JP2007050447A - System and method for bending by robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bending system and a bending method in which a measuring device for measuring a one-sided elongation value of a work clamped by a robot is small-sized and its constitution is simple and, the efficiency of measurement is improved by shortening measuring time, the range of the measurement is expanded by taking a work the bending angle of which is not only 90° but also acute or obtuse as the object of measurement, the work is positioned by using the measuring device for measuring the one-sided elongation value of the work and the bending work is performed with the robot without interfering with a machine main body. <P>SOLUTION: This apparatus has a gripper 14 of a robot 13 for clamping a work W and a measuring device 1 for measuring the one-sided elongation value α of the work W which is attached to the gripper 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, the measuring device for measuring the half elongation value of the workpiece gripped by the robot is small in size and simple in configuration, and the measuring time is shortened to improve the measuring efficiency and the bending angle is only 90 °. In addition, by using a workpiece with an acute or obtuse angle as a measurement target, the range of the measurement target is expanded and the workpiece is positioned using a measuring device that measures the half elongation value of the workpiece, and the robot interferes with the machine body. The present invention relates to a bending system and a bending method by a robot that performs bending without any problem.

  Conventionally, as shown in FIG. 12, a flange F is formed by bending a flat work W along a bend line m in a bending apparatus (for example, a press brake) having a punch P and a die D. When obtaining a predetermined flange dimension H, the flange dimension H becomes an important dimension.

  Therefore, at the time of workpiece positioning (FIG. 12A), the workpiece portion W1 from the bend line m to the tip portion, which is the important dimension side, is arranged on the back gauge abutment 50 side as shown in the drawing, The dimension-side workpiece part W1 is positioned against the abutment 50.

  As a result, the positioning state of the workpiece part W1 on the important dimension side is stabilized, and the bending line m is not displaced from the mold center C during bending (FIG. 12B), and a more accurate flange dimension H is obtained. It is supposed to be.

  In this case, the abutment dimension L at the time of workpiece positioning (FIG. 12A), that is, the distance L from the position of the bending line m to the tip of the workpiece is calculated, and the back gauge abutment 50 is placed at the position of the abutment dimension L. Need to be positioned.

  For this reason, as is well known, in consideration of a slight extension of the workpiece W during bending (FIG. 12B), a single elongation value α (FIG. 4), which is an elongation value, is measured in advance. A value obtained by subtracting the single elongation value α from the predetermined flange dimension H is calculated as an abutment dimension L.

  This means that, as shown in FIG. 13, a new flange F2 is formed along the other bend line m2 of the workpiece W where one flange F1 is already formed along the bend line m1, and a predetermined bottom portion is formed. The same applies to the case where the dimension A is to be obtained, and this bottom dimension A is an important dimension.

  Accordingly, at the time of workpiece positioning (FIG. 13A), the workpiece portion W2 from the bend line m2 to the flange F1, which is the important dimension side, is arranged on the back gauge abutment 50 side as shown in FIG. The dimension-side work part W2 is positioned against the abutment 50.

  Thereby, similarly, the positioning state of the work part W2 on the important dimension side is stabilized, and the position of the bend line m2 is not displaced from the mold center C at the time of bending (FIG. 13B). A is obtained.

  In this case as well, the abutting dimension L at the time of workpiece positioning (FIG. 13A), that is, the distance L from the position of the bend line m2 to the outside of the flange F1 is calculated, and the back of the abutting dimension L is calculated. The gauge abutment 50 needs to be positioned. Therefore, the above-described single elongation value α (FIG. 4) is measured in advance, and a value obtained by subtracting the single elongation value α from the predetermined bottom dimension A is obtained. The abutting dimension L is calculated.

  However, the piece elongation value α is often different depending on conditions such as the thickness of the workpiece W. In actual machining, the piece elongation value α measured in a certain process is reflected in the abutting dimension of the next process. To correct.

  For example, in FIG. 12, when the single elongation value α is measured in a certain process, the abutting dimension L in the next process is calculated by subtracting the single elongation value α from the predetermined flange dimension H in the next process. The abutting dimension value set in advance from CAD information or the like is corrected.

  This is the same when the operator manually grips and bending the workpiece W, or when the workpiece W is gripped by a robot gripper and bent.

  For example, when the workpiece W is gripped by a gripper of a robot and bent, a flange dimension is measured in place of the above-described single elongation value α (FIG. 4), and the measured value of the flange dimension and the target Japanese Patent Laid-Open No. 5-154560 discloses means for correcting the abutting dimension (bending position data) in the next process when the difference from the value exceeds the allowable range.

For example, the measurement of the half elongation value α described in FIG. 12 and the measurement of the flange dimension disclosed in JP-A-5-154560 are both corrected for the abutting dimension using the measurement value. By doing so, the measurement of the half elongation value α and the measurement of the flange dimension are synonymous with each other in terms of obtaining a more accurate flange dimension.
JP-A-5-154560

  The means disclosed in JP-A-5-154560 includes a motor as a drive source installed behind the upper table, and a ball screw coupled to the motor via a gear and a nut and extending downward. , An inverted L-shaped bending length detector attached to the lower end of the ball screw, a potentiometer provided in the bending length detector, and a support attitude detector installed on the die.

  However, this means is too large as a whole, has a complicated structure, and costs increase accordingly.

  Also, after bending the workpiece gripped by the robot, the robot must take out the V-bent workpiece from the V groove of the die and move it to the upper surface of the die, and position the flange portion below the potentiometer 1.

  For this reason, the entire measurement time from the end of processing to the end of measurement of the flange dimension is lengthened, and the measurement efficiency is lowered.

  Further, at the time of measurement, in order to improve accuracy, it is necessary to level the work using the above-described support posture detector, and in this respect as well, the entire measurement time becomes longer and the measurement efficiency is lowered. Furthermore, conventionally, since the flange dimension is measured by vertically lowering the potentiometer and bringing it into contact with the end of the flange, only the workpiece having a flange angle of 90 ° is measured (see above). In the summary column of JP-A-5-154560, it is described as “right-angled” in the third line of the composition column.) For this reason, workpieces with an acute or obtuse bending angle are not subject to measurement. The scope of the subject is very narrow.

  On the other hand, as described in FIG. 12 and FIG. 13, in order to obtain an accurate flange dimension H and (FIG. 12) bottom dimension A (FIG. 13), in any case, the important dimension side work part W1. , W2 is abutted against the abutment 50 side of the back gauge and positioned, thereby stabilizing the positioning state of the important dimension side work parts W1, W2.

  However, when the workpiece W is gripped and bent by the gripper 51 of the robot, and the dimension of the workpiece part gripped by the gripper 51 on the opposite side is smaller than that of the important dimension side workpiece part, , Bending may not be possible.

  For example, in FIG. 13A, the dimension of the work part W3 gripped by the gripper 51 is clearly smaller than the dimension of the important dimension side work part W2, and therefore the gripper 51 is too close to the machine body of the press brake. ing.

  Accordingly, when the workpiece W jumps up as the bending process proceeds and the gripper 51 tries to follow the jumping operation, the gripper 51 may interfere with the machine body, and the bending process cannot actually be performed. .

  However, conventionally, by enabling the workpiece W to be positioned with the gripper 51 gripping the important dimension side workpiece portion W2 having a long dimension as described above, the gripper 51 and the machine main body that perform the workpiece follow-up operation during bending are provided. No means for avoiding the interference and realizing the bending is disclosed.

  An object of the present invention is to make a measuring device for measuring a half elongation value of a work gripped by a robot small in size and simple in configuration. By reducing the measuring time, the measuring efficiency is improved and the bending angle is 90. By measuring not only ° but also sharp and obtuse workpieces, the range of the measurement target is expanded and the workpiece is positioned using a measuring device that measures the workpiece's half-elongation value, and the robot interferes with the machine body. Provided are a bending system and a bending method by a robot that performs bending without performing the bending process.

In order to solve the above problems, the present invention provides:
As described in claim 1,
A gripper 14 of the robot 13 that grips the workpiece W;
A robot bending process characterized by having a measuring device 1 attached to the gripper 14 for measuring a piece elongation value α of the workpiece W;
As described in claim 3,
A measuring device 1 that is attached to the gripper 14 of the robot 13 and measures a single elongation value α of the workpiece W gripped by the gripper 14;
Robot control means 10F for driving and controlling the robot 13,
The measurement device 1 that measures the single elongation value α of the workpiece W is driven and controlled. The value a ₀ indicated by the measurement device 1 at the time of positioning of the workpiece by the robot 13 and the measurement device 1 at the end of the workpiece follow-up operation by the robot 13 are detected. Measuring device control means 10E for detecting the value a indicated by
A bending system by a robot, characterized by comprising machining information calculation means 10D for calculating a piece elongation value α of the workpiece W based on the detected values a ₀ and a of the measuring device 1;
As described in claim 4,
A bending method in the bending system by the robot according to claim 1 or 3,
(1) In the process, after measuring the elongation value α of the workpiece W,
(2) In the subsequent steps, based on the measured elongation value α, the abutting dimension L is corrected and used for the back gauge position.
(3) For the second and subsequent workpieces W, the abutting dimension L is corrected based on the half elongation value α measured for the first workpiece W in (1) above, and used for the back gauge position. And a bending method characterized in that, and
A bending method in the bending system by the robot according to claim 1 or 3,
Whether the robot 13 positions the workpiece W using the back gauge abutment 23 or the workpiece W using the measuring device 1 that measures the half elongation value α attached to the gripper 14 during bending. The method of the bending process characterized by having made it possible to select is taken.

