JPH0542704U - Directional control valve device - Google Patents
Directional control valve deviceInfo
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- JPH0542704U JPH0542704U JP10063591U JP10063591U JPH0542704U JP H0542704 U JPH0542704 U JP H0542704U JP 10063591 U JP10063591 U JP 10063591U JP 10063591 U JP10063591 U JP 10063591U JP H0542704 U JPH0542704 U JP H0542704U
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- pressure
- valve
- directional control
- control valve
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Abstract
(57)【要約】 （修正有）
【目的】方向制御弁装置において、安全弁を１つにし特
定方向制御弁に接続したアクチュエータの最高作動力を
安全弁セット圧より高くして、他の方向制御弁に接続し
たアクチュエータの最高圧力より高くする。
【構成】弁ブロック３０のスプール孔３１内に主スプー
ル４９を摺動自在に嵌挿して方向制御弁とし、弁ブロッ
クに第１、第２圧力検出ポート１００，１０１を形成し
て連通口凹部１０２に開口すると共にボール１０３及び
透孔１０４を設ける。複数の弁ブロックを接合して各第
１、第２圧力検出ポートを透孔に連通し、隣接する弁ブ
ロック間にボールを付勢するカバーブロックを設けると
共にボールの押し付け力を調整するバネ力調整機構を設
け、透孔を１つの安全弁に連通する。
(57) [Summary] (Modified) [Purpose] In a directional control valve device, one safety valve is used and the maximum operating force of the actuator connected to the specific directional control valve is made higher than the safety valve set pressure, and other directional control valves are used. Higher than the maximum pressure of the actuator connected to. A main spool 49 is slidably fitted in a spool hole 31 of a valve block 30 to form a directional control valve, and first and second pressure detection ports 100 and 101 are formed in the valve block to form a communication port recess 102. And a ball 103 and a through hole 104 are provided. A plurality of valve blocks are joined to communicate each of the first and second pressure detection ports with the through hole, and a cover block for urging the ball is provided between the adjacent valve blocks, and a spring force adjustment for adjusting the pressing force of the ball is provided. A mechanism is provided to connect the through hole to one safety valve.
Description
【０００１】[0001]
本考案は、油圧ポンプの吐出圧油を複数の方向制御弁で複数のアクチュエータ に供給する方向制御弁装置に関する。 The present invention relates to a directional control valve device that supplies the discharge pressure oil of a hydraulic pump to a plurality of actuators with a plurality of directional control valves.
【０００２】[0002]
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にはアクチュエータ と同数の方向制御弁を設け、その各方向制御弁を切換え操作して各アクチュエー タに油圧ポンプの吐出圧油を供給している。 前記方向制御弁としては例えば図１に示すように、弁ブロック１のスプール孔 ２内にスプール３を嵌挿し、このスプール３を左右に摺動することでポンプポー ト４を第１・第２アクチュエータポート５，６の一方に連通し、かつ第１・第２ アクチュエータポート５，６の他方をタンクポート７に連通するようにしたもの が知られている。 In order to supply the hydraulic oil discharge pressure oil to multiple actuators, the same number of directional control valves as the actuators are provided, and each directional control valve is switched to supply the hydraulic pump discharge pressure oil to each actuator. .. As the directional control valve, for example, as shown in FIG. 1, a spool 3 is fitted in a spool hole 2 of a valve block 1 and the spool 3 is slid right and left to move the pump port 4 to the first and second actuators. It is known that one of the ports 5 and 6 communicates with the other, and the other of the first and second actuator ports 5 and 6 communicates with the tank port 7.
【０００３】[0003]
かかる方向制御弁にあっては第１・第２アクチュエータポート５，６の最高圧 力を規定して各部が破損等しないように、図１に示すように弁ブロック１に第１ ・第２安全弁８，９を第１・第２アクチュエータポート５，６に開口して取付け ている。 このように、１つの方向制御弁に２つの安全弁が必要であるから、複数の方向 制御弁を組み合せて方向制御弁装置とした場合に、方向制御弁の数の２倍の安全 弁が必要となってコストが高くなるばかりか、方向制御弁装置全体が大きくなっ て設置面積が大となる。 In such a directional control valve, as shown in FIG. 1, the first and second safety valves are provided in the valve block 1 so that the maximum pressure of the first and second actuator ports 5 and 6 is regulated so that each part is not damaged. 8 and 9 are attached to the first and second actuator ports 5 and 6 by opening them. In this way, one directional control valve requires two safety valves. Therefore, when multiple directional control valves are combined to form a directional control valve device, the number of safety valves is twice the number of directional control valves. Not only does this increase the cost, but the directional control valve device as a whole also becomes large and the installation area becomes large.
