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US 10,539,162 B2Granted
Hydraulic system for work machine
AssigneeKubota Corporation
InventorHiroshi Horii
Life of this patent
Estimating the term…
Abstract
A hydraulic system for a work machine includes a first control valve including a first direction switch to switch a direction in which the operation fluid is to flow through a first hydraulic actuator and a pressure compensator to maintain a differential pressure to a constant pressure, the differential pressure being a difference between a pressure of the operation fluid to be inputted to the pressure compensator and a pressure of the operation fluid to be outputted from the pressure compensator. And, the hydraulic system includes a second control valve including a second direction switch to switch a direction in which the operation fluid is to flow through a second hydraulic actuator and a flow rate prioritizer to prioritize a flow rate of the operation fluid to be outputted to the second hydraulic actuator.
Claims11
A hydraulic system for a work machine, comprising:
- a first hydraulic actuator;
- a second hydraulic actuator;
- a hydraulic pump to supply an operation fluid;
- a first control valve to control the first hydraulic actuator, the first control valve comprising:
- a first direction switch to switch a direction in which the operation fluid is to flow through the first hydraulic actuator;
- and
- a pressure compensator to maintain a differential pressure to a constant pressure, the differential pressure being a difference between a pressure of the operation fluid to be inputted to the pressure compensator and a pressure of the operation fluid to be outputted from the pressure compensator;
- and
- a second control valve to control the second hydraulic actuator, the second control valve comprising:
- a second direction switch to switch a direction in which the operation fluid is to flow through the second hydraulic actuator;
- and
- a flow rate prioritizer to prioritize a flow rate of the operation fluid to be outputted to the second hydraulic actuator,
- wherein the flow rate prioritizer includes:
- a spool configured to move between a first position where a flow rate of the operation fluid outputted to the second hydraulic actuator is increased and a second position where the operation fluid of a flow rate smaller than the flow rate at the first position is supplied to the second hydraulic actuator;
- a pressing member to press the spool toward the first position;
- a first pressure receptor to receive a pressure of the operation fluid outputted from the second direction switch to the flow rate prioritizer;
- and
- a second pressure receptor to receive a pressure of the operation fluid outputted from the hydraulic pump, and
- wherein the spool includes a first flow path with a throttle to decrease the flow rate of the operation fluid to less than the flow rate at the first position when the spool is at the second position and a second flow path without the throttle when the spool is at the first position, the spool being configured to be pressed toward the first position by a pressing force of the pressing member and by the pressure of the operation fluid received by the first pressure receptor such that the operation fluid is to flow toward the second hydraulic actuator via the second flow path, and is pressed toward the second position by the pressure of the operation fluid received by the second pressure receptor such that the operation fluid is to flow toward the second hydraulic actuator via the first flow path.
16 more elements
A hydraulic system for a work machine, comprising:
- a first hydraulic actuator;
- a second hydraulic actuator;
- a hydraulic pump to supply an operation fluid;
- a first control valve to control the first hydraulic actuator, the first control valve comprising:
- a first direction switch to switch a direction in which the operation fluid is to flow through the first hydraulic actuator;
- and
- a pressure compensator to maintain a differential pressure to a constant pressure, the differential pressure being a difference between a pressure of the operation fluid to be inputted to the pressure compensator and a pressure of the operation fluid to be outputted from the pressure compensator;
- and
- a second control valve to control the second hydraulic actuator, the second control valve comprising:
- a second direction switch to switch a direction in which the operation fluid is to flow through the second hydraulic actuator;
- and
- a flow rate prioritizer to prioritize a flow rate of the operation fluid to be outputted to the second hydraulic actuator,
- wherein the flow rate prioritizer includes:
- a spool configured to move between a first position where a flow rate of the operation fluid outputted to the second hydraulic actuator is increased and a second position where the operation fluid of a flow rate smaller than the flow rate at the first position is supplied to the second hydraulic actuator;
- a pressing member to press the spool toward the first position;
- a first pressure receptor to receive a pressure of the operation fluid outputted from the second direction switch to the flow rate prioritizer;
- and
- a second pressure receptor to receive a pressure of the operation fluid outputted from the hydraulic pump,
- wherein the spool is configured to be pressed toward the first position by a pressing force of the pressing member and by the pressure of the operation fluid received by the first pressure receptor, and is pressed toward the second position by the pressure of the operation fluid received by the second pressure receptor, and
- wherein the spool is configured such that the flow rate of the operation fluid outputted to the second hydraulic actuator when the spool is at the second position is greater than zero.
17 more elements
Dependencies are inferred from the claim text.