JPH0532802U - Pressure oil supply device - Google Patents
Pressure oil supply deviceInfo
- Publication number
- JPH0532802U JPH0532802U JP8952491U JP8952491U JPH0532802U JP H0532802 U JPH0532802 U JP H0532802U JP 8952491 U JP8952491 U JP 8952491U JP 8952491 U JP8952491 U JP 8952491U JP H0532802 U JPH0532802 U JP H0532802U
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- pressure
- port
- valve
- spool
- check valve
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Abstract
(57)【要約】 （修正有）
【目的】 弁ブロックに方向制御弁と圧力補償弁をコン
パクトに収納し、第１・第２負荷圧検出ポートを連通す
る構造の圧油供給装置を提供する。
【構成】 弁ブロック３０のスプール孔３１に主スプー
ル４９を嵌挿して方向制御弁５５とし、合せ面に第１・
第２負荷圧検出ポート４５，４６を開口させ、かつ凹部
５３で連通し、チェック弁用孔３７にポンプポート３９
と方向制御弁の入力ポート４４を連通・遮断するスプー
ル６０を嵌挿してチック弁部６３とし、減圧弁用孔３８
に第１ポート４２と第２ポート４３を連通遮断するスプ
ール６４を嵌挿して第１圧力室６５と第２圧力室６６を
構成し、第１圧力室を方向制御弁５５の負荷圧検出ポー
トに連通し、第２圧力室を第２ポート４３に連通し、ス
プール６４をばね６９でチェック弁部６３のスプール６
０側に押して減圧弁部７４とし、チェック弁部６３と減
圧弁部７４で圧力補償弁７５とする。
(57) [Summary] (Modified) [Purpose] To provide a pressure oil supply device having a structure in which a directional control valve and a pressure compensation valve are compactly housed in a valve block and the first and second load pressure detection ports are in communication with each other. . [Structure] The main spool 49 is fitted into the spool hole 31 of the valve block 30 to form a direction control valve 55, and the first and second
The second load pressure detection ports 45 and 46 are opened and communicated with each other through the recess 53, and the check valve hole 37 is connected to the pump port 39.
And a spool 60 that connects and disconnects the input port 44 of the directional control valve with the directional control valve is fitted to form the tick valve portion 63, and
A first pressure chamber 65 and a second pressure chamber 66 are formed by inserting a spool 64 that shuts off the first port 42 and the second port 43 into the first pressure chamber 65 and the second pressure chamber 66, and the first pressure chamber is used as a load pressure detection port of the directional control valve 55. The second pressure chamber is communicated with the second port 43, and the spool 64 is connected to the spool 6 of the check valve portion 63 by the spring 69.
The pressure reducing valve portion 74 is pushed to the 0 side, and the check valve portion 63 and the pressure reducing valve portion 74 serve as a pressure compensating valve 75.
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 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とを組み合せて圧油供給装置を構成する場合、実用化 段階で方向制御弁２２と圧力補償弁２５を１つの弁ブロック内に組み込むことが コンパクト化を図る上で必要となるが、方向制御弁２２と圧力補償弁２５を１つ の弁ブロックに組み込むことが弁ブロック間のポート連通などによって大変困難 である。 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. When the pressure oil supply device is configured by combining the directional control valve 22 and the pressure compensating valve 25, the directional control valve 22 and the pressure compensating valve 25 are practically used. It is necessary to incorporate the valve into one valve block in order to achieve compactness, but it is very difficult to incorporate the directional control valve 22 and the pressure compensating valve 25 into one valve block due to port communication between the valve blocks. Is.
【０００５】 そこで、本考案は前述の課題を解決できるようにした圧油供給装置を提供する ことを目的とする。Therefore, an object of the present invention is to provide a pressure oil supply device capable of solving the above-mentioned problems.
