JP3304374B2 - Hydraulic circuit - Google Patents
Hydraulic circuitInfo
- Publication number
- JP3304374B2 JP3304374B2 JP35564791A JP35564791A JP3304374B2 JP 3304374 B2 JP3304374 B2 JP 3304374B2 JP 35564791 A JP35564791 A JP 35564791A JP 35564791 A JP35564791 A JP 35564791A JP 3304374 B2 JP3304374 B2 JP 3304374B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- load
- valve
- oil
- load pressure
- 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 - Fee Related
Links
Landscapes
- 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
出圧油を複数のアクチュエータに供給する油圧回路に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic circuit for supplying pressure oil discharged from one hydraulic pump to a plurality of 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
と複数のアクチユエータに圧油を同時に供給する際に、
負荷の小さなアクチュエータにのみ圧油が供給されて負
荷の大きなアクチュエータに圧油が供給されなくなって
しまう。このことを解消する油圧回路として、例えば特
公平２−４９４０５号公報に示すものが提案されてい
る。2. Description of the Related Art In order to supply pressure oil discharged from one hydraulic pump to a plurality of actuators, a plurality of operation valves are provided in a discharge path of the hydraulic pump, and the operation valves are switched to supply pressure oil to each actuator. In this case, when supplying pressure oil to multiple actuators at the same time,
The pressure oil is supplied only to the actuator with a small load, and the pressure oil is not supplied to the actuator with a large load. As a hydraulic circuit for solving this problem, for example, a hydraulic circuit disclosed in Japanese Patent Publication No. 2-49405 has been proposed.
【０００３】かかる油圧回路を模式的に示すと図１に示
すようになる。つまり、油圧ポンプ１の吐出路１ａに複
数の操作弁２を設け、各操作弁２と各アクチュエータ３
を接続する回路４に圧力補償弁５をそれぞれ設けると共
に、各回路４の圧力、つまり負荷圧における最も高い圧
力をチェック弁６で負荷圧検出路７に検出し、その検出
した負荷圧を各圧力補償弁５の受圧部５ａに作用してそ
の負荷圧に見合う圧力にセットし、各操作弁２の出口側
圧力を等しくして各操作弁２を同時操作した時に各操作
弁の開口面積に比例した分流比で各アクチュエータ３に
圧油を供給できるようにしてある。FIG. 1 schematically shows such a hydraulic circuit. That is, a plurality of operation valves 2 are provided in the discharge path 1a of the hydraulic pump 1, and each operation valve 2 and each actuator 3
And a pressure compensating valve 5 is provided in each of the circuits 4 to which the pressure is applied, and the pressure of each circuit 4, that is, the highest pressure in the load pressure is detected by a check valve 6 in a load pressure detecting path 7, and the detected load pressure is detected by each pressure. The pressure acting on the pressure receiving portion 5a of the compensating valve 5 is set to a pressure corresponding to the load pressure, and the outlet side pressure of each operating valve 2 is made equal, and when each operating valve 2 is simultaneously operated, it is proportional to the opening area of each operating valve. Pressure oil can be supplied to each of the actuators 3 at the determined split ratio.
【０００４】[0004]
【発明が解決しようとする課題】かかる油圧回路である
と、圧力補償弁５の機能によって各アクチュエータ３の
負荷の大小に無関係に操作弁２の開口面積に比例した流
量分配ができるから、１つの油圧ポンプ１の吐出圧油を
操作弁２の操作量に比例して各アクチュエータ３にそれ
ぞれ供給できる。In such a hydraulic circuit, the function of the pressure compensating valve 5 allows the flow rate to be distributed in proportion to the opening area of the operating valve 2 irrespective of the magnitude of the load on each actuator 3. The pressure oil discharged from the hydraulic pump 1 can be supplied to each actuator 3 in proportion to the operation amount of the operation valve 2.
