The hottest 3D parameterized plate based on Proeng

  • Detail

3D parametric sheet metal part drawing library based on pro/engineer

[Abstract] Based on pro/engineer 3D CAD design software, a 3D parametric sheet metal part drawing library is established to quickly complete the design of sheet metal parts of different sizes through the change of control parameters. The actual system test shows that the system realizes the high integration of the solid model of sheet metal parts and the rapid generation of 2D drawings

[Key words] parameterization of sheet metal parts pro/engineer

1 overview

sheet metal parts are a kind of common structural parts, which have been widely used in various industries or equipment such as intelligent feedback computing, electronics, switches, electrical appliances, control cabinets, etc. At the same time, compared with ordinary mechanical parts, the main structural characteristics and processing technology of sheet metal parts determine that it is a special part, which is generally obtained by forming, bending, stamping and other methods. For a long time, the processing of sheet metal parts in our company has been designed by designers, and the workshop technicians re input the computer to carry out lofting according to the drawings. This production method has the inevitable disadvantages of high labor intensity and low efficiency. During the "Ninth Five Year Plan" period, our company introduced advanced turret CNC punch and profiling laser cutting machine tools. It only takes a few minutes to process the sheet metal parts. It takes tens of minutes for technicians to complete the lofting. The lofting of sheet metal parts has become a bottleneck restricting the production progress

after introducing the 3D design software pro/engineer developed by American PTC company in 2002, our company can easily complete the work of converting 3D drawings into 2D engineering drawings of pro/engineer. The complete pro/sheetmetal sheet metal design module does not separate the fiber from the resin, which can help users to establish various sheet metal features and create unfolded drawings of sheet metal parts. However, the following sheet metal parts are used in the design process

(1) the modeling and unfolding of sheet metal parts are complex and tedious, and designers can only design by themselves when necessary, which inevitably increases the repeated work of designers

(2) some designed sheet metal parts cannot be unfolded normally due to different levels of designers and different modeling methods

(3) incorrect setting of sheet metal characteristics makes the unfolded drawing inconsistent with the actual production and cannot correctly guide the production

2 modeling method and parametric drawing principle of 3D sheet metal drawing library

pro/sheetmetal extends the design function of pro/engineer. Users can establish parametric sheet metal modeling and assembly, including generating sheet metal models and unfolding them. Pro/sheetmetal provides the ability to bend and level by referencing the bending library model. The bending allowance is the function of attaching features to the model in the bending or flattening state. At the same time, it supports the generation, library storage and replacement of user-defined features

2.1 main features

(1) wall. A planar wall connects a cosmetic wall to a selected edge of the model. Punch wall can select the edge vertically along the model to punch out the schematic shape of the wall

(2) bending. It allows the user to specify how to bend the plane part of a model without adding a new material

(3) shape. Allows the blending of complex shaped surfaces into sheet metal parts. The user-defined shape feature library can be generated by generating features other than user-defined shape features

(4) perforation. The punch feature allows the user to pre define the shapes of their dies and add them to the library. The perforation consists of a coordinate system that is used to perform a relative datum for tool positioning data using pro/manufacturing

(5) slot. Provide a form library of slots, which can be pre-defined by the user—— The digitalization and intellectualization of R & D and design technologies are accelerated. Only two positioning benchmarks are needed to open slots relying on Internet, big data and cloud computing platforms

2.2 main operations

(1) flattening. Unfold a curved sheet metal part into a plane figure, which can be carried out in a user-defined way

(2) bending. Bend a plane figure into the bending state of the original sheet metal part

pro/sheetmetal includes the function of referring to a series of bending tables when leveling. Bending allowance is a function of material thickness, material, radius and angle. Tables can be generated externally and modified using the bend table command. Pro/sheetmetal allows you to set the bending order of sheet metal parts and save the bending order table, just like a reference for bending and flattening

in the principle of parametric drawing, we make full use of the parametric function of pro/engineer software. After modifying multiple dimensions in the drawing, the sheet metal model and drawing will be updated automatically. We can use this method to build a 3D sheet metal drawing library. The sheet metal parts in the library are controlled by their own features and parameters, which not only occupies a small space, but also is easy to add, delete and modify. Combined with the pro/sheetmetal design module, the secondary development of pro/engineer is carried out to make and organize the commonly used sheet metal models and drawings of smoke machine products, and establish a three-dimensional parametric sheet metal drawing library. Designers only need to call the engineering drawings in the library, and modify the relevant parameters in the engineering drawing environment to get the required models and unfolded drawings

