Robot control device and plasma cutting method

Abstract

The invention provides a robot control device and a plasma cutting method, which can shorten the takt time through a teaching program for appropriately moving a plasma cutting robot. A robot control device (100) is provided with: a program reading unit (121) that reads a teaching program (PG) for operating a plasma cutoff robot (20); a program interpretation unit (122) that interprets the read-out teaching program (PG); when an arc start command (AS) for plasma cutting is interpreted in the teaching program (PG), the program interpretation unit (122) uses position information of the plasma cutting robot (20) included in the movement command (MOVE) after the arc start command (AS), and executes the interpreted teaching program (PG) by using the position information of the plasma cutting robot (20) included in the movement command (MOVE) after the arc start command (AS). The arc start height of the welding torch (21) in the plasma cutting robot (20) included in the arc start command (AS) is set.

Description

Technical Field

[0001] The invention relates to a robot control device and a plasma cutting method. Background Art

[0002] A plasma cutting robot that performs plasma cutting generally moves the welding torch along a cutting line that is set in advance by teaching, and cuts the workpiece to be cut. In plasma cutting, after the welding torch is moved to the penetration height and an arc is formed between the welding torch and the workpiece to penetrate the penetration hole, the welding torch is moved to the cutting height to cut the workpiece. At this time, it is important to move the welding torch appropriately to the penetration height and the cutting height.

[0003] In the cutting action control device of the cutting robot disclosed in Patent Document 1, data indicating the distance between the penetration height and the cutting height is set as the cutting processing condition, and only the path to the cutting height is taught. And, during playback, the robot moves to the cutting height along the taught path to the cutting height, and moves vertically upward from there by the distance indicated by the cutting processing condition data, thereby moving to the penetration height. Furthermore, during cutting, the robot moves vertically downward by the distance indicated by the above data to perform cutting.

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 7-88656 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] However, in the cutting motion control device of the cutting robot disclosed in Patent Document 1, since only the path up to the cutting height is taught, it is necessary to move to the cutting height once and then move to the penetration height based on the cutting height, which causes a problem of a longer cycle time.

[0009] Therefore, an object of the present invention is to provide a robot control device and a plasma cutting method capable of shortening the tact time by a teaching program for causing a plasma cutting robot to move appropriately.

[0010] Means for solving problems

[0011] A robot control device involved in one embodiment of the present invention is a teaching playback type robot control device that controls the movement of a plasma cutting robot programmed by teaching, and comprises: a program reading unit that reads out a teaching program for causing the plasma cutting robot to move; a program interpretation unit that interprets the read teaching program; and a program execution unit that executes the interpreted teaching program. When the program interpretation unit interprets a plasma cutting start command that includes an arc starting condition for plasma cutting in the teaching program, the program interpretation unit uses the position information taught by the moving command after the plasma cutting start command to set the arc starting height of the welding torch in the plasma cutting robot included in the arc starting condition in the plasma cutting start command.

[0012] According to this method, the program interpretation unit interprets the teaching program read by the program reading unit, and when interpreting the plasma cut start command including the arc start condition, the position information taught by the movement command after the plasma cut start command is used to set the arc start height included in the arc start condition in the plasma cut start command. In addition, the program execution unit executes the teaching program interpreted by the program interpretation unit. Thus, the cycle time can be shortened by the teaching program that causes the plasma cut robot to move appropriately. In addition, since the arc start height included in the arc start condition in the plasma cut start command is set using the position information taught by the movement command, the plasma cut start command including the common arc start condition can be used as the generated teaching program.

[0013] In the above aspect, the arc start height may be a cutting height of a welding torch in a plasma cutting robot or an ignition height higher than the cutting height.

[0014] According to this aspect, since the cutting height or the ignition height is set as the arc starting height, and an appropriate height is set, the time required for the plasma cutting robot (welding torch) to move to the arc height can be shortened, thereby shortening the cycle time.

[0015] In the above method, it may also include: a teaching device that allows the user to select either a first mode in which the cut-off height is the same as the ignition height, or a second mode in which the cut-off height is different from the ignition height, and a teaching program is generated to set the cut-off height or the ignition height for the arc starting height based on the selected first mode or second mode.

