JPS6330452B2 - - Google Patents

Info

Publication number
JPS6330452B2
JPS6330452B2 JP56024786A JP2478681A JPS6330452B2 JP S6330452 B2 JPS6330452 B2 JP S6330452B2 JP 56024786 A JP56024786 A JP 56024786A JP 2478681 A JP2478681 A JP 2478681A JP S6330452 B2 JPS6330452 B2 JP S6330452B2
Authority
JP
Japan
Prior art keywords
control valve
pressure
swing
circuit
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.)
Expired
Application number
JP56024786A
Other languages
Japanese (ja)
Other versions
JPS57140434A (en
Inventor
Hideaki Yoshimatsu
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.)
Kobe Steel Ltd
Original Assignee
Kobe Steel 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 Kobe Steel Ltd filed Critical Kobe Steel Ltd
Priority to JP2478681A priority Critical patent/JPS57140434A/en
Publication of JPS57140434A publication Critical patent/JPS57140434A/en
Publication of JPS6330452B2 publication Critical patent/JPS6330452B2/ja
Granted 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
    • E02F9/2278—Hydraulic circuits
    • E02F9/2292—Systems with two or more pumps
    • 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

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)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、２ポンプ方式の油圧シヨベルの油圧
回路に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulic circuit for a two-pump type hydraulic excavator.

（従来技術） 従来、油圧シヨベルの基本回路は、一般に第１
図に示すように２個の油圧ポンプP1，P2の吐出
油を２組のコントロールバルブV1，V2′で制御す
るいわゆる２ポンプ方式の油圧回路となつてい
る。なお、第１図において、M1，M2は左右の走
行モータ、M3は旋回モータ、C1はブームシリン
ダ、C2はアームシリンダ、C3はバケツトシリン
ダを示し、１１は左走行用、１２はブーム１速
用、１３はバケツト用、１４はアーム２速用、１
５は右走行用、１６は旋回用、１７はアーム１速
用、１８はブーム２速用の各方向制御弁を示し、
２１，２２はメインリリーフ弁を示す。(Prior art) Conventionally, the basic circuit of a hydraulic excavator has generally been
As shown in the figure, it is a so-called two-pump type hydraulic circuit in which the oil discharged from two hydraulic pumps P 1 and P 2 is controlled by two sets of control valves V 1 and V 2 '. In Figure 1, M 1 and M 2 are left and right travel motors, M 3 is a swing motor, C 1 is a boom cylinder, C 2 is an arm cylinder, C 3 is a bucket cylinder, and 11 is for left travel. , 12 is for boom 1st speed, 13 is for bucket, 14 is for arm 2nd speed, 1
5 indicates each direction control valve for right running, 16 for turning, 17 for arm 1st speed, and 18 for boom 2nd speed,
21 and 22 indicate main relief valves.

上記従来回路によれば、旋回が慣性負荷として
の性格が強いため、旋回加速時に旋回モータM3
に流れる流量はポンプP2の吐出量の全量ではな
く、一部がブリードオフされる。この欠点を補う
ために、ブーム回路およびアーム回路を旋回回路
とパラレルに接続し、旋回回路でブリードオフさ
れる流量をブーム回路およびアーム回路に流入さ
せてエネルギーロスを少なくしている。 According to the above conventional circuit, since the swing has a strong character as an inertial load, the swing motor M 3
The flow rate flowing through is not the entire discharge amount of pump P2 , but a portion is bled off. To compensate for this drawback, the boom circuit and arm circuit are connected in parallel to the swing circuit, and the flow rate bleed off in the swing circuit is allowed to flow into the boom circuit and arm circuit, thereby reducing energy loss.

