JPS5844133A - Oil-pressure circuit for oil-pressure shovel - Google Patents

Oil-pressure circuit for oil-pressure shovel

Info

Publication number
JPS5844133A
JPS5844133A JP56142525A JP14252581A JPS5844133A JP S5844133 A JPS5844133 A JP S5844133A JP 56142525 A JP56142525 A JP 56142525A JP 14252581 A JP14252581 A JP 14252581A JP S5844133 A JPS5844133 A JP S5844133A
Authority
JP
Japan
Prior art keywords
hydraulic
actuator
oil
pressure
circuit
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
JP56142525A
Other languages
Japanese (ja)
Inventor
Kunihiko Yoshida
邦彦 吉田
Takeshi Yamaguchi
武 山口
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.)
Hitachi Construction Machinery Co Ltd
Original Assignee
Hitachi Construction Machinery 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 Hitachi Construction Machinery Co Ltd filed Critical Hitachi Construction Machinery Co Ltd
Priority to JP56142525A priority Critical patent/JPS5844133A/en
Publication of JPS5844133A publication Critical patent/JPS5844133A/en
Pending 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
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • 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
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
    • 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
    • E02F9/2278—Hydraulic circuits
    • E02F9/2296—Systems with a variable displacement pump

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Operation Control Of Excavators (AREA)

Abstract

PURPOSE:To secure the concurrent operation of plural actuators by a method in which a variable capacity type oil-pressure motor is provided for each actuator, and the discharge side pipeline of each oil-pressure motor is connected with a booster pump through a convergent valve. CONSTITUTION:At least one variable capacity type first oil-pressure pumps 19- 24 are provided for the actuators 3-8 of an oil-pressure shovel, and a booster pump 34 to be connected with the discharge side pipelines 29-33 of oil-pressure pumps 20-24 through covergent valves 46-50 is provided. Signals from the manual operation board 79 of each actuator, output signals from the pressure sensors 67-78 of each actuators 3-8, and signals of the tilting amounts of oil- pressure pumps 19-24 are put in a computer 80 and the speed and direction of the commands of the operation board 79 are controlled in such a way that they do not exceed the output horse power of a prime mover.

Description

【発明の詳細な説明】 この発明は油圧ショベルの油圧回路に関するものである
。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic circuit for a hydraulic excavator.

第１図は従来の油圧ショベルの油圧回路を示す図である
。図において１ａ、１１）、２ａ、２１〕は呵変容星形
の油圧ポンプ、６は左走行モータ、４はアームシリンダ
、５は族ｌモータ、６は右走行モータ、７はバケットシ
リンダ、８はフ゛−ノ、シリンダ、９．１０はそれぞれ
油圧ポツプ１　ａ、１１）７１１１１Ｅポンプ２１１．
２ｂに接続されたコントロールバルブ、１１〜１８は方
向切換弁で、方向切換弁１１〜１４、方向切換弁１５〜
１８は並列ｅこ接続されており、方向切換弁１１〜１８
の出力ポートはアクチーエータに接続されている。FIG. 1 is a diagram showing a hydraulic circuit of a conventional hydraulic excavator. In the figure, 1a, 11), 2a, 21] are star-shaped hydraulic pumps, 6 is a left travel motor, 4 is an arm cylinder, 5 is a group I motor, 6 is a right travel motor, 7 is a bucket cylinder, and 8 is a The fan, cylinder, and 9.10 are respectively hydraulic pops 1a and 11) 71111E pump 211.
Control valves 11 to 18 are directional valves connected to 2b, directional valves 11 to 14, and directional valves 15 to 18.
18 are connected in parallel, and the directional control valves 11 to 18
The output port of is connected to the actuator.

