1. Selection, replacement and precautions for upper and lower dies

Press Brake Bending Animation

1) Selection of the top punch

A) The selection of the top punch depends on the bending force, and cannot exceed the ultimate load of the mold;

B) Users can choose special molds, and if so, pay special attention to the fact that the load on these molds is different from the normal mold.

2) Selection of the bottom die

The width of the V-opening of the lower die must be determined by the thickness S of the sheet material. The general formula is:

S<3mm   V=(6~8)×S;

S>3mm   V=(8~12)×S;

S: sheet thickness (mm);

b: the minimum bending width (mm);

V: width of the lower die opening (mm);

The minimum bend width b and the bend angle change accordingly. Only in this way can the limit of the shape of the lower die be determined scientifically.

2. Precautions for installation of upper and lower molds and installation methods

1) Precautions

A) In the dangerous area of the press brake machine, the operator must observe the safety principles when installing the mold;

B) The hand or body is not allowed to pass through the mold;

2) Installation of the upper mold

A) Switching the machine control mode to the manual mode via the key switch;

B) Press manual control in manual mode;

C) Press the machine axis start button;

D) Step on the foot switch, let the ram of the press brake machine slowly move down and stop at the bend conversion point;

E) Press the machine axis stop button;

F) Loosen the mold clamps to install or replace the top punch;

G) Fix the upper mold and the upper mold base, slightly tighten the clamping screw or close the mold clamps;

3) Installation of the lower mold

A) When installing or replacing the lower die, first loosen the lower die clamping screw;

B) Manually align the center of the lower die opening to the center of the upper punch;

C) Press the machine axis start button

D) Step on the pedal switch;

E) In the manual position mode, manually move the hand wheel slowly to move the ram down;

F) Pressing the mold together with a small force, the center of the upper mold and the center of the lower mold must be on the same line;

G) After all the sides of the die edge are in contact, tighten the clamping part of the upper and lower die;

3. Tightening adjustment of the timing belt

A) Make the machine in the stop state;

B) Open the rear protective cover of the machine;

C) Loosen the intermediate position of the press brake machine or the tightening screw of the tensioning wheel at the position of the X-axis motor connecting plate;

D) Adjust the tensioning wheel to the appropriate position;

E) Fasten the tensioner set screw;

F) Install the rear guard of the machine;

4. Accuracy adjustment of the backgauge

Transmission failure of the back gauge

A) Check the accuracy of the back finger after movement;

B) Measuring the error of the two back fingers with a depth gauge;

C) Adjust the back finger so that the distance from the two back finger to the center of the lower die opening is consistent;

D) Trial bending the workpiece and measure the X-axis accuracy error;

E) Modify the X-axis correction;

F) Trial bending the workpiece and use it for normal bending after confirming correct.

5. X-axis reference point adjustment

A) Trial bending the workpiece, measure the accuracy of the X-axis, and calculate the error;

B) In automatic mode or manual mode, lower the ram below the bend transition point;

C) Modify the X-axis reference point value;

D) After the machine tool returns to the reference point, use it for normal bending after confirming correct;

6. Adjustment method in which the X axis is parallel to the lower mold

A) Check whether the center of the upper die and the center of the lower die are coincident;

B) The top mold is used as a reference, and a back finger is used to measure the error at both ends of the X-axis beam (the hand or the body is not allowed to enter the mold)

C) Open the rear protective cover of the machine;

D) Loosen the fastening screw on the timing belt on the front end of the screw on the right side of the X-axis beam of the press brake machine;

E) Fix the right box connector to prevent it from moving back and forth;

F) Adjust the timing belt to move the screw on the left side of the X-axis beam forward or backward;

G) Then the upper mold is used as the reference, and the error is measured at both ends of the X-axis beam by one back finger; continue to adjust if there is any error, the error at both ends does not exceed 0.20 mm;

H) Tighten the fastening screws on the timing belt on the right side of the box;

I) Loosen the fixing of the right box connector;

J) The machine returns to the reference point;

K) Trial bending the workpiece, measure the accuracy of the X-axis, and calculate the error;

L) Modify the number of X-axis reference points;

M) After the machine tool returns to the reference, try to bend  the workpiece to confirm the correct and normal processing;

7. Y-axis reference point adjustment

A) Trial bending the workpiece and measure the accuracy error of the Y1 and Y2 axes (based on 90 degrees);

