In the mechanical processing process, the commonly used methods for sheet metal cutting include manual cutting, semi-automatic cutting machine cutting, and CNC cutting machine cutting. Manual cutting is flexible and convenient, but it has poor quality, large size errors, large material waste, large subsequent processing workload, and poor labor conditions, resulting in low production efficiency. The profile cutting machine in semi-automatic cutting machines has good quality in cutting workpieces, but due to its use of cutting molds, it is not suitable for cutting single pieces, small batches, and large workpieces. Other types of semi-automatic cutting machines, although reducing labor intensity for workers, have simple functions and are only suitable for cutting parts with more regular shapes. Compared to manual and semi-automatic cutting methods, CNC cutting can effectively improve the efficiency and quality of sheet metal cutting, and reduce the labor intensity of operators. In some small and medium-sized enterprises in China, even in some large enterprises, manual cutting and semi-automatic cutting methods are still relatively common.
The usage of steel in China’s mechanical industry has reached over 300 million tons, and the cutting volume of steel is very large; With the development of modern mechanical industry, the requirements for the work efficiency and product quality of sheet metal cutting processing have also increased. Therefore, the market potential of CNC cutting machines is still great and the market prospects are relatively optimistic. 1. After decades of development, CNC cutting machines have made significant progress in both cutting energy and CNC control systems. Cutting energy has evolved from a single flame energy source to multiple energy sources (flame, plasma, laser, high-pressure water jet) for cutting; The control system of CNC cutting machines has evolved from simple functions, complex programming and input methods, and low automation to a fully functional, intelligent, graphical, and networked control method; The driving system has also evolved from stepper drive and analog servo drive to today’s fully digital servo drive;
The main varieties of CNC cutting machines include the following:
CNC flame cutting machine
CNC plasma cutting machine
CNC laser cutting machine
CNC high-pressure water jet cutting machine
Other specialized special cutting equipment (such as CNC pipe cutting machines, CNC profile cutting machines, and other non-metallic special cutting equipment, etc.)
2. Characteristics and application of various types of CNC cutting machines
CNC flame cutting machine has the ability to cut thick carbon steel with low cutting cost, but it has large cutting deformation, low cutting accuracy, low cutting speed, long cutting preheating time and perforation time, making it difficult to adapt to the needs of fully automated operations. Its application is mainly limited to the cutting of carbon steel and large thickness plates, and it will gradually be replaced by plasma cutting in the cutting of medium and thin carbon steel plates.
CNC plasma cutting machine, with a wide cutting field, can cut all metal plates, with fast cutting speed and high efficiency, and a cutting speed of over 10m/min. Plasma underwater cutting can eliminate the noise, dust, harmful gases, and arc pollution generated during cutting, effectively improving the working environment. The use of fine plasma cutting has made the cutting quality close to the level of laser cutting. With the maturity of high-power plasma cutting technology, the cutting thickness has exceeded 100mm, expanding the cutting range of CNC plasma cutting machines.
CNC laser cutting machine has the characteristics of fast cutting speed and high accuracy. Laser cutting machines are expensive and expensive, and are only suitable for thin plate cutting with high precision requirements,
CNC high-pressure water jet cutting machine is suitable for cutting any material (metal, non-metal, composite material), with high cutting accuracy, no thermal deformation, and an environmentally friendly cutting method. Its drawbacks include slow cutting speed, low efficiency, and high cutting costs.
Other CNC cutting machines: including CNC pipe cutting machines, CNC steel cutting machines, CNC groove cutting machines, CNC woodworking cutting machines. These specialized cutting equipment are mainly used for CNC cutting of various specialized profiles, and there are not many manufacturers in the market. With the development of modern mechanical processing industry, the requirements for cutting quality and accuracy are constantly improving, and the requirements for improving production efficiency, reducing production costs, and having highly intelligent automatic cutting functions are also increasing. The development of CNC cutting machines must meet the requirements of modern mechanical processing industry development.
1. The development of CNC cutting machines. From the application of several universal CNC cutting machines, it can be seen that the functions and performance of CNC flame cutting machines are relatively complete. However, their material cutting limitations (only cutting carbon steel plates), slow cutting speed, low production efficiency, and their applicability are gradually shrinking, making it impossible for the market to increase significantly.
Plasma cutting machines have the characteristics of wide cutting range (capable of cutting all metal materials), fast cutting speed, and high work efficiency. The future development direction lies in the improvement of plasma power technology and the coordination between CNC systems and plasma cutting. For example, the increase in power can cut thicker plates; The improvement and improvement of fine plasma technology can improve the cutting speed, surface quality, and cutting accuracy; The improvement and improvement of CNC systems to adapt to plasma cutting can effectively improve work efficiency and cutting quality.
