RU2386523C1 - Device for cutting of volume parts with fibre laser - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to device for cutting of volume parts by fibre laser and may be used in dimensional processing of parts having complex spatial shape. Rotary laser cutting head of device comprises body with vertical axis of rotation (26), body installed on it with horizontal axis of rotation (30) and optical focusing head. Mentioned head is installed on hollow support arranged in the form of vertically moving slider installed on mechanical system of positioning and displacement. Body with vertical axis of rotation and body with horizontal axis of rotation have electric drives, are arranged as hollow and have rotary prisms for transportation of laser beam to optical focusing head. Slider is arranged with a mount seat for installation of collimator (6) with connector arranged on it with fibre cable (2), which transports laser radiation. Hollow shaft (24) of slider (1) is installed coaxially with collimator (6) and bears body with vertical axis of rotation and rotor of vertical electric drive on its lower end. Body with horizontal axis of rotation (30) is installed on hollow shaft (28) installed in bearing supports of intermediate body (21), installed on vertical end of body with vertical axis of rotation, and bearing rotor (27) of horizontal electric drive.

EFFECT: invention provides for high quality of cutting at high speeds and dimensions of processed parts.

1 dwg

Description

Technical field

The invention relates to laser processing of materials, in particular, to gas-laser cutting, and can be used for dimensional processing of parts of complex spatial shapes with a fiber laser.

State of the art

Known devices of the laser cutting head of the firm "Resites" (Germany) [Prospectus of the company "Precitec" from the exhibition "Metalworking-2007"], in which the connector (tip) of the transporting optical cable is connected by a QBH connector with a collimator, which in turn is precision mounted coaxially with optical cutting head. Then such a cutting head is mounted in the support of the laser complex with the ability to move it in three or more coordinates, which allows dimensional processing of the workpieces.

The disadvantage of such a cutting head is that it is possible to cut only flat parts or volumetric parts of the simplest form, which naturally limits the product range used in modern mechanisms, where it is necessary to provide a complex trajectory of the laser beam along several coordinates.

At present, this problem is being solved by combining an optical cutting head with a manipulator of existing robotic systems, for example, the development of Cook (Germany), ESAB (Sweden) and several other foreign companies.

The solution to this issue is associated with great difficulties due to maintaining a constant gap between the machined surface and the nozzle of the cutting head. Failure to do so even in a few tenths of a millimeter leads to a decrease in cutting quality.

Therefore, all laser cutting heads are equipped with a built-in sensor with automatic maintenance of a given distance. The control circuit required for distance sensors has, as a rule, the following components:

- a cutting head with a built-in proximity sensor for measuring distance;

- automated drives for positioning the cutting head according to a signal from a processing electronic device;

- electronic devices for processing sensor signals and controlling drives.

If for flat workpieces this system works very quickly and reliably, then for bulk workpieces with a complex surface in the sensor (especially a capacitive type) side interference occurs, which leads to a malfunction in the electronic system.

In this case, Precitec uses sensors with Lasermatic Z analyzing electronic systems, characterized in that the sensor is made not of ceramic parts and a nozzle electrode, but in the form of a mouthpiece that is thin with an insulating structure and is insensitive to side interference, which allows partially circumventing the data Problems.

The authors of the patent EP 1249299, В23К 26/03, 2002 (JP 2001 112678) from the company “Fanuc Ltd.”, who proposed replacing the optical cutting head mounted in the robot arm, previously instead of a collimator, with the fiber cable connector articulated with it, a mini television camera, the image from which is transmitted via a fiber cable to the robot operating system for its preliminary training, which then allows the optical cutting head to repeat the entire contour being processed of the product.

But a significant drawback of this equipment is that the parameters of industrial robots are limited by both a maximum speed of ~ 10 m / min and a movement size of ~ 1.5 m, which limits the processing speed and dimensions of the machined parts.

The closest solution to this problem is the development of a laser cutting head by Prima North America Corporation (Prospectus of Prima Industrie from the Hanover 2007 exhibition), which introduced 3D laser cutting, creating a 5-coordinate laser complex based on a powerful technological CO2 laser with high-speed axial drives and a rotary cutting head with direct drives.

The essence of this laser cutting head is as follows. For laser cutting of products with complex spatial shapes, it is necessary that the laser beam is perpendicular to the surface of the workpiece, and this requires a change in orientation in time and space of the laser beam. This can be achieved by rotating the cutting optical head around a vertical axis (coordinate C) and deviating it from a vertical position by rotating around a horizontal axis (coordinate B), plus moving the laser cutting head itself as a whole along the three coordinates X, Y, Z. Therefore, such a device called a five-axis laser cutting head.

Turns around the vertical axis (C coordinate) and around the horizontal axis (B coordinate) are carried out by synchronous circular motors located directly in the cutting head, and the laser beam, thanks to two prisms with mirrors, rotates 90 degrees on each and is directed to the focusing lens of the cutting optical head .

