Hydraulic controller for working machine

A hydraulic controller for a working machine comprising:

• a pilot pressure input unit;
• a plurality of pilot-operated hydraulic devices adapted to be operated remotely by switching between a supply of an input signal of a pilot pressure and a stop of the supply to said pilot pressure input unit and provided with mutually different pilot pressure input conditions;
• a pilot hydraulic pressure source connected in common to each pilot pressure input unit of said pilot-operated hydraulic devices;
• a pilot pressure input switching valve provided in common for said pilot-operated hydraulic devices and adapted to be switchable between a pilot pressure input position where to input a pilot pressure from said pilot hydraulic pressure source to each pilot pressure input unit of said pilot-operated hydraulic devices and a pilot pressure relief position where to relieve said pilot pressure;
• and
• switching control means for controlling a switching of said pilot pressure input switching valve based on the operating state of said working machine and the pilot pressure input conditions of said respective pilot-operated hydraulic devices,
• wherein said each pilot-operated hydraulic devices is provided with a priority for pilot pressure input control and said switching control means is adapted to control the switching of said pilot pressure input switching valve based on said priority,
• wherein if the operating state of said working machine meets the pilot pressure input condition of higher-priority pilot-operated hydraulic devices among said plurality of pilot-operated hydraulic devices having mutually different priorities, said switching control means is adapted to switch said pilot pressure input switching valve to said pilot pressure input position regardless of whether or not the operating state meets the pilot pressure input condition of lower-priority pilot-operated hydraulic devices, while if the operating state does not meet a specific pilot pressure input condition of higher-priority pilot-operated hydraulic devices, said switching control means is adapted to control the switching of said pilot pressure input switching valve based on the pilot pressure input condition of the lower-priority pilot-operated hydraulic devices.

A hydraulic controller for a working machine comprising:

• a pilot pressure input unit;
• a plurality of pilot-operated hydraulic devices adapted to be operated remotely by switching between a supply of an input signal of a pilot pressure and a stop of the supply to said pilot pressure input unit and provided with mutually different pilot pressure input conditions;
• a pilot hydraulic pressure source connected in common to each pilot pressure input unit of said pilot-operated hydraulic devices;
• a pilot pressure input switching valve provided in common for said pilot-operated hydraulic devices and adapted to be switchable between a pilot pressure input position where to input a pilot pressure from said pilot hydraulic pressure source to each pilot pressure input unit of said pilot-operated hydraulic devices and a pilot pressure relief position where to relieve said pilot pressure;
• and
• switching control means for controlling a switching of said pilot pressure input switching valve based on the operating state of said working machine and the pilot pressure input conditions of said respective pilot-operated hydraulic devices,
• wherein said each pilot-operated hydraulic devices is provided with a priority for pilot pressure input control and said switching control means is adapted to control the switching of said pilot pressure input switching valve based on said priority,
• wherein said pilot-operated hydraulic devices include a traveling motor having a capacity variable depending on the supply of the input signal of the pilot pressure, said traveling motor being provided with a priority higher than those of the other pilot-operated hydraulic devices, and wherein if said working machine is in a non-traveling state, said switching control means is adapted to control the switching of said pilot pressure input switching valve based on the pilot pressure input conditions of the other pilot-operated hydraulic devices.

A hydraulic controller for a working machine comprising:

• a pilot pressure input unit;
• a plurality of pilot-operated hydraulic devices adapted to be operated remotely by switching between a supply of an input signal of a pilot pressure and a stop of the supply to said pilot pressure input unit and provided with mutually different pilot pressure input conditions;
• a pilot hydraulic pressure source connected in common to each pilot pressure input unit of said pilot-operated hydraulic devices;
• a pilot pressure input switching valve provided in common for said pilot-operated hydraulic devices and adapted to be switchable between a pilot pressure input position where to input a pilot pressure from said pilot hydraulic pressure source to each pilot pressure input unit of said pilot-operated hydraulic devices and a pilot pressure relief position where to relieve said pilot pressure;
• and
• switching control means for controlling a switching of said pilot pressure input switching valve based on the operating state of said working machine and the pilot pressure input conditions of said respective pilot-operated hydraulic devices,
• wherein said pilot-operated hydraulic devices include first pilot-operated hydraulic device having a pilot pressure input condition that a specific parameter related to the operating state of said working machine is equal to or greater than a predetermined level and second pilot-operated hydraulic device having a pilot pressure input condition that said parameter is less than said predetermined level, and wherein in the case of employing the pilot pressure input condition of either said first pilot-operated hydraulic device or said second pilot-operated hydraulic device, said switching control means is adapted to control the switching of said pilot pressure input switching valve based on the pilot pressure input condition of said first pilot-operated hydraulic device if said parameter is equal to or greater than said predetermined level, while based on the pilot pressure input condition of said second pilot-operated hydraulic device if said parameter is less than said predetermined level.