Detection supporting method for eliminating self-weight deformation of workpiece

Abstract

The invention discloses a detection support method for eliminating self-weight deformation of a workpiece, which relates to the technical field of precision measurement, adopts a simulation analysis means to quickly optimize and iterate the optimal number and position distribution of workpiece support points and the reaction force of each point, and eliminates the self-weight deformation of a structure in a multi-point dispersed support mode. The detection precision of the workpiece can be effectively improved; the supporting position and the bearing reaction value of each supporting point can be directly obtained through simulation analysis optimization, the defect of high theoretical calculation difficulty caused by complex workpiece configuration is avoided, the process is simple, convenience and rapidness are achieved, and the result precision is high; different shapes of workpieces can be rapidly adapted by adjusting the supporting height of each supporting unit, the weight of the workpieces is evenly distributed by feeding back in real time and accurately controlling the size of bearing reaction force, and gravity deformation of the structure is effectively eliminated.

Description

Technical Field

[0001] This invention relates to the field of precision measurement technology, and in particular to a detection support method for eliminating workpiece deformation due to its own weight. Background Technology

[0002] With the rapid development of industrial manufacturing technology, the demand for high-precision inspection of large-sized workpieces such as large mechanical components and aerospace parts is becoming increasingly urgent. These workpieces are typically heavy and complex in shape, often exhibiting characteristics such as large openings, long beams, thin walls, or cantilever structures. During the inspection process, uneven weight distribution or unreasonable support methods can lead to uneven local stress and deformation due to self-weight, resulting in significant measurement errors and affecting inspection accuracy.

[0003] In fields such as precision instruments and optomechanical structures, extremely high dimensional and geometric accuracy is required for workpieces, typically reaching sub-micron levels or even higher. However, traditional workpiece inspection methods often employ direct placement on an inspection platform or three-point support using pads. These methods have significant limitations when dealing with large workpieces. Insufficient flatness of the workpiece's bottom support surface or unreasonable distribution of support points can easily lead to uneven stress on the workpiece, causing localized deformation due to its own weight in areas far from the support points. This deformation not only affects the accuracy of the measurement results but may also be further amplified by the inherent precision limitations of the support method itself. Therefore, effectively reducing or eliminating measurement errors caused by workpiece deformation due to its own weight during inspection has become one of the key challenges in the high-precision inspection of large workpieces.

[0004] Based on the above-mentioned technical problems, those skilled in the art urgently need to develop a detection support method to eliminate workpiece deformation due to its own weight. This method can eliminate workpiece deformation due to its own weight during detection by optimizing the distribution of support points and precisely controlling the support force. Summary of the Invention

[0005] The purpose of this invention is to provide a detection support method for eliminating workpiece deformation due to its own weight. By optimizing the distribution of support points and precisely controlling the support force, the deformation due to the own weight of the workpiece during detection can be eliminated.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a detection support method for eliminating workpiece deformation due to its own weight, the support method comprising the following steps: S01, confirm the shape characteristics of the workpiece to be inspected, the items to be inspected, and the tolerance accuracy of the data to be inspected through drawings; S02, determine the allowable value of the self-weight deformation of the workpiece based on the flatness tolerance accuracy requirements of the workpiece to be inspected; S03. Based on the shape characteristics of the workpiece to be tested, a three-point support method is initially adopted, and the gravity deformation of the workpiece is calculated by finite element simulation analysis. S04. Based on the analysis results of the previous step, obtain the self-weight deformation cloud map of the workpiece under this support state, and find the area of ​​large self-weight deformation of the workpiece. S05, add support points to areas of the workpiece with large deformation and recalculate the gravity deformation through simulation analysis; S06. Based on the analysis results, the influence of the self-weight deformation of the workpiece under the previous support state on the flatness is calculated by surface fitting. S07, determine whether the influence of self-weight deformation on flatness meets the requirements. If it is greater than the maximum allowable value of self-weight deformation, repeat S04-S07, and perform multiple rounds of optimization and iteration analysis by adjusting the position of the support point or increasing the number of support points until the influence of self-weight deformation on flatness is less than the maximum allowable value of self-weight deformation of the workpiece to be inspected. S08, based on the final iterative optimization results, outputs the final number and location of support points for the workpiece, as well as the specific values ​​of the support reaction forces at each point; S09, Before actually inspecting the workpiece, arrange the workpiece support points according to the optimization results of the previous step, and place the workpiece on the multi-point support; S10 precisely quantifies and controls the support reaction force at each support point by fine-tuning each support point and using feedback from the force sensor, thereby achieving uniform support for the workpiece. S11. By completing the above steps to eliminate the workpiece's self-weight deformation, subsequent high-precision inspection of the workpiece can be carried out.