【０００５】前述の油圧回路であると各圧力補償弁５は
最も高い負荷圧によってセットされるから、例えばパワ
ーショベルの旋回用モータとブーム用シリンダに圧油を
同時に供給して上部車体を旋回しながらブームを上昇さ
せる場合、旋回初期に旋回用モータの起動トルクが著し
く大となって負荷圧が著しく高圧となり、各圧力補償弁
がその著しく高圧の負荷圧でセットされて通過流量が減
少するためにブーム用シリンダに供給される流量が減少
してブーム上昇速度が著しく遅くなる。このために、従
来は旋回用モータ側の負荷圧検出部に接続した回路に開
閉弁を設け、旋回用モータ以外のアクチュエータに圧油
を供給する時には開閉弁を閉として旋回用モータの負荷
圧が検出されないようにして圧力補償弁を他のアクチュ
エータの負荷圧によってセットしている。In the above-described hydraulic circuit, each pressure compensating valve 5 is set at the highest load pressure. For example, pressurized oil is simultaneously supplied to a turning motor of a power shovel and a boom cylinder to turn the upper body. When raising the boom, the starting torque of the turning motor becomes extremely large at the beginning of turning and the load pressure becomes extremely high, and each of the pressure compensating valves is set at the extremely high load pressure and the passing flow rate decreases. Therefore, the flow rate supplied to the boom cylinder is reduced, and the boom raising speed is significantly reduced. For this purpose, conventionally, an on-off valve is provided in a circuit connected to the load pressure detection unit on the turning motor side, and when supplying hydraulic oil to an actuator other than the turning motor, the on-off valve is closed to reduce the load pressure of the turning motor. The pressure compensating valve is set by the load pressure of another actuator so as not to be detected.
【０００６】しかしながら前述の開閉弁はＯＮ，ＯＦＦ
的に開閉されるので、閉じていた開閉弁を開とすると旋
回用モータの負荷圧が直ちに負荷圧検出路７に流入す
る。このために、開閉弁を閉から開への切替時に負荷圧
検出路７の最高負荷圧が急激に変化し、圧力補償弁のセ
ット圧が急激に変化して通過流量も急激に変化してアク
チュエータへの流量が急激に変化するのでショックを発
生する。However, the above-mentioned on-off valve is turned on and off.
When the closed on-off valve is opened, the
The load pressure of the recycle motor immediately flows into the load pressure detection path 7
You. For this reason, when switching the on-off valve from closed to open, the load pressure
Since the maximum load pressure in the detection path 7 changes rapidly, the set pressure of the pressure compensating valve changes rapidly, the passing flow rate also changes rapidly, and the flow rate to the actuator changes rapidly, causing a shock.
【０００７】そこで、本発明は前述の課題を解決できる
ようにした油圧回路を提供することを目的とする。Therefore, an object of the present invention is to provide a hydraulic circuit which can solve the above-mentioned problems.
【０００８】[0008]
【課題を解決するための手段】本発明は、油圧ポンプ１
と、該油圧ポンプ１の吐出路１ａに複数のアクチュエー
タを設け、前記アクチュエータは各々操作弁２と圧力補
償弁５とを介して接続され、前記各アクチュエータの負
荷圧に応じた圧力を出力する出力手段と、前記出力手段
によって出力された圧力の中で最高の圧力を選択する選
択手段とを備え、前記選択手段によって選択された圧力
を負荷圧検出路７を介して前記各圧力補償弁５に接続
し、前記負荷圧検出路７の圧力によって前記各圧力補償
弁５の設定圧力を制御する油圧回路において、前記複数
のアクチュエータの中の特定のアクチュエータに備えた
前記出力手段は、特定のアクチュエータの負荷圧検出ポ
ート１３と負荷圧検出路７を開閉するポペット１５と、
このポペット１５を閉方向に押すばね１６と、受圧室２
０内の圧油でばね１６を押すピストン１７と、その受圧
室２０内の圧油の圧力を外部から高圧・低圧とするバル
ブで構成したことを特徴とする油圧回路である。 The present invention relates to a hydraulic pump (1).
