JPH02142619A - Press brake - Google Patents

Abstract

PURPOSE:To automatically correct a folding angle of a work by operating the driving-in amount of a depth based on the folded angle of the work, obtaining an amount of crowning and a correction value for the depth based on this operation and determining an amount of correction for a balance between the right and the left based on the driving-in amount and the correction value of the depth. CONSTITUTION:The work is folded by an upper die 86 and a lower die 6. The driving-in amount of the depth at a prescribed position of the work based on the folded angle of the work measured by a folding angle measuring device is obtained by a folding shape arithmetic part. The amount of crowning and the correction value of the depth are obtained by an arithmetic part for correcting the crowning and an arithmetic part for correcting the depth based on the driving in amount of the depth. The correction value for the balance between the right and the left is obtained by an arithmetic part for correcting the balance between the right and the left based on the drivig-in amount and the correction value of the depth. By this method, the folding angle of the work can be corrected automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a press brake that can efficiently correct the bending angle of a bent workpiece without manual intervention.

(b), Prior Art Conventionally, in a press brake, in order to bend a workpiece, the workpiece to be processed is inserted between a lower mold and an upper mold. Next, in this state, data necessary for processing (for example, workpiece material, plate thickness, bending angle, bending width, etc.) is input into the numerical control device of the press brake. Then, the numerical control device lowers the upper mold toward the workpiece, and performs a predetermined folding/bending process by sandwiching the workpiece between the upper mold and the lower mold.

After the workpiece has been bent in this way, the workpiece is temporarily removed from the press brake.

Next, use a bending angle measuring device to check whether the bent portion of the removed workpiece is at the set bending angle or not at any position on the workpiece (for example, both ends and the center of the workpiece). measure. If the measured bending angle differs from the set value, the operator corrects the measured value to match the set value.

(C) Problems that the invention attempts to solveHowever, since such correction work often relies on the experience of the operator,
If the operator is not skilled, it is difficult to determine the appropriate correctability at once, and the work is troublesome and time-consuming.

In view of the above circumstances, it is an object of the present invention to provide a press brake that can efficiently correct the bending angle of a bent workpiece without manual intervention.

(d) Means for Solving Problem 1, ie 1 The present invention provides a bending angle measuring device (61) for measuring the bending angle (θ) of the workpiece, and a lower mold (
A crowning device (7) is provided for crowning the workpiece (25) (PL, P2, P3) based on the bending angle (θ) obtained using the bending angle measuring device (61). Depth reduction amount (d
, , d2, dZ) (95)
and a crowning correction calculation unit (9) that calculates the crowning amount based on the depth reduction amount (dl, d2, d,) determined in the bending shape calculation unit (95).
7) and a depth correction calculation unit (100) for calculating the depth correction value (d knee y work), and furthermore, a depth correction calculation unit (100) for calculating the depth correction value (d knee y
d2, d,) and the depth correction calculation unit (100)
A left-right balance correction calculating section (102) is provided to obtain left-right balance correction values (ΔDL, ΔDR) based on the depth correction value (dx-yx) obtained in .

Note that the numbers in parentheses are for convenience and indicate corresponding elements in one drawing, and therefore, this description is not limited to the description on the drawing. r (e) below
The same applies to the column ``, action''.

(C) 0 action Workpiece (25) bent with the above configuration
is inserted between the lower mold (6) and the upper mold (86), the bending angle (θ) of the workpiece (25) is measured by the bending angle measuring device (61), and the measured bending angle ( Based on θ).

The bending shape calculation unit (95) calculates the depth reduction amount (d-work, d2, di) at a predetermined position (PL, P2, P3) of the workpiece (25). Then, the crowning correction calculation unit (97) calculates the crowning amount, the depth correction calculation unit (100) calculates the depth correction value, and the left-right balance correction calculation unit (102) calculates the left-right balance correction value. The correction value is determined and the workpiece is processed based on the determined correction value.

(f), Example An embodiment of the present invention will be described below based on the drawings.

Fig. 1 is a diagram showing the main parts of the press brake according to the present invention, Fig. 2 is a diagram showing an example of the lower mold part of the press brake shown in Fig. 1, and Fig. 3 is a diagram showing the lower part of the press brake shown in Fig. 2. FIG. 4 is a diagram showing the positional relationship between the mold part and the bending angle meter sub-device, and FIG. 4 is a diagram showing an example of the lower mold of the lower mold part shown in FIG. 2.

Figure 5 shows an example of a workpiece processed using the press brake shown in Figure 1. Figure 6 shows a bending angle measuring device after bending the workpiece using the press brake shown in Figure 1. 7 is a diagram showing an example of a numerical control device for the press brake shown in FIG. 1, and FIG. 8 is a crowning device for the press brake shown in FIG. 1. Figure 9 shows the workpiece bent using the press brake shown in Figure 1. The figure which shows the depth drive amount of.

