|Length of the billet||min 400 mm|
|Maximum billet length||1200 mm|
|Minimum length of the part cut with a saw||250mm|
|Accuracy of billet length||± 1 mm|
|Cutting time (8")||9 sec.|
|Blade diameter||1100 mm|
|Thickness of the blade||6 mm|
|Total cutting cycle||28" sec.|
The cutting of the logs to be sent to the press can be made by means of a shear or saw. Both solutions are installed at the outlet of the rapid-firing heating oven and perform hot cutting.
The Hot Billet Shear cuts through the movement of two blades; the desired length is guaranteed by a mechanical stop and the cut log is unloaded from a tilting cradle and a trolley.
The machine works with a compensation cycle, which allows optimization of the use of the material, thus reducing waste to a minimum.
The hot saw is an alternative to the shear, especially when the entrapment of air in the container becomes a production problem, due to the formation of microcavities in the extruded section. The cut is performed by a circular blade, which allows the user to obtain a perfectly flat cutting surface. The saw is equipped with an efficient suction and briquetting system for chips, which keeps the work area clean and allows the recovery of the material produced by the cutting operation.
Three units form the saw's cutting line: a cradle parking, a cutting unit with a blade, a table drain.
- The parking cradle is positioned between the oven and the saw; It has adjustable feet to align the billets coming out of the oven and to be running using the saw. A hydraulic cylinder can be moved up and down during the cutting cycle of the remaining part of the two sections to avoid scrap (see below the cutting cycles). The saw unit includes the cutting motion which operates horizontally and obtained from a hydraulic cylinder; the speed is controlled by a proportional valve.
- The blade with metal protection is supplied by the safety switch for maintenance purposes; the protection also has the function of improving the collection of chips at the tray.
- The blade rotation speed is controlled in a closed circuit with a frequency converter to ensure that the speed is always the same. The saw unit is equipped with a pair of clamps (one before and one after the blade) to keep the beads from the top during the cutting phase.
The discharge table is placed after the cutting unit and moves sideways from a hydraulic cylinder to allow the means of a second suitably dimensioned hydraulic cylinder, the rail of the return line trains what passes through the blade guard. A third hydraulic cylinder mounted on the discharge table moves longitudinally from idle track rollers to allow removal of the saw billet from the airline's pliers.
MEASURE IN BILLET
The final length of the billet is reached by a mechanical button ("Flag") moved by an electric motor and controlled by the encoder. The movement is obtained by a screw to accurately ensure the desired length.
An automatic pump, through copper pipes, guarantees the lubrication of the sliding components (timed impulses) to reduce friction with the parts subject to wear.
The following cutting cycles are foreseen:
- "Double cut without waste", to avoid rubbish. This cycle can be selected when the length of the billet is more than 3 times the minimum piece managed by the shears (in this case 3 times 200mm = 600mm). The concept is:
The help of the pusher registers them to be loaded in the furnace, then they are measured, so that the length of all the train registers is completely known. The cut sectional PLC always knows the remaining length of the first connection.
When the scale register is less than the prescribed length of the billet, a double cut (or cut) occurs, cutting the remaining part into two parts (the length is known to the computer). The second part is parked on the saddle parking lot. The billet is cut in such a way that the first part (old medium-grandiose log), in addition to the additional part (new register heading), is equivalent to the total length prescribed by the billet.
After the first additional section, the second part of the old register increases with the new register to be reintroduced in the oven.
- Saw face with sawing face ", joining the previous late register with the head of the new register with partial rest Refusal.
- Single-piece billet ", with the complete release of the rest of the register when it is shorter than the desired length, including a certain tolerance for cutting.
All the cycles described above are performed automatically, without any intervention by the operator.