しかしながら、旋回加速とブーム上げとの同時
作業時には、旋回加速圧力がブーム上げの負荷圧
力に支配されて決まるので、一般的には好ましい
回路といえるが、この旋回加速とブーム上げとの
同時作業の場合であつても、傾斜地での作業等、
作業内容によつては旋回とブーム上げとが適正に
作動しない場合がある。また、旋回加速とアーム
引き（アームシリンダC2は伸長）の同時作業の
場合、アームシリンダC2は負荷により伸ばされ
ようとしているため、伸長側の圧力が低く、か
つ、アーム回路も旋回回路とパラレルに接続され
ているため、旋回回路はアーム回路の圧力（低
圧）の影響を受け、ポンプ圧力は低圧となり、旋
回加速がほとんど不可能となる。このため、従来
ではオペレータがアーム回路への供給流量をアー
ム用方向制御弁１７，１４によつて絞りながら、
旋回用方向制御弁１６を操作し、両方の動きを適
合させるように操作する必要があり、この操作は
非常に難しい。 However, when the swing acceleration and boom raising are performed simultaneously, the swing acceleration pressure is determined by the load pressure of the boom raising, so it is generally a preferable circuit. Even if the work is on a slope,
Depending on the content of the work, turning and boom raising may not work properly. In addition, in the case of simultaneous rotation acceleration and arm pulling (arm cylinder C 2 is extended), arm cylinder C 2 is about to be extended by the load, so the pressure on the extension side is low and the arm circuit is also the same as the swing circuit. Since they are connected in parallel, the swing circuit is affected by the pressure (low pressure) of the arm circuit, and the pump pressure becomes low pressure, making it almost impossible to accelerate the swing. For this reason, conventionally, the operator throttles the supply flow rate to the arm circuit using the arm directional control valves 17 and 14.
It is necessary to operate the turning directional control valve 16 to match both movements, and this operation is very difficult.

（発明の目的） 本発明は、このような点に鑑み、旋回加速時の
エネルギー効率を良好にしつつ、旋回回路に独立
性をもたせて良好な旋回性能が得られ、旋回加速
とブーム上げとの同時作業はいうまでもなく、旋
回加速とアーム引きとの同時作業の場合であつて
も両作業を円滑に遂行でき、しかも、走行時に偏
向することなく、直進性を向上できる油圧シヨベ
ルの油圧回路を提供するものである。(Object of the Invention) In view of these points, the present invention improves energy efficiency during turning acceleration, provides independence to the turning circuit, provides good turning performance, and improves the relationship between turning acceleration and boom raising. A hydraulic circuit for a hydraulic excavator that can smoothly perform both operations, not to mention simultaneous operations, such as turning acceleration and arm pulling, and improve straight-line performance without deflecting during travel. It provides:

（発明の構成） 本発明は、２ポンプ方式の油圧シヨベルの油圧
回路において、一方の油圧ポンプに対し、一方の
走行用方向制御弁を介して走行回路をタンデムに
接続し、走行用方向制御弁の下流に旋回回路に圧
油を優先的に導くための圧力補償付流量制御弁を
配置し、この圧力補償付流量制御弁の優先通路を
旋回用方向制御弁の入力側ポートに接続するとと
もに、ブリードオフ通路を下流のアームシリン
ダ、ブームシリンダ等のアクチユエータの方向制
御弁の入力側ポートに接続し、かつ、前記圧力補
償付流量制御弁の設定圧力を、前記ポンプのメイ
ンリリーフ弁の設定圧力および旋回回路に設けら
れたオーバーロードリリーフ弁の設定圧力よりも
低く設定したことを特徴とするものである。(Structure of the Invention) In the hydraulic circuit of a two-pump type hydraulic excavator, the traveling circuit is tandemly connected to one hydraulic pump via one traveling direction control valve, and the traveling direction control valve is connected to one hydraulic pump in tandem. A pressure-compensated flow control valve for preferentially guiding pressure oil to the swing circuit is arranged downstream of the pressure-compensated flow control valve, and the priority passage of the pressure-compensated flow control valve is connected to the input side port of the swing directional control valve. The bleed-off passage is connected to the input side port of a directional control valve of an actuator such as a downstream arm cylinder or boom cylinder, and the set pressure of the flow control valve with pressure compensation is set to the set pressure of the main relief valve of the pump. It is characterized in that the pressure is set lower than the set pressure of the overload relief valve provided in the swing circuit.

この構成によれば、旋回優先の圧力補償付流量
制御弁により、旋回と他のアクチユエータ（ブー
ムシリンダ、アームシリンダ等）との同時作業時
のエネルギー効率を良好にしつつ、旋回回路に独
立性をもたせて良好な旋回性能が得られ、旋回加
速とブーム上げとの同時作業はいうまでもなく、
旋回加速とアーム引きとの同時作業の場合であつ
ても両作業が円滑に遂行され、しかも、走行が旋
回の上流側に配置されているので、走行時に圧力
補償付流量制御弁の影響を受けるおそれがなく、
走行の偏向が防止され、直進性が向上される。 According to this configuration, the flow control valve with pressure compensation that prioritizes the swing improves energy efficiency during simultaneous operation of the swing and other actuators (boom cylinder, arm cylinder, etc.), while providing independence to the swing circuit. It is possible to obtain good turning performance, and it goes without saying that it is possible to simultaneously accelerate the turn and raise the boom.
Even when accelerating the swing and pulling the arm at the same time, both tasks can be carried out smoothly.Moreover, since the travel is located upstream of the swing, the flow control valve with pressure compensation is affected by the flow control valve during travel. There is no fear,
Deflection of running is prevented and straight-line performance is improved.