A plurality of actuators are provided in a discharge path 1a of the hydraulic pump 1, and the actuators are connected via an operation valve 2 and a pressure compensating valve 5, respectively, to output a pressure corresponding to a load pressure of each actuator. Means, and selecting means for selecting the highest pressure among the pressures output by the output means, and applying the pressure selected by the selecting means to each of the pressure compensating valves 5 via a load pressure detecting path 7. In the hydraulic circuit for connecting and controlling the set pressure of each of the pressure compensating valves 5 according to the pressure of the load pressure detecting path 7, the output means provided for a specific actuator among the plurality of actuators includes : Load pressure detection port
A poppet 15 for opening and closing the port 13 and the load pressure detection path 7;
A spring 16 for pushing the poppet 15 in the closing direction and the pressure receiving chamber 2
A piston 17 that presses a spring 16 with pressure oil within 0,
A valve for externally increasing and decreasing the pressure of the pressure oil in the chamber 20
This is a hydraulic circuit characterized in that the hydraulic circuit is constituted by a hydraulic circuit.
【０００９】[0009]
【作 用】本発明によれば、複数のアクチュエータの中
の特定のアクチュエータに備えた出力手段は、そのピス
トン１７の受圧室２０の圧力を高くすることで開弁圧が
高くなるから、特定のアクチュエータの負荷圧が負荷圧
検出路７に流入しないよう にできる。また、ピストン１
７の受圧室２０の圧力を低くすることで開弁圧が低くな
るから、特定のアクチュエータの負荷圧を負荷圧検出路
７に流入できる。 この時、ポペット１５をばね１６に抗
して順次開き側に押して負荷圧検出ポート１３の負荷圧
が負荷圧検出路７に徐々に流入する。したがって、特定
のアクチュエータが旋回用モータの場合に旋回初期に旋
回用モータの負荷圧を検出せずにアーム用シリンダに圧
油を多量に供給できるし、その旋回用モータの負荷圧を
検出する際に負荷圧検出路７の最高負荷圧の圧力変動が
滑らかになってアクチュエータへの流量変化がなめらか
になるので、ショックを低減できる。According to the work for the present invention, the output Hand stage with a particular actuator among the plurality of actuators, the piston
The valve opening pressure is increased by increasing the pressure in the pressure receiving chamber 20 of the ton 17.
Higher, the load pressure of a particular actuator
It can be prevented from flowing into the detection path 7 . Also, piston 1
7, the pressure in the pressure receiving chamber 20 is lowered to lower the valve opening pressure.
Because the load pressure of a specific actuator is
7 can flow. At this time, the poppet 15 is pressed against the spring 16.
And sequentially push it to the open side to load the load pressure at the load pressure detection port 13.
Gradually flows into the load pressure detection path 7. Therefore, when the specific actuator is a turning motor, a large amount of pressure oil can be supplied to the arm cylinder without detecting the load pressure of the turning motor at the beginning of turning, and when detecting the load pressure of the turning motor. flow rate changes to the actuator becomes smooth pressure fluctuations of the load pressure Detchi 7 of the maximum load pressure can be reduced to smoothly such Runode, shock.
【００１０】[0010]
【実施例】図２は負荷圧検出部の横断面図であり、ブロ
ック１０に負荷圧検出路７となる油孔１１が形成され、
この油孔１１がポート１２で複数の負荷圧検出ポート１
３にそれぞれ連通し、その各連通部にチェック弁６が設
けてある。このチェック弁が各アクチュエータの負荷圧
に応じた圧力を出力する出力手段である。油孔１１の圧
力Ｐ1 とポート１２の圧力Ｐ2 をチェック弁６で比較し
てＰ2 ＞Ｐ1 の時にそのポート１２の負荷圧が油孔１１
に流入するようになって油孔１１には各負荷圧検出ポー
ト１３の負荷圧における最高圧が流入するようにしてあ
る。つまり各チェック弁６で前記出力手段によって出力
された圧力の中で最高の圧力を選択する選択手段を形成
