1. Introduction
1.1 Overview of CNC technology
CNC (computer numerical control) technology is the core support for the digital transformation of the manufacturing industry, which accurately controls the movement of machine tools through computer programs to realize the automatic processing of various materials. Compared with traditional manual operation, CNC technology not only controls the machining error to the micron level, but also greatly improves production efficiency - according to industry data, the average production efficiency of CNC machining production lines is more than 40% higher than that of traditional production lines. Today, this technology has been widely used in many high-end manufacturing fields such as aerospace, automobile manufacturing, and precision electronics, and has become an important symbol to measure the production strength of enterprises.
1.2 The importance of CNC tools
If CNC machines are the "precision brains" of the manufacturing industry, then CNC tools are the "key siblings" to achieve machining needs. High-quality and adapted CNC tools can give full play to the precision advantages of machine tools, otherwise it will lead to a decrease in machining accuracy, aggravated tool loss, and even affect the product qualification rate. The practical case of an auto parts company shows that when machining the engine block, the product qualification rate has increased from 89% to 98.5% and the frequency of tool replacement has been reduced by 60%, which fully confirms the decisive role of CNC tools in production.
2. Basic classification of CNC tools
2.1 Tool type
Tools are the core tools that directly act on the workpiece in CNC machining, which can be subdivided into the following three categories according to the processing method and function:
2.1.1 Cutting tools
It is mainly used for cutting the workpiece, removing excess material to form the desired shape. Its core feature is high hardness and wear resistance, and common materials include high-speed steel, carbide, etc. In precision machining, cemented carbide cutting tools account for more than 70% of the application due to their high temperature resistance (can withstand 800-1000°C processing temperature) and high cutting efficiency.
2.1.2 Milling cutter
It is suitable for milling processing of various contours such as planes, grooves, and curved surfaces, and can be divided into end mills, end mills, etc. according to the distribution of tool teeth. For example, in mold machining, ball end mills can accurately machine complex surfaces, while end mills excel in surface finishing.
2.1.3 Drill bits
Focus on drilling workpieces, with key performance indicators such as drilling accuracy and chip evacuation capabilities. Straight shank twist drills are the most commonly used type and are widely used for drilling in common metal materials; For stainless steel materials with high hardness, cobalt-containing twist drills are usually selected.
2.2 Fixtures and fixtures
2.2.1 Functions of the fixture
The core function is to fix the position of the workpiece, ensure that the workpiece does not displace during the processing process, and at the same time ensure the relative position accuracy of the workpiece and the machine tool spindle. High-quality fixtures reduce clamping time and improve consistency in batch processing.
2.2.2 Common fixture types
| Fixture type | Core strengths | Applicable scenarios |
|---|---|---|
| Flat mouth pliers | Simple structure and quick clamping | Processing of small flat plate workpieces |
| Three-jaw chuck | Automatic centering and clamping stability | Batch processing of round workpieces |
| Vacuum suction cup | No clamping marks and uniform force | Thin-walled, precision sheet processing |
2.3 Measuring tools
2.3.1 The role of measuring tools
Throughout the entire process of CNC machining, from workpiece positioning and calibration before machining, to real-time dimensional monitoring during processing, to finished product inspection after processing, it is necessary to rely on measuring tools to ensure machining accuracy.
2.3.2 Common measurement tools
- Micrometer: Used to measure the precision dimensions such as outer diameter and thickness of the workpiece, with an accuracy of up to 0.001mm;
- Dial table: mainly detect the flatness and circular runout tolerance of the workpiece;
- CMM: Suitable for multi-dimensional dimensional measurement of complex workpieces, it is the core equipment for quality inspection in high-end manufacturing.
3. Application of various CNC tools
3.1 Application of tools in machining different materials
The physical properties of different materials vary greatly, and the requirements for tools are also very different. Take the practice of an aviation parts company in processing titanium alloy and aluminum alloy workpieces as an example: when machining titanium alloy, use a cemented carbide milling cutter with a special coating (such as TiAlN coating), and use low-speed and large feed processing parameters to avoid tool wear caused by high temperature; while when processing aluminum alloy, use high-speed steel drill bits and end mills to use their good chip removal performance to prevent aluminum chip adhesion from affecting the machining accuracy.
3.2 The importance of fixtures in the production line
In mass production scenarios, the adaptability of the fixture directly determines production efficiency and product consistency. When producing mobile phone middle frames, an electronic component processing factory initially used ordinary flat pliers to clamp, and the single piece clamping time took 2 minutes, and the scrap rate reached 5% due to positioning errors. After subsequently replacing with customized vacuum suction cup fixtures, the clamping time was shortened to 30 seconds, the scrap rate was reduced to 0.8%, and the production line capacity was increased by 30%.
3.3 The role of measuring tools in quality control
Measuring tools are the "eyes" of quality control. When processing injection molds, a precision mold factory uses a coordinate measuring instrument to detect 100% of the key dimensions of the mold cavity, controlling the dimensional error within ±0.005mm to ensure that the accuracy of the injection molded product meets customer requirements. If there is a lack of accurate measurement tools, once the dimensional deviation is not detected in time, it will lead to the scrapping of the entire batch of products and cause significant economic losses.
4. Choose the right CNC tool
4.1 Considerations
4.1.1 Material type
The tool is selected according to the hardness, toughness, thermal conductivity and other characteristics of the workpiece material. For example, carbide or cubic boron nitride (CBN) tools need to be used to process high-hardness steel (HRC50 or above); For processing non-ferrous metals (such as copper and aluminum), high-speed steel tools can be selected.
4.1.2 Machining accuracy requirements
high-precision processing (such as precision molds, aviation parts) requires the selection of high-precision tools, with precision measuring instruments and other precision measuring equipment; For ordinary precision machining (such as general mechanical parts), conventional precision tools can be used to balance accuracy and cost.
4.1.3 Cost and efficiency
For mass production, high-end tools with strong durability can be selected to reduce unit cost by improving efficiency and reducing replacement frequency. When making small batches of trial production, cost-effective conventional tools can be used to control the initial input.
4.2 Common misunderstandings and suggestions
Common misunderstandings include: blindly pursuing high-end tools and ignoring the adaptability to workpieces and machine tools; Only focus on tool price, ignoring tool life and processing efficiency. Recommendation: Prioritize the adaptability of tools to processing needs when choosing, and consult the professional technicians of the tool supplier; Conduct small-batch trials before bulk purchases to verify the performance and stability of the tool. Establish a tool usage ledger to record the service life and processing effect of the tool, and provide data support for subsequent selection.
5. Conclusion
Different types of CNC tools play different key roles in the machining process, and their selection and application directly impact machining accuracy, production efficiency, and product quality. From basic tools and fixtures to precision measuring tools, each type of tool needs to be scientifically selected based on workpiece materials, machining requirements, and cost budgets. Mastering the classification, application and selection methods of CNC tools is the core prerequisite for improving the level of CNC machining, and it can also lay a solid manufacturing foundation for enterprises in the fierce market competition.
Yigu Technology view
As an enterprise deeply involved in the field of intelligent manufacturing, Yigu Technology believes that the iteration of CNC tools complements the development of CNC technology. At present, with the advancement of Industry 4.0, intelligent CNC tools (such as tools with wear monitoring functions, automated fixtures) are becoming an industry trend. While paying attention to the adaptation of tool types, enterprises should pay more attention to the intelligent upgrade of tools, and realize the digital control of the whole processing process through the collaboration of tools, machine tools and control systems. In the future, we will continue to promote the integration of CNC tools and intelligent technology to provide customers with more efficient and accurate manufacturing solutions.
FAQ
Q1: Can different types of CNC tools be used universally?
It cannot be universal. Different types of CNC tools have different machining methods (cutting, milling, drilling) and workpiece shapes, such as milling cutters cannot replace drills for precise drilling. The corresponding type of tool needs to be selected according to the specific processing needs.
Q2: What factors are prioritized when choosing CNC fixtures?
Prioritize the shape, size, and processing method of the workpiece to ensure that the fixture can hold the workpiece stably; secondly, consider the clamping efficiency, especially the mass production scenario needs to pay attention to the clamping speed; Finally, take into account the versatility and cost of the fixture to avoid excessive customization leading to high cost of later use.
Q3: Do precision measuring tools require regular calibration?
Yes. The accuracy of precision measurement tools will shift with the use time and environmental changes, and regular calibration is the key to ensuring measurement accuracy. It is recommended to have a calibration schedule based on the type of tool and frequency of use, and in general, the core measurement tool is calibrated every 3-6 months.