According to the configuration of the present invention, for example, the measuring device 1 for measuring the half elongation value α (FIG. 4) of the workpiece W gripped by the robot 13 is attached to the gripper 14 of the robot 13 and the measuring device 1 is attached. Since the potentiometer is used, the workpiece W gripped by the gripper 14 of the robot 13 in this step (FIG. 3A) is applied to the back gauge abutment 23 positioned at the position of the preset abutment dimension L. After the abutting and positioning, the work W is fixed with the punch P and the die D in the half clamp state (FIG. 3C), the gripper 14 is advanced, and the potentiometer when the potentiometer 1 outputs an ON signal. The value a _{0 of} 1 and the value a of the potentiometer 1 at the end of the work following operation of the gripper 14 as the bending process proceeds (FIG. 3C). Based on the difference, the piece elongation value α can be measured, and in the subsequent steps, the abutting dimension L is corrected based on the measured piece elongation value α, and the corrected abutting dimension L position is obtained. The back gauge abutment 23 can be positioned.

  Therefore, according to the present invention, since the measuring device 1 is attached to the gripper 14, the overall size is extremely small, the configuration is simple, and in this process (FIG. 3), simultaneously with the end of the bending process. Since the single elongation value α is measured (FIG. 3C), it is possible to improve the measurement efficiency by shortening the measurement time, and further, the rear end of the workpiece W (FIG. 3B). The part elongation value α (FIG. 3C) is measured while the part is kept in contact with the rod 1A of the potentiometer 1 attached to the gripper 14 from the start to the end of the bending process. The measurement can be performed regardless of the bending angle on the tip side of the workpiece W on the side opposite to the gripper 14, and therefore the workpiece can be measured not only with a bending angle of 90 ° but also with an acute angle or an obtuse angle. Therefore, the scope of the measurement target It is possible to expand.

  Further, according to the configuration of the present invention described above, a trajectory (following trajectory) of the workpiece following operation of the robot 13 is calculated for each process (step 201 in FIG. 11), and based on the calculated following trajectory of the robot 13. When the gripper 14 grips the workpiece W and performs bending, it is determined whether or not it interferes with the machine body (step 202 in FIG. 11). Whether the workpiece W is positioned using the back gauge abutment 23 (step 203 in FIG. 11) or the workpiece W is positioned using the measuring device 1 attached to the gripper 14 (step 204 in FIG. 11) is selected. be able to.

  Therefore, according to the present invention, it is possible to position the workpiece W using the measuring apparatus 1 in a state where the workpiece portion W3 (FIG. 9B) on the important dimension side, which has not been possible before, is gripped by the gripper 14 of the robot. As a result, the robot can perform bending without interfering with the machine body.

  As described above, according to the present invention, the measuring device for measuring the half elongation value of the workpiece gripped by the robot is small and simple in configuration, and by improving the measurement efficiency by reducing the measurement time, By measuring not only a bending angle of 90 ° but also a workpiece with an acute angle or an obtuse angle, the range of the measurement target is expanded and the workpiece is positioned using a measuring device that measures the half elongation value of the workpiece. There is an effect of providing a bending system and a bending method by a robot that performs bending without interfering with the machine body.

Hereinafter, the present invention will be described with reference to the accompanying drawings by embodiments.
FIG. 1 is an overall view of the present invention, and a bending system using a robot shown in FIG. 1 inputs CAD information from an NC apparatus 10 of a bending apparatus 11 to indicate bending order, molds P, D, mold layout, and the like. After the calculation, the trajectory of the workpiece following operation of the robot 13 is calculated for each process (bending order) (step 101 to step 103 in FIG. 6). In the first process, a potentiometer, which is a measuring apparatus 1 described later, is used. Then, the piece elongation value α is measured (FIG. 4), and after the second step, the abutting dimension L is corrected using the piece elongation value α measured in the first step and used as the back gauge position (FIG. 4). 6 step 104 to step 105).

  The bending apparatus 11 (FIG. 1) in this case includes a press brake, and as is well known, has a punch P mounted on the upper table 20 and a die D mounted on the lower table 21. ing.

  A back gauge is disposed behind the lower table 21, and the back gauge abutment 23 is attached to a slider 24. The slider 24 is slidably coupled to a stretch 25 extending in the left-right direction (the direction perpendicular to the paper surface). is doing.

  Further, side plates 22 are installed on both sides of the press brake, and each side plate 22 is provided with a ram drive source such as a motor or a hydraulic cylinder. In the descending press brake, the upper table 20 is lowered. In the lift press brake, the workpiece W is bent by the punch P and the die D described above when the lower table 21 is lifted.

  A robot 13 is attached to the base plate 12 of the lower table 21.

  The robot 13 is, for example, a five-axis robot, and includes a left-right direction (X-axis direction) drive unit a of the entire robot, a front-rear direction (Y-axis direction) drive unit b and an up-down direction (Z-axis direction) drive of the arm 19. The part c further includes a horizontal turning (centering on the X axis) driving part d and a vertical turning (centering on the Z axis) driving part e of the gripper 14 at the tip of the arm 19.

  Further, as described above, the robot 13 has the gripper 14 at the tip of the arm 19, and the gripper 14 includes an upper gripper 14A that can move up and down and a fixed lower gripper 14B. The workpiece W to be held is gripped.

