LASER PROCESSING SYSTEM AND LASER PROCESSING PROCESS

Abstract

In laser processing systems, laser processing is sometimes carried out in an automated operating mode, in which a robot and a laser oscillator work automatically according to a processing program. Occupational safety must be ensured in such automated operation. A laser processing system 10 comprises a laser processing head 14; a robot 12 for moving the laser processing head 14; a distance measuring sensor 56 for measuring the distance between the laser processing head 14 and a workpiece; a control device 18 for controlling the laser emission operation of the laser oscillator 16 and the movement operation of the robot 12; and a mode selector switch 52 for selecting an operating mode for the laser processing. The control device 18 executes the laser emission operation and the movement operation as an automatic operating mode when the automatic operating mode has been selected by the mode selector switch 52 and the distance measured by the distance measuring sensor 56 is within a predetermined range.

Description

Technical area

[0001] The present invention relates to a laser processing system and a laser processing method. General state of the art

[0002] A laser processing system for performing laser processing on a workpiece is known (e.g., Patent Literature Example 1). Literature listPatent literature

[0003] PTL 1: JP 2015-167974 A Brief description of the inventionTechnical problem

[0004] The laser processing system can perform laser processing in an automatic drive mode, in which a robot and a laser oscillator are automatically driven according to a processing program. With such an automatic drive, work safety must be ensured. Solution to the problem

[0005] According to one aspect of the present disclosure, a laser processing system is configured to perform laser processing on a workpiece, wherein the laser processing system comprises a laser processing head configured to emit a laser beam generated by a laser oscillator; a robot configured to move the laser processing head relative to the workpiece; a distance measuring sensor configured to measure a distance between the laser processing head and the workpiece; and a controller configured to control a laser emission operation in which the laser oscillator is operated to emit a laser beam from the laser processing head, and a motion operation in which the robot is operated to move the laser processing head relative to the workpiece.and a mode selector switch configured to select a drive mode of laser processing;

[0006] The controller is configured to execute the laser emission operation and the movement operation as the automatic drive mode when an automatic drive mode in which the laser emission operation and the movement operation are automatically executed according to a machining program is selected as the drive mode by the mode selector switch, and the distance measured by the distance measuring sensor is within a predetermined range. Short description of the drawings [ Fig. 1] Fig. 1 is a schematic diagram of a laser processing system according to one embodiment. [ Fig. 2] Fig. Figure 2 is a block diagram of the laser processing system, which is located in Fig. 1 is shown. [ Fig. 3] Fig. 3 is an enlarged view of a laser processing head used in Fig. 1 is shown. [ Fig. 4] Fig. 4 is an enlarged view of a mode selector switch used in Fig. 1 is shown. [ Fig. 5] Fig. Fig. 5 is a view for explaining a function of a contact detection device used in Fig. 2 is shown. [ Fig. 6] Fig. 6 is a flowchart showing an example of an operation of a laser processing head used in Fig. 2 shows. [ Fig. 7] Fig. Fig. 7 is a flowchart showing an example of a flow of step S2 in Fig. 6 shows. [ Fig. 8] Fig. Fig. 8 is a flowchart showing an example of a flow of step S3 in Fig. 6 shows. [ Fig. 9] Fig. 9 is a block diagram showing another function of the laser processing system used in Fig. 2 shows. [ Fig. 10] Fig. 10 is a flowchart showing another example of the flow of step S3 in Fig. 6 shows. [ Fig. 11] Fig. 11 is a flowchart showing still another example of the flow of step S3 in Fig. 6 shows. [ Fig. 12] Fig. 12 is a flowchart showing an example of an operation of the laser processing system used in Fig. 9 shows. [ Fig. 13] Fig. 13 is an enlarged view of a mode selector switch according to another embodiment. [ Fig. 14] Fig. 14 is a flowchart showing an example of a flow of step S2 in Fig. 12 shows. [ Fig. 15] Fig. 15 is a flowchart showing an example of a flow of step S3 in Fig. 12 shows. [ Fig. 16] Fig. 16 is a flowchart showing an example of a flow of step S5 in Fig. 12 shows. [ Fig. 17] Fig. 17 shows an example of a mode selector switch image. [ Fig. 18] Fig. 18 is a schematic diagram of a laser processing system according to another embodiment. [ Fig. 19] Fig. 19 is a block diagram of the laser processing system used in Fig. 18 is shown. Description of embodiments

[0007] Based on the drawings, embodiments of the present disclosure will be described in detail below. It should be noted that in the various embodiments described below, like elements are denoted by like reference numerals, and repeated descriptions will be omitted. First, with reference to Fig. 1 and Fig. 2, a laser processing system 10 according to one embodiment will be described. The laser processing system 10 is a system that, together with an operator, can perform laser processing (laser welding, laser cutting, and the like) on a workpiece W.

[0008] Specifically, the laser processing system 10 includes a robot 12, a laser processing head 14, a laser oscillator 16, and a controller 18. The robot 12 moves the laser processing head 14 with respect to the workpiece W. In the present embodiment, the robot 12 is a vertical articulated robot having a robot base 20, a pivot body 22, a lower arm 24, an upper arm 26, and a wrist 28.

[0009] The robot base 20 is fixed to a floor of a work cell. The pivot body 22 is provided on the robot base 20 and is rotatable about the vertical axis. The lower arm 24 is provided on the pivot body 22 so that it can rotate about a horizontal axis. The upper arm 26 is rotatably provided at the distal end portion of the lower arm 24. The wrist 28 includes a wrist base 28a provided at a distal end portion of the upper arm 26 so that it can rotate about two mutually orthogonal axes, and a wrist flange 28b rotatably provided on the wrist base 28a.

[0010] The components of the robot 12 (ie, the robot base 20, the swivel body 22, the lower arm 24, the upper arm 26 and the wrist 28) are each provided with several servo motors 30 ( Fig. 2). The servomotors 30 cause each of the movable components (the swivel body 22, the lower arm 24, the upper arm 26, the wrist 28, and the wrist flange 28b) of the robot 12 to rotate about a drive axis in response to a command from the controller 18. The robot 12 thereby moves the laser processing head 14 with respect to the workpiece W.

[0011] The laser processing head 14 is detachably mounted on the wrist flange 28b of the robot 12 and emits a laser beam LB generated by the laser oscillator 16. Specifically, the laser processing head 14 has, as shown in Fig. Figure 3 shows a head body 32, a nozzle 34, an attachment tool 36 and a handle 38. The head body 32 is designed to be hollow and accommodates components of an optical system such as an optical lens (e.g. a collimator lens or a focusing lens) and a lens drive unit (e.g. a servo motor) that moves the optical lens in response to a command from the controller 18.

[0012] The nozzle 34 is designed to be hollow and is provided at a distal end portion of the head main body 32. The nozzle 34 has a truncated conical outline with a cross-sectional area that decreases from a base end portion to its distal end portion, and an exit port 34a is formed at the distal end portion. A hollow chamber is formed inside the head main body 32 and the nozzle 34, and an auxiliary gas AG is supplied into the chamber from an externally provided auxiliary gas supply device (not shown). The laser beam LB generated by the laser oscillator 16 propagates in the chamber and is radiated along an optical axis A from the exit port 34a together with the auxiliary gas AG.

[0013] The attachment tool 36 is provided on the head main body 32 and can be attached to and detached from the wrist flange 28b of the robot 12. As one example, the attachment tool 36 may include a fastener such as a screw bolt and be fixed to the wrist flange 28b by the fastener. As another example, the attachment tool 36 may include an engaging portion that is detachably engaged with an engaging portion formed on the wrist flange 28b and can be attached to and detached from the wrist flange 28b through the engagement between the two engaging portions. As yet another example, the attachment tool 36 may include an electromagnet and be clamped and fixed to the wrist flange 28b by an electromagnetic force generated by the electromagnet.The laser processing head 14 is removably attached to the wrist flange 28b of the robot 12 via this attachment tool 36.

[0014] The handle 38 is provided integrally with a base end portion of the head main body 32 so that the handle 38 can be grasped by an operator with one hand. The handle 38 may have an uneven portion corresponding to the fingers of one hand to enable the operator to grasp it with one hand. The operator grasps the handle 38 and detaches the laser processing head 14 from the wrist flange 38a, thereby allowing the operator to carry the laser processing head 14.

[0015] With reference to Fig. 1 and Fig. 2, the laser oscillator 16 internally performs laser oscillation in response to a command (a laser power command or the like) from the controller 18 and generates the laser beam LB. The laser oscillator 16 may be any type of laser oscillator, such as a fiber laser oscillator, a pulsed laser oscillator, a direct diode laser (DDL), a CO2 laser oscillator, or a solid-state laser (YAG) oscillator. The laser oscillator 16 delivers the generated laser beam LB to the laser processing head 14 via a light guide path 39. The light guide path 39 may be composed of an optical fiber, a cavity, a light guide material such as a crystal, a reflection mirror, or an optical lens.

