Hydraulic press brakes are essential tools for many industrial-grade metal fabrication shops not just in America but also around the world—they’ve made entire industries come to life. But many operators still misunderstand the machines, which not only can lead to unproductive work but also cause accidents and poor workmanship.
Fortunately, we gathered the practiced wisdom of press brake techies and owners to help you understand the machine better—whether you already have one or considering getting a brand-new hydraulic press brake for sale.
Unlike a mechanical press brake which uses mechanics, a hydraulic press brake uses hydraulics (various hydraulic press brake components) to force its ram down on a workpiece.
Modern machines have about 12 programmable axes of movement compared to just one in early generations of hydraulic press brakes for sale.
The machines’ coordinates comprise of several axes including Y1 and Y2 which control the ram’s upward and downward movements, V which controls the crowning, and X1, X2, R, Z1, Z2 are all backgauges that control backgauge positioning.
Best use cases include metalworking jobs that demand steady pressure throughout the stroke length of the machine, high-pressure/force, varying force, and varying stroke lengths.
Hydraulic press brake weight can range between 5 tons and over 300 tons. It'll depend on the size of the machine, which, in turn, will determine the size and metalworking capacity of the machine.
Petroleum oil typically serves as the hydraulic oil. It is energized, pressurized, and transmitted by a pump to cylinders (actuators), which in turn direct it to energize the machine’s pistons which then cause bending tools’ motion. De-energized oil travels back to the pump and the process repeats again.
The best hydraulic oil is antiwar hydraulic oil ISO VG46#. Its average value of viscosity is 46mm2/s when operating temperatures are at 40 degrees Celsius.
Try not to use the press brake at temperatures under -5 degrees Celsius. If you must, first run the machine idle to heat it up. For prolonged use, consider also using ISO VG32# hydraulic oil and an oil heater. If temperatures hit 70 degrees Celsius and above, consider using a hydraulic oil cooler.
After every 2000 operation hours, take an oil sample from the tank and have a trusted supplier analyze its viscosity so you can know for sure whether you replace or just filter it for further operation.
When changing hydraulic oil, thoroughly clean the tank before filling in new oil. Do not use cotton yarn as it can leave a residue that can contaminate the oil, clogging the hydraulic circuit, disrupt optimal working conditions, and even shorten the system's life. Use a cleaning towel instead including when drying the tank.
To properly fill the oil, screw the air filter so you can filter the oil through. Only fill oil directly if your oil container has a filter attached. Then look at the oil gauge; the oil should go up to the 80% to 90% level of interspaces when the ram is stopped at the top dead spot.
The hydraulic pump acts as the machine’s generator while the pistons (actuators) act like motors. Their sizes hence power depend on the overall press brake tonnage capacity and required bending-angle.
Traditionally, the hydraulic motors’ power density by volume has exceeded that of electric press brakes by up to 10 times. Note, though, that hydraulic press brake pumps are operated by either an engine attached to gears, flexible couplings, belts or an electric motor.
Expect the pump to be an axial piston, vane pump, radial piston, or gear pump.
For emergency top punch stops, foot pedal switches have one button on top for quick hand operation. For increased safety near the backgauge, the machine should ship with steel safety guards for fitting around it.
Modern hydraulic press brakes also have smart computers that quickly figure optimal tools’ settings to reduce set-up time.
The stroke length of the piston can be programmed to vary per the shop's angle of bend and metal sheet thickness needs. Pressing speed can also be varied or made to remain constant throughout.
Control valves direct even amounts of hydraulic oil (hence fluid quantity and energy level) to specific actuators to control bending action hence angle of bending and its accuracy.
Ultra-modern machines now have interactive touchscreens for even easier data input and output to boost accuracy in workmanship, reduce wastage, and improve productivity.
With these hydraulic press brake tips and tricks, you can confidently lookout for a top-notch hydraulic press brake for sale or have a deeper understanding of preventive maintenance at your fingertips.
Over to you.
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About the Author
Amos Fred Joined: April 24th, 2018 Articles Posted: 205
