JPH1037250A - Hydraulic circuit - Google Patents
Hydraulic circuitInfo
- Publication number
- JPH1037250A JPH1037250A JP19774096A JP19774096A JPH1037250A JP H1037250 A JPH1037250 A JP H1037250A JP 19774096 A JP19774096 A JP 19774096A JP 19774096 A JP19774096 A JP 19774096A JP H1037250 A JPH1037250 A JP H1037250A
- Authority
- JP
- Japan
- Prior art keywords
- valve
- pressure
- load
- load pressure
- operating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Operation Control Of Excavators (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、油圧ショベルの旋
回用油圧モータと作業機シリンダなどの高負荷が作用す
るアクチュエータと低負荷が作用するアクチュエータに
油圧ポンプの吐出圧油を供給する油圧回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic circuit for supplying hydraulic pressure discharged from a hydraulic pump to a high-load actuator and a low-load actuator such as a hydraulic motor for turning a hydraulic shovel and a working machine cylinder. .
【０００２】[0002]
【従来の技術】１つの油圧ポンプの吐出圧油を複数の油
圧アクチュエータに供給するには、油圧ポンプの吐出路
に複数の操作弁を設け、その操作弁を切換えることで各
油圧アクチュエータに圧油を供給すれば良いが、このよ
うにすると複数の油圧アクチュエータに圧油を同時に供
給する際に、負荷の小さな油圧アクチュエータにのみ圧
油が供給されて負荷の大きな油圧アクチュエータに圧油
が供給されなくなってしまう。2. Description of the Related Art In order to supply the hydraulic pressure discharged from one hydraulic pump to a plurality of hydraulic actuators, a plurality of operating valves are provided in the discharge path of the hydraulic pump, and the operating valves are switched to apply hydraulic oil to each hydraulic actuator. In this case, when supplying hydraulic oil to a plurality of hydraulic actuators at the same time, pressure oil is supplied only to hydraulic actuators with a small load, and hydraulic oil is not supplied to hydraulic actuators with a large load. Would.
【０００３】このことを解消する油圧回路として、例え
ば特公平２−４９４０５号公報に示すものが提案されて
いる。As a hydraulic circuit for solving this problem, for example, a hydraulic circuit disclosed in Japanese Patent Publication No. 2-49405 has been proposed.
【０００４】かかる油圧回路を模式的に示すと図１に示
すようになる。つまり、油圧ポンプ１の吐出路１ａに複
数の操作弁２を設け、各操作弁２と各油圧アクチュエー
タ３を接続する回路４に圧力補償弁５をそれぞれ設ける
と共に、各回路４の圧力、つまり負荷圧における最も高
い圧力をチェック弁６で検出し、その検出した負荷圧を
各圧力補償弁５に作用してその負荷圧に見合う圧力にセ
ットし、各操作弁２の出口側圧力を等しくして各操作弁
２を同時操作した時に各操作弁の開口面積に比例した分
流比で各油圧アクチュエータ３に圧油を供給できるよう
にしてある。FIG. 1 schematically shows such a hydraulic circuit. That is, a plurality of operation valves 2 are provided in the discharge path 1a of the hydraulic pump 1, a pressure compensating valve 5 is provided in a circuit 4 connecting each operation valve 2 and each hydraulic actuator 3, and the pressure of each circuit 4, that is, the load The highest pressure in the pressure is detected by the check valve 6, and the detected load pressure is applied to each pressure compensating valve 5 to be set to a pressure corresponding to the load pressure, and the outlet side pressure of each operation valve 2 is made equal. When the respective operation valves 2 are simultaneously operated, the pressure oil can be supplied to the respective hydraulic actuators 3 at a shunt ratio proportional to the opening area of the respective operation valves.
【０００５】かかる油圧回路であると、圧力補償弁５の
機能によって各油圧アクチュエータ３の負荷の大小に無
関係に操作弁２の開口面積に比例した流量分配ができる
から、１つの油圧ポンプ１の吐出圧油を操作弁２の操作
量に比例して各油圧アクチュエータ３にそれぞれ供給で
きる。With such a hydraulic circuit, the function of the pressure compensating valve 5 allows the flow rate to be distributed in proportion to the opening area of the operating valve 2 irrespective of the magnitude of the load on each hydraulic actuator 3. Pressure oil can be supplied to each hydraulic actuator 3 in proportion to the amount of operation of the operation valve 2.
【０００６】しかしながら、この油圧回路は圧力補償弁
５を最も高い負荷圧に見合う圧力にセットされるために
負荷圧の高い方の圧力補償弁５の開度（絞り）が大で、
負荷圧の低い方の圧力補償弁５の開度（絞り）が小とな
るから、負荷圧の差が著しく大きい時には負荷圧の低い
方の圧力補償弁５の開度が著しく小さくなってロスが大
きくなるばかりか馬力制御されている油圧ポンプの場合
にはポンプ吐出量が減少し、結果としてアクチュエータ
の速度が遅くなる。前述の油圧回路を旋回式作業装置の
旋回用油圧モータと作業機用シリンダに圧油を供給する
油圧回路とすると、旋回体と作業機を同時に作動させる
場合に、旋回体の慣性力が大であるから旋回用油圧モー
タの旋回初期の負荷圧が高いため油圧ポンプの吐出量が
減少し作業機の速度が遅くなってしまう。However, in this hydraulic circuit, since the pressure compensating valve 5 is set to a pressure corresponding to the highest load pressure, the opening (throttle) of the pressure compensating valve 5 having a higher load pressure is large.
Since the opening degree (throttle) of the pressure compensating valve 5 having the lower load pressure is small, when the difference between the load pressures is extremely large, the opening degree of the pressure compensating valve 5 having the lower load pressure is extremely small, resulting in a loss. In the case of a hydraulic pump that is not only increased but also controlled by horsepower, the pump discharge rate decreases, and as a result, the speed of the actuator decreases. If the hydraulic circuit described above is a hydraulic circuit for supplying hydraulic oil to the turning hydraulic motor of the turning type working device and the working machine cylinder, the inertia force of the turning body is large when the turning body and the working machine are operated simultaneously. Because of this, the load pressure of the hydraulic motor for turning in the initial stage of turning is high, so that the discharge amount of the hydraulic pump is reduced and the speed of the work machine is reduced.
