JPS6446001A - Hydraulic elevation control device for tractor and the like - Google Patents

Hydraulic elevation control device for tractor and the like

Info

Publication number
JPS6446001A
JPS6446001A JP20242287A JP20242287A JPS6446001A JP S6446001 A JPS6446001 A JP S6446001A JP 20242287 A JP20242287 A JP 20242287A JP 20242287 A JP20242287 A JP 20242287A JP S6446001 A JPS6446001 A JP S6446001A
Authority
JP
Japan
Prior art keywords
unload
valve
unload valve
elevation control
control valve
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
JP20242287A
Other languages
Japanese (ja)
Inventor
Kazuyuki Kikuchi
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.)
Iseki and Co Ltd
Iseki Agricultural Machinery Mfg Co Ltd
Original Assignee
Iseki and Co Ltd
Iseki Agricultural Machinery Mfg 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 Iseki and Co Ltd, Iseki Agricultural Machinery Mfg Co Ltd filed Critical Iseki and Co Ltd
Priority to JP20242287A priority Critical patent/JPS6446001A/en
Publication of JPS6446001A publication Critical patent/JPS6446001A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To accurately maintain function of an unload valve by providing the unload valve and an unload control valve which releases the load pressure of the unload valve at the neutral position of the elevation control valve in a hydraulic control circuit. CONSTITUTION:An unload valve B is connected to the discharge side of a pump P and the port 13 of the unload valve B is connected to an unload control valve H which releases the load pressure of the unload valve B at the neutral position of an elevation control valve A. Consequently, when the elevation control valve A is operated to the neutral position, the load pressure of the unload valve B is released to improve unload ability so that, even though the discharged oil of the pump P leaks in the pressure applying chamber of the unload valve B, the oil is discharged to a tank port. Accordingly, remaining pressure disturbing the unload ability of the unload valve B is eliminated so that the function of the unload valve B can be accurately maintained.
JP20242287A 1987-08-12 1987-08-12 Hydraulic elevation control device for tractor and the like Pending JPS6446001A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP20242287A JPS6446001A (en) 1987-08-12 1987-08-12 Hydraulic elevation control device for tractor and the like

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP20242287A JPS6446001A (en) 1987-08-12 1987-08-12 Hydraulic elevation control device for tractor and the like

Publications (1)

Publication Number Publication Date
JPS6446001A true JPS6446001A (en) 1989-02-20

Family

ID=16457247

Family Applications (1)

Application Number Title Priority Date Filing Date
JP20242287A Pending JPS6446001A (en) 1987-08-12 1987-08-12 Hydraulic elevation control device for tractor and the like

Country Status (1)

Country Link
JP (1) JPS6446001A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0544702A (en) * 1991-08-19 1993-02-23 Nachi Fujikoshi Corp Elevatable cylinder proportional control circuit
US9313382B2 (en) 2010-09-10 2016-04-12 Olympus Corporation Image pickup unit and endoscope distal end portion including the image pickup unit
US9986900B2 (en) 2012-10-22 2018-06-05 Olympus Corporation Endoscope

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62188803A (en) * 1986-02-10 1987-08-18 Kawasaki Heavy Ind Ltd Control valve for working machine

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62188803A (en) * 1986-02-10 1987-08-18 Kawasaki Heavy Ind Ltd Control valve for working machine

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0544702A (en) * 1991-08-19 1993-02-23 Nachi Fujikoshi Corp Elevatable cylinder proportional control circuit
US9313382B2 (en) 2010-09-10 2016-04-12 Olympus Corporation Image pickup unit and endoscope distal end portion including the image pickup unit
US9986900B2 (en) 2012-10-22 2018-06-05 Olympus Corporation Endoscope

Similar Documents

Publication Publication Date Title
WO2002018800A3 (en) Pilot solenoid control valve with an emergency operator
JPS6446001A (en) Hydraulic elevation control device for tractor and the like
EP0416130A4 (en) Hydraulic valve capable of pressure compensation
EP0404946A4 (en) Hydraulic circuit device of construction vehicle
DE3375938D1 (en) Signal valve for pressure compensated system
JPS5311306A (en) Pump unit
EP0438604A4 (en) Hydraulic circuit device
JPS5718867A (en) Pressure control valve
ES8406685A1 (en) Pilot-controlled valve for braking or speed limitation in a hydraulic circuit
JPS57184749A (en) Control device for hydraulic system
JPS6418761A (en) Brake gear
JPS5718485A (en) Liquid pressurizing device of variable volume type
JPS57127103A (en) Pressure fluid circuit
JPS5779306A (en) Hydraulic circuit
JPS5690101A (en) Power unit for hydraulic elevator
JPS5686203A (en) Unloading circuit
JPS5756677A (en) Pressure controller of fluid machine
JPS53140479A (en) Hydraulic pressure controller
EP0092315A3 (en) Hydraulic pump control
JPS5467861A (en) Oil pressure controller
JPS6414433A (en) Boom operator of back hoe
JPS579303A (en) Pressure control circuit for pressure intensifier
JPS57161304A (en) Cylinder device
JPS57126584A (en) Minimum flow control device of variable capacity liquid pressure pump
JPS56141471A (en) Control valve unit