JPS58146634A - Oil-pressure circuit for oil-pressure shovel and the like - Google Patents

Oil-pressure circuit for oil-pressure shovel and the like

Info

Publication number
JPS58146634A
JPS58146634A JP2897482A JP2897482A JPS58146634A JP S58146634 A JPS58146634 A JP S58146634A JP 2897482 A JP2897482 A JP 2897482A JP 2897482 A JP2897482 A JP 2897482A JP S58146634 A JPS58146634 A JP S58146634A
Authority
JP
Japan
Prior art keywords
flow path
switching valve
pressure
valve
pressure oil
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.)
Granted
Application number
JP2897482A
Other languages
Japanese (ja)
Other versions
JPH0470453B2 (en
Inventor
Yukitaka Mimura
三村　幸敬
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.)
Sumitomo Heavy Industries Ltd
Original Assignee
Sumitomo Heavy Industries 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 Sumitomo Heavy Industries Ltd filed Critical Sumitomo Heavy Industries Ltd
Priority to JP2897482A priority Critical patent/JPS58146634A/en
Publication of JPS58146634A publication Critical patent/JPS58146634A/en
Publication of JPH0470453B2 publication Critical patent/JPH0470453B2/ja
Granted legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20538—Type of pump constant capacity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20546—Type of pump variable capacity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/3056—Assemblies of multiple valves
    • F15B2211/3059—Assemblies of multiple valves having multiple valves for multiple output members
    • F15B2211/30595—Assemblies of multiple valves having multiple valves for multiple output members with additional valves between the groups of valves for multiple output members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3122—Special positions other than the pump port being connected to working ports or the working ports being connected to the return line
    • F15B2211/3127—Floating position connecting the working ports and the return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
    • F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/78—Control of multiple output members
    • F15B2211/782—Concurrent control, e.g. synchronisation of two or more actuators

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

PURPOSE:To raise the concurrent operability of actuators by supplying pressure oil from an auxiliary pump to the actuators of a high working pressure through an auxiliary valve interlocked with a switch valve. CONSTITUTION:When the arm switch valve 8 and slewing switch valve 7 in a multiple switch valve 4 are concurrently operated, an auxiliary switch valve 17 interlocked with the arm switch valve 8 is opened, and pressure oil from an auxiliary pump 3 is supplied through a check valve 20 to a neutral pathway upstream of the slewing switch valve 7. Thus, since pressure oil from the main pump 1, supplied through a parallel-pressure pathway 10, is supplied, together with the pressure oil, to the slewing actuator, no lowering of slewing capability occurs even when slewing operation and arm operation are concurrently performed.

Description

【発明の詳細な説明】 この発明は油圧ショベルの旋回操作とアーム操作の如く
、作動圧の異なる複数のアクチュータの同時操作性を向
上させるため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 improving simultaneous operability of a plurality of actuators having different operating pressures, such as swing operation and arm operation of a hydraulic excavator.

従来この種の複数のアクチュエータを駆動する油・、圧
器路としては例えば第１図に示す如く中立流路と並列高
圧流路とにより連結された多連切換弁により行なうもの
が知られているが、この従来の油圧回路では作動圧の異
なるアーム操作と旋回操作とを同時に行なった場合、作
動油は作動圧の低いアームのアクチュエータに多く供給
され、作動圧の高い旋回のアクチュエータへの圧油の供
給が少くなり十分な旋回力が得られない。Conventionally, as an oil/pressure line for driving a plurality of actuators of this type, it has been known to use a multiple switching valve connected by a neutral flow path and a parallel high-pressure flow path as shown in FIG. 1, for example. In this conventional hydraulic circuit, when arm operation and swing operation with different working pressures are performed at the same time, more hydraulic oil is supplied to the arm actuator with lower working pressure, and less pressure oil is supplied to the swinging actuator with higher working pressure. Supply is reduced and sufficient turning force cannot be obtained.

