JP3244335B2 - Control method to avoid dimensional error of plate material in bending of plate material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
In the sheet metal bending work by an NC panel vendor, the bending order (also referred to as a process order) performed as a pre-process or the like for preparing an NC program and the position of each abutment in the bending order are determined by the dimensional error of the plate material. The present invention relates to a control method for avoiding and determining.

[0002]

2. Description of the Related Art Conventionally, press brakes and panel benders have been used.
In particular, when the bending part extends over two or more, if the dimensional accuracy of the material (plate material) is low, it greatly affects the dimensional accuracy of the finished product, and only plate bending with low dimensional accuracy can be performed was there.

In the conventional bending process, in order to avoid as much as possible the dimensional error of the plate material as described above affecting the finished product, the dimensional error of the plate material is not related to the accuracy of the bent sides of the finished product. Bending is performed to escape to a bending side or a bending side where accuracy is not required. For this reason, conventionally, an appropriate bending order and the position of the abutment (backgage) corresponding to the bending order have been calculated by calculation.
The calculation was very complicated.

[0004] That is, even if a bent piece that is not related to the dimensional accuracy of the finished product is included in the bending process, the bending process is performed by calculating the accuracy of all the bent pieces. The folding order and the abutment position were set based on the experience of the user.

[0005] However, with the above-mentioned method, it is necessary to calculate extra labor, that is, the accuracy of the bent side where the accuracy is not required. At present, it is extremely difficult to set or set the abutting position, and as a result, it is impossible to realize a reasonable bending process.

[0006]

Accordingly, the problem to be solved by the present invention is that when a worker performs bending in an arbitrary predetermined bending order and abutting position in each of the bendings, the material is undesirably bent. Before the actual bending process, it detects the dimensional error of the (plate material) that appears on which bending side of the finished product, and detects the bending order and the respective abutment positions are appropriate. It is possible to verify in advance whether or not, and if necessary, change the bending order and the respective abutment positions prior to actual bending processing or creating a program therefor. It is to provide a control method.

[0007]

SUMMARY OF THE INVENTION An object of the present invention, which has been made to solve the above-mentioned problems, is to provide a method for forming a sectional shape from a sectional shape of a finished product formed by bending a plate material. The bending position, the bending direction at each bending position, the bending angle, and the length of each bending side are stored in a computer using bending data indicating the bending positions. The bending order and the position of the abutment in each bending order are input to the computer in the order of the bending position, and the bending data and the bending order are input to the computer.
Depending on the position of the abutment, the dimensional error of the plate material is calculated and displayed on which of the bending sides the bending side appears, and the bending side where the dimensional error appears requires processing accuracy. When the side is a side, the bending order and the abutting position are changed.

[0008]

Next, an embodiment of the control method of the present invention will be described with reference to the drawings. 1 is a block diagram of a control device for executing the control method of the present invention, FIG. 2 is a cross-sectional view of an example of a finished product bent by the control method of the present invention, and FIG. 3 is a bent process of the finished product of FIG. 4 is a side view showing the state immediately before the bending in the first step, FIG. 4 is a side view when the bending in the first step in FIG. 3 is completed, and FIG.
And FIG. 6 is a flowchart showing an example of the procedure of the control method according to the present invention.

In the method of the present invention, when one sheet material W is subjected to a bending process having a plurality of bending sides shown in the cross-sectional shape of the finished product in FIG. 2 as an example, the bending order and abutting position Is a control method for judging whether or not it is appropriate to prevent the dimensional error of the plate material from appearing on the bent side having the required precision. In FIG. 2, P0 and P7 are the front end and the rear end of the plate material W, P1
P6 indicates a bent portion (or also referred to as a bent position), and in this specification, each bent side is referred to as B1, B2, B3, B4, B5, B6, B7, respectively. I will.

[0010] The seven bent sides B1 to B7 in the plate material W
The data relating to the bending process is related to the length of each bent side, the bending direction of each side, the bending angle, the bending order, and the abutting position, as shown in Table 1.

[0011]

[Table 1]

[0012] Of the bending data relating to each of the bending sides B1 to B7 shown in Table 1, the length L1 of each of the bending sides B1 to B7.
L7, the bending directions a1 to a6 at the bending points P1 to P6, and the bending angles θ1 to θ6 are input from the keyboard to the control device shown in FIG. 1 and stored. In FIG. 1, reference numeral 1 denotes a central processing unit (hereinafter, referred to as a CPU 1), 2 denotes a keyboard, 3 denotes a storage device, 4 denotes a display by a CRT or the like. -Bo-
By operating the node 2, the data is temporarily stored in the storage device 3 via the CPU 1 as a database.