[0016] According to this method, the user is allowed to select the first mode or the second mode using the teaching device, and based on this, the cutting height or the ignition height is set as the arc start height. Since the appropriate arc start height is set by the user's selection, the movement time of the plasma cutting robot (welding torch) to the arc start height can be shortened, thereby shortening the cycle time. In addition, ignition can be appropriately performed by arc start.

[0017] In the above aspect, the first mode may be selected when the cutting start position is an end surface among the cutting targets, and the second mode may be selected when the cutting start position is on a plate among the cutting targets.

[0018] According to this aspect, since an appropriate arc start height is set based on whether the cutting start position in the cutting target is an end surface or a plate, ignition can be more appropriately performed by arc start.

[0019] In the above aspect, the device may further include a display unit that displays one of the first mode and the second mode in the display area so that the mode can be selected by the user.

[0020] According to this aspect, the user can easily select an appropriate mode.

[0021] In the above aspect, the display unit may display, in the display area, information on the height of the welding torch that moves in accordance with the first mode or the second mode selected by the user.

[0022] According to this aspect, since the display unit displays the height information of the welding torch that moves in accordance with the first mode or the second mode, the user can appropriately understand the change in the height of the welding torch.

[0023] A plasma cutting method according to one embodiment of the present invention is a plasma cutting method performed by a teaching playback type robot control device for controlling the movement of a plasma cutting robot programmed by teaching, comprising: a program reading step for reading a teaching program for causing the plasma cutting robot to move; a program interpretation step for interpreting the read teaching program; and a program execution step for executing the interpreted teaching program. In the program interpretation step, when a plasma cutting start command including an arc start condition for plasma cutting is interpreted in the teaching program, the arc start height of the welding torch of the plasma cutting robot included in the arc start condition in the plasma cutting start command is set using position information taught by a moving command after the plasma cutting start command.

[0024] According to this method, in the program interpretation step, the teaching program read out in the program reading step is interpreted, and when the plasma cut start command including the arc start condition is interpreted, the arc start height included in the arc start condition in the plasma cut start command is set using the position information taught by the movement command after the plasma cut start command. And, in the program execution step, the teaching program interpreted in the program interpretation step is executed. Thus, the cycle time can be shortened by the teaching program that causes the plasma cut robot to move appropriately. In addition, since the arc start height included in the arc start condition in the plasma cut start command is set using the position information taught by the movement command, the plasma cut start command including the common arc start condition can be used as the generated teaching program.

[0025] Effects of the Invention

[0026] According to the present invention, it is possible to provide a robot control device and a plasma cutting method capable of shortening tact time by using a teaching program for appropriately moving a plasma cutting robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 1 is a system schematic diagram showing a plasma cutting robot system 10 according to an embodiment of the present invention.

[0028] Figure 2 This is a functional block diagram showing each function of the robot control device 100 according to one embodiment of the present invention.

[0029] Figure 3 It is a diagram showing an example of the teaching program PG for operating the plasma cutting robot 20 .

[0030] Figure 4 This is a diagram showing a state of a screen in which the penetration type "end surface" is selected when the penetration position is the end surface of the workpiece.

[0031] Figure 5 This is a diagram showing the change in the height of the welding torch 21 when the teaching program PG is executed in a case where the cutting start position is the end surface of the workpiece.

[0032] Figure 6 This is a diagram showing a state of a screen in which the penetration category "on the board" is selected when the penetration position is on the board of the workpiece.

[0033] Figure 7 This is a diagram showing the change in the height of the welding torch 21 when the teaching program PG is executed when the cutting start position is on the plate of the workpiece.

[0034] Figure 8This is a diagram showing the change in the height of the welding torch 21 when the teaching program PG is executed when the cutting start position is on the plate of the workpiece and the plate thickness of the workpiece is large.

[0035] Fig. 9 This is a flowchart showing the flow of processing of the plasma cutting method M100 executed by the robot control device 100 according to the embodiment of the present invention.