FIG. 10 is a diagram showing the amount of deflection at a predetermined measurement position of the lower mold shown in FIG. 8.

FIG. 11 shows a workpiece that has been bent using the press brake shown in FIG. 1 at a predetermined measurement position. FIG. 12 is a diagram showing the amount of depth reduction, and is a diagram showing the left-right balance correction value at a predetermined measurement position of a workpiece to be bent using the press brake shown in FIG. 1.

As shown in FIG. 1, the press brake 1 has a lower frame 1A, and a mounting surface 1b is formed at the upper part of the lower frame 1A. A lower mold part 2 is mounted on the mounting surface 1b, and the lower mold part 2 is connected to the main body 3. as shown in FIG. It is composed of a lower mold support member 5, a lower mold 6, and the like. That is.

On the mounting surface 1b shown in FIG. 2, a main body 3 extends horizontally in the directions of arrows A and B, and mold supports 3a and 3b are provided at the left and right ends of the main body 3 in the figure. They are formed in opposite shapes.

A lower mold support member 5 is attached between the mold support parts 3a and 3b of the main body 3 shown in FIG. The other end 5a is pivotally attached via a support pin 3g or the like. Further, an elongated hole 5c is bored in the right end 5b of the lower mold support member 5 in the figure, with its longitudinal direction parallel to the directions of arrows A and B. In this case, a support pin 3h provided on the mold support portion 3b is fitted in a slidable manner. Furthermore, as shown in FIG. 3, a support groove 5f is formed in the upper side surface 5e of the lower mold support member 5 in a manner extending in the directions of arrows A and B. A plurality of unit lower molds 6A constituting the mold 6 are installed at a predetermined interval L2.

As shown in FIG. 4, each unit lower mold 6A is formed with a length Ll in the direction of arrows A and B, respectively.
There is a gap between each end 6d and 6e of the adjacent unit lower molds 6A and 6A, respectively. An I constant opening MC is formed.

In addition, each end 6d, 6e has a notch 6f,
6f is recessed into the unit lower mold 6A by a depth L3, and furthermore, on the upper surface 6b of each unit lower mold 6A,
As shown in FIG. 6, Vi16c is formed at an angle θ'.

By the way, the lower mold part 2 is provided with a crowning device 7, as shown in FIG. The mating mechanism 9 is composed of a pressing engaging body 9A, a pressing block 12, etc., and a plurality of pressing engaging bodies 9A (in this embodiment, five pieces) are attached to the lower side surface 5d of the lower mold support member 5 in the figure. ) is formed by connecting wedge members 10 in series in the directions of arrows A and B. On the lower surface of each wedge member 10 shown in FIG. 2, an engagement slope LOa is formed in a shape that is inclined diagonally downward to the right in the figure by a predetermined angle α with respect to the directions of arrows A and B. The engagement body 9A is formed with an engagement surface 9b that connects the engagement slopes 10a of each wedge member 10.

Further, on the bottom surface 3C of the main body 3 of the lower mold part 2, as shown in FIG. , are provided in a form that can be moved in the directions of arrows A and B, and an engagement slope L2a is provided on the upper part of each suppression block 12, respectively.
A predetermined angle α diagonally downward to the right in the figure with respect to the directions of arrows A and B.
It is formed in a tilted shape. In addition, each engagement slope 12a
are in slidable contact with the engagement slopes 10a of the wedge members 10 forming a pair, respectively.

Furthermore, each of the pressing blocks 12 shown in FIG.
A clamp hole 17 is provided in each case in a direction perpendicular to the plane of the drawing. In addition, in the side surface 3d of the main body 3 of the lower mold part 2, a plurality of clamp holes 3e are provided, which are similar to the aforementioned clamp holes 17.
They are provided at predetermined intervals in the directions of arrows A and B in a manner that corresponds to the direction of arrows A and B. Note that each pressing block 12 is provided with a solenoid 26 in a form that can be aligned with the clamp hole 3e.

Each clamp pin 22 is provided in such a manner that it can be freely driven to protrude and retreat through the clamp hole 17 in a direction perpendicular to the paper plane in FIG.