【０００４】 そこで、本考案は前述の課題を解決できるようにした方向制御弁装置を提供す ることを目的とする。Therefore, an object of the present invention is to provide a directional control valve device capable of solving the above-mentioned problems.
【０００５】[0005]
弁ブロック３０のスプール孔３１内に主スプール４９を摺動自在に嵌挿して入 力ポート４４を第１・第２アクチュエータ３４，３５に連通・遮断する方向制御 弁とし、前記弁ブロック３０に第１、第２アクチュエータポート３４，３５に連 通した第１・第２圧力検出ポート１００，１０１を形成し、この第１・第２圧力 検出ポート１００，１０１を弁ブロック３０の一方の接合面に形成した連通用凹 部１０２に開口し、かつ連通用凹部１０２から圧力検出ポートへの圧油流れを阻 止するボール１０３を設け、その連通用凹部１０２と弁ブロック３０の他方の接 合面に亘って透孔１０４を形成し、複数の弁ブロック３０を接合して各第１・第 ２圧力検出ポート１００，１０１を透孔１０４に連通し、隣接する弁ブロック３ ０間に前記ボール１０３を押すバネ１０６を設け、最も端部に位置する弁ブロッ ク７３の一方の接合面にカバーブロック１１０を設け、このカバーブロック１１ ０に前記ボール１０３の押しつけ力を調製するバネ力調整機構１１１を設け、そ の透孔１０４を１つの安全弁１０５に連通した方向制御弁装置。 The main spool 49 is slidably fitted in the spool hole 31 of the valve block 30 to form a directional control valve that connects and disconnects the input port 44 with the first and second actuators 34 and 35. First and second pressure detection ports 100 and 101 communicating with the first and second actuator ports 34 and 35 are formed, and the first and second pressure detection ports 100 and 101 are provided on one joint surface of the valve block 30. A ball 103 is provided which opens in the formed communication recess 102 and blocks the flow of pressure oil from the communication recess 102 to the pressure detection port. The ball 103 is provided on the other contact surface of the communication recess 102 and the valve block 30. A through-hole 104 is formed over the valve block 30, and the plurality of valve blocks 30 are joined to communicate the first and second pressure detection ports 100 and 101 with the through-hole 104. A spring 106 for pushing 103 is provided, a cover block 110 is provided on one joint surface of the valve block 73 located at the end, and a spring force adjusting mechanism 111 for adjusting the pushing force of the ball 103 on the cover block 110. A directional control valve device in which the through hole 104 is connected to one safety valve 105.
【０００６】[0006]
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ることで、 各弁ブロック３０の第１・第２圧力検出ポート１００，１０１が透孔１０４より 安全弁１０５に連通し、かつ低圧側の圧力検出ポート１００２は１０１には高圧 油が流入しないから、複数の方向制御弁における最も高いアクチュエータポート の圧力を１つの安全弁に導くことができ、方向制御弁装置に安全弁を１つ取付け れば良く、安全弁の数が減少してコストが安くなるばかりか、全体がコンパクト になって狭いスペースに取付けできし、端部の特定方向制御弁に接続したアクチ ュエータの最高作動力をバネ調整機構で調整できる。 By connecting the plurality of valve blocks 30 by overlapping the front and rear surfaces 40 and 41 with each other, the first and second pressure detection ports 100 and 101 of each valve block 30 communicate with the safety valve 105 through the through hole 104, and the low pressure. Since the high-pressure oil does not flow into the pressure detection port 1002 on the side 101, the pressure of the highest actuator port of a plurality of directional control valves can be guided to one safety valve, and one safety valve is attached to the directional control valve device. Not only does this reduce the number of safety valves and lower costs, but the overall size is compact and can be installed in a narrow space, and the maximum actuating force of the actuator connected to the directional control valve at the end can be adjusted by the spring adjustment mechanism. Can be adjusted with.