[0036] Description of Reference Numerals

[0037] 10…Plasma cutting robot system, 20…Plasma cutting robot, 21…Welding torch, 30…Teaching pendant, 40…Plasma power supply device, 100…Robot control device, 110…Robot teaching unit, 120…Plasma cutting unit, 121…Program reading unit, 122…Program interpretation unit, 123…Program execution unit, M100…Plasma cutting method, S110~S180…Each step in the plasma cutting method M100. DETAILED DESCRIPTION

[0038] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the embodiments described below are only examples for implementing the present invention, and are not intended to limit the present invention. In addition, in order to facilitate the understanding of the description, the same reference numerals are sometimes added to the same structural elements in each of the accompanying drawings as much as possible, and repeated descriptions are omitted.

[0039] <One Implementation Method>

[0040] [Overview of Plasma Cutting Robot System]

[0041] Figure 1 FIG. 1 is a system schematic diagram showing a plasma cutting robot system 10 according to an embodiment of the present invention. Figure 1 As shown, the plasma cutting robot system 10 includes a plasma cutting robot 20 , a teaching pendant 30 , a plasma power supply device 40 , and a robot control device 100 .

[0042] The plasma cutting robot 20 is connected to the robot control device 100 via a cable, and performs plasma cutting based on an operation command from the robot control device 100. The plasma cutting robot 20 has a welding torch 21 at the front end of its arm, and performs plasma cutting by generating an arc between the front end of the welding torch 21 and a metal material (workpiece) to be cut.

[0043] The welding torch 21 is connected to the plasma power supply device 40 via a cable and receives a supply of voltage and current. During plasma cutting, if the welding torch 21 is brought into instant contact with the metal material and energized, arc discharge is generated between the tip of the welding torch 21 and the metal material, and the heat of the generated arc melts the metal material, thereby performing plasma cutting.

[0044] The teaching pendant 30 receives input from an operator who performs a plasma cutting operation regarding teaching information related to plasma cutting of the plasma cutting robot 20. The operator uses the teaching pendant 30 to input optimal teaching information related to plasma cutting while checking the state of the arc.

[0045] Here, the so-called plasma cutting related teaching information is information related to plasma cutting performed by the plasma cutting robot 20, and includes teaching information for teaching the operation of the plasma cutting robot 20 and plasma cutting conditions. The teaching information of the plasma cutting robot 20 includes information related to the operation of the arm of the plasma cutting robot 20, information related to the position and posture of the plasma cutting robot 20, information related to the tip of the welding torch 21, etc. In addition, the plasma cutting conditions include the arc voltage applied to the welding torch 21, the arc current flowing through the welding torch 21, and the cutting speed indicating the moving speed of the welding torch 21 in the cutting direction during cutting.

[0046] The robot control device 100 is a device that controls the plasma cutting robot 20. The robot control device 100 is connected to the teaching pendant 30 and can obtain the plasma cutting related teaching information input to the teaching pendant 30. The robot control device 100 controls the plasma cutting robot 20 and the plasma power supply device 40 based on the plasma cutting related teaching information.

[0047] The plasma power supply device 40 is connected to the plasma cutting robot 20 via a cable, and supplies arc voltage and arc current to the welding torch 21 in the plasma cutting robot 20 based on a command from the robot control device 100 .

[0048] In addition, Figure 1 In the embodiment, the teaching pendant 30 is connected to the robot control device 100 via a cable, but the connection may be wireless. That is, the teaching pendant 30 and the robot control device 100 may include a communication unit for wireless communication. By wirelessly connecting the robot control device 100 and the teaching pendant 30, the operator will not be troubled by the existence of the cable, nor will he be restricted by the length of the cable in the range of movement, and can input the plasma cutting related teaching information while moving freely.

[0049] [Structure of the robot control device]

[0050] Figure 2 1 is a functional block diagram showing the functions of the robot control device 100 according to one embodiment of the present invention. Figure 2 As shown, the robot control device 100 includes a robot teaching unit 110 and a plasma cutting unit 120. The plasma cutting unit 120 executes the teaching program PG generated by the robot teaching unit 110 to operate the plasma cutting robot 20 to perform plasma cutting. The robot control device 100 is a so-called teaching playback type robot control device that controls the operation of the plasma cutting robot 20 programmed by teaching.

[0051] The robot teaching unit 110 generates a teaching program by teaching the plasma cutting robot 20. For example, an operator uses an operating device (teaching device) such as the teaching pendant 30 to set plasma cutting conditions or register teaching points while operating the plasma cutting robot 20, thereby generating a teaching program PG.

