The Grinding Machine is composed of:
BASE
Structure in normalised and stabilised cast iron with large ground guides. In the middle of the base, there is positioned the re-circulating ball screw with double preloaded nut for the table longitudinal movement. On all the lower part of the perimeter are situated the recesses for machine levelling. Considering the base structure, usually a foundation is not required.
TABLE
The table is manufactured in two parts, both are in normalised and stabilised cast iron. The lower part is lubricated by means of a constant oil flow distributed over the complete length. The upper part, is swivelable in the two directions, suitable for grinding tapered workpieces. It includes a micrometric device with centesimal dial gauge for taper control. The large machine with center distance of 2030 mm. has an air flow system between the two tables to facilitate precise table swivel movement.
WORKHEAD
The structure in normalised, stabilised and well ribbed cast iron, allows to support the workpiece weight and the force generated by the grinding operation. It is equipped with dead and live spindle. The spindle rotates on high precision ball bearings, guaranteeing restricted tolerance and maximum rigidity in the working. The spindle rotation is by means of a brushless motor and the r.p.m. adjustment is programmable. The spindle rotation may be intermittently manual or automatic. The workhead positioning on the table is facilitated by an air flow.
WHEELHEAD
The structure is composed of two carriages in normalised cast iron.
The upper carriage where the hydrodynamic spindle is located, has a manual stroke positioning of 250 mm. and the air flow facilitates the movement.
The lower carriage slides by means of a re-circulating ball screw with double preloaded nut, on guides covered with anti-friction material. The lubrication of the guides and nut is by means of a timer. The brushless motor which moves the screw, is controlled with a closed ring by the incremental optic rule, which guarantees a positioning precision on the complete stroke of 0,001 mm.
The wheelhead may be rotated manually 180°. On request, the wheelhead rotation of 180° may be executed with a HIRTH wheel with index swivel of 2.5°, with manual or automatic positioning.
WHEELHEAD SPINDLE
Hydrodynamic type, rotates on anti-friction metal bushes, which guarantees an high finish degree. The rotation is by means of an a.c. motor. On request, the speed may be regulated by an inverter. The transmission is by means of pulleys and Poly-V belt. On request, the machine may be supplied with a second grinding wheel on the right hand side.
TAILSTOCK
Together with the workhead the tailstock supports the workpiece weight and the force generated by the grinding operation. The structure in normalised and stabilised cast iron, is in two parts, so as to permit the cylindrical manual correction. Equipped with hydraulic treadle drive tailstock and safety deviceagainst accidental opening. The spindle opening is possible only when the grinding wheel is in the back position. The workhead positioning on the table is facilitated by an air flow.
HANDWHEELS (N. 2) MANUAL WHEEL AND TABLE FEED
Electronic type. A selector switch is available to change the division from 0.1 to 0.001 mm.
DIAMOND DRESSER
The external diamond dressing device is very strong and is positioned on the tailstock. With this device it is possible to dress the grinding wheel; in linear and with radius on the edges with the interpolation between "X" and "Z". The internal diamond dressing device is positioned on the table.
EQUIPMENT AND ELECTRICAL PLANT
The electrical (IP 55) cabinet is separate from the machine. The cabinet houses all the electrical / electronic components CNC control, axis motor controllers etc. the internal temperature of the cabinet is controlled by an air-conditioning unit. .
HYDRAULIC PLANT
The hydraulic power pack, is separate from the machine and activates the hydraulic cylinder of the tailstock. It is equipped with an oil-air heat exchanger. Supplied without hydraulic oil.
LUBRICATION PLANT
The lubrication power pack, is separate from the machine and supplies continuous oil to the wheelhead guides and to the re-circulating ball screw nuts, for the working feeds. The recovered oil is filtered and then returned to the power pack.
PNEUMATIC PLANT
This distributes the air cushion to the wheelhead, tailstock, table (over 2030 mm.) and wheelhead top-slide to assist with moving and positioning of the items.
COOLANT PLANT
Large capacity tank for the coolant water, complete with electric equipment, coolant magnet cleaner and coolant paper roll cleaner. The coolant flow and stop is automatically controlled by an electrovalve with pneumatic servo-control.
PROTECTIONS
For the protection of the operator all movable parts are covered with suitable guards. Precisely: protection casing for belts, protection casing for grinding wheel and bellows for guides. The front protections are sheet sliding doors with poly-carbonate shields. A movable shield in sheet, controlled by a pneumatic cylinder, protects the operator, when the grinding wheel is in rotation and the front sliding doors are open. A safety device, does not permit the automatic cycle to start if the front sliding doors are open.