JPH0596504U - Pressure oil supply device - Google Patents
Pressure oil supply deviceInfo
- Publication number
- JPH0596504U JPH0596504U JP4516892U JP4516892U JPH0596504U JP H0596504 U JPH0596504 U JP H0596504U JP 4516892 U JP4516892 U JP 4516892U JP 4516892 U JP4516892 U JP 4516892U JP H0596504 U JPH0596504 U JP H0596504U
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- valve
- actuator
- port
- directional control
- 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.)
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Abstract
(57)【要約】 （修正有）
【目的】 面積が異なる第１室と第２室を有するシリン
ダより成るアクチェエータを同一速度で伸長・縮少でき
るようにする。
【構成】 チェック弁６３と減圧弁部７４で圧力補償弁
７５とし、この圧力補償弁７５の出力側に方向制御弁５
５を設ける。弁ブロック３０にスプール孔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、第１・第２アクチェエータポート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３１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、この主スプール
４９に中間小径部５２と第１・第２切欠部１０１，１０
２を形成して、主スプール４９を左右に摺動した時に入
力ポート４４の圧油を第１又は第２切欠部１０１，１０
２より第１又は第２アクチェエータポート３４，３５に
供給する。
(57) [Summary] (Modified) [Purpose] To make it possible to extend and contract an actuator composed of a cylinder having a first chamber and a second chamber having different areas at the same speed. [Structure] A pressure compensating valve 75 is composed of a check valve 63 and a pressure reducing valve portion 74, and the directional control valve 5 is provided on the output side of the pressure compensating valve 75.
5 is provided. The input port 44 opened in the spool hole 31 in the valve block 30, the first and second load pressure detection ports 45,
46, the first and second actuator ports 34 and 35, and the first and second tank ports 47 and 48, respectively, and the main spool 49 that connects and disconnects the respective ports is inserted into the spool hole 31 for direction. A control valve 55 is provided, and the main spool 49 has a small intermediate diameter portion 52 and first and second cutout portions 101, 10.
2 is formed and the pressure oil of the input port 44 is transferred to the first or second cutouts 101, 10 when the main spool 49 is slid to the left and right.
2 to the first or second actuator port 34, 35.
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ェエータに供給する圧 油供給装置に関する。 The present invention relates to a hydraulic oil supply device that supplies the hydraulic 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３，１３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, 13 are connected in parallel to the discharge conduit 2 of the hydraulic pump 1, and the directional control valves 5, 15 are connected to the outlet conduits 4, 14 of the pressure compensating valves 3, 13. The output sides of the directional control valves 5 and 15 are connected to 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, the pump discharge pressure oil can be supplied to each actuator at a predetermined distribution ratio when a plurality of directional control valves 3 and 13 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６，１２ 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６は自然降下しアクチュエータ６は加速される 。 そこで、本出願人は先に前述の課題を解決できるようにした圧油供給装置を出 願した。In such a pressure oil supply device, the shuttle valve 7 is indispensable in order to compare the load pressure of the actuator and supply the higher load pressure to the pressure compensating valve, and this shuttle valve 7 is also required for the actuator. Only one less than is needed, and the cost is higher. Further, in the above-described pressure oil supply device shown in FIG. 1, it is assumed that the two actuators 6 and 12 are actuated together, 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 lost due to the blowout in the shuttle valve 7, and the pressure in the other conduit 8 is pushed in. Therefore, when the shuttle valve 7 is switched, the actuator 6 transiently descends naturally and the actuator 6 is accelerated. Therefore, the present applicant previously applied for a pressure oil supply device capable of solving the above-mentioned problems.
