A fuselage barrel segment assembly type co-curing positioning and forming device and positioning and forming method

Abstract

The present application relates to a kind of fuselage barrel segment assembly type co-curing positioning forming device and positioning forming method.The forming device includes tool frame, positioning shaft and at least two frame locator assemblies;Each frame locator assembly includes a frame locator, a positioning pin and a frame locator web, the frame locator is fixedly connected with the frame locator web, the frame locator, the frame locator web is sleeved on the positioning shaft and can slide along the axial direction of the positioning shaft, and the frame locator, the frame locator web is positioned on the positioning shaft by the positioning pin.The present application proposes a large-size fuselage barrel segment tank complex structure assembly type co-curing process of high-precision assembly at room temperature and co-curing forming of high-temperature assembly, releases high-temperature linear expansion deformation device by designing the longitudinal length direction and the circumferential direction of tool, and simultaneously uses the same composite material as the molded product in the key position parts of tool, so as to realize the expansion coefficient of assembly jig and the molded product matching.

Description

Technical Field

[0001] This invention relates to an assembly-type co-curing positioning molding device and positioning molding method suitable for high-precision assembly at room temperature and co-curing of high-temperature components for complex structures such as large-size fuselage sections and fuel tanks, belonging to the field of composite material assembly and molding technology. Background Technology

[0002] The co-curing technology for large and complex structures, such as composite material fuel tanks, has long been a goal in the development of integral fuel tanks for aircraft. Sealing large fuel tanks is a major challenge in fuel tank manufacturing, directly impacting their economic cost and service life. Integral fuel tanks offer significant advantages in both sealing performance and service life. The fuselage-section fuel tank structure contains various internal components such as end frames, stringers, and embedded metal blocks, presenting considerable difficulties in assembly and molding processes.

[0003] Large-size fuselage fuel tank assemblies require first assembling composite material parts into components, then applying the outermost skin layer to the assembled components, and finally co-curing at high temperature in an autoclave. Traditional molds cannot achieve high-precision assembly, and traditional assembly tooling cannot ensure that the thermal expansion coefficients and directions of all positioners are consistent during high-temperature molding, thus failing to meet the requirements of the new process. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an assembly-type co-curing positioning molding device and method suitable for complex structures such as large-size fuselage sections and fuel tanks. This device enables high-precision assembly at room temperature and co-curing molding of high-temperature components for complex structures such as large-size fuselage sections and fuel tanks.

[0005] Complex structures in fuselage sections, such as the fuel tank, include end frames, stringers, and embedded metal blocks. This invention allows for high-precision assembly of these complex composite material components at room temperature. A new product structure is then laid on the outer layer of the component using prepreg, and simultaneous co-curing is achieved in an autoclave or oven. This molding process significantly improves the structural strength of the components, reduces mechanical connections of standard parts by over 90%, enhances the overall sealing of the fuel tank, and ensures the overall shape accuracy of the co-cured component. This invention effectively solves the precision challenges of high-precision assembly of jigs at room temperature and addresses the deformation caused by the different thermal expansion coefficients of the tooling materials and composite materials during product molding due to thermal expansion and contraction.

[0006] The present invention discloses a co-curing positioning and molding device for assembly of machine body barrel sections, comprising a tooling frame, a positioning shaft, and at least two frame positioning assemblies. The positioning shaft is fixedly installed on the tooling frame, and the frame positioning assemblies are disposed on the positioning shaft. Each frame positioning assembly includes a frame positioning device, a positioning pin, and a frame positioning device web. The frame positioning device and the frame positioning device web are fixedly connected. The frame positioning device and the frame positioning device web are fitted onto the positioning shaft and can slide along the axial direction of the positioning shaft. The frame positioning device and the frame positioning device web are positioned on the positioning shaft by the positioning pin.

[0007] Furthermore, during high-precision assembly of the composite material product to be formed at room temperature, all locating pins are locked to fix the frame locator and its web plate on the locating shaft; during high-temperature forming, only one locating pin is retained, and all other locating pins are removed or loosened, so that the frame locator and its web plate, after the locating pins have been removed or loosened, can slide axially along the locating shaft to eliminate the axial deformation of the composite material product caused by the inconsistency between the expansion coefficient of the tooling material and the expansion coefficient of the composite material product to be formed.

[0008] Furthermore, the web of the frame locator is made of the same composite material as the composite material product to be formed, so that the composite material product does not deform in the circumferential direction during temperature changes in the forming process.

