I.Introduction
At present, the current situation of the world’s mold manufacturing industry is that there are some problems. For example, there are certain artificial errors and manual operation links in the process of mold manufacturing; the mold manufacturing cycle is long, which requires a lot of human and material resources; the mold manufacturing process is complicated, which is difficult to master and manage. These problems are restricting the rapid development of mold manufacturing enterprises and enhance competition.
Therefore, how to use advanced CNC machining technology to solve these problems is particularly important. In this paper, we will analyze the basic theory and key technology of CNC machining technology, and provide strong support for promoting the development of the mold manufacturing industry in the world by applying it to the mold manufacturing industry.
II. Basic theory of CNC machining technology
1. The concept of CNC machining technology
CNC machining technology is a kind of processing method based on computer control, which can realize precise cutting and machining on the surface of the workpiece. Compared with traditional manual operation, CNC machining has higher precision and efficiency, and at the same time can reduce the influence of human error. Therefore, CNC machining has become an important part of modern manufacturing. The basic principle of CNC machining technology is to control the trajectory of the tool movement through the computer, so as to complete the machining task of the workpiece.
Specifically, the CNC machine will enter the work program into the computer, and then the computer automatically generates the corresponding instructions to drive the movement of the tool. This approach not only improves productivity, but also reduces labor costs. In the field of mold manufacturing, the application of CNC machining technology is also becoming more and more widespread. As molds usually require high precision and stability, and CNC machining technology has exactly these characteristics.
For example, in the process of mold manufacturing, CNC machining technology can be used to produce high-precision and high-efficiency mold modules to improve the quality and efficiency of the entire mold manufacturing process. In addition, CNC machining technology can also be used in the repair and remaking of molds and other aspects. At the same time, CNC machining technology can also improve the speed and efficiency of mold making and reduce costs. Therefore, it is very necessary to adopt CNC machining technology for mold manufacturing enterprises.
2. The characteristics of CNC machining technology
CNC machining technology is a kind of high-efficiency production method, which can realize the high precision and complexity of the parts. Compared with traditional manual production, CNC machining has the following characteristics:
① High precision: CNC machining equipment can precisely control the tool position and speed, thus ensuring the accuracy of the size and shape of the parts;
② High speed: CNC machining equipment can complete complex process operations in a short period of time, improving productivity;
③ Reliability: Since CNC machining equipment adopts computer program to control tool movement trajectory, its working process is more stable and reliable;
④ High degree of automation: CNC machining equipment can be programmed for automated operation, reducing the possibility of manual intervention;
⑤ Higher repeatability and flexibility: CNC machining equipment can be used repeatedly and can be adjusted and modified according to different needs. These features make CNC machining technology an important part of modern manufacturing industry.
3. CNC machining key technology research
3.1 CNC machining tool trajectory generation
CNC machining tool trajectory generation is the key technology of CNC machining, the purpose of which is to realize accurate cutting of the material surface through the computer-controlled robot arm and tool. In CNC machining, the tool trajectory needs to go through a series of complex calculations and optimization processes to get the optimal solution. Among them, the commonly used algorithms include the straight line tracking method, surface tracking method, multi-objective planning method, and so on.
The straight line tracking method is a simple but effective method that moves the tool along a straight line until the desired position is reached. This method is suitable for simple shapes and contour lines, but does not work well for complex shapes and curves.
In contrast, the surface tracking method is more flexible and effective and can be adapted to a wide variety of shapes and contour lines. The method involves determining a datum as a starting point and then drawing a corresponding surface path along this datum.
A computerized control system is used to move the tool along this path. The multi-objective planning method is a method that combines a number of factors, such as speed, accuracy, efficiency and other factors. In this case, it is necessary to use some mathematical models to predict the trajectory of the tool and find the optimal solution.
3.2 CNC machining tool position calculation
Tool position refers to the cutting position and direction of the CNC machine tool when machining the workpiece. Accurately determining the tool position can ensure machining accuracy and efficiency, while reducing the risk of manual operation. In actual production, the determination of the tool position needs to consider a variety of factors, such as the shape of the workpiece, material properties, machining parameters and so on. Among them, workpiece shape is the most important aspect. Since different workpieces have different shapes and sizes, their corresponding tool positions are also different.
Therefore, for different types of workpieces, there are differences in the method of determining the tool position. Currently, the commonly used methods for calculating the tool position mainly include the methods based on geometric models and the methods based on CAD data. The geometric model-based method determines the tool position parameters by measuring the surface contour of the workpiece.
The formula is:
Where X represents the direction of tool movement and Y represents the height of tool movement; a, b, c, and d represent the distances between the four coordinate points of the workpiece, respectively. θ represents the angle of the tool, which can be obtained by devices such as goniometers or lasers. This method is suitable for workpieces that are relatively simple, such as linear parts or circular parts. However, for complex workpieces, this method is difficult to meet the demand. Therefore, methods based on CAD data are becoming mainstream.