【０００４】[0004]
かかる圧油供給装置は図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部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であり、この方向制 御弁２２と圧力補償弁２５は図３に示すように構成してある。 すなわち、弁本体１９のスプール孔１０にスプール１１を嵌挿して方向制御弁 ２２とし、そのスプール１１に連通用溝１７を形成してスプール１１を左右に摺 動することで補償弁部２５の出口ポート１２を第１又は第２ポート２６，２７よ り第１又は第２アクチェエータポート２８，２９に連通してアクチェエータ６の 第１室６ａ又は第２室６ｂに供給するようにしてある。 このために、第１・第２アクチェエータポート２８，２９への供給流量、つま りアクチェエータ６の第１室６ａ、第２室６ｂへの供給流量は１つの連通用溝１ ７の開口によって決定され、スプール１１を左右に同一ストローク操作した時の アクチェエータ６の第１室６ａ、第２室６ｂへの供給流量が等しくなり、シリン ダより成るアクチェエータ６の第１室６ａと第２室６ｂの面積に差があるためア クチェエータ６を伸長、縮少する時の速度が異なってアクチェエータ６を精度良 く動作制御できない。 As shown in FIG. 2, such a pressure oil supply device is provided with a plurality of directional control valves 22 in a discharge passage 21 of a hydraulic pump 20, and a check valve section 23 and a pressure reducing valve section 24 are provided on the inlet side of each directional control valve 22. The pressure compensating valve 25 is provided respectively, and the directional control valve 22 and the pressure compensating valve 25 are constructed as shown in FIG. That is, the spool 11 is fitted into the spool hole 10 of the valve main body 19 to form the directional control valve 22, the communication groove 17 is formed in the spool 11, and the spool 11 is slid to the left and right. The port 12 is connected to the first or second actuator port 28, 29 by the first or second port 26, 27 and is supplied to the first chamber 6a or the second chamber 6b of the actuator 6. For this reason, the supply flow rate to the first and second actuator ports 28 and 29, that is, the supply flow rate to the first chamber 6a and the second chamber 6b of the actuator 6 is determined by the opening of one communication groove 17. The flow rates of the supply to the first chamber 6a and the second chamber 6b of the actuator 6 when the spool 11 is operated to the same stroke to the left and right are determined to be equal, and the first chamber 6a and the second chamber 6b of the actuator 6 composed of a cylinder are set. Due to the difference in the areas of the actuators 6, the speed at which the actuator 6 is expanded and contracted is different, and the actuator 6 cannot be controlled with high accuracy.
【０００５】 そこで、本考案は前述の課題を提供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 that can solve the above-mentioned problems.
【０００６】[0006]
チェック弁部６３と減圧弁部７４より成る圧力補償弁７５と、この圧力補償弁 ７５の出力側に設けた方向制御弁５５とを備えた圧油供給装置において、弁ブロ ック３０にスプール孔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、第１・第２アクチェエータポート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３１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、この主スプール４９に 入力ポート４４に臨む中間小径部５２及びこの中間小径部５２に開口し入力ポー ト４４を前記第１・第２負荷圧検出ポート４５，４６に連通制御する第１・第２ 切欠部１０１，１０２を形成した圧油供給装置。 In the pressure oil supply device including the pressure compensation valve 75 including the check valve portion 63 and the pressure reducing valve portion 74, and the directional control valve 55 provided on the output side of the pressure compensation valve 75, the valve block 30 has a spool hole. An input port 44 opened at 31, a 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 are formed, respectively. A main spool 49 that connects and disconnects each port is inserted into the spool hole 31 to form a directional control valve 55, and an intermediate small diameter portion 52 facing the input port 44 is opened in the main spool 49 and the intermediate small diameter portion 52 is opened for input. A pressure oil supply device having first and second notches 101 and 102 for controlling communication of the port 44 with the first and second load pressure detection ports 45 and 46.
【０００７】[0007]
主スプール４９を左又は右に摺動すると入力ポート４４が第１切欠部１０１又 は第２切欠部１０２を経て第１又は第２アクチェエータポート３４，３５に連通 するので、主スプール４９を左又は右と同一ストローク操作した時に第１又は第 ２アクチェエータポート３４，３５に供給する流量を第１・第２切欠部１０１， １０２の幅あるいは深さを異ならせることでそれぞれ異なる流量とすることがで きるから、シリンダ等のアクチェエータの面積が異なる第１室と第２室への供給 流量を異ならせてアクチェエータを伸長、縮少する時の速度を等しくできる。 When the main spool 49 is slid to the left or right, the input port 44 communicates with the first or second actuator port 34, 35 via the first notch portion 101 or the second notch portion 102. When the same stroke operation as left or right is performed, the flow rate supplied to the first or second actuator port 34, 35 is made different by varying the width or depth of the first and second cutouts 101, 102. Therefore, it is possible to equalize the speeds for extending and contracting the actuator by making the supply flow rates to the first chamber and the second chamber having different areas of the actuator such as a cylinder different.