【０００６】[0006]
弁ブロック３０にスプール孔３１とチェック弁用孔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４４、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３４，３ ５、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、前 記弁ブロック３０の合せ面に第１・第２負荷圧検出ポート４５，４６を開口させ 、かつ凹部５３で連通し、さらに弁ブロック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６ ３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４ ２，４３を形成し、この減圧弁用孔３８にスプール６４を嵌挿して第１圧力室６ ５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、ポンプポート３９、第１ポート４２に油圧ポンプ８０の吐出 路８１を接続し、前記第３ポート４３に負荷圧検出路８２を接続した圧油供給装 置。 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 valve block 30 has an input port 44 and first and second load pressure detection ports 45 opened in the spool hole 31. , 46, the first and second actuator ports 34, 35, and the first and second tank ports 47, 48, respectively, and the main spool 49 that connects and disconnects the respective ports is inserted into the spool hole 31 and the direction is set. The control valve 55 is used, the first and second load pressure detection ports 45 and 46 are opened on the mating surface of the valve block 30 and communicated with the recess 53, and the valve block 30 is opened to the check valve hole 37. An oil passage 56 that connects the pump port 39 and the check valve hole 37 to the input port 44 is formed, and the pump port 39 and the oil passage 56 are connected to and cut off from the check valve hole 37. The spool 60 that is stopped at the position is inserted to form the check valve portion 63, and the valve block 30 is formed with the first and second ports 42 and 43 which open to the pressure reducing valve hole 38. A spool 64 is fitted in the hole 38 to form a first pressure chamber 65 and a second pressure chamber 66, the first pressure chamber 65 is communicated with the second load pressure detection port 46, and the second pressure chamber 66 is connected to the second pressure chamber 66. The spool 64 of the check valve portion 63 is pressed to the shut-off position and held to form a pressure reducing valve portion 74, which communicates with the two port 43 and is urged in one direction by a spring 69 to form a pressure reducing valve portion 74. A pressure oil supply in which the check valve unit 63 serves as a pressure compensation valve 75, the pump port 39 and the first port 42 are connected to the discharge passage 81 of the hydraulic pump 80, and the third port 43 is connected to the load pressure detection passage 82. Equipment.
【０００７】[0007]
弁ブロック３０に方向制御弁５５と圧力補償弁７５をコンパクトに収納できる し、弁ブロック３０の合せ面に形成した凹部５３で第１・第２負荷圧検出ポート ４５，４６を連通できる。 The directional control valve 55 and the pressure compensating valve 75 can be compactly housed in the valve block 30, and the first and second load pressure detecting ports 45 and 46 can be communicated with each other by the recess 53 formed in the mating surface of the valve block 30.
【０００８】[0008]
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ポート、第１・第２ポート３９，４２， ４３が連通すようにしてある。 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、前記第１・第２負荷圧検出ポート４５，４６は図３に 示すように弁ブロック３０の前面に開口し、かつ凹部５３で連通し、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、スプール４９はスプリング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、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圧油供給位置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。 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のポンプポート３９、第１・第２ポート３９ ，４２，４３が連通し、かつ凹部５３が隣接する弁ブロック３０の後面４１で閉 塞されて第１・第２負荷圧検出ポート４５，４６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５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、ポンプポート、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。 As shown in FIG. 3, 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 to open at 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 pump ports, the first and second ports 39, 42, 43 are formed. Will communicate It is to. As shown in FIG. 4, 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, and 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 parts 50, 51 and the communication groove 52. As shown in FIG. 3, the first and second load pressure detection ports 45 and 46 are open to the front surface of the valve block 30 and communicate with each other through the recess 53, and the main spool 49 has the second load pressure detection port 46 and the second load pressure detection port 46. An oil passage 54 that connects and disconnects the tank port 48 is formed, and the spool 49 blocks each port by a spring, and the oil path 54 is located at a neutral position A that connects the second load pressure detection port 46 and the second tank port 48. Held and spool When 9 is slid to the right, the second actuator port 35 is communicated with the second tank port 48 by the second small diameter portion 51, and the input port 44 is communicated with the second load pressure detection port 46 by the communication groove 52. In the first small diameter portion 50, the first actuator port 34 is in communication with the first load pressure detection port 45, and the second load pressure detection port 46 and the second tank port 48 are at the first pressure oil supply position B, When the spool 49 is slid to the left, the first small diameter portion 50 communicates the first actuator port 34 with the first tank port 47, and the communication groove 52 communicates the input port 44 with the first load pressure detection port 45. In the second small diameter portion 51, the second actuator 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 in a second pressure oil supply position C. Constitute a directional control valve 55 Te. 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. Therefore, if a plurality of valve blocks 30 are connected by overlapping the front and rear surfaces 40 and 41, the pump ports 39 and the first and second ports 39, 42 and 43 of each valve block 30 communicate with each other. In addition, since the recess 53 is closed by the rear surface 41 of the adjacent valve block 30 and the first and second load pressure detection ports 45 and 46 communicate with each other, the discharge passage 81 of the hydraulic pump 80 is pumped as shown in FIG. By connecting the port 39 and the first port 42 to each other and connecting the load pressure detection path 82 to the second port 43, a hydraulic circuit similar to that shown in FIG. 2 can be constructed as shown in FIG. A plurality of spool holes 31, check valve holes 37, and pressure reducing valve holes 38 are formed with one valve block 30 as one, and pump ports and first and second ports 39, 42, and 43 are provided for each check valve hole 37. It may be formed over the pressure reducing valve hole 38. 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.
【０００９】 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 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アクチュエータポート３５と第２タンクポート４ ８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（＝２０ｋ ｇ／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８９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 direction 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 port 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 higher than the pump discharge pressure (20 kg / cm 2 ), the check valve portion 63 receives the pressure in the pressure chamber b. 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 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 81. 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 check valve portion 63 is closed by the pressure of the pressure chamber b, and the pressure is reduced by the pressure reducing valve portion 74. Since the pressure reducing valve portion 74 is guided to the one pressure chamber 65, even if the other pressure chamber 66 communicates with the pump discharge passage 81, the pressure reducing valve portion 74 remains stroked. On the other hand, when the pressure (load pressure) in the conduit 89 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 portion 74, and the pressure reducing valve portion 74 is Although the stroke is made by the pressure of one pressure chamber 65, 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 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 is connected to the second oil passage 53 for introducing load pressure, while the second oil passage 53 is connected to the pressure of one of the pressure reducing valve portions 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, the actuator 88 does not naturally descend 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、負荷圧はゼロで、よって圧力室６６内の圧力によって減圧弁部７ ４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／ｃ ｍ2 ）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 directional control valve 55, the load pressure is zero, and therefore the pressure reducing valve portion 74 changes the check valve portion by the pressure in the pressure chamber 66. 63 is urged in the closing direction. On the other hand, since the pump discharge pressure is guided from the pump discharge passage 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 in the load pressure detection passage 82 is totally reduced. (= 20 kg / cm 2 ), the check valve portion 63 and the pressure reducing valve portion 74 are stroked toward the opening direction of the check valve portion 63, but they are slightly stroked so that the pressure at the input port 44 is the differential pressure (= 20 kg / cm 2). If it becomes 2 ), the weak spring 69 makes a receipt, and as a result, the pressure reducing valve portion 74 does not stroke to the stroke end, and there is no effect on the hydraulic control of the directional control valve 55 side. .
【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と第１・第２負荷圧検出ポート４５，４６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、左側のアクチュエータ ８８の負荷圧を１００（ｋｇ／ｃｍ2 ）、右側のアクチュエータ８８の負荷圧を １０（ｋｇ／ｃｍ2 ）とする。負荷圧検出路８２は、絞り９１を介してタンク８ ６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 によってともにストロークし、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と第１・第２負荷圧検 出ポート４５，４６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（ｋｇ／ｃｍ2 ）（１２０−９０）となる状態で、チェック弁部６３及び 減圧弁部７４が圧力バランスする。すなわち、チェック弁部６３及び減圧弁部７ ４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, and the respective input ports 44, the respective conduits 89, and the first and second load pressure detection ports 45, 46 are respectively connected. 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 88 is 100 (kg / cm 2 ) and the load pressure of the right actuator 88 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, the pressure reducing valve portions 74 stroke together by 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 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 is a check valve portion due to the pressure difference (= 90 kg / cm 2 ) between the load pressure detecting path 82 and the first and second load pressure detecting ports 45 and 46. Although the pressure in the pressure chamber a in the opening direction of the check valve portion 63 became 120 (kg / cm 2 ), the pressure of the input port 44 of the directional control valve 55 was set to 30 ( (kg / cm 2 ) (120-90), the check valve portion 63 and the pressure reducing valve portion 74 balance the pressure. That is, the check valve 63 and the pressure reducing valve 7 4 slightly stroke, a state of the check valve unit 63, and squeezed so that a 120 kg / cm 2 or al 30kg / 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。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.
【００１５】[0015]
方向制御弁５５及びチェック弁部６３と減圧弁部７４より成る圧力補償弁７５ を弁ブロック３０にコンパクトに収納して装置全体をコンパクトにできるし、弁 ブロック３０の合せ面に形成した凹部５３で第１・第２負荷圧検出ポート４５， ４６を連通できて、そのための構造が簡単となる。 The directional control valve 55 and the pressure compensating valve 75 including the check valve portion 63 and the pressure reducing valve portion 74 can be compactly housed in the valve block 30 to make the entire device compact, and the concave portion 53 formed on the mating surface of the valve block 30 The first and second load pressure detection ports 45 and 46 can be communicated with each other, and the structure therefor becomes simple.
【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 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.
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…凹部、５
６…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。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 ... Recessed portion, 5
6 ... Oil hole, 58 ... Oil hole, 60 ... Spool, 63 ... Check valve part, 64 ... Spool, 65 ... First pressure chamber, 66 ... Second pressure chamber, 69 ... Spring, 74 ... Pressure reducing valve part, 75 ... Pressure compensation valve, 80 ... Hydraulic pump, 81 ... Pump discharge passage, 82 ...
Load pressure detection path.
Claims (1)
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の合せ面に
第１・第２負荷圧検出ポート４５，４６を開口させ、か
つ凹部５３で連通し、 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１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、ポンプポ
ート３９、第１ポート４２に油圧ポンプ８０の吐出路８
１を接続し、前記第２ポート４３に負荷圧検出路８２を
接続したことを特徴とする圧油供給装置。1. A spool hole 31, a check valve hole 37, and a pressure reducing valve hole 38 are formed in a valve block 30, and an 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 first and second load pressure detecting ports 45 and 46 are opened on the mating surface of the valve block 30 and the concave portion 53 In communication with the valve block 30, a pump port 39 opened in the check valve hole 37 and an oil passage 56 communicating the check valve hole 37 with the input port 44 are formed, and the pump port 39 is provided in the check valve hole 37. And the oil passage 56 are connected and shut off, and a spool 60 that is stopped at the shut-off position is inserted to form a check valve portion 63.
-The second ports 42 and 43 are formed, and the pressure reducing valve hole 38 is formed.
The first pressure chamber 65 and the second pressure chamber 66 are formed by inserting the spool 64 into the first pressure chamber 65, the first pressure chamber 65 is communicated with the second load pressure detection port 46, and the second pressure chamber 66 is connected to the second port 43. And the spool 64 of the check valve portion 63 is pressed and held in the shut-off position to form a pressure reducing valve portion 74, which is connected to the pressure reducing valve portion 74 and the check valve portion. 63 as a pressure compensation valve 75, and the discharge port 8 of the hydraulic pump 80 is connected to the pump port 39 and the first port 42.
1 and the load pressure detection path 82 is connected to the second port 43.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8952491U JP2551546Y2 (en) | 1991-10-07 | 1991-10-07 | Pressure oil supply device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8952491U JP2551546Y2 (en) | 1991-10-07 | 1991-10-07 | Pressure oil supply device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0532802U true JPH0532802U (en) | 1993-04-30 |
| JP2551546Y2 JP2551546Y2 (en) | 1997-10-22 |
Family
ID=13973196
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8952491U Expired - Lifetime JP2551546Y2 (en) | 1991-10-07 | 1991-10-07 | Pressure oil supply device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2551546Y2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112303051A (en) * | 2019-07-31 | 2021-02-02 | 纳博特斯克有限公司 | Fluid control valve, fluid system, and construction machine |
-
1991
- 1991-10-07 JP JP8952491U patent/JP2551546Y2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112303051A (en) * | 2019-07-31 | 2021-02-02 | 纳博特斯克有限公司 | Fluid control valve, fluid system, and construction machine |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2551546Y2 (en) | 1997-10-22 |
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| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |