JPH0791405A - Directional control valve - Google Patents
Directional control valveInfo
- Publication number
- JPH0791405A JPH0791405A JP24128293A JP24128293A JPH0791405A JP H0791405 A JPH0791405 A JP H0791405A JP 24128293 A JP24128293 A JP 24128293A JP 24128293 A JP24128293 A JP 24128293A JP H0791405 A JPH0791405 A JP H0791405A
- Authority
- JP
- Japan
- Prior art keywords
- port
- actuator
- pressure detection
- load pressure
- load
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Operation Control Of Excavators (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、油圧ポンプの吐出圧油
をアクチュエータに供給する方向制御弁に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a directional control valve for supplying pressure oil discharged from a hydraulic pump to an actuator.
【０００２】[0002]
【従来の技術】油圧ポンプの吐出圧油を複数の方向制御
弁に供給する装置としては、例えば特開昭６０−１１７
０６号公報に示すように各方向制御弁の入口側に圧力補
償弁をそれぞれ設け、この各圧力補償弁を各アクチュエ
ータにおける最も高い負荷圧によりセットして負荷圧の
異なるアクチュエータに油圧ポンプの吐出圧油を同時に
供給できるようにしたものが知られている。2. Description of the Related Art As a device for supplying pressure oil discharged from a hydraulic pump to a plurality of directional control valves, for example, Japanese Patent Laid-Open No. 60-117 is known.
No. 06 publication, pressure compensation valves are provided on the inlet side of each directional control valve, and each pressure compensation valve is set by the highest load pressure in each actuator, and the discharge pressure of the hydraulic pump is set to actuators having different load pressures. It is known that oil can be supplied at the same time.
【０００３】前述の圧油供給装置においてはアクチュエ
ータの負荷圧を検出する必要があり、方向制御弁を負荷
圧を検出できるものとしている。例えば、図１に示すよ
うに、弁本体１のスプール孔２にポンプポート３、第１
・第２負荷圧検出ポート４，５、第１・第２アクチュエ
ータポート６，７、第１・第２タンクポート８，９を形
成すると共に、その第１・第２負荷圧検出ポート４，５
を連通させ、前記スプール孔２に嵌挿した主スプール１
０を中立位置から左右に移動して第１又は第２圧油供給
位置とすることでポンプポート３が第１・第２負荷圧検
出ポート４，５を経て第１又は第２アクチュエータポー
ト６，７に連通し、かつ第２又は第１アクチュエータポ
ート７，６が第２又は第１タンクポート９，８に連通す
るようにして第２負荷圧検出ポート５よりアクチュエー
タの負荷圧を検出できるようにしてある。In the above-mentioned pressure oil supply device, it is necessary to detect the load pressure of the actuator, and the directional control valve is capable of detecting the load pressure. For example, as shown in FIG. 1, the pump port 3, the first
-The second load pressure detection ports 4 and 5, the first and second actuator ports 6 and 7, and the first and second tank ports 8 and 9 are formed, and the first and second load pressure detection ports 4 and 5 are formed.
And the main spool 1 inserted into the spool hole 2
By moving 0 from the neutral position to the left and right to the first or second pressure oil supply position, the pump port 3 passes through the first and second load pressure detection ports 4, 5 and then the first or second actuator port 6, 7 so that the second or first actuator port 7, 6 communicates with the second or first tank port 9, 8 so that the load pressure of the actuator can be detected from the second load pressure detection port 5. There is.
【０００４】かかる方向制御弁であると、主スプール１
０を僅かに移動したファインコントロール位置でも負荷
の大きさに関係なく主スプール１０のストローク、つま
り第１・第２アクチュエータポート６，７と第１・第２
負荷圧検出ポート４，５の開口面積に比例した流量がア
クチュエータに供給されることになり、動きはじめのア
クチエータの加速が急になってアクチュエータが飛び出
し的に動きはじめることになる。また、方向制御弁の主
スプール１０を中立位置から圧油供給位置の途中の位置
で停止した時にアクチュエータの負荷が大きくとも開口
面積に比例した流量をアクチュエータに供給するのでア
クチュエータの静定性が悪くなる。With such a directional control valve, the main spool 1
Even at the fine control position where 0 is slightly moved, the stroke of the main spool 10, that is, the first and second actuator ports 6 and 7 and the first and second actuator ports, regardless of the magnitude of the load.
A flow rate proportional to the opening area of the load pressure detection ports 4 and 5 is supplied to the actuator, and the acceleration of the actuator that starts to move becomes sudden, and the actuator starts to jump out. Further, when the main spool 10 of the directional control valve is stopped at a position midway from the neutral position to the pressure oil supply position, even if the load on the actuator is large, a flow rate proportional to the opening area is supplied to the actuator, so the static determinability of the actuator deteriorates. .
【０００５】そこで、本出願人は先に前述の不具合を解
消できるようにした方向制御弁を出願した。Therefore, the present applicant previously applied for a directional control valve capable of solving the above-mentioned problems.