  With this configuration, the robot 13 operates the drive units a to e described above when a drive signal of the five axes is sent from the robot control unit 10F described later, thereby, for example, as described later, Position the workpiece W gripped by the gripper 14 (FIG. 3A), advance the gripper 14 with the workpiece W half-clamped (FIG. 3B), and cause the workpiece W to spring up as the bending progresses. By performing the following operation to follow the workpiece (FIG. 3C), the one-side elongation value α is measured via the measuring device 1.

  Further, on the lower gripper 14B of the gripper 14 (FIG. 2), a measuring device 1 for measuring an elongation value of the workpiece W to be bent, for example, a piece elongation value α (FIG. 4) is attached.

  That is, as described above, in the press brake, the workpiece W is bent by the punch P (FIG. 4) and the die D, but the workpiece region R near the tip of the punch P is rounded during the bending. The rounded surface is formed, the upper surface of the workpiece W is compressed, and the lower surface is pulled, so that the workpiece W is apparently extended, but the apparent elongation value on one side (for example, the right side) of the workpiece W at this time Is referred to as a single elongation value α (see, for example, paragraph number 0004 of JP-A-2002-79317).

  Then, as described above, the single elongation value α is measured by the measuring device 1. As the measuring device 1, for example, there is a potentiometer.

  For example, in the first bending process (step 104 in FIG. 6) to be described later, a workpiece W gripped by the gripper 14 (FIG. 3A) is moved to a predetermined position L (this position is calculated in advance using CAD information). It is abutted against the abutment 23 positioned at a position equal to the abutting dimension L).

  At this time, it is assumed that the rear end portion of the work W and the rod 1 </ b> A of the potentiometer 1 are not in contact with each other as illustrated.

  In this state, for example, the punch P (FIG. 3B) is lowered and stopped at the pinching point, and after fixing the workpiece W on the die D, the upper gripper 14A of the gripper 14 is slightly raised, A gap is formed between W and the gripper 14 to bring the workpiece W into a half clamp state, and then the gripper 14 is advanced.

As a result, when the rear end portion of the workpiece W comes into contact with the rod 1A of the potentiometer 1, the potentiometer 1 outputs an ON signal. The value a ₀ of the potentiometer 1 at the time when the ON signal is output is measured later. The apparatus control means 10E (FIG. 1) detects and stores it in the storage means 10C.

  Thereafter, when the punch P is further lowered (FIG. 3C), the workpiece W jumps up as the bending process proceeds, and the gripper 14 follows the jumped workpiece W, but the punch P reaches a predetermined ram stroke. The value a of the potentiometer 1 in which the rod 1A is immersed at the time when the workpiece follow-up operation of the gripper 14 is finished is similarly detected by the measuring device control means 10E (FIG. 1) and stored in the storage means 10C. Let

Then, based on the values a ₀ and a of the potentiometer 1 stored in the storage means 10C, the machining information calculation means 10D calculates the one-side elongation value α according to the equation α = a−a ₀ , According to the invention, the half elongation value α (FIGS. 3 and 4) is measured via the potentiometer 1 attached to the gripper 14.

  In the bending process after the second process (step 105 in FIG. 6), the abutting dimension L is corrected using the piece elongation value α measured in the first process, and the position of the corrected abutting dimension L is By positioning the back gauge abutment 23, the back gauge position is used.

  FIG. 5 is a diagram showing another embodiment of the measuring apparatus 1 described above, and the measuring apparatus 1 is a CCD camera.

In this case, for example, an image of the rear end portion of the work W taken by the CCD camera is taken into the NC apparatus 10 (FIG. 1), and similarly, the machining information calculation means 10D has α = a (after the work W at the end of the bending process). The one-side elongation value α is calculated according to the equation of end value) −a ₀ (value of the rear end portion of the workpiece W at the time of workpiece positioning).

  The press brake NC device 10 having the above configuration (FIG. 1) includes a CPU 10A, an input / output means 10B, a storage means 10C, a machining information calculation means 10D, a measuring device control means 10E, a robot control means 10F, It has a bending control means 10G.

  The CPU 10A performs overall control of the entire apparatus shown in FIG. 1, such as the machining information calculation means 10D and the measurement apparatus control means 10E.

  The input / output means 10B is, for example, an operation panel (not shown) attached to the upper table 20 of the press brake, and includes input means such as a keyboard and output means such as a liquid crystal screen, and inputs CAD information. The input result can be confirmed on the LCD screen.

The storage means 10C stores the CAD information input via the input / output means 10B, and the initial value a ₀ when measuring the half elongation value α using the potentiometer 1 (FIG. 3) described above. (FIG. 3B), the final value a (FIG. 3C) is stored, and further, a machining program according to the present invention (for example, corresponding to FIGS. 6 to 8) and the like are stored.

  The machining information calculation unit 10D (FIG. 1) calculates a bending order, a mold, a mold layout, and the like based on the CAD information (step 101 in FIG. 6) input via the input / output unit 10B (FIG. 1). 6), for each process (bending order), information necessary for bending the workpiece W is calculated, such as calculating the locus of the workpiece following operation of the robot 13 (step 103 in FIG. 6).

