JPH07314043A - Automatic correcting method for die depth amount - Google Patents

Abstract

PURPOSE:To improve the precision of a bending angle and to shorten the working time even if a work has a bending corner of being hardly measured or unable to be measured. CONSTITUTION:The working factor influencing the bending angle is specified by the data from an NC device 10 in a grouping factor specifying part 13, the allowable range at the time of grouping is set against this specified factor in an allowable range setting part 14 and grouping of bending corners is executed in a corner grouping part 15. Then, the correcting condition is set in a correcting condition setting part 16, based on this set correcting condition, the correcting data of the depth is calculated based on the real depth data of the bending corner worked to an article of good quality in a correcting data calculating part 17 and the process data of bending is changed in a process data changing part 18. In such a way, the depth of the bending corner whose bending angle is not measured is corrected based on the correcting value of depth regarding to the specified bending corner whose bending angle is measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending machine such as a press brake which measures a bending angle of a work during bending and corrects the driving amount of a driving die based on the measured value. The present invention relates to a method for automatically correcting the amount of drive-in.

[0002]

2. Description of the Related Art Conventionally, when a plate-shaped work is bent using a bending machine such as a press brake,
Various information such as work conditions such as plate thickness and material of work, mold conditions, machine conditions, etc. are input to the NC device, and the driving amount of the driving mold is calculated based on these input information and the calculated driving position It is known that an upper die or a lower die is driven to obtain a desired bent product.

However, even if the die is driven based on various information as described above, in actual bending, there are variations in the plate thickness and the characteristic value of the work itself between lots or various processing conditions. In many cases, the desired bending angle cannot be obtained due to the difference in the above, and the fact is that the bending angle error cannot be avoided.

Therefore, in order to eliminate the bending angle error caused by the variation of materials as described above and realize highly accurate bending, the bending angle of the work is measured during the bending and the measured value is used. It has been proposed to correct the amount of driving of the die based on this. As an example of a bending machine provided with such bending angle measuring means, Japanese Patent Laid-Open No. 5-69
There is one disclosed in Japanese Patent Publication No. 046. In the metal plate bending apparatus disclosed in this publication, a linear light projection image formed by projecting slit light on the bent outer surface of the metal plate is imaged by the imaging means, and this is imaged. The bending angle of the metal plate is calculated based on the image to correct the amount of pushing of the die.

[0005]

However, in the bending machine equipped with the conventional bending angle measuring means as described above, the bending angle cannot be measured or is difficult depending on the processing shape of the work to be bent. There is a case where there is a bending corner, and in such a case, there is a problem that the bending angle error for the bending corner cannot be eliminated. In addition, in this type of conventional bending machine, when performing bending of a workpiece having multiple bending corners, it is necessary to stop the driving of the die each time the bending corner is processed and measure the angle. There was also a problem that it took too much processing time.

The present invention has been made in order to solve such a problem, and in a processed product having a plurality of bending corners, even if there is a bending corner that is difficult or impossible to measure, the bending angle accuracy of the bending corner is high. It is an object of the present invention to provide a method for automatically correcting the amount of die pushing in, which can improve the machining efficiency and shorten the processing time.

[0007]

[Means for Solving the Problems and Actions and Effects] In order to achieve the above-mentioned object, the method for automatically correcting the die pushing amount according to the present invention measures a bending angle of a work during bending and measures the measured value. It is a method of automatically correcting the amount of pushing in of a driving die based on the following, which is based on a measurement value of a bending angle related to a specific bending corner when a bending product having a plurality of bending corners is obtained. The present invention is characterized in that a correction value of the die pushing amount for another bending corner is calculated from the correction value of the die pushing amount.