このため例えば、旋回操作とアーム操作とを同時に行な
い穴を掘削する場合、旋回による押付力が不足しアーム
（パケット）が旋回方向に逃るため、掘削穴の端面を直
線的に仕上げることができない不具合を免れなかった。For this reason, for example, when drilling a hole by performing both a swing operation and an arm operation at the same time, the pressing force due to the swing is insufficient and the arm (packet) escapes in the direction of the swing, making it impossible to finish the end face of the drilled hole in a straight line. I couldn't avoid problems.

この発明は上記に鑑みなされたものであって、多連切換
弁を介して複数のアクチュエータを駆動する主ポンプと
該ポンプの外に少くとも１個の補助ポンプを設け、作動
圧の異なる複数のアクチュエータを同時に操作する場合
、一方のアクチュエータに補助切換弁を介して補助ポン
プからの圧油を供給することにより、複数のアクチュエ
ータの同時操作性の向上を計ったものである。This invention was made in view of the above, and includes a main pump that drives a plurality of actuators via a multiple switching valve, and at least one auxiliary pump outside the pump, and a plurality of actuators with different operating pressures. When operating the actuators simultaneously, pressure oil is supplied from the auxiliary pump to one of the actuators via the auxiliary switching valve, thereby improving the simultaneous operation of multiple actuators.

以下、図面に示した実施例に沿い説明する。The following will explain the embodiments shown in the drawings.

第２図の実施例において、１，２は図示しない原動機に
よって駆動される主ポンプ、３は、主ポンプ１，２と同
じ原動機によって駆動される補助ポンプである。In the embodiment shown in FIG. 2, 1 and 2 are main pumps driven by a prime mover (not shown), and 3 is an auxiliary pump driven by the same prime mover as the main pumps 1 and 2.

４は前記主ポンプ１からの圧油の供給を受け、図示しな
いアクチュエータの動作を制御する多連切換弁で、走行
用切換弁５．ブーム用切換弁６．旋回用切換弁７．及び
アーム用切換弁８により構成されており、これらの切換
弁は、中立流路９及び該中立流路９と並列に設けられた
並列高圧流路１０により互に接続されている。Reference numeral 4 designates a multiple switching valve that receives pressure oil from the main pump 1 and controls the operation of an actuator (not shown), including a travel switching valve 5. Boom switching valve6. Swing switching valve7. and an arm switching valve 8, and these switching valves are connected to each other by a neutral flow path 9 and a parallel high pressure flow path 10 provided in parallel with the neutral flow path 9.

１１は前記主ポンプ２からの圧油の供給を受け、図示し
ないアクチュエータの動作を制御する多連切換弁で走行
用切換弁１２．パケット用切換弁１３及びブーム用切換
弁１４により構成されており、これらの切換弁は、前記
多連切換弁４と同様中立流路１５及び該中立流路１５と
並列に設けられた弁８と連動して切換えられると共に、
該弁１７の切換によって補助ポンプ３の吐出流路１８を
タンク１９と逆止弁２０を介して前記旋回用切換弁７上
流側の中立流路９に切換接続する。Numeral 11 is a multiple switching valve that receives pressure oil from the main pump 2 and controls the operation of an actuator (not shown), and is a traveling switching valve 12. It is composed of a packet switching valve 13 and a boom switching valve 14, and these switching valves, like the multiple switching valve 4, have a neutral flow path 15 and a valve 8 provided in parallel with the neutral flow path 15. As well as being switched in conjunction,
By switching the valve 17, the discharge passage 18 of the auxiliary pump 3 is switched and connected to the neutral passage 9 on the upstream side of the swirl switching valve 7 via the tank 19 and the check valve 20.

２０は逆止弁で前記吐出流路１８と中立流路９との接続
点より上流の中立流路９に上流＊（プーム眉切換弁６側
）への逆流を防止するように設けられている。Reference numeral 20 denotes a check valve, which is provided in the neutral flow path 9 upstream from the connection point between the discharge flow path 18 and the neutral flow path 9 to prevent backflow to the upstream* (towards the Poom eyebrow switching valve 6 side). .

