A method for accurately manufacturing a long double-curvature stringer
The method addresses the challenge of inaccurate manufacturing and assembly of double-curved long stringers by using end positioning and marking blocks to ensure precise manufacturing, achieving high accuracy and reducing rework rates.
Patent Information
- Application Number
- CN202211205787.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-30
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2042-09-30
AI Technical Summary
Existing methods for manufacturing double-curved long stringer parts fail to accurately control the entire shape and direction, leading to large gaps and inconsistencies during assembly, resulting in high rework rates and poor assembly quality.
A method involving end positioning and marking using a positioning block and marking block to ensure precise manufacturing, with separate sinking processes and consistent assembly references, reducing errors and deviations.
Achieves high forming accuracy, stable quality, and reduced rework rates by over 90%, improving fit and reducing production costs through precise manufacturing and assembly.
Smart Images
Figure CN115488581B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of plastic forming, and in particular relates to a method for accurately manufacturing a hyperbolic long stringer. Background Art
[0002] The existing manufacturing and inspection of double-curved long stringer parts adopts the method of inspection bracket template (see Figure 1 ), the shape and direction of the long stringer parts are controlled by the line contact between the inspection bracket template and the long stringer parts at the frame position. The determination of the sinking position is controlled by the size of the line drawing according to the line drawing of the inspection bracket template. It is impossible to accurately control the entire shape surface and direction of the long stringer parts. It can only control the shape and direction of the long stringer parts at the frame position. During the assembly process, the shape of the long stringer parts on the assembly jig often has a large gap between the fitting gap with the skin and the sinking position (see Figure 2 ), which cannot meet the assembly requirements and leads to parts rework, thus affecting the assembly cycle and assembly quality. In order to solve the problems of poor manufacturing precision and high rework rate of large aircraft hyperbolic long stringer parts, it is necessary to improve the hyperbolic long stringer. Summary of the invention
[0003] The purpose of the present invention is to provide a method for accurately manufacturing a long double-curvature stringer, which has the characteristics of high forming accuracy, stable quality, high production efficiency, strong versatility and easy operation.
[0004] The technical solution of the present invention is: a method for accurately manufacturing a hyperbolic long stringer, wherein a hyperbolic long stringer that has been shaped is subjected to a sinking process; the processing method is as follows:
[0005] a. Using the head end of the long stringer as the positioning reference, mark the first sinking processing position of the long stringer, and perform stamping processing on the first sinking of the long stringer according to the marked line. After completion, use the mold to detect the sinking of the stamped long stringer;
[0006] b. Repeat step a to complete the stamping process of the remaining long stringers;
[0007] c. After completing the sinking process of all the long beams, cut off the excess length at the other end based on the head end of the long beam.
[0008] In step a of the aforementioned method for accurately manufacturing a hyperbolic stringer, the positioning reference of the head end of the stringer is determined by a positioning block located on one side of the mold surface.
[0009] In step a of the aforementioned method for accurately manufacturing a hyperbolic long stringer, the detection of the long stringer sinking is as follows: placing the hyperbolic long stringer with the long stringer sinking processed thereon on the mold surface and comparing it with the sinking detection line thereon.
[0010] In step c of the aforementioned method for accurately manufacturing a hyperbolic long stringer, the length margin of the other end of the hyperbolic long stringer is cut off by using a marking block provided on the mold surface to mark the stringer and then cutting it off along the marked line.
[0011] In the aforementioned method for accurately manufacturing a hyperbolic long stringer, the marking block is provided with a long stringer passing groove at the bottom, and the outer end contour line of the long stringer passing groove forms an end margin removal line.
[0012] In the aforementioned method for precise manufacturing of a hyperbolic long stringer, the marking process of the marking block is as follows: after one end of the hyperbolic long stringer is positioned using a positioning block, the other end is passed through a long stringer passing groove reserved at the bottom of the marking block, and the hyperbolic long stringer is made to fit. At this time, marking is performed along the end allowance removal line formed by the contour line of the outer end of the long stringer passing groove, thereby determining the bevel angle and notch position of the end of the hyperbolic long stringer.
[0013] In the aforementioned method for accurately manufacturing a hyperbolic long stringer, the marking block is positioned on the mold surface by means of pins.
[0014] In step a of the aforementioned method for accurately manufacturing a hyperbolic long stringer, when marking the sunken processing position of the long stringer, the position of the marking in the length direction is compensated according to the following table:
[0015] Depth of sinking (mm) Compensation value(mm) Less than 1.0 0.1 1.0-1.5 0.2 1.5-2.5 0.25 Greater than 2.5 0.3 .
[0016] The advantages of the present invention are as follows: compared with the prior art, the present invention can ensure the precise manufacturing of aviation long stringer parts; the aviation long stringer reduces the influence of operator's human factors on product quality through the detachable end positioning block, and improves the stability of product quality; the present invention is suitable for the manufacture of all aviation hyperbolic long stringer parts and has strong versatility.
