Dawson HPH 1200, Руководство пользователя

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(iv) It is possible to work the hammer for diagnostic purposes whilst it is laying on the
ground. However, extreme caution must be exercised when doing so as incorrect
operation will cause hammer damage. Always ensure the pendant is in MANUAL mode
and NOT automatic mode. The anvil must be in the ‘up’ position so as to ensure the
trip device is ‘off’. The hammer can be pressurised by ‘tapping’ the ‘start’ push button
on the pendant (power pack running) very gradually building up enough pressure to
move the drop weight. If the button is held for too long the drop weight will possibly
impact the inside top of the hammer - not a good idea!
However, by careful application of this method it is possible to check pressure is
reaching the relevant sensor. If it is not, then the problem may be with the overtravel
valve (part 1-084-00-02) not allowing oil flow to the control side of the hammer. This
can be confirmed by removing the main pressure feed to either sensor - no oil flow
when pressurising the system indicates overtravel valve problems and this item should
be removed for inspection. (The overtravel valve can be removed through the wide slot
in the side of the hammer encased by the rear leg guide and the hammer will require
turning over to do this). Turn the power pack off before removal.
When checking the overtravel valve first check the small restrictor/dowel on its top face
for any blockage. The valve is unlikely to be faulty inside and if this is suspected the
unit should be returned to the manufacturer for checking.
If pressure is reaching the sensor check that the pilot signal from the sensor is reaching
the main control valve block at the top of the hammer when the roller valve is operated.
If not, remove and inspect the roller valve.
g. If this all appears to be in order check the top sensor mechanism in a similar manner to that
described in f. (i) and (ii) above as it may be that the top sensor is jammed on.
Note: The spool inside the roller valve and the roller shaft are not connected so even though
the roller returns when operated it does not follow that the spool has returned. Check
the tension on the roller shaft, if there is none the spool may be stuck open.
h. If all appears well the problem may be with the load holding valve (part 1-073-00-02) or the
main control valve spool. Contact the manufacturer for further details.
6.5 Hammer will lift but not drop
a. Has the hammer been allowed to overtravel. Check reset - see section 3.4.4.
b. Air in hammer hydraulic system - see section 3.4.2.
c. Damaged 'looped' hose from sensor assembly - check by removing front leg guide for inspection.
d. Faulty top sensor assembly - see 6.4.e. as diagnosis is similar to faulty bottom sensor assembly.
e. Faulty bottom sensor assembly i.e. valve is staying on (see section 6.4.f. for similar diagnosis)