4. Travel Pilot Valve (remote control valve

Overall View

Enlarged View

Double-acting circuit (hydraulic fork)

As an example, this section explains the case in which the hydraulic fork attachment is used.

By operating the option remote control valve to the fork close side, the pilot pressure oil is fed to the control valve pa2 port and switches the option spool to the close side.

The discharge oil from hydraulic pump A1 enters the control valve P1 port, is fed from the parallel oil path to the option spool, flows into the hydraulic fork because of the option spool switching and operates to the close side.

At this time, the option pilot pressure switch signal is detected and the auto idle function is released.

The return oil from the hydraulic fork goes through the option spool and returns to the hydraulic oil tank.

Pressure line Tank line Pilot pressure line Pilot tank line Electric line

1 Control valve 8 5 stack solenoid valve 2 Hydraulic fork 9 Console lever lock switch 3 Travel pilot pressure sensor 10 Hydraulic pump 4 Upper pilot pressure sensor 11 Option remote control valve 5 Monitor display 12 Option pilot pressure switch 6 Computer A 13 Check valve 7 Lever Lock 14 Oil cooler

Overall View

Enlarged View

Multi-purpose circuit (breaker Q control)

When the switch in the cab is flipped to the breaker side, the ON signal (24 V) is output from the computer A to the option switchover solenoid valve to switch the valve.

The pilot pressure oil flows from the option switchover solenoid valve B1 port to the A1 port and is fed to the 3-direction valve PP port and shut-off valve PP port and each valve is switched.

Always switch the 2 pumps flow select switch to the 1 pump side.

By operating the option remote control valve to the breaker side, the pilot pressure oil is fed to the control valve pa2 port and switches the option spool.

The discharge oil from hydraulic pump A1 is fed from the control valve P1 port through the parallel oil path and fed to the option spool. Switching the spool lets the oil flow from the shut-off valve A port through the B port and into the breaker.

The breaker set pressure is set by the relief valve built into the shut-off valve.

At this time, the option pilot pressure switch signal is detected, the P1 flow control proportional valve is controlled by the output signals from the computer A to adjust the discharge flow.

The return oil from the breaker returns from the 3-direction valve A1 port through the T1 port and to the hydraulic oil tank.

Because the breaker operating flow can be set to 5 levels on the service support screen of the monitor display, the optimum operating flow can be selected.

Pressure line Tank line Pilot pressure line Pilot tank line Electric line

1 Control valve 12 Lever lock 2 3-direction valve 13 5 stack solenoid valve 3 Shut-off valve 14 Horsepower control proportional valve 4 Breaker 15 P1 pressure sensor 5 Option remote control valve 16 P2 pressure sensor 6 Option pilot pressure switch 17 N1 negative control pressure sensor 7 Multi-purpose circuit switch 18 N2 negative control pressure sensor 8 Computer A 19 P1 flow control proportional valve 9 Monitor display 20 Hydraulic pump 10 Option switchover solenoid valve 21 Check valve 11 Console lever lock switch 22 Oil cooler