Monday, June 18, 2018

Choosing the best press brake clamping system

Clamping of press brake tooling essential for bending accuracy

By the time a part reaches the press brake, it has typically passed through multiple value-added production processes. As a result, press brake operations are subject to stringent accuracy and consistency requirements to avoid costly scrap material. While good press brakes are necessary to meet these requirements, the importance of the right clamping system is too often overlooked. A good clamping system not only saves time, but it also prevents inaccuracies and can reduce the need for test bends. Not sure which clamping system is right for you? WILA has put together an overview of the advantages and disadvantages of various clamping systems. 

Two types of clamping systems

Two types of clamping systems are available for press brake tooling: manual and automatic clamping systems. Several versions of each type are available on the market. 

-1 Manual clamping systems
An effective, economical press brake clamping for infrequent tool changes

Manually clamping tools is the most basic and time-consuming clamping method, requiring the operator to manually tighten separate clamping plates. The separate clamping plates do not form a continuous clamping line, which means plates must be tightened one by one. The added disadvantage is that tools are not immediately aligned correctly and clamping pressure can be unevenly distributed over different tool segments. In order to overcome these disadvantages, WILA has developed a clamping pin frame for its mechanical clamping system that provides consistent clamping force over the entire working length. This means individual tool segments can be clamped separately without any need for fine adjustments. The clamping pin frame features a self-seating and aligning mechanism that precisely centers and positions the tooling.

Mechanical-clamping   
Hardened clamping pins are activated during mechanical clamping

-2 Automatic clamping systems
Press brake clamping for frequent and fast tool changes

Based on a ‘single point operation,’ automatic clamping systems are activated by the single press of a button, eliminating the need for tedious manual tightening. Automatic clamping systems can be powered by electricity, hydraulics, or pneumatics. The most basic automatic clamping systems feature separate clamping plates, equipped with cylinders that are activated by one of the aforementioned power sources. Although this version eliminates time-consuming manual tightening, the same accuracy-related disadvantages associated with individual clamping plates are still present. However, these shortcomings can be overcome by using a medium to activate a mechanism across the entire length of the machine, rather than just activating individual clamping plates. With WILA, automatic clamping is powered by either hydraulic or pneumatic force. Each system activates a mechanism that runs the length of the machine, rather than activating individual clamping plates. 

WILA's automatic clamping systems are based on hydraulics or pneumatics. In hydraulic systems, oil provides the pressure used by hardened clamping pins to clamp tooling across the whole length of the machine. The hydraulic system must always be switched on in order to ensure the clamping function (friction-locked clamping). In pneumatic systems, oil pressure is replaced by air pressure. Air pressure allows tools to be clamped and released much quicker than oil pressure. WILA's pneumatic system only uses air pressure to activate and deactivate the clamping function; the clamping action itself is operated using the Self-Locking® system developed by WILA (form-locked clamping). 

WILA’s advice

Manual clamping systems can be fine in situations where tools are rarely changed. In such cases, WILA recommends its mechanical clamping system: hardened clamping frames will allow (individual) tools to be correctly positioned, centered and clamped, thus guaranteeing bending accuracy. 
We recommend automatic systems if regular tool changes are encountered. This recommendation is based on the following arguments:
  • productivity – automatic clamping can be profitable if you need more than one tool change per shift
  • ergonomics – improves conditions for employees and prevents sick leave
  • availability of skill – it is difficult to find properly trained and skilled people who are able to change tools quickly and efficiently.

If you value sustainability, we recommend using an automatic clamping system based on pneumatics. This helps to limit oil use and reduces energy consumption because clamping systems based on Self-Locking® do not always have to remain operational.


Need assistance with choosing the best clamping system for your needs?

We will be happy to answer any questions you may have. Please contact our Technical Sales Engineers at (443) 459-5496 or send an email to info@wilausa.com

Choosing the best press brake clamping system

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