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CNC, machine tool machining center, also called CNC system, is the control part of the machining center machine tool. It generates a CNC machining program by human-computer interaction according to the input part drawing information, process, and process parameters, and then through the servo drive system, drives the machine components to do the corresponding action.
CNC machining development history
In the traditional CNC machine tools, processing information is usually stored through the NC paper tape, and read through the photoelectric reader to realize the machine tool processing control. With technological advances, computer numerical control systems came into being, with higher functionality, the ability to read all the machining information into the computer memory at once, avoiding the need to frequently start the reader. More advanced CNC machine tools can even eliminate the need for photoelectric readers, through the computer directly programmed or interfaced with the CAPP (Computer Aided Process Planning) system to achieve automatic programming. This type of CNC machine tool has become an important part of the Computer Integrated Manufacturing System (CIMS).
Modern CNC System Functions
Modern CNCs have many advanced features designed to improve machining accuracy, increase productivity, and ensure machine stability. The following are the core functions of a CNC system:
1. Multi-axis coordinated control
Supports simultaneous control of multiple axes, capable of handling complex machining tasks, significantly improving machining accuracy and process complexity, and suitable for high-precision, high-complexity parts machining.
2. Tool position compensation
According to the wear and tear of the tool in actual machining, the system automatically compensates the position to ensure that the size and shape of each workpiece in the machining process meets the requirements, to improve the machining accuracy and stability.
3. System fault diagnosis
Real-time monitoring of the operating status of the CNC system, automatic detection, and diagnosis of potential faults, to help operators quickly find the problem and maintenance, to improve the reliability and stability of the machine tool.
4. Online Programming
Operators can program directly on the CNC machine without relying on an external computer. This not only simplifies the production process but also allows real-time adjustment and optimization of the program to adapt to different machining requirements.
5. Parallel operation of machining and programming
In the machining process, CNC machine tools can be programmed simultaneously, reducing the program preparation time, and thus improving production efficiency, especially suitable for small-batch, diversified production.
6. Machining simulation
Utilizing simulation technology, virtual machining tests are conducted before actual machining. By simulating the machining process, it can predict and avoid possible machining errors and ensure a smooth production process.
7. Tool management and monitoring
The system monitors the use of tools in real-time, including the degree of wear, remaining life, and other information, to help users optimize tool management, timely replacement of tools, and reduce unexpected downtime.
8. Online Inspection
During the machining process, the CNC system can check the machining quality in real-time to ensure that the machining accuracy meets the design requirements. This function helps to find and correct deviations in time, avoiding the generation of defective products.
Application areas of CNC machine tools
CNC machine tools are increasingly being used in a wide range of industries, including aerospace, automotive, food industry, mold making, electrical production, furniture, and other fields. Common types of CNC machine tools include:
CNC lathes: for turning, capable of complex rotationally symmetrical parts processing.CNC milling machine: suitable for milling processing of plane, inclined plane, curved surface, etc..
CNC drilling machine: dedicated to hole processing, including drilling, reaming, reaming, and other operations.
CNC machining center: integrated milling, drilling, and other functions of the machine tool, suitable for multi-process complex processing.
CNC molding EDM machine: mainly used for precision mold processing, complex shapes are processed by EDM.
CNC Wire Cutting: High-precision cutting through fine wire electrodes, widely used in mold manufacturing and precision parts processing.
CNC Water Jet Cutting: utilizing high-pressure water flow for cutting, suitable for cutting materials with high hardness.
CNC Laser Cutting: Utilizing laser beam for precise cutting, commonly used in metal plate and thin plate processing.
CNC Punching Machine: Used for metal plate stamping processing, widely used in metal parts manufacturing.
Furniture CNC machine tools: mainly used in the processing of wood, and plate, widely used in furniture production.
CNC machining technology process
1. CNC Programming
CNC program is generated by G code or CAD/CAM software. Common CAD/CAM software are:
MASTERCAM
PRO/E
UG/II
CATIA
IDEAS
CIMATRON
EDGECAM
This software can generate the corresponding CNC machining path according to the design drawings, and automatically generate the required G code.