  In this case, the trajectory F (following trajectory F) of the workpiece following operation of the robot 13 (FIG. 3C) is calculated based on the workpiece posture state diagram (process diagram).

  That is, the machining information calculation means 10D (FIG. 1) uses the CAD information to determine the workpiece posture state consisting of the posture at the time of positioning of the workpiece W (FIG. 3 (A)) and the posture at the time of jumping up (FIG. 3 (C)). A diagram is created, and the following trajectory F of the robot 13 is calculated based on the created workpiece posture state diagram.

Further, the machining information calculation means 10D (FIG. 1), as already described, is based on the value a ₀ (FIG. 3C), a of the potentiometer 1 stored in the storage means 10C, and the one-side elongation value α ( FIG. 4) is calculated.

The measurement device control means 10E (FIG. 1) controls driving of the potentiometer 1, for example, the measurement device 1, and inputs the ON signal when the potentiometer 1 outputs the ON signal (FIG. 3B). Thus, the value a _{0 of the} potentiometer 1 is detected and stored in the storage means 10C (FIG. 1).

  Further, the measuring device control means 10E is informed by the bending control means 10G, which will be described later, that the punch P (FIG. 3C) has reached a predetermined ram stroke and the bending process has been completed. When the workpiece follow-up operation of the gripper 14 of the robot 13 accompanying the progress is completed (FIG. 3C), the value a of the potentiometer 1 in which the rod 1A is immersed is detected and stored in the storage means 10C (FIG. 1). Let

  As described above, the robot control means 10F controls the drive of the robot 13 by sending a 5-axis drive signal to the robot 13.

  The bending control means 10G drives and controls a ram drive source (such as a motor or a hydraulic cylinder). For example, in the case of a descending press brake, the bending control means 10G lowers the upper table 20 that is a ram so that the punch P and the die D The workpiece W gripped by the gripper 14 of the robot 13 is bent.

  Further, the bending control means 10G positions the back gauge abutment 23 at a predetermined position in advance.

  The operation of the present invention having the above configuration will be described below with reference to FIGS.

(1) The operation until the locus of the workpiece following operation of the robot 13 is calculated.
In step 101 of FIG. 6, CAD information is input. In step 102, bending order, mold, mold layout, and the like are calculated. In step 103, the robot 13 performs the work following operation for each process (bending order). Calculate the trajectory.

  That is, when the CPU 10A detects that CAD information is input via the input / output means 10B (FIG. 1), the CPU 10A controls the machining information calculation means 10D to calculate the bending order, the mold, and the mold layout. For each process, the following trajectory F (FIG. 3C) of the robot 13 is calculated.

(2) Bending operation in the first step.
In step 104 of FIG. 6, the bending process operation of the first process is performed, and the piece elongation value α is measured.

  Details of this step 104 are shown in FIG. 7. After the work W is loaded by the robot 13 (step 104A in FIG. 7), the work W is positioned (step 104B in FIG. 7), and then the ram 20 is lowered (step 104B in FIG. 7). Step 104C in FIG. 7) When the ram 20 reaches the pinching point (YES in Step 104D in FIG. 7), the ram 20 is stopped (Step 104E in FIG. 7).

  That is, when the CPU 10A detects that the machining information calculation means 10D has calculated the following trajectory F of the robot 13 in step 103 of FIG. 6 (FIG. 1), the gripper 14 of the robot 13 via the robot control means 10F. (FIG. 3 (A)), the workpiece W is gripped, and the workpiece W is inserted between the punch P and the die D and loaded into the press brake. Then, the workpiece W is abutted against the back gauge abutment 23 and positioned. The work W on the die D is fixed by lowering the ram 20 (FIG. 1) via the control means 10G and stopping when the punch P (FIG. 3B) reaches the pinching point.

  In this case, the back gauge abutment 23 (FIG. 3A) is positioned at the position of the abutment dimension L calculated in advance by CAD information.

Next, in the half clamp state, the gripper 14 is moved forward (step 104F in FIG. 7), and when the ON signal is output from the potentiometer 1 (YES in step 104G in FIG. 7), the gripper 14 is stopped. The value a ₀ of the potentiometer 1 is detected (step 104H in FIG. 7).

That is, when the CPU 10A detects that the ram 20 has stopped via the bending control means 10G in step 104E of FIG. 7 (FIG. 1), the CPU 10A moves the upper gripper 14A via the robot control means 10F (FIG. 3B). ) After slightly raising the workpiece W to a half clamp state, the gripper 14 is advanced, and when the rear end of the workpiece W comes into contact with the potentiometer 1 and an ON signal is output, the gripper 14 is stopped and measured. The value a ₀ of the potentiometer 1 at that time is detected and stored in the storage means 10C via the device control means 10E (FIG. 1).

