JPH0791403A - Pressure oil supply device - Google Patents
Pressure oil supply deviceInfo
- Publication number
- JPH0791403A JPH0791403A JP5241195A JP24119593A JPH0791403A JP H0791403 A JPH0791403 A JP H0791403A JP 5241195 A JP5241195 A JP 5241195A JP 24119593 A JP24119593 A JP 24119593A JP H0791403 A JPH0791403 A JP H0791403A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- chamber
- cylinder
- pressure oil
- oil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Fluid-Pressure Circuits (AREA)
- Control Of Positive-Displacement Pumps (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、可変容量型油圧ポンプ
の吐出圧油を作業機上下揺動用のシリンダに供給する圧
油供給装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure oil supply device for supplying pressure oil discharged from a variable displacement hydraulic pump to a cylinder for vertically swinging a working machine.
【０００２】[0002]
【従来の技術】パワーショベルのアーム等の作業機を上
下揺動するシリンダに圧油を供給するものとして、例え
ば図１に示すものが知られている。すなわち、可変容量
型油圧ポンプ（以下可変油圧ポンプという）１の吐出路
２にチェック弁部３と減圧弁部４より成る圧力補償弁
５、スプール６を備えた方向制御弁７を設け、その方向
制御弁７の出力側をアームシリンダ８のボトム室８ａ、
ヘッド室８ｂに接続し、前記可変油圧ポンプ１の斜板９
を傾転するサーボシリンダ１０を設け、このサーボシリ
ンダ１０の第１室１０ａにポンプ吐出圧を直接供給し、
第２室１０ｂには第１制御弁１１と第２制御弁１２によ
りポンプ吐出圧を供給するようにしてある。2. Description of the Related Art For example, the one shown in FIG. 1 is known as one for supplying pressure oil to a cylinder that vertically swings a working machine such as an arm of a power shovel. That is, a pressure compensation valve 5 including a check valve portion 3 and a pressure reducing valve portion 4 and a direction control valve 7 including a spool 6 are provided in a discharge passage 2 of a variable displacement hydraulic pump (hereinafter referred to as a variable hydraulic pump) 1 The output side of the control valve 7 is connected to the bottom chamber 8a of the arm cylinder 8,
The swash plate 9 of the variable hydraulic pump 1 is connected to the head chamber 8b.
Is provided with a servo cylinder 10 that tilts the pump cylinder, and the pump discharge pressure is directly supplied to the first chamber 10a of the servo cylinder 10.
Pump discharge pressure is supplied to the second chamber 10b by the first control valve 11 and the second control valve 12.
【０００３】前記第１制御弁１１は受圧部１１ａに作用
するポンプ吐出圧により供給位置ａに作動し、斜板９に
連結したフィードバックリンク１３とばね１４でドレー
ン位置ｂに作動してポンプ吐出圧が高圧となると斜板角
小、ポンプ吐出圧が低圧となると斜板角大となるよう切
換って可変油圧ポンプ１の吸収トルクを一定の値として
いる。The first control valve 11 is operated at the supply position a by the pump discharge pressure acting on the pressure receiving portion 11a, and is operated at the drain position b by the feedback link 13 and the spring 14 connected to the swash plate 9 so that the pump discharge pressure is increased. When the pressure is high, the swash plate angle is small, and when the pump discharge pressure is low, the swash plate angle is large, and the variable hydraulic pump 1 has a constant absorption torque.
【０００４】前記第２制御弁１２は第１受圧部１２ａに
作用するポンプ吐出圧で供給位置ｃに作動し、第２受圧
部１２ｂに作用する負荷圧でドレーン位置ｄに作動して
ポンプ吐出圧と負荷圧の差圧が大きい時には斜板角小と
し、その差圧が小さく時には斜板角大として前記ポンプ
吐出圧と負荷圧の差圧を一定となるように制御する。The second control valve 12 is operated at the supply position c by the pump discharge pressure acting on the first pressure receiving portion 12a, and is operated at the drain position d by the load pressure acting on the second pressure receiving portion 12b. When the differential pressure between the load pressure is large, the swash plate angle is set to be small, and when the differential pressure is small, the swash plate angle is set to be large to control the differential pressure between the pump discharge pressure and the load pressure to be constant.