【０００８】[0008]
図４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。 図５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と中間 小径部５２が形成してあり、弁本体３０には第１・第２負荷圧検出ポート４５， ４６を連通する油孔１００が形成され、主スプール４９には第２負荷圧検出ポー ト４６と第２タンクポート４８を連通・遮断する油路５４が形成され、主スプー ル４９はスプリング５３で各ポートを遮断し、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、図６に示すよう に主スプール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、中間小径部５２と第１切欠部１０１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圧油供給位置Ｂとなり、 図７に示すように主スプール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、中間小径部５２と第２ 切欠部１０２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。 このようであるから、第１切欠部１０１と第２切欠部１０２の幅あるいは深さ を異ならせることで主スプール４９を左右に同一ストローク摺動した時に第１ア クチェエータポート３４と第２アクチェエータポート３５に供給する流量を異な らせることができる。 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。 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は第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。 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８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９に示すように図２と同様の油圧回路を構成できる。 なお、弁ブロック３０を１つとしてスプール孔３１、チェック弁用孔３７、減 圧弁用孔３８を複数形成し、ポンプ・第１・第２ポート３９，４２，４３を各チ ェック弁用孔３７、減圧弁用孔３８に亘って形成しても良い。 図９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。 As shown in FIG. 4, the valve block 30 has a substantially rectangular parallelepiped shape, and a spool hole 31 is formed in the left and right side surfaces 32 and 33 near the upper portion of the valve block 30. The second actuator ports 34 and 35 are formed so as 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 lower part of the valve block 30. First and second ports formed in the pressure reducing valve hole 38, and the pump port 39 opening in the check valve hole 37 is formed in the front and rear surfaces 40, 41. 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. As shown in FIG. 5, in the valve block 30, an input port 44 opened in a spool hole 31, first and second load pressure detection ports 45 and 46, first and second actuator ports 34 and 35, The first and second tank ports 47, 48 are formed, and the main spool 49 fitted in the spool hole 31 is formed with the first and second small diameter portions 50, 51 and the intermediate small diameter portion 52. The main body 30 is formed with an oil hole 100 that communicates the first and second load pressure detection ports 45 and 46, and the main spool 49 communicates and blocks the second load pressure detection port 46 and the second tank port 48. The oil passage 54 is formed, the main spool 49 is blocked by the spring 53 from each port, and is held at the neutral position A which connects the second load pressure detection port 46 and the second tank port 48 by the oil passage 54. Main spool 4 as shown in Sliding to the right causes the second actuator port 35 to communicate with the second tank port 48 at the second small diameter portion 51, and the input port 44 becomes the second load pressure detection port at the intermediate small diameter portion 52 and the first cutout portion 101. The first pressure oil that communicates with the first small diameter portion 50, the first actuator port 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 supply position B is reached and the main spool 49 is slid to the left as shown in FIG. 7, the first actuator port 34 is communicated with the first tank port 47 by the first small diameter portion 50, and the intermediate small diameter portion 52 and the second small diameter portion 52 are connected. The input port 44 communicates with the first load pressure detection port 45 at the notch 102, the second actuator port 35 communicates with the second load pressure detection port 46 at the second small diameter portion 51, and the second load pressure detection port 4 Constitute a directional control valve 55 becomes the second pressurized oil supply position C where the second tank port 48 is blocked. Because of this, by making the width or depth of the first cutout portion 101 and the second cutout portion 102 different, when the main spool 49 slides left and right by the same stroke, the first actuator port 34 and the second cutout portion 34 can be moved. The flow rate supplied to the actuator port 35 can be varied. 