Industrial robot

Abstract

To provide an industrial robot which can stop operation in direct teaching.SOLUTION: An orthogonal robot 10 includes: a hand part 20 which conducts a predetermined operation to a workpiece; a slide drive unit 40 which causes the hand part 20 to slide along a slide axis; and a control unit 100 which controls, according to teaching data, the slide drive unit 40 so as to cause the hand part 20 to slide. The control unit 100 is configured to be executable direct teaching processing in which operation tracks of an arm tip part 54 and the hand part 20 are stored as the teaching data during a teaching period. An enable switch 130 which instructs operation permission and operation stop in the teaching period is provided at a handle 131 provided at the hand part 20.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an industrial robot. [Background technology]

[0002] Conventionally, when teaching industrial robots such as articulated robots, a method of creating an operating program using an operating terminal such as a teaching pendant has been adopted. However, this method has the problem that it is not possible to give intuitive instructions to the robot, and it takes a long time for an inexperienced worker to achieve a desired movement. In recent years, in order to realize more efficient teaching, a method has been proposed in which a worker directly touches the robot to teach it (so-called direct teaching) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 08-216074 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem with direct teaching is that it requires the operator to step away from the operating terminal and teach the robot the trajectory of movement within its range of motion, which could lead to an accident if the robot malfunctions.

[0005] The present invention has been made in consideration of the above circumstances, and has as its main object to provide an industrial robot that can be stopped immediately during direct teaching. [Means for solving the problem]

[0006] The means for solving the above problem is an industrial robot having two or more slide axes where the slide axes intersect, the robot robot comprising: an arm tip to which a robot hand that performs a predetermined operation on a workpiece is attached; a slide drive unit that slides the arm tip along each of the slide axes; and a control unit that controls the slide drive unit to slide the arm tip according to pre-stored teaching data, the control unit being configured to be able to execute a direct teaching process in which, when the arm tip moves due to an externally applied force during a predetermined teaching period, the control unit stores the movement trajectory as the teaching data, and the control unit comprises a handle provided on the arm tip or the robot hand; and an enable switch provided on the handle that instructs permission to operate the industrial robot and stop operation of the industrial robot during the teaching period.

[0007] This allows the user to move the arm tip by holding the handle equipped with the enable switch, even when the user is away from the operation terminal during direct teaching and is memorizing the trajectory of the movement within the operating range of the industrial robot. Therefore, even if the industrial robot malfunctions, the operation can be immediately stopped by operating the enable switch, preventing accidents. [Brief description of the drawings]

[0008] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. 4 is a block diagram showing a control configuration of the Cartesian robot. [Figure 4] FIG. 2A is a front view showing the rotation drive unit and the hand unit, and FIG. 2B is a side view showing the rotation drive unit and the hand unit. [Diagram 5] 11 is a flowchart showing the flow of a direct teaching process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of an "industrial robot" according to the present disclosure will be described with reference to the drawings. In the following embodiments and modifications, parts that are the same or equivalent to each other are given the same reference numerals in the drawings, and the explanations of the parts with the same reference numerals are incorporated herein by reference. In addition to the combinations of configurations explicitly shown in the description of the embodiments and modifications, it is also possible to combine the embodiments and modifications as long as there is no particular problem with the combination.

[0010] 1 and 2 show an orthogonal robot 10 as an industrial robot. The orthogonal robot 10 may be a device that sequentially transports workpieces from a supply location and aligns and loads them at a predetermined position, that is, a palletizing or depalletizing device, or a removal device that removes molded products or runners from a mold. It may also be an assembly device or a processing device. The orthogonal robot 10 is also called a gantry robot or a gantry loader.

[0011] 1 and 2, the Cartesian robot 10 includes a hand unit 20 as a robot hand that performs a predetermined operation on a workpiece (not shown), and a transport mechanism 30 that moves or rotates the hand unit 20. Also, as shown in Fig. 2 and 3, the Cartesian robot 10 includes a control device 100 as a control unit that controls the operations of the hand unit 20 and the transport mechanism 30, a teaching pendant 110 as an information terminal that can input and output various information, a selection panel 120 provided with axis selection buttons 121 to 126 as selection buttons, and a handle 131 provided with an enable switch 130.

[0012] As shown in FIG. 1, the transport mechanism 30 includes a slide drive unit 40 that slides the hand unit 20, and a rotation drive unit 50 that rotates the hand unit 20, and the transport mechanism 30 forms the arm unit of the Cartesian robot 10.

[0013] The slide drive unit 40 has an X-axis guide rail 41 supported by two pillars 11 erected on the installation surface, and a running body 42 running along the X-axis guide rail 41. The X-axis guide rail 41 is formed to extend straight along a predetermined direction so as to be parallel to the installation surface. Hereinafter, the direction in which the X-axis guide rail 41 extends will be referred to as the X-axis direction. The running body 42 is fixed so as to be movable along the X-axis guide rail 41. The running body 42 is drivingly connected to the output shaft of an X-axis servo motor 43 provided next to the X-axis guide rail 41 via a toothed belt or the like. That is, the running body 42 is configured to reciprocate in the X-axis direction along the X-axis guide rail 41 based on the driving force of the X-axis servo motor 43.