【０００５】[0005]
【発明が解決しようとする課題】かかる圧油供給装置に
おいては方向制御弁７のスプール６が中立位置の時に
は、その第１・第２アクチュエータポート１５，１６と
第１・第２負荷圧検出ポート１７，１８が遮断して負荷
圧検出回路１９に負荷圧が導入されず、第２制御弁１２
は第１受圧部１２ａに作用するポンプ吐出圧で供給位置
ｃとなってポンプ吐出圧がサーボシリンダ１０の第２室
１０ｂに供給されて斜板９は最小角位置となる。In such a pressure oil supply device, when the spool 6 of the directional control valve 7 is in the neutral position, the first and second actuator ports 15 and 16 and the first and second load pressure detection ports thereof are provided. Since the load pressure is not introduced to the load pressure detection circuit 19 due to the interruption of the valves 17 and 18, the second control valve 12
Is the supply position c due to the pump discharge pressure acting on the first pressure receiving portion 12a, and the pump discharge pressure is supplied to the second chamber 10b of the servo cylinder 10 so that the swash plate 9 is at the minimum angular position.
【０００６】アームシリンダ８が最縮状態でアームＡが
上方に揺動した状態より方向制御弁７のスプール６を切
換えて第２アクチュエータポート１６に圧油を流してア
ームシリンダ８のボトム室８ａに供給してアームシリン
ダ８を伸長する場合に、アームシリンダ８のヘッド室８
ｂは第１アクチュエータポート１５よりタンクに連通す
ると共に、アームＡは自重により下方に揺動するために
アームシリンダ８は外力によって伸長し、ヘッド室８ｂ
をタンクに連通する戻り回路をかなり絞らない限り、ボ
トム室８ａに負荷圧が生じないから、可変油圧ポンプ１
の吐出路２の圧力が上昇しない。When the arm cylinder 8 is in the most contracted state and the arm A is swung upward, the spool 6 of the directional control valve 7 is switched to flow the pressure oil to the second actuator port 16 to the bottom chamber 8a of the arm cylinder 8. When supplying and extending the arm cylinder 8, the head chamber 8 of the arm cylinder 8
b communicates with the tank from the first actuator port 15, and the arm A swings downward due to its own weight, so that the arm cylinder 8 extends by an external force, and the head chamber 8b.
Since the load pressure does not occur in the bottom chamber 8a unless the return circuit communicating with the tank is considerably narrowed, the variable hydraulic pump 1
The pressure in the discharge passage 2 does not rise.
【０００７】一方、可変油圧ポンプ１の斜板９は方向制
御弁７のスプール６のコントロール切欠６ａの開口面積
に見合う分圧油を吐出しようと傾転角大方向に動こうと
するが、斜板９、サーボシリンダ１０、フィードバック
リンク１３部分の摺動抵抗があるためある一定のポンプ
吐出圧以上ないと動けない。On the other hand, the swash plate 9 of the variable hydraulic pump 1 tries to move in the large tilt angle direction in order to discharge the partial pressure oil corresponding to the opening area of the control notch 6a of the spool 6 of the directional control valve 7. Because of the sliding resistance of the plate 9, the servo cylinder 10, and the feedback link 13, the pump cannot move unless it has a certain pump discharge pressure.
【０００８】このようであるから、前述のように方向制
御弁７のスプール６を中立位置より切換えても最初はア
ームシリンダ８のボトム室８ａの負荷圧が上昇せずにポ
ンプ吐出圧が一定の圧力以上となるまでは斜板９の動く
速度は遅いために可変油圧ポンプ１の吐出量が少なくア
ームシリンダ８のボトム室８ａに圧油が十分に供給され
ない。Because of this, even if the spool 6 of the directional control valve 7 is switched from the neutral position as described above, the load pressure of the bottom chamber 8a of the arm cylinder 8 does not initially rise and the pump discharge pressure remains constant. Until the pressure exceeds the pressure, the moving speed of the swash plate 9 is slow, so the discharge amount of the variable hydraulic pump 1 is small and the pressure oil is not sufficiently supplied to the bottom chamber 8a of the arm cylinder 8.
