Amada MAWA-300B-00-00, Руководство по эксплуатации, Страница: 118 / 168

MAWA-300B
5. Welding
5-10
(6) Touch Start
(6) -1. Overview
The touch start function of this welding power supply is used to perform arc welding by causing the
initial current to flow in the status where the electrode is in contact with a workpiece and keeping the
distance from the arc discharge gap. This is provided with such advantages as shown below.
y
It is not necessary to apply a high voltage to cause a dielectric breakdown of the air.
y An arc discharge is started by touch. This does not cause an accidental fire easily.
y An arc discharge is started by touch. The welding points can be easily specified.
y
No high voltage is generated. This can reduce noise effects.
(6) -2. Operations
To drive the torch by the touch start head ( MH-109TA ), the touch start has three operation modes;
“normal mode”, “auto mode” and “fine weld mode.”
Features of each mode are as follows.
Initial current
time setting
Initial current
monitor time
Main welding
start timing
Advantage Disadvantage
Normal mode FST [ms] > 0 Set time
At the end of the initial
current time after the
head reaches the main
welding position
The welding setting
waveform and the
monitor waveform are
displayed in the same
time series.
The initial current time
setting matched to the
head rising speed is
necessary.
Auto mode FST [ms] = 0
Fixed to
500 ms
Immediately after the
head reaches the main
welding position
The initial current time
setting is unnecessary.
The welding setting
waveform and the
monitor waveform cannot
be displayed in the same
time series.
Fine weld mode FST [ms] = 0
Fixed to
500 ms
When the head moves up
from the initial current
position and the electrode
touch sensor is turned
OFF.
1) Welding with
conditions 30A and
100 ms
2) The weld time during
the head moves up is
shortened.
The welding setting
waveform and the
monitor waveform cannot
be displayed in the same
time series.
*1 *2
To drive the torch by the touch start head (
MH-109TA ), set the Torch drive type to MOTOR and the
pulse output time of the END output to 200 ms.
*1
：
For the initial current monitor time, refer to “4. (3) (m) Waveform display area.”
*2 ： For the main welding current start timing, refer to timing charts in 6. (1), 6. (3) and 6. (4).