According to the present invention, when a bending product having a plurality of bending corners is obtained, the bending angle of the bending corner is measured at the time of bending the specific bending corner, and the mold is calculated from the measured value. Bending of the specific bending corner is performed based on the correction value of the driving amount. Further, when bending a bending corner other than this specific bending corner, a correction value of the die pushing amount of the other bending corner is calculated from the correction value of the die pushing amount of the specific bending corner. The bending process is executed based on the calculated correction value. In this way, it is possible to improve the bending angle accuracy of the bending corner even if it is difficult or impossible to measure, and it is not necessary to measure the angle each time the bending corner is bent. Therefore, the processing time can be shortened.

In the present invention, the bending corners having the same machining factor related to the bending angle are grouped, and when the grouped bending corners are in the same group as the specific bending corner, the other bending corners are included. It is preferable to calculate a correction value for the die-pushing amount according to (1).

Further, when the grouped bending corner is a group different from the specific bending corner, the correlation between the group and the specific bending corner and the same group due to a machining factor related to the bending angle. It is preferable to calculate the correction value of the die driving amount for the bending corners of the different groups according to the correlation.

From the correction value of the die pushing amount relating to the specific bending corner for which the bending angle measurement is performed in this manner, the die pushing amount relating to each bending corner belonging to the same bending group and a different group as the specific bending corner. The correction value of is calculated, and it becomes possible to perform bending processing for all bending corners with high accuracy and in a short time.

Here, in grouping the bending corners by the processing factors related to the bending angle, an allowable range is set in advance, and when the value of the processing factor related to the bending angle is within the allowable range, the bending is set. It is preferable to determine that the processing factors related to the angle are the same. By doing so, the grouping can be easily performed, and the correction value of the die pushing amount can be more easily calculated.

Further, it is preferable that the processing factors related to the bending angle include a target bending angle, a bending line length, an upper die shape and a lower die shape.

Objects of the present invention will become apparent from the detailed description given below. However, while the detailed description and specific examples describe the most preferred embodiments, various modifications and variations within the spirit and scope of the invention will be apparent to those skilled in the art from the detailed description, and therefore, specific examples As described below.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of the method for automatically correcting the amount of die driven in according to the present invention will be described with reference to the drawings.

FIG. 1 shows a system configuration diagram of an embodiment of the present invention. In the press brake 1 of this embodiment, the lower die (die) 3 supported by the pedestal 2 is used.
And an upper die (punch) that is attached to the lower portion of a ram 4 that is provided above the lower die 3 so as to be able to move up and down.
5, a work W made of a metal plate is inserted between the lower mold 3 and the upper mold 5, and the ram 4 is lowered with the work W placed on the lower mold 3. The work W is bent by pinching the work W between the lower mold 3 and the upper mold 5.

On the front portion (man side) of the gantry 2, a slit-shaped light source 6 for projecting a linear light projection image on the bent outer surface of the work W, and a linear light projection image by the light source 6 are picked up. An angle measurement unit 8 including a CCD camera 7 is attached, and the bending angle of the work W is measured by the angle measurement unit 8. The angle measuring unit 8 may be provided at the rear part (machine side) of the gantry 2 instead of being provided at the front part of the gantry 2, or at both of the front part and the rear part of the gantry 2 to provide two workpieces W. The bending angle of the bent outer surface may be measured separately.

The image picked up by the CCD camera 7 is displayed on a monitor television (not shown) and is processed by the bending angle calculator 9 as image data. Then, the bending angle of the work W is calculated by the calculation in the bending angle calculation unit 9, and the calculation result is the NC device 10.
Entered in. In addition to the measurement data of the bending angle of the work W, the NC device 10 previously has work information (material, material,
Bending line length, bending angle, etc., mold information (die height, V groove width, V angle, punch R, etc.), machine information (rigidity, speed specifications, stroke specifications, etc.), etc. are input. There is.

In this NC device 10, the reference lower limit value (reference depth amount) of the ram 4 is calculated based on the input data such as the work information, mold information, machine information, etc., and the ram is calculated based on the calculation result. 4 is controlled and bending is performed. At this time, the actual bending angle of the workpiece W during bending is calculated by the bending angle calculation unit 9 and the calculation result is input to the NC device 10, so that the NC device 10 uses the ram based on this input data. A correction value (correction depth amount) of the lower limit value is calculated, the correction depth amount is added to the reference depth amount to obtain the final depth amount, and the ram 4 is driven based on the final depth amount thus obtained.

By the way, when a bent product having only a single bending corner is obtained, the ram 4 is controlled and the working is executed as described above. For example, as shown in FIG. When it is desired to obtain a bent product having bending corners a to h (in this example, the case where the product is applied to a sash is shown) 11, it is apparent from the working drawing for each step shown in FIG. In addition, there are bending corners in which angle measurement cannot be performed (steps 2 and 4), and when angle measurement is performed for all bending corners, there is a problem that it takes too much processing time. For this reason, in the present embodiment, the final depth amount of another bending corner is calculated by using the data of the specific bending corner whose angle is measured.
In order to execute this calculation, in the control system of the present embodiment, a correction effective corner automatic stratification device 12 (see FIG. 1) is provided, and the calculation data in this correction effective corner automatic stratification device 12 is NC. The data is input to the device 10.

This correction-effective corner automatic stratifying device 12 is
Based on the data from the NC device 10, the target bending angle and bending line length (L ₁ , L
₂ ), the upper die shape (punch R, angle, height, shape), the lower die shape (V width, V angle, height) and the like, and a grouping factor specifying section 13 for specifying the grouping factor. An allowable range setting unit 14 that sets an allowable range for grouping the factors identified by the unit 13, and a corner grouping unit 15 that groups bending corners according to the allowable range set by the allowable range setting unit 14. When,
A correction condition setting unit 16 that sets a correction condition as to how to correct each of the same group or different groups grouped by the corner grouping unit 15 and the correction condition setting unit 16 are set. Correction data for calculating the correction data of the depth amount based on the actual depth data (input data from the NC device 10) of the bending corner in which the bending angle is measured according to the correction condition, in other words, the bending corner in which the non-defective product is processed. Computing unit 1
7 and a process data changing unit 18 for changing the bending process data based on the correction data from the correction data calculating unit 17, and the output data from the process data changing unit 18 is sent to the NC device 10. The depth of the bending corner, which is input and the bending angle is not measured, is corrected as necessary.

Next, the processing flow in the above-mentioned control system will be described with reference to FIG. S1: Processing factor affecting the above-mentioned bending angle related to the bending angle in the grouping factor specifying unit 13 (target bending angle, bending line length, upper die shape, lower die shape, etc.)
Specify. S2: The permissible range for grouping is set in the permissible range setting unit 14 for the specified processing factor. S3: Bending corners are grouped in the corner grouping unit 15. For example, in the case of the bent product 11 shown in FIG. 2, a group (G1) composed of bending corners a, b, c, d, and e according to the bending line lengths L ₁ and L ₂ .
And bending corners f, g, and h (G
2) and can be stratified into two groups.

S4: The correction condition setting unit 16 sets the correction condition according to the correction condition setting table. Here, various cases as shown below can be considered as the correction method. Case 1; Correction of the same group Correct all in the same group, correct only specific steps, collectively correct some arbitrary steps,
Select one of Case 2: In-situ correction of the same group In the case of performing the correction based on the result of bending in the same group halfway, either all correction, only specific process correction, or batch correction of some arbitrary processes Select. Case 3; Correction of different group Select whether to correct different groups or not. Case 4: Acceptance of acceptance of depth value change Select whether or not to forcibly correct only a certain process. Case 5: Correction of different groups Either one of correction in different groups, correction of a specific process, or correction of some arbitrary processes at once is selected. Case 6: In-situ correction of different groups In the case of performing the correction based on the result of bending in the same group in the middle, all are corrected, only specific steps are corrected, or some arbitrary steps are collectively corrected. Select.

Table 1 shows an example of the correction condition setting table for the bent product (sash) shown in FIG.

