Patent ID: 7412826
Filing Date: 2008-08-19
Classification: E02F

Abstract:
1. A hydraulic system for a work vehicle, comprising: a main hydraulic pump; a main supply circuit through which pressurized oil from the main hydraulic pump flows; a sub hydraulic pump; and a sub supply circuit through which pressurized oil from the sub hydraulic pump flows; wherein the main supply circuit supplies pressurized oil to a hydraulic travel motor that drives a travel device, and a service actuator that is disposed in an attachment with which the work vehicle is detachably furnished, and the sub supply circuit merges with the main supply circuit and supplies pressurized oil to the service actuator; and wherein the hydraulic system for a work vehicle further comprises a flow amount adjustment valve that adjusts the flow amount of the pressurized oil from the sub supply circuit that merges with the main supply circuit, the flow amount adjustment valve being provided in a drain channel that branches from the sub supply circuit upstream of the point where the main supply circuit and the sub supply circuit merge and is in communication with a hydraulic tank; and wherein the sub supply circuit is provided with a switch valve that links the sub supply circuit and the drain channel when the travel motor is not being driven, and blocks the drain channel when both the travel motor and the service actuator are driven.