【０００７】このために、旋回体と作業機を同時に作動
する場合における旋回初期に作業機がほとんど作動せず
に旋回体が定常速度で作動し始めてから作業機が作動す
るから、作業機の作動が遅れてしまう。[0007] For this reason, when the revolving superstructure and the work implement are simultaneously operated, the work implement hardly operates in the initial stage of turning and the revolving superstructure starts to operate at a steady speed and then the work implement starts operating. Is delayed.
【０００８】このことを解消する油圧回路として特願平
３−１６６２０３号に示す油圧回路が提案されている。A hydraulic circuit disclosed in Japanese Patent Application No. 3-166203 has been proposed as a hydraulic circuit for solving this problem.
【０００９】この油圧回路は、旋回用油圧モータの負荷
圧を負荷圧導入路に検出するチェック弁を、作業機用シ
リンダに圧油を供給する時に不作動となる構造とした油
圧回路である。This hydraulic circuit is a hydraulic circuit having a structure in which a check valve for detecting a load pressure of a turning hydraulic motor in a load pressure introducing path is inoperative when supplying pressurized oil to a working machine cylinder.
【００１０】この油圧回路であれば、旋回用油圧モータ
と作業機用シリンダを同時作動する時には作業機用シリ
ンダの負荷圧が負荷圧導入路に検出されて圧力補償弁は
その負荷圧でセットされるから開度を大きくして旋回初
期に作業機シリンダに圧油を十分に供給できる。With this hydraulic circuit, when the turning hydraulic motor and the working machine cylinder are operated simultaneously, the load pressure of the working machine cylinder is detected in the load pressure introduction path, and the pressure compensating valve is set at that load pressure. As a result, the opening degree can be increased and sufficient pressure oil can be supplied to the working machine cylinder at the beginning of turning.
【００１１】[0011]
【発明が解決しようとする課題】前述の油圧回路である
とパイロット圧が作用すると圧油が流れない状態となる
複雑構造のチェック弁を用いているのでコストが高い。In the above-described hydraulic circuit, the cost is high because a check valve having a complicated structure is used in which the pressure oil does not flow when the pilot pressure is applied.
【００１２】また、作業機シリンダに圧油を供給する操
作弁を切換えるパイロット圧をチェック弁に作用されて
いるので、複数の作業機シリンダのいずれかと旋回用油
圧モータを同時作動する場合にチェック弁を不作動とす
るような場合には、その複数の作業機シリンダに圧油を
供給する複数の操作弁のパイロット圧のいずれかをチェ
ック弁に作用させるようにする必要があり、そのために
構造が複雑となる。Further, since the pilot pressure for switching the operation valve for supplying the hydraulic oil to the working machine cylinder is applied to the check valve, the check valve is used when simultaneously operating one of the plurality of working machine cylinders and the turning hydraulic motor. When it is necessary to operate the check valve, it is necessary to apply any of the pilot pressures of the plurality of operating valves that supply the hydraulic oil to the plurality of working machine cylinders to the check valve. It gets complicated.
【００１３】例えば、油圧ショベルの場合には旋回用油
圧モータとブームシリンダの同時作動、旋回用油圧モー
タと走行用油圧モータの同時作動などがあり、図２に示
すようにブーム用操作弁を切換えるパイロット圧回路７
ａと走行用操作弁を切換えるパイロット圧回路７ｂをシ
ャトル弁８の入口側に接続し、そのシャトル弁８の出口
側をチェック弁９の受圧部９ａに接続し、どちらのパイ
ロット圧回路７ａ，７ｂにパイロット圧が流れてもチェ
ック弁９を不作動とする構成とするので、その構造が複
雑となる。For example, in the case of a hydraulic excavator, simultaneous operation of a turning hydraulic motor and a boom cylinder, simultaneous operation of a turning hydraulic motor and a traveling hydraulic motor are performed, and the operating valve for the boom is switched as shown in FIG. Pilot pressure circuit 7
a and a pilot pressure circuit 7b for switching the operating valve for traveling are connected to the inlet side of the shuttle valve 8, and the outlet side of the shuttle valve 8 is connected to the pressure receiving portion 9a of the check valve 9, so that either of the pilot pressure circuits 7a, 7b Even if the pilot pressure flows through the check valve 9, the check valve 9 is made inoperative, so that the structure becomes complicated.
【００１４】そこで、本発明は前述の課題を解決できる
ようにした油圧回路を提供することを目的とする。Accordingly, an object of the present invention is to provide a hydraulic circuit capable of solving the above-mentioned problems.
【００１５】[0015]
【課題を解決するための手段及び作用】第１の発明は、
油圧ポンプ１０の吐出路１０ａを第１操作弁１５１、圧
力補償弁１８を経て高負荷が作用する第１のアクチュエ
ータに接続し、前記油圧ポンプ１０の吐出路１０ａを第
２操作弁１５２、圧力補償弁１８を経て低負荷が作用す
る第２のアクチュエータに接続し、前記第１操作弁１５
１と第２操作弁１５２に、中立位置では遮断されて圧油
を供給する位置の時にアクチュエータの負荷圧が作用す
る負荷圧検出ポート３７をそれぞれ形成し、前記第１操
作弁１５１の負荷圧検出ポート３７と第２操作弁１５２
の負荷圧検出ポート３７を、第１・第２操作弁１５１，
１５２を同時操作した時には第１操作弁１５１の負荷圧
検出ポート３７の圧力が第２操作弁１５２の負荷圧検出
ポート３７の圧力までしか上昇しないように接続し、そ
の第２操作弁１５２の負荷圧検出ポート３７に負荷圧導
入路２３を接続し、前記負荷圧導入路２３の負荷圧で前
記圧力補償弁１８をセットするようにしたことを特徴と
する油圧回路である。The first aspect of the present invention provides
Discharge passage 10a of the first operating valve 15 1 of the hydraulic pump 10, the pressure compensating valve 18 via connected to the first actuator a high load is applied, the discharge passage 10a of the second operating valve 15 2 of the hydraulic pump 10, It is connected via a pressure compensating valve 18 to a second actuator on which a low load acts, and the first operating valve 15
The first and second operating valve 15 2 is blocked in the neutral position by forming respectively a load pressure detection port 37 acting load pressure of the actuator when the position for supplying pressurized oil, said first load control valve 15 1 pressure detecting port 37 and the second operation valve 15 2
Of the load pressure detection port 37 of the first and second operation valves 15 1 ,
15 when the 2 co operation was connected to a pressure in the first operating valve 15 1 of the load pressure detection port 37 is only increased to a pressure of the second load control valve 15 2 pressure detecting port 37, the second operating valve 15 connects the load pressure introducing path 23 to the load pressure detection port 37 of the 2, a hydraulic circuit is characterized in that so as to set the pressure compensating valve 18 in the load pressure of the load pressure introducing passage 23.
【００１６】第１の発明によれば、第１操作弁１５１と
第２操作弁１５２を同時操作して第１のアクチュエータ
と第２のアクチュエータを同時作動する場合に、第１の
アクチュエータが高負荷で第２のアクチュエータが低負
荷であっても第１操作弁１５１の負荷圧検出ポート３７
の圧力は第２操作弁１５２の負荷圧検出ポート３７の圧
力までしか上昇しない。According to the first invention, when the first actuator and a first operating valve 15 1 and a second operating valve 15 2 simultaneously operating the second actuator to simultaneous operation, the first actuator high load is the second actuator even at low loads of the first operating valve 15 first load pressure detecting port 37
Pressure can only rise to a pressure in the load pressure detecting port 37 of the second operating valve 15 2.
【００１７】これにより、圧力補償弁１８は低負荷であ
るアクチュエータの負荷圧でセットされて開度が大きく
なり、起動初期に第２のアクチュエータに十分な流量を
供給できる。As a result, the pressure compensating valve 18 is set by the load pressure of the actuator having a low load, the opening degree is increased, and a sufficient flow rate can be supplied to the second actuator at the beginning of startup.
【００１８】また、第１操作弁１５１の負荷圧検出ポー
ト３７と第２操作弁１５２の負荷圧検出ポート３７を接
続しただけであるから、構造簡単でコスト安となる。Further, since only connected to the first operating valve 15 1 of the load pressure detection port 37 of the second operating valve 15 and second load pressure detection port 37, a simple and less costly construction.
【００１９】第２の発明は、第１の発明における第１操
作弁１５１の負荷圧検出ポート３７にチェック弁６０を
介して回路６１を接続し、前記第２操作弁１５２の負荷
圧検出ポート３７にシャトル弁６２の一方の入口側を接
続し、このシャトル弁６２の出口側に負荷圧導入路２３
を接続し、前記回路６１をシャトル弁６２の両方の入口
側に接続した油圧回路である。[0019] The second invention, the first operating valve 15 1 of the load pressure detection port 37 of the first invention through the check valve 60 connects the circuit 61, the second operating valve 15 and second load pressure detection One inlet side of the shuttle valve 62 is connected to the port 37, and the load pressure introduction passage 23 is connected to the outlet side of the shuttle valve 62.
And a hydraulic circuit in which the circuit 61 is connected to both inlet sides of the shuttle valve 62.
【００２０】第２の発明によれば、チェック弁６０とシ
ャトル弁６２を用いているだけであるし、従来の油圧回
路においてもチェック又はシャトル弁を用いているか
ら、コストが安くなる。According to the second aspect, only the check valve 60 and the shuttle valve 62 are used, and the cost is reduced because the check or shuttle valve is used in the conventional hydraulic circuit.
【００２１】また、第２のアクチュエータの負荷圧が第
１のアクチュエータの負荷圧よりも高い場合に第２のア
クチュエータの負荷圧がチェック弁６０で第１操作弁１
５１の負荷圧検出ポート３７に逆流することがない。When the load pressure of the second actuator is higher than the load pressure of the first actuator, the load pressure of the second actuator is changed by the check valve 60 to the first operation valve 1.
5 is not able to flow back into the first load pressure detecting port 37.
【００２２】第３の発明は、第１の発明における第１操
作弁１５１の負荷圧検出ポート３７にチェック弁６０を
介して回路６１を接続し、第２，第３操作弁１５２，１
５３の負荷圧検出ポート３７にシャトル弁６２，６３の
一方の入口側をそれぞれ接続し、前記回路６１を一方の
シャトル弁６２の両方の入口側に接続すると共に、チェ
ック弁６４を介して他方のシャトル弁６３の一方の入口
側に接続し、その一方のシャトル弁６２の出口側を他方
のシャトル弁６２の他方の入口側に接続し、他方のシャ
トル弁６２の出口側に負荷圧導入路２３を接続した油圧
回路である。The third invention is the first operating valve 15 1 of the load pressure detection port 37 of the first invention through the check valve 60 connects the circuit 61, second, third operating valve 15 2, 1
5 3 load pressure detection port 37 into one of the inlet side of the shuttle valve 62, 63 connected respectively with connecting the circuit 61 to the inlet side of both of one of the shuttle valve 62, through a check valve 64 on the other hand , The outlet side of one shuttle valve 62 is connected to the other inlet side of the other shuttle valve 62, and the load pressure introduction path is connected to the outlet side of the other shuttle valve 62. 23 is a hydraulic circuit connected thereto.
