As an important technology to improve the speed, accuracy, and cost control of metal and non-metal cutting, CNC plasma cutting technology is affected by the unstable operation of the CNC system, unused nesting software, single-piece cutting, and thermal deformation, and unrealized impact of automatic cutting targets and other issues have made the technology's practical effects not fully utilized. Based on this, researchers should make full use of the existing science and technology to control the application limitations of CNC plasma cutting technology to accelerate the replacement of high-cost laser cutting technology application status. This is an important topic to promote the rapid and stable development of digital industrialization under the background of modern economic construction. Researchers should pay attention to it to apply it to practice.
Application advantages of CNC plasma cutting technology
Research shows that the application speed of CNC plasma cutting technology is 10 times higher than that of flame cutting technology currently used more frequently, which means that it can cut non-metal and metal materials with diverse characteristics. In actual construction, the CNC plasma cutting machine can complete the cutting operation in an underwater environment. This makes it have environmental protection function, eliminating harmful gases, noise, dust, and arc wind that may appear in sheet cutting. In terms of economy, the laser cutting machines currently used can only be used for cutting thin plates. The plasma cutting machine is maximum cutting thickness can reach 60mm, and the cost is only 1/3 of the laser cutting machine. It can be judged that CNC plasma cutting technology is an important application direction to replace laser cutting machines in the future. Researchers should clarify the status quo of its effects on the actual market environment to find targeted application control strategies. This is the key to making CNC plasma cutting technology effective in the industrialized market environment. The relevant construction personnel should start with the application limitations of this technology to meet the industry's needs is rapid development.
The application status of CNC plasma cutting technology
Stability of the CNC system is not high
When users of CNC plasma cutting machines choose the CNC system, there is a problem of excessive pursuit of high configuration, which affects the CNC system's stability that acts on industrial construction. Specifically, high-frequency CPUs and large hard disks have the characteristics of high power and high heat generation, which can easily lead to overheating problems in the operation of the system, and the cutting machine cannot complete related operations. For this reason, technicians can use industrial fans for air cooling to control heat and overheating problems, but there are still limitations in the efficiency of the cutting machine.
No nesting software is used
When applying CNC plasma cutting technology, the relevant personnel did not pay attention to optimizing the choice of nesting software, but only by calling the NC conversion software and CAD software in the CNC system to perform seven NC files and drawings. In this case, most of the time, the machine tool will be in an idle state waiting for the programming nest, reducing its production and construction efficiency.
Single piece cutting and thermal deformation
When performing parts cutting operations, CNC plasma cutting technicians did not use borrowing, co-edge, and bridge connection cutting methods. Still, it adopted the method of preheating and perforating one by one. This causes thermal deformation of the cutting technology parts, thereby reducing work efficiency and increasing material usage costs.
Automatic cutting has not been realized
The numerical control system is not equipped with an automatic cutting process and parameter data storage library, allowing front-line operators to make appropriate adjustments and controls based on their own experience and naked eyes. This situation makes it difficult for the CNC plasma cutting machine to improve the efficiency of cutting production and construction. Given the impact of the above problems, researchers should start with the application and control process of CNC cutting technology to make its true value fully play out. As shown in Figure 1, it is a schematic diagram of the structure of the CNC plasma cutting machine.
Optimize the application strategy of CNC plasma cutting technology.
According to statistics, the effect of CNC plasma cutting technology is determined by the cutting speed and thickness. If you want to match the speed and thickness of the cutting process with the actual situation, you must check the corresponding material before cutting according to the thickness of the material. The correct choice of nozzle and current. In this way, the current used during the cutting machine operation will not increase the consumption of equipment nozzles, thereby reducing the quality of the plate cutting. The voltage applied by CNC plasma cutting technology is obtained through the power supply is normal output operation. Among them, because the no-load voltage and working voltage of the plasma arc cutting machine is relatively high, it can act on operations under high plasma conditions such as air, hydrogen, or nitrogen. That is to say, the use of this type of cutting machine will increase the voltage while the current does not change, and the voltage increases, which means that while the cutting ability is improved, it can also increase the arc enthalpy. In this case, by increasing the gas flow rate and reducing the jet diameter, the cutting speed and thickness control targets can be achieved.
The nozzle height in the CNC plasma cutting machine is an important part of the entire arc length: the distance between the surface of the cutting machine and the section of the nozzle device. The actual operation process mainly relies on a steep drop or constant current power supply to complete the cutting operation of the plate. When the plate is cut, the operating current of the equipment will decrease with the increase of the nozzle height, thereby increasing the arc voltage, arc length, and power consumption of equipment operation. On the other hand, when the equipment is running, the cutting machine's arc length must be in the complicated operating environment of the system for a long time, which increases the consumption of the arc column. However, the CNC plasma cutting machine can offset the above two defects to improve plate cutting efficiency.
For the actual cutting speed applied by CNC plasma cutting technology, technicians can improve cutting speed control through experiments. It is worth noting that when a metal or non-metal sheet melts, its surface tension, melting point, thickness, material difference, and thermal conductivity will all affect the operating state of the cutting machine. Therefore, relevant construction personnel should adjust the cutting speed. Otherwise, if the cutting speed is too low, the cutting part of the metal sheet will become the anode of the ion arc. The anode area or the anode spot will transmit the conduction current to the vicinity of the slot closest to the arc to maintain its own stability. The cut is widened, the bottom edge gathers, and the molten material on both sides of the cut is solidified. For this reason, technicians should adjust the operating speed of the cutting machine to the state of use according to the thermal conductivity, melting point, material, and cutting thickness change requirements. Figure 2 shows a schematic diagram of the structure of the CNC plasma cutting machine under the high-speed cutting process.
Working gas and flow
For the selection of working gas and flow rate, CNC plasma cutting technicians must determine the type, thickness, and method of cutting according to the cut sheet. Currently, the available working gases include cutting gas and auxiliary gas. Also, for some equipment, an arc starting gas is used for cutting operations. Too small gas flow will make the cutting depth shallower and make the plasma arc lose its proper straightness. Too large gas flow will shorten the length of the jet, take away more arc heat, and cause arc instability, and Cutting ability is reduced. The current plasma arc cutting machine controls the flow mostly by gas pressure. When the aperture of the gun body remains unchanged, the flow is controlled by controlling the gas pressure.