Factors affecting the quality of cnc machined precision parts

Nowadays, mechanization and automation have become the mainstream of industry development. Machine and equipment composed of various parts are prone to problems in the application process due to the lack of coordination or cooperation of certain parts. Raw material specifications, properties, material use, machine vibration, clamping pressure or looseness, elastic deformation process system, worker operation, testing methods, and inspector errors all have an impact on the quality of processed products. When we talk about the quality of working prototypes, it is not difficult to think of the following 5 main factors.

I. , operator
As cnc machine functions become more and more complex, the level of programming and operator varies greatly . Combining superior human skills with computer information technology allows for maximum utilization of the machine. To do this, the machine operator must be familiar with the equipment performance. If the operator does not know enough about the performance of the equipment, he or she may operate it incorrectly, thus accelerating the wear and tear of machine components or even causing damage to the machine.

Therefore, this will require a lot of maintenance costs and longer maintenance time. cnc machine tool operators in order to restore the original accuracy of the equipment, must understand and master the machine manual and its operating precautions to achieve civilized production and safe processing. To strengthen the skills training of the whole staff of processing production, reasonable arrangement of primary and secondary processing positions, improve the quality awareness of personnel and sense of work responsibility.

II. Machine

A complete cnc machining system consists of machine tools, workpieces, fixtures and tools. The machining accuracy is related to the accuracy of the whole process system. Various errors of the process system will be reflected in different forms as machining tolerances under different circumstances. 

cnc machine accuracy is an important factor affecting the quality of prototype parts. When the machine accuracy is poor, some parts are damaged or the clearance of each part is not adjusted properly, various defects will appear in the prototype during cnc machining.

Therefore, we must not only choose the right turning angle, the right cutting volume and cnc machining method, but also understand the impact of machine accuracy on the quality of cnc machining. The maintenance of the machine directly affects the processing quality and productivity of the prototype. In order to ensure the working accuracy and extend its working life, all machines must be properly maintained. Usually after 500 hours of machine operation, a level of maintenance is required.

Three, cnc machining methods

There are many kinds of cnc machining methods, and cutting machining is one of the most common ones. In the cutting process, the workpiece is subjected to changes in force and heat, and the physical and mechanical properties of the metal material are slightly hardened, so the choice of the tool plays an important role.

In general, the material used to make the tool should be selected according to the material of the workpiece to be machined. Otherwise, the surface of the workpiece will form spurs related to the tool, which will easily increase the roughness of the workpiece and at the same time reduce the surface quality. In addition to the tool factor, the cutting environment and cutting processing conditions, such as cutting volume, cutting lubrication, etc. also have an impact on the machining quality.

In the cnc machining process, the machining system is the overall commander of the entire cutting process. All the cnc machining process is executed according to the system, so the accuracy and rigidity of the machining system is also one of the main factors affecting the machining quality.

There are two principles of machining process arrangement.

Machining decentralization: manufacturing complex parts with multiple processes, broken down into multiple machine processing.
Machining concentration: compound machine functions, such as cnc turning and milling, laser ultrasonic vibration processing, grinding, five-axis linkage, etc.

All processes are completed by one machine. According to the structural analysis of the workpiece, the use of different processing methods is also an important factor affecting the quality of machining.

IV. Materials

Machined materials are generally divided into plastic and metal. Each material has its own characteristics. It is also important to choose the right material according to the requirements of the workpiece and the application during machining. The consistency of the material should be good, otherwise the quality of the same part may be different. With the right material hardness, try to ensure that the material is not deformed. These are important prerequisites for assessing quality.

V. Inspection

After the machine has finished machining the workpiece, inspection is the last key step before delivery to the customer. Machining inspection generally requires attention to two aspects.

1. inspection procedures - the inspection process, including the inspection process, as well as relevant regulations, systems, standards, etc.. In general, the inspection process is the inspection in the production process and the way to intervene, including the first inspection, self-inspection, mutual inspection and full-time inspection.

2. Inspection methods - refers to how to test and inspection standards. The inspection of machined parts is generally based on mechanical drawings, through inspection instruments and gauges for product inspection.

Traditional machining inspection and more modern machining inspection

Traditional machining inspection instruments include micrometers, percentages, vernier cards, planes, rulers, levels, and a variety of plug gauges, ring gauges, etc.. More modern machining inspection instruments are optical collimator, projector, three-dimensional measuring instrument, latitude and longitude meter, laser detector, etc.

Qualified mechanical product inspector must master the knowledge of inspection instruments and gauges related to the unit product.
In the process of cnc machining, to control the quality of processing, it is necessary to understand and analyze the various factors affecting the quality of processing does not meet the requirements, while taking effective technical measures to overcome.

With the continuous improvement of modern production levels, the requirements for the quality of machined products are becoming higher and higher. Only by taking comprehensive measures for quality control can we ultimately achieve the purpose of improving the service life of the equipment and increasing the service life of the equipment, taking into account the economic benefits and energy saving in the processing process. At the same time, to ensure the quality of machining, in order to promote the long-term stable development of the machining industry.