CNC machining (computer numerical control machining) is a method of machining using computer-controlled CNC machine tools, which is widely used in parts manufacturing in various industries. It controls the machine tool to cut along the specified path through a pre-written machining program, thereby realizing the machining of the workpiece. This efficient and precise process technology is widely used in aviation, automobile, medical and other fields. The basic process mainly includes programming, checking the program, selecting tools, installing workpieces, adjusting parameters, starting machining, testing quality and post-processing. In the CNC machining process, every step is crucial, and any omission may lead to a decrease in the quality of the workpiece. So, do you know what steps and processes CNC machining must go through to deliver high-quality finished products to customers in a timely manner?
Basic process of CNC machining
- Read drawings and program sheets
- Transfer the corresponding program to the machine tool
- Check program header, cutting parameters, etc.
- Determine the machining dimensions and allowances of the workpiece
- Reasonable clamping of the workpiece
- Accurate alignment of the workpiece
- Accurate establishment of workpiece coordinates
- Reasonable selection of tools and cutting parameters
- Reasonable clamping of tools
- Safe test cutting method
- Observation of the machining process
- Adjustment of cutting parameters
- Timely feedback of problems and relevant personnel during the machining process
- Inspection of workpiece quality after machining
Description of the main steps of the CNC machining process
- Design the product: First, you need to use CAD (computer-aided design) software to draw the three-dimensional model of the product. Designers can set parameters and arrange parts according to needs to ensure the accuracy and manufacturability of the product.
- Select materials: Select appropriate materials according to the characteristics and uses of the product. Commonly used materials include metal, plastic, wood, etc. The processing methods and processes of different materials will also vary.
- Write the processing program: Import the CAD file of the product into CAM (computer-aided manufacturing) software and write the processing program according to the processing requirements. The program contains parameters such as processing path, tool selection, and cutting speed.
- Set up the machine tool: Set up the CNC machine tool according to the needs of the product and the requirements of the processing program. It mainly includes clamping the workpiece, installing the tool, adjusting the processing parameters, etc.
- Processing operation: Start the CNC machine tool and operate according to the processing program. The machine tool will automatically move according to the program to perform processing operations such as cutting, drilling, and milling.
- Inspection and correction: After the processing is completed, the product is inspected and corrected. Use measuring tools and equipment to check product dimensions, flatness, surface quality and other indicators to ensure that the product meets design requirements.
Detailed explanation of the process of machining parts in CNC machining workshops
CNC machining is a high-precision and high-efficiency machining method that is widely used in various manufacturing industries. It converts digital design drawings into actual products through computer-controlled equipment. Next, Elimold will give you a comprehensive introduction to the process and methods of CNC machining to help you better understand and master the knowledge in this field.
Analyze customer drawings and determine processing technology
Business personnel obtain first-hand drawings provided by customers, simply list customer requirements, and submit orders to the engineering department. Engineering personnel will determine the machine tool, tool, positioning clamping device, process, processing sequence and cutting amount based on the material selection, surface treatment, shape, size, accuracy, surface roughness and other requirements of the parts in the drawings and the command functions of the CNC machine tools used, give full play to the advantages and efficiency of the machine tools, and strive to achieve a balance in various aspects such as reasonable processing paths, fewer passes, and short processing time.
Reasonable calculation of tool path coordinate values
According to the geometric dimensions of the machined parts and the set programming coordinate system, the motion trajectory of the tool path center can be calculated using fixed software to obtain all tool position data. Usually, CNC systems have functions such as linear interpolation and circular interpolation. For simple planar parts with a relatively simple shape, only the coordinate values of the starting point and end point of the geometric elements need to be calculated.
For parts with complex shapes (components composed of non-circular curves and surfaces), straight line segments are required to approximate the actual curves or surfaces, and the coordinate values of the nodes are calculated according to the required accuracy.
Programming
Programming is to write programs according to the workpiece drawings and processing requirements. The workpiece drawings contain information such as the shape, size, and process requirements of the workpiece, which is the basis for subsequent processing. This process requires the use of CAD/CAM software to determine the processing path, select appropriate tools, define the installation position of the workpiece, etc. Programmers need to have solid mechanical drawing and programming skills, and the written programs will serve as input for the CNC control system.
Verify the program
Program verification is a key step to ensure machining quality. After the program is written, it is necessary to verify the program through simulation software to check whether the tool path is correct and whether there are interferences. This process can detect and correct errors in time to avoid scrapping workpieces due to program errors.
Choosing tools
Choosing the right tools is crucial for CNC machining workpieces. You need to choose the right tools based on the workpiece material, size, machining accuracy, etc. At the same time, you need to consider factors such as tool life, cutting speed, feed speed, etc. Choosing the right tools can improve machining efficiency and reduce costs.