B) In automatic mode or manual mode, lower the ram below the bend transition point;

C) Select the Y axis parameter;

D) Modify the Y1, Y2 axis reference point position (about 0.07 for one degree);

E) After the machine tool returns to the reference, try to bend the workpiece to confirm the correct and normal processing;

8. Crowning adjustment

Hydraulic Crowning

A)Trial bending the workpiece and measure the intermediate accuracy error of the workpiece (based on 90 degrees);

B) In automatic mode or manual mode, lower the ram below the bend transition point;

C) Select CROWNING axis;

D) Modify the DA minimum value and the DA maximum value according to the actual situation;

E) After the machine tool returns to the reference, try to bend the workpiece to confirm the correct and normal processing;

9. X-axis shake adjustment

Press Brake Axis

A) In automatic mode or manual mode, lower the ram below the bend transition point;

B) Modify (reduce) the X-axis gain as appropriate;

C) After the machine tool returns to the reference and work normal under dry running, the workpiece can be processed;

10. Adjustment of X-axis movement not in place

A) In automatic mode or manual mode, lower the ram below the bend transition point;

B) Modify (increase) the X-axis gain as appropriate;

C) After the machine tool returns to the reference and work normal under dry running, the workpiece can be processed;

11. The ram slides down in the normal state of the press brake machine

press brake ram cannot be quickly down

1) Adjust the backup pressure valve as follows;

A) Loosen the backup valve hex lock nut;

B) Adjust the adjusting screw of the pressure backup valve;

C) Observe whether the value of the ram slide is normal;

D) Processing the workpiece after normal working;

2) Clean the backup valve as follows;

A) Lower the ram to the bottom in manual mode;

B) Turn off the oil pump motor of the machine and turn off the machine power;

C) Remove the backup valve from the valve seat to clean;

D) Install the backup pressure valve after cleaning;

E) After the machine tool returns to the reference and the dry running is normal, the workpiece can be processed;

3) Replace the backup valve as follows;

A) Lower the ram to the bottom in manual mode;

B) Turn off the oil pump motor of the press brake machine and turn off the power;

C) Remove the backup valve from the valve seat;

D) Replace the new backup valve;

E) After the machine tool returns to the reference, the new backup pressure valve is properly adjusted, and the workpiece can be processed after the dry operation is normal;

12. Adjustment of synchronous servo valve

1) The ram does not move under normal conditions. First check if the circuit is normal. After confirming the circuit is normal, the servo valve can be detected as follows:

A) Input command, select valve test;

B) Select the left or right valve;

C) Shake the percentage with the hand wheel to see if the voltage changes;

D) If there is no change, the synchronous servo valve must be cleaned or replaced;

2) The method of cleaning the synchronous servo valve is as follows:

A) Lower the ram to the bottom in manual mode;

B) Turn off the oil pump motor of the machine and turn off the machine power;

C) Remove the plug of the control circuit of the synchronous servo valve;

D) Remove the connecting screw of the synchronous servo valve and the valve seat;

E) Remove the synchronous servo valve and disassemble the synchronous servo valve. (Where there is a paint seal, it is not allowed to open.)

F) Remove the valve core to remove burrs with metallographic sandpaper, so that the valve core can move freely in the valve body;

G) Clean the valve spool with gasoline. Assembling a synchronous servo valve;

H) Fix the connection between the synchronous servo valve and the valve seat with screws;

I) Install the plug of the control circuit of synchronous servo valve;

J) After the installation, test the synchronous servo valve(If it is not normal, it is recommended to replace the synchronous servo valve).

K) After the test is normal, the machine returns to the reference;

L) After the dry operation is normal, the workpiece can be processed;

13. Filter replacement method

After the machine has been working for a period of time, the filter element must be replaced. After every 6 months or 1000 working hours, or the pressure alert cover at the top of the filter is dropped, the filter must be replaced. The method is as follows:

A) In automatic mode or manual mode, lower the ram below the bend transition point;

B) Turn off the oil pump motor of the press brake machine and turn off the machine power;

C) Open the rear protective cover of the machine;

D) Disassemble the filter;

E) Remove the filter element, replace the filter element, and tighten the filter;

F) Install the rear protective cover of the press brake machine;

G) Turn on the machine power and start the motor of the oil pump of the machine;

H) The hydraulic oil must be filtered for 1 hour;

J) The machine tool returns to the normal processing;

