JPS6163317A - Detecting and correcting methods of bend angle - Google Patents

Abstract

PURPOSE:To make the full automation of a bend work easy and to cope with the change in bend angles due to the change of the quality by detecting automatically a bend angle and by performing a re-work in case of the bend being in short. CONSTITUTION:A steel plate 5 is bent by a bend beam 2 upto beta1 taking into consideration a spring back for bending to the bend target angle alpha0. The bend beam 2 is retreated then and a sensor 3 detects that the distance between the steel plate 5 and beam 2 is made (l) and from the bend beam angle beta2 at that time, the angle alpha2 after the spring back of the steel plate 5 is found. In case of a short bend with the comparison of the alpha0 and alpha2, a re-work is performed from the beam 2 upto the beta2, taking into consideration the correction for the spring back angle alpha2-alpha1. After completion of the bend work the beam 2 is retreated and the bend angle of the steel plate 5 is detected and in case of a short bend a similar work is repeated and if there is no shortage the bend is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to VC bending of a steel plate, and particularly to a method for detecting and correcting insufficient bending of a steel plate.

[Background of the invention]

In the bending work of conventional bending equipment and press bending equipment,
Due to changes in the material of the steel plate, changes in pressurizing force due to changes in equipment oil temperature, etc., it became impossible to perform bending under the same conditions, and a phenomenon occurred in which the bending angle α was not constant. For this reason, in manual bending work, the bending angle of the steel plate is measured after the bending process, and if it is insufficient, it is reprocessed and the
Problems such as the repetitive work of measuring the angle of the steel plate, a decrease in work efficiency due to the loading and unloading of the steel plate into the equipment, and variations in accuracy due to bending angle measurement errors have occurred. In recent years, numerical control methods have become mainstream in automatic level bending work, but with this method, variations in the bending angle can occur with constant numerical control data, while changes in the amount of spring/gback due to changes in the material of the steel plate. , which requires manual input of bending numerical control data corresponding to the material of the steel plate, making it impossible to fully automate the process. There is also a method of bending while detecting the bending angle of the steel plate (Japanese Patent Application Laid-Open No. 57-207803), but in this method, after bending, the bending angle due to springback when the die is released is measured before the die is released. Since it is impossible to deal with changes after the mold is released, it is effective to detect the bending angle after releasing the mold and rework the mold if the bending is insufficient, as in this method.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a bending device that automatically detects the bending angle, performs reprocessing if the bending is insufficient, and can cope with changes in the bending angle due to variations in workpiece material.

[Summary of the invention]

A feature of the present invention is that after the steel plate is bent, it can be released from the mold, the bending angle can be detected to determine whether the bending is insufficient, and if the bending is insufficient, reprocessing can be performed. be. Therefore, it is easy to fully automate the bending process, and it is possible to accommodate changes in the bending angle due to changes in material.

[Embodiments of the invention]

FIG. 1 shows the inventive stamp of the folding device. Five steel plates are fixed to the table IVC and bent by the pend beam 2.

The bending angle of the pend beam 2 is detected by an encoder 4 and fed back to a control device 6 of the bending device. In (a), the bending objective angle α. In order to bend the steel plate 5 to β1, the bent beam 2 is bent in consideration of spring back.
Bending process. After completing the bending process, bend beam 2
moves backward, and the sensor 7 detects that the distance between the steel plate 5 and the pend beam 2 has become t, and the angle α2 of the steel plate 5 after springback is determined from the pend beam angle β2 at this time (b). Compare α0 and α2, and if there is insufficient bending, (C
). Taking into account the current correction for the springback angle α2-α1, reprocessing is performed from the pend beam 21C to β. After the bending process is completed, the pend beam 2 moves back,
If the bending angle pattern of the steel plate 5 is detected and the bending is insufficient, the same process is performed again, and if the bending is not insufficient, the bending is completed (d).

FIG. 2 shows an algorithm of the two steps shown in FIG. When the bending angle β1 of the pend beam 2 in execution block B is the first bending angle β1 (i=1),
The bent bicom bending angle for the target bending angle α0 shown in Table 1 is determined from the table in which it is registered, and in the case of rework, the spring angle (old bending angle for the target angle α0) shown in Table 2 is calculated. Determine from the table in which the pe/dopim angle is registered.

- Table 1 Table 2 Table 1 shows an example where the target bending angle is 30' to 120', but other angles may be used. Table 2
Although the springback angle changes due to changes in the material of the steel plate, etc., the correction amount shown in is registered as the correction amount that corrects the minimum case of this change. This is to prevent excessive bending during the first crushing. In the data table of Table 1, since the springback angle also changes depending on the difference in the target bending angle, a springback angle correction table is provided for each target angle. Although the springback angle is shown in the range from 1 o to 20', other angles may be used.

A principle diagram for calculating the bending angle of the steel plate from the angle &β1.1 of the pend beam 2 in the execution block E is shown in FIG.

The sensor 7 shown in FIG. 3 has an M angle 1' (
ml), and the angle θ formed by the steel plate 5 and the bent beam 2 can be determined by tan-' t/a,
□ Angle αI of the steel plate 5 from the angle of the pend beam 2.

teeth, αI*1=β1. I-θ =β141 tan-'- It can be found by

In the above embodiment, the algorithm was to bend the steel plate as many times as needed if the bending angle was insufficient, but if the desired bending angle was within the range of α0±0.3°, the steel plate could be bent in the first bending process. Since the characteristics are known, the bending can be completed on the second bending.

In addition, although the embodiment describes the case where the present invention is applied to a folding machine, even in the case of a press bending machine, it is possible to attach a sensor near the tip of the mold or add a tracking device to hold the steel plate. Alternatively, after bending, it is possible to measure the angle while raising the press die, and if the bending angle is insufficient, it is also possible to rework.

〔Effect of the invention〕

According to the present invention, even if the springback angle of the steel plate is not constant, it is possible to correct insufficient bending. If the present invention is applied to a manual-level device, there is no need to take out the steel plate after bending it, carry it in again for reprocessing, and then take it out again and re-inspect the angle. If applied to an automatic leveling device, there will be no change in bending numerical control data due to changes in the material of the steel plate, and it will be easy to respond to changes in the springback angle.

[Brief explanation of drawings]

FIG. 1 is a step diagram of an embodiment of the present invention, FIG. 2 is an algorithm diagram of an embodiment of the present invention, and FIG. 3 is a diagram of the principle of angle detection by a sensor. 1...Table, 2...Pend beam, 3...Sensor, 4...Work/coder, 5...Steel plate, 6...
For bending equipment --N- No. Z opening

Claims (1)

[Claims] 1. A device comprising a bending device, a table for holding a steel plate, and a follow-up device, wherein the die is released from the steel plate after bending of the steel plate is completed, and then attached to the die. a device that detects the current position of the mold, and a device that detects the current position of the mold, and in the process of the mold moving away from the steel plate, the sensor generates a signal indicating that the steel plate and the mold have become a certain distance apart. A device that detects the bending angle from the current position of the mold detects the bending angle of the steel plate, and if the bending angle is insufficient for the intended bending angle, re-bending is performed to achieve the desired angle. A bending angle detection and correction method characterized by repeating reprocessing until the bending angle is reached.