[0025]

[Table 1]

In Table 1, in the "Group" column, it is shown which of the groups G1 and G2 the bending corner belongs to, and other bending corner symbols of the same group are also written in parentheses. In addition, whether or not the bending angle can be measured is shown in the “Measureability” column, and the correction valid corners in the same group are indicated in the “Correction in the same group” column. However, the instruction data in the "correction within the same group" column is sequentially overwritten for each process, that is, new data has priority. Further, whether or not to accept the correction is shown in the column of "correction acceptability". Further, in the column of "correction between different groups", each data of presence / absence of correction, display of correctable corner, indication of corrective effective corner is shown, and "angle measurement during bending" is shown.
The column indicates whether or not to measure the angle.

This correction condition setting table indicates what kind of correction is to be made for other processes when the bending process of each process is performed. Therefore, the correction is performed on the correction effective corner designated in each process. Further, the fact that the correction effective corner is designated in the column of "correction within the same group" means that the angle measurement is performed in the process. When the correction of the bending corner of the previous process, which has already been processed in the subsequent process, is instructed, the correction is effective from the bending process of the next work.

S5: Bending is performed from step 1. S6 to S7: Read data indicating whether or not to perform angle measurement from the correction condition setting table, and determine whether or not to perform angle measurement. When the measurement is to be performed, the process proceeds to step S8, and when the measurement is not to be performed, the step S8 is performed.
Proceed to 12.

S8 to S9: Since the angle measurement is performed, the bending process accompanied by the angle measurement is executed (S8), and then it is determined whether the measured angle is within the allowable value (S9).
Then, as a result of this determination, if the measured angle is within the allowable value, the process proceeds to step S10, and if it exceeds the allowable value, the process proceeds to step S11. S10: Interpretation of correction conditions and correction process execution routine.
Details will be described later with reference to the flowchart shown in FIG. S11: Since the measured angle exceeds the allowable value, the correction is stopped. S12: Since the angle measurement is not performed, the angle measurement and the bending process without correction based on the angle measurement are executed.

S13: It is judged whether or not the bending processes of all the processes are completed. If completed, the flow is ended, and if not completed, the process proceeds to step S14. S14: Proceed to the next step, and repeat the steps beginning with step S6.

Next, the interpretation of the above correction conditions and the correction processing execution routine (step S10) will be described with reference to FIG.

S10-1 to 10-2: It is judged whether or not the same group is to be corrected (S10-1), and when the correction is performed, the lower limit value of the ram relating to the bending corner whose bending angle is measured is corrected. The ram lower limit value related to the correction effective corner is changed based on the value (S10-2). On the other hand, if the correction is not performed, the process proceeds to step S10-3. S10-3: It is determined whether or not correction between different groups is to be performed. If correction is to be performed, the process proceeds to step S10-4,
When the correction is not performed, the flow ends.

S10-4: Which processing factor is different between the groups is detected from the correction condition setting table, and the correction route is selected by this detection. In the example shown in this flow, the grouping factors are the bending line length and the target bending angle, and one of the three correction routes (route 1, route 2, route 3) is selected by these two factors. It has become so. Although not explicitly shown in Table 1, the correction condition setting table includes, for example, a grouping table as shown in Table 2 which will be described later, and based on this grouping table, differences in processing factors between groups are To be detected.

S10-5 to S10-7: When only the target bending angle is different between the groups, correction calculation is performed for the bending angle difference as route 1 (S10-5), and when only the bending line length is different. A correction calculation is performed on the difference in the bending line length as the route 2 (S10-6), and when both the target bending angle and the bending line length are different, both the bending angle difference and the difference in the bending line length are set as the route 3. Correction calculation is performed (S10-7). S10-8: The ram lower limit value related to the correction effective corner is changed based on the correction value of the ram lower limit value obtained by the correction calculation.

