Laser processing machine

Abstract

The invention relates to a laser processing machine (1) for laser processing a workpiece (2), comprising a laser processing head (3) which is mounted in a receiving device (8) so as to be pivotal about a first axis of rotation (4) of a first shaft (5) and about a second axis of rotation (6) of a second shaft (7). A first actuator (9) for pivoting the laser processing head (3) about the first axis of rotation (4) by external force is coupled to the first shaft (5), and a second actuator (10) for pivoting the laser processing head (3) about the second axis of rotation (6) by external force is coupled to the second shaft (7), wherein a first rotation angle sensor (11) and a second rotation angle sensor (14) are provided on the first shaft (5), and a third rotation angle sensor (16) and a fourth rotation angle sensor (18) are provided on the second shaft (7).

Description

[0001] Laser processing machine

[0002] The present invention relates to a laser processing machine for laser processing a workpiece, comprising a laser processing head which is pivotably mounted in a receiving device about a first axis of rotation of a first shaft and about a second axis of rotation of a second shaft, wherein a first actuator for pivoting the laser processing head about the first axis of rotation by external force is coupled to the first shaft and a second actuator for pivoting the laser processing head about the second axis of rotation by external force is coupled to the second shaft.

[0003] A laser cutting machine is a device, generally known from the prior art, that uses a high-intensity laser beam to cut or engrave various materials. Such laser cutting machines usually have a laser processing head responsible for focusing the laser beam, whereby the laser processing head is movable relative to the workpiece. The laser cutting head usually receives the laser beam from an external radiation source and modifies it so that it is suitable for cutting materials. During operation, the beam passes through at least one focusing optic (lens, lens group, or mirror), usually first a collimating optic (lens, lens group, or mirror) arranged in the laser processing head, which parallelizes it. The focusing optic then focuses the beam onto the workpiece.Typically, at least one nozzle is also present, directing a cutting gas toward the cutting point to remove molten or vaporized material and positively influencing the reactions of the workpiece material at the cutting point. Such a laser processing head often also features a distance sensor that continuously adjusts the distance of the nozzle to the workpiece surface to ensure a constant focus position of the laser beam relative to the workpiece surface and optimal gas coupling into the cutting gap. On the exit side of the laser beam from the laser processing head, facing the workpiece, there is usually at least one protective glass to protect the internal components and optics of the laser processing head from emissions and splashes during the cutting process.Cooling is also often provided to ensure that the temperature of the laser processing head components remains within specified limits to avoid beam distortion or damage to the components.

[0004] So-called 2D laser processing machines are known from the prior art, with which beveled edges prepared for welding, for example, can be cut in a plate-shaped workpiece. To achieve this, it is necessary that the processing beam can be aligned not only perpendicularly, but also at an angle of up to approximately 50° to the surface normal of the (flat) workpiece surface. For this purpose, it is known, for example, to rotate a first structural unit of the processing head or the processing head as a whole about a first axis (A axis) and a second structural unit or the processing head about a second axis (B axis) that is not aligned parallel to the first axis. Different kinematic structures for realizing such a cutting head are described, for example, in EP 2 584 419 A2, US 8946583 B2, WO 2011 / 052093 A1, US 8395075 B2 or EP2 292 361 A1.

[0005] The basic problem with a laser cutting head with two additional rotary axes is that the rotary drives lead to an increase in mass near the head or the tool center point, which in the case of a straight cut in which the head is aligned perpendicular to the workpiece surface, may lead to a significant reduction in the dynamics and thus the productivity of the (cutting) processing, which will be explained in more detail below.

[0006] The precision and quality of laser cutting are significantly influenced by the stability and accuracy of the machine movements, as well as the interaction of the laser beam with the material. Increasing the dynamics of a laser cutting machine—that is, the acceleration and processing speed—can lead to various technical challenges that can lead to a reduction in cutting accuracy.

[0007] As speed and acceleration increase during the laser cutting process, vibrations in the machine's mechanical system can increase. These vibrations can subsequently be transmitted to the cutting head and lead to deviations in the laser beam. Because lasers are extremely precise, even micrometer deviations in the beam path can negatively impact the cutting result. The risk of such vibrations generally increases with increasing mass and the resulting inertia of the laser processing head.

[0008] When laser cutting bevels on sheet metal parts, a technical challenge lies in the required rotation of the laser cutting head around two axes. This rotary motion requires robust, precise, and dynamically controlled control. However, the goal of reducing the weight and size of the drives faces a fundamental problem: Low rigidity in the drive system can lead to positioning inaccuracies. These positioning errors occur particularly when deformations or vibrations occur in the drive system that cannot be detected and thus corrected by the standard motor measurement system. This ultimately impairs the quality of the laser cut.

[0009] It is therefore the object of the invention to avoid or at least reduce the problems known from the prior art and to provide an improved laser processing head and an optimized laser processing machine so that, in particular, increased processing speed can be achieved during the laser processing of a component.

[0010] This object is achieved by a laser processing machine for laser processing a workpiece, comprising a laser processing head which is pivotably mounted in a receiving device about a first axis of rotation of a first shaft and about a second axis of rotation of a second shaft, wherein a first actuator for pivoting the laser processing head about the first axis of rotation by external force is coupled to the first shaft and a second actuator for pivoting the laser processing head about the second axis of rotation by external force is coupled to the second shaft, wherein a first rotation angle sensor is arranged on the first shaft, by means of which a first signal representing a rotation angle position of the first shaft can be provided to a control unit of the laser processing machine, and a second rotation angle sensor is arranged on the first shaft, by means of which a second,a signal representing a rotational angle position of the first shaft can be provided to the control unit of the laser processing machine, wherein a third rotational angle sensor is arranged on the second shaft, by means of which a third signal representing a rotational angle position of the second shaft can be provided to the control unit of the laser processing machine, and a fourth rotational angle sensor is arranged on the second shaft, by means of which a fourth signal representing a rotational angle position of the second shaft can be provided to the control unit of the laser processing machine.

[0011] The laser processing machine according to the invention offers the advantages of enabling high flexibility and precision in laser processing of the workpiece through the pivoting mounting of the laser processing head around two rotational axes. The provision of angle signals by two separate rotational angle sensors for each shaft on a control unit contributes to improving the accuracy and reliability of the positioning of the laser processing head. This leads to higher-quality processing results and reduces the likelihood of manufacturing errors that could lead to production downtime or rejects.