【０００９】したがって、アームＡは自由落下速度でし
か動けないため最初はアームＡ作動速度が遅く、アーム
シリンダ８のボトム室８ａは真空状態となり、アームシ
リンダ８が正常の速度で動くのは可変油圧ポンプ１の斜
板９が所定の傾転角位置に動いて吐出量が大となり、圧
油をアームシリンダ８のボトム室８ａに送り出しボトム
室８ａの真空分が圧油で満たされてからとなる。Therefore, since the arm A can move only at the free fall speed, the operation speed of the arm A is slow at first, the bottom chamber 8a of the arm cylinder 8 is in a vacuum state, and the arm cylinder 8 moves at a normal speed by the variable hydraulic pressure. After the swash plate 9 of the pump 1 moves to a predetermined tilt angle position and the discharge amount becomes large, pressure oil is sent to the bottom chamber 8a of the arm cylinder 8 and the vacuum amount in the bottom chamber 8a is filled with the pressure oil. .
【００１０】このために、アームＡの動作速度は初めゆ
っくりで、シリンダ最縮で最も上方に揺動した状態から
アームＡが垂直に近い状態になり、アームシリンダヘッ
ド室８ｂに自重による外力が小さくなってボトム室８ａ
の真空状態がなくなり、負荷圧が高くなってから前述の
ように斜板９の傾転角が傾転角大の方向へ動くためアー
ムＡの動作速度が急に速くなり正常の速度で動作するの
で、オペレータに異和感を与えることになる。For this reason, the operating speed of the arm A is slow at first, and the arm A is brought into a state close to vertical from the state where it is swung up to the maximum at the cylinder contraction, and the external force due to its own weight is small in the arm cylinder head chamber 8b. The bottom chamber 8a
After the vacuum state disappears and the load pressure increases, the tilt angle of the swash plate 9 moves in the direction of the larger tilt angle as described above, so that the operating speed of the arm A suddenly increases and operates at a normal speed. Therefore, the operator feels strange.
【００１１】そこで、本発明は前述の課題を解決できる
ようにした圧油供給装置を提供することを目的とする。Therefore, an object of the present invention is to provide a pressure oil supply device which can solve the above-mentioned problems.
【００１２】[0012]
【課題を解決するための手段】可変容量型油圧ポンプ１
の吐出圧油を方向制御弁７で作業機上下揺動用のシリン
ダに供給し、前記可変容量型油圧ポンプ１の斜板９をサ
ーボシリンダ１０で傾転し、このサーボシリンダ１０を
傾転角大方向に作動する一方の室に自己のポンプ吐出圧
油を直接供給し、傾転角小方向に作動する他方の室に制
御弁により制御圧を供給し、この制御弁を自己のポンプ
吐出圧と前記シリンダの負荷圧の差圧が大の時に供給位
置ｃ、小さい時にドレーン位置ｄに切換わるものとし、
前記方向制御弁７がシリンダ８のボトム室８ａに圧油を
供給する位置に切換えられた時に、前記サーボシリンダ
１０の一方の室に油圧パイロット弁の圧油を供給する手
段を設けた圧油供給装置。[Means for Solving the Problems] Variable displacement hydraulic pump 1
The discharge pressure oil is supplied to the cylinder for vertically swinging the working machine by the direction control valve 7, the swash plate 9 of the variable displacement hydraulic pump 1 is tilted by the servo cylinder 10, and the servo cylinder 10 is tilted at a large tilt angle. One of the chambers operating in one direction is directly supplied with its own pump discharge pressure oil, and the other chamber operating in the small tilt angle direction is supplied with a control pressure by a control valve. When the differential pressure of the load pressure of the cylinder is large, it is switched to the supply position c, and when it is small, it is switched to the drain position d,
Pressure oil supply provided with means for supplying pressure oil of the hydraulic pilot valve to one chamber of the servo cylinder 10 when the directional control valve 7 is switched to a position for supplying pressure oil to the bottom chamber 8a of the cylinder 8. apparatus.
【００１３】[0013]
【作 用】シリンダ８のボトム室８ａに圧油を供給し
て作業機を下方に揺動する時にサーボシリンダ１０の一
方の室に圧油が供給されて可変容量型油圧ポンプ１の吐
出量がポンプ吐出圧と負荷圧との差圧に関係なく増大す
るので、作業機を最初から正常の速度で動作できる。[Operation] When the pressure oil is supplied to the bottom chamber 8a of the cylinder 8 and the working machine is swung downward, the pressure oil is supplied to one chamber of the servo cylinder 10 and the discharge amount of the variable displacement hydraulic pump 1 is increased. Since the pressure increases regardless of the pressure difference between the pump discharge pressure and the load pressure, the working machine can be operated at a normal speed from the beginning.
