1. Whether the focusing distance of the equipment changes: Re-adjust the focusing distance.

2. Focus lens contamination: clean focus lens.

3. Whether the optical path is offset or not: carefully adjust the optical path.

4. Whether the mirror is contaminated or damaged: Clean or replace the mirror.

5. Whether the cooling water circulates or not: dredging the cooling water channel.

6. Is the cooling water quality or temperature normal: replace the clean cooling water to make its temperature normal?

7. Whether the laser power supply of laser cutting machine is electrified or not: Check the power supply circuit of laser power supply to make it normal.

8. Whether the laser tube is damaged or ageing: replace the laser tube.

9. Whether the laser power supply is damaged or not: replace the laser power supply.

10. Is the temperature of the whole machine too high?

(1) Turn off and let the temperature drop;

(2) Ventilation enhances machine heat dissipation;

(3) Adjusting the ambient temperature.

Essential difference between CO2 laser cutting and optical fiber laser processing in sheet metal market

At present, there are two main laser processing machines for metal sheet metal cutting in the sheet metal processing industry. One is CO2 laser processing machine which was transformed from industrial laser to product about 20 years ago, and the other is optical fiber laser processing machine which was formally transformed from industrial laser to product about 5 years ago. In recent years, according to the number of laser processing optical machines sold in China's sheet metal equipment market, CO2 laser processing machine accounts for 40% and optical fiber laser processing machine accounts for 60%. We know that in recent years, the momentum of optical fiber laser processing machine is fierce, is continuously recognized by the market, sales desk is gradually expanding.

Basic Differences between CO2 Laser and Fiber Laser

Although the current market trend is towards optical fiber laser processing machine, but is optical fiber laser processing machine really the best choice? CO2 laser and optical fiber laser, because of their different physical characteristics, laser processing technology is also different. Of course, in fact, they have their own strengths and weaknesses. According to the different processing objects, they have their own strengths and weaknesses.

CO2 laser is a gas beam generated by exciting carbon dioxide molecules. Its wavelength is 10.6 um. Fiber laser is a solid laser irradiated by a medium Yb (ytterbium) compound in the fiber. Its wavelength is 1.08 um. The physical characteristics of different wavelengths have a great influence on the processing characteristics of the two materials.

At first, the concept of optical fiber laser was recognized because it can propagate through optical fibers. The reason why it can propagate through optical fibers is its wavelength, because it can propagate through optical fibers only because of its wavelength of 1.08 um. The advantage of using optical fibers for transmission is that its optical components have longer service life and higher maintenance performance.

CO2 laser processing machine transmits laser from vibration generator to processing point by means of mirror, usually in the light path isolated from the outside air. Although the light path is filled with air without ordinary dust or foreign matter, the surface of the mirror will be attached to dirty things after a long period of use, and need to be cleaned. In addition, the mirror itself will also be consumed by absorbing a small amount of laser energy, which needs to be replaced. In addition, in order to transmit laser from the generator to the processing point, it is necessary to use multiple mirrors to adjust the angle of laser reflection for propagation, so to maintain normal operation requires certain technical ability and management.

However, from the vibration generator to the processing point, the laser is propagated by a single optical fiber. This optical fiber is generally called a light guide fiber. Because there is no need for optical components like mirrors and laser is propagated in optical fibers isolated from the outside air, the laser will hardly be lost. Strictly speaking, the laser propagates repeatedly around the optical fibers, so the optical fibers themselves will be somewhat lost. However, compared with the mirrors in the CO2 laser processing machine, the service life of the optical fibers will be longer. It's several times longer. In addition, if the propagation path is above the minimum curvature of the optical fiber, then the path can be determined freely, so it is very convenient to adjust and maintain.

In the process of laser generation (laser generator construction), they are also different. The CO2 laser oscillator generates the laser by placing the gas mixed with CO2 in the discharge space. In order to ensure the normal operation of the resonance length derived from the laser output power, the optical parts inside the vibration generator are equipped, and the optical parts inside the vibration generator need to be cleaned and replaced regularly.

Optical fiber laser generator, as mentioned just now, generates laser in the optical fiber interior, and is isolated from the outside air, there is no optical components, so there is almost no need for regular maintenance.

The maintenance period of CO2 laser oscillator is about 4000 hours, while that of optical fiber laser oscillator is about 20000 hours. The aforementioned aspects of service life and maintenance performance can be said to have great advantages for optical fiber laser processing machine.

In addition, we can also try to compare it from the perspective of operating costs such as electricity consumption. The photoelectric conversion rate of CO2 laser oscillator is said to be about 10-15%, while that of optical fiber laser oscillator is about 35-40%. Because of the high photoelectric conversion rate, the electrical energy converted into heat dissipation becomes less, so the optical fiber laser processing machine can control the power consumption of cooling devices such as coolers even lower. Generally speaking, the vibration generator of optical fiber laser processing machine requires higher precision for the cooling temperature management of the oscillator compared with CO2 oscillator. However, under the same laser output power, the cooling capacity of the oscillator of optical fiber laser processing machine with CO2 laser oscillator is about 1/2-2/3 enough. Therefore, considering the power consumption of all the devices of the laser processing machine, the optical fiber laser processing machine can run under about 1/3 of the power consumption of the CO2 laser processing machine, which can be said to be a very energy-saving laser processing machine.

For the laser cutting of flying light path, the beam size before and after focusing is different because of the divergence angle of the beam and the length of the distance between the near end and the far end. The larger the diameter of the incident beam is, the smaller the diameter of the focus beam is. In order to reduce the change of focal spot size caused by the change of beam size before focusing, the manufacturers of laser cutting machines at home and abroad have provided some special devices for users to choose.

1. Collimator. This is a common method, that is, adding a parallel light tube at the output end of the laser to expand the beam. After the beam expanding, the beam diameter becomes larger and the divergence angle becomes smaller, which makes the beam size close to the same before focusing at the proximal end and the distal end in the cutting range.

2. Adding an independent moving lens to the cutting head next week, it is two independent parts with the Z axis which controls the distance between the nozzle and the material surface. When the machine tool table moves or the optical axis moves, the beam moves from the proximal end to the distal end at the same time, so that the spot diameter remains the same throughout the processing area after the beam is focused.

3. Controlling the water pressure of the focusing mirror (usually a metal reflex focusing system). When the size of the focus beam decreases before focusing and the diameter of the focus spot increases, the diameter of the focus spot decreases when the water pressure changes the focus curvature automatically.

4. Adding X-axis and Y-axis compensating optical path system to the flying optical path cutting machine. That is to say, when the distal optical path increases, the compensating optical path will be shortened, whereas when the square near the cutting end decreases, the compensating optical path will be increased to maintain the same optical path length.