JPH0913430A - Control circuit of construction machine - Google Patents
Control circuit of construction machineInfo
- Publication number
- JPH0913430A JPH0913430A JP7160851A JP16085195A JPH0913430A JP H0913430 A JPH0913430 A JP H0913430A JP 7160851 A JP7160851 A JP 7160851A JP 16085195 A JP16085195 A JP 16085195A JP H0913430 A JPH0913430 A JP H0913430A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- flow rate
- pump
- load pressure
- hydraulic pump
- 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
Links
Landscapes
- Fluid-Pressure Circuits (AREA)
- Operation Control Of Excavators (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、油圧ショベル等の建設
機械に備えられ、複数のアクチュエータの中に、作動に
際して主油圧ポンプが吐出可能な最大流量よりも大きな
流量を必要とする特定アクチュエータを含むとともに、
複数のアクチュエータのそれぞれを制御する流量制御弁
に供給される流量を、油圧ポンプの吐出圧力と最大負荷
圧との差圧であるロードセンシング差圧に応じて制御す
るロードセンシングシステムを有する制御回路に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided in a construction machine such as a hydraulic excavator and includes, among a plurality of actuators, a specific actuator that requires a flow rate larger than the maximum flow rate that the main hydraulic pump can discharge during operation. Including
The present invention relates to a control circuit having a load sensing system that controls a flow rate supplied to a flow rate control valve that controls each of a plurality of actuators, according to a load sensing differential pressure that is a differential pressure between a discharge pressure of a hydraulic pump and a maximum load pressure. .
【０００２】[0002]
【従来の技術】図３は、この種の従来の建設機械の制御
回路の一例を示す回路図である。この図３に示す従来技
術は、例えば油圧ショベルに備えられるものであり、原
動機１と、主油圧ポンプを構成する可変容量油圧ポンプ
２と、この油圧ポンプ２から吐出される圧油によって駆
動する複数のアクチュエータ、例えば図示しないアーム
の先端にアタッチメントとして装着される破砕機を駆動
する油圧シリンダ６１、及び旋回モータ等の油圧モータ
６２などのアクチュエータと、これらのアクチュエータ
に対応して設けられ、該当するアクチュエータに供給さ
れる圧油の流れを制御する流量制御弁、例えば油圧シリ
ンダ６１を制御する流量制御弁５１、及び油圧モータ６
２を制御する流量制御弁５２などの流量制御弁とを備え
ている。なお、上述した油圧シリンダ６１は、油圧ポン
プ２の最大吐出可能流量よりも要求流量が大きく、負荷
圧が油圧モータ６２を含む他のアクチュエータよりも大
きくなる特定アクチュエータを構成している。2. Description of the Related Art FIG. 3 is a circuit diagram showing an example of a control circuit of a conventional construction machine of this type. The conventional technique shown in FIG. 3 is provided, for example, in a hydraulic excavator, and includes a prime mover 1, a variable displacement hydraulic pump 2 constituting a main hydraulic pump, and a plurality of hydraulic pumps driven by pressure oil discharged from the hydraulic pump 2. Actuators such as a hydraulic cylinder 61 for driving a crusher mounted as an attachment at the tip of an arm (not shown) and a hydraulic motor 62 such as a swing motor, and actuators provided corresponding to these actuators. Flow control valve for controlling the flow of pressure oil supplied to the cylinder, for example, a flow control valve 51 for controlling the hydraulic cylinder 61, and the hydraulic motor 6.
2 and a flow rate control valve such as a flow rate control valve 52 for controlling the control unit 2. The hydraulic cylinder 61 described above constitutes a specific actuator having a required flow rate higher than the maximum dischargeable flow rate of the hydraulic pump 2 and a load pressure higher than that of other actuators including the hydraulic motor 62.
【０００３】また、この従来技術は、上記アクチュエー
タのそれぞれに対応して設けられ、該当するアクチュエ
ータの負荷圧を検出する負荷圧検出管路、例えば油圧シ
リンダ６１の負荷圧ＰＬを検出する負荷圧検出管路３
０、及び油圧モータ６２の負荷圧を検出する負荷圧検出
管路３１などの負荷圧検出管路と、これらの負荷圧検出
管路の圧力のうちの最大負荷圧ＰＬｍａｘを取り出すシ
ャトル弁３２，３３と、シャトル弁３３で取り出された
最大負荷圧ＰＬｍａｘを導く最大負荷圧検出管路７０
と、油圧ポンプ２の吐出圧力ＰＳを検出するポンプ圧検
出管路８０とを備えている。なお、上記した負荷圧検出
管路３０は特定アクチュエータである油圧シリンダ６１
の負荷圧を検出する特定負荷圧検出管路を構成してい
る。Further, this prior art is provided corresponding to each of the above-mentioned actuators and detects a load pressure of a corresponding actuator, for example, a load pressure detection line for detecting a load pressure PL of a hydraulic cylinder 61. Pipeline 3
0 and the load pressure detection conduits such as the load pressure detection conduit 31 for detecting the load pressure of the hydraulic motor 62, and the shuttle valves 32, 33 for extracting the maximum load pressure PLmax of the pressures in these load pressure detection conduits. And a maximum load pressure detection conduit 70 that guides the maximum load pressure PLmax taken out by the shuttle valve 33.
And a pump pressure detection conduit 80 for detecting the discharge pressure PS of the hydraulic pump 2. The load pressure detection conduit 30 described above is provided in the hydraulic cylinder 61, which is a specific actuator.
A specific load pressure detection pipe line for detecting the load pressure of is configured.
【０００４】また、同図３に示すように、流量制御弁５
１，５２等のそれぞれに対応して設けられ、該当する流
量制御弁に係る負荷圧検出管路で導かれる負荷圧に応じ
て駆動し、該当する流量制御弁の上流側の圧力と下流側
の圧力との差である前後差圧を制御可能な圧力補償弁４
１，４２等とを備えている。油圧シリンダ６１を制御す
る流量制御弁５１に係る圧力補償弁４１は、上流圧検出
管路３４で導かれる流量制御弁５１の上流側の圧力と、
負荷圧検出管路３０で導かれる油圧シリンダ６１の負荷
圧ＰＬとの差である前後差圧が、ポンプ圧検出管路８０
で導かれる油圧ポンプ２の吐出圧力ＰＳと、最大負荷圧
検出管路７０で導かれる最大負荷圧ＰＬｍａｘとの差に
等しくなるように制御される。同様に、例えば油圧モー
タ６２を制御する流量制御弁５２に係る圧力補償弁４２
は、上流圧検出管路３５で導かれる流量制御弁５２の上
流側の圧力と、負荷圧検出管路３１で導かれる油圧モー
タ６２の負荷圧との差である前後差圧が、ポンプ圧検出
管路８０で導かれる油圧ポンプ２の吐出圧力ＰＳと、最
大負荷圧検出管路７０で導かれる最大負荷圧ＰＬｍａｘ
との差であるロードセンシング差圧Δに等しくなるよう
に制御される。すなわち、各圧力補償弁４１，４２等を
介して、該当する流量制御弁５１，５２等の前後差圧
が、共通のロードセンシング差圧Δ（＝ＰＳ−ＰＬｍａ
ｘ）によって制御されるようになっている。Further, as shown in FIG. 3, the flow control valve 5
1, 52, etc. are provided corresponding to each of the flow control valves, and are driven according to the load pressure guided by the load pressure detection pipes of the corresponding flow control valve, and the pressure on the upstream side and the pressure on the downstream side of the corresponding flow control valve are driven. Pressure compensating valve 4 capable of controlling the differential pressure across the pressure, which is the difference with the pressure
1, 42 and the like. The pressure compensating valve 41 related to the flow control valve 51 that controls the hydraulic cylinder 61 has a pressure on the upstream side of the flow control valve 51 that is guided by the upstream pressure detection conduit 34,
The differential pressure across the hydraulic cylinder 61, which is guided by the load pressure detection line 30, and the load pressure PL is a pump pressure detection line 80.
