Advanced Press Brake Technologies

Advanced
Press Brake Technologies
John Kemp
Bystronic, Inc.
What you will learn about
 Why is Press Brake tooling so important
 Why is this different than before
 Current trend
 Future trends
 Blank size and bend allowance
 Bend and flatten
 Short flanges
 Tryout tools and other home remedies
 Adjustable dies
 Tool storage
FABTECH Canada 2014
Why is Press Brake tooling so important
Press Brake bending performance ultimately is determined by the
geometry of three critical points. The Upper Punch tip and the
Lower Die shoulders.
These are the only items that will ever contact the material!
Why is this different than before
Recent advances in Press Brake control systems have eliminated the
majority of manual operator machine tending.
Because of these high performance machines, manual operator tool
tending now consumes 90% or more of the total setup time.
What is the current trend
Almost every Press Brake sold today includes some sort of precision
ground, ergonomic tool handling system.
Traditional aligning and seating is eliminated!
What is the future trends
Better tool changing systems? Maybe?
Better tool shapes that are more versatile? Probable!
What difference does this make?
Blank size and bend allowance
What does tooling have to do with blank size?
This is how most systems assess bend allowance and blank size!
k
Here is the formula used by most CAD
systems to assess the k-factor or neutral axes:
r
k = 0.65 + 0.5 * log (r / t)
In this formula to assess the k-factor, what 4 variables are missing?
k
Here is the formula used by most CAD
systems to assess the k-factor or neutral axes:
k = 0.65 + 0.5 * log (r / t)
In this formula to assess the k-factor,
what 4 variables are missing?
Punch radius
Material type
Die Radius
Bend angle
r
What difference does this make?
Example:
Material Type = Cold Rolled Steel
Material thickness = .060”
Bend angle = 90 degrees
Punch Radius = .060”
Die opening = .500”
Die radius = .060”
DIN bend allowance = .118”
Actual bend allowance = .114”
Results:
Without taking tooling and
material into consideration an
error of .004” is introduced at
step one!
Per bend!
Bend and flatten
Flattening operations require a significant amount of force!
Thickness Force TPF
24 ga .023"
3
20 ga .036"
4
18 ga .048"
6
16 ga .060"
8
14 ga .075"
14
C
.125"
.125"
.137"
.137"
.188"
Force TPF
10
11
15
16
20
D
.046"
.072"
.096"
.120"
.150"
Modern tooling and machine features minimize setup times
Traditional hemming toolset method
Integrated hemming table method
How to “tool” for short flanges
The demand for lighter and more complicated products have driven
some flange lengths below the traditional tool limits!
Rocker dies are an effective flexible alternative to hard tooling
Sample rocker die in
action
How to “design” for short flanges
The demand for lighter and more complicated products have driven
some flange lengths below the traditional tool limits!
Creative design is an even more effective alternative to hard
tooling!
Relief cuts prevent bulging of the hexagonal holes during
the bend process
Tryout tools
Due to the demand for rapid prototyping, Press Brake tooling is sometimes
made from segments flame cut segments.
These tools are typically used for determination of special tool
shapes and not ideal not for mass production.
Take this process to
the highest level with
LASER cut quality
and many special
tools can be made
in-house, on
demand.
Adjustable dies
Just-in-time, one-piece-flow and rapid prototyping effect heavy plate users
too. Adjustable V-dies do offer some advantages. Cost and complexity
however restrict many of their applications.
Home remedies
The demand for lighter and more complicated products have driven
some flange lengths below the traditional tool limits!
Magnetic wear strips also help reduce excessive marking associated
with short flanges.
Tool storage
With tooling setups consuming the majority of the total Press Brake
setup time, small improvements in tools handling can represent huge
productivity gains!
Many well organized and easy access systems are available.
What to look for?
Tools should be located at an ergonomic height.
Recessed slots should be provided to prevent
tool tipping.
No drawers to open/close.
Visualization and random access to all tools at
once.
Door can remain open during production
without obstructing operator workspace.
Thank
You
John Kemp
Bystronic, Inc.