JPH05169143A - Press brake work bending order selection device - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to make it possible to automatically select an optimum order of bending by press brake in a short time. [Structure] In the case of bending n times, in the nth final step, n
Interference is examined n times assuming that each bending angle is bent by a press brake. At this time, the bending angle at which interference is minimized is the bending angle that should be bent in the final step. Then, assuming that this bending angle is unprocessed, the n-
Similarly, in the first step, the interference is examined n-1 times, and the bending angle with the least interference is selected. Hereafter, n-
By examining the n-2, n-3, ... interferences in the steps of 2, n-3, ..., The bending angle to be finally bent in each step can be obtained. After all, n + (n-1) + (n-2) +
(N−3) + ... = (n / 2) · (n + 1) times of interference only needs to be examined, and the conventional n!・ Remarkably less than n times, and faster selection of machining order is achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work piece when a finished product is manufactured through a plurality of bending processes using a press brake.
The present invention relates to a press bend work bending sequence selection device capable of performing optimum selection of the processing sequence of the bending angle of the work.

[0002]

2. Description of the Related Art In a press brake, a product such as a box is completed by repeating the process of bending each part of the work a plurality of times. Therefore, the shape of the work changes sequentially with each step, and there is a risk that the work interferes with the press break depending on the processing order of the portion to be bent. Therefore, in each process, it is necessary to select the processing order of the parts other than the part to be bent of the work to be bent so that the work does not interfere with the press brake, and to perform the bending process sequentially in this order.

For example, it is assumed that the work WK is processed to produce a finished product having a cross sectional shape as shown in FIG. 10 (a). In the following, when the sectional shape of the work WK is shown, the portion of the work WK to be bent will be referred to as "bending angle". Assuming that the bending angles are numbered 1, 2 and 3 from the left as shown in FIG.
As shown in the sectional view of FIG. 2, if the work WK is bent in the order of bending angles 1 → 3 → 2 by the punch PT of the press brake and the die D, the work WK is pressed by the press brake (punch P).
It can be seen that the work is performed safely without interfering with T and die D). However, if the work WK is bent in the order of bending angles 1 → 2 → 3 as shown in FIG. 7 (b), the work WK as shown by an imaginary line in the arrow A in the third step. Interferes with the punch PT, making it impossible to perform machining. As described above, in the bending work performed by the press break, the optimum bending order in which the work WK can perform the work without interfering with the press break is the above "1 → 3 → 2".
Exists like.

Therefore, conventionally, such an optimum processing sequence "1
"→ 3 → 2" was selected and decided by a skilled operator who had a good understanding of the bending work by the press brake, based on his experience and intuition.

On the other hand, there is a technique for automatically selecting a machining order by a computer without depending on human experience or intuition (Japanese Patent Laid-Open No. 63-36925). According to this technique, all possible processing sequences are listed.
Then, it is checked whether the work is not interfered with the press brake over all the steps in each processing order, and any one of the processing orders which is determined not to interfere in all the steps is selected.
adopt. That is, for example, in the example shown in FIG. 10 in which three bending points are processed, the processing sequence “1 →
Work is press-blended in each of the three steps "2 → 3"
Check if it interferes with Ki. At this time, since interference occurs in the third step, this machining order "1 → 2 → 3" is not adopted. The other machining order “2 → 3 → 1” ... Is similarly examined, and since there is no interference in the three steps in the above-mentioned machining order “1 → 3 → 2”, this machining order is adopted. In this way, the number of types of processing order is 3! (!
Means factorial), and these 3! It is necessary to check three steps for each type of machining order, and the number of steps to be checked is 3!・ 3 = 18.

[0006]

As described above, in the case of relying on the experience and intuition of the operator, even a skilled operator may make a mistake in selection, or require skill to make the optimum selection. However, this has a drawback in that it lacks certainty and imposes a heavy burden on the operator. In addition, since it is a human judgment, there is an inconvenience that it takes time to make a selection.