Installing the workpiece
The accuracy and stability of the workpiece installation position have a direct impact on the quality and efficiency of CNC machined workpieces. When installing the workpiece, it is necessary to follow the principle of “reference coincidence” to ensure that the workpiece is firmly installed without shaking. At the same time, it is necessary to ensure the accuracy of the workpiece coordinate system so that subsequent processing can proceed smoothly.
Adjust parameters
By adjusting the relevant parameters of CNC machine tools, such as feed speed, tool speed, etc., the machining process can be optimized and the workpiece quality can be improved. When adjusting parameters, it is necessary to comprehensively consider factors such as workpiece material and tool type to select the best parameter combination. At the same time, it is necessary to pay attention to the stability of parameter adjustment to avoid workpiece errors caused by parameter fluctuations.
Start processing
After the above steps, you can start the CNC machining operation. During the operation, it is necessary to ensure the safety and stability of the machine operation, follow the operating procedures, and avoid safety accidents or workpiece scrapping caused by misoperation. At the same time, it is necessary to pay close attention to abnormal conditions during the processing, such as sudden changes in cutting force, tool wear, etc., and take timely measures to solve them.
Quality inspection
The processed parts need to be inspected for quality according to the requirements, and only after the qualified rate is confirmed to meet the standards can they be processed later. The quality inspection methods include appearance inspection, size inspection, performance inspection, etc. Inspection tools include measuring tools, thermometers, test equipment, etc. During the inspection process, relevant standards and specifications need to be followed to ensure the accuracy and reliability of the inspection results.
Post-processing
After the parts meet the specifications after verification and testing, they can be post-processed, such as sorting, packaging, etc. The post-processing method depends on the actual needs, which can be simple manual processing or automated processing. During the post-processing process, it is necessary to pay attention to protecting the surface quality and integrity of the workpiece to avoid damage or contamination of the workpiece due to improper handling.
Packaging and Delivery
The finished CNC machined parts are carefully packaged to protect them during shipping. They are then delivered to the customer or to the next stage of the manufacturing process.
Common CNC machining process methods
- Milling: Milling is one of the most commonly used CNC machining methods. It removes material from the workpiece by rotating the tool to achieve the purpose of machining shape and size. Common milling methods include plane milling, vertical milling, vertical and horizontal milling, etc.
- Drilling: Drilling is a processing method in which a rotating tool is pushed into the center of the workpiece to form a hole. CNC machine tools can accurately control the position and size of the hole by controlling the movement of the tool.
- Cutting: Cutting is a processing method in which the material on the workpiece is cut off by the relative movement of the tool and the workpiece. It is suitable for the processing of materials such as metals and plastics, and can achieve high efficiency and high precision.
- Turning: Turning is a processing method in which the tool is moved linearly relative to the workpiece by rotating the workpiece. It can be used to process shapes such as threads and outer circles with high precision and high surface quality.
- Laser cutting: Laser cutting is a processing method that uses a high-energy laser beam to cut materials. It can achieve dimensional precision and high speed processing effects, and is widely used in the field of metal processing.
Application fields of CNC machining
CNC machining provides a parts manufacturing solution with high efficiency, high precision, flexibility, repeatability and versatility. It is widely used in various industries, such as aerospace, automobile, electronics, medical equipment, mold manufacturing, etc.
In the aerospace field, CNC machining can manufacture complex-shaped aviation parts such as turbine blades, engine parts, aerospace structural parts, etc. Due to the high precision and repeatability of CNC machining, the quality and performance requirements of parts can be ensured.
In the automotive industry, CNC machining can manufacture automotive engine parts, chassis parts, body parts, etc. Through CNC machining, high precision and consistency of parts can be achieved, and the performance and safety of automobiles can be improved.
In the electronics field, CNC machining can manufacture electronic parts, circuit boards, housings, etc. Due to the high efficiency and flexibility of CNC machining, it can meet the rapid development and production needs of electronic products.
In the medical equipment field, CNC machining can manufacture medical device parts, artificial joints, dental equipment, etc. The high precision and repeatability of CNC machining can ensure the quality and safety of medical equipment.
In the field of mold manufacturing, CNC machining can manufacture various types of molds, such as injection molds, die-casting molds, stamping molds, etc. Due to the versatility of CNC machining, high-precision processing of complex molds can be achieved.
Summary
CNC machining is versatile. By choosing different tools and processing methods, you can achieve a variety of processing operations such as drilling, milling, cutting, turning, etc. to meet the processing needs of different parts. This makes CNC machining a versatile manufacturing process. At the same time, it is also a complex and systematic project that requires the coordination of multiple links to achieve high-quality processing results. By continuously optimizing and improving the process and technical level of each link, the efficiency and accuracy of CNC machining can be improved, providing strong support for the development of the manufacturing industry. A detailed understanding of the CNC machining process can improve your communication with the CNC machining workshop, saving time and cost. If you need to customize CNC parts, you can contact Elimold to serve you.