A capacitive-type sensor for controlling the gap between the nozzle and the surface being processed, together with Precitec Lasermatic Z analyzing electronic system, provides high-precision measurement of the gap at high speeds, which allows laser cutting of products with complex spatial shapes.

Such cutting conditions are achieved by program control of all five coordinates using the control system.

Similar 5-coordinate laser systems were also developed by Trumf, Mazak, and others.

The disadvantage of this laser cutting head is that it is designed for a CO2 laser, where laser radiation with a small angle of divergence is transported to it by the traditional method using rotary stationary mirrors located on movable carriages, the so-called "flying optics", but this scheme not suitable for a fiber laser, complex in design and reduces the technological capabilities of gas laser cutting.

SUMMARY OF THE INVENTION

The objective of the invention is the development of a laser cutting head for a fiber laser, which would expand the technological capabilities of gas laser cutting, namely cutting parts of complex spatial shapes and provide high quality cuts at high speeds and dimensions of the machined parts, limited only by the dimensions of the machine itself.

This object is achieved in that in a device for cutting fiber-optic volumetric parts with a fiber laser, comprising a rotary laser cutting head including a housing with a vertical axis of rotation, a housing with a horizontal axis of rotation mounted on a housing with a vertical axis of rotation, and an optical focusing head, wherein the laser cutting head is mounted on a hollow caliper made in the form of a vertically moving slider mounted on a mechanical positioning and moving system, and the body with a vertical axis of rotation and a housing with a horizontal axis of rotation, equipped with electric drives, made hollow and equipped with rotary prisms for transporting the laser beam to the optical focusing head, the slider is made with a seat for installing a collimator with a connector on it with a fiber cable transporting laser radiation, and equipped with a hollow shaft mounted coaxially with the collimator and bearing at its lower end a housing with a vertical axis of rotation and a rotor of a vertical electric drive, and a housing with a horizontal axis of rotation is mounted on a hollow shaft installed in the bearings of the intermediate housing mounted on a vertical end of the housing with a vertical axis of rotation and carrying a horizontal electric rotor.

This embodiment of a device for cutting fiber-optic volumetric parts with a fiber laser can improve the quality of the parts while increasing productivity.

The invention is illustrated in the drawing, which shows a General view of a laser cutting head in section.

The implementation of the invention

In accordance with the invention, a device for cutting volumetric parts with a fiber laser includes a rotatable laser cutting head mounted on a hollow support made in the form of a vertically moving slide mounted on a mechanical positioning and moving system.

The laser cutting head comprises a housing with a vertical axis of rotation and a housing with a horizontal axis of rotation mounted on a housing with a vertical axis of rotation. A body with a horizontal axis of rotation carries an optical focusing head. In this case, the housing with a vertical axis of rotation and the housing with a horizontal axis of rotation are equipped with electric drives for their movement, made hollow and equipped with rotary prisms for transporting the laser beam to the optical focusing head.

The slider is made with a seat for installing a collimator with a connector placed on it with a fiber cable transporting laser radiation, and is equipped with a hollow shaft mounted coaxially with the collimator and bearing at its lower end a body with a vertical axis of rotation and a rotor of a vertical electric drive, and the body with a horizontal the axis of rotation is mounted on a hollow shaft installed in the bearings of the intermediate housing mounted on the vertical end of the housing with a vertical axis of rotation and carrying a rotor horizontal electric drive.

An example embodiment of the invention

To move the laser cutting head, there is a machine part made in the form of a portal structure, which is justified by the large amount of displacements of the working bodies along the X and Y coordinates. This arrangement provides higher rigidity.

The machine part of the complex includes the following main components and devices:

- a mechanical positioning and moving system, including: a base, a traverse, a transverse carriage, a support made in the form of a vertically moving slider mounted on a transverse carriage;

- camera;

- a device for removing gases from the cutting zone;

- device for supplying pneumatic power supply and cooling;

- device of autonomous closed cooling;

- control system;

- pneumatic equipment.

The base fixed on the foundation is the base unit for moving the beam, consisting of the following welded units - two frames interconnected, on which racks with rails are installed on the left and right sides. On racks on four ball rolling bearings, a slide is mounted on which the beam is mounted.

Traverse, a welded aluminum beam with two rows of hardened rails, moves along the racks of the base (X coordinate). The traverse with the slide is moved by two linear drives operating synchronously.

The carriage is transverse, moving along the guides of the beam (Y coordinate) on four ball bearings. The movement is carried out by a similar linear drive.

A slider (welded aluminum), with two rows of hardened rails, moves vertically (Z coordinate) along four ball bearings mounted motionless on the transverse carriage using a synchronous motor with an integrated gapless planetary gear through a rack and pinion transmission. To unload the mass of the slider, as well as fixing its position when stopped, a pneumatic cylinder is installed with the rod fixed when the drive is turned off in the Z coordinate.

Laser radiation is transported from the fiber laser through a fiber cable laid in flexible cable chains along the coordinates X, Y and Z to a transition device that is precision coupled with a collimator.

The rotary laser cutting head (see Figure 1) is attached to the end face of the slide 1 and has the ability to move as a whole unit along the X, Y coordinate at a speed of 100 m / min, and along the Z coordinate at a speed of 30 m / min.

Fiber cable 2 serves to transport laser radiation λ = 1.07 μm from the emitter to the laser cutting head and consists of quartz fiber with a diameter of d = 50 μm, located in reflective and protective sheaths and ends with a connector.

The length of such a light guide can be up to 30 meters or more, the energy loss in this case is less than 0.5%, and the optical quality of the radiation emerging from the connector is <2.5 mm mrad.

The connector is a quartz cube, optically welded to a fiber cable, and serves to output laser radiation. For greater heat removal, the quartz cube is embedded in a metal casing and cooled with distilled water, for which there are two fittings in the connector - an inlet and an outlet (not shown in Fig. 1).

The adapter 3 is a hollow cylinder, in the upper part of which there is a seat for precision connection to the fiber cable connector 2, the so-called QBH-type connector, and in the lower part there are screws that connect the device coaxially with the collimator 6.

Collimator 6 is an optical device that converts a diverging laser beam emerging from the connector into plane-parallel, for this purpose, a lens 5 is mounted in the cylindrical body of the collimator, located at a distance of the focal length of ~ 73 mm from the output end of the connector.

The collimator 6 is mounted on the horizontal wall of the slider 1, and the slider is equipped with a hollow shaft 24 mounted on the bearing bearings 33, 35 coaxially with the collimator and bearing on its lower end a housing with a vertical axis of rotation 26, fixed with screws (in figure 1 not indicated), and the rotor 23 of the vertical electric drive, made in the form of a toroidal synchronous motor 7.

A housing with a horizontal axis of rotation 30 is mounted on a hollow shaft 28 mounted in the bearings of the intermediate housing 21 mounted on a vertical end of the housing with a vertical axis of rotation and a rotor 27 of a horizontal electric drive made in the form of a toroidal synchronous motor 8.

The motor 7 is installed in the housing 20, which is screwed through the flange 22 to the lower end of the slider 1. On the upper part of the shaft entering the inside of the slider, there are contact rings 4 with brush assemblies for transmitting power to the toroidal motor 8 and transmitting feedback signals.

The cavity inside the shaft is intended for the passage of laser radiation into the processing zone.

Inside the housing with a vertical axis of rotation 26 is a rotary prism with a mirror 9 and a cooler 34.

To fine-tune the angle of the mirror 9 with a cooler 34 is mounted using fixing screws (not shown in figure 1). This design allows you to rotate the laser beam passing from the collimator 6 inside the hollow shaft 24 and the hole in the housing 26 by 90 °, and direct it in a horizontal plane. A housing with a vertical axis of rotation 26 together with a mirror 9 and a cooler 34 is rotated around the Z axis by a toroidal motor 7 through an angle of ± 360 ° × n.

The toroidal engine 7 itself is cooled by a stream of distilled water and air, for which there are special underwater grooves in the manifold 25.

To the vertical end of the housing 26 is attached screws (not shown in FIG. 1), the intermediate housing 21 of the coordinate B with the built-in toroidal synchronous motor 8. The rotor 27 of the toroidal motor 8 is mounted on the hollow shaft 28, which rotates on the bearing bearings 36. At the end of the hollow shaft 28 is fixed screws (not shown in figure 1) the housing with a horizontal axis of rotation 30.

A housing with a horizontal axis of rotation 30 carries an optical focusing head and also has two mutually perpendicular holes, one coaxial with the hollow shaft 28, and the other with the optical focusing head so that the beam reflected from the mirror 9 through the hole in the housing 26, the hollow shaft 28 and the housing 30, it lands on a mirror 10 with a cooler 19 mounted on a wall of a rotary prism 30 inclined at an angle of 45 °. The mirror 10 with a cooler 19 is attached to the rotary prism 30 with fixing screws (not shown in FIG. 1) and has the ability to irovki relative thereto, which allows the laser beam is rotated by 90 ° and directs it to an optical focusing head.

A housing with a horizontal axis of rotation 30 with a mirror 10, a cooler 19 and an optical focusing head is rotated around a horizontal axis (coordinate B) by an angle of ± 120 ° using a toroidal motor 8.

Thus, the optical focusing head with the help of toroidal motors can rotate around the Z axis (coordinate C) by ± 360 ° × n and around the horizontal axis by an angle of ± 120 ° (coordinate B) at a speed of 360 deg / s. The optical focusing head consists of a cylindrical body 11, in the upper part of which is inserted coaxially a cartridge 31 with a focusing lens 12 with a focal length F = 150 mm, and in the lower part - a protective glass 17. The lens has the ability to move in a horizontal plane in two mutually perpendicular directions in ± 1.5 mm for more accurate alignment with the optical axis of the laser beam, as well as in a vertical plane along the Z coordinate ± 10 mm for more accurate focusing on the work surface. For this, there are two screws in the case located at an angle of 90 ° with the heads for the Allen key, and the lens itself is located in a removable cartridge and is positioned by the adjustment wheel with an accuracy of 0.05 mm (they are not shown in FIG. 1). A hollow cone — a nozzle 14 — which ends with an output mouthpiece with a sensor 15, is attached to the lower part of the housing 11 by means of a union nut 13.

In the nozzle 14 there is a fitting 16 for supplying a process gas coaxially with the laser beam, which serves to carry the decay products during laser cutting of the processed material into the suction system. At the same time, part of the process gas is diverted to cool the protective glass 17, transparent to λ = 1.07 μm, which serves to protect the focusing lens from reactive emissions of the processed material.

The capacitive type sensor 15 serves to maintain a constant gap between the output mouthpiece and the surface 29. The signal from the sensor is transmitted through a preamplifier (not shown in FIG. 1) to a collector 4 with a removable device located on the rotary head, and then transmitted to the control device (controller distance), which analyzes it and provides the necessary analog signal to the control system for controlling linear drives. The CNC system generates a specific command with the 3D-regulation function to maintain the selected gap.

The device operates as follows.

The workpiece is installed on the table of the laser machine in a special mounting device that strictly orientates the workpiece in a certain position.

Then, the ytterbium fiber laser is turned on from the control panel of the laser machine, the radiation of which is transported via an optical fiber cable 2, laid in flexible cable-bearing coordinate chains X, Y, Z to the laser cutting head, namely, to the adapter 3. Exiting from the fiber cable connector 2, the diverging laser beam passes through the collimator 6, where it is collimated using the lens 5. Next, the laser beam enters through the hollow shaft 24 of the toroidal synchronous motor 7 and the hole in the rotary prism 18 on the mirror Lo 9, where it rotates through an angle of 90 ° in a horizontal plane.

Radiation turned into a horizontal plane propagates inside the cavity of the shaft 28, the holes in the housing 30, and enters the rotary mirror 10, where it rotates again through an angle of 90 ° and is sent to the optical focusing head.

Then, the radiation using the lens 12 of the optical focusing head is focused on the surface of the workpiece 29. Coaxially with the laser radiation, the process gas is simultaneously supplied to the treatment zone under pressure through the nozzle 16, which carries the laser cutting decay products into the suction system.

Due to movements in five coordinates (X, Y, Z, B, C), the cutting optical head directs the laser beam perpendicular to the surface to be machined, and using the signal from sensor 15, the 3D control function, which is a CNC program function, maintains a constant distance between the mouthpiece 15 nozzles 14 and workpiece 29.

Thus, the diverging laser beam emerging from the connector with the collimator becomes flat parallel, and thanks to two prisms with mirrors located in the rotary head, it rotates 90 ° on each and is directed to the lens of the cutting optical head, which focuses it on the surface to be treated.

Using a numerical control system (CNC) using the available drives, it is possible to maintain the optical focusing head during processing in a position perpendicular to the surface to be machined, and thereby allows gas-laser cutting of parts of complex spatial shapes, and the 3D control function of the control system automatically stabilizes the distance between mouthpiece and workpiece surface.

Thus, the use of this device allows gas-laser cutting of products of complex spatial shapes with a fiber laser at high speeds and large sizes (more than six meters) with good cut quality.

Claims (1)

A device for cutting volumetric parts with a fiber laser, comprising a rotary laser cutting head, including a body with a vertical axis of rotation, a body with a horizontal axis of rotation mounted on it, and an optical focusing head, while the rotary laser cutting head is mounted on a hollow support made in the form of a vertically a moving slider mounted on a mechanical positioning and moving system, and a body with a vertical axis of rotation and a body with a horizontal axis of rotation have the electric drives for their movement are hollow and equipped with rotary prisms for transporting the laser beam to the optical focusing head, characterized in that the slider is made with a seat for mounting the collimator with a connector on it with a fiber cable transporting laser radiation, and equipped with a hollow shaft, mounted coaxially with the collimator and bearing at its lower end a housing with a vertical axis of rotation and a rotor of a vertical electric drive, and a housing with a horizontal axis of rotation of the mouth updated on the hollow shaft, which is installed in the bearings of the intermediate housing, mounted on the vertical end of the housing with a vertical axis of rotation, and carrying a horizontal electric rotor rotor.