In this embodiment, a plurality of bending corners are divided into two groups G1 and G2 according to the bending line lengths, but the corners having different bending angles as shown in FIG. 6 are used. In the case of a bent product having the following characteristics, there are five groups (G1, G2, G3, G4, G4) depending on the two processing factors of the target bending angle and the bending line length.
5) stratified. Table 2 shows an example of the grouping table in this case.

[0036]

[Table 2]

In this embodiment, as a bending angle measuring device,
The bending angle is measured by image processing by including a slit-shaped light source and a CCD camera that captures a linear light projection image by the light source, but the bending angle measuring device is not limited to such a device. Various types of sensors can be used, such as those that measure the difference in distance to the workpiece with multiple distance sensors (eddy current sensor, capacitance sensor, etc.) to detect the bending angle, and contact type measuring devices. .

In this embodiment, the lower die is fixed and the upper die is driven (so-called overdrive type), and the lower limit of the ram for driving the upper die is corrected. Can also be applied to a so-called underdrive type press brake in which the upper mold is fixed and the lower mold is driven. Of course, in the case of this underdrive type, the upper limit value of the ram for driving the lower mold is corrected by the same method as described above.

As mentioned above, it is obvious that the present invention can be variously modified. Such modifications are within the spirit and scope of the invention, and all such variations and modifications apparent to those skilled in the art are intended to be within the scope of the following claims.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of a bent product in the present embodiment.

FIG. 3 is a diagram showing a processing drawing for each step in this embodiment.

FIG. 4 is a flowchart showing a processing flow in the control system of this embodiment.

5 is a flow chart showing an interpretation of correction conditions and a correction processing execution routine in FIG.

FIG. 6 is a perspective view showing another example of the bent product in the present embodiment.

[Explanation of symbols]

1 Press Brake 3 Lower Die 4 Ram 5 Upper Die 6 Light Source 7 CCD Camera 8 Angle Measuring Unit 9 Bending Angle Calculation Unit 10 NC Device 11 Bending Product 12 Corrected Effective Corner Automatic Layering Device 13 Grouping Factor Identification Part 14 Allowable Range setting unit 15 Corner grouping unit 16 Correction condition setting unit 17 Correction data calculation unit 18 Process data change unit a to h Bending corners L ₁ and L ₂ Bending line length W Work

Claims (6)

[Claims] 1. A method for automatically correcting the amount of drive of a driving die, which measures a bending angle of a work during bending and corrects the amount of drive of a drive die based on the measured value, wherein the bending has a plurality of bending corners. When a processed product is obtained, a correction value for a die pushing amount related to another bending corner is calculated from a correction value for a die pushing amount based on a measured value of a bending angle relating to a specific bending corner. Automatic correction method for the amount of mold pushing. 2. Bending corners having the same machining factor related to the bending angle are grouped, and when the grouped bending corners are in the same group as the specific bending corner, the metal relating to the other bending corners is grouped. The method for automatically correcting the amount of die pushing in according to claim 1, wherein a correction value of the amount of die pushing in is calculated. 3. An allowable range is set in advance when the bending corners are grouped by a processing factor related to the bending angle, and when the value of the processing factor related to the bending angle is within the allowable range, the bending angle is set. 3. The method for automatically correcting the amount of die pushing in according to claim 2, wherein it is determined that the processing factors related to are the same. 4. When the grouped bending corner is a group different from the specific bending corner, the correlation between the group and the specific bending corner and the same group due to a machining factor related to the bending angle. 3. The method for automatically correcting the amount of pushing in a die according to claim 2, wherein a correction value of the amount of pushing in the die associated with the bending corners of the different groups is calculated according to the correlation. 5. An allowable range is set in advance when the bending corners are grouped by a processing factor related to the bending angle, and when the value of the processing factor related to the bending angle is within the allowable range, the bending angle is set. 5. The method for automatically correcting the amount of die pushing in according to claim 4, wherein it is determined that the processing factors related to are the same. 6. The processing factor related to the bending angle includes a target bending angle, a bending line length, an upper die shape and a lower die shape. A method for automatically correcting the amount of die driven in according to.