[0052] The plasma cutting unit 120 operates the plasma cutting robot 20 according to the teaching program PG. The plasma cutting unit 120 includes a program reading unit 121, a program interpreting unit 122, and a program executing unit 123.

[0053] The program reading unit 121 reads the teaching program PG for operating the plasma cutting robot 20, and the program interpreting unit 122 interprets the teaching program PG read by the program reading unit 121. The teaching program PG mainly includes an arc start command (AS), a move command (MOVE), and an arc end command (AE).

[0054] Figure 3 FIG. 2 is a diagram showing an example of a teaching program PG for operating the plasma cutting robot 20. Figure 3 As shown in FIG. 1 , the teaching program PG includes an arc start command (AS), a movement command (MOVE), and an arc end command (AE). In addition, the movement command (MOVE) is described as a linear movement command (LIN).

[0055] Specifically, the arc start command (AS) includes the following processing: moving the welding torch 21 to the position where the arc starts (arc start height), turning on the arc (igniting), and then performing perforation (piercing the penetration hole). In addition, the moving speed of the welding torch 21 at this time, the arc voltage and / or arc current, and the time required to penetrate the penetration hole (penetration delay) may be included, which are appropriately set according to the material and thickness of the workpiece, etc., and are taught by the robot teaching unit 110. In addition, the position where the arc starts (arc start height) is set for the welding torch 21 based on the cutting height, and the details thereof will be described later.

[0056] The movement command (MOVE) includes the following processing: in order to cut the workpiece, the welding torch 21 is moved in a substantially horizontal direction above the workpiece in a state where an arc is generated. Here, the movement command (MOVE) is recorded as a plurality of linear movement commands (LIN), but is not limited thereto, and may be, for example, a circular movement command (CIR), or a combination thereof. In addition, it may include the position at which the welding torch 21 is moved, the height position of the welding torch 21 from the workpiece (cutting height), the movement speed of the welding torch 21, the arc voltage and / or the arc current, which are appropriately set according to the material and thickness of the workpiece, and are taught by the robot teaching unit 110.

[0057] Here, the cutting height is appropriately set according to the material and thickness of the workpiece, and is taught by the robot teaching unit 110. The aforementioned arc start height is set based on the cutting height in the movement command (MOVE). For example, in the arc start command (AS), the cutting height in the movement command (MOVE) is referred to and a given height is added to the cutting height, thereby setting it as the arc start height. In addition, the given height added to the cutting height can be pre-set according to the material and thickness of the workpiece.

[0058] The arc end command (AE) includes a process for ending the arc.

[0059] In this way, the teaching program PG interpreted by the program interpretation unit 122 is executed by the program execution unit 123. In particular, the program interpretation unit 122 sets the arc start height included in the arc start command (AS) based on the cutting height included in the movement command (MOVE) after the arc start command (AS).

[0060] Since the arc start height included in the arc start command (AS) is set based on the cutting height included in the moving command (MOVE) in the teaching program PG, if a moving command (MOVE) including the cutting height is generated, the teaching program PG can be generated as a common arc start command (AS) without changing the arc start command (AS).

[0061] Furthermore, the arc starting height is preferably set to an appropriate height based not only on the material and thickness of the workpiece, but also on the cutting start position, i.e., the penetration position. Specifically, different heights are set when the cutting start position (penetration position) is the end face of the workpiece and when it is on the plate of the workpiece.

[0062] [About the height setting of the welding torch]

[0063] Figure 42 is a diagram showing a screen in which the penetration category "end face" is selected when the penetration position is the end face of the workpiece. Figure 4 As shown, in the screen operated by the user, "end surface" (display unit) is selected from the penetration categories "on the plate" and "end surface" by the radio button.

[0064] For example, when an operator uses an operating device (teaching device) such as the teaching pendant 30 to set plasma cutting conditions, or when registering teaching points while operating the plasma cutting robot 20, the display unit displays the plasma cutting conditions. Figure 4 The screen shown is displayed on the teaching device. When the cutting start position of the workpiece to be cut is the end face of the workpiece, the operator may select the penetration type "end face".

[0065] When the cutting start position is the end surface of the workpiece, the position (arc start height) at which the arc of the welding torch 21 is started may be the same as the cutting height, that is, the arc is connected (ignited) at the cutting height (first mode).

[0066] Figure 5 2 is a diagram showing the change in the height of the welding torch 21 when the teaching program PG is executed when the cutting start position is the end surface of the workpiece. Figure 5 As shown, the height of the welding torch 21 becomes the cutting height under the arc start command (AS), the arc is turned on, and the penetration hole is penetrated by the penetration delay. After that, the height of the welding torch 21 is maintained at the cutting height, and the welding torch 21 is moved under the movement command (MOVE) to cut the workpiece, and the arc end command (AE) is executed.

[0067] As the teaching program PG, when the penetration type "end surface" is selected, it is sufficient to generate such that the cutting height included in the movement command (MOVE) is set to the arc start height included in the arc start command (AS).

[0068] Figure 6 2 is a diagram showing a situation in which a screen of the penetration category "on the board" is selected when the penetration position is on the board of the workpiece. Figure 6 As shown, in the screen operated by the user, "on board" (display unit) is selected from the penetration categories "on board" and "end surface" by the radio button.

[0069] For example, when an operator uses an operating device (teaching device) such as a teaching pendant 30 to set plasma cutting conditions, or when registering a teaching point while operating the plasma cutting robot 20, the display unit displays the plasma cutting conditions. Figure 6 The screen shown is displayed on the teaching device. Furthermore, when the cutting start position of the workpiece to be cut is on the plate of the workpiece, the operator can select the penetration type "on the plate".

[0070] When the cutting start position is on the plate of the workpiece, the arc starting position of the welding torch 21 (arc starting height) can be set to a height different from the cutting height, that is, the arc is connected (ignited) at an ignition height higher than the cutting height (second mode).

[0071] Figure 7 2 is a diagram showing the change in the height of the welding torch 21 when the teaching program PG is executed when the cutting start position is on the plate of the workpiece. Figure 7 As shown, the height of the welding torch 21 becomes an ignition height higher than the cutting height under the arc start command (AS), the arc is connected, and the penetration hole is penetrated by the penetration delay. After that, the height of the welding torch 21 becomes the cutting height, and the cutting height is maintained unchanged. By moving the welding torch 21 under the movement command (MOVE), the workpiece is cut, and the arc end command (AE) is executed.

[0072] When the penetration type "on-board" is selected, the teaching program PG may be generated so that the arc start height included in the arc start command (AS) is set to an ignition height obtained by adding a given height to the cutting height included in the move command (MOVE).

[0073] As described above, in the teaching program PG, the arc start height included in the arc start command (AS) is not necessarily the same as the arc start height when the cutting start position is the end face of the workpiece ( Figure 4 as well as Figure 5 ) and when the cutting start position is on the plate of the workpiece ( Figure 6 as well as Figure 7 ), but are all set based on the cutting height included in the movement command (MOVE) after the arc start command (AS). It can be seen that by selecting the penetration category "end face" or "on plate", the appropriate arc start height is set in the common arc start command (AS).

[0074] In addition, further, when the starting position of cutting the workpiece is on the plate of the workpiece, when the plate thickness of the workpiece is large (for example, above 40 mm, etc.), the height of the welding torch 21 can be set to different heights according to the ignition height for arc connection (ignition) and the penetration height under the penetration delay until the penetration hole is penetrated.

[0075] Figure 8 2 is a diagram showing the change in the height of the welding torch 21 when the teaching program PG is executed when the cutting start position is on the plate of the workpiece and the plate thickness of the workpiece is large. Figure 8As shown, the height of the welding torch 21 becomes the ignition height higher than the cutting height under the arc start command (AS), the arc is connected, and further becomes the penetration height higher than the ignition height, and the penetration hole is penetrated by the penetration delay. After that, the height of the welding torch 21 becomes the cutting height, and the cutting height is maintained unchanged. By moving the welding torch 21 under the movement command (MOVE), the workpiece is cut, and the arc end command (AE) is executed.

[0076] As a teaching program PG, when the penetration category "on the plate" is selected, an ignition height obtained by adding a given height to the cutting height included in the move command (MOVE) can be generated for the arc start height included in the arc start command (AS), and a penetration height obtained by further adding a given height corresponding to the plate thickness of the workpiece can be set.