【００１４】[0014]
【実 施 例】本発明の実施例を図２に基づいて説明す
る。なお、従来と同一部材は符号を同一とする。方向制
御弁７のスプール６はスプリング２０で中立位置に保持
され、第１受圧室２１の圧力で第１位置に押され、第２
受圧室２２の圧力で第２位置に押される。前記スプール
６が第１位置となるとポンプポート２３に流入した圧油
が切欠６ａ，第２負荷圧検出ポート１８、油孔２４、第
１負荷圧検出ポート１７より第１アクチュエータポート
１５に流れ、第２アクチュエータポート１６は第２タン
クポート２５に連通する。前記スプール６が第２位置と
なるとポンプポート２３に流入した圧油が切欠６ａ、第
１負荷圧検出ポート１７、油孔２４、第２負荷圧検出ポ
ート１８より第２アクチュエータポート１６に流れ、第
１アクチュエータポート１５は第１タンクポート２６に
連通する。EXAMPLE An example of the present invention will be described with reference to FIG. It should be noted that the same members as those in the related art have the same reference numerals. The spool 6 of the directional control valve 7 is held in the neutral position by the spring 20, and is pushed to the first position by the pressure of the first pressure receiving chamber 21.
It is pushed to the second position by the pressure of the pressure receiving chamber 22. When the spool 6 reaches the first position, the pressure oil flowing into the pump port 23 flows from the notch 6a, the second load pressure detecting port 18, the oil hole 24, the first load pressure detecting port 17 to the first actuator port 15, The two-actuator port 16 communicates with the second tank port 25. When the spool 6 is in the second position, the pressure oil flowing into the pump port 23 flows from the notch 6a, the first load pressure detecting port 17, the oil hole 24, and the second load pressure detecting port 18 to the second actuator port 16, The first actuator port 15 communicates with the first tank port 26.
【００１５】油圧パイロット弁３０は操作レバー３１を
操作することで減圧弁３２を作動して補助油圧ポンプ３
３の吐出圧油を第１・第２パイロット回路３４，３５に
出力するものであり、その第１・第２パイロット回路３
４，３５は前記方向制御弁７の第１・第２受圧室２１，
２２にそれぞれ接続し、第２パイロット回路３５はチェ
ック弁３６を介して前記サーボシリンダ１０の第１室１
０ａに接続してある。The hydraulic pilot valve 30 operates the pressure reducing valve 32 by operating the operation lever 31 to operate the auxiliary hydraulic pump 3.
The discharge pressure oil of No. 3 is output to the first and second pilot circuits 34 and 35, and the first and second pilot circuits 3
4, 35 are the first and second pressure receiving chambers 21 of the directional control valve 7,
22 and the second pilot circuit 35 is connected to the first chamber 1 of the servo cylinder 10 via a check valve 36.
0a.
【００１６】前記圧力補償弁５のチェック弁部３は入口
ポート４０と出口ポート４１を連通・遮断するスプール
４２を備え、入口ポート４０の圧油を油孔４３で圧力室
４４に供給してスプール４２を連通方向に押す。The check valve portion 3 of the pressure compensating valve 5 is provided with a spool 42 that connects and disconnects the inlet port 40 and the outlet port 41, and supplies the pressure oil of the inlet port 40 to the pressure chamber 44 through the oil hole 43. 42 is pushed in the communication direction.
【００１７】前記減圧弁部４は第１ポート４５と第２ポ
ート４６を連通、遮断するスプール４７を備え、このス
プール４７は第１受圧室４８の圧力で連通方向に押さ
れ、第２受圧室４９の圧力とばね５０で遮断方向に押さ
れ、かつロッド５１を介して前記チェック弁部３のスプ
ール４２を遮断方向に押し、その第１受圧室４８は第２
負荷圧検出ポート１８に連通し、第２受圧室４９は第２
ポート４６に連通し、その第２ポート４６が負荷圧検出
回路１９に連通し、第１ポート４５が可変油圧ポンプ１
の吐出路２に連通している。The pressure reducing valve section 4 is provided with a spool 47 which connects and disconnects the first port 45 and the second port 46, and the spool 47 is pushed in the communication direction by the pressure of the first pressure receiving chamber 48 and the second pressure receiving chamber. The pressure of 49 and the spring 50 push in the shut-off direction and push the spool 42 of the check valve portion 3 in the shut-off direction via the rod 51, and the first pressure receiving chamber 48 of the second pressure chamber 48
The second pressure receiving chamber 49 communicates with the load pressure detection port 18
The second port 46 communicates with the port 46, the second port 46 communicates with the load pressure detection circuit 19, and the first port 45 communicates with the variable hydraulic pump 1.