[0017] The present invention analyzes the problems existing in the manufacturing, inspection and assembly process of the hyperbolic long stringer parts based on the inspection bracket template. The main reasons for the high rework and repair rate of parts and unstable quality are the inconsistency of the manufacturing datum and assembly datum of the long stringer parts, the inaccurate control of the marking and machining allowance cutting of the long stringer ends, the large deviation of the sunken forming position, and the large gap between the tires. These are the common problems that cause the hyperbolic long stringer parts to have large errors in the length, curvature and lower limit position, and the low fit between the long stringer parts and the skin during the assembly process. In order to solve this problem, the present invention makes the following improvements to the manufacturing process of the hyperbolic long stringer parts:
[0018] (1) Unify parts manufacturing and assembly standards
[0019] When manufacturing parts, the ends of the long stringers and the sunken forming datums are unified and consistent with the assembly positioning datums, so as to achieve the goal of changing the positioning of the long stringers from the sunken position to the end positioning, and reduce the error accumulation caused by the inconsistency of the parts manufacturing and assembly positioning datums;
[0020] (2) Control the marking of the ends of the long beams and the cutting of the machining allowance
[0021] By controlling the size of the end of the long stringer (assembly positioning reference end), a positioning block is added to the inspection mold (fetal membrane surface) of the long stringer (see Figure 3 and Figure 4 ) to ensure the accuracy and consistency of the assembly positioning end; at the same time, a marking block is designed (see Figure 3 , 5 , 6), realizes the accurate control of cutting line drawing at the end of the long stringer.
[0022] (3) Control the position of the sinking forming
[0023] The sinks are formed by drawing lines separately to reduce the position deviation caused by material shrinkage during sink stamping. At the same time, the process method is improved to clarify that the sinking should be formed after the shape forming of the long stringer parts is completed. When the sinking is formed, the assembly reference end should be used as the reference for drawing lines to ensure that the relative position of the sink is consistent with the assembly requirements; when there are 2 or more sinks in the long stringer, they are drawn and formed separately (that is, after the first sink is formed, the next sink is drawn and formed) to ensure the accuracy of the relative position between the sinks.
[0024] For specific technical effects, see Figure 7-Figure 10 ,Depend on Figure 7 It can be seen that: before implementation: the deviation of the part manufacturing shape reached 15mm. After implementation: the deviation of the part manufacturing shape can be controlled within 0.4mm, and the effect is significant; Figure 8 and 9 It can be seen that before implementation: the maximum gap between the tire and the tyre reached 5mm, and the fit between the long stringer parts and the skin was low. After implementation: the gap between the tire and the tyre was less than 0.4mm, and the fit between the long stringer parts and the skin was significantly improved. Fig.10 It can be seen that the parts manufactured by the present invention have very small deviation in the length direction.
[0025] In summary, the present invention significantly improves the problems of large deviation in appearance and sunken position of hyperbolic long stringer parts, low fit with the skin, etc. by unifying parts manufacturing and assembly benchmarks, accurately controlling the drawing of long stringer end heads and the cutting of machining allowances, controlling the sinking forming position and other improvement measures. It realizes precise manufacturing of hyperbolic long stringer parts, reduces the workload of milling and repair at the assembly site, reduces the rework rate of hyperbolic long stringer parts by more than 90%, effectively improves the quality of parts assembly, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 This is a schematic diagram of the traditional manufacturing and inspection methods of double-curved long stringer parts;
[0027] Figure 2 Schematic diagram of common manufacturing problems for traditional double-curved long stringer parts;
[0028] Figure 3 It is a schematic diagram of the structure of the present invention;
[0029] Figure 4 for Figure 3 A schematic diagram of the enlarged structure at position I;
[0030] Figure 5 for Figure 3 Schematic diagram of the enlarged structure at Ⅱ;
[0031] Figure 6 It is a schematic diagram of the block structure;
[0032] Figure 7 To compare the shape deviation of the long stringer parts on the tooling after implementing the present invention and the traditional method;
[0033] Figure 8 Comparison of the gap between the long stringer parts on the mold after the present invention and the traditional method are implemented;
[0034] Fig. 9 To compare the fit between the long stringer parts and the skin after implementing the present invention and the traditional method;
[0035] Fig.10 The length deviation of the long stringer parts on the mold after the implementation of the present invention and the traditional method is compared.
[0036] Among them: 1-mold profile, 2-positioning support block, 3-marking support block, 4-long stringer passing slot, 5-end excess removal line, 6-pin, 7-hyperbolic long stringer, 8-sag detection line. DETAILED DESCRIPTION
[0037] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.
[0038] Example 1. A method for accurately manufacturing a long double-curvature stringer, see Figure 3-6 , the double-curved long stringer 7 that has been shaped is subjected to sinking processing; the processing method is as follows:
[0039] a. Using the head end of the long stringer as the positioning reference, mark the first sinking processing position of the long stringer, and perform stamping processing on the first sinking of the long stringer according to the marked line. After completion, use the mold tire profile 1 to detect the sinking of the long stringer that has been stamped; when manufacturing parts, unify and keep the long stringer end and the sinking forming reference consistent with the assembly positioning reference, so as to achieve the goal of changing the positioning of the long stringer from the sinking position to the end positioning, and reduce the error accumulation caused by the inconsistency of the part manufacturing and assembly positioning reference;
[0040] b. Repeat step a to complete the stamping process of the remaining long stringer sinks; through steps a and b, the sinks are respectively drawn and formed to reduce the position deviation caused by material shrinkage during the sinking stamping. At the same time, the process method is improved to clarify that the sinking is formed after the long stringer parts are completed. When the sinking is formed, the assembly reference end should be used as the reference for drawing and forming to ensure that the relative position of the sink is consistent with the assembly requirements; when there are two or more sinks in the long stringer, they are drawn and formed separately (that is, after the first sink is formed, the next sink is drawn and formed) to ensure the accuracy of the relative position between the sinks.