【０００６】すなわち、図２に示すように、主スプール
１０に、その主スプール１０を中立位置からあるストロ
ーク摺動した範囲内で第１負荷圧検出ポート４と第１ア
クチュエータポート６を連通する連通孔１１及び第２負
荷圧検出ポート５を第２アクュエータポート７に連通す
る開口１２を形成し、前記連通孔１１に第１アクチュエ
ータポート１６から第１負荷圧検出ポート４への圧油流
れを阻止するロードチェック弁１３を設けた方向制御弁
を出願した。That is, as shown in FIG. 2, the main spool 10 communicates with the first load pressure detecting port 4 and the first actuator port 6 within a range in which the main spool 10 is slid by a stroke from the neutral position. An opening 12 that connects the hole 11 and the second load pressure detection port 5 to the second actuator port 7 is formed, and the flow of pressure oil from the first actuator port 16 to the first load pressure detection port 4 is formed in the communication hole 11. Applied for a directional control valve provided with a load check valve 13 for preventing the above.
【０００７】かかる方向制御弁であれば主スプール１０
を中立位置からあるストローク摺動した範囲内では第１
負荷圧検出ポート４に流入した油圧ポンプの吐出圧油は
アクチュエータの負荷圧に見合う圧力に上昇するまでロ
ードチェック弁１３によって第１アクチュエータポート
６に流出することが阻止され、その圧油の一部は開口１
２より第２アクチュエータポート７を経て第２タンクポ
ート９に流出するし、その流出量はアクチュエータの負
荷に比例するので、負荷に応じてアクチュエータの動き
はじめがゆっくりとなるし、そのタンクポートに流出す
る流量によって減衰が大きくなるためにアクチュエータ
の静定性が向上する。With such a directional control valve, the main spool 10
Within the range of sliding a stroke from the neutral position
The discharge pressure oil of the hydraulic pump that has flowed into the load pressure detection port 4 is prevented from flowing out to the first actuator port 6 by the load check valve 13 until the pressure oil corresponding to the load pressure of the actuator rises. Is opening 1
2 flows out to the second tank port 9 through the second actuator port 7, and since the outflow amount is proportional to the load of the actuator, the movement of the actuator starts slowly according to the load, and it flows out to the tank port. The damping is increased depending on the flow rate of the flow, which improves the static determinability of the actuator.
【０００８】[0008]
【発明が解決しようとする課題】先に出願した方向制御
弁であればアクチュエータの静定性を向上できるが外力
により作動するアクチュエータ、例えばパワーショベル
の上部車体を旋回する旋回モータの場合には坂道におい
て上部車体の自重により坂下に向けて旋回しようとする
ために次の不具合を生じる。With the directional control valve filed previously, the static determinability of the actuator can be improved, but in the case of an actuator that operates by an external force, for example, a swing motor that swings the upper car body of a power shovel, on a slope. Due to the weight of the upper body, the following problems occur because the vehicle tries to turn downhill.
【０００９】例えば、旋回モータ１４が上部車体の自重
により矢印方向に回転しようとする場合に主スプール１
０を右方に移動して第１アクチュエータポート６より第
１ポート１４ａに圧油を供給して矢印と反対方向に回転
する際に、主スプール１０を僅かに移動した時に第２ア
クチュエータポート７と第２タンクポート９が連通する
が第１負荷圧検出ポート４が第１アクチュエータポート
６に連通しない。For example, when the turning motor 14 tries to rotate in the direction of the arrow due to the weight of the upper vehicle body, the main spool 1
When 0 is moved to the right and pressure oil is supplied from the first actuator port 6 to the first port 14a to rotate in the direction opposite to the arrow, when the main spool 10 is slightly moved, The second tank port 9 communicates, but the first load pressure detection port 4 does not communicate with the first actuator port 6.
【００１０】このために、旋回モータ１４の第２ポート
１４ｂの圧油が第２アクチュエータポート７より第２タ
ンクポート９に流れて旋回モータ１４が外力により矢印
方向に回転し、第１ポート１４ａに圧油が供給されない
のでその分だけ真空となり、旋回モータ１４の第１ポー
ト１４ａにキャビテーションが発生し易くなる。For this reason, the pressure oil of the second port 14b of the swing motor 14 flows from the second actuator port 7 to the second tank port 9, and the swing motor 14 is rotated in the arrow direction by an external force to the first port 14a. Since the pressure oil is not supplied, a vacuum is generated correspondingly, and cavitation is likely to occur in the first port 14a of the turning motor 14.
【００１１】このことを防止するには旋回モータ１４の
第１・第２ポート１４ａ，１４ｂ側に吸込弁１５をそれ
ぞれ設けてタンク１６より第１ポート１４ａに圧油を吸
込むようにすれば良いが、旋回モータ１４を微速で動作
するようにコントロールしている状態なので十分にタン
ク回路に圧力が上昇していないため吸込弁１５を介して
旋回モータ１４の第１ポート１４ａへ真空を埋める分の
圧油が供給されずに第１ポート１４ａにキャビテーショ
ンが発生し易くなる。In order to prevent this, suction valves 15 may be provided on the first and second ports 14a and 14b of the swing motor 14 so that the pressure oil is sucked from the tank 16 to the first port 14a. Since the swing motor 14 is controlled so as to operate at a low speed, the pressure in the tank circuit is not sufficiently increased, so that the first port 14a of the swing motor 14 via the suction valve 15 is filled with the vacuum pressure oil. Is not supplied, and cavitation easily occurs in the first port 14a.
【００１２】前述のように旋回モータ１４の第１ポート
１４ａにキャビテーションが発生すると旋回モータ１４
に振動を引き起こすので微速でコントロールしようとし
ている時に非常に操作性が悪くなる。As described above, when cavitation occurs in the first port 14a of the swing motor 14, the swing motor 14
Since it causes vibrations in the operation, the operability becomes extremely poor when trying to control at a slow speed.
【００１３】そこで、本発明は前述の課題を解決できる
ようにした方向制御弁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 capable of solving the above-mentioned problems.
【００１４】[0014]
【課題を解決するための手段】弁本体２０のスプール孔
２１に、ポンプポート２２、第１・第２負荷圧検出ポー
ト２３，２４、第１・第２アクチュエータポート２５，
２６、第１・第２タンクポート２７，２８を形成し、そ
の第１・第２負荷圧検出ポート２３，２４を連通すると
共に、前記弁本体２０のスプール孔２１に主スプール３
０を嵌挿し、その主スプール３０が中立位置の時には各
ポートを遮断し、主スプール３０が第１圧油供給位置の
時にはポンプポート２２と第２負荷圧検出ポート２４、
第１負荷圧検出ポート２３と第１アクチュエータポート
２５、第２アクチュエータポート２６と第２タンクポー
ト２８をそれぞれ連通し、主スプール３０を第２圧油供
給位置とした時にはポンプポート２２と第１負荷圧検出
ポート２３，第１アクチュエータリポート２５と第１タ
ンクポート２７の第２負荷圧検出ポート２４と第２アク
チュエータポート２６が連通するようにし、前記主スプ
ール３０を中立位置から第１又は第２圧油供給位置に向
けてあるストローク移動した時に第１アクチュエータポ
ート２５と第２アクチュエータポート２６を連通し、か
つロードチェック弁３６を介して圧油を流通し、主スプ
ール３０を更に移動した時に第１、第２アクチュエータ
ポート２５，２６の一方をポンプポート２２に連通し、
かつ他方を第１又は第２タンクポート２７，２８に連通
するようにした方向制御弁。A spool port 21 of a valve body 20 has a pump port 22, first and second load pressure detection ports 23 and 24, first and second actuator ports 25,
26, first and second tank ports 27 and 28 are formed to communicate the first and second load pressure detection ports 23 and 24, and the main spool 3 is connected to the spool hole 21 of the valve body 20.
0 is inserted, and when the main spool 30 is in the neutral position, each port is shut off, and when the main spool 30 is in the first pressure oil supply position, the pump port 22 and the second load pressure detection port 24,
When the first load pressure detection port 23 and the first actuator port 25 communicate with each other, the second actuator port 26 and the second tank port 28 communicate with each other, and the main spool 30 is at the second pressure oil supply position, the pump port 22 and the first load The pressure detection port 23, the first actuator report 25, the second load pressure detection port 24 of the first tank port 27, and the second actuator port 26 are made to communicate with each other, and the main spool 30 is moved from the neutral position to the first or second pressure. When the stroke is moved toward the oil supply position, the first actuator port 25 and the second actuator port 26 are communicated with each other, and the pressure oil is circulated through the load check valve 36. , One of the second actuator ports 25, 26 communicates with the pump port 22,
A directional control valve having the other connected to the first or second tank port 27, 28.
【００１５】[0015]
【作 用】主スプール３０を第１又は第２圧油供給位
置に向けて移動した時に第１アクチュエータポート２５
と第２アクチュエータポート２６がロードチェック弁３
６を介して連通し、この後更に主スプール３０を移動す
ると第１・第２アクチュエータポート２５，２６の一方
がポンプポート２２、他方が第１・第２タンクポート２
７，２８に連通するので、アクチュエータが外力により
作動した時のアクチュエータの戻り圧油をアクチュエー
タに供給して真空となることを防止でき、アクチュエー
タにキャビテーションが発生することがない。[Operation] When the main spool 30 is moved toward the first or second pressure oil supply position, the first actuator port 25
And the second actuator port 26 is the load check valve 3
6 through which the main spool 30 is further moved, one of the first and second actuator ports 25 and 26 is the pump port 22, and the other is the first and second tank port 2
Since it communicates with the actuators 7 and 28, it is possible to prevent the return pressure oil of the actuator from being supplied to the actuator when the actuator is actuated by an external force to prevent a vacuum and to prevent cavitation in the actuator.
