Operational Manual Hydraulic MB8-300T3200 Press Brake

The Use and Characteristics of the Hydraulic MB8-300T3200  Press Brake Machine

 

(1)  Hydraulic MB8-300T3200  Press Brake Use  

The machine is a kind of general equipment used for completing metal bending. It can compress metal sheet into a certain geometric shape through simpler common molds. When bending the sheet metal of different thickness and shape, you should make the options of corresponding shape of V-shape lower die of different opening size. The bending force can be figured out from the Bending Force Table or the Formula of the Bending Force Calculation.(refer to figure 17)

By using different shapes of molds, it can bend workpieces into various shapes (refer to figure 2). Meanwhile it can be used for punching, pressure ripple, light stretching and so on if it is equipped with the corresponding process devices. So the machine is widely used for electrical appliances, automobiles, shipbuilding, daily-use hardware, machinery manufacturing and other process departments.

（2）MB8-300T3200  Press Brake Characteristics

① Cylinders at the two ends are placed on columns at the both sides which directly drive the ram work. The machine’s structure is simple and the rigidity is excellent.

② The machine adopts steel torsion bar to maintain the ram’s synchronization; the ram also can withstand a certain degree of partial load.

① The machine adopts configuration welded with steel plates which has high strength and  excellent rigidity. 

② To meet the need of free bending, the ram’s downward stroke is adjusted by mechanical block(refer to figure 3); to control the stroke of ram, the upper limited position of ram is adjusted by upper stop-point block of the ram(refer to figure 5)

③ The linking parts of the upper die is equipped with compensation mechanism which is capable of compensating deflection of workbench and ram while bending and ensures the workpiece to achieve high bending accuracy.

④  The machine adopts electrical hydraulic control, so the ram can be adjusted freely with single stroke, recurrent stroke, inching and half-way stop operation and it is easy to realize automotive operation.

⑤ There is powroff device between the door of electric box and the ark which ensures the safety of operation and maintenance. As long as you open the door of electric box the power will be off.

4  Introduction of the Machine’s Structure

 The machine is made up of 9 parts, including the body, the torsion bar, the ram, the stroke adjustment, the front support bracket , molds, the hydraulic system and electrical system

1 The body(refer to figure 1)

The machine is welded with right and left upright columns, beams and the front and rear bearing which ensures it to achieve a high rigidity and accuarcy. A plate is welded on the top of right and left columns which is used to fix the right and left cylinders; A piece of iron is installed at the lower part of the columns to increase the contcat area to prevent the dumping of the machine in the hauling process which can be removed after mounting.

2 Ram and the adjustment of stroke(refer to figure 3,4,5)

The ram is made from single piece steel. The right and left cylinders are fixed on their corresponding columns and are connected with the ram through the piston rod. The cylinder is fixed on the body of the machine and makes the piston rod drive the ram to run through hydraulic-drive. In the cylinder there are mechanical blocks which control the lower limited postion of the ram. The location of mechanical block is adjusted through the worm gear drive and displayed by Stroke Counter L.

3  Synchronous System

The Synchronization during the running of ram adopts torsion axis synchronous system

4 Front support carrier（refer to figure 6）

5 Back block carrier  （refer to figure 7）

Through the adjustment of front and back position of the block carrier, the back positioning of workpiece can be realized. The position of block carrier is adjusted initially by mechanical transmission systems and then carried out fine-tuning by handle. The carrier’s position is displayed by digital tubes. In cases that the displayed value is not consisted with the actual measurement, you can modify the system to make the vaule be consisted with the actual size. The modification of the system’s X axis is carried out on PAC01 and press the right button to realize . The block carrier is equipped with embossing nut. The block rod can move up and down which keeps it at the same level with the top of lower die.

 6  Mold（refer to figure 8）

Plate that is uesd for quick connecting mold is installed on the upper part of the upper die. The upper die can have a slight displacement in the vertical direction through the adjustment of bevel iron’s right and left position. By adjusting the position of each bevel iron, the opening of the upper die can obtain a specific curve over the full length of the machine which can compensate the defection generated over the workbench and ram during the loading of the machine. Moreover, it can effectively improve the bending accuarcy.