In the present invention, after inputting the above data, the bending order b1 to b6 of each of the bending points P1 to P6 and the abutment positions r1 to r1 in each bending step in this bending order. r6
Is input from the keyboard 2 as which part P0 to P7 of the plate W is brought into contact with the abutment.

FIG. 3 and FIG. 4 show that the plate material W is press-brazed.
FIG. 3 is a side view showing an example of the case of bending with a key, FIG. 3 shows a state before bending, and FIG. 4 shows a state at the time of completion of bending. In the press brake shown in FIGS. 3 and 4, reference numeral 5 denotes an upper die, 6 denotes a lower die, 7 denotes an abutment (backgage). Tip of
P0 (sometimes P7) is pressed, the upper mold 5 is lowered, and the plate material W is sandwiched between the upper and lower molds 5 and 6 to be bent. 5 is lifted, and the plate material W is repositioned for the next bending.

The position of the abutment 7 in each of the bending steps after the second step is determined according to the bending order of the bending points P1 to P6 of the plate material W in any of the positions P0 to P7 in the next bending step. 3 and 4 is determined in advance depending on whether it is applied to the right or left. In this embodiment, in order to bend the plate material W into the cross-sectional shape shown in FIG. 2, the bending order b1 to b6 of each bending point P1 to P6 and the position data r1 of the butting 7 in this order. To r6 are input from the keyboard 2.

The order of bending for each of the bending points P1 to P6
When b1 to b6 and the position data r1 to r6 of the abutment 7 in the bending order are input from the keyboard 2, they are first input from the keyboard 2 and stored. The numerical values of the existing database and the data inputted later are processed in the CPU 1 in accordance with the flowchart shown in FIG. Whether or not
That is, it is possible to determine in advance whether or not the dimensional error of the plate material W appears at a bending position (any of the bending sides B1 to B7) where the accuracy of the finished bent product is required. The operation procedure of the method of the present invention will be described below with reference to the flowchart of FIG.

First, the control device shown in FIG. 1 is activated, and the keyboard 2 is operated to operate the respective bent portions P1 to P6 of the plate material W, the number n of bent sides formed by the bending, and Bending side B1
Length of L1 to L7 to B7, indicating the bending direction at each bending point P1 to P6, 10, each bending angle θ1 to θ6, each bending point
Position data based on the bending orders b1 to b6 of P1 to P6 and the positions P0 to P7 of the plate material W abutted against the abutment 7 in each bending order are input from the keyboard 2. Thus, in the first step S1, the data is read into the storage device 3 as a database.

Next, in the second step S2, the process number m (1 to 1 in this embodiment) indicating the bending order is set in the previously set number n (7 in this embodiment) of the bent side of the finished product. 6) and bent sides B1 to B1 to be formed in each step.
In B7, variables in which Xi = 0 when a dimensional error of the plate material W is included and Xi = 1 when the dimensional error is not included are initialized. Third step
In S3, for example, when the first bending order (step) No. 1 is set, a place P1 to be bent in the first step,
The length of the bent side B1 to be formed in the first step is the data L1 to L7 of the length of the bent side in the database.
Is selected from

In the fourth step S4, the distance from the front end P0 of the plate material W to the point P1 to be bent in the first step,
Compare the distance (distance to the front end P0 of the plate material W) at which the butting 7 is positioned with respect to the bent portion P1, here L1,
It is calculated whether a dimensional error of the plate material W appears on the bending side B1 in this bending. This calculation is based on the length of the side B1 where the abutting position viewed from the bending point P1 is bent in the first step.
It is determined whether it is larger or smaller than L1. If it is larger, the process proceeds to the fifth step S5, and if smaller, the process proceeds to the sixth step S6. Even if there is a dimensional error on either side of the plate material W,
Since the bent side B1 in the first step is not affected,
In any of the sixth steps S5 and S6, Xi = 1.

Therefore, in the fifth step S5 or the sixth step S6, the length of the side B1 bent in the first step is not affected by the dimensional error of the plate material W. The process proceeds to the seventh step S7, proceeds to the next second step in the seventh step S7, and in the next eighth step S8, the second step (m = 2) is performed based on the number of bent sides (n = 7). It is determined whether it is large or small, and if small, the third step S3
In the third step S3, the same operation as in the first step is repeated up to the eighth step S8 with the process order m = 2. When Xi = 1 in each step, that is, when the dimensional error of the plate material W does not appear on the bent side formed in each step, an indication to that effect is displayed on the display 4 in a ninth step S9. In this way, several tens of steps
The operations from the third step S3 to the eighth step S8 are repeated for each step until (m11) becomes equal to the number n of the bent sides (7 in the embodiment), and when Xi = 1 in each step Is displayed each time.