On the other hand, the latter technique has an advantage that an optimum selection can be surely made, but whether or not the work interferes with the press break over the entire process of all conceivable processing sequences. Since it has to be examined, there is a drawback that it takes time for the calculation performed by the computer. Generally, assuming that the bending angle is n, the number of processes n!・
Therefore, the number of steps to be inspected dramatically increases with an increase in the number of bends.
Eight in bending!・ A huge number of processes, 8 = 322,560, must be investigated.

The present invention has been made in view of the above circumstances, and an object thereof is to be able to automatically select an optimum sequence of bending by press brake in a short time.

[0009]

SUMMARY OF THE INVENTION The present invention is a finished product work.
If the bending angle that minimizes interference in each process is selected in order by tracing the shape of the preceding process in order from the curved shape, it is possible to ensure the optimal bending order with a smaller number of times without checking multiple processing orders. It is based on the idea that

That is, according to the present invention, in the press-brake work bending order selecting device for selecting the bending order of the press break of the work having a plurality of bending angles, it is determined that each bending angle is the easiest to bend. The first process for selecting the bending angle to be performed and the second process for developing the bending angle selected in the first process are sequentially performed from the cross-sectional bending state of the work in the final product state to the unworked state of the work. After repeated execution, the reverse order of the selection order by the first process is determined as the bending order by the press brake, and in the first process, the cross-sectional shape of the work at each processing stage and the preset press brake are set. -Drying the work with respect to the press brake for each state where each bending angle is bent by the press brake based on the data showing the cross-sectional shape of the key. It calculates the amount of each, and to select a bending angle minimum amount of interference among these calculation results.

[0011]

As described above, in the present invention, in the case of bending n times, n
In the second and final step, n pieces of bending angle are bent by press break and interference is examined n times. At this time, the bending angle at which interference is minimized is the bending angle that should be bent in the final step. Then, assuming that this bending angle is in a non-machined state, the interference is similarly examined n-1 times in the n-1th step of the previous stage, and the bending angle with the smallest interference is selected. Hereinafter, if the n-2, n-3, ... times of interference are sequentially examined in the steps of n-2, n-3, ..., The bending angle to be bent in each step is finally obtained. After all, n + (n
−1) + (n−2) + (n−3) + ... + (n−n) =
(N / 2) · (n + 1) times of interference need only be examined, and the conventional n!・ Remarkably less than n times, and faster selection of machining order is achieved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a press bending work bending sequence selecting device according to the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of the embodiment apparatus.
As shown in the side view of the press brake 10 in the figure, the press brake 10 is largely composed of a die D supported on a fixed table and a punch P supported on a movable table so as to be vertically movable.
It is composed of T and T. That is, press brake 1
0 lowers the movable table by a predetermined hydraulic mechanism,
The punch PT is lowered to the (target point) toward the die D to bend the work WK (Fig. 3), and after bending,
The punch PT is raised to its original position (top dead center). Backstop 11 is a work WK for Die D
Is provided on the side opposite to the insertion direction of the work WK and is movable in the left-right direction in the drawing so that the insertion position of the work WK can be regulated at any position. The press break robot 12 is a multi-joint robot provided for handling the work WK, and is controlled by driving and controlling each axis.
The operation of inserting and removing the KU WK between the punch PT and the die D of the press brake 10 is performed.

The data input device 20 selects the result of selection of a finished product to be obtained, leg length, bending angle, abutting, and the like.
The data WD is an input device that is input by the operator, and this input data WD is added to the NC device 30 and the off-line programmer 40, respectively. NC device 30
Is to create an NC program for driving the press brake 10 based on the input work data WD, and the off-line programmer 40 is based on the work data WD. −
A robot program for driving and controlling the key 10 is created.
The robot controller 13 is an offline programmer 40.
Each axis of the robot 12 is driven and controlled in accordance with the robot program created in. Hereinafter, the data input device 2
The work data WD which is supposed to be input to 0 will be described. The display unit 33 has a display screen, for example, a CRT screen, and the display unit 33 is adapted to interactively show the input result of the work data WD on the CRT screen. The operator switches the CRT screen to a drawing screen as shown in FIG. 2 and roughly draws a desired work shape on the CRT screen. The input device 20 assigns bending angle identification numbers (0 to 9) and side numbers (to) to the drawn work. Here, the "bending angle" refers to a portion that is bent by the press brake 10, but in this embodiment, it includes the end point of the work WK. Further, the bending angle number and the side number are given in order from the left. It is also possible from the right.

