A welding quality assessment method based on measured data

Abstract

The present invention proposes a welding quality assessment method based on measured data to solve the welding quality problem that the bottom surface of the stud and the surface of the structural part are not completely fitted after welding and the problem of uneven stud arrangement. Specifically, the overall outer dimensions and surface of the structural part are measured, and the inconsistency of the outer dimensions and surface of the structural part is determined according to the measurement results, the flatness of the surface is obtained, and the flatness of the area where the stud and the structural part are in contact is obtained. By comparing and analyzing the flatness of the local area with the overall flatness, the fitting of the stud and the surface of the structural part is predicted, and it is judged whether there are defects. If there are defects, the stud is re-welded, which provides a basis for ensuring the consistency of stud welding and predicting the quality of stud welding.

Description

Technical Field

[0001] The invention belongs to the technical field of welding and relates to a welding quality assessment method. Background Art

[0002] Structural parts such as the body are the main components of special vehicles. Welding studs on the surface of structural parts and using studs to fix other special material parts for protection is a commonly used method. When welding the studs, place a template with circular holes on the surface of the structural parts and weld the studs at the position of the circular holes.

[0003] Defects of background technology:

[0004] Combination Figure 1 , 2 3. The structural parts are welded together by multiple plate-shaped parts. Since the flatness of different areas on the plate surface is inconsistent and the outer dimensions are inconsistent with the theoretical values, the template is designed according to the theoretical dimensions of the plate. The operator uses the stud welding template to weld the studs on the surface of the structural parts. After welding, there are welding quality problems such as the bottom surface of the studs not fully fitting with the surface of the structural parts and the uneven arrangement of the studs, which affects the assembly of parts in the subsequent processes. Summary of the invention

[0005] The purpose of the present invention is to propose a welding quality assessment method based on measured data to solve the welding quality problem that the bottom surface of the stud and the surface of the structural part are not completely fitted after welding and the problem of uneven stud arrangement. Specifically, the overall size and surface of the structural part are measured, and the inconsistency of the size and surface of the structural part is determined according to the measurement results, the flatness of the surface is obtained, and the flatness of the area where the stud and the structural part are in contact is obtained. By comparing and analyzing the flatness of the local area with the overall flatness, the fitting of the stud and the surface of the structural part is predicted, and it is judged whether there are defects. If there are defects, the stud is re-welded, which provides a basis for ensuring the consistency of stud welding and predicting the quality of stud welding.

[0006] The technical solution of the present invention:

[0007] A welding quality assessment method based on measured data, characterized in that the method comprises the following steps:

[0008] Step 1: Plane A is any plane with welding studs on the structural part; plane A is scanned by laser to obtain point cloud data corresponding to plane A;

[0009] Step 2: First, the point cloud data corresponding to plane A selects a reference, which is the reference of the design model of plane A. Then, the point cloud data corresponding to plane A is fitted into a plane, which is used as the reference plane for stud welding, namely plane 1.

[0010] Step 3: On plane 1, determine the position of the studs according to the stud arrangement rules, and obtain the welding coordinate value of each stud;

[0011] Step 4: Interact the coordinate values ​​used for stud welding on plane 1 with the point cloud data of plane A, find the coordinate value closest to the coordinate value used for stud welding in the point cloud data, fit the point cloud data within the radius Rmm with the coordinate value as the center, and obtain plane X;

[0012] Step 5: Compare plane X with plane 1 to find out the misalignment between the two and use it as the basis for determining whether the stud position is qualified.

[0013] Technical effects of the present invention:

[0014] The studs are arranged based on measured data, and the quality of stud welding is predicted in advance through simulation analysis and comparison, which greatly improves the consistency of stud welding, expands the application scope of automated welding, and can find the error problems of the previous process (structural parts) through data accumulation, providing an effective method for process optimization of structural parts. The present invention has a wide range of uses, and predicts the welding or assembly process based on measured data, solving the problems of long manufacturing cycle and high cost caused by traditional post-testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Structural schematic diagram of structural parts;

[0016] Figure 2 Schematic diagram of stud welding template;

[0017] Figure 3 Stud schematic.

[0018] Figure 4 Flowchart of the method of the present invention. DETAILED DESCRIPTION

[0019] A welding quality assessment method based on measured data of the present invention is characterized in that the method comprises the following steps:

[0020] Step 1: Analyze the structural component plane A, and the other planes are processed in the same way as plane A.