（実施例） 本発明の実施例を第２図によつて説明する。(Example) An embodiment of the present invention will be explained with reference to FIG.

第２図において、第１図に示した従来回路と同
一機器には同一符号を付している。一方の油圧ポ
ンプP1には、上記従来回路と同様に、メインリ
リーフ弁２１と、左走行用、ブーム１速用、バケ
ツト用、アーム２速用の各方向制御弁１１，１
２，１３，１４を備えたコントロールバルブV1
を介して左走行モータM1、ブームシリンダC1、
バケツトシリンダC3、アームシリンダC2を接続
している。ただし、走行回路はタンデムとなつて
いる。また、他方のポンプP2には、従来のコン
トロールバルブV2′とは異なるコントロールバル
ブV2を介して右走行モータM2、旋回モータM3、
アームシリンダC2、ブームシリンダC1を接続し
ている。 In FIG. 2, the same equipment as the conventional circuit shown in FIG. 1 is given the same reference numeral. One of the hydraulic pumps P 1 includes a main relief valve 21 and directional control valves 11, 1 for left travel, for boom 1st speed, for bucket, and for arm 2nd speed, as in the conventional circuit.
Control valve V 1 with 2, 13, 14
Left travel motor M 1 , boom cylinder C 1 ,
Bucket cylinder C 3 and arm cylinder C 2 are connected. However, the running circuit is tandem. In addition, the other pump P 2 is connected to a right travel motor M 2 , a swing motor M 3 ,
Arm cylinder C 2 and boom cylinder C 1 are connected.

すなわち、コントロールバルブV2において、
上流から右走行用方向制御弁１５、旋回用方向制
御弁１６、アーム１速用方向制御弁１７、ブーム
２速用方向制御弁１８を順次配置し、かつ、右走
行用方向制御弁１５と旋回用方向制御弁１６との
間に、旋回優先の圧力補償付流量制御弁３１を配
置し、この圧力補償付流量制御弁３１の入口側を
走行用方向制御弁１５の下流に接続し、その出口
側の優先通路３２を旋回用方向制御弁１６の入力
側ポートに接続するとともに、ブリードオフ通路
３３を下流の各方向制御弁１７，１８の入力側ポ
ートおよび方向制御弁１７のアンロード通路３４
にパラレルに接続している。 That is, in control valve V 2 ,
From upstream, the right travel direction control valve 15, the turning direction control valve 16, the arm 1st speed direction control valve 17, and the boom 2nd speed direction control valve 18 are arranged in this order, and the right travel direction control valve 15 and the turning direction control valve 18 are arranged in this order. A pressure-compensated flow control valve 31 with priority for turning is arranged between the travel direction control valve 16, and the inlet side of the pressure-compensated flow control valve 31 is connected to the downstream side of the travel direction control valve 15. The side priority passage 32 is connected to the input side port of the turning directional control valve 16, and the bleed-off passage 33 is connected to the input side port of each downstream directional control valve 17, 18 and the unload passage 34 of the directional control valve 17.
are connected in parallel.

上記圧力補償付流量制御弁３１は、一端にパイ
ロツト通路３５を介して旋回用方向制御弁１６の
入口側の圧力を導き、他端のばね側にパイロツト
通路３６を介して同方向制御弁１６の出口側の圧
力つまり旋回モータM3の負荷圧を導いて方向制
御弁１６の入口側と出口側の差圧を一定に制御す
る圧力補償制御を行うものであり、そのパイロツ
ト通路３６に絞り３７を設け、その絞り３７の後
にリリーフ弁３８を設けている。 The pressure compensated flow rate control valve 31 introduces the pressure on the inlet side of the swing directional control valve 16 through a pilot passage 35 at one end, and the pressure at the inlet side of the swing directional control valve 16 through a pilot passage 36 at the other end on the spring side. Pressure compensation control is performed to control the differential pressure between the inlet side and the outlet side of the directional control valve 16 to a constant level by guiding the pressure on the outlet side, that is, the load pressure of the swing motor M3 , and a throttle 37 is provided in the pilot passage 36. A relief valve 38 is provided after the throttle 37.