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 cuts off the communication between the pump port 39 and the input port 44, and the valve 60 is a plug. A check rod 63 is formed by a stopper rod 62 provided at 61, which is regulated so as not to slide to the left from the illustrated position and is held at the shutoff position. The pressure reducing valve hole 38 communicates with the second load pressure detection port 46 through the third port 57 and the oil passage 58, and the spool 64 is fitted into the pressure reducing valve hole 38 to connect the first pressure chamber 65 and the second pressure chamber 65. A pressure chamber 66 is formed, the first pressure chamber 65 communicates with the third port 57, the second pressure chamber 66 communicates with the second port 43, and the free piston 68 inserted in the blind hole 67 of the spool 64 and a blind piston 68. A spring 69 is provided between the free piston 68 and the bottom of the hole 67 so that the free piston 68 abuts on the plug 70, and a push rod 71 integrally provided on the spool 64 projects from the through hole 72 so that the valve 60 is stopped by 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 portion 63 are connected to each other. Pressure compensating valve 75. Because of this, if a plurality of valve blocks 30 are connected by overlapping the front and rear surfaces 40, 41, the pump / first / second ports 39, 42, 43 of each valve block 30 communicate with each other. When the discharge passage 81 of the hydraulic pump 80 is connected to the pump port 39 and the first port 42 as shown in FIG. 8 and the load pressure detection passage 82 is connected to the second port 43, as shown in FIG. A hydraulic circuit similar to can be configured. A single valve block 30 is used to form a plurality of spool holes 31, check valve holes 37, pressure reducing valve holes 38, and pump / first / second ports 39, 42, and 43 are provided for each check valve hole 37. Alternatively, it may be formed over the pressure reducing valve hole 38. In FIG. 9, 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.
【０００９】 次に作動を図９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 圧検出路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２０ｋ ｇ／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 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, and therefore 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 pressure detecting path 82. Now, assuming that this differential pressure is 20 kg / cm 2 , the pressure in the load pressure detection path 82 is zero, so the pump discharge pressure rises to 20 kg / cm 2, and at the same time, the pump discharge pressure enters the pressure chamber a of the check valve 63. After flowing in, 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 when it becomes equal, a receipt is made by the weak spring 69. The pressure reducing valve unit 74 connects the pump discharge passage 81 and the pressure chamber 66 only at the end of the stroke, while the check valve unit 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.
【００１０】 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、すなわち負荷圧が油孔１００、通路５ ８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８１ 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、ポンプ調整用方向制御弁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 ５５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と負荷圧導入用の油孔１００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, when the pressure (load pressure) in the conduit 89 connecting the first actuator port 34 and the actuator 88 is larger 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 of the conduit 89 of the actuator 88, that is, the load pressure, is guided to the one pressure chamber 65 of the pressure reducing valve portion 74 from the oil hole 100 and the passage 58. 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 81 and the load are discharged. The pressure detection path 82 communicates. When the pressure (load pressure) in the conduit 89 is higher than the pump discharge pressure (= 20 kg / cm 2 ), the pressure is closed in the pressure chamber b of the check valve portion 63, and the pressure is reduced to one of the pressure reducing valve portion 74. Since the pressure chamber 65 is guided to the pressure chamber 65, the pressure reducing valve portion 74 continues to stroke even when the other pressure chamber 66 communicates with the pump discharge passage 81. On the other hand, when the pressure (load pressure) in the conduit 41 is smaller 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. If the pressures in 66 become equal, the weak spring 69 makes contact with the closing check valve 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 adjusted by the pump adjustment directional control valve 85 by a certain differential pressure (here, 20 kg / cm 2 ). The pressure is controlled to be higher than the pressure in 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 oil hole 100 for introducing the load pressure are connected, while the second oil passage 53 is connected to the pressure chamber 65 of the pressure reducing valve portion 74. However, since the load pressure in the pressure reducing valve section 74 is used only as pilot pressure (set pressure of the pressure reducing valve section), the pressure is not lost, that is, the directional control valve 55 is stroked. At this time, the actuator 88 does not naturally drop due to the load pressure being removed.