[0014] The traveling body 42 has a Y-axis guide rail 44 extending along the Y-axis direction, and a vertical movement mechanism 45 that travels along the Y-axis guide rail 44. The Y-axis direction is perpendicular to the X-axis direction and parallel to the installation surface. The vertical movement mechanism 45 is fixed so as to be movable along the Y-axis guide rail 44. The vertical movement mechanism 45 is drivingly connected to an output shaft of a Y-axis servo motor 46 provided at an end of the Y-axis guide rail 44 (the end on the X-axis guide rail 41 side) via a toothed belt or the like. That is, the vertical movement mechanism 45 is configured to reciprocate in the Y-axis direction along the Y-axis guide rail 44 based on the driving force of the Y-axis servo motor 46.

[0015] The vertical movement mechanism 45 has a Z-axis guide rail 47 extending along the Z-axis direction and a connecting mechanism 48 running along the Z-axis guide rail 47. The Z-axis direction is a direction perpendicular to the X-axis direction and the Y-axis direction, and is a vertical direction with respect to the installation surface. The connecting mechanism 48 is fixed so as to be movable along the Z-axis guide rail 47. The connecting mechanism 48 is drivingly connected to the output shaft of a Z-axis servo motor 49 provided next to the Z-axis guide rail 47 via a toothed belt or the like. That is, the connecting mechanism 48 is configured to reciprocate in the Z-axis direction along the Z-axis guide rail 47 based on the driving force of the Z-axis servo motor 49. In this embodiment, the X-axis guide rail 41, the Y-axis guide rail 44, and the Z-axis guide rail 47 each correspond to a slide shaft, and hereinafter, these may be collectively referred to as a "slide shaft".

[0016] A rotary drive unit 50 is fixed to the tip of the connecting mechanism 48. As shown in Fig. 4, the tip of this rotary drive unit 50 is an arm tip unit 54 to which the hand unit 20 is attached. The rotary drive unit 50 can rotate the hand unit 20 attached to the arm tip unit 54.

[0017] 4, the rotation drive unit 50 has a plurality of rotation axes (three axes in this embodiment) and can rotate the hand unit 20 attached to the arm tip unit 54 around these rotation axes. Specifically, the rotation drive unit 50 includes an A-axis rotation mechanism 51 that rotates the hand unit 20 in an A-axis direction, which is a rotation axis with the X-axis direction as the base axis, a B-axis rotation mechanism 52 that rotates the hand unit 20 in a B-axis direction, which is a rotation axis with the Y-axis direction as the base axis, and a C-axis rotation mechanism 53 that rotates the hand unit 20 in a C-axis direction, which is a rotation axis with the Z-axis direction as the base axis. The rotation mechanisms 51 to 53 for the respective rotation axes are composed of a servo motor, a reducer, and the like.

[0018] The hand unit 20 is fixed to the arm tip 54 of the rotation drive unit 50. The hand unit 20 includes a base unit 21 and one or more tools 22 fixed to the base unit 21. In this embodiment, the base unit 21 is configured by a chuck plate formed into a metal plate shape, and is fixed to the arm tip 54 of the rotation drive unit 50. Note that the base unit 21 does not need to be configured in a plate shape like the base unit 21, and may be configured by combining a frame, a rod-shaped pipe, or the like.

[0019] The tool 22 is an end effector, and varies depending on the action it is to perform on the workpiece. For example, the tool 22 may be a suction pad that uses air or magnetic force to suction the workpiece, a gripper that holds the workpiece, a cutting tool such as a nipper, a welding tool for welding, a driver tool for performing a screw tightening process, a polishing tool for removing burrs, etc.

[0020] As described above, the transport mechanism 30 is configured to be able to move the hand unit 20 linearly in two directions (X-axis direction and Y-axis direction) that are orthogonal to the horizontal direction, and in the up-down direction (Z-axis direction). The transport mechanism 30 is also configured to be able to rotate the hand unit 20 in the A-axis direction, B-axis direction, and C-axis direction. This allows the Cartesian robot 10 to move the hand unit 20 fixed to the transport mechanism 30 to a desired position, and have the tool 22 of the hand unit 20 perform a predetermined operation on the workpiece.

[0021] Next, the control configuration of the Cartesian robot 10 will be described with reference to FIG. 3. The control device 100 of the Cartesian robot 10 is an electronic control device equipped with a well-known microcomputer including a CPU, a ROM, a RAM, a flash memory, etc. In this embodiment, as shown in FIG. 2, it is installed alongside the X-axis guide rail 41. The control device 100 includes a drive circuit for driving the various servo motors 43, 46, 49 and the various rotation mechanisms 51 to 53 described above, and is configured to be able to control the operation of the various servo motors 43, 46, 49 and the various rotation mechanisms 51 to 53 via the drive circuit. The control device 100 is also configured to be able to control the operation of the various tools 22.

