JPH0643301U - Directional control valve device - Google Patents
Directional control valve deviceInfo
- Publication number
- JPH0643301U JPH0643301U JP7761592U JP7761592U JPH0643301U JP H0643301 U JPH0643301 U JP H0643301U JP 7761592 U JP7761592 U JP 7761592U JP 7761592 U JP7761592 U JP 7761592U JP H0643301 U JPH0643301 U JP H0643301U
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- valve
- ports
- directional control
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Abstract
(57)【要約】
【目的】 複数の方向制御弁と複数の圧力補償弁より成
る方向制御弁装置をコンパクトにする。
【構成】 弁ブロック３０に方向制御弁５５の主スプー
ル４９、圧力補償弁７５のチェック弁部６３と減圧弁部
７４を設け、この弁ブロック３０を複数連結して各弁ブ
ロック３０の第１・第２タンクポート４７，４８及びポ
ンプポートをそれぞれ連通し、いずれか１つの弁ブロッ
ク３０の第１・第２タンクポート４７，４８を主タンク
ポートに連通し、かつポンプポートを主入力ポートに連
通する。
(57) [Summary] [Purpose] To make a directional control valve device composed of a plurality of directional control valves and a plurality of pressure compensation valves compact. [Structure] The valve block 30 is provided with a main spool 49 of a directional control valve 55, a check valve portion 63 and a pressure reducing valve portion 74 of a pressure compensating valve 75, and a plurality of valve blocks 30 are connected to form the first and second valve blocks 30 of each valve block 30. The second tank port 47, 48 and the pump port are communicated with each other, the first and second tank ports 47, 48 of any one valve block 30 are communicated with the main tank port, and the pump port is communicated with the main input port. To do.
Description
【０００１】[0001]
本考案は、１つの油圧ポンプの吐出圧油を複数のアクチュエータに流量分配し て供給する圧油供給装置に用いる方向制御弁装置に関する。 The present invention relates to a directional control valve device used in a pressure oil supply device that distributes the flow rate of pressure oil discharged from one hydraulic pump to a plurality of actuators.
【０００２】[0002]
特開昭６０−１１７０６号公報に示す圧油供給装置が知られている。 すなわち、図１に示すように油圧ポンプ１の吐出導管２に複数の圧力補償弁３ ，１３を並列に接続し、各圧力補償弁３，１３の出口導管４，１４に方向制御弁 ５，１５をそれぞれ設けこの各方向制御弁５，１５の出力側をアクチュエータ６ ，１６にそれぞれ接続し、前記圧力補償弁３，１３をポンプ吐出圧と方向制御弁 出口圧で開き方向に押され、方向制御弁入口圧と最も高い負荷圧で閉じ方向に押 される構造とした圧油供給装置である。 この圧油供給装置であれば、複数の方向制御弁５，１５を同時操作した時に各 アクチュエータにポンプ吐出圧油を所定の分配比で供給できる。 A pressure oil supply device disclosed in Japanese Patent Laid-Open No. 60-11706 is known. That is, as shown in FIG. 1, a plurality of pressure compensating valves 3 and 13 are connected in parallel to a discharge conduit 2 of a hydraulic pump 1, and directional control valves 5 and 15 are connected to outlet conduits 4 and 14 of each pressure compensating valve 3 and 13. The output sides of the directional control valves 5 and 15 are connected to the actuators 6 and 16, respectively, and the pressure compensating valves 3 and 13 are pushed in the opening direction by the pump discharge pressure and the directional control valve outlet pressure to control the direction. It is a pressure oil supply device that is structured to be pushed in the closing direction by the valve inlet pressure and the highest load pressure. With this pressure oil supply device, pump discharge pressure oil can be supplied to each actuator at a predetermined distribution ratio when a plurality of directional control valves 5, 15 are simultaneously operated.
【０００３】 かかる圧油供給装置であるとアクチュエータの負荷圧を比較して高い方の負荷 圧を圧力補償弁に供給するためにシャトル弁７が必ず必要であり、しかもこのシ ャトル弁７はアクチュエータの数より１つ少ない数だけ必要であり、それだけコ ストが高くなる。 また、前述の図１に示す圧油供給装置であると２つのアクチュエータ６，１６ をともに作動させ、それらの負荷圧のうち、アクチュエータ６側の負荷圧が大き いとする。このときは、導管８内の圧力が最高負荷圧としてシャトル弁７によっ て導管９に導かれる。次に、負荷圧が変動して、アクチュエータ１６側の負荷圧 の方がアクチュエータ６側の負荷圧より大きくなったとする。その際、すなわち シャトル弁７が切換わる際、シャトル弁７内の吹きぬけにより導管１８内の圧力 がぬけ、他方の導管８内の圧力が押しこめられる。そのため、シャトル弁７の切 換え時、過渡的にアクチュエータ１６は自然降下しアクチュエータ６は加速され る。In such a pressure oil supply device, the shuttle valve 7 is indispensable for comparing the load pressure of the actuator and supplying the higher load pressure to the pressure compensating valve, and moreover, the shuttle valve 7 is the actuator. Only one less than is needed, and the cost is higher. Further, in the pressure oil supply device shown in FIG. 1 described above, it is assumed that the two actuators 6 and 16 are both actuated, and the load pressure on the actuator 6 side is large among those load pressures. At this time, the pressure in the conduit 8 is guided to the conduit 9 by the shuttle valve 7 as the maximum load pressure. Next, it is assumed that the load pressure fluctuates and the load pressure on the actuator 16 side becomes larger than the load pressure on the actuator 6 side. At that time, that is, when the shuttle valve 7 is switched, the pressure in the conduit 18 is released by the blowout in the shuttle valve 7, and the pressure in the other conduit 8 is pushed. Therefore, when the shuttle valve 7 is switched, the actuator 16 transiently descends naturally and the actuator 6 is accelerated.
【０００４】 この課題を解決できるようにした圧油供給装置としては、図２に示すように、 油圧ポンプ２０の吐出路２１に複数の方向制御弁２２を設け、この各方向制御弁 ２２の入口側にチェック弁２３と減圧弁部２４より成る圧力補償弁２５をそれぞ れ設けたものが知られている。As a pressure oil supply device capable of solving this problem, as shown in FIG. 2, a plurality of directional control valves 22 are provided in a discharge passage 21 of a hydraulic pump 20, and an inlet of each directional control valve 22 is provided. It is known that a pressure compensating valve 25 including a check valve 23 and a pressure reducing valve portion 24 is provided on each side.
【０００５】[0005]
かかる圧油供給装置においては複数の方向制御弁２２と複数の圧力補償弁２５ を有するから、それらを組み合せた場合に装置全体が大きくなって設置スペース が大きくなるので、例えば小型の建設機械では設置スペースが確保できないこと がある。 Since such a pressure oil supply device has a plurality of directional control valves 22 and a plurality of pressure compensation valves 25, when they are combined, the entire device becomes large and the installation space becomes large. Space may not be secured.
【０００６】 そこで、本考案は前述の課題を解決できるようにした方向制御弁装置を提供す ることを目的とする。Therefore, an object of the present invention is to provide a directional control valve device capable of solving the above-mentioned problems.
【０００７】[0007]
弁ブロック３０に入力ポート４４と第１・第２アクチュエータポート３４，３ ５と第１・第２タンクポート４７，４８を連通・遮断する主スプール４９を設け て方向制御弁５５とし、前記弁ブロック３０にチェック弁部６３と減圧弁部７４ を設けてポンプポートの圧油を負荷圧で圧力補償して前記入力ポート４４に供給 する圧力補償弁７５とし、前記弁ブロック３０を複数連結して各第１・第２タン クポート４７，４８と各ポンプポートを連通し、いずれか１つのポンプポートに 主入力ポート１０３を接続し、いずれか１つの第１・第２タンクポート４７，４ ８を主タンクポート１０４に接続して成る方向制御弁装置。 The valve block 30 is provided with a main spool 49 that connects and disconnects the input port 44, the first and second actuator ports 34 and 35, and the first and second tank ports 47 and 48 to form a directional control valve 55. 30 is provided with a check valve portion 63 and a pressure reducing valve portion 74 to form a pressure compensating valve 75 that pressure-compensates the pressure oil of the pump port with the load pressure and supplies the pressure oil to the input port 44. The first and second tank ports 47, 48 are connected to each pump port, the main input port 103 is connected to any one pump port, and any one of the first and second tank ports 47, 48 is connected to the main A directional control valve device connected to the tank port 104.
