Speed step profiling / comparator switching points
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11.1.4 Speed step profiling / comparator switching points
Application:
A bore spindle should be guided to the surface of the workpiece using a rapid feed movement. The bore is
then bored to a defined depth using a considerably longer feed. When reversing the bore spindle, the unit
should travel at a slow velocity while the drill is still in the bore. The remaining travel to the idle position is
performed at a rapid speed.
The bore spindle should be switched on just before the boring process commences and should be switched
off immediately after it has been removed from the bore. Movement of the conveyor belt should be blocked
for as long as there is a risk of collision between the workpiece and drill.
Assignments:
200
100
0
position/mm
100
0
O8
O7
0
1
0
1
course command line N011: POSA 200mm
speed
mm/s
200
100
0
position/mm
100
0
O8
O7
0
1
0
1
course command line N016: POSA 0mm
speed
mm/s
Function:
The feed movement is implemented using speed step profiling. The initial speed is first set to 100 mm/s
using the "SPEED 100%" command (N007). This speed can be used until the start of the boring process.
After a travel distance of 120 mm, the boring begins and the speed should then be 10 mm/s. The "POSR 120
mm SPEED 10%" command (N011) ensures that the speed is reduced from 100 mm/s to 10 mm/s for the
following positioning after a distance of 120 mm. The position as of which the speed is then 10 mm/s
depends on the set braking ramp (N001) and the output speed (N007). This means that braking is initiated
from an appropriate stopping distance from the position where the bore starts.
When returning, the initial speed is set to 50 mm/s (N012) and, as of a travel distance of 70 mm, is
accelerated to 100 mm/s (N013).
The bore spindle is switched on and off with the aid of the comparator switching points. During the feed
movement, the spindle is switched on after a travel distance of 100 mm (N009). By the time the boring
process begins after 130 mm, the spindle must have reached its operating speed. The spindle is switched off
again when returning once the drill has left the bore (N014).
The conveyor belt is blocked for as long as the axis is located at a position of between 25 mm and 200 mm
(N008 and N015).
