Processing method of long and thin solid composite edging

Abstract

The invention belongs to the technical field of composite material processing, and provides a processing method of a long and thin solid composite material edging, which comprises the following steps: dividing an edging structure area; building a processing edging blank; establishing a processing coordinate system; processing at a first station; processing at a second station; and cutting off the product. The technical problems of product surface layering, low machining efficiency and high cost in the edge strip machining process are solved, and the product machining efficiency and quality are improved while the product machining precision requirement is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of aviation composite material parts processing, and in particular relates to a high-precision numerical control processing method for a long, thin, solid composite material edge strip in an aileron structure. Background Art

[0002] Ailerons are small, movable surfaces mounted on the outside of the trailing edge of an aircraft's wingtip. They are a crucial component for achieving lateral control and are typically composed of a functional wave-transparent skin, a honeycomb sandwich structure, and composite components. The front end of the aileron is typically composed of a solid composite component (solid composite strake). Due to the aileron's special structure and electrical performance requirements, most solid composite strakes are long, thin, and complex, requiring appropriate molding and machining processes. During strake manufacturing, the composite flat sheet is typically formed and then manufactured using five-axis CNC machining. Machining accuracy and quality are key concerns during the manufacturing process.

[0003] Traditionally, trim strips are machined using a five-axis machine tool in two stations. The process involves first milling out the required rectangular blank, then using a CNC program to remove the product's largest contours. Rough and finish machining of the surface is then performed at the first station. After the product is machined at the first station, a foam fixture is fabricated to match the product's profile. The product is flipped over and secured to the foam fixture using double-sided tape, followed by rough and finish machining at the second station. This method suffers from low efficiency, high cost, and limited precision, making it difficult to meet the current quality and precision requirements for trim strips on ailerons.

[0004] Current edge strip processing methods are affected by workstation flipping and workpiece clamping, resulting in low precision. Furthermore, the product and foam tooling have poor clamping stability, which can easily cause surface slippage during processing, leading to misalignment in the finished product. Furthermore, delamination of the composite material is a common problem.

[0005] The purpose of the present invention is to provide a new method for processing long, thin, solid composite edge strips to solve the problems in existing processing technology solutions. Summary of the Invention

[0006] The present invention addresses the problems of product surface stratification, low processing efficiency and high cost in the existing edge strip processing process, and provides a CNC processing method for long, thin solid composite edge strips. While ensuring the product processing accuracy requirements, the product processing efficiency and quality are improved and the occurrence of stratification is avoided.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A method for processing a long, thin, solid composite edge strip comprises the following steps: Divide the edge structure area; Create machining edge strip blank; Establish processing coordinate system; First station processing; Second station processing; Product cut off.

[0008] As a further solution of the present invention: the division of the edge strip structure area is specifically as follows: First, the edge strip structure area is divided into three parts, mainly into the assembly surface that matches the honeycomb sandwich, the profile and tip wing surface, and the boss structure.

[0009] As a further solution of the present invention: the assembly surface is the side surface of the edge strip body, and also includes the side surface of the boss structure.

[0010] As a further solution of the present invention, the edge strip blank is specifically established as follows: the edge strip blank is a rectangular parallelepiped. When the blank is established, the side surface of the blank in the thickness direction is required to be parallel to the edge strip assembly surface. Based on this, the size of the blank is determined to ensure that the effective margin of the blank in the length and width directions is not less than 10 mm, and the single-side margin in the thickness direction is not less than 1.5 mm. Use sawing to cut blanks on composite panels.

[0011] As a further solution of the present invention: the establishment of the processing coordinate system is specifically as follows: the origin of the coordinate system establishes the geometric center of the bottom surface of the blank, the X direction is parallel to the length of the blank, the Y direction is parallel to the width of the blank, and the Z direction is perpendicular to the bottom surface and upward.

[0012] As a further solution of the present invention: check whether the assembly surface of the product is parallel to the XOZ surface of the blank. If not, readjust the relative position of the assembly surface and the side surface of the blank until they are parallel. During the processing, mill the single long side and wide side of the blank to align the workpiece and establish the coordinate system.

[0013] As a further solution of the present invention: the first station processing is specifically as follows: First, perform rough and fine machining of the product profile, tip wing surface, and boss; Secondly, the assembly surface contour of the blank is projected onto the XOY plane to form the assembly surface contour line, and the assembly surface contour cutting program is compiled using the contour line. When compiling the program, two-station processing and cutting are adopted. At the first station, only half of the blank thickness is processed and a 0.15mm allowance is left. The remaining blank thickness is used for support during processing at the second station.

[0014] As a further solution of the present invention: the second station processing is specifically as follows: The blank processed at the first station is rotated 180° around the X axis. The origin is established at the geometric center of the upper surface of the blank. The X direction is still parallel to the length direction of the blank. After the coordinate system is established, rough and fine machining of the tip wing surface, product surface and boss is carried out; Among them, the geometric centers of the first and second workstations must remain consistent.

[0015] As a further solution of the present invention: the product cutting is specifically as follows: after the rough and fine processing of the second station is completed, the contour cutting of the product assembly surface is carried out, which is the same as the contour cutting procedure of the first station, but also requires a 0.15mm margin to be reserved, and finally cut by feed or wallpaper knife cutting, and the cut joint surface is polished and smoothed with sandpaper.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. During the establishment of the processing digital model, the parallelism of the edge strip assembly surface and the blank XOZ surface must be ensured. After projecting the assembly surface contour, a two-station three-axis contour cutting program is compiled to avoid the risk of composite material delamination caused by contour beveling.

[0017] 2. This application no longer adopts the process method of processing the maximum contour during the first processing station and using foam tooling to support the product. Instead, during the first processing station, the wing surface at the tip of the edge strip is completely processed, and only a blank of half the thickness of the blank is left at the assembly surface contour for product support during the second processing station. This not only improves the processing accuracy of the product, but also avoids the delamination phenomenon during processing with foam tooling support.

[0018] 3. This application has been applied to the edge processing of multiple product models. Processing efficiency has increased by approximately 20%, with a processing accuracy of ±0.15mm, and no delamination caused by composite processing has occurred. Furthermore, no foam tooling is required for support, reducing processing costs by approximately 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic flow chart of a method for processing a long, thin, solid composite edge strip according to the present invention; Figure 2 This is a schematic structural diagram of a long, thin, solid composite edge strip of the present invention; Figure 3 A requirement diagram is established for the edge strip blank of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in the embodiments of the present invention.

[0021] In the drawings, the same or similar reference numerals throughout the drawings represent the same or similar elements or elements having the same or similar functions. The described embodiments are only some of the embodiments of the present invention, but not all of the embodiments.

[0022] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0023] The following is combined with Figure 1-3 The embodiments of the present invention are described in detail.

[0024] Example 1 In order to express this processing method more clearly, it is introduced through the following case and flow chart.

[0025] like Figure 1 As shown, the digital model processing method of a product edge strip process: The method of establishing the processing digital model is as follows: Step 1: Create the blank. When creating the blank, ensure that the product assembly surface and the bottom surface of the blank are perpendicular, that is, to ensure the +Z axis processing during contour processing to prevent processing delamination and other phenomena. In terms of blank size, it is required to ensure that the blank length and width allowances are not less than 10mm, and the thickness side allowance is not less than 1.5mm. Figure 2 shown.

[0026] Step 2: The first station machining coordinate system is established, with the origin established at the geometric center of the bottom surface of the blank, the X axis is parallel to the length direction of the blank, the Y axis is parallel to the width direction of the blank, and the Z axis is vertically upward; Step 3: Prepare the roughing program for the first station, including the roughing program for the tip wing surface and the edge strip profile. The roughing area is required to be larger than the maximum outer contour of the product but not exceed the outer contour of the blank. Step 4: Prepare the finishing program for the first station, including the tip wing surface and the surface finishing. When machining the tip wing surface, it is necessary to ensure that all the machinable areas are fully machined when the tool axis is in the +Z axis; Step 5: Prepare the cutting program for the first station. Project the assembly surface contour line to the bottom surface and use it as a reference to prepare the assembly surface processing program. The cutting program is a three-axis program. Note that the cutting program for the first station only processes half of the blank thickness and a 0.15mm thickness allowance must be reserved. The other half of the blank thickness is used to support the processing of the second station. Step 6: The second station machining coordinate system is established. The blank is rotated 180° around the X axis of the first station. The origin is established at the geometric center of the upper surface of the blank. The X axis is still parallel to the length direction, the Y axis is parallel to the width direction, Z0 is located on the upper surface of the blank, and the Z axis is vertically upward; Step 7: The programming of the second station's roughing, finishing and cutting procedures is the same as that of the first station.

[0027] The on-site operation process is as follows: Step 1: Saw and cut the edge strip blank to ensure that the effective margin of the blank is not less than the size required by the processing digital model; Step 2: Use double-sided tape or other auxiliary holding tools to stick the blank to the flat tooling. When sticking, use the surface with better flatness as the bonding surface and ensure that the parallelism between the length direction of the single side of the blank and the X-axis of the machine tool does not exceed 0.5mm; Step 3: Mill the two adjacent sides of the blank flat as a reference for establishing the machining coordinate system; Step 4: Establish the machining coordinate system of the first station according to the requirements of the machining digital model; Step 5: Execute the CNC program according to the machining digital model program and process parameters to complete the rough and fine machining of the tip wing surface, profile surface, and boss of the first station; Step 6: After processing is completed, remove the blank and rotate it 180° around the X-axis of the first station. Paste the blank onto the flat tooling again and use the processed adjacent side surfaces to establish the second station coordinate system. Step 7: Complete the rough and fine machining of the tip wing surface, profile surface and boss of the second station product according to the second station processing procedure; Step 8: At this point, there is still 0.3mm thick blank support remaining on the assembly surface, which needs to be cut with a wallpaper knife or feed knife to remove the product; Step 9: Use sandpaper to smooth the remaining blank on the assembly surface.

[0028] Example 2 Aiming at the shortcomings of the current edge strip processing technology, a new edge strip processing method is proposed, which mainly includes the following points: 1. Divide the edge strip structure area. In order to quickly and accurately complete the edge strip processing, the edge strip structure area is first divided into three parts, mainly divided into the assembly surface that matches the honeycomb sandwich, the profile surface and the tip wing surface, the boss and other structures. Among them, the assembly surface is generally the side of the edge strip body, in addition, it also includes the side of the boss structure. The overall structure is as follows Figure 1 shown.

[0029] 2. Create the edge strip blank for machining. Edge strip blanks are typically rectangular. When creating the blank, ensure that the sides of the blank in the thickness direction are parallel to the edge strip assembly surface. Based on this, determine the blank dimensions, ensuring that the effective margins in the length and width directions are no less than 10mm, and the thickness margin on one side is no less than 1.5mm. Cut the blank onto the composite panel using a saw.

[0030] 3. Establish the machining coordinate system. The coordinate system origin is the geometric center of the blank's bottom surface, with the X direction parallel to the blank's length, the Y direction parallel to the blank's width, and the Z direction perpendicular to the bottom surface, pointing upward. At this point, check that the product assembly surface is parallel to the blank's XOZ plane. If not, readjust the relative position of the assembly surface and the blank's side until they are parallel. During machining, mill the blank's individual long and wide sides to align the workpiece and establish the coordinate system.

[0031] 4. First station processing. First, perform rough and fine processing of product profiles, tip wing surfaces, bosses, etc.; secondly, project the contour of the blank assembly surface onto the XOY plane to form the assembly surface contour line, and use the contour line to compile the assembly surface contour cutting program. When compiling the program, two-station processing and cutting are used. At the first station, only half of the blank thickness is processed and a 0.15mm margin is left. The remaining blank thickness is used for support during processing at the second station. At this point, the first station processing is completed. Subsequently, the corresponding tools are used for complete cutting, and sandpaper is used for polishing and shaping. The contour cutting program is executed last among all the programs of a single station.

[0032] 5. Second-station processing. The blank processed at the first station is rotated 180° around the X-axis, and the origin is established at the geometric center of the upper surface of the blank. The X direction is still parallel to the length direction of the blank. The geometric centers of the first and second stations must be consistent. After the coordinate system is established, the rough and fine processing of the tip wing surface, product surface, and boss is carried out. This process no longer uses traditional foam tooling or other material support methods for processing, but directly uses the remaining blank thickness from the first station processing as support.

[0033] 6. Product cutting. After the second station rough and fine processing is completed, the contour cutting of the product assembly surface is carried out. The processing method is the same as the contour cutting process of the first station, but a 0.15mm margin must also be reserved. Finally, the product is cut by feeding or wallpaper knife cutting. The cut joint surface is polished and smoothed with sandpaper.

[0034] So far, the purpose of the present invention has been achieved.

[0035] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for processing long, thin, solid composite edge strips, characterized in that: The following steps are involved: Divide the edge structure area; Create machining edge strip blank; Establish processing coordinate system; First station processing; Second station processing; Product cut off.

2. A method for processing a long, thin, solid composite edge strip according to claim 1, characterized in that: The division of the side strip structure area is specifically as follows: First, the edge strip structure area is divided into three parts, mainly into the assembly surface that matches the honeycomb sandwich, the profile and tip wing surface, and the boss structure.

3. The method for processing a long, thin, solid composite edge strip according to claim 2, characterized in that: The assembly surface is the side surface of the edge strip body, and also includes the side surface of the boss structure.

4. The method for processing a long, thin, solid composite edge strip according to claim 1, characterized in that: The edge strip blank is specifically established as follows: the edge strip blank is a rectangular parallelepiped. When the blank is established, the side surface of the blank in the thickness direction is required to be parallel to the edge strip assembly surface. Based on this, the blank size is determined to ensure that the effective margin of the blank in the length and width directions is not less than 10 mm, and the single-side margin in the thickness direction is not less than 1.5 mm. Use sawing to cut blanks on composite panels.

5. The method for processing a long, thin, solid composite edge strip according to claim 1, characterized in that: The establishment of the machining coordinate system is specifically as follows: the origin of the coordinate system establishes the geometric center of the bottom surface of the blank, the X direction is parallel to the length of the blank, the Y direction is parallel to the width of the blank, and the Z direction is perpendicular to the bottom surface and upward.

6. The method for processing a long, thin, solid composite edge strip according to claim 5, characterized in that: Check whether the assembly surface of the product is parallel to the XOZ surface of the blank. If not, readjust the relative position of the assembly surface and the side surface of the blank until they are parallel. During the processing, mill the single long side and wide side of the blank to align the workpiece and establish the coordinate system.

7. The method for processing a long, thin, solid composite edge strip according to claim 1, characterized in that: The first station processing is specifically as follows: First, perform rough and fine machining of the product profile, tip wing surface, and boss; Secondly, the assembly surface contour of the blank is projected onto the XOY plane to form the assembly surface contour line, and the assembly surface contour cutting program is compiled using the contour line. When compiling the program, two-station processing and cutting are adopted. At the first station, only half of the blank thickness is processed and a 0.15mm allowance is left. The remaining blank thickness is used for support during processing at the second station.

8. The method for processing a long, thin, solid composite edge strip according to claim 7, characterized in that: The second station processing is specifically as follows: The blank processed at the first station is rotated 180° around the X axis. The origin is established at the geometric center of the upper surface of the blank. The X direction is still parallel to the length direction of the blank. After the coordinate system is established, rough and fine machining of the tip wing surface, product surface and boss is carried out; Among them, the geometric centers of the first and second workstations must remain consistent.

9. The method for processing a long, thin, solid composite edge strip according to claim 1, characterized in that: The product cutting is specifically as follows: after the rough and fine processing of the second station is completed, the contour cutting of the product assembly surface is carried out. The processing method is the same as the contour cutting procedure of the first station, but a 0.15mm margin must also be reserved. Finally, it is cut by feed or wallpaper knife cutting, and the cut joint surface is polished and smoothed with sandpaper.

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