Minster IOI, Руководство по обслуживанию

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Air Pressure Adjustments
The counterbalance air pressure can be regulated to
offset various die weights by adjustment of the associ-
ated air regulator. An accurate and reliable pressure
gauge and regulator must be part of the system. A
counterbalance data plate (see Figure 7E for an exam-
ple) should be attached to the press and may be used
as a guide in setting the correct operating pressure.
The plate indicates the amount of air pressure required
for zero die weight and other selected amounts. The
Minster data plate has a box marked as effective area
(EFF. AREA XX SQ IN.) This effective area is the total
square inches of surface area of your counterbalance
cylinder pistons. In Figure 7E shown, with 1 psi the
system will provide 97 lbs. of lift. Thus if it takes 60 psi
to balance just the slide, the slide would weigh 5820
lbs., (60 lbs./in
2 x 97 in 2 .) Any pressure above 60 psi is
being used to balance the upper die weight. Thus if the
die weighed 970 lbs. it would take 10 psi (970 lbs./ 97
in
2 ) plus 60 psi, or a total of 70 psi to balance the slide
and upper die weight.
Each data plate is calibrated for specific use on the
machine to which it is attached; retain its usefulness by
checking the accuracy of the counterbalance pressure
gauge frequently. If the data plate is missing from your
Minster press, a replacement can be obtained from
Minster (Minster part no. 330-0085.)
Determining Die Weight
Dies should have upper, lower and total die weight
clearly identified to facilitate both safe die handling and
correct counterbalance setting. Safety laws require
that dies be stamped to indicate upper die weight for
proper air counterbalance pressure adjustment and to
assist in handling the total die during transport.
A general rule of thumb to determine the weight of your
upper die is the following:
Take the length x width x height in inches of the upper
die and divide by 4. Dividing by 4 is the same as mul-
tiplying by 0.25 (Approx. 0.283 LBS/in
3 minus the
holes.)
Alternate Methods of
Air Pressure Adjustment
Balancing Slide and Die Weight
If the upper die weight is not known, the following pro-
cedure can also be followed:
1. With the die installed INCH slide until it reaches a
point midway up in the stroke.
2. Turn off the main drive motor and make certain fly-
wheel has stopped turning completely.
3. Adjust counterbalance pressure to approximate the
lift required to balance the slide and upper die
weight.
4. Release clutch/brake by tapping the INCH buttons
repeatedly and observe slide movement while actu-
ating the INCH buttons. (As previously instructed-
Flywheel must be STOPPED during the test.)
5. Adjust air pressure slowly until counterbalance
holds the slide at the midstroke position while the
INCH buttons are being actuated.
NOTE: Excessive counterbalance pressure will force
the slide upward and conversely, low pressure
will allow the slide to drift downward as the
clutch/brake is momentarily released.
Percent of Motor Load
Counterbalance air pressure can be set by observing
the press percent of load meter, or an ammeter in the
main drive motor circuit. The upper die should be
installed, but with no material being fed into the die.
Then cycle press continuously, by holding INCH but-
tons depressed. Adjust counterbalance pressure until
meter (percent of load meter or ammeter) registers
minimum swing or deflection.
As an example assume the counterbalance pressure is
low. As the slide travels up in the stroke the motor
struggles to lift the weight of the slide/die thus the motor
load increases. As the slide travels down in the stroke
the motor is more free thus the motor load decreases.
This action results in a swing from high to low motor
load. Adjust the counterbalance pressure so that the
swing in motor load is at a minimum.
E - 8
97
0
485
970
1450
1940
60
65
70
75
80
Figure 7E. Counterbalance data plate.