[0012] The laser processing machine according to the invention is therefore particularly suitable for demanding cutting and machining processes. The machine comprises a laser processing head that can be pivoted about two orthogonal axes of rotation – a first axis of rotation and a second axis of rotation. The precise sensory measurement of the rotational position of the respective shafts by the sensors arranged in pairs on the shafts enables fine and accurate actuator-based adjustment of the head angle, which is crucial for the quality of the laser processing. The direct measurement of the rotation angles using the rotation angle sensors on the shafts makes it possible to detect and compensate for inaccuracies that could arise, for example, due to mechanical weaknesses or play in any existing gears or the surrounding structure.This not only significantly improves the positioning and location accuracy of the cutting head, but also increases the quality of the manufactured parts.

[0013] If direct measuring systems, as proposed by the invention, were not used, the actuator drives would have to be designed significantly more rigidly, which would result in larger and heavier components. This would not only reduce the overall dynamics of the machine, but would also restrict the swivel and machining range and result in higher costs. The complexity and rigidity of the drives would also have a negative impact on the flexibility of the system.

[0014] The laser processing machine according to the invention thus enables efficient, economical and high-quality processing of a workpiece through precise control and accurate positioning of the laser processing head as well as increased dynamics.

[0015] The laser cutting head is a component of a laser cutting machine that is responsible for focusing and aligning the laser beam onto the component to be processed.

[0016] The laser processing head consists of several technical components, for example selected from a group comprising a cutting head housing, a collimation optics, a focusing optics, a nozzle, a shaft rotating about an A-axis, a shaft rotating about a B-axis.

[0017] The pivot axis of the laser processing head preferably runs approximately centrally through the longitudinal extension of the laser processing head. Particularly preferably, the pivot axis runs through the center of gravity of the laser processing head. Since, in this preferred embodiment, the center of gravity of the laser head is located on the rotation axis, the inertial forces that arise during movement of the laser processing head are minimized. This is particularly important for rapid changes in direction of the laser processing head or when high travel speeds of the laser processing head are to be achieved.

[0018] Preferably, the laser cutting head has a weight of less than 10 kg, particularly preferably less than 5 kg.

[0019] The laser processing head can preferably have a cutting head housing. The cutting head housing primarily serves as a structural support and protective cover within which the sensitive optical components, such as lenses and mirrors, required for beam shaping are housed. The structure of the cutting head housing preferably has, on the one hand, high rigidity to ensure the positioning accuracy of the focused laser beam, and, on the other hand, sufficiently high thermal stability to prevent unwanted deformations due to heat generation.

[0020] Furthermore, the cutting head housing can have a mechanical coupling for pivoting the laser processing head around the A-axis and / or B-axis. Furthermore, the cutting head housing can also be mechanically coupled to a cutting head mount.

[0021] The laser processing head is preferably coupled to a mechanical movement device, by means of which the laser processing head can be moved relative to a workpiece. It is particularly preferred that the mechanical movement device of the laser cutting machine enables movement of the laser processing head in an X-axis and a Y-axis perpendicular thereto. It can also be further preferred that the mechanical movement device enables a movement, in particular a linear movement, of the laser processing head along a Z-axis that runs perpendicular to the X-axis and / or Y-axis. For this purpose, a mechanical movement device can preferably have one or more linear guides, which are then each aligned in one of the axial directions (X-, Y-, Z-axis).

[0022] Advantageously, the mechanical movement device is operatively connected to at least one drive unit, by means of which an externally force-induced movement of the laser processing head can be effected through the kinematics predefined via the mechanical movement device. In this context, it is further preferred that each movement axis of the mechanical movement device has an individually assigned drive unit. Thus, it is preferred that a separate (X) drive unit is provided for moving the laser processing head along the X-axis and / or a separate (Y) drive unit is provided for moving the laser processing head along the Y-axis and / or a separate (Z) drive unit is provided for moving the laser processing head along the Z-axis, which enables a correspondingly precise and dynamic movement of the laser processing head relative to the workpiece.

[0023] For example, the drive units and the mechanical movement device are configured so that the laser processing head can be moved along the X or Y axis at a maximum speed of 120 m / s.

[0024] The drive units and the mechanical movement device are further configured, for example, so that the laser processing head can be accelerated to a maximum of 7 m / s 2 can be moved along the X or Y axis.

[0025] Preferably, the laser processing head is coupled to the mechanical movement device via the receiving device of the laser processing head.

[0026] The laser processing head is preferably pivotably mounted in a mounting fixture. The mounting fixture serves to support and position the laser processing head by enabling its movement and fixation around defined rotation axes. The mounting fixture thus has the task of precisely guiding the rotations of the processing head while simultaneously maintaining the necessary rigidity to absorb the forces generated during laser processing and minimize vibrations.

[0027] In particular, the support device consists of a structural frame or housing designed to securely hold the laser processing head and allow it to move about the first and second axes of rotation.

[0028] Furthermore, a guide and / or bearing, in particular a rolling or sliding bearing of the shafts of the machining head, as well as the integration and / or connection of the components necessary for the movement and positioning of the head, such as actuators and sensors, can be provided on and / or in the receiving device.

[0029] Preferably, the mounting device is designed to form a substantially U-shaped mounting area, which in turn consists of a first and a second mounting arm, between which the first shaft is mounted. This configuration provides high stability and helps prevent deformation of the device and resulting inaccuracies in laser processing. A laser processing head can also be easily mounted and dismounted thanks to the U-shaped mounting area.

[0030] Advantageously, the fixture can be made of high-strength materials such as steel, aluminum, or composite materials to provide an optimal strength-to-weight ratio and improve machine dynamics. In another preferred embodiment, the fixture can include modular elements or interchangeable components to enable easy adaptation to different processing requirements or rapid maintenance and repair. Configurations are also conceivable in which the fixture has integrated cooling systems that dissipate the heat generated during laser processing to ensure thermal stability. For the purposes of this patent application, an axis of rotation is a geometric line around which rotation of the laser processing head takes place and which defines the direction of the rotational movement.

[0031] The function of the rotation axes within the laser processing machine is to fix the pivot points of the laser processing head in a defined orientation, enabling controlled pivoting movement around each of the two axes. A first rotation axis is preferably arranged in a horizontal plane, while a second rotation axis is advantageously located in a horizontal plane orthogonal to it. This allows the processing head multidimensional freedom of movement in space.

[0032] The first shaft, representing the first axis of rotation, enables the pivoting movement of the machining head, preferably in the XZ plane, whereas the second shaft, representing the second axis of rotation, allows the pivoting movement, preferably in the YZ plane. The interaction of both axes of rotation enables the laser machining head to be fully oriented in space, allowing the workpiece to be machined from virtually any angular direction.

[0033] Preferably, the first axis of rotation is aligned perpendicular to the second axis of rotation. Furthermore, it is preferred if the first axis of rotation and the second axis of rotation are aligned parallel to a plane of a workpiece support of the laser processing machine.

[0034] The laser processing head can be pivoted around two different axes using two shafts.

[0035] A shaft for pivoting the laser processing head about an axis is a mechanical element that enables a controllable pivoting movement of the laser processing head. Preferably, a shaft has a circular cross-sectional contour.

[0036] It may also be preferred for the shaft to be formed from a metallic material. To achieve weight optimization, it may also be advantageous to construct a shaft from aluminum. In principle, it is also conceivable in this context to construct a shaft from a plastic, in particular from a fiber-reinforced plastic.

[0037] A shaft can preferably be designed as a hollow shaft, which on the one hand allows components to be passed through the hollow shaft and on the other hand enables a reduction in weight, which can also have a positive effect on the machine dynamics of the laser processing head or the laser processing machine.

[0038] It is also possible to construct a shaft in one piece or in multiple parts. A multi-part shaft can, for example, be arranged on opposite sides of the cutting head housing, with the preferably two sections of the shaft being aligned with each other on the rotation axis.

[0039] A shaft can also have a surface profile, at least in sections. For example, it would be conceivable for the shaft to have a toothed profile. A shaft can also contain gear rings, pulleys, or other drive elements that are coupled to a drive unit, such as an electric motor, to generate the rotary motion.

[0040] Preferably, a shaft is mounted in at least one bearing seat, which is preferably arranged in or on the receiving device of the laser processing head. The bearing seat for a shaft for pivoting a laser processing head is a component of the mechanical structure, preferably the receiving device, of a laser cutting machine, which enables the rotation or pivoting movement of the laser processing head. The bearing seat is designed such that it can accommodate a shaft that serves as a pivot axis for the laser processing head. In an advantageous embodiment, the laser processing head is mounted at one end of the shaft and can be positioned along one or more axes by the pivoting movement. The bearing seat is preferably designed such that it can absorb the axial and radial loads that occur during operation due to the movement of the laser processing head and the interaction with the workpiece.

[0041] A rolling bearing or plain bearing can preferably be placed in the bearing seat to accommodate the shaft.

[0042] For the purposes of this patent application, an actuator is a component of the laser processing machine that carries out an externally induced movement of the laser processing head about at least one predefined axis and thereby provides the drive energy required for the rotational movement.

[0043] An actuator can be designed as an electrical actuator, hydraulic actuator or pneumatic actuator.

[0044] An electric actuator preferably comprises an electric motor that is mechanically coupled to a shaft and supplies torque to it. This torque is converted into a rotary motion, which enables the precise positioning of the laser processing head connected to the shaft.

[0045] Preferred embodiments of the actuator can include not only simple electric motors but also servomotors, which, thanks to their precise controllability and feedback capabilities, enable particularly finely controlled movement. These servomotors can be coupled to a gear unit that converts the motor torque to a usable value, thus finely adjusting the movement of the laser processing head.

[0046] A key aspect of the actuator function is the ability to execute fast and precise movements under the control of a control unit. The control unit uses signals from the angle sensors to precisely regulate or control the position of the laser processing head. Furthermore, actuator versions with integrated measuring systems are conceivable. These measuring systems can detect position or orientation deviations directly in the actuator, thus further improving the accuracy of the motion control.

[0047] In some embodiments, the actuator can also be designed as a linear drive that generates linear movements, which are then converted into rotational movements via suitable mechanisms. An example of this would be a solenoid.

[0048] In principle, in order to reduce the system complexity and increase the uniformity in the laser processing machine, it would be conceivable for the first actuator and the second actuator to be designed essentially identically.

[0049] For the purposes of this patent application, a rotary angle sensor is a measuring device that is used to detect the rotational movement and / or angular position of a shaft, convert it into electrical signals and transmit these to a control unit as information for position determination.

[0050] An angle sensor can detect the absolute or incremental position of a shaft, allowing the precise angular position of the shaft connected to the laser processing head to be determined. This information is then used to control and regulate the positioning of the laser processing head as precisely as possible during laser processing.

[0051] The design of an angle sensor can incorporate an optical, magnetic, or capacitive measuring principle. The sensor preferably consists of a stationary part (stator) and a moving part (rotor), the latter being directly attached to the rotating shaft and detecting the rotational movement of the rotor relative to the stator. The mechanical movement can then be converted into an electrical signal using a series of measuring sections that generate different signals depending on the rotational position of the shaft.

[0052] Preferred embodiments of the angle sensor can be designed to operate as absolute angle sensors, which assign a unique value to each angular position and can thus immediately provide the current position even after the machine has been switched off and on again, without requiring a reference run. Alternatively, angle sensors can also be designed as incremental angle sensors, which detect changes in the angular position relative to a starting point, which is sufficient in many applications and enables more cost-effective solutions.

[0053] An optical angle sensor, which uses light barriers or reflectors, offers high measurement accuracy and resolution. Magnetic angle sensors, based on the principle of magnetic induction, are robust and resistant to dirt and vibration. Capacitive angle sensors, which detect changes in capacitance during rotary movements, are advantageous when interference-free signal transmission is required.

[0054] The control unit of the laser processing machine is used to control the laser processing head. It processes CAD data of the workpiece to be processed and translates this data into movement instructions for the laser processing machine, which then moves the laser cutting head accordingly relative to the workpiece.

[0055] For the purposes of this patent application, a control unit is in particular an electronic system which is responsible for processing the input signals from sensors, in particular the angle of rotation sensors, and for the control of the actuators based thereon in order to ensure precise movement and positioning of the laser processing head.