[0007] Furthermore, each support point of the workpiece to be inspected is an independently adjustable support unit. The support unit includes a base with a through hole on its upper end face and a lower end face for placing on the inspection platform. Adjusting bolt, which is a cylindrical straight rod with external threads; The adjusting nut is a block-shaped structure with an internal thread that matches the adjusting bolt. The adjusting nut is placed on the upper surface of the base, and the adjusting bolt is installed on the adjusting nut through a threaded fit. The bolt is then lowered into the base through a through hole on the upper surface of the base. Rotating the adjusting nut drives the adjusting bolt to move up and down, thereby controlling the height of the support unit. A force sensor mounted on the upper end of the adjusting bolt is used to detect the supporting force; The tip is set at the top of the force sensor.

[0008] Furthermore, since the workpiece to be inspected has multiple surfaces to be inspected, the specific location of the support point should be selected based on the structural characteristics of the workpiece, choosing the intersection of the internal vertical ribs, and avoiding selecting the internal hollow areas and thin-walled flanges.

[0009] The detection support method for eliminating workpiece deformation due to its own weight, provided by the present invention, has the following beneficial effects: The present invention provides a detection support method for eliminating workpiece self-weight deformation. It uses simulation analysis to quickly optimize and iterate the optimal number and location distribution of workpiece support points and the support reaction force at each point. By using multi-point distributed support, the self-weight deformation of the structure is eliminated, which can effectively improve the detection accuracy of the workpiece. This invention utilizes simulation analysis to directly obtain the support position and support reaction force values ​​of each support point, avoiding the drawback of high theoretical calculation difficulty caused by complex workpiece configuration. The process is simple, convenient, and fast, and the results are highly accurate. The support unit of this invention has a simple configuration and flexible operation. It can quickly adapt to different shapes of workpieces by adjusting the support height of each support unit. By providing real-time feedback and precisely controlling the magnitude of the support reaction force, the weight of the workpiece can be evenly distributed, effectively eliminating gravitational deformation of the structure. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0011] Figure 1 A flowchart of a detection support method for eliminating workpiece deformation due to its own weight, provided in an embodiment of the present invention; Figure 2 A schematic diagram of a support example of a detection support method for eliminating workpiece deformation due to its own weight is provided for embodiments of the present invention. Figure 3 This is a schematic diagram of the structure of the support unit in a detection support method for eliminating workpiece deformation due to its own weight, provided in an embodiment of the present invention. Figure 4 The workpiece inspection case provided in this embodiment of the invention shows the self-weight deformation cloud diagram of the workpiece during preliminary analysis (three-point support); Figure 5 The workpiece inspection case provided in this embodiment of the invention is a self-weight deformation cloud map of the workpiece after final optimization; Figure 6 This is a schematic diagram of the final optimized fulcrum position in the workpiece inspection case provided in this embodiment of the invention; Figure 7 This is a table of support reaction force data for two support methods in the workpiece inspection case provided in the embodiments of the present invention.

[0012] Explanation of reference numerals in the attached figures: 1. Workpiece to be inspected; 2. Support unit; 101. Surface to be inspected; 201. Base; 202. Adjusting nut; 203. Adjusting bolt; 204. Force sensor; 205. Top. Detailed Implementation

[0013] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0014] See Figures 1-7 As shown; See appendix Figure 1-2 This embodiment is used to perform high-precision flatness detection on a workpiece 1 to be inspected. The workpiece is a large frame plate of a space camera with an envelope size of 1700mm*2100mm*125mm. There are three large openings in the middle of the workpiece. The interior of the workpiece has a lightweight hollow structure and a weight of 166kg.