[0009] Furthermore, the outer diameter of the web of the frame locator is designed to match the inner diameter of the composite material product to be formed, so as to position the composite material product to be formed.

[0010] Furthermore, the web of the frame locator is circular with a hole in the middle for the locating shaft to pass through.

[0011] Furthermore, a slide rail guide pin and a matching slide rail groove are provided between the frame positioner and the positioning shaft. The slide rail groove is arranged along the axial direction of the positioning shaft, and the slide rail guide pin can slide along the slide rail groove so that the frame positioner moves only along the axial direction of the positioning shaft.

[0012] Furthermore, the slide rail groove is provided on the frame locator, and the slide rail directional pin is provided on the positioning shaft.

[0013] The present invention provides a method for co-curing and positioning molding of fuselage barrel segments, which utilizes the aforementioned co-curing and positioning molding device for fuselage barrel segments to achieve the molding process. The method includes the following steps:

[0014] When performing high-precision assembly of composite material products to be formed at room temperature, all locating pins are locked to fix the frame locator and the web of the frame locator on the locating shaft.

[0015] During high-temperature molding, only one locating pin is retained, and all other locating pins are removed or loosened, so that the frame locator and the web of the frame locator with the locating pins removed or loosened can slide along the axial direction of the locating shaft, thereby eliminating the axial deformation of the composite material product caused by the inconsistency between the expansion coefficient of the tooling material and the expansion coefficient of the composite material product to be molded.

[0016] The web of the frame locator is made of the same composite material as the composite material product to be formed, so that the composite material product does not deform in the circumferential direction during temperature changes in the forming process.

[0017] Furthermore, during the temperature rise process, the tooling frame and the positioning shaft will undergo thermal expansion along the axial direction of the positioning shaft. The frame positioner with the locking positioning pin uses its positioning pin as the positioning reference. The thermal expansion coefficient of the composite material product itself is close to 0. The frame positioner with the positioning pin removed or loosened uses the composite material product as the positioning reference. The frame positioner with the positioning pin removed or loosened and the web of the frame positioner slide along the axial direction of the positioning shaft through the slide rail directional pin and the slide rail groove, thereby stopping at the theoretical assembly position at room temperature, and at the same time completing the forming strength support of the product in the circumferential direction.

[0018] Furthermore, during the temperature reduction process, the tooling frame and the positioning shaft undergo cold contraction along the axial direction of the positioning shaft. The frame positioner and the web of the frame positioner, which have had their positioning pins removed or loosened, slide along the axial direction of the positioning shaft through the slide rail directional pins and slide rail grooves, thereby stopping at the theoretical assembly position at room temperature. After the temperature returns to room temperature, the removed or loosened positioning pins are relocked to complete the repositioning of the product.

[0019] The beneficial effects of this invention compared to the prior art are as follows:

[0020] (1) This invention employs a unique method to eliminate the impact of longitudinal thermal expansion of the tooling on the product. By using a directional slider, the product remains stationary under the action of the slider during the thermal expansion of the tooling positioner, and will not deform with the tooling. At the same time, it can also ensure the positioning accuracy of the product and the strength required during molding.

[0021] (2) In view of the fact that the thermal expansion coefficient of composite materials is close to 0, the present invention uses composite materials as the manufacturing material of the circumferential positioner of the assembly tooling, which ensures that the product will not be thermally expanded and deformed during the high-temperature molding process.

[0022] (3) The present invention solves the process problem of tooling that can assemble composite material components and then co-curing them into a whole. The product's shape and assembly airtightness meet the design requirements.

[0023] (4) This invention is expected to become the main process for integral molding of large-size composite fuel tank components in the future. It has good versatility in the production of other products, which can reduce processing costs and time, and increase product profitability;

[0024] (5) By using the method of the present invention, multiple forming fixtures and multiple assembly fixtures can be combined into one fixture to complete product manufacturing, which saves a lot of production time, reduces scrap rate, and increases product added value.

[0025] (6) This invention has good promotion and application value and can effectively promote the development and application of co-curing molding of large-size composite fuel tanks in the aerospace field.

[0026] Instruction manual illustrations

[0027] Figure 1 This is a front view of the large-size fuselage fuel tank assembly co-curing positioning molding device of the present invention; wherein 1-6 are frame locators, 7-12 are positioning pins, 13-18 are frame locator webs, 19 is positioning shaft, and 20 is tooling frame.

[0028] Figure 2 This is a schematic diagram showing the frame locator 1, locating pin 7, and frame locator web 13 mounted on the locating shaft 19.

