4. Room Lamp

39

Travel Circuit

Travel low-speed circuit

As an example, this section explains the forward travel operation.

The travel motor 2-stage tilting angle is a large angle side.Even if the travel switchover is set to the high-speed side, switching the key switch OFF and then ON again always returns the system to this state.

By operating the travel remote control valve to the forward side, the pilot pressure oil is fed to the control valve pa1 port and switches the left travel spool to the forward side.

At the same time, the oil is also fed to the pa6 port to switch the right travel spool to the forward side.

The discharge oil from hydraulic pump A1 enters the control valve P1 port and the discharge oil from hydraulic pump A2 enters the control valve P2 port. Each flows to the respective travel motor and causes forward travel through the left and right travel spools being switched.

The return oil from the travel motor goes through the left and right travel spools and returns to the hydraulic oil tank.

The travel high-speed solenoid valve goes OFF, the travel motor P port oil connects with the tank line, and the travel motor tilting angle moves to the large tilting side.

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

1 Travel motor 10 Console lever lock switch 2 Travel high-speed select switch 11 Hydraulic pump 3 Computer A 12 Travel remote control valve 4 Control valve 13 Check valve 5 Travel (left) 14 Oil cooler 6 Travel (right) 15 Backward left 7 Travel high speed 16 Forward left 8 Lever lock 17 Backward right 9 5 stack solenoid valve 18 Forward right