Safety automatic press system

Abstract

We provide a press system that is easy to reconfigure and reliably prevents accidents. [Solution] A robot 3, which sets material into a press machine 1 by repeating pre-programmed actions, is mounted on a mobile carriage 12. A safety device 2 is positioned between the robot 3 and the press machine 1 to allow or prohibit the robot 3 from setting material into the press machine 1. The safety device controller 21 includes a retreat detection means for detecting when the robot 3 has retreated outside the press machine 1 after performing the material setting operation, and a press start means for outputting a start signal to move the slide 5 up and down when the retreat detection means detects that the robot 3 has retreated outside the press machine 1. The robot controller 22 also includes a position detection means for detecting the relative position to the press machine 1, and a correction means for correcting the material setting operation to the press machine 1 based on the relative position detected by the position detection means.

Description

Technical Field

[0001] The present invention relates to an automatic press system in which a robot sets materials for a press machine.

Background Art

[0002] Press working such as drawing, bending, or shearing of various materials such as metals and synthetic resins is performed by lowering an upper die after setting the material in a lower die. Although the operation is a simple up-and-down movement, since the load is extremely large, when a person performs operations such as setting materials and taking out processed products, if an accident occurs, it will become a serious accident. Therefore, various safety devices have been developed and safety measures have been defined. The safety device or safety measure forces a person to perform an operation indicating that a safe state is established when the person performs an operation. For example, a start switch is provided by being assigned to both the left and right hands, and it is configured to force the operation with both the left and right hands at the same time, or a configuration that forces an operator to evacuate not only the hands but also the entire body outside a predetermined range around the press machine.

[0003] For press work by a person, operations for safety are added as described above, and while safety can be achieved, the burden on the operator increases, or the work efficiency is affected. On the other hand, if the robot is used to set materials and take out press products instead of a person, safety devices for a person become unnecessary, and it is possible to automate the handling of materials and press products to improve work efficiency. However, even in that case, it is necessary to avoid interference between the press machine and the robot, and in addition, it is necessary to surround the entire processing line composed of the robot and the press machine with a safety fence. For example, in the device described in Patent Document 1, the press machine is in a processing operation and the press crank angle is in a predetermined angle range that does not allow the entry of the robot, and the movement target position of the robot belongs to a range where interference is possible. The movement of the robot to the target position is configured to be standby only when the conditions are satisfied.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-202419 [Overview of the project] [Problems that the invention aims to solve]

[0005] If the process of setting materials for the press is automated and performed by a robot instead of a human, the efficiency of the press operation can be improved. However, as described in Patent Document 1, it is necessary to provide a configuration to prevent accidents caused by interference between the robot and the press. However, a configuration that reflects the operating state or position of the press in the control of the robot creates a so-called interlock between the press and the robot. While this strengthens the cooperation between the press and the robot, it may restrict the freedom to change the manufacturing process, including the press, such as when changing the mold due to a change in the processed product, or when repurposing the robot for another press. In other words, it is likely unsuitable for high-mix, low-volume production.

[0006] This invention has been made in view of the above technical problems, and aims to provide a press system that can automatically set materials into a press machine, is easy to reconfigure, and reliably avoids accidents. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a safe automatic press system comprising a press machine that performs press processing by the reciprocating motion of a slide, and a robot that repeatedly performs material setting operations for the press machine, which are stored in a prior teaching, wherein the robot is mounted on a predetermined machine stand and is equipped with a robot controller, and a safety device having a safety device controller that permits and prohibits the press operation of the press machine is arranged between the robot and the press machine, and the safety device controller is characterized in that it comprises a retreat detection means that detects when the robot has retreated to the outside of the press machine after performing the material setting operation, and a press start means that outputs a start signal to move the slide up and down when the retreat detection means detects that the robot has retreated to the outside of the press machine.

[0008] In the present invention, the robot controller may include a position detection means for detecting the relative position with respect to the press machine, and a correction means for correcting the material setting operation with respect to the press machine based on the relative position detected by the position detection means.

