JPS63190538U - - Google Patents
Info
- Publication number
- JPS63190538U JPS63190538U JP8209487U JP8209487U JPS63190538U JP S63190538 U JPS63190538 U JP S63190538U JP 8209487 U JP8209487 U JP 8209487U JP 8209487 U JP8209487 U JP 8209487U JP S63190538 U JPS63190538 U JP S63190538U
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- oil
- hydraulic cylinder
- hydraulic pump
- 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
- 238000010276 construction Methods 0.000 claims 3
- 230000002265 prevention Effects 0.000 claims 2
- 230000001133 acceleration Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 4
Landscapes
- Component Parts Of Construction Machinery (AREA)
- Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
- Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
- Operation Control Of Excavators (AREA)
Description
第１図は本考案を車輪式トラクタシヨベルに適
用したときの油圧系統図、第２図は第１図の油圧
シリンダの拡大図、第３図は本考案の第２実施例
を示す電気・油圧系統図、第４図は従来の車輪式
トラクタシヨベルの油圧系統図、第５図はエンジ
ン出力軸の回転数とトルクの関係を示す線図であ
る。
１６……油圧シリンダ、１８……パイロツト圧
切換弁、１９……パイロツト作動形リリーフ弁、
２２……開閉弁、２４，２５……ベント管路、３
２……圧力スイツチ、３６……電磁開閉弁。
Fig. 1 is a hydraulic system diagram when the present invention is applied to a wheeled tractor shovel, Fig. 2 is an enlarged view of the hydraulic cylinder in Fig. 1, and Fig. 3 is an electric/hydraulic system diagram showing a second embodiment of the present invention. FIG. 4 is a hydraulic system diagram of a conventional wheeled tractor shovel, and FIG. 5 is a diagram showing the relationship between engine output shaft rotation speed and torque. 16... Hydraulic cylinder, 18... Pilot pressure switching valve, 19... Pilot operated relief valve,
22...Opening/closing valve, 24, 25...Vent pipe, 3
2...Pressure switch, 36...Solenoid on-off valve.
Claims (1)
出圧油により各種のアクチユエータを作動させる
建設機械の油圧回路において、油圧ポンプの圧油
吐出回路に、設定圧力の異なる２個のリリーフ弁
を介してベント管路をタンクに連通したベントポ
ート付きのパイロツト作動形リリーフ弁と、上記
２個のリリーフ弁のうち、低圧に設定したリリー
フ弁側のベント管路には、受信部に信号が作用す
ると内部油路を閉路し、常時は、ばねの付勢力で
開路している開閉弁と、油圧ポンプの吐出圧油の
圧力が所定値を越えると、その圧油がパイロツト
油室に作用して内部油路を切換え、油圧シリンダ
の油室に、上記油圧ポンプの吐出圧油を供給し、
該油圧シリンダを、内蔵のばねの付勢力に抗して
伸長させることによりエンジンの加速装置を調節
可能な作動片を介して増速側に押し、油圧ポンプ
の吐出圧油の圧力が所定値以下になると内部油路
が切換わり、上記油圧シリンダの油室をタンクに
連通させるパイロツト圧切換弁とを設け、前記開
閉弁の受信部には、油圧シリンダの油室に発生す
る圧力信号を導いたことを特長とする建設機械の
エンジン過負荷防止装置。 (2) 油圧シリンダの油室に通じる管路に、該管
路の圧力が上昇すると内部電気回路を閉路する圧
力スイツチを介して開閉弁の受信部に電源を導い
たことよりなる上記実用新案登録請求の範囲第(1
)項記載の建設機械のエンジン過負荷防止装置。[Scope of Claim for Utility Model Registration] (1) In a hydraulic circuit of a construction machine that operates various actuators using pressure oil discharged from a hydraulic pump driven by an engine, the pressure oil discharge circuit of the hydraulic pump has two different set pressures. A pilot-operated relief valve with a vent port that communicates the vent pipe line with the tank through two relief valves, and a vent line on the side of the relief valve set to low pressure of the two relief valves mentioned above have a receiving side. When a signal is applied to the on-off valve, the internal oil passage is closed, and when the pressure of the pressure oil discharged from the hydraulic pump exceeds a predetermined value, the pressure oil is released into the pilot oil. acting on the chamber to switch the internal oil path and supply the discharge pressure oil of the hydraulic pump to the oil chamber of the hydraulic cylinder,
By extending the hydraulic cylinder against the biasing force of the built-in spring, the engine acceleration device is pushed to the speed increasing side via the adjustable actuation piece, and the pressure of the pressure oil discharged from the hydraulic pump is lower than a predetermined value. A pilot pressure switching valve is provided to connect the oil chamber of the hydraulic cylinder to the tank by switching the internal oil passage and communicating the oil chamber of the hydraulic cylinder with the tank. Engine overload prevention device for construction machinery. (2) Registration of the above-mentioned utility model in which power is led to a receiving part of an on-off valve via a pressure switch that closes an internal electric circuit when the pressure in the pipe increases to a pipe leading to the oil chamber of a hydraulic cylinder. Claim No. 1
Engine overload prevention device for construction machinery as described in item ).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8209487U JPS63190538U (en) | 1987-05-27 | 1987-05-27 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8209487U JPS63190538U (en) | 1987-05-27 | 1987-05-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63190538U true JPS63190538U (en) | 1988-12-08 |
Family
ID=30934438
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8209487U Pending JPS63190538U (en) | 1987-05-27 | 1987-05-27 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63190538U (en) |
-
1987
- 1987-05-27 JP JP8209487U patent/JPS63190538U/ja active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2002018800A3 (en) | Pilot solenoid control valve with an emergency operator | |
| JPS63190538U (en) | ||
| JPS63190537U (en) | ||
| JPS5690105A (en) | Controlling valve for farm working machinery of agricultural tractor | |
| JPH07293589A (en) | Semiautomatic clutch operating device | |
| JPH0393661U (en) | ||
| JPH0313364U (en) | ||
| JPH03108901U (en) | ||
| JPS621455Y2 (en) | ||
| JPS626267Y2 (en) | ||
| JPH088355Y2 (en) | Control device for hydraulic clutch of vehicle | |
| JPH033802B2 (en) | ||
| JPH01133504U (en) | ||
| JPH0351273U (en) | ||
| JPS6240352U (en) | ||
| JPH03100659U (en) | ||
| JPH01144172U (en) | ||
| JPH0187302U (en) | ||
| JPS6425504U (en) | ||
| JPH01173577U (en) | ||
| JPS6448403U (en) | ||
| JPH0293907U (en) | ||
| JPS6453605U (en) | ||
| JPH0198903U (en) | ||
| JPH0376061U (en) |