[0056] The control unit's function includes collecting, analyzing, and processing the data provided by the angle sensors to determine the position of the machining head, particularly in real time. It then generates control signals based on the machining requirements. These signals are sent to the actuators and control the necessary drive force for the required movements of the machining head. The control unit thus acts as an interface between the physical movement of the machine and its operational control by the machine operator or through preprogrammed machining processes.

[0057] A control unit can comprise a variety of components, such as microprocessors, drive controllers, digital and analog input / output interfaces, and software for executing algorithms for motion control and monitoring. This control unit can preferably also be modular in design to allow flexible adaptation to different machine configurations and machining tasks.

[0058] Advantageously, the control unit can also include diagnostic and self-test functions, allowing early detection of operational errors and thus proactive maintenance. Furthermore, designs that support network-based communication are conceivable, for example, to exchange data for preventive maintenance purposes or to enable integration into networked manufacturing systems.

[0059] In a laser cutting process, the workpiece is the material or object from which workpiece parts are cut using a laser beam. It thus acts as the substrate for the cutting or engraving actions. The workpiece absorbs the laser radiation emitted by the laser, causing a portion of the material to be melted, vaporized, or removed through a chemical reaction with the cutting gas to achieve the desired cut or engraving.

[0060] In 2D laser cutting systems, workpieces are cut in the form of flat plates. In principle, it is also conceivable for the workpiece to have a cylindrical or profile-shaped basic shape or a three-dimensional shape. It is further preferred that the workpiece be formed entirely or partially from a material selected from a group comprising metal, in particular steel, aluminum, non-ferrous metal or titanium, plastic, wood, or a composite material.

[0061] According to an advantageous embodiment of the invention, it can be provided that the first angle of rotation sensor is integrated into the first actuator and / or the third angle of rotation sensor is integrated into the second actuator. Advantageously, the invention is also further developed such that the integration of the first angle of rotation sensor in the first actuator and / or the third angle of rotation sensor in the second actuator leads to a reduction in the number of required components. This can contribute to lowering the manufacturing costs of the machine and also minimizes potential sources of error, since there are fewer connections and interfaces between the components. The integration also facilitates the maintenance and servicing of the machine and contributes to a more compact design.

[0062] According to a further preferred development of the invention, it can also be provided that the first angle of rotation sensor is positioned outside the first actuator and / or the third angle of rotation sensor is positioned outside the second actuator. This development of the invention offers the advantage of a modular design by allowing the angle of rotation sensors to be positioned outside the actuators. This allows for different actuator designs and specifications to be accommodated without compromising the accuracy of the sensors. Likewise, the replaceability of components in the event of wear or defects is facilitated, which reduces the operating and maintenance costs of the machine and increases operational availability.

[0063] Furthermore, according to a likewise advantageous embodiment of the invention, it can be provided that the first angle of rotation sensor and / or the second angle of rotation sensor and / or the third angle of rotation sensor and / or the fourth angle of rotation sensor is each an absolute angle of rotation sensor, an optical angle of rotation sensor, or an incremental angle of rotation sensor. This offers the advantage of high flexibility with regard to the selection of suitable sensors. Absolute angle of rotation sensors, for example, allow immediate position determination after the machine is switched on, without the need for a reference run, which increases operating efficiency. Optical sensors offer high precision, while incremental angle of rotation sensors can represent a more cost-effective solution.

[0064] In this context, it is particularly preferred that the angle of rotation sensors on a shaft operate according to the same measuring principle. Furthermore, it is preferred that the angle of rotation sensors on a shaft be essentially identical. However, it would also be conceivable in principle for the angle of rotation sensors on a shaft to operate according to different measuring principles.

[0065] According to a further particularly preferred embodiment of the invention, it can be provided that the second rotation angle sensor and the fourth rotation angle sensor are designed essentially identically and / or the first rotation angle sensor and the third rotation angle sensor are designed essentially identically. Advantageously, the invention can therefore be further developed with essentially identically designed second and fourth rotation angle sensors as well as first and third rotation angle sensors, thereby achieving standardization of components within the laser processing machine. This standardization facilitates the storage of spare parts, reduces costs, and enables faster replacement during servicing. Furthermore, it simplifies the design and manufacture of the machine, which can lead to cost reduction and faster production cycles.

[0066] Furthermore, the invention can also be further developed such that the first actuator has a first electric motor connected to the first shaft in a torque-transmitting manner, and / or the second actuator has a second electric motor connected to the second shaft in a torque-transmitting manner. The use of a first and second electric motor in the respective actuators to generate torque offers the advantage of precise and dynamic control of the rotary movement. The direct coupling of the electric motors to the shafts allows positioning and movement processes to be carried out quickly and accurately, leading to improved machining speeds and more precise machining results.

[0067] In a likewise preferred embodiment of the invention, it can also be provided that the first actuator has a first electric motor with a first gear coupled to the first electric motor, which is connected to the first shaft in a torque-transmitting manner, and / or the second actuator has a second electric motor with a second gear coupled to the second electric motor, which is connected to the second shaft in a torque-transmitting manner. Because the first and second actuators each contain an electric motor and a gear, a very high degree of accuracy in position control can be achieved. Servomotors can be controlled precisely, and the gears enable fine resolution of the rotary movement and high torque transmission. These features are particularly advantageous for applications requiring extreme precision and fine control of laser processing.

[0068] It may also be advantageous to further develop the invention such that the first rotation angle sensor is arranged in the direction of torque flow between the first electric motor and the first gearbox and / or the third rotation angle sensor is arranged in the direction of torque flow between the second electric motor and the second gearbox. Positioning the first and third rotation angle sensors directly between the motor and gearbox in the direction of torque flow offers the advantage of highly accurate detection of the rotational positions, unaffected by play or gearing in the gearbox. This leads to improved precision in the control of the machining process and increases the quality of the machining results. Furthermore, the influence of external disturbances, such as vibrations, can be minimized in this way.According to a further preferred embodiment of the subject matter of the invention, it can be provided that the holding device has a substantially U-shaped holding area with a first holding arm and a second holding arm extending parallel to the first holding arm, wherein the first (two-part) shaft is rotatably mounted in the first holding arm and the second holding arm. The design of the holding device with a U-shaped holding area and two holding arms extending parallel to one another, in which the first shaft is rotatably mounted, offers a stable and robust holder for the laser processing head. This ensures precise guidance of the processing head during the processing and contributes to uniform processing quality. At the same time, this design enables easy accessibility for maintenance work and quick replacement of components.