It is controlled so as to be equal to the difference between the discharge pressure PS of the hydraulic pump 2 which is introduced in step S4 and the maximum load pressure PLmax which is introduced in the maximum load pressure detection line 70. Similarly, for example, the pressure compensation valve 42 related to the flow control valve 52 that controls the hydraulic motor 62.
Is the difference between the pressure on the upstream side of the flow rate control valve 52 guided by the upstream pressure detection pipeline 35 and the load pressure of the hydraulic motor 62 guided by the load pressure detection pipeline 31. The discharge pressure PS of the hydraulic pump 2 guided by the pipeline 80 and the maximum load pressure PLmax guided by the maximum load pressure detection pipeline 70.
It is controlled so as to be equal to the load sensing differential pressure Δ which is the difference between and. That is, the differential pressure across the corresponding flow control valves 51, 52, etc., via the respective pressure compensating valves 41, 42, etc., becomes a common load sensing differential pressure Δ (= PS-PLma).
x).
【０００５】また、油圧ポンプ２の吐出管路２ｂにロー
ドセンシング差圧Δに応じて制御されるアンロード弁３
を備えているとともに、流量制御弁５１，５２等のそれ
ぞれに供給される流量を、ロードセンシング差圧Δに応
じて制御する流量制御手段、例えば油圧ポンプ２の傾転
量を制御し、ロードセンシング差圧Δが目標とする設定
差圧となるように、油圧ポンプ２の吐出流量Ｑを制御す
るレギュレータ２ａを備えている。図４は図３に示す従
来技術で得られる特性を示している。この図４に示すよ
うに、ロードセンシング差圧Δとポンプ吐出流量Ｑとの
相関関係を示す特性線９０は、右上がりの曲線となって
いる。また、ロードセンシング差圧Δの設定差圧に対応
するポンプ吐出流量をＱｐで示してある。レギュレータ
２ａは、例えば油圧ポンプ２の吐出圧力ＰＳにより油圧
ポンプ２の最大吐出流量を制御する定トルク制御をおこ
なうものである。Further, the unload valve 3 controlled in the discharge line 2b of the hydraulic pump 2 in accordance with the load sensing differential pressure Δ.
And the flow control means for controlling the flow rate supplied to each of the flow rate control valves 51, 52, etc. according to the load sensing differential pressure Δ, for example, the tilting amount of the hydraulic pump 2 to control the load sensing. A regulator 2a that controls the discharge flow rate Q of the hydraulic pump 2 is provided so that the differential pressure Δ becomes a target set differential pressure. FIG. 4 shows the characteristics obtained by the conventional technique shown in FIG. As shown in FIG. 4, the characteristic line 90 showing the correlation between the load sensing differential pressure Δ and the pump discharge flow rate Q is an upwardly rising curve. Further, the pump discharge flow rate corresponding to the set differential pressure of the load sensing differential pressure Δ is shown by Qp. The regulator 2a performs constant torque control for controlling the maximum discharge flow rate of the hydraulic pump 2 by the discharge pressure PS of the hydraulic pump 2, for example.
【０００６】この従来技術では、図示しない破砕機の単
独駆動時には、油圧ポンプ２の全量が圧力補償弁４１、
流量制御弁５１を介して特定アクチュエータである油圧
シリンダ６１に供給される。また、図示しない破砕機と
図示しない旋回体等の複合駆動時には、油圧ポンプ２の
吐出流量Ｑｐが該当する各圧力補償弁４１，４２等に分
流されて、各流量制御弁５１，５２等を介して油圧シリ
ンダ６１、油圧モータ６２等に供給される。In this prior art, when the crusher (not shown) is driven independently, the entire amount of the hydraulic pump 2 is the pressure compensating valve 41,
It is supplied to the hydraulic cylinder 61 which is a specific actuator via the flow control valve 51. Further, during combined driving of a crusher (not shown) and a revolving structure (not shown), the discharge flow rate Qp of the hydraulic pump 2 is diverted to the corresponding pressure compensating valves 41, 42, etc., and is passed through the flow rate control valves 51, 52, etc. Are supplied to the hydraulic cylinder 61, the hydraulic motor 62, and the like.
【０００７】なお、この種のロードセンシングシステム
を含む制御回路を備えた公知技術としては、例えば特開
昭６０−１１７０６号公報に記載のものがある。As a known technique having a control circuit including this type of load sensing system, for example, there is one disclosed in Japanese Patent Laid-Open No. 60-11706.
【０００８】[0008]
【発明が解決しようとする課題】上述の従来技術では、
油圧シリンダ６１の要求流量が油圧ポンプ２の最大可能
吐出流量よりも大きく、したがって、破砕機のみの単独
駆動に際し、油圧ポンプ２から最大の流量を油圧シリン
ダ６１に供給しても破砕機を望ましい作動速度で駆動し
得ない場合があり、破砕機を介しておこなわれる作業の
能率の向上を見込み難い問題がある。また、破砕機と他
の作業機等の複合操作にあっては、これがより著しくな
り、油圧シリンダ６１に供給される流量がさらに小さく
なることから、破砕機を介しておこなわれる作業の作業
性が低下しやすい。In the above-mentioned prior art,
The required flow rate of the hydraulic cylinder 61 is larger than the maximum possible discharge flow rate of the hydraulic pump 2. Therefore, when the crusher alone is driven, even if the maximum flow rate is supplied from the hydraulic pump 2 to the hydraulic cylinder 61, the crusher can be operated in a desirable manner. In some cases, it cannot be driven at a high speed, and there is a problem that it is difficult to expect improvement in the efficiency of the work performed through the crusher. Further, in the combined operation of the crusher and other work machines, this becomes more remarkable and the flow rate supplied to the hydraulic cylinder 61 is further reduced, so that the workability of the work performed through the crusher is improved. Easy to fall.
【０００９】なお、上述では特定アクチュエータを破砕
機を駆動する油圧シリンダ６１として説明したが、特定
アクチュエータが他の作業機を駆動するものであっても
同様の問題がある。Although the specific actuator has been described as the hydraulic cylinder 61 for driving the crusher, the same problem occurs even if the specific actuator drives another working machine.
