JP2874303B2 - Variable displacement hydraulic device - Google Patents
Variable displacement hydraulic deviceInfo
- Publication number
- JP2874303B2 JP2874303B2 JP2210948A JP21094890A JP2874303B2 JP 2874303 B2 JP2874303 B2 JP 2874303B2 JP 2210948 A JP2210948 A JP 2210948A JP 21094890 A JP21094890 A JP 21094890A JP 2874303 B2 JP2874303 B2 JP 2874303B2
- Authority
- JP
- Japan
- Prior art keywords
- control
- pressure
- passage
- pressure chamber
- 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 - Fee Related
Links
Landscapes
- Reciprocating Pumps (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、吐出圧力を設定値に保持する圧力補償制御
と、吐出流量を設定値に制限制御する流量制御とを可能
にした可変容量形液圧装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a variable displacement type that enables pressure compensation control for maintaining a discharge pressure at a set value and flow control for limiting and controlling a discharge flow rate to a set value. It relates to a hydraulic device.
（従来の技術） 従来、吐出圧力を設定値に保持する圧力補償制御（以
下PC制御ともいう）付の液圧装置では、例えば特公昭60
−39878号公報に開示され且つ第５図に示すように、可
変制御要素たる斜板（Ｘ）が中立位置とされるPC制御
時、操作プランジャ（Ｐ）の制御圧室（Ｆ）をドレン
（Ｄ）に開口する漏らし通路（Ｒ）をシリンダ（Ｓ）に
設けたり、実公昭62−33993号公報に記載され且つ第６
図に示すように、常時、制御圧室（Ｆ）に開口するチョ
ーク（Ｃ）付きの漏らし通路（Ｒ′）を操作プランジャ
（Ｐ）に設けたりして、PC制御時、制御系内にある程度
の量の制御流体を流し続けて余剰流体はドレンに排出す
ることにより、外乱等による悪影響を低減して安定な制
御が行えるようにしている。(Prior art) Conventionally, in a hydraulic device with pressure compensation control (hereinafter also referred to as PC control) for maintaining a discharge pressure at a set value, for example,
As shown in FIG. 5 and disclosed in FIG. 5, during the PC control in which the swash plate (X) as a variable control element is in the neutral position, the control pressure chamber (F) of the operation plunger (P) is drained ( A leakage passage (R) opening to D) is provided in the cylinder (S) or described in Japanese Utility Model Publication No. Sho 62-33993.
As shown in the figure, a leakage passage (R ') with a choke (C) that always opens into the control pressure chamber (F) is provided in the operation plunger (P), and a certain degree of control in the control system during PC control. The amount of the control fluid is kept flowing, and the excess fluid is discharged to the drain, so that the adverse effect due to disturbance or the like is reduced and stable control can be performed.
（発明が解決しようとする課題） しかし、PC制御の他、吐出流量を設定値に制限制御す
る流量制御（以下FC制御ともいう）を行うものでは、PC
制御時の制御流体のみならず、FC制御時の制御流体をも
ドレンに漏らす必要があるが、第５図のものでは、斜板
（Ｘ）が中立位置とされるPC制御時は制御流体を漏らす
ことができるが、斜板（Ｘ）が任意角度とされるFC制御
時は、制御圧室（Ｆ）が漏らし通路（Ｒ）に開口いない
ため、制御圧室（Ｆ）に導入した制御流体を漏らすこと
ができず、FC制御時の安定化を図ることができない問題
がある。又、これを回避するため、第５図中想像線で示
すように、制御圧室（Ｆ）にFC制御時の漏らし通路
（Ｒ″）を併設することも考えられるが、この場合、PC
制御時、２つの漏らし通路（Ｒ）（Ｒ″）を介して制御
流体が漏れることになり、PC制御時の漏らし量が増えて
ロスが大きくなる問題がある。(Problems to be Solved by the Invention) However, in the case of performing flow control (hereinafter also referred to as FC control) for controlling the discharge flow rate to a set value in addition to the PC control, the PC
It is necessary to leak not only the control fluid at the time of control but also the control fluid at the time of FC control to the drain. In the case of FIG. 5, the control fluid is used at the time of PC control in which the swash plate (X) is in the neutral position. Although the swash plate (X) can be leaked at the time of FC control, the control pressure chamber (F) does not open to the leak passage (R), so the control fluid introduced into the control pressure chamber (F) And there is a problem that it is not possible to stabilize the FC control. In order to avoid this, as shown by the imaginary line in FIG. 5, a leakage path (R ″) for FC control may be provided in the control pressure chamber (F).
At the time of control, the control fluid leaks through the two leak passages (R) (R ″), and there is a problem that the amount of leak at the time of PC control increases and the loss increases.
又、第６図のものでは、漏らし通路（Ｒ′）は制御圧
室（Ｆ）に常時開口しているため、FC制御時にも制御流
体を漏らすことができるが、FC制御時の漏らし通路とPC
制御時の漏らし通路とが兼用されることになるため、FC
制御単独でその最適漏らし量を設定することができず、
FC制御及びPC制御双方について最適な安定制御が行い難
い問題がある。In FIG. 6, since the leak passage (R ') is always open to the control pressure chamber (F), the control fluid can be leaked even at the time of FC control. PC
Since it also serves as a leakage path during control, FC
It is not possible to set the optimum leak amount by control alone,
There is a problem that it is difficult to perform optimal stable control for both FC control and PC control.
本発明の目的は、PC制御時の漏らし量を増やすことな
く、しかも、FC制御単独でその漏らし量を設定すること
ができ、PC制御及びFC制御双方の制御の安定化を良好に
図ることができる可変容量形液圧装置を提供することに
ある。An object of the present invention is to improve the stability of both the PC control and the FC control without increasing the leakage amount during the PC control, and by setting the leakage amount by the FC control alone. It is an object of the present invention to provide a variable displacement type hydraulic device which can be used.
（課題を解決するための手段） そこで、本発明は、上記の目的を達成するため、可変
制御要素（１）と、該要素（１）の変位量を調節する操
作プランジャ（２）と、圧力補償弁（３）及び流量制御
弁（４）を備え、前記圧力補償弁（３）の二次側を前記
プランジャ（２）の制御圧室（６）に接続すると共に、
前記流量制御弁（４）の二次側を前記圧力補償弁（３）
の二次側を介して前記制御圧室（６）に接続し、吐出圧
力を設定値に保持する圧力補償制御と吐出流量を設定値
に制限制御する流量制御とを可能にした可変容量形液圧
装置において、前記制御圧室（６）に、圧力補償制御時
の制御流体をドレンに漏らす第１漏らし通路（７）を開
口すると共に、流量制御時に前記制御圧室（６）に連通
され且つ圧力補償制御時に前記制御圧室（６）に対し遮
断される流路に、流量制御時の制御流体をドレンに漏ら
す第２漏らし通路（８）を開口した。(Means for Solving the Problems) In order to achieve the above object, the present invention provides a variable control element (1), an operation plunger (2) for adjusting a displacement amount of the element (1), and a pressure control element. A compensating valve (3) and a flow control valve (4) are provided, and a secondary side of the pressure compensating valve (3) is connected to a control pressure chamber (6) of the plunger (2).
The secondary side of the flow control valve (4) is connected to the pressure compensating valve (3).
A variable displacement type liquid connected to the control pressure chamber (6) through the secondary side of the above and capable of pressure compensation control for maintaining the discharge pressure at a set value and flow control for limiting the discharge flow rate to the set value In the pressure device, the control pressure chamber (6) is opened with a first leak passage (7) for leaking a control fluid at the time of pressure compensation control to the drain, and is communicated with the control pressure chamber (6) during flow rate control; A second leak passage (8) for opening a control fluid at the time of flow rate control to the drain is opened in a flow path that is shut off from the control pressure chamber (6) during the pressure compensation control.
又、上記構成で第２漏らし通路（８）を、圧力補償弁
（３）のスプール（30）に設けた。In the above configuration, the second leak passage (8) is provided in the spool (30) of the pressure compensating valve (3).
（作用） 第１漏らし通路（７）によりPC制御時の制御の安定化
が、第２漏らし通路（８）によりFC制御時の制御の安定
化が各々図れ、しかも、第２漏らし通路（８）のみ単独
でFC制御時の漏らし量を設定することができ、又、該第
２漏らし通路（８）は、PC制御時、制御圧室（６）に対
し遮断され、PC制御時の漏らし量を必要以上に増加させ
ることもない。(Operation) The first leakage path (7) can stabilize control during PC control, and the second leakage path (8) can stabilize control during FC control. In addition, the second leakage path (8) Only the amount of leakage during FC control can be set alone, and the second leakage passage (8) is shut off from the control pressure chamber (6) during PC control, and the amount of leakage during PC control is reduced. It does not increase more than necessary.
