The non-standard parts are mainly the other parts that are not controlled by the company but have no strict standard specifications and no related parameters. The more mature an industry is, the higher the degree of generalization of standardization, the more standard parts, and the lower the industry cost. However, over-standardization should be avoided, resulting in monotonous product categories and low-end competition. There are many varieties of non-standard parts, there is no very standardized classification, are generally based on market needs and their own brand development, and extend the vitality of the product and independent research and development. Non-standard parts refer to the commonly used non-standard parts such as screws, keys, pins, rolling bearings, etc., which have been completely standardized in terms of structure, dimensions, drawing, marking, etc., and are produced by specialized factories.
184,Modern foreign thread processing technology, which is embodied in several aspects?
Modern Foreign Thread Machining Technology: From the end of the 20th century, the thread processing technology of foreign industrial developed countries has undergone a fundamental leap, and the quality of thread processing has been significantly improved. Specifically embodied in the following aspects:
1) Machine tool adjustment technology: Due to the use of thread indication gauges and thread single element error separation technology (differential measurement), the machine tool can be adjusted abroad to produce threads close to the theoretically correct dimensions. In this way, on the one hand, the quality level of the processed thread is greatly increased; on the other hand, the force on the machine tool and the cutting tool is reduced, so that the wear is reduced, and the life of the machine tool and the cutting tool is increased.
2) Process parameter control technology: In order to monitor the high-speed operation of each thread, a foreign sensor is installed in the cutting tool support mechanism to measure the stress of each thread. The maximum amplitude of the allowable change in the force is specified on the basis of a force curve that is processed close to the theoretical correct thread size. When the force exceeds the specified range, the equipment automatically stops, waiting for the technician to analyze the cause of the accident and readjust the equipment. This force monitoring device has been manufactured by specialized manufacturers, and thread processing companies can modify the existing equipment without a monitor. In addition, in order to detect the abnormality of the cutting tools early, some equipments are also equipped with a high-frequency sounding instrument, which can avoid the occurrence of cutting tools.
Some foreign companies use SPC technology to measure the thread size during the machining process, monitor the thread parameter change process, and control the threading process error within 60% of the product's specified tolerance.
3) 100% measurement technology: Using laser photography technology, each thread can be tested and unqualified products can be singled out in time.
4) CNC machine tools and computerized information management: In order to respond to the market requirements of small batches, varieties, and short delivery times, foreign companies began to use CNC machine tools and computerized information management technologies to process thread products. CNC machine tools can memorize the adjustment position of the same thread previously processed, which greatly reduces the time for adjusting the machine tool.