[0009] In the present invention, the robot further comprises an arm portion that moves forward and backward relative to the press machine, and a hand portion provided at the tip of the arm portion, and the retraction detection means may be configured to detect when the arm portion and the hand portion have been retracted to the outside of the press machine.

[0010] In the present invention, the safety device further comprises a guard plate that obstructs the material setting path by the robot, the safety device controller further comprises a closing means that moves the guard plate to a closed position that obstructs the setting path when the retreat detection means detects that the robot has retreated to the outside of the press machine, and the press start means may be configured to output the start signal when the guard plate is moved to the closed position by the closing means.

[0011] In the present invention, the robot further comprises a sensor for detecting the guard plate obstructing the set path, and the robot controller may further comprise a stopping means for stopping the robot's movement at a position where it will not collide with the guard plate, based on the sensor detecting the guard plate.

[0012] In the present invention, the robot may be a collaborative robot that slows down its movement and even stops when it detects that a predetermined moving object, including a person, has entered a pre-set area. [Effects of the Invention]

[0013] In this invention, a robot sets the material into the press machine. The robot can set the material even in press machines that are mounted on a machine stand and are therefore configured for a human operator to set the material. In particular, in this invention, a safety device placed between the press machine and the robot outputs a press machine start signal according to the robot's movements. That is, the safety device is configured to confirm that the robot does not interfere with the operation of the press machine, and there is no interlock that directly links the robot and the press machine. Therefore, when assigning the robot to a specific press machine, or conversely, when changing the material setting from a robot to a human operator, there is no need to make any special changes to the control systems of the robot or the press machine. As a result, it becomes easier to replace a manufacturing line or system including a press machine, or to easily replace a human operator with a robot, thereby reducing manpower in a manufacturing line including a press machine.

[0014] Furthermore, in this invention, by using a safety device with a guard plate, it is possible to physically prevent the scattering of workpieces and mold parts during press working. In addition, if the robot moves toward the press machine due to some abnormality, the robot can detect the presence of the guard plate using sensors or the like and stop its operation. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing an example of a press system according to the present invention. [Figure 2] This is a schematic perspective view showing the safety device. [Figure 3] This is a schematic diagram of an example in which a pair of inner and outer optical sensors are provided, with a guard plate in between. [Figure 4] This block shows the functional configuration of each controller. [Figure 5] Figure 1 is a simplified process diagram illustrating the operation of the press system. [Figure 6] This is a schematic diagram showing an example of a chuck configured to hold both a material and a workpiece. [Modes for carrying out the invention]

[0016] Next, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the embodiments described below are merely examples of how the present invention can be implemented and do not limit the invention.

[0017] Figure 1 schematically shows a press system according to the present invention, which comprises a press machine 1, a safety device 2, and a robot 3 as its main components. The press machine 1 is a suitable press machine such as a conventionally known mechanical press, pneumatic / hydraulic press, or servo-controlled press, and has a bolster 4 and a slide 5 that reciprocates relative to the bolster 4 to which a suitable die (not shown) is attached, and a load is applied to a material set in the lower die by the upper die to process it into a pressed product (not shown) of a predetermined shape.

[0018] The safety device 2 is disposed between the press 1 and the robot 3 and is a device for preventing interference between the robot 3 and the press 1. More specifically, it is a device that permits or prohibits the pressing operation of the press 1 according to the operating state of the robot 3, or conversely, a device that blocks the operation of the robot 3 directed toward the press 1. An example of the safety device 2 is shown in FIGS. 1 and 2. Note that in FIG. 1, the safety device 2 is shown in a state separated from the press 1.

[0019] The safety device 2 is attached to the front side of the press 1, and an opening serving as a setting path for setting a material between the bolster 4 and the slide 5 (that is, between the upper and lower dies) is formed by the frame 6 from the front side of the press 1. As shown in FIGS. 1 and 3, an outer optical sensor 7o and an inner optical sensor 7i that output a detection signal when light is blocked are attached to the frame 6. These optical sensors 7o, 7i are conventionally known sensors having a light emitter that emits light such as laser light or visible light and a light receiver that receives the light, and are configured to irradiate light in a direction crossing the setting path (that is, the opening).

