START-UP INSTRUCTIONS FOR CP 477 HYDRAULIC SHEARS

Device is delivered with the following settings: they may be re-adjusted by user.

- 1A pressure setting valve for accumulator and blank holder pre-setting	= 70 bar (= 7 M Pa = 1000 PSI)
- 1B pressure setting valve for cutting pre-setting	= 250 bar (= 25 M Pa = 3600 PSI)
- 1G differential valve pre-setting	= 220 bar (= 22 M Pa = 3150 PSI)
- "X" external pilot line for accumulator

Note: Should the max pressure valve be set at a value below 230 bar (= 23 M Pa = 3300 PSI), then differential valve is to be adjusted at a proportionally lower setting too. One revolution of the adjusting screw corresponds to a pressure variation of 115 bar (= 11,5 M pa = 1656 PSI) for the max pressure valve, of 45 bar (= 4,5 M Pa = 648 PSI) for the differential valve.

CYCLE DESCRIPTION

Filling up
Decrease pressure of “1B” valve to about 10 bar (= 1 M Pa = 140 PSI). For this purpose, use only the 19 mm (3/4”) hex plug. Then, energize “E4” electrovalve and get the pump running, in order to feed “C”. Pipe connection to upper side of small cylinder should be kept loose to facilitate air elimination.

Note: Guides of shear holder must be so adjusted as to allow for shear coming down to the end of stroke when “E2” is energized, while pump is off.

Start up tuning
- In a situation of running pump and with the blade up, adjust “1A” valve in order to get, at “M A”, a static pressure of about 5 bar (= 0.5 M Pa = 70 PSI).
- Check also that, during down stroke of blade, pressure reading at “M A” never shows a value below 10 bar (= 1 M Pa = 140 PSI). If this is not the case,”1G” screw plug (which is placed close to “MB”) must be tightened.

Blank holder
By energizing “E1” (alone) blank holder comes down (cutting mark) using accumulator pressure. Optionally, it is possible to increase down speed of blank holder by adding a plate, which allows installation of an accumulator (3/4”G fittings) and of a 6 mm electrovalve: using its double ports yields to increase (two or three times) down speed of blank holder cylinders (possibility of screwing M8 plug on “A” port). Such electrovalve has to be switched on together with “E1” and shall be turned off only after the “up limit switch” has been left free.

Shearing
When both “E1” and “E5” are energized, downwards motion of cutting blade takes place if counter-pressure in blank holder reaches a value of at least 70% of accumulator pressure.

Shear up stroke
Normally, actuation of “shear down limit switch” causes “E1” and “E5” de-energizing. In this case, blank holder comes up and, at the same time, the shear begins its back stroke up to the tracing zone where, in the last 2 or 3 mm of stroke, the “up limit switch” is actuated and enables starting a new cycle. Optionally, it is possible to get the blank holder coming up first (by de-energizing “E5”) and, later on, to begin the back stroke of shear, by delaying de-energization of “E1”.
If you want a softer inversion you can change the nozzle e Ø 0,4 mm with one Ø 0,3 mm.

+ Angle
Energize “E3”.

- Angle
Energize “E4”.

Slow down-stroke /accumulator discharge
Keeping the pump off and with the blade in tracing position (up), switch “E2” on. After accumulator discharge completion, the blade will begin coming down slowly, at a speed which may be controlled by nozzle placed underneath “1M” electrovalve.