第２漏らし通路（８）を圧力補償弁（３）のスプール
（30）に設けることにより、通路構成の簡素化が図れ
る。By providing the second leak passage (8) in the spool (30) of the pressure compensating valve (3), the structure of the passage can be simplified.
（実施例） 第１図に示す可変容量形液圧装置は、本体ハウジング
（10）の内部に、傾斜角度の変更により吐出通路（９）
の吐出流量を変更する斜板から成る可変制御要素（１）
と、制御圧室（６）に導入する制御流体によりバイアス
ピストン（21）及びバイアススプリング（22）に抗して
移動を起こし、円筒形の回動体（23）及び連結アーム
（24）を介して前記要素（１）の変位量を最大傾斜位置
から図示の中立位置にわたり調節する操作プランジャ
（２）とを備えている。(Embodiment) The variable displacement hydraulic device shown in FIG. 1 has a discharge passage (9) inside a main body housing (10) by changing a tilt angle.
Variable control element (1) consisting of a swash plate for changing the discharge flow rate
Then, the control fluid introduced into the control pressure chamber (6) causes the piston to move against the bias piston (21) and the bias spring (22), and moves via the cylindrical rotating body (23) and the connecting arm (24). An operating plunger (2) for adjusting the amount of displacement of the element (1) from the maximum tilt position to the neutral position shown.
併設する弁ハウジング（11）の内部には、スプール
（30）をもち、一端に吐出通路（９）から一次側室（3
1）に導く吐出圧力を、他端に調節器（33）で調節され
るPC制御圧設定バネ（34）を各々作用させる圧力補償弁
（３）と、スプール（40）もち、一端に吐出通路（９）
から一次側室（41）に導く吐出圧力を、他端に、第２図
に示す通り吐出通路（９）に介装する絞り（45）の出口
からバネ室（46）に導く圧力及び調節器（43）で調節さ
れる駆動差圧設定バネ（44）を各々作用させる流量制御
弁（４）とを備えている。そして、圧力補償弁（３）の
二次側室（32）を、制御通路（５）を介して制御圧室
（６）に、流量制御弁（４）の二次側室（42）を、連通
路（50）を介して圧力補償弁（３）の二次側室（32）に
接続している。A spool (30) is provided inside the associated valve housing (11), and one end of the primary housing (3) is connected to the discharge passage (9) at one end.
A pressure compensating valve (3) for actuating a PC control pressure setting spring (34) controlled by a regulator (33) at the other end to guide the discharge pressure guided to 1), and a spool (40). (9)
At the other end, the pressure and the regulator (from the outlet of the throttle (45) interposed in the discharge passage (9) to the spring chamber (46) are introduced to the spring chamber (46), as shown in FIG. And a flow rate control valve (4) for operating a drive differential pressure setting spring (44) adjusted by (43). The secondary chamber (32) of the pressure compensating valve (3) is connected to the control pressure chamber (6) via the control passage (5), and the secondary chamber (42) of the flow control valve (4) is connected to the communication passage. It is connected to the secondary side chamber (32) of the pressure compensating valve (3) via (50).
こうして、第３図に示すように、PC制御圧設定バネ
（34）の調節による設定圧力（Pm）で、圧力補償弁
（３）のスプール（30）を作動させ、その一次側室（3
1）から制御通路（５）を経て制御圧室（６）に制御流
体を導入し、可変制御要素（１）をほゞ中立位置にし
て、吐出圧力を設定値に保持する圧力補償制御（PC制
御）と、絞り（45）の調節による開口面積と差圧設定バ
ネ（44）の調節による絞り（45）前後の差圧とで決まる
設定流量（Qd）が得られるように、流量制御弁（４）の
スプール（40）を作動させ、その一次側室（41）から連
通路（50）及び制御通路（５）を経て制御圧室（６）に
制御流体を導入し、可変制御要素（１）の変位量を最大
傾斜位置と中立位置との間の所定位置に調節し、その吐
出流量を、最大傾斜位置で得られる最大吐出流量（Qm）
に対し小さい前記設定値（Qd）に制限制御する流量制御
（FC制御）とを可能にしている。In this way, as shown in FIG. 3, the spool (30) of the pressure compensating valve (3) is operated at the set pressure (Pm) by adjusting the PC control pressure setting spring (34), and the primary side chamber (3
Pressure compensation control (PC) that introduces a control fluid from 1) to the control pressure chamber (6) through the control passage (5), sets the variable control element (1) to a substantially neutral position, and maintains the discharge pressure at a set value. Control) and a flow rate control valve (Qd) determined by the opening area by adjusting the throttle (45) and the differential pressure across the throttle (45) by adjusting the differential pressure setting spring (44). The control fluid is introduced into the control pressure chamber (6) from the primary side chamber (41) via the communication passage (50) and the control passage (5) by operating the spool (40) of 4). Is adjusted to a predetermined position between the maximum tilt position and the neutral position, and the discharge flow rate is adjusted to the maximum discharge flow rate (Qm) obtained at the maximum tilt position.