Communicating with the discharge passage 2 of.
【００１８】次に、方向制御弁７のスプール６が中立位
置で可変油圧ポンプ１の斜板９が最小角度で、アームシ
リンダ８が最縮状態でアームＡが上方に揺動した状態よ
り方向制御弁７のスプール６を切換えて第２アクチュエ
ータポート１６に圧油を流してアームシリンダ８のボト
ム室８ａに供給してアームシリンダ８を伸長する場合の
動作を説明する。油圧パイロット弁３０の操作レバー３
１を操作して第２パイロット回路３５にパイロット圧油
を出力し、方向制御弁７の第２受圧室２２に圧油を供給
してスプール６を第２位置とする。Next, the direction control is performed from the state where the spool 6 of the directional control valve 7 is in the neutral position, the swash plate 9 of the variable hydraulic pump 1 is at the minimum angle, the arm cylinder 8 is in the most contracted state, and the arm A is swung upward. The operation when the spool 6 of the valve 7 is switched to flow pressure oil to the second actuator port 16 and supply the pressure oil to the bottom chamber 8a of the arm cylinder 8 to extend the arm cylinder 8 will be described. Operation lever 3 of hydraulic pilot valve 30
1 is operated to output pilot pressure oil to the second pilot circuit 35, and the pressure oil is supplied to the second pressure receiving chamber 22 of the directional control valve 7 to bring the spool 6 to the second position.
【００１９】これと同時にチェック弁３６を介してサー
ボシリンダ１０の第１室１０ａに圧油が供給されるの
で、そのサーボシリンダ１０の第１室１０ａ内の圧力は
油圧パイロット弁３０の出力圧（例えば３０ｋｇ／ｃｍ
2 ）となる。このために、可変油圧ポンプ１の吐出圧が
３０ｋｇ／ｃｍ2 よりも低い圧力であってもサーボシリ
ンダ１０は容量大方向に作動して斜板９の傾動角を大き
くするので、可変油圧ポンプ１の吐出量は自己のポンプ
吐出圧、負荷圧によらず油圧パイロット弁３０の出力圧
に見合う値となる。At the same time, since pressure oil is supplied to the first chamber 10a of the servo cylinder 10 via the check valve 36, the pressure in the first chamber 10a of the servo cylinder 10 is the output pressure of the hydraulic pilot valve 30 ( For example, 30 kg / cm
2 ) For this reason, even if the discharge pressure of the variable hydraulic pump 1 is lower than 30 kg / cm 2, the servo cylinder 10 operates in the direction of large capacity to increase the tilt angle of the swash plate 9, so the variable hydraulic pump 1 The discharge amount of is a value commensurate with the output pressure of the hydraulic pilot valve 30 regardless of its own pump discharge pressure and load pressure.
【００２０】したがって、前述のようにアームシリンダ
８のボトム室８ａ内に負荷圧が生じない場合でも方向制
御弁７を切換えると直ちに可変油圧ポンプ１の吐出量が
増大し、アームシリンダ８のボトム室８ａに圧油を十分
に供給してアームＡを最初から正常の速度で動作でき
る。また、可変油圧ポンプ１の吐出圧が油圧パイロット
弁３０の出力圧よりも高圧となってもチェック弁３６に
よりサーボシリンダ１０の第１室１０ａからポンプ吐出
圧が第２パイロット回路３５に逆流することがない。Therefore, as described above, even when the load pressure is not generated in the bottom chamber 8a of the arm cylinder 8, when the directional control valve 7 is switched, the discharge amount of the variable hydraulic pump 1 immediately increases, and the bottom chamber of the arm cylinder 8 is increased. Sufficient supply of pressure oil to 8a allows arm A to operate at a normal speed from the beginning. Further, even if the discharge pressure of the variable hydraulic pump 1 becomes higher than the output pressure of the hydraulic pilot valve 30, the check valve 36 causes the pump discharge pressure to flow backward from the first chamber 10a of the servo cylinder 10 to the second pilot circuit 35. There is no.