【００２３】第３の発明によれば、第１操作弁１５１と
第２操作弁１５２、第１操作弁１５１と第３操作弁１５
３を同時操作した時に前述と同様になるし、シャトル弁
とチェック弁を組み合せれば良いから構造が簡単とな
る。According to the third invention, the first operating valve 15 1 and the second operating valve 15 2, first operating valve 15 1 and the third operating valve 15
3 is operated at the same time, and the structure is simplified because the shuttle valve and the check valve may be combined.
【００２４】[0024]
【発明の実施の形態】図３に示すように、油圧ポンプ１
０は斜板１１の角度を変更することで容量、つまり１回
転当り吐出流量が変化する可変容量型の油圧ポンプとな
り、その斜板１１は大径ピストン１２で容量減方向に傾
動し、小径ピストン１３で容量増方向に傾動する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG.
Numeral 0 denotes a variable displacement type hydraulic pump in which the displacement, that is, the discharge flow rate per rotation, is changed by changing the angle of the swash plate 11, and the swash plate 11 is tilted by a large-diameter piston 12 in the capacity decreasing direction, and 13 tilts in the capacity increasing direction.
【００２５】前記大径ピストン１２の受圧室１２ａは制
御弁１４で油圧ポンプ１０の吐出路１０ａに連通・遮断
され、小径ピストン１３の受圧室１３ａは前記吐出路１
０ａに接続してある。The pressure receiving chamber 12a of the large-diameter piston 12 is connected to and blocked from the discharge passage 10a of the hydraulic pump 10 by a control valve 14, and the pressure-receiving chamber 13a of the small-diameter piston 13 is connected to the discharge passage 1a.
0a.
【００２６】前記油圧ポンプ１０の吐出路１０ａには第
１・第２操作弁１５1 ，１５2 が設けてあり、第１・第
２操作弁１５1 ，１５2 と旋回用油圧ポンプ１６1 ，作
業機用シリンダ１６2 を接続する回路１７に圧力補償弁
１８がそれぞれ設けてある。The discharge passage 10a to the Yes and the first and second operating valves 15 1, 15 2 are provided, the first and second operating valves 15 1, 15 2 and the swing hydraulic pump 16 1 of the hydraulic pump 10, a circuit 17 for connecting the working machine cylinder 16 2 is provided a pressure compensating valve 18, respectively.
【００２７】該圧力補償弁１８は第１受圧部１９の圧油
とバネ２０で遮断位置側に押され、第２受圧部２１の圧
油で連通位置側に押される構成としてあり、第２受圧部
２１は圧力補償弁１８の入口側に接続されて入口側圧力
が供給され、第１受圧部１９はシャトル弁２２を経て負
荷圧導入路２３と保持圧導入路２４に接続されて最も高
い負荷圧又はアクチュエータ保持圧が供給される。The pressure compensating valve 18 is configured to be pushed to the shut-off position side by the pressure oil of the first pressure receiving portion 19 and the spring 20 and to the communication position side by the pressure oil of the second pressure receiving portion 21. The section 21 is connected to the inlet side of the pressure compensating valve 18 to supply the inlet side pressure, and the first pressure receiving section 19 is connected to the load pressure introducing path 23 and the holding pressure introducing path 24 via the shuttle valve 22 to provide the highest load. Pressure or actuator holding pressure is supplied.
【００２８】前記保持圧導入路２４は前記回路１７にお
けるロードチェック弁２５の出力側に接続され、このロ
ードチェック弁２５は圧力補償弁１８の出口側圧力で開
作動する。前記回路１７におけるロードチェック弁２５
と油圧アクチュエータ１６との間は安全弁２６と吸込弁
２７を経てドレーン路２８に接続してある。The holding pressure introducing passage 24 is connected to the output side of the load check valve 25 in the circuit 17, and the load check valve 25 is opened by the pressure on the outlet side of the pressure compensating valve 18. Load check valve 25 in circuit 17
The hydraulic actuator 16 is connected to a drain passage 28 through a safety valve 26 and a suction valve 27.
【００２９】前記切換弁１４は吐出路１０a 内の圧力、
つまり油圧ポンプ１０の吐出圧Ｐ1で連通位置Ｂ方向に
押され、バネ２９のバネ力と受圧部１４ａに作用する前
記負荷圧ＰLSでドレーン位置Ａ方向に押されて、吐出圧
Ｐと負荷圧ＰLSの圧力差（Ｐ1 −ＰLS）△ＰLSがバネ２
９のバネ力よりも高くなると連通位置Ｂに押されて大径
ピストン１２の受圧部１２ａに吐出圧Ｐ1 を供給して斜
板１１を容量減方向に傾動し、前記圧力差△ＰLSがバネ
２９のバネ力より低くなると切換弁１４がドレーン位置
Ａに押されて大径ピストン１２の受圧部１２ａ内の圧油
をタンク側に流出して斜板１１を容量増方向に傾動す
る。The pressure of the switching valve 14 is a discharge path 10 a,
That pushed to the communicating position B direction in the discharge pressure P 1 of the hydraulic pump 10, it is pushed by the drain position A direction by the load pressure P LS acting on the spring force and the pressure receiving portion 14a of the spring 29, the discharge pressure P and the load Pressure difference of pressure P LS (P 1 −P LS ) △ P LS is spring 2
Becomes higher than the spring force of 9 is pressed by the communicating position B to supply the discharge pressure P 1 on the pressure receiving portion 12a of the large diameter piston 12 to tilt the swash plate 11 in the volume decrease direction, the pressure difference △ P LS is When the spring force is lower than the spring force of the spring 29, the switching valve 14 is pushed to the drain position A, and the pressure oil in the pressure receiving portion 12a of the large diameter piston 12 flows out to the tank side to tilt the swash plate 11 in the capacity increasing direction.