【００１６】[0016]
【実 施 例】図３に示すように、弁本体２０にのスプ
ール孔２１にポンプポート２２、第１・第２負荷圧検出
ポート２３，２４、第１・第２アクチュエータポート２
５，２６、第１・第２タンクポート２７，２８が形成さ
れ、その第１・第２負荷圧検出ポート２３，２４は油孔
２９で連通している。前記スプール孔２１に嵌挿した主
スプール３０には中間小径部３１と第１・第２切欠３
２，３３及び第１小径部３４と第３・第４切欠３５，３
６並びに第２小径部３７と第５・第６切欠３８，３９が
形成され、この主スプール３０は左右のスプリング３１
で各ポートを遮断する中立位置に保持され、第１受圧室
３２に供給される圧油で右方に押されて第１圧油供給位
置となり、第２受圧室３３に供給される圧油で左方に押
されて第２圧油供給位置となる。[Example] As shown in FIG. 3, the spool hole 21 in the valve body 20 has a pump port 22, first and second load pressure detection ports 23 and 24, and first and second actuator ports 2.
5, 26 and first and second tank ports 27 and 28 are formed, and the first and second load pressure detection ports 23 and 24 are communicated with each other through an oil hole 29. The main spool 30 fitted in the spool hole 21 has an intermediate small-diameter portion 31 and first and second cutouts 3.
2, 33 and the first small diameter portion 34 and the third and fourth notches 35, 3
6, the second small diameter portion 37 and the fifth and sixth notches 38 and 39 are formed, and the main spool 30 is provided with the left and right springs 31.
Is held in a neutral position that shuts off each port, and is pushed to the right by the pressure oil supplied to the first pressure receiving chamber 32 to the first pressure oil supply position, where the pressure oil is supplied to the second pressure receiving chamber 33. It is pushed to the left to the second pressure oil supply position.
【００１７】前記主スプール３０には第１負荷圧検出ポ
ート２３と第１アクチュエータポート２５を連通・遮断
する第１連通孔３４と第２負荷圧検出ポート２４と第２
アクチュエータポート２６を連通・遮断する第２連通孔
３５が形成され、この第１・第２連通孔３４，３５にア
クチュエータポートから負荷圧検出ポートへの圧油流れ
を阻止するロードチェック弁３６がそれぞれ設けられて
いる。The main spool 30 has a first communication hole 34 for connecting and disconnecting the first load pressure detection port 23 and the first actuator port 25, a second load pressure detection port 24, and a second load pressure detection port 24.
A second communication hole 35 that communicates / blocks the actuator port 26 is formed, and a load check valve 36 that blocks the flow of pressure oil from the actuator port to the load pressure detection port is formed in each of the first and second communication holes 34 and 35. It is provided.
【００１８】前記第１・第２連通孔３４，３５は軸孔４
０と径方向の第１・第２油孔４１，４２より成り、ロー
ドチェック弁３６は主スプール３０の軸心に形成した盲
穴４３内に弁４４を設け、この弁４４とプラグ４５との
間にばね４６を設けて弁４１を軸孔４０に圧接して成
る。The first and second communication holes 34 and 35 are the shaft holes 4.
0 and radial first and second oil holes 41 and 42, the load check valve 36 is provided with a valve 44 in a blind hole 43 formed in the axial center of the main spool 30. A spring 46 is provided between the valve 41 and the shaft hole 40 so that the valve 41 is pressed against the shaft hole 40.
【００１９】前記主スプール３０には第１負荷圧検出ポ
ート２３と第１アクチュエータポート２５を連通・遮断
するスリット状の第１開口４７及び、第２負荷圧検出ポ
ート２４と第２アクチュエータポート２６を連通遮断す
るスリット状の第２開口４８が形成されている。The main spool 30 is provided with a slit-shaped first opening 47 for connecting and disconnecting the first load pressure detecting port 23 and the first actuator port 25, the second load pressure detecting port 24 and the second actuator port 26. A slit-shaped second opening 48 that blocks communication is formed.
【００２０】前記第１・第２アクチュエータポート２
５，２６は外力により動作するアクチュエータ、例えば
パワーショベルの上部車体を旋回する旋回モータ４９の
第１・第２ポート４９ａ，４９ｂに接続し、この第１・
第２ポート４９ａ，４９ｂ側は吸込弁５０を介してタン
ク５１に連通している。The first and second actuator ports 2
Reference numerals 5 and 26 are connected to actuators operated by an external force, for example, first and second ports 49a and 49b of a swing motor 49 that swings an upper vehicle body of a power shovel.
The second ports 49a and 49b are in communication with the tank 51 via the suction valve 50.
【００２１】前記ポンプポート２２は圧力補償弁５２を
構成するチェック弁部５３を経て油圧ポンプ５４の吐出
路５５に接続し、この油圧ポンプ５４は斜板５６の傾転
角を変えて容量を可変とするもので、その斜板５６の傾
転角を変更するポンプ調整用方向制御弁５７に負荷圧検
出路５８が接続し、この負荷圧検出路５８は前記圧力補
償弁５２を構成する減圧弁部５９により油圧ポンプ５４
の吐出路５５に連通・遮断される。The pump port 22 is connected to a discharge passage 55 of a hydraulic pump 54 via a check valve portion 53 which constitutes a pressure compensating valve 52. The hydraulic pump 54 changes the tilt angle of a swash plate 56 to change its capacity. The load pressure detection path 58 is connected to a pump adjusting directional control valve 57 for changing the tilt angle of the swash plate 56, and the load pressure detection path 58 is a pressure reducing valve constituting the pressure compensating valve 52. Hydraulic pump 54 by the part 59
The discharge passage 55 is communicated with or cut off.
【００２２】次に作動を説明する。なお、旋回モータ４
９は上部車体の自重で第２ポート４９ｂに圧油を吐出す
る方向に回転するものとする。主スプール３０が図３に
示す中立位置の時。各ポートは遮断されてポンプポート
２２に流入した圧油は行き止まりとなると共に、旋回モ
ータ４９の第１・第２ポート４９ａ，４９ｂからの圧油
は行き止まりとなって旋回モータ４９は外力によって回
転しない停止状態となり、坂道のパワーショベルの上部
車体は自重によって旋回せずに停止する。Next, the operation will be described. The turning motor 4
Reference numeral 9 indicates the weight of the upper vehicle body, which rotates in the direction in which pressure oil is discharged to the second port 49b. When the main spool 30 is in the neutral position shown in FIG. Each port is shut off and the pressure oil flowing into the pump port 22 becomes a dead end, and the pressure oil from the first and second ports 49a and 49b of the turning motor 49 becomes a dead end and the turning motor 49 does not rotate due to an external force. The vehicle is stopped and the upper body of the power shovel on the slope stops without turning due to its own weight.
【００２３】主スプール３０を図３の中立位置より右方
に僅かにＬ1 だけ移動した時。第２開口４８により第２
負荷圧検出ポート２４と第２アクチュエータポート２６
が連通すると同時に第１連通孔３４により第１負荷圧検
出ポート２３と第１アクチュエータポート２５が連通す
る。この時、第２切欠３３によりポンプポート２２と第
２負荷圧検出ポート２４が連通しないし、第４切欠３６
で第１負荷圧検出ポート２３と第１アクチュエータポー
ト２５が連通せず、しかも第６切欠３９で第２アクチュ
エータポート２６と第２タンクポート２８が連通しな
い。When the main spool 30 is moved slightly to the right of the neutral position in FIG. 3 by L 1 . Second through the second opening 48
Load pressure detection port 24 and second actuator port 26
The first communication hole 34 allows the first load pressure detection port 23 and the first actuator port 25 to communicate with each other. At this time, the pump port 22 and the second load pressure detection port 24 are not communicated with each other by the second cutout 33, and the fourth cutout 36 is formed.
Therefore, the first load pressure detection port 23 and the first actuator port 25 do not communicate with each other, and the sixth actuator 39 does not communicate with the second actuator port 26 and the second tank port 28.
【００２４】これにより、旋回モータ４９の第２ポート
４９ｂの圧油は、第２アクチュエータポート２６、第２
開口４８、第２負荷圧検出ポート２４、油孔２９、第１
負荷圧検出ポート２３、第１連通孔３４、第１アクチュ
エータポート２５より旋回モータ４９の第１ポート４９
ａに流れるので、旋回モータ４９の第１ポート４９ａに
油圧ポンプ５２の吐出圧油を供給する以前に第２ポート
４９ｂの圧油を第１ポート４９ａに供給できるから第１
ポート４９ａが真空とならずにキャビテーション発生を
防止でき、旋回モータ４９の微速コントロールが可能と
なる。As a result, the pressure oil of the second port 49b of the swing motor 49 is transferred to the second actuator port 26 and the second port.
Opening 48, second load pressure detection port 24, oil hole 29, first
From the load pressure detection port 23, the first communication hole 34, the first actuator port 25 to the first port 49 of the swing motor 49.
Therefore, the pressure oil of the second port 49b can be supplied to the first port 49a before the discharge pressure oil of the hydraulic pump 52 is supplied to the first port 49a of the swing motor 49.
The port 49a does not become a vacuum and cavitation can be prevented from occurring, and the turning motor 49 can be controlled at a fine speed.
【００２５】前述の状態より主スプール３０を更に右方
Ｌ2 だけ移動した時。中間小径部３１、第２切欠３３に
よりポンプポート２２が第２負荷圧検出ポート２４に連
通するが、第６切欠３９で第２アクチュエータポート２
６は第２タンクポート２８に連通しない。これにより、
油圧ポンプ５４の吐出圧油は、ポンプポート２２、中間
小径部３１、第２の切欠き３３、第２負荷圧検出ポート
２４、油孔２９、第１負荷圧検出ポート２３、第１連通
孔３４でロードチェック弁３６の手前まで流入し、油圧
ポンプ５４の吐出圧油は行き止まりとなるから、油圧ポ
ンプ５４の吐出圧が上昇し、その吐出圧がロードチェッ
ク弁３６に作用する保持圧まで上昇するとロードチェッ
ク弁３６が開き、油圧ポンプ５４の吐出圧油がロードチ
ェック弁３６により第１孔４１を通って第１アクチュエ
ータポート２５より旋回モータ４９の第１ポート４９ａ
に供給される。When the main spool 30 is further moved rightward L 2 from the above-mentioned state. The pump port 22 communicates with the second load pressure detection port 24 by the intermediate small-diameter portion 31 and the second cutout 33, but the second actuator port 2 is connected by the sixth cutout 39.
6 does not communicate with the second tank port 28. This allows
The discharge pressure oil of the hydraulic pump 54 is pump port 22, intermediate small diameter portion 31, second notch 33, second load pressure detection port 24, oil hole 29, first load pressure detection port 23, first communication hole 34. Therefore, when the discharge pressure of the hydraulic pump 54 rises and the discharge pressure rises to the holding pressure acting on the load check valve 36, the discharge pressure oil of the hydraulic pump 54 reaches a dead end. The load check valve 36 is opened, and the pressure oil discharged from the hydraulic pump 54 passes through the first hole 41 by the load check valve 36 and from the first actuator port 25 to the first port 49a of the swing motor 49.
Is supplied to.
【００２６】前述の状態より主スプール３０を右方にＬ
3 だけ移動した時。第２アクチュエータポート２６が第
６切欠３９で第２タンクポート２８に連通し、油圧ポン
プ５４の吐出圧油の一部は第２開口４８より第２タンク
ポート２８に流出することになり、その流出する流量は
第１アクチュエータポート２５に作用する負荷圧（旋回
モータ４９の保持圧）の大きさに比例して多くなるの
で、旋回モータ４９の負荷（保持圧）が大きい時には第
２タンクポート２８に流出する流量が多くなるし、負荷
圧が小さいときには第２タンクポート２８に流出する流
量が少なくなるために負荷に応じて旋回モータ４９の動
きはじめの加速がゆるやかになりとび出し感がなくなる
し、第２タンクポート２８に流出する流量によって減衰
が大きくなるため旋回モータ４９の静定性が向上する。
前記ストリット状の第２開口４８は第６の切欠き３９、
第１連通孔３４に比べて開口面積が非常に小さいので第
２タンクポート２８に流出する流量によって旋回モータ
４９の加速が遅くなりすぎることはない。From the above state, the main spool 30 is moved to the right by L
When moving only 3 . The second actuator port 26 communicates with the second tank port 28 through the sixth cutout 39, and a part of the pressure oil discharged from the hydraulic pump 54 flows out to the second tank port 28 through the second opening 48. The flow rate to be increased increases in proportion to the magnitude of the load pressure (holding pressure of the swing motor 49) acting on the first actuator port 25, so that when the load (holding pressure) of the swing motor 49 is large, the flow rate is increased to the second tank port 28. When the load pressure is small, the flow rate that flows out increases and the flow rate that flows out into the second tank port 28 decreases. Therefore, the acceleration at the beginning of the movement of the swing motor 49 becomes gentle according to the load, and the feeling of popping out disappears. Since the damping increases due to the flow rate flowing out to the second tank port 28, the static determinability of the turning motor 49 improves.
The striation-shaped second opening 48 has a sixth notch 39,
Since the opening area is much smaller than that of the first communication hole 34, the acceleration of the swing motor 49 does not become too slow due to the flow rate flowing out to the second tank port 28.
【００２７】前述の状態より主スプール３０は更に右方
にＬ4 移動した時。ストリット状の第２開口４８によっ
て第２負荷圧検出ポート２４と第２アクチュエータポー
ト２６が連通しなくなって油圧ポンプ５４の吐出圧油が
主スプール３０の第１小径部３４と第２切欠３６による
第１負荷圧検出ポート２３と第１アクチュエータポート
２５の開口面積に比例した量だけ供給されて旋回モータ
４９の作動速度は速くなる。When the main spool 30 is further moved to the right by L 4 from the above-mentioned state. The second striation-shaped opening 48 prevents the second load pressure detection port 24 and the second actuator port 26 from communicating with each other, so that the discharge pressure oil of the hydraulic pump 54 is discharged by the first small diameter portion 34 of the main spool 30 and the second notch 36. The operation speed of the swing motor 49 is increased by supplying an amount proportional to the opening areas of the first load pressure detection port 23 and the first actuator port 25.
