JP3097041B2 - Return flow sharing circuit for pressure oil supply device - Google Patents
Return flow sharing circuit for pressure oil supply deviceInfo
- Publication number
- JP3097041B2 JP3097041B2 JP05201613A JP20161393A JP3097041B2 JP 3097041 B2 JP3097041 B2 JP 3097041B2 JP 05201613 A JP05201613 A JP 05201613A JP 20161393 A JP20161393 A JP 20161393A JP 3097041 B2 JP3097041 B2 JP 3097041B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- hydraulic actuator
- chamber
- control valve
- valve
- 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.)
- Expired - Lifetime
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2221—Control of flow rate; Load sensing arrangements
- E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mining & Mineral Resources (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Operation Control Of Excavators (AREA)
- Fluid-Pressure Circuits (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、１つの油圧ポンプの吐
出圧油を複数の油圧アクチュエータに供給する圧油供給
装置において特定の油圧アクチュエータから大流量をタ
ンクに流出する戻り流量分担回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a return flow sharing circuit for discharging a large flow from a specific hydraulic actuator to a tank in a hydraulic oil supply device for supplying hydraulic pressure discharged from one hydraulic pump to a plurality of hydraulic actuators.
【０００２】[0002]
【従来の技術】１つの油圧ポンプの吐出圧油を複数の油
圧アクチュエータに供給するには、油圧ポンプの吐出路
に複数の操作弁を設け、その操作弁を切換えることで各
油圧アクチュエータに圧油を供給すれば良いが、このよ
うにすると複数の油圧アクチュエータに圧油を同時に供
給する際に、負荷の小さな油圧アクチュエータにのみ圧
油が供給されて負荷の大きな油圧アクチュエータに圧油
が供給されなくなってしまう。2. Description of the Related Art In order to supply the hydraulic pressure discharged from one hydraulic pump to a plurality of hydraulic actuators, a plurality of operating valves are provided in the discharge path of the hydraulic pump, and the operating valves are switched to apply hydraulic oil to each hydraulic actuator. In this case, when supplying hydraulic oil to a plurality of hydraulic actuators at the same time, pressure oil is supplied only to hydraulic actuators with a small load, and hydraulic oil is not supplied to hydraulic actuators with a large load. Would.
【０００３】このことで解消する圧油供給装置としては
図１に示すものが知られている。すなわち、図１に示す
ように、油圧ポンプ１０は斜板１１の角度を変更するこ
とで容量、つまり１回転当たり吐出流量が変化する可変
容量型の油圧ポンプとなり、その斜板１１は大径ピスト
ン１２で容量減方向に傾動し、小径ピストン１３で容量
増方向に傾動する。前記大径ピストン１２の受圧室１２
ａは切換弁１４で油圧ポンプ１０の吐出路１０ａに連通
・遮断され、小径ピストン１３の受圧室１３ａは前記吐
出路１０ａに接続してある。FIG. 1 shows a known pressure oil supply device that solves this problem. That is, as shown in FIG. 1, the hydraulic pump 10 is a variable displacement hydraulic pump in which the displacement, that is, the discharge flow rate per rotation, is changed by changing the angle of the swash plate 11, and the swash plate 11 has a large-diameter piston. 12 tilts in the capacity decreasing direction, and the small diameter piston 13 tilts in the capacity increasing direction. The pressure receiving chamber 12 of the large-diameter piston 12
Reference numeral a denotes a switching valve 14 which is communicated with and blocked from the discharge passage 10a of the hydraulic pump 10, and the pressure receiving chamber 13a of the small diameter piston 13 is connected to the discharge passage 10a.
【０００４】前記油圧ポンプ１０吐出路１０ａには複数
の方向制御弁１５が設けてあり、各方向制御弁１５と油
圧アクチュエータ１６を接続する回路１７に圧力補償弁
１８がそれぞれ設けてあり、該圧力補償弁１８は第１受
圧部１９の圧油で低圧セット側に押され、第２受圧部２
０の圧油で高圧セット側に押され、第２受圧部２０の圧
油で高圧セット側に押される構成としてあり、第１受圧
部１９は方向制御弁１５の出口側に接続して出口側圧力
が供給され、第２受圧部２０はシャトル弁２１を経て各
回路１７に接続されて最も高い負荷圧が供給される。A plurality of directional control valves 15 are provided in the discharge path 10a of the hydraulic pump 10, and a pressure compensating valve 18 is provided in a circuit 17 connecting each directional control valve 15 and a hydraulic actuator 16, respectively. The compensating valve 18 is pushed to the low pressure set side by the pressure oil of the first pressure receiving portion 19,
The first pressure receiving portion 19 is connected to the outlet side of the directional control valve 15 and is connected to the outlet side of the directional control valve 15. The pressure is supplied, and the second pressure receiving section 20 is connected to each circuit 17 via the shuttle valve 21 so that the highest load pressure is supplied.
【０００５】前記切換弁１４は吐出路１０ａ内の圧力で
連通方向に押され、バネ２２と前記負荷圧でドレーン方
向に押されて、吐出圧力Ｐ1 が高くなると大径ピストン
１２の受圧室１２ａに吐出圧を供給して斜板１１を容量
減方向に傾動し、吐出圧力Ｐ1 が低くなると大径ピスト
ン１２の受圧室１２ａをタンク側に流出して斜板１１を
容量増方向に傾動する。[0005] The switching valve 14 is pushed in the communication direction by a pressure in the discharge passage 10a, is pushed in the drain direction at the load pressure and the spring 22, the discharge pressure P 1 is increased when the pressure-receiving chamber 12a of the large diameter piston 12 by supplying discharge pressure to tilt the swash plate 11 in the volume decrease direction, tilts the swash plate 11 from flowing out to the tank side pressure receiving chamber 12a of the large diameter piston 12 when the discharge pressure P 1 becomes lower in the capacity increase direction .
【０００６】前記負荷圧を切換弁１４の受圧部１４ａに
供給する回路２３、つまり、受圧部１４ａとシャトル弁
２１の出力側を接続する回路２３は絞り２４を経てタン
ク２５に接続している。A circuit 23 for supplying the load pressure to the pressure receiving portion 14a of the switching valve 14, that is, a circuit 23 for connecting the pressure receiving portion 14a to the output side of the shuttle valve 21 is connected to a tank 25 via a throttle 24.