[0020] By providing the inner and outer optical sensors 7i, 7o, it becomes possible to detect that the material setting operation is being performed or that the retraction operation after setting the material has been performed based on the order in which the light is blocked and the order in which the blockage is released. That is, if it is detected that the inner optical sensor 7i closer to the press 1 is blocked after the outer optical sensor 7o farther from the press 1 is blocked among the inner optical sensor 7i and the outer optical sensor 7o, it can be determined that the material has been inserted. Also, if it is detected that the outer optical sensor 7o is unblocked after the inner optical sensor 7i is unblocked, it can be determined that the robot 3 has left the press 1 after setting the material.

[0021] In the examples shown in FIGS. 1 and 2, the safety device 2 has a guard plate 8. The guard plate 8 is a switch plate for physically closing a set path (or opening) formed between the frames 6, and is composed of, for example, a pair of transparent acrylic plates or polycarbonate plates. As shown in FIG. 2, the guard plate 8 has an upper guard plate 8a and a lower guard plate 8b that move up and down along the frame 6. As the upper guard plate 8a descends, the lower guard plate 8b ascends, and the upper guard plate 8a and the lower guard plate 8b abut against each other to shield the set path.

[0022] An actuator 9 for moving the upper guard plate 8a and the lower guard plate 8b up and down is provided at the upper part of the safety device 2. The actuator 9 may be an appropriate driving device such as a linear motion air cylinder, a hydraulic cylinder, or a motor. By the actuator 9, the mechanism for moving the upper guard plate 8a and the lower guard plate 8b up and down may be a mechanism using a link, a chain, a belt, or a feed screw mechanism. For example, while transmitting the descending motion of the actuator 9 to the lower guard plate 8b, the descending motion of the actuator 9 can be converted into an upward motion by an appropriate link to pull up the upper guard plate 8a. Note that the mechanism for moving the guard plate 8 up and down preferably has a configuration in which the guard plate 8 closes when the actuator 9 is in a so-called OFF state or fails, that is, a configuration having a so-called fail-safe function.

[0023] The robot 3 is an articulated arm-type robot, and is preferably a collaborative robot so that it can be arranged in a manufacturing process where an operator is present. A collaborative robot is an industrial robot that satisfies the safety requirements described in ISO 10218 and ISO / TS 15066. In the example shown in FIG. 1, it includes an arm part 10 that is connected by a plurality of joints and can bend and rotate freely, and a hand part 11 provided at its tip, and is mounted on a predetermined machine base that is fixed or movable. In the example shown here, it is mounted on a mobile cart 12.

[0024] The mobile trolley 12 is equipped with casters 13 and fixed legs 14 at its base. The casters 13 support the entire structure, making it movable, and the fixed legs 14 can be extended to support the entire structure, allowing it to be fixed in a predetermined location. The mobile trolley 12 also houses a power supply unit and control circuits (not shown). Furthermore, a camera 15 attached to the hand unit 11 and a chuck 16 for picking up materials are detachably arranged on the mobile trolley 12 at predetermined locations. Reference numeral 17 in Figure 1 indicates a stacker, and the stacker 17 is provided at a predetermined location on the mobile trolley 12.

[0025] Even if collaborative robots can be used alongside human workers on a predetermined processing or manufacturing line, contact with workers must be avoided. To this end, robot 3 is equipped with a laser scanner 18 that monitors a predetermined area. The laser scanner 18 is configured to measure the distance to moving objects in the surrounding area and to output a detection signal if the measured distance is shorter than the distance defining the area. Specifically, if an object is detected within the outer area set as a predetermined distance range from robot 3, the robot 3's movement is slowed down, and if an object is detected in the inner area which is closer than the outer area, robot 3 is stopped. Furthermore, a proximity sensor 19 is provided at the tip of the hand unit 11. The proximity sensor 19 is a non-contact sensor that measures the distance to an object in front of the hand unit 11, and is configured to detect, for example, the closed guard plate 8, and to stop robot 3 before the hand unit 11 or the chuck 16 attached thereto comes into contact with the guard plate 8.