[0069] Finally, the invention can also be advantageously implemented in such a way that the second shaft is designed as a flange attached to the mounting device. Designing the second shaft as a flange attached to the mounting device offers the advantage of a simpler and more stable construction, which can reduce manufacturing and assembly costs. A strong connection to the mounting device increases the stability and accuracy of the positioning of the machining head, which is reflected in improved machining quality.

[0070] In principle, however, it is also conceivable that the second shaft is formed in one piece, in particular monolithically, with the receiving device.

[0071] The invention can also be further developed such that the first rotation angle sensor is arranged in the region of the first support arm and the second rotation angle sensor is arranged in the region of the second support arm, so that the laser processing head is positioned on the first (two-part) shaft between the first rotation angle sensor and the second rotation angle sensor. The spatial arrangement of the two rotation angle sensors on the corresponding support arms of the support device enables excellent precision in detecting the rotation angle of the first shaft. This leads to precise and stable control of the laser processing head and excellent repeatability during processing. The separate positioning of the sensors can also help minimize errors such as hysteresis effects, which could otherwise impair sensor performance.

[0072] It may also be preferred that the first actuator and the second sensor, as well as a mass element arranged in the region of the second sensor, are designed and arranged such that the center of gravity of the mass moving about the second axis of rotation is located between ±0-10% of the geometric center of the distance between the two support arms. Configuring the center of gravity of the moving mass close to the geometric center of the distance between the support arms minimizes vibrations and ensures balanced mass distribution. This promotes smooth and precise guidance of the laser processing head and reduces the mechanical load on the system, which in turn increases the service life of the machine and reduces maintenance costs.

[0073] The mass element here is a weight or mass positioned to influence the center of gravity distribution of the pivoting structure. It is positioned in functional proximity to the second rotation angle sensor.

[0074] The described arrangement of the masses (in particular the first actuator, second sensor, and mass element) allows the pivot point for rotary movements of the laser processing head to be stabilized. A center of gravity located close to the center of the movement axis minimizes the inertial forces resulting from the rotary movement and leads to a more efficient and controlled pivoting movement of the laser head. This reduces mechanical loads on the surrounding structure, which reduces wear on bearings and drives and thus potentially increases the service life of the machine. Furthermore, this enables more precise positioning of the laser processing head, as less correction effort is required by the machine control system to compensate for movements due to inertial forces. The accuracy of the processing processes is also improved, as the processing head is subject to fewer vibration-related deviations.

[0075] The distance described in percent refers to the position of the center of gravity of the mass moving around the second rotation axis relative to the geometric center of the distance between the two support arms. This distance in percent is determined using the following steps:

[0076] First, the geometric center point between the two support arms is determined. This is done by measuring the distance between the two points where the support arms hold the shaft and dividing it by two.

[0077] Next, the center of gravity of the moving mass rotating around the second axis of rotation is identified. This center of gravity results from the mass distribution of all components involved, including the laser processing head, the relevant shafts, actuators, sensors, and the mass element. The distance from this center of gravity to the previously determined geometric center is then measured.

[0078] To determine the percentage distance of the center of gravity from the geometric center, the measured distance of the center of gravity is set in relation to the total length of the distance between the recording arms.

[0079] The percentage calculation is based on the following formula:

[0080] {Percentage distance} = ({Center of gravity distance to geometric center} / {Total distance between the support arms}) * 100%

[0081] Assuming that the total distance between the support arms is 10 cm and the center of gravity of the moving masses is 0.5 cm from the geometric center, then the center of gravity is shifted by 5% from this geometric center.

[0082] 5% = ({0.5cm} / {10cm} ) * 100%

[0083] This stipulates that the center of gravity should preferably be within ±0-10% of the geometric center of the distance, meaning that the center of gravity lies in a region encompassing up to 10% of the total distance on either side of the geometric center. This specific center of gravity position serves to optimize the dynamic behavior of the machine, particularly its response to movements and inertial forces.

[0084] Furthermore, it is advantageous that the first actuator and the second sensor, as well as a mass element arranged in the region of the second sensor, are designed and arranged such that the center of gravity, starting from the intersection point of the first axis of rotation with the second axis of rotation, is offset by 0-10% towards a nozzle of the laser processing head. By placing the center of gravity of the mass moving about the second axis of rotation in the immediate vicinity of the intersection point of the axes of rotation, the inertial forces caused by acceleration and deceleration movements are reduced. This results in minimized stress on the drive components and leads to less wear and tear as well as an extended service life of the machine. The proximity of the center of gravity to the first axis of rotation also enables rapid rotational movements with less energy expenditure, allowing the machine to operate more dynamically, which leads to increased processing efficiency and shorter cycle times.Centering the center of gravity also stabilizes the movements of the laser processing head, especially at high speeds or during abrupt changes in direction. Furthermore, a laser processing machine configured in this way exhibits less tendency toward vibrations, which can impair processing precision and lead to unwanted markings on the workpiece. Positioning the center of gravity close to the rotation axis also facilitates positioning and motion control, as the machine's control unit requires fewer corrections due to inertial effects.

[0085] The percentage distance of the center of gravity from a specific intersection point, according to the claim, is determined or calculated as follows. First, the intersection point of the first axis of rotation with the second axis of rotation is identified. This serves as the reference point for the calculation. Next, the location of the center of gravity of the mass moving about the second axis of rotation is determined. This center of gravity refers to the center of mass of the system that performs the rotational movement about the second axis. The linear distance between the center of gravity and the intersection point of the axes of rotation is then measured.

[0086] The linear distance from the intersection of the rotational axes to the nozzle tip of the laser processing head is also measured. This distance serves as the baseline for the percentage calculation. The measured center of gravity distance is then set in relation to the total distance from the intersection of the rotational axes to the nozzle and converted into a percentage.

[0087] The general formula for calculating the percentage distance is:

[0088] {Percentage distance} = ({Central gravity center distance to intersection point} / {Total distance nozzle tip to intersection point}) * 100

[0089] For example, if the distance from the intersection of the rotation axes to the nozzle tip is 200 mm and the center of gravity is 10 mm from the intersection point in the direction of the nozzle, the percentage distance is 5%.

[0090] 5% = ( {10mm} / {200mm} ) * 100%

[0091] To be within the specified range of 0-10%, the center of gravity must be no more than 20 mm (10% of 200 mm) from the intersection point. A negative percentage would mean that the center of gravity is shifted in the opposite direction of the nozzle, whereas a positive value indicates a shift toward the nozzle.