と（Ｄ油圧回路においては、方向切換弁１１〜１８、を
切換えれば、油圧ポンプ１ａ、１１）、２・意、２１）
の圧油がアクチーエータに供給され、アクチーエータが
作動する。しかし、同じ油圧ポツプ”で駆動される２つ
のアクチーエータを同時に操作すると、油圧ポンプの圧
油が負荷圧力の低いアクー升＝エータに流れ、負荷圧力
の高いアクチーニー、−，９には流れないので、負荷圧
力の高いアクチー・エータが作動しない。たとえば、左
右走行モータ６．６とブーム／リンダ８とを同時に操作
すると、左右走行モータ５．６の負荷圧力がブーツ、７
リンダ８の負荷圧力より低いときには、油圧ポツプ１　
ａｌｂ、２ａ、２ｂの圧油が左右走行モータ６．６に流
れ、アームシリンダ８には流れないので、ブームを上げ
ることができない。また、ブームシリンダ８とアームシ
リンダ４とを同時に操作したとき、ブームシリンダ８と
バケットシリンダ７とを同時に操作したときなどにも、
負荷圧力が高いアクチーエータは作動し々い。(In the D hydraulic circuit, if the directional control valves 11 to 18 are switched, the hydraulic pumps 1a, 11), 2, 21)
Pressure oil is supplied to the actuator, and the actuator operates. However, when two actuators driven by the same hydraulic pump are operated at the same time, the pressure oil of the hydraulic pump flows to the actuator with the lower load pressure, and does not flow to the actuator with the higher load pressure. The actuator with a high load pressure does not operate.For example, if the left and right travel motors 6.6 and the boom/linder 8 are operated at the same time, the load pressure of the left and right travel motors 5.6 will be
When the pressure is lower than the load pressure of cylinder 8, hydraulic pop 1
Since the pressure oil in alb, 2a, and 2b flows to the left and right travel motors 6.6, but not to the arm cylinder 8, the boom cannot be raised. Also, when the boom cylinder 8 and the arm cylinder 4 are operated at the same time, when the boom cylinder 8 and the bucket cylinder 7 are operated at the same time, etc.
An actuator with a high load pressure is difficult to operate.

この発明は上述の問題点を解決するためになされたもの
で、複数のアクチーエータを同時に操作したとき、それ
らのアクチーエータの負荷圧力が異なっていたとしても
、各アクチーエータを確実に作動することができる油圧
ンヨベルの油圧回路を提供することを目的とする。This invention was made in order to solve the above-mentioned problems, and is capable of providing hydraulic pressure that can reliably operate each actuator even if the load pressures of the actuators are different when multiple actuators are operated simultaneously. The purpose is to provide a hydraulic circuit for use in a treadmill.

この目的を達成するため、この発明においては各アクチ
ーエータに対応して少なくとも１つの可変容祉形の油圧
ポンプを設け、その油圧ポンプの吐出側管路と接続され
たブーストポンプを少なくとも１つ設け、そのブースト
ポンプと上記吐出側管路とを接続する合流管路に合流開
閉弁を設ける。In order to achieve this object, the present invention provides at least one variable displacement hydraulic pump corresponding to each actuator, and at least one boost pump connected to the discharge side pipe of the hydraulic pump, A merging opening/closing valve is provided in the merging pipe line that connects the boost pump and the discharge side pipe line.