２１は前記旋回用切換弁７の圧油供給流路で、該流路２
１は前記中立流路９と中立流路９側への逆流を防止する
逆止弁２２を介して接続されると共に、前記並列高圧流
路１０と並列高圧流路側への逆流を防止する逆止弁２３
を介して接続されている。Reference numeral 21 denotes a pressure oil supply passage for the swing switching valve 7;
1 is connected via a check valve 22 that prevents backflow to the neutral flow path 9 and the neutral flow path 9 side, and a check valve 22 that prevents backflow to the parallel high pressure flow path 10 and the parallel high pressure flow path side. valve 23
connected via.

２４は前記アーム用切換弁８の圧油供給流路で、該流路
２４は前記中立流路９と中立流路９側への逆流を防止す
る逆止弁２５を介して接続されると共に、前記並列高圧
流路１０にも接続されている。Reference numeral 24 denotes a pressure oil supply flow path for the arm switching valve 8, and the flow path 24 is connected to the neutral flow path 9 via a check valve 25 that prevents backflow to the neutral flow path 9 side. It is also connected to the parallel high pressure flow path 10.

２６は前記圧油供給流路２４に設けたロードチェック弁
、２７はリリーフ弁である。26 is a load check valve provided in the pressure oil supply channel 24, and 27 is a relief valve.

第３図乃至第５図はこの発明の他の実施例を示すもので
、第２ＦＩｌと同−物或は均等物は同一符号を付ｈす、
第２図と相違する部分について以下に説明する。3 to 5 show other embodiments of the present invention, and the same or equivalent parts as the second FIl are given the same reference numerals.
The parts that are different from FIG. 2 will be explained below.

第３図に示した実施例も基本的には第２１ｉ！ｆｆの実
施用切換弁８が旋回用切換弁フの上流側に設けられてい
るため、アーム用切換弁８への圧油の供給は従来の並列
高圧流路１０のみとの接続と実質的には同一であると共
に補助ポンプ３の吐出流路１８と中立流路９との接続点
が、アーム用切換弁８の下流であるため、旋回用切換弁
７が中立位置の場合でも、第２図の実施例の如くアーム
用アクチュエータに主ポンプ１と補助ポンプ３双方から
の圧油を供給することもできないので、アーム用切換弁
８の圧油供給流路２４と中立流路９とを連結する流路及
び該流路に設けた逆止弁２５は省略されている。The embodiment shown in FIG. 3 is also basically the 21i! Since the switching valve 8 for implementing ff is provided on the upstream side of the swing switching valve ff, the supply of pressure oil to the arm switching valve 8 is substantially as simple as connecting only to the conventional parallel high-pressure flow path 10. are the same, and since the connection point between the discharge flow path 18 of the auxiliary pump 3 and the neutral flow path 9 is downstream of the arm switching valve 8, even if the swing switching valve 7 is in the neutral position, Since it is not possible to supply pressure oil from both the main pump 1 and the auxiliary pump 3 to the arm actuator as in the embodiment, the pressure oil supply passage 24 of the arm switching valve 8 and the neutral passage 9 are connected. The flow path and the check valve 25 provided in the flow path are omitted.

また第４１ｉ！ｆｆに示した実施例では、第２図に示し
た実施例に更にアーム用切換弁８の圧油供給流路２４量 と並列高圧流路１０とを接続する流路に滝列高圧流路１
０側への逆流を防止する逆止弁２８を設けた点が相違し
ている。See you at 41i! In the embodiment shown in ff, in addition to the embodiment shown in FIG.
The difference is that a check valve 28 is provided to prevent backflow to the 0 side.

これは、旋回用切換弁７が中立位置にある場合、補助ポ
ンプ３からの圧油がアーム用アクチュエータに供給され
ず、並列高圧流路１０を介して上流の走行或はブーム用
アクチュエータに逆流するのを防止するためであり、こ
の場合ロートチェ、り弁２６は省略しても良い。This is because when the swing switching valve 7 is in the neutral position, the pressure oil from the auxiliary pump 3 is not supplied to the arm actuator, but flows back to the upstream traveling or boom actuator via the parallel high-pressure flow path 10. This is to prevent this, and in this case, the funnel check and the valve 26 may be omitted.