[0022] As shown in Fig. 3, the control device 100 is connected to various sensors (not shown), a teaching pendant 110, axis selection buttons 121 to 126, an enable switch 130, etc., and is configured to be able to acquire various information. The control device 100 also has various functions, and executes the various functions based on the acquired information. These functions are realized by executing a program stored in a storage device (storage memory) included in the control device 100. The various functions may be realized by electronic circuits, which are hardware, or at least a part of them may be realized by software, that is, by processing executed on a computer.

[0023] The teaching pendant 110 is a device for generating a program for the operation of the Cartesian robot 10, and inputting and operating for starting, stopping, and teaching the Cartesian robot 10. The teaching pendant 110 is connected to the control device 100 of the Cartesian robot 10 by wire or wirelessly. It is not shown in Figs. 1 and 2. The teaching pendant 110 is equipped with a liquid crystal monitor, a touch panel, and the like, and is configured to be able to execute various inputs and operations while watching the monitor. For example, by inputting information such as the movement order and movement distance of the hand unit 20 through the teaching pendant 110, teaching data (operation program) of the Cartesian robot 10 can be generated and stored. In other words, the teaching pendant 110 can be used to teach the Cartesian robot 10 to perform operations. Then, by operating the teaching pendant 110, the Cartesian robot 10 can be started and various operations can be performed according to the stored teaching data. In addition, by operating the teaching pendant 110, the Cartesian robot 10 can be stopped during operation.

[0024] However, teaching using the teaching pendant 110 requires specialized knowledge, and not everyone can do it. Therefore, direct teaching is used to make teaching more efficient. Direct teaching is a method of creating and storing teaching data that reproduces the movement (motion trajectory) of the Cartesian robot 10 by directly touching and moving the robot during a predetermined teaching period. This makes it possible to intuitively and efficiently teach the robot without specialized knowledge.

[0025] However, there are some problems with direct teaching. For example, it is difficult to make the Cartesian robot 10 accurately memorize the correct movement trajectory. Specifically, even if it is desired to move the hand unit 20 in a straight line in a predetermined direction, the hand unit 20 moves in a direction unexpected by the operator if an unnecessary force is applied because the hand unit 20 is operated by directly touching it, making it difficult to memorize a straight trajectory. In particular, when the hand unit 20 or the rotary drive unit 50 is heavy, it is difficult to move and stop it accurately because a force is required to move and stop it, making direct teaching difficult.

[0026] Furthermore, when performing direct teaching, since the operator directly touches the Cartesian robot 10, the operator inevitably enters the operating range of the Cartesian robot 10. Therefore, if the Cartesian robot 10 malfunctions or if the heavy hand unit 20 moves unexpectedly due to inertia, it may come into contact with the operator, leading to an accident.

[0027] In this embodiment, therefore, some measures have been taken to solve the problems in direct teaching. These will be explained in detail below. In the following, unless otherwise specified, the arm tip 54 and the hand unit 20 attached to the arm tip 54 will be simply referred to as the arm tip 54.

[0028] As a first innovation, the control device 100 is provided with an axis selection function that can select and set the direction in which movement and rotation of the arm tip 54 are permitted during the teaching period in direct teaching. Also, the axis selection buttons 121 to 126 are configured to allow the control device 100 to select and instruct the direction in which movement and rotation of the arm tip 54 are permitted.

[0029] As a second innovation, before direct teaching, when the Cartesian robot 10 is stationary, the load applied to each axis, i.e., the holding torque generated in the slide drive unit 40 and the rotation drive unit 50 due to the weight generated by the hand unit 20, etc., is measured, and a torque control function is provided to perform torque control so as to cancel out the weight of the hand unit 20, etc., on axes that are permitted to move or rotate during the teaching period.

[0030] As a third innovation, an enable switch 130 for stopping the operation of the Cartesian robot 10 is provided and installed near the hand unit 20, so that the Cartesian robot 10 can be brought to an emergency stop by releasing (or pushing) the enable switch 130 without operating the teaching pendant 110.

[0031] Each of these features will be described in detail below. First, the axis selection function will be described. As shown in Fig. 4, axis selection buttons 121-126 and setting completion button 127 are provided together on selection panel 120. Selection panel 120 is attached to the side of rotation drive unit 50. Axis selection buttons 121-126 are buttons for selecting a movable or rotatable axis, and setting completion button 127 is a button for completing the setting selected by axis selection buttons 121-126.

[0032] More specifically, the axis selection button 121 is a selection button for setting permission to move the arm tip 54 in the X-axis direction. That is, when the setting completion button 127 is turned on after the axis selection button 121 is turned on, the traveling body 42 can be moved back and forth in the X-axis direction along the X-axis guide rail 41 during the teaching period. On the other hand, when the axis selection button 121 is turned off, the traveling body 42 cannot be moved in the X-axis direction.

[0033] Similarly, axis selection button 122 is a selection button for setting permission to move arm tip 54 in the Y-axis direction. That is, when setting completion button 127 is turned on after axis selection button 122 is turned on, vertical movement mechanism 45 can be moved back and forth in the Y-axis direction along Y-axis guide rail 44 during the teaching period. On the other hand, when axis selection button 122 is off, vertical movement mechanism 45 cannot be moved in the Y-axis direction.