【０００７】[0007]
図２は複数の方向制御弁を同時操作して各アクチュエータに１つの油圧ポンプ の吐出圧油を所定の分配比で供給できるようにした圧油供給装置の回路図であり 、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、複数の方向制御弁２２を同時操作した時に各圧力補償弁２５で圧力 補償して各アクチュエータ２６に１つの油圧ポンプ２０の吐出圧油を供給できる ようにしてあり、方向制御弁２２と圧力補償弁２５が後述する弁ブロックに設け られ、その弁ブロックを重ね合せて方向制御装置２７としてある。 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が連通するようにしてある。 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、第１・第２アクチ ュエータポート３４，３５に開口した第１・第２圧力検出ポート１００，１０１ が形成され、その第１・第２圧力検出ポート１００，１０１は図３のように弁ブ ロック３０の前面４０に形成した連通用凹部１０２に開口し、かつチェック弁を 構成するボール１０３がそれぞれ設けてあり、その連通用凹部１０２と後面４１ に亘って透孔１０４が形成され、複数の弁ブロック３０を前後面４０，４１相互 を重ね合せると図５のように、各弁ブロック３０の第１・第２圧力検出ポート１ ００，１０１が連通用凹部１０２と透孔１０４でそれぞれ連通し、かつボール１ ０３によって低圧側の圧力検出ポート１００又は１０１に高圧が流入しないよう になり、透孔１０４には各弁ブロック３０の第１・第２圧力検出ポート１００， １０１における最も高い圧力が導入され、その透孔１０４が図７のように１つの 弁ブロック３０に設けた安全弁１０７の入口側に連通してある。 FIG. 2 is a circuit diagram of a pressure oil supply device in which a plurality of directional control valves are simultaneously operated so that the discharge pressure oil of one hydraulic pump can be supplied to each actuator at a predetermined distribution ratio. A plurality of directional control valves 22 are provided in the passage 21, and a pressure compensating valve 25 composed of a check valve portion 23 and a pressure reducing valve portion 24 is provided on the inlet side of each directional control valve 22. When the valves are simultaneously operated, the pressure compensation valve 25 compensates the pressure so as to supply the pressure oil discharged from one hydraulic pump 20 to each actuator 26. The directional control valve 22 and the pressure compensation valve 25 are provided in a valve block described later. The valve blocks are overlapped with each other to form a direction control device 27. 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. Communicate Unishi are. 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 First and second tank ports 47 and 48, and first and second pressure detecting ports 100 and 101 opened to the first and second actuator ports 34 and 35 are formed, and the first and second pressure detecting ports 100 and 101 are formed. As shown in FIG. 3, 101 is opened to a communication recess 102 formed on the front surface 40 of the valve block 30 and is provided with a ball 103 that constitutes a check valve. The communication recess 102 and the rear surface 41 extend over the ball 103. When the through holes 104 are formed and the front and rear surfaces 40, 41 of the plurality of valve blocks 30 are overlapped with each other, the first and second pressure detection ports 100, 101 of the respective valve blocks 30 are arranged as shown in FIG. The communication recess 102 and the through hole 104 communicate with each other, and the ball 103 prevents the high pressure from flowing into the low pressure side pressure detection port 100 or 101. The highest pressure is introduced into the pressure detection ports 100 and 101, and the through hole 104 is connected to the inlet side of the safety valve 107 provided in one valve block 30 as shown in FIG.
【０００８】 前記チェック弁となるボール１０３は弁ブロック３０の後面４１に形成した凹 部１０５に設けられたバネ１０６で第１・第２圧力検出ポート１００，１０１の 開口周縁に押しつけられ、そのボール１０３はバネ１０６による押しつけ力以上 の力が作用すると第１・第２圧力検出ポート１００，１０１の開口周縁から離れ て第１・第２圧力検出ポート１００，１０１と連通用凹部１０２が連通するので 、チェック弁が開放する圧力はバネ１０６のバネ力と安全弁１０７のセット圧に よって決定され、高圧の第１又は第２圧力検出ポート１００，１０１の圧力が前 記チェック弁を開放する圧力以上となると、チェック弁を開放してその高圧の第 １又は第２圧力検出ポート１００，１０１が連通用凹部１０２に連通するが低圧 側の第１・第２圧力検出ポート１００，１０１はボール１０３によって閉じられ て連通用凹部１０２と遮断される。 これによりアクチュエータの最高作動圧力は安全弁セット圧を高くすることによ って高くできるが、前記バネ１０６は小さな凹部１０５内に配設されるからバネ 力を強くできないし、バネ力を調整できず、アクチュエータの最高作動圧力を安 全弁セット圧より高くできないし、その最高作動圧力を調整できない。 このようであるから、複数の方向制御弁における１つの特定方向制御弁で圧油 が供給される特定アクチュエータの最高作動圧力を他の方向制御弁で圧油が供給 される他のアクチュエータより高くできないし、調整できない。 このために、図５，図６に示すように端部の弁ブロック３０の前面４０にカバ ーブロック１１０を取付け、このカバーブロック１１０にバネ力調整機構１１１ を取付けてある。 該バネ力調整機構１１１はカバーブロック１１０の孔１１２に嵌挿した押圧ピ ストン１１３をバネ１１４でボール１０３に押しつけ、このバネ１１４のバネ受 け１１５を孔１１２のネジ部１１２ａにネジ合いしてロックナット１１６でロッ クした構造となり、ロックナット１１６を弛めてバネ受け１１５を締付けること でバネ１１４のバネ力を大きくすることでボール１０３の第１・第２圧力検出ポ ート１００，１０１の開口周縁への押しつけ力を大きくすれば、チェック弁が開 口する圧力が高くなって端部の弁ブロック３０の特定方向制御弁で圧油が供給さ れる特定アクチュエータの最高作動圧力を安全弁セット圧より高くして他のアク チュエータの最高作動圧力より高くできるし、そのバネ力を調整することで特定 アクチュエータの最高作動圧力を調整できる。 前記スプール孔３１に嵌挿した主スプール４９には第１・第２小径部５０，５ １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４ ９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４ ８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でポンプポート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４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。The ball 103 serving as the check valve is pressed against the opening peripheral edges of the first and second pressure detection ports 100 and 101 by a spring 106 provided in a recess 105 formed in the rear surface 41 of the valve block 30, and the ball 103 is When a force greater than the pressing force of the spring 106 acts on 103, the first and second pressure detecting ports 100 and 101 and the communication recess 102 communicate with each other apart from the opening peripheral edge of the first and second pressure detecting ports 100 and 101. The pressure at which the check valve opens is determined by the spring force of the spring 106 and the set pressure of the safety valve 107, and the pressure at the high pressure first or second pressure detection port 100 or 101 is equal to or higher than the pressure at which the check valve is opened. Then, the check valve is opened and the high pressure first or second pressure detection port 100 or 101 communicates with the communication recess 102, but the low pressure side. The first and second pressure detection ports 100 and 101 are closed by a ball 103 to be disconnected from the communication recess 102. As a result, the maximum operating pressure of the actuator can be increased by increasing the safety valve set pressure, but since the spring 106 is arranged in the small recess 105, the spring force cannot be increased and the spring force cannot be adjusted. , The maximum operating pressure of the actuator cannot be higher than the safety valve set pressure, and the maximum operating pressure cannot be adjusted. Because of this, the maximum operating pressure of a specific actuator to which pressure oil is supplied by one specific direction control valve among multiple direction control valves cannot be made higher than other actuators to which the pressure oil is supplied by other direction control valves. However, it cannot be adjusted. For this purpose, as shown in FIGS. 5 and 6, the cover block 110 is attached to the front surface 40 of the valve block 30 at the end, and the spring force adjusting mechanism 111 is attached to the cover block 110. The spring force adjusting mechanism 111 presses the pressing piston 113 inserted into the hole 112 of the cover block 110 against the ball 103 with the spring 114, and the spring receiver 115 of this spring 114 is screwed into the screw portion 112a of the hole 112. The structure is locked by the lock nut 116, and the spring force of the spring 114 is increased by loosening the lock nut 116 and tightening the spring receiver 115, so that the first and second pressure detecting ports 100, 101 of the ball 103 are formed. If the pressing force of the check valve to the peripheral edge of the opening is increased, the pressure at which the check valve opens increases, and the pressure oil is supplied by the specific direction control valve of the valve block 30 at the end. It can be higher than the pressure and higher than the maximum working pressure of other actuators, and by adjusting the spring force of a particular actuator Maximum operating pressure can be adjusted. The main spool 49 fitted in the spool hole 31 is formed with first and second small diameter portions 50, 51 and a communication groove 52, and the first and second load pressure detection ports 45, 46 are shown in FIG. As shown in FIG. 3, an oil passage 54 that opens to the front surface of the valve block 30 and communicates with the concave portion 53, and that communicates and blocks the second load pressure detection port 46 and the second tank port 48 is formed in the main spool 49. The spool 49 is held at the neutral position A where the second load pressure detection port 46 and the second tank port 48 communicate with each other by the oil passage 54 by shutting off each port with a spring, and when the spool 49 slides to the right, The second small diameter portion 51 connects the second actuator port 35 to the second tank port 48, the communication groove 52 connects the input port 44 to the second load pressure detection port 46, and the first small diameter portion 50 connects the first actuator. Port 34 The first pressure oil supply position B 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 shut off. When the spool 49 is slid to the left, the first small diameter portion is reached. 50 connects the first actuator port 34 to the first tank port 47, the communication groove 52 connects the input port 44 to the first load pressure detection port 45, and the second small diameter portion 51 connects the second actuator port 35. The directional control valve 55 is configured as a second pressure oil supply position C that communicates with the second load pressure detection port 46 and that shuts off the second load pressure detection port 46 and the second tank port 48. The check valve hole 37 is opened to the pump 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. A stopper rod 62 provided on the plug 61 regulates the stopper valve 62 so that it does not slide to the left from the illustrated position and is held at the shutoff position to form a check valve portion 63. The pressure reducing valve hole 38 communicates with the second load pressure detecting port 46 through the fourth 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.
【０００９】 以上の様であるから、複数の弁ブロック３０を重ね合せて連結することで、 １つの安全弁に最も高いアクチュエータポートの圧力が導入されるから、複数の 方向制御弁を備えた方向制御弁装置において安全弁を１つとすることができし、 特定の方向制御弁によるアクチュエータの最高作動圧力を安全弁セット圧より高 くして他の方向制御弁によるアクチュエータの最高作動圧力よりも高くできるし 、その最高作動圧力を調整できる。 また複数の弁ブロック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、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７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８に示すように図２と同様の油圧回路を構成でき る。 図８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、８６はタンク、８７はバネである 。As described above, since the highest actuator port pressure is introduced into one safety valve by overlapping and connecting a plurality of valve blocks 30, the directional control with a plurality of directional control valves is provided. In the valve device, one safety valve can be used, and the maximum working pressure of the actuator by a specific directional control valve can be made higher than the safety valve set pressure and higher than the maximum working pressure of the actuator by another directional control valve. Maximum working pressure can be adjusted. If a plurality of valve blocks 30 are connected by overlapping the front and rear surfaces 40 and 41, the pump ports of the valve blocks 30 communicate with the first and second ports 39, 42 and 43, and the recess 53 is adjacent. Since the first and second load pressure detection ports 45 and 46 are closed by being blocked by the rear surface 41 of the valve block 30, 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. If the load pressure detection path 82 is connected to the second port 43, a hydraulic circuit similar to that of FIG. 2 can be constructed as shown in FIG. In FIG. 8, 83 is a swash plate that controls the discharge flow rate of the hydraulic pump 80, 84 is a servo cylinder, 85 is a directional control valve for pump adjustment, 86 is a tank, and 87 is a spring.
【００１０】 次に前述の油圧回路の作動を図８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 of the above hydraulic circuit 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.
【００１１】 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.
【００１２】 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／ｃｍ2 ）によってチェック弁部６３及び減圧弁部７ ４をチェック弁部６３の開く方向にストロークさせるが、わずかにストロークし 入力ポート４４の圧力がその差圧（＝２０ｋｇ／ｃｍ2 ）になれば、弱いばね６ ９によってレシートし、結果として、ストロークエンドまで減圧弁部７４がスト ロークすることはなく、方向制御弁５５側の油圧制御には、何ら影響することは ない。The load pressure detection path 82 is also connected to the other pressure chamber 66 of the pressure reducing valve portion 74 of the pressure compensating valve 75 disposed in the other directional control valve 55, but the pressure reducing valve portion 74 Since one of the pressure chambers 65 is connected to the tank 86 by the neutral position A of the direction control valve 55, the load pressure is zero, and thus the pressure in the pressure chamber 66 causes the pressure reducing valve portion 74 to change to the check valve portion. 63 is urged in the closing direction. On the other hand, since the pump discharge pressure is introduced from the pump discharge path 81 to the pressure chamber a in the direction of opening the check valve portion 74, the difference between the pump discharge pressure and the pressure in the load pressure detection path 82 is () as a whole. = 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 they are slightly stroked, and the pressure at the input port 44 is the differential pressure (= 20 kg / cm 2 ). In this case, the weak spring 69 causes a receipt, and as a result, the pressure reducing valve portion 74 does not stroke to the stroke end, and there is no influence on the hydraulic control of the directional control valve 55 side.
【００１３】 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 becomes 120 (Kg / cm 2 ), the pressure of the input port 44 of the directional control valve 55 becomes 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 so that the pressure of the input port 44 of the high-pressure side directional control valve 55 is 120 kg / cm 2 , and the pressure of the input port 44 of the low-pressure side directional control valve 55 is 30 kg / cm 2. 2 , that is, the difference between the inlet pressure and the outlet pressure (load pressure) of the two directional control valves 55, 55 is maintained at 20 kg / cm 2 , so that the two directional control valves 55, 55 are In both cases, the flow rate supplied to the actuators 88, 88 can be controlled only by the stroke amount.
【００１４】 −各アクチュエータ８８，８８に必要とされる流量の合計が油圧ポンプ８ ０の最大吐出流量以上のとき。 いま、アクチュエータ８８，８８の負荷圧および必要流量を左側のアクチュエ ータ８８が１００ｋｇ／ｃｍ2 、５０１／ｍｉｎ、右側のアクチュエータ８８が １０ｋｇ／ｃｍ2 、５０１／ｍｉｎとする。油圧ポンプ８０の最大吐出流量が１ ００１／ｍｉｎ以上のときは、前述の通り、方向制御弁５５，５５の入口圧と出 口圧の差が一定に保たれる（＝２０ｋｇ／ｃｍ2 ）ため、ストロークによって流 量制御ができ、５０１／ｍｉｎずつ流量分配することはできる。 次に、油圧ポンプ８０の最大吐出量が７０１／ｍｉｎになったとする。二つの 方向制御弁５５，５５の入口圧は前述の通り１２０ｋｇ／ｃｍ2 、３０ｋｇ／ｃ ｍ2 であるので、高圧側の方向制御弁５５への流量が５０１／ｍｉｎから２０１ ／ｍｉｎに減る。低圧側の方向制御弁５５への流量は、５０１／ｍｉｎのままで ある。二つの方向制御弁５５，５５のストローク（開口面積）を変えないとする と、高圧側の方向制御弁５５の入口圧と出口圧の差圧が流量が減った分、２０ｋ ｇ／ｃｍ2 から下がる。いま、差圧が１４ｋｇ／ｃｍ2 、すなわち、入口圧が、 １２０ｋｇ／ｃｍ2 から１１４（１００＋１４）ｋｇ／ｃｍ2 に下がったとする 。この時圧力補償弁７５の減圧弁部７４の二つの圧力室６５，６６の圧力は、と もに１００ｋｇ／ｃｍ2 のままであるから、減圧弁部７４は弱いばね６９によっ てチェック弁部６３に当接しているだけであり、チェック弁部６３の閉じる方向 の圧力室ｂ内の圧力が１２０ｋｇ／ｃｍ2 から１１４ｋｇ／ｃｍ2 に減少すれば 、チェック弁部６３が開いたまま（ストロークエンド）で、チェック弁部６３の 開く方向の圧力室ａ内の圧力、すなわち、ポンプ吐出圧が１２０ｋｇ／ｃｍ2 か ら１１４ｋｇ／ｃｍ2 に減少する。この時（ポンプ吐出流量不足時）にはポンプ 吐出圧は、ポンプ調整用方向制御弁８５の制御によらなくなる。 一方、低圧側の圧力補償弁７５の減圧弁部７４の二つの圧力室６５と６６は、 １００ｋｇ／ｃｍ2 、１０ｋｇ／ｃｍ2 のままで、その差圧９０ｋｇ／ｃｍ2 で チェック弁部６３の閉じる方向に付勢し続ける。一方、チェック弁部６３の開く 方向の圧力室ａ内の圧力、すなわちポンプ吐出圧が１１４ｋｇ／ｃｍ2 に減少し たので、チェック弁部６３の閉じる方向の圧力室ｂ内の圧力が３０ｋｇ／ｃｍ2 から２４ｋｇ／ｃｍ2 に減少した状態でチェック弁部６３及び減圧弁部７４が圧 力バランスする。よって、低圧側の方向制御弁５５の入口圧と出口圧の差圧は２ ０ｋｇ／ｃｍ2 から１４ｋｇ／ｃｍ2 （２４−１０）に減少する。方向制御弁５ ５のこの差圧の減少により低圧側のアクチュエータ８８への供給流量は５０１／ ｍｉｎから減少し、その分高圧側のアクチュエータ８８への供給流量が２０１／ ｍｉｎから増える。 すなわち、方向制御弁５５および５５の入口圧と出口圧の差圧が等しく、かつ 、二つのアクチュエータ８８，８８への供給量がともに３５１／ｍｉｎずつに分 配される状態で、この油圧制御系がつり合う。-When the total flow rate required for each actuator 88, 88 is greater than or equal to the maximum discharge flow rate of the hydraulic pump 80. Now, the load pressure and the required flow rate of the actuator 88, 88 left actuator 88 is 100kg / cm 2, 501 / min , the right actuator 88 and 10kg / cm 2, 501 / min . When the maximum discharge flow rate of the hydraulic pump 80 is 1001 / min or more, the difference between the inlet pressure and the outlet pressure of the directional control valves 55, 55 is kept constant (= 20 kg / cm 2 ) as described above. The flow rate can be controlled by the stroke, and the flow rate can be distributed by 501 / min. Next, assume that the maximum discharge amount of the hydraulic pump 80 becomes 701 / min. Since the inlet pressure of the two directional control valves 55, 55 are described above 120kg / cm 2, 30kg / c m 2, flow to the direction control valve 55 of the high-pressure side is reduced to 201 / min from 501 / min. The flow rate to the directional control valve 55 on the low pressure side remains 501 / min. Assuming that the stroke (opening area) of the two directional control valves 55, 55 is not changed, the pressure difference between the inlet pressure and the outlet pressure of the directional control valve 55 on the high pressure side is reduced by 20 kg / cm 2 due to the decrease in the flow rate. Go down. Now, 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.
【００１５】 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.
【００１６】[0016]
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ることで、 各弁ブロック３０の第１・第２圧力検出ポート１００，１０１が透孔１０４より 安全弁１０５に連通し、かつ低圧側の圧力検出ポート１００または１０１には高 圧油が流入しないから、複数の方向制御弁を備えた方向制御弁装置に安全弁を１ つ取付ければ良く、安全弁の数が減少してコストが安くなるばかりか、全体がコ ンパクトになって狭いスペースに取付けできし、特定の方向制御弁に接続したア クチュエータの最高作動力を安全弁セット圧より高くして他の方向制御弁に接続 したアクチュエータの最高作動圧力より高くできると共に、その最高作動圧力を 任意に調整できる。 By connecting the plurality of valve blocks 30 by overlapping the front and rear surfaces 40 and 41 with each other, the first and second pressure detection ports 100 and 101 of each valve block 30 communicate with the safety valve 105 through the through hole 104, and the low pressure. Since high pressure oil does not flow into the pressure detection port 100 or 101 on the side, it is sufficient to attach one safety valve to a directional control valve device equipped with multiple directional control valves, reducing the number of safety valves and reducing costs. Not only that, but the whole becomes compact and can be installed in a narrow space, and the maximum operating force of the actuator connected to a specific directional control valve is made higher than the safety valve set pressure, and that of an actuator connected to another directional control valve. It can be higher than the maximum working pressure and the maximum working pressure can be adjusted arbitrarily.
【図１】従来の方向制御弁の断面図である。FIG. 1 is a sectional view of a conventional directional control valve.
【図２】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.
【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圧力検出ポ
ート部分の横断面図である。FIG. 5 is a cross-sectional view of a pressure detection port portion showing a connection state of a plurality of valve blocks.