【００１０】本発明は、上記した従来技術における実情
に鑑みてなされたもので、その第１の目的は、要求流量
が主油圧ポンプの最大可能吐出流量よりも大きな特定ア
クチュエータの単独操作時に、この特定アクチュエータ
に主油圧ポンプの吐出流量よりも大きな流量を供給する
ことができる建設機械の制御回路を提供することにあ
る。The present invention has been made in view of the above-mentioned circumstances in the prior art. A first object of the present invention is to operate the specific actuator independently when the required flow rate is larger than the maximum possible discharge flow rate of the main hydraulic pump. It is an object of the present invention to provide a control circuit for a construction machine capable of supplying a specific actuator with a flow rate larger than the discharge flow rate of a main hydraulic pump.
【００１１】また、第２の目的は、特定アクチュエータ
と、この特定アクチュエータの負荷圧よりも小さな負荷
圧となる他のアクチュエータとの複合操作時に、主油圧
ポンプの吐出流量よりも総和が大きくなる流量を各アク
チュエータに供給できるとともに、特定アクチュエータ
に流量を優先して供給できる建設機械の制御回路を提供
することにある。A second object is a flow rate whose total sum is larger than the discharge flow rate of the main hydraulic pump during a combined operation of the specific actuator and another actuator having a load pressure smaller than the load pressure of the specific actuator. It is to provide a control circuit for a construction machine that can supply each of the actuators with each other and can supply the flow rate to the specific actuator with priority.
【００１２】[0012]
【課題を解決するための手段】この目的を達成するため
に、本発明の請求項１に係る発明は、主油圧ポンプと、
この主油圧ポンプから吐出される圧油によって駆動する
複数のアクチュエータと、これらのアクチュエータに対
応して設けられ、該当するアクチュエータに供給される
圧油の流れを制御する流量制御弁と、上記アクチュエー
タのそれぞれに対応して設けられ、該当するアクチュエ
ータの負荷圧を検出する負荷圧検出管路と、これらの負
荷圧検出管路の圧力のうちの最大負荷圧を検出する最大
負荷圧検出管路と、上記主油圧ポンプの吐出圧を検出す
るポンプ圧検出管路と、上記流量制御弁のそれぞれに対
応して設けられ、該当する流量制御弁に係る負荷圧検出
管路で導かれる負荷圧に応じて駆動し、該当する流量制
御弁の上流側の圧力と下流側の圧力との差である前後差
圧を制御可能な圧力補償弁とを備えるとともに、上記複
数のアクチュエータが、上記主油圧ポンプが吐出可能な
最大流量よりも大きい流量を要求する特定アクチュエー
タを含み、上記流量制御弁のそれぞれに供給される流量
を、上記ポンプ圧検出管路によって導かれる上記主油圧
ポンプの吐出圧力と、上記最大負荷圧検出管路によって
導かれる最大負荷圧との差圧であるロードセンシング差
圧に応じて制御する流量制御手段とを備えた建設機械の
制御回路において、上記特定アクチュエータに係る特定
負荷圧検出管路に設けた抵抗要素と、補助ポンプと、こ
の補助ポンプの吐出流量を上記特定負荷圧検出管路の上
記抵抗要素の上流側に供給する補助管路とを備えた構成
にしてある。In order to achieve this object, the invention according to claim 1 of the present invention comprises a main hydraulic pump,
A plurality of actuators driven by pressure oil discharged from the main hydraulic pump, a flow control valve provided corresponding to these actuators for controlling the flow of pressure oil supplied to the corresponding actuators, A load pressure detection pipeline that is provided corresponding to each of the load pressures of the corresponding actuators, and a maximum load pressure detection pipeline that detects the maximum load pressure of the pressures of these load pressure detection pipelines, Depending on the load pressure guided by the pump pressure detection pipeline for detecting the discharge pressure of the main hydraulic pump and the flow control valve, which is provided in the load pressure detection pipeline associated with the corresponding flow control valve. A pressure compensation valve that is driven and is capable of controlling a front-back differential pressure that is a difference between the upstream pressure and the downstream pressure of the corresponding flow control valve; The main hydraulic pump includes a specific actuator that requires a flow rate larger than the maximum flow rate that the main hydraulic pump can discharge, and the flow rate supplied to each of the flow rate control valves is guided by the pump pressure detection conduit. Discharge pressure and a flow control means for controlling in accordance with a load sensing differential pressure which is a differential pressure between the maximum load pressure detected by the maximum load pressure detection pipe line and the specific actuator. A resistance element provided in the specific load pressure detection pipeline, an auxiliary pump, and an auxiliary pipeline that supplies the discharge flow rate of the auxiliary pump to the upstream side of the resistance element of the specific load pressure detection pipeline. It is configured.
【００１３】[0013]
【作用】本発明の請求項１に係る発明は、特定アクチュ
エータの単独操作時には、主油圧ポンプの最大吐出流量
が圧力補償弁、流量制御弁を介して特定アクチュエータ
に供給されるとともに、補助ポンプの流量が補助管路、
抵抗要素、特定負荷圧検出管路を介して特定アクチュエ
ータに供給される。すなわち、特定アクチュエータに
は、主油圧ポンプの最大吐出流量よりも総和が大きくな
る主油圧ポンプ、補助ポンプの合流流量が供給される。
これにより、特定アクチュエータの増速を実現できる。According to the first aspect of the present invention, when the specific actuator is operated independently, the maximum discharge flow rate of the main hydraulic pump is supplied to the specific actuator via the pressure compensation valve and the flow rate control valve, and the auxiliary pump is operated. Flow rate is an auxiliary line,
It is supplied to a specific actuator via a resistance element and a specific load pressure detection conduit. That is, the combined flow rate of the main hydraulic pump and the auxiliary pump whose sum is larger than the maximum discharge flow rate of the main hydraulic pump is supplied to the specific actuator.
As a result, it is possible to increase the speed of the specific actuator.