14. Crowning cylinder replacement method

A) In automatic mode or manual mode, lower the ram below the bend transition point;

B) Turn off the oil pump motor of the machine and turn off the machine power;

C) Open the rear protective cover of the machine;

D) Disassemble the connecting oil pipe of the crowning cylinder;

E) Disassemble the crowning cylinder guard;

F) Disassemble the bracket connecting the crowning cylinder and the machine frame;

G) Tap the crowning cylinder with a wooden stick at the back of the machine and take out the crowning cylinder from the front of the machine;

H) Remove the joint on the crowning cylinder and install it in the new crowning cylinder;

I) Install the new crowning cylinder from the front of the machine;

J) Connect the oil circuit of the crowning cylinder;

K) Fix the connection between the crowning cylinder and the machine frame with a bracket;

L) Install the crowning cylinder front cover and install the rear protective cover of the machine;

M) Turn on the machine power and start the oil pump motor of the machine;

N) The machine returns to the reference and is processed normally.

15. Hydraulic oil replacement

Hydraulic oil

A) In the automatic mode or manual mode, the ram is raised to the top dead center and support well;

B) Turn off the oil pump motor of the machine and turn off the machine power;

C) Open the rear protective cover of the machine;

D) Open the shutoff valve at the bottom of the tank to drain the hydraulic oil. Connecting the oil pipe to the oil outlet of the shut-off valve and introducing the oil pipe into the oil receiving barrel;

E) The oil filter refills the new hydraulic oil to the middle of the oil level gauge and stops the ram at the top dead center position;

F) Turn on the machine power and start the oil pump motor of the machine;

G) The hydraulic oil must be filtered for 1 hour;

H) Lower the ram below the bend transition point;

I) The machine returns to the reference and is processed normally.

16. The press brake machine does not work

A) The “Emergency Stop” button is pressed;

Solution:

Reset the “Emergency Stop” button.

B) There is CNC alarm or servo alarm;

Solution:

Check the alert content and handle the alert accordingly.

C) An error message is displayed on the CNC display (Windows startup is not completed);

Solution:

Check the CNC unit.

D) The control circuit is unable to prepare the machine;

Solution:

Check the control circuit.

17. The foot switch is pressed and the ram does not move

Press Brake Foot Pedal Switch

A) The foot switch contact is damaged or the cable is damaged;

Solution:

Replace the new foot switch.

B) The return is not finished;

Solution:

Run the return reference process.

C) Bottom dead point is not set;

Solution:

Set the bottom dead point.

D) The ram is not at the top dead position;

Solution:

Move the ram to the top dead position.

E) The motor does not turn;

Solution:

Check the electrical system.

F) Control circuit failure or damage;

Solution:

Check the circuit and connections.

18. Ram movement is unstable

A) Improper parameter setting;

Solution:

Check to make sure the parameters are set correctly.

B) The bolt connecting the ram is loose;

Solution:

Check the connection and tighten the bolts.

C) The control device is out of order;

Solution:

Check the controls.

19. When the machine is working, the back gauge parts have abnormal noise

A) Improper timing belt tension;

Solution:

Adjust the tension of the timing belt.

B) The guide rail and the ball screw lack lubricating grease;

Solution:

Fuel the parts.

20. The bending angle is different between the middle and the ends

The compensation amount of the worktable crowning device is not set correctly;

Solution:

Reset the amount of compensation.

21. The bending angles at the ends are different from each other

Fig. 6 Long parts bending and crowning

A) The pressure is too low;

Solution:

Increase the pressure.

B) The ram is out of parallel in the vertical position;

Solution:

Check the Y-axis initial value to adjust the ram parallelism.

C) The parallelism of the mold is out of tolerance;

Solution:

Adjust or replace the mold and reset the work table compensation amount.

D) Cause of workpiece quality (inconsistent thickness, etc.);

Solution:

Use the workpieces with consistent quality.

22. The bending angle is different from the set angle

A) The pressure is too low;

Solution:

Increase the pressure.

B) The holding time is too short;

Solution:

Extend the holding time.

C) The bending speed is too slow;

Solution:

Increase the bending speed.

D) Causes of workpiece quality (inconsistent thickness, change in tensile strength, etc.);

Solution:

Use the workpieces with consistent quality.

E) The width of vee opening of the lower die is too small;

Solution:

Replace the lower die with a larger vee opening.