[0029] Figure 3 This is a front view of the web of the frame locator of the present invention;

[0030] Figure 4 This is a cross-sectional view of the slide rail groove of the present invention; wherein, 22 is the slide rail directional pin, and 21 is the slide rail groove; Detailed Implementation

[0031] The present invention will now be described in detail with reference to specific examples and accompanying drawings.

[0032] The principle of this invention is as follows: First, in the product's length direction, all positioners in the tooling utilize sliding rail devices. During high-precision assembly at room temperature, they are locked in place using positioning pins. During high-temperature molding, only one end positioning pin is retained, and all other positioning pins are removed, allowing the positioners to slide precisely along the positioning axis. This eliminates axial deformation of the composite material caused by the inconsistency between the tooling material's coefficient of thermal expansion and the composite product's coefficient of thermal expansion. Second, in selecting the material for the circumferential positioners of the tooling, a composite material with the same resin system as the product is used for molding and machining. Since the composite positioners and the composite product are made of the same material, their coefficients of thermal expansion match, eliminating circumferential deformation of the composite product.

[0033] In one embodiment of the present invention, an assembly-type co-curing positioning molding device suitable for large-size fuselage barrel section fuel tanks is provided, such as... Figure 1 As shown, the fixture includes frame locators 1-6, locating pins 7-12, frame locator web plates 13-18, locating shaft 19, and tooling frame 20. A handle for rotating the locating shaft is provided on each of the left and right sides of the locating shaft 19. The tooling frame 20 is a base and support structure located below the locating shaft 19, and may include a bottom support bracket, reinforcing angle iron, and a bracket to prevent deformation of the locating shaft, primarily used to support and fix the locating shaft 19.

[0034] A frame locator assembly consists of a frame locator, a locating pin, and a frame locator web. For example, frame locator 1, locating pin 7, and frame locator web 13 constitute a frame locator assembly. Figure 1 There are a total of 6 frame positioner assemblies. Each frame positioner includes a sleeve structure that fits onto the positioning shaft 19. Taking frame positioner 1 as an example, it is equipped with a positioning pin 7. When the positioning pin 7 is locked, frame positioner 1 can be positioned on the positioning shaft 19.

[0035] Taking frame locator 1 as an example, the web plate 13 of the frame locator is fixed to one side of the frame locator 1 by bolts or other means, such as... Figure 1 , Figure 2 As shown on the right side. The web plate 13 of the frame locator is circular, as shown... Figure 3 As shown, there is a hole in the middle for the positioning shaft 19 to pass through. Additionally, the web plate 13 of the frame positioner can also be provided with positioning holes, such as positioning holes for positioning the product frame, and positioning holes for the tool ball of the laser tracker. The outer diameter of the web plate 13 of the frame positioner is designed to match the inner diameter of the composite material product to be formed, in order to position the composite material product to be formed.

[0036] Among them, the web plate 13-18 of the frame locator is made of the same composite material as the product to be formed, and its coefficient of expansion is close to 0. Therefore, the product will not deform in the circumferential direction during the temperature change (rise or fall) process of the forming process.

[0037] exist Figure 1 In the illustrated embodiment, after locking the positioning pins 7-12, the frame positioner 1-6 and the frame positioner web plate 13-18 can be positioned on the positioning shaft 19. The positioning shaft 19 ensures the overall product positioning accuracy and also ensures that the product maintains high precision in the axial direction, preventing deformation caused by tooling expansion and contraction. The high-precision positioning pins 7-12 ensure tooling positioning, allowing for high-precision repositioning even after repeated disassembly, maintaining high-precision positioning of the product and tooling before and after entering the autoclave.

[0038] To ensure that the frame positioner 1-6 moves only axially along the positioning shaft and avoids rotation on the positioning shaft, thereby accurately positioning the product to be molded, the present invention also provides a slide rail guide pin and a matching slide rail groove between the frame positioner 1-6 and the positioning shaft 19. Figure 4 As shown, the right side is a cross-sectional view of the positioning shaft 19. The slide rail groove 21 is disposed on the frame locator (e.g., frame locator 1), and the slide rail directional pin 22 is disposed on the positioning shaft 19. In other embodiments, the slide rail groove can also be disposed on the positioning shaft, and the slide rail directional pin can be disposed on the frame locator. The slide rail groove 21 is disposed along the axial direction of the positioning shaft 19, and the slide rail directional pin 22 can slide along the slide rail groove 20, thereby ensuring that the frame locator does not rotate when sliding along the positioning shaft 19.