【図６】複数の弁ブロックの接続状態を示す圧力検出ポ
ート部分の縦断面図である。FIG. 6 is a vertical sectional view of a pressure detection port portion showing a connection state of a plurality of valve blocks.
【図７】複数の弁ブロックの接続状態を示す斜視図であ
る。FIG. 7 is a perspective view showing a connected state of a plurality of valve blocks.
【図８】その油圧回路図である。FIG. 8 is a hydraulic circuit diagram thereof.
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、１００…第１圧力検出ポート、１０１…
第２圧力検出ポート、１０２…連通用凹部、１０３…ボ
ール、１０４…透孔、１０６…バネ、１０７…安全弁、
１１０…カバーブロック、１１１…バネ力調整機構。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, 100 ... First pressure detection port, 101 ...
Second pressure detection port, 102 ... Communication recess, 103 ... Ball, 104 ... Through hole, 106 ... Spring, 107 ... Safety valve,
110 ... Cover block, 111 ... Spring force adjusting mechanism.
Claims (1)
スプール４９を摺動自在に嵌挿して入力ポート４４を第
１・第２アクチュエータポート３４，３５に連通・遮断
する方向制御弁とし、 前記弁ブロック３０に第１、第２アクチュエータポート
３４，３５に連通した第１・第２圧力検出ポート１０
０，１０１を形成し、この第１・第２圧力検出ポート１
００，１０１を弁ブロック３０の一方の接合面に形成し
た連通用凹部１０２に開口し、かつ連通用凹部１０２か
ら圧力検出ポートへの圧油流れを阻止するボール１０３
を設け、その連通用凹部１０２と弁ブロック３０の他方
の接合面に亘って透孔１０４を形成し、複数の弁ブロッ
ク３０を接合して各第１・第２圧力検出ポート１００，
１０１を透孔１０４に連通し、隣接する弁ブロック３０
間に前記ボール１０３を第１・第２圧力検出ポート１０
０，１０１に押しつけるバネ１０６を設け、最も端部に
位置する弁ブロック３０の一方の接合面にカバーブロッ
ク１１０を設け、このカバーブロック１１０に前記ボー
ル１０３を第１・第２圧力検出ポート１００，１０１に
押しつけるバネ１１４のバネ力を調整するバネ力調整機
構１１１を設け、その透孔１０４を１つの安全弁１０５
に連通したことを特徴とする方向制御弁装置。1. A directional control valve that slidably inserts a main spool 49 into a spool hole 31 of a valve block 30 to connect / disconnect an input port 44 to first / second actuator ports 34, 35. The first and second pressure detection ports 10 that communicate with the valve block 30 and the first and second actuator ports 34 and 35.
0, 101 are formed, and the first and second pressure detection ports 1
Balls 103 that open 00, 101 to a communication recess 102 formed on one joint surface of the valve block 30 and prevent the flow of pressure oil from the communication recess 102 to the pressure detection port.
Is formed, a through hole 104 is formed across the communication recess 102 and the other joint surface of the valve block 30, and a plurality of valve blocks 30 are joined to each of the first and second pressure detection ports 100,
Valve block 30 adjacent to the valve block 30
The ball 103 is installed between the first and second pressure detection ports 10
A spring 106 that presses 0, 101 is provided, a cover block 110 is provided on one joint surface of the valve block 30 located at the end, and the ball 103 is provided on the cover block 110 for the first and second pressure detection ports 100, A spring force adjusting mechanism 111 for adjusting the spring force of the spring 114 to be pressed against 101 is provided, and the through hole 104 is provided as one safety valve 105.
A directional control valve device characterized by being communicated with the.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10063591U JP2550774Y2 (en) | 1991-11-12 | 1991-11-12 | Direction control valve device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10063591U JP2550774Y2 (en) | 1991-11-12 | 1991-11-12 | Direction control valve device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0542704U true JPH0542704U (en) | 1993-06-11 |
| JP2550774Y2 JP2550774Y2 (en) | 1997-10-15 |
Family
ID=14279296
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10063591U Expired - Lifetime JP2550774Y2 (en) | 1991-11-12 | 1991-11-12 | Direction control valve device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2550774Y2 (en) |
-
1991
- 1991-11-12 JP JP10063591U patent/JP2550774Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2550774Y2 (en) | 1997-10-15 |
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