China Cnc Milling Service – What Is Cnc Milling – Plunge Precision Milling Machining

Workable Materials: we can do CNC machining for most of the machinable metals and plastics.

Include but not limited to:

• Aluminum alloy: 6060, 6061, 6082,7075, 2014.
• Brass alloy, Bronze alloy, Copper, Titanium alloy.
• Steel: 1010, 1018,1020, 1045,12L14,4140, 4130,42CrMo
• Stainless steel: 303, 304, 316, 316L, 17-4, 17-4PH
• Plastics: ABS, Acetal, Delrin, Nylon, HDPE, Polypropylene,PET, PTFE, PVC, Teflon

Application: metal parts for electronic component, office equipment, auto parts, computer, mobile phone, etc.

Our secondary operation including Deburring, Drilling, Tapping, Sand Blasting, Anodizing, Hard Oxidation, Plating, Polishing, Grinding,, Heat Treating Salt Spray Testing, Painting, Powder Coating, Screen Printing, Ultrasonic Cleaning, Spot Welding , Riveting, subassembly and more.Whatever you need prototypes or production parts, our machining services will be your best choice. Contact us via Email:[email protected] today to get your machining parts done in as fast as 5 days!

Cnc Milling Define

The development of science and technology and the rise and continuous maturity of the world’s advanced manufacturing technology have put forward higher requirements for CNC machining technology; the application of ultra-high-speed cutting, ultra-precision machining and other technologies has greatly affected the CNC system, servo performance, and spindle drive of CNC machine tools. The rapid development of FMS and the continuous maturity of CIMS will put forward higher requirements for the reliability, communication function, artificial intelligence and adaptive control of CNC machine tools. With the development of microelectronics and computer technology, the performance of numerical control system is improving day by day, and the application field of numerical control technology is expanding day by day.

CNC milling machine is a CNC machine tool with strong processing functions. The rapidly developed machining centers and flexible machining units are all based on CNC milling machines and CNC boring machines, both of which are inseparable from milling methods. Because the CNC milling process is the most complex and the technical problems that need to be solved are the most, people have always focused on milling when researching and developing software for CNC systems and automatic programming languages.

The Emergence And Development Of CNC Machine

With the rapid development of social production and science and technology, mechanical products are becoming more sophisticated and complex, and require frequent modifications, especially for mechanical parts required in aerospace, shipbuilding, military and other fields, with high precision requirements, complex shapes and small batches. Processing such products requires frequent modification or adjustment of equipment, and ordinary machine tools or automated machine tools with a high degree of specialization can no longer meet these requirements. In order to solve the above problems, a new type of machine tool – CNC machine tool came into being. This new type of machine tool has the advantages of strong adaptability, high machining accuracy, stable machining quality and high production efficiency. It comprehensively applies the technical achievements of electronic computer, automatic control, servo drive, precision measurement and new mechanical structure, and is the development direction of CNC machine tools in the future.
The production of CNC machine tools

The world’s first successfully developed CNC machine tool is a three-coordinate CNC milling machine, which was completed in 1952 by the American Parsons Corporation (Parsons) and the Massachusetts Institute of Technology (MIT). As early as 1948, the United States put forward the initial idea of ​​developing a CNC machine tool when it was developing the task of processing a machine tool for processing helicopter blade contour inspection templates. In 1949, with the support of the US Air Force Department, Parsons officially accepted the commission to cooperate with the MIT Servo Mechanism Laboratory and began to engage in the development of CNC machine tools. After three years of research, the world’s first experimental prototype of CNC machine tools was successfully trial-produced in 1952. This is a true line interpolation three-coordinate continuous control milling machine using the principle of pulse multiplier. Its control device consists of more than 2,000 electronic tubes, occupying the size of an ordinary laboratory. The birth of this CNC milling machine marks the beginning of the digital control era of mechanical manufacturing.

CNC Milling Machine Processing

The shape of the machined surface of the milling machine is generally composed of straight lines, arcs or other curves. Ordinary milling machine operators according to the requirements of the drawing. Constantly changing the relative position between the tool and the workpiece, and then coordinating with the selected milling cutter speed, the tool can cut the workpiece, and various shapes of workpieces can be processed.

CNC machining is to divide the motion coordinates of the tool and the workpiece into the smallest unit, that is, the smallest displacement. According to the requirements of the workpiece program, the numerical control system moves each coordinate by several minimum displacements, so as to realize the relative movement of the tool and the workpiece to complete the machining of the parts.
Features

In addition to the characteristics of ordinary milling machine processing, CNC milling has the following characteristics:

1. The parts have strong adaptability and flexibility, and can process parts with particularly complex contours or difficult to control dimensions, such as mold parts, shell parts, etc.;
2. It can process parts that cannot be processed by ordinary machine tools or are difficult to process, such as complex curve parts and three-dimensional space surface parts described by mathematical models;
3. Parts that need to be processed in multiple processes after one clamping and positioning can be processed;
4. High processing precision, stable and reliable processing quality, the pulse equivalent of the numerical control device is generally 0.001mm, and the high-precision numerical control system can reach 0.1μm. In addition, the numerical control processing also avoids the operator’s operating errors;
5. The production automation is high, which can reduce the labor intensity of the operator. Conducive to production management automation;
6. High production efficiency. CNC milling machines generally do not need to use special process equipment such as special fixtures. When replacing workpieces, it is only necessary to call the processing programs, clamping tools and adjustment tool data stored in the CNC device, thus greatly shortening production. cycle. Secondly, the CNC milling machine has the functions of milling machine, boring machine and drilling machine, which makes the process highly concentrated and greatly improves the production efficiency. In addition, the spindle speed and feed speed of the CNC milling machine are infinitely variable, so it is beneficial to choose the best cutting amount;

What Is Plunge Milling

Manufacturing is the basic industry that creates material wealth in social life, and is an important and indispensable part of the national economy. Manufacturing is a direct reflection of a country’s productivity level. Throughout history and at home and abroad, the manufacturing industry of any world power occupies an important position in the national economy. Improving my country’s manufacturing level will help improve my country’s comprehensive national strength and international competitiveness, help ensure the smooth operation of the national economy and the prosperity and stability of social life, and help improve my country’s ability to respond to emergencies. At present, my country has become the only country in the world that has all the industrial categories listed in the United Nations Industrial Classification. The output value of my country’s manufacturing industry has surpassed the United States to become the first in the world. It is a veritable first manufacturing industry with a complete industrial system. Great country. “Large and comprehensive” is an important feature of my country’s manufacturing industry.

Although my country has become the world’s largest manufacturing power, it is “big but not strong”, and there is still a certain gap between it and a manufacturing power. Especially in recent years, Western countries represented by the United States have put forward measures to “return to manufacturing” after recognizing the social problems brought about by the relocation of manufacturing industries; developing countries represented by Vietnam rely on low labor costs The advantages of vigorously develop the manufacturing industry. However, my country is facing the pressure of rising production costs including labor costs year by year, which can be described as “internal and external troubles”. Therefore, we must improve the core competitiveness of my country’s manufacturing industry, improve the manufacturing capacity of major core equipment and its components, and key basic equipment, and master advanced manufacturing technologies including advanced machining technology and advanced machining tools to ensure product quality. machining quality, improve production efficiency, reduce production costs, and improve product competitiveness.

The integral impeller is the core component of major equipment such as large centrifugal compressors and high-thrust aero-engines, and molds are key basic equipment widely used in the manufacturing industry. Large-scale centrifugal compressors are important equipment related to national industrial development and stable social and economic operation, and are widely used in important fields such as petrochemicals and natural gas transportation. Therefore, large centrifugal compressors have extremely high requirements for their stability and reliability during use. Generally speaking, an overhaul period of large centrifugal compressors is as long as 1 year or even 3 years, and the equipment is not allowed during the overhaul period. down. The impeller is the core component of the centrifugal compressor, which is called the heart of the centrifugal compressor. The quality of the impeller directly affects the reliability of the centrifugal compressor. In order to ensure the stable operation of large centrifugal compressors, the impeller generally adopts integral impeller, and the impeller material is generally high-strength stainless steel. The integral impeller is also the core component of the aero-engine. Aero-engines are known as the jewel in the crown of human industry, representing the most advanced industrial technology of human beings. Compared with aero-engines, large thrust-weight is more related to the national defense security. With the official service of China’s fifth-generation fighter jets, the demand for large thrust-weight ratio aero-engines is more urgent, and the use of integral impellers instead of conventional impellers is an effective way to improve the thrust-weight ratio of aero-engines.

Plunge milling is an efficient roughing technique, also known as Z-axis milling, that can be traced back more than 60 years to the traditional process of axially feeding a form mill to machine bullets. As shown in Figure 1.3, plunge milling completes the feed movement of the tool along the axial direction during the machining process. When a certain machining position reaches the machining depth, the tool is lifted and stepped to the next machining position, and the cutting continues along the axial direction. Repeat the feeding-knife-lifting-stepping movement until the machining of the cavity is completed. Therefore, plunge milling has the characteristics of axial feed, small radial force, and stable cutting, and can perform efficient machining of deep groove cavities. There are two main processing methods for plunging: slot plunging and wall plunging. There are also forming plunging tools for chamfering, round holes, and cylindrical arrays, but they are relatively rare. Wall plunging mainly utilizes the features of axial feed in plunging to complete the finishing of the side walls with high verticality requirements. Slotting and plunging has the advantages of small radial force and stable cutting. Large cutting parameters can be used for efficient plunging, and efficient machining of deep-slotted cavity parts can be achieved. Slotting and plunging is the most widely used machining method in plunging.

The double-row slotting milling method [9] is an efficient slotting milling method. The double-row slotting processing of the impeller flow channel is shown in Figure 1.4. Since the diameter of the tool is a standardized sequence, when grooving the pocket, the diameter of the tool can be selected according to the formula H/2, where H is the width of the pocket and D is the diameter of the plunging tool. In this way, only two rows of plunge milling tool paths are needed to complete the machining of the cavity, which not only ensures the machining efficiency, but also meets the machining of complex cavity.