Next, the operator selects a basic bending pattern corresponding to the drawn work shape. That is, the work
The finished product obtained by subjecting the WK to a series of bending processes can be classified into several types of basic bending patterns. The finished product to be obtained can be obtained by appropriately repeating or omitting the required bending steps of one of the basic bending patterns. Therefore, rib bending having both forward and reverse bending is selected as the basic pattern corresponding to the drawn work shape. The selection result is input to the bending condition creation unit 31 via the data input device 20. Specifically, the CRT display unit 33
The basic bending patterns such as rib bending and box bending are displayed on the screen, and which basic bending pattern the operator wants to process from these is to be completed based on the basic bending patterns. Judgment is made, and the judged basic bending pattern is selected.

When the selection of the basic bending pattern is completed in this way, the operator switches the CRT screen to the data input screen and sequentially inputs the length of each side and the bending angle. For example, in the case of the work shape shown in FIG. 3, as shown in FIG. 4, the bending angle (θ) and leg length (side length (L)) etc. are set to the bending angle number (P). Enter correspondingly. By the way, bending angle 0, bending angle 180.00, leg length 1
0.00 means that the bending angle 0 is "not bent (end point), and the next bending angle (1) is 180 ° with respect to the reference.
Is. The leg length of the side between the bending angle 0 and the next bending angle 1 is 10 mm ".

Next, the operator switches the CRT screen to the process input screen, and the data concerning the press brake 10
In other words, while instructing the type of die D and punch PT,
Indicate the data such as the work WK and the thickness of the plate.
In this embodiment, the bending angle order is automatically selected and determined even if the operator does not instruct the bending angle processing order of the work WK. Below, the fifth
This bending order selection processing will be described with reference to FIGS. Bending condition creation unit 3 of NC device 30 in FIG.
1, the procedure shown in FIG. 5 is executed based on the input work data WD.

That is, the number of the bending angle input is 1 to
Since it is 9, the bending angle at which bending is performed by the press brake 10 excluding the end points is determined to be "8". As a result, it is determined that the bending process S is performed eight times. Therefore, processing for initializing the contents of the bending angle data DT is executed. Here, the bending angle data DT is the number of the bending angle (hereinafter referred to as the processed bending angle) which has been processed by the press brake 10 for the eight bending angles of the work WK, and the press brake 10. Bending angle that has not been processed (hereinafter referred to as unprocessed bending angle)
The data is classified into Therefore, as an initial condition, it is now assumed that the work WK has a shape in the final step in which all eight bending angles have been processed, and the content of the bending angle data DT is "processed bending angles are 1 to 8". , No unprocessed bending angle ”(step 101; see FIG. 6 (1)). Here, the principle applied to this embodiment will be described with reference to FIG. FIG. 8 shows a cross section of the work WK ′ and a cross section of the press brake 10 (punch PT and die D) in which the shape of the finished product of the embodiment is different from the work WK for convenience of explanation. The geometric relationship is shown. The figure shows a state in which the processed bending angle 1 of the bending angles of the work WK 'is bent by the punch PT. The work WK 'is in a processed state in the final step, that is, in the shape of a finished product. Here, the cross-sectional shapes of the punch PT and the die D, that is, the widths WP and WD thereof, are automatically determined when the types of the die D and the punch PT are instructed as described above. Then, the following processing is executed for bending angles 0, 2 to 8 other than the processed bending angle 1. The position of the processed bending angle 1 is the origin P of the XY coordinate system.
_{As 1} (0, 0), the coordinate position P ₀ of each bending angle _{0, 2 to 8}
(X ₀ , Y ₀ ) ... Is calculated. These coordinate positions can be easily obtained from the input work data WD, such as bending angle and leg length. Then, it is checked whether the Y coordinate positions of the bending angles 0 and 2 to 8 are 0 or more and smaller than 0.

