A method for online inspection of 3D printed parts

Abstract

The application discloses a kind of 3D printing part online inspection method, it is related to 3D printing technical field, comprising the following steps: S1: 3D design file, user designs the 3D model file required by three-dimensional modeling design software, and carries out upload;After user selects appropriate material, the parameter of selected printing material is automatically determined by system;After uploading 3D file, system automatically identifies file, and carries out grid division and file optimization to the file, to calculate the basic parameter calculation of part;The basic requirement based on 3D printing is checked one by one to part, and the place where part is not in compliance is split, and different problems are marked using color, and the corresponding problem is explained, for the check item with problem, point out problem area to user, and provide modification guide.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to an online inspection method for 3D printed parts. Background Art

[0002] 3D printing (also known as additive manufacturing or layer-by-layer manufacturing) is a technology that uses digital model files as the basis and uses adhesive materials such as powdered metal or plastic to construct objects by printing layer by layer. 3D printing is often used to make models in fields such as mold manufacturing and industrial design, and has gradually been used for the direct manufacturing of some products. It has a profound impact on traditional process flows, production lines, factory models, and industrial chain combinations, and is a representative disruptive technology in the manufacturing industry.

[0003] During the 3D printing process, users first need to draw a 3D model design of the product and select materials for printing based on the 3D model design. However, since 3D printing has basic requirements for parts, such as watertightness, size, wall thickness, cavity, quantity, etc., and there are also restrictions on materials, this step traditionally requires offline consultation with professional 3D printing manufacturers for inspection. As a result, this step not only requires a lot of manpower and communication costs, but also has high technical requirements for users and manufacturers. It is also cumbersome to operate and cannot intuitively understand the problem. Therefore, we have proposed an online inspection method for 3D printed parts to address this problem. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides an online inspection method for 3D printed parts, which solves the problems raised in the above background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A 3D printed parts online inspection method, comprising the following steps:

[0006] S1: 3D design file, the 3D model file required by the user through 3D modeling design software;

[0007] S2: Select materials. The user enters the system interface and selects the product printing material online according to the product requirements. After selecting the printing material, the system automatically determines the parameters of the selected printing material, including the maximum printing size of the material, the minimum printing wall thickness of the material, the minimum printing gap of the material, whether the material can make a cavity, the material accuracy, the basic unit price of the material, and the basic printing period required for the material, and displays them to the user;

[0008] S3: Upload 3D files and perform recognition, and can parse and read common 3D file formats;

[0009] S4: Grid division and file optimization, 3D file, based on finite element method for mesh division, and filter interference surface and interference hole,

[0010] Identify interference surface: first calculate the number of interference surface, the number of independent sheet less than n is marked, then calculate the perimeter and surface area of the marked surface, the perimeter is less than I or the surface area is less than m, which is marked as interference surface and deleted;

[0011] S5: Basic parameter calculation, including the size, surface area and volume of the part;

[0012] Minimum envelope size calculation: the minimum envelope size is the size of the part in a certain attitude, which has the smallest volume after multiplying the length, width and height. In order to reduce the calculation amount of traversal, first determine the minimum size in three dimensions, then take the size as the axis, take the size as the axis, and traverse the minimum projection area of the other two surfaces with a step S degree. After determining the minimum projection area, take the normal direction of the surface as the rotation axis, and traverse the minimum size of the other edge, so as to convert the three-dimensional problem into two one-dimensional traversal problems, thereby greatly saving the calculation amount;

[0013] S6: Online inspection, based on the basic requirements of 3D printing, the part is checked one by one, and the inspection content includes water tightness check, size check, wall thickness check, cavity check and quantity check;

[0014] Wall thickness calculation: the conventional finite element wall thickness calculation method will misreport the corner material of the part. In order to prevent misreporting, the algorithm of part corner identification is added: when the corner of the part appears acute angle, mark the corner, and ignore the wall thickness deficiency in the area with the distance L from the top edge of the acute angle;