【００２１】以上の実施例ではチェック弁部３と減圧弁
部４より成る圧力補償弁５を用いたが、通常一般の圧力
補償弁を用いても良いし、この圧力補償弁を用いない場
合にも本発明を適用できる。In the above embodiment, the pressure compensating valve 5 including the check valve portion 3 and the pressure reducing valve portion 4 is used. However, a general pressure compensating valve may be used, or when this pressure compensating valve is not used. The present invention can also be applied.
【００２２】[0022]
【発明の効果】シリンダ８のボトム室８ａに圧油を供給
して作業機を下方に揺動する時にサーボシリンダ１０の
一方の室に圧油が供給されて可変容量型油圧ポンプ１の
吐出量がポンプ吐出圧と負荷圧との差圧に関係なく増大
するので、作業機を最初から正常の速度で動作できる。The pressure oil is supplied to one chamber of the servo cylinder 10 when the working oil is rocked downward by supplying the pressure oil to the bottom chamber 8a of the cylinder 8 to discharge the variable displacement hydraulic pump 1. Increases regardless of the pressure difference between the pump discharge pressure and the load pressure, so that the working machine can be operated at a normal speed from the beginning.
【図１】従来例の説明図である。FIG. 1 is an explanatory diagram of a conventional example.
【図２】本発明の実施例を示す説明図である。FIG. 2 is an explanatory diagram showing an example of the present invention.
１…可変容量型油圧ポンプ、３…チェック弁部、４…減
圧弁部、５…圧力補償弁、６…スプール、７…方向制御
弁、８…アームシリンダ、８ａ…ボトム室、８ｂ…ベル
ト室、９…斜板、１０…サーボシリンダ、１０ａ…第１
室、１０ｂ…第２室、１１…第１制御弁、１２…第２制
御弁、２１…第１受圧室、２２…第２受圧室、３０…油
圧パイロット弁、３４…第１パイロット回路、３５…第
２パイロット回路、３６…チェック弁。DESCRIPTION OF SYMBOLS 1 ... Variable displacement hydraulic pump, 3 ... Check valve part, 4 ... Pressure reduction valve part, 5 ... Pressure compensation valve, 6 ... Spool, 7 ... Direction control valve, 8 ... Arm cylinder, 8a ... Bottom chamber, 8b ... Belt chamber , 9 ... swash plate, 10 ... servo cylinder, 10a ... first
Chamber, 10b ... 2nd chamber, 11 ... 1st control valve, 12 ... 2nd control valve, 21 ... 1st pressure receiving chamber, 22 ... 2nd pressure receiving chamber, 30 ... Hydraulic pilot valve, 34 ... 1st pilot circuit, 35 … Second pilot circuit, 36… Check valve.
Claims (3)
向制御弁７で作業機上下揺動用のシリンダに供給し、前
記可変容量型油圧ポンプ１の斜板９をサーボシリンダ１
０で傾転し、このサーボシリンダ１０を傾転角大方向に
作動する一方の室に自己のポンプ吐出圧油を直接供給
し、傾転角小方向に作動する他方の室をポンプ吐出圧と
負荷圧の差圧で切換わって傾転角小方向へ作動する制御
弁により制御圧を供給し、 前記方向制御弁７がシリンダ８のボトム室８ａに圧油を
供給する位置に切換えられた時に、前記サーボシリンダ
１０の一方の室に第３の補助圧油を供給する手段を設け
たことを特徴とする圧油供給装置。1. Discharge pressure oil of a variable displacement hydraulic pump 1 is supplied to a cylinder for vertically swinging a working machine by a directional control valve 7, and a swash plate 9 of the variable displacement hydraulic pump 1 is connected to a servo cylinder 1
When the servo cylinder 10 is tilted at 0, the self pump discharge pressure oil is directly supplied to one chamber that operates in the large tilt angle direction, and the other chamber that operates in the small tilt angle direction is used as the pump discharge pressure. When the directional control valve 7 is switched to the position for supplying the pressure oil to the bottom chamber 8a of the cylinder 8, the control pressure is supplied by the control valve which is switched by the differential pressure of the load pressure and operates in the small tilt angle direction. A pressure oil supply device comprising means for supplying a third auxiliary pressure oil to one chamber of the servo cylinder 10.