【０００７】かかる圧油供給装置であれば各方向制御弁
１５を中立位置ａから供給位置ｂに切換えると油圧ポン
プ１０の吐出圧油が油圧アクチュエータ１６に供給され
ると共に、高い方の負荷圧がシャトル弁２１で検出され
て圧力補償弁１８の第２受圧部２０にそれぞれ作用し、
各圧力補償弁１８を最も負荷圧によりセットされるか
ら、油圧ポンプ１０の吐出圧油を負荷の異なる複数の油
圧アクチュエータに供給できる。In such a pressure oil supply device, when each directional control valve 15 is switched from the neutral position a to the supply position b, the discharge pressure oil of the hydraulic pump 10 is supplied to the hydraulic actuator 16 and the higher load pressure is reduced. It is detected by the shuttle valve 21 and acts on the second pressure receiving portion 20 of the pressure compensating valve 18 respectively.
Since each pressure compensating valve 18 is set at the highest load pressure, the discharge pressure oil of the hydraulic pump 10 can be supplied to a plurality of hydraulic actuators having different loads.
【０００８】[0008]
【発明が解決しようとする課題】かかる圧油供給装置に
おいては油圧アクチュエータ１６からタンクへ流出する
戻り流量による圧力損失は方向制御弁のメータアウト開
口面積によって決定され、特定の油圧アクチュエータ１
６、例えばパワーショベルのブームシリンダ、アームシ
リンダから大流量をタンクへ流出する場合には、その方
向制御弁を大型としてメータアウト開口面積を大きくし
圧力損失を小さくする。In such a pressure oil supply device, the pressure loss due to the return flow flowing from the hydraulic actuator 16 to the tank is determined by the meter-out opening area of the directional control valve.
6. For example, when a large flow is discharged from the boom cylinder or the arm cylinder of the power shovel to the tank, the directional control valve is made large to increase the meter-out opening area and reduce the pressure loss.
【０００９】特に、ブームシリンダ、アームシリンダを
縮み作動する場合にはシリンダの縮み室に圧油を供給
し、伸び室の圧油をタンクに流出するが、シリンダの伸
び室の面積が縮み室の面積よりも大きく、縮み室に供給
した流量よりも伸び室よりタンクに流出する流量が多く
なり、ブームシリンダ、アームシリンダを速く縮み作動
するために伸び室から大流量をタンクに流出する必要が
ある。In particular, when the boom cylinder and the arm cylinder are operated to contract, the pressurized oil is supplied to the contraction chamber of the cylinder and the pressure oil in the extension chamber flows out to the tank, but the area of the extension chamber of the cylinder is reduced. The flow rate is larger than the area, the flow rate to the tank is larger than the flow rate supplied to the contraction chamber, and the flow rate to the tank is larger than the flow rate supplied to the contraction chamber. .
【００１０】しかしながら、方向制御弁１５を大型とす
ると他の方向制御弁と大きさが異なって兼用できずにコ
ストが高くなる。However, if the size of the directional control valve 15 is increased, the size of the directional control valve is different from that of the other directional control valves, and the size of the directional control valve 15 cannot be shared.
【００１１】そこで、本発明は前述の課題を解決できる
ようにした圧油供給装置の戻り流量分担回路を提供する
ことを目的とする。Accordingly, an object of the present invention is to provide a return flow sharing circuit of a pressure oil supply device which can solve the above-mentioned problems.
【００１２】[0012]
【課題を解決するための手段】第１の発明は、油圧ポン
プ１０の吐出路１０ａに複数の方向制御弁１５を設け、
この各方向制御弁１５の出口側を圧力補償弁１８を経て
油圧アクチュエータ１６にそれぞれ接続し、この各圧力
補償弁１８をポンプ吐出圧と各油圧アクチュエータ１６
の最高負荷圧によりセットするようにした圧油供給装置
において、前記特定の油圧アクチュエータ１６に圧油を
供給する特定の方向制御弁１５を、特定の油圧アクチュ
エータ１６の一方の室に圧油を供給し、かつ他方の室の
圧油をタンクに流出する第１の位置と特定の油圧アクチ
ュエータ１６の他方の室に圧油を供給し、かつ一方の室
の圧油をタンクに流出する第２の位置に切換え可能と
し、前記油圧ポンプ１０の吐出路１０ａと特定の油圧ア
クチュエータ１６の一方の室を接続する回路に補助方向
制御弁３０、圧力補償弁１８、チェック弁５４を順次設
け、この補助方向制御弁３０を、油圧ポンプ１０の吐出
圧油を圧力補償弁１８、チェック弁５４を経て特定の油
圧アクチュエータ１６の一方の室に供給する第３の位置
と、特定の油圧アクチュエータ１６の一方の室の圧油を
タンクに流出する第４の位置に切換え可能とし、前記回
路に設けた圧力補償弁１８をポンプ吐出圧と各油圧アク
チュエータ１６の最高負荷圧によりセットしたことを特
徴とする圧油供給装置の戻り流量分担回路である。第２
の発明は、油圧ポンプ１０の吐出路１０ａに複数の圧力
補償弁１８を設け、この各圧力補償弁１８の出口側に方
向制御弁１５をそれぞれ設けて各油圧アクチュエータ１
６に圧油を供給するようにし、前記各圧力補償弁１８を
ポンプ吐出圧と各油圧アクチュエータ１６の最高負荷圧
によりセットするようにした圧油供給装置において、前
記特定の油圧アクチュエータ１６に圧油を供給する特定
の方向制御弁１５を、特定の油圧アクチュエータ１６の
一方の室に圧油を供給し、かつ他方の室の圧油をタンク
に流出する第１の位置と特定の油圧アクチュエータ１６
の他方の室に圧油を供給し、かつ一方の室の圧油をタン
クに流出する第２の位置に切換え可能とし、前記油圧ポ
ンプ１０の吐出路１０ａと特定の油圧アクチュエータ１
６の一方の室を接続する回路に補助方向制御弁３０、圧
力補償弁１８、チェック弁５４を順次設け、この補助方
向制御弁３０を、油圧ポンプ１０の吐出圧油を圧力補償
弁１８、チェック弁５４を経て特定の油圧アクチュエー
タ１６の一方の室に供給する第３の位置と、特定の油圧
アクチュエータ１６の一方の室の圧油をタンクに流出す
る第４の位置に切換え可能とし、前記回路に設けた圧力
補償弁１８をポンプ吐出圧と各油圧アクチュエータ１６
の最高負荷圧によりセットしたことを特徴とする圧油供
給装置の戻り流量分担回路である。According to a first aspect of the present invention, a plurality of direction control valves 15 are provided in a discharge path 10a of a hydraulic pump 10,
The outlet side of each directional control valve 15 is connected to a hydraulic actuator 16 via a pressure compensating valve 18, and each pressure compensating valve 18 is connected to the pump discharge pressure and each hydraulic actuator 16.