【００１４】また、特定アクチュエータと、この特定ア
クチュエータの負荷圧よりも小さな負荷圧となる他のア
クチュエータとの複合操作に際しては以下のように作用
する。 すなわち、特定負荷圧検出管路に設けた抵抗要
素を補助ポンプの流量が通過するときに圧損が生じる
が、この圧損が特定アクチュエータの負荷圧に加算さ
れ、特定負荷圧検出管路の圧力が負荷圧よりも高くな
り、これに伴って、最大負荷圧検出管路で検出される圧
力も特定アクチュエータの負荷圧に対応する最大負荷圧
よりも、前述の抵抗要素の圧損分だけ高くなる。この大
きくなった見かけ上の最大負荷圧により、ロードセンシ
ング差圧が一旦小さくなり、流量制御手段により、所定
の設定差圧を保持しようとして流量制御弁に供給される
流量を増量させる制御がおこなわれる。したがって、特
定アクチュエータと他のアクチュエータに供給される流
量の総和は、増量させた流量制御弁への供給流量と、補
助ポンプの流量との合流流量となる。また、このとき特
定負荷圧検出管路の圧力が特定アクチュエータの負荷圧
よりも高くなることから、特定アクチュエータを駆動す
る流量制御弁を制御する圧力補償弁の制御部に、特定負
荷圧検出管路を介して特定アクチュエータの負荷圧より
も高い圧力が与えられ、他のアクチュエータに係る圧力
補償弁の制御部には自己の負荷圧検出管路を介して、特
定アクチュエータの負荷圧よりも小さな自己の負荷圧が
与えられる。したがって、特定アクチュエータに係る圧
力補償弁は、他のアクチュエータに係る圧力補償弁より
も開口量が大きくなるように制御される。これにより、
特定アクチュエータに他のアクチュエータに比べて優先
して大きな流量を供給する複合操作を実現できる。Further, in the combined operation of the specific actuator and another actuator having a load pressure smaller than the load pressure of the specific actuator, the following operation is performed. That is, pressure loss occurs when the flow rate of the auxiliary pump passes through the resistance element provided in the specific load pressure detection pipeline, but this pressure loss is added to the load pressure of the specific actuator, and the pressure in the specific load pressure detection pipeline is changed to the load. The pressure becomes higher than the pressure, and accordingly, the pressure detected by the maximum load pressure detecting conduit also becomes higher than the maximum load pressure corresponding to the load pressure of the specific actuator by the pressure loss of the resistance element. Due to this increased apparent maximum load pressure, the load sensing differential pressure is once reduced, and the flow rate control means controls to increase the flow rate supplied to the flow rate control valve in order to maintain a predetermined set differential pressure. . Therefore, the sum of the flow rates supplied to the specific actuator and the other actuators is the combined flow rate of the increased flow rate of the flow rate control valve and the flow rate of the auxiliary pump. Further, at this time, since the pressure in the specific load pressure detection pipe becomes higher than the load pressure of the specific actuator, the control unit of the pressure compensation valve that controls the flow control valve that drives the specific actuator is connected to the specific load pressure detection pipe. A pressure higher than the load pressure of the specific actuator is given through the control unit of the pressure compensating valve related to the other actuator, and the control unit of the pressure compensating valve related to the other actuator is controlled by the control unit of the load pressure detecting line of its own. Load pressure is applied. Therefore, the pressure compensating valve related to the specific actuator is controlled to have a larger opening amount than the pressure compensating valve related to the other actuators. This allows
It is possible to realize a composite operation in which a specific actuator is preferentially supplied with a larger flow rate than other actuators.
【００１５】[0015]
【実施例】以下、本発明の建設機械の制御回路の実施例
を図に基づいて説明する。図１は本発明の建設機械の制
御回路の請求項１，２，３，４，５に係る発明に相当す
る一実施例を示す回路図である。図２は図１に示す実施
例で得られる特性を示す図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a control circuit for a construction machine according to the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment corresponding to the invention according to claims 1, 2, 3, 4, and 5 of a control circuit for a construction machine of the present invention. FIG. 2 is a diagram showing the characteristics obtained in the embodiment shown in FIG.
【００１６】図１は前述した図３に対応させて描いたも
のであり、油圧ショベルに適用させた実施例を示してい
る。この図１において前述した図３に示したものと同等
のものは、同じ符号で示してある。すなわち、この図１
に示す実施例にあっても、原動機１と、主油圧ポンプを
構成する可変容量油圧ポンプ２と、複数のアクチュエー
タ、例えば破砕機を駆動する油圧シリンダ６１、及び旋
回モータ等の油圧モータ６２などのアクチュエータと、
これらのアクチュエータに対応して設けた流量制御弁、
例えば油圧シリンダ６１を制御する流量制御弁５１、及
び油圧モータ６２を制御する流量制御弁５２などの流量
制御弁とを備えている。なお、油圧シリンダ６１は、油
圧ポンプ２の最大吐出可能流量よりも要求流量が大き
く、負荷圧が油圧モータ６２を含む他のアクチュエータ
よりも大きくなる特定アクチュエータを構成している。FIG. 1 is drawn corresponding to FIG. 3 described above, and shows an embodiment applied to a hydraulic excavator. In FIG. 1, the same components as those shown in FIG. 3 described above are designated by the same reference numerals. That is, this FIG.
In the embodiment shown in FIG. 1, the prime mover 1, the variable displacement hydraulic pump 2 constituting the main hydraulic pump, the plurality of actuators such as the hydraulic cylinder 61 driving the crusher, and the hydraulic motor 62 such as a swing motor are also included. An actuator,
Flow control valves provided corresponding to these actuators,
For example, a flow control valve 51 that controls the hydraulic cylinder 61 and a flow control valve such as a flow control valve 52 that controls the hydraulic motor 62 are provided. The hydraulic cylinder 61 constitutes a specific actuator whose required flow rate is larger than the maximum dischargeable flow rate of the hydraulic pump 2 and whose load pressure is larger than that of other actuators including the hydraulic motor 62.
【００１７】また、該当するアクチュエータの負荷圧を
検出する負荷圧検出管路、例えば油圧シリンダ６１の負
荷圧ＰＬを検出する負荷圧検出管路３０、及び油圧モー
タ６２の負荷圧を検出する負荷圧検出管路３１などの負
荷圧検出管路と、これらの負荷圧検出管路３０，３１等
の圧力のうちの最大負荷圧αＰＬｍａｘを取り出すシャ
トル弁３２，３３と、シャトル弁３３で取り出された最
大負荷圧αＰＬｍａｘを導く最大負荷圧検出管路７０
と、油圧ポンプ２の吐出圧力ＰＳを検出するポンプ圧検
出管路８０とを備えている。なお、上記した負荷圧検出
管路３０は特定アクチュエータである油圧シリンダ６１
の負荷圧を検出する特定負荷圧検出管路を構成してい
る。Further, a load pressure detecting conduit for detecting the load pressure of the corresponding actuator, for example, a load pressure detecting conduit 30 for detecting the load pressure PL of the hydraulic cylinder 61, and a load pressure for detecting the load pressure of the hydraulic motor 62. The load pressure detection pipes such as the detection pipe 31 and the shuttle valves 32 and 33 that take out the maximum load pressure αPLmax of the pressures of the load pressure detection pipes 30 and 31 and the maximum that is taken out by the shuttle valve 33. Maximum load pressure detection line 70 that guides the load pressure αPLmax
And a pump pressure detection conduit 80 for detecting the discharge pressure PS of the hydraulic pump 2. The load pressure detection conduit 30 described above is provided in the hydraulic cylinder 61, which is a specific actuator.
A specific load pressure detection pipe line for detecting the load pressure of is configured.
