WO1997030804A1

WO1997030804A1 - Method of operating robot for press-brake, and control device

Info

Publication number: WO1997030804A1
Application number: PCT/JP1997/000496
Authority: WO
Inventors: Yukimasa Shiomichi; Tatsuhiko Tanaka
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 1996-02-23
Filing date: 1997-02-21
Publication date: 1997-08-28
Also published as: AU1811097A; JP3165638B2; JPH09225536A

Abstract

An operation method in efficiently manufacturing even a small lot of products by the use of equipment including an existing press-brake and a feeding and taking-out robot. The method of operating a robot for a press-brake comprises the steps of grasping a work by an operation of a manipulator (step N1), inserting the work into a press-brake (step N2), detecting a present position while grasping the work in automatic operation, calculating parameters for follow-up operation which accompanies bending of the work, and carrying out bending while performing follow-up operation (step N3), taking out a product by an operation of a manipulator (step N4), and loading the product on a carriage (step N5).

Description

Description Operating method and control device for press brake robot

The present invention relates to a method for operating a press brake robot and a control device used for the method. More specifically, the present invention relates to an operation method and a control device suitable for bending a small lot of work using a press brake robot. Background art

The present applicant has previously proposed a robot for feeding and unloading a work to and from a press brake, which can be bent and formed by a press brake while holding the work (see Japanese Patent Application Laid-Open No. 59-175968). This robot 1 shown in Fig. 7 has a first axis J1, which is substantially concentric with the center axis of the lower mold 7 of the press brake 2, a second axis J2, a third axis J3 parallel to the first axis, and a vertical axis. This is an articulated robot that controls the position and angle of the hand 3 using four axes, which is the direction of the rotation axis J4. The rotation around these axes is performed in each servo mode M1 to M4.

When bending four sides of the work 4 using the robot 1, as shown in the flowchart of FIG. 8 and the process diagram of FIG. 9, first, the work 4 is picked up one by one from the supply table 5 (S110 to S110). (S150), then insert one side of the work 4 into the press brake 2 (S210 to S230), and lower or raise the ram of the press brake 2 while holding the work to perform bending (S150). 240). Further, the work 4 is once extracted from the press brake 2 (S 250 to S 260), returned to a horizontal position and swiveled around the swing axis J 4 (S 270), and the other sides are sequentially bent as necessary (S 30). 0), The obtained box-shaped products are stacked horizontally (S630) or vertically (S63OA) on the mounting table 6 (S610 to S650).

Such a robot 1 is a so-called playback-type robot in which the trajectory, order, speed, and the like of the movement of the hand 3 are programmed in advance, and substantially the same operation is repeated according to the program. And on the supply table 5 according to the number of repetitions The height of the work 4 and the product height of the mounting table 6 are calculated, and the position where the work is gripped and the position where the product is released are changed according to the calculated height. These calculations are usually performed by the CPU and RAM incorporated in the control panel 8, the basic program is stored in ROM, and the data is stored in RAM.

As a method of programming the trajectory and order of movement of the hand 3 of the robot 1 described above, for example, the target position and the target passing position of several places are designated by coordinates, and the speed of movement between the target positions is further designated. And program them to follow those target passage positions in order. In practice, a method of automatically programming is adopted simply by rewriting the position data and speed data of the basic program. Disclosure of the invention

In any of the above methods, trial and error is performed many times to set the speed as fast as possible without actually dropping the workpiece while avoiding interference with others in the movement route. This is extremely troublesome because it repeatedly rewrites position data and speed data. Also, when manufacturing the same product, the program used last time is called and used, but for fine movements, several trial runs and fine adjustment are also indispensable. For this reason, there is a problem that the production efficiency is greatly reduced if the number of lots is large, but if the number is small. In view of such circumstances, it is an object of the present invention to provide a method of operating a robot capable of efficiently producing a product having a small number of units, and a control device used therefor.

The method of operating the robot for press brake of the present invention is such that the steps of supplying the work to the press brake, bending the work by the press brake while holding the work, and taking out the work are automatically performed in accordance with the procedures taught in advance. This is a method of operating a playback-type pot that can be manually operated and remote-controlled for each step. The work is manually supplied to the press brake by remote control, and then the hand holding the workpiece is controlled. Based on the current position, a parameter that follows the bending movement of the work is calculated, and based on the result, the work is bent automatically, and then the work is manually removed by remote control. ing. When calculating the parameters based on the current position of the hand, the current position of the hand and the half width of the work are read in a state where the work is pressed against the back gauge of the press brake and stopped, and the read values are used. It is preferable that the parameters be calculated based on the parameters. Also, the work may be automatically taken out of the supply table before the work supply step, and the product may be automatically placed on the product mounting table after the work removal step.