また、旋回回路にはオーバーロードリリーフ弁
４１，４２およびカウンタバランス弁４３を設け
てある。このカウンタバランス弁４３は省略して
もよい。 Further, overload relief valves 41 and 42 and a counterbalance valve 43 are provided in the swing circuit. This counterbalance valve 43 may be omitted.

上記回路において、メインリリーフ弁２２の設
定圧力をPa、オーバーロードリリーフ弁４１，
４２の設定圧力をPb、圧力補償付流量制御弁３
１のリリーフ弁３８の設定圧力をPcとすると、 Pc＜Pa、Pc＜Pb となるように設定する。さらに具体的には、たと
えば、 Pa＝250Kg／cm2 Pb＝210Kg／cm2 Pc＝190Kg／cm2 とする。 In the above circuit, the set pressure of the main relief valve 22 is Pa, the overload relief valve 41 is
Set pressure of 42 to Pb, flow control valve with pressure compensation 3
When the set pressure of the relief valve 38 of No. 1 is Pc, the pressure is set so that Pc<Pa and Pc<Pb. More specifically, for example, Pa=250Kg/cm 2 Pb=210Kg/cm 2 Pc=190Kg/cm 2 .

次に、上記回路の作動について説明する。 Next, the operation of the above circuit will be explained.

旋回を使つた場合、 旋回用方向制御弁１６が上または下位置に切
替えられると、油圧ポンプP2の吐出油は、前
記弁３１、優先通路３２、方向制御弁１６、カ
ウンタバランス弁４３を経て旋回モータM3に
流入し、同モータM3の吸込み側の圧力が次第
に上昇して旋回が加速される。このとき、優先
通路３２に導かれる方向制御弁１６の入口側圧
力が一次圧力としてパイロツト通路３５に導か
れ、前記旋回モータM3の負荷圧力が二次圧力
としてパイロツト通路３６に導かれ、その一次
圧力と、二次圧力とばね力と和とのバランスに
よつて前記弁３１による圧力補償制御が行わ
れ、前記ポンプP2からの吐出油が旋回モータ
M3に優先的に流入して旋回加速が行われる。 When the swing is used, when the swing directional control valve 16 is switched to the upper or lower position, the oil discharged from the hydraulic pump P2 passes through the valve 31, the priority passage 32, the directional control valve 16, and the counterbalance valve 43. It flows into the swing motor M3 , and the pressure on the suction side of the motor M3 gradually increases, accelerating the swing. At this time, the pressure on the inlet side of the directional control valve 16 led to the priority passage 32 is led to the pilot passage 35 as a primary pressure, and the load pressure of the swing motor M3 is led to the pilot passage 36 as a secondary pressure. Pressure compensation control is performed by the valve 31 based on the balance between the pressure, the secondary pressure, the spring force, and the sum of the pressure, and the oil discharged from the pump P2 is supplied to the swing motor.
Turning acceleration is performed by preferentially flowing into M3 .

この旋回加速時において、旋回加速圧力は、
前記弁３１に付設のリリーフ弁３８の設定圧力
Pcたとえば190Kg／cm2まで上昇し、設定圧力Pc
以上になると、リリーフ弁３８がリリーフす
る。そして、旋回加速圧力が前記弁３１による
圧力補償制御により圧力Pc（190Kg／cm2）に保
持されたまま、油圧ポンプP2の吐出量のうち
旋回用方向制御弁１６のスプール開度により決
まる必要流量だけが旋回モータM3に優先的に
流入し、その余剰油が前記弁３１により通路３
３にブリードオフされる。 During this turning acceleration, the turning acceleration pressure is
Setting pressure of the relief valve 38 attached to the valve 31
Pc rises to, for example, 190Kg/ cm2 , and the set pressure Pc
When this occurs, the relief valve 38 is relieved. Then, while the swing acceleration pressure is maintained at pressure Pc (190 Kg/cm 2 ) by pressure compensation control by the valve 31, the discharge amount of the hydraulic pump P 2 must be determined by the spool opening of the swing direction control valve 16. Only the flow rate preferentially flows into the swing motor M3 , and the excess oil is transferred to the passage 3 by the valve 31.
Bleed off in 3.