  Thereafter, the ram 20 is lowered again (step 104J in FIG. 7), the workpiece 13 is followed by the robot 13 (step 104K in FIG. 7), and when a predetermined ram stroke is reached (YES in step 104L in FIG. 7). The ram 20 is stopped (step 104M in FIG. 7), the value a of the potentiometer 1 at that time is detected, and the one-side stretch value α is calculated (step 104N in FIG. 7).

That, CPU 10A is (1), at step 104H in FIG. 7, the gripper 14 is stopped through the robot control unit 10F, the value a ₀ of the potentiometer 1 at that time is detected via the measuring device control section 10E stores When it is detected that the data is stored in the means 10C, the ram 20 is lowered again via the bending control means 10G (FIG. 1), the punch P (FIG. 3C) is further lowered, and the robot control means 10F (FIG. 1), the robot 13 holding the workpiece W is caused to perform a workpiece follow-up operation. When a predetermined ram stroke is reached, the ram 20 is stopped via the bending control means 10G, and the measuring device control means 10E (FIG. 1), the value a of the potentiometer 1 at that time (FIG. 3C) is detected and stored in the storage means 10C.

Then, the CPU 10A calculates the one-side elongation value α according to the equation α = a−a ₀ via the machining information calculation unit 10D based on the values a ₀ and a of the potentiometer 1 stored in the storage unit 10C. .

  Thus, as described above, according to the present invention, the half elongation value α (FIGS. 3 and 4) was measured via the potentiometer 1 attached to the gripper 14.

(3) Bending operation after the second step.

  In step 105 of FIG. 6, the bending process operation | movement after the 2nd process is performed, the abutting dimension L is correct | amended using the piece elongation value (alpha) measured at the said 1st process, and it uses as a back gauge position.

  Details of this step 105 are shown in FIG. 8, and the abutting dimension L is corrected based on the one-side stretch value α (step 105A in FIG. 8), and the abutment 23 is brought to the position of the corrected abutting dimension L. Positioning is performed (step 105B in FIG. 8).

  That is, the CPU 10A (FIG. 1) detects the value a of the potentiometer 1 via the measuring device control means 10E in step 104N of FIG. 7 and stores it in the storage means 10C, and stretches one side via the machining information calculation means 10D. When it is detected that the value α is calculated, the machining information calculation unit 10D is controlled again, and the abutting dimension L is corrected based on the piece elongation value α.

  In this case, the machining information calculation unit 10D (FIG. 1) corrects the abutting dimension L according to the equation L = H−α, for example, when the flange dimension calculated in advance by CAD information is H.

  Then, the CPU 10A (FIG. 1) positions the back gauge abutment 23 at the position of the corrected abutment dimension L via the bending control means 10G.

  Thereafter, the work W is carried in by the robot 13 (step 105C in FIG. 8), the work W is positioned (step 105D in FIG. 8), the ram 20 is lowered (step 105E in FIG. 8), and the work following by the robot 13 is performed. The operation is performed (step 105F in FIG. 8), and when the predetermined ram stroke is reached (YES in step 105G in FIG. 8), the ram 20 is stopped (step 105H in FIG. 8).

That is, when the CPU 10A detects in step 105B in FIG. 8 that the back gauge abutment 23 is positioned at the position of the corrected abutment dimension L via the bending control means 10G (FIG. 1), the robot control means After gripping the workpiece W by the gripper 14 of the robot 13 through 10F (FIG. 1), inserting the workpiece W from between the punch P and the die D and carrying it into the press brake, the workpiece W is moved to the corrected thrust. A robot that abuts against the back gauge abutment 23 positioned at the position of the contact dimension L and then lowers the ram 20 via the bending control means 10G and grips the workpiece W via the robot control means 10F. 13, the ram 20 is stopped via the bending control means 10G when a predetermined ram stroke is reached. Make.
The above is for the first workpiece W, but the second and subsequent workpieces W are similarly used by using the single elongation value α of the first workpiece W measured in step 104 of FIG. In addition, the abutting dimension L can be corrected based on the one-side elongation value α and used for the back gauge position.
For example, in the case of bending 100 workpieces W having the same thickness and other conditions, first, if the above-mentioned single elongation value α is measured for the first workpiece W, the next second to 100 sheets are measured. For the workpiece W up to the eye, it is not necessary to newly measure the single elongation value α. Based on the single elongation value α measured for the first workpiece W, the abutting dimension L is corrected, and the corrected The back gauge abutment 23 can be positioned at the position of the abutment dimension L.

  9 to 11 show other examples of the bending method according to the present invention. In the bending process, the robot 13 positions the workpiece W using the back gauge abutment 23 or sets the one-side elongation value α. It is possible to select whether the workpiece W is positioned using the measuring device 1 to be measured.

  In this case, before machining, a trajectory of the workpiece following operation of the robot 13, that is, a following trajectory F (for example, corresponding to FIG. 3C) is calculated in advance for each process (step 201 in FIG. 11). Any of the above-described workpiece positioning can be selected by simulation using the following trajectory F.