In the pressure oil supply device set at the maximum load pressure, a specific direction control valve 15 for supplying pressure oil to the specific hydraulic actuator 16 is supplied to one chamber of the specific hydraulic actuator 16. And a second position for supplying the pressure oil to the other position of the specific hydraulic actuator 16 and the first position at which the pressure oil of the other chamber flows out to the tank and discharging the pressure oil of the one chamber to the tank. The auxiliary direction control valve 30, the pressure compensating valve 18, and the check valve 54 are sequentially provided in a circuit connecting the discharge path 10a of the hydraulic pump 10 and one chamber of the specific hydraulic actuator 16, The third position where the control valve 30 supplies the pressure oil discharged from the hydraulic pump 10 to one chamber of the specific hydraulic actuator 16 via the pressure compensating valve 18 and the check valve 54, and the specific hydraulic actuator That the pressure oil in one chamber of the heater 16 can be switched to the fourth position where the oil flows out to the tank, and that the pressure compensating valve 18 provided in the circuit is set by the pump discharge pressure and the maximum load pressure of each hydraulic actuator 16. It is a return flow sharing circuit of the pressure oil supply device, which is a feature. Second
According to the invention, a plurality of pressure compensating valves 18 are provided in a discharge path 10a of a hydraulic pump 10, and a directional control valve 15 is provided at an outlet side of each of the pressure compensating valves 18 so that each hydraulic actuator 1
6, the hydraulic oil is supplied to the specific hydraulic actuator 16, and the pressure compensating valve 18 is set according to the pump discharge pressure and the maximum load pressure of the hydraulic actuator 16. A first directional control valve 15 for supplying pressure oil to one chamber of a specific hydraulic actuator 16 and a first position for supplying pressure oil in the other chamber to a tank and a specific hydraulic actuator 16
To supply the pressure oil to the other chamber and to switch the pressure oil from the one chamber to the second position where the oil flows out to the tank.
The auxiliary directional control valve 30, the pressure compensating valve 18, and the check valve 54 are sequentially provided in a circuit connecting one of the chambers 6, and the auxiliary directional control valve 30 is connected to the pressure compensating valve 18 for checking the pressure oil discharged from the hydraulic pump 10. A third position for supplying one chamber of the specific hydraulic actuator 16 via the valve 54 to a fourth position for discharging the pressure oil in one chamber of the specific hydraulic actuator 16 to the tank; The pressure compensating valve 18 provided for the pump discharge pressure and each hydraulic actuator 16
The return flow sharing circuit of the pressure oil supply device is set at the maximum load pressure.
【００１３】[0013]
【作 用】第１の発明によれば、特定の方向制御弁１
５を第２の位置、補助方向制御弁３０を第４の位置に切
換えることで特定の油圧アクチュエータ１６の一方の室
の圧油が特定の方向制御弁１５、補助方向制御弁３０を
経てタンクに流出する。したがって、特定の油圧アクチ
ュエータ１６の一方の室から大流量をタンクに流出する
際、圧力損失を小さくできるので、特定の方向制御弁１
５を他の方向制御弁１５と同一大きさにできて兼用でき
るからコストを安くできる。しかも、特定の油圧アクチ
ュエータ１６の一方の室の圧油が圧力補償弁１８に流れ
ることをチェック弁５４で防止され、その圧油は補助方
向制御弁３０からタンクに確実に流出する。また、特定
の方向制御弁１５を第１の位置、補助方向制御弁３０を
第３の位置に切換えることで、特定の油圧アクチュエー
タ１６の一方の室に油圧ポンプ１０の吐出圧油が特定の
方向制御弁１５、補助方向制御弁３０を経て供給され
る。したがって、特定の方向制御弁１５を他の方向制御
弁１５と同一大きさで特定の油圧アクチュエータ１６の
一方の室に多量の圧油を供給できる。しかも、補助方向
制御弁１５から特定の油圧アクチュエータ１６の一方の
室に供給される圧油は、特定の方向制御弁１５から特定
の油圧アクチュエータ１６の一方の室に供給される圧油
と同様に圧力補償されるから、油圧ポンプ１０の吐出圧
油を特定の油圧アクチュエータ１６の一方の室と他の油
圧アクチュエータ１６に同時に供給できる。第２の発明
によれば、特定の方向制御弁１５を第２の位置、補助方
向制御弁３０を第４の位置に切換えることで特定の油圧
アクチュエータ１６の一方の室の圧油が特定の方向制御
弁１５、補助方向制御弁３０を経てタンクに流出する。
したがって、特定の油圧アクチュエータ１６の一方の室
から大流量をタンクに流出する際、圧力損失を小さくで
きるので、特定の方向制御弁１５を他の方向制御弁１５
と同一大きさにできて兼用できるからコストを安くでき
る。しかも、特定の油圧アクチュエータ１６の一方の室
の圧油が圧力補償弁１８に流れることをチェック弁５４
で防止され、その圧油は補助方向制御弁３０からタンク
に確実に流出する。また、特定の方向制御弁１５を第１
の位置、補助方向制御弁３０を第３の位置に切換えるこ
とで、特定の油圧アクチュエータ１６の一方の室に油圧
ポンプ１０の吐出圧油が特定の方向制御弁１５、補助方
向制御弁３０を経て供給される。したがって、特定の方
向制御弁１５を他の方向制御弁１５と同一大きさで特定
の油圧アクチュエータ１６の一方の室に多量の圧油を供
給できる。しかも、補助方向制御弁１５から特定の油圧
アクチュエータ１６の一方の室に供給される圧油は、特
定の方向制御弁１５から特定の油圧アクチュエータ１６
の一方の室に供給される圧油と同様に圧力補償されるか
ら、油圧ポンプ１０の吐出圧油を特定の油圧アクチュエ
ータ１６の一方の室と他の油圧アクチュエータ１６に同
時に供給できる。According to the first aspect, the specific directional control valve 1 is provided.
5 is switched to the second position and the auxiliary directional control valve 30 is switched to the fourth position, so that the pressure oil in one chamber of the specific hydraulic actuator 16 passes through the specific directional control valve 15 and the auxiliary directional control valve 30 to the tank. leak. Therefore, when a large flow rate flows from one chamber of the specific hydraulic actuator 16 to the tank, the pressure loss can be reduced.
5 can be made the same size as the other directional control valves 15 and can also be used, so that the cost can be reduced. In addition, the check valve 54 prevents the pressure oil in one chamber of the specific hydraulic actuator 16 from flowing to the pressure compensating valve 18, and the pressure oil surely flows out of the auxiliary direction control valve 30 into the tank. Further, by switching the specific direction control valve 15 to the first position and the auxiliary direction control valve 30 to the third position, the discharge pressure oil of the hydraulic pump 10 is supplied to one chamber of the specific hydraulic actuator 16 in the specific direction. It is supplied via the control valve 15 and the auxiliary direction control valve 30. Therefore, a large amount of pressure oil can be supplied to one chamber of the specific hydraulic actuator 16 with the specific directional control valve 15 having the same size as the other directional control valves 15. Moreover, the pressure oil supplied from the auxiliary direction control valve 15 to one chamber of the specific hydraulic actuator 16 is the same as the pressure oil supplied from the specific direction control valve 15 to one chamber of the specific hydraulic actuator 16. Since the pressure is compensated, the discharge pressure oil of the hydraulic pump 10 can be simultaneously supplied to one chamber of the specific hydraulic actuator 16 and another hydraulic actuator 16. According to the second aspect, by switching the specific direction control valve 15 to the second position and the auxiliary direction control valve 30 to the fourth position, the pressure oil in one chamber of the specific hydraulic actuator 16 can be switched to the specific direction. It flows out to the tank via the control valve 15 and the auxiliary direction control valve 30.
Therefore, when a large flow rate flows from one chamber of the specific hydraulic actuator 16 to the tank, the pressure loss can be reduced, so that the specific directional control valve 15 is replaced with the other directional control valve 15.
The cost can be reduced because the same size can be used and can be used for both. In addition, the check valve 54 checks that the pressure oil in one chamber of the specific hydraulic actuator 16 flows to the pressure compensating valve 18.
And the pressure oil surely flows out of the auxiliary directional control valve 30 into the tank. Also, the specific directional control valve 15 is
And the auxiliary direction control valve 30 is switched to the third position, the discharge pressure oil of the hydraulic pump 10 is supplied to one chamber of the specific hydraulic actuator 16 via the specific direction control valve 15 and the auxiliary direction control valve 30. Supplied. Therefore, a large amount of pressure oil can be supplied to one chamber of the specific hydraulic actuator 16 with the specific directional control valve 15 having the same size as the other directional control valves 15. Moreover, the pressure oil supplied from the auxiliary direction control valve 15 to one chamber of the specific hydraulic actuator 16 is supplied from the specific direction control valve 15 to the specific hydraulic actuator 16.
The pressure is compensated in the same manner as the pressure oil supplied to one of the chambers. Therefore, the discharge pressure oil of the hydraulic pump 10 can be simultaneously supplied to one chamber of the specific hydraulic actuator 16 and another hydraulic actuator 16.
【００１４】[0014]
【実 施 例】本発明の実施例を図２以降を参照して説
明する。なお、従来と同一部材は同一符号とする。な
お、説明の簡素化のため圧力補償弁１８は一方の回路１
７にのみ設け、他方の回路には図示を省略してある。図
２に示すように油圧ポンプ１０の吐出路１０ａに補助方
向制御弁３０を設け、この補助方向制御弁３０の第１ア
クチュエータポート３１を回路３２を経て一方の油圧ア
クチュエータ１６の伸び室１６ａに接続してある。前記
補助方向制御弁３０は第１・第２アクチュエータポート
３１，３３とポンプポート３４とタンクポート３５を有
し、各ポートを遮断する中立位置ｃ、ポンプポート３４
を第２アクチュエータポート３３に連通し、かつ第１ア
クチェータポート３１をタンクポート３５に連通する第
１位置ｄ、ポンプポート３４と第１アクチュエータポー
ト３１を遮断し、かつ第２アクチュエータポート３３を
タンクポート３５に連通する第２位置ｅに切換えられ
る。Embodiment An embodiment of the present invention will be described with reference to FIGS. The same members as those in the related art are denoted by the same reference numerals. In order to simplify the explanation, the pressure compensating valve 18 is connected to one circuit 1
7 and the other circuit is not shown. As shown in FIG. 2, an auxiliary direction control valve 30 is provided in a discharge path 10a of the hydraulic pump 10, and a first actuator port 31 of the auxiliary direction control valve 30 is connected to an extension chamber 16a of one hydraulic actuator 16 via a circuit 32. I have. The auxiliary directional control valve 30 has first and second actuator ports 31, 33, a pump port 34, and a tank port 35.
Is connected to the second actuator port 33 and the first actuator port 31 is connected to the tank port 35 at a first position d, the pump port 34 and the first actuator port 31 are shut off, and the second actuator port 33 is connected to the tank port. The position is switched to the second position e communicating with 35.
【００１５】パイロットバルブ４０はパイロット用油圧
ポンプ４１の吐出圧油を第１・第２パイロット回路４
２，４３に供給するもので、その第１パイロット回路４
２は前記補助方向制御弁３０の第１受圧部３０ａと一方
（右側）の方向制御弁１５の第１受圧部１５ａに接続
し、第２パイロット回路４３は補助方向制御弁３０の第
２受圧部３０ｂと一方（右側）の方向制御弁１５の第２
受圧部１５ｂに接続している。The pilot valve 40 supplies the pressure oil discharged from the pilot hydraulic pump 41 to the first and second pilot circuits 4.
2, 43, and the first pilot circuit 4
2 is connected to the first pressure receiving portion 30a of the auxiliary direction control valve 30 and the first pressure receiving portion 15a of the one (right) direction control valve 15, and the second pilot circuit 43 is connected to the second pressure receiving portion of the auxiliary direction control valve 30. 30b and the second of the one (right) directional control valve 15
It is connected to the pressure receiving part 15b.
【００１６】このようであるから、パイロットバルブ４
０により第１パイロット回路４２にパイロット圧油を供
給すると一方の方向制御弁１５が右方の供給位置ｂ、補
助方向切換弁３０が第１位置ｄとなり、油圧ポンプ１０
の吐出圧油は一方（右側）の油圧アクチュエータ１６の
縮み室１６ｂに供給され、伸び室１６ａの戻り油は一方
の方向制御弁１５及び補助方向切換弁３０よりタンクに
流出する。したがって、一方の油圧アクチュエータ１６
の伸び室１６ａから戻り流量による圧力損失は一方の方
向制御弁１５と補助方向制御弁３０のメータアウト開口
面積の和の２乗に反比例するので、戻り流量によるロス
を低減できる。Because of this, the pilot valve 4
0, the pilot pressure oil is supplied to the first pilot circuit 42 so that the one directional control valve 15 is at the right supply position b, the auxiliary direction switching valve 30 is at the first position d, and the hydraulic pump 10
Is supplied to the contraction chamber 16b of the one (right side) hydraulic actuator 16, and the return oil of the extension chamber 16a flows out of the one direction control valve 15 and the auxiliary direction switching valve 30 into the tank. Therefore, one hydraulic actuator 16
The pressure loss due to the return flow from the extension chamber 16a is inversely proportional to the square of the sum of the meter-out opening areas of the one directional control valve 15 and the auxiliary directional control valve 30, so that the loss due to the return flow can be reduced.
【００１７】パイロット弁４０により第２パイロット回
路４３にパイロット圧油を供給した時には一方の方向制
御弁１５が左方の供給位置ｂ、補助方向制御弁３０が第
２位置ｅとなるが、補助方向制御弁３０が第２位置ｅの
時にはポンプポート３３と第１アクチュエータポート３
１が遮断されるので一方の方向制御弁１５のみより一方
（右側）の圧油アクチュエータ１６の縮み室１６ｂより
タンクに圧油が流出する。When pilot pressure oil is supplied to the second pilot circuit 43 by the pilot valve 40, the one directional control valve 15 is at the left supply position b and the auxiliary directional control valve 30 is at the second position e. When the control valve 30 is in the second position e, the pump port 33 and the first actuator port 3
Since the pressure control valve 1 is shut off, the pressure oil flows out of the contraction chamber 16b of the pressure oil actuator 16 on one side (right side) from only one of the direction control valves 15 into the tank.
【００１８】このように、一方の油圧アクチュエータ１
６の伸び室１６ａより大流量を低圧損タンクに流出でき
るから、例えばパワーショベルの、アームシリンダを速
く縮み作動できてダンプ時に有利となる。As described above, one hydraulic actuator 1
Since the large flow rate can flow out to the low pressure drop tank from the extension chamber 16a of 6, the arm cylinder of, for example, a power shovel can be quickly contracted and operated, which is advantageous during dumping.
【００１９】図３は第２実施例を示し、油圧アクチュエ
ータ１６はパワーショベルのアームシリンダとなり、補
助方向制御弁３０をポンプポート５０、第１・第２アク
チュエータポート５１，５２、タンクポート５３を有
し、ばね力で各ポートを遮断する中立位置ｆに保持し、
第１受圧部３０ａの圧力で第２アクチュエータポート５
２とタンクポート５３を連通し、かつポンプポート５０
と第１アクチュエータポート５１を遮断する第１位置ｇ
となり、第２受圧部３０ｂの圧力でポンプポート５０と
第１アクチュエータポート５１を連通し、かつ第２アク
チュエータポート５２とタンクポート５３を連通する第
２位置ｈとなるようにしてある。前記第１アクチュエー
タポート５１は圧力補償弁１８、チェック弁５４を介し
て回路５５で油圧アクチュエータ１６の伸び室１６ａに
接続し、第２アクチュエータポート５２が回路５６で回
路５５におけるチェック弁５４より上流側に接続してあ
る。FIG. 3 shows a second embodiment, in which the hydraulic actuator 16 is an arm cylinder of a power shovel, and the auxiliary directional control valve 30 has a pump port 50, first and second actuator ports 51 and 52, and a tank port 53. And hold at a neutral position f where each port is shut off by a spring force,
With the pressure of the first pressure receiving portion 30a, the second actuator port 5
2 and the tank port 53, and the pump port 50
And the first position g for shutting off the first actuator port 51
The second position h connects the pump port 50 and the first actuator port 51 with each other and the second actuator port 52 with the tank port 53 with the pressure of the second pressure receiving portion 30b. The first actuator port 51 is connected to the extension chamber 16a of the hydraulic actuator 16 by a circuit 55 via the pressure compensating valve 18 and the check valve 54, and the second actuator port 52 is a circuit 56 upstream of the check valve 54 in the circuit 55. Connected to
【００２０】このようにすれば、方向制御弁１５を右側
の供給位置ｂとして油圧アクチュエータ１６の伸び室１
６ａに圧油を供給する時には補助方向制御弁３０が第２
位置ｈとなって圧力補償弁１８を経て油圧アクチュエー
タ１６の伸び室１６ａに圧油を供給できるし、方向制御
弁１５を左側の供給位置ｂとして油圧アクチュエータ１
６の縮み室１６ｂに圧油を供給する時には補助方向制御
弁３０が第１位置となって油圧アクチュエータ１６の伸
び室１６ａ内の圧油をタンクに流出できる。In this way, the direction control valve 15 is set to the right supply position b to extend the extension chamber 1 of the hydraulic actuator 16.