The control device of the present invention, which is used in combination with a robot automatically and manually, automatically performs the steps of supplying the work to the press brake, bending the work by the press brake while holding the work, and taking out the work in accordance with the procedures taught in advance. This is a control device for a playback type robot that can perform remote control manually for each process, and can manually control the supply of the work to the press brake and press the work while holding the work. Equipped with switching means for switching between automatic operation of bending using a brake and manual remote operation for unloading the workpiece.Before automatic operation, the workpiece is bent based on the current position of the hand holding the workpiece. Calculates parameters that follow the movement of the robot and activates the press brake based on the calculation result Causes, is characterized in that the robot so as to follow the hand the movement of the workpiece and a command means for automatic operation.

The means for calculating the parameter is a means for detecting and reading the current position of the robot hand, a means for calculating a distance from the gripping portion of the work to the bending position based on the current position, It can be constituted by means for calculating the moving locus, moving speed, passing position and final position of the hand from the distance thus set and the angular velocity of the work at the time of bending by the press brake set in advance. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic flowchart showing one embodiment of the operation method of the present invention. FIG. 2 is a flowchart of the automatic bending process in FIG. FIG. 3 is a side view showing the relationship between each parameter in the automatic bending process and the dimensions of the bending process. FIG. 4 is a plan view showing a process of detecting the current position of the hand before the automatic bending process. FIG. 5 is a schematic flow chart showing another embodiment of the operation method of the present invention. It is a bird. FIG. 6 is a flowchart showing the main part. FIG. 7 is a perspective view showing an example of a conventional robot. FIG. 8 is a flowchart showing an example of the bending process by the robot. FIG. 9 is a process chart showing an example of a processing step of the bending operation by the robot. BEST MODE FOR CARRYING OUT THE INVENTION

The work is supplied to the press brake only by changing the angle of the joint of the hand and moving the position of the hand and turning it around the turning axis. It can be easily operated manually while checking visually so as not to interfere with the camera. And because it is a manual operation, there is no need to modify programs or data during that time. Also, at the time of bending, the work bends to a predetermined angle around the bending line as the press brake ram descends or rises. During that time, follow-up operation by manual operation, which is relatively difficult, is not performed, and automatic operation is followed by automatic follow-up operation. During this bending, the workpiece bends to a predetermined angle around the bending line, so if the initial position and the distance from the bending line to the center of the hand are known, the program and data Modification is easy. When picking up a workpiece from the supply table or loading a product on the product mounting table, the height or position of the hand to be gripped changes little by little within the predetermined range. Therefore, even if the vehicle is driven automatically, it does not interfere with other things. Moreover, it is difficult to change the height manually. When these gripping and ridge placement are performed by automatic operation, it is easier than manual operation, and it is easy to change programs and data.

Next, an operation method and a control device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic flowchart showing one embodiment of the operation method of the present invention, FIG. 2 is a flowchart of the automatic bending process in FIG. 1, and FIG. 3 is a graph showing the parameters of the automatic bending process and the dimensions of the bending process. FIG. 4 is a plan view showing a process of detecting the current position of the hand before the automatic bending process, FIG. 5 is a schematic flowchart showing another embodiment of the operation method of the present invention, and FIG. 4 is a flowchart showing the main part. First, the overall flow will be described with reference to FIG. In the operation method shown in Fig. 1, most steps are performed by manual manipulator operation, and only the bending step N3 (S240 in Fig. 9) is performed automatically. In other words, the overall flow can be roughly divided into a process N1 for picking up a work from a reference position (see S100 in FIG. 9), a process N2 for supplying to a press brake, a process N3 for bending, and a takeout process. The process is performed in the order of the process N4 and the process N5 of placing the product on the product table. All operations are manual except for the bending step N3. Generally, as shown in Fig. 4, each side of a rectangular work (see Fig. 4) with four corners cut out is often bent and formed into a box shape. Steps N 2 ”to“ Step N 4 ”are repeated several times. However, for simplicity, only the case where one side of the workpiece is bent is shown in detail in Fig. 1, and the other three sides are shown in a single block as the `` process NN for bending the other side ''. ing.