【０００８】[0008]
１つの弁ブロック３０に方向制御弁５５の主スプール４９と圧力補償弁７５の チェック弁部６３、減圧弁部７４を組み込み、その弁ブロック３０を複数連結し て圧力補償弁を有する方向制御弁装置としたから、全体がコンパクトになって設 置スペースを小さくできるので、小さな建設機械に設置できる。 The main spool 49 of the directional control valve 55, the check valve portion 63 and the pressure reducing valve portion 74 of the pressure compensating valve 75 are incorporated in one valve block 30, and a plurality of valve block 30 are connected to each other to provide a pressure compensating valve. Since it is compact, the installation space can be reduced and it can be installed on a small construction machine.
【０００９】[0009]
図３に示すように、弁ブロック３０は略直方体形状となり、この弁ブロック３ ０の上部寄りにスプール孔３１が左右側面３２，３３に開口して形成され、この スプール孔３１に開口した第１・第２アクチュエータポート３４，３５が上面３ ６に開口して形成してあり、弁ブロック３０の下部寄りには左側面３２に開口し たチェック弁用孔３７と右側面３３に開口した減圧弁用孔３８が同心状に形成さ れ、前記チェック弁用孔３７に開口したポンプポート３９が前後面４０，４１に 開口して形成され、前記減圧弁孔３８に開口した第１、第２ポート４２，４３が 前後面４０，４１に開口して形成してあり、複数の弁ブロック３０の前後面４０ ，４１を突き合せて連結すると各ポンプ・第１・第２ポート３９，４２，４３が 連通するようにしてある。 As shown in FIG. 3, the valve block 30 has a substantially rectangular parallelepiped shape, and a spool hole 31 is formed near the upper portion of the valve block 30 by opening to the left and right side surfaces 32 and 33. The second actuator ports 34, 35 are formed to open on the upper surface 36, and the check valve hole 37 opened on the left side surface 32 and the pressure reducing valve opened on the right side surface 33 are formed near the bottom of the valve block 30. First and second ports that are formed in the check valve hole 37 and that have pump ports 39 that open in the front and rear surfaces 40 and 41, and that open in the pressure reducing valve hole 38. 42, 43 are formed by opening the front and rear surfaces 40, 41, and when the front and rear surfaces 40, 41 of the plurality of valve blocks 30 are butted and connected to each other, the respective pumps, first and second ports 39, 42, 43 are connected. To communicate And Aru.
【００１０】 図４に示すように、前記弁ブロック３０にはスプール孔３１に開口した入力ポ ート４４、第１・第２負荷圧検出ポート４５，４６、前記第１・第２アクチュエ ータポート３４，３５、第１、第２タンクポート４７，４８が形成され、そのス プール孔３１に嵌挿した主スプール４９には第１・第２小径部５０，５１と連通 用溝５２が形成してあり、主スプール４９には第１・第２負荷圧検出ポート４５ ，４６を常時連通する第１油路５３及び第２負荷圧検出ポート４６と第２タンク ポート４８を連通・遮断する第２油路５４が形成され、スプール４９はスプリン グで各ポートを遮断し、第２油路５４で第２負荷圧検出ポート４６と第２タンク ポート４８を連通する中立位置Ａに保持され、スプール４９を右方に摺動すると 第２小径部５１で第２アクチュエータポート３５を第２タンクポート４８に連通 し、連通用溝５２で入力ポート４４が第２負荷圧検出ポート４６に連通し、第１ 小径部５０で第１アクチュエータポート３４が第１負荷圧検出ポート４５に連通 し、かつ第２負荷圧検出ポート４６と第２タンクポート４８が遮断する第１油圧 供給位置Ｂとなり、スプール４９を左方に摺動すると第１小径部５０で第１アク チュエータポート３４を第１タンクポート４７に連通し、連通用溝５２で入力ポ ート４４が第１負荷圧検出ポート４５に連通し、第２小径部５１で第２アクチュ エータポート３５が第２負荷圧検出ポート４６に連通し、かつ第２負荷圧検出ポ ート４６と第２タンクポート４８が遮断する第２圧油供給位置Ｃとなって方向制 御弁５５を構成している。As shown in FIG. 4, the valve block 30 has an input port 44 opened to the spool hole 31, first and second load pressure detection ports 45 and 46, and first and second actuator ports 34. , 35, first and second tank ports 47, 48 are formed, and first and second small diameter portions 50, 51 and a communication groove 52 are formed in the main spool 49 fitted in the spool hole 31. Yes, the main spool 49 has a first oil passage 53 that constantly connects the first and second load pressure detection ports 45 and 46, and a second oil that connects and disconnects the second load pressure detection port 46 and the second tank port 48. The passage 54 is formed, the spool 49 blocks each port by the spring, and the spool 49 is held at the neutral position A where the second load pressure detection port 46 and the second tank port 48 communicate with each other by the second oil passage 54. When sliding to the right, The second small diameter portion 51 connects the second actuator port 35 to the second tank port 48, the communication groove 52 connects the input port 44 to the second load pressure detection port 46, and the first small diameter portion 50 connects the first actuator port. 34 is in the first hydraulic pressure supply position B in which 34 communicates with the first load pressure detection port 45 and the second load pressure detection port 46 and the second tank port 48 shut off. When the spool 49 slides to the left, the first small diameter The portion 50 communicates the first actuator port 34 with the first tank port 47, the communication groove 52 communicates the input port 44 with the first load pressure detection port 45, and the second small diameter portion 51 communicates with the second actuator. The data port 35 communicates with the second load pressure detection port 46, and the second load pressure detection port 46 and the second tank port 48 are shut off from each other to become the second pressure oil supply position C, and the direction control valve 55 is opened. Constitution To have.
【００１１】 前記チェック弁用孔３７は油路５６で入力ポート４４に開口し、そのチェック 弁用孔３７には前記ポンプポート３９と入力ポート４４を連通遮断する弁６０が 嵌挿され、その弁６０はプラグ６１に設けたストッパ杆６２で図示位置より左方 に摺動しないように規制されて遮断位置に保持されてチェック弁部６３を構成し ている。The check valve hole 37 is opened to the input port 44 by the oil passage 56, and the check valve hole 37 is fitted with a valve 60 that shuts off the communication between the pump port 39 and the input port 44. Reference numeral 60 denotes a stopper rod 62 provided on the plug 61, which is regulated so as not to slide to the left from the illustrated position and is held at the shutoff position to form a check valve portion 63.
【００１２】 前記減圧弁用孔３８は第３ポート５７と油路５８で第２負荷圧検出ポート４６ に連通し、この減圧弁用孔３８にはスプール６４が嵌挿されて第１圧力室６５と 第２圧力室６６を形成し、第１圧力室６５を第３ポート５７に連通し、第２圧力 室６６は第２ポート４３に連通し、前記スプール６４の盲穴６７に挿入したフリ ーピストン６８と盲穴６７底部との間にばね６９が設けられてフリーピストン６ ８はプラグ７０に当接し、かつスプール６４に一体的に設けた押杆７１が透孔７ ２より突出して前記弁６０をストッパ杆６２に当接しており、前記スプール６４ には第１ポート４２を盲穴６７に連通する細孔７３が形成されて減圧弁部７４を 構成し、この減圧弁部７４と前記チェック弁部６３とで圧力補償弁７５を構成し ている。The pressure reducing valve hole 38 communicates with the second load pressure detecting port 46 through the third port 57 and the oil passage 58, and the spool 64 is fitted in the pressure reducing valve hole 38 to insert the first pressure chamber 65. And the second pressure chamber 66 is formed, the first pressure chamber 65 is communicated with the third port 57, the second pressure chamber 66 is communicated with the second port 43, and the free piston is inserted into the blind hole 67 of the spool 64. A spring 69 is provided between 68 and the bottom of the blind hole 67 so that the free piston 68 abuts on the plug 70, and the pushing rod 71 integrally provided on the spool 64 projects from the through hole 72 and the valve 60 Is in contact with the stopper rod 62, and the spool 64 is formed with a fine hole 73 for communicating the first port 42 with the blind hole 67 to form a pressure reducing valve portion 74. The pressure reducing valve portion 74 and the check valve The pressure compensating valve 75 with the part 63 There is.
