JPH0616994B2 - Bending machine - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a folding machine such as a press brake, and
The present invention relates to a bending apparatus that is organically combined with a robot that supplies and supports plate materials to the bending machine.

[Technical background of the invention and its problems] In recent years, for the purpose of improving workability and ensuring safety when bending a work by a folding machine, supplying the work to the folding machine and supporting the work during machining , A robot has been developed for performing a series of operations such as transfer of a work to the next process.

By the way, as shown in FIG. 1, during machining of the work, the robot 2 is in a gripping state along a movement path (Q ₁ → Q ₂ ) of jumping up accompanying bending of the work W by the upper die 4. Keep following and move following. As a follow-up method, conventionally, for example, a work surface is detected by an indicator, and the robot 2 is moved following the detected amount. However, in this method, the workpiece is shaken during the bending process, and the shake is detected. As a result, the robot 2
The gripping portion 2a also vibrates, so that the work cannot be accurately followed and supported, and there is a problem in improving the bending accuracy.

[Object and Outline of the Invention] The present invention has been made in view of the above, and an object thereof is to support a work at an appropriate position even when the work tends to bend due to its own weight. An object of the present invention is to provide a bending apparatus capable of improving the bending accuracy.

In order to achieve the above-mentioned object, the present invention is a robot comprising a gripping portion for gripping a front end portion of the work in front of a folding curve for bending a work by cooperation of a lower die and an upper die. Based on an image pickup signal output from this image pickup device, and an image pickup device for picking up an image of the processing position of the work by the lower die and the upper die and the rear end of the work. An image pickup signal processing device for recognizing a pattern and measuring a distance from a bending point of a work to a rear end portion, a movement amount of the rear end portion in the Z-axis direction and a rising angle of the rear end portion during bending processing, The triangle between the initial position of the rear end of the work, the moving position of the rear end during bending and the bending point is the initial position of the front end of the work and the moving position and bending of the front end during bending. So that the triangle formed by the points always retains a similar shape, An arithmetic device for calculating the movement locus of the gripping position of the front end of the workpiece based on the measurement result of the imaging signal processing device, and a follow-up control for controlling the movement locus of the gripping part in the robot based on the arithmetic result of this arithmetic device. And a device.

[Embodiment of the Invention] FIG. 3 shows an embodiment of the present invention.
A lower table TD is provided on the lower front side of the frame F, and a lower die 4A is mounted on the upper portion of the lower table TD. Further, an upper die 4B is provided below the upper table TU provided on the upper front side of the frame F.
Is installed. Therefore, the lower table TD
Alternatively, one of the upper tables TU is moved up and down by a driving device such as a hydraulic cylinder (not shown), so that the lower die 4A and the upper die 4B cooperate to work W.
Bending will be performed.

An appropriate image pickup device 5, such as a television camera, for picking up an image in the broken-line circular area in FIG. 3 is arranged near the side of the folding machine 9. Also, folding machine 9
A robot 2 is arranged in front of the robot 2, and the robot 2 is provided with a grip portion 2a of the grip device 1.

The robot 2 is driven and controlled according to a processing program stored to supply the work W to a predetermined processing position on the folding curve 9 taught in advance, or image processing of the imaging signal from the imaging device 5 and the processing result. A drive control processing device 13 including, for example, a microcomputer is connected to the robot 2.

The drive control processing device 13 has a CPU 15, a ROM 17 in which a processing program is stored, a RAM 19 for temporarily storing data, and an input / output port 21.

The drive control device 13 performs the following calculation based on the image pickup signal from the image pickup device 5 (see FIG. 4), and drives and controls each joint of the robot 2 according to the calculation result. In FIG. 4, when the work W is bent, the front end side edge of the work W gripped by the robot 2 moves from the initial position Q ₁ to the moving position Q ₂ opposite to the gripping side. The rear end side of the side is the initial position P
_{From 1} to the movement position P ₂ , each repulsively rises and moves.
Here, if the X axis, Z axis, and P axis are set as shown in FIGS. 3 and 4, this movement causes the position of the grip portion 2a to change to Q.
The movement amount (X ₁ , X ₂ , Z ₂ , β) of each axis (X, Z, P) when moving from ₁ to Q ₂ is ΔAP ₁ P ₂ and ΔAQ ₁
Since Q ₂ has a similar shape with the similarity ratio L / l, it can be expressed by the following equation.

X ₁ = x ₁ · L / l X ₂ = x ₂ · L / l Z ₂ = z ₂ · L / l β = tan ⁻¹ (z ₂ / x ₂ ) Based on the above equation, each axis of the robot 2 Amount of movement (Z _T ,
When X _T , P _T ) is calculated, it can be expressed by the following equation.

_{Z T = Z 2 + asinβ =} z 2 · L / l + asin (tan -1 z 2 / x 2) X T = (X 1 + a) - (X 2 + acosβ) = (x 1 · L / l + a) - {x 2・ L / l + acos (t
an ⁻¹ z ₂ / x ₂ )} = (x ₁ −x ₂ ) · L / l + a · {1-cos (tan ⁻¹⁾
z ₂ / x ₂ )} P _T = β = tan ⁻¹ (z ₂ / x ₂ ) Next, the operation of this embodiment will be described with reference to FIG.

The CPU 15 sets the coordinate system of each axis (X, Z, P) by recognizing the pattern by the image pickup signal processing device 6 based on the image pickup signal output from the image pickup device 5 and bending points of the work W. After measuring the distance x ₁ from A to the end P ₁ on the side opposite to the gripping side of the work W, a bending command is output to the bending machine 9 (steps 100 to 130). When the bending is started, the CPU 15 moves the amount of movement of the side end of the work W on the side opposite to the gripping side, that is, in the X-axis direction and the Z-axis direction, based on the imaging signal. At the same time as measuring the movement amount component continuously or by time sampling, the rising angle β of the opposite side end is measured (steps 140 and 150). From this measurement result, the CPU 15 determines each axis (X, Z,
P) The movement amount is calculated by the calculation device 3 as described above,
In response to this, in order to drive each joint of the robot 2, a movement pulse signal for driving the motor is output via the tracking control device 7 (steps 160 to 240). By continuing this series of processing (steps 140 to 240) until the bending process is completed (step 250), the robot 2 can perform the follow-up operation while maintaining the gripped state of the work W.

[Effects of the Invention] As will be understood from the above description of the embodiments, the present invention is, in short, the front of the bending machine 9 for bending the work W by the cooperation of the lower mold 4A and the upper mold 4B. And a robot 2 having a gripping part 2a for gripping the front end of the work W is arranged in the bending machine to form the lower die 4
An image pickup device 5 for picking up an image of the processing position of the work W and the rear end of the work W by the upper die 4B, and a bending point of the work W by pattern recognition based on an image pickup signal output from the image pickup device 5. An imaging signal processing device 6 for measuring a distance x ₁ from A to the rear end portion, a movement amount z _{2 of the} rear end portion in the Z-axis direction during bending, and a rising angle β of the rear end portion.
And a triangle formed by the initial position P ₁ of the rear end of the work W, the moving position P ₂ of the rear end during bending, and the bending point A is the same as the initial position Q ₁ of the front end of the work W. Based on the measurement result of the imaging signal processing device 6, the gripping position of the front end of the work W is set so that the triangle formed by the moving position Q ₂ of the front end during processing and the bending point A always maintains a similar shape. It is provided with a computing device 3 for computing a movement locus, and a follow-up control device 7 for controlling the movement locus of the grip portion 2a in the robot 2 based on the computation result of the computation device 3.

As is apparent from the above-described configuration, in the present invention, the location where the image is captured by the imaging device 5 is the processing position of the work W and the range of the short rear end portion of the work W. Then, the imaging device 5
The image pickup signal processing device 6 recognizes the pattern based on the image pickup signal, and the distance x ₁ from the bending point A of the work W to the rear end portion,
Amount z of movement of the rear end portion in the Z-axis direction during bending
₂ and the rising angle β of the rear end portion are measured, and based on the measurement result, and the position of the rear end portion of the work W and the position of the front end portion thereof have a predetermined positional relationship, The movement locus of the gripping position of the front end is calculated by the calculation device 3, and based on the calculation result of this calculation device 3, the gripping part 2 of the robot 2 is calculated.
The tracking control device 7 controls the movement trajectory of a.

By the way, as is well known, when the work W is bent by a bending machine such as a press brake, the size of the work projected from the position of the upper and lower dies to the front is larger than the size of the work projected from the front. Is generally extremely small, the front end portion of the work W tends to bend due to its own weight, and even if vibration tends to occur during processing, the rear end portion bends, and the vibration is extremely small compared to the front end portion. There are few.

As will be understood, the present invention is based on the inclination of the rear end of the work W by utilizing the fact that the inclination of the front end and the inclination of the rear end of the work are equal when the work W is bent. The work W is grasped and supported by calculating the movement locus of the gripping position of the front end and controlling the movement of the gripping portion 2a of the robot 2 so as to follow the movement locus of the gripping position. Since the front end portion of the workpiece W is supported in a state where the bending and the like are corrected, the accuracy of bending the work W can be improved.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a follow-up operation in a work gripping state by a robot, FIG. 2 is a complaint correspondence diagram, FIG. 3 is a block diagram showing a configuration of an embodiment of the present invention, and FIG. 4 is a process by a drive control processing device. FIG. 5 is a flow chart of the operation shown in FIG. (Explanation of symbols representing main parts of the drawing) 1 ... Gripping device 2 ... Robot, 2a ... Gripping portion 3 ... Computing means, 5 ... Imaging device 7 ... Control device, 9 ... Bending machine 13 ... Drive control processing device

Claims (1)

[Claims] 1. A front end portion of the work (W) is provided in front of a folding machine (9) for bending the work (W) by cooperation of a lower die (4A) and an upper die (4B). The gripping part (2
The robot (2) provided with a) is arranged to be a bending apparatus, and the processing position of the work (W) and the work (W) by the lower die (4A) and the upper die (4B) are set. Imaging device (5) for imaging the rear end portion, and this imaging device (5)
The pattern recognition is performed based on the image pickup signal output from the device, and the distance from the bending point (A) of the work (W) to the rear end portion
₁ ), an image pickup signal processing device (6) for measuring a movement amount (z ₂ ) of the rear end portion in the Z-axis direction and a rising angle (β) of the rear end portion during bending, and a work (W) The triangle formed by the initial position (P ₁ ) of the rear end part, the moving position (P ₂ ) of the rear end part during bending and the bending point (A) is the initial position of the front end part of the work (W). Based on the measurement result of the image pickup signal processing device (6), the triangle formed by (Q ₁ ) and the moving position (Q ₂ ) of the front end portion during bending and the bending point A always has a similar shape. Calculating device (3) for calculating the movement locus of the gripping position of the front end of the workpiece (W), and the movement locus of the gripping part (2a) in the robot (2) based on the calculation result of this calculating device (3). And a follow-up control device (7) for controlling the bending device.