【００３０】前記第１・第２操作弁１５1 ，１５2 は第
１・第２パイロット制御弁３０1 ，３０2 よりのパイロ
ット圧油に比例して開口面積が増大する方向に操作さ
れ、そのパイロット圧油はレバー３０ａの操作ストロー
クに比例する。すなわち、前記第１、第２パイロット制
御弁３０1 ，３０2 はパイロット用油圧ポンプ３１の吐
出圧油をレバー３０ａの操作ストロークに比例して出力
する複数の減圧部３２を備え、その減圧部３２の出力側
が第１・第２操作弁１５1 ，１５2 の受圧部１５ａにそ
れぞれ接続し、レバー３０ａを操作して１つの減圧部３
２より圧油を出力すると第１・第２操作弁１５1 ，１５
2 が中立位置Ｎから第１又は第２圧油供給位置Ｃ，Ｄに
切換えられ、その切換えストロークは減圧部３２よりの
パイロット圧油に比例する。The first and second operation valves 15 1 and 15 2 are operated in a direction in which the opening area increases in proportion to the pilot pressure oil from the first and second pilot control valves 30 1 and 30 2. The pilot pressure oil is proportional to the operation stroke of the lever 30a. That is, the first and second pilot control valves 30 1 and 30 2 are provided with a plurality of pressure reducing sections 32 which output the pressure oil discharged from the pilot hydraulic pump 31 in proportion to the operation stroke of the lever 30a. Are connected to the pressure receiving portions 15a of the first and second operation valves 15 1 and 15 2 respectively, and by operating the lever 30a, one pressure reducing portion 3 is operated.
When the pressure oil is output from the second control valve 15, the first and second operation valves 15 1 , 15
2 is switched from the neutral position N to the first or second pressure oil supply position C, D, and the switching stroke is proportional to the pilot pressure oil from the pressure reducing section 32.
【００３１】前記第１・第２操作弁１５1 ，１５2 は第
１・第２ポンプポート３３，３４と第１・第２タンクポ
ート３５，３６と負荷圧検出ポート３７と第１・第２ア
クチュエータポート３８，３９と第１・第２補助ポート
４０，４１を備え、第１・第２ポンプポート３３，３４
は油圧ポンプ１０の吐出路１０ａに接続し、第１・第２
タンクポート３５，３６は前記ドレーン路２８に接続
し、第１・第２アクチュエータポート３８，３９は各圧
力補償弁１８の入口側に接続し、第１・第２補助ポート
４０，４１は短絡路４３で回路１７におけるロードチェ
ック弁２５の出力側に接続している。The first and second operating valves 15 1 and 15 2 are provided with first and second pump ports 33 and 34, first and second tank ports 35 and 36, a load pressure detecting port 37, and first and second pump ports. Actuator ports 38 and 39 and first and second auxiliary ports 40 and 41 are provided, and first and second pump ports 33 and 34 are provided.
Are connected to the discharge path 10a of the hydraulic pump 10, and the first and second
The tank ports 35 and 36 are connected to the drain path 28, the first and second actuator ports 38 and 39 are connected to the inlet side of each pressure compensating valve 18, and the first and second auxiliary ports 40 and 41 are short-circuited. 43 is connected to the output side of the load check valve 25 in the circuit 17.
【００３２】前記第１・第２操作弁１５1 ，１５2 が中
立位置Ｎの時には第１・第２タンクポート３５，３６と
第１・第２アクチュエータポート３８，３９が通路４４
で連通し、かつ負荷圧検出ポート３７が遮断し、第１・
第２ポンプポート３３，３４と第１・第２補助ポート４
０，４１がそれぞれ遮断され、第１圧油供給位置Ｃの時
には第１ポンプポート３３と第１アクチュエータポート
３８が主通路１５ｂで連通し、かつ第１ポンプポート３
３と第１補助ポート４０が第１絞り４５とロードチェッ
ク弁４６と第２絞り４７を備えた通路４８で連通し、こ
の通路４８の第１絞り４５とロードチェック弁４６との
間が通路４９で負荷圧検出ポート３７に連通し、第２補
助ポート４１が第２タンクポート３６に連通し、第２圧
油供給位置Ｄの時には第２ポンプポート３４と第２アク
チュエータポート３９が主通路１５ｂで連通し、かつ第
２ポンプポート３４と第２補助ポート４１が前述と同様
に第１絞り４５、ロードチェック弁４６、第２絞り４７
を備えた通路４８で連通し、この通路４８の第１絞り４
５とロードチェック弁４６との間が通路４９で負荷圧検
出ポート３７に連通し、第１補助ポート４０が第１タン
クポート３５に連通する。つまり、操作弁１５はクロー
ズドセンタ型の操作弁となっている。When the first and second operation valves 15 1 and 15 2 are in the neutral position N, the first and second tank ports 35 and 36 and the first and second actuator ports 38 and 39 are connected to the passage 44.
And the load pressure detection port 37 is shut off,
Second pump ports 33 and 34 and first and second auxiliary ports 4
The first pump port 33 and the first actuator port 38 communicate with each other through the main passage 15b at the first pressure oil supply position C, and the first pump port 3
3 and the first auxiliary port 40 communicate with each other through a passage 48 provided with a first throttle 45, a load check valve 46, and a second throttle 47, and a passage 49 between the first throttle 45 and the load check valve 46 in the passage 48. , The second auxiliary port 41 communicates with the second tank port 36, and the second pump port 34 and the second actuator port 39 communicate with the main passage 15b at the second pressure oil supply position D. The second pump port 34 and the second auxiliary port 41 communicate with each other, and the first throttle 45, the load check valve 46, the second throttle 47
And a first throttle 4 of the passage 48.
The passage 49 connects the load pressure detection port 37 with the load pressure detection port 37, and the first auxiliary port 40 communicates with the first tank port 35. That is, the operation valve 15 is a closed center type operation valve.
