JPS5779303A - Automatic load/unload changeover controller - Google Patents
Automatic load/unload changeover controllerInfo
- Publication number
- JPS5779303A JPS5779303A JP15453080A JP15453080A JPS5779303A JP S5779303 A JPS5779303 A JP S5779303A JP 15453080 A JP15453080 A JP 15453080A JP 15453080 A JP15453080 A JP 15453080A JP S5779303 A JPS5779303 A JP S5779303A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- hydraulic pump
- valve
- spool
- unload
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Fluid-Pressure Circuits (AREA)
Abstract
PURPOSE: To enable automatic changeover between the loading and unloading of a hydraulic pump, reduce troubles and heighten the reliability and other properties of operation, by using a device which operates in response to the pressure difference between the hydraulic pump and an actuator.
CONSTITUTION: While a throttle valve 5 is closed, the pressure at an actuator is lower than that at pumps. For that reason, the pressurized oil of a main hydraulic pump 1 is bled off from a pressure control circuit 6. Since the pressure of elastic-pressurization-side oil chamber 18 of a control valve 10 becomes lower than that of its operating-side chamber 15, a spool 12 is moved rightward by the pressure difference so that pressurized oil at the secondary pressure side 97 of an unload valve 9 flows to a tank from a pilot circuit 91 through a passage 14. As a result, the pressure falls, a spool 95 moves and an accessory hydraulic pump 2 is unloaded. When the throttle valve 5 is opened, the valve 61 of the oil pressure control circuit 6 is entirely closed and the pressure difference between the chambers 15, 18 decreases. As a result, the spool 12 moves leftward and the unload valve 9 is closed.
COPYRIGHT: (C)1982,JPO&Japio
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15453080A JPS5779303A (en) | 1980-10-31 | 1980-10-31 | Automatic load/unload changeover controller |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15453080A JPS5779303A (en) | 1980-10-31 | 1980-10-31 | Automatic load/unload changeover controller |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5779303A true JPS5779303A (en) | 1982-05-18 |
Family
ID=15586264
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP15453080A Pending JPS5779303A (en) | 1980-10-31 | 1980-10-31 | Automatic load/unload changeover controller |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5779303A (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS498664A (en) * | 1972-05-30 | 1974-01-25 |
-
1980
- 1980-10-31 JP JP15453080A patent/JPS5779303A/en active Pending
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS498664A (en) * | 1972-05-30 | 1974-01-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE3470081D1 (en) | Hydraulic system with a variable-delivery pump and a priority valve | |
JPS5659005A (en) | Controller for hydraulic circuit including plural variable-capacity pumps in parallel | |
AU559879B2 (en) | An open center hydraulic system | |
WO2002018800A3 (en) | Pilot solenoid control valve with an emergency operator | |
JPS5779303A (en) | Automatic load/unload changeover controller | |
JPS56104186A (en) | Flow controller for power steering working fluid | |
JPS607024A (en) | Hydraulic pneumatic controller for electric circuit breaker | |
JPS57116917A (en) | Compound control valve with valve for attachment | |
JPS57110856A (en) | Controller of oil hydraulic device | |
JPH04248001A (en) | Pressure oil supply device | |
JPH08100805A (en) | Pressure control valve | |
JPS5776304A (en) | Hydraulic circuit for construction machinery | |
JPS5751006A (en) | Composite control valve for conflluence | |
JPS57107403A (en) | Hydraulic control unit | |
JPH0544702A (en) | Elevatable cylinder proportional control circuit | |
JPS5690773A (en) | Control device of power assisted steering gears | |
JPH0649128Y2 (en) | Electromagnetic proportional control valve for work equipment | |
JPH0742857A (en) | Back pressure valve | |
JPS6446001A (en) | Hydraulic elevation control device for tractor and the like | |
JPS5481474A (en) | Fluid control system | |
JPS5740106A (en) | Hydraulic pressure system controller | |
JPS5680527A (en) | Hydraulic buffer | |
JPH0526207A (en) | Controlling method for branch hydraulic circuit | |
JPS5467861A (en) | Oil pressure controller | |
JPS57161238A (en) | Control valve device |