Design steps and requirements:
Big Large number of production types;
Craft Process analysis of parts [using the new national standard];
(3) Determine the type, shape, size and accuracy of the blank;
⑷ Draw up the process route. This is a key step in the development of process specifications. Its main tasks are: selecting a positioning benchmark, determining the processing method of each surface, arranging the processing sequence, determining the degree of process concentration and dispersion, and arranging heat treatment, inspection and other auxiliary processes. When formulating the process route, generally several possible schemes are proposed, analyzed and compared, and finally an optimal scheme is determined;
⑸Determine the equipment used in the process. When selecting a machine tool, you should pay attention to the following basic principles:
① The processing size range of the machine should be adapted to the external dimensions of the workpiece.
② The accuracy of the machine tool should be compatible with the accuracy required by the process.
③ The productivity of the machine tool should be adapted to the production type of the workpiece. If the size of the workpiece is too large and the accuracy is too high, when there is no suitable equipment to choose from, the modification of the machine tool or the design of a special machine tool should be considered. At this time, it is necessary to propose a machine tool modification (or design) task book according to the specific process. The task book should provide the necessary data and information related to the process.
For example: process size, process tolerance and technical requirements, workpiece positioning, clamping method, and overall layout of the machine tool, productivity of the machine tool, etc .;
⑹ Determine the process equipment used in each process.
The following principles should be noted when selecting process equipment:
① Selection of fixture.
②Selection of cutters: Generally, standard cutters should be selected as far as possible. When processing on combined machine tools, the production is organized according to the principle of process concentration, and special compound tools can be used.
③ Selection of measuring tools: The measuring tools are mainly selected according to the type of production and the required inspection accuracy. General small-scale fixtures should be used for single-piece small batch production, and limit gauges and high-productivity inspection fixtures and instruments should be used for large-scale production;
⑺Determine the machining allowance of each process, calculate the process size and tolerance;
⑻Determine the cutting amount for each process. However, for large-scale assembly line production, especially automatic line production, each process and step needs to specify the cutting amount in order to calculate the production cycle of each process.
⑼ Determine the time quota;
⑽Fill in the process file
Post time: Nov-05-2020