第２図はこの発明に係る油圧ンヨベルの油圧回路を示す
図である。図において１９〜２４はそれぞれ旋回モータ
５、左走行モータ６、右走行モータ６、アームシリンダ
８、アームシリンダ４、ノくケソトンリンダ７に対応し
て設けらねた町変容（１（形の油圧ポンプで、油［Ｅポ
ンプ１９と族１０１モータ５とは閉回路で接続されてお
り、油圧ポンプ２０〜２４とそれらに対応するアクチー
エータとは、開回路そ接続されている。２５．２６は油
圧ポンプ１９と旋回モータ５とを接続して閉回路を構成
する管路、２７は管路２５．２６間に設けられたフラッ
シング弁、２８はチャージポンプ、２９〜６６は油圧ポ
ンプ２０〜２４の吐出側管路、６４６５はブーストポン
プ、６６〜４０．４１〜４５はブーストポンプ３４．６
５と吐出側管路２９〜３６とを接続する合流管路、４６
〜５５は合流管路６６〜４５に設けられた合流開閉弁、
５６〜６０は油圧ポンプ２０〜２４と左走行モータ６、
右走行モータ６、ブームシリンダ８、アームシリンダ４
、バケットシリンダ７との間に設けられた方向切換弁、
６１〜６５はＡ位置で方向切換弁５６〜６０のタンクポ
ートとタンクとを接続し、１号位置で方向切換弁５６〜
６０のタンクポートと油圧モータ６６とを接続する方向
切換弁、６７−〜７８はアクチーエータの両ポートの圧
力を検出する圧カセ／す、７９は各アクチーエータの手
動操作信号を出力する操作盤、８０は操作盤７９の手動
操作信号、圧力センサ６７〜７８の出力信号、油圧ポン
プ１９〜２４の傾転量の信号を入力して油圧ポンプ１９
〜２４、合流開閉弁４６〜５５、方向切換弁５６〜６０
、方向切換弁６１〜６５、油圧モータ６６を制御するコ
ンビーータ（ケーブルの図示を省略）で、コンビーータ
８０．は操作盤７９により指令される各アクチュエータ
の速度、方向が得られるように、所定の優先順位に従っ
てブーストポンプ６４．３５が各アクチーエータと接続
されるように、かつ油圧ポンプ１９〜２４の人力馬力の
合計値が原動機（図示せず）の出力馬力を越えないよう
に、油圧ポンプ１９〜２４の傾転量、方向切換弁５６〜
６０、合流開閉弁４６〜５５を制御するとともに、左走
行モータ６、右走行モータ６、アームシリンダ８、アー
ムシリンダ４、バケットシリンダ７の戻り側圧力が所定
値より低いとき方向切換弁６１〜６５をＡ位置とし、」
二記戻り側圧力が所定値より高いとき方向ｑノ換弁６１
〜６５をＢ位置として、操作盤７９により指令されろ各
アクチュエータの速度に応じて油圧モータ６６の傾転量
を制御する。FIG. 2 is a diagram showing the hydraulic circuit of the hydraulic yawbel according to the present invention. In the figure, reference numerals 19 to 24 indicate hydraulic pumps (1), which are provided corresponding to the swing motor 5, left travel motor 6, right travel motor 6, arm cylinder 8, arm cylinder 4, and nokkesoton cylinder 7, respectively. The oil pump 19 and the group 101 motor 5 are connected in a closed circuit, and the hydraulic pumps 20 to 24 and their corresponding actuators are connected in an open circuit. 25 and 26 are hydraulic pumps. A pipe line connecting 19 and the swing motor 5 to form a closed circuit, 27 a flushing valve provided between the pipe lines 25 and 26, 28 a charge pump, and 29 to 66 discharge sides of hydraulic pumps 20 to 24 Pipeline, 6465 is boost pump, 66-40. 41-45 is boost pump 34.6
5 and the discharge side pipes 29 to 36, a confluence pipe line 46
~55 is a confluence opening/closing valve provided in confluence pipes 66 to 45;
56 to 60 are hydraulic pumps 20 to 24 and left travel motor 6;
Right travel motor 6, boom cylinder 8, arm cylinder 4
, a directional control valve provided between the bucket cylinder 7,
61 to 65 connect the tank port of the directional control valves 56 to 60 to the tank at the A position, and connect the directional control valves 56 to 65 at the No. 1 position.
A directional control valve connects the tank port 60 and the hydraulic motor 66; 67-78 a pressure casing/susceptor for detecting the pressure of both ports of the actuator; 79 a control panel for outputting manual operation signals for each actuator; 80; inputs manual operation signals from the operation panel 79, output signals from the pressure sensors 67 to 78, and signals for tilting amounts of the hydraulic pumps 19 to 24 to operate the hydraulic pump 19.
~24, merging on/off valves 46~55, directional switching valves 56~60
, the directional control valves 61 to 65, and a conbeater (the cables are not shown) that control the hydraulic motor 66, and the conbeater 80. The boost pumps 64 and 35 are connected to each actuator according to a predetermined priority order so that the speed and direction of each actuator commanded by the operation panel 79 can be obtained, and the human horsepower of the hydraulic pumps 19 to 24 is The amount of tilting of the hydraulic pumps 19 to 24 and the direction switching valves 56 to 24 are adjusted so that the total value does not exceed the output horsepower of the prime mover (not shown).
60. Directional switching valves 61 to 65 which control the merging on-off valves 46 to 55, and when the return side pressures of the left travel motor 6, right travel motor 6, arm cylinder 8, arm cylinder 4, and bucket cylinder 7 are lower than a predetermined value. is the A position,
2. When the return side pressure is higher than the predetermined value, the direction q switching valve 61
- 65 is set as the B position, and the amount of tilting of the hydraulic motor 66 is controlled according to the speed of each actuator commanded by the operation panel 79.

