Clamping Force Check / Clamping Fixtures Without Permanent Pressure Supply; Rigidity Of The Workpiece To Be Clamped - Rohm Norm RN 1391 Informaciones Y Directivas Generales Para El Empleo De Instalaciones De Sujeción Accionadas Por Fuer

1.2.7 Clamping Force Check / Clamping Fixtures without Permanent
Pressure Supply
a) Clamping force check (general)
In accordance with § 6.2 No. d) EN 1550, static clamping force measuring
devices must be used to check the operating condition at regular intervals
in accordance with the maintenance instructions. According to this, the
clamping force must be checked after approx. 40 operating hours - inde-
pendently of the clamping frequency. If necessary, special clamping force
measuring jaws or fixtures (load cells) are to be used.
b) Clamping force check (specific)
Hydraulic supplies, especially with large cable cross-sections, entail a risk
that, due to dynamic effects, the peak pressure - and therefore also the
actuating force peak - are significantly higher than the set pressure. This
may lead to a mechanical overload of the components. Therefore, the ac-
tually achieved total clamping force is to be measured on start-up. The
pressure may only be set so high that the max. total clamping force (at
standstill) specified on the drawing or in the operating instructions is not
exceeded.
c) Clamping fixtures without permanent pressure supply
With some clamping fixtures, the hydraulic or pneumatic connection to the
pressure source is interrupted during operation (e.g. with LVE = pneu-
matic front end chuck / HVE = hydraulic front end chuck). This may lead
to a gradual decrease in pressure. The clamping force may then decrease
by so much that the workpiece is no longer sufficiently clamped. To com-
pensate for this loss of pressure, for safety reasons, the clamping pres-
sure must be activated every 10 minutes for at least 10 seconds. This
also applies after extended downtimes, e.g. if machining is interrupted
overnight and only continued the next morning.
Recommended clamping force measurement system F-SENSO CHUCK
(only for external clamping force measurement)
F-SENSO CHUCK.
1.2.8

Rigidity of the Workpiece to be Clamped

To ensure safe clamping of the workpiece with the machining forces which oc-
cur, the clamped material must have adequate rigidity for the clamping force
and may only be slightly compressible.
Non-metals such as plastics, rubber etc. may only be clamped and machined
with the written permission of the manufacturer!
RN-1391
Safety Instructions and Guidelines | 1
ID no. 179800
33 / 138
EN