第５図は補助切換弁１７の他の実施例を示すもので、ｆ
ｓ２図乃至第４図の実施例ではアー、ム眉切換弁８を左
・右いずれに切換えても補助切換弁１７が中立流路９と
１流する場合について例示しているが、この実施例では
左又は右いずれか一方（例えばアームの引込み側）に切
換た場合に中立流路９と合流する。FIG. 5 shows another embodiment of the auxiliary switching valve 17.
The embodiments shown in Figs. Then, when switching to either the left or right side (for example, to the retracting side of the arm), it merges with the neutral flow path 9.

なお、本実施例では、補助切換弁１７は多連切換弁４と
別体にしたものについて例示しているが、両者を一体構
造とすること、或はリリーフ弁６を公知のアンロード弁
に置換すること等が可能なことは言うまでもない。In this embodiment, the auxiliary switching valve 17 is shown as being separate from the multiple switching valve 4, but the two may be integrated into one structure, or the relief valve 6 may be replaced with a known unload valve. Needless to say, it is possible to replace them.

以上の通り、本発明によれば、多連切換弁４の走行用切
換弁５、ブーム用切換弁６及び旋回用切換弁７の操作は
従来装置と全く同様であるが、アーム用アクチュエータ
を操作するためにアーム用切換弁８を中立位置から左・
右いずれか（第５図の実施例では、左又は右のいずれか
一方のみ）に切換えると、この切換に連動して補助切換
弁１７が切換わり、該弁１７を介して、補助ポンプ３の
吐出油が旋回用切換弁７の上流側中立流路９に合流する
。As described above, according to the present invention, the operation of the traveling switching valve 5, the boom switching valve 6, and the swing switching valve 7 of the multiple switching valve 4 is completely the same as in the conventional device, but the arm actuator is operated. In order to
When switching to the right side (in the embodiment shown in FIG. 5, only either the left or right side), the auxiliary switching valve 17 is switched in conjunction with this switching, and the auxiliary pump 3 is switched through the valve 17. The discharged oil joins the neutral flow path 9 on the upstream side of the swirl switching valve 7.

このため、旋回用切換弁７とアーム用切換弁８とを同時
に操作した場合、一般的には両者の作動圧が異なる（ア
ームの方が小さい）ので、従来の如く並列高圧流路１０
からのみ両者に同時に（並列に）圧油を供給した場合作
動圧の低い方（アーム）に主として供給され、作動圧の
高い方（旋回）への圧油の供給が十分なされない不具合
を免れないが、本発明によればアーム用切換弁８の操作
に連動して、補助ポンプ３の吐出（油が旋回用切換弁７
の上流側中立流路９に供給されるから、旋回用切換弁７
を操作した場合、旋回用アクチュエータには、該切換弁
７を介し従来の並列高圧流路１０からの圧油の供給と同
時に、中立流路９に合流した補助ポンプ３からの圧油が
旋回用アクチュエータのみに供給されるので、アームと
旋回とを同時に操作する場合にも旋回操作に必要な作動
圧油が得られる。Therefore, when the swing switching valve 7 and the arm switching valve 8 are operated at the same time, the operating pressures of the two are generally different (lower for the arm), so the parallel high-pressure flow path 10 is
If pressure oil is supplied to both at the same time (in parallel), it will be mainly supplied to the side with lower operating pressure (arm), and there will be a problem that insufficient pressure oil will be supplied to the side with higher operating pressure (swivel). However, according to the present invention, in conjunction with the operation of the arm switching valve 8, the discharge of the auxiliary pump 3 (the oil flows through the swing switching valve 7).
Since it is supplied to the neutral flow path 9 on the upstream side of the
When operated, the swing actuator is supplied with pressure oil from the conventional parallel high-pressure flow path 10 via the switching valve 7, and at the same time, pressure oil from the auxiliary pump 3 that has merged into the neutral flow path 9 is supplied to the swing actuator. Since it is supplied only to the actuator, the hydraulic oil necessary for the swing operation can be obtained even when the arm and swing are operated at the same time.

