JPS6446001A - Hydraulic elevation control device for tractor and the like - Google Patents
Hydraulic elevation control device for tractor and the likeInfo
- 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
Links
Landscapes
- Lifting Devices For Agricultural Implements (AREA)
- Fluid-Pressure Circuits (AREA)
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.
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)
| 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)
| 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 |
-
1987
- 1987-08-12 JP JP20242287A patent/JPS6446001A/en active Pending
Patent Citations (1)
| 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)
| 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 |
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