The principle and advantages of plasma cutting machine
The working principle and advantages of plasma cutting machine
Plasma cutting machine is a machine that uses plasma cutting technology to process metal materials.A processing method that uses the heat of the high-temperature plasma arc to partially or partially melt (and evaporate) the metal at the incision of the workpiece, and uses the momentum of the high-speed plasma to remove the molten metal to form the incision.
Features of plasma cutting machine：
1. Double mode selection of automatic and semi-automatic cutting
2. Digital precision control of cutting length
3. Easy to operate
Structural performance of plasma cutting machine：
1. The frame adopts a fully welded structure, which is firm and reasonable, easy to operate, and durable.
2. Fast cutting speed and high precision. The cutting opening is small, neat, and there is no slag drop phenomenon. On the basis of the traditional numerical control system, the control method for cutting is improved, and the secondary trimming processing is avoided.
3. Suitable for low-carbon steel, copper, iron, aluminum, galvanized, titanium and other metal plates.
4. The CNC system has a high configuration. Automatic arc ignition, stable performance, and the success rate of arc ignition is over 99%.
5. Support standard G code path files generated by Wentai, Beihang Haier, ARTCAM, Type3 and other software. The control system adopts U disk to exchange processing files, which is convenient and quick to operate
Working principle of plasma cutting machine：Plasma is a gas that is heated to a very high temperature and is highly ionized. It transfers the arc power to the workpiece. The high heat causes the workpiece to melt and be blown off, forming the working state of plasma arc cutting.
After the compressed air enters the cutting torch, it is distributed by the gas chamber to form plasma gas and auxiliary gas. The plasma gas arc serves to melt the metal, while the auxiliary gas cools the various parts of the torch and blows off the molten metal.
The cutting power supply includes two parts: the main circuit and the control circuit. The electrical principle: the main circuit includes a contactor, a three-phase power transformer with high leakage reactance, a three-phase bridge rectifier, a high-frequency arc ignition coil, and a protection element. Caused by the high leakage reactance, the external power supply characteristics are steep. The control circuit completes the entire cutting process through the button switch on the cutting torch:
Pre-venting-main circuit power supply-high frequency arc ignition-cutting process-interest arc-stop.
The power supply of the main circuit is controlled by the contactor; the gas flow is controlled by the solenoid valve; the control circuit controls the high-frequency oscillator to ignite the arc, and stops the high-frequency operation after the arc is established.
In addition, the control circuit also has the following internal locking functions: the thermal switch operates and stops working.
1. Before use and when cutting
1. Check and confirm that the power supply, air source, and water source have no leakage, air leakage, or water leakage, and the grounding or zero connection is safe and reliable.
2. The trolley and the workpiece should be placed in an appropriate position, and the workpiece should be connected to the positive electrode of the cutting circuit, and there should be a slag pit under the cutting working surface.
3. The nozzle aperture should be selected according to the material, type and thickness of the workpiece, and the cutting power, gas flow and electrode shrinkage should be adjusted.
4. The automatic cutting trolley should be run empty and the cutting speed should be selected.
5. The operator must wear protective masks, welding gloves, hats, filter membrane dust masks and soundproof earmuffs. Personnel who do not wear protective goggles are strictly prohibited from directly observing the plasma arc, and bare skin is strictly prohibited from approaching the plasma arc.
6. When cutting, the operator should stand upwind to operate. Air can be drawn from the lower part of the workbench, and the open area on the workbench should be reduced.
7. When cutting, when the no-load voltage is too high, check the electrical grounding, zero connection and the insulation of the torch handle. The workbench should be insulated from the ground, or a no-load circuit breaker should be installed in the electrical control system.
8. The high-frequency generator should be equipped with a shielding cover, and the high-frequency circuit should be cut off immediately after the high-frequency arc is used.
9. The use of thorium and tungsten electrodes should meet the requirements of Article 12.7.8 of JGJ33-2001.
2. Cutting operation and protection of cooperating personnel
1. The plasma cutting machine used on site should be equipped with rainproof, moisture-proof, and sun-proof sheds, and corresponding fire-fighting equipment should be installed.
2. When cutting at high altitude, safety belts must be worn. Fire prevention measures should be taken around and below the cutting, and special personnel should be supervised.
3. When it is necessary to cut pressure containers, sealed containers, oil drums, pipes, and workpieces stained with flammable gases and solutions, first eliminate the pressure in the containers and pipes, eliminate flammable gases and solutions, and then flush toxic, harmful, and flammable Substance: For containers with residual grease, rinse them with steam and alkaline water first, and open the lid to confirm that the container is cleaned, and then fill with water before cutting. Measures to prevent electric shock, poisoning and suffocation should be taken when welding and cutting in the container. Air holes should be left for cutting sealed containers, and equipment ventilation equipment should be installed at the air inlet and outlet when necessary; the lighting voltage in the container should not exceed 12V, and the welder and the workpiece should be insulated; a special person should be supervised outside the container. It is strictly forbidden to cut in the container that has been sprayed with paint and plastic.
4. It is strictly forbidden to cut pressure vessels and pipelines, live equipment, load-bearing parts of the load-bearing structure, and containers containing flammable and explosive materials under pressure.
5. Welding and cutting are not allowed in the open air on rainy days. When working in a humid area, the operator should stand in a place covered with insulating materials and wear insulating shoes.
6. After the operation, the power supply should be cut off, and the air and water sources should be turned off.
The advantages of the plasma cutting machine are that the plasma arc energy is more concentrated, the temperature is higher, the cutting speed is faster, and the deformation is small. It can also cut stainless steel, aluminum and other materials. The disadvantages of plasma cutting are that the arc is strong, the noise is large, and there is a lot of dust, which has a certain degree of pollution to the environment. For many medium thicknesses, underwater plasma cutting is used, and the cutting thickness is also limited. Similarly, gas flow, arc length, telegraph quality, current size, and cutting speed all affect the quality. It is not as simple as flame cutting. Plasma cutting guns should not be too many, because the cutting speed is faster, it is easy to be affected by the above factors, and the cutting quality is not the same. Generally speaking, for thin plate cutting, the surface quality of plasma cutting incision is better than that of fire filling, and there is little slag.
In recent years, by improving the design of the cutting moment, the quality of the cutting surface of the workpiece has been significantly improved. The verticality of the shaft edge can reach 0-1.5°, which is especially beneficial to improve the cutting quality of thick plates. Due to the improved cutting gun, the electrode life has been increased several times. However, the distance between the cutting torch and the steel plate is relatively high, and the height sensor on the cutting torch is required to be more sensitive and the cutting torch to react faster when moving up and down.
Therefore, plasma cutting of 4-30 mm steel plate is an ideal method, which can avoid the disadvantages of slow oxygen acetylene cutting speed, large deformation, severe cutting and severe slagging. Obtained a certain thickness of stainless steel and other materials.
Anhui Runbang Heavy Industry Machinery Co., Ltd., a company dedicated to the production of heavy industry machinery. We have high-quality plasma cutting machines, reliable after-sales service and low prices. If you have mechanical needs in this regard, please feel free to contact us