[0039] In one embodiment of the present invention, a molding method using the above-described assembly-type co-curing positioning molding device is provided, the specific steps of which are as follows:

[0040] 1) Tighten the positioning pins 7-12 to position the frame positioner 1-6 and the frame positioner web plate 13-18 on the positioning shaft 19.

[0041] 2) Position the frame of the composite material product to be formed (i.e., the product skeleton, such as carbon fiber preform) on the frame positioner components 1-6 and the frame positioner web plate 13-18. That is, fit the frame of the composite material product to be formed (such as carbon fiber preform) outside the frame positioner web plate 13-18, and position the frame of the composite material product through the frame positioner web plate 13-18.

[0042] 3) Remove or loosen positioning pins 8-12, leaving only positioning pin 7 (in the locked state). Then, the frame of the composite material product and the above-mentioned prefabricated co-curing positioning molding mechanism are placed in the autoclave for high-temperature treatment.

[0043] 4) During the temperature rise process, the tooling frame and the positioning shaft will undergo thermal expansion in the axial direction (e.g., the coefficient of expansion is 1mm x 10). -5 This results in elongation displacement. At this time, frame locator 1 uses locating pin No. 7 as the positioning reference. The thermal expansion coefficient of the composite material product itself is close to 0. Frame locators 2-6 use the composite material product as the positioning reference. Frame locators 2-6 and the web plate 14-18 will slide along the axial direction of the positioning shaft through slide rail directional pin 22 and slide rail groove 21, thereby stopping at the theoretical assembly position at room temperature, and at the same time completing the forming strength support of the product in the circumferential direction.

[0044] During the temperature rise process, the frame positioner 2-6 is in a state where it can slide with high precision along the positioning axis. This can eliminate the situation where the axial deformation of the composite material is caused by the inconsistency between the expansion coefficient of the tooling material and the thermal expansion coefficient of the composite material product.

[0045] 5) During the temperature rise process, the web plate 13-18 of the frame positioner is made of the same composite material as the product to be formed, and its coefficient of expansion is close to 0, so the product will not deform in the circumferential direction.

[0046] 6) After the product molding is completed, the temperature begins to drop. The tooling frame and positioning shaft will undergo cold contraction along the axial direction of the positioning shaft, that is, a shortening displacement will occur. The frame positioning device 2-6 and the frame positioning device web plate 14-18 will slide along the axial direction of the positioning shaft through the slide rail directional pin 22 and the slide rail groove 21, thereby stopping at the theoretical assembly position at room temperature.

[0047] During the temperature reduction process, the frame positioner 2-6 is in a state where it can slide with high precision along the positioning axis. This can eliminate the situation where the axial deformation of the composite material is caused by the inconsistency between the expansion coefficient of the tooling material and the thermal expansion coefficient of the composite material product.

[0048] 7) During the temperature reduction process, the web plate 13-18 of the frame locator has an expansion coefficient close to 0, so the product will not deform in the circumferential direction.

[0049] 8) Once the temperature returns to room temperature, reinsert and tighten the positioning pins 8-12 to complete the product repositioning and finalize the assembly.

[0050] exist Figure 1 In the illustrated embodiment, the web of the frame locator is fixed only by a frame locator on one side. In other embodiments, a frame locator can be provided on each side of the web of the frame locator, and the two frame locators can be designed symmetrically to sandwich the web of the frame locator in the middle, thereby better fixing the web of the frame locator.

[0051] exist Figure 1 In the illustrated embodiment, there are a total of 6 frame locator assemblies (each frame locator assembly includes a frame locator, a locating pin, and a frame locator web). In other embodiments, other numbers of frame locator assemblies may be provided, such as 4, 5, 8, 10, etc., depending on the structure and size of the product to be formed.

[0052] In summary, this invention proposes a co-curing assembly process for complex structures such as large-size fuselage sections and fuel tanks, involving high-precision assembly at room temperature and co-curing of components at high temperatures. By designing high-temperature linear expansion deformation release devices in the longitudinal and circumferential directions of the tooling, and by using the same composite material as the molded product for parts in key positions of the tooling, the expansion coefficient of the assembly fixture matches that of the molded product. Through a combination of these methods, the expansion coefficient of the assembly fixture is matched with that of the molded product.

[0053] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0054] The specific embodiments of the present invention disclosed above are intended to help understand the content of the present invention and to implement it accordingly. Those skilled in the art will understand that various substitutions, changes, and modifications are possible without departing from the spirit and scope of the present invention. The present invention should not be limited to the content disclosed in the embodiments of this specification; the scope of protection of the present invention is defined by the claims.