【００１３】 このようであるから、複数の弁ブロック３０を前後面４０，４１相互を重ね合 せて連結すれば、各弁ブロック３０のポンプ・第１・第２ポート３９，４２，４ ３が連通するから、図５に示すように油圧ポンプ８０の吐出路８１をポンプポー ト３９、第１ポート４２に連通し、第２ポート４３に負荷圧検出路８２を接続す れば図６に示すように１つの油圧ポンプの吐出圧油を複数のアクチュエータに流 量分配して供給する油圧回路を構成できる。 図６において、８３は油圧ポンプ８０の吐出流量を制御する斜板、８４はサー ボシリンダ、８５はポンプ調整用方向制御弁である。Therefore, if a plurality of valve blocks 30 are connected by overlapping the front and rear surfaces 40 and 41, the pumps, the first and second ports 39, 42 and 43 of each valve block 30 are connected. As shown in FIG. 5, if the discharge passage 81 of the hydraulic pump 80 is connected to the pump port 39 and the first port 42 and the load pressure detection passage 82 is connected to the second port 43 as shown in FIG. It is possible to configure a hydraulic circuit in which the hydraulic fluid discharged from one hydraulic pump is flow-distributed and supplied to a plurality of actuators. In FIG. 6, 83 is a swash plate that controls the discharge flow rate of the hydraulic pump 80, 84 is a servo cylinder, and 85 is a directional control valve for pump adjustment.
【００１４】 図７は弁ブロック３０の連結状態を示す平面図であり、中間ブロック１００の 両側面１０１，１０２に弁ブロック３０の左右側面３２，３３をそれぞれ接続し 、中間ブロック１００に主入力ポート１０３と主タンクポート１０４を形成し、 その主入力ポート１０３を両側面１０１，１０２に開口して左右の弁ブロック３ ０のポンプポート３９と第１ポート４２にそれぞれ連通すると共に、主タンクポ ート１０４を両側面１０１，１０２に開口して左右の弁ブロック３０の第１・第 ２タンクポート４７，４８にそれぞれ連通してある。FIG. 7 is a plan view showing the connected state of the valve block 30. The left and right side surfaces 32 and 33 of the valve block 30 are connected to both side surfaces 101 and 102 of the intermediate block 100, respectively, and the intermediate block 100 is connected to the main input port. 103 and the main tank port 104 are formed, and the main input port 103 is opened to both side surfaces 101 and 102 to communicate with the pump port 39 and the first port 42 of the left and right valve blocks 30, respectively, and the main tank port 104 is opened on both side surfaces 101 and 102 and communicates with the first and second tank ports 47 and 48 of the left and right valve blocks 30, respectively.
【００１５】 また、図８に示すように任意の弁ブロック３０の下面に主入力ポート１０５を 形成し、最外端の弁ブロック３０に主タンクポート１０６を形成して複数の弁ブ ロック３０を直接連結するようにしても良い。 なお、弁ブロック３０の下面に形成した主入力ポート１０５は例えば図４に仮 想線で示すように形成すれば良い。Further, as shown in FIG. 8, a main input port 105 is formed on the lower surface of an arbitrary valve block 30, and a main tank port 106 is formed on the outermost valve block 30 to connect a plurality of valve blocks 30. You may make it connect directly. The main input port 105 formed on the lower surface of the valve block 30 may be formed as shown by a phantom line in FIG. 4, for example.
【００１６】 次に作動を図６に基づいて説明する。 方向制御弁５５が中立位置Ａのとき。 油圧ポンプ８０によってタンク８６から吸上げられた油は、吐出路８１を通っ てチェック弁部６３の開く方向の圧力室ａに案内される。この時、減圧弁部７４ の圧力室６５，６６は、ともにタンク８６に通じているので、この圧力室６５， ６６の圧力はともにゼロで、よって減圧弁部７４は、弱いばね６９によって押さ れ杆体７１がチェック弁部６３に当接しているだけである。 一方、ポンプ吐出圧は、ポンプ調整用方向制御弁８５のばね８７によって負荷 検出路８２の圧力との差圧がある一定に保たれる。いま、この差圧を２０ｋｇ／ ｃｍ2 とすると負荷圧検出路８２の圧力はゼロなので、ポンプ吐出圧は２０ｇ／ ｃｍ2 まで上昇し、同時にチェック弁部６３の圧力室ａにポンプ吐出圧が流入し て方向制御弁５５の入口圧（チェック弁部６３の出口圧）がポンプ吐出圧と等し くなるまでストロークし、等しくなれば、弱いばね６９によってレシートする。 減圧弁部７４は、ストロークエンド時のみ、ポンプ吐出路８１と圧力室６６を 連通させる一方、チェック弁部６３は、ストロークエンドに達する前に、ポンプ 吐出路８１と出口側を連通させるので、方向制御弁５５が中立位置Ａのときは、 ポンプ吐出路８１と圧力室６６が連通することはなく、圧力室６５の圧力はゼロ のままである。Next, the operation will be described with reference to FIG. When the directional control valve 55 is in the neutral position A. The oil sucked up from the tank 86 by the hydraulic pump 80 is guided through the discharge passage 81 to the pressure chamber a in the opening direction of the check valve portion 63. At this time, since the pressure chambers 65 and 66 of the pressure reducing valve portion 74 both communicate with the tank 86, the pressures of the pressure chambers 65 and 66 are both zero, so the pressure reducing valve portion 74 is pressed by the weak spring 69. The rod 71 is only in contact with the check valve portion 63. On the other hand, the pump discharge pressure is kept constant by the spring 87 of the pump adjusting directional control valve 85, which is a differential pressure from the pressure of the load detection path 82. Now, assuming that this pressure difference is 20 kg / cm 2 , the pressure in the load pressure detection path 82 is zero, so the pump discharge pressure rises to 20 g / cm 2, and at the same time the pump discharge pressure flows into the pressure chamber a of the check valve 63. Then, the stroke is made until the inlet pressure of the directional control valve 55 (the outlet pressure of the check valve portion 63) becomes equal to the pump discharge pressure, and if they become equal, the weak spring 69 makes a receipt. The pressure reducing valve portion 74 connects the pump discharge passage 81 and the pressure chamber 66 only at the end of the stroke, while the check valve portion 63 connects the pump discharge passage 81 and the outlet side before reaching the stroke end. When the control valve 55 is in the neutral position A, the pump discharge passage 81 and the pressure chamber 66 do not communicate with each other, and the pressure in the pressure chamber 65 remains zero.