[0016] The controller 18 controls a laser emission operation LO, in which the laser oscillator 16 is operated to emit the laser beam LB from the laser processing head 14, and a motion operation MO, in which the robot 12 is operated to move in relation to the workpiece W, with the laser processing head 14 attached to the robot 12.

[0017] Specifically, the control 18 is as in Fig. 2 shows a computer including a processor 40, a memory 42, and an I / O interface 44. The processor 40 includes a CPU or a GPU, is communicatively connected to the memory 42 and the I / O interface 44 via a bus 46, and executes various types of computational processing in communication with these components to perform laser processing described below. The memory 42 includes a RAM or a ROM and temporarily or permanently stores various types of data used for the computational processing performed by the processor 40 and various types of data generated during the computational processing.

[0018] The I / O interface 44 includes, for example, an Ethernet (registered trademark) port, a USB port, an optical fiber connector, or an HDMI (registered trademark) port, and performs wired or wireless data communication with an external device according to a command from the processor 40. The robot 12 (specifically, each servo motor 30), the laser processing head (specifically, the lens drive unit), and the laser oscillator 16 are communicatively connected to the I / O interface 44.

[0019] The controller 18 is further provided with an input device 48 and a display device 50. The input device 48 comprises a keyboard, a mouse, or a touchscreen and receives data input from an operator. The display device 50 comprises a liquid crystal display or an organic EL display and displays various types of data.

[0020] The input device 48 and the display device 50 are connected to the I / O interface 44 so that they can communicate in a wired or wireless manner. Note that the input device 48 and the display device 50 may be incorporated into a housing of the controller 18 or may be provided separately from the housing of the controller 18, for example, as a computer (PC or the like).

[0021] The laser processing system 10 further comprises a mode selector switch 52, a force sensor 54 ( Fig. 2), a distance measuring sensor 56, an input device 58, and a contact detection device 60. The mode selector switch 52 is used to select a drive mode for the laser processing performed by the controller 18. In the present embodiment, the mode selector switch 52 is implemented as a unit with the controller 18.

[0022] More precisely, the mode selector switch 52 is as in Fig. 4, the control unit 18 is configured to switch the drive mode DM between an automatic drive mode DM1, indicated as "AUTO," and a manual drive mode DM2, indicated as "MANUAL." The automatic drive mode DM1 is the drive mode DM in which the processor 40 of the controller 18 automatically executes the laser emission mode LO and the movement mode MO according to a pre-created machining program.

[0023] Specifically, upon receiving an automatic drive start command CM1 described later, the processor 40 sequentially generates commands for the laser oscillator 16 following the machining program PP, and automatically executes the laser emission operation LO in which the laser oscillator 16 is operated according to the commands and the laser beam LB is emitted from the laser machining head 14.

[0024] Together with the laser emission operation LO, the processor 40 generates commands (a position command, a speed command, a torque command and the like) for the robot 12 (specifically, each servo motor 30) in sequence according to the machining program PP and automatically executes the motion operation MO, in which the robot 12 is operated according to the commands and the laser processing head 14 is moved in relation to the workpiece W.

[0025] This machining program PP is created in advance by the operator and stored in the memory 42. It should be noted that the machining program PP is a first machining program PP A , which defines the operation of the laser oscillator 16, and a second processing program PP B which defines the operation of the robot 12.

[0026] On the other hand, the manual drive mode DM2 is the drive mode DM in which the operator grasps and carries the laser processing head 14 by hand, manually causes the controller 18 to execute the laser emission operation LO, and manually performs laser processing on the workpiece W with the laser beam LB emitted from the laser processing head 14. In this manual drive mode DM2, the operator manually issues a manual laser emission command CM2 described later to the controller 18, and the processor 40 of the controller 18 executes the laser emission operation LO in response to the manual laser emission command CM2.

[0027] The operator can switch the drive mode DM between the automatic drive mode DM1 and the manual drive mode DM2 by operating the mode selector switch 52. Fig. 4 shows a state in which the automatic drive mode DM1 (“AUTO”) is selected by the mode selector switch 52.

[0028] When the automatic drive mode DM1 is selected by the mode selector switch 52, the mode selector switch 52 sends a command CM3 to the controller 18 to switch to the automatic drive mode. Conversely, when the manual drive mode DM2 is selected by the mode selector switch 52, the mode selector switch 52 sends a command CM4 to the controller 18 to switch to the manual drive mode. The command CM3 for switching to the automatic drive mode and the command CM4 for switching to the manual drive mode can be ON / OFF signals (command CM3 for switching to the automatic drive mode: ON signal or "1" signal, command CM4 for switching to the manual drive mode: OFF signal or "0" signal).

[0029] The force sensor 54 ( Fig. 2) is provided on the robot 12 and detects an external force F applied to the robot 12. As an example, the force sensor 54 is attached to each servo motor 30 of the robot 12 and includes a plurality of torque sensors 54A configured to detect a torque applied to an output shaft of a servo motor 30.

[0030] As another example, force sensor 54 is attached to a component (e.g., robot base 20 or wrist 28) of robot 12 and includes a six-axis force sensor 54B capable of detecting a force in the direction of the six axes. Based on detection data DF of force sensor 54, processor 40 of controller 18 can obtain the magnitude and direction of external force F applied to robot 12 and determine the part of robot 12 to which the external force F is applied (e.g., wrist 28).

[0031] The distance measuring sensor 56 measures a distance d between the laser processing head 14 (e.g., the exit opening 34a) and the workpiece W. Specifically, the distance measuring sensor 56 is, for example, a capacitance-type, infrared-type, laser-type, or acoustic wave-type (e.g., ultrasonic-type) distance measuring sensor. For example, in the case of the capacitance-type, the distance measuring sensor 52 is provided on the head main body 32 (or the nozzle 34) to measure the distance to an object located at a position closest to the laser processing head 14.

[0032] On the other hand, in the case of the infrared type, the laser type, or the sound wave type, the distance measuring sensor 56 is positioned on the main body 32 (or the nozzle 34) of the laser processing head 14 such that the measuring direction D (in other words, the emission direction of the infrared beam, the laser, or the sound waves) is parallel to the optical axis A. That is, in this case, the distance measuring sensor 56 measures the distance d between the laser processing head 14 (the output aperture 34a) and the workpiece W in the direction of the optical axis A.

[0033] The input device 58 receives an actuation signal to input the manual laser emission command CM2, which instructs the processor 40 of the controller 18 to execute the laser emission operation LO. Specifically, the input device 58 comprises a push button, a switch, or a touchscreen, enabling manual input by the operator, and is located on the laser processing head 14 (e.g., the head body 32 or the handle 38). Upon receiving the input signal from the operator, the input device 58 transmits the manual laser emission command CM2 to the controller 18. The manual laser emission command CM2 can be an ON signal (or a "1" signal).

[0034] Upon receiving the manual laser emission command CM2 during the execution of the manual drive mode DM2, the processor 40 of the controller 14 executes the laser emission command LO in response to the manual laser emission command CM2. This allows the operator to manually perform laser processing on the workpiece W in the manual drive mode DM2 by the laser beam LB emitted from the output port 34a of the laser processing head 14 while carrying the laser processing head 14 by hand. In the present embodiment, the input device 258 is provided on the laser processing head 14 adjacent to the handle 38, so that the operator can perform the input operation with one hand grasping the handle 38.

[0035] The contact detection device 60 detects whether the laser processing head 14 and the workpiece W are in contact or not in contact. Specifically, the contact detection device 60 comprises a conductive cable 60a and a resistance sensor 60 ( Fig. 2 and Fig. 5). One end of the conductive cable 60a is electrically connected to the head main body 32 of the laser processing head 14, and the other end is electrically connected to the workpiece W, thereby electrically connecting the laser processing head 14 and the workpiece W.

[0036] Here, in the present embodiment, at least a part of the head main body 32 and the nozzle 34 of the laser processing head 14 is made of a conductive material (e.g., a metal). The workpiece W is made of metal (e.g., iron or copper). Therefore, the workpiece W, the head main body 32 and the nozzle 34 of the laser processing head 14, and the conductive cable 60a form a closed circuit 62 when the distal end 34 of the laser processing head 14 comes into contact with the workpiece W, as shown in Fig. 5 is shown.

[0037] The resistance sensor 60b measures a resistance R of the closed circuit 62 by applying a voltage to this closed circuit 62. As in Fig. 5, the resistance R measured by the resistance sensor 60b is an extremely small value R0 (R0 ≈ 0) when the laser processing head 14 and the workpiece W are in contact with each other. On the other hand, the resistance R measured by the resistance sensor 60b is an extremely large value R1 (R1 ≈ ∞ >> R0) when the laser processing head 14 and the workpiece W are not in contact with each other (that is, when the distal end of the nozzle 34 is separated from the workpiece W).

[0038] The contact detection device 60 can detect whether the laser processing head 14 and the workpiece W are in contact or not in contact based on the resistance R measured by the resistance sensor 60b. The resistance sensor 60b provides measurement data of the measured resistance R or contact determination data indicating the contact or non-contact between the laser processing head 14 and the workpiece W to the controller 18 as detection data DD.

