Combination Work

Canadian Industrial Machinery asked TRUMPF Inc. TruPunch Product Manager Mike Kroll to explain the workings of a punch/laser system

August 1, 2010

Reducing the number of secondary operations is one key to successful manufacturing. Another is completing a part with minimal or even no handling, which dramatically reduces the cost to produce the part.

In combination-style systems, finished parts can be produced using one machine with one setup, instead of multiple setups on separate machines. This allows users to run smaller part lot sizes without increasing the cost per part.

Generally speaking, fabricators buy a combination punch/laser machine to get the benefits of both technologies, although certain parts can lend themselves to a single technology. How the part is ultimately processed is generally determined by the programmer, who finds the fastest, most cost-effective way to produce the part.

In a punch/laser combination machine, for example, part processing can be broken down into several stages: the programming, material loading, punching, laser cutting, part removal, and skeleton removal.

Here is a look at each stage.

Programming

According to Kroll, the programming stage for combination equipment is just as easy as for a punch-only or laser-only machine. Parameters are entered and the sheet is processed with certain geometries and features made by the punching tools and contours cut by the laser.

Material Loading

Raw material usually is fed to the machine via automation, since combo systems are designed for minimal human interaction and idle time.

“Since part costs are calculated on the time required to produce them, downtime plays an important role,” explained Kroll. “If a machine is not producing parts, and loading and unloading operations are too time-consuming, the lost production time needs to be added as additional part costs.”

Punching

In a combination punch/laser cutting system, sheets are punched first and then laser-cut. This is because it is still faster and less expensive to punch a single hole through the material and more cost-effective to laser-cut the outside contour and remove the part.

“Combination parts are generally hole-intensive with contoured edges,” said Kroll. “During the punching process, tool sets are preloaded into cartridge systems and placed into tool stations on a linear rail system. One tool is automatically loaded into or exchanged in the single-head punch processing system, which features 360-degree tool rotation. The sheet is then moved under the punching head in multiple directions and the punch penetrates the material into the die to make the desired hole.”

While this is occurring the laser resonator is on an air cushion bladder system to ensure that beam alignment is not affected.

Laser Cutting

According to Kroll, when the laser is activated, the air bladders deflate and the resonator seats itself on four common posts. A protective guard shields the laser cutting head. Then, similar to the punching process, the laser stays stationary and the sheet moves under the cutting head.

Part/Skeleton Removal

“Smaller finished parts can be removed during the fabrication process through a parts chute door, and larger parts are removed from the sheet by the use of a suction frame and deposited in a separate area,” explained Kroll.

These processes take only a few seconds to complete, minimizing machine idle time.

“The sheet skeleton can be cut up into smaller parts and deposited through a parts chute door to a separate container,” he added. “Larger skeletons are removed and separated to a separate platform with a grip removal system. The key here is the ability to separate finished parts from scrap.”

For more information, visit www.us.trumpf.com.