And the flow rate control (FC control) for limiting the control to the small set value (Qd).
尚、第１図のスプール位置は、ノーマルポジションを
示しており、前記制御圧室（６）は、前記制御通路
（５）及び連通路（50）並びに、第１ドレン通路（3
5）、圧力補償弁（３）のバネ室（36）及び第２ドレン
通路（37）を介してドレン（Ｄ）に開放されており、本
来、操作プランジャ（２）はバイアススプリング等によ
り図中下方部に押し込まれ、可変制御要素（１）は最大
傾斜位置を維持することになる。The spool position shown in FIG. 1 indicates a normal position, and the control pressure chamber (6) is provided with the control passage (5), the communication passage (50), and the first drain passage (3).
5), which is opened to the drain (D) through the spring chamber (36) of the pressure compensating valve (3) and the second drain passage (37), and the operation plunger (2) is originally provided by a bias spring or the like in the figure. Pushed into the lower part, the variable control element (1) will maintain the maximum tilt position.
以上の構成で、第１図に示すように、前記制御圧室
（６）に、圧力補償制御（PC制御）時の制御流体をドレ
ン（Ｄ）に漏らす第１漏らし通路（７）を開口する。具
体的には、この第１漏らし通路（７）は、操作プランジ
ャ（２）の作動を案内するシリンダ（20）の壁部に設け
るものであり、PC制御時、図示のように、操作プランジ
ャ（２）のスカート部（25）に設ける複数の横穴（26）
を介して制御圧室（６）に連通される環状溝（27）に開
口して、PC制御時の制御流体をドレン（Ｄ）に漏らすよ
うにしている。In the above configuration, as shown in FIG. 1, a first leak passage (7) for opening a control fluid for pressure compensation control (PC control) to the drain (D) is opened in the control pressure chamber (6). . Specifically, the first leak passage (7) is provided in the wall of the cylinder (20) for guiding the operation of the operation plunger (2). Plural side holes (26) provided in the skirt (25) of 2)
An opening is formed in the annular groove (27) communicating with the control pressure chamber (6) through the control valve, so that the control fluid during PC control leaks to the drain (D).
こうして、PC制御時、前記第１漏らし通路（７）から
ドレン（Ｄ）に漏らす流量分の流体を制御系内に流すこ
とにより、該PC制御時の制御の安定化が図れる。In this way, during the PC control, the flow of the fluid leaking from the first leak passage (7) to the drain (D) flows into the control system, thereby stabilizing the control during the PC control.
又、流量制御（FC制御）時に前記制御圧室（６）に連
通され且つPC制御時に前記制御圧室（６）に対し遮断さ
れる流路に、FC制御時の制御流体をドレンに漏らす第２
漏らし通路（８）を開口する。In addition, a control fluid flowing through the control pressure chamber (6) at the time of flow rate control (FC control) and being shut off from the control pressure chamber (6) at the time of PC control is discharged to the drain through the control fluid. 2
Open the leak passage (8).
具体的に、前記第２漏らし通路（８）は、圧力補償弁
（３）のスプール（30）に設ける径方向穴（81）と横方
向穴（82）とを備え、流量制御弁（４）の二次側室（4
2）から延びる連通路（50）を、前記径方向穴（81）及
び横方向穴（82）並びに、バネ受（38）に設ける軸穴
（39）を介してバネ室（36）ひいてはドレン（Ｄ）に連
通させるようにしている。Specifically, the second leak passage (8) includes a radial hole (81) and a lateral hole (82) provided in the spool (30) of the pressure compensating valve (3), and the flow control valve (4). Secondary room (4
The communication passage (50) extending from 2) is connected to the spring chamber (36) and, consequently, the drain (81) through the radial hole (81) and the lateral hole (82) and the shaft hole (39) provided in the spring support (38). D).