[0077] In addition, the penetration height is recorded in advance at an appropriate height corresponding to the plate thickness of the workpiece. For example, the operator can use the teaching pendant 30 or the like to operate the machine (teaching device). Figure 4 as well as Figure 6 In the screen shown, the thickness of the workpiece to be cut is input and set.

[0078] In addition, Figure 4 as well as Figure 6 In the screen shown, the display unit may be configured to display specific values ​​of the cutting height, ignition height, and penetration height set in accordance with the operator's selection (e.g., penetration type) and input (e.g., plate thickness of the workpiece), and the operator may confirm the values. Furthermore, the displayed items are not limited to these, and for example, the penetration speed, ignition delay, and movement delay may be displayed.

[0079] [Plasma cutting method]

[0080] Next, a method of plasma cutting a workpiece to be cut by operating the plasma cutting robot according to a teaching program will be described in detail.

[0081] Fig. 9 1 is a flowchart showing the process flow of the plasma cutting method M100 executed by the robot control device 100 according to one embodiment of the present invention. Fig. 9 As shown, the plasma cutting method M100 includes steps S110 to S180 , and each step is executed by a processor included in the robot control device 100 .

[0082] In step S110 , the robot control device 100 reads a teaching program for operating the plasma cutting robot 20 (program reading step). As a specific example, the program reading unit 121 reads a teaching program PG generated by teaching by the robot teaching unit 110 .

[0083] In step S120 , the robot controller 100 interprets the teaching program (program interpretation step). As a specific example, the program interpretation unit 122 interprets the teaching program PG read out in step S110 for each command included in the teaching program PG.

[0084] In step S130, the robot controller 100 determines whether it is an arc start command (program interpretation step). As a specific example, the program interpretation unit 122 interprets each command included in the teaching program PG, and if the command is an arc start command, the process proceeds to step S140 ("Yes" in step S130), and if the command is not an arc start command, the process proceeds to step S180 ("No" in step S130).

[0085] In step S140 , the robot controller 100 refers to the movement command after the arc start command (program interpretation step). As a specific example, the program interpretation unit 122 acquires the cutting height included in the movement command after the arc start command.

[0086] In step S150, the robot control device 100 determines the mode selected by the user (program interpretation step). As a specific example, the program interpretation unit 122 interprets what mode is selected by the operator using the teaching pendant 30 or other operating device (teaching device) when the robot teaching unit 110 teaches the operation of the plasma cutting robot 20. Figure 4 In the screen shown, when "end face (first mode)" is selected as the starting position (penetration position) for cutting the workpiece, the processing proceeds to step S160, and when "on the plate (second mode)" is selected as the starting position (penetration position) for cutting the workpiece, the processing proceeds to step S170.

[0087] In step S160, the robot controller 100 sets the cutting height to the arc starting height (program interpretation step). As a specific example, the program interpretation unit 122 sets the cutting height acquired in step S140 as the arc starting height included in the arc starting command.

[0088] In step S170, the robot controller 100 sets the ignition height for the arc start height (program interpretation step). As a specific example, the program interpretation unit 122 sets the ignition height obtained by adding a given height to the cutting height obtained in step S140 as the arc start height included in the arc start command.

[0089] In step S180, the robot control device 100 executes the teaching program (program execution step). As a specific example, the program execution unit 123 executes the teaching program PG explained in steps S120 to S170. Thus, the robot control device 100 operates the plasma cutting robot 20 according to the teaching program PG, thereby performing plasma cutting on the workpiece to be cut.

[0090] As described above, according to the robot control device 100 and the plasma cutting method M100 involved in one embodiment of the present invention, the program reading unit 121 reads the teaching program PG generated by the robot teaching unit 110, and the program interpretation unit 122 interprets the teaching program PG. When interpreting the arc start command (AS) included in the teaching program PG, the program interpretation unit 122 uses the cutting height included in the moving command (MOVE) after the arc start command (AS) to set an appropriate height as the arc start height included in the arc start command (AS) by using the mode selected by the operator using the teaching device. Thus, the cycle time can be shortened by the teaching program PG that allows the plasma cutting robot 20 to move appropriately. In addition, since the arc start height included in the arc start command (AS) is set using the cutting height included in the moving command (MOVE), a common arc start command (AS) can be used as the generated teaching program PG.

