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Tools for Heavy Duty Bending

Applying technology to safely bend thick and high-strength materials.

Bearings facilitate easy loading and unloading
by a single operator with maximum speed and
safety. The ‘E2M’ feature is available for Wila ‘HD’
Heavy Duty Punches and Punch Holders.

Bending thick materials or high strength alloys are manufacturing operations that fabricators are undertaking in ever greater numbers, according to press brake experts, and seemingly every week a steel manufacturer releases a new material or invests in new production capabilities to make these high-end products.

Press brake operators that use these materials face a variety of issues, says Dave Bishop, business development manager for Wila USA, Hanover, Md. These challenges include increased springback and abrasiveness that Bishop says can “tear up” the punches and dies if these tools are not durable.

In the past, when companies were bending thick materials, Bishop says that the thicker the material, the fewer the options that were available to them. “Some companies would use old planermade dies in the press brakes, and they would wear out over time because the material was so abrasive, and the tonnage levels required to bend the materials was so great,” he says. “In a lot of cases, the tooling would look terrible from the wear, and results would be very inconsistent.”

But, today, things are changing. Press brake manufacturers have developed specific lines to tackle and compensate for these issues. At Wila, for instance, designers and engineers developed a product to bend these materials, focusing on accuracy, durability, safety, and ease of use.

The Wila Multi-V Die with a Large Radius Punch and Punch Holder come with V-openings ranging between 0.945 in. (24mm) and 15.748 in. (400mm). Hardened replaceable rollers on the shoulders provide virtually infinite tool life and long-term accuracy retention. When properly equipped, they can eliminate die changes to maximize operator safety.

What they came up with was the HD heavy-duty tooling system that was designed to bend thicker sheet materials. These tools are designed for fabricators bending 5/16 in. to 1 in. (8–25mm) thick plate and for those that have bending applications that generate high-concentrated loads such as when bending high-tensile strength materials in dies with smaller than normal V-openings.

The modular system features hydraulic clamping systems, crowning systems, bottom tool holders, punches and dies, tool storage and a tool loading system. The HD hydraulic clamping system has a maximum load rating of 269 tons/ft. (800 tons/meter) and can pull up, seat, and align a punch that weighs as much as 700 lbs/ft with a push of a single button. The HD crowning systems and bottom tool holders also have maximum loadratings of 269 tons/ft.

The HD punches are available in straight and gooseneck profiles with larger punch tip radii of 0.236 in. (6mm) and 0.492 in. (12.5mm). HD single V-Dies come with V-openings of 3.15 in. (80mm) to 7.874 in. (200mm) and feature an included angle of 60 degrees to accommodate the large springback that is common with today’s high-tensile strength materials, Bishop says. If the company needs an even larger die, Bishop adds that Wila offers the Multi-V Die that come with V-openings ranging between 0.945 in. (24mm) and 15.748 in. (400mm).

“With the focus on flexibility, we wanted to be able to handle just about whatever would arrive at the press brake,” he says. “The standard dies provided with the HD system feature 30 deg. of springback compensation making it possible to bend virtually anything that is within the acceptable range of the various V-openings.”

The Wila ‘HD’ Heavy Duty CNC crowning system with optional pillars that allow for the use of dies with large V-openings and Wila Multi-V Dies.

When bending thick materials, one of the biggest concerns is handling the large press brake punches and dies that must be used. “A 10-ft. or 20-ft. long die is a very dangerous thing to move around the shop,” he adds. “When you are in front of a press brake that is using really large, heavy tools, often they must be moved in and out of the press brake with a crane or a forklift. And because of the size and the weight of them, they can be dangerous to handle.”

To solve this problem, the HD system utilizes an Easy to Move (E2M) rollerbearing system that Bishop says can literally be activated within a split second, lifting the tool and making it easy to move quickly and safely. The tool storage unit can be located on theleft or right side of the press brake, and stores the punches and dies at the same level as the clamping and crowning systems, or the bottom tool holders, so that they can be horizontally moved into position. Using the E2M technology in tandem with the ToolStation, one operator can handle even large punches and dies.

The Wila ‘HD’ System includes a clamping system, crowning system, tooling, and proprietary ToolStation. Load/unload arms makes it easy to transfer tooling between the press brake and the tool station by a single operator with maximum speed and safety.

“The operator,” says Bishop, “is never handling the tooling itself, or loading and unloading them without the support of the loading arm. There is never a time when the tool is being handled that it will come loose, because everything is moved horizontally with those E2M rollers, and the tooling is always engaging with the clamping system, ToolStation, or loading arm.”

Another safety concern is that a punch could tilt because of its weight and shape. A roller system keeps the punch securely upright, maintaining proper alignment with the clamping system, loading arm, and the tool station. In addition, Wila offers optional pillars that stabilize dies that might be wider than the crowning systems themselves. The pillars support the outside of the die.

Another safety mechanism is foundat the end of the clamping and the crowning system. There, a guard is set in place to ensure that the punch and die cannot go off the end of the press brake. “So, there’s no chance of a tool being rolled out of the clamping system or the crowning system,” says Bishop.

To improve durability, Bishop adds that tooling is tempered by a process the company calls CNC Deephardening. The tooling, which is made from a chrome molybdenum alloy, a hard and durable material, goes through a process during which the company applies heat at a controlled rate with a controlled hold time and a controlled cooling time. “The end result is when you combine proprietary steel and the CNC Deephardening process, we get a hardened zone that is 50 to 60 Rockwell C and over 0.157-in. “(4mm) deep,” Bishop says. “Then we draw back from that point to a hardness of approximately 35 Rockwell C at the core of the tool, so that the tool does not become brittle and unsafe if the operator over-tonnages the tool, shattering it, and [resulting in] pieces flying out of the brake.”

Wila USA