Repeated use of laser cutting machine circular polarizing mirror

- Jul 04, 2019-

At present, laser beams have been successfully used in the industry for cutting, punching, welding, and surface modification. The key part of the laser cutting machine is the laser generator. However, due to the early development of the machine tool, the 810 laser generator is made in the United States, especially the 450 circularly polarized mirror is basically imported. After use, the original design of the machine guiding light system is partially insufficient. The mirror lens has a high failure rate and a service life of only 6 to 8 months. The lens is expensive and difficult to purchase, which affects both production and cost. Here is a method of repeating the use of a mirror lens repeatedly.

      When the laser cutting machine is used, it suddenly does not emit light, and other actions are normal. Upon inspection, it was found that the 45° circularly polarized mirror coating was burnt at the reflection point and the diameter was up to 6 mm. The center plating layer was burned and radiated to the periphery, and the electrical thermal protection device on the lens did not operate. The reasons for the damage are as follows:

(1) The gas in the light path is not clean. In the laser cutting process, a large amount of metal dust is generated, and a large amount of particles are focused on the light for a long time, so that the lens is locally overheated and burned.

(2) The laser is incident on the 45° circularly polarized mirror through the front and rear mirrors. Once the dust in the light path is attached to the front mirror or the rear mirror, the dust absorbs heat after the laser is irradiated, and the front mirror or the rear mirror is thermally deformed to have a slight convexity and concave, so that the light is focused and irradiated onto the mirror to be damaged.

(3) The mirror is aging and exceeds the service life.

      After analysis, the lens (φ50mm) is burnt out at the center and is intact. Therefore, considering how to get the light person to the intact part of the mirror, the damaged lens can continue to be used. Here, the mirror and the entire mirror are simultaneously translated to make the mirror eccentric. In this way, the lens can be reused 9 times, and the assembly and maintenance is simple and does not affect the optical path of the laser cutting machine.

The specific method is: (1) remove the lens holder, separate the upper cover and the base, take out the lens for cleaning, and save it for use. (2) The eight M3 positioning holes of the base are translated 11 mm in the same direction (here to the left) and re-punched to change the reflection point on the lens. (3) Translate the entrance of the base and the center of the circular hole of the exit port by 11 mm in the same direction as a growing circular hole. (4) After installing the base, first use ammonia and sunlight to check whether the entrance and exit of the mirror block block the optical path. When the base and optical path are normal, install the 45° mirror and the upper cover according to the normal procedure. After the white carbon dioxide light, you can try cutting.

      After adopting the above measures, after one year of use, the product cuts are smooth and burr-free, maintaining the original level.