3 establishment and use of sheet metal part drawing library

below, we introduce the process of realizing this method by creating an example of an oblique cut cylindrical pipe

3.1 creation of a sheet metal part template

when a sheet metal is bent, the sheet metal material will be stretched, so the length of the material will increase. On the contrary, when the bent sheet metal is flattened, the material will be compressed, that is, the length of the material will decrease. The extent of material increase or decrease is affected by the following factors: material type, material thickness, material heat treatment and processing conditions, and bending angle. In pro/engineer, there are two ways to automatically calculate the flattened length dimension at the position where bending is used to improve the ability of American enterprises to produce advanced polymer composites. One is to use y coefficient or K coefficient, and the other is to use bending table. Due to space limitations, it will not be introduced here. Please refer to relevant materials

set the working directory to e:sheetmetal folder, and create the sheet metal template YJ in one of the above two ways as required_ t。 Add the following configuration to the configuration file o to specify the defined default sheet metal template path: set template to_ The sheetmetalpart parameter points to the location of the template you have created (e.g. e:sheetmetalyju T), making YJ_ T becomes the default sheet metal part template

3.2 creation of sheet metal model and drawing_ drawing_ picture_ The value of file is set to both to embed the picture file in the drawing for preview. Create the oblique cut cylindrical tube sheet metal part model according to the dimensioning method shown in the sheet metal unfolding technical manual, as shown in Figure 1

Figure 1 oblique cut cylindrical tube model

create a drawing of the sheet metal part of the oblique cut cylindrical tube, select the drop-down menu: view → display and wipe, display all dimensions, adjust the position of the dimensions and wipe off the excess dimensions, so that the dimensioning method is as shown in the sheet metal unfolding technical manual, and the obtained drawing is as shown in Figure 2

Figure 2 engineering drawing of oblique cylindrical pipe

3.3 establishment and use of sheet metal part library

o or P file, specify Pro_ library_ The dir parameter points to the library directory you have created, such as the e:sheetmetal folder. Put the sheet metal parts in this folder, create a new u menu template file in the e:sheetmetal folder, and use Notepad to edit the file. In this example, the format of u is as shown in Figure 3, so as to complete the establishment of a 3D parameterized sheet metal drawing library. In this way, when you open the file in pro/engineer, you can find the "Qinhuangdao tobacco machine sheet metal parts Gallery" in the directory tree, and you can easily find and preview the required sheet metal parts from the folder, as shown in Figure 4

Figure 3 menu template file contents

Figure 4 calling of sheet metal parts

when a new sheet metal part needs to be designed, open the similar sheet metal parts in the sheet metal part library and back them up to the current working directory (drop-down menu: file → backup → OK), so as to ensure that the changes to the newly designed sheet metal parts will not affect the sheet metal parts in the library. Open the model and drawing in the current working directory and rename them to the file names you need (drop-down menu: file → rename → OK)

modify the dimension marked in the drawing, and the sheet metal model will change accordingly, so as to obtain the required sheet metal model and unfolded drawing. The modification methods in the drawing environment are as follows: (drop-down menu: [] → [value]) select the value to be changed, and click (menu manager: 【 regenerate 】→ [model 】) after completion. For example, the height of the oblique cut cylindrical pipe is changed to 500, the diameter is changed to 100, the oblique cut angle is changed to 10 °, and the wall thickness is changed to 10, and the engineering drawing shown in Figure 5 is obtained

Figure 5 engineering drawing of regenerated oblique cut cylindrical pipe

designers can also add new features (such as perforation) to the invoked sheet metal parts to generate new parts that meet the design requirements, without repeating the previous design steps and considering how to unfold and other cumbersome processes, so as to realize the rapid variant design of such products

4 conclusion

the CAD modeling technology based on pro/engineer software introduced in this paper has developed a parameterized sheet metal part drawing library for smoke machine products, which solves the limitations of the previous two-dimensional design. Based on the three-dimensional feature model, the drawing library can quickly complete the design and lofting of common sheet metal parts, reduce the repeated modeling time, improve the design efficiency, and enable designers to have more time for product design. By referencing sheet metal parts in the library, designers can ensure design consistency to comply with the company's unified standards. This method is simple to use and widely applicable. Common parts and serial parts can also be organized and managed by this method. (end)

Copyright © 2011 JIN SHI