この油圧回路においては、複数のアクチ・エータが同時
に操作されたとき、１つの油圧ポツプの。In this hydraulic circuit, when multiple actuators are operated simultaneously, one hydraulic pop.

圧油が操作されたアクチーエータに同時に供給されるこ
とはないから、それらのアクチーエータの負荷圧力が異
なっていたとしても、各アクチーエータは指令された速
度で作動する。たとえば、左右走行モータ６．６とブー
ムシリンダ８とを同時に操作したときには、合流開閉弁
４６．５２が開となり、左走行モータ３には油圧ポンプ
２０、ブーストポンプ６４の圧油、右走行モータ６には
油圧ポンプ２１、ブーストポンプ６５の圧油、アームシ
リンダ８には油圧ポンプ２２の圧油がそれぞれ供給され
る。したがって、左右走行モータ６、乙の負荷圧力がブ
ームシリンダ８の負荷圧力より低いときでも、ブームシ
リンダ８が指令された速度で作動する。ところで、たと
えばブーム下げ操作時においては、ブームシリンダ８の
戻り油が直接タンクに戻されるときには、ブームの重力
によりアームシリンダ８の戻り油が供給油よりも多く排
出されるので、キヤビテーシヨンが生ずるとともに、ブ
ームの下降速度を制御することができない。しかし、こ
の油圧回路においては、アームシリンダ８の戻り側圧力
が所定値より高くなると、方向切換弁６３が１３位置に
切換わるので、ブームシリンダ８の戻り油が油圧モータ
６６に供給されかつ油圧モータ６６の傾転量がブームシ
リンダ８０指令速度に応じて制御されるから、ブームシ
リンダ８は指令速度で作動し、キャビテーションが生ず
るのを防止することができるとともに、戻り油により油
圧モータ６６が駆動されるので、油圧モータ６６により
動力を回収することが可能である。このように、アクチ
ュエータの戻り側圧力が高いときでも、アクチュエータ
を指令速度で作動することができ、キャビテーションが
生ずるのを防ｊ１すること力旨ｆ能であり、さらに動す
を回収することができる。さらに、油圧ポンプ１９〜２
４ブーストポツプ３４．３５の人力馬力の合Ｍ値が原動
機の出力馬力を越えない範囲で最大となるようにコンビ
ーータ８０により制御すわば、原動機の出力馬力を有効
に利用することができる。また〜油圧ポンプ１９〜２４
、ブーストポンプ６４．６５の傾転量の速度をコンビー
ータ８０により適正に制御すれば、アクチーエータの起
動、＜４　＋）、時の衝撃を緩和することも可能である
。Since pressure oil is not supplied to the operated actuators at the same time, each actuator operates at the commanded speed even if the load pressures of the actuators are different. For example, when the left and right travel motors 6.6 and the boom cylinder 8 are operated simultaneously, the merging on-off valve 46.52 is opened, and the left travel motor 3 is supplied with the hydraulic pump 20, the pressure oil of the boost pump 64, and the right travel motor 6. Pressure oil is supplied from the hydraulic pump 21 and the boost pump 65, and pressure oil from the hydraulic pump 22 is supplied to the arm cylinder 8, respectively. Therefore, even when the load pressure of the left and right traveling motors 6 and B is lower than the load pressure of the boom cylinder 8, the boom cylinder 8 operates at the commanded speed. By the way, when the return oil of the boom cylinder 8 is directly returned to the tank during a boom lowering operation, for example, the return oil of the arm cylinder 8 is discharged in an amount greater than the supply oil due to the gravity of the boom, causing cavitation. Unable to control boom lowering speed. However, in this hydraulic circuit, when the return side pressure of the arm cylinder 8 becomes higher than a predetermined value, the directional control valve 63 is switched to the 13 position, so that the return oil of the boom cylinder 8 is supplied to the hydraulic motor 66 and the hydraulic motor Since the amount of tilting of the boom cylinder 80 is controlled according to the commanded speed of the boom cylinder 80, the boom cylinder 8 operates at the commanded speed and cavitation can be prevented, and the hydraulic motor 66 is driven by the return oil. Therefore, power can be recovered by the hydraulic motor 66. In this way, even when the return side pressure of the actuator is high, the actuator can be operated at the command speed, preventing cavitation from occurring, and furthermore, the movement can be recovered. . Furthermore, hydraulic pumps 19-2
The output horsepower of the prime mover can be effectively utilized by controlling it by the combiner 80 so that the total M value of the human horsepower of the four boost pops 34.35 is maximized within a range that does not exceed the output horsepower of the prime mover. Also ~ hydraulic pump 19~24
If the speed of the tilting amount of the boost pumps 64 and 65 is properly controlled by the conbeater 80, it is possible to reduce the impact when the actuator is activated.

なお、上述実施例においては、各つ′クチ−エータに対
応して１つの油圧ポンプ１９〜２４を設けたが、各アク
チーエータに対応して２つ以」二の油圧ポンプを設けて
もよい。また、上述実施例においては、ブーストポンプ
を２つ設けたが、１つでもよく、また６つ以上設けても
よい。さらに、この発明を大型の油圧ンヨベルの油圧回
路に適用すればより効果的である。In the above embodiment, one hydraulic pump 19-24 is provided for each actuator, but two or more hydraulic pumps may be provided for each actuator. Further, in the above embodiment, two boost pumps are provided, but one or six or more boost pumps may be provided. Furthermore, it will be more effective if this invention is applied to the hydraulic circuit of a large-sized hydraulic mobile.

以上説明したように、この発明に係る油圧／ｊベベル油
圧回路においては、複数のアクチュエータを同時に操作
したときにも、各アクチーエータを確実に作動すること
ができるから、操作性が向上する。また、油圧モータに
より動力を回収すれば、エネルギを有効に利用すること
ができる。さらに、原動機の出力馬力を有効に利用すわ
ば、油圧ショベルの作業能率が向上する。また、アクチ
ーエータの起動、停止時の衝撃を緩和することも可能で
ある。このように、この発明の効果は顕著である。As explained above, in the hydraulic/j-bevel hydraulic circuit according to the present invention, even when a plurality of actuators are operated simultaneously, each actuator can be operated reliably, so that operability is improved. Moreover, if power is recovered by a hydraulic motor, energy can be used effectively. Furthermore, by effectively utilizing the output horsepower of the prime mover, the working efficiency of the hydraulic excavator is improved. It is also possible to reduce the impact when starting and stopping the actuator. As described above, the effects of this invention are remarkable.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は従来の油圧ショベルの油圧回路を示す図、第２
図はこの発明に係る油圧ンヨベルの油圧回路を示す図で
ある。 ６・・・左走行モータ　　　４・・・アームシリンダ５
・・・旋回モータ　　−　　６・・・右走行モータ６・
・・左走行モータ　　　７・・・バケットシリンダ８・
・・ブームシリンダ　１９〜２４・・・油圧ポンプ２９
〜３３・・・吐出側管路 ６４．６５・・ブーストポンプ ６６〜４５・合流管路　４６〜５５・・・合流開閉弁５
６〜６０・・・方向切換弁 ６１〜６５・・・方向切換弁 ６６・・油圧モータ　　　６７〜７８・・・圧カセ／ヅ
７９・・操作盤　　　　　８０・・コンビ・・−タ代理
人弁理士　中村純之助Figure 1 shows the hydraulic circuit of a conventional hydraulic excavator, Figure 2 shows the hydraulic circuit of a conventional hydraulic excavator.
The figure is a diagram showing a hydraulic circuit of a hydraulic swivel according to the present invention. 6...Left travel motor 4...Arm cylinder 5
... Swivel motor - 6 ... Right travel motor 6.
・・Left travel motor 7・Bucket cylinder 8・
...Boom cylinder 19-24...Hydraulic pump 29
~33...Discharge side pipe line 64.65...Boost pump 66~45/merging pipe line 46~55...merging on/off valve 5
6-60...Directional switching valve 61-65...Directional switching valve 66...Hydraulic motor 67-78...Pressure cassette/ㅅ79...Operation panel 80...Combi...-ta agent patent attorney Junnosuke Nakamura

Claims (1)

【特許請求の範囲】 （１）　　各アクチーエータに対応して少なくとも１つ
の口Ｔ変容財形の第１油圧ポンプを設け、ソノ第１油圧
ポンプの吐出側管路に接続されたブースＩ・ボ／プを少
なくとも１つ設け、そのブーストポ／プと上記吐出側管
路とを接続する合流管路に合流開閉弁を設けたことを特