ここで、下流のたとえばアーム１速用方向制
御弁１７を上または下位置に切替えると、前記
余剰油が通路３３から方向制御弁１７を経てア
ームシリンダC2に流入し、旋回加速とアーム
との同時作業が行われる。さらにこの場合、ア
ーム回路圧力が旋回回路圧力よりも低くたとえ
ば50Kg／cm2とすると、前記余剰油は50Kg／cm2で
アームシリンダC2に流入し、また、アーム回
路圧力が旋回回路圧力よりも高くたとえば230
Kg／cm2とすると、油圧ポンプP2の吐出圧力が
230Kg／cm2＋前記弁３１の圧力損失分だけ上昇
し、前記余剰油が230Kg／cm2でアームシリンダ
C2に流入する。しかし、旋回モータM3に流入
する油は、前記の如く旋回優先形の圧力補償付
流量制御弁３１によつて制御されるので、アー
ム回路圧力に影響されることなく、弁３１に付
設のリリーフ弁３８の設定圧力Pcに対応する
圧力すなわち190Kg／cm2で旋回が加速され、か
つ、最大流量はその方向制御弁１６のスプール
開度により決定される。これによつて旋回加速
とアームとの同時作業が円滑に行われ、油圧ポ
ンプP2の吐出油が有効に利用され、エネルギ
ーロスが少なくなる。 Here, when the downstream directional control valve 17 for arm 1st speed is switched to the upper or lower position, the excess oil flows from the passage 33 through the directional control valve 17 to the arm cylinder C2 , resulting in rotational acceleration and arm rotation. Simultaneous work is done. Furthermore, in this case, if the arm circuit pressure is lower than the swing circuit pressure, for example 50Kg/cm 2 , the excess oil flows into the arm cylinder C 2 at 50Kg/cm 2 , and the arm circuit pressure is lower than the swing circuit pressure. High for example 230
Kg/cm 2 , the discharge pressure of hydraulic pump P 2 is
230Kg/cm 2 + the pressure loss of the valve 31 increases, and the excess oil reaches 230Kg/cm 2 and reaches the arm cylinder.
Flows into C 2 . However, since the oil flowing into the swing motor M3 is controlled by the swing-priority type pressure-compensated flow control valve 31 as described above, the oil flowing into the swing motor M3 is not affected by the arm circuit pressure. The rotation is accelerated at a pressure corresponding to the set pressure Pc of the valve 38, that is, 190 kg/cm 2 , and the maximum flow rate is determined by the spool opening of the directional control valve 16. As a result, rotational acceleration and simultaneous work with the arm can be performed smoothly, the oil discharged from the hydraulic pump P2 can be used effectively, and energy loss can be reduced.

また、旋回加速とブーム上げとの同時作業時
に、ブーム２速用方向制御弁１８を操作して
も、上記旋回加速とアームとの同時作業時と同
様に、円滑に作業が行える。 Further, even if the second-speed boom directional control valve 18 is operated during the simultaneous work of accelerating the swing and raising the boom, the work can be carried out smoothly in the same way as when the simultaneous work of accelerating the swing and raising the arm is performed.

すなわち、従来の旋回とブームのパラレル回
路では、平地での一般的な作業の場合には問題
はないが、傾斜地での旋回ブームとの同時作業
時にはそのバランスが崩れ、たとえば傾斜地を
上る方向に旋回しながらブーム上げ作業を行う
場合には、旋回圧力が高くなるにも拘らず、ブ
ーム圧力は平地作業とほぼ同一であるため、旋
回が不可能になる場合がある。 In other words, with the conventional parallel circuit of swing and boom, there is no problem in general work on level ground, but when working simultaneously with a swing boom on slope, the balance is lost, for example, when swinging in the direction up the slope. When lifting the boom while doing so, the boom pressure is almost the same as when working on level ground, even though the swinging pressure is high, so swinging may become impossible.

