Patent ID: 8671986
Filing Date: 2014-03-18
Classification: E02F,F15B,Y10T

Abstract:
1. A hydraulic controller comprising: a pair of supply/drain pipes that are continuous with an actuator; pressure-oil paths that are continuous with a pump; oil-return paths that are continuous with a tank; a housing having a switch-spool insertion hole through an intermediation of which the supply/drain pipes, the pressure-oil paths, and the oil-return paths are communicated with each other; and a switch-spool valve that is liquid-tightly inserted into the switch-spool insertion hole so as to form a desired oil path, wherein the pair of supply/drain pipes are respectively communicable with a pair of oil sumps through an intermediation of a pair of respective extended paths, the pair of oil sumps being formed in the switch-spool insertion hole and being switchable between a state of being selectively communicated with any one of the respective pressure-oil paths and the respective oil-return paths according to a movement of the switch-spool valve and a state of not being communicated with any of the pressure-oil paths and the oil-return paths; and a non-leak valve, which is closable to prevent communication of oil toward the switch-spool insertion hole, is provided over respective connection portions between the pair of supply/drain pipes and the pair of extended paths, wherein the non-leak valve is maintained at a predetermined position, without movement, in a state of being opened so as to allow communication of oil toward the switch-spool insertion hole when the switch-spool valve is in a state: capable of causing the pair of supply/drain pipes to switch between a state of communicating with the respective pressure-oil paths and a state of communicating with the respective oil-return paths; and having completed moving to a section where driving of the actuator can be controlled.