[0039] The processor 40 of the controller 18 can determine the contact or non-contact between the laser processing head 14 and the workpiece W from the detection data DD of the resistance sensor 60b. The resistance sensor 60b can be incorporated into the head main body 32. Note that the force sensor 54, the distance measuring sensor 56, the input device 58, and the contact detection device 60 (the resistance sensor 60b) can be connected to the I / O interface 44 of the controller 18 so that they can communicate in a wireless or wired manner.

[0040] Next, with reference to Fig. Section 6 describes the operation of the laser processing system 10. The processor 40 of the controller 18 begins the sequence of Fig. 6, for example, when it receives an operation start command (e.g. the power supply switch-on command) from the operator, a host controller or an operating program OP.

[0041] At step S1, the processor 40 determines whether the automatic drive mode DM1 is selected by the mode selector switch 52. Specifically, the processor 40 determines whether the command CM3 to transition to the automatic drive mode or the command CM4 to transition to the manual drive mode has been received from the mode selector switch 52. The processor 40 determines YES if it has received the command CM3 to transition to the automatic drive mode and determines NO if it has received the command CM4 to transition to the manual drive mode.

[0042] In step S2, the processor 40 switches the drive mode DM to the automatic drive mode DM1 and executes the automatic drive mode DM1 process. After switching to the automatic drive mode DM1, the processor 40 is placed in a state where it can receive the command CM1 to start the automatic drive and rejects a command CM2 supplied from the input device 58 to start the manual drive. Referring to Fig. 7, the flow of the automatic drive mode DM1 at step S2 is described below.

[0043] At step S11, the processor 40 determines whether the automatic drive start command CM1 has been received to start the automatic drive in the automatic drive mode DM1. Specifically, the processor generates an automatic drive start image IM1 (not shown) including an image of a button to start the automatic drive and displays it on the display device 50.

[0044] The operator operates the input device 48 of the controller 18 to click the button image displayed in the image IM1 for starting the automatic drive, thereby making an input to issue the command CM1 for starting the automatic drive to the processor 40. If the processor 40 receives the command CM1 for starting the automatic drive, it determines YES and proceeds to step S14, while if it determines NO, it proceeds to step S12.

[0045] At step S12, the processor determines whether or not an operation end command (e.g., a shutdown command) has been received from, for example, the operator, the host controller, or the operating program OP. If the processor 40 has received the operation end command, it determines YES and terminates the Fig. The sequence of steps S2 shown in section 7 results in the following: Fig. 6 is terminated. On the other hand, if the processor 40 determines NO, it proceeds to step S13.

[0046] At step S13, the processor 40 determines whether or not the automatic drive mode DM1 is still selected by the mode selector switch 52. If the processor determines YES, it returns to step S11. On the other hand, if the processor 40 determines NO (ie, the mode selector switch 52 has been operated to switch to the manual drive mode DM2), it goes to step S3 in Fig. 6 over.

[0047] On the other hand, if the processor 40 determines YES in step S11, it starts an operation to obtain the external force F applied to the robot 12 and an operation to obtain the distance d between the laser processing head 14 and the workpiece W in step S14. Specifically, the processor 40 continuously (e.g., periodically) acquires the detection data DF from the force sensor 54 and, based on the detection data DF, continuously acquires the external force F applied to the robot 12. The processor 40 continuously (e.g., periodically) acquires the distance d between the laser processing head 14 and the workpiece W measured by the distance measuring sensor 56. Thereby, the processor 40 monitors the external force F and the distance d after starting step S14.

[0048] At step S15, the processor 40 determines, as in step S13 described above, whether or not the automatic drive mode DM1 is still selected by the mode selector switch 52. If the processor 40 determines YES, it proceeds to step S16, and if it determines NO, it proceeds to step S25.

[0049] At step S16, the processor 40 determines whether the distance d between the laser processing head 14 and the workpiece W, which was last obtained, is within a predetermined range RG. For example, this distance RG may be defined as a range of d ≤ d th (e.g., d th = 3 mm) be defined, or can it be defined as a range of [d th1 , d th2 ] (e.g., d th1 = 0.1 mm, d th2 = 3 mm) (ie, d th1 ≤ d ≤ d th2). If the distance d is within this range RG, the processor determines YES and proceeds to step S17. On the other hand, if the distance d is outside the range RG, the processor 40 determines NO and proceeds to step S23.

[0050] At step S17, the processor 40 begins automatic driving. Specifically, the processor 40 reads and executes the machining program PP from the memory 42, and sequentially generates a command to the laser oscillator 16 and a command to the robot 12 according to the machining program PP. Thus, the processor 40 begins automatic driving, in which the laser emission operation LO and the movement operation MO are automatically executed according to the machining program PP.

[0051] As described above, in the present embodiment, the processor 40 executes the laser emission operation LO and the movement operation MO as the automatic drive mode DM1 when the conditions that the automatic drive mode DM1 is selected by the mode selection switch 52 (when YES is determined at step S15) and the distance d measured by the distance measuring sensor 56 is within the range RG (when YES is determined at step S16) are satisfied.

[0052] At step S18, the processor 40 determines, as in step S13 described above, whether or not the automatic drive mode DM1 is still selected by the mode selector switch 52. If the processor 40 determines YES, it proceeds to step S19, and if it determines NO, it proceeds to step S24.

[0053] At step S19, the processor 40 determines, as in step S16 described above, whether the distance d between the laser processing head 14 and the workpiece W, which was last obtained, is within the range RG or not. If the processor 40 determines YES, it proceeds to step S20, and if it determines NO, it proceeds to step S22.

[0054] At step S20, processor 40 determines whether the external force F that was last obtained exceeds a predetermined threshold F. th1 exceeds (F > F th1 ) or not. Processor 40 determines YES if F > F th1 is present, and proceeds to step S22, or determines NO if F ≤ F th1 is present and proceeds to step S21.

[0055] Based on the detection data DD of the force sensor 54, the processor 40 can monitor the external force F1 exerted on a specific part (e.g., the upper arm 26 or the wrist 28) of the robot 12 and determine YES if the external force F1 exceeds the threshold value F1 at step S20. th1 exceeds (F1 > F1 th1 ).

[0056] At step S21, the processor 40 determines whether the automatic drive has ended or not. For example, the processor 40 can determine from the executed machining program PP whether all command codes for the laser emission mode LO and the movement mode MO defined in the machining program PP have been executed or not.

[0057] If the processor 40 determines YES, it returns to step S12, and if it determines NO, the processor 40 returns to step S18. Thereby, the processor 40 repeatedly executes the loop of steps S18 to S21 until NO is determined at step S18 or S19 or YES is determined at step S20 or S21, and continuously executes the laser emission operation LO and the movement operation MO as the automatic drive mode DM1.

[0058] On the other hand, if the processor 40 determines NO in step S19 or YES in step S20, it stops at least one of the laser emission mode LO and the movement mode MO in the automatic drive mode DM1 in step S22. As an example, the processor 40 stops both the laser emission mode LO and the movement mode MO in step S22.

[0059] Specifically, the processor 40 stops the operation of the servo motors 30 by issuing a command (a torque command or the like) to each servo motor 30 of the robot 12, thereby stopping the motion operation MO. Alternatively, if a braking mechanism configured to brake the output shaft of each servo motor 30 is provided, the processor 40 may forcibly stop the operation of each servo motor 30 by operating the braking mechanism, thereby stopping the motion operation MO.

[0060] The processor 40 stops the laser emission operation LO by stopping the laser beam generation operation of the laser oscillator 16. If the laser oscillator 16 is provided with a shutter (not shown) configured to automatically open and close an optical path of the laser beam LB, the processor 40 may alternatively stop the laser emission operation LO by covering the laser beam LB with the shutter.

[0061] As another example, the processor 40 may stop the laser emission operation LO and continue the movement operation MO at step S22 after determining NO at step S19, and stop both the laser emission operation LO and the movement operation MO at step S22 after determining YES at step S20.

[0062] As described above, the robot 12 in the present embodiment is a cooperative robot capable of immediately stopping the movement operation MO in response to the external force F detected by the force sensor 54. If the cooperative robot is capable of immediate stopping as described above, the operator's safety can be ensured by stopping only the laser emission operation LO even if the determination is NO in step S19.

[0063] At step S23, the processor 40 generates an alarm signal AL. For example, if NO is determined at step S16 or S19, the processor 40 generates an alarm signal AL1 at step S23 consisting of an image display or a voice prompt, "The workpiece may not be set up in a suitable position with respect to the laser processing head. Please check the setup status of the workpiece."

[0064] On the other hand, if YES is determined in step S20, the processor 40 generates an alarm signal AL2 in step S23 from an image or a voice prompting "The robot may collide with an object in the surroundings. Please check the surroundings of the robot." The processor may display the generated alarm signal AL1 or AL2 as an image on the display device 50 or output the alarm signal AL1 or AL2 as a voice through a speaker (not shown) provided on the controller 18. After step S23, the processor 40 returns to step S12.

[0065] On the other hand, if NO is determined in step S18, the processor 40 stops at least one of the laser emission mode LO and the movement mode MO in step S24, as in the above-described step S22. For example, the processor 40 stops both the laser emission mode LO and the movement mode MO in step S24.

[0066] In step S25, the processor 40 generates the alarm signal AL. For example, the processor 40 generates an alarm signal AL3 from an image representation or a voice utterance "automatic drive cannot be performed because the drive mode has been changed." The processor 40 can display the generated alarm signal AL3 as an image representation on the display device 50 or output the alarm signal AL3 as a voice utterance through the loudspeaker. After step S25, the processor 40 returns to step S3 in Fig. 6 back.

[0067] With further reference to Fig. 6, the processor 40 sets the drive mode DM upon a determination of NO at step S1 (alternatively, upon a determination of NO at step S13 in Fig. 7 or after step S25) to the manual drive mode DM2 and executes the sequence of the manual drive mode DM2 at step S3.

[0068] After transitioning to the manual drive mode DM2, the processor 40 is placed in a state where it accepts the manual laser emission command CM2 supplied from the input device 58, while rejecting the command CM1 for starting the automatic drive. The flow of the manual drive mode DM2 at step S3 will be described below with reference to Fig. 8 will be described.

[0069] At step S31, the processor 40 begins an operation to detect contact or non-contact between the laser processing head 14 and the workpiece W by the contact detection device 60. Specifically, the processor 40 causes the resistance sensor 60b to measure the resistance R and begins an operation to continuously (e.g. periodically) obtain the detection data DD from the resistance sensor 60b.

[0070] At step S32, the processor 40 determines whether the manual laser emission command CM2 has been received from the input device 58. If the manual laser emission command CM2 has been received from the input device 58, the processor 40 determines YES and proceeds to step S33. On the other hand, if NO, the processor 40 proceeds to step S41 without executing the laser emission operation LO in the manual drive mode DM2. If the laser emission operation LO of step S35 described later is being executed at the start time of step S32 and NO is determined at step S32, the processor 40 stops the laser emission operation LO.

[0071] At step S33, the processor 40 determines, as in step S1 described above, whether or not the automatic drive mode DM1 is selected by the mode selector switch 52. If YES is determined (i.e., if the mode selector switch 52 has been switched to the automatic drive mode DM1), the processor 40 proceeds to step S37. On the other hand, if NO is determined (i.e., if the manual drive mode DM2 is still selected by the mode selector switch 52), the processor 40 proceeds to step S34.

[0072] At step S34, the processor 40 determines whether the laser processing head 14 and the workpiece W are in contact with each other or not. Specifically, based on the detection data DD last acquired from the resistance sensor 60b, the processor 40 determines whether the contact detection sensor 60 detects contact or non-contact between the laser processing head 14 and the workpiece W. If contact between the laser processing head 14 and the workpiece W is detected, the processor 40 determines YES and proceeds to step S35. On the other hand, if non-contact between the laser processing head 14 and the workpiece W is detected, the processor 40 determines NO and proceeds to step S39.

[0073] At step S35, the processor 40 executes the laser emission operation LO as the manual drive mode DM2 in response to the manual laser emission command CM2 received through the input device 58. Here, in the present embodiment, a data table DT is stored in advance in the memory 42, and in the data table DT, machining conditions C P of the workpiece W in the manual drive mode DM2 and output conditions Co of the laser beam LB emitted by the laser emission mode LO in the manual drive mode DM2 are stored in association with each other.

[0074] The processing conditions C Pinclude, for example, a material (SUS, aluminum, and the like), a thickness [mm], and a melting point [°C] of the workpiece W. On the other hand, the output conditions include, for example, a laser power [kW], a duty ratio [%], and a pulse oscillation frequency [Hz] of the laser beam LB. The data table DT stores the output conditions Co (the laser power, the duty ratio, and the pulse oscillation frequency) in association with each of the plurality of machining conditions C. P (the material, the thickness and the melting point).

[0075] The processor 40 predefines the output conditions Co in manual drive mode DM2 based on data table DT. For example, the operator can set the output conditions Co, which correspond to the processing conditions C. P(e.g., the material and thickness) of the workpiece W, which is the target of the machining, manually select from the data table DT. In this case, the processor can generate an image representation of the data table DT and display it on the display device 50.

[0076] By operating the input device 48 of the controller 18 and observing the image representation of the data table DT, the operator searches in the data table DT for the output conditions Co which correspond to the processing conditions C P of the workpiece W, which is the machining target, and selects them. The processor 40 receives the operator's input via the input device 48 and sets the output conditions Co selected from the data table DT as the output conditions in the manual drive mode DM2.

[0077] As another example, the operator may operate the input device 48 to set the machining conditions C Pof the workpiece W, which is the machining target. In this case, the processor 40 automatically searches the data table DT for the output conditions Co corresponding to the machining conditions C P input by the operator via the input device 48, and sets the found output conditions Co as the output conditions in the manual drive mode DM2. Thus, the processor 40 sets the output conditions Co in the manual drive mode DM2 in advance based on the data table DT.

[0078] At step S35, in response to the manual laser emission command CM2, the processor 40 generates a command to the laser oscillator 16 in accordance with the predetermined output conditions Co, and executes the laser emission operation LO so that the laser beam LB is generated with the power, duty cycle, and pulse oscillation frequency defined in the output conditions Co. As a result, the operator can manually perform laser processing on the workpiece by irradiating the laser beam LB under the desired output conditions Co from the laser processing head 14 grasped with one hand.

[0079] At step S36, the processor 40 determines whether an operation end command has been received or not, as in step S12 described above. If YES, the processor 40 ends the Fig. 8 shown flow of step S3 and thereby terminates the process shown in Fig. 6 is shown. If, on the other hand, NO was determined, processor 40 returns to step S32.

[0080] Thus, the processor 40 repeatedly executes the loop of steps S33 to S36 while determining YES at step S32 (i.e., while receiving the manual laser emission command CM2 from the input device 58) until YES is determined at step S33 or S36 or NO is determined at step S34, and continuously executes the laser emission operation LO as the manual drive mode DM2. This allows the operator to manually perform laser processing on the workpiece W by gripping the laser processing head 14 with one hand.

[0081] On the other hand, if YES is determined in step S33, the laser emission operation LO is stopped in the manual drive mode in step S37. For example, the processor 40 stops the laser beam generation operation of the laser oscillator 16 or covers the laser beam LB with the above-described shutter, thereby stopping the laser emission operation LO.

[0082] In step S38, the processor 40 generates the alarm signal AL. For example, the processor 40 generates an alarm signal AL4 from an image representation or a voice utterance "manual drive mode cannot be executed because the drive mode has been changed." The processor 40 can display the generated alarm signal AL4 as an image representation on the display device 50 or output the alarm signal AL4 as a voice utterance through the loudspeaker. After step S38, the processor 40 returns to step S2 in Fig. 6 back.

[0083] On the other hand, if NO is determined in step S34, the processor 40 stops the laser emission operation LO in the manual drive mode DM2 in step S39, as in step S37 described above. Then, in step S40, the processor 40 generates the alarm signal AL. For example, the processor 40 may generate an alarm signal AL5 from an image display or a voice utterance "the laser processing head may be separated from the workpiece. Please bring the laser processing head into contact with the workpiece," and display the alarm signal AL5 on the display device 50 or output the alarm signal AL5 through the speaker. After step S40, the processor 40 returns to step S32.

[0084] On the other hand, if NO was determined in step S32, the processor 40 determines in step S41, as in the above-described step S33, whether or not the automatic operation mode DM1 has been selected by the mode selection switch 52. The processor 40 proceeds to step S2 in Fig. Step 6 is skipped if YES was determined, and goes to step S36 if NO was determined.

[0085] As described above, in the present embodiment, the controller 18 (concretely, the processor 40) executes the laser emission operation LO and the movement operation MO as the automatic drive mode DM1 when the automatic drive mode DM1 in which the laser emission operation LO and the movement operation MO are automatically executed according to the machining program PP is selected by the mode selection switch 52 (when YES is determined at step S15 or step S18), and when the distance d measured by the distance measuring sensor 18 is within the predetermined range RG (when YES is determined at step S16 or S19).

[0086] That is, in the present embodiment, it is necessary for the operator to satisfy two conditions, that is, to manually operate the mode selector switch 52 to select the automatic drive mode DM1, and to set the workpiece W at an appropriate position with respect to the laser processing head 14 where the distance d is within the range RG, in order to cause the controller 18 to execute automatic driving of the laser emission operation LO and the movement operation MO in the automatic drive mode.

[0087] This configuration can reliably prevent the laser emission operation LO from being inadvertently executed in the automatic drive mode DM1 and the laser beam LB from being emitted from the laser processing head 14 in an unintentional direction other than toward the workpiece W (e.g., toward the operator) during the laser emission operation LO. Therefore, the automatic drive of the laser processing system 10 can be reliably executed.

[0088] In the present embodiment, the input device 58 receives an operation to input the manual laser emission command CM2 to cause the controller 18 to execute the laser emission operation LO. The contact detection device 60 detects the contact or non-contact between the laser processing head 14 and the workpiece W. The mode selection switch 52 is configured to switch the drive mode DM between the automatic drive mode DM1 and the manual drive mode DM2.

[0089] Then, when the manual drive mode DM2 is selected by the mode selector switch 52 and the contact detecting device 60 detects contact between the laser processing head 14 and the workpiece W, the controller executes the laser emission operation LO in response to the manual laser emission command CM2 received by the input device 58 as the manual drive mode DM2.

[0090] That is, in the present embodiment, the operator needs to satisfy two conditions, that is, manually operate the mode selection switch 52 to select the manual drive mode DM2 and bring the laser processing head 14 into contact with the workpiece W to cause the controller 18 to execute the laser emission operation LO in the manual drive mode DM2.

[0091] This design reliably prevents the laser emission operation LO from being unintentionally executed in manual drive mode DM2 and ensures that the laser beam LB from the laser processing head 14 is emitted in a direction other than towards the workpiece W (e.g., towards the operator) during laser emission operation LO. Therefore, the operator can safely perform manual laser processing.

[0092] In the present embodiment, the contact detection device 60 has the conductive cable 60a, which is configured to electrically connect the laser processing head 14 and the workpiece W, and the resistance sensor 60b, which is configured to measure the resistance R of the closed circuit 62 formed by the workpiece W, the laser processing head 14 in contact with the workpiece W and the conductive cable 60a.

[0093] Therefore, the contact detection device 60 is configured to detect contact or non-contact between the laser processing head 14 and the workpiece W based on the resistance R measured by the resistance sensor 60b. This design allows for rapid and reliable detection of contact or non-contact between the laser processing head 14 and the workpiece W using a relatively simple setup.

[0094] In the present embodiment, the controller 18 stops the laser emission operation LO when the mode selector switch 52 is actuated to deselect the manual drive mode DM2 (if YES is determined in step S33), or when the contact detection device 60 detects a non-contact during the execution of the laser emission operation LO in the manual drive mode DM2 (if NO is determined in step S34).

[0095] This configuration can prevent the laser beam LB from being emitted from the laser processing head 14 in an unwanted direction (e.g., toward the operator) when the mode selector switch 52 is inadvertently switched to another drive mode DM (concretely, the automatic drive mode DM1) during execution of the laser emission operation LO in the manual drive mode DM2.

[0096] During the execution of the laser emission operation LO in the manual drive mode DM, the laser processing head 14 can be prevented from being separated from the workpiece W and the laser beam LB from being emitted from the laser processing head 14 in an unintended direction. This can further reliably ensure the safety of the operator in the manual drive mode DM2.

[0097] In the present embodiment, the laser processing head 14 has a handle 38 that can be grasped by the operator with one hand, and the input device 58 is provided on the laser processing head 14 next to the handle 38 to enable input operation with the one hand grasping the handle 38. This design allows the operator to easily perform the laser emission operation LO in manual drive mode DM2 by grasping the handle 38 with one hand, removing the laser processing head 14 from the robot 12, and operating the input device 58 with that one hand.

[0098] In the present embodiment, upon receiving the automatic drive start command CM1 to start the automatic drive mode DM1 (when determined as YES in step S11), the controller 18 does not start at least one (e.g., both) of the laser emission mode LO and the movement mode MO as the automatic drive mode DM1 if the automatic drive mode DM1 has been deselected by the mode selector switch 52 (determined as NO in step S15) or the distance d selected by the distance measuring sensor 56 is outside the range RG (determined as NO in step S16). With this configuration, the operator's safety can be reliably ensured when the automatic drive starts.

[0099] When the processor 40 receives the command CM1 to start the automatic drive, it is possible that it starts the laser emission operation LO or the movement operation MO as the automatic drive mode DM1 even if the automatic drive mode DM is deselected by the mode selector switch 52 or the distance d is outside the range RG.

[0100] Specifically, the operator's safety can be ensured if the robot 12 is a cooperative robot capable of immediate stopping as described above, even if the automatic drive mode DM1 is deactivated by the mode selector switch 52 or if the operator is outside the RG area at a distance d, and even if the motion operation MO has been started as automatic drive mode DM1. Alternatively, the operator's safety can be ensured if the operator is located outside a safety fence (not shown) that is set up in a work cell to surround the operating area of ​​the robot 12, even if the laser emission operation LO has been started as automatic drive mode DM1.

[0101] In the present embodiment, when the mode selection switch 52 is operated to deselect the automatic drive mode DM1 (NO at step S18) or the distance d measured by the distance measuring sensor 56 is outside the range RG (NO at step S19) while the laser emission mode LO and the movement mode MO are being executed as the automatic drive mode DM1, the controller 18 stops at least one of the laser emission mode LO and the movement mode MO (steps S22 and S24). With this configuration, the operator's safety can be reliably ensured during the automatic drive.

[0102] It is possible to omit the input device 58 and the contact detection device 60 from the laser processing system 10. It is possible that only the automatic drive mode DM1 can be set as the drive mode DM, and the mode selection switch 52 is configured to select the automatic drive mode DM1 and an OFF mode in which no drive mode DM is selected. In this case, the processor 40 only needs to execute the automatic drive mode DM1 processing at step S2.

[0103] It is possible to omit steps S15 and S16 from the process of step S2. Alternatively, it is possible to omit steps S18 and S19 from the process of step S2. Note that the contact detection device 60 is not limited to the form including the conductive cable 60a and the resistance sensor 60b, but may include any sensor, such as a proximity sensor, that can detect the contact between the laser processing head 14 and the workpiece W.

[0104] It should be noted that during the execution of the manual drive mode DM2, the processor 40 can execute a cooperative operation program COP, causing the robot 12 to perform a cooperative operation to support manual laser processing by the operator. This cooperative operation program COP can, for example, be designed to cause the robot 12 to perform a cooperative operation in which it holds and moves (e.g., rotates) the workpiece W or loads the workpiece W onto a jig while the operator manually performs the laser processing.

[0105] In this case, a robot hand can be attached to the wrist 28 of the robot 12 in addition to (or instead of) the laser processing head 14. This configuration allows the operator to efficiently perform manual laser processing in cooperation with the robot 12.

[0106] Next, with reference to Fig. 9, other functions of the laser processing system 10 will be described. In the present embodiment, the controller 18 further includes a timing unit 64. The timing unit 64 is communicatively connected to the processor 40 via the bus 46 and, in response to a command from the processor 40, records a elapsed time t from a specific point in time. It should be noted that the timing unit 64 may be incorporated into the housing of the controller 18. Alternatively, the timing unit 64 may be mounted externally to the housing of the controller 18, for example, as an electronic clock, and connected to the I / O interface 44.

[0107] The processor 40 of the controller 18, which in Fig. 9, as step S3 in Fig. 6 the process of Fig. 10. It should be noted that the procedure described in Fig. 10, processes that are similar to those in the course of Fig. 8 are the same, are designated by the same step numbers, and a repeated description is omitted. Here, in the present embodiment, the processor 40 sets a waiting time t in advance. th1 from a time t0 at which non-contact between the laser processing head 14 and the workpiece W was detected by the contact detection device 60 (ie, NO was detected at step S34) until the laser emission operation LO is stopped at step S39.

[0108] For example, the operator actuates the input device 48 of the controller 18 to set the waiting time t th1 to enter (e.g., t th1 = 0.3 [s]). The processor 40 stores the entered waiting time t th1 in the memory 42 and records it as waiting time setting information. As a result, the processor 40 sets the waiting time t th1 fixed in advance..

[0109] If the processor 40 in the Fig. 10, it begins measuring the elapsed time t at step S42. Specifically, the processor 40 activates the timing unit 64 to begin measuring the elapsed time t from the time t0 at which NO was determined at step S34.

[0110] At step S43, the processor 40 determines whether the measured elapsed time t exceeds the predetermined waiting time t th1 has been reached (ie, t ≥ t th1 ) or not. The processor 40 determines YES and proceeds to step S39 if t ≥ t th1 exists, and determines NO and proceeds to step S44 if t < t th1 consists.

[0111] In step S44, the processor 40 determines, as in step S34 described above, whether the contact detection device 60 has detected contact between the laser processing head 14 and the workpiece W. The processor 40 returns to step S32 if the result is YES, and returns to step S43 if the result is NO (i.e., if the laser processing head 14 and the workpiece W are still not in contact).

[0112] The technical significance of steps S42 to S44 will be described below. According to steps S42 to S44, if laser emission operation LO is ongoing (i.e., if a YES determination is still in effect at step S32) and if a NO determination is still in effect at step S34, then processor 40 does not execute step S39 after the execution of step S35 (in other words, it continues laser emission operation LO) until the waiting time t has elapsed. th1from the time t0 at which NO was determined at step S34 (ie, until YES is determined at step S43).