【００１７】 方向制御弁５５のいずれか一方のみ第１圧油供給位置Ｂにストロークさせる とき。 いま、左側の方向制御弁５５を第１圧油供給位置Ｂにストロークさせ、右側の 方向制御弁５５は、中立位置Ａとする。 方向制御弁５５をストロークさせ入力ポート４４と第１アクチュエータポート ３４を接続させ、同時に、第２アクチュエータ３５と第２タンクポート４８を接 続させる。この時第１アクチュエータポート３４とアクチュエータ８８を接続す る導管８９内の圧力（負荷圧）がポンプ吐出圧（２０ｋｇ／ｃｍ2 ）より大きい ときはチェック弁部６３が圧力室ｂの圧力でレシートするため、アクチュエータ ８８の自然降下を防止することができる。 アクチュエータ８８の導管８９の圧力、すなわち負荷圧が第１油路５３、通路 ５８より減圧弁部７４の一方の圧力室６５に導かれる。他方の圧力室６６の圧力 はゼロであるため、減圧弁部７４は、チェック弁部６３から解離する方向にスト ロークエンドまでストロークし、減圧弁部７４の絞りを介して、ポンプ吐出路８ １と負荷圧検出路８２が連通する。前記導管８９内の圧力（負荷圧）がポンプ吐 出圧（＝２０ｋｇ／ｃｍ2 ）より大きいときは、チェック弁部６３の圧力室ｂの 圧力で閉じ、その圧力が、減圧弁部７４の一方の圧力室６５に導かれるため、他 方の圧力室６６とポンプ吐出路８１が連通しても、減圧弁部７４はストロークし たままである。一方、導管４１内の圧力（負荷圧）がポンプ吐出圧（＝２０ｋｇ ／ｃｍ2 ）より小さいときは、その負荷圧が減圧弁部７４の一方の圧力室６５に 導かれ、減圧弁部７４が一方の圧力室６５の圧力でストロークするが、他方の圧 力室６６の圧力が一方の圧力室６５の圧力（すなわち負荷圧）まで上昇すると、 弱いばね６９によって閉じチェック弁部６３に当接する。 いずれの場合でも、減圧弁部７４は、一方の圧力室６５内の圧力と他方の圧力 室６６内の圧力が等しくなるまで、ポンプ吐出路８１と圧力室６６を連通させ、 両圧力室６５，６６内の圧力が等しくなれば弱いばね６９によって閉じチェック 弁部６３に当接する。結果として負荷圧検出路８２内の圧力は、負荷圧と等しく なり、ポンプ吐出圧は、ポンプ調整用孔制御弁８５によって、ある差圧（ここで は２０ｋｇ／ｃｍ2 ）分だけ、負荷圧検出路８２内の圧力より高い圧力に制御さ れる。このポンプ吐出圧は、チェック弁部６３を介して、入力ポート４４に導か れているので、すなわち、方向制御弁５５の入口圧と出口圧（＝負荷圧）の間に は、差圧（＝２０ｋｇ／ｃｍ2 ）が保たれることになる。よって、方向制御弁５ ５のストロークに伴なう入口側と出口側の間の絞りの開口面積の変化によっての み、アクチュエータ８８へ供給される流量が制御される。 方向制御弁５５をストロークさせる際、アクチュエータ８８の導管８９あるい は９０と負荷圧導入用の第２油路５３が接続され、一方、第２油路５３は、減圧 弁部７４の一方の圧力室６５と接続されているが、減圧弁部７４において負荷圧 は、パイロット圧力（減圧弁部のセット圧力）としてのみ使われるので、その圧 力がぬけることはなく、すなわち、方向制御弁５５をストロークさせた際、負荷 圧がぬけることによるアクチュエータ８８の自然降下はない。When only one of the directional control valves 55 is stroked to the first pressure oil supply position B. Now, the left direction control valve 55 is stroked to the first pressure oil supply position B, and the right direction control valve 55 is set to the neutral position A. The directional control valve 55 is stroked to connect the input port 44 and the first actuator port 34, and at the same time, connect the second actuator 35 and the second tank port 48. At this time, if the pressure (load pressure) in the conduit 89 connecting the first actuator port 34 and the actuator 88 is higher than the pump discharge pressure (20 kg / cm 2 ), the check valve portion 63 receives the pressure in the pressure chamber b. Therefore, it is possible to prevent the actuator 88 from naturally descending. The pressure in the conduit 89 of the actuator 88, that is, the load pressure, is introduced from the first oil passage 53 and the passage 58 into the pressure chamber 65 of the pressure reducing valve portion 74. Since the pressure in the other pressure chamber 66 is zero, the pressure reducing valve portion 74 strokes in the direction of disengagement from the check valve portion 63 to the stroke end, and through the throttle of the pressure reducing valve portion 74, the pump discharge passage 8 1 And the load pressure detection path 82 communicate with each other. When the pressure (load pressure) in the conduit 89 is higher than the pump discharge pressure (= 20 kg / cm 2 ), the pressure is closed by the pressure in the pressure chamber b of the check valve portion 63, and one of the pressure reducing valve portions 74 is closed. Since the pressure reducing valve portion 74 is guided to the pressure chamber 65, the pressure reducing valve portion 74 remains in a stroke even when the other pressure chamber 66 and the pump discharge passage 81 communicate with each other. On the other hand, when the pressure (load pressure) in the conduit 41 is lower than the pump discharge pressure (= 20 kg / cm 2 ), the load pressure is guided to one pressure chamber 65 of the pressure reducing valve unit 74, and the pressure reducing valve unit 74 is The stroke is made by the pressure of one pressure chamber 65, but when the pressure of the other pressure chamber 66 rises to the pressure of one pressure chamber 65 (that is, the load pressure), the weak spring 69 closes and abuts against the check valve portion 63. In any case, the pressure reducing valve unit 74 keeps the pump discharge passage 81 and the pressure chamber 66 in communication until the pressure in the one pressure chamber 65 and the pressure in the other pressure chamber 66 become equal to each other. When the pressures in 66 become equal, the weak spring 69 abuts the closing check valve portion 63. As a result, the pressure in the load pressure detection path 82 becomes equal to the load pressure, and the pump discharge pressure is detected by the pump adjusting hole control valve 85 by a certain differential pressure (here, 20 kg / cm 2 ). The pressure is controlled to be higher than the pressure in the passage 82. This pump discharge pressure is guided to the input port 44 via the check valve portion 63, that is, between the inlet pressure and the outlet pressure (= load pressure) of the directional control valve 55, the differential pressure (= 20 kg / cm 2 ) will be maintained. Therefore, the flow rate supplied to the actuator 88 is controlled only by the change in the opening area of the throttle between the inlet side and the outlet side due to the stroke of the directional control valve 55. When the directional control valve 55 is stroked, the conduit 89 or 90 of the actuator 88 and the second oil passage 53 for introducing the load pressure are connected, while the second oil passage 53 is connected to one pressure of the pressure reducing valve portion 74. Although it is connected to the chamber 65, the load pressure in the pressure reducing valve portion 74 is used only as pilot pressure (set pressure of the pressure reducing valve portion), so the pressure is not lost, that is, the directional control valve 55 is When the stroke is made, there is no spontaneous lowering of the actuator 88 due to the release of the load pressure.
【００１８】 前記負荷圧検出路８２はもう一方の方向制御弁５５に配設されている圧力補償 弁７５の減圧弁部７４の他方の圧力室６６にも接続されているが、減圧弁部７４ の一方の圧力室６５は、方向制御弁５５の中立位置Ａによってタンク８６と接続 しているため、負荷圧導入用の第１油路５３内の圧力はゼロで、よって圧力室６ ６内の圧力によって減圧弁部７４は、チェック弁部６３を閉じる方向に付勢する 。一方、チェック弁部７４を開く方向の圧力室ａには、ポンプ吐出路８１よりポ ンプ吐出圧が導かれるため、全体として、ポンプ吐出圧と負荷圧検出路８２内の 圧力の差圧分（＝２０ｋｇ／ｃｍ2 ）によってチェック弁部６３及び減圧弁部７ ４をチェック弁部６３の開く方向にストロークさせるが、わずかにストロークし 入力ポート４４の圧力がその差圧（＝２０ｋｇ／ｃｍ2 ）になれば、弱いばね６ ９によってレシートし、結果として、ストロークエンドまで減圧弁部７４がスト ロークすることはなく、方向制御弁５５側の油圧制御には、何ら影響することは ない。The load pressure detection path 82 is also connected to the other pressure chamber 66 of the pressure reducing valve portion 74 of the pressure compensating valve 75 arranged in the other directional control valve 55, but the pressure reducing valve portion 74 Since one of the pressure chambers 65 is connected to the tank 86 by the neutral position A of the direction control valve 55, the pressure in the first oil passage 53 for introducing the load pressure is zero, and therefore the pressure chamber 66 is The pressure reducing valve 74 urges the check valve 63 in the closing direction. On the other hand, since the pump discharge pressure is introduced from the pump discharge passage 81 to the pressure chamber a in the direction of opening the check valve portion 74, the difference between the pump discharge pressure and the pressure in the load pressure detection passage 82 is () as a whole. = 20kg / cm 2) by it is a stroke in the opening direction of the check valve portion 63 a check valve 63 and the pressure reducing valve 7 4 slightly stroke and the pressure input port 44 is the differential pressure (= 20kg / cm 2) In this case, the weak spring 69 causes a receipt, and as a result, the pressure reducing valve unit 74 does not stroke to the stroke end, and the hydraulic control on the directional control valve 55 side is not affected at all.