徴とする油圧／１ベルの油圧回路。 （２）上記第１油圧ポンプ、上記ブーストボンゾの傾転
量、上記合流開閉弁の制御をコンビーータにより行なう
ことを特徴とする特許請求の範囲第１項記載の油圧ショ
ベルの油圧回路。 （ろ）上記アクチーエータの少々くとも１つとそのアク
チーエータと対応して設けられた第１油月ニポンプとを
開回路で接続し、そのアクチーエータと第１油圧ポンプ
との間に第１方向切換弁を設けＡ位置でその第１方向切
換弁のタンクポートとタンクとを接続し、Ｂ位置でその
タンクポートと油圧モータとを接続し、かつ上記アクチ
ーエータの戻り側圧力が所定値より低いときＡ位置とな
り、上記戻り側圧力が所定値より高いときＢ位置となる
第２方向切換弁を設けたことを特徴とする特許請求の範
囲第１項または第２項記載の油圧ショベルの油圧回路。 （４）上記油圧モータの傾転量の制御をコンビーータに
より行なうことを特徴とする特許請求の範囲第６項記載
の油圧ショベルの油圧回路、。 （５）　　旋回モータとその旋回モータに対応して設け
られた第１油圧ポンプとを閉回路で接続したことを特徴
とする特許請求の範囲第１項、第２項、第６項または第
４項記載の油圧ショベルの油圧回路。[Scope of Claims] (1) At least one first hydraulic pump of the T-transformable type is provided corresponding to each actuator, and the booth I/bo/pump is connected to the discharge side conduit of the first hydraulic pump. 1. A 1-bell hydraulic circuit, characterized in that a merging opening/closing valve is provided in a merging pipe line connecting the boost pop/p with the discharge side pipe line. (2) The hydraulic circuit for a hydraulic excavator according to claim 1, wherein the first hydraulic pump, the tilting amount of the boost bonzo, and the merging on/off valve are controlled by a conbeater. (B) Connect at least one of the actuator and the first hydraulic pump provided correspondingly to the actuator in an open circuit, and connect the first directional valve between the actuator and the first hydraulic pump. The tank port of the first directional switching valve is connected to the tank at the A position, and the tank port and the hydraulic motor are connected at the B position, and the actuator becomes the A position when the return side pressure of the actuator is lower than a predetermined value. 3. The hydraulic circuit for a hydraulic excavator according to claim 1, further comprising a second directional switching valve which is in position B when the return side pressure is higher than a predetermined value. (4) The hydraulic circuit for a hydraulic excavator according to claim 6, wherein the amount of tilting of the hydraulic motor is controlled by a converter. (5) Claims 1, 2, 6, or 4, characterized in that a swing motor and a first hydraulic pump provided corresponding to the swing motor are connected in a closed circuit. Hydraulic circuit of the hydraulic excavator described in section.
JP56142525A 1981-09-11 1981-09-11 Oil-pressure circuit for oil-pressure shovel Pending JPS5844133A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56142525A JPS5844133A (en) 1981-09-11 1981-09-11 Oil-pressure circuit for oil-pressure shovel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56142525A JPS5844133A (en) 1981-09-11 1981-09-11 Oil-pressure circuit for oil-pressure shovel

