JP2862871B2 - Bending device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a bending apparatus for bending a sheet metal, and more particularly, to a robot for feeding and positioning a sheet metal to the bending apparatus. The present invention relates to a bending device formed by combining (Prior Art) Japanese Patent Application Laid-Open No. Sho 59-227379 discloses a prior art example of a bending apparatus having a configuration in which a robot is disposed in front of a bending machine for bending a sheet metal. (Problems to be Solved by the Invention) In the conventional configuration according to the above-described prior example, when the sheet metal held by the robot hand is positioned between the upper and lower dies, the bending machine is provided so as to be movable and positionable in the front-rear direction. The positioning is performed by bringing a sheet metal into contact with a sensor provided on the back gauge. Then, after positioning, the upper and lower molds are engaged to bend the sheet metal.However, in a press brake in which the lower frame supporting the lower mold moves up and down, the sheet metal placed and positioned on the lower mold is In addition, a slight displacement may occur due to a slight vibration or the like when the lower frame moves up and down. If a slight displacement of the sheet metal occurs before the sheet metal is clamped by the upper and lower molds,
The bending process is performed in a state where the slight displacement occurs. In addition, if the grip of the robot hand is loosened during the bending of the sheet metal, a positional shift occurs after re-gripping, and there is a problem in performing accurate bending continuously. (Means for Solving the Problems) In view of the above-described conventional problems, the present invention provides a lower frame having a lower die opposed to an upper die provided on an upper frame so as to be able to move up and down. On the front side of a sheet metal bending apparatus provided with a back gauge that can be moved and positioned in the front-rear direction with respect to the position of the bending line by the mold and that can be moved up and down integrally with the lower frame, In a bending device in which a positionable robot is arranged, a plurality of sensors consisting of linear transducers having a long measurement stroke are provided on the back gauge at right and left distances, and a sheet metal held by a robot hand of the robot is provided. A side gauge for detecting one side edge in the left-right direction and a positional relationship in the left-right direction of the robot is provided. The rear edge of the sheet metal is set in parallel with the bending line based on the difference between the detection value of each sensor when the rear edge of the sheet metal abuts on each of the sensors and the detection value detected by the side gauge. A calculation unit for calculating a movement amount and a direction including turning of the robot hand around a specific point on a rear end edge of the sheet metal to maintain the relationship, and a calculation unit based on the movement amount and the direction calculated by the calculation unit. A movement control unit that performs a sheet metal position correction process, and determines whether or not a difference between position information where the sheet metal held in the storage unit is to be arranged and a detection value of each sensor is within an allowable range. A determination control unit for issuing a command to sandwich the sheet metal by the upper and lower molds to the sheet metal bending apparatus, from when the command is issued to sandwich the sheet metal until the sheet metal is clamped by the upper and lower molds. Slight displacement of sheet metal between Is made of a structure to perform further applied several times the sheet metal position correction processing for correcting. (Example) Hereinafter, an example of a bending device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a bending device, and FIG. 2 is a side view of the same. In FIG. 1, a sheet metal bending apparatus 1 comprises, for example, a press brake or the like. A bending robot 3 is mounted on the front side of the sheet metal bending apparatus 1. This bending robot 3
Has five movable axes of X, Y, Z, A, and B. At the side of the sheet metal bending apparatus 1, a magazine section 5 accommodating the sheet metal W is provided, and a transfer device 7 for transferring the bent product P to the next step is arranged.
Since the configurations of the magazine unit 5 and the transport device 7 may be general configurations, detailed description thereof will be omitted. The sheet metal bending apparatus 1 includes an upper frame 9 and a lower frame 11 similarly to a general press brake, and an upper die 13 is detachably mounted on the upper frame 9. The lower frame 11 has a lower mold 15
Is installed. As is well known, in the sheet metal bending apparatus 1 having the above-described configuration, one of the upper and lower frames 9 and 11 is moved up and down to engage the upper mold 13 and the lower mold 15, thereby forming the upper mold 13 and the lower mold 15. The sheet metal W positioned between the lower mold 15 and the lower mold 15 is bent. Although not shown in detail, in the bending device according to this embodiment, the lower frame 11 is configured to move up and down. Further, the sheet metal bending apparatus 1 is provided with a back gauge 17 for positioning the sheet metal W in the front-rear direction (left-right direction in FIG. 2; Y-axis direction) so as to be movable in the front-rear direction. This back gauge 17 is similar to the general configuration of a press brake in which the lower frame 11 moves up and down,
It is provided so as to move up and down integrally with the lower frame 11. A plurality of sheet metal W
The sensor 19 for detecting this is mounted. This sensor 19 is, for example, like a direct-acting potentiometer,
It consists of a linear transducer whose length can be measured and whose measurement process is relatively long. With such a configuration, when the bending robot 3 abuts the rear edge of the sheet metal W and positions the back gauge 17 previously positioned by ordinary means, the output of each of the sensors 19 at a plurality of locations becomes a predetermined output value. By detecting whether or not they match, it is known whether or not the rear end edge of the sheet metal W is parallel to a bending line (hereinafter, referred to as a bending axis C as necessary) by the upper and lower dies 13,15. And accurate positioning of the sheet metal W can be performed. An output signal from the sensor 19 is input to a robot controller 21 mounted on the upper frame 9. The robot controller 21 controls the operation of the bending robot 3, the operation of each operating unit in the sheet metal bending apparatus 1, and the operation of the back gauge 17.