【００１９】 方向制御弁５５のいずれも第１圧油供給位置Ｂにストロークさせるとき。 −各アクチュエータ８８に必要とされる流量の合計が油圧ポンプ２０の最 大吐出流量以下のとき。 いま、方向制御弁５５をともに第１圧油供給位置Ｂにストロークさせ、各入力 ポート４４と各導管８９と各負荷圧導用の第１油路５３をそれぞれ接続させたと する。 一方の減圧弁部７４は、圧力室６６内の圧力が一方の圧力室６５内の圧力に等 しくなるまで、また他方の減圧弁部７４は、圧力室６６内の圧力が、一方の圧力 室６５内の圧力に等しくなるまで、それぞれストロークエンドまでストロークし たままである。いま、二つのアクチュエータ８８，８８の負荷圧のうち、左側の アクチュエータ８８の負荷圧がより大きいとする。仮に、左側アクチュエータ２ ６の負荷圧を１００（ｋｇ／ｃｍ2 ）、右側のアクチュエータ２７の負荷圧を１ ０（ｋｇ／ｃｍ2 ）とする。負荷圧検出路８２は、絞り９１を介してタンク８６ と接続されているので、方向制御弁ストローク前は負荷圧検出路８２内の圧力は ゼロである。よって、各減圧弁部７４は負荷圧検出用の第１油路５３内の圧力に よってもストロークし、ポンプ吐出圧が圧力検出導管３４内の圧力と連通させる 。 負荷圧検出路８２内の圧力が低圧側である右側のアクチュエータ８８の導管９ ０内の圧力（１０ｋｇ／ｃｍ2 ）まで上昇すると、まず、右方の圧力補償弁７５ の減圧弁部７４が閉じる。左方の圧力補償弁９０の減圧弁部７４はストロークし たままであり、負荷圧検出路８２内の圧力はポンプ吐出圧（２０ｋｇ／ｃｍ2 ） と等しくなるまで上昇する。このとき高圧側である左側のアクチュエータ８８の 方向制御弁５５の入力ポート４４の圧力は１００（ｋｇ／ｃｍ2 ）であり、圧力 補償弁７５のチェック弁部６３は閉じていて、減圧弁部７４とは解離している。 一方圧力補償弁７５の減圧弁部７４は、二つの圧力室６５と６６内の圧力の差（ ２０−１０＝１０ｋｇ／ｃｍ2 ）でチェック弁部６３を閉じる方向に付勢する。 一方、チェック弁部６３の開く方向の圧力室ａ内の圧力（ポンプ吐出圧）２０（ ｋｇ／ｃｍ2 ）であるため、結果として方向制御弁５５の入力ポート４４の圧力 が１０（ｋｇ／ｃｍ2 ）になるまでチェック弁部６３が開いた後、弱いばね６９ によってレシートする。 ポンプ調整用方向制御弁８５によって、ある差圧（２０ｋｇ／ｃｍ2 ）分だけ 、負荷圧検出路８２内の圧力（２０ｋｇ／ｃｍ2 ）より高い圧力にポンプ吐出圧 が制御される（４０ｋｇ／ｃｍ2 ）。このときも高圧側の圧力補償弁７５のチェ ック弁部６３は閉じたままで減圧弁部７４はストロークしたままで負荷圧検出路 ８２内の圧力は４０（ｋｇ／ｃｍ2 ）となり、一方、低圧側の圧力補償弁７５の 減圧弁部７４は、負荷圧検出路８２と負荷圧導入用の第１油路５３内の圧力差（ ＝３０ｋｇ／ｃｍ2 ）でチェック弁部６３を閉じる方向に付勢し、結果として方 向制御弁５５の入力ポート４４の圧力は１０ｋｇ／ｃｍ2 のままである。 このようにして、負荷圧検出路８２内の圧力とポンプ吐出圧が上昇し続け、や がてポンプ吐出圧が高圧側のアクチュエータ８８の負荷圧（１００ｋｇ／ｃｍ2 ）と等しくなると、高圧側の圧力補償弁７５の減圧弁部６３の二つの圧力室６５ と６６内の圧力はともに１００ｋｇ／ｃｍ2 となり、弱いばね６９によって、閉 じてチェック弁部６３に当接する。このとき低圧側の圧力補償弁７５の減圧弁部 ７４は負荷圧検出路８２と負荷圧導入用の第１油路５３内の圧力差（１００−１ ０＝９０ｋｇ／ｃｍ2 ）でチェック弁部６３を閉じる方向に付勢し、結果として 低圧側の方向制御弁５５の入力ポート４４の圧力は１０ｋｇ／ｃｍ2 のままであ る。 再び、ポンプ調整用方向制御弁８５によって、ポンプ吐出圧が１２０（ｋｇ／ ｃｍ2 ）に制御される。 このとき高圧側の圧力補償弁７５の減圧弁部６３は、弱いばね６９によってチ ェック弁部６３に当接しているだけであり、チェック弁部６３の二つの圧力室ａ とｂの圧力差によって、ここで初めてチェック弁部６３が開き、ポンプ吐出圧（ １２０ｋｇ／ｃｍ2 ）が方向制御弁５５の入力ポート４４に導かれる。一方、低 圧側の圧力補償弁７５の減圧弁部７４は負荷圧検出路８２と負荷圧導入用の第１ 油路５３内の圧力差（＝９０ｋｇ／ｃｍ2 ）分でチェック弁部６３を閉じる方向 に付勢し続けるが、チェック弁部６３の開く方向の圧力室ａ内の圧力が１２０（ ｋｇ／ｃｍ2 ）になったので方向制御弁５５の入力ポート４４の圧力が３０（ｋ ｇ／ｃｍ2 ）（１２０−９０）となる状態で、チェック弁部６３及び減圧弁部７ ４が圧力バランスする。すなわち、チェック弁部６３及び減圧弁部７４はわずか にストロークし、チェック弁部６３において、１２０ｋｇ／ｃｍ2 から３０ｋｇ ／ｃｍ2 になるように絞っている状態となる。 ここで初めて、この油圧制御系はつり合い、高圧側の方向制御弁５５の入力ポ ート４４の圧力が１２０ｋｇ／ｃｍ2 、低圧側の方向制御弁５５の入力ポート４ ４の圧力が３０ｋｇ／ｃｍ2 となり、すなわち、二つの方向制御弁５５，５５の 入口圧と出口圧（負荷圧）の差は、ともに２０ｋｇ／ｃｍ2 に保たれることによ り、二つの方向制御弁５５，５５はともに、ストローク分だけで、アクチュエー タ８８，８８に供給する流量を制御することができるようになる。When any of the directional control valves 55 is stroked to the first pressure oil supply position B. -When the total flow rate required for each actuator 88 is less than or equal to the maximum discharge flow rate of the hydraulic pump 20. Now, it is assumed that the directional control valve 55 is both stroked to the first pressure oil supply position B to connect the respective input ports 44, the respective conduits 89 and the respective first oil passages 53 for guiding the load pressure. One of the pressure reducing valve portions 74 has a pressure in the pressure chamber 66 equal to the pressure in one of the pressure chambers 65, and the other pressure reducing valve portion 74 has a pressure in the pressure chamber 66 of one pressure chamber 66. It continues to stroke to the end of each stroke until it becomes equal to the pressure in 65. Now, assume that the load pressure of the left actuator 88 is larger than the load pressure of the two actuators 88, 88. It is assumed that the load pressure of the left actuator 26 is 100 (kg / cm 2 ) and the load pressure of the right actuator 27 is 10 (kg / cm 2 ). Since the load pressure detection path 82 is connected to the tank 86 via the throttle 91, the pressure in the load pressure detection path 82 is zero before the stroke of the directional control valve. Therefore, each pressure reducing valve portion 74 also strokes due to the pressure in the first oil passage 53 for detecting the load pressure, and the pump discharge pressure communicates with the pressure in the pressure detecting conduit 34. When the pressure in the load pressure detection path 82 rises to the pressure (10 kg / cm 2 ) in the conduit 90 of the actuator 88 on the right side on the low pressure side, first, the pressure reducing valve portion 74 of the pressure compensating valve 75 on the right side is closed. . The pressure reducing valve portion 74 of the pressure compensating valve 90 on the left side remains stroked, and the pressure in the load pressure detecting path 82 rises until it becomes equal to the pump discharge pressure (20 kg / cm 2 ). At this time, the pressure of the input port 44 of the directional control valve 55 of the left side actuator 88, which is the high pressure side, is 100 (kg / cm 2 ), the check valve portion 63 of the pressure compensation valve 75 is closed, and the pressure reducing valve portion 74 is closed. Is dissociated from. On the other hand, the pressure reducing valve portion 74 of the pressure compensating valve 75 biases the check valve portion 63 in the closing direction by the difference in pressure between the two pressure chambers 65 and 66 (20-10 = 10 kg / cm 2 ). On the other hand, since the pressure in the pressure chamber a in the opening direction of the check valve portion 63 (pump discharge pressure) is 20 (kg / cm 2 ), as a result, the pressure at the input port 44 of the directional control valve 55 is 10 (kg / cm 2). After the check valve 63 is opened until the condition 2 ) is reached, a receipt is made by the weak spring 69. The pump adjusting directional control valve 85 controls the pump discharge pressure to a pressure higher than the pressure (20 kg / cm 2 ) in the load pressure detection path 82 by a certain pressure difference (20 kg / cm 2 ) (40 kg / cm 2 ). 2 ). Also at this time, the pressure in the load pressure detection path 82 becomes 40 (kg / cm 2 ) while the check valve portion 63 of the high-pressure side pressure compensation valve 75 remains closed and the pressure reducing valve portion 74 remains in the stroke. The pressure reducing valve portion 74 of the pressure compensating valve 75 on the low pressure side is configured to close the check valve portion 63 due to the pressure difference (= 30 kg / cm 2 ) in the load pressure detecting passage 82 and the first oil passage 53 for introducing the load pressure. It is energized so that the pressure at the input port 44 of the directional control valve 55 remains at 10 kg / cm 2 . In this way, the pressure in the load pressure detection path 82 and the pump discharge pressure continue to rise, and when the pump discharge pressure eventually becomes equal to the load pressure (100 kg / cm 2 ) of the high pressure side actuator 88, the high pressure side The pressures in the two pressure chambers 65 and 66 of the pressure reducing valve portion 63 of the pressure compensating valve 75 are both 100 kg / cm 2 , and the weak spring 69 closes and abuts against the check valve portion 63. At this time, the pressure reducing valve portion 74 of the pressure compensating valve 75 on the low pressure side has a check valve portion due to a pressure difference (100-10 = 90 kg / cm 2 ) in the load pressure detecting passage 82 and the first oil passage 53 for introducing the load pressure. 63 is urged in the closing direction, and as a result, the pressure of the input port 44 of the low-pressure side directional control valve 55 remains 10 kg / cm 2 . Again, the pump adjusting directional control valve 85 controls the pump discharge pressure to 120 (kg / cm 2 ). At this time, the pressure reducing valve portion 63 of the pressure compensating valve 75 on the high pressure side is only in contact with the check valve portion 63 by the weak spring 69, and due to the pressure difference between the two pressure chambers a and b of the check valve portion 63. For the first time, the check valve portion 63 is opened and the pump discharge pressure (120 kg / cm 2 ) is introduced to the input port 44 of the directional control valve 55. On the other hand, the pressure reducing valve portion 74 of the pressure compensating valve 75 on the low pressure side closes the check valve portion 63 by the pressure difference (= 90 kg / cm 2 ) in the load pressure detecting passage 82 and the first oil passage 53 for introducing the load pressure. However, since the pressure in the pressure chamber a in the opening direction of the check valve portion 63 became 120 (kg / cm 2 ), the pressure at the input port 44 of the directional control valve 55 was 30 (kg / cm 2 ). cm 2 ) (120-90), the check valve portion 63 and the pressure reducing valve portion 74 are pressure balanced. That is, the check valve portion 63 and the pressure reducing valve portion 74 make a slight stroke, and the check valve portion 63 is in a state of being squeezed so as to be 120 kg / cm 2 to 30 kg / cm 2 . For the first time, this hydraulic control system is balanced so that the pressure of the input port 44 of the high-pressure side directional control valve 55 is 120 kg / cm 2 , and the pressure of the input port 44 of the low-pressure side directional control valve 55 is 30 kg / cm 2. 2 , that is, the difference between the inlet pressure and the outlet pressure (load pressure) of the two directional control valves 55, 55 is maintained at 20 kg / cm 2 , so that the two directional control valves 55, 55 are In both cases, the flow rate supplied to the actuators 88, 88 can be controlled only by the stroke amount.
【００２０】 −各アクチュエータ８８，８８に必要とされる流量の合計が油圧ポンプ８ ０の最大吐出流量以上のとき。 いま、アクチュエータ８８，８８の負荷圧および必要流量を左側のアクチュエ ータ８８が１００ｋｇ／ｃｍ2 、５０１／ｍｉｎ、右側のアクチュエータ８８が １０ｋｇ／ｃｍ2 、５０１／ｍｉｎとする。油圧ポンプ８０の最大吐出流量が１ ００１／ｍｉｎ以上のときは、前述の通り、方向制御弁５５，５５の入口圧と出 口圧の差が一定に保たれる（＝２０ｋｇ／ｃｍ2 ）ため、ストロークによって流 量制御ができ、５０１／ｍｉｎずつ流量分配することはできる。 次に、油圧ポンプ８０の最大吐出量が７０１／ｍｉｎになったとする。二つの 方向制御弁５５，５５の入口圧は前述の通り１２０ｋｇ／ｃｍ2 、３０ｋｇ／ｃ ｍ2 であるので、高圧側の方向制御弁５５への流量が５０１／ｍｉｎから２０１ ／ｍｉｎに減る。低圧側の方向制御弁５５への流量は、５０１／ｍｉｎのままで ある。二つの方向制御弁５５，５５のストローク（開口面積）を変えないとする と、高圧側の方向制御弁５５の入口圧と出口圧の差圧が流量が減った分、２０ｋ ｇ／ｃｍ2 から下がる。いま、差圧が１４ｋｇ／ｃｍ2 、すなわち、入口圧が、 １２０ｋｇ／ｃｍ2 から１１４（１００＋１４）ｋｇ／ｃｍ2 に下がったとする 。この時圧力補償弁７５の減圧弁部７４の二つの圧力室６５，６６の圧力は、と もに１００ｋｇ／ｃｍ2 のままであるから、減圧弁部７４は弱いばね６９によっ てチェック弁部６３に当接しているだけであり、チェック弁部６３の閉じる方向 の圧力室ｂ内の圧力が１２０ｋｇ／ｃｍ2 から１１４ｋｇ／ｃｍ2 に減少すれば 、チェック弁部６３が開いたまま（ストロークエンド）で、チェック弁部６３の 開く方向の圧力室ａ内の圧力、すなわち、ポンプ吐出圧が１２０ｋｇ／ｃｍ2 か ら１１４ｋｇ／ｃｍ2 に減少する。この時（ポンプ吐出流量不足時）にはポンプ 吐出圧は、ポンプ調整用方向制御弁８５の制御によらなくなる。 一方、低圧側の圧力補償弁７５の減圧弁部７４の二つの圧力室６５と６６は、 １００ｋｇ／ｃｍ2 、１０ｋｇ／ｃｍ2 のままで、その差圧９０ｋｇ／ｃｍ2 で チェック弁部６３の閉じる方向に付勢し続ける。一方、チェック弁部６３の開く 方向の圧力室ａ内の圧力、すなわちポンプ吐出圧が１１４ｋｇ／ｃｍ2 に減少し たので、チェック弁部６３の閉じる方向の圧力室ｂ内の圧力が３０ｋｇ／ｃｍ2 から２４ｋｇ／ｃｍ2 に減少した状態でチェック弁部６３及び減圧弁部７４が圧 力バランスする。よって、低圧側の方向制御弁５５の入口圧と出口圧の差圧は２ ０ｋｇ／ｃｍ2 から１４ｋｇ／ｃｍ2 （２４−１０）に減少する。方向制御弁５ ５のこの差圧の減少により低圧側のアクチュエータ８８への供給流量は５０１／ ｍｉｎから減少し、その分高圧側のアクチュエータ８８への供給流量が２０１／ ｍｉｎから増える。 すなわち、方向制御弁５５および５５の入口圧と出口圧の差圧が等しく、かつ 、二つのアクチュエータ８８，８８への供給量がともに３５１／ｍｉｎずつに分 配される状態で、この油圧制御系がつり合う。