The formula is:
Among them, X indicates the direction of tool movement, Y indicates the height of tool movement; x1, y1, z1 are the positions of three coordinate points of the workpiece. This method can automatically recognize the shape of the workpiece and give the corresponding tool position parameters. At the same time, different tool position parameters can be set according to different parts of the workpiece to realize multi-level tool position control. The application range of this method is very wide, including mechanical parts, electronic components, automobile parts and so on.
3.3 CNC Programming Technology
CNC programming technology directly affects the precision and efficiency of CNC machine tools. In CNC machining, the design and realization of CNC program is a very important part. In order to ensure the quality of the CNC program, it is necessary to carry out strict data acquisition, analysis and verification work.
At the same time, the CNC program needs to be optimized and improved to enhance its performance and reliability. At present, the commonly used CNC programming software are UGNX, CATIA, SolidWorks and so on. Among them, UGNX is a universal CNC programming language, which is widely used in the field of CNC machining;
CATIA is one of the software for integrated CAD/CAE design, with powerful modeling functions and visualization design capabilities; while SolidWorks focuses more on the design of mechanical parts and three-dimensional modeling and other applications. In the actual production process, it is necessary to clarify the requirements of the target task and process parameters, and then determine the required machining steps and parameters through data acquisition and analysis.
Programming and debugging can be performed using the appropriate CNC programming tools. The program is sent to the CNC machine for machining operations. In addition to specific programming methods, attention should be paid to the safety of the CNC program. Since CNC programs involve complex control systems and equipment, errors or loopholes may lead to serious consequences. Therefore, attention needs to be paid to issues such as safety measures and risk assessment when writing and running programs.
IV.CNC processing technology in mold manufacturing application
1.Mold Design
The design of the mold is the basis of the entire production process, and CNC machining technology can provide a more accurate and efficient means for mold design. Through the use of CNC machining technology for mold design work, you can ensure the accuracy of the mold at the same time to improve production efficiency.
CNC machining technology can achieve three-dimensional modeling through computer-aided design (CAD) software. This method can transform the designer’s ideas into a digital model, and optimize and adjust the model. At the same time, CAM software can be used to generate tool path diagrams to enable the machining of molds.
These tools make mold design more accurate and faster. CNC machining technology can also help mold designers better understand the working principle and structural characteristics of the mold. For example, by simulating the motion trajectory and pressure distribution of a mold, it is possible to predict problems and defects that may occur in the actual production of the mold. CNC machining technology also provides a new way of making molds – 3D printing. This method can be used to manufacture complex mold shapes and complex geometries, and has a high degree of precision and reliability.
2. CNC machining programming
In the mold manufacturing process, CNC machining programming refers to the mold design drawings into specific operating instructions that can be processed by CNC machine tools. This process requires a certain understanding of the mold design and process, while taking into account the characteristics and limitations of the actual processing equipment.
For the mold design drawings, it is necessary to label and mark the subsequent programming work. In this process, you need to pay attention to the location of the mark is accurate, as well as the content of the mark is clear and concise. For specific machining requirements, it is necessary to develop appropriate machining programs and process arrangements.
This includes selecting the appropriate tool type and size, determining the machining sequence, setting reasonable feed speed and depth, etc.. The entire machining process also needs to be simulated, tested and optimized. Through these steps, it can ensure that the final generated CNC machining program has high precision and stability.
In the actual CNC machining program preparation, some details need to be paid attention to. For example, for different materials and shapes of parts, different machining methods and parameters need to be used; at the same time, it is necessary to consider the abnormalities that may occur in the machining process, and take appropriate measures to solve them.
3. CNC machining tool selection
Tool selection for mold manufacturing is an important factor affecting the efficiency and quality of mold production. With the development of CNC machining technology, more and more companies are beginning to use CNC machining tools for mold making. Relative to the traditional manual preparation methods, CNC machining tools have the advantages of high precision, speed, simple operation, etc., can significantly improve the speed and efficiency of mold manufacturing.
In the mold manufacturing process, you need to choose the tool suitable for different materials. For carbide, stainless steel and other easily deformable materials, you can choose high-speed cutting tools; and for aluminum alloy, copper alloy and other metal materials that are easy to oxidize, you need to use a good wear resistance and not easy to oxidize the tool.
In addition, it is also necessary to consider the size and shape of the tool and other factors on the mold performance. Therefore, when selecting CNC machining tools, it is necessary to consider various factors and make a reasonable decision. In addition to tool selection, there are other critical factors that need attention. For example, the installation position of the tool, the clearance between the tool and the workpiece, and the wear of the tool need to be taken into account. All these factors will directly affect the forming effect and life of the mold.
V.Conclusion
In summary, this paper introduces the basic principles and characteristics of CNC machining technology by studying the application of CNC machining technology in mold manufacturing and finds that CNC machining technology is a very promising technical means in the current field of mold manufacturing. It has the advantages of high precision and high efficiency, which can effectively improve the quality and efficiency of mold production. Therefore, the key technology of CNC machining is analyzed, including tool trajectory generation, tool position calculation and other aspects, and CNC machining technology is applied to mold manufacturing, which effectively solves the shortcomings of traditional handmade molds and improves the quality and efficiency of mold production