[0015] The workpiece 1 to be inspected contains twelve surfaces 101 to be inspected. According to the functional requirements of the workpiece, the overall coplanarity requirement of the twelve surfaces 101 to be inspected is 0.005mm. If the workpiece is placed directly on the table for inspection, the insufficient flatness of the bottom of the workpiece will result in uneven contact support on the table. The parts of the workpiece far from the support (especially the three long beam configurations in the middle) will experience large self-weight deformation, which will lead to inspection errors and affect the accuracy of the inspection.

[0016] Therefore, in order to perform high-precision inspection of the workpiece 1, a support unit 2 is used to support the workpiece at multiple points, thereby evenly distributing the workpiece's weight. This eliminates the workpiece's weight-induced deformation, thus improving inspection accuracy.

[0017] The present invention provides a detection support method for eliminating workpiece deformation due to its own weight, the support method comprising the following steps: S01. The structural characteristics of the workpiece 1 to be inspected are confirmed through the workpiece drawing. There are twelve surfaces 101 to be inspected, and the coplanarity tolerance of the twelve surfaces 101 to be inspected is 0.005mm.

[0018] S02, the allowable value of the workpiece's self-weight deformation is determined by the flatness tolerance accuracy requirement of the workpiece. Generally, for the inspection of high-precision workpieces, the self-weight deformation is required to be less than 20% of the drawing tolerance. Since the coplanarity tolerance requirement of the inspection surface 101 in this embodiment is 0.005mm, the self-weight deformation of the workpiece must be controlled within 0.001mm.

[0019] S03, initially using a three-point support method, the workpiece's gravity deformation was calculated using finite element simulation analysis. The self-weight deformation of the twelve test surfaces 101 of the workpiece using the three-point support method reached 0.068mm, which is far greater than the test tolerance requirements.

[0020] S04, Based on the analysis results of the previous step, the self-weight deformation cloud diagram of the workpiece under this support state is obtained, as shown in the attached diagram. Figure 4 As shown, locate the areas where the workpiece deforms significantly due to its own weight.

[0021] S05, add support points to areas of workpiece with large deformation, and re-perform simulation analysis and iterative calculation of gravity deformation.

[0022] S06. Based on the analysis results, the influence of the workpiece's self-weight deformation on flatness under the previous support state is calculated through surface fitting.

[0023] S07, determine whether the influence of self-weight deformation on flatness meets the requirements. If it exceeds the maximum allowable value of self-weight deformation, repeat S04-S07, adjusting the support point positions or increasing the number of support points, and performing multiple rounds of optimization iteration analysis until the influence of self-weight deformation on flatness is less than the maximum allowable value of self-weight deformation of the workpiece. In this embodiment, after iterative optimization, 12-point support is used. Under this support state, the self-weight deformation of the twelve surfaces 101 to be inspected is 0.0007mm, which meets the inspection accuracy requirements.

[0024] S08, based on the final iterative optimization results, outputs the final number and location of support points on the workpiece, as well as the specific values ​​of the support reaction forces at each point, as shown in the appendix. Figure 5-7 As shown.

[0025] S09, When actually inspecting the workpiece, the workpiece support unit 2 is arranged according to the final optimization result, and the workpiece 1 to be inspected is placed on the multi-point support.

[0026] S10 precisely quantifies and controls the support reaction force at each support point by fine-tuning each support point and using feedback from the force sensor 204, requiring the support reaction force at each point to be consistent with the analyzed and optimized data, thereby achieving uniform support for the workpiece.

[0027] S11. After the above steps, the workpiece has eliminated its own weight deformation and can be subjected to subsequent high-precision inspection.

[0028] When using the support method described in this invention to inspect a workpiece, the workpiece's self-weight deformation is eliminated by flexibly and uniformly supporting it at multiple points. The measurement error caused by the workpiece's self-weight deformation can be controlled to within sub-micrometers or even higher.

