This article will systematically break down the core knowledge of milling engineering for you, from basic cognition to practical steps, to advanced techniques, and help you build a complete knowledge system in easy-to-understand conversational language. Whether you are new to milling engineering or an experienced technician looking to improve your skills, you can get practical operation methods and professional insights.
1. Introduction
1.1 What is milling engineering?
Milling engineering is a core branch of mechanical manufacturing, which refers to the engineering technology of cutting the workpiece by driving the milling cutter to rotate through a milling machine tool to obtain the desired shape, size and surface quality. In simple terms, it is like "machining engraving", through the relative movement of the tool and the workpiece, excess material is removed, and the shape of the workpiece is accurately shaped. For example, the processing of daily automobile engine blocks and mobile phone frames is inseparable from the support of milling projects.
1.2 The importance of milling engineering
Milling engineering occupies an indispensable position in the manufacturing industry, and its importance is reflected in three core dimensions: first, it has a wide range of processing, which can handle a variety of materials such as steel, aluminum, copper, plastic, etc., covering aerospace, automotive, electronics, molds and other industries; second, high processing accuracy, modern milling technology can achieve micron-level accuracy to meet the manufacturing needs of high-end products; Third, the production efficiency is excellent, and mass production can be achieved with automation equipment to reduce unit costs. According to industry data, milling accounts for more than 35% of the global machining industry, making it one of the most widely used cutting methods.
2. Basic knowledge of milling engineering
2.1 Definition and principle of milling
Milling is a cutting method that uses the rotational motion of the milling cutter as the main motion and the linear or curved motion of the workpiece as the feed motion, and the two work together to complete the material removal. Its core principle is to alternately cut multiple distributed cutting edges on the milling cutter, reducing the load on a single cutting edge while improving machining efficiency. Unlike turning, milling can realize the processing of various features such as planes, grooves, gears, and curved surfaces, and the application scenarios are more flexible.
2.2 Types of milling machine tools
Common milling machine tools can be divided into the following categories according to control methods and structures, the specific comparisons are as follows:
| Machine type | Core features: | Applicable scenarios | Machining accuracy |
|---|---|---|---|
| Ordinary milling machine (vertical/horizontal) | Manual or semi-automatic control, low operating threshold and affordable cost | Simple parts processing, small batch production | ±0.02~±0.05mm |
| CNC Milling Machine (CNC) | Computer program control, high degree of automation, strong stability | Complex parts, medium and medium series production | ±0.005~±0.02mm |
| Machining centers | Integrated milling, drilling, boring and other functions, automatic tool change | High-precision complex parts, mass production | ±0.001~±0.005mm |
2.3 Common milling tools and materials
Commonly used milling tools can be divided into flat milling cutters, end mills, end mills, keyway mills, etc. according to their uses, and their material selection directly affects the machining effect. The following are the applications of mainstream milling cutter materials:
- High-speed steel milling cutter: good toughness, impact resistance, suitable for processing mild steel, cast iron and other materials, low cost, often used in ordinary milling machines;
- Carbide milling cutter: high hardness, high temperature resistance, can process high-strength steel, aluminum alloy, etc., the service life is 5~10 times that of high-speed steel, is the mainstream choice of CNC milling;
- PCD/PCBN milling cutter: superhard material, suitable for processing non-ferrous metals and superhard materials, high processing accuracy, but high cost, mostly used for high-end precision machining.
3. Steps of the milling process
3.1 Preparation and material selection
Preliminary preparation is the basis for ensuring milling quality, and the core steps include: first, clarify the processing requirements of the workpiece, such as dimensional tolerance, surface roughness, etc.; secondly, choose suitable materials according to requirements, such as machining high-precision parts, preferring quenched and tempered alloy structural steel; Finally, check the material condition and remove impurities such as oxide scale and burrs on the surface. Case sharing: When processing engine connecting rods in an auto parts factory, the tool wear out too quickly during the milling process due to the failure to check the hardness of the material in advance, and the scrap rate reached 15%.
3.2 Machine tool setting and debugging
The machine tool setting should be operated according to the following process: (1) install the fixture to ensure that the fixture is tightly fitted to the worktable, and the positioning accuracy error is controlled within 0.01mm; (2) clamp the workpiece to avoid the workpiece deformation caused by over-clamping, or the displacement during machining caused by too looseness; (3) install the milling cutter and check the tool runout to ensure that it is within 0.005mm; (4) set the machining parameters to determine the cutting speed, feed and back eating amount according to the material and tool material. In the commissioning stage, trial cutting is required, and the parameters are fine-tuned until the requirements are met by measuring the size of the test piece.
3.3 Execution of milling operations
When formal milling, it is necessary to follow the principle of "empty operation first, then formal cutting": first start the machine tool to let the milling cutter idle, and check whether the motion trajectory is normal; During the cutting process, the operating status of the machine tool, tool wear and the surface quality of the workpiece are observed in real time to avoid problems such as chatter and edged accumulation. If complex curved surfaces are processed, layered cutting is required to gradually remove material to ensure machining accuracy.