Then, Y with bending angles of 0, 2, 3, 4, 5
It is checked whether the coordinate position is 0 or more and the bending angle number is larger or smaller than the processed bending angle number 1.

Since the bending angles of 2, 3, 4, 5 are larger than the processed bending angle of 1, the bending angles 2, 3, 4,
4,5 and right side surface of the punch PT - calculating a distance _{d 2, d 3, d 4} , d 5 and (Wa click insertion direction side). Here, the punch PT is symmetrical with respect to the Y coordinate, the width of the punch PT is given as WP, and the width on the left side of the bending center is given as WP '. Therefore, these distances d ₂ , d ₃ , d ₄ , d ₅ are Easily required.

On the other hand, since the bending angle of 0 has a smaller number than that of the processed bending angle of 1, for this bending angle 1, the bending angle and the left side surface of the punch PT (back stop 11
The distance d ₀ from the side) is similarly calculated.

Next, it is assumed that the Y coordinate positions of the bending angles 6, 7, and 8 are smaller than Y ₁ = 0. For these bending angles, the bending angle number is the same as the processed bending angle number 1.
Find out if it is greater or less than.

Since all the bending angles of 6, 7 and 8 are larger than the processed bending angle of 1, these bending angles 6,
7,8 and right side surface of the die D - calculating a distance D _6, D _7, D ₈ and (Wa click insertion direction side). In this example, there is no bending angle whose number is smaller than the processed bending angle of 1, but if the bending angle of 0 exists as being smaller than the Y coordinate 0, this bending angle 0 and die The distance D _{0 from} the left side surface of D (on the side of the backstop 11) is calculated.

Next, the total of the calculated distances, that is, the interference amount in the final step, Q1 = Σd + ΣD (1) is calculated. Q1 calculated by means the degree of interference of the work WK 'with the press brake 10, that is, the amount of interference. This is based on the idea that the more the bending angle gets into the punch PT and the die D, the greater the interference. The larger the amount of interference Q1, the more work WK '
Is more likely to interfere with the press brake 10 and work WK
It means that it is difficult to process ´. Further work WK
In the state of ', since the bending angle 1 is pressed by the press brake 10, it is a state after processing, so Q1 is referred to as a post-processing interference amount.

Next, the processing from the above is executed with the processed bending angle 1 as an unprocessed bending angle, that is, with the bending angle 1 expanded, and similarly the interference amount, that is, before processing in the final step. Interference amount Q2 is calculated. Then, the total Q of the post-machining interference amount Q1 obtained by and the pre-machining interference amount Q2 obtained by is set as the interference amount for the processed bending angle 1. The same processing as above is executed for the other processed bending angles 2 to 7, and the interference amounts Q1 to Q8 are calculated.

(10) Then, the processed bending angle with the smallest interference amount Q is selected. Here, the smallest amount of interference means that if the processed bending angle is bent by the press brake 10, the work WK 'is inserted between the die D and the punch PT (pre-processing interference). Quantity Q2),
This means that the work WK ′ has the smallest degree of interference with the press brake 10 in the state where the punch PT is lowered (interference amount Q1 after processing), and thus is most easily processed. It is assumed that the processed bending angle thus selected is the bending angle to be processed in the final step.

