Drawings are important auxiliary materials for sheet metal machining, so it is very important to understand and analyze sheet metal machining drawings. The view of sheet metal bending drawings is very similar to the mechanical view.
In simple terms, sheet metal bending is very similar to the folding of a carton. The opening of the carton can be regarded as a sheet metal opening diagram, and the bending is the shape of folding the paper into a carton. Regarding the viewing method of sheet metal bending drawings, let us introduce in detail below.
Ⅰ. Pay attention to the perspective of sheet metal machining and bending drawings
Sheet metal bending drawings may be the top perspective or the third perspective. When looking at the drawings, you should first distinguish whether it is the top perspective or the third perspective. The national standard does not have certain angle method symbols in the title bar, and the rules of the national standard are drawn and viewed according to the first angle method.
Ⅱ. How to understand the drawings for sheet metal machining and bending
1. Looking at the title bar, there is another thing to pay attention to is the plate thickness. Sheet metal machining and bending should adjust the bending die according to the plate thickness information. Before sheet metal processing and bending, be sure to confirm whether the drawing is the same as the bending workpiece.
2. Place the sheet metal bending workpiece according to the main view, pay attention to the direction of drawing or burrs, so that it is easy to identify the direction, and simply check whether the drawing is correct. When you look at the drawing, you must look at the whole, and you can't neglect any part. For some products, due to structural reasons, some parts that need to be bent cannot be displayed in the normal three views, so partial views are needed.
3. It is necessary to see whether the bending edge of the sheet metal machining drawing is a solid line or a dashed line. The solid line represents the bending upwards, the dashed line represents the thickness of the plate, that is, the invisible side, so fold it downwards.
Because many SECC sheet metal parts processing drawings are drawn by 3D software, sometimes the tangent line of the bending edge covers the dashed line, which makes it difficult to see whether it is bending upwards or downwards. At this time, it should be viewed in conjunction with the side view to see the bending direction.