Here, in the case where there is a dimensional error in the plate material W, if the plate 7 is bent one or more times and then the butting 7 is applied to the outside of the bent side of the plate W, the abutting 7 Is set as having no dimensional error in the plate material W, the bent side formed by the bending in the next step is bent at a position shifted by the dimensional error of the plate material W, and finally, The dimensional error becomes apparent in the length of the bent side in the bending step.

That is, for example, when bending the finished product having the cross-sectional shape shown in FIG. 2 in the bending process order shown as (a) to (f) in FIG. Assuming that there is a dimensional error, the dimensional error eventually becomes apparent at the bent side B4 formed at the end of the process. Accordingly, in the flowchart of FIG. 6, the calculation of the bending order and the abutting position of each bending point P1 to P6 is completed, and the ninth step is performed.
In S9, it is displayed that the dimensional error of the plate material W affects the length of the bent side B4 only in the bending step of the bent side B4. If dimensional accuracy is not required for B4,
In step S10, it is determined that there is no problem in the bending process based on the set bending order and the abutting position, and a message to that effect is displayed. FIG. 5A shows each step.
In (f), the solid line indicates the plate material W before bending, and the broken line indicates the plate material W after bending in each step. Further, in the plate material W shown by the solid line and the broken line, the bold line indicates a bending position which is not affected by the dimensional error of the plate material W in the previous bending.

On the other hand, in the bending processing in which dimensional accuracy is required for the bending side B4 formed last in the above example, the processing based on the bending order set and calculated in the above example and verified and the abutting position is performed. If this is done, the dimensional error of the plate material W will not allow the required dimensional accuracy to be obtained on the bent side B4 formed in the final bending step. This is the tenth step
Judging that the bending order is not appropriate in S10,
Returning to step S1, the input of the database is changed.

In the above case, according to the method of the present invention, as an example, the bending order of the bent portions P2, P3, P4, P5 and the abutting positions at that time are changed in the first step S1 in the first step S1. Input as a database, and after initializing variables in a second step S2, a third step S3 to an eighth step S8
Calculation processing is performed in the order of each bending set changed up to.
If it is confirmed in the ninth step S9 that the dimensional error of the plate material W does not occur on the bending side B4 by this arithmetic processing, it is possible to judge that the changed bending order and the setting of the abutting position are appropriate. According to the changed setting contents, an actual bending process is started or a program for NC press brake is created.

[0025]

The present invention is as described above. If there is a dimensional error in the plate material W, even if the error is on the tenth side or one side with respect to the accurate dimension, the folding is performed in two or more steps. By arbitrarily setting each bending order and the abutting position at that time in the bending process, the dimensional error of the plate material is apparent at any bending side in the bending by the set bending order and the abutting position. Can be checked before the actual bending process, so that complicated calculations and trial bending are not required for setting the bending conditions in the press brake, etc. This processing can be started depending on the conditions of the bending order and the abutting position, which is extremely reasonable.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control device for executing a control method of the present invention.

FIG. 2 is a cross-sectional view of an example of a finished product bent by the control method of the present invention.

1. FIG. 3 is a side view of the completed product of FIG. 2 immediately before bending in a first step in bending.

FIG. 4 is a side view when the bending in the first step of FIG. 3 is completed.

FIG. 5 is a side view showing a side surface shape of a plate material in each bending step of the finished product in FIG. 2 in the order of steps (a) to (f).

FIG. 6 is a flowchart showing an example of a procedure of the control method of the present invention.
Figure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Central processing unit 2 Keyboard 3 Storage device 4 Display 5 Upper die 6 Lower die 7 Butt (back gauge) W Plate P0 Tip of plate

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B21D 5/02 B30B 15/26

Claims (1)

(57) [Claims] 1. A sectional shape of a finished product formed by bending a sheet material, from each bending position forming the cross-sectional shape, a bending direction at each bending position, a bending angle, and each bending side. The lengths are stored in a computer by means of bending data indicating the lengths, and the bending order at each bending position and the abutting position in each bending order are determined in the order of the bending positions. An input is made to the computer, and a calculation is made as to which of the bending sides the dimensional error of the plate material appears on the basis of the bending data, the bending order, and the abutting position. When the bending side where the dimensional error appears is the side where the processing accuracy is required, the bending order and the abutting position are changed. Control method to avoid dimensional errors.