Plunge milling, however, has been plagued by cutting shock issues. As shown in Figure 1.5, when performing double-row slotting plunging, the first row is full-width plunging, and the cutting area is a complete crescent shape. The tool gradually cuts in and out of the workpiece during cutting, and the cutting force changes. Relatively gentle; the second column is half-width plunging. At the cut-in position of climb milling and the cut-out position of up-cut milling, the contact width between the tool and the workpiece suddenly increases or decreases, and the cutting force will change abruptly, resulting in a large Impact load. Since the width of the cavity varies randomly, and the tool size is a standardized sequence, the two-column tool path is almost the minimum number. When performing slotting and plunging with more than two columns, except the first column is full-width plunging, the subsequent Several rows are half-width plunging, so half-width plunging is unavoidable and more common in slotting plunging. In particular, because the tool lifting movement in plunge milling is an idle stroke, plunge milling has more advantageous machining efficiency than layer milling, and the material removal rate during the machining is at least twice that of layer milling, so In plunge milling, high-efficiency cutting with large cutting parameters is generally required, which in turn leads to more significant cutting impact problems. Shock loads can generate several times the failure stress of static or quasi-static loads at the same amplitude [10]. Because of the impact load, carbide inserts are prone to breakage and failure, which limits the tool life of half-width plunge milling, which results in frequent insert replacement during machining. Moreover, the size of the insert of the plunging tool protruding from the tool body is small. If the insert is damaged and cannot be replaced in time, the cutting conditions will deteriorate rapidly, and even lead to the direct contact between the tool body and the workpiece, resulting in damage to the tool body. will damage the workpiece. The problem of premature tool failure caused by impact load in half-width plunge milling not only increases the cost of the tool, but also reduces the machining reliability, increases the auxiliary working time and labor intensity of the workers during the machining, and reduces the plunge milling. The high machining efficiency has become a bottleneck restricting the wide application of plunge milling technology. Therefore, research on this issue is of great significance.

The Impact Characteristics of Cutting Force in the Efficient Plunge Milling

The integral impeller is the core component of the centrifugal compressor and the mold is widely used in the processing of industrial products, both of which have typical cavity structures in structure. When processing the cavity, large amount of material is removed with the low processing efficiency.

The plunge milling process can significantly improve the cavity processing efficiency, but when performing high-efficiency plunge milling, especially the half width and high-efficiency plunge milling, there is a significant impact at the cut-in position of down milling and cut-out position of up milling which can lead to a significant reduction in the service life of milling tools. Aiming at this problem, this paper studies the factors and laws that affect the cutting impact force and analyzes the failure process of plunge milling tools and designs plunge milling tools based on the principle of wave chip separation. The main research contents are as follows: Firstly, the cutting characteristics of plunge milling and the main factors affecting the cutting impact are analyzed, and then the plunge milling experiment is designed and carried out accordingly.

A single variable method is used to cut 40Cr material with a single-edge plunge milling tool, and then the plunge cutting force is measured to analyze the influence of cutting parameters and tool geometry parameters on cutting impact. The study found that the plunge milling impact is the largest when the radial depth of cutting is equal to half width of the radius of the tool, and plunge milling impact is the smallest when the radial depth of cutting is equal to full width of the radius of the tool. The cutting force increases with the increase of cutting speed, feed rate and plunge step, but the influence degree is different that he feed rate has the greatest influence, the slotting step is the second, and the cutting speed has the smallest influence. The cutting impact is the smallest when the tool’s main declination angle is 93° to 96° and the blade inclination angle is about 5°. Secondly, the tool’s failure process and tool life when cutting 40Cr alloy steel and FV520B stainless steel wire by different plunge milling techniques are studied. Through experiments, it is found that the failure of plunge milling tool is the result of the combined action of wear and damage.

The failure process can be divided into three stages: early stage, middle stage and late stage, in which the early and middle stages are mainly worn, and the late stage is mainly damaged. When plunge milling 40Cr alloy steel, the cutting temperature is the main factor that affects the tool life and he tool life is the shortest when the full width plunge milling is used, so that the up milling method should be preferred when half width plunge milling.

When plunge milling FV520B stainless steel, the problem of impact is the main factor that affects the tool life and the tool life of the half width plunge milling is shorter than that of the full width plunge milling. At the same time, the up milling method should be avoided when the half width plunge milling FV520B. Finally, the cutting characteristics of the wave edge plunge milling tool are analyzed and it is found that the wave edge can increase the cutting thickness and the cutting width in the plunge milling, which are beneficial to reduce cutting deformation, cutting force and cutting temperature.

Wave edge plunge milling tool was designed using the three-blade chip splitting scheme and the cutting experiments were carried out to compare the cutting performance of wave edge plunge milling tool, chip slot plunge milling tool and straight edge plunge milling tool. During the cutting process, the cutting force of wave edge milling tool is significantly lower than the cutting force of chip slot plunge milling tool and straight edge plunge milling tool, which shows that the wave cutting edge can effectively reduce plunge milling cutting force.