NC Press Brake Functions and Parts Explained: Work Table, Back Gauge, Front Support ＆ More

Previous article: NC Press Brake Functions and Parts Explained: Body, Controller, Ram and Stroke

We discussed some parts and funtions of a NC press brake, this article we will explore remaining parts and learn about the functions.

Other Important Parts of NC Press Brake

Press Brake Worktable

The back stopper moves forwards and backwards through the operation of a motor, and the CNC controller controls its moving distance with a minimum reading of 0.01mm. There are stroke limit switches at both the front and back positions to limit the movement of the back stopper.

Synchronization System

The mechanical synchronization mechanism is made up of components such as torsion, swing arm, and joint bearings. It has a straightforward design, provides stable and reliable performance, and boasts high synchronization precision.

The position of the mechanical press brake stops is adjusted through the operation of a motor, and the data is controlled by the CNC controller.

Press Brake Back Gauge

BACK GAUGES are the reference points for positioning the sheet metal. The sheet metal is laid onto dies and then pushed against the back gauges. Their movement, governed by numerical control, follows the working program entered by the operator.

Back gauges can usually y rotate upwards because, during bending, the sheet metal may collide with the lower part of a back gauge and lift it.

However, some types of back gauges make sure that the sheet metal is always stable for every kind of profile

The CNC press brake‘s back gauge uses motor-driven transmission to achieve synchronized movement through the use of two ball screws and a timing belt. The back gauge’s distance is controlled by the CNC controller.

Press brake axis

THE MAIN AXES of a press brake are X, Y, Z and R. The X, Y and Z axes can be driven by the numerical control or by the operator depending on the features of the press brake.

The directions of the press brake in the X, Y, and Z axes are indicated by the positive arrow in the figure.

Y Axis: the upper beam moves along this axis （up and down） and as it does so, the bend angle changes. During the bending phase the operator must check that the Y1 and Y2 axes are aligned, because a 0.05mm difference in a 3m machine would cause a 1° difference between the two sides of the table.

The operator must therefore check the alignment of the two pistons before starting bending by zeroing the machine using the appropriate NC button.

Should any problems arise, the operator must check the condition of the surface of the upper can modify the Y axis.

X Axis: this axis determines the bending depth, i.e. the distance between the back gauges and the centre of the die.

The cross-bar where the back gauges are mounted moves along the X axis towards and away from the Y axis.

Z Axis: back gauges move along the cross-bar on which they are mounted and each stops in a specific position depending on the length of the sheet metal and on the part of the press brake where the bending is to be carried out （in the middle or to one side of the press brake）.

In a press brake there are a minimum of 2 and a maximum of 4 back gauges. The operator must know the limits of movement along the Z axis, for example, the maximum movement allowed along the table or the minimum distance between two back gauges.

R Axis: the R axis adjusts the cross-bar in height, so that back gauges always adapt to dies with different height and sheet metal always rests against theback gauges.

The press brake axes can be categorized as follows:

Y1: the left cylinder of the ram
Y2: the right cylinder of the ram
W: the lower beam’s convex compensation cylinder (i.e., the deflection compensation system)
X, X1, X2: the back gauge’s back-and-forth movement
R, R1, R2: the back gauge’s up-and-down movement
Z, Z1, Z2: the back gauge’s left-right movement
Note: The position of the ram can be programmed using either an absolute value equation or an angular value.

he location of each control axis of the press brake is presented in the table below:

Press Brake Front Support

The front support arms of the press brake are attached to the T-groove or linear guide located in front of the machine. They have been designed with a manually adjustable back position claw.

FRONT SHEET SUPPORTING ARMS are optional items of equipment that support the sheet metal during press braking and prevent it from falling during the upper beam return.

They are mostly used during the bending of heavy or big sheets of metal but there are differenttypes of supporting arms to help the operator during bending.

Press Brake Pedal Switch

The pedal switch of the press brake primarily serves to control the movement of the top punch during the bending operation, raising and lowering it. Additionally, there is an emergency button located on top of the pedal switch for emergency situations.

Press Brake Punch Clamps

The press brake clamps consist of standard clamps and fast clamping tools that are used for quickly changing the top punch. The use of fast clamping tools significantly simplifies the process of changing the punch die, making it not only convenient but also time-efficient.

Conclusion

In addition to the machine parts introduced above, there are many parts of the bending machine. If you want to know about accessories, please consult KRRASS customer service.