How To Choose CNC Press Brake Anti Deflection Table
In the process of bending, the CNC press brake exerts force on the sheet metal, at the same time, the sheet metal will also produce a reaction force on the bending machine, which will make the machine frame deformation, thus affecting the accuracy of the bending sheet metal. Therefore, in order to improve the bending accuracy, two kinds of press brake machine anti delfection methods, mechanical anti deflection and hydraulic anti-deflection , emerged as the times require. When choosing CNC bending machine, we should consider not only the number of tons of bending machine (bending force of bending machine), knife edge width, throat depth and column spacing, but also the compensation mode of CNC bending machine.
Because the two kinds of bending compensation modes have different requirements for the operators, different product precision, and it is very important for the buyers to know what compensation mode to choose.
Hydraulic compensation means that there are several small cylinders under the worktable. When the machine is deformed, additional force is applied through these small cylinders to compensate, so as to reduce the influence of machine deformation on the folded plate. In the CNC system of the machine, the parameters of the CNC system of the bending machine are set according to the length and thickness of the folded plate. The required compensation amount is calculated by the computer system, and the instructions are transmitted to the compensation amplifier. Hydraulic compensating proportional valve receives the signal from compensating amplifier to control the small cylinder beneath the worktable to protrude and reduce the deflection and deformation of the sheet metal.
However, the compensation amount of hydraulic compensation is affected by many factors, such as whether the hydraulic oil leaks, joint loosening, etc., which will affect each hydraulic compensation amount, resulting in inconsistencies and differences in each processing plate. Hydraulic compensation system is more complex, which may cause oil leakage and loosening of sealing ring. The advantage of hydraulic compensation is that with the increasing use of time, the machine will not have wear problems, while mechanical compensation will have wear problems.
Comparing with mechanical compensation, the hydraulic compensation machine is simple to operate and has low requirement for workers, so the workpiece with high precision can be folded out. Moreover, the machine with hydraulic compensation system can ensure the full contact between the upper die and the sheet metal, so as not to allow the displacement of the sheet metal. Considering the durability of the machine and the simplicity of operation, it is better to choose the hydraulic compensation machine.
Hydraulic compensation uses small cylinders to compensate the worktable, while mechanical compensation uses wedge blocks to compensate the worktable. The oblique wedge block can be divided into single oblique wedge block and multi-group oblique wedge block. The mechanical compensation consisting of several groups of inclined wedges has more compensation points, more than three compensation points of common hydraulic compensation. There is no compensation blind zone. The workpiece folded has high precision, and the difference between sheets processed each time is small. It is suitable for batch production. The mechanical compensation system is simpler than the hydraulic compensation system. It will not leak oil and other conditions. It has low failure rate and is environmentally friendly. However, the mechanical compensation will wear with the passage of time, which will affect the compensation effect. Mechanical compensation operation requires high requirements. If the same workpiece needs bending several times, workers need to adjust it in real time. Even if the worker has enough experience, unpredictable errors will occur. If the workpiece does not need multiple bending, the worker has higher technology. Considering the accuracy of the workpiece, mechanical compensation can be chosen. However, in actual production, the cost of the worker with high technology is also high, so it should be considered comprehensively.