しかしながら、上記本発明の回路によれば、
旋回回路の上流側に旋回優先の圧力補償付流量
制御弁３１を設け、この弁３１により油圧ポン
プP2の吐出油を旋回回路に優先的に流入させ、
かつ、弁３１によりブリードオフされた余剰油
をブーム２速に流入させるようにしてあるの
で、上記旋回とアームとの同時作業時と同様
に、旋回回路がブーム回路の圧力に影響され
ず、前記リリーフ弁３８の設定圧力に対応する
圧力および方向制御弁１６のスプール開度に応
じた流量で旋回を加速できる。従つて、上記従
来のような不都合が生じることはなく、この旋
回加速とブーム上げとの同時作業を円滑に行う
ことができ、油圧ポンプP2の吐出油を有効に
利用でき、エネルギーロスを少なくできる。 However, according to the circuit of the present invention,
A pressure-compensated flow control valve 31 giving priority to swing is provided on the upstream side of the swing circuit, and this valve 31 allows the discharge oil of the hydraulic pump P2 to flow preferentially into the swing circuit.
In addition, since the surplus oil bleed-off by the valve 31 is made to flow into the second gear of the boom, the swing circuit is not affected by the pressure of the boom circuit and the swing circuit is not affected by the pressure of the boom circuit, as in the case of simultaneous work with the swing and arm. The rotation can be accelerated with a pressure corresponding to the set pressure of the relief valve 38 and a flow rate corresponding to the spool opening degree of the directional control valve 16. Therefore, the above-mentioned conventional inconveniences do not occur, and simultaneous acceleration of the swing and lifting of the boom can be performed smoothly, and the oil discharged from the hydraulic pump P2 can be used effectively, reducing energy loss. can.

なお、上記旋回加速時において、下流のアー
ム２速およびブーム２速を使わない場合は、前
記弁３１でブリードオフされた余剰油は通路３
３からアンロード通路３４を経てタンクＴに戻
される。 In addition, when the downstream arm 2nd speed and boom 2nd speed are not used during the above-mentioned turning acceleration, the excess oil bleed off by the valve 31 is drained into the passage 3.
3 and is returned to the tank T via the unload passage 34.

旋回を使つていない場合 旋回用方向制御弁１６が中立位置にあり、そ
の入力側ポートがブロツクされているので、前
記弁３１のパイロツト通路３４に導かれる一次
圧力（弁１６の入口側圧力）が上昇し、この弁
３１のばねにより設定された圧力になると、弁
３１が図示の上位置から下位置に切替えられ、
油圧ポンプP2の吐出油は通路３２には流れず
に、その全量が前記弁３１によりブリードオフ
され、通路３３を経て下流の各方向制御弁１
７，１８に導かれる。この状態で方向制御弁１
７，１８を操作すれば、アーム１速、ブーム２
速を従来回路と同様に使用できる。この場合、
前記弁３１の圧力損失分だけ圧力が下がるが、
その圧力損失分は５Kg／cm2程度であり、実用上
はほとんど支障はない。 When the swing is not used, the swing directional control valve 16 is in the neutral position and its input side port is blocked, so the primary pressure led to the pilot passage 34 of the valve 31 (inlet side pressure of the valve 16) rises and reaches the pressure set by the spring of this valve 31, the valve 31 is switched from the upper position shown in the figure to the lower position,
The discharge oil of the hydraulic pump P2 does not flow into the passage 32, but the entire amount is bled off by the valve 31, and passes through the passage 33 to each downstream directional control valve 1.
7, 18. In this state, directional control valve 1
If you operate 7 and 18, arm 1st speed, boom 2nd
speed can be used in the same way as conventional circuits. in this case,
The pressure decreases by the pressure loss of the valve 31, but
The pressure loss is about 5 kg/cm 2 , which poses almost no problem in practice.

