Lighten the Load of Dealing With Heavy Press Brake Tooling

Multi-V adjustable dies are available with V-openings from 0.95 to 15.75 in., and come with hardened roller bars to bend a large variety of thick plate material without having to move dies in and out of the press brake.

Multi-V adjustable dies are available with V-openings from 0.95 to 15.75 in., and come with hardened roller bars to bend a large variety of thick plate material without having to move dies in and out of the press brake.

Large, high-tonnage press brakes frequently present unique challenges to fabricators. They normally involve the forming of large, heavy, and often cumbersome parts that may require multiple operators or special sheet support systems to handle them.

Similarly, these massive press brakes usually require large, heavy, and often dangerous-to-handle tools that are capable of withstanding the high tonnage loads needed for bending thick materials. Handling these large tools can be difficult and time-consuming and present a host of safety risks to the operator.

In recent years a number of new product developments have made it easier, faster, and much safer to form thick heavy plate materials on large press brakes.

Segmented, Precision-ground Tooling Assist Setup

Changing long lengths of punches and dies on a large press brake almost always requires the use of a forklift and multiple operators, who are often taken from other machines. This non-value-added activity can typically take an hour or longer and even now is rarely figured into the overall cost to produce the final product. This makes it exceedingly difficult to produce small batch sizes in an efficient and cost-effective manner.

For over four decades, precision-ground and segmented press brake tooling has made tooling setup markedly faster, more flexible, and more ergonomic for operators that bend materials in the range of 20 gauge through ¼ in. thick.

More recently the precision grinding and segmenting of large press brake tools for bending thick plate materials have become increasingly common. It is now possible to purchase large punches in heights of 12 in. or taller, and single V-dies with V-openings up to 8 in. segments of 20 in. in length and shorter. This has brought faster setups, greater flexibility, single operator tool loading and unloading, and far better ergonomics to large press brakes.

Roller Bearings Help Tool Exchange

A large gooseneck punch and single V-die with roller bearings allow heavy tools to be easily moved into position. Wila Easy-To-Move® (E2M®) tools are pictured.

A large gooseneck punch and single V-die with roller bearings allow heavy tools to be easily moved into position. Wila Easy-To-Move® (E2M®) tools are pictured.

Just as the push-button tool change has made the vertical loading/unloading of press brake punches possible, the development of roller bearing technology has revolutionized the loading/unloading of large, heavy press brake tools. Roller bearings can be added to the tang of heavier New Standard-style punches in place of the fixed safety pins that are normally provided.

For very large gooseneck punches, a second, larger roller can be added to the rear of the punch to provide balance and stability to the tool for virtually effortless loading/unloading. On heavy bottom dies, the roller bearings are added to the tang.

When not in service, the rollers are recessed within the tang and are kept out of the way. When activated, they are extended downward so that they can engage the bottom of the slot in the die holder or crowning system. This is accomplished via a hydraulic lift option, which is located within the die holder or crowning system, or via a simple half-turn of a T-handled wrench that drives a cam-action mechanism that is built into the die. This feature provides quick, safe, and easy loading/unloading of even the heaviest dies by a single operator.

Storage and Loading System Handles Heavy Tools

One of the problems with large, heavy press brake tools is their space requirements. They are difficult to store at the press brake or in a typical tooling cabinet. Most often they are stored in a rack behind the machine, or worse, in a rack at the back of the shop. As addressed previously, this results in increased setup time as a forklift and often multiple operators are required to move the tooling to the machine and load or unload it and place it back in the storage rack.

To provide faster, more efficient, and safer storage for heavy press brake tools, a new storage concept has been developed. For example, the ToolStation is designed to hold New Standard-style tooling and to store it at the right or left end of the machine.

It comes with a loading arm that makes it safe and easy for a single operator to transport the tools between the storage modules and the press brake. The loading arm is precision aligned with the slot in the bottom of the crowning system or die holder, while the ram of the press brake can be lowered to align and interlock with the loading arm and the upper clamping system. The loading arm then can be easily moved via a linear guide rail to any tool storage slot along the full length of the storage system, making it possible to store and retrieve any punch or die from any position. Additional tool storage modules can be added to increase tooling storage capacity.