[0091] In addition, in this embodiment, Figure 4 as well as Figure 6 In the screen shown in FIG. 1 , an example of specific values ​​of the cut height, ignition height, and penetration height set in accordance with the selection and input of the operator is shown, but the present invention is not limited to this. Figure 4 as well as Figure 6 together with the screen shown, or as another screen, display Figure 5 , 7 8 and a diagram showing the change in height of the welding torch 21. Thus, the operator can visually and intuitively grasp the change in height of the welding torch 21 in response to the operator's selection (e.g., penetration type) and input (e.g., plate thickness of the workpiece).

[0092] In addition, in the present embodiment, as the arc starting height, when the cutting start position is the end face of the workpiece, the cutting height is set, when the cutting start position is on the plate of the workpiece, the ignition height higher than the cutting height is set, and further, when the plate thickness of the workpiece is large, the penetration height higher than the ignition height is set, and the above-mentioned example is described, but it is not limited to these. For example, the appropriate ignition height and penetration height can be set corresponding to various conditions including the type and size of the workpiece, the cutting start position, and the type and performance of the plasma cutting robot 20.

[0093] In addition, in this embodiment, the teaching program PG composed of the arc start command (AS), the move command (MOVE), and the arc end command (AE) is mainly cited as an example for explanation, but the structure of the teaching program PG is not limited to these. For example, the teaching program can constitute a plasma cut start command including an arc start condition for plasma cut, and can also constitute a plasma cut start command including an arc start command (AS). These can be one command or multiple commands (arc start command + plasma cut command = plasma cut start command).

[0094] The embodiments described above are intended to facilitate understanding of the present invention and are not intended to limit the present invention for interpretation. The various elements and their configurations, materials, conditions, shapes, and sizes of the embodiments are not limited to the examples illustrated, but can be appropriately changed. In addition, the structures shown in different embodiments can be partially replaced or combined with each other.

Claims

1. A robot control device, which is a teaching playback type robot control device for controlling the movement of a plasma cutting robot programmed by teaching, The robot control device is characterized by comprising: A program reading unit that reads a teaching program for causing the plasma cutting robot to operate; a program interpretation unit that interprets the read teaching program; and a program execution unit, executing the explained teaching program, When the program interpretation unit interprets a plasma cutting start command including an arc starting condition for plasma cutting in the teaching program, the program interpretation unit uses the position information taught in the movement command after the plasma cutting start command to set the arc starting height of the welding torch in the plasma cutting robot included in the arc starting condition in the plasma cutting start command.

2. The robot control device according to claim 1, wherein: The arc start height is a cutting height of a welding torch in the plasma cutting robot or an ignition height higher than the cutting height.

3. The robot control device according to claim 2, wherein: The robot control device comprises: The teaching device allows the user to select either a first mode in which the cut-off height is the same as the ignition height or a second mode in which the cut-off height is different from the ignition height. The teaching program is generated so as to set the cutoff height or the ignition height for the arc start height based on the selected first mode or second mode.

4. The robot control device according to claim 3, wherein: The first mode is selected when the cutting start position is an end surface of the cutting object. The second mode is selected when the cutting start position is on a plate among the cutting targets.

5. The robot control device according to claim 3, wherein: The robot control device comprises: The display unit displays either the first mode or the second mode in a display area in a manner selectable by a user.

6. The robot control device according to claim 5, wherein: The display unit displays, on the display area, information on the height of the welding torch that moves in accordance with the first mode or the second mode selected by the user.

7. A plasma cutting method, which is performed by a robot control device of a teaching playback type for controlling the movement of a plasma cutting robot programmed by teaching, The plasma cutting method is characterized by comprising: A program reading step of reading a teaching program for causing the plasma cutting robot to operate; A program explanation step of explaining the read teaching program; as well as Program execution steps, execute the teaching program explained, In the program interpretation step, when a plasma cutting start command including an arc starting condition for plasma cutting is interpreted in the teaching program, the arc starting height of the welding torch in the plasma cutting robot included in the arc starting condition in the plasma cutting start command is set using the position information taught in the moving command after the plasma cutting start command.

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