[0041] c. After all the long stringer sinking processing is completed, the length margin at the other end is cut off based on the long stringer head end. By controlling the size of the long stringer end assembly positioning reference end, a positioning block is added to the long stringer inspection mold (fetal membrane surface) (see Figure 3 ), to ensure the accuracy and consistency of the assembly positioning end; at the same time, a marking block 3 is designed to achieve accurate control of the cutting and marking of the long stringer end.
[0042] In step a, the positioning reference of the head end of the long stringer is determined by the positioning block 2 located on one side of the mold tire surface 1.
[0043] In step a, the detection of the sinking of the long stringer is as follows: the hyperbolic long stringer processed with the sinking of the long stringer is placed on the mold surface 1 and compared with the sinking detection line 8 thereon.
[0044] In step c, the excess length of the other end of the hyperbolic stringer is cut off by marking it with a marking block 3 provided on the mold surface 1 and then cutting it off along the marked line.
[0045] The aforementioned marking block 3 is provided with a long stringer passing groove 4 at the bottom, and the outer end contour line of the long stringer passing groove 4 forms an end margin removal line 5.
[0046] The marking process of the aforementioned marking block 3 is as follows: after positioning one end of the hyperbolic long stringer using the positioning block 2, the other end passes through the long stringer passing groove 4 reserved at the bottom of the marking block 3, and the hyperbolic long stringer is made to fit. At this time, marking is performed along the end excess removal line 5 formed by the outer end contour line of the long stringer passing groove 4, thereby determining the bevel angle and notch position of the end of the hyperbolic long stringer.
[0047] The aforementioned marking block 3 is positioned on the mold surface 1 through the pin 6.
[0048] In step a, when marking the sunken processing position of the long stringer, the position of the marking in the length direction is compensated according to the following table.
[0049] Depth of sinking (mm) Compensation value(mm) Less than 1.0 0.1 1.0-1.5 0.2 1.5-2.5 0.25 Greater than 2.5 0.3 .
Claims
1. A method for accurately manufacturing a hyperbolic long stringer, characterized in that: The double-curved long stringer that has been shaped is subjected to sinking processing; the processing method is as follows: a. Using the head end of the long stringer as the positioning reference, the first sinking processing position of the long stringer is marked, and the first sinking of the long stringer is stamped according to the marked line. After completion, the mold tire surface (1) is used to detect the sinking of the stamped long stringer; b. Repeat step a to complete the stamping process of the remaining long stringers; c. After all the sinking processing of the long stringers is completed, the length margin at the other end is cut off based on the head end of the long stringer; In step c, the excess length of the other end of the hyperbolic long stringer is cut off by using a marking block (3) provided on the mold base surface (1) to mark the line and then cut off along the line; The marking block (3) is provided with a long stringer passing slot (4) at the bottom, and the outer end contour line of the long stringer passing slot (4) forms an end excess removal line (5); The marking process of the marking block (3) is as follows: after one end of the hyperbolic long stringer is positioned using the positioning block (2), the other end passes through the long stringer passing groove (4) reserved at the bottom of the marking block (3), and the hyperbolic long stringer is made to fit, and then the end excess removal line (5) formed by the outer end contour line of the long stringer passing groove (4) is marked, thereby determining the bevel angle and notch position of the end of the hyperbolic long stringer.
2. The method for accurately manufacturing a hyperbolic long stringer according to claim 1, characterized in that: In step a, the positioning reference of the head end of the long stringer is determined by a positioning block (2) located on one side of the mold surface (1).
3. The method for accurately manufacturing a hyperbolic long stringer according to claim 1, characterized in that: In step a, the detection of the sinking of the long stringer is as follows: placing the hyperbolic long stringer processed with the sinking of the long stringer on the mold surface (1) and comparing it with the sinking detection line thereon.
4. The method for accurately manufacturing a hyperbolic long stringer according to claim 1, characterized in that: The marking block (3) is positioned on the mold surface (1) through a pin (6).
5. The method for accurately manufacturing a hyperbolic long stringer according to claim 1, characterized in that: In step a, when marking the processing position of the long stringer sink, the position of the marking in the length direction is compensated as follows: when the sink depth range is less than 1.0 mm, the compensation value is 0.1 mm; when the sink depth range is 1.0 mm to 1.5 mm, the compensation value is 0.2 mm; when the sink depth range is 1.5 mm to 2.5 mm, the compensation value is 0.25 mm; when the sink depth range is greater than 2.5 mm, the compensation value is 0.3 mm 。