High-Load-Capacity Clamping and Crowning

The use of hydraulic clamping to automatically clamp, seat, and align tools in the press brake greatly speeds up setup time. More recently hydraulic upper clamping systems, crowning systems, and die holders have been designed to hold large, heavy press brake tooling and to withstand the extremely high tonnage loads that are typically applied in large press brakes. Heavy-duty upper hydraulic clamping systems are now available to lift and self-seat tools weighing up to 700 lbs./ft. and provide a maximum load capacity of 269 tons/ft.

A loading arm, part of a Wila ToolStation system, moves large punches and dies into a press brake equipped with a heavy-duty hydraulic clamping system on the ram and a 10 in. crowning system on the bed with added support pillars.

A loading arm, part of a Wila ToolStation system, moves large punches and dies into a press brake equipped with a heavy-duty hydraulic clamping system on the ram and a 10 in. crowning system on the bed with added support pillars.

Heavy-duty crowning systems and die holders are available in standard widths of 6 in. and 10 in. and have maximum load capacities up to 269 tons/ft. The larger width makes it possible to use very large dies with large V-openings, while dissipating the force generated during bending over a much wider area, reducing wear and tear on the press brake.

A system of adjustable pillars can also be installed on the front and back of these crowning systems and die holders to provide additional support for very large tools, thus eliminating the need to make the crowning system or die holder even wider and more costly to manufacture.

Interchangeable-Radius Tooling for Versatility

As large, high-tonnage press brakes are primarily designated to bend thick plate materials, a single punch holder with various sizes of interchangeable radius punch inserts will provide a tremendous amount of versatility and can often meet all of the fabricator’s needs when it comes to punches. These radius punch holders are offered in both straight and gooseneck profiles to meet many part requirements. Standard radius punches are bolted to these punch holders.

Another option that is available, which provides much faster setups, are punch holders that use slide-on radius punches that self-seat when bending. These radius punches are CNC deep-hardened to 56 to 60 HRC to a minimum depth of 0.157 in.to provide maximum durability and long-term accuracy when bending even the most abrasive materials.

Radius punches and punch holders are offered in standard lengths of 20 in. to minimize weight and provide for safe single-operator loading/unloading. With the slide-on type radius punches, the punch holders can remain in the machine, and changing punches is simply a matter of sliding one radius size punch out of the machine and sliding in another. Radius punches are available with tip radii from 1/8 in.to 8 in.

Multi-V Adjustable Bottom Tools Eliminate Die Changes

Another option that is becoming increasingly popular among fabricators of thick, heavy plate materials is a relatively new series of multi-V dies. Rather than exchanging single V-dies to bend various sheet thicknesses, fabricators can adjust multi-V dies on the machine to V-openings widths of 0.95 in. to as large as 15.75 in. to provide a large range of V-openings.

This process can be accomplished manually, semiautomatically, or fully automatically via motorized control by a single operator. This results in a reduction of setup time, significantly reduces the need for tooling storage, and, very importantly, eliminates the exposure to the unsafe conditions created when moving large, heavy tools in and out of the press brake.

Multi-V dies are available in modular lengths of 20 in., 24 in., and 40 in. to facilitate easier and safer handling. They are also less costly to repair or replace.

The bending radii on adjustable multi-V dies are made from replaceable hardened roller bars. These roller bars reduce the tonnage required by approximately 10 per cent. They also reduce part marking by reducing the amount of friction created by the part moving across the rollers versus the fixed radii shoulders of a traditional single V-die.

Many of today’s heavy bending applications require the forming of high-tensile strength materials. These materials inherently generate a lot of springback, often 10 to 20 degrees or more. Multi-V dies are ideally suited to these materials as their V-openings can be adjusted to the ideal requirement for specific material types and thicknesses. Their deep forming capability also allows them to make acute angle bends to compensate for the large amounts of springback that are common to these materials.

Finally, with multi-V Dies, a series of insertable die holders are available, which makes it possible to use dies with smaller V-openings when it becomes necessary to bend parts made of thin, light-gauge materials or if additional down-flange clearance is required.

Technology has finally caught up to the fabrication of thick, heavy plate materials and high-strength steels. If you are fabricating these thicker materials, a range of tools are available to help you to maximize your press brake productivity, create a safer environment for press brake operators, maximize tooling life, and increase finished-part quality while reducing the overall amount of tooling and tooling storage that was previously required.

Gunter Glocker is president of Wila USA, 443-459-5496, www.wilausa.com.