ROHM Tool clamping units - Manual (Page 13)

Tightening torques in Nm:
Class M5 M6 M8 M10 M12 M14 M16 M18 M20 M22 M24
A wide range of media are required during opera-
tion of a clamping device for lubrication, cooling etc.
This are normally distributed to the clamping device
via the distribution housing. The most common sub-
stances used are hydraulic oil, lubricating oil/grease
and cooling agents. When handling the clamping
device care must be taken to ensure that these
substances do not come in contact with the soil or
water. Warning, environmental hazard!
This applies in particular
¯ during assembly/disassembly, as residues
can be contained in the pipes and piston shafts,
¯ to porous, defective or incorrectly mounted seals,
¯ to lubricants which are emitted or ejected from
the clamping device during operation for
constructional reasons.
These discharged substances should therefore be
collected and either re-used or disposed of in
accordance with valid regulations!
4. Safety requirements for power clamping
equipment
4.1 The machine spindle may only be
started once the clamping position on
the stroke control has been reached
and has been scanned by an inductive
sensor with function monitoring or an
inductive safety sensor as per DIN VDE
0660 Part 209.
4.2 The pressure may only be released when
the machine spindle is stationary.
4.3 A signal must be emitted to stop the
spindle immediately in the event of a failure
of the clamping power.
4.4 In the case of a hydraulic or electrical
break-down, the tool mounting remains in
the securely clamped position.
4.5 In the event of power failure and subse-
quent resumpt. of supply, no change may be
made to the switch position as at that time.
2.6 Clamping force check:
According to Standard EN 1550 s. 6.2 No. d),
static instruments for measuring the clamping
force must be used at regular intervals to check
whether servicing is required in accordance with
the maintenance instructions. Following this, after
approx. 40 operating hours a clamping force
check must be carried out -- regardless of the
clamping frequency.
If need be, special instruments for measuring
the clamping force (holding force gages) should
be used.
2.7 Strength of the tool shank to be clamped:
To ensure that the tool shank is securely clamped
to cope with the machining forces which arise,
the draw-in bolt being used must have a strength
appropriate to the clamping force (holding force)
and may only be extensible to a minimal degree.
Non-metals such as plastic, rubber etc, may only
be used with the written authorization of the ma-
nufacturer!
2.8 Assembly and tool-setting work:
as a result of clamping motions, short distances
are covered in short time periods under the effect
of forces which in some cases are considerable.
It is imperative therefore that the drive device for
operating the tool clamping unit is switched off
during assembly or tool-setting work.
2.9 Replace and loosing of screws
When screws are replaced or loosened, defec-
tive replacements or inadequate fastening may
cause personal injuries and material damage.
Unless specified otherwise, all fastening screws
must be tightened to the torques recommended
by the screw manufacturer for the relevant
strendth class.
All fastening screws, which account of their appli-
cation, must be frequently loosened and retighte-
ned, in conjunction with resetting work for exam-
ple, must be coated with antiseize (grease paste)
in the thread area and on the head contact sur-
face at intervals of 6 months.
When replacing the original screws, make sure
that the replacements have the same strength
class (normally 12.9). The tightening torques for
sizes M5-M24, classes 8.8, 10.9 and 12.9, are li-
sted in the table at the top of this page.
Always use class 12.9 for screw fastening clam-
ping inserts, top jaws, stationary locators, cylin-
der covers and similar elements.
3. Environmental hazards
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
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