Research application of optical system of fiber laser cutting machine

Fiber laser cutting machine is a kind of photoelectric integrated equipment that completes laser marking. Its marking system is composed of laser transmitter, optical path, galvanometer, field lens, control board, and upper computer. The laser beam with a diameter of about 8 mm generated by the laser transmitter is scanned on X and Y axes by the galvanometer, and then focused by the field lens, so that the previously thicker laser beam is focused on the marking surface, so as to obtain the smallest but energy The most dense laser spot, the laser spot makes the appearance of the marking surface quickly generate high temperature, and the upper layer material of the workpiece is vaporized to expose the deep layer material, completing the marking process.

Industrial application status of fiber laser cutting machine

In the industrial field, when the fiber laser cutting machine is used, the laser marking head and the workpiece are usually required to be unchanged, so as to guarantee the engraving The appearance is about ±1 mm before and after the laser beam converges (related to the material to be marked and marking accuracy requirements) to guarantee the marking result. Regarding the application scenarios where the workpiece cannot be accurately positioned on the manufacturing line, we usually experience the use of extra laser ranging sensors to perform distance measurement on the workpiece, supplemented by moving the laser marking head for position error compensation, so as to guarantee the marking results. This undoubtedly increases the complexity of the system.

At present, in order to solve the problem of workpiece positioning error, the United States Telesis company, Japan Keyence company, etc. have developed three-axis fiber laser cutting machines that are different from the ancient XY axis. The greater improvement lies in the growth. The Z-axis, while satisfying the ranging function, actively compensates the error value of the interval. Compared with international brands' experience of optical components in mediation to complete distance measurement-the active core function method, most of the domestic ones rely on relatively machines and ancient methods, that is, through external laser sensors and action control implementation agencies to complete.

The research application of the optical system of the fiber laser cutting machine

In the manufacturing reality, the fiber laser cutting machine is about the distance between the workpiece and the field lens (standard working distance). ) Usually, a relatively large and reasonable threshold is set. Within this reasonable threshold (such as ±1 mm near the ideal position), the marking results of the marking machine can be acquiesced to be the same. However, for forgings that have a small marking surface and are not in the same plane as the surroundings, the application of a self-powered laser ranging sensor will greatly increase the complexity of the system. This is because if the laser ranging sensor adopts oblique placement, it will greatly reduce the accuracy of the ranging, and if it is considered to be perpendicular to the marking surface, it will block the laser beam. Regarding this environment, the current industrial manufacturing management plan is to place the laser ranging sensor at one end of the cylinder to experience the ups and downs during ranging to avoid irritated baldness. The structure of this plan is complicated and not easy to structure.

From the basic principles of the laser rangefinder, after the laser rangefinder sensor actively emits the laser beam to the surface to be measured, the beam will be reflected to the installed linear CCD photosensitive device , The actual displacement offset of the measured object from the reference point can be obtained by calculating the offset interval of the image position on the linear CCD photosensitive device of the laser light point. In normal times, the range accuracy of the laser ranging sensor is above ±0.05 mm, which is far beyond the fiber laser cutting machine's request for spacing accuracy.

Based on the current industrial application status of domestic fiber laser cutting machines, it is expected that a laser beam emitted by the fiber laser cutting machine itself will be reflected by the marking surface and experienced in the general industry. A plan to obtain the core position error value of the appearance of the marking surface interval through image processing and image processing. The index of this article is to use laser triangulation measurement techniques to provide strong appearance support for reasonable optical path planning, structural structure and distance measurement plan.