Malfunction analysis of CNC Press Brake

Views: 1368     Author: Durmapress     Publish Time: 2020-06-08      Origin: Durmapress


Malfunction analysis of CNC Press Brake

The guide rail of the slider must be lubricated once a day. Generally, before starting the Press Brake machine, the slider is in the bottom dead center position.

Lubricate the guide rail of the slider once, and clean and lubricate the ball screw and linear guide weekly.

Lubricate the guide rails and screws of other sliding parts. After the new machine has been running for half a year, you must replace No. 46 or No. 32 anti-wear hydraulic oil

And high pressure filter element, replace hydraulic oil and high pressure filter element once a year. Every month should check whether the connection between the cylinder and the slider is loose

Whether the backgauge timing belt is loose or not, check the gap between the longitudinal rail and the lateral rail every month, and adjust it in time.

1.Press Brake Mechanical Questions

Press Brake Mechanical Questions.

Fault 1: The guiding gap between the slider and the guide rail is too large, and an abnormal noise is emitted. This type of failure is due to the long use time of the guide rail,

Being worn causes the gap to increase. Need to check the degree of wear of the guide rail pressure plate, depending on the degree of wear to determine whether to replace the guide

Adjust the rail pressure plate to meet the required gap.

Fault 2: The rear gear transmission is invalid. The failure of the backgauge transmission is due to the separation of the transmission shaft and the key bar of the synchronous pulley or the synchronous leather

Take off. Such faults need to reassemble the key bar and timing belt, and check the electrical part.

Trouble three: The parallelism deviation between the linear guide of the backgauge beam and the center line of the mold is too large. Such failures need to be released with the "X" axis of the Steel Bending Machine is the same

Step belt, readjust to the parallelism tolerance range, re-install the timing belt.

Fault 4: The connection between the cylinder and the slider is loose, causing the bending angle to be inaccurate or the machine unable to find the reference point. Such failures require heavy

Newly check and tighten the connecting nut between the slider and the cylinder.

2. Press Brake Hydraulic Questions

Press Brake Hydraulic Questions

Fault 1: No pressure in the hydraulic system of CNC Bending Machine. 

1). Whether the solenoid coil of the proportional overflow valve is energized and whether the voltage of the proportional solenoid coil matches

Meet the requirements, such as the above reasons, please check the relevant electrical reasons. 

2). Check whether the cartridge valve is stuck or the main spool is

Whether it is stuck, and the damping hole is blocked, if it is the above reason, please remove the overflow valve to clean it, reinstall it


3). The phase adjustment of the three-phase power supply causes the motor to reverse.

Fault 2: The slider turns fast and slow, and the time pauses too long. 

1). Check whether the oil level of the fuel tank is too low and the filling port is not submerged.

When fast-forwarding, the upper chamber of the cylinder is filled with liquid and sucked up, causing insufficient filling. Such as the above reasons, you can add tank oil to the filling port5mm square or more so that the filling hole is completely submerged. 

2). Check whether the fast forward speed is too fast, causing insufficient liquid filling. Such as

The above reasons can reduce the fast forward speed by modifying the system parameters Of Metal Bending Machine

3). Check whether the filling valve is fully opened, eg.

If the oil is contaminated, the spool of the filling valve will be inflexible and stuck, which will cause insufficient filling. Need to clear

The refill valve is reinstalled to make the valve core flexible and free.

Trouble three: The return of the slider is normal, the fast forward is normal, the manual cannot slow down, and the folding plate is weak. 

1). Check control filling control

Whether the "two-position four-way" directional valve of the oil circuit is working properly, if it is, it causes the filling valve not to be closed, so that the upper chamber and theThe filling ports of the fuel tank are connected and pressure cannot be built. The reason why the valve does not work properly is that it is not energized or stuck.

2). Check whether the filling valve is stuck. If so, please clean the filling valve and reinstall it to make the valve core flexible and free.

Fault 4: The return speed of the slider is too slow, and the return pressure is high. The main reason Of the Hydraulic Bending Machine for this type of failure is that the filling valve is not opened. This phenomenon is just the same as the above.

The logical relationship of the phenomenon of fault three is opposite, and it can be handled by referring to the solution of fault three.

3. Press Brake Electrical system Questions

Press Brake Electrical system Questions

Fault 1: After the oil pump is started, the low-voltage circuit breaker trips. Such faults require the following checks: 

1). Check the lack of phase of the power supply.

2). Check whether the high-pressure filter element is seriously blocked, resulting in too much current of the oil pump motor. 3. Check if the low voltage circuit breaker is .No setting is too small.

Fault 2: After turning on, the reference point cannot be found when returning to the reference point 

1). Because the connection part of the reading head of the grating ruler is loose, the guide

When the machine is returning, the reading head cannot coincide with the reference point of the grating ruler and the stroke of the oil cylinder has been used up at this time.

