pre-positioned on the outer shape clamping plates of the positioning fixture by a clamping device; data on the distribution of the gap thickness between the entire composite material door body and the inner side surface of the outer shape clamping plates under the application of the allowable clamping force are obtained; a gasket with a thickness corresponding to the gap thickness is added to a corresponding area on the inner side surface of the outer shape clamping plates to form a positioning inner side surface of the outer shape clamping plates; after the positioning inner side surface is consistent with the outer profile of the composite material door body, the composite material door is positioned on the outer shape clamping plates of the fixture by a clamping device to achieve clamping and positioning of the composite material door.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft assembly, and is a method suitable for high-precision assembly and positioning of integral composite material cabin doors. Background Art

[0002] As the various technical indicators of aircraft continue to improve, the requirements for the appearance of aircraft cabin doors are also getting higher and higher. However, the shape control of aircraft cabin doors has always been a difficult problem. For integral composite cabin doors, the assembly process includes positioning and hole making connections. The main factor affecting the cabin door assembly technical indicators is the positioning accuracy of the cabin door body. The positioning accuracy of the cabin door mainly depends on the tightness of the fit between the cabin door body and the tooling shape pallet. During the assembly process of traditional cabin doors, the theoretical shape and the edge of the door body are usually used as the positioning reference. The theoretical shape pallet and clamping device are set on the tooling. When the cabin door is positioned, the cabin door shape fits the tooling pallet, and the door body is fixed by the clamping device to achieve micro-correction and precise positioning of the door body. Unlike traditional metal door assembly, the integral composite door is extremely rigid, and the deformation errors generated during the manufacturing process of the door parts cannot be eliminated by forced correction through the clamping device; the traditional assembly method of positioning and forcing the door to be clamped is adopted. Since the applied clamping force is inconsistent with the stress state of the door when it is installed on the fuselage, when the door is separated from the tooling locator and restored to its original manufacturing state, the relative position relationship between other connecting parts on the door and the door body shape changes, which is inconsistent with the assumed relative position relationship, and ultimately causes the door installed on the fuselage to fail to meet the technical index requirements of aerodynamic shape, seam gap, step difference, etc.; and since the assembly process is to ensure a close fit between the door shape and the pallet, the applied clamping force is often large, which may cause damage to the inside of the composite door. Therefore, the magnitude of the clamping force needs to be controlled during the assembly process.

[0003] To ensure that the stress state of the composite hatch during assembly is consistent with the installed state, and that the clamping force applied by the tooling does not cause damage to the interior of the composite hatch, the allowable clamping force for hatch assembly is specified during the product design phase. However, for larger composite hatches, the allowable clamping force provided by the clamping device alone during positioning cannot overcome the influence of factors such as friction between the product and the tooling. Furthermore, due to manufacturing errors in the composite hatch's shape, it cannot fit tightly with the pallet's shape, resulting in the hatch being unable to be accurately positioned. Therefore, a reliable positioning process is needed to ensure that the overall composite hatch's shape fits tightly with the pallet under the allowable clamping force, achieving the goal of precise assembly and positioning. Summary of the Invention

[0004] In order to solve the above problems, the present application provides a method for clamping and positioning a composite material hatch. Starting from the assembly perspective, the present application takes into account the errors existing in the manufacturing of the overall composite material hatch itself, and equips the tooling clamping device with a force feedback module. At the same time, combined with digital measurement means, a method suitable for high-precision assembly and positioning of the overall composite material hatch is formed, providing a solution for the high-precision assembly of the overall composite material hatch.