[0034] Similarly, axis selection button 123 is a selection button for setting permission to move arm tip 54 in the Z-axis direction. That is, when setting completion button 127 is turned on after axis selection button 123 is turned on, rotation drive unit 50 connected to coupling mechanism 48 can be moved back and forth in the Z-axis direction along Z-axis guide rail 47 during the teaching period. On the other hand, when axis selection button 123 is off, it is not possible to move rotation drive unit 50 in the Z-axis direction.

[0035] Furthermore, the axis selection button 124 is a selection button for setting permission for rotation of the arm tip portion 54 in the A-axis direction. That is, when the setting completion button 127 is turned on after the axis selection button 124 is turned on, the hand portion 20 can be rotated in the A-axis direction during the teaching period. On the other hand, when the axis selection button 124 is turned off, the hand portion 20 cannot be rotated in the A-axis direction.

[0036] Similarly, the axis selection button 125 is a selection button for setting permission for rotation of the arm tip portion 54 in the B-axis direction. That is, when the setting completion button 127 is turned on after the axis selection button 125 is turned on, the hand portion 20 can be rotated in the B-axis direction during the teaching period. On the other hand, when the axis selection button 125 is turned off, the hand portion 20 cannot be rotated in the B-axis direction.

[0037] Similarly, the axis selection button 126 is a selection button for setting permission for rotation of the arm tip 54 in the C-axis direction. That is, when the setting completion button 127 is turned on after the axis selection button 126 is turned on, the hand unit 20 can be rotated in the C-axis direction during the teaching period. On the other hand, when the axis selection button 125 is turned off, the hand unit 20 cannot be rotated in the C-axis direction.

[0038] As shown in Fig. 3, these axis selection buttons 121-126 and setting completion button 127 are connected to the control device 100, which is configured to be able to input the on / off states of each of the axis selection buttons 121-126 and the setting completion button 127. The control device 100 inputs the on / off states of each of the axis selection buttons 121-126 and the setting completion button 127, and sets the movement permission and movement restriction, and the rotation permission and rotation restriction of the hand unit 20 for each axis. In this way, the axis selection function is realized by the control device 100. Hereinafter, the slide axis that is permitted to move and the rotation axis that is permitted to rotate during the teaching period (during direct teaching) by the axis selection function may be simply referred to as the selected axis.

[0039] Next, the torque control function will be described. In direct teaching, before the teaching period is set and the arm tip 54 is stationary, the control device 100 measures the load applied to each selected axis, that is, the holding torque generated by the weight of the hand unit 20 and the like. Specifically, when the X-axis direction is selected as the selected axis, before the teaching period is set and the arm tip 54 is stationary, the control device 100 measures the holding torque generated in the X-axis servo motor 43 by the traveling body 42 in the X-axis direction. If the X-axis guide rail 41 is kept horizontal, the holding torque is almost zero, whereas if the X-axis guide rail 41 is inclined, a holding torque is generated.

[0040] Similarly, when the Y-axis direction is selected as the selected axis, before the teaching period is set and when the arm tip 54 is stationary, the control device 100 measures the holding torque in the Y-axis direction generated in the Y-axis servo motor 46 by the vertical movement mechanism 45. If the Y-axis guide rail 44 is kept horizontal, the holding torque is nearly zero, whereas if the Y-axis guide rail 44 is inclined, a holding torque is generated.

[0041] Similarly, when the Z-axis direction is selected as the selected axis, before the teaching period is set and when the arm tip 54 is stationary, the control device 100 measures the holding torque generated in the Z-axis servo motor 49 in the Z-axis direction by the connecting mechanism 48 that moves on the Z-axis guide rail 47, the rotation drive unit 50, the hand unit 20, etc.

[0042] Similarly, when the A-axis direction is selected as the selected axis, before the teaching period is set and when the arm tip 54 is stationary, the control device 100 measures the holding torque generated in the A-axis rotation mechanism 51 by the hand unit 20 or the like in the A-axis direction. Similarly, when the B-axis direction is selected as the selected axis, before the teaching period is set and when the arm tip 54 is stationary, the control device 100 measures the holding torque generated in the B-axis rotation mechanism 52 by the hand unit 20 or the like in the B-axis direction. Similarly, when the C-axis direction is selected as the selected axis, before the teaching period is set and when the arm tip 54 is stationary, the control device 100 measures the holding torque generated in the C-axis rotation mechanism 53 by the hand unit 20 or the like in the C-axis direction.

[0043] During the teaching period, the control device 100 performs torque control so that the torque generated by the conveyance mechanism 30 in the selected axis falls within a torque setting range determined by the measured holding torque.

[0044] More specifically, when the X-axis direction is selected, during the teaching period, the control device 100 controls the torque of the X-axis servo motor 43 so that the torque generated by the X-axis servo motor 43 is equal to the measured holding torque in the X-axis direction. In other words, the control device 100 controls the torque of the X-axis servo motor 43 so that the torque generated by the weight of the traveling body 42 in the X-axis direction is cancelled by the torque generated by the X-axis servo motor 43.

[0045] Similarly, when the Y-axis direction is selected, during the teaching period, the control device 100 controls the torque of the Y-axis servo motor 46 so that the torque generated by the Y-axis servo motor 46 is equal to the measured holding torque in the Y-axis direction. In other words, the control device 100 controls the torque of the Y-axis servo motor 46 so that the torque generated by the weight of the vertical movement mechanism 45 in the Y-axis direction is cancelled out by the torque generated by the Y-axis servo motor 46.

[0046] Similarly, when the Z-axis direction is selected, during the teaching period, the control device 100 controls the torque of the Z-axis servo motor 49 so that the torque generated by the Z-axis servo motor 49 is equal to the measured holding torque in the Z-axis direction. In other words, the control device 100 controls the torque of the Z-axis servo motor 49 so that the torque generated by the weight of the rotation drive unit 50, the hand unit 20, etc. in the Z-axis direction is cancelled out by the torque generated by the Z-axis servo motor 49.

[0047] Similarly, when the A-axis direction is selected, during the teaching period, the control device 100 controls the torque of the A-axis rotation mechanism 51 so that the torque generated by the A-axis rotation mechanism 51 is equal to the measured holding torque in the A-axis direction. In other words, the control device 100 controls the torque of the A-axis rotation mechanism 51 so that the torque generated by the weight of the hand unit 20, etc. in the A-axis direction is cancelled out by the torque generated by the A-axis rotation mechanism 51.

[0048] Similarly, when the B-axis direction is selected, during the teaching period, the control device 100 controls the torque of the B-axis rotation mechanism 52 so that the torque generated by the B-axis rotation mechanism 52 is equal to the measured holding torque in the B-axis direction. In other words, the control device 100 controls the torque of the B-axis rotation mechanism 52 so that the torque generated by the weight of the hand unit 20, etc. in the B-axis direction is cancelled out by the torque generated by the B-axis rotation mechanism 52.

[0049] Similarly, when the C-axis direction is selected, during the teaching period, the control device 100 controls the torque of the C-axis rotation mechanism 53 so that the torque generated by the C-axis rotation mechanism 53 is equal to the measured holding torque in the C-axis direction. In other words, the control device 100 controls the torque of the C-axis rotation mechanism 53 so that the torque generated by the weight of the hand unit 20, etc. in the C-axis direction is cancelled out by the torque generated by the C-axis rotation mechanism 53.

[0050] Next, the enable switch 130 will be described. As shown in Fig. 4, the hand unit 20 is provided with a handle 131 which is held by the operator when performing direct teaching. To explain in detail, the handle 131 is formed in a bent rod shape or an arc shape, and is attached to the base unit 21 so as to surround the periphery of the base unit 21. In this embodiment, the handle 131 is bent to form a gentle curve and is generally L-shaped.

[0051] An enable switch 130 is provided at one end of the handle 131 to instruct the operation permission and operation stop of the Cartesian robot 10 during the teaching period. The enable switch 130 is a three-position enable switch 130 that has three positions, instructs operation permission in the intermediate position, and instructs operation stop in the other positions. That is, when the position of the enable switch 130 is the first position where it is not pressed (open state) or the third position where it is deeply pressed, it instructs operation stop, while when the position of the enable switch 130 is the second position where it is lightly pressed and is between the first and third positions, it instructs operation permission. As shown in FIG. 3, the enable switch 130 is connected to the control device 100 and outputs a signal indicating which position it is in.

[0052] Here, operation means that the Cartesian robot 10 (more specifically, the arm tip 54) is operating (moving, whether automatically or manually). Therefore, permission to operate the Cartesian robot 10 means that the Cartesian robot 10 is permitted to move, and stopping the operation of the Cartesian robot 10 means that the movement of the Cartesian robot 10 is stopped. Stopping the operation of the Cartesian robot 10 does not mean cutting off the power supply, stopping various functions of the Cartesian robot 10, disabling operations on the Cartesian robot 10, etc.

[0053] The enable switch 130 is provided at the tip of the handle 131, and the direction in which the enable switch 130 is pushed in is the same as the direction in which the tip of the handle 131 extends. The handle 131 is configured to be detachable from the hand unit 20, and is removed together with the enable switch 130 when direct teaching is not being performed.

[0054] Next, the flow of direct teaching will be described. The control device 100 executes a direct teaching process related to direct teaching at a predetermined timing, for example, based on the operation of the teaching pendant 110. The direct teaching process is executed by executing a control program stored in the storage device of the control device 100. This direct teaching process will be described with reference to FIG. 5.

[0055] When the direct teaching process is started, the control device 100 sets an axis selection period for selecting an axis for which movement or rotation is permitted (step S101). During this axis selection period, the control device 100 inputs signals from the axis selection buttons 121 to 126 that are turned on. Note that the axis for which movement or rotation is permitted may be selected by the teaching pendant 110.

[0056] Thereafter, the control device 100 determines whether or not the setting button 127 has been operated and the setting has been completed (step S102). Note that the completion of the setting may be notified by the teaching pendant 110 instead of the setting button 127.

[0057] If the result of this determination is negative, the control device 100 executes step S101 again. On the other hand, if the result of this determination is positive, the control device 100 sets the axis corresponding to the axis selection button 121-126 selected in step S101 as the selected axis. The control device 100 also measures the holding torque of the selected axis (step S103). As described above, for example, if the selected axis is the Z-axis direction, the holding torque of the Z-axis servo motor 49 is measured.

