What are The Hydraulic Systems of The Bending Machine?

Bending machine is a widely used bending machine, which has already been hydraulicized. As an important piece of sheet metal processing equipment, the bending machine plays an irreplaceable role and plays a decisive role in the quality, processing efficiency and accuracy of the product.

What are the hydraulic systems of the bending machine?

Bending machine

　　 Generally, the hybrid hydraulic press brake is an upper piston press, which is composed of a frame, a slider, a hydraulic system, a front support frame, a back gauge, a mold, and an electrical system.

Two parallel working hydraulic cylinders form vertical downward pressure to drive the mold on the bending beam to perform bending work. As the brain of the bending machine, the hydraulic control system mainly controls the synchronous operation of the bending process and the positioning of the hydraulic cylinder when the machine is working at full load. I will take a certain type of universal bending machine as an example to analyze the hydraulic system.

⑴Oil pump starts

The motor rotates in the direction marked by the pump arrow, that is, clockwise, driving the axial plunger pump to run. The oil enters the valve plate and the electromagnetic overflow valve return tank through the pipeline. When the No. 19 valve is closed, the No. 20 cylinder lower chamber The oil keeps the slider at a fixed position.

⑵ downward movement

The rapid downward movement of the bending machine is generated by the weight of the bending machine beam and various accessories and the pressure of the oil. During this process, the rodless cavity of the hydraulic cylinder is filled with oil through the filling valve. The rod cavity will generate back pressure and the oil will flow back quickly. The fast-forward movement starts from the top dead center. After a short deceleration stage, the speed of the slider slows down at a certain distance close to the bent sheet.

⑶ bending

The bending stage starts from the pressure build-up of the rodless cavity. The bending speed of Anhui Yongya is limited on the one hand by the fuel supply of the oil pump, on the other hand, it can be adjusted by the proportional valve directional valve. At the same time, the directional valve also controls the synchronous operation of the bending beam and the positioning of the bottom dead center. The limit of the bending force is accomplished by the proportional relief valve to limit the pressure of the pump. The corresponding given values ​​of speed, synchronization, positioning and pressure all come from the CNC.

⑷Decompression

The decompression of the rodless cavity starts when it reaches the bottom dead center, or after a short holding time, so that the material has enough time to shape and further improve the dimensional accuracy of the part. Both holding and decompression are completed by the proportional directional valve in accordance with the instructions of the CNC. In order to improve processing efficiency, the decompression time must be as short as possible, but in order to avoid unloading impact in the entire system, it is required to extend the decompression time as much as possible. In short, the decompression curve should be as stable as possible and not too steep. The optimization of the whole process is realized by the proportional directional valve.

⑸Master cylinder return

The flow rate of the pump and the pressure bearing area of ​​the rod cavity of the hydraulic cylinder determine the maximum return speed. In most cases, it is close to the maximum speed.

The return stroke also requires synchronous operation, from the beginning of the decompression of the rod cavity to the end of the top dead center.

At the moment of the return stroke, the No. 8 YV2 electromagnet is required to reset for 2 seconds to relieve the pressure, and then the No. 11 YV3 and No. 24 YV6 electromagnets work, the slider returns, and the return speed is constant.