また、第２図及び第４図の実施例では旋回用切換弁７が
アーム用切換弁８の上流側にあるため、アーム用切換弁
８を操作し旋回用切換弁７の操作を行なわない場合、補
助ポンプ３からの圧油が中立流□ 路９を介してアーム用切換弁８に供給されるので、並列
高圧流路１０を介して供給される主ポンプ１からの圧油
と合せてアームの増速操作が可能となる。Furthermore, in the embodiments shown in FIGS. 2 and 4, the swing switching valve 7 is located upstream of the arm switching valve 8, so when the arm switching valve 8 is operated but the swing switching valve 7 is not operated. Since the pressure oil from the auxiliary pump 3 is supplied to the arm switching valve 8 through the neutral flow path 9, the pressure oil from the main pump 1 supplied through the parallel high pressure flow path 10 is speed increase operation is possible.

以上の通りこの発明によれば、多連切換弁により作動圧
の異なる例えば旋回とアームの同時操作を行なう場合、
作動圧の低い方（アーム）のアクチュエータ用切換弁の
切換に連動して補助切換弁を切換え、該切換弁を介して
補助ポンプの吐出圧油を作動圧の高い方（旋回）のアク
チーエータ用切換弁の上流側中立流路に供給するから作
動圧の高いアクチーエータにも十分な作動圧油の供給が
可能である。As described above, according to the present invention, when simultaneous operation of a swing and an arm using different operating pressures is performed using a multiple switching valve,
The auxiliary switching valve is switched in conjunction with the switching of the switching valve for the actuator with lower operating pressure (arm), and the discharge pressure oil of the auxiliary pump is switched to the actuator with higher operating pressure (swivel) via the switching valve. Since it is supplied to the neutral flow path on the upstream side of the valve, it is possible to supply sufficient working pressure oil even to actuators with high operating pressure.

従って、この発明を油圧ショベルに応用し旋回操作によ
りバケ、ット（アーム）を壁面に押付けながらアームを
操作して壁面掘削を行なう場合にも十分な旋回押付力が
得られる。Therefore, even when the present invention is applied to a hydraulic excavator and excavation is performed on a wall surface by operating the arm while pressing the bucket and kit (arm) against the wall surface by the swing operation, a sufficient turning pressing force can be obtained.

また、補助ポンプ３の吐出圧油は旋回用アクチュエータ
のみに供給されるので鎗旋回押付力は補助ポンプ３のリ
リーフ弁２７により設定された力となり、アームの作動
圧の影響を受けないと共に、補助ポンプ３の吐出流量を
適切に選択することによって、旋回押付時のリリーフ損
失を小さくでき、かつ、アームは主ポンプからの圧油の
供給により作業速度を速くでき、作業能率の向上並びに
適切な油温管理等も可能になる等の効果を有する。In addition, since the discharge pressure oil of the auxiliary pump 3 is supplied only to the swing actuator, the force for pressing the swivel is the force set by the relief valve 27 of the auxiliary pump 3, and is not affected by the operating pressure of the arm. By appropriately selecting the discharge flow rate of the pump 3, the relief loss during turning and pressing can be reduced, and the working speed of the arm can be increased by supplying pressure oil from the main pump, improving work efficiency and ensuring proper oil supply. This has the effect of making it possible to control temperature, etc.