Publications (1)

Publication Number Publication Date
JPS5844133A true JPS5844133A (en) 1983-03-15

Family

ID=15317379

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56142525A Pending JPS5844133A (en) 1981-09-11 1981-09-11 Oil-pressure circuit for oil-pressure shovel

Country Status (1)

Country Link
JP (1) JPS5844133A (en)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6255664U (en) * 1985-09-26 1987-04-07
EP0874090A1 (en) * 1996-06-11 1998-10-28 Hitachi Construction Machinery Co., Ltd. Hydraulique drive device
JP2008115989A (en) * 2006-11-07 2008-05-22 Hitachi Constr Mach Co Ltd Hydraulic drive mechanism for construction machine
JP2008115990A (en) * 2006-11-07 2008-05-22 Hitachi Constr Mach Co Ltd Hydraulic drive mechanism for construction machine
US8863509B2 (en) 2011-08-31 2014-10-21 Caterpillar Inc. Meterless hydraulic system having load-holding bypass
US8893490B2 (en) 2011-10-21 2014-11-25 Caterpillar Inc. Hydraulic system
US8910474B2 (en) 2011-10-21 2014-12-16 Caterpillar Inc. Hydraulic system
US8919114B2 (en) 2011-10-21 2014-12-30 Caterpillar Inc. Closed-loop hydraulic system having priority-based sharing
US8944103B2 (en) 2011-08-31 2015-02-03 Caterpillar Inc. Meterless hydraulic system having displacement control valve
US8943819B2 (en) 2011-10-21 2015-02-03 Caterpillar Inc. Hydraulic system
US8966891B2 (en) 2011-09-30 2015-03-03 Caterpillar Inc. Meterless hydraulic system having pump protection
US8966892B2 (en) 2011-08-31 2015-03-03 Caterpillar Inc. Meterless hydraulic system having restricted primary makeup
US8973358B2 (en) 2011-10-21 2015-03-10 Caterpillar Inc. Closed-loop hydraulic system having force modulation
US8978374B2 (en) 2011-10-21 2015-03-17 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US8978373B2 (en) 2011-10-21 2015-03-17 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US8984873B2 (en) 2011-10-21 2015-03-24 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US9051714B2 (en) 2011-09-30 2015-06-09 Caterpillar Inc. Meterless hydraulic system having multi-actuator circuit
US9057389B2 (en) 2011-09-30 2015-06-16 Caterpillar Inc. Meterless hydraulic system having multi-actuator circuit
US9068578B2 (en) 2011-10-21 2015-06-30 Caterpillar Inc. Hydraulic system having flow combining capabilities
US9080310B2 (en) 2011-10-21 2015-07-14 Caterpillar Inc. Closed-loop hydraulic system having regeneration configuration
US9151018B2 (en) 2011-09-30 2015-10-06 Caterpillar Inc. Closed-loop hydraulic system having energy recovery
US9279236B2 (en) 2012-06-04 2016-03-08 Caterpillar Inc. Electro-hydraulic system for recovering and reusing potential energy
US9290911B2 (en) 2013-02-19 2016-03-22 Caterpillar Inc. Energy recovery system for hydraulic machine

