What are the positioning benchmarks for stamping processing?

Precision stamping parts manufacturers need to choose the correct positioning datum when designing the process regulations. This has a great impact on ensuring the processing requirements of metal stamping parts and whether the processing sequence can be reasonably arranged. Then positioning in the stamping process What are the benchmarks and how to choose them, let's take a look. First of all, let's explain what is the positioning datum. During processing, the datum used to determine the correct position of the workpiece on the machine tool or in the fixture is called the positioning datum. The positioning datum can be divided into fine datum and rough datum. The unprocessed surface on the blank as the positioning datum is called the rough datum. The processed surface is used as a positioning datum, and this positioning datum is called a fine datum. When we choose the positioning datum, we usually first select the fine datum according to the processing requirements of the stamping parts, push forward from the process route, and then consider which group of surfaces to use as the rough datum to process the fine datum. 1. Selection principle of fine datum (1) Principle of datum coincidence: Choose the design datum of the processed surface as the fine datum as much as possible to avoid positioning errors caused by datum misalignment. (2) The principle of mutual reference: When the position accuracy requirements between the two machined surfaces on the workpiece are relatively high, the method of repeated machining of the two machined surfaces can be used as a reference to each other. (3) Self-reference principle: Some surface finishing processes require small and uniform machining allowances, and the machined surface itself is often used as a finishing reference. (4) Uniform datum principle: The same set of fine datums should be used to process as many surfaces as possible on the workpiece to ensure the relative position accuracy between the processed surfaces. The above four principles of choosing rough benchmarks sometimes cannot be taken into account at the same time, and they are based on the main choice. 2. The selection principle of rough reference (1) The rough reference should be used for the first process of workpiece processing. Whether the rough reference is selected correctly or not is not only related to the processing of the first process, but also has a significant impact on the entire process of workpiece processing. . (2) The principle of reasonable allocation of machining allowance: Considering to ensure that the machining allowance of important surfaces is even, the important surface should be selected as the rough reference. (3) The principle that rough benchmarks are generally not allowed to be reused. (4) The principle of easy clamping: In order to make the workpiece positioning stable and the clamping reliable, the rough datum selected is required to be as smooth and clean as possible. Forging flash, pouring riser cut marks or other defects are not allowed, and there must be Sufficient supporting area. [Related recommendation] Learn more: What are the methods for polishing the surface of stainless steel? Learn more: Manufacturing characteristics of automobile stamping parts molds Learn more: Points to note in the design of continuous stamping dies (2)