[0015] Cavity identification: 3D printing can make cavity parts, identifying cavity parts can more accurately quote, for the model with negative volume in the volume calculation process, detect the nearby positive volume model, if there is a positive volume model completely wrapping the negative volume model, it is determined that the negative volume model is the cavity of the positive volume model, and a model can have multiple cavities;

[0016] Size check: in the case of having calculated the minimum envelope size of the part, compare the maximum size in three dimensions with the maximum size of the 3D printer, the second size with the second size of the 3D printer, and the third size with the third size of the 3D printer. If any of the sizes does not meet the requirements, it is determined that the size does not meet the printing requirements, and is marked;

[0017] S7: 3D display of inspection results, the inspection results are displayed through 3D display, 3D display allows customers to rotate, translate, zoom and other viewing functions,

[0018] Region division: split the non-compliant parts, and mark different problems with different colors, and explain the corresponding problems of the marked colors;

[0019] S8: modification guide, for the user to point out the problem area, and provide modification guide,

[0020] S9: complete online inspection, the drawing online inspection work is completed, the user modifies the drawing according to the color and modification guide, reuploads and detects again.

[0021] The printing material types in S2 include engineering plastics, photosensitive resins, rubber materials, and the commonly used 3D file formats in S2 include but are not limited to STL format, STP format, STEP format, OBJ format, IGS format and IGES format.

[0022] Preferably, the printing material types in S2 include engineering plastics, photosensitive resins, rubber materials, metal materials, ceramic materials, colored gypsum materials, artificial bone powder, cell biological raw materials and sugar materials.

[0023] The present application provides a kind of 3D printing part online inspection method, with the following beneficial effects:

[0024] 1、The 3D printing part online inspection method allows users to design drawings, freely select materials, and the system automatically determines the parameters of the selected printing material, and displays the parameters to the user for easy viewing and selection of appropriate printing materials;After uploading the 3D file, the system automatically identifies the file and performs grid division and file optimization to calculate the basic parameters of the part;Using the minimum envelope size calculation algorithm, the three-dimensional problem is converted into two one-dimensional traversal problems, thereby greatly saving the calculation amount and improving the user experience;Based on the basic requirements of 3D printing, the parts are checked one by one, and the inspection content includes water tightness inspection, size inspection, wall thickness inspection, cavity inspection and quantity inspection. After inspection, the inspection results are displayed by 3D display, which allows customers to rotate, translate, zoom and view other functions. Split the non-compliant parts, and mark different problems with different colors, and explain the corresponding problems of the marked colors. For the user to point out the problem area, and provide modification guide, so that customers can check the product design file online and get qualified 3D printing part design file. At the same time, it can intuitively understand the basic parameters of the required materials, provide support for subsequent processing, and is convenient, time-saving and efficient. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The structure of the present application is shown in the figure. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] See also Figure 1 The present invention provides a technical solution: a method for online inspection of 3D printed parts, comprising the following steps:

[0028] Step 1: 3D printing part design file. The user uses 3D modeling design software to design the 3D model drawing file to be printed;

[0029] Step 2: Select materials. The user enters the system interface and selects product printing materials online according to product requirements. The types of printing materials include engineering plastics, photosensitive resins, rubber materials, metal materials, ceramic materials, colored gypsum materials, artificial bone powder, cell biological raw materials and sugar materials. This technology covers all types of printing materials currently on the market, which is convenient for users to choose. Since different types of printing materials have different parameters, the parameters of the products used for printing are also different. Therefore, after selecting the printing material, the system automatically determines the parameters of the selected printing material. The material parameters include the maximum printing size of the material, the minimum printing wall thickness of the material, the minimum printing gap of the material, whether the material can make a cavity, the material accuracy, the basic unit price of the material, and the basic printing period required for the material printing. The parameters are displayed to the user, allowing the user to select the printing material suitable for the product and understand the price, construction period and other information so that the user has a clear idea.