-When the total flow rate required for each actuator 88, 88 is greater than or equal to the maximum discharge flow rate of the hydraulic pump 80. Now, the load pressure and the required flow rate of the actuator 88, 88 left actuator 88 is 100kg / cm 2, 501 / min , the right actuator 88 and 10kg / cm 2, 501 / min . When the maximum discharge flow rate of the hydraulic pump 80 is 1001 / min or more, the difference between the inlet pressure and the outlet pressure of the directional control valves 55, 55 is kept constant (= 20 kg / cm 2 ) as described above. , The flow rate can be controlled by the stroke, and the flow rate can be distributed by 501 / min. Next, assume that the maximum discharge amount of the hydraulic pump 80 becomes 701 / min. Since the inlet pressure of the two directional control valves 55, 55 are described above 120kg / cm 2, 30kg / c m 2, flow to the direction control valve 55 of the high-pressure side is reduced to 201 / min from 501 / min. The flow rate to the directional control valve 55 on the low pressure side remains 501 / min. Assuming that the stroke (opening area) of the two directional control valves 55, 55 is not changed, the pressure difference between the inlet pressure and the outlet pressure of the directional control valve 55 on the high pressure side is reduced by 20 kg / cm 2 due to the decrease in the flow rate. Go down. Now, assume that the differential pressure is 14 kg / cm 2 , that is, the inlet pressure is reduced from 120 kg / cm 2 to 114 (100 + 14) kg / cm 2 . At this time, the pressures in the two pressure chambers 65 and 66 of the pressure reducing valve portion 74 of the pressure compensating valve 75 remain at 100 kg / cm 2 only , so the pressure reducing valve portion 74 uses the weak spring 69 to check the valve portion. If the pressure in the pressure chamber b in the closing direction of the check valve portion 63 decreases from 120 kg / cm 2 to 114 kg / cm 2 , the check valve portion 63 remains open (stroke end). ), the pressure in the direction of the pressure chamber a to open the check valve unit 63, i.e., the pump discharge pressure is reduced to 120 kg / cm 2 or et 114 kg / cm 2. At this time (when the pump discharge flow rate is insufficient), the pump discharge pressure is not controlled by the pump adjustment directional control valve 85. On the other hand, the two pressure chambers 65 and 66 of the pressure reducing valve portion 74 of the pressure compensating valve 75 on the low pressure side remain at 100 kg / cm 2 and 10 kg / cm 2 , and the differential pressure of 90 kg / cm 2 causes the check valve portion 63 to have a pressure difference of 90 kg / cm 2 . Continue to push in the closing direction. On the other hand, since the pressure in the pressure chamber a in the opening direction of the check valve portion 63, that is, the pump discharge pressure is reduced to 114 kg / cm 2 , the pressure in the pressure chamber b in the closing direction of the check valve portion 63 is 30 kg / cm 2. When the pressure is reduced from 2 to 24 kg / cm 2 , the check valve portion 63 and the pressure reducing valve portion 74 balance the pressure. Therefore, the differential pressure between the inlet pressure and the outlet pressure of the directional control valve 55 on the low pressure side is reduced from 20 kg / cm 2 to 14 kg / cm 2 (24-10). Due to this decrease in the differential pressure of the directional control valve 55, the supply flow rate to the low-pressure side actuator 88 decreases from 501 / min, and the supply flow rate to the high-pressure side actuator 88 increases from 201 / min. That is, in the state where the differential pressure between the inlet pressure and the outlet pressure of the directional control valves 55 and 55 is equal, and the supply amounts to the two actuators 88 and 88 are both divided into 351 / min, the hydraulic control system is controlled. Balance.
【００２１】 一つの油圧ポンプ８０によって負荷されるアクチュエータが３つ以上のとき 。 アクチュエータが３つ以上のときも、方向制御弁と油圧ポンプの間に、同じチ ェック弁部６３及び減圧弁部７４を備えた圧力補償弁７５を配設し、各減圧弁部 の閉じる方向の圧力差を負荷圧検出路８２によってすべて連通するだけで、アク チュエータが３つ以上のときも前述の作動原理による作動が実現される。 以上の実施例では油圧ポンプ８０を可変容量型としたが、油圧ポンプ８０を固 定容量型としても良く、この場合には油圧ポンプ８０のポンプ吐出路８１にアン ロード弁を設ければ良い。When the number of actuators loaded by one hydraulic pump 80 is three or more. Even when there are three or more actuators, a pressure compensating valve 75 having the same check valve portion 63 and pressure reducing valve portion 74 is arranged between the directional control valve and the hydraulic pump to prevent the pressure reducing valve portion from closing in the closing direction. Even if the number of actuators is three or more, the operation according to the above-described operation principle can be realized by simply communicating all the pressure differences through the load pressure detection path 82. Although the hydraulic pump 80 is a variable displacement type in the above embodiments, the hydraulic pump 80 may be a fixed displacement type, and in this case, an unload valve may be provided in the pump discharge passage 81 of the hydraulic pump 80.
【００２２】[0022]
１つの弁ブロック３０に方向制御弁５５の主スプール４９と圧力補償弁７５の チェック弁部６３、減圧弁部７４を組み込み、その弁ブロック３０を複数連結し て圧力補償弁を有する方向制御弁装置としたから、全体がコンパクトになって設 置スペースを小さくできるので、小さな建設機械に設置できる。 The main spool 49 of the directional control valve 55, the check valve portion 63 and the pressure reducing valve portion 74 of the pressure compensating valve 75 are incorporated in one valve block 30, and a plurality of valve block 30 are connected to each other to provide a pressure compensating valve. Since it is compact, the installation space can be reduced and it can be installed on a small construction machine.
【図１】従来の圧油供給装置の回路図である。FIG. 1 is a circuit diagram of a conventional pressure oil supply device.
【図２】先に出願した圧油供給装置の回路図である。FIG. 2 is a circuit diagram of a pressure oil supply device previously applied.
【図３】本考案の実施例を示す弁ブロックの斜視図であ
る。FIG. 3 is a perspective view of a valve block according to an embodiment of the present invention.
【図４】弁ブロックに主スプール、スプールを組み込ん
だ状態の断面図である。FIG. 4 is a cross-sectional view showing a state where a main spool and a spool are incorporated in a valve block.
【図５】複数の弁ブロックの接続状態を示す斜視図であ
る。FIG. 5 is a perspective view showing a connected state of a plurality of valve blocks.
【図６】図５に示すものの回路図である。FIG. 6 is a circuit diagram of what is shown in FIG.
【図７】複数の弁ブロックを組み合せた一例を示す平面
図である。FIG. 7 is a plan view showing an example in which a plurality of valve blocks are combined.
【図８】複数の弁ブロックを組み合せた他の例を示す平
面図である。FIG. 8 is a plan view showing another example in which a plurality of valve blocks are combined.