【００１８】また、同図１に示すように、該当する流量
制御弁に係る負荷圧検出管路で導かれる負荷圧に応じて
駆動し、該当する流量制御弁の上流側の圧力と下流側の
圧力との差圧である前後差圧を制御可能な圧力補償弁４
１，４２等とを備えている。油圧シリンダ６１を制御す
る流量制御弁５１に係る圧力補償弁４１は、上流圧検出
管路３４で導かれる流量制御弁５１の上流側の圧力と、
負荷圧検出管路３０で導かれる油圧シリンダ６１の負荷
圧ＰＬとの差圧である前後差圧が、ポンプ圧検出管路８
０で導かれる油圧ポンプ２の吐出圧力ＰＳと、最大負荷
圧検出管路７０で導かれる最大負荷圧αＰＬｍａｘとの
差圧に等しくなるように制御される。同様に、例えば油
圧モータ６２を制御する流量制御弁５２に係る圧力補償
弁４２は、上流圧検出管路３５で導かれる流量制御弁５
２の上流側の圧力と、負荷圧検出管路３１で導かれる油
圧モータ６２の負荷圧との差である前後差圧が、ポンプ
圧検出管路８０で導かれる油圧ポンプ２のポンプ圧ＰＳ
と、最大負荷圧検出管路７０で導かれる最大負荷圧αＰ
Ｌｍａｘとの差圧であるロードセンシング差圧αΔに等
しくなるように制御される。すなわち、各圧力補償弁４
１，４２等を介して、該当する流量制御弁５１，５２等
の前後差圧が、共通のロードセンシング差圧αΔ（＝Ｐ
Ｓ−αＰＬｍａｘ）によって制御されるようになってい
る。Further, as shown in FIG. 1, the drive is performed in accordance with the load pressure introduced in the load pressure detection pipe of the corresponding flow control valve, and the pressure on the upstream side and the pressure on the downstream side of the corresponding flow control valve are driven. Pressure compensating valve 4 that can control the differential pressure across the pressure, which is the differential pressure
1, 42 and the like. The pressure compensating valve 41 related to the flow control valve 51 that controls the hydraulic cylinder 61 has a pressure on the upstream side of the flow control valve 51 that is guided by the upstream pressure detection conduit 34,
The differential pressure between the front and rear, which is the differential pressure from the load pressure PL of the hydraulic cylinder 61 guided by the load pressure detection pipeline 30, is the pump pressure detection pipeline 8.
It is controlled so as to be equal to the differential pressure between the discharge pressure PS of the hydraulic pump 2 that is guided by 0 and the maximum load pressure αPLmax that is guided by the maximum load pressure detection conduit 70. Similarly, for example, the pressure compensating valve 42 related to the flow rate control valve 52 that controls the hydraulic motor 62 includes the flow rate control valve 5 that is guided by the upstream pressure detection conduit 35.
2 is the difference between the pressure on the upstream side of 2 and the load pressure of the hydraulic motor 62 guided by the load pressure detection conduit 31, the pump pressure PS of the hydraulic pump 2 guided by the pump pressure detection conduit 80.
And the maximum load pressure αP guided by the maximum load pressure detection line 70
It is controlled so as to be equal to the load sensing differential pressure αΔ which is the differential pressure from Lmax. That is, each pressure compensation valve 4
1, 42, etc., the differential pressure across the flow control valves 51, 52, etc. corresponding to the common load sensing differential pressure αΔ (= P
S-αPLmax).
【００１９】また、油圧ポンプ２の吐出管路２ｂにロー
ドセンシング差圧αΔに応じて制御されるアンロード弁
３を備えているとともに、流量制御弁５１，５２等のそ
れぞれに供給される流量を、ロードセンシング差圧αΔ
に応じて制御する流量制御手段、例えば油圧ポンプ２の
傾転量を制御し、ロードセンシング差圧αΔが目標とす
る設定差圧となるように、油圧ポンプ２の吐出流量Ｑを
制御するレギュレータ２ａを備えている。このレギュレ
ータ２ａは、例えば吐出圧力ＰＳにより油圧ポンプ２の
最大吐出流量を制御する定トルク制御をおこなうもので
ある。Further, the discharge line 2b of the hydraulic pump 2 is provided with an unload valve 3 controlled according to the load sensing differential pressure αΔ, and the flow rate supplied to each of the flow rate control valves 51, 52 and the like is controlled. , Load sensing differential pressure αΔ
Flow rate control means for controlling the displacement amount of the hydraulic pump 2, for example, a regulator 2a that controls the displacement amount of the hydraulic pump 2 and controls the discharge flow rate Q of the hydraulic pump 2 so that the load sensing differential pressure αΔ becomes a target set differential pressure. Is equipped with. The regulator 2a performs constant torque control for controlling the maximum discharge flow rate of the hydraulic pump 2 by the discharge pressure PS, for example.
【００２０】以上の構成については、前述した図３に示
したものとほぼ同等である。The above structure is almost the same as that shown in FIG.
【００２１】そして特に、本実施例では、特定負荷圧検
出管路を構成する負荷圧検出管路３０に圧損ＰＰを生じ
させる抵抗要素、例えば絞り１０６を設けるとともに、
原動機１により油圧ポンプ２と同期して駆動する補助ポ
ンプ１００を設け、この補助ポンプ１００から吐出され
る流量Ｑｓを、上述した負荷圧検出管路３０の絞り１０
６の上流側に供給する補助管路１０４を設けてある。ま
た、補助管路１０４には、補助ポンプ１００方向への圧
油の逆流を防止する逆止弁１０５を設けてあるととも
に、補助ポンプ圧検出管路１０２を介して導かれる補助
ポンプ圧、すなわち絞り１０６の上流圧と、負荷圧検出
管路１０３を介して導かれる油圧シリンダ６１の負荷圧
ＰＬ、すなわち絞り１０６の下流圧との差圧（絞り１０
６の圧損ＰＰ）に応じて制御される補助ポンプ用アンロ
ード弁１０１を設けてある。In particular, in this embodiment, the load pressure detection conduit 30 constituting the specific load pressure detection conduit is provided with a resistance element, such as a throttle 106, which causes a pressure loss PP, and
An auxiliary pump 100 that is driven by the prime mover 1 in synchronization with the hydraulic pump 2 is provided, and the flow rate Qs discharged from the auxiliary pump 100 is determined by the throttle 10 of the load pressure detection conduit 30 described above.
An auxiliary pipe line 104 is provided to supply the upstream side of No. 6. In addition, the auxiliary pipe 104 is provided with a check valve 105 for preventing the backflow of the pressure oil toward the auxiliary pump 100, and the auxiliary pump pressure introduced through the auxiliary pump pressure detection pipe 102, that is, the throttle. The pressure difference between the upstream pressure of 106 and the load pressure PL of the hydraulic cylinder 61 guided via the load pressure detection pipe 103, that is, the downstream pressure of the throttle 106 (throttle 10
An unload valve 101 for an auxiliary pump, which is controlled according to the pressure loss PP of No. 6, is provided.
【００２２】このように構成した実施例では、要求流量
が主油圧ポンプである油圧ポンプ２の最大可能吐出流量
よりも大きい特定アクチュエータ、すなわち図示しない
破砕機を駆動する油圧シリンダ６１の単独操作時には、
流量制御弁５１の切換えに伴って、油圧ポンプ２の吐出
流量が圧力補償弁４１、流量制御弁５１を介して油圧シ
リンダ６１に供給されるとともに、補助ポンプ１００の
流量Ｑｓが、補助管路１０４、逆止弁１０５、絞り１０
６を介して負荷圧検出管路３０に供給され、さらに流量
制御弁５１を介して油圧シリンダ６１に供給される。す
なわち、油圧シリンダ６１には、油圧ポンプ２の最大吐
出流量よりも大きい油圧ポンプ２、補助ポンプ１００の
合流流量が供給される。これにより、油圧シリンダ６１
の増速を実現させることができる。In the embodiment thus constructed, when the specific actuator whose required flow rate is larger than the maximum possible discharge flow rate of the hydraulic pump 2 which is the main hydraulic pump, that is, the hydraulic cylinder 61 for driving the crusher (not shown) is operated independently,
With the switching of the flow rate control valve 51, the discharge flow rate of the hydraulic pump 2 is supplied to the hydraulic cylinder 61 via the pressure compensation valve 41 and the flow rate control valve 51, and the flow rate Qs of the auxiliary pump 100 is changed to the auxiliary pipeline 104. , Check valve 105, throttle 10
It is supplied to the load pressure detection conduit 30 via 6 and is further supplied to the hydraulic cylinder 61 via the flow control valve 51. That is, the combined flow rate of the hydraulic pump 2 and the auxiliary pump 100, which is larger than the maximum discharge flow rate of the hydraulic pump 2, is supplied to the hydraulic cylinder 61. As a result, the hydraulic cylinder 61
It is possible to increase the speed.
