The laser beam focused by the 1000W laser welding machine has a waist near the focus, and the smallest section of the waist is the focal plane of the lens. That's where the smallest spot of light is. The focal depth increases with the increase of focal number. In the range of focal depth, the power density changes little.
Laser welding machine how to adjust the focus, the key tip if there is no special technical training, please do not carry out the following operations, because the laser welding machine laser and focus adjustment must be specially trained personnel, otherwise it will cause damage to other components of the optical road due to laser imbalance or deviation.
1. Check reference light source
The red semiconductor laser is the benchmark for the entire optical path, and its accuracy must be ensured first. Use a simple height gauge to check whether the red light is parallel to the top surface of the guide rail of the light holder and on the center line between the two guide rails of the light holder. If there is any deviation, it can be adjusted by 6 fastening screws. After the adjustment, check again whether all screws are completely tightened.
2. Adjust the position of the output mirror (output medium diaphragm)
Before adjusting the output mirror, remove the condenser with YAG rod to avoid the accuracy of adjustment due to the refraction deviation of YAG rod in the optical path.
The exact position of the diaphragm of the output medium shall be such that the red light is centered and fully reflected back to the red light, otherwise it shall be carefully adjusted by means of the knob of the diaphragm stand. Note that after adjustment, the locking ring on the adjusting knob of the diaphragm frame should be completely locked to ensure the stability of its position, and then check again whether the position of the reflected light remains in the original position.
3. Check the YAG rod installation position
Stick the two ends of YAG rod sleeve with transparent adhesive paper respectively to observe whether the red light spot is in the middle position of the two rod sleeve. If there is any deviation, it should be corrected by adjusting the position of the concentrating cavity. Then observe the position of the reflected light of YAG rod, which should coincide with the perforating of red light. Otherwise, adjust the position of the concentrating cavity on the premise of keeping the red light in the center of rod and casing as much as possible, so that the reflected light is close to the perforating as far as possible, and at least ensure that the deviation between the reflected light and the perforating is less than 1mm.
4. Adjust the position of the all - reaction mirror (all - reaction media diaphragm)
The first step: check whether the red light is in the middle position of the dielectric diaphragm, or adjust the installation position of the dielectric diaphragm frame so that the red light is in the center of the dielectric diaphragm.
Step 2: coarsely adjust the media diaphragm stand knob to reflect the red light back out of the perforation.
Step 3: Open laser, 200 a, pulse width adjusted to about 2 ms, repetition frequency adjusted to 0 hz, stepping on the pedal switch makes the pulse xenon lamp flashes, completely with the exposure of all black like paper in the output mirror, can observe laser output, two knob adjustment diaphragm frame, make the output light spot most round and even, then gradually reduce the current 120 a, Further, carefully fine-tune the knob repeatedly so that the roundest and strongest part of the spot hitting the paper is centered as much as possible.
Step 4: To check whether the laser overlapped with the red light, fix the image paper at the front end of the laser output mirror and keep away from the position of the output mirror as far as possible, send out a laser pulse, observe whether the spot center on the image paper overlapped with the red light center, if not, you can fine-tune the output mirror and all mirror to make the spot overlapped with the red light. Then, the image paper is fixed 800~1000mm away from the laser output mirror, and the spot is checked again to see if it coincides with the red light. If the coincidence can be better, the laser is adjusted to the best state.
Step 5: lock each adjusting knob, check again whether the light spot on the paper is good, and coaxial with the red light. Otherwise, it should be readjusted.
5. Check the position of the light switch
Artificial rotary reflection lens bracket, push the brake light to light blocking position, observe whether the red light in the center of the lens, the reflected light is located in the center of the beam end device on the absorption of the cone, such as the position is not right can be a little adjustment, finally, should pay special attention to carefully check whether the brake light reflection lens cleaning, contaminated the lens in use will soon burst.
In addition to the thermal and physical properties of the material itself, the welding pool is mainly affected by laser spot properties, power density, welding speed, and protective gas.