[0058] Next, the control device 100 judges whether the position of the enable switch 130 is at the second stage that permits the operation of the Cartesian robot 10 (step S104). If the judgment result is negative, the control device 100 transitions to step S104 again after a predetermined time, and repeats the execution until the judgment result becomes positive.

[0059] If the result of this determination is positive, the control device 100 starts the teaching period and permits the movement or rotation of the arm tip 54 in the selected axis (step S105). That is, manual operation is permitted. This allows the operator to move or rotate the arm tip 54 together with the hand unit 20 by operating the handle 131 while lightly pressing the enable switch 130, that is, while maintaining the second stage position. At this time, only the movement or rotation in the selected axis is permitted. Also, as described above, during the teaching period, the control device 100 controls the torque of the slide drive unit 40 and the rotation drive unit 50 so that the generated torque generated by the slide drive unit 40 or the rotation drive unit 50 in the selected axis is the same as the measured holding torque. That is, the control device 100 controls the torque of the transport mechanism 30 so as to cancel the weight of the hand unit 20 and the like.

[0060] Thereafter, the control device 100 sequentially judges whether the position of the enable switch 130 is in the first stage or the third stage (step S106). If the result of this judgment is negative (if the position is in the second stage), the control device 100 continues the teaching period, that is, permits the movement or rotation of the arm tip 54 in the selected axis, and executes the judgment of step S104 again after a predetermined time.

[0061] On the other hand, if the determination result in step S106 is positive (if the first or third stage has been reached), the control device 100 stops the operation of the Cartesian robot 10 and interrupts the teaching period (step S107). Then, the control device 100 stores operation information for reproducing the movement trajectory during the teaching period, more specifically, while the position of the enable switch 130 is set to the second stage. The operation information includes, for example, the moving direction (or rotating direction) of the arm tip 54 during the teaching period, the moving distance (or rotating angle), the coordinates at the start and interruption, the selected axis, and the like. It is not necessary to store all of this information, and it is sufficient to store information sufficient to reproduce the movement trajectory. For example, only the coordinates (position coordinates) at the start and interruption of the teaching period may be stored.

[0062] Thereafter, the control device 100 judges whether an operation indicating the end of direct teaching has been inputted by the teaching pendant 110 or the like (step S108). If the judgment result is positive, the control device 100 generates teaching data for reproducing a movement trajectory from the stored driving information, stores the generated teaching data (step S109), and ends the direct teaching process. If a plurality of pieces of driving information are stored, the control device 100 connects them in order to form a series of movement trajectories, and generates teaching data for reproducing the movement trajectory. For example, if the selection axis is changed multiple times and the coordinates move each time the axis is changed, the control device 100 generates teaching data for reproducing a movement trajectory that follows the coordinates in order. Incidentally, even if the selection axis is not changed multiple times, the teaching period may be interrupted intermittently by the operation of the enable switch 130, and a plurality of pieces of driving information may be stored. In this case, the pieces of driving information are also connected to form a series of movement trajectories.

[0063] On the other hand, if the determination result in step S108 is negative, the control device 100 again proceeds to the process of step S101, sets an axis selection period, and selects an axis that is permitted to move or rotate. That is, it executes control to change the selected axis. After that, the same series of processes are repeated until an operation indicating the end of direct teaching is input.

[0064] According to the Cartesian robot 10 of the above embodiment, the following effects are achieved.

[0065] During the teaching period, the control device 100 sets either permission to move or restriction of movement of the arm tip 54 and the hand unit 20 for each slide axis (X-axis direction, Y-axis direction, Z-axis direction, the same applies below) along which the slide movement is to be performed. This makes it possible to easily memorize the trajectory for sliding the hand unit 20 straight along any slide axis in direct teaching. This also reduces the possibility of the hand unit 20 moving in an unintended direction, improving safety.

[0066] Furthermore, the control device 100 can set rotation permission and rotation restriction for each rotation axis (A-axis direction, B-axis direction, C-axis direction, the same applies below). This makes it possible to easily memorize the trajectory for rotating the arm tip portion 54 and the hand unit 20 around any rotation axis. This also reduces the possibility of the hand unit 20 rotating in an unintended direction, improving safety.

[0067] The axis selection buttons 121-126 are attached closer to the arm tip 54 than the slide drive unit 40. That is, the selection panel 120 having the axis selection buttons 121-126 is attached to the side of the rotation drive unit 50, and slides together with the arm tip 54 and the hand unit 20. Therefore, in direct teaching, when changing the setting of the axis (selected axis) for which movement or rotation is permitted after moving the arm tip 54 and the hand unit 20, it is no longer necessary to move away from the hand unit 20 to press the axis selection buttons 121-126 or to operate the teaching pendant 110, improving operability.

