Maeda MK0003, Service Manual, Page: 114 / 348

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9.4 METHODS FOR OPERATION ADJUSTMENT
6-port directional switching valve (D-HD-01081)
1) Pilot switching valve: Energizing the solenoid of D-HD-01068 allows the PLT X port of pilot
switching valve to generate and apply pressure to the PLT X port of 6-port directional switching
valve: D-HD-01081.This pilot pressure pushes the spool of 6-port directional switching valve to
generate the flow of A1 to A3, and B1 to B3 in order to allow actuators to work. Turning off the
power supply to the solenoid causes the spring to push back the spool of 6-port switching valve
to result flows of A1 to A2 and B1 to B2.
2) When electrical checking cannot be exercised, pressing the manual operating pin of 6-port
directional switching valve enables the checking of operation.
Precautions:
1) If tightened excessively, a mounting bolt may give rise to strain in the body, resulting in
malfunctioning. Limit the tightening torque of a mounting bolt within a range of 6 to 8 N·m.
2) When tightening a mounting bolt, pay attention to prevent the O-ring from being squeezed out
and the valve from being dropped or mounted in a wrong direction.
3) This valve has been manufactured by high-precision machining. If it is clogged with a foreign
matter, even if it is a minute particle, the spool may fail to move and may no longer perform the
valve functions. To allow it to work normally, execute a sufficient flushing of piping and use a
strainer and filter with pores no larger than 100
μ .
4) For the hydraulic oil, we recomment oils conforming to ISO VG32, ISO VG46, or an equivalent
one.
5) To maintain the specified viscosity, be cautious of oil temperature. Use hydraulic oils within the
temperature range specified below: (Recommended values)
Oil type Oil temperature Viscosity
ISO VG32 0 to 60°C Approx. 15 to 340 mm
2
/s
ISO VG46 6 to 65°C Approx. 18 to 340 mm
2
/s
Manual operation pin
6-port directional switching valve Pilot switching valve