[0005] A method for clamping and positioning a composite material door, wherein the theoretical model and allowable clamping force of the composite material door are known, a plurality of outer shape clamps and a plurality of matching clamping clamps are provided on a positioning fixture, and the composite material door is clamped and positioned between the outer shape clamps and the clamping clamps, and the method is characterized in that it includes the following contents: 1) the inner side surface of the outer shape clamps matches the outer side surface of the theoretical model of the composite material door, a plurality of clamping devices are provided on the clamping clamps, and the clamping force of the clamping devices is perpendicular to the inner side surface of the outer shape clamps; 2) the entire composite material door body is pre-positioned on the outer shape clamps of the positioning fixture by the clamping devices, and the clamping devices distributed on the clamping clamps are adjusted so that the clamping devices at each location reach the allowable clamping force of the composite material door, and the composite material door is pressed against the inner side surface of the outer shape clamps by the clamping devices. 3) obtaining the gap thickness distribution data between the integral composite material hatch body and the inner side surface of the outer shape pallet under the state of applying the allowable clamping force by scanning; 4) releasing the pre-positioning state of the composite material hatch and the positioning fixture; 4) according to the gap thickness distribution data obtained in step 3), adding a gasket with a thickness corresponding to the gap thickness to the corresponding area of ​​the inner side surface of the outer shape pallet to form the positioning inner side surface of the outer shape pallet, and the positioning inner side surface is consistent with the outer surface of the composite material hatch body; 5) then positioning the composite material hatch on the outer shape pallet of the fixture through the clamping device, adjusting the clamping devices distributed on the clamping pallet so that each clamping device reaches the allowable clamping force, so that the outer surface of the integral composite material hatch body is completely fitted with the positioning inner side surface of the outer shape pallet, thereby realizing the clamping and positioning of the composite material hatch.

[0006] The composite material hatch clamping and positioning method is characterized in that a pressing force feedback module is provided on the pressing device, and the pressing force value of the pressing device can be obtained through the pressing force feedback module.

[0007] The composite material hatch door clamping and positioning method is characterized in that in step 3), the physical shape data of the integral composite material hatch door body under the state of applying allowable clamping force is obtained by a scanner; the physical shape data of the integral composite material hatch door body is compared with the theoretical model of the composite material hatch door to obtain the gap thickness distribution data between the physical shape of the integral composite material hatch door body and the tooling shape clamping plate.

[0008] The advantage of this application is that it solves the problem that the positioning accuracy of traditional hatch door bodies is not high and the positioning is only qualitative but not quantitative. In the positioning process of the integral composite hatch door body, the deviation of the parts manufacturing itself is fully considered, and a clamping device with force feedback is introduced on the tooling to achieve the state adjustment of the integral composite hatch door body under the allowable clamping force, thereby avoiding the generation of excessive stress during the assembly process; at the same time, digital measurement methods are used to obtain the physical shape data of the integral composite hatch door body, conduct deviation analysis, and make advance compensation through gaskets on the shape card plate of the tooling, thereby avoiding the problem of insufficient positioning accuracy caused by the non-fitting of the integral composite hatch door body and the shape card plate of the tooling, improving the positioning accuracy of the integral composite hatch door body, and providing a universal method for high-precision assembly and positioning of hatch doors of other similar structures.

[0009] The present application is further described below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the positioning method for the integral composite hatch.

[0011] Figure 2 Schematic diagram of the pre-positioning status of the integral composite hatch.

[0012] Figure 3 Schematic diagram of the positioning status of the integral composite hatch.

[0013] Explanation of numbers in the figure: 1 composite material door body, 2 positioning tool, 3 shape clamp, 4 clamping clamp, 5 clamping device, 6 gap, 7 gasket. DETAILED DESCRIPTION

[0014] Referring to the accompanying drawings, the theoretical model of the integral composite hatch and the allowable clamping force given by the design are known in the embodiment, but the composite hatch body 1 actually manufactured deviates from the theoretical model, and the deviation meets the technical index requirements on the basis of applying the allowable stress.

[0015] When assembling the composite door body 1, it is necessary to ensure that the composite door body 1 is completely fitted with the outer shape card plate 3 of the positioning tool. Figure 1 As shown, a plurality of outer shape clamps 3 and a plurality of matching clamping clamps 4 are provided on the positioning fixture, and the composite hatch door body 1 is clamped and positioned between the outer shape clamps 3 and the clamping clamps 4. The inner side surface of the outer shape clamp 3 of the positioning fixture matches the outer side surface of the theoretical model of the composite hatch door. The clamping clamp 4 is provided with a plurality of clamping devices 5. The clamping force of the clamping device 5 is perpendicular to the inner side surface of the outer shape clamp. In practice, in order to control the clamping force of the clamping device not to exceed the allowable clamping force of the composite hatch door body, a clamping force feedback module is provided on each clamping device 5. The clamping force value of the clamping device can be obtained through the clamping force feedback module.

