TM 5-3805-280-24-1
Adjustment of drilling automatisms
ADJUSTMENT OF DRILLING AUTOMATISMS
LOCATION OF ADJUSTING SCREWS
3
2
4
5
1
6
1)
V1 Feed pressure
4)
V3 Drifter power regulation
V3 measures actual feed force by sensing both
This valve setting is made while setting up the
forward and return feed pressures.
machine on site, to suit bit type and diameter.
The V3 adjustment sets the feed pressure limit
Presetting can be made in a static mode prior to
below which the drifter power will be reduced.
drilling by feeding the bit against some resistance.
This control will continue to reduce the drifter
Final setting is made at full percussion power
power level to a 60 bar (870 psi) preset minimum as
while drilling in the hardest, most homogeneous
rock resistance decreases.
competent rock encountered.
5)
Feed flow regulator
2)
MP Maximum percussion pressure
This flow regulator adjusts the feed maximum
flow to slightly above the drill rate in the hardest rock
It sets the drifter maximum percussion pressure
encountered.
when drilling with cold oil while starting up.
t If the feed flow while drilling in softer rock condi
ions reaches the preset maximum, the resulting
This factory setting must not be altered.
back pressure makes the feed force to decrease and
act on V3.
3)
V2 Operating percussion pressure
This acts as both an Anti-Void and Collaring
Control.
It sets the drifter percussion power to a suitable
level for bit size and rock hardness. The setting
6) V4 Progressive feed control and
should be approximately :
antijam
- 120 - 130 bar (1715- 1850 psi) for Hc 80
- 130 - 140 bar (1850 - 2000 psi) for Hc 120
V4 is an adjustable regulator which senses the
- 140 - 160 bar (2000 - 2285 psi) for Hc 150
pressure differential across the rotation motor and
depending upon the appropriate drifter power level.
acts directly upon feed flows.
10-10