Laser cutting machines have the characteristics of fast cutting speed, good accuracy and cutting quality. Laser cutting technology has always been a high-tech supported and promoted by the state, especially the government’s emphasis on revitalizing the manufacturing industry, which brings development opportunities for the application of laser cutting technology. When the country formulates long-term development plans, laser cutting is also listed as a key supporting technology because it involves national security, national defense construction, industrialization of high-tech, and the development of cutting-edge technology. This elevates laser cutting to a high level of importance and will inevitably bring great business opportunities to the manufacturing and upgrading of laser cutting machines. In recent years, most of the laser cutting machines sold in China were imported products, with a small share of domestic products. With the gradual deepening understanding and exemplary adoption of laser cutting technology by users, it has driven domestic enterprises to develop and produce laser cutting machines.
2. The development of specialized CNC cutting machines. The CNC pipe cutting machine is suitable for cutting cylindrical orthogonal, oblique, and eccentric intersecting holes, square holes, and elliptical holes on various pipes, and can cut intersecting lines at the end of the pipe. This type of equipment is widely used in the production of metal structural components, power equipment, boiler industry, petroleum, chemical and other industrial sectors. CNC groove cutting machine is one of the more high-end products in the industry, and the rotary groove cutting function of this type of equipment can meet the requirements of opening different angles of grooves for different plates in the welding process. With the development of China’s shipbuilding industry, shipyards took the lead in introducing and using CNC plasma cutting machines. With the development of technology, domestic and foreign shipyards have equipped CNC plasma cutting machines with rotary groove cutting function to meet the construction requirements of high-tech and high value-added ships. From the application situation of various CNC cutting machines, the overall level of technology and overall performance of domestically produced CNC cutting machines has made gratifying progress, gradually catching up with the international advanced level, meeting the needs of users, and further improving market competitiveness. Some CNC plasma cutting products in China have formed their own unique characteristics in many aspects, achieving “automation, multifunctional, and high reliability”. In some aspects, the technical performance of the product even exceeds that of foreign products.
From the perspective of development trends, CNC flame cutting machines will maintain their basic market in the CNC cutting machine market, and the water jet cutting market will increase to a certain extent. CNC plasma cutting machines and CNC laser cutting machines will become the mainstream forces in the sheet metal cutting market, and specialized CNC cutting equipment for profile materials, contact and non-contact non-metallic special CNC cutting equipment will also have significant development space, The entire CNC cutting machine market will continue to expand. Improving the production efficiency and cutting quality of CNC cutting machines, reducing production and usage costs, improving the automation level and system stability of the entire machine, and improving system functions have become the direction of its technological development.
But when making a purchase, the following points should be taken into consideration:
1、 Cutting accuracy
The general requirement for use in the construction industry is below ± 0.5mm; However, the requirement for automotive reflectors is below ± 0. Olmm. The cutting accuracy provided by various mechanical manufacturers is generally within ± 0 Below 2mm, but this cannot be solely based on the introduction of the product manual. During acceptance, there should be a complete set of procedures for testing cutting accuracy, which should be based on measuring the actual cutting accuracy of the product. We usually have more than ten test samples. Through testing, we can comprehensively grasp the flatness of the cutting platform and the synchronous control level of the control system.
2、 Cutting speed
We can only discuss speed if the cutting accuracy is met. Due to the short cutting platform, it is difficult to judge whether the maximum speed has been reached with the eyes. We can use the software simulation function equipped with the servo driver of the cutting machine to check whether the motor speed has reached the maximum speed. When testing the cutting speed, do not use actual cutting and increase the acceleration and deceleration speed. Each axis can be tested separately or simultaneously.
3、 Automatic layout optimization function
At the edge of the cutting machine, considering the processing cost and the special nature of the film making job, it is generally not arranged for highly educated personnel to do it. This requires that the operation of the cutting machine be simple, easy to understand, and not too complex, otherwise it will cause an awkward situation where the machine cannot be afford to maintain. It is best to have the function of avoiding defects, as there may be defective products in domestic bottom glass. The graphic library for irregular cutting should be diverse and flexible, and CAD generated graphics should also be able to participate in layout and development.
4、 Easy maintenance
I/0 signals and mechanical sensors should not be equipped with too many, and unnecessary switches and indicator lights should be minimized as much as possible. Once a certain component on the machine malfunctions, it will affect the use of the cutting machine. With fewer components, the probability of failure is low, and wiring is also limited, making it easy to find faults and replace components. It is best to debug the status of each I/0 signal on the screen. Maintenance costs are an important factor that must be considered when purchasing a machine.
5、 Energy saving
Choosing energy-efficient cutting opportunities can bring many benefits to enterprises when they can also meet the cutting size requirements. One is to protect the environment and save energy; The second is to save the daily expenses of the enterprise. The cutting circular machine is made of high-strength aluminum alloy die-casting, lightweight and portable. It is widely used in fields such as petroleum, chemical, shipbuilding, and mechanical manufacturing to cut pipes
