The sheet metal CNC press brake bending machine is a widely used CNC press brake bending machinery that has already achieved hydraulics and quickly realized numerical control in the 1980s. According to incomplete statistics, CIMT95 exhibited 18 CNC press brake bending machines, including 7 from foreign countries and 11 from China (including 1 from Taiwan). Except for one in Taiwan, all 17 of them are CNC press brake bending machines. At previous international machine tool exhibitions in China, there were many CNC press brake bending machines exhibited this time, and there were also many domestically produced CNC press brake bending machines with high levels of expertise. The sheet metal CNC press brake bending machine can perform various angles of straight bending on metal sheets using simple molds to obtain complex-shaped metal sheet parts. It is easy to operate, has strong mold versatility, and low operating costs, thus it has been widely used. Sheet metal CNC press brake bending machines can be divided into two categories based on their transmission form: mechanical CNC press brake bending machines and hydraulic CNC press brake bending machines. At present, mechanical CNC press brake bending machines have been replaced by hydraulic CNC press brake bending machines. The advantage of hydraulic CNC press brake bending machine is that it has a large working stroke and can generate nominal force at any point of the stroke; Adjustable bending stroke, pressure, and speed, easy to implement numerical control; Can achieve fast approaching and slow bending, meeting the process requirements for workpiece bending; By adopting a multi cylinder synchronous system, the bending accuracy has been greatly improved, and the linkage of multiple CNC press brake bending machines has been achieved, expanding the process range of the CNC press brake bending machine. The CNC hydraulic sheet metal CNC press brake bending machine is a metal sheet processing machine tool that has been introduced early, widely used, and produced by many domestic enterprises. It has developed from the early 3-axis to the current 8-axis control, and can be used in conjunction with loading and unloading robots and bending robots to form a CNC bending unit.
The emerging building material decoration industry at home and abroad has put forward higher requirements for the required metal decoration materials, which require that the bent metal sheet metal workpiece has the smallest possible edge radius and no refraction on the surface of the metal sheet workpiece; The bending section shape of metal sheet workpieces is required to be more complex, which can better reflect the designer’s trendy design style.
To design a vertical sheet metal CNC press brake bending machine, a hydraulic transmission is proposed for the up and down movement of the slider and bending mechanism. The working cycle required to be achieved through electro-hydraulic control is: fast descent → slow pressure (bending) → fast return. Bending force Fmax=0.5 × 106N, slider gravity G=12000N, rapid descent speed v=20mm/s, slow pressure (bending) speed vg=10mm/s, rapid ascent speed vg=45mm/s; The stroke of rapid descent is 150mm, the stroke of slow pressure (bending) is 30mm, and the stroke of rapid ascent is 180mm; Start and brake time △ t=0.15s. Require hydraulic balancing of the weight of the slider and bending mechanism to prevent self-weight sliding; The friction force of the slider guide rail can be ignored. As an executing component, it drives the slider and bending mechanism to perform bending operations on the sheet metal.