7  Hydraulic System  

With the hydraulic system, the ram can achieve idle running, ram’s fast descending, ram’s slowly descending and the ram’s pullback .

8  Electrical System

    There are various operation button in the electric box (refer to figure 11). The electric box is equipped with mechanical lock so you should cut off the power when opening the box’s door. If it need to be checked and manitaned in the power on condition, you can manually reset.

 5  Hydraulic System

   

    The system enables various activities including the ram’s fast and slow descending, working

speed bending, fast pullback and urgent stop during descending process.

With the power supply is switched on to start the motor，hydraulic oil returns to the oil tank via the electromagnetic overflow valve and the pump is idle running.

When pressing feetswitch and the ram runs downwards ,YV1 and YV4 are in the power. The pressure oil enters the upper cavity of the oil cylinder via electromagnetic reversing valve and the throttle hole(d3.2). The hydraulically controlled one-way valve opens because of the increase of the pressure before the throttle hole. Hence the ram descends rapidly due to its own gravity and oil’s pressure.The oil in the lower cavity of the oil cylinder returns to oil tank via hydraulically controlled one-way valve, electromagnetic reversing valve and the throttle hole. During the course of ram’s rapid descending, the upper cavity becomes vacuum and be filled with oil through one-way valve. When the stroke switch SQ1(refer to figure 5) and YV2 and YV5 are in the power, the ram’s rapid descending changes to slow descending due to effect of the throttle hole . when the ram reaches the upper die and contacts the workpiece, it bends the workpiece under the pressure at working speed. When it descends to the preset position, the mechanical block in the cylinder prevents it to decline and makes it stop there and the pressure oil returns to the tank via overflow valve. 

When pressing feetswitch, YV1 and YV3

are in the power. The pressure oil enters the lower cavity of the cylinder via 

electromagnetic valve and the throttle hole which pushes the piston rod to drive the ram to

go upwards. The oil in the upper cavity returns to oil tank via electromagnetic valve and the

throttle hole. When the ram runs upwards till it reaches the stroke switch’s SQ2 and touches

the top stop block, YV1 and YV3 are power off and hydraulic oil returns to tank via

electromagnetic overflow valve. Then the ram stops and the pump turns to be idle running

again.

Remote pressure regulating valve can adjust working pressure. The valves’ pressure that need to be adjusted are as follows:

 

            Overflow valve 5            adjusted pressure 23MPa

remote high-pressure valve 9    adjusted pressure 3-23MPa

6  Electrical  System

 

1 Characteristics（refer to electrical principle）

(1) The machine adopts three-phrase AC 220V/60HZ. AC 24V and 29V used by circuit is supplied by transformer

within the machine

(2) Electrial box is equipped with mechanical lock. So once you open the lock the power will be off automatively.

(3) The breaker and overload of main electric circuit is protected by automative breaker QF1.

(4)When the machine running in the mode of “inching operation” and “single stroke”, it functions

footswitch. The mode of “recurrent stroke” is realized by lock transformation.

(5) When the ram stops at lower limited position, the machine’s pressure maintaining is carried out by KT1.

And the pressure release is carried out by KT2 before the ram going upward.

(6) Only when the ram stops at the upper limited position(SQ2-1), you can start the motor of backguage and

the motor of the stroke. 

(7)When the machine is not running, you should put the button of manual operation and foot operation to

the manual position and then pull out the lock.

 

2 Adjustment and operation of Electrical System

 

Connect three-phrase power cords with the input terminal（L1、L2、L3）and QF1 and then close the door of electric box.

(1) Firstly, start the motor of oil pump for a short while in order to check if the rotation direction is correct or not.

If adjustment is reqired, you can change the input power cord’s order, but never change any wiring within the machine itself.

(2) The operation should be processed according to the operation prodecure.

