Note: The maintenance of the portable fiber laser welding machine must be carried out by specially trained personnel, otherwise it is easy to cause serious man-made damage.
1. In order to ensure that the laser of the portable fiber laser welding machine is always in normal working condition, after two weeks of continuous work or when it is stopped for a period of time, the components in the optical path such as the YAG rod, dielectric diaphragm and lens protection glass should be checked before starting the machine to ensure that the optical components are free of dust pollution, mildew and other abnormal phenomena. If there are any abnormal phenomena, they should be handled in time to ensure that the optical components will not be damaged under strong laser irradiation. (If the use environment of the portable fiber laser welding machine is relatively clean, the above inspection can be extended to one month or even longer).
2. The purity of cooling water: It is the key to ensure the laser output efficiency of the portable fiber laser welding machine welding gun and the life of the laser focusing cavity component. The conductivity of the internal circulating water should be checked once a week during use. The internal circulating deionized water must be replaced once a month. Pay attention to the color changes of the ion exchange column in the cooling system at any time. Once the color of the resin in the exchange column is found to be dark brown or even black, the resin should be replaced immediately.
3. Adjustment method:
Equipment operators can often use black photo paper to check the laser output spot of the portable fiber laser welding machine. Once the spot is uneven or the energy is reduced, the laser resonant cavity should be adjusted in time to ensure that the laser output beam quality is stable.
Note:
①Direct strong laser irradiation can cause serious damage to human skin, especially blinding the eyes. The debugging operator must have common sense of laser security and wear special laser protective glasses during work.
②When the strong laser directly irradiates flammable materials such as wood, it will produce open flames. During the debugging process, a piece of black metal material with good absorption performance should be placed on the optical path of the laser output as a beam terminator to prevent fire accidents.
③The adjustment of the laser must be carried out by specially trained personnel, otherwise the laser will be misaligned or misaligned, causing damage to other components on the optical path.
The adjustment steps of the laser resonant cavity are as follows:
1. Check the reference light source: The red semiconductor laser is the reference of the entire optical path. Use a simple height gauge to check whether the red light is parallel to the top surface of the optical bench rail and is on the middle line between the two rails of the optical bench. If there is a deviation, it can be adjusted through 6 fastening screws. After adjustment, check again whether all fastening screws have been fully tightened.
2. Adjust the position of the output mirror (output medium diaphragm): Before adjusting the output mirror, the focusing cavity with the YAG rod should be removed to avoid affecting the accuracy of the adjustment due to the refraction deviation of the YAG rod in the optical path. The accurate position of the output medium diaphragm should be so that the red light is in its middle position and can completely reflect the red light back to the exit hole of the red light, otherwise it should be carefully adjusted through the knob of the diaphragm frame. Note that after adjustment, the locking ring on the diaphragm frame adjustment knob should be completely locked to keep its position stable, and then check again whether the position of its reflected light remains in place.
3. Check the installation position of the YAG rod: Use transparent tape to stick on both ends of the YAG rod sleeve, and observe whether the red light spot is in the middle of the two rod sleeves. If there is a deviation, it should be corrected by adjusting the position of the focusing cavity. Then observe the position of the reflected light of the YAG rod, which should coincide with the exit hole of the red light. Otherwise, adjust the position of the focusing cavity while keeping the red light in the middle of the rod sleeve as much as possible, so that the reflected light is as close to the exit hole as possible, and at least ensure that the deviation from the exit hole is less than 1mm.
4. Adjust the position of the total reflector (total reflective dielectric diaphragm):
① Check whether the red light is in the middle of the dielectric diaphragm, otherwise adjust the installation position of the dielectric diaphragm frame so that the red light is in the middle of the dielectric diaphragm.
② Initially adjust the knob of the dielectric diaphragm frame to reflect the red light back to the exit hole.
③ Turn on the laser of the portable fiber laser welding machine, adjust the pulse width to about 2ms, adjust the repetition frequency to 0Hz, step on the foot switch to make the pulse xenon lamp flash, then put the fully exposed black photo paper in front of the output mirror, and you can observe the laser output. Repeatedly adjust the two knobs of the film frame to make the output spot very round and uniform, then gradually reduce the current to about 120A, and further repeatedly and carefully fine-tune the knob to make the spot on the photo paper as round as possible and the strong part concentrated in the middle of the spot.
④ Check whether the laser coincides with the red light, fix the photo paper at the front end of the laser output mirror and as far away from the output mirror as possible, send a laser pulse, and observe whether the middle of the spot on the photo paper coincides with the middle of the red light. If not, you can fine-tune the output mirror and the full reflector to make the spot coincide with the red light, and then fix the photo paper 800~1000mm away from the laser output mirror, and check again whether the spot coincides with the red light. If it can coincide well, the laser is adjusted to a good state.
⑤ Lock each adjustment knob and check again whether the light spot on the photo paper is good and coaxial with the red light. Otherwise, it should be readjusted.
5. Check the position of the shutter:
Manually rotate the reflective lens bracket and push the shutter to the light blocking position to observe whether the red light is in the middle of the lens and whether its reflected light is located on the absorption cone in the middle of the beam terminator. If the position is incorrect, it can be slightly adjusted. Pay special attention to carefully check whether the shutter reflective lens is clean. The contaminated lens will soon burst during use. At this point, the adjustment of the laser part of the portable fiber laser welding machine is completed.
6. The main contents of the maintenance of the portable fiber laser welding machine cooling system include checking the water quality of the cooling water, cleaning the water tank and pipes, and checking whether the protection circuit is operating normally. In the case of frequent use, the water quality must be checked once a week to ensure the quality of the cooling medium at any time. Inspection method:
① Set the multimeter to the 2MW resistance range, insert the exposed metal parts of the two probes into the cooling water surface in parallel with a distance of 1cm. The resistance reading at this time should be at least greater than 250kW. If the reading is lower than this value, the cooling water should be replaced immediately.
② Check the protection interlocking circuit Stainless steel welding rod This cooling system is specially designed for the characteristics of laser equipment, and has designed protection measures such as over-temperature sound warning, over-temperature interlocking, flow switch interlocking, and liquid level protection interlocking. The above protection circuits should be checked frequently during use to ensure that they function normally. The inspection work can be carried out when changing water.
③ Precautions In a high temperature or humid environment, the portable fiber laser welding machine laser should always pay attention to whether there is "condensation" caused by too low water temperature on the cooling water circulation pipe or laser focusing cavity during operation. "Condensation" will cause damage to the end face of the YAG crystal, resulting in a decrease in output power or even failure to emit light. Be sure to pay attention during use. If "condensation" occurs, the portable fiber laser welding machine should be stopped immediately. After the moisture on the surface of the focusing cavity dries naturally, recheck the condition of the YAG optical surface and determine whether to clean the YAG rod. The machine can be turned on again only when everything is normal. Before turning on the portable fiber laser welding machine, pay attention to properly adjust the lower limit setting temperature of the thermostat. During normal operation, pay attention to whether there is frost on the titanium tube of the refrigeration system. If frost occurs on the portable fiber laser welding machine, it may be caused by insufficient Freon in the refrigeration system. Please ask the relevant maintenance personnel to replenish it immediately and check for leaks.