している。前記各チェック弁６における１つのチェック
弁１４、（複数のアクチュエータの中の特定のアクチュ
エータに備えた前記出力手段）例えば図２で最下部のチ
ェック弁１４は旋回用モータに接続した負荷圧検出ポー
ト１３のポート１２と油孔１１を開閉するようになり、
そのチェック弁１４は下記のように構成してある。すな
わち、油孔１１とポート１２を開閉するポペット１５
と、このポペット１５を閉方向に押すばね１６と、その
ばね１６及びポペット１５を押すピストン１７と、その
ピストン１７が当接するバランスピストン１８と、ピス
トン１７を押すばね１９より成り、ピストン１７の受圧
室２０に供給される圧油の圧力Ｐ 0 が 高くなるとばね１
６によってポペット１５を閉方向に押す力が大きくな
り、ポペット１５の開弁圧、つまりポペット１５が開放
する時のポート１２の圧力Ｐ 2 と油孔１１の圧力Ｐ 1 と
の差圧（Ｐ 2 −Ｐ 1 ）が高くなる。 前記受圧室２０に供
給される圧油の圧力Ｐ 0 が低くなるとばね１６によって
ポペット１５を閉方向に押す力が小さくなり、前記開弁
圧が低くなる。 前記受圧室２０に圧油が供給されない時
にはチェック弁１４の開弁圧は他のチェック弁１４と同
様となる。前記受圧室２０には、レバー操作により圧力
が徐々に高圧・低圧となるバルブより圧油が供給され
る。例えば旋回用モータ以外のアクチュエータ、例えば
ブーム用シリンダに圧油を供給する操作弁の受圧部に切
替用パイロット圧油を供給するブーム用パイロットバル
ブの圧油が供給される。FIG. 2 is a cross-sectional view of a load pressure detecting section. An oil hole 11 serving as a load pressure detecting path 7 is formed in a block 10.
This oil hole 11 is a port 12 and a plurality of load pressure detection ports 1
3 and a check valve 6 is provided at each communication portion. This check valve is output means for outputting a pressure corresponding to the load pressure of each actuator. Pressure oil holes 11 P 1 and P 2 by comparing the pressure P 2 in the check valve 6 ports 12> load pressure oil hole 11 of the port 12 when the P 1
The maximum pressure of the load pressure of each load pressure detection port 13 flows into the oil hole 11. That is, each check valve 6 forms a selecting means for selecting the highest pressure among the pressures output by the output means. One check valve 14 in each check valve 6 (the output means provided for a specific actuator among a plurality of actuators) For example, the lowermost check valve 14 in FIG. 2 is a load pressure detection port connected to a turning motor 13 to open and close the port 12 and the oil hole 11,
The check valve 14 is configured as follows. That is, the poppet 15 for opening and closing the oil hole 11 and the port 12
, A spring 16 for pushing the poppet 15 in the closing direction, a piston 17 for pushing the spring 16 and the poppet 15, a balance piston 18 with which the piston 17 abuts, and a spring 19 for pushing the piston 17.
Pressure P 0 of the hydraulic fluid supplied to the chamber 20 is high when the spring 1
6 increases the force for pushing the poppet 15 in the closing direction.
The poppet 15 opens, that is, the poppet 15 opens.
The pressure P 2 of the port 12 and the pressure P 1 of the oil hole 11 when
Is higher (P 2 −P 1 ). Provided in the pressure receiving chamber 20
When the pressure P 0 of the supplied pressure oil decreases, the spring 16
The force for pushing the poppet 15 in the closing direction is reduced, and the valve is opened.
The pressure drops. When the pressure oil is not supplied to the pressure receiving chamber 20, the valve opening pressure of the check valve 14 becomes the same as the other check valves 14. Pressure oil is supplied to the pressure receiving chamber 20 from a valve whose pressure gradually increases and decreases according to lever operation. For example, pressure oil of a boom pilot valve that supplies switching pilot pressure oil to an actuator other than the turning motor, for example, a pressure receiving portion of an operation valve that supplies pressure oil to a boom cylinder, is supplied.