[0016] During clamping and positioning, the entire composite hatch door body 1 is first pre-positioned on the outer shape clamping plate 3 of the positioning fixture 2 through the clamping device 5, and the clamping devices 5 distributed on the clamping clamping plate 4 are adjusted so that each clamping device 5 reaches the allowable clamping force of the composite hatch door body 1. The composite hatch door body 1 is pressed against the inner side of the outer shape clamping plate 3 by the clamping device 5. At this time, due to manufacturing errors, under the action of the allowable clamping force, there is still an allowable error gap 6 between the composite hatch door body 1 and the outer shape clamping plate 3, as shown in FIG. Figure 2 As shown, the gap 6 cannot meet the positioning and clamping requirements of the composite material cabin door body 1.

[0017] In order to fill the gap 6, during implementation, the physical shape data of the integral composite cabin door body 1 under the state of applying allowable compression force is obtained by a scanner; the physical shape data of the integral composite cabin door body 1 is compared with the theoretical model of the composite cabin door to obtain the thickness distribution data of the gap 6 between the physical shape of the integral composite cabin door body and the tooling shape plate.

[0018] After releasing the pre-positioning state of the composite hatch door body 1 and the positioning fixture 2, the inner surface of the outer shape card plate 3 is repaired and compensated based on the thickness distribution data of the gap 6 between the physical shape of the overall composite hatch door body 1 and the outer shape card plate 3. A gasket 7 with a thickness corresponding to the thickness of the gap 6 is added to the corresponding area of ​​the inner side of the outer shape card plate 3 to form the inner positioning side of the outer shape card plate 3. The gasket 7 fits tightly on the inner side of the outer shape card plate 3 to form an integral structure with the outer shape card plate. The inner positioning side is consistent with the outer surface of the composite hatch door body 1. Finally, the composite hatch door body 1 is positioned on the outer shape card plate 3 of the fixture through the clamping device 5, and the clamping devices 5 distributed on the clamping card plate 4 are adjusted so that each clamping device 5 reaches the allowable clamping force, so that the outer surface of the overall composite hatch door body 1 is completely fitted with the inner positioning side of the outer shape card plate 3, realizing the clamping and positioning of the composite hatch door.

Claims

1. A method for clamping and positioning a composite material door. The theoretical model and allowable clamping force of the composite material door are known. A plurality of outer shape clamps and a plurality of matching clamping clamps are provided on a positioning fixture. The composite material door is clamped and positioned between the outer shape clamps and the clamping clamps. The method is characterized in that The method comprises the following contents: 1) the inner side surface of the outer shape card plate matches the outer side surface of the theoretical model of the composite material door, and a plurality of clamping devices are provided on the clamping card plate, and the clamping force of the clamping devices is perpendicular to the inner side surface of the outer shape card plate; 2) the integral composite material door body is pre-positioned on the outer shape card plate of the positioning fixture through the clamping device, and the clamping devices distributed on the clamping card plate are adjusted so that the clamping devices at each location reach the allowable clamping force of the composite material door, and the composite material door is clamped to the inner side surface of the outer shape card plate through the clamping device; 3) the clearance between the integral composite material door body and the inner side surface of the outer shape card plate under the state of applying the allowable clamping force is obtained by scanning. Gap thickness distribution data; 4) release the pre-positioning state of the composite material door and the positioning tooling; 4) according to the gap thickness distribution data obtained in step 3), add a gasket with a thickness corresponding to the gap thickness in the corresponding area of ​​the inner side surface of the outer shape pallet to form a positioning inner side surface of the outer shape pallet, and the positioning inner side surface is consistent with the outer surface of the composite material door body; 5) then position the composite material door on the outer shape pallet of the tooling through a clamping device, adjust the clamping devices distributed on the clamping pallet, so that the clamping device at each location reaches the allowable clamping force, so that the outer surface of the entire composite material door body is completely fitted with the positioning inner side surface of the outer shape pallet, and the clamping positioning of the composite material door is realized.

2. The composite material door clamping and positioning method according to claim 1, characterized in that: The pressing device is provided with a pressing force feedback module, through which the pressing force value of the pressing device can be obtained.

3. The composite material door clamping and positioning method according to claim 1, characterized in that: In step 3), the physical shape data of the integral composite hatch door body under the state of applying allowable compression force is obtained by a scanner; the physical shape data of the integral composite hatch door body is compared with the theoretical model of the composite hatch door to obtain the gap thickness distribution data between the physical shape of the integral composite hatch door body and the tooling shape card plate.

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