Automobile inspection tool design generally relies on GD&T drawings. GD&T is the abbreviation of Geometric Dimensioning and Tolerancing, that is, we often say 'shape and position tolerance'. For a novice design opponent, reading GD&T drawings may be like a book, but as long as you have received professional training, you can learn to read GD&T drawings in a short period of time, and then go through a few simple checker design to cooperate with GD&T drawings After training, he quickly grew from a rookie who knew nothing about inspection tools to a design apprentice who could do some simple sheet metal inspection tools.
????????How do you know where you need to test when designing a car inspection tool through GD&T drawings? Don't look at the GD&T chart, it looks very dense, it feels very complicated. In fact, the GD&T diagram of a set of inspection tools contains two kinds of information, positioning and detection. Not to mention the positioning, today we mainly talk about how car inspection tools know where to detect. A car product usually consists of holes (or columns), faces and trims. These three components are where we need to test. But not all places need to be tested, this is the need to use GD&T drawings. Corresponding to the GD&T diagram, 'shape' refers to the surface contour and trimming contour to be detected. The tolerance of the surface contour is generally represented by a closed semicircle symbol; the tolerance of the trimming contour is generally represented by an unclosed semicircle symbol. 'Position' refers to the hole (or column) to be tested. The position tolerance is generally expressed by the full circle and the center line of the circle. Seeing these symbols, it is the place to be detected.
????????When the customer does not provide GD&T drawings, how does the car inspection tool know where to detect? At this time, the customer can be asked to provide the opponent parts (also called environmental parts) of the automobile product. Through the cooperation between the opponent parts and the inspected product, the holes, faces and trims to be detected can be visually seen in the 3D digital model. In fact, the GD&T diagram is the design specification of the automobile inspection tool extracted by the automobile manufacturer according to the matching relationship of the automobile products and the actual assembly tolerance requirements.
????????Someone asked, what if the customer did not provide either GD&T or counterparts? In this case, it is really impossible to design the inspection tool. After all, it is hard for a clever woman to cook without rice! The design of the car inspection tool is not out of nothing, it is done by imagination. The design of each inspection tool is traceable and evidence-based.