また、左右の走行用方向制御弁１１，１５を
上または下位置に切替えると、各油圧ポンプ
P1，P2の吐出油が各走行モータM1，M2に流入
され、走行作業が行われる。この場合、各走行
用方向制御弁１１，１５を上流側に配置してあ
るので、走行が他のアクチユエータ用方向制御
弁および圧力補償付流量制御弁３１に影響され
ることはない。すなわち右側のコントロールバ
ルブV2において、旋回優先の圧力補償付流量
制御弁３１の下流に走行用方向制御弁１５を配
置することが考えられるが、そうした場合、左
側の走行用方向制御弁１１に油圧ポンプP1の
吐出油が直接導かれるのに対し、右側の走行用
方向制御弁１５には圧力補償付流量制御弁３１
を通過した後の油が導かれるため、圧力補償付
流量制御弁３１の圧力損失分だけ右側の走行圧
力が低くなるおそれがあり、これに起因して走
行が偏向するおそれがある。そこで、上記のよ
うに右側の走行用方向制御弁１５をタンデムで
圧力補償付流量制御弁３１の上流側に配置して
おけば、走行回路が圧力補償付流量制御弁３１
の影響を受けるおそれがなくなる。これによつ
て走行の偏向が防止され、直進性が向上され
る。 In addition, when the left and right travel direction control valves 11 and 15 are switched to the upper or lower position, each hydraulic pump
Discharged oil from P 1 and P 2 flows into each travel motor M 1 and M 2 to perform travel work. In this case, since the travel direction control valves 11 and 15 are arranged on the upstream side, travel is not affected by other actuator direction control valves and pressure compensated flow rate control valve 31. In other words, in the right control valve V 2 , it is possible to arrange the travel direction control valve 15 downstream of the pressure-compensated flow rate control valve 31 that prioritizes turning. The discharge oil of the pump P 1 is directly guided, whereas the right travel direction control valve 15 has a pressure compensated flow control valve 31.
Since the oil after passing through is guided, there is a risk that the running pressure on the right side will be lowered by the pressure loss of the pressure compensated flow control valve 31, and there is a risk that the running will be deflected due to this. Therefore, if the right travel direction control valve 15 is arranged in tandem on the upstream side of the pressure compensated flow control valve 31 as described above, the travel circuit can be connected to the pressure compensated flow control valve 31.
There is no risk of being affected by This prevents deflection of the vehicle and improves straight-line performance.

ところで、図例では、油圧ポンプP1，P2を
固定容量形ポンプとした場合を示しているが、
可変容量形油圧ポンプを用いても上記と同様の
作用効果を奏することができる。 By the way, the illustrated example shows the case where the hydraulic pumps P 1 and P 2 are fixed displacement pumps, but
Even if a variable displacement hydraulic pump is used, the same effects as described above can be achieved.

（発明の効果） 以上のように本発明は、旋回加速時に、ポンプ
吐出油を圧力補償付流量制御弁により旋回回路に
優先的に流入させるとともに、同弁によりブリー
ドオフした油を下流のアーム、ブーム等のアクチ
ユエータに流入させて利用できるので、エネルギ
ーロスを少なくでき、効率よく使用できる。しか
も、旋回と、他のアクチユエータつまりアームま
たはブーム等との同時作業時に、ポンプ吐出油を
常に旋回回路に優先的に流入させて旋回回路を独
立させることができるので、旋回圧力がアーム圧
力またはブーム圧力に影響されることなく、旋回
加速を常に確実に効率よく行うことができ、上記
同時作業を円滑に行うことができる。さらに、走
行を上記圧力補償付流量制御弁の上流側に配置し
てあるので、走行時に、走行回路が圧力補償付流
量制御弁の影響を受けることがなく、走行に偏向
が生じることなく、直進性を向上でき、的確に走
行させることができる。(Effects of the Invention) As described above, the present invention allows the pump discharge oil to flow preferentially into the swing circuit using the pressure-compensated flow control valve during swing acceleration, and the oil bleed off by the valve to the downstream arm. Since it can be used by flowing into an actuator such as a boom, energy loss can be reduced and it can be used efficiently. Moreover, when simultaneously working on the swing and other actuators, such as the arm or boom, the pump discharge oil always flows preferentially into the swing circuit, making the swing circuit independent. Turning acceleration can always be performed reliably and efficiently without being affected by pressure, and the above-mentioned simultaneous operations can be performed smoothly. Furthermore, since the travel circuit is located upstream of the pressure-compensated flow control valve, the travel circuit is not affected by the pressure-compensated flow control valve during travel, and the travel is not deflected, allowing the vehicle to travel straight. It is possible to improve performance and drive accurately.