The auxiliary directional control valve 30 is connected to the second
The pressure oil can be supplied to the extension chamber 16a of the hydraulic actuator 16 via the pressure compensating valve 18 at the position h, and the directional control valve 15 is set to the left supply position b so that the hydraulic actuator 1
When the pressure oil is supplied to the contraction chamber 16b, the auxiliary direction control valve 30 is in the first position, and the pressure oil in the extension chamber 16a of the hydraulic actuator 16 can flow out to the tank.
【００２１】以上の各実施例は圧力補償弁１８を方向制
御弁１５と油圧アクチュエータ１６との間に設けたが、
図４に示すように油圧ポンプ１０と方向制御弁１５との
間に圧力補償弁１８を設けても良い。この場合には補助
方向制御弁３０を第１・第２アクチュエータポート３
１，３３と第１・第２タンクポート３６，３７を有し、
第１位置ｄの時に第１アクチュエータポート３１と第１
タンクポート３６を連通するものとする。In each of the above embodiments, the pressure compensating valve 18 is provided between the directional control valve 15 and the hydraulic actuator 16.
As shown in FIG. 4, a pressure compensating valve 18 may be provided between the hydraulic pump 10 and the direction control valve 15. In this case, the auxiliary direction control valve 30 is connected to the first and second actuator ports 3.
1 and 33 and first and second tank ports 36 and 37,
When in the first position d, the first actuator port 31 and the first
It is assumed that the tank port 36 is connected.
【００２２】[0022]
【発明の効果】請求項１に係る発明によれば、特定の方
向制御弁１５を第２の位置、補助方向制御弁３０を第４
の位置に切換えることで特定の油圧アクチュエータ１６
の一方の室の圧油が特定の方向制御弁１５、補助方向制
御弁３０を経てタンクに流出する。したがって、特定の
油圧アクチュエータ１６の一方の室から大流量をタンク
に流出する際、圧力損失を小さくできるので、特定の方
向制御弁１５を他の方向制御弁１５と同一大きさにでき
て兼用できるからコストを安くできる。しかも、特定の
油圧アクチュエータ１６の一方の室の圧油が圧力補償弁
１８に流れることをチェック弁５４で防止され、その圧
油は補助方向制御弁３０からタンクに確実に流出する。
また、特定の方向制御弁１５を第１の位置、補助方向制
御弁３０を第３の位置に切換えることで、特定の油圧ア
クチュエータ１６の一方の室に油圧ポンプ１０の吐出圧
油が特定の方向制御弁１５、補助方向制御弁３０を経て
供給される。したがって、特定の方向制御弁１５を他の
方向制御弁１５と同一大きさで特定の油圧アクチュエー
タ１６の一方の室に多量の圧油を供給できる。しかも、
補助方向制御弁１５から特定の油圧アクチュエータ１６
の一方の室に供給される圧油は、特定の方向制御弁１５
から特定の油圧アクチュエータ１６の一方の室に供給さ
れる圧油と同様に圧力補償されるから、油圧ポンプ１０
の吐出圧油を特定の油圧アクチュエータ１６の一方の室
と他の油圧アクチュエータ１６に同時に供給できる。請
求項２に係る発明によれば、特定の方向制御弁１５を第
２の位置、補助方向制御弁３０を第４の位置に切換える
ことで特定の油圧アクチュエータ１６の一方の室の圧油
が特定の方向制御弁１５、補助方向制御弁３０を経てタ
ンクに流出する。したがって、特定の油圧アクチュエー
タ１６の一方の室から大流量をタンクに流出する際、圧
力損失を小さくできるので、特定の方向制御弁１５を他
の方向制御弁１５と同一大きさにできて兼用できるから
コストを安くできる。しかも、特定の油圧アクチュエー
タ１６の一方の室の圧油が圧力補償弁１８に流れること
をチェック弁５４で防止され、その圧油は補助方向制御
弁３０からタンクに確実に流出する。また、特定の方向
制御弁１５を第１の位置、補助方向制御弁３０を第３の
位置に切換えることで、特定の油圧アクチュエータ１６
の一方の室に油圧ポンプ１０の吐出圧油が特定の方向制
御弁１５、補助方向制御弁３０を経て供給される。した
がって、特定の方向制御弁１５を他の方向制御弁１５と
同一大きさで特定の油圧アクチュエータ１６の一方の室
に多量の圧油を供給できる。しかも、補助方向制御弁１
５から特定の油圧アクチュエータ１６の一方の室に供給
される圧油は、特定の方向制御弁１５から特定の油圧ア
クチュエータ１６の一方の室に供給される圧油と同様に
圧力補償されるから、油圧ポンプ１０の吐出圧油を特定
の油圧アクチュエータ１６の一方の室と他の油圧アクチ
ュエータ１６に同時に供給できる。According to the first aspect of the present invention, the specific directional control valve 15 is set to the second position, and the auxiliary directional control valve 30 is set to the fourth position.
To the specific hydraulic actuator 16
The pressure oil in one of the chambers flows out to the tank via the specific directional control valve 15 and the auxiliary directional control valve 30. Therefore, when a large flow rate flows from one chamber of the specific hydraulic actuator 16 to the tank, the pressure loss can be reduced, so that the specific directional control valve 15 can be made the same size as the other directional control valves 15 and can also be used. Costs can be reduced. In addition, the check valve 54 prevents the pressure oil in one chamber of the specific hydraulic actuator 16 from flowing to the pressure compensating valve 18, and the pressure oil surely flows out of the auxiliary direction control valve 30 into the tank.
Further, by switching the specific direction control valve 15 to the first position and the auxiliary direction control valve 30 to the third position, the discharge pressure oil of the hydraulic pump 10 is supplied to one chamber of the specific hydraulic actuator 16 in the specific direction. It is supplied via the control valve 15 and the auxiliary direction control valve 30. Therefore, a large amount of pressure oil can be supplied to one chamber of the specific hydraulic actuator 16 with the specific directional control valve 15 having the same size as the other directional control valves 15. Moreover,
From the auxiliary direction control valve 15 to the specific hydraulic actuator 16
The pressure oil supplied to one of the chambers is supplied to a specific directional control valve 15.
Is compensated in the same manner as the pressure oil supplied to one chamber of the specific hydraulic actuator 16 from the hydraulic pump 10.