【００２８】以上の説明は主スプール３０を右方に移動
した場合であるが、旋回モータ４９が上部車体の自重で
第１ポート４９ａに圧油を吐出する方向に回転する場合
には主スプール３０を左方に移動した時に同様となる。
また、アクチュエータがブームシリンダ、アームシリン
ダのように外力により一方向にのみ作動する場合には第
１・第２開口４７，４８及び第１・第２連通孔３４，３
５の一方のみを形成すれば良い。The above description is for the case where the main spool 30 is moved to the right. However, when the turning motor 49 rotates in the direction for discharging the pressure oil to the first port 49a due to the weight of the upper vehicle body, the main spool 30 is rotated. The same applies when is moved to the left.
Further, when the actuator operates only in one direction by an external force like a boom cylinder and an arm cylinder, the first and second openings 47 and 48 and the first and second communication holes 34 and 3 are formed.
It suffices to form only one of No.
【００２９】[0029]
【発明の効果】主スプール３０を第１又は第２圧油供給
位置に向けて移動した時に第１アクチュエータポート２
５と第２アクチュエータポート２６がロードチェック弁
３６を介して連通し、この後更に主スプール３０を移動
すると第１・第２アクチュエータポート２５，２６の一
方がポンプポート２２、他方が第１・第２タンクポート
２７，２８に連通するので、アクチュエータポートが外
力により作動した時のアクチュエータの戻り圧油をアク
チュエータに供給して真空となることを防止でき、アク
チュエータにキャビテーションが発生することがない。When the main spool 30 is moved toward the first or second pressure oil supply position, the first actuator port 2
5 and the second actuator port 26 communicate with each other via the load check valve 36, and when the main spool 30 is further moved thereafter, one of the first and second actuator ports 25 and 26 is the pump port 22 and the other is the first and second actuator ports 26. Since the two tank ports 27 and 28 are communicated with each other, it is possible to prevent the return pressure oil of the actuator from being supplied to the actuator when the actuator port is actuated by an external force to prevent a vacuum and to prevent cavitation in the actuator.
【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】先に出願した方向制御弁の断面図である。FIG. 2 is a cross-sectional view of the directional control valve filed previously.
【図３】本発明の実施例を示す方向制御弁の断面図であ
る。FIG. 3 is a sectional view of a directional control valve showing an embodiment of the present invention.
２０…弁本体、２１…スプール、２２…ポンプポート、
２３…第１負荷圧検出ポート、２４…第２負荷圧検出ポ
ート、２５…第１アクチュエータポート、２６…第２ア
クチュエータポート、２７…第１タンクポート、２８…
第２タンクポート、２９…油孔、３４…第１連通孔、３
５…第２連通孔、３６…ロードチェック弁、４７…第１
開口、４８…第２開口、４９…旋回モータ、４９ａ…第
１ポート、４９ｂ…第２ポート、５４…油圧ポンプ。20 ... Valve body, 21 ... Spool, 22 ... Pump port,
23 ... 1st load pressure detection port, 24 ... 2nd load pressure detection port, 25 ... 1st actuator port, 26 ... 2nd actuator port, 27 ... 1st tank port, 28 ...
Second tank port, 29 ... Oil hole, 34 ... First communication hole, 3
5 ... 2nd communicating hole, 36 ... Load check valve, 47 ... 1st
Opening, 48 ... Second opening, 49 ... Slewing motor, 49a ... First port, 49b ... Second port, 54 ... Hydraulic pump.
Claims (2)
ポート２２、第１・第２負荷圧検出ポート２３，２４、
第１・第２アクチュエータポート２５，２６、第１・第
２タンクポート２７，２８を形成し、その第１・第２負
荷圧検出ポート２３，２４を連通すると共に、前記弁本
体２０のスプール孔２１に主スプール３０を嵌挿し、そ
の主スプール３０が中立位置の時には各ポートを遮断
し、主スプール３０が第１圧油供給位置の時にはポンプ
ポート２２と第２負荷圧検出ポート２４、第１負荷圧検
出ポート２３と第１アクチュエータポート２５、第２ア
クチュエータポート２６と第２タンクポート２８をそれ
ぞれ連通し、主スプール３０を第２圧油供給位置とした
時にはポンプポート２２と第１負荷圧検出ポート２３，
第１アクチュエータリポート２５と第１タンクポート２
７の第２負荷圧検出ポート２４と第２アクチュエータポ
ート２６が連通するようにした方向制御弁において、 主スプール３０を中立位置から第１又は第２圧油供給位
置に向けてあるストローク移動した時に第１アクチュエ
ータポート２５と第２アクチュエータポート２６を連通
し、かつロードチェック弁３６を介して圧油を流通し、
主スプール３０を更に移動した時に第１、第２アクチュ
エータポート２５，２６の一方をポンプポート２２に連
通し、かつ他方を第１又は第２タンクポート２７，２８
に連通するようにした方向制御弁。1. A spool port 21 of a valve body 20, a pump port 22, first and second load pressure detection ports 23, 24,
First and second actuator ports 25 and 26 and first and second tank ports 27 and 28 are formed to communicate the first and second load pressure detection ports 23 and 24, and the spool hole of the valve body 20. When the main spool 30 is in the first position, the main spool 30 is inserted into the main spool 30, and each port is cut off. When the main spool 30 is in the first pressure oil supply position, the pump port 22 and the second load pressure detection port 24 When the load pressure detection port 23 and the first actuator port 25 are communicated with each other, the second actuator port 26 and the second tank port 28 are communicated with each other, and the main spool 30 is at the second pressure oil supply position, the pump port 22 and the first load pressure detection are performed. Port 23,
First actuator report 25 and first tank port 2
In the directional control valve in which the second load pressure detection port 24 and the second actuator port 26 of 7 communicate with each other, when the main spool 30 is moved from the neutral position to the first or second pressure oil supply position by a stroke. The first actuator port 25 and the second actuator port 26 are communicated with each other, and the pressure oil is circulated through the load check valve 36,
When the main spool 30 is further moved, one of the first and second actuator ports 25 and 26 communicates with the pump port 22 and the other one of the first and second tank ports 27 and 28.
