CNC Press Brake Repair: Your Ultimate Guide

General requirements

Lubrication part:

Check the lubrication of the guide rail, bearing, bolt, chain and all moving and drive parts to ensure they are clean, rust-free and properly lubricated (replace the lubricating oil if necessary).

Fill the lubricating oil according to the specified brand, check and drain the lubricating nozzle and piping to ensure normal operation.

Mechanical part:

Check whether the transmission parts function normally and whether they are worn, and the fastening of the screws of the main parts.

Hydraulic part:

Clean or replace the filter, dredge the hydraulic pipeline, clean the oil tank, check the condition of the oil, filter or replace the appropriate hydraulic oil if necessary, check the hydraulic pipeline, tighten the pipe joint to prevent oil leakage.

Electrical part:

(Turn off the power supply) clean the electrical cabinet, clean the surface of the motor, tidy up the wires and gutters of the cabinet, make sure they are clean and beautiful, there are no sundries in the cabinet, and remove dust from the cabinet.

Check the operating condition of the extractor fan and motor fan to ensure they are working properly.

Replace damaged switches, buttons, indicator lights and instruments, and tighten the main circuit terminal of electrical appliances above 5kW into the electrical panel.

Machine surface:

Scrub the outer surface of the machine such as guide rail, column, protective cover, etc.

Security devices:

Various equipment safety devices are effective without fail, such as photoelectric protection switch, emergency stop button, etc.

Press Brake Maintenance Chart

▲Spot check ■Cleaning ●Supplement ★Replace

CNC press brake maintenance

Hydraulic system

Hydraulic oil

1) Hydraulic oil filling method

• Move the ram to top dead center and support both ends of the ram with wooden blocks of equal height.
• Unscrew the oil drain plug at the bottom of the oil tank to drain the hydraulic oil.
• Clean the oil tank.
• Refill with new hydraulic oil through the air filter in the oil filler to the 2/3 oil standard position and stop the ram in the top dead center position.
• Let the hydraulic oil circulate for about 1 hour before restarting the machine
• After circulation, reinsert a 10um filter element

2) The following hydraulic oils are recommended for press brake

Note: Do not mix hydraulic oils from different brands.

3) Some precautions

The oil level must be checked quarterly.

When the ram is in the top dead center position, the oil level can be seen by observing the liquid level scale line and the liquid temperature agent.

If necessary, fill with hydraulic oil through the air filter in the oil tank filler neck.

When the ram is in the top dead center position, the oil level should reach the upper traced line of the liquid temperature agent (visible on the back of the oil tank).

After 200 working hours, the filter element must be cleaned and checked every 6 months or 1000 working hours.

The oil temperature in the oil tank works in the range of 10℃~60℃. If it exceeds this range, temperature increase or decrease measures must be taken.

Hydraulic oil should be changed every 2 years or 4,000 working hours, and the first time should be after 2,000 working hours of the machine. 500 labor hours for the first exchange and 2,000 labor hours for future use will be a good option.

Oil filter

Regularly clean the system oil filter with solvent (gasoline, trichloroethylene, etc.).

The CNC press brake should be cleaned for the first time one month after commissioning and then regularly every two months.

Air filter

The air filter is installed on the oil tank cover.

It must be cleaned for the first time two months after the machine is commissioned.

After washing with solvent (gasoline, trichloroethylene, etc.), it must be cleaned regularly every four months.

Pipe connection

In case of leakage, tighten the pipe joint. If that doesn't help, replace the gasket.

Sometimes the high pressure oil pipe in the hydraulic oil circuit must be replaced.

When installing the ferrule type pipe joint on the high pressure pipe, the following provisions must be observed:

• The pipe cutting angle must be correct and the pipe hole must be deburred
• The nut and ring can slide on the tube and the thick edge of the ferrule faces the nut
• The thread of the pipe joint, ferrule and nut must be lubricated and screwed manually at the beginning
• Then tighten it with a wrench until the pipe cannot rotate in the pipe joint
• Then tighten the nut with a wrench for 1 ~ 1.25 turns

Seals

If the valve block leaks, replace the corresponding sealing ring or matched sealing ring in time.

If the oil cylinder leaks, please replace the oil cylinder sealing ring in time.

Mechanical parts

Regularly check the fasteners of all mechanical parts for looseness, lubrication and wear of the sliding block guide rail.

If any abnormalities are found, they must be corrected in time before they can be used again.

Good lubrication is an important condition to ensure normal operation and extend the life of the press brake.

The machine must be lubricated weekly (or every 40 hours of work). No. 3 calcium-based grease is selected and injected into each lubrication point with a grease gun.

Even if there is no lubrication point on the sliding surface of exposed parts and bearings, it should also be lubricated once a week.

The location and name of each lubrication point are shown in the figure below:

Main Overflow Valve

Adjustment of the main relief valve is very important for the operation of the machine. The normal setting value is equal to the maximum allowable pressure.

Weekly inspection

• Basic detection
• Check parallelism
• Inspect unit components
• Mold: Check for Cleanliness and Damage
• All threaded connection tests
• Guide rail detection
• Guide rails: Lubrication
• Sensor signal transmission detection
• Ram tightness test
• Rear stop: check synchronous belt tension
• The reference point position of each rear stop axle should be tested once a week. If there is any deviation, it must be compensated in the NC system
• Rear stop trigger detection
• Rear retention material tightness test

Precautions for maintenance

When operating or overhauling the press brake, follow the following specifications to ensure safety.

1. When energizing the machine, confirm the safety of the surrounding environment.
2. Stop the machine and cut off the power before replacing components, checking and repairing.
3. Do not wear loose clothing, gloves and ties to operate the machine.
4. When operating the machine, the electrical panel door must be closed and the external power supply must be cut off when performing maintenance on the electrical panel.
5. At the beginning of the operation, it is necessary to check whether there are obstacles within the movement range of each axis.
6. Do not disconnect electrical components, cable plugs and wiring when the machine is on and in operation.
7. To ensure safety, the machine must operate in a bright, clean and orderly environment.
8. When entering the hazardous area of ​​the machine, make sure the emergency stop button on the operation panel is pressed.