【００３３】前記油圧ポンプ１０の吐出路１０ａにはア
ンロード弁５０が設けられ、このアンロード弁５０は吐
出圧Ｐと負荷圧ＰLSの圧力差（Ｐ−ＰLS）△ＰLSが設定
圧以上となるとアンロードする構成となり、前記圧力差
△ＰLSが大きい時に開いて油圧ポンプ１０の吐出油をタ
ンクに逃がして吐出圧Ｐ1 のピーク圧を低減させ、また
各操作弁１５が中立位置の時に油圧ポンプ１０の吐出油
をタンクへドレーンするようにしてある。An unload valve 50 is provided in the discharge passage 10a of the hydraulic pump 10. The unload valve 50 is configured to set a pressure difference (P-P LS ) △ P LS between the discharge pressure P and the load pressure P LS. When the pressure difference ΔP LS is large, the unloading mechanism is opened, and the discharge oil of the hydraulic pump 10 is released to the tank to reduce the peak pressure of the discharge pressure P 1 when the pressure difference ΔP LS is large. At this time, the oil discharged from the hydraulic pump 10 is drained to the tank.
【００３４】以上の構成は、負荷圧検出ポート３７と負
荷圧導入路２３の接続、及び負荷圧検出ポート３７が中
立位置Ｎで遮断される点以外が特願平３−１６６２３０
号と同一となっている。The above configuration is the same as that of Japanese Patent Application No. 3-166230 except that the connection between the load pressure detection port 37 and the load pressure introduction passage 23 and the point that the load pressure detection port 37 is cut off at the neutral position N.
It is the same as the issue.
【００３５】次に負荷圧検出ポート３７と負荷圧導入路
２３の接続について説明する。第１操作弁１５１の（高
負荷側のアクチュエータに接続した操作弁）の負荷圧検
出ポート３７はチェック弁６０で回路６１に接続し、第
２操作弁１５２（低負荷側のアクチュエータに接続した
操作弁）の負荷圧検出ポート３７はシャトル弁６２の一
方の入口側に接続している。Next, the connection between the load pressure detecting port 37 and the load pressure introducing passage 23 will be described. Load pressure detection port 37 of the first operating valve 15 1 (operation valve connected to the high-load side of the actuator) is connected to the circuit 61 by the check valve 60, connected to a second operating valve 15 2 (the low-load side of the actuator The load pressure detection port 37 of the operated valve is connected to one inlet side of the shuttle valve 62.
【００３６】前記回路６１はシャトル弁６２の一方の入
口側と他方の入口側に接続し、そのシャトル弁６２の出
口側が負荷圧導入回路２３に接続している。The circuit 61 is connected to one inlet side and the other inlet side of the shuttle valve 62, and the outlet side of the shuttle valve 62 is connected to the load pressure introducing circuit 23.
【００３７】このようであるから、第１操作弁１５１の
負荷圧検出ポート３７の圧力は第２操作弁１５２の負荷
圧検出ポート３７の圧力以上には高くならないし、第２
操作弁１５２の負荷圧検出ポート３７の圧力はチェック
弁６０を設けたことによって第１操作弁１５１の負荷圧
検出ポート３７の圧力以上に高くすることができる。[0037] Since this be the case, to the pressure of the first operating valve 15 1 of the load pressure detection port 37 is not high than the pressure of the second operating valve 15 and second load pressure detection port 37, a second
The pressure of the load pressure detecting port 37 of the operating valve 15 2 may be higher than the pressure of the first operating valve 15 1 of the load pressure detection port 37 by providing the check valve 60.
【００３８】次に作動を説明する。第１・第２パイロッ
ト制御弁３０１，３０２を操作して第１・第２操作弁１
５１，１５２を第２圧油供給位置Ｄ、Ｄとして油圧ポン
プ１０の吐出圧油を旋回用油圧モータ１６１と作業機用
シリンダ１６２に同時に供給する場合には、第１操作弁
１５１の負荷圧検出ポート３７の圧力は第２操作弁１５
２の負荷圧検出ポート３７の圧力まで上昇しないから、
旋回用油圧モータ１６１の旋回初期には作業機シリンダ
１６２の負荷圧までしか圧力が上昇しない。Next, the operation will be described. By operating the first and second pilot control valves 30 1 and 30 2 , the first and second operation valves 1
5 1, 15 2 second pressurized oil supply position D, in the case of simultaneously supplying a discharged pressurized fluid of the hydraulic pump 10 to the swing hydraulic motor 16 1 and the working machine cylinder 16 2 as D, the first operating valve 15 1 pressure load pressure detection port 37 and the second operating valve 15
Since the pressure does not increase to the pressure of the load pressure detection port 37 of No. 2 ,
In the initial stage of cornering swing hydraulic motor 16 1 it does not increase the pressure only to the load pressure of the working machine cylinder 16 2.
【００３９】このために、負荷圧導入路２３には作業機
用シリンダ１６２の低圧である負荷圧が導入されて各圧
力補償弁１８の第１受圧部１９には作業機用シリンダ１
６２の負荷圧がそれぞれ作用してその負荷圧に見合う圧
力にセットされ、各圧力補償弁１８の開度は作業機用シ
リンダ１６２の負荷圧に見合う値となり、油圧ポンプ１
０の吐出圧油は負荷圧の低い作業機用シリンダ１６２に
供給されるし、旋回用油圧モータ１６１にも供給されて
旋回用油圧モータ１６１をゆっくりと旋回させる。[0039] For this, the load pressure introduction passage 23 working machine cylinder 1 to the first pressure receiving portion 19 of the pressure compensating valve 18 is introduced load pressure is low pressure working machine cylinder 16 2 is in
Load pressure of 6 2 is set to a pressure commensurate with the load pressure acting respectively, opening of the pressure compensating valve 18 becomes a value commensurate with the load pressure of the working machine cylinder 16 2, the hydraulic pump 1
Discharging pressurized fluid of 0 to be supplied to the lower working machine cylinder 16 2 of load pressure, is also supplied to the swing hydraulic motor 16 1 is slowly turning the swing hydraulic motor 16 1.
