The working principle of laser welding is to use high-energy laser pulse to heat in the small area of the material.
The high-temperature energy diffuses from the material surface to the interior, and forms a specific molten pool after melting.
The materials in the whole process are in high temperature state.
So how can we safely use the laser welding machine?
Precautions for safe use of laser welding machine
1. During operation, in case of emergency, such as water leakage or abnormal laser sound, it is necessary to immediately press the emergency stop button and quickly cut off the power supply.
2. The external circulating water switch of laser welding must be turned on before operation, because the laser system adopts water cooling mode and the laser power supply adopts air cooling mode.
If the cooling system fails, it is strictly prohibited to start up.
3. It is forbidden to touch all circuit components in the machine during operation.
When the laser welding machine is working, the circuit is in the state of high voltage and strong current.
Untrained personnel are forbidden to operate the machine.
4. It is forbidden to scan the laser directly with eyes when the laser is working, so as to avoid eye injury.
It is forbidden to use external equipment to reflect the laser when the laser is working.
5. Do not disassemble any parts of the machine at will, do not weld when the safety door of the machine is opened, and do not aim the laser head at the equipment parts.
6. Do not place inflammable and explosive materials in the place where the laser light path or laser beam can irradiate, so as to avoid fire and explosion.
Safety and protection of laser welding machine during laser welding
The laser of laser welding machine has biological effects (ripening effect, light effect, pressure effect and electromagnetic field effect) like ordinary light.
While this biological effect brings benefits to human beings, if there is no protection or poor protection, it will also cause direct or indirect damage to human tissues such as eyes, skin and nervous system.
In order to ensure the safety and protection of laser welding, we must strictly control the laser hazards, and do a good job in engineering control, personal protection and safety management.
1. Engineering control
- Engineering control refers to the structural safety measures taken for the laser or laser processing system, mainly including:
- Protective cover – used to prevent workers from receiving more than the maximum allowable exposure;
- Safety interlock refers to the automatic device connected with the protective cover and can avoid radiation when the protective cover is removed;
- Safe optical path – close the optical path that may cause combustion or secondary radiation by irradiation;
- Key switch – generally refers to the laser turning when the key is removed;
- Beam termination – in order to keep the laser beam from exceeding the controlled processing area, a beam terminator attenuator can be used.
2. Personal protection
It mainly refers to wearing fire-resistant and heat-resistant laser protective clothing, laser protective glasses that can selectively attenuate specific laser wavelength, laser protective mask for UV laser source, and laser protective gloves that can avoid damage caused by direct or scattered laser.
3. Safety management
Safety management mainly includes setting up special institutions or personnel, clarifying responsibilities and rights, including safety training and supervision.
Safe operation process of optical fiber laser welding machine
1. Give priority to inspect whether all parts of the welding machine work normally.
Before the laser welding operation, inspect whether all parts of the laser welding machine work normally.
After the operation, check the welding machine and work site to eliminate hidden dangers and ensure safety without accidents.
2. Avoid fire caused by laser irradiation.
Direct irradiation or strong reflection of laser beam will cause combustible combustion and fire. In addition, there are thousands to tens of thousands of volts of high voltage in the laser, which will be injured by electric shock.
The optical path system of laser must be completely enclosed with metal to prevent direct irradiation.
The worktable of laser welding should also be shielded to prevent radiation.
3. The damage of laser to eyes should be avoided.
The laser power (referring to the work done by the object in unit time) density (unit: g / cm3 or kg / m3) used by the laser welding machine is very large, and the beam is very thin, which is easy to cause damage to people’s eyes and skin.
Therefore, the eyes should be protected and professional laser protective glasses should be equipped during the laser welding operation.
4. Avoid burning the skin by laser.
Direct irradiation of the skin by laser will burn the skin.
Due to the long-term influence of diffuse reflection, it will also lead to skin aging, inflammation and skin cancer of the operator.
Field operators shall wear work clothes to reduce the influence of diffuse reflection.
Precautions for use of laser welding machine
Laser welding is the use of high-efficiency laser single pulse to heat up some parts of the raw materials in fine areas.
The kinetic energy of the laser radiation source spreads to the interior of the raw materials according to the heat conduction, and the raw materials are melted to produce a special solution pool.
Laser welding is a new welding method.
The key is that for the electric welding of thick wall raw materials and high-precision parts, it can complete welding, butt welding, overlap welding, sealing welding, etc., with high depth length width ratio, small total welding width, small heat hazard area and small deformation.
The electric welding speed is faster, the welding is flat and beautiful.
It does not need to be solved or simply solved after welding, high welding quality, no air holes, accurate operation and small focus spot, High precision level, easy to complete automation technology.
How to use laser welding machine properly?
Safety analysis of common problems in proper application of laser welding machine:
1. Preparation before starting the laser welding machine
- Check whether the switching power supply and water circulation system of laser welding machine are normal;
- Check whether the steam connection of machinery and equipment in the equipment is normal;
- Check that the surface of the equipment is free of dust, spots, oil stains, etc.
2. Laser welding machine on / standby
Laser welding machine start:
- Connect the switching power supply and turn on the main switch of the main power supply;
- Turn on the chiller and laser generator in sequence;
- Open the argon gate valve and adjust the total atmospheric flow with strong function;
- Type in the main parameters of the work to be implemented today;
- Implement the actual operation of electric welding.
Laser welding machine standby:
- Withdraw the program flow and turn off the laser generator;
- Turn off the dust remover, chiller and other machinery and equipment in sequence;
- Close the gate valve of argon cylinder;
- Turn off the main power switch.
3. Common problems in safety application of laser welding machine
- During the operation process, in case of emergency (water seepage, abnormal sound of laser generator, etc.), immediately press and hold the change direction and quickly disconnect the switching power supply;
- Be sure to turn on the external cooling circulating water power switch of laser welding before operation.
- Since the cooling water method is selected for the system software of the laser generator and the air cooling method is selected for the laser generator, it is forbidden to start the operation in case of common faults in the refrigeration system.
- Do not disassemble and assemble all components in the equipment at will, and do not weld when the protective door of the equipment is opened;
- It is forbidden to look at the laser or reflector laser with both eyes while the laser generator is working, and face the laser welding head with both eyes to prevent injury to both eyes;
- Do not place inflammable, inflammable and explosive raw materials on the laser light path or in the area where the laser can irradiate, so as to prevent fire accidents and explosions.
- When the laser welding machine is working, the power circuit is under high voltage and strong current flow.
- It is forbidden to touch the electronic devices of each power circuit in the equipment during working;
- Without learning and training, staff are strictly prohibited from actually operating the equipment.