[0021] By using laser scanning on plane A where studs need to be welded, point cloud data corresponding to plane A that represents the surface flatness state and external dimension information of plane A can be obtained quickly and efficiently;

[0022] Step 2: Select a reference that is the same as the design model of plane A for the point cloud data corresponding to plane A (align the surface of the point data set of the two planes A with the reference of the design model), and fit the point cloud data corresponding to plane A into a plane, which is used as the reference plane for stud welding (plane 1);

[0023] Step 3: On plane 1, determine the position of the studs according to the stud arrangement rules (stud positions designed in the drawing) and obtain the (three-dimensional) coordinate value for welding of each stud;

[0024] Obtain the dimensional information of plane 1, distribute all studs evenly on plane 1 according to the number of studs specified in the drawing, and obtain the welding coordinate value of each stud.

[0025] Step 4: Interact the coordinate values ​​used for stud welding on plane 1 with the point cloud data of plane A, find the theoretical coordinate value closest to the coordinate value used for stud welding, fit the point cloud data within a radius of 1 mm with the theoretical coordinate value as the center, and obtain the plane of the actual surface state of the welding area of ​​each stud, that is, plane X;

[0026] Step 5: Compare plane X with plane 1 to find out the misalignment between the two and use it as the basis for determining whether the stud position is qualified.

[0027] Furthermore, if the angle between the normal of plane X and the normal of plane 1 is greater than 5°, the stud position is judged to be unqualified, and the stud needs to be manually inspected and confirmed and re-welded; otherwise, the stud position is judged to be qualified, that is, the stud welding quality is qualified. By evaluating the qualified status of the stud position, the consistency and quality of all stud welding are ensured, and the influence of poor working conditions in the previous process on the welding quality of this process is solved.

[0028] The principle of the present invention is:

[0029] 1. Stud arrangement based on actual measurement data ensures uniformity of stud arrangement.

[0030] 2. The stud welding position is obtained through simulation, the stud welding quality is predicted through automatic analysis, and the studs with quality risks are repaired through repair welding, ensuring the assembly quality and use requirements of the subsequent process.

Claims

1. A welding quality assessment method based on measured data, characterized in that: The method comprises the following steps: Step 1: Plane A is any plane with welding studs on the structural part; plane A is scanned by laser to obtain point cloud data corresponding to plane A; Step 2: First, the point cloud data corresponding to plane A selects a reference, which is the reference of the design model of plane A. Then, the point cloud data corresponding to plane A is fitted into a plane, which is used as the reference plane for stud welding, namely plane 1. Step 3: On plane 1, obtain the plane dimension information, distribute all studs evenly on the plane according to the number of studs specified in the drawing, and obtain the welding coordinate value of each stud; Step 4: Interact the coordinate values ​​used for stud welding on plane 1 with the point cloud data of plane A, find the coordinate value closest to the coordinate value used for stud welding in the point cloud data, fit the point cloud data within the radius Rmm with the coordinate value as the center, and obtain plane X; Step 5: Compare plane X with plane 1 to find out the misalignment between the two and use it as the basis for determining whether the stud position is qualified.

2. A welding quality assessment method based on measured data according to claim 1, characterized in that: In step 4, the point cloud data within a radius of 1 mm is fitted.

3. A welding quality assessment method based on measured data according to claim 1, characterized in that: Obtain the plane dimension information, distribute all studs evenly on the plane according to the number of studs specified in the drawing, and obtain the welding coordinate value of each stud.

4. The welding quality assessment method based on measured data according to claim 1, characterized in that: If the angle between the normal of plane X and the normal of plane 1 is greater than 5°, the stud position is deemed unqualified.

5. The welding quality assessment method based on measured data according to claim 1, characterized in that: If the angle between the normal of plane X and the normal of plane 1 is greater than 5°, the stud position is judged to be unqualified and the stud needs to be manually inspected and confirmed and re-welded; otherwise, the stud position is judged to be qualified, that is, the stud welding quality is qualified.

6. The welding quality assessment method based on measured data according to claim 1, characterized in that: The stud arrangement rules determine the position of the studs, which can be determined by the stud positions designed in the drawings.

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