Electric welding machine The English name is electric welding machine, in fact, it is a welding machine that converts electrical energy into welding energy.
We all know that the electric welding machine is very useful, but it also has many dangers. Many electric welding workers and people watching electric welding will experience the symptoms of “welding holes” when the welding is not properly protected. So we should choose a suitable welding machine and use it correctly.
1 Introduction of electric welding machine
Electric welding machine uses the high-temperature arc generated when the positive and negative poles are short-circuited instantaneously to melt the solder on the electrode and the material to be welded, so as to combine the objects to be contacted. Its structure is very simple, it is a high-power transformer. Welding machines are generally divided into two types according to the type of output power, one is AC power and the other is DC. They use the principle of inductance, the inductance will produce huge voltage changes when it is turned on and off, and use the high-voltage arc generated when the positive and negative poles are short-circuited to melt the solder on the electrode, so that they can achieve the purpose of atomic bonding .
2 Advantages and disadvantages of electric welding machines
Advantages
Electric welding machines use electric energy, which instantly converts electric energy into heat energy. Electricity is very common, and electric welding machines are suitable for use in dry Working in the environment does not require too many requirements. Because of its small size, simple operation, convenient use, fast speed, and strong weld after welding, it is widely used in various fields, especially for parts that require high strength. Instantly connect the same metal materials (and dissimilar metals can also be connected, but the welding method is different) permanently. After heat treatment, the welding seam has the same strength as the base metal, and the sealing is very good, which is a good solution for the manufacture of storage gas and liquid containers. issues of sealing and strength.
Disadvantages
During the use of the electric welding machine, a certain magnetic field will be generated around the welding machine. When the arc burns, it will generate radiation to the surrounding area. There are infrared, ultraviolet and other light species, as well as harmful substances such as metal vapor and smoke, so sufficient protective measures must be taken during operation. Welding is not suitable for the welding of high carbon steel. Due to the crystallization, segregation and oxidation of the weld metal, the welding performance of high carbon steel is poor, and it is easy to crack after welding, resulting in hot and cold cracks. Low carbon steel has good welding performance, but it must be handled properly in the process, and the rust removal and cleaning are more cumbersome. Sometimes the welds will have defects such as slag inclusion, cracks, stomata, etc., but proper operation will reduce the occurrence of defects.
3 Models of electric welding machines
1. Category, application code
A-installation wire, B-insulated wire, C-marine cable, K-control cable, N-agricultural cable, R-cord.
U-mine cable, Y-mobile cable, JK-insulated overhead cable, M-coal mine, ZR-flame-retardant, NH-fire-resistant.
ZA-A flame retardant, ZB-B flame retardant, ZC-C flame retardant, WD-low smoke halogen free type.
2. Conductor code
T—copper wire, L—aluminum core.
3. Insulation layer code
V—PVC plastic, YJ—XLPE insulation, X—rubber, Y—polyethylene material, F—polytetrafluoroethylene.
4. Sheath code
V-PVC sheath, Y-polyethylene material, N-nylon sheath, P-copper wire braided shield, P2-copper tape shield, L -Cotton yarn weaving coated with wax gram, Q-lead bag.
4 Power of electric welding machine
Electric welding machine power can be estimated according to different types of electric welding machine, how much current is used for welding, and the length of welding cable.
1. AC welding machine: commonly known as arc welding transformer, mainly BX1-500, BX3-500; Efficiency 80%, utilization rate 70%, welding voltage 32V calculation);
2. Thyristor rectifier welding: ZX5-500; if welding with 300A current, its power consumption per hour is about 8.96 degrees ( Calculated according to welding machine efficiency of 75%, utilization rate of 70%, and welding voltage of 32V);
3. Inverter welding machine: ZX7-500: If welding with 300A current, its power consumption per hour is about It is 7.47 degrees (calculated according to the efficiency of the welding machine is 90%, the utilization rate is 70%, and the welding voltage is 32V);
5 The principle of the electric welding machine
is to use the high-temperature arc generated when the positive and negative poles are short-circuited to melt the electric welding The solder on the strip and the material to be soldered to achieve the purpose of bonding them. The structure of the electric welding machine is very simple. To put it bluntly, it is a high-power transformer that converts 220V AC into a low-voltage, high-current power supply, which can be either DC or AC.
Welding transformers have their own characteristics, that is, they have the characteristics of a sharp drop in voltage. After the electrode is ignited, the voltage drops. In the adjustment of the working voltage of the welding machine, in addition to the one-time 220/380 voltage conversion, the secondary coil also has a tap to change the voltage, and at the same time, it is adjusted by the iron core. It is a high-power transformer, which is made of the principle of inductance. The inductance will produce a huge voltage change when it is turned on and off. It uses the high-voltage arc generated when the positive and negative poles are short-circuited to melt the electrode on the electrode. solder to make them bond. A voltage is applied between the electrode and the workpiece, the arc is ignited by scratching or contacting, and the energy of the arc is used to melt the electrode and heat the base metal.
6 Classification of electric welding machines
1. The welding machines mainly used by industrial and mining enterprises are: AC arc welding machine, DC electric welding machine, argon arc welding machine, carbon dioxide shielded welding machine, butt welding machine, spot welding machine, Submerged arc welding machine, high frequency welding machine, flash butt welding machine, pressure welding machine, butt welding machine laser welding machine.
2. There are two types of DC welding machines: one is to install rectifier components on the basis of AC motor, and the other is DC generator. The DC welding machine mainly welds non-ferrous metals and pig iron. The AC welding machine mainly welds steel plates.
3. TIG welding machine, carbon dioxide shielded welding machine, high frequency welding machine, flash butt welding machine. The argon arc welding machine and the carbon dioxide gas shielded welding machine can mainly weld thin plates and non-ferrous gold layers below 2MM. The flash butt welding machine is mainly used to butt copper and aluminum joints and other objects, and the high frequency butt welding machine is mainly used to weld steel pipes in pipe factories.
4. Submerged arc welding mainly welds thick steel structural materials such as steel structural parts, bridge H steel, and I-shaped room beams.
5. Gas shielded welding machine: argon arc welding and carbon dioxide shielded welding. Under the protection of gas, the welding machine will not be oxidized, the welding will be firm, and it can weld non-ferrous gold layers and thin materials.
6. Laser Welder: Weldable leads inside the transistor.
7. Butt welding machine: The cable and chain factory mainly welds iron cables and other objects on anchors. It can be connected to Yuan steel, etc.
7 Purchase of electric welding machine
1. When purchasing electric welding machine products, it is necessary to go to regular production enterprises or large shopping malls, and to purchase famous brand products with high market share. Don’t be greedy for cheap purchases in small stores, where the quality of welding machines cannot be guaranteed.
2. When purchasing, check whether the nameplate on the product has the manufacturer’s name, production address, specification and model, welding current adjustment range, duty cycle, input voltage and current, etc. You need to determine the welding machine you want to buy.
3. You can ask the dealer to provide the product quality inspection report or certificate when purchasing. Because the electric welding machine product is a national compulsory certification product, it is necessary to confirm whether the product has passed the “3C” certification when purchasing. You can also check online.
4. When purchasing, be sure to check whether the product has grounding screws. The connection of the grounding screw should be well grounded without paint. Whether the movement is clean and the insulation is damaged to ensure the safety of use, it can also be checked if necessary.
5. Before purchasing, check the operation, conversion and installation of the switches on the panel, whether the power indicator light is on and off, whether the fan is normal, and whether there is abnormal vibration and buzzing in the power supply. Whether there is peculiar smell, whether there is heat phenomenon such as discoloration on the appearance, in order to ensure the quality of the electric welding machine and give full play to the performance of the electric welding machine.
6. If you want to buy a gas shielded welding machine, you should also check whether the accessories are complete before purchasing, whether the wire feeder is oily, whether the rotation is stable, whether the connecting cable matches whether the external insulation is damaged, and whether the insulation is damaged. Ensure the stability of the arc.
Welding Machine Operating Regulations
1. Preparation before welding, the electric welding machine should be placed in a ventilated and dry place and placed stably. Check that the welding mask should be free of light leakage and damage.
2. Matters needing attention in welding, choose a reasonable welding process according to the technical conditions of the work, do not allow overload use, do not use high current for welding, and do not use electric welding machines for metal cutting operations . During load welding, the temperature rise of the welding machine should not exceed 60 degrees for Class A and 80 degrees for Class B, otherwise it should be stopped to cool down before welding. The working place of the electric welding machine should be kept dry and well ventilated. When moving the electric welding machine, the power supply should be cut off, and the electric welding machine should not be moved by pulling the power source. If there is a sudden power failure during welding, the power should be cut off. During welding, current regulation is not allowed.
3. Precautions after welding. After the welding operation is completed, the power supply should be cut off immediately, the switch of the welding machine should be turned off, and the power supply and ground wire of the welding tongs should be cleaned and adjusted separately, so as to avoid short circuit caused by closing. Wear glasses when removing weld slag. Pay attention to avoid the direction of the welding slag splashing on the head to avoid injury. Welding slag should not be tapped at those present.
9 Maintenance of the electric welding machine
1. The electric welding machine motor must not be affected by moisture and must be stored in a dry place. When storing, cover it with oil cloth, etc. to prevent moisture from entering.
2. The intrusion of dirt, water droplets, metal or other debris must be avoided as much as possible during storage or operation.
3. Do not cover the motor with other debris during operation, so as not to hinder the heat dissipation and cause the motor to overheat and burn out.
4. Pay attention to the heating of the motor at any time, and pay attention not to overload the current and voltage.
5. Always check the collector ring for abnormal sparks. If there is abnormal noise when the motor is running, check it immediately.
6. The silicon rectifier should be well ventilated, and the radiator and cover should not be covered with objects that prevent heat dissipation.
7. Regularly clean all the dirt, check the fastening screws to prevent loosening.
8. Regularly check the control circuit for de-soldering, broken ends, loose screws, etc.
10 Hazards of Welding Machines
(1) Influence of Pneumoconiosis and Lung Function of Welders
(2) Manganese Poisoning
(3) Welding Fume Heat
(4) Effects on nervous system
(5) Effects on eyes and skin
(6) Effects on reproductive system
(7) Effects on enzyme and antibody levels in vivo
(8) Effects on internal organs
(9) Effects on trace elements in vivo