[0026] The press machine 1, safety device 2, and robot 3 are each equipped with controllers 20, 21, and 22. These controllers 20, 21, and 22 are each primarily composed of microcomputers and are configured to output command signals for pre-programmed actions based on the input signals. For example, the press machine controller 20 is programmed to start and stop the slide 5, change its operating speed, and perform a press operation that strokes it a predetermined distance with a predetermined load, and performs this press operation each time a start signal is input.

[0027] The safety device controller 21 is configured to primarily control the opening and closing of the guard plate 8 and the output of the activation signal based on signals from the optical sensors 7i and 7o described above. As described above, the order in which the outer optical sensor 7o and the inner optical sensor 7i block light and pass through can detect the setting of material by the arm 10 or the operator on the press machine 1 and its retreat from the press machine 1. Therefore, the safety device controller 21 controls the opening and closing of the guard plate 8 and the output of the activation signal based on signals from these optical sensors 7i and 7o. In the example shown in Figure 3, a work sensor Ws is provided to detect the presence or absence of material or the orientation of the set material. In such a configuration, the safety device controller 21 controls the opening and closing of the guard plate 8 and the output of the activation signal based on signals from the work sensor Ws in addition to signals from these optical sensors 7i and 7o.

[0028] First, the safety device controller 21 has the function of detecting the sequence of light blocking (when the light-receiving parts of the optical sensors 7i and 7o stop receiving light) and light transmission (when the light-receiving parts start receiving light) to detect when the robot 3 or the operator's hand has been inserted into the press machine 1 and when the robot has retreated from the press machine 1. The safety device controller 21 has the functional configuration shown in Figure 4, and the insertion detection means 21a detects that the light blocking at the optical sensors 7o and 7i occurred in the order of "outer optical sensor 7o → inner optical sensor 7i", indicating that the robot 3 has entered the press machine 1 to set the material or to remove the processed product. The retreat detection means 21b detects that the light transmission at the optical sensors 7o and 7i occurred in the order of "inner optical sensor 7i → outer optical sensor 7o", indicating that the robot 3 has retreated outside the press machine 1 after setting the material or grasping the processed product.

[0029] Furthermore, the safety device controller 21 has a closing means 21c that controls the closing of the guard plate 8. The safety device controller 21 can perform a so-called one-time control (1 break) in which the guard plate 8 is closed each time material is set, and a so-called two-time control (2 breaks) in which the guard plate 8 is closed after the processed pressed product (processed product) is removed and the setting of new material is completed. In the case of 1 break, after the insertion detection means 21a detects that the robot 3 or the operator's hand is inserted into the press machine 1, the retraction detection means 21b detects that the robot 3 or the operator's hand has retracted to the outside of the press machine 1, and each time the closing means 21c executes a control to close the guard plate 8. In contrast, in the case of 2 breaks, even if the retraction detection means 21b detects that the pressed product has been removed and the robot 3 or the operator's hand has retracted to the outside of the press machine 1, the closing means 21c maintains the guard plate 8 in an open state. Subsequently, when the material setting operation is performed, the closing means 21c closes the guard plate 8 based on signals from the insertion detection means 21a and the retraction detection means 21b described above. In other words, in the 2-break operation, the closing means 21c closes the guard plate 8 when the robot 3 or the operator's hand performs two reciprocating movements: removing the workpiece from the press machine 1 and setting the material.

[0030] Furthermore, if a work sensor Ws is provided, the closing means 21c may be configured to maintain the guard plate 8 in an open state based on the signal from the work sensor Ws. That is, if the work sensor Ws does not detect a material, the closing means 21c maintains the guard plate 8 in an open state without executing a control to close the guard plate 8. Here, if the work sensor Ws does not detect a material, this includes not only cases where no material is set, but also cases where the position or orientation of the set material is deviated from the correct position or orientation.

[0031] As described above, the closing means 21c operates the actuator 9 in the safety device 2 based on the detection of the retraction operation by the retraction detection means 21b, thereby moving the guard plate 8 to the closed position and closing the set path, i.e., the opening. The closing of the guard plate 8 may be detected by the actuator 9, the link mechanism between it and the guard plate 8, or a limit switch (not shown) that is operated by the moving member such as the guard plate 8. Based on the closing of the guard plate 8, a press activation means 21d is provided in the safety device controller 21 that outputs an activation signal.

[0032] Robot 3 is an automated machine that repeatedly performs taught actions. The robot 3 described here is taught to pick up material from the stacker 17, pass the material through the opening in the safety device 2 and set it on the lower die of the press machine 1, then return to the mobile carriage 12 and wait in a predetermined position, or pick up the material again and wait in a predetermined position, and so on, repeating this series of actions. A set path storage means 22a is provided to store the set path, which is the movement path, as well as the movement speed and timing. The teaching can be done in the same way as conventional industrial robot teaching, by operating the robot 3 in the same manner as the planned set operation and sequentially storing the position data during the process.

[0033] While the stored position data is based on a predetermined origin or reference point during teaching, the robot 3 is movable relative to the press machine 1, and even if it is placed in the same position as during teaching, an unavoidable shift in relative position occurs. This shift in position manifests as a malfunction of the robot 3, so to avoid this, a position detection means 22b is provided to detect the relative position with respect to the press machine 1. The position detection means 22b is configured to detect the position of the robot 3 relative to the press machine 1. Specifically, a mark indicating a reference position is provided at a predetermined location on the press machine 1 side (for example, in front of the safety device 2), and the robot 3 captures an image of this mark with a camera 15 attached to its hand part 11. Based on the obtained image, the position is analyzed by measuring in three dimensions to detect the position of the robot 3 relative to the press machine 1. For example, the mark is a two-dimensional pattern 23 in which multiple dots are arranged in a matrix, and the position in the up, down, left, and right directions is detected based on a reference dot or pattern within it, and the distance (i.e., depth) between the robot 3 and the press machine 1 is detected based on the distance at which it comes into focus or the spacing of the dots in the obtained image. This position detection may be performed using methods or means that are used in conventional robots.

[0034] A correction means 22c is provided that compares the detected position of the robot 3 relative to the press machine 1 with a position preset in teaching, and corrects the data defining the set path. This correction may be performed by correcting the origin of the coordinates defining the set path to correct the entire set path, or by correcting the coordinate values ​​of multiple points defining the set path; in either case, a conventionally known method or means may be employed.

[0035] Furthermore, the robot controller 22 is equipped with a stopping means 22d for temporarily stopping the robot 3. The stopping means 22d controls the movement of the arm 10 when the distance to an object in front of it, detected by the proximity sensor 19 attached to the hand 11 of the robot 3, becomes less than or equal to a predetermined distance. For example, when the hand 11 approaches a closed guard plate 8 and the distance becomes less than or equal to a predetermined distance, the movement of the robot 3 stops, and contact or collision between the robot 3 and the safety device 2 is avoided.

[0036] As shown in Figure 4, in the system according to the present invention, the press machine 1 and the safety device 2 are linked so that data is transmitted and received between the press machine controller 20 and the safety device controller 21, whereas the robot controller 22 is so-called independent and does not transmit or receive data with the press machine controller 20 and the safety device controller 21. In other words, there is no need to construct a special system for interlocks or the like between the robot 3 and the press machine 1 or the safety device 2, and thus the configuration of the press system employing the robot 3 can be simplified while ensuring safety by preventing interference between the robot 3 and the press machine 1.

[0037] Next, the operation of the press system according to the present invention described above will be explained. It should be assumed that the robot 3 has already been taught for the press machine 1, and the material setting path has been stored as data. The press machine 1 is fitted with the safety device 2 described above, and is set to open and close the material setting path to the die (not shown) attached to the bolster 4 and slide 5. As mentioned above, the robot 3 is independent of the safety device 2 and the press machine 1, and when performing press work, it is moved to a predetermined position on the front side of the safety device 2 and fixed to the work floor by the fixing legs 14. In this state, the position of the robot 3 relative to the press machine 1 is not determined in terms of control. Therefore, first, as shown in Figure 5, the robot 3 attaches a camera 15 to its hand part 11 and captures the two-dimensional pattern 23 described above with the camera 15 (step S1).

[0038] Based on the obtained image data, the relative position of the robot 3 to the press machine 1 is determined and compared with the data stored through teaching. If there is an error, the stored data is corrected (step S2). In the example shown in Figure 1, the stacker 17 on which the material is placed is mounted on the mobile carriage 12, and its position does not differ from the taught position, so the correction is performed on the data that controls the operation of the press machine 1.

[0039] After performing these preliminary steps to begin the press work, the robot 3 replaces the camera 15 with the chuck 16 and attaches it to the hand unit 11. This action is pre-programmed, and involves moving the camera 15 to a predetermined position on the mobile carriage 12, hooking it onto an appropriate hook or hanger (not shown), and transferring it to the mobile carriage 12. The reverse action is then performed for the chuck 16, attaching it to the hand unit 11 (step S3).

[0040] The chucks 16 are pre-configured to suit the shape of the material, such as vacuum suction type and finger gripping type. Robot 3 moves the chuck 16 to the stacker 17 and picks up the material prepared there (step S4). Then, the arm section 10 and hand section 11 operate as taught, and the hand section 11, holding the material, passes through the opening of the safety device 2 and enters the inside of the press machine 1. In this case, the optical sensors 7o and 7i of the safety device 2 have never had their illumination blocked, so the guard plate 8 has retracted to the open position. Also, naturally, the press machine 1 has not received the start signal to lower the slide 5, so the slide 5 is pulled up. The hand section 11 releases the material it is holding on the lower die and sets the material in the press machine 1 (step S5). Then, the hand section 11 retracts from the press machine 1 back to its original position (step S6).

[0041] In this way, as the hand portion 11 or arm portion 10 moves in and out of the press machine 1 through the safety device 2, the light emitted by the optical sensors 7o and 7i of the safety device 2 is temporarily blocked, and then the blockage is released and the light receiver detects the light. Because this blocking and transmission of light occurs within a predetermined short time, the safety device controller 21 detects that the robot 3 has moved to the outside of the press machine 1 after performing the material setting operation. As a result, a closing signal is output to close the guard plate 8 in the safety device 2, and the guard plate 8 closes the opening in the safety device 2 (step S7). A closing confirmation switch (not shown) detects the closing of the guard plate 8 and outputs a signal, causing the press starting means 21d to output a starting signal (step S8). The press machine controller 20 receives this starting signal, causing the press machine 1 to operate (step S9), the slide 5 to stroke once, and the press work is performed. In that case, since the guard plate 8 is closed, even if metal fragments are scattered due to the pressing process, the guard plate 8 prevents these metal fragments from flying out of the press machine 1, thus ensuring safety in this respect as well.

[0042] Then, just before the press machine 1 starts up and the slide 5 moves down to the bottom dead center (for example, when the crank angle is around 150° to 160°), the closing control of the guard plate 8 by the aforementioned closing means 21c is released and the guard plate 8 begins to open (step S10). That is, a guard open signal is transmitted from the press machine controller 20 to the safety device controller 21 and the guard plate 8 begins to open. The robot 3 then starts the next operation at a predetermined timing or time interval.

[0043] Furthermore, the removal of the processed press product (step S11) may be performed by providing the press machine 1 with a mechanism for removing the processed product, such as a knockout pin or an air blower, and using that mechanism to move the press product on the lower die to a predetermined location. In this case, the safety device 2 will perform the so-called 1-break described above, so the process will return from step S10 to step S4 described above and the above operations will be repeated. Alternatively, the press product can be removed by the robot 3. In that case, the safety device 2 will open and close the guard plate 8 with the so-called 2-break described above.

[0044] Furthermore, it is possible to remove the processed product (pressed product) and set the material in a single break. As mentioned above, a single break is a control that opens and closes the guard plate 8 once in one cycle when the robot 3 inserts the hand unit 11 into the press machine 1 and then pulls the hand unit 11 back out of the press machine 1. When removing the processed product and setting the material in this single break, the chuck 16 used is a chuck 16 equipped with a first chuck 16a for holding and releasing the processed product and a second chuck 16b for holding and releasing the material, as shown in Figure 6, for example. The robot 3 is taught to perform a series of operations with the chuck 16 inserted into the press machine 1, moving the first chuck 16a to a position for holding the processed product, then moving the second chuck 16b to a position for setting the material, such as on the lower die, and then pulling the hand unit 11 back out of the press machine 1.

[0045] The first chuck 16a and the second chuck 16b may be configured to hold materials or workpieces using any of the following methods: vacuum suction, magnetic suction, gripping, etc., and the control of holding and releasing them is performed by programming the robot controller 22. The hand unit 11 is movable in any direction, up and down and left and right, and the chucks 16 can also be rotated in the horizontal plane. Therefore, the first and second chucks 16a and 16b can be arranged in the order of the second chuck 16b and the first chuck 16a from the robot 3 side, as shown in Figure 6, or in the reverse order, or even rotated 90° from the state shown in Figure 6 (so-called sideways). The order of such arrangement can be determined according to the location where the workpiece will be received.

[0046] Referring to Figure 6, an example of the operation when removing a workpiece and setting the material in a single break is explained. With the guard plate 8 open, the robot 3 inserts its hand unit 11 into the press machine 1 and positions the first chuck 16a on the lower die D. The first chuck 16a moves up and down relative to the lower die D to receive the workpiece P from the lower die D. After that, the robot 3 moves the second chuck 16b, which is holding the material W, onto the lower die D, and the second chuck 16 moves up and down relative to the lower die D to set the material W on the lower die D. If the case C in which the workpiece P will be placed is beyond the lower die D, the hand unit 11 is moved further in to position the first chuck 16a above the case C. In this state, the first chuck 16a releases its grip on the workpiece P, and the workpiece P is placed into the case C. After that, the robot 3 operates to pull the hand unit 11 back out of the press machine 1.

[0047] During this series of operations, the optical sensors 7o and 7i are shielded from light by the arm portion 10 of the robot 3, and therefore the guard plate 8 remains open. When the hand portion 11 and the chuck 16 held by the hand portion 11 move outside the safety device 2, the light is no longer blocked from the optical sensors 7o and 7i, so the safety device 2 closes the guard plate 8 and transmits a start signal to the press machine controller 20. If the case C containing the workpiece P is located on the robot 3 side of the safety device 2, the hand portion 11 moves outside the safety device 2 while the first chuck 16a holds the workpiece P. After that, the guard plate 8 closes and a start signal is output. In this way, the removal of the workpiece P and the setting of the material W are completed while the guard plate 8 is open once. This reduces the number of breaks from two to one, thereby improving the processing efficiency of the press-formed product or the manufacturing efficiency of products using it.

[0048] In the press system according to the present invention described above, there is no configuration that functions as an interlock between the robot 3 and the press machine 1 or safety device 2, and the robot 3 is, so to speak, independent from the press machine 1 and safety device 2. Therefore, the robot 3 can perform material gripping operations or press product storage operations even when the guard plate 8 of the safety device 2 is closed. In that case, the proximity sensor 19 provided on the hand part 11 that is moving toward the press machine 1 detects the guard plate 8 and stops in front of the guard plate 8. In other words, contact or interference between the robot 3 and the safety device 2 or press machine 1 is prevented, and safety in this respect is ensured.