The process N1 for picking up the work is performed in the order of "hand moving operation" by manipulator operation, "work holding operation" for holding the work, and "work moving operation". Here, the manipulator operation means manually operating the dial, switch or r joy stake on the control panel (reference numeral 8 in Fig. 7) and moving the hand in the X, Y, and Z directions. This is a so-called mass-slave-type remote servo control operation that moves linearly or curvilinearly, and further manually performs gripping and releasing operations. Generally, it is used when teaching a moving route, but here it is used as a manual for manual remote control.

The workpiece supply process N2 following the process of picking up the workpiece N1 is a "work movement operation" that holds the workpiece from below by manipulator operation and makes the side to be processed parallel to the press brake. The operation is performed in the order of "work insertion operation" for moving the work in the mold in parallel, and "work gage operation" for abutting the tip of the work against the back gauge (9 in FIG. 4) of the press brake.

As shown in detail in Fig. 2, the subroutine of the automatic work bending process N3 first determines whether or not a command for "work bending operation" has been issued (step 2 41), and executes "Yes". If there is, automatic operation is performed according to the following automatic bending flow. If “No”, wait until a command is issued. In this case, “waiting” means that every time a timing signal is output, it is determined whether or not a command for the workpiece bending operation has been issued.If the command has been issued, the process proceeds to the next step for the first time. I do.

In the case of “Y es”, first, the current position of the hand is read by the encoder attached to the motor of each joint (step S2422). Here, it may be configured to determine whether or not the workpiece is hitting the gauge in the previous step (gage applying operation). The current position is based on the first axis (see Fig. 3; the axis in the longitudinal direction of the tip of the upper mold 10). The X-axis value (Xh) in the front-rear direction, the Y-axis value (Yh) in the vertical direction, It is determined by the rotation angle around the first axis (Ah) and the rotation angle around the rotation axis J4 (Bh).

Next, the half width W of the gripped work is obtained (step S243). As can be seen from FIGS. 3 and 4, the half width W can be calculated by W = (Xh-Xs) / cos (Ah). Here, X s is a correction value for deviation from the X-direction coordinate of the robot.

Next, an appropriate operation speed according to the size of the work is calculated (step S244). The operation speed Spd is calculated by Spd = W / Ws * Spds. Where “S p d s” is the standard speed and varies with the ¾ width.

Further, the target passing positions Xc and Yc are calculated for the X-axis and the Y-axis (step S245). As can be seen from Fig. 3, the target passing position is a position between the current position (Xh, Yh) and the target position (X, Y), and is calculated in advance to define the arc trajectory. The target passing position can be obtained from Xc = W * cos ((As—Ah) / 2) and Yc = W * sin ((As—Ah) / 2). Then, the target positions X and Y are calculated from X = cos (Ah) and Y = sin (Ah) (step S246). Then, after judging whether or not to follow the bending) Step S 2 4 7) While actually lowering or raising the ram of the press brake, move the hand toward the target position (X, Y, B h) and set the target passage position. (Xc, Yc, Bh) and move at the operating speed (Spd) (Step S248).

Therefore, as shown in FIG. 3, as the upper mold 10 descends, the tip portion 4a of the work 4 is bent at a predetermined angle, and at the same time, the hand 3 moves the arrow 4 as the arrow A s Follows to rotate like. Hand 3 The bending process can be performed while holding the workpiece 4, and the process can proceed to the next step as it is.

When the whole machine is to be operated automatically, as in the case of mass production, the most appropriate numerical values for these half-width work, operating speed, target passage position, and target position are determined in advance and stored in RAM. However, in the operating method of the present invention, these numerical values are automatically calculated during the operation, so that it is not necessary to set and store them in advance. Therefore, even in small-lot production, automatic bending that follows the rotation of the work can be easily performed.

After the bending operation is completed, as shown in Fig. 1, the operation returns to the standby state again, and the work is taken out from the press brake mold by the manual operation. Operate manually in the order of “Work moving operation” to move to a position away from the press brake, and “Work rotating operation” to swivel around swivel axis J4. Then, as described above, the other side is automatically bent as needed.

The obtained box-shaped product performs “work moving operation” toward the loading table 6 by manipulator operation, performs “work loading operation” for loading the product on the loading table, and then performs the reference position. Return to "Hand return operation". In addition, since it is a manual operation, the user may be directed to the work mounting table in order to go to get the joint work as it is.

