28/05/2009

Spanish company launches production of railway wheels for global market on new Schuler press

After Easter 2009, production was launched on a huge hydraulic press supplied by Schuler SMG in Waghäusel, Germany, to the Spanish company CAF in Beasain. The company specializes in producing all types of railway wagons. From simple wagons to underground trains, and from locomotives to high-speed trains, CAF’s facility in Beasain produces virtually everything that rolls on rails. The production of railway wheels, however, plays a special role. Only about one tenth of the wheels are for CAF’s own needs; the rest is exported around the world.

The new hydraulic press supplied by Schuler SMG is responsible for the first stage in the production of railway wheels. With a press force of 10,000 metric tons, the pre-forming press compresses a round block of steel heated to around 1,200 degrees Celsius into a kind of “cake”. This is then forged into a pre-formed wheel in a second stage. A wheel rolling machine then continues to form the pre-formed product into a wheel. Finally, the wheel receives its final shape and the hub is punched in a 2,500-ton press.

The new pre-forming press was integrated into a completely redesigned production environment within just ten days. Teams of suppliers had previously been given three months to install the 10,000-ton press during production and to equip the furnace, descaling plant, press and wheel rolling machine with robots in order to link them into a fully automatic line with automatic ejector stations. The complete line was put into operation in record time during the Easter holidays 2009.

Nearly all forms of railway wheels can be pre-formed using the Schuler press. The power and high press force of the machine become apparent from its impressive statistics: the main cylinder has a diameter of around three meters. The respective hydraulic system contains 30,000 liters of hydraulic oil to help the cylinder do its work. The whole system requires four megawatts of power. Lubrication and cooling ensure the process goes as smoothly as possible. Three robots cool the dies before, during and after the forming process and spray them with a water-graphite mixture.

The process is capable of producing railway wheels with a maximum diameter of around one-and-a-half meters and a weight of over one metric ton. “The line is designed in such a way that a fully formed wheel leaves the line every 90 seconds,” states Dr. Walter Osen, Head of the Solid Forming Business Unit at Schuler SMG in Waghäusel.

“Thanks to the new 10,000-ton press, the pre-form can be sized much more precisely and there is thus less rolling work required in the downstream wheel rolling machine. This significantly reduces the line’s cycle time,” says Mikel Mendoza, the project manager responsible for wheel production at CAF.

In order to tap the full potential of the new pre-forming press, new dies were developed in cooperation with Schuler, which are being successively tried out at present during running production. “The aim is to reduce input weight by up to ten percent with the aid of the new dies,” explains Dr. Walter Osen.

Automatic linkage results in a corresponding reduction in transport times from the oven to the press and to the wheel rolling machine. As a result, the furnace temperature can be lowered and energy savings can be made,” says Mikel Mendoza.

In a second step, the 2,500-ton press for the final pressing and punching of the wheel hubs will be replaced in summer 2009 by a new 5,000-ton crimping press supplied by Schuler SMG. This will close the last gap in CAF’s fully automatic wheel production process.