【００２３】また、特定アクチュエータである油圧シリ
ンダ６１と、この油圧シリンダ６１の負荷圧ＰＬよりも
小さな負荷圧である図示しない旋回体を駆動する旋回モ
ータ６２、あるいは図示しない他のアクチュエータとの
複合操作に際しては以下のようになる。Further, a combined operation of the hydraulic cylinder 61 which is a specific actuator and a swing motor 62 which drives a swing body (not shown) having a load pressure smaller than the load pressure PL of the hydraulic cylinder 61 or another actuator (not shown) In that case, it is as follows.
【００２４】すなわち、特定負荷圧検出管路を構成する
負荷圧検出管路３０に設けた絞り１０６を、補助ポンプ
１００の流量が通過するときに圧損ＰＰが生じるが、こ
の圧損ＰＰが油圧シリンダ６１の負荷圧ＰＬに加算さ
れ、負荷圧検出管路３０の圧力が負荷圧ＰＬよりも高く
なる（ＰＬ＋ＰＰ）。この圧力（ＰＬ＋ＰＰ）が、シャ
トル弁３２，３３を介して取り出され、最大負荷圧αＰ
Ｌｍａｘ（＝ＰＬ＋ＰＰ）として最大負荷圧検出管路７
０に導かれる。前述した最大負荷圧ＰＬｍａｘ（このよ
うな複合操作時にはＰＬに等しい）よりも絞り１０６の
圧損ＰＰ分だけ最大負荷圧が大きくなったことから、一
旦ロードセンシング差圧αΔが小さくなり（αΔ＝ＰＳ
−αＰＬｍａｘ）、レギュレータ２ａは、ロードセンシ
ングαΔを所定の設定差圧とするように油圧ポンプ２の
吐出量を増加させるように駆動する。図２に示す特性図
は、このときのロードセンシング差圧αΔと油圧ポンプ
２の吐出流量Ｑとの相関関係を示している。同図２中、
特性線９０は前述した図４に示した特性線であり、例え
ば油圧シリンダ６１を除く他のアクチュエータの複合操
作に活用される。今のように、油圧シリンダ６１と他の
アクチュエータの複合操作時には、絞り１０６の圧損Ｐ
Ｐにより、上述のように増加した吐出流量αＱｐの得ら
れる特性線９１となる。したがって、油圧シリンダ６１
と他のアクチュエータに供給される流量の総和は、同図
２の特性線９２で示される油圧ポンプ２の増加した吐出
流量αＱｐと、補助ポンプ１００の流量Ｑｓの合流流量
（αＱｐ＋Ｑｓ）となる。That is, when the flow rate of the auxiliary pump 100 passes through the throttle 106 provided in the load pressure detection conduit 30 which constitutes the specific load pressure detection conduit, a pressure loss PP is generated. This pressure loss PP is caused by the hydraulic cylinder 61. Is added to the load pressure PL, and the pressure in the load pressure detection conduit 30 becomes higher than the load pressure PL (PL + PP). This pressure (PL + PP) is taken out via the shuttle valves 32 and 33, and the maximum load pressure αP
Maximum load pressure detection line 7 as Lmax (= PL + PP)
Lead to zero. Since the maximum load pressure is increased by the pressure loss PP of the throttle 106 than the maximum load pressure PLmax (equal to PL in such a composite operation) described above, the load sensing differential pressure αΔ is once decreased (αΔ = PS.
-ΑPLmax), the regulator 2a is driven so as to increase the discharge amount of the hydraulic pump 2 so that the load sensing αΔ becomes a predetermined set differential pressure. The characteristic diagram shown in FIG. 2 shows the correlation between the load sensing differential pressure αΔ and the discharge flow rate Q of the hydraulic pump 2 at this time. In FIG.
The characteristic line 90 is the characteristic line shown in FIG. 4 described above, and is utilized for composite operation of other actuators except the hydraulic cylinder 61, for example. As described above, when the hydraulic cylinder 61 and another actuator are combined, the pressure loss P of the throttle 106 is reduced.
With P, a characteristic line 91 is obtained in which the discharge flow rate αQp increased as described above. Therefore, the hydraulic cylinder 61
And the sum of the flow rates supplied to the other actuators are the combined flow rate (αQp + Qs) of the increased discharge flow rate αQp of the hydraulic pump 2 and the flow rate Qs of the auxiliary pump 100, which is indicated by the characteristic line 92 in FIG.
【００２５】また、このとき、油圧シリンダ６１に係る
負荷圧検出管路３０の圧力は、前述のように負荷圧ＰＬ
よりも絞り１０６の圧損ＰＰだけ高い圧力（ＰＬ＋Ｐ
Ｐ）であり、油圧シリンダ６１に係る圧力補償弁４１の
制御部には流量制御弁５１の下流圧として、この圧力
（ＰＬ＋ＰＰ）が供給され、他のアクチュエータである
油圧モータ６２に係る流量制御弁５２の制御部には流量
制御弁５２の下流圧として、油圧シリンダ６１の負荷圧
ＰＬよりも小さい油圧モータ６２の負荷圧が与えられ
る。したがって、油圧シリンダ６１に係る圧力補償弁４
１は、油圧モータ６２に係る圧力補償弁４２に比べて開
口量が大きくなるように制御される。これにより、上述
した合流流量の分流に際して、圧力補償弁４１側に、よ
り大きい流量が優先して供給され、油圧シリンダ６１に
比較的大きな流量が供給される。すなわち、油圧シリン
ダ６１のある程度の作動速度を確保した複合操作を実現
させることができる。At this time, the pressure in the load pressure detecting conduit 30 relating to the hydraulic cylinder 61 is equal to the load pressure PL as described above.
The pressure (PL + P
P), and this pressure (PL + PP) is supplied as the downstream pressure of the flow control valve 51 to the control portion of the pressure compensation valve 41 related to the hydraulic cylinder 61, and the flow control valve related to the hydraulic motor 62 that is another actuator. A load pressure of the hydraulic motor 62, which is smaller than the load pressure PL of the hydraulic cylinder 61, is applied to the control unit 52 as the downstream pressure of the flow control valve 52. Therefore, the pressure compensation valve 4 related to the hydraulic cylinder 61
1 is controlled so that the opening amount is larger than that of the pressure compensation valve 42 related to the hydraulic motor 62. As a result, in dividing the combined flow rate described above, a larger flow rate is preferentially supplied to the pressure compensating valve 41 side, and a relatively large flow rate is supplied to the hydraulic cylinder 61. That is, it is possible to realize a composite operation that secures a certain operating speed of the hydraulic cylinder 61.
