RU2064388C1 - Laser treatment apparatus - Google Patents

Abstract

FIELD: laser treatment, namely, treatment of different materials with thickness changeable along path of treatment, treatment of complex-shape parts. SUBSTANCE: apparatus provides for operative changing of its focal distance that may be realized smoothly upon laser beam passing through focusing members. Apparatus includes two mutually normal optically semitransparent focusing rods having variable curvature of surface along their cross section. Both rods have driver mechanisms and they are moved according to order of common control system of laser plant along two horizontal directions. Motions of rods are mutually dependable, and it allows to provide for accurate focusing. EFFECT: enhanced serviceability. 6 dwg

Description

 The invention relates to the field of laser processing of materials using laser radiation, in particular for processing (cutting, welding) of various materials with a variable thickness along the path.

 Known devices for laser processing of materials [1] [2] including a housing, a focusing element (lens), a nozzle block. The laser beam, passing through such a device, is focused by the lens and then through the nozzle block is directed to the workpiece (s).

 The disadvantage of this device is its limited technological capabilities of processing materials of the same thickness. When changing the processed material to another, with a different thickness, it is necessary to disassemble the device (cutter) and change the lens to another with the necessary focal length or change the cutter. This operation is time consuming and highly skilled. In addition, the presence of personnel near the zone of passage of laser radiation reduces the safety of the laser installation.

 Another disadvantage of the above design is the inability to process materials with a thickness that varies on the processing path.

 It is known that for processing materials with different thicknesses, focusing elements with different focal lengths are necessary, and, in general, the greater the thickness of the processed material, the greater the focal length of the focusing device is required for its processing (Fig. 1).

 A known device for laser processing [3] incorporating a cartridge with interchangeable focusing lenses. Each focusing lens has its own specific focal length. The cassette has a rotation drive around a vertical axis. When the cartridge rotates into the zone of passage of laser radiation, depending on the specific task, this or that lens can be supplied. Thus, it is possible to quickly change the focal length of the entire device.

 However, the above device has the following disadvantage of a stepwise change in focal length and, therefore, limited technological capabilities. For example, with such a device, it is impossible to process the widespread in practice details presented in FIG. The focus path for processing part 1 is shown by a dashed line. Refining the focus path using vertical movements of the focusing device will not lead to a positive result, since processing various thicknesses with a device with a constant focal length leads to inconsistent processing quality and, consequently, to a general deterioration in the quality of processing.

 Another disadvantage of the device under consideration is the need to stop the operation of the laser system (turning off the laser) with every change in focus.

 The aim of the invention is to expand the technological capabilities of the device.

 The above goal is achieved by the fact that in the known structure comprising a housing, a nozzle block, the focusing element is made in the form of two rods arranged one above the other in mutually perpendicular planes with cross sections of variable curvature, both rods having their own displacement drives in the horizontal plane, and sections rods with the same radii of curvature of the surface lie in one plane coinciding with the optical axis.

 The invention is illustrated in figure 3.

 The device consists of a housing 1, a nozzle block 2, a focusing optically transparent rod 3, moving along the X axis and drive 4 to it. Perpendicular to the first rod is placed focusing optically transparent rod 5, moving along the axis Y, and drive 6 to it. A general view of a focusing optically transparent rod is shown in FIG. Both drives are controlled by a common control system 7 of the laser system, which includes this device (not shown in Fig. 3).

 The device operates as follows.

 The laser beam incident on the focusing rod is focused in a line with a length equal to the diameter of the laser beam (Fig. 4). Another focusing rod mounted perpendicular to the first focuses the laser beam in a line perpendicular to the first line. Total focus radiation point. Moving the focusing rod under a stationary vertical laser beam leads to a change in focal length. Moreover, the dependence of the focal length on the amount of movement of the focusing rods is linear (figure 5). When processing materials with a constant thickness, the rods are motionless and focus the laser beam like an ordinary lens. When processing materials with variable thickness (Fig. 1), the control system 7, according to a given part processing program, controls the operation of drives 4 and 6, which move the focusing rods to a predetermined distance at the required speed. Thus, during operation, a smooth change in focus of the device.

 In order to ensure focusing of radiation to a point when changing the focus, it is necessary at any movement that sections of both focusing rods having the same radius of curvature of the surfaces are located under the laser beam. Therefore, the movements of both rods are interdependent. From external influences, the rods are closed by the housing 1; after passing the focusing rods, the radiation enters the nozzle block 2 and then from it to the workpiece (s).

 Using the proposed device allows you to automatically smoothly change focus and thereby use it to process materials with variable thickness. The stepless change of focus also makes it possible to easily programmatically process the parts shown in Fig. 6 (surfaces A are machined), and changing the sizes and shapes of the parts, as well as changing the nomenclature, do not entail the replacement of focusing elements.

Claims (1)

 A laser processing device, comprising a housing with focusing optically transparent elements placed therein and a nozzle block, characterized in that the focusing optically transparent elements are made in the form of two rods with cross sections of variable curvature located one above the other in mutually perpendicular planes with the possibility of movement, and equipped with two drives kinematically connected with the respective rods, and sections of the rods with the same radii of curvature lie in the same plane STI, which coincides with the optical axis.

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