2
8.25.8 Automatic Threading Cycle (G 76) (Cent’d)
The sign of figure following the address I is
decided by the direction of position B‘ view-
ed from position C .
x
I
,Z
Fig. 2.51
The following shows the cuttin~ position
around poin~ B (In case of tap~r”thread) .
The G76 cycle starts and ends at point A.
2ND
3RD
(2)
NTH
CYCLE
CYCLE
CYCLE
CYCLE
‘-----
j>
FIXED AMOUNT
(SETTING .6206)
Fig. 2.52
The depth of cut in Nth cycle is:
Fig. 2.53
(3) Rapid threading pull-out
If “Rapid threading pull-out input (CD Z )“
is on when G76 is specified, Rapid threading
pull-out is performed. (y) may be set to
parameter #6080, in the range of O to 25.5L
and in increments of O.lL , where L is the
lead of the specified thread.
Notes :
1.
2.
The following six angles can be used as the
command of thread angle.
3.
A = 0°, 29°, 30°, 55°, 600, 80°
Cutting in final cycle is made with the depth
of fixed amount a,
which is set by the setting
#6206.
Straight thread
The depth of cut D in the first cycle is re-
stricted by height of thread K as follows.
,
Addresses K and D must be programmed
without signs.
When taper threading is commanded with an
effective angle, except O, X coordinate of
threading start position does not extend to
the depth of cut.
’441
THREADING
~.
L).
,q:~
.-. _
-..
THRE4DING
START
POSITION
If the thread angle other than the above list-
ed (0°, 29°, 30°, 55°, 60°, 80°) is arbitrarily
commanded, the next larger angle is selected.
EXAMPLE
(Command) A15 _
(Execution) A29
When A j 80°, A80 is executed.
When the address I is O or not designated,
a straight thread is cut as shown below.
110
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