Manufacturer upgrades metal-press safety and control functions with automated safety system

The integration of safety and standard control systems allows users to return the machine to full production after a shut down.

In the metal-press industry, the difference between success and failure is nearly microscopic – often just a fraction of a millimeter.

That’s true at North American Tillage Tools (NATT), where harrow discs that exceed a half-millimeter wobble tolerance won’t meet customers’ stringent quality requirements. The plant revolves around precise manufacturing and safety standards.

NATT is one of North America’s premier disc-tillage manufacturers. Each year, the business produces about 1.8 million steel discs, which are sold to farm equipment manufacturers and dealers for use in planting, tillage and seeding tools.

NATT’s automated plant uses material-handling robots to ensure efficiency and maximize throughput. Efficiency is especially critical now that the company is experiencing growing demand for its disc components. Thanks to its highly automated disc-processing plant, NATT’s heat-treated disc components – all 800 SKUs – meet OEM’s and farmers’ needs for precise and durable components.

In recent years, the factory ramped up to 24/7 operations to fill increased orders – but discovered it needed even more production capacity. NATT made the decision to add another metal press. The company worked with its machine supplier and system integrator, Allied Innovations Inc., to procure an additional press. The team selected a press that met all of the plant’s quality requirements. However, it lacked the safety requirements the plant needed and wouldn’t easily integrate with the facility’s existing control system.

“We wanted to integrate our new press into our automated process line, including all safety and motion control functions,” said Tom Dyment, major projects manager for NATT. “And we wanted the same control platform that we already had.” Using a common control platform, Dyment felt, was critical to ensuring consistent, reliable operations throughout the plant.

Allied Innovations retrofitted the press control system with an Allen-Bradley GuardLogix programmable automation controller (PAC) for safety control.

Based on the Logix control platform, the Compact GuardLogix PAC integrates with other Logix-based controllers used across the facility. All controllers share a common programming and configuration software – Rockwell Software RSLogix 5000 – easing programming and start-up. The press includes an Allen-Bradley GuardLogix Point I/O safety module and an Allen-Bradley PowerFlex 70 variable frequency drive (VFD). The new controller uses an EtherNet/IP network to control the drives and to communicate with remote safety I/O.

The controller makes it easy for NATT to integrate a variety of components into the automation line, including its robots, access safety gates, various presses and heating equipment. NATT can perform “zone control,” in which one zone of the machine/line is brought to a safe state while others continue to operate. This is possible because the control and safety systems coexist on the same network, and share data between the safety and standard applications.

Allen-Bradley PanelView Plus 6 human-machine interface software gives operators access to the press machine’s data with screen displays that clearly show machine status, menus and more.

By integrating the safety and standard control systems, operators have visibility into all machine events – including safety events – via the HMI, allowing operators to more quickly return the machine to full production after a shutdown.

The system integration was completed on time and on budget. The programming environment used with the GuardLogix controllers was so flexible that it integrated easily with the other components. As a result, NATT was able to get the new machine online and in production quickly. The company is counting on the system’s flexibility to accommodate inevitable future changes, too.

Rockwell Automation
www.rockwellautomation.com