[0030] Step 3: Upload the 3D file and recognize it. It can parse and read common 3D file formats, including but not limited to step TL format, step TP format, step TEP format, OBJ format, IG step format, IGE step format, etc. By supporting the recognition of multiple 3D file formats, users can design with different software instead of being limited to one or several formats, which is very inclusive.

[0031] Step 4: Mesh division and file optimization: mesh the 3D file based on the finite element method and filter out interference surfaces and interference holes.

[0032] Identify interference surfaces: First, count the number of interference surfaces and mark independent facets with a number less than n. Then, calculate the perimeter and surface area of ​​the marked faces. Facets with a perimeter less than 1 or a surface area less than m are marked as interference surfaces and deleted.

[0033] Step 5: Basic parameter calculation, basic parameters include the size, surface area, volume of the part, minimum envelope size calculation, the minimum envelope size is the size of the part in a certain attitude, the length, width, and height are multiplied to get the minimum volume, in order to reduce the calculation amount of traversal, first determine the minimum size in three dimensions, then take the size as the axis, take the size as the axis, and traverse the minimum projection area of the other two faces with a step S degree, determine the minimum projection area, then take the normal direction of the face as the rotation axis, and traverse the minimum size of the other edge, thereby converting the three-dimensional problem into two one-dimensional traversal problems, thereby greatly saving the calculation amount;

[0034] Step 6: Online inspection, based on the basic requirements of 3D printing, the part is checked one by one, the inspection content includes water tightness check, size check, wall thickness check, cavity check, quantity check,

[0035] Wall thickness calculation: the conventional finite element wall thickness calculation method will misreport the part corner material, in order to prevent misreporting, the part corner recognition algorithm is added: when the part corner appears an acute angle, mark the corner, then ignore the wall thickness deficiency in the region with an inward distance of L from the top edge of the acute angle;

[0036] Cavity recognition: 3D printing can make cavity parts, identifying cavity parts can more accurately quote, for models with negative volume in volume calculation, detect nearby positive volume models, if there is a positive volume model completely wrapping the negative volume model, it is determined that the negative volume model is the cavity of the positive volume model, and a model can have multiple cavities;

[0037] Size check: in the case of having calculated the minimum envelope size of the part, by comparing the maximum size in three dimensions with the maximum size of the 3D printer, the second size with the second size of the 3D printer, and the third size with the third size of the 3D printer, if any of the sizes does not meet the requirements, it is determined that the size does not meet the printing requirements, and is marked;

[0038] Step 7: 3D display of inspection results, the inspection results are displayed through 3D display, 3D display allows customers to rotate, translate, zoom, and other viewing functions,

[0039] Region division: split the part that does not meet the requirements, and mark different problems with different colors, and explain the corresponding problems of the marked colors;

[0040] Step 8: modification guide, for the problem inspection items, point out the problem area to the user and provide a modification guide,

[0041] Step 9: complete the online inspection, the drawing online inspection job is completed, the user modifies the drawing according to the color and modification guide, re-uploads and detects again, so that the customer can check the product design file online, and obtain qualified 3D printing part design file, and can intuitively understand the basic parameters of the required material, thereby providing support for subsequent processing.

[0042] To sum up, the 3D printing part online inspection method, when in use, the user enters the system interface, selects the product printing material online according to the product demand, uploads the 3D file and performs identification, divides the 3D file into grids based on the finite element method, filters the interference surface and interference hole, calculates the number of interference surfaces, marks the independent surface with a number less than n, then calculates the perimeter and surface area of the marked surface, marks the surface with a perimeter less than I or a surface area less than m as an interference surface, deletes the interference surface, calculates the basic parameters of the part, including the size, surface area and volume of the part,

[0043] The part is checked one by one based on the basic requirements of 3D printing, the inspection content includes watertightness inspection, size inspection, wall thickness inspection, cavity inspection and quantity inspection, the inspection results are displayed in the form of 3D display, the part is split at the non-compliant place, different colors are used for marking, the problem area is pointed out for the user, and a modification guide is provided, the drawing online inspection job is completed, the user modifies the drawing according to the color and modification guide, re-uploads and detects again.

[0044] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A 3D printed parts online inspection method, characterized in that: The following steps are involved: S1: 3D design file, the 3D model file required by the user through 3D modeling design software; S2: Select materials. The user enters the system interface and selects the product printing material online according to the product requirements. After selecting the printing material, the system automatically determines the parameters of the selected printing material, including the maximum printing size of the material, the minimum printing wall thickness of the material, the minimum printing gap of the material, whether the material can make a cavity, the material accuracy, the basic unit price of the material, and the basic printing period required for the material, and displays them to the user; S3: Upload 3D files and identify, parse and read common 3D file formats; S4: Meshing and file optimization: Meshing the 3D file based on the finite element method, and filtering out interference surfaces and interference holes. Identify interference surfaces: First, count the number of interference surfaces and mark independent facets with a number less than n. Then, calculate the perimeter and surface area of ​​the marked faces. Facets with a perimeter less than 1 or a surface area less than m are marked as interference surfaces and deleted. S5: Calculation of basic parameters, including the size, surface area, and volume of the part; Minimum envelope size calculation: The minimum envelope size is the minimum size of the part after multiplying the length, width and height in a certain posture. In order to reduce the amount of calculation required for traversal, first determine the minimum size in the three-dimensional size, then use this size as the axis and traverse the minimum projection area of ​​the other two faces with a step length of S degrees. After determining the minimum projection area, use the normal direction of the face as the rotation axis to traverse the minimum size of the other side, thereby converting the three-dimensional problem into two one-dimensional traversal problems, thereby greatly saving the amount of calculation; S6: Online inspection: Check each part one by one based on the basic requirements of 3D printing. The inspection contents include watertightness inspection, size inspection, wall thickness inspection, cavity inspection, and quantity inspection. Wall thickness calculation: Conventional finite element wall thickness calculation methods may misreport part scraps. To prevent this, an algorithm for identifying part corners has been added: When a sharp corner appears on a part's corner, the corner is marked, and then the area within a distance L from the top edge of the sharp corner is calculated, ignoring any insufficient wall thickness. Cavity identification: 3D printing can produce cavity parts. Identifying cavity parts can provide more accurate quotes. For models with negative volume during volume calculation, the system detects nearby positive volume models. If a positive volume model completely encloses the negative volume model, the negative volume model is determined to be a cavity of the positive volume model. Multiple cavities are allowed for a model. Dimension check: After the minimum envelope size of the part has been calculated, compare the largest dimension of the three-dimensional dimensions with the maximum dimension of the 3D printer, the second dimension with the second dimension of the 3D printer, and the third dimension with the third dimension of the 3D printer. If any of the dimensions does not meet the requirements, the dimension is determined to be unsatisfactory and marked. S7: 3D display of inspection results. The inspection results are displayed in 3D. The 3D display allows customers to perform viewing functions such as rotation, translation, and zoom. Area division: Separate the non-compliant parts and mark different problems with colors, and explain the problems corresponding to the marked colors; S8: Modification wizard, for problematic inspection items, points out the problem areas for users and provides modification wizards. S9: Online inspection is completed. The online inspection of the drawing is completed. The user modifies the drawing according to the color and modification wizard, re-uploads it and inspects it again.

2. The method for online inspection of 3D printed parts according to claim 1, wherein: Formats of 3D files commonly used in S2 include, but are not limited to, STL format, STP format, STEP format, OBJ format, IGS format, and IGES format.

3. The online inspection method for 3D printed parts according to claim 1, characterized in that: The types of printing materials in S2 include engineering plastics, photosensitive resins, rubber materials, metal materials, ceramic materials, colored gypsum materials, artificial bone powder, cell biological raw materials and sugar materials.

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