[0029] As a further introduction to this embodiment, each support point of the workpiece 1 to be tested is an independently adjustable support unit 2. The support unit 2 includes a base 201, with a through hole on its upper end face and a lower end face for placing on the testing platform. Adjusting bolt 203 is a cylindrical straight rod with external threads; The adjusting nut 202 is a block structure with an internal thread that matches the adjusting bolt 203. The adjusting nut 202 is placed on the upper surface of the base 201. The adjusting bolt 203 is installed on the adjusting nut 202 through the threaded engagement and sinks into the base 201 through the through hole on the upper surface of the base 201. The adjusting bolt 203 is driven to move up and down by rotating the adjusting nut 202 to control the height of the support unit 2. A force sensor 204, installed on the upper end of the adjusting bolt 203, is used to detect the supporting force; The tip 205 is set on the upper end of the force sensor 204.

[0030] As a further introduction to this embodiment, the workpiece 1 to be tested has multiple surfaces 101 to be tested. The specific location of the support point should be selected according to the structural characteristics of the workpiece 1 to be tested, and the intersection of the internal vertical ribs should be selected, avoiding the selection of the internal hollow area and the thin-walled flange.

[0031] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A detection support method for eliminating workpiece deformation due to its own weight, characterized in that, The support method includes the following steps: S01, confirm the shape characteristics, inspection items and tolerance accuracy of the workpiece (1) to be inspected through the drawings; S02, determine the allowable value of the self-weight deformation of the workpiece by the flatness tolerance accuracy requirement of the workpiece (1) to be inspected; S03, based on the shape characteristics of the workpiece (1) to be tested, a three-point support method is initially adopted, and the gravity deformation of the workpiece is calculated by finite element simulation analysis. S04. Based on the analysis results of the previous step, obtain the self-weight deformation cloud map of the workpiece (1) under this support state, and find the area where the self-weight deformation of the workpiece (1) is large. S05, add support points to the area of ​​the workpiece (1) with large deformation, and re-perform simulation analysis and iterative calculation of gravity deformation; S06, Based on the analysis results, the influence of the self-weight deformation of the workpiece (1) under the previous support state on the flatness is calculated by surface fitting; S07, determine whether the influence of self-weight deformation on flatness meets the requirements. If it is greater than the maximum allowable value of self-weight deformation, repeat S04-S07, and perform multiple rounds of optimization and iteration analysis by adjusting the position of the support point or increasing the number of support points until the influence of self-weight deformation on flatness is less than the maximum allowable value of self-weight deformation of the workpiece to be inspected (1) Detect the maximum allowable value of self-weight deformation. S08, based on the final iterative optimization results, outputs the final number and location of support points for the workpiece, as well as the specific values ​​of the support reaction forces at each point; S09, Before actually inspecting the workpiece, arrange the workpiece support points according to the optimization results of the previous step, and place the workpiece on the multi-point support; S10, by fine-tuning each support point and using feedback from the force sensor (204), precisely quantifies and controls the support reaction force at each point to achieve uniform support for the workpiece; S11. By completing the above steps to eliminate the workpiece's self-weight deformation, subsequent high-precision inspection of the workpiece can be carried out.

2. The detection support method for eliminating workpiece self-weight deformation according to claim 1, characterized in that, Each support point of the workpiece (1) to be inspected is an independently adjustable support unit (2). The support unit (2) includes a base (201), with a through hole on its upper end face and a lower end face for placing on the inspection platform. Adjusting bolt (203), which is a cylindrical straight rod with external threads; The adjusting nut (202) is a block structure with an internal thread that matches the adjusting bolt (203). The adjusting nut (202) is placed on the upper surface of the base (201). The adjusting bolt (203) is installed on the adjusting nut (202) through the threaded engagement and sinks into the base (201) through the through hole on the upper surface of the base (201). The adjusting bolt (203) is driven to move up and down by rotating the adjusting nut (202) to control the height of the support unit (2). A force sensor (204) installed on the upper end of the adjusting bolt (203) is used to detect the supporting force; The tip (205) is set on the upper end of the force sensor (204).

3. The detection support method for eliminating workpiece self-weight deformation according to claim 1, characterized in that, The workpiece (1) to be tested has multiple surfaces (101) to be tested. The specific location of the support point should be selected according to the structural characteristics of the workpiece (1) to be tested, and the intersection of the internal vertical ribs should be selected, avoiding the selection of the internal hollow area and the thin-walled flange.

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