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

第１図は従来の一般的な油圧シヨベルの基本回
路を示す油圧回路図、第２図は本発明の実施例を
示す油圧回路図である。 P1，P2……油圧ポンプ、M1，M2……走行モー
タ、M3……旋回モータ、C1……ブームシリンダ、
C2……アームシリンダ、C3……バケツトシリン
ダ、１１……左走行用方向制御弁、１２……ブー
ム１速用方向制御弁、１３……バケツト用方向制
御弁、１４……アーム２速用方向制御弁、１５…
…右走行用方向制御弁、１６……旋回用方向制御
弁、１７……アーム１速用方向制御弁、１８……
ブーム２速用方向制御弁、２１，２２……メイン
リリーフ弁、３１……旋回優先の圧力補償付流量
制御弁、３２……優先通路、３３……ブリードオ
フ通路、３７……絞り、３８……リリーフ弁、４
１，４２……オーバーロードリリーフ弁。 FIG. 1 is a hydraulic circuit diagram showing the basic circuit of a conventional general hydraulic excavator, and FIG. 2 is a hydraulic circuit diagram showing an embodiment of the present invention. P 1 , P 2 ... Hydraulic pump, M 1 , M 2 ... Travel motor, M 3 ... Swing motor, C 1 ... Boom cylinder,
C 2 ... Arm cylinder, C 3 ... Bucket cylinder, 11 ... Directional control valve for left running, 12 ... Directional control valve for boom 1st speed, 13 ... Directional control valve for bucket, 14 ... Arm 2 Speed directional control valve, 15...
... Directional control valve for right travel, 16... Directional control valve for turning, 17... Directional control valve for arm 1st speed, 18...
Directional control valve for boom 2nd speed, 21, 22...Main relief valve, 31...Flow rate control valve with pressure compensation for turning priority, 32...Priority passage, 33...Bleed-off passage, 37... Throttle, 38... ...Relief valve, 4
1,42...Overload relief valve.

Claims (1)

【特許請求の範囲】[Claims] １ ２ポンプ方式の油圧シヨベルの油圧回路にお
いて、一方の油圧ポンプに対し、一方の走行用方
向制御弁を介して走行回路をタンデムに接続し、
走行用方向制御弁の下流に旋回回路に圧油を優先
的に導くための圧力補償付流量制御弁を配置し、
この圧力補償付流量制御弁の優先通路を旋回用方
向制御弁の入力側ポートに接続するとともに、ブ
リードオフ通路を下流のアームシリンダ、ブーム
シリンダ等のアクチユエータの方向制御弁の入力
側ポートに接続し、かつ、前記圧力補償付流量制
御弁の設定圧力を、前記ポンプのメインリリーフ
弁の設定圧力および旋回回路に設けられたオーバ
ーロードリリーフ弁の設定圧力よりも低く設定し
たことを特徴とする油圧シヨベルの油圧回路。1. In the hydraulic circuit of a two-pump type hydraulic excavator, the traveling circuit is tandemly connected to one hydraulic pump via one traveling direction control valve,
A flow control valve with pressure compensation is placed downstream of the travel directional control valve to preferentially guide pressure oil to the swing circuit.
Connect the priority passage of this flow control valve with pressure compensation to the input side port of the swing directional control valve, and connect the bleed-off passage to the input side port of the directional control valve of the downstream actuator such as an arm cylinder or boom cylinder. , and a hydraulic excavator characterized in that the set pressure of the flow control valve with pressure compensation is set lower than the set pressure of the main relief valve of the pump and the set pressure of an overload relief valve provided in the swing circuit. hydraulic circuit.
JP2478681A 1981-02-20 1981-02-20 Oil-pressure circuit for oil-pressure shovel Granted JPS57140434A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2478681A JPS57140434A (en) 1981-02-20 1981-02-20 Oil-pressure circuit for oil-pressure shovel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2478681A JPS57140434A (en) 1981-02-20 1981-02-20 Oil-pressure circuit for oil-pressure shovel

Publications (2)

Publication Number Publication Date
JPS57140434A JPS57140434A (en) 1982-08-31
JPS6330452B2 true JPS6330452B2 (en) 1988-06-17

Family

ID=12147862

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2478681A Granted JPS57140434A (en) 1981-02-20 1981-02-20 Oil-pressure circuit for oil-pressure shovel

Country Status (1)

Country Link
JP (1) JPS57140434A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998012391A1 (en) * 1996-09-19 1998-03-26 Yanmar Diesel Engine Co., Ltd. Hydraulic circuit for turning excavator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2680300B2 (en) * 1986-07-29 1997-11-19 東芝機械株式会社 Hydraulic shovel hydraulic circuit
JP4838555B2 (en) * 2005-09-05 2011-12-14 株式会社渋彰建設 Hydraulic circuit, electric control circuit and hydraulic motor cutting device

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5774441A (en) * 1980-10-27 1982-05-10 Daikin Ind Ltd Construction machinery such as power shovel

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998012391A1 (en) * 1996-09-19 1998-03-26 Yanmar Diesel Engine Co., Ltd. Hydraulic circuit for turning excavator

Also Published As

Publication number Publication date
JPS57140434A (en) 1982-08-31

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