  For example, in the present embodiment, it is assumed that the flat workpiece W shown in FIG. 10A is bent, and in the first step, the flange F1 is formed by bending along the bending line m1 (FIG. 10). 10 (B)), because the predetermined flange dimension H is obtained, this flange dimension H becomes an important dimension, and in the second step, the flange is opposed to the flange F1 by bending along the bend line m2. Since F2 is formed (FIG. 10C) and a predetermined bottom dimension A is obtained, this bottom dimension A becomes an important dimension.

  Then, in the first step, when the gripper 14 grips the workpiece portion on the side opposite to the important dimension side workpiece portion and performs bending processing in the first step, the gripper 14 It is determined whether or not it interferes with the machine body (step 202 in FIG. 11).

  In this case, in the first step, as described above, the important dimension side workpiece part is W1 (FIG. 10A), and this important dimension side workpiece part W1 is usually placed on the back gauge abutment 23 side. The gripper 14 grips the workpiece portion W2 on the opposite side.

  This state is shown in FIG. 9A. In this state, when the punch P is lowered and the workpiece W is bent in cooperation with the die D, the workpiece W jumps up, and the gripper 14 moves the calculated following locus. F (corresponding to FIG. 3C) is drawn.

  In the case of FIG. 9 (A), if the dimension of the workpiece part W2 gripped by the gripper 14 on the opposite side is larger than the dimension of the workpiece part W1 on the critical dimension side on the abutment 23 side, Even if processing is performed, the gripper 14 does not interfere with the machine body such as the punch P (NO in step 202 in FIG. 11).

  Therefore, even during actual bending, as shown in FIG. 9A, the workpiece W is positioned using the back gauge abutment 23 (step 203 in FIG. 11). Bending is performed along the bend line m1 to obtain a predetermined flange dimension H which is an important dimension (FIG. 10B), and thereafter, the process proceeds to the next second step (FIG. 11).

  In this case, the back gauge abutment 23 in the first step (FIG. 9 (A)) is in the position of the corrected abutment dimension L = H−α in consideration of the already described single elongation value α (FIG. 4). It is positioned.

  In the second step, as described above, the important dimension side workpiece part is W3 (FIG. 10B), and this important dimension side workpiece part W3 is usually placed on the back gauge abutment 23 side. While abutting and stabilizing the positioning state, the work part W4 on the opposite side is gripped by the gripper.

  However, in this case, if the dimension of the workpiece part W4 gripped by the gripper 14 on the opposite side is smaller than the dimension of the workpiece part W3 on the critical dimension side on the abutment 23 side, 13 (A).

  For this reason, when the workpiece W is bent in cooperation with the die D by lowering the punch P, the workpiece W jumps up and the gripper 14 draws the calculated following locus F (corresponding to FIG. 3C). Obviously, however, the gripper 14 interferes with the machine body (YES in step 202 in FIG. 11).

  Therefore, in the actual bending process, as will be described later, the workpiece W is positioned by using the measuring device 1 attached to the gripper 14 (step 204 in FIG. 11).

  That is, in the actual bending process, first, as shown in the upper diagram of FIG. 9B, the important dimension side work part W3 having a large dimension is held by the gripper 14 and attached to the gripper 14. After positioning the gripper 14 so that the position of the rod 1A of the measuring device 1 is at the position of A (bottom dimension) −α (one-side stretch value) = N (remaining dimension), the upper gripper 14A is slightly raised. The workpiece W is in a half clamp state.

  At this time, the flange F1 formed in the first step is not in contact with the rod 1A, and the bending line m2 of the workpiece W on the die D is slightly behind the die center C (the abutment 23 side). Further, the abutment 23 is located slightly rearward of the workpiece W tip.

  Next, in this state, as shown in the lower diagram of FIG. 9B, when the abutment 23 is advanced and the workpiece W is pushed into the gripper 14 side, the flange F1 at the rear end portion of the workpiece W becomes the measuring device. Since the measuring device 1 is in contact with the first rod 1A, an ON signal is output. At that time, the abutment 23 is stopped, and then the upper gripper 14A is lowered to grip the workpiece W.

  As a result, the workpiece W can be positioned using the measuring device 1 that measures the half elongation value α, the position of the bending line m2 on the workpiece W coincides with the mold center C, and the workpiece W is gripper. 14 and the abutment 23, the positioning state of the workpiece W is stabilized.

  Thereafter, if the workpiece W on the die D is bent along the bending line m2 by lowering the punch P, even if the gripper 14 holding the important dimension side workpiece portion W3 performs the workpiece following operation, the machine The bending process proceeds without interfering with the main body, and a predetermined bottom dimension A which is an important dimension is obtained (FIG. 10C).

  In the case of FIG. 9 to FIG. 11, the determination as to whether or not the gripper 14 interferes with the machine main body (step 202 in FIG. 11) is, for example, the interference availability determination means 10H constituting the NC device 10 (FIG. 1). Based on the trajectory of the workpiece following operation of the robot 13 for each process calculated by the machining information calculation unit 10D (step 201 in FIG. 11), the interference availability determination unit 10H performs each process as described above. In addition, when the gripper 14 grips the workpiece portion opposite to the important dimension side workpiece portion and performs bending, it is determined whether or not the gripper 14 interferes with the machine body (step 202 in FIG. 11). ).

  In the present invention, the measuring device for measuring the half elongation value of the workpiece gripped by the robot is small in size and simple in configuration, and the measuring time is shortened to improve the measuring efficiency and the bending angle is only 90 °. In addition, by using a workpiece with an acute or obtuse angle as a measurement target, the range of the measurement target is expanded and the workpiece is positioned using a measuring device that measures the half elongation value of the workpiece, and the robot interferes with the machine body. More specifically, a robot having a gripper of a robot that grips a workpiece and a potentiometer that is attached to the gripper and measures a half elongation value of the workpiece In the process, after measuring the elongation value of the workpiece, the measurement is performed in the subsequent process. It is useful for the bending method that corrects the abutting dimension based on the half elongation value and uses it at the back gauge position. There is also a bending method that can be used to select whether to position the workpiece using a back gauge abutment or to position the workpiece using a potentiometer that measures the stretch value attached to the gripper. .

1 is an overall view of the present invention. It is a figure which shows the robot 13 of this invention. It is operation | movement explanatory drawing of the robot 13 of this invention. It is explanatory drawing of the piece elongation value (alpha) by this invention. It is a figure which shows the other Example of the measuring apparatus 1 which comprises this invention. It is a flowchart for demonstrating the whole operation | movement of this invention. It is a flowchart for demonstrating operation | movement of the 1st process by this invention. It is a flowchart for demonstrating the operation | movement after the 2nd process by this invention. It is a figure which shows the other example of the bending method by this invention. It is a figure which shows the example of the workpiece | work W bent by FIG. It is a flowchart for demonstrating the operation | movement of FIG. It is a figure which shows an example of a prior art. It is a figure which shows the other example of a prior art.

Explanation of symbols

1 Measuring device 10 NC device 10A CPU
10B Input / output means 10C Storage means 10D Processing information calculation means 10E Measuring device control means 10F Robot control means 10G Bending control means 11 Bending processing device 12 Base plate 13 Robot 14 Gripper 14A Upper gripper 14B Lower gripper 19 Arm 20 Upper table 21 Lower table 22 Side plate 23 Bump 24 Slider 25 Stretch D die P Punch W Workpiece

Claims (9)

The gripper of the robot that grips the workpiece,
A robot bending process characterized by having a measuring device attached to the gripper and measuring a piece elongation value of a workpiece. 2. The robot bending system according to claim 1, wherein the measuring device is constituted by a potentiometer or a CCD camera. A measuring device attached to a gripper of a robot and measuring a half elongation value of a work held by the gripper;
Robot control means for driving and controlling the robot;
A measurement device that controls and drives a measurement device that measures a single elongation value of the workpiece, and detects a value indicated by the measurement device at the time of workpiece positioning by the robot and a value indicated by the measurement device at the time of completion of the workpiece follow-up operation by the robot Control means;
A robot bending process system comprising machining information calculation means for calculating a piece elongation value of a workpiece based on each value of the detected measuring device. A bending method in the bending system by the robot according to claim 1 or 3,
(1) In this process, after measuring the elongation value of the workpiece,
(2) In the subsequent steps, based on the measured stretch value, the abutment dimension is corrected and used for the back gauge position.
(3) The second and subsequent workpieces are also used in the back gauge position by correcting the abutting dimension based on the half elongation value measured for the first workpiece in (1) above. Bending method. In the above (1), the workpiece gripped by the gripper of the robot is positioned, and then the workpiece is fixed with a punch and a die in a half clamp state, and then the gripper is moved forward so that the potentiometer outputs the ON signal. The single elongation value is measured by a difference between the value of the potentiometer and the value of the potentiometer when the work following operation of the gripper is completed as the work is bent by bending the work with a punch and a die. Bending method. 5. The bending process according to claim 4, wherein in (2), the abutting dimension is corrected based on the half elongation value measured in (1), and the back gauge abutting is positioned at the position of the corrected abutting dimension. Method. A bending method in the bending system by the robot according to claim 1 or 3,
When bending, the robot can select whether to position the workpiece using a back gauge abutment or to position the workpiece using a measuring device that measures the stretch value attached to the gripper. A characteristic bending method. The bending method according to claim 7, wherein which of the workpiece positioning is selected is performed based on a locus of the workpiece following operation of the robot calculated for each process. When the robot gripper does not interfere with the machine body when the robot gripper grips the workpiece part on the side opposite to the important dimension side workpiece part based on the calculated locus of the workpiece following operation of the robot, When bending, the robot gripper positions the workpiece using the back gauge abutment while holding the workpiece on the side opposite to the workpiece on the critical dimension side. 9. The bending method according to claim 8, wherein the gripper of the robot positions the workpiece using a measuring device for measuring a single elongation value attached to the gripper side in a state where the gripper of the important dimension side is gripped. .

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