Delta HES Series User Manual page 39

Chapter 3 Flow of machine Adjustment|HES Series
Step 6. Bleed the circuit and make sure if there is any plastic material in the barrel.
The machine can start operation only when there are no plastic materials
inside the barrel.
For low-pressure and low-speed conditions (within 30% of the rated values), use the
"manual operation" through the controller for the operation of each cylinder. During the
operation, check the pipe connection for leaks or strange noise in the pump.
When the air is bleeding completely, if there is any pressure fluctuation during operation,
please adjust the pressure control Parameter PI in accordance with the method described
in the "Description of Parameters".
Step 7. Adjustment for injection/pressure holding
Heat up the barrel to the required temperature and set the controller in manual control
mode.
Set the Ki value of the three-stage PI to 0 (Pr. 00-21, 00-23, and 00-25）and the three-stage
Kp value to be small (≦50.0)
Execute the injection, with "Preset Target" set at low pressure (＜50Bar) and low flow rate
(＜30%)
Press "Injection" on the controller and the injection will be started or the system will directly
enter the pressure holding operation (depending on the location of the oil cylinder)
In the hold up state, Increase the speed bandwidth to the maximum value of 40Hz (Pr.
00-10) while causing no vibration to the hybrid servo motor.
In the pressure holding state, when the pressure gauge needle or the monitored waveform
shows no signs of vibration, the pressure feedback is stabilizing. Now the three sets of Kp
values can be increased.
When the pressure feedback becomes unstable, lower the three sets of Kp values by 20%
(Example: lower the preset values of the three sets of Kp values from 100% to 80%),
followed by adjusting the three sets of Ki values to eliminate the steady-state error and
speed up the system response.
Upon completion of the above steps, increase the pressure command of "Preset Target".
Observe if the pressure feedback becomes stable. Proceed with troubleshooting in case of
any anomaly, as described below:
Troubleshooting for Pressure Instability
Unstable pressure over the entire section
1. Set Pr. 00-09 = 0 for speed control
2. With the oil line in the closed state, send the low speed rotation command to make the
pressure feedback 40~50% of the pressure command value (Pr. 00-07)
3. Check if the pressure waveform shows any jitters through the monitoring software.
Jitter in Pressure Waveform
The possible cause is interference from ground. If the motor or the three-phase
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