[0092] According to a further preferred embodiment of the invention, it may also be advantageous for the mass element to be a locking unit, by means of which the first shaft can be locked and unlocked with respect to its rotational movement. The mass element as an integrated locking unit offers the advantage of increased safety and stability during machining. The ability to lock the rotational movement of the first shaft minimizes vibrations and movements during critical machining steps, increasing process accuracy and reducing potential error risks.

[0093] In this context, it is also advantageous if the mass element and the second sensor are integrated into a common housing. The mass element and the second sensor, integrated into a common housing, offer the advantage of a compact design and a reduction in the number of components. This leads to reduced manufacturing and assembly costs, as well as simplified maintenance and repair, as fewer individual parts need to be considered. The integrated design can also contribute to improved protection against environmental influences such as dust and moisture.

[0094] It may also be preferable for the first angle of rotation sensor to be arranged on the side of the first support arm facing the laser processing head. Due to its proximity to the laser processing head, the angle of rotation sensor detects changes in the angle of rotation more directly, which leads to a more accurate determination of the angular position. This is particularly advantageous for precision work where very accurate positioning of the processing head is crucial. The proximity of the sensor to the processing head also minimizes the possibility of transmission errors that can arise when the measuring system is further away from the location of the actual movement. Such errors can be caused, for example, by play in the mechanical connections or by elastic deformation. By mounting the sensor close to the processing head, the installation space can also be used more effectively.

[0095] In a further preferred embodiment of the invention, the first rotation angle sensor can be arranged on the side of the first support arm facing away from the laser processing head. Due to its positioning, the sensor is then further away from the heat and particle emissions that can occur during laser processing. This protects the sensor from potential damage, which contributes to increased reliability and a longer service life. Since the laser processing head usually contains high-precision optical components and can emit electromagnetic interference, placing the sensor further away from these sources offers the further advantage of minimizing possible interference. Placing the sensor away from the processing head can also improve systemic stability by making the mass distribution more balanced and thus the center of gravity of the moving masses more optimized.Finally, it is also possible to more easily provide sensors that are not located directly next to the processing location with additional protective measures such as housings or shielding without hindering the processing processes.

[0096] According to a further embodiment of the invention, the second angle of rotation sensor can be arranged on the side of the first support arm facing the laser processing head. Analogous to the first angle of rotation sensor, a more direct connection to the laser processing head ensures that the sensor detects its movements more precisely. This means that the actual angular positions of the head are reproduced more precisely, which is particularly important for complex edge cuts or welds. Due to its proximity to the laser processing head and the shielding provided by the first support arm, the sensor is also protected from external mechanical influences, such as tool collisions. As with the first angle of rotation sensor, the spatial proximity to the processing point means that the second angle of rotation sensor is less likely to be affected by vibrations of the entire machine system.In a further possible embodiment of the invention, the second rotation angle sensor can also be arranged on the side of the second receiving arm facing away from the laser processing head.

[0097] In principle, it is also conceivable for the fourth angle sensor to be arranged between the receiving device and the second actuator. Positioning the angle sensor directly between the receiving device and the second actuator can increase the accuracy of the angle detection, as mechanical interference, which can arise, for example, from gears or other drive components, is reduced. This also allows the angle sensor to detect possible inaccuracies in the actuator's movement earlier and more accurately.

[0098] The invention will be explained in more detail below with reference to figures without limiting the general inventive concept.

[0099] It shows:

[0100] Figure 1 shows a first embodiment of a laser processing machine in a schematic representation,

[0101] Figure 2 shows a second embodiment of a laser processing machine in a schematic representation,

[0102] Figure 3 shows a third embodiment of a laser processing machine in a schematic representation,

[0103] Figure 4 shows a fourth embodiment of a laser processing machine in a schematic representation,

[0104] Figure 5 shows a fifth embodiment of a laser processing machine in a schematic representation, Figure 6 shows a sixth embodiment of a laser processing machine in a schematic representation,

[0105] Figure 7 shows a seventh embodiment of a laser processing machine in a schematic representation,

[0106] Figure 8 shows a laser processing head of a laser processing machine in a first perspective view,

[0107] Figure 9 shows a laser processing head of a laser processing machine in a second perspective view,

[0108] Figure 10 shows a movement unit of a laser processing machine in a perspective view.

[0109] Figures 8-10 show a laser processing machine 1 configured as a 2D laser cutting machine for laser processing a workpiece 2, comprising a laser processing head 3, which is designed here as a laser cutting head, and which is pivotably mounted in a receiving device 8 about a first axis of rotation 4 of a first shaft 5 and about a second axis of rotation 6 of a second shaft 7, wherein a first actuator 9 for externally force-induced pivoting of the laser processing head 3 about the first axis of rotation 4 is coupled to the first shaft 5 and a second actuator 10 for externally force-induced pivoting of the laser processing head 3 about the second axis of rotation 6 is coupled to the second shaft 7.

[0110] As can be seen in Figure 10, the laser processing head 3 of the laser processing machine 1 is arranged on a mechanical movement device having two rails running in the X direction and a carrier running in the Y direction, which is guided on the rails so as to be linearly displaceable in the X direction. The laser processing head 3 can be displaced in the Y direction on the carrier. In addition, it is possible for the laser processing head 3 to be mounted relative to the carrier in the Z direction, i.e., height-adjustable. The laser processing head 3 is connected to a light guide, via which the laser light is guided from a stationary laser to the laser processing head 3. The light guide is arranged together with other supply lines in a tubular energy guide chain 36.

[0111] As can be seen in the embodiments of Figures 1-7, a first rotation angle sensor 11 is arranged on each of the first shafts 5, by means of which a first signal 12 representing a rotation angle position of the first shaft 5 can be provided to a control unit 13 of the laser processing machine 1. Furthermore, a second rotation angle sensor 14 is arranged on the first shaft 5, by means of which a second signal 15 representing a rotation angle position of the first shaft 5 can be provided to the control unit 13 of the laser processing machine 1.