Further, as shown in FIG. 2, the pressing engagement mechanism 9 is connected to a pressing drive mechanism 11, and the pressing driving mechanism 11 has a pressing rod 13 and a drive motor 19v. That is, a press rod 13 is provided in the lower mold part 2 in a manner that it can move freely in the directions of arrows A and B through the stepped hole 12b of each press block 12. stopper 15
are provided at predetermined intervals in the directions of arrows A and B. A spring 16 is provided between each stopper 15 and the stepped hole 12b of each suppression block 12 so as to surround the pressing rod 13, and at the right end of the pressing rod 13 in the figure.
A drive motor 19 is connected via a motion conversion device 20 . The drive motor 19 includes a rotary encoder 19.
A crowning device drive control section 96 shown in FIG. 7, which will be described later, is connected to the drive motor 19 and rotary encoder 19a.

By the way, as shown in FIG. 3, on the side surface 3j of the main body 3 of the lower mold part 2, a guide rail 60 is provided extending in the directions of arrows A and B. (three in this embodiment) bending angle measuring devices 6
1 are mounted so that they can move in the directions of arrows A and B independently of each other. Each bending angle measuring device 61 has a main body 62, and each main body 62 is provided with an arm support portion 63 that can be freely moved and driven in the directions of arrows C and D, which are the up and down directions in FIG. . An arm 65 is provided on the arm support portion 63 so as to be freely protrusive and retractable in the directions of arrows E and F.
As shown in the figure, a probe section 66 is provided.

The probe section 66 shown in FIG.
It has 67, 69, 70, 71 etc. probes,
At the upper part of the tip 65a of the arm 65 in the figure, there is a probe 6.
7 is provided in such a manner that it can be freely moved and driven in the directions of arrows C and D with respect to a probe 69, which will be described later. At the tip of the probe 67.

A work contact portion 67a is formed to protrude in the direction of arrow C, and a probe 69 that is paired with the probe 67 is located below the probe 67 in the figure, and is movable in the directions of arrows C and D. It is set in the form. At the tip of the probe 69, a workpiece contact portion 69a protrudes in the direction of arrow C.
and arrow E from the workpiece contacting part 67a of the probe 67.
It is formed in a shape that protrudes by a set distance H2 in the direction,
Further, below the probe 69 in the figure, a probe 70 is provided.
It is provided so that it can be moved and driven in directions of arrows C and D with respect to a probe 71 that will be described later.

A workpiece contacting portion 7Oa protrudes from the tip of the probe 70 in the direction of arrow C, and the workpiece contacting portion 6 of the probe 69
The probe 9a is formed to protrude by a predetermined distance in the direction of the arrow E, and further, a probe 71 to be paired with the probe 70 is provided below the probe 70 in the figure.

A workpiece contacting portion 71a protrudes in the direction of arrow C at the tip of the probe 71, and a workpiece contacting portion 71a of the probe 70
The probes 67 and 70 are formed to protrude by a set distance H1 in the direction of the arrow E from the probe 0a, and the probes 67 and 70 are each biased in the direction of the arrow C through elastic means such as springs (not shown). has been done.

A probe displacement detection section 72 is connected to the probe section 66 shown in FIG. 6, and the probe displacement detection section 72 includes two differential transformers 73a and 73b and a detection control section 7.
It has a rank of 5. That is, the probe 6 of the probe section 66
Differential transformers 73a and 73b are connected to the probe 7.69 and the probe 70.71, respectively.
3a and 73b are connected to variable positions 76a and 76b that constitute the detection control section 75, respectively. displacement meter 76a,
Pulse generators 77a and 77b constituting the detection control section 75 are connected to the pulse generator 76b, respectively.
7a and 77b are connected to a bending shape calculating section 95 shown in FIG. 7, which will be described later.

On the other hand, an upper mold part 8 is located above the lower mold part 2 shown in FIG.
1 is provided, and the upper mold part 81 is connected to the upper frame LB.
, Q moving cylinder 82, 83, ram 85, and upper mold 86
etc. That is, two drive cylinders 82.83 are provided on the upper frame IB at a predetermined distance apart in the directions of arrows A and B.
3, rods 82a and 83a are respectively indicated by arrows C and D.
It is installed so that it can be moved in any direction. Note that the drive cylinders 82 and 83 have respective rods 82a and 83a.
A movement amount adjustment device (not shown) capable of adjusting the movement stroke in the directions of arrows C and D is connected to the movement amount adjustment device, and the movement amount adjustment device includes an upper mold drive control section 101 shown in FIG.
is connected.

Further, a ram 85 is provided between the drive cylinders 82 and 83, with its left and right ends supported by rods 82a and 83a, and an upper mold 86 is provided at the lower end of the ram 85 in the figure. It is installed.

Furthermore, the press brake 1 has a numerical control device 89, as shown in FIG. 7, and the numerical control device 89 has a main control section 90. The main control unit 9o has a bus XIA9
1, keyboard 92, display 93. Bending shape calculation section 95. Crowning device drive control section 96
．． Crowning correction calculation unit 971 Bending angle meter side control unit 9
9. Depth correction calculation section 100, upper mold drive control section 101
, left-right balance correction calculation section 102. Processing data memory 1
03 etc. are connected.

Since the press brake 1 has the above configuration,
In order to bend a workpiece 25 having a thickness t shown in FIG. 5 at a predetermined angle using this press brake 1, the bending portion 25a of the workpiece 25 is positioned on the lower mold 6 shown in FIG. It is inserted and supported between the lower mold 6 and the upper mold 86 in such a manner. Next, the worker determines the material of the workpiece 25,
Plate thickness t, set bending angle θ. 9 Processing data D such as bending width
The AT is stored in the processed data memory 103 via the keyboard 92 shown in FIG. Furthermore, the worker
The machining start command D1 is sent to the main control unit 9 via the keyboard 92.
Output to o.

Then, in response to this, the main control section 9o instructs the upper mold drive control section 101 shown in FIG. 7 to lower the upper mold 86 shown in FIG. 1 by a predetermined distance in the direction of the arrow. .

In response to this, the upper mold drive control unit 101 synchronously drives the drive cylinders 82.83 via a movement amount adjustment device (not shown) to move each rod 82a, 83a a predetermined distance S1.52 ( = S1) in the direction of the arrow. Then, the ram 85, together with the upper mold 86,
2a and 83a, it descends in the direction of the arrow from the position indicated by the imaginary line in Figure 1, and the tip 86a of the upper mold 86 comes into contact with the work 25.
direction, and presses the workpiece 25 against the V-groove 6c of the lower mold 6 with a predetermined pressing force. As a result, work 2
The number 5 is folded into a figure 7 shape.

When the workpiece 25 has been bent in this way,
A plurality of bending angle measuring devices 6 shown in FIG.
1, each measurement part 25 of the workpiece 25 shown in FIG.
The angles θ0, θ2 .h, 25i, 25j. Measure θ. That is, after the bending process is completed, the main control section 90 shown in FIG. 7 first causes the upper mold drive control section 101 to position the upper mold 86 shown in FIG. A command is given to release the pressing relationship with the mold 6. Then, the upper mold drive control unit 101 drives the drive cylinders 82 and 83 shown in FIG. 1 to move the respective rods 82a and 83a backward by a predetermined distance in the direction of arrow C. Then, the ram 85, together with the upper mold 86,
With the tip 86a of the upper mold 86 in contact with the bent portion 25a of the workpiece 25 shown in FIG.
The tip 86 of the upper mold 86 is raised by a predetermined distance in the direction
a is positioned at the standby position WPI shown in FIG.

At this time, the part 25a to the right of the bent part 25a in the figure is heavier than the part 25f to the left of the bent part 25a, so the entire work 25 is biased in the direction of arrow G by the weight of the right part 25e. in the form of
While being supported by the tip 86a of the upper mold 86 and the right upper edge 6g of the groove 6c, it rotates in the direction of arrow G and leaves the groove 6c. Then, the workpiece 25 springs back, and its bending angle θ is changed by the bending angle θ of the lower mold 6 by the upper mold 86.
The angle when being pressed against the groove 6c (i.e., V t
angle θ′) of ut 6 c.

Next, the main control section 90 shown in FIG. 7 causes the bending angle measurement control section 99 to control the workpiece measurement positions P1, P2, and
The folded part of the workpiece 25 shown in FIG. 5 corresponding to 3 (
That is, the measurement site 25h.

25i, 25j), the zero bending angle measurement control unit 99 instructs to measure the bending angles θ1, θ2, and θ3 of the bending angles θ1, θ2, and θ3. The arm support portions 63 are appropriately moved in the directions of arrows C and D together with the arms 65, and each arm 65 is caused to protrude in the direction of the arrow E together with the probe portion 66 shown in FIG. 6, respectively. Then, the tip 65a of each arm 65
and the probe portion 66 are inserted into the measurement gap MC, respectively, and the probe 66 is positioned below the measurement portions 25h, 25i, and 25j of the workpiece 25 to be measured. At this time, each measurement gap MC has a width of L4 (=L2+2) due to the notch 7.7, as shown in FIG.
・L3), and the width L4 is larger than @L5 of the arm 65 in the direction of arrows A and B shown in FIG. 3, so the arm 65 etc. may collide with the lower mold 6 etc. Never.

Next, the bending angle measurement control section 99 shown in FIG. 7 controls the arm support section 63 of each bending angle measurement device 61 shown in FIG.
It is raised together with each arm 65 in the direction of arrow C.