3.4 Quality control and testing
After the processing is completed, it needs to be tested by professional equipment: vernier calipers, micrometers, coordinate measuring instruments, etc. can be used for dimensional inspection, and surface roughness can be detected by roughness meter. Focus on the tolerance range of key dimensions, such as the flatness requirement of a precision mold part ≤ 0.003mm, which needs to be inspected in all directions by a coordinate measuring instrument. If unqualified products are found, the cause should be analyzed, and the processing parameters or tools should be adjusted to avoid the recurrence of the problem.
4. Advanced technology of milling engineering
4.1 CNC milling technology
CNC Milling is the core advanced technology of modern milling engineering, which realizes automated and high-precision machining of machine tools by writing programs such as G code and M code. Its advantage is that it can process complex special-shaped parts, and the processing stability and consistency are strong, making it suitable for mass production. At present, the mainstream CNC systems include Fanuc, Siemens, Mitsubishi, etc., and the operation logic of different systems is slightly different, but the core principles are the same. With the development of Industry 4.0, CNC milling is gradually developing in the direction of intelligence, which can realize functions such as automatic tool wear monitoring and adaptive adjustment of machining parameters.
4.2 Tool management and optimization
Tool management is the key to improving milling efficiency and reducing costs, and the core optimization measures include: (1) Establish a tool life ledger, set a reasonable tool replacement cycle according to the processing material and working conditions, and avoid excessive wear affecting the machining quality; (2) The tool preset instrument is used to adjust the length and radius compensation value of the tool in advance to reduce the debugging time of the machine tool; (3) Choose coated tools, such as TiN and TiAlN coatings, which can improve the hardness and lubricity of the tools and extend the service life by more than 30%.
4.3 Innovation and development of milling processes
The current innovation direction of milling technology is mainly focused on three major areas: high-speed milling, micro-milling and green milling: the cutting speed of high-speed milling can reach 1000~5000m/min, which can greatly improve the processing efficiency and improve the quality of the machining surface; Micro milling is mainly used for micro parts processing, which can achieve micron-level material removal, and is suitable for high-end fields such as electronics and medical care. Green milling reduces energy consumption and environmental pollution by using environmentally friendly cutting fluids and optimizing machining parameters, which is in line with the concept of sustainable development.
5. Conclusion
Mastering milling engineering requires starting from basic cognition, gradually mastering core skills such as machine tool operation, process setting, and quality control, and then advancing to advanced technologies such as CNC milling. Its core lies in combining theoretical knowledge with practical experience, and improving machining accuracy and efficiency by continuously summarizing cases and optimizing parameters. With the intelligent upgrading of the manufacturing industry, milling engineering will develop in the direction of more efficient, more precise and more environmentally friendly, and practitioners need to continue to learn new technologies to adapt to the development needs of the industry.
【Yigu Technology's Opinion】As the basic core technology of the manufacturing industry, milling engineering directly promotes the development of high-end manufacturing. Yigu Technology believes that the competitiveness of milling engineering in the future will be concentrated in "intelligence + precision", and enterprises need to strengthen the integration of CNC system and intelligent monitoring technology, while paying attention to talent training, so that technicians have both theoretical depth and practical ability. We will also continue to invest in research and development to provide more efficient intelligent monitoring equipment and solutions for the field of milling engineering to help the high-quality development of the industry.
FAQ
1. What is the core difference between milling and turning engineering? The core difference lies in the main motion and processing range: milling is mainly based on the rotation of the milling cutter, which can process various features such as planes, grooves, and curved surfaces; Turning is mainly used for the processing of shaft and disc parts, and the processing range is relatively single.
2. What core knowledge do I need to master to get started with CNC milling? It is necessary to master three core knowledge: first, the basic principles of CNC milling and machine tool structure; second, programming basics such as G code and M code; The third is tool selection, parameter setting and clamping skills, and basic quality inspection capabilities are required.
3. How can I troubleshoot chatter issues during milling? It can be solved in four aspects: (1) reduce the cutting speed or feed and reduce the cutting load; (2) Increase the diameter of the tool or shorten the protruding length of the tool to improve the rigidity of the tool; (3) Reinforce the workpiece clamping to avoid loosening the workpiece; (4) Check the gap of the machine tool guide rail and adjust the fastening in time.
4. What are the types of cutting fluids commonly used in milling projects, and how to choose them? Commonly used cutting fluids are divided into two categories: oil-based and water-based: oil-based cutting fluids have good lubricity and are suitable for processing high-strength steel, cast iron, etc.; Water-based cutting fluid has excellent cooling properties, making it suitable for high-speed milling and machining aluminum alloys. When choosing, it is necessary to make a comprehensive judgment based on the processing material, tool material and processing conditions.
