JPS56160459A - Pressure control unit for a hydraulic closed device - Google Patents

Pressure control unit for a hydraulic closed device

Info

Publication number
JPS56160459A
JPS56160459A JP6393780A JP6393780A JPS56160459A JP S56160459 A JPS56160459 A JP S56160459A JP 6393780 A JP6393780 A JP 6393780A JP 6393780 A JP6393780 A JP 6393780A JP S56160459 A JPS56160459 A JP S56160459A
Authority
JP
Japan
Prior art keywords
pump
output
revolution
slanting angle
pressure
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.)
Granted
Application number
JP6393780A
Other languages
Japanese (ja)
Other versions
JPS6255023B2 (en
Inventor
Kazuo Honma
Yoshio Nakajima
Eiki Izumi
Hiroshi Watanabe
Yukio Aoyanagi
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.)
Hitachi Construction Machinery Co Ltd
Original Assignee
Hitachi Construction Machinery 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 Hitachi Construction Machinery Co Ltd filed Critical Hitachi Construction Machinery Co Ltd
Priority to JP6393780A priority Critical patent/JPS56160459A/en
Publication of JPS56160459A publication Critical patent/JPS56160459A/en
Publication of JPS6255023B2 publication Critical patent/JPS6255023B2/ja
Granted legal-status Critical Current

Links

Landscapes

  • Control Of Fluid Gearings (AREA)

Abstract

PURPOSE: To be capable of controlling the pressure even at the time of a negative pressure of an inertia load redution operation etc. by adjusting a pump revolution slanting angle using a result of a comparison with a preset value while detecting the oil pressures at an outlet and inlet of a hydraulic pump in the titled unit used for the construction machines etc.
CONSTITUTION: A variable displacement type hydraulic pump 2 and a hydraulic motor 3 are connetcted through a hydraulic colsed system. A pressure detector 10a and 10b are provided to an outlet side and an inlet side of the pump 2 to detect the each circuit pressure Pa and Pb. The outputs from the detectors 10a and the 10b are led to a function generators 15a and 15b and the outputs from the generators 15a and 15b become "0" when the detected pressure value is lower than a preset value Pr and increase depending upon the excessive amount if the detected pressure value is higher than the preset value Pr. The output from the generator 15a is subtracted from the output of a lever operation amount detctor 11a in the adder 16, while the output from the generator 15b is added in the adder 16, then the adder output X is given to a displacement amount control unit 14 as a set value for controlling the revolution slanting angle Y of the pump 2, for the unit 14 to control the pump revolution slanting angle Y by outputting an signal to a displacement amount operation mechanism 2a so that the difference between the output X and the revolution slanting angle Y obtained by being compared in the unit 14 becomes zero.
COPYRIGHT: (C)1981,JPO&Japio
JP6393780A 1980-05-16 1980-05-16 Pressure control unit for a hydraulic closed device Granted JPS56160459A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6393780A JPS56160459A (en) 1980-05-16 1980-05-16 Pressure control unit for a hydraulic closed device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6393780A JPS56160459A (en) 1980-05-16 1980-05-16 Pressure control unit for a hydraulic closed device

Publications (2)

Publication Number Publication Date
JPS56160459A true JPS56160459A (en) 1981-12-10
JPS6255023B2 JPS6255023B2 (en) 1987-11-18

Family

ID=13243754

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6393780A Granted JPS56160459A (en) 1980-05-16 1980-05-16 Pressure control unit for a hydraulic closed device

Country Status (1)

Country Link
JP (1) JPS56160459A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59205062A (en) * 1983-05-09 1984-11-20 Hitachi Constr Mach Co Ltd Driving control device for hydraulic pump in hydraulic pressure closed circuit
US5170625A (en) * 1989-07-27 1992-12-15 Hitachi Construction Machinery Co., Ltd. Control system for hydraulic pump

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59205062A (en) * 1983-05-09 1984-11-20 Hitachi Constr Mach Co Ltd Driving control device for hydraulic pump in hydraulic pressure closed circuit
JPS6323419B2 (en) * 1983-05-09 1988-05-16 Hitachi Construction Machinery
US5170625A (en) * 1989-07-27 1992-12-15 Hitachi Construction Machinery Co., Ltd. Control system for hydraulic pump

Also Published As

Publication number Publication date
JPS6255023B2 (en) 1987-11-18

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