4 Rolls Plate Bending Machine


The RI72 is an hydraulically operated 4 roll plate bending machine with double pre-bending. The rolls have a linear movement along bronze guides.
The RI72 series bending machines are available with a capacity from 25mm to 300mm and roll length from 1000mm to 6000mm.

The RI72’s Key Features

PRE-BENDING is perfect with a minimum straight section (3-4 times shorter than planetary “PSG” technology) due to the high power force of the cylinders on the bottom rolls, that thanks to the linear motion are fitted directly under the rolls and do not use any system of levers.

Positioning PRECISION of the rolls maintained over time thanks to the linear guide system. The bottom rolls are guided within the structure of the machine, eliminating the possibility of clearance due to machine wear and tear, contrary to what happens on machines with a planetary (PSG”)/lever system.

CANCELLATION of the sliding friction of rolls, ensured by a system of lubricated bronze guides.

PARALLELISM of bottom rolls perfectly assured by a system that uses a two linear potentiometer for each roll. The rolls are independently adjustable and tilt easily to allow for the execution of cone bending.

ROBUSTNESS is characterised by solid structural steelwork and linear structures.

SPEED and RELIABILITY of high quality work

EASY to use and maintain thanks to easy accessibility of the hydraulic parts and the diagnostics on the control panel, that are always within reach of the operator.

How to use it

1. Insert the plate between the rolls
2. Align the plate with the side roll (angled)
3. Clamp the plate between roll D and C
4. Create the pre-bending using roll A
5. Continue with forming the required diameter of plate between the rolls using both roll A and roll B.
6. Create the second pre-blending using roll B.

STRUCTURE OF RI72 (CE certified bending machine):

Crossbeams made of electro-welded steel, subjected to normalising heat treatment.
The supporting frames of the rolls’ movement cylinders are made of electro-welded steel, subjected to normalising heat treatment

Rolls in special carbon steel (C45 or C50) subjected to thermal hardening treatment.
– Two rolls are motorised with no. 2 epicyclic reduction gears and no. 2 hydraulic motors for their rotation.
– The side rolls and bottom roll have independent positioning movement by means of the hydraulic cylinders.
– Side rolls are electronically tilted (controlled by the PLC) for the production of conical plates.
– Movement of side and bottom rolls with a straight guide system
– The rotation system of the rolls consists of two hydraulic motors coupled with two epicyclic reduction gears, directly fitted on the rolls.

Automatic speed/pressure balance between the upper roll and bottom rolls;

Linear potentiometers fitted on each roll (two on each roll) that allow electronic control of parallelism between rolls.
Radial bearings fitted on all rolls, self-aligning as double row SKF or FAG branded bearings

Two pumps or up to six for the bigger sizes for maximum linear and rotational thrust. Having a system with more pumps always produces simultaneous movements, including the possibility of both rotating and pressing up to the maximum capacity, and in the event of pump failure, the machine can also be operated, even if the performance is reduced.

The cylinders are made of alloy steel and carbon steel with a chrome-plated rod and use seals from the primary brands.

Hydraulic control unit consisting of: motor pump unit, electro valves, pressure relief valves which guarantee overload protection.

Hydraulic opening handle to allow the produced tube removal in horizontal position.
Automatic centralised lubrication system with a pump which has an autonomous tank, programmable from the touch panel.

Siemens, ABB, Telemecanique, Moeller electrical system. It consists of a mobile console control panel connected to the machine with low voltage and a general cabinet where there are all of the other electrical components, as well as the machine control PLC SIEMENS S7.

Independent SIEMENS KTP1200 PN control Touch Panel with a 12” touch screen colour display. By changing pages it is possible to see on the display the position, the balance of the rolls, to setup and read the tilting of the rolls, to set their speed (two rotation speeds), the diagnostic functions and machine alarm.

Modem to remotely control the PLC in case of software changes and resolution of machine faults.

Heat exchanger for the hydraulic oil;


– Normalising, induction hardening treatment and surface grinding of the rolls
– Device for cone bending
– Hydraulic side arm for plate support
– Hydraulic side arm for double articulation plate support
– Hydraulic side arm for double articulation plate support, complete with hydraulic pistons for handling the tube.
– Hydraulic overhead plate support
– Motorisation of side rolls
– Plate conveyor
– NC control with 12” Siemens TP 1200 Comfort Touch Panel
– CNC Siemens TP 1200 Comfort 15” Touch Panel with parametric programming and plate data input, for the automatic production of cylindrical, elliptical and polycentric shells.
– Hot-forming package up to 1000°