The Work Principle of the Hydraulic Press Brake

The hydraulic press brake can be divided into three varieties according to the different synchronization methods: torsion shaft synchronization, mechanical-hydraulic synchronization, and electro-hydraulic synchronization. The machine also falls into two types according to the different modes of motion of the bottom blade: fixed bottom blade or moving bottom blade.

The hydraulic press brake includes the support, a work table, and pinch-off blades which clamp the workpiece in a tight manner. Located on top of the support, the worktable consists of a pressure plate and the foundation to which the pinch-off blades are connected via hinges. The foundation is constructed of a shell, coil, and cover plate. The coil is placed inside the groove of the shell. On the top of the groove there is a cover plate.

The press brake can achieve a high bend angle precision of ±0.5° over the whole length of the bend. According to the customer's requirements, a 6-meter-long ball screw can be fitted to the machine. Driven by the servo motor, the ball screw can complete the task of precise positioning along the X-axis. Its positioning precision is ±0.05mm. The resolution of the servo motor is 0.01mm. The machine also can be installed with the CNC system. After operators get familiar with the CNC operation, they can use the machine to make complex bends with various bend angles and bend lengths. For the heavy-duty press brake, a deflection compensation device is adopted to control the deflection no more than 0.75mm/meter. The heavy-duty press brake can be supplied with weights ranging from 5 tons to 5000 tons. It is commonly used to process workpiece with huge weight and ultra-long lengths ranging from 1.6m to 8m. The machine is also suitable for mass production applications. Its critical parts are imported from foreign countries.

During operation, the wire passes current through the coil. The coil inside the foundation then produces electromagnetic force to attract the pressure plate by pulling it down to form a clamp between the pressure plate and the foundation. The clamp will hold the workpiece firmly which enables the machine to suit various processing applications. This type of press brake can process workpice with side walls. By changing the types of dies, the machine can be used for different forming jobs.

The CP series hydraulic press brake adopts a movable upper die and CNC system. Via the movement of the servo and proportional valves, the left and right cylinders are controlled to extend and return. This process moves the ram in the lowering and lifting movement. The synchronized movement of the ram is accomplished by using the electric ruler for signal feedback, servo-proportional valve for producing hydraulic flow, and the Sweden Cybelec CNC system for computer numeric control. The CNC system is equipped with 10-inch LCD screen, allowing human-machine dialogue. Workpice with various bend angles can be formed at one time.

The CP series press brake can accomplish three-point air bending with receiving signal feedback. Its top blade and bottom V die determine the bend angle of the workpiece. The reading accuracy of the electric ruler is 0.005mm. This ensures an accurate lowering distance for the movable ram. Repeated positioning precision along Y-axis is very high. This series of machine can handle cone-shaped workpiece. For example, the bend angle of the left side of the workpiece can be 88° while bend angel for the other side is 92°. The machine can be used to bend workpiece into various different angles at one time according to the operators' required specifications.