[0049] Such operations, which are independent of the press machine 1, are similar to the actions performed by an operator, such as setting materials and removing pressed parts, and safety is ensured in these operations. Therefore, the replacement of the operator with the robot 3 can be easily performed without changing the system configuration. For example, by having the robot 3 perform the press-related tasks that were previously done by an operator, it becomes possible to reduce the number of operators required in the production process or press-working line.

[0050] Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. The safety device may be configured to detect the robot's movement using an optical sensor, such as PSDI (Presence Sensing Device Initiation), and control the output of a start signal, without using a physical closing member such as a guard plate. Furthermore, in the case of a safety device having a guard plate, the opening and closing direction of the guard plate does not have to be vertical; the safety device may have a guard plate that opens and closes horizontally, and there may be one guard plate or three or more guard plates. In addition, the detection of the robot's relative position to the press machine may be performed not only by the image data of the two-dimensional pattern 23 described above, but also by an appropriate contact-type or non-contact-type sensor. [Explanation of symbols]

[0051] 1 Press machine 2 Safety equipment 3 Robots 4 bolster 5 slides 6 frames 7i (internal) optical sensor 70 (Outer) Optical Sensor 8 Guard plates 8a Upper guard plate 8b Lower guard plate 9 Actuators 10 Arm section 11 Handball 12 Mobile cart 13 Caster 14 Fixed legs 15 Cameras 16 Chuck 16a First Chuck 16b Second Chuck 17 Stacker 18 Laser Scanners 19. Proximity sensor 20 Press machine controller 21 Safety device controller 21a Insertion detection means 21b Evacuation detection means 21c Closing means 21d Press activation means 22 Robot Controllers 22a Set path storage means 22b Position detection means 22c Correction means 22d Stopping means 23 Two-dimensional patterns C Case D Lower mold P Processed products W Material Ws Work Sensor

Claims

1. A safe automatic press system comprising a press machine that performs press processing by the reciprocating motion of a slide, and a robot that repeatedly performs material setting operations for the press machine, which are stored in memory through pre-programmed teaching, The robot is mounted on a predetermined platform and is equipped with a robot controller. A safety device having a safety device controller that permits and prohibits the pressing operation of the press machine is placed between the robot and the press machine. The safety device controller includes a retreat detection means for detecting when the robot has retreated outside the press machine after performing the material setting operation, and a press activation means for outputting an activation signal to move the slide up and down when the retreat detection means detects that the robot has retreated outside the press machine. A safety-oriented automatic press system characterized by the following features.

2. A safety automatic press system according to claim 1, The aforementioned robot controller is A position detection means for detecting the relative position to the press machine, The system includes a correction means for correcting the material setting operation relative to the press machine based on the relative position detected by the position detection means. A safety-oriented automatic press system characterized by the following features.

3. A safety automatic press system according to claim 1 or 2, The robot further comprises an arm portion that moves forward and backward relative to the press machine, and a hand portion provided at the tip of the arm portion. The retraction detection means is configured to detect when the arm and hand portions have been retracted to the outside of the press machine. A safety-oriented automatic press system characterized by the following features.

4. A safety automatic press system according to claim 1 or 2, The safety device further comprises a guard plate that obstructs the material setting path by the robot, The safety device controller further includes a closing means that, when the retreat detection means detects that the robot has retreated outside the press machine, moves the guard plate to a closed position that blocks the set path. A safety-oriented automatic press system characterized by the following features.

5. A safety automatic press system according to claim 4, The robot further includes a sensor that detects the guard plate obstructing the set path, The robot controller further includes a stopping means that stops the robot's movement at a position where it will not collide with the guard plate, based on the detection of the guard plate by the sensor. A safety-oriented automatic press system characterized by the following features.

6. A safety automatic press system according to claim 1 or 2, The aforementioned robot is a collaborative robot that slows down its movement and eventually stops when it detects that a predetermined moving object, including a person, has entered a pre-defined area. A safety-oriented automatic press system characterized by the following features.

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