JPS6027421A - Automatic bender for plate-shaped body - Google Patents

Abstract

PURPOSE:To force a gripper to follow up the spring-up of a plate-shaped material according to the ascension of a lower die and to bend exactly said material by forming a gripper which grips the plate-shaped body disposed at least in front of a bender having upper and lower dies in such a way that said gripper can be positioned around the horizontal shaft intersecting orthogonally with the perpendicular plane in the forward and backward direction of the bending machine. CONSTITUTION:The position of a gripper G is so controlled as to follow up the spring-up of a work piece according to the height (h) of a lower die 1c of a bender 1. Therefore bending load can be exerted to the work piece by raising the die 1c while the work piece is held gripped by the gripper G and the need for changing the gripping of the work piece with the gripper G is eliminated.

Description

[Detailed Description of the Invention] Field of the Invention The present invention relates to an automatic plate-shaped object folding device, and more specifically, a device for automatically folding a plate-shaped body, such as a press brake-type folding machine, which supplies a plate-shaped body such as an iron plate, bends it, and carries it out. , relating to a general-purpose automatic folding device.

Prior to the description of the prior art, press brake type bending machines and the like had been used to bend plate-shaped bodies such as iron plates, but all of these were controlled manually, resulting in very low work efficiency. It was bad and required a lot of workers.

Therefore, the present applicant has previously proposed an automatic folding device that is equipped with a robot that cooperates with a press brake type folding machine and can thereby automatically fold a plate-shaped body. Such a proposed automatic folding device is disclosed in, for example, Japanese Patent Application Laid-Open No. 180468/1983 published on October 9, 1979, and
80) Japanese Patent Application Laid-open No. 55-484 published on April 7th
No. 25, JP-A No. 55-54215 published on April 21, 1980, and
1980) Japanese Unexamined Patent Application Publication No. 1983, published on October 80th
-189121, etc. Especially in JP-A-5
No. 5-189121 discloses specific control of a robot.

These conventional automatic folding devices? In either case, when positioning a workpiece or a plate-shaped body with respect to a folding machine, the plate-shaped body is gripped and positioned by a gripper. However, as the upper die is lowered (or there are some models in which the lower die is raised), the end of the plate-like object springs up from the horizontal position, so the bending operation is performed while holding the plate-like object with the gripper. I couldn't do that.

Therefore, conventionally, the plate-shaped body is positioned and, for example, in 1, where the upper die comes into contact with the plate-shaped body, the plate-shaped body is gripped with a gripper.
After that, the gripper is released and the upper mold is further lowered to bend the plate-like body. Then, after bending, the plate-shaped body is gripped again at an appropriate position with the gripper, and the upper die is raised. The gripper then positions the sheet for further folding or releases it once the second fold is complete. In such conventional methods, it is necessary to release the gripper from the plate-like object or to change the grip to another position. However, depending on the type of plate-shaped object, plastic deformation or bending occurs during the bending operation, and therefore the position where the plate-like object is gripped again by the gripper becomes unclear and deviates from the initially gripped position. This will result in a product with an incorrectly bent shape, so it is preferable not to let go of the gripper or change its grip midway through the process.

OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide an improved automatic folding device for a plate-like object so that the folding operation can be performed while holding the plate-like object using grits.

SUMMARY OF THE INVENTION In the automatic folding device according to the present invention, the gripper has a bottom mold that is configured to be positionable in a vertical plane in the front-rear direction of the folding machine and around a horizontal axis perpendicular to the vertical plane. The end of the plate-like body is displaced (jumps up) as it rises. In order to make the gripper follow the displacement, the position of the grits is sequentially controlled based on the information on the ascending position of the lower die.

Effects of the Invention According to the present invention, there is no need to release the plate-shaped body using a gripper or change the grip during the bending operation, and the plate-shaped body can be held at a fixed position, so that the plate-shaped body can be bent easily. The shape can be made accurately.

The above objects and other objects and features of the invention will become more apparent from the following detailed description with reference to the drawings.

Embodiment 1 is a press brake type folding machine, which has columns 1a at both ends in the width direction (left and right direction).

The upper parts of both columns 1a are connected, and an upper mold 1b is attached to the lower surface thereof. A lower mold IC is supported between the lower parts of both columns 1a by a hydraulic cylinder (not shown) so as to be movable up and down in the H direction. The lower die IC is raised and lowered by a control device (not shown), and the upper die 1b and the lower die IC are prepared in a plurality of types, each having a different cutting edge shape and die groove. It may be configured such that any upper mold or lower mold can be selected. Ep is means (encoder) for generating information regarding the position of the lower IC in the H direction.