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

第り図は従来の油圧回路図、第２図乃至第４図は本発明
の油圧回路図、第５図は補助切換弁の他の実施例を示す
図である。 １　：　主ポンプ　　　　３　：　補助ポンプ４　：　
多連切換弁　　　５〜８　：　切換弁９　二　中立流路
　　　　１０　：　並列高圧流路１７−：＠助切換弁　
　２２．２３．２５　　：　逆止弁第４図 −１７９−Figure 2 is a conventional hydraulic circuit diagram, Figures 2 to 4 are hydraulic circuit diagrams of the present invention, and Figure 5 is a diagram showing another embodiment of the auxiliary switching valve. 1: Main pump 3: Auxiliary pump 4:
Multiple switching valves 5 to 8: Switching valve 9 Two neutral flow path 10: Parallel high pressure flow path 17-: @Auxiliary switching valve
22.23.25: Check valve Fig. 4-179-

Claims (1)

【特許請求の範囲】[Claims] 多連切換弁を介して複数のアクチュエータを駆動する主
ポンプと該ポンプの外に少くとも１個の補助ポンプを設
け、かつ、該補助ポンプの吐出流路を多連切換弁中の１
個の切換弁と連動して切換られる補助切換弁を介して他
の切換弁の上流側中立流路に接続すると共に、その接続
点より上流の中立流路に上流への逆流を防止する逆止弁
を設け、更に接続点及び並列高圧流路と他の切換弁の圧
油供給流路との間に、それぞれ、圧油供給流路側から中
立流路側及び並列高圧流路側への逆流を防止する逆止弁
を設けたことを特徴とする油圧ショベル等の油圧回路。At least one auxiliary pump is provided in addition to a main pump that drives a plurality of actuators via a multiple switching valve, and the discharge flow path of the auxiliary pump is connected to one of the multiple switching valves.
A non-return valve that connects to the upstream neutral flow path of another switching valve through an auxiliary switching valve that switches in conjunction with the switching valve, and prevents backflow upstream from the neutral flow path upstream from the connection point. A valve is provided between the connection point and the parallel high-pressure flow path and the pressure oil supply flow path of the other switching valve to prevent backflow from the pressure oil supply flow path side to the neutral flow path side and the parallel high-pressure flow path side, respectively. A hydraulic circuit for a hydraulic excavator, etc., characterized by being provided with a check valve.
JP2897482A 1982-02-26 1982-02-26 Oil-pressure circuit for oil-pressure shovel and the like Granted JPS58146634A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2897482A JPS58146634A (en) 1982-02-26 1982-02-26 Oil-pressure circuit for oil-pressure shovel and the like

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2897482A JPS58146634A (en) 1982-02-26 1982-02-26 Oil-pressure circuit for oil-pressure shovel and the like

Publications (2)

Publication Number Publication Date
JPS58146634A true JPS58146634A (en) 1983-09-01
JPH0470453B2 JPH0470453B2 (en) 1992-11-11

Family

ID=12263386

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2897482A Granted JPS58146634A (en) 1982-02-26 1982-02-26 Oil-pressure circuit for oil-pressure shovel and the like

Country Status (1)

Country Link
JP (1) JPS58146634A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0791754A1 (en) * 1995-09-18 1997-08-27 Hitachi Construction Machinery Co., Ltd. Hydraulic system
CN111512051A (en) * 2017-12-28 2020-08-07 日立建机株式会社 Hydraulic drive device for working machine

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5384301A (en) * 1976-12-29 1978-07-25 Yutani Juko Kk Hydraulic circuit for excavator

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5384301A (en) * 1976-12-29 1978-07-25 Yutani Juko Kk Hydraulic circuit for excavator

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0791754A1 (en) * 1995-09-18 1997-08-27 Hitachi Construction Machinery Co., Ltd. Hydraulic system
EP0791754A4 (en) * 1995-09-18 2000-09-20 Hitachi Construction Machinery Hydraulic system
CN111512051A (en) * 2017-12-28 2020-08-07 日立建机株式会社 Hydraulic drive device for working machine
EP3715642A4 (en) * 2017-12-28 2021-08-11 Hitachi Construction Machinery Co., Ltd. Hydraulic drive device of work machine
US11208787B2 (en) 2017-12-28 2021-12-28 Hitachi Construction Machinery Co., Ltd. Hydraulic drive system for work machine
CN111512051B (en) * 2017-12-28 2022-07-26 日立建机株式会社 Hydraulic drive device for working machine

Also Published As

Publication number Publication date
JPH0470453B2 (en) 1992-11-11

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