Overview of Welding Machines
2024-08-18 5972An electric welding machine uses the high-temperature arc generated by the instantaneous short circuit between the positive and negative poles to melt the solder and the material to be welded on the electrode, in order to bond the objects in contact. Its structure is very simple, just a high-power transformer. Welding machines can generally be divided into two types based on the type of output power source, one is AC power source and the other is DC power source. They use the principle of inductance, which produces a huge voltage change when the inductance is turned on and off. They use the high-voltage arc generated by the instantaneous short circuit between the positive and negative poles to melt the solder on the welding electrode, achieving the purpose of atomic bonding.
Characteristics of welding machine
1、 Advantages of electric welding machine: Electric welding machines use electrical energy to instantly convert electrical energy into heat energy. Electricity is very common, and electric welding machines are suitable for working in dry environments without too many requirements. Due to their small size, simple operation, convenient use, fast speed, and strong weld seam after welding, they are widely used in various fields, especially for parts that require high strength. They can instantly connect the same metal material (or connect dissimilar metals, just with different welding methods) permanently. After heat treatment, the weld seam has the same strength as the base material and is well sealed, which solves the problems of sealing and strength for the manufacturing of gas and liquid storage containers.
2、 Disadvantages of electric welding machines: During use, a certain magnetic field is generated around the welding machine, and the arc combustion will emit radiation to the surrounding area. The arc light contains harmful substances such as infrared and ultraviolet rays, as well as metal vapor and smoke. Therefore, sufficient protective measures must be taken during operation. Welding is not suitable for welding high carbon steel. Due to processes such as metal crystallization, segregation, and oxidation in the welding seam, the welding performance of high carbon steel is poor, and it is prone to cracking after welding, resulting in hot and cold cracks. Low carbon steel has good welding performance, but proper operation is also necessary during the process. Rust removal and cleaning are relatively cumbersome, and sometimes defects such as slag inclusion, cracks, porosity, and undercutting may occur in the weld seam. However, proper operation can reduce the occurrence of defects.
Main characteristics of welding machine
1、 Efficient and energy-saving
The energy saving of welding machines is reflected in two aspects: no-load energy saving and load energy saving. When unloaded, the welding machine can put the main circuit, fan, etc. into a stopped state, and the unloaded power consumption is only a few watts; The efficiency of the welding machine under load is higher than that of the thyristor rectifier welding machine. According to relevant parameter statistics, the demand for DC welding machines in China's welding industry in 2008 was 890000 units. If all DC welding machines were used, it could directly save 43000 tons of copper, 64000 tons of steel, and 680 million KW of electricity H， Indirectly saved 566500 tons of coal, 10.34 million tons of water, and reduced CO2 emissions by 1.1445 million tons. It can be seen that vigorously promoting DC welding machines has enormous economic and social benefits.
2、 Stable welding performance
Due to the working frequency of the welding machine being above 20KHZ, it has a fast response speed and can control the droplet transition in multiple stages. For CO2 gas shielded welding, it can significantly reduce spatter, effectively control the stability of jet transfer for pulse melting electrode MIG/MAG welding, and combine the movement of droplet transfer and wire feeding mechanism to further control the droplet transfer process, resulting in good weld formation and stable welding performance. These are all things that traditional rectifier welding machines cannot achieve.
3、 Realize centralized control
Welding machines extensively use digital controllers such as microcontrollers, DSPs, and FPGAs to achieve network communication between multiple welding machines or between upper computers and welding machines through Ethernet and fieldbus. Not only does it solve the problem of multiple welding machines working together, facilitating centralized control during the welding process, but it also enables remote setting or monitoring of welding machine parameters, making remote fault diagnosis and maintenance of welding machines possible.
