December 13, 2010
Advancements in turret punch presses have paved the way for specialty tool innovations that allow fabricators to produce high-quality parts using fewer secondary operations.
New advancements in turret punch press technology have made these machines more versatile than ever before. The most significant advancement for tooling manufacturers is the number of punch press equipment suppliers building forming stations that permit the use of high-form tooling, either through a lower unit ram or by the ability to raise a forming tool into position.
Because of the increase in forming height, fabricators are able to fully utilize the turret’s feed clearance. They also are able to keep sheets in a constant level position during the forming action. This helps minimize, or even eliminate, sheet distortion.
Tooling manufacturers must work within the confines of the machines. But as the machines becoming more versatile—for example, the lower unit moving as well as the upper unit— tooling manufacturers have a wider variety of strategies to choose from for designing the tools.
Twenty years ago turret punch presses produced form heights of about 1/8 to maybe ¼-inch — enough for extruding or embossing. Today form heights well over 0.300 in. are readily available, and some machines offer nearly an inch. Punch press manufacturers are pushing the limits to the point where the limit becomes what the sheet itself allows.
More than anything else, fabricators want to know how they can make their products faster and cheaper. Tooling manufacturers are responding by developing specialty forming tools that can help them reduce part handling and eliminate secondary operations.
For instance, it’s now possible to perform simple 90-degree bends on a punch press. Specialty tooling creates a 90-degree form (Figure 1) using a rotating cam built into the die that acts much like a bending machine. This process leaves little to no sheet marking. For fabricators that want to create a large flange without having to move the sheet to the press brake, using this type of tooling reduces part handling and increases productivity.
Once upon a time, creating texture, like taking a piece of steel and making it look like the surface of a brick wall, meant using a 200-ton press and hard tooling. Today this same effect can be achieved using specialty tooling in a turret.
Scribing is a type of tooling and a technique that many fabricators are using to accomplish myriad operations, from creating a unique texture to adding a logo to parts. The scribe tool has a diamond tip that produces accurate, consistent marks when it is dragged across the sheet.
The scribe or sheet-marking tool can be used for both sheet scribing and dot matrix marking on various materials by switching out the insert from diamond to carbide, which eliminates the need to purchase another tool. Another benefit of this type of tooling is that it doesn’t deform the material or mark the underside of the sheet. It is a versatile tool that can create amazing effects when programmed by a skilled operator.
Typical methods of fastening parts together, such as welding and grinding, can be time-consuming and labor-intensive and therefore expensive. Specialty tooling makes it possible to join together two parts in less time and just as tightly with a punch press as with conventional methods.
These special lance and form tools fabricate snaps to join metal parts together so tightly that they cannot be pulled apart. This tooling can join together coated parts or parts made of two different metals. Creating fastening forms on the punch press is fast and may be less expensive than joining them in secondary operations.
More often than not, when a part calls for a hinge, fabricators use a piano hinge. Fabricating piano hinges is a cumbersome process that requires many hits for every knuckle. Sometimes, a piano hinge is not really necessary, however.
Specialty tools for the turret press can produce strong, functional hinges in a single hit. These single-hit hinge tools (Figure 2) produce half of a knuckle. The half-knuckles then are married up and joined by sliding a pin through them to create a complete functioning hinge. Because only one hit is required, programming is faster and easier.
Single-hit hinge tools help reduce running costs and increase productivity.
Along with improvements in punch press machines, the marketplace has seen an explosion in the introduction of 3-D CAD software, which allows nearly anyone to create something and become more of an artist than a designer. The downside is that some designed parts can’t be created out of sheet metal.
For tooling designers, the challenge becomes how to connect with the people designing the parts to let them know the tooling’s capabilities and what the material likely will allow. Creating tooling that uses the punch press to its fullest potential requires pushing expertise all the way back upstream to the person designing the sheet metal part.
From the ordinary to the extraordinary, specialty punch press tooling can help fabricators eliminate secondary operations, reduce waste, and increase productivity.