[0113] Then, if at step S44 until the waiting time t th1 is determined to be NO continuously (ie, if over the period t h1 (If a continuous lack of contact between the laser processing head 14 and the workpiece W is detected), the processor 14 stops the laser emission operation LO at step S39. If, on the other hand, JA is determined at step S44 before the waiting time t th1 has expired, the processor 40 continues the laser emission operation LO without executing step S39.

[0114] As described above, in the present embodiment, when the laser emission operation LO is executed in the manual drive mode DM2, the controller 18 sets a waiting time t th1from time t0, at which the contact detection device 60 detected the lack of contact, until the laser emission operation LO stops. Then the controller 18 stops the laser emission operation LO in manual drive mode DM2 if the waiting time t has elapsed since time t0. th1 has passed.

[0115] Here, the operator can perform the laser processing in the manual drive mode DM2 with the laser beam LB emitted by the laser processing head 14, while moving the laser processing head 14 in relation to the workpiece W and bringing the distal end of the laser processing head 14 into contact with the workpiece W.

[0116] In this case, for example, it may happen that the laser processing head 14 is momentarily separated from the workpiece W by an uneven portion on the surface of the workpiece W (e.g., for only 0.1 [s]). Even if the laser processing head 14 is momentarily separated from the workpiece W in this way, there is only a small possibility that the laser beam LB is emitted from the laser processing head 14 in the direction toward the operator, and therefore the safety of the operator can be ensured.

[0117] According to the present embodiment, the laser emission operation LO can be controlled by setting the waiting time t th1until the laser emission operation is stopped at step S39, even if the above-described momentary separation of the laser processing head 14 from the workpiece W occurs. On the other hand, if the non-contact between the laser processing head 14 and the workpiece W continues even after the expiration of the waiting time t th1 is still detected, the laser emission operation LO can be stopped by immediately executing step S39. Therefore, the laser processing operation in the manual drive mode DM2 in the present embodiment can be efficiently performed, and the operator's safety can be reliably ensured.

[0118] Next, with reference to Fig. 11 shows another sequence of step S3, which is shown in Fig. 9 is executed. In the present embodiment, the processor 40 sets, in addition to the above-described waiting time th1 in advance a second waiting time t th2 fixed from the time when NO was determined at step S34 until the generation of the alarm signal at step S40.

[0119] For example, the operator actuates the input device 48 of the controller 18 to set the second waiting time t th2 as a time t th2 , which are longer than the waiting time t th1 is (t th2 > t th1 ), enter (e.g., t th2 = 0.4 [s]). The processor 40 stores the entered waiting time t th2 in memory 42 and records them together with the waiting time t th1 as waiting time setting information.

[0120] Fig. Fig. 11 shows the flow of step S3 according to the present embodiment. It should be noted that in the flow shown in Fig. 11, processes similar to those in the course of Fig. 10 are the same, are labeled with the same step numbers and a repeated description is omitted. In the process of Fig. 11, after stopping the laser emission operation at step S39, the processor 40 further executes steps S45 and S46.

[0121] Specifically, at step S45, the processor 40 determines whether the elapsed time t measured by the timing unit exceeds the predetermined second waiting time t th2 has been reached (ie, t ≥ t th2 ) or not. The processor 40 determines YES and proceeds to step S40 if t ≥ t th2 exists, and determines NO and proceeds to step S46 if t th1 ≤ t < t th2 consists.

[0122] At step S46, the processor 40 determines, as in step S44 described above, whether or not the contact between the laser processing head 14 and the workpiece W has been detected by the contact detection device 60. The processor 40 returns to step S32 if the determination is YES, and to step S45 if the determination is NO.

[0123] Therefore, in the present embodiment, the processor 40 does not execute step S40 after step S39 until another period t' = t th2 - t th1 has passed. According to this configuration, the alarm signal AL5 can be generated and reported to the operator only when the non-contact between the laser processing head 14 and the workpiece W is detected for a long period of time. This can prevent the alarm signal AL5 from being sent frequently.

[0124] Next, with reference to Fig. 12 shows another example of the operation of the laser processing system 10, which is shown in Fig. 9. In the present embodiment, the processor 40 executes a direct teaching mode DM3 in addition to the automatic drive mode DM1 and the manual drive mode DM2 described above. The direct teaching mode DM3 is the drive mode DM in which the processor 40 operates the robot 12 according to the external force F applied to the robot 12 by the operator and executes the laser emission operation LO in response to the manual laser emission command CM2 input by the operator via the input device 58.

[0125] As in Fig. As shown in Fig. 13, the mode selector switch 52 in the present embodiment is configured to switch between the automatic drive mode DM1: "AUTO," the manual drive mode DM2: "MANUAL," and a direct teaching mode DM3, which is shown as "TEACH." When the direct teaching mode is selected by the mode selector switch 52, the mode selector switch 52 provides the controller 18 with a command CM5 to transition to the direct teaching mode.

[0126] The following is a summary of the Fig. 12. An operating sequence of the laser processing system 10 according to the present embodiment is described. It should be noted that in the sequence described in Fig. Figure 12 shows processes that occur during the course of Fig. 6 are the same, are labeled with the same step numbers and a repeated description is omitted. In the process described in Fig. 12, if NO is determined at step 1, the processor 14 determines at step 4 whether or not the manual drive mode DM2 has been selected by the mode selector switch 52 or the direct teaching mode DM3 has been selected.

[0127] Specifically, upon receiving the command CM4 to transition to the manual drive mode from the mode selector switch 52, the processor 40 determines YES and proceeds to step S3. On the other hand, upon receiving the command CM5 to transition to the direct teaching mode from the mode selector switch 52, the processor 40 determines NO and proceeds to step S5.

[0128] Fig. 14 shows the flow of step S2 in Fig. 12. It should be noted that the procedure described in Fig. 14, processes similar to those in the course of Fig. 7 are the same, are designated with the same step numbers and a repeated description is omitted. If the process described in Fig. 14, where NO was determined at step S13, the processor 40 determines at step S26, similarly to step S4 described above, whether the manual drive mode DM2 or the direct teaching mode DM3 has been selected by the mode selection switch 52.

[0129] If the manual drive mode DM2 has been selected, the processor 40 determines YES and goes to step S3 in Fig. 12 while determining NO and proceeding to step S5 in Fig. 13 if the direct teaching mode DM3 has been selected. After step S25, the processor 40 proceeds to step S26.

[0130] Fig. 15 shows the flow of step S3 in Fig. 12. It should be noted that the procedure described in Fig. 15, processes similar to those in the course of Fig. 11 are the same, are designated by the same step numbers, and repeated description will be omitted. In the flow shown in step S15, if NO is determined at step S33, the processor 40 determines at step S47 whether the direct teaching mode DM3 has been selected (ie, the command CM5 to transition to the direct teaching mode has been received) or not. If the processor 40 determines YES, it proceeds to step S48, while if NO is determined, it proceeds to step S34.

[0131] At step S48, the processor 40 stops the laser emission operation LO in the manual drive mode DM2 as in the above-described step S37. Then, at step S49, the processor 40 generates the alarm signal AL4 as in the above-described step S38 and goes to step S5 in Fig. 12 over.

[0132] If, on the other hand, NO was determined at step S41, processor 40 determines at step S50, as in step S47 described above, whether the direct teaching mode DM3 was selected or not. If processor 40 determines YES, it proceeds to step S5. Fig. 12, while if NO, it proceeds to step S36.

[0133] With further reference to Fig. 12, the processor 40 sets the drive mode DM when determining NO at step S4 (alternatively, when determining NO at step S26 in Fig. 14, after step S49 in Fig. 15 or when YES is determined at step S50 in Fig. 15) to the direct teaching mode DM3 and executes the process of the direct teaching mode DM3 at step S5.

[0134] After transitioning to the direct teaching mode DM3, the processor 40 is brought into a state where it can receive the manual laser emission command CM2 through the input device 58 and rejects the command CM1 to start the automatic drive. The flow of the direct teaching mode DM3 at step S5 will be described below with reference to Fig. 16. It should be noted that the process described in Fig. 16, processes similar to those in the course of Fig. 15 are the same, are designated with the same step numbers and a repeated description is omitted.

[0135] At step S51, the processor 40 begins an operation to obtain the external force F applied to the robot 12. Specifically, the processor 40 continuously (e.g., periodically) obtains the detection data DF from the force sensor 54 and, based on the detection data DF, continuously obtains the magnitude and direction of the external force F applied to the robot 12 and the part of the robot 12 to which the external force F is applied. Thereafter, the processor 40 executes the above-described step S31.

[0136] After step S31, processor 40 determines in step S52 whether the last obtained magnitude of the external force F exceeds a predetermined threshold value F. th2 (F > F th2 ) or not. This threshold F th2 can be set as a value that is less than the threshold F th1 is to be referred to in step S20 described above ( Fig. 7 and Fig. 14) Reference was made to (F th2 < F th1 ). The processor 40 determines YES and proceeds to step S53 if F > F th2 exists, and is determined at F ≤ F th2 NO and proceeds to step S32.