【００２６】このように構成した実施例にあっては、特
定アクチュエータである油圧シリンダ６１の単独操作に
際しては、この油圧シリンダ６１に油圧ポンプ２の流量
よりも大きな流量を供給でき、油圧シリンダ６１を増速
させて図示しない破砕機を速く作動させ、その作業能率
を向上させることができる。In the embodiment thus constructed, when the hydraulic cylinder 61, which is a specific actuator, is operated independently, a larger flow rate than that of the hydraulic pump 2 can be supplied to the hydraulic cylinder 61. By increasing the speed, the crusher (not shown) can be operated quickly, and the work efficiency can be improved.
【００２７】また、油圧シリンダ６１と他のアクチュエ
ータとの複合操作に際しては、油圧ポンプ２の吐出流量
を増加させることにより大きな合流流量を各アクチュエ
ータに供給できるとともに、他のアクチュエータよりも
油圧シリンダ６１に流量を優先して供給でき、この油圧
シリンダ６１のある程度の速い作動速度を確保した複合
操作を実現させることができ、破砕機と、旋回体の旋回
等を含む他の作業機の複合駆動にあたって、破砕機によ
る良好な作業能率を得ることができる。Further, in the combined operation of the hydraulic cylinder 61 and other actuators, a large combined flow rate can be supplied to each actuator by increasing the discharge flow rate of the hydraulic pump 2, and the hydraulic cylinder 61 can be supplied to the hydraulic cylinder 61 more than other actuators. It is possible to supply the flow rate preferentially, realize a composite operation that secures a certain high operating speed of the hydraulic cylinder 61, and perform a combined drive of the crusher and another working machine including the swinging of the swing body, Good work efficiency with a crusher can be obtained.
【００２８】なお、上記実施例では特定アクチュエータ
として、破砕機を駆動する油圧シリンダ６１を挙げた
が、本発明はこのような油圧シリンダ６１には限定され
ず、各種の作業機を駆動するアクチュエータに適用可能
である。Although the hydraulic cylinder 61 for driving the crusher is given as the specific actuator in the above embodiment, the present invention is not limited to such a hydraulic cylinder 61, but may be applied to an actuator for driving various working machines. Applicable.
【００２９】また、上記実施例では、負荷圧検出管路３
０に抵抗を付与する抵抗要素として、絞り１０６を挙げ
たが、この絞り１０６に代えて、負荷圧検出管路３０の
一部の管径を抵抗を付与し得る程度に小さく設定する構
成にしてもよい。Further, in the above embodiment, the load pressure detecting conduit 3
As the resistance element that gives resistance to 0, the throttle 106 has been described. However, instead of the throttle 106, a part of the load pressure detection pipe line 30 is configured to have a small diameter so as to give resistance. Good.
【００３０】また、上記実施例では、適用される建設機
械として油圧ショベルを挙げたが、本発明は、この油圧
ショベルに適用することに限られない。要求流量が主油
圧ポンプの最大可能吐出流量よりも大きい特定クアチュ
エータを有し、基本的に主油圧ポンプの吐出圧力が最大
負荷圧よりも目標とする設定差圧だけ大きくなるよう
に、流量制御弁に供給される流量を制御するロードセン
シングシステムを有する建設機械であれば適用可能であ
る。Further, in the above embodiment, the hydraulic excavator was mentioned as the construction machine to be applied, but the present invention is not limited to the application to this hydraulic excavator. Flow control so that the required flow rate is higher than the maximum possible discharge flow rate of the main hydraulic pump, and the discharge pressure of the main hydraulic pump is basically higher than the maximum load pressure by the target set pressure difference. It is applicable to any construction machine having a load sensing system that controls the flow rate supplied to the valve.
【００３１】[0031]
【発明の効果】本発明は以上のように構成してあるの
で、要求流量が主油圧ポンプの最大可能吐出流量よりも
大きな特定アクチュエータの単独操作時に、この特定ア
クチュエータに主油圧ポンプの最大吐出可能流量よりも
大きな流量を供給でき、従来技術に比べて特定アクチュ
エータを増速させてこの特定アクチュエータで駆動する
作業機等を速く作動させ、その作業能率を従来よりも向
上させることができる。Since the present invention is configured as described above, the maximum discharge of the main hydraulic pump can be made to this specific actuator when the specific actuator whose required flow rate is larger than the maximum possible discharge flow of the main hydraulic pump is operated independently. A flow rate larger than the flow rate can be supplied, the specific actuator can be accelerated and the working machine or the like driven by the specific actuator can be operated faster than in the prior art, and the work efficiency can be improved as compared with the related art.
【００３２】また、特定アクチュエータと、この特定ア
クチュエータの負荷圧よりも小さな負荷圧となる他のア
クチュエータとの複合操作時に、主油圧ポンプの吐出流
量よりも総和が大きくなる流量を各アクチュエータに供
給できるとともに、特定アクチュエータに流量を優先し
て供給でき、特定のアクチュエータのある程度の速い作
動速度を確保した複合操作を実現させることができ、他
のアクチュエータよりも特定のアクチュエータで駆動す
る作業機等と、他のアクチュエータで駆動する他の作業
機等の複合駆動にあたって、特定のアクチュエータで駆
動する作業機等の良好な作業能率を得ることができる。Further, in a combined operation of a specific actuator and another actuator having a load pressure smaller than the load pressure of this specific actuator, a flow rate whose total sum is larger than the discharge flow rate of the main hydraulic pump can be supplied to each actuator. At the same time, the flow rate can be preferentially supplied to the specific actuator, and it is possible to realize a composite operation that secures a certain high operating speed of the specific actuator, and a work machine that is driven by the specific actuator more than other actuators, In composite driving of other working machines driven by other actuators, good working efficiency of working machines driven by specific actuators can be obtained.
【図１】本発明の建設機械の制御回路の一実施例を示す
回路図である。FIG. 1 is a circuit diagram showing an embodiment of a control circuit for a construction machine according to the present invention.
【図２】図１に示す実施例で得られる特性を示す図であ
る。FIG. 2 is a diagram showing characteristics obtained in the embodiment shown in FIG.
【図３】従来の建設機械の制御回路の一例を示す回路図
である。FIG. 3 is a circuit diagram showing an example of a control circuit of a conventional construction machine.
【図４】図３に示す従来例で得られる特性を示す図であ
る。FIG. 4 is a diagram showing characteristics obtained in the conventional example shown in FIG.