Then, the probe portion 66 provided at the tip 65a of each arm 65 shown in FIG. 6 also rises in the direction of arrow C in FIG.
7a, 69a come into contact with the right side portion 25e of each measurement site 25h, 25i, 25j of the workpiece 25 shown in FIG. 6, and further press the right side portion 25g in the direction of arrow C with a predetermined pressure. Further, each workpiece contact portion 70a, 71a of the probe 70°71 is connected to each measurement portion 25h of the workpiece 25.
, 25i, 25j, and further presses the portion 25f in the direction of arrow C with a predetermined pressure.

At this time, as shown in FIG. 6, the workpiece 25 is supported by the tip 86a of the upper mold 86 and the upper right edge 6g of the V-groove 6c of the lower mold 6. Even if the probe 67 of the bending angle measuring device 61 or the like presses the workpiece 25 in the direction of arrow C.

The workpiece 25 moves in the directions of arrows C and D, etc., and the lower mold 6
There is no chance of it falling off.

In this way, the probe section 66 of each bending angle measuring device 61 can measure the measurement portions 25h, 251, . . . of the workpiece 25 shown in FIG.
25j, the bending angle measurement control section 99 shown in FIG. 7 activates the probe displacement detection section 72 shown in FIG. 6. Then, the differential transformer 73a of each probe displacement detection section 72 outputs a voltage v1 corresponding to the relative displacement of each workpiece contacting section 67a, 69a of the probe 67, 69 in the directions of arrows C and D to the displacement meter 76a. do. Further, the differential transformer 73b of each probe displacement detection section 72 is
A voltage v2 corresponding to the relative displacement of the probes 70 and 71 in the directions of arrows C and D is outputted to the displacement meter 76b, respectively. Then, each displacement meter 76a, 76b has voltage Vl, V, respectively.
2 (i.e., the distance HD 2, D shown in FIG.
The amount of displacement corresponding to the distance is calculated. Further, each displacement meter 76a, 76b has a pulse generator 77, respectively.
a, 77b, a pulse Ps corresponding to the determined displacement amount
i, PS2 are output to the folded shape calculation section 95 shown in FIG. In response to this, the bending shape calculation unit 95
Measurement parts 25h, 25i, 2 of the workpiece 25 shown in FIG.
Each bending angle θ0.02.0 at 5j. The following formula + f)
Seek more.

θ=θL+02=arctan(H1/D,)+
arctan (H, /Dz) + f ・+・■ (Here, θ1 and θ2 are the centers C and L of the lower mold 6 shown in FIG. This is the angle formed between CL and the right side portion 25a of the work 25.

Further, Hyu and H2 are respective set distances in the directions of arrows E and F of each workpiece contacting portion 70a, 71a of probe 70.71 and each workpiece contacting portion 67a, 69a of probe 67.69.

Furthermore, E is a correction value. ) The bending angles θ1, θ2, θ thus obtained.

is output from the bending shape calculating section 95 shown in FIG. 7 to the processing data memory 103 and stored in the memory 103. In addition, the determined bending angle θ, θ2, θ, is
Set value θ as described below. If it is different from the above, the angle 01 etc. is the set value θ. Do the work to correct it.

For example, when the thickness t of the workpiece 25 is large, the upper mold 86 is recessed upward when the workpiece 25 is pressurized, as shown in FIG. bend. Then, compared to the other measurement parts 25h and 25j, the measurement part 25i of the workpiece 25 shown in FIG. , measurement part 2 of workpiece 25
The bending angle θ2 of 5i is larger than the bending angles θ2 of the other measurement parts 25h and 25j.

Therefore, the numerical control device 89 shown in FIG.

All of the bending angles θ□, θ2, and θ3 of the workpiece 25 are set values θ. In other words, the main control unit 9o of the numerical control bag M89 first performs crowning correction, depth correction, and left-right balance correction, which will be described later, so that the workpiece 25 is equal to
A depth calculation command D5 is output to the bending shape calculation unit 95 so as to obtain the depth amounts ΔD, ΔD2, and ΔD shown in FIG. 9 at the measurement sites 25h and 251.25j. Here, the depth amount ΔD means that the bent portion 25 of the bent workpiece 25 is
between the upper surface 6b of the lower mold 6 and the bent portion 25a of the workpiece 25 when the lower mold 6 is supported by the upper edges 6h and 6g of the lower mold 6 in such a manner that a is positioned at the center CL of the lower mold 6. This is the distance in the directions of arrows C and D.

The bending shape calculation section 95 shown in FIG. 7 receives the depth amount calculation command D5, and calculates the positional relationship between the groove 6c of the lower mold 6 shown in FIG. Bending angles θ0, θ2, θ.