【００１１】このようであるから、受圧室２０に供給さ
れる圧油の圧力Ｐ 0 を高くして開弁圧を高くすること
で、旋回負荷圧が油孔１１に流入する時の油孔１１の圧
力Ｐ1と負荷圧Ｐ2 の差圧が順次高くなり、旋回初期時
の著しく高圧な負荷圧が油孔１１に流入することを防止
できる。また、受圧室２０の圧油の圧力Ｐ 0 を低下して
開弁圧を低くすることで、旋回負荷圧が油孔１１に流入
する時の前述の負荷圧Ｐ 2 と油孔１１の圧力Ｐ 1 の差圧
が小さくなって旋回動作中の低圧の負荷圧を油孔１１に
流入することができる。 また、受圧室２０の圧力を高圧
・低圧としてピストン１７でばね１６を押す力を変えて
ばね１６の取付荷重を変更することで開弁圧を制御して
いるので、油孔１１の圧力Ｐ 1 と負荷圧Ｐ 2 との差圧が開
弁圧に見合う大きさとなった場合に、ポペット１５をば
ね１６に抗して開き側に順次押して負荷圧検出ポート１
３の負荷圧が油孔１１に流入する。 したがって、負荷圧
が油孔１１に徐々に流入し、その油孔１１の圧力変動が
滑らかになる。 [0011]Because of this, the pressure supplied to the pressure receiving chamber 20 is
Pressure P 0 To increase the valve opening pressure
The pressure of the oil hole 11 when the turning load pressure flows into the oil hole 11
Force P1And load pressure PTwoDifferential pressure rises gradually at the beginning of turning
Prevents extremely high load pressure from flowing into oil hole 11
it can.Also, the pressure P of the pressure oil in the pressure receiving chamber 20 0 Lower
The swirl load pressure flows into the oil hole 11 by lowering the valve opening pressure.
Load pressure P Two And pressure P of oil hole 11 1 Differential pressure
And the low load pressure during turning operation is
Can flow in. Further, the pressure in the pressure receiving chamber 20 is increased to a high pressure.
・ Change the force to push the spring 16 with the piston 17 as low pressure
By controlling the valve opening pressure by changing the mounting load of the spring 16,
The pressure P in the oil hole 11 1 And load pressure P Two Differential pressure with
When the size becomes suitable for the valve pressure, poppet 15
Load pressure detection port 1
The load pressure of No. 3 flows into the oil hole 11. Therefore, the load pressure
Gradually flows into the oil hole 11, and the pressure fluctuation in the oil hole 11
Become smooth.
【００１２】[0012]
【発明の効果】請求項１に係る発明によれば、複数のア
クチュエータの中の特定のアクチュエータに備えた出力
手段は、そのピストン１７の受圧室２０の圧力を高くす
ることで開弁圧が高くなるから、特定のアクチュエータ
の負荷圧が負荷圧検出路７に流入しないようにできる。
また、ピストン１７の受圧室２０の圧力を低くすること
で開弁圧が低くなるから、特定のアクチュエータの負荷
圧を負荷圧検出路７に流入できる。 この時、ポペット１
５をばね１６に抗して順次開き側に押して負荷圧検出ポ
ート１３の負荷圧が負荷圧検出路７に徐々に流入する。
したがって、特定のアクチュエータが旋回用モータの場
合に旋回初期に旋回用モータの負荷圧を検出せずにアー
ム用シリンダに圧油を多量に供給できるし、その旋回用
モータの負荷圧を検出する際に負荷圧検出路７の最高負
荷圧の圧力変動が滑らかになってアクチュエータへの流
量変化がなめらかになるので、ショックを低減できる。Effects of the Invention According to the invention of claim 1, the output <br/> hand stage with a particular actuator among the plurality of actuators, to raise the pressure in the pressure receiving chamber 20 of the piston 17
The valve opening pressure is increased by
Can be prevented from flowing into the load pressure detection path 7 .
Further, the pressure in the pressure receiving chamber 20 of the piston 17 is reduced.
, The valve opening pressure decreases, so the load on the specific actuator
The pressure can flow into the load pressure detection path 7. At this time, poppet 1
5 is sequentially pushed to the open side against the spring 16 so that the load pressure detection port
The load pressure of the port 13 gradually flows into the load pressure detection path 7.
Therefore, when the specific actuator is a turning motor, a large amount of pressure oil can be supplied to the arm cylinder without detecting the load pressure of the turning motor at the beginning of turning, and when detecting the load pressure of the turning motor. Load load detection path 7
Flow rate changes to the actuator pressure fluctuations Ni圧 becomes smooth can reduce smoothly such Runode shock.