2. Preparation and adjustment of fixtures
Fixture is used to fix the parts to ensure the stability and accuracy of the position of the parts during the machining process. Preparation and adjustment of fixtures is a key step to ensure machining accuracy.
3. CNC Operation
The operator operates the machine according to the generated CNC program to perform the actual machining task. The operator needs to have the skillful operation of the CNC machine to ensure that the machining process goes smoothly.
Learn the necessary knowledge and skills of CNC machining technology
Machine operation and debugging: familiar with the basic operation of CNC machine tools and debugging methods.
Machining process and technology: understand the selection and optimization of the machining process to adapt to the processing requirements of different parts.
Selection and management of machining tools: select suitable tools according to the machining tasks and manage the tools.
Fixture and Gage Use: Master the use of fixtures and gauges to ensure machining accuracy and stability.
G-code programming: Familiar with the syntax and application of G-code, able to manually write or optimize programs.
CAD/CAM software operation: master the commonly used CAD/CAM software and be able to design, program, and simulate.
Conclusion
With the continuous progress of technology, modern CNC machine tools and CNC systems have become indispensable core equipment in the manufacturing industry. Their powerful functions not only greatly improve processing accuracy and productivity, but also effectively reduce human error in operation and promote the development of industrial automation and intelligent manufacturing. From the traditional photoelectric readers to modern computer numerical control systems, to today’s highly integrated intelligent machine tools, the evolution of CNC technology has significantly improved the productivity and flexibility of the manufacturing industry.
During the learning process of CNC machining technology, it is crucial to acquire knowledge and skills in machine tool operation, machining processes, tool management, and G-code programming. Only with comprehensive technical literacy can we stand out in the ever-changing market demand and drive enterprises to a higher level of intelligent production.
In the future, with the further application of artificial intelligence, big data, and other emerging technologies, the function of CNC machine tools will be more intelligent and sophisticated, bringing more innovative opportunities and challenges to various industries. For manufacturing industry practitioners, keeping pace with the pace of technological development and improving their own CNC technology capabilities will be the key to enhancing competitiveness and staying ahead of the industry.
What are the main functions of a modern CNC system?
Modern CNC systems perform several key functions, including:
- Automated control of machining tools.
- Precision movement along multiple axes.
- Tool path programming for complex geometries.
- Real-time monitoring of operations.
- Error detection and correction for accuracy
What types of machines use CNC systems?
Common CNC machine tools include:
- CNC Lathes: For turning operations.
- CNC Mills: For cutting, drilling, and shaping.
- CNC Routers: For wood, plastic, and metal cutting.
- CNC Plasma Cutters: For cutting metals using a plasma torch.
- CNC EDM Machines: For electrical discharge machining.
How does a CNC system ensure accuracy and repeatability?
CNC systems use servo motors, precise linear guides, and advanced programming to maintain consistent and repeatable movement along predefined paths, ensuring tight tolerances.
What are the benefits of using CNC machine tools over traditional machines?
CNC machine tools offer:
- Higher precision and accuracy.
- Increased efficiency and speed.
- Reduced human error.
- Capability to handle complex designs.
- Automation for 24/7 operation.
What materials can be processed using CNC machine tools?
CNC machines can handle a variety of materials, including metals (steel, aluminum, titanium), plastics, composites, wood, and even ceramics. The type of material depends on the machine and tool capabilities.
What role does CAD/CAM software play in CNC machining?
CAD (Computer-Aided Design) software creates the design, while CAM (Computer-Aided Manufacturing) software converts the design into tool paths for CNC machines. Together, they streamline the programming and machining process.
How do CNC systems handle multi-axis machining?
Modern CNC systems support multi-axis machining (e.g., 3-axis, 5-axis) by coordinating movements across multiple axes simultaneously. This enables the creation of complex shapes and reduces the need for repositioning the workpiece.
What safety features are included in modern CNC systems?
Modern CNC systems include features such as:
- Emergency stop buttons.
- Toolpath simulation to prevent collisions.
- Real-time error detection.
- Automatic tool changers with safety protocols.
- Enclosures to protect operators from debris and accidents.