[0137] At step S53, the processor 40 operates the robot according to the most recently acquired external force F. Specifically, the processor 40 generates a command (a torque command or the like) to move a part (e.g., the wrist 28) of the robot 12 to which the most recently acquired external force F was applied in the direction of the external force F, and drives each servo motor 30 of the robot 12 according to the command. As a result, the robot 12 moves the part to which the external force F was applied in the direction of the external force F according to the external force F.

[0138] For example, assume that the operator grasps the handle 38 of the laser processing head 14, applies an external force F to the laser processing head 14, and pushes the laser processing head 14 in a desired direction φ. The external force F thus applied in the direction φ is applied by the laser processing head 14 to the wrist flange 28a of the robot and detected by the force sensor 54.

[0139] In this case, the processor 40 operates the robot 12 according to the external force F detected by the force sensor 54 to move the wrist flange 28b (i.e., the laser processing head 14) of the robot 12 in the direction φ. This allows the operator to manually operate the robot 12 so that the laser processing head 14 is moved in the desired direction φ by operating the robot 12.

[0140] At step S53, the processor 40 may move the part (e.g., the wrist flange 28b) of the robot 12 to which the external force F was applied at a predetermined constant speed V over a predetermined distance δ. The speed V and distance δ may be determined in advance by the operator as required values ​​for the direct teaching mode DM3.

[0141] After step S53, the processor 40 executes the above-described steps S32 and S33. If NO was determined in step S33, the processor 40 determines in step S54 whether the manual drive mode DM2 has been selected (ie, the command CM4 to transition to the manual drive mode has been received) or not. If the processor 40 determines YES, it executes the above-described steps S48 and S49 in sequence and proceeds to step S3 in Fig. 12 over.

[0142] On the other hand, if the processor 40 determines NO in step S54, it executes the above-described steps S34 to S36, S42 to S44, S39, S45, S46, and S40 in sequence. If NO was determined in step S39, YES was determined in step S44 or S46, or after executing step S40, the processor 40 returns to step S52.

[0143] On the other hand, if the processor 40 determines NO in step S41, it determines in step S55 whether the manual drive mode DM2 has been selected or not, as in step S54 described above. If YES, the processor 40 proceeds to step S3 in Fig. 12 and if NO, proceed to step S36.

[0144] Thus, processor 40 operates robot 12 in the direct teaching mode DM3 in which in Fig. 16 according to the external force F applied by the operator (step S53), and executes the laser emission operation LO according to the manual laser emission command CM2 input by the operator by operating the input device 58 while moving the laser processing head 14 in the direction φ.

[0145] The operator manually controls the robot 12 to move the laser processing head 14 in the desired direction φ and activates the input device 58 to manually emit the laser beam LB from the laser processing head 14, thereby performing the laser processing on the workpiece W. The robot 12 can move the laser processing head 14 at a constant speed V, as described above. This configuration improves the final quality of the laser processing.

[0146] If the laser processing head 14 and the workpiece W are held for the waiting time t th1 are not in contact with each other while laser processing is being performed in the direct teaching mode DM3 (when YES is determined in step S43), the laser emission operation LO can be stopped in step S39. Therefore, worker safety can also be ensured.

[0147] It should be noted that steps S45 and S46 are removed from the process described in Fig. 16 can be omitted and a process similar to that shown in Fig. 10. Alternatively, steps S42 to S46 may be selected from the sequence shown in Fig. As shown in 16, it can be omitted and a process that corresponds to the one shown in Fig. 8. If steps S42 to S46 are executed from the process shown in Fig. As shown in 16, it can be omitted; the in Fig. 2 Control unit 18 shown, in which the timing unit 64 is omitted, the sequence of Fig. 16 execute.

[0148] During the process of step S5, which in Fig. As shown in 16, step S34 can be used instead of the one shown in Fig. Step S19, as shown in section 14, can be applied, and steps S42 to S44, S45, S46, and S40 can be omitted. In this case, step S31 is removed from the sequence of Fig. 16 is omitted and the processor 40 starts in step S51 as in step S14 of Fig. 14, the operation of acquiring the external force F and the distance d. Then, if NO is determined at step S54, the processor 40 executes step S19 and determines whether the distance d is within the range RG or not. If the distance d is within the range RG, the processor 40 determines YES and proceeds to step S35.

[0149] On the other hand, if the distance d is outside the range RG, the processor 40 determines NO, executes step S39 to stop the laser emission operation LO, and then executes the above-described step S23 to generate the alarm signal AL1. After that, the processor 40 returns to step S52. That is, in this case, if the distance d between the laser processing head 14 and the workpiece W is outside the predetermined range RG, the processor 40 stops the laser emission operation LO while executing the laser emission operation LO (step S35) in the direct teaching mode DM3.

[0150] In step S2 described above (the sequence of automatic drive mode DM1), the processor can perform a gap control GC after the automatic drive is started in step S17, in which the distance d between the laser processing head 14 and the workpiece W is controlled to a predetermined target distance d0. This target distance d0 can be set by the operator, for example, as a value in the range RG (e.g., d). th1 < d0 < D th2 ) referred to in steps S16 and S19

[0151] In this gap control GC, the processor 40 performs feedback control of each servomotor 30 of the robot 12 on the basis of the distance d obtained from the distance measuring sensor 56 and regulates the position in the direction of the optical axis A of the laser processing head 14 by operating the robot in such a way that the distance d corresponds to the target distance d0.

[0152] It should be noted that the processor 40 executes the sequence of Fig. 6, the process of step S2, which in Fig. 7 is shown, and the sequence of step S3, which is in Fig. 8, Fig. 10 or Fig. 11, according to the operating program OP. This operating program OP can be prepared by the operator in advance and stored in the memory 42 as a program different from the machining program PP described above.

[0153] In this case, the processor 40 executes the process from step S2 in Fig. 7 according to the operation program OP and reads the machining program PP from the memory 42 and executes it when step S17 is started, thereby starting the automatic drive of the laser emission operation LO and the movement operation MO.

[0154] Furthermore, a gap control program GP can be prepared for the gap control GC described above. In this case, upon starting step S17, the processor 40 executes the gap control program GP in parallel with the machining program PP and the gap control GC in parallel with the automatic drive.

[0155] The operating program OP can be a first operating program OP1, which directs processor 40 to execute the sequence of Fig. 6, a second operating program OP2 which causes the processor 40 to execute the process of step S2, and a third operating program OP3 which causes the processor 40 to execute the process of step S3.

[0156] Likewise, the processor 40 can control the execution of Fig. 12, the process of step S2, which is shown in Fig. 14, the flow of step S3 shown in Fig. 15 is shown, and the sequence of step S5, which is in Fig. As shown in section 16, the operating program OP can be executed. In this case, the operating program OP can be the first operating program OP1, which directs the processor 40 to execute the sequence of Fig. 12, the second operating program Op2, which causes the processor 40 to execute the process of step S2, the third operating program OP3, which causes the processor 40 to execute the process of step S3, and a fourth operating program OP4, which causes the processor 40 to execute the process of step S5.

[0157] It should be noted that the input device 58 does not have to be provided on the laser processing head 14 and can, for example, be provided separately from the laser processing head 14 as a portable keypad that the operator can carry with them, or as a foot pedal (or foot switch) that allows the operator to perform input with their foot. The distance measuring sensor 56 does not have to be provided on the laser processing head 14, but can, for example, be provided next to the workpiece W.

[0158] The laser processing system 10 may further include a second input device configured to receive an input operation for an auxiliary gas emission command to cause the laser processing head 14 to emit the auxiliary gas AG in the manual drive mode DM2 at step S3. When the operator operates the second input device during execution of the manual drive mode DM2, the processor 40 operates the auxiliary gas supply in response to the auxiliary gas emission command sent from the second input device, thereby supplying the auxiliary gas AG to the laser processing head 14. In this case, the second input device may be provided adjacent to the handle 38 on the laser processing head 14 to enable input operation with one hand gripping the handle 38.

[0159] The mode selection switch 52 is not limited to the controller 18, but may be provided on any component. For example, the mode selection switch 52 may be provided on the laser processing head 14 or implemented as a portable switch provided separately from the controller 18 and carried by the operator. Alternatively, the mode selection switch 52 may be communicatively connected to the controller 18 and provided on a teaching device (a teach pendant, a tablet terminal device, and the like) for teaching operation of the robot 12 and the laser oscillator 16.

[0160] Note that in the above-described embodiment, a case was described where the mode selection switch 52 is provided as a physical switch on the controller 18. However, the mode selection switch 52 may be provided as a software switch (alternatively, as a virtual switch) on the controller 18.

[0161] For example, the processor 40 of the controller 18 generates a mode selector image for selecting the drive mode DM and displays it on the display device 50. Fig. 17 shows an example of the mode selector image 100. The mode selector image 100 is a graphical user interface (GUI) that allows the operator to select the drive mode DM and includes a button image 102 for the automatic drive and a button image 104 for the manual drive.