In the above embodiment, when the current position is obtained, the rotation angle “B h” around the turning axis is also detected. However, as shown in FIG. 4, when the work 4 is pressed against the left and right gauges 9, the work is bent while maintaining the value of the turning angle Bh. To switch between manipulator operation and automatic operation as described above, for example, the control panel (see reference numeral 8 in FIG. 7) must be equipped with “automatic bending operation”, “automatic workpiece gripping operation”, “automatic product loading operation”, etc. A switch means such as a push button switch for command may be provided, and the manipulator may be operated by the push button switches when the manipulator operation is completed. Further, it is preferable to provide a pilot lamp for indicating whether the vehicle is operating automatically or operating the manipulator. Note that the robot 1, the operation devices by the manipulator, the control circuit for automatic operation, and the like can be shared with those of the conventional case of automatic operation. Next, another embodiment of the operation method of the present invention will be described with reference to FIGS. The overall flow of the operation method of FIG. 5 is almost the same as that of the above-described embodiment of FIG. 1, and includes a step Nl for picking up a peak, a step N2 for supplying to a press brake, and a step N3 for bending. The process N 4 includes a take-out process N 4 and a process N 5 for placing the product on the product stand. In the “process N1 for picking up the work”, the operation of moving the hand in the first half to the work supply table is still manual, but the hand is moved closer to the work supply table in the second half. The hand is held in contact with the workpiece, and the operation of separating again is performed automatically. Similarly, the latter half of the process N5 for loading products on the product platform is automatically operated.

In the flow chart of the automatic operation in this case, as shown in FIG. 6, it is determined whether or not a work bending operation is performed in step S241, and in the case of Yes, the operation proceeds to the automatic bending operation (step 2442). In the case of No, it is determined whether or not an instruction for an automatic work gripping operation has been issued (step S100). If “Y e s”, the process proceeds to the automatic work grasping operation (steps S 110 to 150). When the automatic work grasping operation is completed, the process returns to the standby state again. On the other hand, in the case of "No", it is determined whether or not an instruction for the automatic product loading operation has been issued (step S600), and in the case of "Yes", the flow proceeds to the automatic product loading operation (step 61). 0-650). When the automatic product loading operation is completed, the operation returns to the standby state again. On the other hand, if “No”, the standby state is continued. Here, the “standby state” means, as in the above case, when no command is issued for any of the work bending operation, automatic work gripping operation, and automatic product bran operation, and each time a timing signal is output, the work Enter the step (S24.1) for determining whether or not the automatic bending operation is performed. This means that the above subroutine is repeated.

In the above embodiment, the operator is relieved of the trouble of operating while putting a nerve on the distance between the hand and the work. Also, automatic operation does not involve turning of the work, etc., so there is almost no danger of hitting other things.Moreover, by controlling the number of times of processing and changing the height every time according to the remaining amount However, it is possible to place the product by gripping the hook at an appropriate position. Industrial applicability

According to the operation method of the present invention, it is not necessary to specify the movement path of the hand every time the shape of the work is changed or to perform fine adjustment again, which is convenient particularly for bending work using a small lot of press brakes. According to the control device of the present invention, the above operation method can be smoothly performed.

Claims

The scope of the claims

1. The work supply to the press brake, the bending by the press brake while holding the work, and the work take-out process can be automatically performed according to the procedures taught in advance, and manual remote control is performed for each process. This is a playback type robot operation method that can supply work to the press brake by manual remote control, and then adjusts the bending movement of the work based on the current position of the hand holding the work. Calculate the parameters to follow and, based on the result, let the workpiece bend and process automatically and then take out the workpiece by remote control manually. Method.

2. When calculating parameters based on the current position of the hand, the current position of the hand and the half width of the work are read while the work is pressed against the back gauge of the press brake and stopped, and these are read. 2. The operating method according to claim 1, wherein the parameter is calculated based on the value.

3. A request that includes a step of automatically picking up the work from the work supply table before the work supply step, and a step of automatically placing the product on the product stack table after the work removal step. Operation method described in item 1.

4. The process of supplying the work to the press brake, bending by the press brake while holding the work, and taking out the work can be performed automatically according to the procedure taught in advance, and manual remote control for each process This is a playback type robot controller that can switch between manual remote operation of supplying and unloading the work to and from the press brake and automatic operation of bending using the press brake while holding the work. Means for calculating a parameter that follows the bending movement of the workpiece based on the current position of the hand holding the workpiece before automatic operation, and press brake based on the calculation result. And a command means for automatically operating the robot so that the hand follows the movement of the workpiece.

5. The means for calculating the parameters is a means for detecting and reading the current position of the robot hand, a means for calculating the distance from the gripping portion of the work to the bending position based on the current position, 5. The apparatus according to claim 4, further comprising: means for calculating a movement trajectory, a movement speed, a passing position, and a final position of the hand from the calculated distance and a predetermined angular velocity of the workpiece at the time of bending by the press brake. Control device.