Now, at step 102, the same processing as that described above is executed by replacing the work WK 'with the work WK. That is, it is assumed that each of the processed bending points 1 to 8 is bent by the press brake 10 based on the content of the bending angle data DT, and the pre-processing interference amount Q1 and the post-processing interference amount Q2 are obtained, and the sum Q of these is obtained. Is calculated. Next, the processed bending angle that provides the minimum interference amount among the interference amounts Q of the processed bending points 1 to 8 is selected. FIG. 7 (a) shows that the processed bending angle 2 is bent, and it is clear from FIG. 7 (a) that the post-processing interference amount Q1 is Q1 = Σd + ΣD = d ₀ + d ₄ (2) Become. On the other hand, since the pre-processing interference amount Q2 is obviously 0 from the same figure (b), the interference amount Q is: Q = d ₀ + d ₄ (3) It is assumed that the interference amount Q of the processed bending angle 2 is finally minimized in comparison with the interference amounts Q1 ... Of the other processed bending angles 1, 3 to 8. When the interference amount Q has the same value, for example, the one having a smaller bending angle number is selected. Then, this processed bending angle 2 is the final step (S =
In step 8), the bending angle to be processed is stored (step 103; see FIG. 6 (1)). Next, step 103
The contents of the bending angle data DT are updated assuming that the bending angle 2 obtained in step 1 is a non-machined bending angle (step 104). Then, the process is incremented by -1, and 7 in the previous stage of the final process
The process is shifted to the second process (step 105). Then, it is determined whether or not the content of the process S has reached the first process 1 (step 106), and since the result of the determination is NO, the procedure moves to step 101 again. This time, as shown in (2) of FIG. 6, the same processing as in steps 101 to 106 is performed for the work shape in which the bending angle 2 to be bent last time is the undeveloped developed bending angle 2. Is executed. In the seventh step, after all, when the processed bending angle 1 is bent by the press brake 10, it is judged that the interference amount Q becomes the minimum, and the bending angle 1 is regarded as the bending angle to be processed. Then, the bending angle data DT is updated with the bending angle 1 as the unprocessed bending angle.

Thereafter, similarly, (3) in FIG. 6,
As shown in (4), (5), (6), and (7), 6,
The bending angles 7, 8, 4, 3, 6 to be machined in the fifth, fourth, third and second steps are sequentially selected, and the contents of the bending angle data DT are sequentially updated. Here, since the content of S is 1, the determination result of step 106 is YES, and the finally remaining processed bending angle 5 is unconditionally the bending angle to be processed in the first step (step 107; (See FIG. 6 (8)). When the bending angles 5, 6, 3, 4, 8, 8, 7, 1 and 2 in the respective steps 1 to 8 are obtained in this way, an NC program for driving the press brake 10 to perform bending processing in this order is created. .. The bending condition creating unit 31 finds the abutting portion of the work WK with respect to the backstop 11 in each step based on the bending order obtained as described above. This is because when bending angle 2 shown in FIG. 7 is processed, bending angle 1 is as shown in FIG.
Is the abutting part. When the abutting portion in each process is obtained in this way, the abutting portion, the bending order, and the regulation position of the backstop 11, that is, the backstop 11 based on the dimensions of each side of the work in the work data WD.
The horizontal position of the drawing in FIG. 1 is calculated for each process. Further, a target height position for lowering the punch PT is calculated for each bending process based on the work plate thickness, the bending angle, and the dimensions of the die D and the punch PT.

On the other hand, the work data WD input through the data input device 20 is the offline programmer 40.
Is also entered. The off-line programmer 40 is arranged inside the robot controller 13. In the off-line programmer 40, the desired bending pattern (finished product) of the operator and the basic bending pattern selected by the operator are selected from the input work data WD and data such as the bending order. Then, a robot program describing the movement of each axis of the robot 12 for obtaining the bending pattern is created. Here, the basic bending pattern is stored and stored in advance as a program that describes the movement of each axis of the robot 12, so by correcting this, the process of creating the program relating to the desired bending pattern is simple and easy. It will be finished in a short time. Note that various patent applications have been filed by the applicant of the technology relating to such program creation (Japanese Patent Application No. 1-283929, etc.), and the detailed description thereof is omitted because it is different from the gist of the present application.