The PR is an industrial robot of a Cartesian coordinate system in this embodiment, which is arranged facing the front and rear of the folding machine 1 and has a pair of grippers G on each side. In addition, the robot PR uses grits (G) at least with the bending machine 1.
It can be positioned in a vertical plane in the front-rear direction and around a horizontal axis perpendicular to the vertical plane.

The configuration of the robot PR will be described below, but since the configuration is the same both before and after, the explanation of the later robot PR will be omitted and only the previous robot PR will be explained.

2 is a robot P fixed on the floor in front of the bending machine 1.
It is the foundation of R. Left and right rails 3.3 are installed on the base 2, and two Y-direction moving platforms 4 are installed on these rails 3.3.
They are mounted on a stand and are driven synchronously via a hydraulic motor M1 and a known reduction gear and transmission mechanism. El is
A position detector (encoder) is connected between each motor M and the speed reducer. Furthermore, a longitudinal rail 5.5 is installed on each moving platform 4, and an X-direction moving column 6 is mounted on each of these rails 5.5. and are driven synchronously. Company E, each motor M2
and a position detector (
encoder). Furthermore, each column 6 has a folding machine 1.
Lifting bodies 7 are supported on the side surfaces, respectively, and are driven synchronously (in two directions) via hydraulic motors M3 and known reduction gears and transmission mechanisms. E3 is each motor M
3, and a position detector (encoder) connected between the speed reducers and the speed reducers. Furthermore, each elevating body 7 is provided with a rotating body 8 that faces each other and is rotatable around the Y axis (α direction).
are each supported and driven synchronously via a hydraulic motor M4 and a known reduction gear and transmission mechanism.

E4 is a position detector (encoder) connected between each motor M4 and the speed reducer. Furthermore, each rotating body 8 is provided with a gripper G facing each other, and when the gripper G is opened and closed by a hydraulic cylinder Ga,
It is configured so that the left and right portions of the plate-shaped body 100 can be grasped.

Further, below each elevating body 7 of each column 6, a supporter support stand 9 is supported so as to be movable up and down, and each is driven via a hydraulic motor M6 and a known transmission mechanism. In this embodiment, the motor M6 is equipped with a two-position switching valve sV and two IJ valves RVl and RV2, as shown in FIG.
is piped between the hydraulic source P and the tank T. When the switching valve SV is in the left position as shown in FIG. 8, each motor M6 is rotated in a direction to raise each support stand 9,
An appropriate force is applied to push up each elevator platform 7 according to the set value of the relief valve RV1. Therefore, in this case, as each elevating body 7 moves up and down, each support stand 9 is also moved up and down while being integrated with each elevating body 7. On the other hand, when the switching valve SV is in the right position, each motor M6 is rotated in the direction of lowering each support stand 9, and after each support stand 9 reaches the lower end position, the load is applied according to the set value of the relief valve RV2. Each support stand 9 is configured to be stopped in a state in which the motor M6 is applied to each motor M6.

Furthermore, rails 10 and 10 in the Y direction are fixed to one of the support stands 9 (on the right side in FIG. 1), and these rails 10.
The middle portion of the support base 10 is slidably supported by the other support base 9. A supporter 11 of a plate-shaped body (workpiece) 100 is supported on the rails 1o and 10 between both support stands 9, and is connected to the i-direction (parallel to the Y-direction) via a hydraulic motor M5, a known reduction gear, and a transmission mechanism. ) driven. E5 is a position detector (encoder) connected between motor M5 and the reduction gear. Note that when the supporter 11 is in a state where the switching valve Sv is in the left position as shown in FIG.
Its height is set so that its upper end is located slightly below the height of the rotation center line of both rotating bodies 8.

C is a control device mainly composed of a CPU and a memo 'JMEM, and as shown in Fig. 7, the pass line BL is connected to a motor (including a motor M5 and an encoder E5), a motor M6, a cylinder Ga for opening and closing the gripper, etc. has been done.

Next, a model diagram (FIG. 2) of the folding process, which forms the theoretical basis of this invention, will be explained.

The tip of the upper mold 1b is formed as a circular arc having a radius (ru). The lower IC has a side portion forming a groove, and the top portion of the side portion that contacts the workpiece 100 has a radius (r
d) is formed in a circular arc shape. Let the distance from the center of curvature of this top part to the center of the mold groove be (w). The thickness of the workpiece 100 existing between the lower die Wlc and the upper die 1b is (1), and the workpiece 100 is bent into an arc shape having a predetermined radius of curvature (R) as the lower die IC rises. shall be taken as a thing. The center of curvature at the tip of the upper mold 1b and the lower mold 1c
The distance in the Z direction (height) between the center of curvature at the top of (h)
shall be. Information regarding this height h) is obtained from the encoder Ep shown in FIG. As the lower Wlc is raised, that is, as the height h) becomes smaller, the workpiece 100 jumps up from the horizontal state, and the angle of the jump is (θ).0 Assuming such a model, the following equation (1) is obtained. is obtained,
Subtracting R from equation (1) gives equation (2).