The pump is under working load. If this is the reason, you need to press the red stop button of the CNC system to stop the return

Reference point, reconnect the connecting plate of the corrected grating ruler, and then enter the manual mode working state, make the slider hand

Move down, when the slider and the lower die coincide, then enter the manual or semi-automatic mode, and return to the reference point,


2). After the last operation of the Bending Machine for sheet Metal, the operator did not shut down the machine strictly according to the operation.

Stop the slider at the top dead center before the power is turned off, and the next time you turn it on, the slider is not manually moved down and placed up and down

The position after the mold overlaps, and the reference point return operation is performed, causing the reference point cannot be retrieved for this operation, if this is the case

For one reason, you need to turn the system to manual state, the manual mode will move the slider down to the upper and lower mold coincident position,

Under the state of semi-automatic or automatic mode, find the reference point again.

Fault 3: For the display of DNC60 or DNC600 CNC system, there is no display, and the gray and white programming key indicator flashes.

The main obstacle is that the operator of the system did not effectively replace the original The program is emptied, and it is directly modified on the last work product program.The buffer memory program is full, and the system program cannot run normally. First disconnect the power supply of the host Simultaneously press and hold the "+ +" and "One -" keys on the system keyboard to turn on the power and make the system enter the initialization state. The display will appear as follows: Then, enter the item you need to clear before the item: "1" means to enter the item .After clearing the sky, after entering the password "817", press the confirm key to confirm, the screen will prompt you "executed" at this time .The content to be emptied has been completed.

Fault 4: "Inaccurate counting" of the grating ruler causes the error of the bending angle. Such faults mainly reflect the "Y1" and "Y2"

Accuracy error of repeated positioning accuracy increases, and the angle error of the bending workpiece is large, and the angle error is based on the previous

The accumulation increases. The main reason is that the feedback signal counting loophole of the grating ruler drops the pulse number. Need to disassemble the grating ruler.Clean and dustproof and anti-vibration measures, redesign the unreasonable installation method until the installation is reasonable, and return to the scale failure. Return to the manufacturer for repair or replacement.

Fault 5: After the Durma Press Brake is programmed, the back gauge "X" axis "R" axis safety distance alarm. Such faults are mainly caused by the mold preparation.

The setting of the safety distance of the upper and lower molds, as well as the setting of the X-axis and R-axis limit positions in the system and the current product

The compiled program "X" axis "R" axis docking position conflicts, and the system prompts an alarm. For safety, the system

It will not operate normally. Need to reprogram the product or modify the product or modify the parameters of the mold to meet the requirements

Request, that is, the alarm is released before operation.

Fault 6: The rear gear X axis and R axis have a drive motor error alarm. Such faults need to open the electric box first, see the drive display

Alarm code, check the driver manual according to the alarm code prompted by the drive to find out the cause of the alarm. Common newspaper

There are two types of alarms: 16# alarm, which prompts that the drive motor is overloaded. We can check the transmission of the rear block X axis and Y axis.

Whether the movement is flexible, the resistance is too large, and whether the X axis and R axis have reached the mechanical limit. If so, eliminate the mechanical failure.

22# alarm, it prompts the encoder feedback signal alarm, causing this phenomenon, it may be that the "connector" has poor contact

Welding or disconnection and signal interference need to be checked one by one.

Fault 7: The computer display position of Y1 and Y2 does not match the actual position. This type of fault is mainly due to the inaccurate change of the original reference point.

The reference point needs to be reinitialized.

Fault 8: The system computer X-axis R-axis positioning does not match the actual positioning. This type of failure is mainly due to the machine's X-axis when the power is off.The position of the R axis has been moved. At this time, the computer still remembers the position before the shutdown, so the actual position of the X axis R axis is caused.If the setting changes, you need to re-initialize the X-axis and R-axis positions.

Fault 9: The position deviation between the Y1 axis and the Y2 axis exceeds the distance allowed by the system parameters, and the skateboard cannot move up and down Make. This type of failure is mainly due to the failure of putting the slider into the contact position of the upper and lower molds before shutting down the machine. Electrical shutdown, at this time, due to the reason of knife loss, the actual positions of the Y1 and Y2 axes are beyond the limit. Need to change Y1

The actual positions of the two ends of the Y2 axis are adjusted uniformly. The position where the computer displays the current value should also be equal, the device can proceed

Normal operation. Solution Modify the machine tool parameters in the system to increase 5mm on the original basis, and then enter the manual mode

In manual mode, the system will automatically correct the position after manual downward, and the system will resume normal work.

Fault 10: System signal interference alarm This type of fault is mainly due to poor shield grounding or loose grounding.

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