JPS6414434A - Fluid pressure circuit for back hoe - Google Patents

Fluid pressure circuit for back hoe

Info

Publication number
JPS6414434A
JPS6414434A JP17078487A JP17078487A JPS6414434A JP S6414434 A JPS6414434 A JP S6414434A JP 17078487 A JP17078487 A JP 17078487A JP 17078487 A JP17078487 A JP 17078487A JP S6414434 A JPS6414434 A JP S6414434A
Authority
JP
Japan
Prior art keywords
pressure
valve
path
relief
boom
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
JP17078487A
Other languages
Japanese (ja)
Other versions
JPH0637780B2 (en
Inventor
Kazuyoshi Arii
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.)
Kubota Corp
Original Assignee
Kubota Corp
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 Kubota Corp filed Critical Kubota Corp
Priority to JP17078487A priority Critical patent/JPH0637780B2/en
Publication of JPS6414434A publication Critical patent/JPS6414434A/en
Publication of JPH0637780B2 publication Critical patent/JPH0637780B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Operation Control Of Excavators (AREA)

Abstract

PURPOSE:To prevent damage to an operator by providing a pilot circuit for giving the fluid pressure between a throttle mechanism and a fluid pressure cylinder as an operating pressure to reduce the set relief pressure for a relief valve when a boom goes down. CONSTITUTION:When a excavation is made by operation of a boom, a switch valve 21 is operated by a force transmitted through a pilot circuit 20 from the path 11a of a center bypass 11 for an operating valve V2. The pressure from a reduced pressure valve 22 is transmitted through a pilot pressure path 28 to a relief valve 14, and the relief pressure is reduced to the first reduced pressure condition. When a boom is lowered, the pressure of a supply path F rises beyond the pressure of a return path B on which the throttle mechanism 29 of the valve V2 acts and a flow path switching valve 16 is operated by an automatic valve operating means 17. The pressure from the path B is transmitted through a pilot circuit 15 to the valve 14, and the relief pressure becomes the second reduced pressure condition lower than the first reduced pressure condition.
JP17078487A 1987-07-08 1987-07-08 Backhoe fluid pressure circuit Expired - Lifetime JPH0637780B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP17078487A JPH0637780B2 (en) 1987-07-08 1987-07-08 Backhoe fluid pressure circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP17078487A JPH0637780B2 (en) 1987-07-08 1987-07-08 Backhoe fluid pressure circuit

Publications (2)

Publication Number Publication Date
JPS6414434A true JPS6414434A (en) 1989-01-18
JPH0637780B2 JPH0637780B2 (en) 1994-05-18

Family

ID=15911303

Family Applications (1)

Application Number Title Priority Date Filing Date
JP17078487A Expired - Lifetime JPH0637780B2 (en) 1987-07-08 1987-07-08 Backhoe fluid pressure circuit

Country Status (1)

Country Link
JP (1) JPH0637780B2 (en)

Also Published As

Publication number Publication date
JPH0637780B2 (en) 1994-05-18

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