OKADA TOP Series, Инструкция и перечень запасных частей для владельцев и операторов

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b) Cold
Low temperature causes a working tool to be more susceptible to fatigue failure. Tools should be warmed
before use.
c) Mechanical and thermal damage
Any form of damage to the surface of a working tool renders it more liable to suffer fatigue failure. Thus
all care must be exercised to prevent accidental gouging, or contact welding (‘galling’ or ‘pick up’) due to
contact between the tool and the bushings through the lack of lubrication or excessive bending ( see
Figure 2 )
Fig. 2
d) Lubrication
Care must be taken to avoid metal to metal contact that, as a result of galling or pick-up, could cause
deep damage marks which, in turn, lead to the formation of fatigue cracks and eventual failure of the
working tool. Ensure that the shank of the working tool is well lubricated before locating in the machine.
e) Corrosion
A rusty working tool is more likely to suffer fatigue failure, thus keep tools well greased and sheltered
from the weather when not in use.
Demolition Tool Fatigue Failure
A working tool fatigue failure will generally occur approximately 100 mm (4”) either side of the chuck front
face (see Figure 3) or through the retainer pin flat.
Another slightly less common failure area can fall approximately 200 mm (8”) from the working end, subject
to nature of use.
The fracture face itself will normally exhibit a semi circular polished area with the remainder being of a
rougher appearance ( see Figure 4 ).
Fig. 3 Fig. 4
The polished semi-circular are in Figure 4 is the fatigue area and generally stars from a damage mark or
other stress raiser on the outside of the working tool and spreads inwards. The fatigue area slowly widens
until the stresses being applied to the working tool cause sudden failure of the remaining section.