A brief analysis of CNC machining Fault curve of die casting


The failure curve of die casting cnc machining can conceptually represent the relationship between the failure rate and time of cnc machining. Since this curve is shaped like a bathtub, it is often called the "bathtub curve". It divides the use period of CNC machine tools into three stages, namely, early failure period, occasional failure period and wear failure period.
The failure rate of the machine tool in the early failure period shows a negative exponential curve function. At the beginning, the failure rate is very high, but as the operating time increases, the failure rate quickly decreases and enters the constant failure rate stage. There are many reasons for the high early failure rate, such as design defects, errors in manufacturing and installation, and errors in the processing and use of hardware parts. The cause of the fault was found out after running-in and eliminated, and the fault rate gradually stabilized. This stage is called the trial run period or running-in period. The early failure period not only occurs in the early stage when the new machine tool is put into use, but also when the parts of the machine tool are repaired or replaced and put into use again.
The occasional failure period is also called the effective failure period. In this period, the failure rate is the lowest and the failure rate is constant. Under normal circumstances, this stage should not cause the main failure. It is the best working period for die casting cnc processing. However, due to improper use, operating errors or other unexpected reasons, some failures can also be caused. In addition, if some components are designed with a small safety factor and encounter the upper limit of the load in use, they may be damaged due to overload and malfunction. Therefore, special attention should be paid to reasonable use during the accidental failure stage, maintenance should be strengthened, operation errors should be avoided, and the effective life of the machine tool should be extended as much as possible.
After entering the failure period of CNC machining loss of die castings, the failure rate has risen again due to the normal wear and tear of machine tool parts, chemical corrosion, changes in physical and electrical properties, and material fatigue. For CNC machine tools, if various diagnostic techniques can be used to master the wear and tear of parts and components, and corresponding maintenance or replacement measures can be taken before the parts enter their failure period, the occurrence of wear failures can be controlled, and the CNC machining of the equipment can be extended. Actual life.