[0112] Analogously, a third rotation angle sensor 16 is arranged on the second shaft 7, by means of which a third signal 17 representing a rotation angle position of the second shaft 7 can be provided to the control unit 13 of the laser processing machine 1. Furthermore, a fourth rotation angle sensor 18 is arranged on the second shaft 7, by means of which a fourth signal 19 representing a rotation angle position of the second shaft 7 can be provided to the control unit 13 of the laser processing machine 1.

[0113] A key advantage of the arrangement of these measuring systems is that they do not unnecessarily enlarge the structure of the processing unit consisting of the laser processing head 3, the mounting device 8, and its attachments. Particularly on the first rotation axis 4 (also referred to as the B-axis), the arrangement of the second rotation angle sensor 14 allows for minimal additional projection, which prevents any restriction of movement and does not reduce the processing area. “Additional projection” refers to the part of the second rotation angle sensor 14 that protrudes beyond the general dimensions of the mounting device 8. The second rotation angle sensor 14 is therefore designed and integrated in such a way that it does not protrude further into the work area or beyond the dimensions of the mounting device 8 than absolutely necessary.The small physical size ensures that the swivel range or movement of the laser processing head 3 is not restricted or only restricted to a small extent by the second rotation angle sensor 14.

[0114] On the side of the second rotational axis 6 (also referred to as the A-axis), the measuring system comprising the angle sensors 16, 18 is located at a virtually torque-free location, which means that the measurements are not distorted by torsional forces and a very high level of positioning accuracy is achieved. Utilizing the free installation space on the torque-free side and avoiding a bulky connection on the motor side also ensures that maximum inclination around the first rotational axis 4 remains possible.

[0115] The receiving device 8 has a substantially U-shaped receiving area 22 with a first receiving arm 23 and a second receiving arm 24 extending parallel to the first receiving arm 23, wherein the first shaft 5 is rotatably mounted in the first receiving arm 23 and the second receiving arm 24. The first shaft 5 is formed in two parts, with a first part (left) extending from the laser processing head 3 through the first receiving arm 23 in the direction of the first actuator 9 and a second part (right) which is fastened to the laser processing head 3 and passes through the second receiving arm 24.

[0116] The second shaft 7 is designed as a flange attached to the receiving device 8. In principle, it would also be conceivable to form the second shaft 7 in one piece, in particular monolithically, with the receiving device 8. Figure 1 shows an embodiment in which the first rotation angle sensor 11 is in the first actuator 9 and the third rotation angle sensor 16 is in the second actuator

[0117] 10 is integrated.

[0118] In the embodiment shown in Figure 3, however, the first angle of rotation sensor 11 is positioned outside the first actuator 9 and the third angle of rotation sensor 16 is positioned outside the second actuator 10.

[0119] To pivot the laser processing head 3, the laser processing machine 1 has a first actuator 9, which has a first electric motor 20, which is connected to the first shaft 5 in a torque-transmitting manner. The second actuator 10 also has a second electric motor 27, which is connected to the second shaft 7 in a torque-transmitting manner.

[0120] With the exception of the embodiment of Figure 4, the first actuator 9 has a first electric motor 20 with a first gear 21 coupled to the first electric motor 20, which is connected to the first shaft 5 in a torque-transmitting manner. Similarly, the second actuator 10 has a second electric motor 27 with a second gear 28 coupled to the second electric motor 27, which is connected to the second shaft 7 in a torque-transmitting manner.

[0121] Figures 6-7 show embodiments in which the first rotation angle sensor 11 is arranged in the torque flow direction between the first electric motor 20 and the first transmission 21. Similarly, the third rotation angle sensor 16 can also be arranged in the torque flow direction between the second electric motor 27 and the second transmission 28, although this is not shown in the figures.

[0122] In all embodiments shown, except for the one shown in Figure 6, the first rotation angle sensor 11 is arranged in the region of the first receiving arm 23 and the second rotation angle sensor 14 is arranged in the region of the second receiving arm 24, so that the laser processing head 3 is positioned on the first shaft 5 between the first rotation angle sensor 11 and the second rotation angle sensor 14.

[0123] As can be understood from Figure 3, the first actuator 9 and the second sensor 14 and a mass element 32 arranged in the region of the second sensor 14 are designed and arranged such that the center of gravity 29 of the mass moved about the second axis of rotation 6 is located between ±0-10% from the geometric center 33 of the distance 34 between the two receiving arms 23, 24.

[0124] Furthermore, the first actuator 9 and the second sensor 14 and a mass element 32 arranged in the region of the second sensor 14 are designed and arranged such that the center of gravity 29 between the intersection point 35 of the first axis of rotation 4 and the second axis of rotation 6 is offset between 0-10% from the intersection point 35 in the direction of a nozzle 31 of the laser processing head 3, which can be clearly seen from a combination of Figures 4 and 8. It can also be clearly seen that the first axis of rotation 4 is aligned perpendicular to the second axis of rotation 6. It can also be seen from a combination of Figures 4 and 8 that the first axis of rotation 4 and the second axis of rotation 6 are aligned parallel to a plane of a workpiece support or the workpiece 2 of the laser processing machine 1.

[0125] In the embodiments shown, the mass element 32 is a locking unit by means of which the first shaft 5 can be locked and unlocked with respect to its rotational movement. Even if the mass element 32 is not explicitly shown in Figures 1-2 and 5-7, it can of course also be present in these embodiments. It is preferred that the mass element 32 and the second sensor 14 are integrated into a common housing.

[0126] Figures 1-7 show different positions of the angle sensors

[0127] 11, 14, 16, 18. For example, Figures 5-6 show embodiments in which the first rotation angle sensor 11 is arranged on the side of the first mounting arm 23 facing the laser processing head 3. In Figures 1-4 and 6-8, however, the first rotation angle sensor 11 is arranged on the side of the first mounting arm 23 facing away from the laser processing head 3. Figures 5 and 7 show embodiments in which the second rotation angle sensor 14 is arranged on the side of the second mounting arm 24 facing the laser processing head 3.

[0128] In Figure 6, the second rotation angle sensor 14 is arranged on the side of the first support arm 23 facing the laser processing head 3. Figures 1-4, however, illustrate embodiments in which the second rotation angle sensor 14 is arranged on the side of the second support arm 24 facing away from the laser processing head 3.

[0129] It can also be seen from Figures 1-7 that the fourth rotation angle sensor 18 is arranged between the receiving device 8 and the second actuator 1.

