
B-64663EN/01 LASER FUNCTION 6.TRACING CONTROL
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6.1.4 Approach
Approach
If tracing is started when the nozzle is raised from the workpiece, the
nozzle will start moving towards the workpiece. This operation is
referred to as approach.
Approach speed
The speed of the approach motion is calculated using the folmula
below.
Vz=60×K×(∆E-E
0
) (1)
where,
Vz: Approach speed (mm/min)
K: Tracking speed voltage conversion coefficient
∆E: Amount of shift (mm)
Eo: Standard shift (mm)
The upper limit of the speed is controlled by parameter No. 15553.
Approach completion
When tracing is started by G13, the approach state is set, and the
nozzle continues its approach until the amount of shift satisfies the
formula shown below.
Upon reaching this point, approach completion is assumed, and
operation proceeds to the next block.
-A
PRCH
≤∆E-E
0
≤A
PRCH
where,
∆E: Amount of shift (mm)
E
0
: Standard shift (mm)
A
PRCH
: Approach-completion-sensing band width (parameter No.
15550) mm
When the machine does not move to the approach sensing position
because of an excessive load torque in the drive system, set an
approach-completion-sensing bandwidth in parameter No. 15550. If
approach completion is not detected with the standard setting value,
check the load torque in the drive system for abnormalities. When
there are no abnormalities, increase the setting.
When tracing is started, approach completion may be detected even
while the nozzle is lifted away from the workpiece. In such a case,
change the approach completion interval, set with parameter No.
15551. This problem occurs because a transient sense signal variation
caused by a disturbance (such as mechanical vibration) when tracing
is started does not lie within the specified interval.