【００４０】前述の状態で旋回用油圧モータ１６１によ
り旋回体が定常速度で回転し始めると、旋回用油圧モー
タ１６１の負荷圧が作業機用シリンダ１６２の負荷圧よ
り低くなるが、チェック弁６０で逆流が防止されるし、
圧力補償弁１８が前述のように作業機用シリンダ１６２
の負荷圧に見合う圧力でセットされているから開度が小
さくなって油圧ポンプ１０の吐出圧油を旋回用油圧モー
タ１６１と作業機用シリンダ１６２に供給して旋回体を
定常速度で旋回させるから作業機を作動できる。[0040] When the pivot member by the turning hydraulic motor 16 1 in the above state begins to rotate at a steady rate, although the load pressure of the swing hydraulic motor 16 1 is lower than the load pressure of the working machine cylinder 16 2, check Backflow is prevented by valve 60,
As described above, the pressure compensating valve 18 is provided with the working machine cylinder 16 2.
And supplying the discharged pressurized fluid to the swing hydraulic motor 16 1 and the working machine cylinder 16 2 of the hydraulic pump 10 opening is reduced from being set at a pressure commensurate with the load pressure turning the turning body at a steady rate Work machine can be operated.
【００４１】操作弁が３つ以上ある場合には、図４に示
すように第３操作弁１５３の負荷圧検出ポート３７をシ
ャトル弁６３の一方の入口側に接続し、前記回路６１を
チェック弁６４を介してシャトル弁６３の一方の入口側
に接続する。第２操作弁１５２の負荷圧検出ポート３７
に接続されたシャトル弁６２を回路６５で第３操作弁１
５３のシャトル弁６３の他方の入口側に接続する。[0041] When the operating valve there are more than two, connects the third operating valve 15 load pressure detection port 37 of 3 as shown in FIG. 4 in one of the inlet side of the shuttle valve 63, check the circuit 61 It is connected to one inlet side of the shuttle valve 63 via a valve 64. The load pressure of the second operation valve 15 2 out port 37
The shuttle valve 62 connected to the third operating valve 1
5 3 connection to the other inlet of the shuttle valve 63.
【００４２】このようにすれば、第１操作弁１５１の負
荷圧検出ポート３７がチェック弁６０、チェック弁６４
を経て第２・第３操作弁１５２，１５３の負荷圧検出ポ
ート３７にそれぞれ連通するので、第１操作弁１５１と
第２操作弁１５２の同時操作時及び第１操作弁１５１と
第３操作弁１５３の同時操作時に前述と同様となる。[0042] In this way, the first operating valve 15 1 of the load pressure detection port 37 check valve 60, check valve 64
Each so communicating with the second and third operating valve 15 2, 15 3 of the load pressure detection port 37 via the first operating valve 15 1 and the second time of simultaneous operation of the operation valve 15 2 and the first operating valve 15 1 When the same manner as described above when the third operating valve 15 3 concurrent operations.
【００４３】また、第２操作弁１５２と第３操作弁１５
３を同時操作した時には高い方の負荷圧が負荷圧導入路
２３に導入される。[0043] The second operating valve 15 2 and the third operating valve 15
3 are operated simultaneously, the higher load pressure is introduced into the load pressure introduction passage 23.
【図１】従来の油圧回路図である。FIG. 1 is a conventional hydraulic circuit diagram.
【図２】チェック弁にパイロット圧を作用させる例を示
す回路図である。FIG. 2 is a circuit diagram showing an example in which a pilot pressure is applied to a check valve.
【図３】本発明の実施の形態を示す油圧回路図である。FIG. 3 is a hydraulic circuit diagram showing an embodiment of the present invention.
【図４】３つの操作弁を用いた場合の負荷圧検出用の油
圧回路図である。FIG. 4 is a hydraulic circuit diagram for detecting load pressure when three operation valves are used.
７ａ…パイロット圧回路 ７ｂ…パイロット圧回路 ８…シャトル弁 ９…チェック弁 １０…油圧ポンプ １０ａ…吐出路 １５１…第１操作弁 １５２…第２操作弁 １５３…第３操作弁 １６１…旋回用油圧モータ １６２…作業機シリンダ １８…圧力補償弁 ２３…負荷圧導入路 ３７…負荷圧検出ポート ６０…チェック弁 ６１…回路 ６２…シャトル弁 ６３…シャトル弁 ６４…チェック弁 ６５…回路7a ... pilot pressure circuit 7b ... pilot pressure circuit 8 ... shuttle valve 9 ... check valve 10 ... hydraulic pump 10a ... discharge path 15 1 ... first operating valve 15 2 ... second operating valve 15 3 ... third operating valve 16 1 ... Hydraulic motor for turning 16 2 … Work machine cylinder 18… Pressure compensating valve 23… Load pressure introducing path 37… Load pressure detecting port 60… Check valve 61… Circuit 62… Shuttle valve 63… Shuttle valve 64… Check valve 65… Circuit
Claims (3)
作弁１５１、圧力補償弁１８を経て高負荷が作用する第
１のアクチュエータに接続し、前記油圧ポンプ１０の吐
出路１０ａを第２操作弁１５２、圧力補償弁１８を経て
低負荷が作用する第２のアクチュエータに接続し、 前記第１操作弁１５１と第２操作弁１５２に、中立位置
では遮断されて圧油を供給する位置の時にアクチュエー
タの負荷圧が作用する負荷圧検出ポート３７をそれぞれ
形成し、 前記第１操作弁１５１の負荷圧検出ポート３７と第２操
作弁１５２の負荷圧検出ポート３７を、第１・第２操作
弁１５１，１５２を同時操作した時には第１操作弁１５
１の負荷圧検出ポート３７の圧力が第２操作弁１５２の
負荷圧検出ポート３７の圧力までしか上昇しないように
接続し、その第２操作弁１５２の負荷圧検出ポート３７
に負荷圧導入路２３を接続し、 前記負荷圧導入路２３の負荷圧で前記圧力補償弁１８を
セットするようにしたことを特徴とする油圧回路。1. A discharge passage 10a of a hydraulic pump 10 is connected to a first actuator on which a high load is applied via a first operation valve 15 1 and a pressure compensating valve 18, and a discharge passage 10a of the hydraulic pump 10 is connected to a second actuator. operated valve 15 2, via the pressure compensating valve 18 is connected to a second actuator low load is applied, the first operating valve 15 1 and the second operating valve 15 2, supplying blocked by pressure oil in the neutral position an actuator load pressure is respectively formed a load pressure detection port 37 acting, the first operating valve 15 1 of the load pressure detection port 37 and the second operating valve 15 and second load pressure detection port 37 of the time in the position, the When the first and second operation valves 15 1 and 15 2 are simultaneously operated, the first operation valve 15
The pressure of the load pressure detecting port 37 of 1 is connected to only rises to the pressure of the second operating valve 15 and second load pressure detection port 37, port 37 exits the second load control valve 15 2 pressure
A hydraulic pressure circuit, wherein the pressure compensating valve 18 is set with the load pressure of the load pressure introducing path 23.