 (2.1) Inching operation

6  Electrical  System

 

1 Characteristics（refer to electrical principle）

(1) The machine adopts three-phrase AC 220V/60HZ. AC 24V and 29V used by circuit is supplied by transformer

within the machine

(2) Electrial box is equipped with mechanical lock. So once you open the lock the power will be off automatively.

(3) The breaker and overload of main electric circuit is protected by automative breaker QF1.

(4)When the machine running in the mode of “inching operation” and “single stroke”, it functions

footswitch. The mode of “recurrent stroke” is realized by lock transformation.

(5) When the ram stops at lower limited position, the machine’s pressure maintaining is carried out by KT1.

And the pressure release is carried out by KT2 before the ram going upward.

(6) Only when the ram stops at the upper limited position(SQ2-1), you can start the motor of backguage and

the motor of the stroke. 

(7)When the machine is not running, you should put the button of manual operation and foot operation to

the manual position and then pull out the lock.

 

2 Adjustment and operation of Electrical System

 

Connect three-phrase power cords with the input terminal（L1、L2、L3）and QF1 and then close the door of electric box.

(1) Firstly, start the motor of oil pump for a short while in order to check if the rotation direction is correct or not.

If adjustment is reqired, you can change the input power cord’s order, but never change any wiring within the machine itself.

(2) The operation should be processed according to the operation prodecure.

 (2.1) Inching operation

9  THE TRIAL RUN AND OPERARION PROCEDURE

 

1 Preparation for Trial Run

①The preson who operates the machine must read the instruction manual carefully and acquaints with the main structure, peformance and the use of the machine.

②Fill the oil tank with hydraulic oil N32-N46 till the level reaches the engraving line.

③Connect with the power supply line and ensure the direction is right.

④Release the handle of the remote adjusting valve( tightening it gradually during the trial run to improve the pressure of the sysytem).

⑤Twist the switch to the "inching operation” position and start the trial run. 

 

2 OPERATION PROCEDURE

①Two operation molds to control the running of ram, by hand or feet, which supports inching operation, single and recurrent stroke. So the trial run must be done seperately according to different operation molds.

②When trial run, the machine must firstly operate without load; then operate with load and increase the bending force gradually till up to its max load capccity.

③Start the motor of block adjusting (refer to figure 3); the lower limited position changes correspondingly when the ram going downward;the position of lower limited position is displayed by stroke counter I and the max displayed value should not be more than 105 mm.

④When pressing button SB3 or SB4 in the button box(refer to figure 7), the backgauge carrier moves forward or backward. The distance of backgauge is displayed by the counter II in the button box.

In the process of trial run, please check weather all the running sections are flexible ,reliable and

in normal condition. Make sure there is no leakage at seals and linking parts.

10  ADJUSTMENT OF THE MACHINE

 

1 Adustment of Workbench and Ram’s Parallelism

We have adjusted ram’s parallelism for you when the machine left the factory, so you do not have to adjust it again. If you want to adjust it yourself, the adjusting procedure is as follows: firstly, stop the ram on the upper part of the machine; then adjust the stroke of mechanical block in the oil cylinder at both ends to be consistent; to achieve that, firstly you should release the connecting rod and turn the worm rod on the right. At that time the position of mechancial block changes slightly. Following, move the ram to its lower limited position and check the parallelism of workbench and ram. Finally link the connecting rod.  

2  Adjustment of Machine’s Angle

   Use ram adjustment device(refer to figure 3&4). Start the motor of block adjustment and when the value displayed by the counter is decreaseing, the ram’s lower limited position descends and the bending angle increases. Adjusting range is diaplayed by stroke counter and it can accurate to 0.1mm.

3、Adjustment of ram’s upper stop position

Decline the position of the block of ram’s upper stop point, the ram’s upper stop point rises. Otherwise it descends.

4、Adjustment of velocity-change point(refer to figure 5&9)

When moving block of adjusting ram’s descending slowly downward, stroke switch SQ2 acts

head of time and YV3 is power on. With the throttling effect of the hole within the machine ,