HYDRO-HOLD HYDRAULIC HOLDDOWN SYSTEM
It has two HYDRO-HOLD hydraulic holddown systems consisting of a cams, or cams, operating a pump, or pumps
and hydraulically actuating fingers that will effectively clamp and securely hold irregular or different thicknesses of material
during a cut. Each system is well designed for the particular work that it must do. For this reason, the 0200, 0300, 0400
and 0600 series shears use 2 one-pump system while the 0800 and 1000 series, because of the large volume and lighter
pressure required, use a two-pump system.
To obtain trouble-free service, it, is necessary to use oil that is perfectly clean to prevent scoring the pistons and to
assure positive closing of the check valves incorporated in the system.
When starting the machine for the first time or after it as been idle for a long period of time, it is necessary to bleed
the hydraulic system of air. On the 0200, 0300, 0400, and 0600 series shears, a bleed valve is located at the left end of
the holddown bar (Figure 5). When bleeding the system, open the valve and jog the slide down; close the valve and jog
the slide up. Repeat this procedure during a sufficient number of times until the system is cleared of air. The 0800 and
1000 series are provided with two bleed valves, one at the left end of the holddown bar Like the smaller shears and the
other on the pump case (Figure 1). The bleeding operation on the 0800 and 1000 series is the same as for the smaller
shears except that first, the bleeding should be done on the pump case and then at the end of the holddown bar.
Hydraulic holddown pressure is set at the factory and generally, no further adjustment is necessary, however, it is
sometimes desirable to reduce the pressure when shearing soft material or where a good surface finish is important.
The holdown system relief valve is set for maximum pressure, depending on the capacity of the shear, as follows.
0200 series and 0214, 0216 -
450 psi
0600 series and 0614, 0616, 0606-H
-800 psi
0300 series and 0314-
500 psi
0800 series
- 1400 psi
0400 series and 0414, 0416 -
600 psi
1000 series
- 1400 pat
1012
- 1600 psi
The 0800 and 1000 series shear has a second pressure relief valve for its low pressure cylinder. This low pressure
relief valve is set for a maximum of 230 psi at the factory, and this setting- should not be changed. Any hydraulic pressure
change should be made by adjusting the high pressure relief valve.
To check pressure on the holddown system, the bleed valve located on the left end of the holddown bar has been
provided with a threaded female connection to receive a pressure. When checking pressure a good quality gauge should
be used having a dial reading higher than 1400 psi and preferably one with a dial reading of about 2000 psi. When
checking pressure, always turn the Selector switch to 'Inch" to run the shear rough its cycle and remember to open the
bleed valve after the pressure gauge has been installed.
If it is necessary to change the hydraulic pressure to the holddown the pressure relief valve is adjusted Do not
attempt to adjust the relief valve without a pressure gauge.
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