ROHM OVUSHH - hydraulic operated duble piston cylinders - Manual (Page 12)

The threads and head contact surfaces of all securing
screws which are frequently released and retightened
due to their application (e.g. for retooling) must be coa-
ted with a lubricant (grease paste) at six-monthly inter-
vals.
Even securely tightened screws can become loose
under adverse outside conditions such as, for instance,
vibrations. In order to prevent this happening, all sa-
fety--related screws (clamping fixture fastening screws,
clamping set fastening screws etc.) must be checked
and, if necessary, tightened at regular intervals.
2.9 Safety valves
In the event of a power failure (e.g. electric power sup-
ply) the safety valves must prevent loss of pressure,
which would release the clamping device. It must, ho-
wever, be pointed out that, due to the reaction times or
seal wear, a pressure loss of approx. 20% of the output
pressure of hydraulic cylinders may be experienced.
In unfavourable circumstances and despite the fact that
safety valves have been fitted this can lead to a situa-
tion where the residual clamping force is no longer suf-
ficient to retain the workpiece in the clamping device.
2.10. Stroke control monitoring
If a laser sourced stroke control unit is used with the
clamping cylinder/oil distributor it’s beam is not suppo-
sed to hit the eye. Though normally only safe laser
sources of safety class II according to EN 60825 will be
used, the retina could be irreparably damaged when
looking into a direct laser beam
3. Inspections
Stroke monitoring
The stroke monitor device should be adjusted to suit the new
situation if the clamping device is newly mounted.
Service inspections
Reliability of the power clamping fixture can only be ensured
if service regulations in the operating instructions are followed
exactly.
4. Environmental Hazards
A wide range of media are required during operation of a
clamping device for lubrication, cooling etc. This are normally
distributed to the clamping device via the distribution housing.
The most common substances used are hydraulic oil, lubrica-
ting oil/grease and cooling agents. When handling the clam-
ping device care must be taken to ensure that these substan-
ces do not come in contact with the soil or water. Warning, en-
vironmental hazard!
This applies in particular
D
during assembly/disassembly, as residues can be contai-
ned in the pipes and piston shafts,
D
to porous, defective or incorrectly mounted seals,
D
to lubricants which are emitted or ejected from the clam-
ping device during operation for constructional reasons.
These discharged substances should therefore be collected
and either re-used or disposed of in accordance with valid re-
gulations!
5. Safety requirements for power clamping equipment:
5.1 The machine spindle may not start until the clamping
pressure has been reached in the clamping cylinder
and clamping has been effected within the permissible
working range.
5.2 The pressure may only be released when the machine
spindle is stationary.
Exceptions are only permissible if the complete machi-
ning sequence of loading and unloading is performed
with the spindle in motion and the design of the distri-
butor/cylinder permits this.
5.3 A signal must be emitted to stop the spindle immedia-
tely in the event of a failure of the clamping power.
5.4 The workpiece must remain tightly clamped until the
spindle is stationary in the event of a failure of the
clamping power.
5.5 Changes of the current switch position should not be
possible during an electrical power failure and subse-
quent restoration.
6. Spare Parts
Only use ORIGINAL RÖHM spare parts or components
obtained from authorised RÖHM suppliers. RÖHM GmbH
does not accept any liability for damage resulting from the
employment of parts supplied by other manufacturers.
Note: For simple ordering of spare parts or individual com-
ponents always state the 6-digit ID number engraved on
the assembly and, if available, the works number. This
comprises a letter with two digits and possibly a series
number, stated either on the rating plate or next to the ID
number.
Safety notes
Tightening torques in Nm:
Class M5 M6 M8 M10 M12 M14 M16 M18 M20 M22 M24
8.8 5,9 10,1 24,6 48 84 133 206 295 415 567 714 Nm
10.9 8,6 14,9 36,1 71 123 195 302 421 592 807 1017 Nm
12.9 10 17,4 42,2 83 144 229 354 492 692 945 1190 Nm