(R+h-ru)2+w2= (R+t+rd)2-・
-(1)R2+'2R(h-ru) + (h-ru)
2-hv2= R2+2R(t+rd) + (t+r
d)2 On the other hand, from equations (3) and (4) and equation (2), as shown in equation (5), the jump angle (θ) of the workpiece 100 is the height of the lower IC, expressed as a function.

(R+t+rd)sinθ=w ””・・・・・・
−(8)(R+ t +rd) cosθ= (R+ h
-ru) ””””””(4)θ=: tan-1(
, w/(R0h-ru) 1... (5) In a preferred embodiment of the invention, such a jump is 9
Focusing on the correlation between the angle (θ) and the height (h) of the lower IC, the gripper G is controlled to follow by utilizing the nine angle (θ). For this purpose, the above formula (5) and the necessary data (ru.

t, rd, etc.) are stored as a table in the memory MEM (FIG. 7).

Here, with reference to FIG. 8, position data (xi, zi) for follow-up control of the gripper G is determined.

In FIG. 3, the distance between the center of curvature of the top of the lower mold 1c and the center of rotation of the gripper G is (4).As shown in FIG. When it is bent by the same amount, point A moves to A. From this FIG.

zi) is given by equation (6).

zi-(-rd+(rd+H)cosθ14-4sin
θ −・−・(6) By substituting equation (5) into equation (6), this position (xi.

It is clear that each of zi) can be expressed as a function of the height h) (FIG. 2) of the lower mold 1c.

In this invention, the position of the center of rotation of the gripper G is sequentially calculated according to changes in the height of the lower die 1c, and the necessary angle and position of the control axis are calculated based on the calculated position information. , hydraulic motors such as M2+M3 and M4, thereby allowing the gripper to perform the bending operation while gripping the workpiece.

Furthermore, with reference to FIG. 4, the relationship between the (xi, zi) position in the coordinate system of the folding machine 1 calculated by equation (6) and the position in the coordinate system of the robot PR of this embodiment will be explained.

Center of rotation of gripper G (i.e. center of rotation of rotating body 8)
The position (xj) of the column 6 with respect to the movable table 4, the position (zj) of the elevating body 7 with respect to the column 6, and the rotation angle of the rotating body 8 ( β) are (7) and (8), respectively.
, is determined by equation (9). In addition, in Figure 4, 0
The point indicates the origin in the coordinates of the folding machine 1.

xj−2゜+xi ・(7) z j = z o+z i −−−(8) β=90−
θ ・・・・・・・・・(9) Note (xi), (zi)
, and (+9) can be determined from equation (6).

The positions of the column 6, the elevating body 7, and the rotating body 8 may be controlled as shown in equations (7), (8), and (9) above.

Next, the operation of this embodiment will be described based on the flowchart of FIG. 9 while referring to FIG. 5.6.

Now, the workpiece 100 is controlled by the motor M1~
It is assumed that the left and right portions have already been gripped by controlling M4 and cylinder Ga. Also, the switching valve Sv is the eighth
When it is in the left position as shown in the figure, a certain rising force is applied to the support base 9, and the upper end of the support base 9 is pressed against the lower surface of the elevating body 7, so that the two are in a state of being integrated. It is also assumed that the supporter 11 is positioned approximately at the center of the left and right columns 6.6. Therefore, the left-right center portion of the workpiece 100 gripped by the gripper G is prevented from being deflected by the supporter 11.

First, in step 5101, the CPU controls the motors M2 to M4 to position the workpiece 100 gripped by the grits G with respect to the folding machine 1 as shown by the solid line in FIG.

In the next step 5102, a command is output to set the counter K provided in the control device C0RAM to 1.

Furthermore, in step 5104, simultaneously with the command output in step 5103, a command is output to the servo system H8 to raise the lower mold IC at the above-mentioned constant speed.

Therefore, in the end, the elevating body 7, the support base 9, and the lower W 1 c are as follows.
Both will rise at the same time and at the same speed.

At this time, in step 5105, information corresponding to the height h) of the lower IC is taken into the CPU from the encoder Ep.

Then, in step 8106, based on this height h), it is determined whether the model car described in FIG. 2.8 is within the applicable range. Specifically, (h)≦(
ru+t+rd) or not, i.e. workpiece 10
The judgment is made based on whether or not the upper surface of the upper mold 1b has come into contact with the lower end of the upper mold 1b as shown by the two-dot chain line in FIG. The fact that (h) is larger than (ru+t+rd) means that the workpiece 100 is
Since the above-mentioned model cannot be applied because the object has not yet come into contact with the object, the process jumps directly to step 5IIO. If h)≦(ru ten to tenrd), then
Next step si.

