JPS63190537U - - Google Patents
Info
- Publication number
- JPS63190537U JPS63190537U JP8209387U JP8209387U JPS63190537U JP S63190537 U JPS63190537 U JP S63190537U JP 8209387 U JP8209387 U JP 8209387U JP 8209387 U JP8209387 U JP 8209387U JP S63190537 U JPS63190537 U JP S63190537U
- Authority
- JP
- Japan
- Prior art keywords
- oil
- engine
- hydraulic
- pressure oil
- 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 2
- 230000002265 prevention Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 5
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
用したときの電気・油圧系統図、第２図は本考案
の第２実施例を示す油圧系統図、第３図は従来の
車輪式トラクタシヨベルの油圧系統図、第４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。
１７……リミツトスイツチ、１８，３８……パ
イロツト圧切換弁、１９……パイロツト作動形リ
リーフ弁、２２……電磁開閉弁、２４，２５……
ベント管路、３６……開閉弁、３７……切換弁。
Figure 1 is an electrical/hydraulic system diagram when the present invention is applied to a wheeled tractor shovel, Figure 2 is a hydraulic system diagram showing a second embodiment of the present invention, and Figure 3 is a diagram of a conventional wheeled tractor shovel. Bell's hydraulic system diagram, FIG. 4, is a diagram showing the relationship between the rotation speed and torque of the engine output shaft. 17... Limit switch, 18, 38... Pilot pressure switching valve, 19... Pilot actuated relief valve, 22... Solenoid on-off valve, 24, 25...
Vent pipe line, 36... open/close valve, 37... switching valve.
Claims (1)
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、油圧ポンプの吐出圧油
の回路に、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、受信部に信号が作用すると
内部油路を開閉する開閉弁と、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
リンダの油室に圧油を供給して該油圧シリンダを
、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、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、ばねで付勢さ
れた作動子が、エンジンの加速装置上の可動部と
連動して、低速回転域の位置にあるときにのみ信
号を発する信号装置とを設け、該発信装置からの
信号を前記開閉弁の受信部に導いたことを特長と
する油圧式建設機械のエンジン過負荷防止装置。 In a hydraulic circuit for construction machinery that operates various actuators using the discharge pressure oil of a hydraulic pump driven by an engine, a vent pipe is connected to the discharge pressure oil circuit of the hydraulic pump via two relief valves with different set pressures. a pilot-operated relief valve with a vent port that communicates with the tank;
Among the relief valves, there is an on-off valve that opens and closes the internal oil passage when a signal is applied to the receiving part of the vent pipe on the relief valve side that is set to low pressure, and the pressure of the discharge pressure oil of the hydraulic pump exceeds a predetermined value. Then, the pressure oil acts on the pilot oil chamber to switch the internal oil path, supplying pressure oil to the oil chamber of the hydraulic cylinder and causing the hydraulic cylinder to extend against the biasing force of the built-in spring. When the engine's accelerator is pushed to the speed increasing side and the pressure of the hydraulic pump's discharge pressure oil falls below a predetermined value, the internal oil passage is switched, and the pilot pressure switching valve and spring connect the oil chamber of the hydraulic cylinder to the tank. A signal device is provided that emits a signal only when the energized actuator is in a low speed rotation range in conjunction with a movable part on the accelerator of the engine, and the signal from the transmitter is transmitted to the on-off valve. An engine overload prevention device for hydraulic construction machinery, which is characterized by guiding the engine to the receiving section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8209387U JPS63190537U (en) | 1987-05-27 | 1987-05-27 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8209387U JPS63190537U (en) | 1987-05-27 | 1987-05-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63190537U true JPS63190537U (en) | 1988-12-08 |
Family
ID=30934436
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8209387U Pending JPS63190537U (en) | 1987-05-27 | 1987-05-27 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63190537U (en) |
-
1987
- 1987-05-27 JP JP8209387U patent/JPS63190537U/ja active Pending
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