1. Overview of sheet metal parts manufacturing industry

Sheet metal parts are parts with a certain shape, size and performance obtained through the stamping process. Because the cold stamping process has the advantages of high production rate and suitable for mass production, sheet metal parts are widely used in aerospace, automotive, shipbuilding, machinery, chemical, food processing machinery and other industries, and are gradually used in the current parts processing industry. Become an important part. The traditional design method of sheet metal parts is that the sheet metal engineer conceives a three-dimensional product in the brain, and then expresses the product on a two-dimensional pattern through the geometric projection of the brain. The engineer has more than half of his workload in three-dimensional entities and two-dimensional engineering drawings. The mutual transformation and tedious look-up tables and calculations are in progress. And the manufacturing workers have to reflect the two-dimensional pattern in the brain to reflect the three-dimensional entity and then process it-scribing (staking out), cutting, forming, connecting and assembling, which is time-consuming and labor-intensive. If computer-aided design and manufacturing are applied to sheet metal parts manufacturing, especially UG software is applied to the design and manufacture of sheet metal parts, the design of sheet metal parts can be made very fast, and the manufacturing and assembly efficiency can be significantly improved.

2UG software is applied to the main steps in the design and manufacture of sheet metal parts

2.1 Design of sheet metal parts

People’s original impulse when designing parts is three-dimensional, and the result of design implementation is a three-dimensional entity with related concepts such as color, material, hardness, shape, size, position, related parts, and manufacturing process. But in the traditional design, the information transmission between the two turned out to be all two-dimensional graphical expressions. Due to the limited previous methods, people had to agree on the two-dimensional view expression rules of parallel orthographic projection in the quadrant (the United States is the third quadrant), and use a limited number of associated two-dimensional projections to express their three-dimensional vision. This kind of information expression is extremely incomplete, and drawing and image reading must be carried out by specially trained people.

If you can directly start the design with a three-dimensional concept, especially with the support of UG software, you can more intuitively and accurately express all the geometric parameters of the design concept, and the entire design process can be fully discussed on the three-dimensional model. UG software provides the sheet metal design module UG/SheetMetalDesign for sheet metal design, which can help sheet metal engineers rationalize the design process from the perspective of design and manufacturing, and gradually create sheet metal from the generation of sheet materials and the completion of various processes. Gold parts. It can be regarded as a virtual environment for processing sheet metal parts. Engineers can design and assemble parts directly on the computer screen. The production process of the product is almost the same as the real product manufacturing process. The product on the computer screen is the future product. Three-dimensional image.

After the design of a single sheet metal part is completed, the three-dimensional model of multiple parts can be simulated and assembled. Each part in the assembly model is related: if a part in the assembly model is modified, other parts will be automatically made accordingly. Corresponding modifications can greatly shorten the product design and processing cycle, and improve the accuracy of product design.

2.2 Unfolding of sheet metal parts

After the design of the sheet metal parts is completed, in order to facilitate processing, it must be converted into an expanded drawing to determine the required sheet size and shape of the sheet. When traditional sheet metal parts are unfolded, they are all obtained through manual empirical calculations. This has three disadvantages: (1) The workload is large and the deployment process is cumbersome. (2) The efficiency is low, and it is easy to make mistakes for ordinary engineers during deployment. (3) The accuracy is low, and most of the development is obtained through experience, resulting in a large amount of food costs for materials and labor.

Using the automatic unfolding function of its sheet metal module UG/SheetMetalDesign in UG, the automatic unfolding of sheet metal parts can be completed. The shape and size of the unfolded sheet can be obtained through automatic calculation, so it has the advantages of high speed, high precision, zero error rate and simple operation.

2.3 Simulation of the processing of sheet metal parts

Using the automatic unfolding function and arbitrary angle change function in the UG/SheetMetalDesign module, the machining process of sheet metal parts can be simulated to determine the best production route of the part and complete the process analysis of the part. In the process of simulating the machining process, the selection of the bending tool is completed.

2.4 The output of the processing technology of sheet metal parts

Utilizing the powerful drawing function of UG/Drafting module to draw two-dimensional views can draw various required process diagrams conveniently, quickly and accurately, which is convenient for the production and inspection of subsequent processes. Due to UG's single database, the two-dimensional engineering drawing and the three-dimensional solid model are completely related. If the sheet metal modeling is changed, the two-dimensional view will automatically change accordingly, thus greatly improving the accuracy of the two-dimensional drawing and the efficiency of drawing output. .

2.5 Layout of sheet metal parts

The UG/SheetMetalNesting module can be used to optimize the layout of several varieties of parts on a blank. The user only needs to provide the types of parts, the quantity of each part and the specifications of the sheets used, and the system can carry out "automatic nesting" and select the best combination of different layouts. The module can also optimize the stamping process, reduce tool replacement, and reduce the repositioning of the plate when stamping parts. Users can also nest directly on the board in interactive graphics mode.

2.6 Preparation and output of NC machining program for sheet metal parts

The UG/Manufacturing module provides a complete programming method for programmers to choose. Including two-axis to five-axis CNC milling, two-axis to four-axis CNC wire cutting, three-axis CNC EDM, turret multi-station stamping and other processing methods. Programmers can carry out numerical control programming according to their needs, and use the UG processing simulation module to perform processing simulation on the programmed program. If the processing effect is not ideal, it can be corrected in time to obtain the ideal processing effect.

2.7 CNC machining of sheet metal parts

Use the corresponding post-processing file to convert the tool location file into an NC code program that can be recognized by the machine tool, and input it to the corresponding CNC machine tool through the serial interface to perform CNC machining of sheet metal parts.