給される圧油でシリンダ８のヘッド室８ｂに圧油を供給
する位置に切換わり、第２受圧室２２に供給される圧油
でシリンダ８のボトム室８ａに圧油を供給する位置に切
換わるものとし、この第１・第２受圧室２１，２２に油
圧パイロット弁３０の第１・第２パイロット回路３４，
３５をそれぞれ接続し、その第２パイロット回路３５を
前記サーボシリンダ１０の一方の室に接続した請求項１
記載の圧油供給装置。2. The directional control valve 7 is switched to a position for supplying pressure oil to the head chamber 8b of the cylinder 8 with the pressure oil supplied to the first pressure receiving chamber 21, and the pressure supplied to the second pressure receiving chamber 22 is changed. It is assumed that the oil is switched to a position where pressure oil is supplied to the bottom chamber 8a of the cylinder 8, and the first and second pressure receiving chambers 21 and 22 are connected to the first and second pilot circuits 34 of the hydraulic pilot valve 30.
35, respectively, and the second pilot circuit 35 is connected to one chamber of the servo cylinder 10.
The pressure oil supply device described.
弁３６を介してサーボシリンダ１９の一方の室に接続し
た請求項２記載の圧油供給装置。3. The pressure oil supply device according to claim 2, wherein the second pilot circuit 35 is connected to one chamber of the servo cylinder 19 via a check valve 36.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5241195A JPH0791403A (en) | 1993-09-28 | 1993-09-28 | Pressure oil supply device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5241195A JPH0791403A (en) | 1993-09-28 | 1993-09-28 | Pressure oil supply device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0791403A true JPH0791403A (en) | 1995-04-04 |
Family
ID=17070628
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5241195A Pending JPH0791403A (en) | 1993-09-28 | 1993-09-28 | Pressure oil supply device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0791403A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102410267A (en) * | 2011-11-03 | 2012-04-11 | 徐州雷曼机械科技有限公司 | Synchronous control device of revolving speed of hydraulic walking mechanism engine and discharge of main pump |
-
1993
- 1993-09-28 JP JP5241195A patent/JPH0791403A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102410267A (en) * | 2011-11-03 | 2012-04-11 | 徐州雷曼机械科技有限公司 | Synchronous control device of revolving speed of hydraulic walking mechanism engine and discharge of main pump |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3119722B2 (en) | Hydraulic circuit of 4-position closed center switching valve by pressure proportional control valve | |
| JPH0893002A (en) | Hydraulic control device of excaving machine | |
| JP6789843B2 (en) | Control device for hydraulic machinery | |
| JP2001323902A (en) | Hydraulic driven device | |
| JPH0882289A (en) | Displacement control device of variable displacement hydraulic pump | |
| JPH0791403A (en) | Pressure oil supply device | |
| JPH1037907A (en) | Pressure oil supply device | |
| KR0169880B1 (en) | Boom ascending and revolution velocity control devices of dredger | |
| JP6782272B2 (en) | Construction machinery | |
| JP2721384B2 (en) | Hydraulic circuit of work machine | |
| JP3553651B2 (en) | Displacement control device for variable displacement hydraulic pump | |
| KR101241713B1 (en) | Apparatus for controlling the flow rates of the hydraulic pump of a wheel loader | |
| JPH07293508A (en) | Hydraulic control device | |
| JP2839567B2 (en) | Hydraulic drive for construction machinery | |
| JPH0510269A (en) | Method for controlling absorption torque of variable displacement type hydraulic pump | |
| JP3097041B2 (en) | Return flow sharing circuit for pressure oil supply device | |
| JPS6342051B2 (en) | ||
| JPH05172107A (en) | Capacity control device for variable hydraulic pump | |
| JP3307436B2 (en) | Hydraulic control device | |
| JP2556998B2 (en) | Hydraulic circuit | |
| JP2563216B2 (en) | Hydraulic circuit | |
| JP2004270780A (en) | Hydraulically driven device for construction machine | |
| JPH06117402A (en) | Load-sensing type oil pressure control device | |
| JPH0112962B2 (en) | ||
| JP3084570B2 (en) | Load pressure detection type hydraulic circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Effective date: 20040113 Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Effective date: 20040113 Free format text: JAPANESE INTERMEDIATE CODE: A61 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |