SWDM240B OPERATION & MAINTENANCE MANUAL
perpendicularity display, and adjust the mast cylinder till the pointer aiming at the scale. If not
adjust perpendicularity before piling, the Kelly will bearing force at the inclined status for a
long time, it’s easy to result in inclined pile hole, broken spline bar or pipe casing crack
extending to Kelly breakage. Thus, mast perpendicularity should be adjusted before piling to
ensure Kelly in the center position of rotary head.
Aim：aim Kelly at the barrel center.
Lower ： lower rear main winch rope, and then lower Kelly section from outer to inner
successively, observe the display distance and decrease the lowering speed till 3 meter to the
hole bottom, not colliding drill bucket with the hole bottom.
Find：After drill bit touches with the bottom, lift and rotate rotary head anticlockwise slowly to
adjust the height, then find pressure steps, and rotate it clockwise making inner spline of every
section entering into the range of pressure steps, press it down and lock, at last rotate rotary
head clockwise downward to drill.
Retract：After grabbing soil, keep the drill bucket close to the bottom surface and lift and rotate
rotary head clockwise at small range, then rotate anticlockwise to separate pressure table and
drive sleeve inner spline of each layer, making the inner spline entering into the sliding groove
of Kelly and close the bucket, confirm unlock completely, keep rotary head anticlockwise
rotation, lift main winch, at last retract the core bar. When retracting each section completely,
the disc always collide with the end surface of the drive sleeve slightly, causing slight nodding
to the rotary drilling rig, and winch tension increase in a sudden then back to stable, thus, the
operator should be familiar with that nodding depth.
8.1.3.2 Ten Forbidden Operation
One
：
It’s forbidden to operate ignoring the abnormal conditions on the working site.
If any abnormality is found, stop work at once to check problem, avoiding accidents in the hole.
The serious accident is to smash the Kelly caused by Kelly following.
Two: It’s forbidden to refit Kelly.
It’s forbidden to operate baking, spot welding, welding and grinding freely by non-professional
personnel.
Three: It’s forbidden to pressurize the machine-lock Kelly freely at any position and use it as a
friction Kelly.
Pressurize the Kelly directly without finding pressure point, this will result in the abrasion,
stuck or rolling spline for the Kelly caused by too much pressure with small contacting area on
the pressure side surface or inclined plate.
Four: It’s forbidden to tilt the front end of track and mast rearward.
The front end of track tilt when drilling, that will not increase any effective pressure but
increase lateral force to the Kelly and lead to crack and even breakage. Any problem is found,
release the pressure at once replacing with intermittent pressure.
Five: It’s forbidden to loosen main winch excessively.
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