１ 原動機 ２ 可変容量油圧ポンプ（主油圧ポンプ） ２ａ レギュレータ（流量制御手段） ２ｂ 吐出管路 ３ 主ポンプ用アンロード弁 ３０ 負荷圧検出管路 ４１ 圧力補償弁 ４２ 圧力補償弁 ５１ 流量制御弁 ５２ 流量制御弁 ６１ 油圧シリンダ（特定アクチュエータ） ６２ 油圧モータ ７０ 最大負荷圧検出管路 ８０ ポンプ圧検出管路 １００ 補助ポンプ １０１ 補助ポンプ用アンロード弁 １０２ 補助ポンプ圧検出管路 １０３ 負荷圧検出管路 １０４ 補助管路 １０５ 逆止弁 １０６ 絞り（抵抗要素） 1 prime mover 2 variable displacement hydraulic pump (main hydraulic pump) 2a regulator (flow rate control means) 2b discharge line 3 main pump unload valve 30 load pressure detection line 41 pressure compensation valve 42 pressure compensation valve 51 flow control valve 52 flow rate Control valve 61 Hydraulic cylinder (specific actuator) 62 Hydraulic motor 70 Maximum load pressure detection conduit 80 Pump pressure detection conduit 100 Auxiliary pump 101 Auxiliary pump unload valve 102 Auxiliary pump pressure detection conduit 103 Load pressure detection conduit 104 Auxiliary Pipe line 105 Check valve 106 Throttle (resistive element)
Claims (5)
吐出される圧油によって駆動する複数のアクチュエータ
と、これらのアクチュエータに対応して設けられ、該当
するアクチュエータに供給される圧油の流れを制御する
流量制御弁と、 上記アクチュエータのそれぞれに対応して設けられ、該
当するアクチュエータの負荷圧を検出する負荷圧検出管
路と、これらの負荷圧検出管路の圧力のうちの最大負荷
圧を検出する最大負荷圧検出管路と、上記主油圧ポンプ
の吐出圧を検出するポンプ圧検出管路と、 上記流量制御弁のそれぞれに対応して設けられ、該当す
る流量制御弁に係る負荷圧検出管路で導かれる負荷圧に
応じて駆動し、該当する流量制御弁の上流側の圧力と下
流側の圧力との差である前後差圧を制御可能な圧力補償
弁とを備えるとともに、 上記複数のアクチュエータが、上記主油圧ポンプが吐出
可能な最大流量よりも大きい流量を要求する特定アクチ
ュエータを含み、 上記流量制御弁のそれぞれに供給される流量を、上記ポ
ンプ圧検出管路によって導かれる上記主油圧ポンプの吐
出圧力と、上記最大負荷圧検出管路によって導かれる最
大負荷圧との差圧であるロードセンシング差圧に応じて
制御する流量制御手段とを備えた建設機械の制御回路に
おいて、 上記特定アクチュエータに係る特定負荷圧検出管路に設
けた抵抗要素と、 補助ポンプと、 この補助ポンプの吐出流量を上記特定負荷圧検出管路の
上記抵抗要素の上流側に供給する補助管路とを備えたこ
とを特徴とする建設機械の制御回路。1. A main hydraulic pump, a plurality of actuators driven by the pressure oil discharged from the main hydraulic pump, and a flow of the pressure oil provided corresponding to these actuators and supplied to the corresponding actuators. A flow rate control valve to be controlled, a load pressure detection pipe which is provided corresponding to each of the above actuators, and which detects the load pressure of the corresponding actuator, and the maximum load pressure of the pressures in these load pressure detection pipes. The maximum load pressure detection pipeline for detection, the pump pressure detection pipeline for detecting the discharge pressure of the main hydraulic pump, and the flow control valve are provided corresponding to the load pressure detection for the relevant flow control valve. A pressure compensating valve that is driven according to a load pressure guided by a pipe line and that can control a differential pressure across the flow rate control valve, which is a difference between an upstream pressure and a downstream pressure, is provided. In addition, the plurality of actuators include a specific actuator that requires a flow rate larger than the maximum flow rate that the main hydraulic pump can discharge, and the flow rate supplied to each of the flow rate control valves is determined by the pump pressure detection pipeline. Of the discharge pressure of the main hydraulic pump guided by the flow rate control means for controlling according to the load sensing differential pressure which is the differential pressure between the maximum load pressure guided by the maximum load pressure detection conduit In the control circuit, the resistance element provided in the specific load pressure detection conduit relating to the specific actuator, the auxiliary pump, and the discharge flow rate of the auxiliary pump are supplied to the upstream side of the resistance element in the specific load pressure detection conduit. A control circuit for a construction machine, comprising: an auxiliary pipeline.
であるとともに、上記流量制御手段が、上記可変容量油
圧ポンプの傾転量を制御するレギュレータであることを
特徴とする請求項１記載の建設機械の制御回路。2. The construction according to claim 1, wherein the main hydraulic pump is a variable displacement hydraulic pump, and the flow rate control means is a regulator for controlling a tilt amount of the variable displacement hydraulic pump. Machine control circuit.
ードセンシング差圧に応じて駆動する主ポンプ用アンロ
ード弁を設けるとともに、上記補助管路に補助ポンプ用
アンロード弁を設けたことを特徴とする請求項１または
２記載の建設機械の制御回路。3. An unload valve for the main pump, which is driven according to the load sensing differential pressure, is provided in the discharge line of the main hydraulic pump, and an unload valve for the auxiliary pump is provided in the auxiliary line. The control circuit for a construction machine according to claim 1 or 2, characterized in that:
する請求項１〜３のいずれかに記載の建設機械の制御回
路。4. The control circuit for a construction machine according to claim 1, wherein the resistance element is a diaphragm.
徴とする請求項１〜４のいずれかに記載の建設機械の制
御回路。5. The construction machine control circuit according to claim 1, wherein the construction machine is a hydraulic excavator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16085195A JP3600316B2 (en) | 1995-06-27 | 1995-06-27 | Construction machine control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16085195A JP3600316B2 (en) | 1995-06-27 | 1995-06-27 | Construction machine control circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0913430A true JPH0913430A (en) | 1997-01-14 |
| JP3600316B2 JP3600316B2 (en) | 2004-12-15 |
Family
ID=15723777
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16085195A Expired - Fee Related JP3600316B2 (en) | 1995-06-27 | 1995-06-27 | Construction machine control circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3600316B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100473238B1 (en) * | 1997-12-26 | 2005-06-10 | 볼보 컨스트럭션 이키프먼트 홀딩 스웨덴 에이비 | Hydraulic system for construction machinery and its control method |
| JP2011017213A (en) * | 2009-07-10 | 2011-01-27 | Nippon Pneumatic Mfg Co Ltd | Hydraulic control device of attachment in construction machine |
| CN112064714A (en) * | 2020-08-26 | 2020-12-11 | 合肥工业大学 | Novel hydraulic excavator flow control system |
-
1995
- 1995-06-27 JP JP16085195A patent/JP3600316B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100473238B1 (en) * | 1997-12-26 | 2005-06-10 | 볼보 컨스트럭션 이키프먼트 홀딩 스웨덴 에이비 | Hydraulic system for construction machinery and its control method |
| JP2011017213A (en) * | 2009-07-10 | 2011-01-27 | Nippon Pneumatic Mfg Co Ltd | Hydraulic control device of attachment in construction machine |
| CN112064714A (en) * | 2020-08-26 | 2020-12-11 | 合肥工业大学 | Novel hydraulic excavator flow control system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3600316B2 (en) | 2004-12-15 |
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