Faccin – Plate rolls
Faccin solutions for metal forming machinery
Introduction
For over 60 years, Faccin has been the leading manufacturer of plate rolls, angle rolls, and production lines for dome ends
In the metal plate rolling process, it is extremely important to control the main process parameters, such as roll position and oil pressure and temperature. Gefran is Faccin’s ideal partner because it offers a complete range of sensors, from position to temperature, to satisfy the customer’s needs.
The customer
Faccin, founded 60 years ago, is the leading designer and manufacturer of plate rolls, angle rolls, and production lines for dome ends.
Based in Visano (BS), Italy, it operates the world’s largest bending roll factory.
Faccin offers undisputed quality because it keeps all the technological and manufacturing know-how for its machines – design, machining, automation, and assembly – in the company.
Il processo
Plate rolling is an industrial process in which metal sheets are run through rollers in a circular trajectory and maintain a set radius of curvature. There may be three or four rolls, in parallel axes, whose reciprocal position is controlled. In this way, metal sheets or profiles can be cold-rolled to obtain conical or cylindrical curves. The two external rolls, adjustable in position, roll the bottom of the material while the internal roll (normally in a fixed position) presses the top.
On machines with three adjustable rolls, the top roll moves vertically while the two side rolls move horizontally and independently. With this special design, the distance between points of curvature can be set as required, according to the same principle used with a variable V die.
The problem
One of the main demands of plate roll manufacturers is perfect control of sheets to minimize the distance between points of curvature. It is essential to check the radius of curvature and the parallelism of the rolls, controlled by measuring roll shift with a precision of 0.05 mm.
The solution
Gefran’s case history devoted to plate rolls confirms its capacity as solution provider for the metal working industry. Specifically, Gefran has supplied Faccin with a complete package of sensors that transmit feedback to the control system to check the main machine parameters.
Various types of sensors were installed on the roll to measure position, pressure, and temperature.
Linear displacement transducers, installed outside the machine, are used to precisely control distance and parallelism between the rolls.
The choice of the PC-M/PZ-34 series (potentiometers) or the MK4/IK4 series (magnetostrictives) depends on the degree of precision required and on performance in terms of IP rating.
Specifically, the potentiometer series has non-linearity values of 0.05% FS, while the magnetostrictive series achieves values of 0.01% FS.
The MK4/IK4 magnetostrictive series is rated IP67, while the PC-M/PZ-34 series is rated IP65.
The pressure transmitters measure the hydraulic pressure of the entire machine and, in particular, thrust pressure on the rolls.
The KS series of pressure transmitters, built with thick film technology on stainless steel, is accurate, robust, and compact, offering significant added value in terms of functional safety. The KS series has SIL2 certification.
Plate feed is managed by the encoder, which controls plate rotation. Specifically, the EG02 series encoder acts as a sensor to check slipping.
The AR6M series temperature sensors keep oil temperature under control in the hydraulic power unit. This extremely reliable component is a PT100 resistance thermometer built with mineral oxide (MgO) technology and has a 4-20mA amplified output signal.