Common problems of bending and clamping
In the long-term processing, although the Press Brake is regularly maintained, for the wear-resistant parts such as fixtures and molds, simple maintenance can no longer guarantee its bending accuracy requirements, resulting in the angle of the formed workpiece often fluctuating. The excessive bending angle will affect the bending accuracy of the workpiece, and even affect the normal progress of subsequent welding and other processes.
As a result, the operator complained that it took time to install the knife to tighten the screw, set the knife, knock on the splint / clamp, and die pad paper under bending, etc., which made the debugging of the product longer and longer; the management complained that the waiting time of the equipment increased The production schedule was postponed, the product quality was reduced, and lean production was nowhere in sight; the boss complained that the personnel cost had not decreased, the equipment was depreciated as usual, and the product accuracy was getting lower and lower.
Clamping system upgrade case
How to help sheet metal companies improve productivity, improve product processing accuracy, and reduce unnecessary waste of equipment downtime by upgrading the bending system of the Press Brake? For this reason, WILA provides an efficient solution for upgrading the clamping system of the Press Brake. Taking a precision sheet metal customer project in Shandong as an example, the nominal pressure of the customer's Press Brake is 80t, the table length is 2.6m, the maximum opening height is 500mm, and the bending upper die fastening method is manual quick clamping, as shown in Figure 1. As shown, the lower mold base is locked on the lower mold guide rail by screws.
The equipment was put into use in 2007. The equipment is in good operating condition and the overall production efficiency is slow.
⑴ It takes 5 to 10 minutes to fill the full length of the upper die. Select the segmented upper die, especially when clamping the special position, it takes longer to install the knife.
⑵ There is no quick clamping function when the upper die is bent and reversed. It is necessary to manually tighten the screws. It takes 15 to 30 minutes to fill the full length of the upper die. If a segmented upper die is selected and the clamping is performed at a special location, the time will increase accordingly.
⑶Bending the special-shaped workpiece needs to consider the mold clamping position, manually move the quick clamp multiple times.
⑷After replacing the mold, the upper and lower molds need to be adjusted frequently.
⑸The lower mold base needs to be disassembled and turned direction, which increases the labor intensity of the operator.
⑹The angle deviation is large when bending long workpieces, and the angle needs to be adjusted by means of paper padding, knocking the clamp block and other means.
According to the structural form, opening height and product characteristics of the upper beam and lower beam of the Press Brake, the upgrade and transformation plan mainly uses the upper hydraulic clamp of the WILA standard model NSCL-I-HC / ES II-2550 and the model OB-I-HC -Ty / ES IV-2550's lower hydraulic clamps, these hydraulic clamps have the characteristics of fast, safe and uniform force, which can make the mold automatically sit and automatically calibrate, and the bending process saves time and effort, as shown in Figure 2. In addition, the transformation program also selects the upper mold of model BIU-021 and the lower mold of model OZU-010. The key dimension accuracy of these molds can reach ± 0.01mm. Due to the use of CNC deep quenching hardening technology, its hardness can reach 56 ~ 60HRC, hardening depth up to 4mm, while ensuring high precision and durability.
Figure 2 Hydraulic clamping system used for upgrading
After the upgrade is complete, the new clamping system (Figure 3) implements the following functions.
⑴ One button signal can realize clamping of all upper and lower molds in about 3 seconds.
⑵ After the fixture is installed and calibrated for the first time, Tx / Ty alignment is completed. Subsequent replacement of the mold is permanently free of tool setting, and the mold is installed and ready to use.
⑶The front and back of the mold are equipped with knives, and the center line of the upper and lower molds is consistent.
⑷It takes only 1 to 2 minutes to fill the full length of the upper mold, and the upper and lower molds can be clamped at the same time.
⑸The mold can be clamped at any position of the fixture.
⑹The fixture has a local angle fine-tuning function, which can compensate the accumulated errors of plates and equipment.
Figure 3 Upgraded equipment
Many times using full-length carbon steel plates for bending tests, the bending angle deviation range is controlled within ± 0.2 °, in addition to the accuracy of the bending angle reaching the customer's requirements, due to the need for tool-free, quick clamping of hydraulic clamping A series of advantages, equipment downtime and waiting time are greatly reduced, reducing the operator's experience requirements and labor intensity, and the overall use efficiency is increased by 30%.
In the context of economic globalization, companies are increasingly demanding lean production, efficiency improvement and cost control. The efficient solution for upgrading the WILA clamping system meets the requirements of customers for the quality of precision sheet metal, while greatly increasing the discount Bending productivity, with a high return on investment.
——From "Durmapress" No.0506001, 2020