Claims

1. A co-curing positioning and molding device for assembly of machine body barrel sections, characterized in that, The system includes a tooling frame, a positioning shaft, and at least two frame positioner assemblies. The positioning shaft is fixedly mounted on the tooling frame, and the frame positioner assemblies are mounted on the positioning shaft. Each frame positioner assembly includes a frame positioner, a positioning pin, and a frame positioner web. The frame positioner and the frame positioner web are fixedly connected. The frame positioner and the frame positioner web are fitted onto the positioning shaft and can slide along the axial direction of the positioning shaft. The frame positioner and the frame positioner web are positioned on the positioning shaft by the positioning pin. During high-precision assembly of the composite material product to be molded at room temperature, all positioning pins are locked to fix the frame positioner and the frame positioner web on the positioning shaft. During high-temperature molding, only one positioning pin is retained, and all other positioning pins are removed or loosened, allowing the frame positioner and the frame positioner web, with the positioning pin removed or loosened, to slide along the axial direction of the positioning shaft, thereby eliminating the axial deformation of the composite material product caused by the inconsistency between the expansion coefficient of the tooling material and the expansion coefficient of the composite material product to be molded.

2. The assembly-type co-curing positioning and molding device for fuselage barrel sections according to claim 1, characterized in that, The web of the frame locator is made of the same composite material as the composite material product to be formed, so that the composite material product does not deform in the circumferential direction during temperature changes in the forming process.

3. The assembly-type co-curing positioning and molding device for fuselage barrel sections according to claim 1, characterized in that, The outer diameter of the web plate of the frame locator is designed to match the inner diameter of the composite material product to be formed, so as to position the composite material product to be formed.

4. The assembly-type co-curing positioning and molding device for fuselage barrel sections according to claim 1, characterized in that, The web of the frame locator is circular, with a hole in the middle for the locating shaft to pass through.

5. The assembly-type co-curing positioning and molding device for fuselage barrel sections according to claim 1, characterized in that, A slide rail guide pin and a matching slide rail groove are provided between the frame positioner and the positioning shaft. The slide rail groove is arranged along the axial direction of the positioning shaft, and the slide rail guide pin can slide along the slide rail groove so that the frame positioner can move only along the axial direction of the positioning shaft.

6. The assembly-type co-curing positioning and molding device for fuselage barrel sections according to claim 5, characterized in that, The slide rail groove is provided on the frame locator, and the slide rail directional pin is provided on the positioning shaft.

7. A method for co-curing and positioning assembly of fuselage barrel sections, characterized in that, The molding process is achieved using the assembly-type co-curing positioning molding device for fuselage barrel sections as described in any one of claims 1 to 6. Includes the following steps: When performing high-precision assembly of composite material products to be formed at room temperature, all locating pins are locked to fix the frame locator and the web of the frame locator on the locating shaft. During high-temperature molding, only one locating pin is retained, and all other locating pins are removed or loosened, so that the frame locator and the web of the frame locator with the locating pins removed or loosened can slide along the axial direction of the locating shaft, thereby eliminating the axial deformation of the composite material product caused by the inconsistency between the expansion coefficient of the tooling material and the expansion coefficient of the composite material product to be molded. The web of the frame locator is made of the same composite material as the composite material product to be formed, so that the composite material product does not deform in the circumferential direction during temperature changes in the forming process.

8. The method according to claim 7, characterized in that, During the temperature rise process, the tooling frame and the positioning shaft will thermally expand along the axial direction of the positioning shaft. The frame positioner with the locking positioning pin uses its positioning pin as the positioning reference. The thermal expansion coefficient of the composite material product itself is close to 0. The frame positioner with the positioning pin removed or loosened uses the composite material product as the positioning reference. The frame positioner and the web of the frame positioner with the positioning pin removed or loosened slide along the axial direction of the positioning shaft through the slide rail directional pin and slide rail groove, thereby stopping at the theoretical assembly position at room temperature, and at the same time completing the forming strength support of the product in the circumferential direction.

9. The method according to claim 7, characterized in that, During the temperature drop, the tooling frame and positioning shaft undergo cold contraction along the axial direction of the positioning shaft. The frame positioner and frame positioner web plate, with the positioning pins removed or loosened, slide along the axial direction of the positioning shaft through the slide rail directional pins and slide rail grooves, thus stopping at the theoretical assembly position at room temperature. After the temperature returns to room temperature, the removed or loosened positioning pins are relocked to complete the repositioning of the product.

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