In step 7, the CPU calculates the rotation center position (XjlZ'l) of the gripper G to be followed using equations (7) and (8). Furthermore, in step 5108, angle (5) of rotating body 8 is also calculated using equation (9).

Then, in step 5109, a command is output to the servo system %S to move the column 6 to the K' (xj) position, and a command is output to the servo system %S to move the elevating body 7 to the (zz) position. A command is output, and further a command is output to the servo system αS to rotate the rotating body 8 at the correct angle.

By following the point at which the workpiece 100 is gripped in this way, the gripper G moves to the workpiece 1.
00 can be bent while holding the workpiece 100.The CPU then returns to step 5110.
At , it is determined whether the lower mold 1c has reached the target position %k or not.

This can be determined by looking at the information from the servo system H8. If the position has not been reached in %, judge whether it has been reached or not. This can be determined by checking whether the content k of a counter provided in the RAM of the control device C is the number required for one bending operation. If the lower IC has not yet reached the final target position,
In step 5112, the CPU increments a counter k in RAM. Then, proceed to step 5104.

If the lower mold 1c has reached the final target position, the workpiece 100 has been completely bent as shown in FIG.
A stop command is output to s.

If it is detected in step 5114 that the lower mold 1c has stopped, the CPU executes the subsequent steps 8115 to 118, and returns the lower mold 1c to its initial position, that is, the lower end position.

In this way, follow-up control of the rotation center of the gripper G is achieved.

Note that once the first bending is completed, workpiece 10
Workpiece 1 with gripper G holding 0
Since the deflection of 00 will be reduced, if the deflection does not have a negative effect on the bending, when bending for the second and subsequent times, switch the switching valve Sv to the right position to move the supporter 11 away from the support base. 9 should be lowered to the lower end position.

The above description is just an example; for example, in the case of Robot PR, either the front or rear of the folding machine 1 may be discontinued. Further, the robot PR may be a mobile platform 4.4 equipped with a polar coordinate system or an articulated coordinate system. In this case, the rotation center position (xi,
zi) may be determined as the position of each control axis not in rectangular coordinates as shown in FIG. 4, but in polar coordinates or articulated coordinates of the robot.

Although this invention uses a folding machine 1 in which the upper die 1b is fixed and the lower die IC moves up and down, it is easily possible to combine the robot PR with a folding machine in which the upper die and the lower die move up and down together. Will.

As described above, this invention is designed to control the position of the gripper G so that the jump of the workpiece 100 follows the jump of the workpiece 100 according to the height of the lower die 1c of the bending machine 1. Therefore, the workpiece 100 can be gripped by the gripper G and bent by -1:. In other words, gripper G grips workpiece 100.
While holding the , work piece 100 with the lower IC.
A bending load can be applied to the Therefore, there is no need to change the grip of the workpiece 100 using the gripper G as in the conventional case, and the control is simple.

Moreover, the workpiece can be bent very accurately.

[Brief explanation of the drawing]

The figures all show one embodiment of the invention apparatus, with Figure 1 being a partially omitted overall perspective view, Figure 2 being a model showing the relationship between the upper mold, lower mold and workpiece during the bending operation, and Figure 3 is a model for determining the position to be controlled by the gripper in a folding and bending machine, Fig. 4 is a model for obtaining data necessary for controlling an industrial robot, Fig. 5.6 is an explanatory diagram of the folding process, FIG. 7 is a block diagram of the control device, FIG. 8 is a hydraulic circuit diagram, and FIG. 9 is a flowchart for explaining the operation. In the figure, 1... bending machine, 1b... upper die, I
C...lower die, PR...industrial robot, G...gripper, 100...plate-shaped body (workpiece), M2
+M3+M4...each is a hydraulic motor. Applicant ShinMaywa Industries Co., Ltd.

Claims (2)

[Claims] (1) A folding machine having a lower die and an upper die for folding a plate-shaped body, and a gripper disposed at least in front of the folding machine to grip the plate-shaped body, the gripper being a part of the folding machine. It can be positioned in a vertical plane in the front-rear direction and around a horizontal axis perpendicular to the vertical plane, and the portion of the plate-shaped body gripped by the gripper springs up as the lower die rises, and A plate-like object automatic bending device, comprising means for calculating a follow-up position of the gripper with respect to the jumping-up of the plate-like object, and means for controlling the position of the gripper according to the calculation result. (2) means for generating information regarding the position of the lower mold, the calculating means comprising: means for calculating a spring-up angle of the plate-like body from the information regarding the position of the lower mold; 2. The automatic folding device for a plate-like object according to claim 1, further comprising means for calculating necessary control elements from nine corners of the folded body.