【００１１】 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７４ 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６９ 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. Since one pressure chamber 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, so that the pressure chamber 66 in 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 guided from the pump discharge path 81 to the pressure chamber a in the direction of opening the check valve portion 74, the pressure difference between the pump discharge pressure and the pressure inside the load pressure detection path 82 is totally divided. (= 20 kg / cm 2 ), the check valve portion 63 and the pressure reducing valve portion 74 are stroked in the opening direction of the check valve portion 63, but the stroke of the check valve portion 63 and the pressure at the input port 44 is slightly different (= 20 kg / cm 2). ), The weak spring 69 makes a receipt, and as a result, the pressure reducing valve unit 74 does not strike until the stroke end, and the hydraulic control on the directional control valve 55 side is not affected at all.
【００１２】 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と各負荷圧導用の油孔１００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は負荷圧検出用の油孔１００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）は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６ ９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、ここで始めてチェック弁部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の入口ポート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 input ports 44, the conduits 89, and the load pressure guiding oil holes 100, respectively. One of the pressure reducing valve sections 74 has the pressure in the pressure chamber 66 equal to the pressure in the one pressure chamber 65, and the other pressure reducing valve section 74 has the pressure in the pressure chamber 66 equal to that of the one pressure chamber. 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 passage 82 is connected to the tank 86 via the throttle 91, the pressure in the load pressure detection passage 82 is zero before the stroke of the directional control valve. Therefore, each pressure reducing valve portion 74 makes a stroke even by the pressure in the oil hole 100 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 closes. .. 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 urges 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, the pressure (pump discharge pressure) in the pressure chamber a in the opening direction of the check valve portion 63 is 20 (kg / cm 2 ), and as a result, the pressure of the input port 44 of the directional control valve 55 is 10 (kg / Cm 2 ), the check valve portion 63 is opened, and then a receipt is made by the weak spring 69. By a pump adjusting direction control valve 85, there differential pressure (20kg / cm 2) amount corresponding, pump discharge pressure from the high pressure pressure (20kg / cm 2) of the load pressure Detchi 82 is controlled (40 kg / cm 2 ). Also at this time, the pressure in the load pressure detection path 82 becomes 40 (kg / cm 2 ) with the check valve portion 63 of the high-pressure side pressure compensating valve 75 kept closed and the pressure reducing valve portion 74 still having a 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 are closed by the weak spring 69 to contact 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 at the input port 44 of the directional control valve 55 on the low pressure side 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 becomes 120 (kg / cm 2 ), the pressure at the inlet port 44 of the directional control valve 55 becomes 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 from 120 kg / cm 2 to 30 kg / cm 2 . For the first time, this hydraulic control system is balanced and 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.
【００１３】 −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 actuators 88, 88 are 100 kg / cm 2 , 501 / min for the left actuator 88 and 10 kg / cm 2 , 501 / min for the right actuator 88. 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, it is assumed 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 , and therefore the pressure reducing valve portion 74 is checked by the weak spring 69. 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 100 kg / cm 2 and 10 kg / cm 2 , and the differential pressure of 90 kg / cm 2 causes the check valve portion 63 of 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. With the pressure 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 the 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.
【００１４】 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。 なお、弁ブロック３０の油孔１００の代りに主スプール４９内に第１負荷圧検 出ポート４５と第２負荷圧検出ポート４６を連通する油路を形成して負荷圧を減 圧弁部７４の第１受圧室６５に供給するようにしても良い。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 disposed between the directional control valve and the hydraulic pump, and the pressure compensating valve 75 is arranged in the closing direction of each pressure reducing valve portion. 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. In place of the oil hole 100 of the valve block 30, an oil passage that connects the first load pressure detection port 45 and the second load pressure detection port 46 is formed in the main spool 49 to reduce the load pressure. It may be supplied to the first pressure receiving chamber 65.
【００１５】[0015]
主スプール４９を左又は右に摺動すると入力ポート４４が第１切欠部１０１又 は第２切欠部１０２を経て第１又は第２アクチェエータポート３４，３５に連通 するので、主スプール４９を左又は右に同一ストローク操作にしたときに第１又 は第２アクチェエータポート３４，３５に供給する流量を第１・第２切欠部１０ １，１０２の幅あるいは深さを異ならせることでそれぞれ異なる流量とすること ができるから、シリンダ等のアクチェエータの面積が異なる第１室と第２室への 供給流量を異ならせてアクチェエータを伸長、縮少する時の速度を等しくできる 。 When the main spool 49 is slid to the left or right, the input port 44 communicates with the first or second actuator port 34, 35 via the first notch portion 101 or the second notch portion 102. When the same stroke operation is performed to the left or right, the widths or depths of the first and second cutouts 101 and 102 are made different so as to supply the flow rates to the first or second actuator ports 34 and 35. Since the flow rates can be different from each other, it is possible to equalize the speeds at which the actuator is extended and contracted by making the flow rates supplied to the first chamber and the second chamber having different areas of the actuator such as a cylinder different.
【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】先に出願した圧油供給装置の具体例を示す断面
図である。FIG. 3 is a cross-sectional view showing a specific example of the pressure oil supply device previously applied.
【図４】本考案の実施例を示す弁ブロックの斜視図であ
る。FIG. 4 is a perspective view of a valve block according to an embodiment of the present invention.
【図５】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. 5 is a cross-sectional view showing a state where a main spool and a spool are incorporated in a valve block.
【図６】方向制御弁の動作説明図である。FIG. 6 is an operation explanatory view of the directional control valve.
【図７】方向制御弁の動作説明図である。FIG. 7 is an operation explanatory view of the directional control valve.
【図８】複数の弁ブロックの接続状態を示す斜視図であ
る。FIG. 8 is a perspective view showing a connected state of a plurality of valve blocks.
【図９】図５に示すものの回路図である。FIG. 9 is a circuit diagram of what is shown in FIG.
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、５２ 中間小径
部、５５方向制御弁、５６ 油孔、５８ 油孔、６０
スプール、６３ チェック弁部、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、１０１ 第１切欠
部、１０２ 第２切欠部。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, 52 middle small diameter portion, 55 directional control valve, 56 oil hole, 58 oil hole, 60
Spool, 63 Check valve part, 64 Spool, 65
1st pressure chamber, 66 2nd pressure chamber, 69 spring, 74 pressure reducing valve part, 75 pressure compensation valve, 80 hydraulic pump, 81
Pump discharge passage, 82 load pressure detection passage, 101 first notch, 102 second notch.
Claims (1)
る圧力補償弁７５と、この圧力補償弁７５の出力側に設
けた方向制御弁５５とを備えた圧油供給装置において、 弁ブロック３０にスプール孔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、第１・
第２アクチェータポート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、この主スプール４９に入力ポー
ト４４に臨む中間小径部５２及びこの中間小径部５２に
開口し入力ポート４４を前記第１・第２負荷圧検出ポー
ト４５，４６に連通制御する第１・第２切欠部１０１，
１０２を形成したことを特徴とする圧油供給装置。1. A pressure oil supply device comprising a pressure compensation valve 75 comprising a check valve portion 63 and a pressure reducing valve portion 74, and a directional control valve 55 provided on the output side of the pressure compensation valve 75. Input port 44 opened to the spool hole 31, first and second load pressure detection ports 45, 46, first
The second actuator ports 34 and 35 and the first and second tank ports 47 and 48 are formed respectively, and the spool hole 3
A main spool 49 that connects and disconnects each port is fitted into 1 to form a directional control valve 55, and an intermediate small diameter portion 52 facing the input port 44 and the intermediate small diameter portion 52 are opened in the main spool 49 to open the input port 44. First and second cutouts 101 for controlling communication with the first and second load pressure detection ports 45 and 46,
102 is a pressure oil supply device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4516892U JPH0596504U (en) | 1992-06-08 | 1992-06-08 | Pressure oil supply device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4516892U JPH0596504U (en) | 1992-06-08 | 1992-06-08 | Pressure oil supply device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0596504U true JPH0596504U (en) | 1993-12-27 |
Family
ID=12711739
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4516892U Pending JPH0596504U (en) | 1992-06-08 | 1992-06-08 | Pressure oil supply device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0596504U (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5934006A (en) * | 1982-08-17 | 1984-02-24 | Daikin Ind Ltd | Fluid control device |
-
1992
- 1992-06-08 JP JP4516892U patent/JPH0596504U/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5934006A (en) * | 1982-08-17 | 1984-02-24 | Daikin Ind Ltd | Fluid control device |
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