Can be simultaneously supplied to one chamber of the specific hydraulic actuator 16 and the other hydraulic actuator 16. According to the second aspect of the present invention, by switching the specific direction control valve 15 to the second position and the auxiliary direction control valve 30 to the fourth position, the pressure oil in one chamber of the specific hydraulic actuator 16 is specified. Through the directional control valve 15 and the auxiliary directional control valve 30. Therefore, when a large flow rate flows from one chamber of the specific hydraulic actuator 16 to the tank, the pressure loss can be reduced, so that the specific directional control valve 15 can be made the same size as the other directional control valves 15 and can also be used. Costs can be reduced. In addition, the check valve 54 prevents the pressure oil in one chamber of the specific hydraulic actuator 16 from flowing to the pressure compensating valve 18, and the pressure oil surely flows out of the auxiliary direction control valve 30 into the tank. By switching the specific directional control valve 15 to the first position and the auxiliary directional control valve 30 to the third position, the specific hydraulic actuator 16
The discharge pressure oil of the hydraulic pump 10 is supplied to one of the chambers via a specific direction control valve 15 and an auxiliary direction control valve 30. Therefore, a large amount of pressure oil can be supplied to one chamber of the specific hydraulic actuator 16 with the specific directional control valve 15 having the same size as the other directional control valves 15. Moreover, the auxiliary directional control valve 1
The pressure oil supplied to one chamber of the specific hydraulic actuator 16 from 5 is pressure-compensated similarly to the pressure oil supplied to one chamber of the specific hydraulic actuator 16 from the specific directional control valve 15. The discharge pressure oil of the hydraulic pump 10 can be simultaneously supplied to one chamber of the specific hydraulic actuator 16 and another hydraulic actuator 16.
【図１】従来例の説明図である。FIG. 1 is an explanatory diagram of a conventional example.
【図２】本発明の第１実施例を示す説明図である。FIG. 2 is an explanatory diagram showing a first embodiment of the present invention.
【図３】本発明の第２実施例を示す説明図である。FIG. 3 is an explanatory view showing a second embodiment of the present invention.
【図４】本発明の第３実施例を示す説明図である。FIG. 4 is an explanatory view showing a third embodiment of the present invention.
１０…油圧ポンプ、１０ａ…吐出路、１５…方向制御
弁、１６…油圧アクチュエータ、１８…圧力補償弁、３
０…補助方向制御弁、４０…パイロットバルブ。DESCRIPTION OF SYMBOLS 10 ... Hydraulic pump, 10a ... Discharge path, 15 ... Direction control valve, 16 ... Hydraulic actuator, 18 ... Pressure compensation valve, 3
0: auxiliary direction control valve, 40: pilot valve.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平４−210102（ＪＰ，Ａ) 特開 昭56−131806（ＪＰ，Ａ) 特開 平２−125034（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) F15B 11/00 - 11/22 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-210102 (JP, A) JP-A-56-131806 (JP, A) JP-A 2-125034 (JP, A) (58) Survey Field (Int.Cl. 7 , DB name) F15B 11/00-11/22
Claims (2)
方向制御弁１５を設け、この各方向制御弁１５の出口側
を圧力補償弁１８を経て油圧アクチュエータ１６にそれ
ぞれ接続し、この各圧力補償弁１８をポンプ吐出圧と各
油圧アクチュエータ１６の最高負荷圧によりセットする
ようにした圧油供給装置において、 前記特定の油圧アクチュエータ１６に圧油を供給する特
定の方向制御弁１５を、特定の油圧アクチュエータ１６
の一方の室に圧油を供給し、かつ他方の室の圧油をタン
クに流出する第１の位置と特定の油圧アクチュエータ１
６の他方の室に圧油を供給し、かつ一方の室の圧油をタ
ンクに流出する第２の位置に切換え可能とし、 前記油圧ポンプ１０の吐出路１０ａと特定の油圧アクチ
ュエータ１６の一方の室を接続する回路に補助方向制御
弁３０、圧力補償弁１８、チェック弁５４を順次設け、
この補助方向制御弁３０を、油圧ポンプ１０の吐出圧油
を圧力補償弁１８、チェック弁５４を経て特定の油圧ア
クチュエータ１６の一方の室に供給する第３の位置と、
特定の油圧アクチュエータ１６の一方の室の圧油をタン
クに流出する第４の位置に切換え可能とし、前記回路に
設けた圧力補償弁１８をポンプ吐出圧と各油圧アクチュ
エータ１６の最高負荷圧によりセットしたことを特徴と
する圧油供給装置の戻り流量分担回路。 A plurality of discharge paths (10a ) of a hydraulic pump (10 ) are provided.
A directional control valve 15 is provided, and the outlet side of each directional control valve 15 is provided.
To the hydraulic actuator 16 via the pressure compensating valve 18
And each pressure compensating valve 18 is connected to the pump discharge pressure.
Set by the maximum load pressure of the hydraulic actuator 16
In the pressure oil supply device configured as described above, the pressure oil is supplied to the specific hydraulic actuator 16.
The fixed directional control valve 15 is connected to a specific hydraulic actuator 16.
Supply pressure oil to one chamber and pressurize oil to the other chamber.
The first position and the specific hydraulic actuator 1
6 to supply pressure oil to the other chamber, and
To a second position where the fluid flows out to the discharge passage 10a of the hydraulic pump 10 and a specific hydraulic actuator.
Auxiliary direction control for the circuit connecting one chamber of the heater 16
A valve 30, a pressure compensating valve 18, and a check valve 54 are sequentially provided,
The auxiliary directional control valve 30 is connected to the discharge pressure oil of the hydraulic pump 10.
Through the pressure compensating valve 18 and the check valve 54
A third position for supplying one chamber of the actuator 16;
The pressure oil in one chamber of the specific hydraulic actuator 16 is
Switchable to the fourth position, which flows into the circuit
The pressure compensating valve 18 provided is connected to the pump discharge pressure and each hydraulic actuator.
It is characterized by being set by the maximum load pressure of the eta 16.
Return flow sharing circuit of the pressurized oil supply device.
