JPS5779303A - Automatic load/unload changeover controller - Google Patents

Automatic load/unload changeover controller

Info

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
Application number
JP15453080A
Other languages
Japanese (ja)
Inventor
Michiaki Takizawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nissei Plastic Industrial Co Ltd
Original Assignee
Nissei Plastic Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nissei Plastic Industrial Co Ltd filed Critical Nissei Plastic Industrial Co Ltd
Priority to JP15453080A priority Critical patent/JPS5779303A/en
Publication of JPS5779303A publication Critical patent/JPS5779303A/en
Pending legal-status Critical Current

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
JP15453080A 1980-10-31 1980-10-31 Automatic load/unload changeover controller Pending JPS5779303A (en)

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)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS498664A (en) * 1972-05-30 1974-01-25

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS498664A (en) * 1972-05-30 1974-01-25

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