【図１】油圧回路図である。FIG. 1 is a hydraulic circuit diagram.
【図２】負荷圧検出部の横断面図である。FIG. 2 is a cross-sectional view of a load pressure detector.
１…油圧ポンプ、１ａ…吐出路、２…操作弁、３…アク
チュエータ、４…回路、５…圧力補償弁、５ａ…受圧
部、６…チェック弁、７…負荷圧検出路、１４…特定の
チェック弁。DESCRIPTION OF SYMBOLS 1 ... Hydraulic pump, 1a ... Discharge path, 2 ... Operation valve, 3 ... Actuator, 4 ... Circuit, 5 ... Pressure compensation valve, 5a ... Pressure receiving part, 6 ... Check valve, 7 ... Load pressure detection path, 14 ... Specific Check valve.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) F15B 11/00 - 11/22 E02F 9/20 - 9/22 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. 7 , DB name) F15B 11/00-11/22 E02F 9/20-9/22
Claims (1)
設け、 前記アクチュエータは各々操作弁２と圧力補償弁５とを
介して接続され、 前記各アクチュエータの負荷圧に応じた圧力を出力する
出力手段と、前記出力手段によって出力された圧力の中
で最高の圧力を選択する選択手段とを備え、 前記選択手段によって選択された圧力を負荷圧検出路７
を介して前記各圧力補償弁５に接続し、 前記負荷圧検出路７の圧力によって前記各圧力補償弁５
の設定圧力を制御する油圧回路において、 前記複数のアクチュエータの中の特定のアクチュエータ
に備えた前記出力手段は、特定のアクチュエータの負荷
圧検出ポート１３と負荷圧検出路７を開閉するポペット
１５と、このポペット１５を閉方向に押すばね１６と、
受圧室２０内の圧油でばね１６を押すピストン１７と、
その受圧室２０内の圧油の圧力を外部から高圧・低圧と
するバルブで構成したことを特徴とする油圧回路。 1. A hydraulic pump 1 and a plurality of actuators are provided in a discharge path 1a of the hydraulic pump 1. The actuators are connected via an operation valve 2 and a pressure compensating valve 5, respectively. Output means for outputting a pressure corresponding to the pressure, and selecting means for selecting the highest pressure among the pressures output by the output means.
Are connected to the respective pressure compensating valves 5 through the pressure compensating valves 5 by the pressure of the load pressure detecting path 7.
In the hydraulic circuit for controlling the set pressure, the output means provided for a specific actuator among the plurality of actuators, the load of the specific actuator
Poppet for opening and closing pressure detection port 13 and load pressure detection path 7
15, a spring 16 for pushing the poppet 15 in the closing direction,
A piston 17 for pressing the spring 16 with pressure oil in the pressure receiving chamber 20,
The pressure of the pressure oil in the pressure receiving chamber 20 is changed from high pressure and low pressure from outside.
A hydraulic circuit, comprising:
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35564791A JP3304374B2 (en) | 1991-12-24 | 1991-12-24 | Hydraulic circuit |
| US08/244,439 US5481872A (en) | 1991-11-25 | 1992-11-25 | Hydraulic circuit for operating plural actuators and its pressure compensating valve and maximum load pressure detector |
| PCT/JP1992/001540 WO1993011364A1 (en) | 1991-11-25 | 1992-11-25 | Hydraulic circuit for operating plural actuators and its pressure compensating valve and maximum load pressure detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35564791A JP3304374B2 (en) | 1991-12-24 | 1991-12-24 | Hydraulic circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05172106A JPH05172106A (en) | 1993-07-09 |
| JP3304374B2 true JP3304374B2 (en) | 2002-07-22 |
Family
ID=18445049
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP35564791A Expired - Fee Related JP3304374B2 (en) | 1991-11-25 | 1991-12-24 | Hydraulic circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3304374B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4994048B2 (en) * | 2007-01-18 | 2012-08-08 | カヤバ工業株式会社 | Hydraulic control device |
-
1991
- 1991-12-24 JP JP35564791A patent/JP3304374B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05172106A (en) | 1993-07-09 |
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