Based on the above, each depth amount ΔD0, ΔD2, and ΔD3 is determined. That is, △D□= (V/2) ・1 /jan(θ, /
2)-=・■ΔD2=(V/2)・l/1an(θ
2/ 2)”’ ”’■ΔD, = (V/2)・l/1a
n(θ, /2)・・・・・・■(Here, ■ is the lower mold 6
This is the distance between the upper edges 6g and 6h of the V-groove 6c in the directions of arrows A and B. ) Further, the bending shape calculating section 95 shown in FIG. 7 calculates the calculated ΔD1. ΔD2. ΔD, is calculated by the crowning correction calculation unit 9
Output to 7. Then, the crowning correction calculation unit 97 calculates each of the determined depth amounts ΔD□, ΔD2. From ΔD, the set angle θ of the workpiece 25. The value obtained by subtracting the depth amount ΔD corresponding to , that is, the depth drive amount d□, d2, and d3 is calculated. That is, d□=ΔD yo -ΔD.

=(V/2)・(1/1an(θl/ 2 E 1 /
1an(θ./2))...(■ d, = ΔD, -ΔD0 = (V/2)・(1/1an(θ□/2)-1/1
an(θfi/2))...-■ In this way, when each depth ID, d2, d, is obtained, the reference point S of the workpiece 25 shown in FIG.
When the value of the depth push-in amount changes linearly from dl to d as you go from P in the direction of arrow B, find the further necessary push-in amount at measurement position P2, that is, the amount to be corrected by crowning correction. (Note that crowning means bending the lower mold 6 in such a way that it protrudes toward the upper mold 86.) Therefore, the main control section 90 shown in FIG.
A command is given to obtain the crowning correction amount Δda shown in the figure. Here, the crowning correction amount Δdc is the 11th
Assuming that the depth reduction amount d between the measurement positions P1 and 23 of the workpiece 25 shown in the figure changes linearly, the virtual depth reduction id,' at the measurement position P2 and the measurement position obtained by the bending shape calculation unit 95. It means the deviation from the depth drive amount d2 at P2.

Here, the measurement positions of the workpiece 25 shown in FIG. 11 @P1, P
3, and the virtual depth depth d 2+ at the measurement position P2, and the distances of the measurement positions P1, P2, and P3 from the reference point sp, that is, Qo, (121+92), (Q From +Q, +Il,), (d, -d): (Lll,) = (d2' - d,):
Q2 = Δdc work: Q2 (However, Δdc work = (d, '-d□)) Transforming the above formula, Δdc work = (nz (da d work)) / (xz + x,)
holds true. Therefore, the crowning correction amount Δdc is as follows: Δdc=d2−Δdc1−d.

=di-(Q2・(d,-d1)/(9,2+Q
3))-d.

becomes.

Next, the amount of displacement y of the lower mold 6 in the direction of arrow C1D that occurs during processing is determined at each measurement position PL, P2, and P3. That is, assuming that the distributed load in the press operation is W, the modulus of longitudinal elasticity is E, the moment of inertia of the lower die is E, and the bending width of the workpiece is L, the amount of displacement at each position is given by the following equation. That is, y,=<W/C2,4-E-1))・Q,-(
Q□-2・L・Q 2 + L 3) yz=(w/(24・E・I))・(Qyo+Q2)'
((”t+uz)3-2・L・(0□10Q2)2+L3
))ya=(w/(24・E・I)E(12x+
Qz + nz)・((ffyo+Q2+Q,)3−2・
L・(12, +Q.

+ a 3) 2+ LJ)) Therefore, at position P2, if the displacement is.

If the amount of displacement between positions P1 and 23 is assumed to change linearly from y to y is Vz', then the actual position P
The deviation from the displacement amount y2 at 2 is the crowning amount Δyc
If adopted as , the crowning amount Δyc corresponds to the crowning correction amount Δdc.

That is, in Fig. 10, ΔyC=3'z Qz Also, Cyz'-y□): (ya-y□)=2□=(12□+
pa)'/2'-'/ENG: (Q2・(ya-y,)
)/(12z+base,)”/z”((Ax・(ys−y 工))/(L+ρ,)+y□Substitute into the above formula.

Δ'I C"yz-)'z':)'z-(Qz・(ys-y 工))/(Q2+ Q:
+)-y engineering.

Therefore, the distributed load W such that Δdc=Δyc is determined from the above equation. The distributed load W of the crowning device 2 is
This is because it is proportional to the amount of movement flc of the suppression block 12 in the directions of arrows A and B shown in FIG.

The movement mQc=-wc (where K is a proportionality constant) is the crowning correction value.