[0068] Before the teaching period, when the Cartesian robot 10 is stationary, the control device 100 measures the load for each slide axis, that is, the holding torque generated in the slide drive unit 40 due to the weight generated by the hand unit 20 and the like. Then, during the teaching period, the control device 100 controls the torque of the slide drive unit 40 so that the generated torque of the slide drive unit 40 is within a torque setting range determined by the measured holding torque in the slide axis for which movement permission is set. Specifically, during the teaching period, the control device 100 controls the torque of the slide drive unit 40 so that the generated torque of the slide drive unit 40 is the same as the measured holding torque in the slide axis for which movement permission is set. As a result, when the hand unit 20 is slid during the teaching period, a torque can be generated in the slide drive unit 40 so as to cancel the weight of the hand unit 20. Therefore, during direct teaching, the hand unit 20 can be moved without the operator feeling the weight of the hand unit 20 and the like. Therefore, the operator does not need to apply excessive force, and it is possible to move it accurately.

[0069] Even if the hand unit 20 attached to the arm tip 54 is changed and the load on the arm tip 54 is changed, the hand unit 20 can be moved accurately without the worker feeling the weight. The same torque control is also performed on the rotation drive unit 50, and the same effect is achieved.

[0070] The handle 131 is provided with an enable switch 130 for instructing whether to permit or stop operation of the Cartesian robot 10 during a teaching period. As a result, even when moving away from the teaching pendant 110 during direct teaching and memorizing the trajectory of movement within the operating range of the Cartesian robot 10, the arm tip 54 and the hand unit 20 can be moved by using the handle 131 having the enable switch 130. Therefore, even if the Cartesian robot 10 malfunctions, the operation can be immediately stopped by operating the enable switch 130, thereby preventing accidents.

[0071] The enable switch 130 is of a three-position type. For this reason, unless the enable switch 130 is lightly pressed, operation is not permitted, and even if the enable switch 130 is pressed too far, operation is not permitted. In other words, if the handle 131 is released due to some impulse or if the enable switch 130 is pressed too far, operation is stopped. Therefore, during direct teaching, it is necessary to move the hand unit 20 with the handle 131 while lightly pressing the enable switch 130.

[0072] On the other hand, if force is applied to move the hand unit 20 in the same direction as the pressing direction of the enable switch 130, there is a possibility that the enable switch 130 will be pressed too far or, conversely, the enable switch 130 will be released.

[0073] Therefore, the enable switch 130 is provided at the tip of the handle 131. When a force is applied in a direction perpendicular to the pushing direction of the enable switch 130, the handle 131 is gripped and pushed or pulled, so that the enable switch 130 can be prevented from being pushed in by mistake. The handle 131 is formed in a bent rod shape or a circular arc shape. In this embodiment, it is formed in a substantially L-shape. Therefore, when a force is applied in the same direction as the pushing direction of the enable switch 130, the end of the handle 131 on the side where the enable switch 130 is not provided can be gripped with the hand opposite to the hand that pushes the enable switch 130, and force can be applied. This makes it possible to prevent the enable switch 130 from being pushed in by mistake.

[0074] In addition, since the shape and size of the hand unit 20 are likely to be changed, when the handle 131 is attached to the arm tip unit 54 or the rotation drive unit 50, depending on the attachment position and shape of the handle 131, it may interfere with the hand unit 20 and become a hindrance, or the handle 131 may be difficult to hold. Therefore, by attaching the handle 131 to the base unit 21 of the hand unit 20, it is possible to make the handle 131 easy to hold without getting in the way of the hand unit 20 even if the shape or size of the hand unit 20 is changed. In addition, since the base unit 21 generally has a higher rigidity than the tool 22, the handle 131 can be firmly fixed.

[0075] In addition, the handle 131 is detachably attached to the hand unit 20. As a result, when direct teaching is completed, unnecessary handles 131 can be removed to reduce weight. In addition, when the hand unit 20 moves, the handles 131 attached to the hand unit 20 can be prevented from interfering with the movement. In addition, the removed handles 131 can be reused for other Cartesian robots 10.

[0076] (Modification) The configuration of the Cartesian robot 10 in the above embodiment may be partially modified. Below, a modified example in which the configuration is partially modified will be described.

[0077] In the above embodiment, the handle 131 may be attached to the base unit 21 in a changeable attachment position. That is, during direct teaching, depending on the motion trajectory to be memorized, it is conceivable that the angle or position of the handle 131 is poor, making it difficult to operate the handle 131. Therefore, by making the attachment position changeable, the handle 131 can be changed to a position where it is easy to operate.

[0078] In the above embodiment, the enable switch 130 may be provided at any location other than the tip of the handle 131. Also, the pushing direction of the enable switch 130 may be changed as desired.

[0079] In the above embodiment, the enable switch 130 does not have to be a three-position switch. For example, it may be a two-position switch (on / off switch).

[0080] In the above embodiment, the configuration of the handle 131 may be changed as desired. For example, the handle 131 may be annular or rod-shaped. In other words, it does not have to be curved.

[0081] In the above embodiment, the handle 131 does not have to be configured to be detachable. In other words, it may be fixed to the hand unit 20 so as not to be detachable. In addition, the handle 131 may be provided on the side of the rotation drive unit 50 or the slide drive unit 40, such as the arm tip unit 54.

[0082] In the above embodiment, the rotation drive unit 50 does not have to be provided. In other words, the hand unit 20 does not have to be rotatable.