[0130] The invention is not limited to the embodiments illustrated in the figures. The above description is therefore not to be considered restrictive, but rather explanatory. The following claims are to be understood as meaning that a stated feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. Where the claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a priority. List of reference symbols

[0131] 1 laser processing machine

[0132] 2 Workpiece

[0133] 3 laser processing head

[0134] 4 axis of rotation

[0135] 5 Wave

[0136] 6 axis of rotation

[0137] 7 Wave

[0138] 8 Mounting device

[0139] 9 Actuator

[0140] 10 Actuator

[0141] 11 Angle sensor

[0142] 12 Signal

[0143] 13 Control unit

[0144] 14 Angle sensor

[0145] 15 Signal

[0146] 16 Angle sensor

[0147] 17 Signal

[0148] 18 Angle sensor

[0149] 19 Signal

[0150] 20 electric motor

[0151] 21 gearboxes

[0152] 22 Recording area

[0153] 23 Recording arm

[0154] 24 Recording arm

[0155] 27 Electric motor

[0156] 28 gearboxes

[0157] 29 Focus

[0158] 31 nozzle

[0159] 32 mass element

[0160] 33 Center distance Intersection energy chain

Claims

Claims 1 . Laser processing machine (1) for laser processing a workpiece (2) comprising a laser processing head (3) which is rotatable about a first axis of rotation (4) of a first shaft (5) and about a second axis of rotation (6) of a second shaft (7) is pivotally mounted in a receiving device (8), wherein a first actuator (9) for pivoting the laser processing head (3) about the first axis of rotation (4) by external force is connected to the first shaft (5) and a second actuator (10) for pivoting the laser processing head (3) about the second axis of rotation (6) is coupled to the second shaft (7), characterized in that a first rotation angle sensor (11) is arranged on the first shaft (5), by means of which a first signal (12) representing a rotation angle position of the first shaft (5) can be provided to a control unit (13) of the laser processing machine (1), and a second rotation angle sensor (14) is arranged on the first shaft (5), by means of which a second signal (15) representing a rotation angle position of the first shaft (5) can be provided to the control unit (13) of the laser processing machine (1), wherein a third rotation angle sensor (16) is arranged on the second shaft (7), by means of which a third signal (17) representing a rotation angle position of the second shaft (7) can be provided to the control unit (13) of the laser processing machine (1), and a fourth rotation angle sensor (18) is arranged on the second shaft (7), by means of which a fourth,a signal (19) representing a rotational angle position of the second shaft (7) can be provided to the control unit (13) of the laser processing machine (1).

2. Laser processing machine (1) according to claim 1, characterized in that the first rotation angle sensor (11) is integrated in the first actuator (9) and / or the third rotation angle sensor (16) is integrated in the second actuator (10).

3. Laser processing machine (1) according to claim 1 or 2, characterized in that the first rotation angle sensor (11) is positioned outside the first actuator (9) and / or the third rotation angle sensor (11) is positioned outside the second actuator (10).

4. Laser processing machine (1) according to one of the preceding claims, characterized in that the first rotation angle sensor (11) and / or the second rotation angle sensor (14) and / or the third rotation angle sensor (16) and / or the fourth rotation angle sensor (18) is / are each an absolute rotation angle sensor or an optical rotation angle sensor or an incremental rotation angle sensor.

5. Laser processing machine (1) according to one of the preceding claims, characterized in that the second rotation angle sensor (14) and the fourth rotation angle sensor (18) are designed substantially identically and / or the first rotation angle sensor (11) and the third rotation angle sensor (16) are designed substantially identically.

6. Laser processing machine (1) according to one of the preceding claims, characterized in that the first actuator (9) has a first electric motor (20) which is connected to the first shaft (5) in a torque-transmitting manner and / or the second actuator (10) has a second electric motor (27) which is connected to the second shaft (7) in a torque-transmitting manner.

7. Laser processing machine (1) according to one of the preceding claims, characterized in that the first actuator (9) has a first electric motor (20) with a first gear (21) coupled to the first electric motor (20), which is connected to the first shaft (5) in a torque-transmitting manner and / or the second actuator (10) has a second electric motor (27) with a second gear (28) coupled to the second electric motor (27), which is connected to the second shaft (7) in a torque-transmitting manner.

8. Laser processing machine (1) according to claim 7, characterized in that the first rotation angle sensor (11) is arranged in the torque flow direction between the first electric motor (20) and the first gear (21) and / or the third rotation angle sensor (16) is arranged in the torque flow direction between the second electric motor (27) and the second gear (28).

9. Laser processing machine (1) according to one of the preceding claims, characterized in that the receiving device (8) has a substantially U-shaped receiving area (22) with a first receiving arm (23) and a second receiving arm (24) extending parallel to the first receiving arm (23), wherein the first shaft (5) is rotatably mounted in the first receiving arm (23) and the second receiving arm (24).

10. Laser processing machine (1) according to claim 9, characterized in that the second shaft (7) is designed as a flange fastened to the receiving device (8).

11. Laser processing machine (1) according to one of claims 9 or 10, characterized in that the first rotation angle sensor (11) is arranged in the region of the first receiving arm (23) and the second rotation angle sensor (14) is arranged in the region of the second receiving arm (24), so that the laser processing head (3) is positioned on the first shaft (5) between the first rotation angle sensor (11) and the second rotation angle sensor (14).

12. Laser processing machine (1) according to one of the preceding claims, characterized in that the first actuator (9) and the second sensor (14) and a mass element (32) arranged in the region of the second sensor (14) are designed and arranged such that the center of gravity (29) of the mass moved about the second axis of rotation (6) is between ±0-10% from the geometric center point (33) of the distance (34) between the two receiving arms (23, 24).

13. Laser processing machine (1) according to one of the preceding claims, characterized in that the first actuator (9) and the second sensor (14) and a mass element (32) arranged in the region of the second sensor (14) are designed and arranged such that the center of gravity (29) is offset by 0-10% in the direction of a nozzle (31) of the laser processing head (3) starting from the point of intersection (35) of the first axis of rotation (4) with the second axis of rotation (6).

14. Laser processing machine (1) according to claim 12 or 13, characterized in that the mass element (32) is a locking unit by means of which the first shaft (5) can be locked and unlocked with respect to its rotational movement.

15. Laser processing machine (1) according to one of claims 12-14, characterized in that the mass element (32) and the second sensor (14) are arranged in a common Housing is integrated.

Images