Hydraulic press brakes range from portable 50 ton units to 3,000 ton models. They may come with an advanced user interface, programmable tooling and CNC tool supports. Though the average press brake has become smarter, the underlying mechanics haven’t changed. The hydraulic circuit, mechanical system, tooling and electrical system all need to be maintained. Here are the fundamentals of proper press brake maintenance.
Perform a Daily Inspection
At the start of each day, inspect the machine. This allows you to identify problems before they are serious. Make sure the press brake is clean. The table and die shouldn’t have any mill scale on them. If there is already tooling on the machine, make certain the punch and die alignment are correct. Check that the back gauge fingers are located where the readout says they are located.
Verify that the punches and dies don’t have any dents. Don’t use any tooling that’s cracked because this indicates it needs to be repaired or replaced. Significant warping of the press surface or major oil leaks are red flags. This might be a sign that press brakes need to be replaced.
Before you start work, make certain all safety measures are working correctly. For example, check the palm buttons, foot pedal controls, and indicator lights. Verify that any other guarding that is present is set up correctly. If there is swelling in the hose lines between the system and the hydraulic pump, the pipes need to be replaced.
Maintain the Hydraulics
You’ll need to keep the reservoir full and the oil clean. You can check the hydraulic oil level just as you would your car oil. What you can’t afford to do is ignore this since insufficient oil levels will interfere in the operation of the ram. If it is bad, the hydraulic pump could be damaged. At a minimum, the extra wear and tear shorten the pump’s life. Therefore, add oil as required, but make sure it is the same type of oil as is already in the system.
If the press brake comes with a hydraulic tool clamping system such as those used for punch and die clamping, the oil level in this needs to be checked, too. It is a simple visual check, but it will be in addition to the system’s own oil level indicator.
Check the Oil Quality
The oil level check should be done daily, though a machine shop using the unit consistently may do so every shift. After every 2,000 hours of operation, the oil’s quality and viscosity should be checked.
After all, most problems with pumps and valves are due to dirt present in the oil. You perform this check by cleaning the tank and suction filters. There will be both a screener filter by the pump inlet and one at the pump outlet. Clean the filters, or if really dirty, replace them. Check the air filter on the oil tank’s cover. It may be cleaned with compressed air, but it may need a more vigorous cleaning or outright replacement. The next step is checking the cleanliness of the oil. It should have a cleanliness of five microns unless the press brakes have proportional valves in place of the more common servo valves.
While most pumps have a built-in warning light for when maintenance is required, you don’t want to wait for that to go off. However, if it does, then either the oil temperature is out of range or the oil filters need to be replaced.
Conclusion
Your press brake must be well-maintained if you’re going to avoid defective products. And good maintenance will extend its life and minimize costly breakdowns.
Image source: Wikipedia Commons