[0083] In the above embodiment, the direction and number of the rotation axes of the hand unit 20 may be changed as desired.

[0084] In the above embodiment, the driving information is stored each time the teaching period is interrupted (each time step S106 is judged to be positive), but each time the teaching period is interrupted, teaching data for reproducing the movement trajectory from the start of the teaching period to the time of interruption may be generated. Then, when the direct teaching ends (when step S108 is judged to be positive), the control device 100 may sequentially connect the teaching data generated up to that point to generate one piece of teaching data for reproducing the movement trajectory from the start to the end of the direct teaching.

[0085] In the above embodiment, during the teaching period (during direct teaching), the control device 100 may also measure the speed and acceleration of the arm tip 54 and generate teaching data to reproduce these as well.

[0086] In the above embodiment, the number of slide shafts may be one or more, and the number and directions of the slide shafts may be changed as desired. Also, the slide shafts do not have to be perpendicular to each other.

[0087] In the above embodiment, it is not necessary to set the movement permission and the movement restriction for each slide axis. Similarly, it is not necessary to set the rotation permission and the rotation restriction for each rotation axis.

[0088] In the above embodiment, the selection axes for setting the movement permission and rotation permission may be two or more axes. For example, the X-axis direction and the Y-axis direction may be set to be movable simultaneously.

[0089] In the above embodiment, some or all of the axis selection buttons 121 to 126 may not be provided. In other words, axis selection may be set only on the teaching pendant 110.

[0090] In the above embodiment, torque control does not need to be performed during direct teaching.

[0091] In the above embodiment, the generated torque is the same as the holding torque, but the generated torque may be changed as desired as long as it is within a torque setting range determined by the holding torque. For example, a torque assist function may be provided to assist the force of the operator by providing a force sensor or a torque sensor so that the hand unit 20 can move and stop smoothly.

[0092] In the above embodiment, the holding torque may be detected by a torque sensor or the like.

[0093] In the above embodiment, the axis selection buttons 121 to 126 may be provided at any desired locations. For example, they may be provided on the handle 131. [Explanation of symbols]

[0094] 10... Cartesian robot, 20... hand unit, 21... base unit, 22... tool, 30... transport mechanism, 40... slide drive unit, 41... X-axis guide rail, 42... running body, 43... X-axis servo motor, 44... Y-axis guide rail, 45... up and down movement mechanism, 46... Y-axis servo motor, 47... Z-axis guide rail, 49... Z-axis servo motor, 50... rotation drive unit, 51... A-axis rotation mechanism, 52... B-axis rotation mechanism, 53... C-axis rotation mechanism, 54... arm tip, 100... control device, 110... teaching pendant, 120... selection panel, 121 to 126... axis selection buttons, 130... enable switch, 131... handle.

Claims

1. In an industrial robot having two or more slide shafts, the slide shafts intersect with each other, An arm tip portion to which a robot hand that performs a predetermined operation on a workpiece is attached; a slide driving unit that slides the arm tip along each of the slide shafts; a control unit that controls the slide drive unit to slide the arm tip portion in accordance with pre-stored teaching data, the control unit is configured to be able to execute a direct teaching process in which, when the arm tip portion moves due to an externally applied force during a predetermined teaching period, the control unit stores the movement trajectory as the teaching data; A handle provided on the arm tip or the robot hand; an enable switch provided on the handle for instructing permission to operate the industrial robot and stopping operation of the industrial robot during the teaching period.

2. The enable switch is a three-position enable switch having three positions, instructing operation permission in an intermediate position and instructing operation stop in the other positions, The handle is formed in a bent rod shape or a circular arc shape, 2. The industrial robot according to claim 1, wherein the enable switch is provided at a tip of the handle, and a pushing direction of the enable switch is the same as a direction in which the tip of the handle extends.

3. the robot hand is composed of a base portion attached to the arm tip portion and one or more tools attached to the base portion, 3. The industrial robot according to claim 2, wherein the handle is formed in an L-shape so as to surround a periphery of the base portion and is attached to the base portion.

4. The industrial robot according to claim 3 , wherein the handle is detachably attached to the base portion.

5. The industrial robot according to claim 3 , wherein the handle is attached to the base portion in such a manner that an attachment position of the handle can be changed.

6. a selection button for selecting permission to move or restriction to move the arm tip portion for each slide axis during the teaching period and instructing the control unit; The industrial robot according to any one of claims 1 to 5, wherein the selection button is attached closer to the arm tip than the slide drive unit and slides along the slide axis together with the arm tip.

7. a rotation drive unit provided between the slide drive unit and the arm tip unit to rotate the arm tip unit, The rotation drive unit has one or more rotation shafts for rotating the arm tip end, and rotates the arm tip end in one or more directions around the rotation shafts, The control unit controls the rotation drive unit to rotate the arm tip portion in accordance with the teaching data, a selection button for selecting whether to permit rotation of the arm tip portion or restrict rotation of the arm tip portion for each of the rotation axes and instructing the control unit; The industrial robot according to any one of claims 1 to 5, wherein the selection button is attached closer to the arm tip than the slide drive unit and slides along the slide axis together with the arm tip.

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