[0162] The keypad image 102, displayed as "AUTO", corresponds to automatic drive mode DM1, and the keypad image 104, displayed as "MANUAL", corresponds to manual drive mode DM2. The operator can select automatic drive mode DM1 or manual drive mode DM2 by viewing the mode selector switch image 100, which is displayed on the display device 50 of the control unit 18, by actuating the input device 48 and clicking the image, keypad image 102 for automatic drive, or keypad image 104 for manual drive.

[0163] Upon receiving an input for selecting the automatic drive button image 102 (i.e., the command CM3 for transitioning to the automatic drive mode) from the operator via the input device 48, the processor 40 switches the drive mode DM to the automatic drive mode DM1 (the above-described step S2). On the other hand, upon receiving an input for selecting the manual drive button image 104 (i.e., the command CM4 for transitioning to the manual drive mode) from the operator via the input device 48, the processor switches the drive mode DM to the manual drive mode DM2 (the above-described step S3).

[0164] As described above, the automatic drive button image 102 and the manual drive button image 104 constitute the mode selector switch 52 as a software, and the operator can switch the operation mode DM between the automatic drive mode DM1 and the manual drive mode DM2 by operating the mode selector switch 52 on the image.

[0165] It should be understood that the mode selector switch 52 can be implemented in software to select the automatic drive mode DM1, the manual drive mode DM2, or the direct teaching mode DM3. The mode selector switch 52 in software is not limited to the controller 18, but can be implemented on the teaching device described above or any other communication device (PC, tablet terminal) that is communicatively connected to the controller 18.

[0166] In the above embodiment, the automatic drive mode DM1, the manual drive mode DM2, and the direct teaching mode DM3 were exemplified as the drive modes DM. However, the drive mode DM is not limited to this, but may include any other drive mode DM, such as a teaching mode DM4 for teaching the robot 12 and the laser oscillator 16 an operation.

[0167] Furthermore, in the above-described embodiments, a case is described in which the controller 18 controls the robot 12 and the laser oscillator 16. Alternatively, the controller 18 may include a first controller 18A configured to control the robot 12 and a second controller 18B configured to control the laser oscillator 16. Such a form is shown in Fig. 18 and Fig. 19 shown.

[0168] In a laser processing system 10', which is Fig. 18 and Fig. As shown in Figure 19, the controller 18 includes the first controller 18A configured to control the movement operation MO of the robot 12, and the second controller 18B configured to control the laser emission operation LO of the laser oscillator 16. The first controller 18A is a computer including a processor 40A, a memory 42A, an I / O interface 44A, and a bus 46A.

[0169] The robot 12 (the servo motors 30), the laser processing head 14 (the lens drive unit), an input device 48A, a display device 50A, the force sensor 54, the distance measuring sensor 56, the input device 58, and the contact detection device 60 (the resistance sensor 60b) are communicatively connected to the I / O interface 44A of the first controller 18A. The mode selection switch 52 described above is provided on the first controller 18A.

[0170] The second controller 18B is a computer that includes a processor 40B, a memory 42B, an I / O interface 44B, and a bus 46B. An input device 48B, a display device 50B, the laser oscillator 16, and the I / O interface 44A of the first controller 18A are communicatively connected to the I / O interface 44B of the second controller 18B.

[0171] It should be noted that the laser oscillator 16, the second controller 18B, the input device 48B, and the display device 52B may be combined into a common housing to form a single laser oscillator device 72. The processor 40A of the first controller 18A and the processor 40B of the second controller 18B may perform the operations described in Fig. 6 to 8, 10 to 12 and 14 to 16, communicating with each other.

[0172] The laser processing head 14 can be any type of processing head, such as a laser scanner (alternatively, a galvano scanner). This laser scanner includes a plurality of mirrors, each reflecting the laser beam LB supplied by the laser oscillator 16, a plurality of mirror drive units that individually drive the plurality of mirrors, and an optical lens that condenses the laser beam reflected by the mirrors. The laser scanner can move an irradiation point of the laser beam irradiated onto the workpiece at high speed on the surface of the workpiece by changing the orientations of the plurality of mirrors with the mirror drive units.

[0173] It should be noted that the robot 12 is not limited to a vertical articulated robot, but may be, for example, a horizontal articulated robot or a parallel kinematics robot, and may be configured to have first and second ball screw mechanisms that move the workpiece W in the horizontal plane and a third ball screw mechanism that moves the laser processing head 14 in the vertical direction. The light guide path 39 may be omitted from the laser processing system 10 or 10'. In this case, the laser oscillator 16 may be directly coupled to the laser processing head 14. Although the present disclosure has been described above by means of embodiments, the above-described embodiments do not limit the scope of the invention claimed in the claims. List of reference symbols 10, 10' laser processing system 12 robots 14 Laser processing head 16 laser oscillator 18 Control 40, 40A, 40B processor 48, 48A, 48B, 58 input device 52 mode selector switch 54 force sensor 56 Distance measuring sensor 60 contact detection device QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2015-167974 A

[0003]

Claims

[1] Laser processing system arranged to perform laser processing on a workpiece, wherein the laser processing system a laser processing head configured to emit a laser beam generated by a laser oscillator; a robot configured to move the laser processing head relative to the workpiece; a distance measuring sensor configured to measure a distance between the laser processing head and the workpiece; a controller configured to control a laser emission operation in which the laser oscillator is operated to emit a laser beam from the laser processing head, and a movement operation in which the robot is operated to move the laser processing head with respect to the workpiece; and a mode selector switch configured to select a laser processing drive mode, has, wherein the controller is arranged so that when an automatic drive mode is selected by the mode selector switch, in which the laser emission operation and the movement operation are carried out automatically according to a machining program, and When the distance measured by the distance measuring sensor is within a predetermined range, executes the laser emission operation and the movement operation as automatic drive mode. [2] The laser processing system according to claim 1, further comprising: an input device configured to receive an input operation for a manual laser emission command to cause the controller to execute the laser emission operation; and a contact detection device configured to detect contact or non-contact between the laser processing head and the workpiece, wherein the mode selection switch is configured to switch the drive mode between the automatic drive mode and a manual drive mode in which the controller executes the laser emission operation in response to the manual laser emission command, and wherein the controller is configured to execute the laser emission operation in response to the manual laser emission command received by the input device as the manual drive mode when the manual drive mode is selected by the mode selection switch and the contact detection device detects the contact. [3] Laser processing system according to claim 2, wherein the contact detection device a conductive cable that electrically connects the laser processing head and the workpiece; and a resistance sensor configured to measure the resistance of a closed circuit formed by the workpiece, the laser processing head in contact with the workpiece, and the conductive cable, wherein the contact detection device is configured to detect contact or non-contact based on the resistance measured by the resistance sensor. [4] The laser processing system according to claim 2 or 3, wherein the controller is configured to stop the laser emission operation when, during execution of the laser emission operation in the manual drive mode, the mode selection switch is operated to deselect the manual drive mode or the contact detection device detects the non-contact. [5] Laser processing system according to one of claims 2 to 4, wherein the controller is arranged to sets a waiting time from a time when the contact detection device detects the non-contact during the execution of the laser emission operation in the manual drive mode until the laser emission operation is stopped; and stops the laser emission operation in the manual drive mode when the waiting time has elapsed from that time. [6] The laser processing system according to any one of claims 2 to 5, wherein the laser processing head has a handle that can be gripped by an operator with one hand, and wherein the input device is provided on the laser processing head adjacent to the handle to enable the input operation with the one hand gripping the handle. [7] The laser processing system according to any one of claims 1 to 6, wherein the controller is configured not to start at least one of the laser emission operation and the movement operation as the automatic drive mode when the automatic drive operation is deselected by the mode selection switch or the distance measured by the distance measuring sensor is out of the range when the controller has received an automatic operation start command to start the automatic drive mode. [8] The laser processing system according to any one of claims 1 to 7, wherein the controller is arranged to stop at least one of the laser emission operation and the movement operation when, during the execution of the laser emission operation and the movement operation as the automatic drive mode, the mode selection switch is operated to deselect the automatic drive mode or the distance measured by the distance measuring sensor is out of the range. [9] The laser processing system according to any one of claims 1 to 8, wherein the controller is arranged to perform gap control for the operation of the robot during the execution of the laser emission operation and the movement operation as the automatic drive mode on the basis of the distance measured by the distance measuring device so that the distance coincides with a predetermined target distance. [10] A method for performing laser processing using the laser processing system according to any one of claims 1 to 9, wherein the method determining by the controller whether or not the automatic drive mode is selected by the mode selector switch; determining by the controller whether the distance measured by the distance measuring sensor is within the range or not; and executing the laser emission operation and the movement operation by the controller as the automatic drive mode when the automatic drive mode is selected by the mode selector switch and the distance measured by the distance measuring sensor is within the range.

Images