PIM00411
13-11
13.6.2
Cleaning method
Blow air onto the filter to blow off dust accumulated on/adhering to the filter. Remove dust from inside of the
strainer cylinder.
13.6.3
Reassembling
After cleaning is completed, reassemble the suction strainer. Follow the removing procedure in reverse.
(Suction strainer: Tightening torque 39.0 N · m; Cleaning palate nut: Tightening torque 9.0 ~ 10.0 N · m)
After reassembling is completed, conduct the test run procedure according to "Chapter 10 Test Run" to make sure
that the hydraulic unit normally operates.
WARNING
During air blow, wear protective goggles to prevent accumulated substances or dust from touching your eyes.
13.7
High-pressure Safety Valve Adjustment Procedure
In the following three conditions, please re-adjust the setting of the high-pressure safety valve, by referring to
“High-pressure Safety Valve Adjustment Procedure” described below.
1. Even if the hydraulic unit is used with the maximum pressure setting, the safety valve will not be activated
under normal pressure control (except for the transient period when the circuit is blocked due to stop of
the master machine hydraulic actuator). However, the safety valve set pressure will be lowered due to
long-term repeated operations and contaminants in the hydraulic oil. If the safety valve is activated even
with normal conditions, safety valve adjustment is required.
[Judgment criteria]
The hydraulic oil temperature rising time is shorter than before.
When the safety valve adjusting screw is turned in the tightening direction, the rpm indication in the
pressure hold status is lowered.
2. To minimize surge pressure that much exceeds a setting pressure, safety valve adjustment is required in
consideration of the withstand pressure of the hoses being used.
3. When the pressure set value is changed from the factory setting.
In order to suppress the surge pressure for protecting actuator and pressure gauge, it is recommended
that the pressure setting of the safety valve should be the following value showing in the table below.
[High-pressure Safety Valve Adjustment Procedure]
[1] Referring to the enlarged view of the high-pressure safety valve shown in the
next page, loosen the lock nut.
(M10 lock nut, Width across flats: 14 mm)
[2] According to the pressure adjusting screw length reference chart, determine the
screw length corresponding to a desired control pressure setting. The reference
chart is different depending on different model.Refer to the table below, and
refer to the reference chart in the next page.
(The adjustment screw tip has been chamfered in 7mm width.)
[3] Turn ON the hydraulic unit power supply, and select the setting mode through panel key operation. Then, set a
desired pressure.
[4] Select [n05] (rpm display) in the monitor mode through panel key operation to show the current rpm.
[5] Adjust the pressure adjusting screw length in the longitudinal direction, and find an activation starting point as
shown on the right.
[6] Turn the pressure adjusting screw clockwise from the activation starting point to tighten the adjusting screw.
Please refer to the following table for the amount of rotation.
[7] Tighten the lock nut. The safety valve adjustment procedure is completed.
(When tightening the lock nut, be careful not to allow the adjusting screw to turn.)
rpm
Pressure adjusting screw length
Activation starting point