After the crowning correction value Qc has been determined in this way, the main control section 90 shown in FIG. 7 outputs a crowning correction value command to the crowning device drive control section 96. In response to this, the crowning device drive control section 96 rotates the drive motor 19 shown in FIG. 8 by a predetermined amount in the direction of arrow F. Then, the drive motor 19 converts the motion converter 20
, the press rod 13 is pulled in the direction of arrow B by a distance corresponding to the amount of rotation of the drive motor 19. Then, the press rod 13
moves in the direction of arrow B in the stepped hole 12b of each suppression block 12 by the crowning correction value QC while compressing each spring 16 via each stopper 15. At this time, the rotation amount of the drive motor 19 is determined by the rotary encoder 1.
9a, and the moving distance of the press rod 13 is detected based on the measured rotation amount.
can be moved exactly by a preset distance.

In this way, when the pressing rod 13 moves a predetermined distance in the direction of arrow B in FIG. While bringing the engagement slope 12a into sliding contact with the engagement slope 10a of each wedge member 1o, it moves a predetermined distance in the direction of arrow B from the predetermined position X2, X, X+, X. Then, each engagement slope 10a is
, since it is tilted diagonally downward to the right in the figure with respect to the B direction,
An upward pressing force is applied to each wedge member 10 from the suppression block 12 via the engagement slope 10a. Then, the lower mold support member 5 is pushed upward via each wedge member 1o, and as shown in FIG. 8, it bends in the form of protruding upward in the figure. Therefore, the upper surface 6b of the lower mold 6 also
As shown in the figure, it is bent upward in the figure,
Crowned.

Note that when the workpiece 25 is bent with the lower die 6 crowned in this manner, the bending depth of the workpiece is deeply corrected by 660 minutes at the measurement position P2 of the workpiece 25 shown in FIG.
, P3, the workpiece 25 can be properly machined. To do this, the following depth correction is performed, and the depth amount at position iP1 is first corrected to ΔD0.

That is, the depth drive amount at one position P1 is the lower mold 6
Due to the crowning, it becomes (d knee y yo). Next, the main control section 90 shown in FIG.
0 plus the crowning of the lower mold 6 is commanded. Then, the depth correction calculation section 1
00 is a depth correction value such that the depth amount at the measurement position P1 of the workpiece 25 shown in FIG.
Output to 1. In response to this, the upper mold drive control unit 101 controls the rods 82a and 83a of the drive cylinders 82 and 83 shown in FIG. The movement stroke S1 in the direction of the arrow is calculated by the depth correction value (d□−yz)
Adjust it so that it is longer. Note that when the workpiece 25 is bent with the depth corrected in this manner, an appropriate depth amount ΔD0 can be obtained at position P1, but the depth amount at position 2P3 is not ΔDo. Therefore, in order to obtain the appropriate depth ΔD in the first place ff1P, at the measurement position P3, ((ctx-ya)-
(d knee y□)) An additional depth reduction amount corresponding to (d knee y □)) is required.

Therefore, the main control unit 9o shown in FIG. 7 instructs the left-right balance correction calculation unit 102 to obtain a left-right balance correction value in order to set the depth amount at position P3 to ΔD0. In response to this, the left-right balance correction calculation unit 102 determines that the workpiece 25 shown in FIG. 1 has a depth reduction amount<(d3
The attitude of the upper mold 86 is adjusted so that it is displaced by -y3)-(d knee y□)). Here, crowning correction,
As shown in FIG. 12, the following equation holds true based on the depth drive amounts at the measurement positions P1 and P3 after depth correction.

ΔDR: (Q2+Q3+24)” [(d3-y3)-(ct i-y□)]:
CQZ+23) Therefore, ΔDR=(n□+ρ3+l14)・((d−y3)−(
dyo - yyo))/(Q2+Q,) ΔDL:Q□=((d,=y,)+(dnee y□)):
(Qz”xa) Therefore, ΔDL=Q・((d3− y z)−(d, + y
i))/(Q2÷Q3) Here, ΔDL is the amount of depth driven in at the standard position SP of the workpiece 25 shown in FIG. 1, and ΔDR is the standard position SP
This is the amount of depth reduction at a position further away by a distance f%iL in the direction of arrow B.

Note that the left-right balance correction calculation unit 102 shown in FIG.
The obtained ΔDR1ΔDL is output to the upper mold drive control unit lot as a left-right balance correction value. Then, when processing the workpiece 25, the upper mold drive control unit 101 adjusts the movement strokes S1 and S2 of the rods 82a and 83a of the drive cylinders 82 and 83 shown in FIG. By lowering the mold 86 toward the lower mold 6, the workpiece 25 has a length ΔD in the direction of the arrow at the reference position SP.
Pressure is applied in a manner in which the pressure is varied by a length ΔDR in the direction of the arrow at a position that is a distance away from the reference position sp in the direction of the arrow B.

In this way, by performing crowning correction, depth correction, and further right-left balance correction, the workpiece 25 is machined over its entire length so that the depth amount ΔD is obtained, and the bending angle θ of the bent portion 25a is equal to the total length of the workpiece. Set value θ. It is corrected so that

(g) 0 Effects of the Invention As described above, according to the present invention, the bending angle measuring device 61 for measuring the bending angle such as the bending angle θ of the workpiece 25 is provided, and the crowning for crowning the lower mold 6 is provided. A device 7 is provided, and based on the bending angle determined using the bending angle measuring device 61, the workpiece 25 is
A folding shape calculating unit 95 is provided to calculate the depth driving amounts d□, d2, d at predetermined positions (for example, measurement positions P1, P2, P3), and the depth driving Ad□, which is calculated in the bending shape calculating unit 9S, is provided. d2, d,
A crowning correction calculation unit 97 that calculates the crowning amount Δyc based on the amount Δyc and a depth correction calculation unit 100 that calculates the depth correction value (d x −y) are provided.
The left and right balance correction value Δ is calculated based on the depth correction value obtained in the depth correction calculation unit 100 and the depth correction calculation unit 100.
Since the configuration includes the left-right balance correction calculation unit 102 that calculates DR1ΔDL, the bending angle of the bent workpiece 25 is measured by the bending angle measuring device 61, and the depth drive amount d is calculated based on the measured bending angle.
□, d2, and d3 can be corrected to zero using the crowning correction calculation section 97, the depth correction calculation section 100, and the left-right balance correction calculation section 102. As a result, it becomes possible to automatically correct the bending angle of the bent workpiece without any manual intervention.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the main parts of the press brake according to the present invention, Fig. 2 is a diagram showing an example of the lower mold part of the press brake shown in Fig. 1, and Fig. 3 is a diagram showing the lower part of the press brake shown in Fig. 2. A diagram showing the positional relationship between the mold section and the bending angle measuring device, FIG. 4 is a diagram showing an example of the lower mold part of the lower mold section shown in FIG. 2, and FIG. 5 is a diagram showing the lower mold part of the lower mold part shown in FIG. FIG. 2 is a diagram showing an example of a workpiece processed by Figure 6 is a diagram showing how the bending angle of the workpiece is measured using the bending angle measuring device after the workpiece is bent using the press brake shown in Figure 1; Figure 7 is shown in Figure 1. Figure 8 shows an example of a numerical control device for a press brake. Using the press brake crowning device shown in Figure 1, a workpiece is placed with the lower mold protruding symmetrically toward the upper mold. A diagram showing how the bending process is performed. FIG. 9 is a diagram showing the depth of the workpiece bent using the press brake shown in FIG. 1, FIG. 10 is a diagram showing the amount of deflection at a predetermined measurement position of the lower mold shown in FIG. 8, FIG. 11 shows a workpiece that has been bent using the press brake shown in FIG. 1 at a predetermined measurement position. The figure which shows the depth drive amount. FIG. 12 is a diagram showing the left-right balance correction value at a predetermined measurement position of a workpiece to be bent using the press brake shown in FIG. 1...Press brake 6...Lower mold 7...Crowning device 61...Bending angle measuring device 95...Bending shape calculation section 97 ...Crowning correction calculation section 100...
... Depth correction calculation section 102 ... Left and right balance correction calculation section dL, d2
．． d,... Depth driving amount P1, P2. P3・
...Predetermined position (measurement position) θ ...Bending angle (bending angle) Applicant Yamazaki Mazak Co., Ltd. Agent Patent attorney Phase 1) Shinji (and 1 other person) 5f Figure Figure -B P

Claims (1)

[Claims] In a press brake that has a lower mold extending in a predetermined installation direction and further includes an upper mold that is movably driven relative to the lower mold, the bending angle of the workpiece can be adjusted. A bending angle measuring device is provided for measuring the bending angle, and a crowning device is provided for crowning the lower die, and the depth reduction amount at a predetermined position of the workpiece is determined based on the bending angle obtained using the bending angle measuring device. A folding shape computing section is provided, and a crowning correction computing section for calculating a crowning amount based on the depth drive amount determined in the folding shape computing section and a depth correction computing section for calculating a depth correction value are provided; further, the folding shape computing section is provided. A press brake comprising: a left-right balance correction calculation unit that calculates a left-right balance correction value based on the depth drive amount calculated in the step and the depth correction value calculated by the depth correction calculation unit.