圧力補償弁１８を設け、この各圧力補償弁１８の出口側
に方向制御弁１５をそれぞれ設けて各油圧アクチュエー
タ１６に圧油を供給するようにし、前記各圧力補償弁１
８をポンプ吐出圧と各油圧アクチュエータ１６の最高負
荷圧によりセットするようにした圧油供給装置におい
て、前記特定の油圧アクチュエータ１６に圧油を供給する特
定の方向制御弁１５を、特定の油圧アクチュエータ１６
の一方の室に圧油を供給し、かつ他方の室の圧油をタン
クに流出する第１の位置と特定の油圧アクチュエータ１
６の他方の室に圧油を供給し、かつ一方の室の圧油をタ
ンクに流出する第２の位置に切換え可能とし、 前記油圧ポンプ１０の吐出路１０ａと特定の油圧アクチ
ュエータ１６の一方の 室を接続する回路に補助方向制御
弁３０、圧力補償弁１８、チェック弁５４を順次設け、
この補助方向制御弁３０を、油圧ポンプ１０の吐出圧油
を圧力補償弁１８、チェック弁５４を経て特定の油圧ア
クチュエータ１６の一方の室に供給する第３の位置と、
特定の油圧アクチュエータ１６の一方の室の圧油をタン
クに流出する第４の位置に切換え可能とし、前記回路に
設けた圧力補償弁１８をポンプ吐出圧と各油圧アクチュ
エータ１６の最高負荷圧によりセットしたことを特徴と
する圧油供給装置の戻り流量分担回路。 2. A plurality of pressure compensating valves (18) are provided in a discharge path (10a) of the hydraulic pump (10), and directional control valves (15) are provided on the outlet side of each of the pressure compensating valves (18) to supply pressure oil to each hydraulic actuator (16). So that each of the pressure compensating valves 1
In the pressure oil supply apparatus that is set by the 8 pump discharge pressure and the maximum load pressure among the hydraulic actuators 16, especially for supplying pressure oil to the particular hydraulic actuator 16
The fixed directional control valve 15 is connected to a specific hydraulic actuator 16.
Supply pressure oil to one chamber and pressurize oil to the other chamber.
The first position and the specific hydraulic actuator 1
6 to supply pressure oil to the other chamber, and
To a second position where the fluid flows out to the discharge passage 10a of the hydraulic pump 10 and a specific hydraulic actuator.
Auxiliary direction control for the circuit connecting one chamber of the heater 16
A valve 30, a pressure compensating valve 18, and a check valve 54 are sequentially provided,
The auxiliary directional control valve 30 is connected to the discharge pressure oil of the hydraulic pump 10.
Through the pressure compensating valve 18 and the check valve 54
A third position for supplying one chamber of the actuator 16;
The pressure oil in one chamber of the specific hydraulic actuator 16 is
Switchable to the fourth position, which flows into the circuit
The pressure compensating valve 18 provided is connected to the pump discharge pressure and each hydraulic actuator.
It is characterized by being set by the maximum load pressure of the eta 16.
Return flow sharing circuit of the pressurized oil supply device.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05201613A JP3097041B2 (en) | 1993-08-13 | 1993-08-13 | Return flow sharing circuit for pressure oil supply device |
| GB9600385A GB2294978B (en) | 1993-08-13 | 1994-08-12 | Flow control device for hydraulic circuit |
| US08/583,017 US6026730A (en) | 1993-08-13 | 1994-08-12 | Flow control apparatus in a hydraulic circuit |
| PCT/JP1994/001346 WO1995005545A1 (en) | 1993-08-13 | 1994-08-12 | Flow control device for hydraulic circuit |
| DE4496043T DE4496043T1 (en) | 1993-08-13 | 1994-08-12 | Flow control loop in a hydraulic circuit |
| KR1019960700368A KR960704164A (en) | 1993-08-13 | 1996-01-19 | Flow control apparatus in a hydralic circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05201613A JP3097041B2 (en) | 1993-08-13 | 1993-08-13 | Return flow sharing circuit for pressure oil supply device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0754805A JPH0754805A (en) | 1995-02-28 |
| JP3097041B2 true JP3097041B2 (en) | 2000-10-10 |
Family
ID=16443968
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP05201613A Expired - Lifetime JP3097041B2 (en) | 1993-08-13 | 1993-08-13 | Return flow sharing circuit for pressure oil supply device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3097041B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100451352C (en) * | 2003-08-20 | 2009-01-14 | 株式会社小松制作所 | Hydraulic drive control device |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4642269B2 (en) * | 2001-05-21 | 2011-03-02 | 株式会社小松製作所 | Hydraulic circuit for construction machinery |
| JP5554575B2 (en) * | 2010-01-15 | 2014-07-23 | 住友建機株式会社 | Hydraulic circuit for construction machinery |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5744224U (en) * | 1980-08-28 | 1982-03-11 | ||
| JPH0527765U (en) * | 1991-09-13 | 1993-04-09 | 株式会社リコー | Development unit driving device for image forming apparatus |
| JP3796364B2 (en) * | 1999-01-27 | 2006-07-12 | キヤノン株式会社 | Electrophotographic image forming apparatus |
| JP2003139221A (en) * | 2001-11-06 | 2003-05-14 | Funai Electric Co Ltd | Gear mounting structure |
| JP2005241946A (en) * | 2004-02-26 | 2005-09-08 | Konica Minolta Business Technologies Inc | Image forming apparatus and driving transmitting joint |
| JP4431467B2 (en) * | 2004-09-03 | 2010-03-17 | 株式会社リコー | Image forming apparatus. |
| JP2007147881A (en) * | 2005-11-25 | 2007-06-14 | Brother Ind Ltd | Developing cartridge and image forming apparatus |
| JP4604063B2 (en) * | 2007-06-11 | 2010-12-22 | キヤノン株式会社 | Image forming apparatus |
| JP5039481B2 (en) * | 2007-08-31 | 2012-10-03 | 株式会社リコー | CONNECTION DEVICE, CONNECTION METHOD, AND IMAGE FORMING DEVICE |
| JP5471015B2 (en) * | 2009-04-28 | 2014-04-16 | ブラザー工業株式会社 | Image forming apparatus |
-
1993
- 1993-08-13 JP JP05201613A patent/JP3097041B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100451352C (en) * | 2003-08-20 | 2009-01-14 | 株式会社小松制作所 | Hydraulic drive control device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0754805A (en) | 1995-02-28 |
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