JPS56139319A - Liquid pressure circuit for construction machine - Google Patents

Liquid pressure circuit for construction machine

Info

Publication number
JPS56139319A
JPS56139319A JP3911680A JP3911680A JPS56139319A JP S56139319 A JPS56139319 A JP S56139319A JP 3911680 A JP3911680 A JP 3911680A JP 3911680 A JP3911680 A JP 3911680A JP S56139319 A JPS56139319 A JP S56139319A
Authority
JP
Japan
Prior art keywords
discharge
valve
directed
pump
during
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
JP3911680A
Other languages
Japanese (ja)
Other versions
JPS623010B2 (en
Inventor
Tadao Karakama
Kazuo Uehara
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.)
Komatsu Ltd
Original Assignee
Komatsu 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 Komatsu Ltd filed Critical Komatsu Ltd
Priority to JP3911680A priority Critical patent/JPS56139319A/en
Publication of JPS56139319A publication Critical patent/JPS56139319A/en
Publication of JPS623010B2 publication Critical patent/JPS623010B2/ja
Granted legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2292—Systems with two or more pumps

Abstract

PURPOSE:To obtain a system in which during the rated-speed turning of a variable capacity pump, its discharge pressure is directed to the circuit; while during the low-idling period, the discharge pressure of plural variable capacity pumps is directed to the circuit; but on the other hand, at the braking period, the discharge of each variable pump is fixed at a maximum. CONSTITUTION:The discharge pressures P1 and P2 of variable capacity pumps 1 and 2 are supplied to a steering cylinder 15 through a damand valve 6 and a steering valve 8 and also partly to the cylinder 23 of operating machine through a closed center valve 13. During the low-speed operation of engine, the discharge pressures P1 and P2 of the pumps 9 and 2 are jointed, but during the high-speed operation, the discharge pressure P1 of the pump 1 is directed to the circuit through 6a of the demand valve 6 and also the discharge pressure P2 of the pump 2 is led to a braking valve 30 in such a way that the braking operation is fixed on the maximum discharge of the pumps 1 and 2, and excessive pressure oil is directed to the brake- cooling system and also partly drained to a tank 11.
JP3911680A 1980-03-28 1980-03-28 Liquid pressure circuit for construction machine Granted JPS56139319A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3911680A JPS56139319A (en) 1980-03-28 1980-03-28 Liquid pressure circuit for construction machine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3911680A JPS56139319A (en) 1980-03-28 1980-03-28 Liquid pressure circuit for construction machine

Publications (2)

Publication Number Publication Date
JPS56139319A true JPS56139319A (en) 1981-10-30
JPS623010B2 JPS623010B2 (en) 1987-01-22

Family

ID=12544104

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3911680A Granted JPS56139319A (en) 1980-03-28 1980-03-28 Liquid pressure circuit for construction machine

Country Status (1)

Country Link
JP (1) JPS56139319A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0879921A1 (en) * 1995-05-17 1998-11-25 Komatsu Ltd. Hydraulic circuit for hydraulically driven working vehicles
CN110630571A (en) * 2019-09-26 2019-12-31 湖北航天技术研究院特种车辆技术中心 Centering control valve group

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0421200Y2 (en) * 1987-12-23 1992-05-14

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0879921A1 (en) * 1995-05-17 1998-11-25 Komatsu Ltd. Hydraulic circuit for hydraulically driven working vehicles
EP0879921A4 (en) * 1995-05-17 1998-11-25
CN110630571A (en) * 2019-09-26 2019-12-31 湖北航天技术研究院特种车辆技术中心 Centering control valve group
CN110630571B (en) * 2019-09-26 2021-04-13 湖北航天技术研究院特种车辆技术中心 Centering control valve group

Also Published As

Publication number Publication date
JPS623010B2 (en) 1987-01-22

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