ト３７にチェック弁６０を介して回路６１を接続し、前
記第２操作弁１５２の負荷圧検出ポート３７にシャトル
弁６２の一方の入口側を接続し、このシャトル弁６２の
出口側に負荷圧導入路２３を接続し、前記回路６１をシ
ャトル弁６２の両方の入口側に接続した請求項１記載の
油圧回路。2. A connecting circuit 61 via a check valve 60 to the load pressure detection port 37 of the first operating valve 15 1, one of the shuttle valve 62 to the load pressure detection port 37 of the second operating valve 15 2 2. The hydraulic circuit according to claim 1, wherein an inlet side of the shuttle valve is connected, a load pressure introducing passage 23 is connected to an outlet side of the shuttle valve 62, and the circuit 61 is connected to both inlet sides of the shuttle valve 62.
７にチェック弁６０を介して回路６１を接続し、第２，
第３操作弁１５２，１５３の負荷圧検出ポート３７にシ
ャトル弁６２，６３の一方の入口側をそれぞれ接続し、
前記回路６１を一方のシャトル弁６２の両方の入口側に
接続すると共に、チェック弁６４を介して他方のシャト
ル弁６３の一方の入口側に接続し、その一方のシャトル
弁６２の出口側を他方のシャトル弁６２の他方の入口側
に接続し、他方のシャトル弁６２の出口側に負荷圧導入
路２３を接続した請求項１記載の油圧回路。3. A first operating valve 15 1 of the load pressure detection port 3
7 is connected to a circuit 61 via a check valve 60,
One of the inlet side was connected to the shuttle valve 62 and 63 to the third operating valve 15 2, 15 3 of the load pressure detection port 37,
The circuit 61 is connected to both inlet sides of one shuttle valve 62, and is connected to one inlet side of the other shuttle valve 63 via a check valve 64, and the outlet side of one shuttle valve 62 is connected to the other side. The hydraulic circuit according to claim 1, wherein the load valve is connected to the other inlet side of the shuttle valve 62, and the load pressure introduction path 23 is connected to the outlet side of the other shuttle valve 62.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19774096A JPH1037250A (en) | 1996-07-26 | 1996-07-26 | Hydraulic circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19774096A JPH1037250A (en) | 1996-07-26 | 1996-07-26 | Hydraulic circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1037250A true JPH1037250A (en) | 1998-02-10 |
Family
ID=16379560
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19774096A Pending JPH1037250A (en) | 1996-07-26 | 1996-07-26 | Hydraulic circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1037250A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000065238A1 (en) * | 1999-04-26 | 2000-11-02 | Hitachi Construction Machinery Co., Ltd. | Hydraulic circuit device |
-
1996
- 1996-07-26 JP JP19774096A patent/JPH1037250A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000065238A1 (en) * | 1999-04-26 | 2000-11-02 | Hitachi Construction Machinery Co., Ltd. | Hydraulic circuit device |
| US6378302B1 (en) | 1999-04-26 | 2002-04-30 | Hitachi Construction Machinery Co., Ltd. | Hydraulic circuit system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6170261B1 (en) | Hydraulic fluid supply system | |
| EP1672128B1 (en) | Hydraulic control device of an excavator with improved loading performance on a slope | |
| JP3124094B2 (en) | Control device for multiple actuators | |
| US6026730A (en) | Flow control apparatus in a hydraulic circuit | |
| US5481872A (en) | Hydraulic circuit for operating plural actuators and its pressure compensating valve and maximum load pressure detector | |
| JP2003148407A (en) | Oil pressure circuit | |
| JP6891079B2 (en) | Hydraulic drive system for construction machinery | |
| JP3562657B2 (en) | Capacity control device for variable displacement hydraulic pump | |
| JPH0841933A (en) | Hydraulic controller for excavator | |
| JP3101830B2 (en) | Hydraulic circuit of swivel working equipment | |
| JP2799045B2 (en) | Hydraulic circuit for crane | |
| JPH1037250A (en) | Hydraulic circuit | |
| JP3155243B2 (en) | Hydraulic control device with regeneration function | |
| KR20200103537A (en) | Driver and construction machine | |
| JP3095240B2 (en) | Hydraulic working circuit | |
| JP3853123B2 (en) | Hydraulic drive | |
| JP3097041B2 (en) | Return flow sharing circuit for pressure oil supply device | |
| JP2000240604A (en) | Revolving controller in construction machine | |
| JP3499601B2 (en) | Hydraulic circuit of construction machinery | |
| JP2556998B2 (en) | Hydraulic circuit | |
| JPH04136508A (en) | Control valve for hydraulic circuit | |
| JP3444507B2 (en) | Directional control valve | |
| JP3487367B2 (en) | Pressure oil supply control device | |
| JP2749317B2 (en) | Hydraulic drive | |
| JP2764683B2 (en) | Flow rate support circuit of pressure oil supply device |