When the output signal from each of the sensors 19 is input, the operation of the bending robot 3 is controlled so that the output value of each sensor 19 becomes a desired output value. In this embodiment, the bending robot 3 is mounted on a base plate 23 integrally mounted on the lower frame 11 which can be moved up and down, and is configured to move up and down integrally with the lower frame 11. More specifically, the base plate 23 is provided long in the left-right direction (X-axis direction) along the longitudinal direction of the lower mold 15,
A first movable table 25 is supported on the front surface of the base plate 23 so as to be movable in the X-axis direction. The first moving table 25 includes
A pinion (not shown) meshing with a rack rod 27 in the X-axis direction provided on the base plate 23 is rotatably provided, and a first servomotor 29 for controlling the rotation of the nion is provided. The first servo motor
The power transmission mechanism for rotating the pinion 29 by a general configuration may be a general configuration, and the detailed description thereof will be omitted. The first servomotor 29 is composed of, for example, a stepping motor or the like, and includes a position detecting device such as an encoder. With the above configuration, the first moving table 25 can be moved in the X-axis direction by operating the first servomotor 29, and the moving position of the first moving table 25 in the X-axis direction with respect to the reference position can be detected. Can be. As is clear from FIGS. 1 and 2, the first movable table 25 is provided with a fan-shaped portion 31 whose upper side is enlarged in the front-rear direction (Y-axis direction). Is provided with an arc-shaped rack member 33. This rack member
A second movable table 35 that is movable in the Y-axis direction along the rack member 33 is supported by the 33. In this second mobile platform 35,
A pinion (not shown) meshed with the rack member 33 is rotatably provided, and a second servomotor 37 for rotating the pinion is mounted. The second servomotor 37 is provided with a position detecting device such as an encoder like the first servomotor 29. With the above configuration, by driving the second servomotor 37, the second movable table 35 is moved along the rack member 33 in an arc shape in the Y-axis direction. The position of the second movable table 35 in the Y-axis direction is detected by a position detecting device provided in the second servomotor 37. As is clear from FIGS. 1 and 2, the second moving table 35 is supported with a lifting column 39 which is movable in the vertical Z-axis direction perpendicular to the moving direction of the second moving table 35. ing. A vertical rack is formed on the lifting column 39. A pinion (not shown) meshed with the rack is rotatably supported by the second movable table 35, and a third servomotor 41 for rotating the pinion is provided by a second movable table 35.
Adhered to. The third servomotor 41 is provided with a position detecting device like the first servomotor 29. With the above configuration, the lifting column 39 is connected to the third servomotor 41.
It can be understood that the actuator is moved up and down by the drive, and the up and down movement position is detected by the position detecting device. An arm 43 which is long in the Y-axis direction is appropriately fixed on the upper part of the elevating column 39. A robot hand 45 capable of gripping one side edge of the sheet metal W is attached to the distal end of the arm 43. More specifically, as shown in FIGS. 1 and 2, the robot hand 45 is provided so as to be rotatable up and down around a B-axis parallel to the X-axis. It is provided so as to be pivotable about an orthogonal A axis. A fourth servo motor 47 for turning the robot hand 45 about the A axis and a fifth servo motor 49 for turning the robot hand 45 up and down about the B axis.
Are mounted on the arm 43. Each of the fourth and fifth servo motors 47 and 49 has a position detecting device like the first servo motor 29 described above. The power transmission mechanism for turning the robot hand 45 around the A axis by the fourth servomotor 47 and the power transmission mechanism for turning the robot hand 45 up and down by the fifth servomotor 49 may have various configurations. Since it is possible and does not have a feature in this configuration, a detailed description thereof will be omitted. Further, in FIG. 1, an auxiliary gripping device 87 capable of temporarily holding the sheet metal W is mounted on one side of the lower frame 11 or the base plate 23, and a side gauge 89 is provided via an appropriate bracket. It is installed. The auxiliary gripping device 87 includes an upper jaw 91 and a lower jaw 93 for gripping the sheet metal W.
, The sheet metal W can be gripped in the same manner as the robot hand 45. The side gauge 89 is used to detect a left-right positional relationship between one side edge of the sheet metal W held by the robot hand 45 of the bending robot 3 and the bending robot 3 in the left-right direction. It has 95. Like the sensor 19 provided in the back gauge 17, the side sensor 95 is formed of a linear transducer such as a direct-acting potentiometer. The output value of the side sensor 95 is input to the robot controller 21. Accordingly, one side edge of the sheet metal W gripped by the robot hand 45 abuts on the side sensor 95, and when the output value of the side sensor 95 is a predetermined output value, the bending robot 3 in the X-axis direction Is detected by reading the detection value of the position detecting device provided in the first servomotor 29 into the robot controller 21. Then, by comparing with the position detection value of the reference position when the sheet metal W is not gripped,
The positional relationship in the X-ray direction between one side edge of the sheet metal W held by the robot hand 45 in the left-right direction and the bending robot 3 can be known. Therefore, the sheet metal W can be accurately positioned in the X-axis direction with respect to the dies 13 and 15 with reference to the side gauge 89. FIG. 3 is an explanatory diagram of the main internal configuration of the robot controller 21 and the position correcting operation of the sheet metal W of the bending robot 3 in the system of the above-described embodiment. When the rear edge S of the linear structure portion of the sheet metal W in the front-rear direction is substantially parallel to the bending line C, which is a bending line formed by the upper and lower dies 13 and 15, the back gauge 17 is used.
A plurality of A / Ds 51A to 51B are provided in the robot controller 21 for inputting the detection values of the contact position of the sheet metal W from the plurality of sensors 19A to 19B mounted on the robot and converting the values into digital values. Then, the detection values from the plurality of sensors 19A to 19B converted into digital values by the plurality of A / Ds 51A to 51B are received, and a specific point of the sheet metal W, for example, an intermediate point P of the rear edge S is moved to the center of movement. There is a calculation unit 61 that calculates the movement amount, direction, and route of the robot hand 45 including rotation. Further, a movement control unit 63 that controls the movement of the robot hand 45 about a specific point (for example, the point P) of the sheet metal W in accordance with the movement amount, the direction, and the path of the robot hand 45 calculated by the calculation unit 61. There is. There are servo amplifiers 71 to 77 for each axis that drive the servo motors 29, 37, 41, 47, and 49 for each axis of the bending robot 3 according to the control by the movement control unit 63. Further, the sensors 19A to 19B input to the arithmetic unit 61
, The processing target edge S of the sheet metal W is bent axis C
A determination control unit 65 is provided for determining whether or not it is substantially parallel to the control unit and controlling the calculation unit 61, the movement control unit 63, and the like according to the determination. Further, there is a storage unit 67 for storing various information such as the shape of the sheet metal W to be processed, a processing target portion, and the current gripping point being recognized. Next, the operation of the system of this embodiment will be described. 4 and 5 are flowcharts of positioning control when the sheet metal W is arranged between the upper and lower dies 13, 15 of the sheet metal bending apparatus 1. FIG. The operation of holding the sheet metal W which is the workpiece to be processed by the robot hand 45 of the bending robot 3 and arranging the rear edge S between the upper and lower dies 13 and 15 is started (step 101 in FIG. 4). First, the rear end edge S of the sheet metal W is moved to a position slightly before the approximate arrangement position from the gripping point information of the sheet metal W held in the storage unit 67 and the information such as the position and angle at which the sheet metal W is to be arranged. Then, it is moved forward slowly and brought into contact with the sensors 19A and 19B (step 103). Next, the position of the sheet metal W is corrected while detecting input values from at least two sensors 19A and 19B (step 105). The details of the position correction processing of the sheet metal W are shown in FIG. When the sheet metal position correction process is started (FIG. 5, step 20)
1) First, detection values are input from the plurality of sensors 19A and 19B (step 203). Then, the absolute value of the difference (error) between the position information, at which the sheet metal W is to be placed, held in the storage unit 67 and the input values from the plurality of sensors 19A, 19B is obtained (step 205). Next, the determination control unit 65 compares the absolute value of the error with a value in an allowable range held in the storage unit 67 (step 207). As a result of the comparison, if the error is out of the allowable range (No in step 207), the arithmetic unit 61 calculates a specific point on the sheet metal W, for example, the inside of the edge S of the sheet metal W according to the value of the error. Point P
The calculation unit 61 calculates the moving amount, direction, and path of the robot hand 45, including rotation, with respect to the movement center (step 209). More specifically, in FIG.
However, if the sensors are not sufficiently parallel to the bending axis C as shown by a two-dot chain line, for example,
At least one of 9B exceeds the allowable range value held in the storage unit 67. Now, it is assumed that the degree of contact with the sensor 19A is extremely small, and the difference between the input value from the sensor 19A and the standard position information held in the storage unit 67 is larger than the allowable range. The calculation unit 61 sets the specific point P of the sheet metal W as the movement center,
The movement amount of the robot hand 45 holding the sheet metal W is calculated. That is, the rotation angle of the robot hand 45 gripping the sheet metal W about the point P, and the sensors 19A and 19B
The movement amount is calculated by adding the forward movement amount of the robot hand 45 obtained from both of the current values. Then, the movement amount and direction of each axis of the bending robot 3 necessary to realize this movement amount are calculated. Fig. 3, 2
In the case of the dotted line, the axes involved are the A-axis (rotation), the X-axis (movement to the right), and the Y-axis (reciprocation). In this movement, both the target sheet metal W and each part of the bending robot 3 are moved by the sheet metal bending apparatus 1.
Consider the travel route so as not to touch anywhere. For this reason, the remaining axes of the bending robot 3; the B axis and the Z axis may need to be moved. According to the movement amount, direction and route calculated in this way,
The movement control unit 63 operates the servo amplifiers 71 to 77 of each axis of the robot to be moved, and drives the servo motor of that axis (step 211 in FIG. 5). When one movement of the robot hand 45 holding the sheet metal W is thus completed, the process returns to input of the detection values of the sensors 19A and 19B again (step 203). On the other hand, when the difference between the input value of the sensor and the standard value thereof is within the allowable range (Yes at step 207), this state is further maintained n times (for example, 4 times) continuously. It is determined whether or not it is (step 213).
This means that the detection values of the above sensors 19A and 19B are not temporary and are stably detected, that is, that values within the allowable range are not detected accidentally and instantaneously. This is a process for realizing the accurate arrangement of the sheet metal W by checking. Of course, this process is incidental and not essential. If the value within the permissible range is not detected n times consecutively (No in step 213), the process returns to the input of the detection values of the sensors 19A and 19B (step 20).
3). If the above state is detected n times consecutively (Yes in step 213), the sheet metal position correction process ends (step 215). Returning to FIG. 4, when the sheet metal position correcting process is completed, the bending table, that is, the lower frame of the sheet metal bending apparatus 1
A command to raise the lower mold 15 as the lower mold attached to the upper mold 9 and sandwich the sheet metal W between the lower mold 15 and the upper mold 13 attached to the upper frame 9 is sent from the judgment control unit 65 to the sheet metal bending apparatus. 1 (step 107 in FIG. 4). Then, the sheet metal W is perfectly sandwiched between the upper and lower molds 13 and 15, and it is determined whether the sheet metal W has reached a pinching point immediately before the bending of the sheet metal W is actually started (the same step). 109). If the pinching point has not yet been reached (No in Step 109), the sheet metal position correction process is performed again (Step 111). This is carried out on the assumption that the sheet metal W is pushed up with the rise of the lower mold 15 which is the lower mold, and the position of the sheet metal W is slightly displaced by the vibration when the lower frame 11 is raised. . However, in the sheet metal position correction process at this time, it is checked that the number is within the above-mentioned n consecutive allowable range (step 213 in FIG. 5).
Is omitted. After the sheet metal position correction processing is performed, it is checked whether the pinching point has been reached again (step in FIG. 4).
Return to 109). If the pinching point has been reached (Yes at step 109), the sheet metal positioning process ends (step 11).
3), bending of the sheet metal W is started (Step 11)
Five). At this time, the robot hand 45 loosens the grip of the sheet metal W and prepares for the lifting of the grip position of the sheet metal W due to the bending. In this manner, the bending of the sheet metal W of the work to be processed is executed, and when the bending is completed, the robot hand 45 sets the sheet metal W
Grab again. At this time, if an error occurs between the recognition position of the holding point of the sheet metal W held by the robot hand 45 in the storage unit 67 and the actual holding point due to re-gripping, Since the corrected position correction processing and the like are performed again, the accuracy with respect to the processing position does not deteriorate. In this way, it is possible to perform the bending process or the like on each side of the sheet metal W with high accuracy while holding the sheet metal W by the robot hand 45. Then, the sheet metal W after the bending process is transferred to the position of the transfer device 7 by the bending robot 3, and then transferred to the next process as the product P by the transfer device 7. [Effects of the Invention] As can be understood from the above description of the embodiment, in the present invention, a plurality of sensors provided on the back gauge 17 are provided.
19A and 19B are linear transducers having a long measurement process, and the detection values of the sensors 19A and 19B when the rear edges of the sheet metal are brought into contact with the sensors 19A and 19B are stored in the storage unit 67. Robot hand for making the rear edge parallel to the folding line C based on the difference from the position information where the sheet metal W is to be arranged
The movement amount and direction of 45 are calculated by the calculation unit 61, and the movement control unit 63 performs sheet metal position correction processing based on the calculation result. Then, it is determined by the determination control unit 65 whether or not the difference between the position information at which the sheet metal W stored in the storage unit 67 is to be disposed and the detection value of each of the sensors 19A and 19B is within an allowable range. A command is issued to sandwich the sheet metal W between the upper and lower molds 13 and 15, and the sheet metal W from when this command is issued until the sheet metal W is clamped by the upper and lower molds 13 and 15. Since the sheet metal position correction process for correcting the slight positional shift of the sheet metal W is performed, a slight positional shift occurs in the sheet metal W due to vibration or the like during the approach movement of the upper and lower molds 13 and 15 with the lower frame 11 raised. Even in this case, even a slight displacement of the sheet metal W can be corrected, and even if the bending apparatus is of a type in which the lower frame 11 moves up and down, the bending operation is performed with more accurate positioning of the sheet metal W. Is what you can do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing the entire bending apparatus, and FIG. 2 is a side view. FIG. 3 is a diagram showing a gripping state of a workpiece and an internal configuration of a robot controller in the embodiment.
FIG. 4 and FIG. 5 are operation flowcharts in the embodiment. DESCRIPTION OF SYMBOLS 1 ... Sheet metal bending apparatus, 3 ... Bending robot, 19, 19A, 19B, 95 ... Sensor, 45 ... Robot hand, 51A, 51B ... A / D, 61 ... Calculation part, 63 ... Movement control unit, 65 ... Judgment control unit, 67 ... Storage unit

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Sadao Abe               200 Ishida, Isehara-shi, Kanagawa Stock Association               Inside Amada                (56) References JP-A-59-227379 (JP, A)                 JP-A-61-810 (JP, A)                 JP-A-61-270032 (JP, A)

Claims (1)

(57) [Claims] A lower frame (11) having a lower mold (15) opposed to an upper mold (13) provided in the upper frame (9) is provided so as to be able to move up and down, and a folding line (10) is formed by the upper and lower molds (13, 15). The back gauge (1) which can be moved and positioned in the front-rear direction with respect to the position C) and which can be moved up and down integrally with the lower frame (11)
7) A bending apparatus comprising a sheet metal bending apparatus (1) provided with a robot (3) capable of positioning a sheet metal (W) with respect to the bending line (C) in front of the bending apparatus (1). The back gauge (17) is provided with a plurality of sensors (19A, 19B) composed of linear transducers having a long measurement process and separated from each other, and a sheet metal (W) held by the robot hand (45) of the robot (3). ) Is provided with a side gauge (89) for detecting the positional relationship in the left-right direction of the robot (3) with respect to one side edge in the left-right direction, and the sheet metal (W) held in the storage unit (67) should be disposed. Position information and the rear edge of the sheet metal (W) are connected to the sensors (19A, 19A).
B) The rear edge of the sheet metal (W) is bent along the bending line based on the difference between the value detected by each of the sensors (19A, 19B) and the value detected by the side gauge (89). (C)
A calculation unit (61) for calculating a movement amount and a direction including a turn of the robot hand (45) around a specific point (P) on a rear end edge of the sheet metal (W) so as to maintain a relationship parallel to A movement control unit (63) for performing a sheet metal position correction process based on the movement amount and direction calculated by the calculation unit (61); and a sheet metal (W) held in the storage unit (67). It is determined whether or not the difference between the position information to be detected and the detection value of each of the sensors (19A, 19B) is within an allowable range.
A determination control section (65) for issuing to the sheet metal bending apparatus (1) a command to sandwich the sheet metal (W) according to (3, 15), and the instruction to sandwich the sheet metal (W) is issued. A configuration in which the sheet metal position correction processing is further performed an appropriate number of times in order to correct a slight positional shift of the sheet metal (W) between the time when the sheet metal (W) is clamped by the upper and lower molds (13, 15). A bending device, characterized in that: