Application of Group Technology in NC Machining

Group technology GT is based on the similarity of things. Wherever similarities exist, the principles of group technology can be applied. At present, group technology has been successfully applied in all aspects of production activities, including product design, manufacturing process, and production management. Especially in recent years, the development of group technology has appeared in a new situation combined with numerical control technology. Both group technology and numerical control technology are aimed at improving the production level of multiple varieties and small batches. The former is through the rational organization of the processing objects, and the latter is through the realization of flexible automation of the process. Although Cnc Machining has various advantages, it is still difficult to obtain good economic results if it is not properly organized in production. Many companies have purchased With a considerable number of Cnc Machine tools, they cannot give full play to their effectiveness. More companies conduct economic analysis based on the current production method, and it is impossible to even have the motivation to purchase CNC machine tools. This makes advanced equipment and processing methods aimed at improving the level of multi-variety and small-batch production have long been rejected from multi-variety , Outside of small-batch production enterprises, or even if enterprises are introduced, they cannot play their due role. The implementation of group technology will enable enterprises to solve the above-mentioned problems under the condition of normal production tasks, and the use of CNC machining in enterprises that implement group technology will further improve the implementation effect of group technology. The combination of group technology and CNC machining will make it possible for these two technologies with a common goal to exert the greatest benefits. This article makes a simple discussion on how to apply group technology in CNC machining, hoping to get criticism from colleagues 1 The application of group technology in CNC machining 1.1 Choose appropriate and sufficient processing objects for CNC machine tools The price ratio of CNC machine tools Ordinary machine tools are much higher. Only in a relatively short period of time that the investment of CNC machine tools can be repaid, can the economic effect of CNC machining be shown. Therefore, it is necessary to select the appropriate machining parts for the CNC machine tools as much as possible to make it work at full capacity. Foreign studies believe that it is better to maintain continuous work in two shifts for general CNC machine tools (taking into account the high additional wages for night shifts), so that it is possible to recover the equipment investment within 7 years. But for the extremely expensive machine tools, many companies make them work around the clock in addition to maintenance in order to make full use of them. However, there are still many problems in the rational use and utilization of CNC machine tools in many companies. The contradiction between high-efficiency equipment and low utilization has not been completely resolved, and the situation is particularly serious in some Chinese companies.

If the coding and grouping of parts have been implemented in the factory, appropriate criteria can be specified for the parts suitable for processing by each CNC machine tool, and a search command can be formed. Using this kind of retrieval command, it is possible to retrieve parts or part families suitable for processing on each type of CNC machine tool from a large number of parts produced by the enterprise. In the future, the parts in the new products that are constantly appearing can also be used to judge whether they are suitable for processing on the CNC machine tool. In this way, the parts processed on the CNC machine tool can be appropriately and adequately selected, so that the CNC machine tool can be used rationally. .

1.2 Programming the part family In order to be able to process a certain part on the CNC machine tool, the CNC machining program must be compiled in advance for the part processing. The usual NC machining programming work is carried out separately for each part, which requires a lot of manpower, time and expense.

Even if computer-assisted programming is used, people are required to analyze the process of the parts, write the source program, and then add calculations until the control belt is made and the control belt is checked. It is not only a lot of work and a long programming cycle, but also There are often many repetitive tasks.

If the group technology is implemented and the production is organized according to the part family, since the various parts in the part family have similar process characteristics, the CNC machining procedures must be similar. At this time, a unified CNC machining can be developed for each part family The program system, which includes all common or similar program units of the same NC machining process of the part family, is stored in the computer in the form of a computer program, as the basis of the NC machining programming of each part family, this is the so-called “part family programming ”

When compiling a data processing program for a part, as long as calling the main program of the corresponding part family and inputting a small amount of different information of this kind of part, the numerical control processing program of this kind of part can be compiled on the basis of the main program of the part family. Obtain a control zone.

1.3 Use group technology to organize production and give full play to the effectiveness of CNC machine tools. Although CNC machining realizes the automation of the process and saves the auxiliary time of the machining process, at the same time, due to its adaptability to the transformation of machining objects, it also greatly reduces the adjustment time of the machine tool. , But if the production is still organized in the traditional way, there will be problems such as long and complicated workpiece transportation routes in multi-variety, small-batch production, large quantities of work in progress, long production cycles, and often machine tool stoppages. In this way, CNC machining cannot play its due role in improving the level of multi-variety and small-batch production.

Organize production according to group technology, through scientific organization of processing objects and processing equipment, reasonable distribution of machine tool load and arrangement of operation plans, the above problems can be satisfactorily resolved. In such a production environment, CNC machining has obtained the opportunity to give full play to its advantages.

Secondly, a group of equipment organized according to group technology, its processing object is always a group or several groups of similar parts. For each machine tool, the processing object has only a small range of change, which reduces the requirements for the adaptability of the CNC machine tool. In this case, you can choose a CNC machine tool with fewer functions or smaller specifications , Which can save the investment of numerical control equipment.

1.4 Improve the production level of the group production unit Table 3 Various types of mining machinery noise intensity equipment type noise level dB belt conveyor 75-85 motor, gear drive 85-95 compressor, diesel engine, ventilator 9-100 pneumatic filling machine 95 -105 Ground Main Ventilator 100 120 Scrapers 10th110 Pneumatic Rock Drill, Pneumatic Loader 105-120 Two Pneumatic Rock Drills in the Roadway 12th130 Table 4 Underground Atmospheric Sanitation Standards Efforts: First, improve the equipment that affects the dust concentration, in rock drilling , Install an effective dust removal device on the crushing machinery; the second is to use a local air flow system to alleviate the dust problem, that is, use the ventilation equipment to change the main air flow direction to avoid dust sources or change the flow direction of dusty air to avoid equipment operators.

3 Special attention to safety is a matter of course, and mining machinery must continue to work hard for the safety of mining operations. Currently, there are several trends in this area: ①Improve equipment reliability; ②Use remote control equipment; ③Pay attention to ergonomics. For all mobile equipment in the mine, especially mining vehicles, in order to ensure safe operation, the reliability of the braking system, steering system, and operating system will be continuously improved.

Mine mechanization can increase productivity, which has been recognized by everyone, but mechanization itself may not improve production safety conditions. In fact, some safety accidents are caused by equipment, and of course there are some environmental hazards other than machinery. The use of remote control equipment can achieve the dual goals of increasing labor productivity and improving production safety conditions. For mining vehicles such as scrapers, the use of ergonomics to create comfortable working conditions for drivers is essential to the safety of drivers. For example, the size of the cab must meet three basic requirements: ① space comfort; ② work comfort; ③ observation comfort.

4 Conclusion 4.1 All countries in the world attach great importance to the safety of mining operations 4.2 In the entire life cycle of mining machinery, especially in the planning, design, manufacturing and other stages, it will be vital to pay attention to greatly improving the reliability and maintainability of mining machinery of.

4.3 Environmental pollution caused by mining machinery is mainly noise, exhaust gas and dust. Therefore, the focus of controlling environmental pollution is to control it within the limits specified by the standard.