３０…弁ブロック、３１…スプール孔、３４…第１アク
チュエータポート、３５…第２アクチュエータポート、
３７…チェック弁用孔、３８…減圧弁用孔、３９…ポン
プポート、４２…第１ポート、４３…第２ポート、４４
…入力ポート、４５…第１負荷圧検出ポート、４６…第
２負荷圧検出ポート、４７…第１タンクポート、４８…
第２タンクポート、４９…主スプール、５３…第１油
路、５６…油孔、５８…油孔、６０…弁、６３…チェッ
ク弁、６４…スプール、６５…第１圧力室、６６…第２
圧力室、６９…ばね、７４…減圧弁部、７５…圧力補償
弁、８０…油圧ポンプ、８１…ポンプ吐出路、８２…負
荷圧検出路、１０３…主入力ポート、１０４…主タンク
ポート。30 ... Valve block, 31 ... Spool hole, 34 ... First actuator port, 35 ... Second actuator port,
37 ... Check valve hole, 38 ... Pressure reducing valve hole, 39 ... Pump port, 42 ... First port, 43 ... Second port, 44
... input port, 45 ... first load pressure detection port, 46 ... second load pressure detection port, 47 ... first tank port, 48 ...
Second tank port, 49 ... Main spool, 53 ... First oil passage, 56 ... Oil hole, 58 ... Oil hole, 60 ... Valve, 63 ... Check valve, 64 ... Spool, 65 ... First pressure chamber, 66 ... Two
Pressure chamber, 69 ... Spring, 74 ... Pressure reducing valve section, 75 ... Pressure compensation valve, 80 ... Hydraulic pump, 81 ... Pump discharge passage, 82 ... Load pressure detection passage, 103 ... Main input port, 104 ... Main tank port.
Claims (2)
・第２アクチュエータポート３４，３５にと第１・第２
タンクポート４７，４８を連通・遮断する主スプール４
９を設けて方向制御弁５５とし、前記弁ブロック３０に
チェック弁部６３と減圧弁部７４を設けてポンプポート
の圧油を負荷圧で圧力補償して前記入力ポート４４に供
給する圧力補償弁７５とし、前記弁ブロック３０を複数
連結して各第１・第２タンクポート４７，４８と各ポン
プポートを連通し、いずれか１つのポンプポートに主入
力ポート１０３を接続し、いずれか１つの第１・第２タ
ンクポート４７，４８を主タンクポート１０４に接続し
て成る方向制御弁装置。1. The valve block 30 includes an input port 44 and a first port.
・ First and second actuator ports 34 and 35 and first and second actuator ports
Main spool 4 that connects and disconnects tank ports 47 and 48
9 is provided as a directional control valve 55, and the valve block 30 is provided with a check valve portion 63 and a pressure reducing valve portion 74, and the pressure oil of the pump port is pressure-compensated by the load pressure to be supplied to the input port 44. 75, a plurality of the valve blocks 30 are connected to communicate the first and second tank ports 47 and 48 with the respective pump ports, and one of the pump ports is connected to the main input port 103, and any one of them is connected. A directional control valve device formed by connecting the first and second tank ports 47, 48 to the main tank port 104.
ック弁用孔３７と減圧弁用孔３８を形成し、前記弁ブロ
ック３０にはスプール孔３１に開口した入力ポート４
４、第１・第２負荷圧検出ポート４５，４６、第１・第
２アクチュエータポート３４，３５、第１・第２タンク
ポート４７，４８をそれぞれ形成し、このスプール孔３
１に各ポートを連通・遮断する主スプール４９を嵌挿し
て方向制御弁５５とし、前記弁ブロック３０にはチェッ
ク弁用孔３７に開口したポンプポート３９及びチェック
弁用孔３７を入力ポート４４に連通する油路５６を形成
し、そのチェック弁用孔３７にポンプポート３９と油路
５６を連通・遮断し、かつ遮断位置でストップされるス
プール６０を挿入してチェック弁部６３とし、前記弁ブ
ロック３０には減圧弁用孔３８に開口する第１・第２ポ
ート４２，４３を形成し、この減圧弁用孔３８にスプー
ル６４を嵌挿して第一圧力室６５と第２圧力室６６を形
成し、その第１圧力室６５を第２負荷圧検出ポート４６
に連通し、第２圧力室６６を第２ポート４３に連通し、
前記スプール６４をばね６９で一方向に付勢して前記チ
ェック弁部６３のスプール６０を遮断位置に押しつけ保
持して減圧弁部７４とし、この減圧弁部７４と前記チェ
ック弁部６３で圧力補償弁７５とし、前記弁ブロック３
０を複数連結して各第１・第２タンクポート４７，４８
と各ポンプポート３９と第１ポート４２をそれぞれ連通
し、その１つのポンプポート３９、第１ポート４２に主
ポンプポート１０３を連通し、１つの第１・第２タンク
ポート４７，４８に主タンクポート１０４を連通した請
求項１記載の方向制御弁装置。2. A spool hole 31, a check valve hole 37, and a pressure reducing valve hole 38 are formed in the valve block 30, and the input port 4 opened in the spool hole 31 is formed in the valve block 30.
4, first and second load pressure detection ports 45 and 46, first and second actuator ports 34 and 35, and first and second tank ports 47 and 48, respectively.
A main spool 49 for connecting / disconnecting each port is fitted into 1 to form a directional control valve 55, and the valve block 30 has a pump port 39 and a check valve hole 37 opened in the check valve hole 37 as an input port 44. An oil passage 56 is formed to communicate with the check valve hole 37. The pump port 39 and the oil passage 56 are communicated with and cut off from the check valve hole 37, and a spool 60 that is stopped at the cutoff position is inserted to form a check valve portion 63. The block 30 is formed with first and second ports 42 and 43 which open to the pressure reducing valve hole 38, and a spool 64 is fitted into the pressure reducing valve hole 38 to form a first pressure chamber 65 and a second pressure chamber 66. And forms the first pressure chamber 65 in the second load pressure detection port 46.
To communicate the second pressure chamber 66 to the second port 43,
The spool 64 is urged in one direction by a spring 69 to press and hold the spool 60 of the check valve portion 63 at a shut-off position to form a pressure reducing valve portion 74. The pressure reducing valve portion 74 and the check valve portion 63 compensate pressure. Valve 75, and the valve block 3
A plurality of 0s are connected to connect each of the first and second tank ports 47, 48.
And each of the pump ports 39 and the first port 42 are communicated with each other, the main pump port 103 is communicated with the one pump port 39 and the first port 42, and one main tank is connected with one of the first and second tank ports 47 and 48. The directional control valve device according to claim 1, wherein the port 104 is communicated.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7761592U JPH0643301U (en) | 1992-11-11 | 1992-11-11 | Directional control valve device |
| US08/411,817 US5651390A (en) | 1992-10-23 | 1993-10-22 | Pressurized fluid supply system |
| PCT/JP1993/001534 WO1994010454A1 (en) | 1992-10-23 | 1993-10-22 | Pressure oil supply system having a pressure compensating valve |
| KR1019950701574A KR950704617A (en) | 1992-10-23 | 1993-10-22 | Pressurized fluid supply system |
| EP93923052A EP0747601B1 (en) | 1992-10-23 | 1993-10-22 | Pressure oil supply system having a pressure compensating valve |
| DE69328382T DE69328382T2 (en) | 1992-10-23 | 1993-10-22 | PRESSURE OIL SUPPLY SYSTEM WITH PRESSURE COMPENSATING VALVE |
| US08/600,505 US5784885A (en) | 1992-10-23 | 1996-02-13 | Pressurized fluid supply system |
| US08/742,777 US5845678A (en) | 1992-10-23 | 1996-10-31 | Pressurized fluid supply system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7761592U JPH0643301U (en) | 1992-11-11 | 1992-11-11 | Directional control valve device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0643301U true JPH0643301U (en) | 1994-06-07 |
Family
ID=13638825
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7761592U Pending JPH0643301U (en) | 1992-10-23 | 1992-11-11 | Directional control valve device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0643301U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024009619A1 (en) * | 2022-07-08 | 2024-01-11 | 株式会社小松製作所 | Hydraulic valve apparatus |
| WO2024009620A1 (en) * | 2022-07-08 | 2024-01-11 | 株式会社小松製作所 | Hydraulic valve device |
-
1992
- 1992-11-11 JP JP7761592U patent/JPH0643301U/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024009619A1 (en) * | 2022-07-08 | 2024-01-11 | 株式会社小松製作所 | Hydraulic valve apparatus |
| WO2024009620A1 (en) * | 2022-07-08 | 2024-01-11 | 株式会社小松製作所 | Hydraulic valve device |
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