Using the high-temperature arc generated by the instantaneous short circuit between the positive and negative poles to melt the solder and the welded material on the welding electrode, in order to achieve the purpose of bonding them. The structure of an electric welding machine is very simple, in other words, it is a high-power transformer that converts 220V AC power into a low voltage, high current power source, which can be DC or AC. Welding transformers have their own characteristics, which are the sharp drop in voltage. After the welding rod ignites, the voltage drops. In addition to a 220/380 voltage conversion, the secondary coil also has a tap to change the voltage, and an iron core is used to adjust the working voltage of the welding machine. Adjustable iron core welding machines are generally high-power transformers made using the principle of inductance. The inductance will produce a huge voltage change when it is turned on and off. The high-voltage arc generated by the instantaneous short circuit of the positive and negative poles is used to melt the solder on the welding rod and achieve the purpose of bonding them. Apply voltage between the welding rod and the workpiece, ignite the arc through scratching or contact, and use the energy of the arc to melt the welding rod and heat the base material.
1. The main welding machines used by industrial and mining enterprises include: AC arc welding machine, DC welding machine, argon arc welding machine, carbon dioxide protection welding machine, butt welding machine, spot welding machine, submerged arc welding machine, high-frequency welding machine, flash butt welding machine, pressure welding machine, collision welding machine, and laser welding machine.
The main difference between the application fields of AC welding machines and DC welding machines is that AC welding machines are generally used in steel structure manufacturing units or general general machinery or agricultural machinery manufacturing units. DC is mainly used in welding machines for manufacturing pressure vessel boilers, pipelines, or important structural manufacturing units.
The main application areas of inverter welding machines are the same, except that welding machines are more energy-efficient and lightweight.
The main application areas of submerged arc welding machines are large-scale steel structure manufacturing units and pressure vessel boiler manufacturing units.
The main application areas of gas shielded welding machines are large-scale steel structure manufacturing units or general machinery agricultural machinery, automobile manufacturing plants, anti-theft door processing plants, and units manufacturing pressure vessel boilers. Gas shielded welding machines are now widely used.
The argon arc welding machine is mainly used in pipelines, pressure vessels, boilers, and stainless steel processing enterprises.
⑸ The argon arc welding machine is mainly used by aluminum welding manufacturing units and aluminum container manufacturing units. Aluminum radiator welding.
2. There are two types of DC welding machines: one is to install rectifier components on the basis of an AC motor, and the other is a DC generator. DC welding machines mainly weld non-ferrous metals and pig iron. The communication welding machine mainly welds steel plates.
3. Argon arc welding machine, carbon dioxide protection welding machine, high-frequency spot welding machine, flash butt welding machine. Argon arc welding machine and carbon dioxide gas shielded welding machine can mainly weld thin plates and colored gold layers below 2MM. Flash butt welding machines are mainly used to connect copper aluminum joints and other objects, while high-frequency butt welding machines are mainly used by pipe manufacturers to weld steel pipes.
4. Submerged arc welding mainly welds thick steel structural materials such as steel structural components, bridge H-beams, and I-beams.
5. Gas shielded welding machine: argon arc welding, carbon dioxide shielded welding. When welding under gas protection, it will not oxidize, and the solution welding is firm. It can weld colored gold layers and thin materials.
6. Laser welding machine: capable of welding the internal leads of transistors.
7. Welding machine: The cable chain factory mainly welds iron cables and other objects on the anchor. Can be connected to Yuan Steel, etc.
AC welding machine is essentially a special type of step-down transformer. Convert 220V and 380V AC power into low-voltage DC power, and the AC welding machine is a type of welding machine with AC power output.
In order to ensure smooth welding, this transformer power supply can have the following characteristics according to the needs of the welding process:
AC welding machine has the characteristic of sudden voltage drop
General electrical equipment requires that the voltage of the power supply does not change with the load, and its voltage is constant, such as 380V (single-phase) or 220V. Although the voltage connected to the welding transformer is constant, such as 380V or 220V, the output voltage through this transformer can vary with the change of output current (load), and the voltage rapidly decreases with the increase of load, which is called steep drop characteristic or descent characteristic. This adapts to the various voltage requirements required for welding:
(1) Primary voltage: refers to the external voltage connected to the welding machine.
Due to the requirement of a single voltage of 380V at both ends of the primary coil of the arc welding transformer, the voltage for connecting an AC welding machine to the power grid is generally 380V for a single voltage.
(2) Zero voltage: In order to ensure frequent short circuits (contact between the welding rod and the workpiece) during the welding process, it is required that the voltage automatically drops to near zero to limit the short-circuit current from increasing infinitely and burning out the power supply.
(3) No load voltage: In order to meet the needs of arc initiation and safety, a no-load voltage of about 60-80V is required during no-load (welding), which can smoothly initiate the arc and is relatively safe for personnel.
(4) Working voltage: After the welding arc starts, it is required that the voltage automatically drops to the voltage required for normal arc operation, which is the working voltage, about 20-40 V, which is also a safe voltage.
(5) Arc voltage: refers to the voltage at both ends of the arc, which is within the range of operating voltage. When welding, the length of the arc will change: if the arc length is longer, the arc voltage should be higher; If the arc length is short, the arc voltage should be lower. Therefore, arc welding transformers should adapt to changes in arc length to ensure the stability of the arc.
The current and voltage are stepped down by a three-phase main transformer, rectified by thyristor components, and the output current is controlled by changing the trigger angle phase of the thyristor. Extract the current signal from the shunt at the DC output terminal of the rectifier as a negative feedback signal. As the DC output current increases, the negative feedback also increases, the conduction angle of the thyristor decreases, and the output current and voltage decrease, thereby obtaining a decreasing external characteristic. The thrust circuit increases the output current when the output voltage is below 15V, especially during short circuits, forming an external drag characteristic that makes the welding rod less prone to sticking. The arc initiation circuit increases the given voltage for a short period of time each time an arc is initiated, making the arc initiation current larger and easier to initiate.
From the above description, it can be seen that when welding starts, the circuit is in a short circuit state, the voltage drops sharply, and the current needs to be very large; After starting the arc, it is necessary to stabilize the arc. At this time, the solution between the welding rod and the tank is still in a short-circuit transition state, the voltage still drops, and the current is still high; After the transition is completed, it is in a normal welding state, with voltage increasing and current decreasing. When using an AC welding machine, it is necessary to wire it correctly, that is, the shell and secondary side of the welding machine should be reliably protected with a neutral or ground connection to prevent the dew point of the shell or high voltage from entering low voltage and causing electric shock hazards to the human body, as shown in the following figure. However, its welding clamp end cannot be protected with a neutral or ground connection. The power cord of the welding machine should be a three core rubber flexible wire. Repair or replace damaged parts, check whether the insulation of the wires and cables is damaged, and keep the equipment in good technical condition.
Adjustable Welding Current of AC Welding Machine
In order to meet the welding requirements of different materials and plate thicknesses, the welding current can be adjusted from tens of amperes to hundreds of amperes, and the required current value can be arbitrarily adjusted according to the thickness of the workpiece and the diameter of the welding rod used. The regulation of current is generally divided into two levels: the first level is coarse adjustment, which is commonly used to change the connection of the output line head (position I connection or position II connection), thereby changing the number of turns of the internal coil to achieve a wide range of current regulation. During coarse adjustment, the power should be cut off to prevent electric shock injury; The other level is fine adjustment, commonly used to change the position of the "movable iron core" (moving iron core type) or "movable coil" (moving coil type) inside the welding machine to achieve the desired current value. The fine adjustment operation is achieved by rotating the handle. When the handle rotates counterclockwise, the current value increases, and when the handle rotates clockwise, the current decreases. Fine adjustment should be carried out in an unloaded state. The range of coarse and fine adjustment for various models of welding machines can be found in the instructions on the label
Possible causes and troubleshooting methods for fault phenomena
Transformer overheating 1. Overload 2. Transformer winding short circuit 1. Reduce welding current 2. Eliminate short circuit fault
The welding current is too low. 1. The secondary power cord is too long or too thin (the voltage drop of the wire is too large). 2. The secondary power cord is coiled into a circle (the inductance is too large). 3. The secondary power cord has poor contact (the contact resistance at the connection is too high or poor contact with the overcurrent). 1. Reduce the length or enlarge the area. 2. Remove the circle shape. 3. Reconnect to reduce the contact resistance.
Welding current too high or too low 1. Insulation damage due to inductive reactance in the circuit (causing excessive current) 2. Eddy current generated in the magnetic circuit (causing current reduction) 1. Repair insulation damage 2. Adjust iron core gap
Welding power cord overheating 1. Whole wire overheating: wire cross-sectional area is too small 2. Connection overheating: contact resistance at the connection is too high 1. Replace larger area wire 2. Reconnect to reduce contact resistance
The welding current fluctuates greatly, and the position of the moving iron core is unstable during welding. Fixed adjustment handle or moving iron core
There is a buzzing noise during welding, and the brake screw or spring of the moving iron core is too loose. Tighten the brake screw or adjust the spring pressure
Safety operating procedures for AC welding machines
(1) Welding operators and coordinating personnel must wear labor protection equipment according to regulations. And safety measures must be taken to prevent accidents such as electric shock, falling from heights, gas poisoning, and fires.
(2) The welding machine used on site should be equipped with a rain proof, moisture-proof, and sun proof shed, and corresponding fire-fighting equipment should be installed.
(3) Within a 10m radius of the welding site, flammable and explosive materials such as oil, wood, oxygen cylinders, acetylene generators, etc. shall not be stacked.
(4) Before use, it is necessary to check and confirm that the primary and secondary wiring is correct, the input voltage meets the requirements of the welding machine nameplate, and after connecting the power supply, it is strictly prohibited to touch the live parts of the primary circuit. The primary and secondary wiring connections must be equipped with protective covers.
(5) The secondary tap connection copper plate should be tightly pressed, and the terminal post should have a washer. Before closing, the wiring nuts, bolts, and other components should be carefully inspected and confirmed to be intact, complete, and free from looseness or damage. There are protective covers at the terminal posts.
(6) When multiple welding machines are used together, they should be connected separately to the three-phase power network to balance the three-phase loads. The grounding devices of multiple welding machines should be connected separately from the grounding electrode and should not be connected in series.
(7) When moving the welding machine, the power should be cut off and the welding machine should not be moved by dragging the cable. When there is a sudden power outage during welding, the power supply should be immediately cut off.
(8) It is strictly prohibited to weld on pressure pipelines, containers containing flammable and explosive materials, and load-bearing components during operation.
(9) When welding non-ferrous metals such as copper, aluminum, zinc, tin, and lead, it must be done in a well ventilated area, and welding personnel should wear gas masks or breathing filters.
(10) When welding inside a container, the following measures must be taken: there must be air inlet and outlet ports on the container, and ventilation equipment must be installed; The lighting voltage inside the container must not exceed 12V, and someone must be present to monitor welding. It is strictly prohibited to weld in containers that have already been sprayed with paint or adhesive. (11) When welding preheating parts, a baffle should be installed to isolate the radiation heat emitted by the preheating welding parts.
(12) When welding at high altitude, safety belts must be hung up, and fire prevention measures should be taken around and below the welded parts with dedicated personnel for supervision.
(13) When welding wires pass through roads, they must be elevated or buried underground in protective pipes. If passing through tracks, they must pass under the tracks.
(14) Grounding wires and handle wires should not be placed on flammable, explosive, or heat source materials. Grounding wires should not be connected to pipelines, machine tools, equipment, building metal structures, or rails. The insulation should be good, and the grounding resistance of the casing should not exceed 4 Ω.
(15) Outdoor welding is not allowed on rainy days. When working in humid areas, operators should stand in areas covered with insulating materials and wear insulated shoes.
(16) Welding machines used for long-term power outages must have their insulation resistance checked with a shaking table to ensure it is not less than 0.5M Ω, and the wiring must not have corrosion or moisture.
(17) Welding tongs should have good insulation and thermal insulation capabilities. The handle of the welding tongs must be well insulated, and the connection between the handle and the wire should be secure and in good contact. The connection should be wrapped in insulating cloth and not exposed. Operators are not allowed to hold welding tongs with their arms.
(18) When removing weld slag, protective goggles should be worn and the head should avoid hitting the direction of slag splashing.
(19) During load operation, welding personnel should regularly check the temperature rise of the welding machine. If it exceeds 60 ℃ for Class A and 80 ℃ for Class B, it must be stopped and cooled down.
(20) After the homework is completed, clean up the site, extinguish the fire, cut off the power supply after the residual heat of the fire welding parts, lock the switch box, and then leave.
International standard situation
1 GB/T2900.22-2005 Electrical terminology - Welding machines
2 GB/T8118-1995 Electric arc welding machine; General Technical Conditions
3 GB/T8366-2004 Mechanical and electrical requirements for resistance welding machines
GB/T10235-2000 Arc Welding Transformer Anti Electric Shock Device
5 GB/T10249-1988 Method for Model Designation of Welding Machines
6 GB/T13164-2003 Submerged Arc Welding Machine
GB/T13165-1991 Determination method for noise of arc welding machines
8 GB15578-1995 Safety Requirements for Resistance Welding Machines
9 GB15579.1-2004 Arc Welding Equipment Part 1: Welding Power Sources
GB/T15579.5-2005 Safety requirements for arc welding equipment Part 5: Wire feeding device
11 GB/T15579.7-2005 Safety requirements for arc welding equipment Part 7: Welding torches (guns)
12 GB15579.11-1998 Safety requirements for arc welding equipment Part 11: Welding tongs
13 GB15579.12-1998 Safety Requirements for Arc Welding Equipment Part 12: Welding Cable Coupling Devices
14 GB/T18495-2001 Resistance Welding - Transformers Integrated with Welding Clamp
15 GB19213-2003 Safety Requirements for Small Arc Welding Transformers
16 JB/T2751-2004 plasma arc cutting machine
17 JB/T3158-1999 Resistance Spot Welding Straight Electrode
18 JB/T3946-1999 Convex Welding Machine Electrode Plate Slot
19 JB/T3947-1999 Resistance Spot Welding Electrode Joints
20 JB/T3948-1999 Resistance Spot Welding Electrode Cap
21 JB/T3957-1999 Spot Welding Equipment - Electrode taper fit dimensions
22 JB/T4158-1999 Seam Welding Wheel Blank Size
23 JB/T5249-1991 Mobile Spot Welding Machine
24 JB/T5250-1991 seam welding machine
25 JB/T5251-1991 Fixed Welding Machine
26 JB/T5252-1991 Spare graphic symbols for resistance welding equipment
27 JB/T5256-1991 Inspection and Sampling Methods for Welding Machines
28 JB/T5340-1991 Special Technical Conditions for Resistance Welding Transformers for Multipoint Welding Machines
29 JB/T6230-1992 Technical Conditions for Small Electric Welding Rod Drying Furnaces
30 JB/T6231-1992 Resistance Spot Welding Equipment Electrode Cooling Tube
31 JB/T6232-1992 Technical Conditions for Welding Rod Insulation Cylinder
32 JB/T6233-1992 Dimensions of welding wire reels and coils
33 JB/T7106-1993 Water Compressed Air Plasma Arc Cutting Machine
34 JB/T7108-1993 Carbon arc air planer
35 JB/T7109-1993 plasma arc welding machine
36 JB/T7783-1995 Technical Conditions for Pneumatic Pipe beveling Machine
37 JB/T7824-1995 Technical Conditions for Inverter Arc Welding Rectifiers
38 JB/T7834-1995 Arc Welding Transformer
39 JB/T7835-1995 arc welding rectifier
40 JB/T8086-1999 Friction Welding Machine
41 JB/T8323-1996 Screw Welding Machine
42 JB/T8442.1-1996 Resistance Welding Water Cooled Secondary Connection Cables Part 1: Specification and Technical Requirements for Double Core Connection Cables
43 JB/T8442.2-1996 Resistance Welding Water Cooled Secondary Connection Cables Part 2: Specifications and Technical Requirements for Single Core Connection Cables
44 JB/T8442.3-1996 Resistance Welding Water Cooled Secondary Connection Cable Part 3: Test Requirements
45 JB/T8442.3-1996 Safety requirements for cooling fans used in welding machines
46 JB/T8588-1997 Technical Conditions for Steel Bar Electric Slag Pressure Welding Machine
47 JB/T8597-1997 Technical Conditions for Manual Tungsten Inert Gas Shielded Arc Welding Machine (TIG Welding Machine)
48 JB/T8748-1998 MIG/MAG arc welding machine
49 JB/T8805-1998 Technical Conditions for Pressure Reducing Devices for Gas Protection
50 JB/T8806-1998 Technical Conditions for Gas Mixture Proportioners for Gas Protection
51 JB/T9527-1999 Spot Welding Equipment Cone Plug Gauge and Cone Ring Gauge
52 JB/T9528-1999 prime mover arc welding generator set
53 JB/T9529-1999 General Technical Conditions for Resistance Welding Machine Transformers
54 JB/T9530-1999 Insulation caps and insulation bushings for resistance welding equipment
55 JB/T9531-1999 Spot Welding Electrode Blocks and Clamp Blocks
56 JB/T9534-1999 Technical Conditions for Arc Ignition Devices
57 JB/T995-1999 Resistance Welding Electrode Joint with Internal Conical Angle of 1:10
58 JB/T9960-1999 Resistance Spot Welding Convex Electrode Cap
59 JB/T10101-2000 Fixed Point and Convex Welding Machine
60 JB/T10110-1999 General Technical Conditions for Resistance Welding Machine Controllers
61 JB/T10113-2002 Dimensions and characteristics of secondary connection cables connected to water-cooled connection blocks at both ends of resistance welding equipment
62 JB/T10255-2001 Resistance Welding Equipment - Electrode Joints, External taper 1:10 Part 1: Conical Fit, taper 1:10
63 JB/T10256.1-2001 Resistance spot welding - Electrode holder - Part 1: Fitting taper 1:10
64 JB/T10256.2-2001 Resistance spot welding - Electrode holder - Part 2: Mohs taper fit
65 JB/T10256.3-2001 Resistance Spot Welding - Electrode Grip Part 3:
End insertion cylindrical handle fit
66 JB/T10257-2001 Resistance Welding Equipment - Insulation Pin for Electrode Block
67 JB/T10258-2001 Convex Points for Resistance Welding
68 JB/T10498-2005 Special Conversion Switch for Welding Machines
Welding machines have a wide range of applications. Welding machines are indispensable tools for large shipbuilding enterprises, industrial and mining enterprises, and various construction enterprises. Welding machines are used for material welding and are charged during use. Especially for small construction units who purchase cheap welding machines to save costs, using them in harsh environments on construction sites can easily cause electric shock, fire, and detachment, which can endanger personal and property safety. Poor welding quality can also cause "tofu residue" engineering.
Several requirements to pay attention to when choosing an electric welding machine:
1、 When choosing welding machine products, it is necessary to go to formal production enterprises or large shopping malls to purchase, and to choose high-quality products from brands with high market share. Don't be tempted by cheap prices and buy from small shops, as the quality of the welding machines there cannot be guaranteed.
2、 When making a purchase, check whether the nameplate on the product contains the manufacturer's name, production address, specifications, welding current adjustment range, load duration, input voltage and current, and other information. Then, determine the welding machine you want to purchase according to your work needs.
3、 When purchasing, you can request the distributor to provide a product quality inspection report or certificate of conformity.
4、 When purchasing, be sure to check if the product has a grounding screw, and the connection of the grounding screw should be free of paint and well grounded. Check whether the movement is clean and whether the insulation is damaged to ensure safe use. If necessary, it can also be inspected.
5、 Before purchasing, you can turn on the power to check the operation, conversion, and installation of the switches on the panel, the on/off of the power indicator light, whether the fan is normal, whether there are any abnormal vibrations or buzzing sounds in the power supply, whether there is any odor, and whether there is any discoloration or heating phenomenon on the appearance to ensure the quality of the welding machine and fully utilize its performance.
6、 If you want to purchase a gas shielded welding machine, you should also check whether the accessories are complete, whether the wire feeder has oil stains, whether the rotation is smooth, whether the connecting cables match, and whether the external insulation is damaged before purchasing to ensure the stability of the arc.
Daily maintenance of welding machine
1. Check that the output wiring of the welding machine is standardized and secure, and that the outgoing direction is close to vertical and the angle with the horizontal must be greater than 70 °.
2. Check the tightness of the screws at the cable connection. The screw specification is hexagonal bolt M10 × 30, with complete flat and spring washers, and no defects such as rust or oxidation.
3. Check that the exposed length of the cable at the wiring point is less than 10mm.
4. Check that the welding machine casing is securely grounded.
5. Check that the welding machine power supply and base metal grounding are good and standardized.
6. Check the cable connection for reliable insulation and wrap it with tape.
7. Is the screen cover of the connection between the power cord, welding cable, and welding machine intact.
8. Whether the cooling fan of the welding machine rotates flexibly and normally.
9. Whether the power switch, power indicator light, and adjustment handle knob are intact, whether the pointers of the ammeter and voltmeter are flexible and accurate, and whether the surface is clear and free of cracks. The watch cover is intact and can be opened and closed freely.
10 Check CO2 Is there any leakage of gas.
Check whether the appearance of the welding machine is good and there is no serious deformation.
Check if the hexagonal screws at the connection between the CO2 welding gun and the CO2 wire feeding device are tightened and if the CO2 welding gun is loose.
13. Check whether the CO2 wire feeding device cable and air pipe are properly wrapped and fixed.
Check the CO2 wire feeding device for wear and replace the correction wheel and wire feeding wheel in a timely manner.
Check whether the motor fixing and insulation coil are intact.
Check if the remote control box on the CO2 wire feeding device is loose.
When installing the CO2 welding gun, tighten the welding gun switch plug to align with the guide slot insertion. After the welding gun is installed, tighten the fastening screws.
Whether the 18 electrode welding tongs are damaged, whether the upper and lower covers are loose and affect insulation, whether the fastening screws of the cover are loose, and whether they are firmly connected to the cable with good conductivity
Is the wheel of the 19 welding machine complete and flexible in rotation.
Thoroughly clean the surface oil stains of the equipment once a week.
Clean the dust inside the welding machine with compressed air (without moisture) every six months (be sure to cut off the power before cleaning). When removing dust, the upper and side panels should be removed, and then blown from top to bottom in order. Any attached grease should be wiped clean with a cloth.
The 22 maintenance items are undertaken by the operator.
Technical maintenance
Follow the 'Daily Maintenance' project and add the following tasks.
1. Check if all lines and accessories are intact.
3. Check if the fuse meets the requirements. If it is found to be oxidized, severely overheated, or discolored, replace the fuse.
The current regulating device should meet the requirements of the regulating range.
5. Check the lubrication condition of each part of the equipment.
matters needing attention
1. New or long unused welding machines often experience a significant decrease in insulation resistance between windings and between windings and the casing due to moisture, which can lead to short circuits and grounding at the beginning of use, causing equipment and personal accidents. Therefore, before use, a shaking table should be used to check whether the insulation resistance is qualified.
2. Before starting a new welding machine, it is necessary to check whether the contactor part of the electrical system is in good condition. If it is considered normal, it can be started for trial operation under no load. Only when there is no electrical hazard can it be tested under load conditions and finally put into normal operation.
3. DC welding machines should rotate in the specified direction. For those with ventilation fans, attention should be paid to whether the fan rotation direction is correct, and they should be blown out from above. To achieve the purpose of cooling the welding machine.
1、 Preparation before welding
1. The welding machine should be placed in a ventilated and dry place, and placed steadily.
2. Check that the welding mask has no light leakage or damage. Welding personnel and auxiliary personnel should wear appropriate personal protective equipment.
3. The welding tongs, power cords, and various joint parts of the electric welding machine should be connected reliably and insulated well. Overheating is not allowed at the wiring points, and the power supply wiring terminals must not be exposed. They should be wrapped with electrical adhesive cloth.
4. The length of the wire between the welding machine and the welding tongs shall not exceed 30 meters, and in special circumstances shall not exceed 50 meters. If the wire is damp or has broken strands, it should be replaced immediately.
When welding wires pass through roads, they must be elevated or buried underground in protective pipes. If passing through tracks, they must pass under the tracks.
6. The primary and secondary wiring of the AC welding machine should be accurate and the input current should meet the equipment requirements. It is strictly prohibited to come into contact with live parts of primary circuits.
7. The secondary tap connection copper plate must be tightly pressed, and the terminal post should have a coil. Before closing, carefully inspect the contact bolts and other components to ensure that they are not loose or damaged.
2、 Precautions during welding
1. Reasonable welding processes should be selected based on the technical conditions of the work. Overloading is not allowed, high current welding is not allowed, and metal cutting operations using electric welding machines are not allowed.
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, the machine should be stopped and cooled down before welding.
3. The working environment of the welding machine should be kept dry and well ventilated. When moving the welding machine, the power supply should be cut off and the welding machine should not be moved by dragging the power supply. If there is a sudden power outage during welding, the power should be cut off.
4. It is not allowed to adjust the current during welding. When stopping welding, the adjustment handle must be used to adjust it, not too quickly or too forcefully, in order to avoid damaging the regulator.
5. It is prohibited to perform welding operations under the workpiece during the operation of the crane.
6. When welding in areas with crane wire ropes, care should be taken not to accidentally touch the ground wire of the welding machine with the lifted wire rope, in order to avoid sparks and accidents.
When construction must be carried out in damp areas, welders must stand on insulated wooden boards and are not allowed to touch the welding machine wires or use arms to hold live welding tongs.
3、 Precautions after welding
After completing the welding operation, the power supply should be immediately cut off, the welding machine switch should be turned off, and the welding tongs power supply and ground wire should be cleaned and organized separately to avoid short circuit caused by closing.
If the automatic stopping device is found to be malfunctioning during welding, the machine should be stopped immediately and the power should be cut off for maintenance.
3. Wear glasses when removing welding slag from the weld seam. Pay attention to avoiding the direction of welding slag splashing on the head to avoid injury. Do not hit the welding slag on the personnel present.
After completing outdoor work, the welding machine should be covered to prevent rain.
5. When welding is not being carried out (such as moving, repairing, adjusting, or taking breaks during work), the power should be cut off to avoid accidents.
6. Check the welding machine once a month to ensure reliable grounding.
Welding machine auxiliary equipment includes gas welding goggles to prevent operators from being injured by ultraviolet, infrared, or other radiation generated by welding arcs or other welding energy sources, face shields to protect welders' eyes, face, and neck during arc welding, white work clothes, welder gloves, and foot protection, etc.
The welding machine industry is a small industry, but its products involve multiple disciplines and edge disciplines, closely intersecting with many disciplines such as machinery, electronics, mechanics, control, metallurgy, materials, and computer science. To a large extent, it also relies on the maturity and progress of other industries, such as insulation materials, electromagnetic materials, power electronic devices, computer technology, etc. Due to various factors such as technological foundation and funding, it is difficult for China's welding machine industry to achieve sustainable and leapfrog development by relying solely on its own capital and strength, or by relying solely on imported materials and components to achieve product updates and rapid development. This phenomenon actually reflects that the development of the welding machine industry will inevitably be limited by China's overall technological strength, and the development of application-oriented industries cannot be separated from the progress of the country's basic industries< br /> China has become a major manufacturer of welding machines in the world, and the market capacity of welding machines has ended the stage of rapid development and entered a relatively stable development cycle.
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