Haeusler AG, based in Duggingen, Switzerland, is a leader in implementing large-scale facilities for forming metal plates. Haeusler is a specialized machine manufacturer that employs around 120 staff today. Since its founding in 1936, the company has developed a wide variety of machines and production lines, including customer-specific designs, for processing sheet metal for use in applications such as wind turbine towers, pipelines, the Ariane rocket, shipbuilding and enclosures within power plants and reactors.
At the end of 2020, the machine builder delivered a giant 1,245-ton straightening machine to one of the largest shipyards in China. One of the largest of its kind in the world, the machine is used in the oil tanker hull production. After an 18-month design and construction period, the latest RI 4000 X 87 straightening machine was delivered to the Chinese customer.
Proven Machine Expertise
Haeusler’s RI machine series is fitted with five, seven, nine or 11 straightening rollers, depending on the technical specification. This includes the latest, gigantic forming system, the RI 4000 X 87, which draws on the company’s 80 years of experience in the field.
Standing 12 meters high, coming in at a dead weight of 1,245 tons and equipped with five large straightening rollers, this most recent system can apply up to 19,000 tons of force during the forming processes. It is capable of machining 120-mm-thick, 4-m-wide and 12-m-long high-strength steel plates (1,000 N/mm2 yield strength) weighing up to 45 tons. Haeusler officials said the capacity to process these huge metal plate dimensions provides significant advantages compared to traditional straightening solutions.
Machining this kind of steel plate is simply not comparable with forming typical sheet metal that is just a few millimeters thick. Here, it is more a matter of evenly aligning the plates as a rule—which are sometimes slightly wavy after manufacturing—for the subsequent work steps. Another task is to homogenize the stresses occurring in the sheet through several passes of cold rolling.
For these purposes, the RI series offers a number of features, such as special individual roller adjustment for optimal straightening of both thin and very thick sheets. The direct roller drive provides automatic speed compensation and integrated overload protection. For this need, Haeusler turned to PC-based control technology from Beckhoff to ensure the enormous forces for precisely forming steel parts are guided in the right direction.
Intelligent Machine Control
Another feature of the RI series is its intelligent machine control system, according to Haeusler. The Beckhoff control technology allows users to achieve optimum machining results within a short amount of time. The modular components are distributed and networked with the high-performance EtherCAT communication system, which can be ideally adapted to the special requirements of the straightening machine.
“The strength of Beckhoff lies in the breadth of the portfolio and in particular in how open PC-based control and EtherCAT technology is,” said Patrick Stadler, deputy head of the electrical department at Haeusler. “This means that if third-party components such as position measuring systems are required, they can be integrated without a huge amount of effort.
“What’s more, a second control computer was installed in the plant for a downstream measuring application, which enables quality inspections to be performed after straightening,” Stadler continued. “Using the EL6695 EtherCAT bridge terminal, both controllers could be connected to allow real-time data communication with minimal effort. We also use ADS to transfer process parameters between the controllers via TCP/IP and to the HMI that we developed ourselves, and we appreciate how open the interface is in this respect, too.”
As another example, Stadler mentions a highly precise laser used for measuring the flatness of the straightened steel plates: “The laser has an RS422 interface, and could be easily integrated with the EL6021 serial interface and the corresponding TwinCAT library without painstaking project planning.
“A complex hydraulic system is fed from an 8,000-liter oil tank, which transfers up to 3,500 liters of oil per minute,” he added. “Hydraulic torque control of seven axes simultaneously has been implemented, with torques of up to 10 million Nm. The system is supplied with up to 2,500 A power (at full load), the majority of which is used for the hydraulics.”
Stadler also sees another advantage in the TwinCAT OPC UA Server (TS6100): “With this OPC UA interface, we provide the end customer with the option to efficiently integrate the machine into their shop floor management,” he said.
Peter Reinstadler is area sales manager for Beckhoff Switzerland.