A directional control valve designed to communicate with.
ト２３と第１アクチュエータポート２５を連通・遮断す
る第１連通孔３４と、第２負荷圧検出ポート２４と第２
アクチュエータポート２６を連通・遮断する第２開口４
８を形成し、この第１連通孔３４と第２開口４８を、主
スプール３０が中立位置の時には各ポートを遮断し、第
１圧油供給位置に向けてあるストローク移動すると各ポ
ートを連通し、かつ更に移動するとポンプポート２２と
第２負荷圧検出ポート２４が連通し、第２アクチュエー
タポート２６と第２タンクポート２８が連通し、第１負
荷圧検出ポート２３が第１アクチュエータポート２５に
連通するようにし、前記第１連通孔３４に第１アクチュ
エータポート２５から第１負荷圧検出ポート２３への圧
油流れを阻止するロードチェック弁３６を設けた請求項
１記載の方向制御弁。2. The main spool 30, a first communication hole 34 for connecting and disconnecting the first load pressure detection port 23 and the first actuator port 25, a second load pressure detection port 24, and a second connection hole.
Second opening 4 for connecting / disconnecting the actuator port 26
8, the first communication hole 34 and the second opening 48 are closed when the main spool 30 is in the neutral position, and the ports are connected when the stroke movement toward the first pressure oil supply position is made. When further moved, the pump port 22 and the second load pressure detection port 24 communicate with each other, the second actuator port 26 and the second tank port 28 communicate with each other, and the first load pressure detection port 23 communicates with the first actuator port 25. The directional control valve according to claim 1, wherein the first communication hole 34 is provided with a load check valve 36 that blocks the flow of pressure oil from the first actuator port 25 to the first load pressure detection port 23.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24128293A JP3444507B2 (en) | 1993-09-28 | 1993-09-28 | Directional control valve |
| PCT/JP1994/001607 WO1995009282A1 (en) | 1993-09-28 | 1994-09-28 | Pressure oil supply apparatus |
| KR1019960701658A KR960705114A (en) | 1993-09-28 | 1994-09-28 | Pressurized fluid feed system |
| DE4497280T DE4497280T1 (en) | 1993-09-28 | 1994-09-28 | Pressurized fluid supply system |
| US08/617,758 US5794510A (en) | 1993-09-28 | 1994-09-28 | Pressurized fluid feed system |
| GB9606348A GB2300027B (en) | 1993-09-28 | 1994-09-28 | Pressurized fluid feed system |
| DE4497280A DE4497280C2 (en) | 1993-09-28 | 1994-09-28 | Pressurized fluid supply system |
| GB9718500A GB2313629B (en) | 1993-09-28 | 1994-09-28 | Directional control valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24128293A JP3444507B2 (en) | 1993-09-28 | 1993-09-28 | Directional control valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0791405A true JPH0791405A (en) | 1995-04-04 |
| JP3444507B2 JP3444507B2 (en) | 2003-09-08 |
Family
ID=17071948
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24128293A Expired - Lifetime JP3444507B2 (en) | 1993-09-28 | 1993-09-28 | Directional control valve |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3444507B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE112011101173T5 (en) | 2010-03-30 | 2013-01-10 | Sekisui Plastics Co., Ltd. | Foamable composite resin particles for frozen storage |
-
1993
- 1993-09-28 JP JP24128293A patent/JP3444507B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE112011101173T5 (en) | 2010-03-30 | 2013-01-10 | Sekisui Plastics Co., Ltd. | Foamable composite resin particles for frozen storage |
| US8933137B2 (en) | 2010-03-30 | 2015-01-13 | Sekisui Plastics Co., Ltd. | Foamable composite resin particle for frozen storage |
| DE112011101173B4 (en) | 2010-03-30 | 2022-01-05 | Sekisui Plastics Co., Ltd. | Composite expandable resin particles for freeze storage, method for producing the same, expanded molded article, method for storing composite expandable resin particles, and freeze-stored composite expandable resin particles |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3444507B2 (en) | 2003-09-08 |
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