The robot program created by the off-line programmer 40 is a robot controller 13 and a server.
Added to the vocoder controller 32. The robot controller 13 and the servo controller 32 are operated in accordance with the robot program, and the press brake robot 12 is operated.
The press brake 10 is driven and controlled. As a result,
The work WK is processed without interfering with the press brake 10 in the manners shown in (8) to (1) of FIG. In the embodiment, the interference amount Q is calculated on the basis of the amount of bending points entering the punch and the die, but the embodiment shown in FIG. 9 is also possible.
That is, the figure shows a work WK ″ having a bending angle of 6 and a bending angle of 3
Shows a bent state, and the work WK '
Bending points 0, 1, 2, 4, 5, before and after processing of ′ (the state before processing is indicated by a solid thick line, and the state after processing is indicated by a one-dot chain line).
6 is an arcuate locus l ₀ , l ₁ , l ₂ , l ₄ , l ₅ , l ₆
Draw. Therefore, of these trajectories, punch PT and die D
The sum of the lengths of the parts inside is the amount of interference.
Apparent from the figure, the length L ₂ of the trajectory l _2, and only the length L ₅ of the trajectory l ₅ is present within the punch PT, die D. Therefore, the sum of these is calculated as the interference amount Q as follows.

Q = L ₂ + L ₅ Furthermore, the calculation of the interference amount is not limited to the above-described one, and any calculation can be used as long as it indicates the degree to which the work interferes with the press brake.

[0031]

As described above, according to the present invention, since the bending angle that causes the least interference is selected sequentially from the final step, the bending order is obtained, and therefore, the bending order in which the interference is least likely occurs. Can be selected reliably and in a short time. Therefore, the working efficiency of the press brake is greatly improved, and the accidental interference between the press brake and the work is prevented.

[Brief description of drawings]

FIG. 1 is a control block diagram showing the configuration of an apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram used for explaining an input mode of work data for the NC device shown in FIG.

FIG. 3 is a diagram used for explaining an input mode of work data for the NC device shown in FIG.

FIG. 4 is a diagram used for explaining an input mode of work data for the NC device shown in FIG.

FIG. 5 is a flowchart showing a processing procedure of an embodiment of a press bending work bending sequence selecting apparatus according to the present invention.

FIG. 6 is a diagram used for explaining the flow chart shown in FIG.

7 (a) and 7 (b) are views used to explain the flow chart shown in FIG. 5, and are sectional views showing the geometrical relationship between the work and the press brake.

FIG. 8 is a view used for explaining the flow chart shown in FIG. 5, and is a sectional view showing a geometrical relationship between a work and a press brake.

FIG. 9 is a view used to explain another embodiment, and is a diagram
Cross-sectional view showing the geometrical relationship between black and press brake

10 (a), (b) and (c) are diagrams used for explaining a conventional technique.

[Explanation of symbols]

WK, WK '... Work, PT ... Punch, D ... Die, 10
… Press brake, 12… Press brake robot, 2
0 ... Data input device, 30 ... NC device.

Claims (1)

[Claims] 1. A press break work for selecting a bending order of a work break having a plurality of bending angles by a press break.
In the bending order selection device, the first process of selecting the bending angle determined to be the most easily bent among the bending angles and the second process of developing the bending angle selected in the first process are performed in the final product state. After sequentially repeating from the cross-section bending state of the work to the unworked state of the work, the reverse order of the selection order by the first process is determined as the bending order by the press brake, and in the first process. Is based on the cross-sectional shape of the work at each processing stage and the data indicating the preset cross-sectional shape of the press brake, and the work of each work is bent at each bending angle by the press break. The press shake is characterized in that the interference amount with respect to the press brake is calculated, and the bending angle that gives the minimum interference amount is selected from the calculation results. Key Wa - click bending order selecting device.