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6255664U (en) * 1985-09-26 1987-04-07
JPH0352279Y2 (en) * 1985-09-26 1991-11-12
EP1447482A3 (en) * 1996-06-11 2004-10-13 Hitachi Construction Machinery Co., Ltd. Hydraulic drive system
EP0874090A4 (en) * 1996-06-11 2000-03-29 Hitachi Construction Machinery Hydraulique drive device
US6244048B1 (en) 1996-06-11 2001-06-12 Hitachi Construction Machinery Co., Ltd. Hydraulique drive device
EP1447483A2 (en) * 1996-06-11 2004-08-18 Hitachi Construction Machinery Co., Ltd. Hydraulic drive system
EP1447482A2 (en) * 1996-06-11 2004-08-18 Hitachi Construction Machinery Co., Ltd. Hydraulic drive system
EP1447483A3 (en) * 1996-06-11 2004-10-13 Hitachi Construction Machinery Co., Ltd. Hydraulic drive system
EP0874090A1 (en) * 1996-06-11 1998-10-28 Hitachi Construction Machinery Co., Ltd. Hydraulique drive device
JP2008115989A (en) * 2006-11-07 2008-05-22 Hitachi Constr Mach Co Ltd Hydraulic drive mechanism for construction machine
JP2008115990A (en) * 2006-11-07 2008-05-22 Hitachi Constr Mach Co Ltd Hydraulic drive mechanism for construction machine
US8863509B2 (en) 2011-08-31 2014-10-21 Caterpillar Inc. Meterless hydraulic system having load-holding bypass
US8966892B2 (en) 2011-08-31 2015-03-03 Caterpillar Inc. Meterless hydraulic system having restricted primary makeup
US8944103B2 (en) 2011-08-31 2015-02-03 Caterpillar Inc. Meterless hydraulic system having displacement control valve
US9151018B2 (en) 2011-09-30 2015-10-06 Caterpillar Inc. Closed-loop hydraulic system having energy recovery
US9057389B2 (en) 2011-09-30 2015-06-16 Caterpillar Inc. Meterless hydraulic system having multi-actuator circuit
US9051714B2 (en) 2011-09-30 2015-06-09 Caterpillar Inc. Meterless hydraulic system having multi-actuator circuit
US8966891B2 (en) 2011-09-30 2015-03-03 Caterpillar Inc. Meterless hydraulic system having pump protection
US8919114B2 (en) 2011-10-21 2014-12-30 Caterpillar Inc. Closed-loop hydraulic system having priority-based sharing
US8973358B2 (en) 2011-10-21 2015-03-10 Caterpillar Inc. Closed-loop hydraulic system having force modulation
US8978374B2 (en) 2011-10-21 2015-03-17 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US8978373B2 (en) 2011-10-21 2015-03-17 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US8984873B2 (en) 2011-10-21 2015-03-24 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US8943819B2 (en) 2011-10-21 2015-02-03 Caterpillar Inc. Hydraulic system
US8910474B2 (en) 2011-10-21 2014-12-16 Caterpillar Inc. Hydraulic system
US9068578B2 (en) 2011-10-21 2015-06-30 Caterpillar Inc. Hydraulic system having flow combining capabilities
US9080310B2 (en) 2011-10-21 2015-07-14 Caterpillar Inc. Closed-loop hydraulic system having regeneration configuration
US8893490B2 (en) 2011-10-21 2014-11-25 Caterpillar Inc. Hydraulic system
US9279236B2 (en) 2012-06-04 2016-03-08 Caterpillar Inc. Electro-hydraulic system for recovering and reusing potential energy
US9290911B2 (en) 2013-02-19 2016-03-22 Caterpillar Inc. Energy recovery system for hydraulic machine

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