これにより、FC制御時、前記第２漏らし通路（８）か
らドレン（Ｄ）に漏らす流量分の流体を制御系内に流す
ことにより、該FC制御時の制御の安定化が図れる。Thus, during the FC control, the fluid corresponding to the flow rate leaking from the second leak passage (8) to the drain (D) flows into the control system, thereby stabilizing the control during the FC control.
又、この第２漏らし通路（８）は、PC制御時、圧力補
償弁（３）のスプール（３）の作動により制御通路
（５）ひいては制御圧室（６）に対し遮断されるため、
PC制御時の漏らし量を必要以上に増加させることもな
く、PC制御時のロスを低減することができる。Further, since the second leak passage (8) is shut off from the control passage (5) and thus the control pressure chamber (6) by the operation of the spool (3) of the pressure compensating valve (3) during the PC control,
Loss during PC control can be reduced without unnecessarily increasing the leakage amount during PC control.
更に、FC制御時は、可変制御要素（１）は所定の角度
に位置され中立位置にないため、第１漏らし通路（７）
は制御圧室（６）に開口されることがなく、該FC制御時
の制御流体の漏らし量は、第２漏らし通路（８）のみに
より単独で設定することができ、該FC制御時に合わせた
適正な漏らし量を設定することができると共に、PC制御
時は、逆に第１漏らし通路（７）のみにより単独でその
漏らし量を設定することができ、該PC制御時に合わせた
適正な漏らし量を設定することができる。Further, during FC control, since the variable control element (1) is located at a predetermined angle and is not in the neutral position, the first leak passage (7)
Is not opened to the control pressure chamber (6), and the amount of control fluid leakage at the time of the FC control can be independently set by only the second leak passage (8). It is possible to set an appropriate amount of leakage, and at the time of PC control, conversely, the amount of leakage can be set independently only by the first leakage passage (7), and an appropriate amount of leakage adjusted during the PC control can be set. Can be set.
ところで、以上の実施例では、第２漏らし通路（８）
を圧力補償弁（３）のスプール（30）に設けたが、その
他、第４図に示すように、連通路（50）と第１ドレン通
路（35）との間に、チョーク（83）をもつ漏らし通路
（８）を設けてもよく、上記同様の作用効果が得られ
る。By the way, in the above embodiment, the second leak passage (8)
Is provided on the spool (30) of the pressure compensating valve (3). In addition, as shown in FIG. 4, a choke (83) is provided between the communication passage (50) and the first drain passage (35). A leakage path (8) may be provided, and the same operation and effect as described above can be obtained.
（発明の効果） 以上、本発明では、操作プランジャ（２）の制御圧室
（６）に、PC制御時の制御流体をドレンに漏らす第１漏
らし通路（７）を開口すると共に、FC制御時に制御圧室
（６）に連通され且つPC制御時に制御圧室（６）に対し
遮断される流路に、FC制御時の制御流体をドレンに漏ら
す第２漏らし通路（８）を開口したから、PC制御及びFC
制御双方について制御の安定化が図れ、しかも、第２漏
らし通路（８）のみ単独でFC制御時の漏らし量を設定す
ることができると共に、従来のようにPC制御時の漏らし
量を必要以上に増加させることもなく、良好な制御が行
える。(Effects of the Invention) As described above, according to the present invention, the first pressure passage (7) for leaking the control fluid at the time of PC control to the drain is opened in the control pressure chamber (6) of the operation plunger (2), and the control pressure chamber during the FC control is opened. Since the second leak passage (8) for opening the control fluid at the time of FC control to the drain is opened in the flow path which is communicated with the control pressure chamber (6) and is cut off from the control pressure chamber (6) at the time of PC control, PC control and FC
It is possible to stabilize the control for both controls, and to set the amount of leakage during FC control using only the second leakage passage (8) alone, and to reduce the amount of leakage during PC control more than necessary as in the past. Good control can be performed without increasing.
又、前記第２漏らし通路（８）を圧力補償弁（３）の
スプール（30）に設ける場合、通路構成の簡素化をも図
ることができる。When the second leak passage (8) is provided in the spool (30) of the pressure compensating valve (3), the structure of the passage can be simplified.
第１図は本発明に係る可変容量形液圧装置の断面図、第
２図は同回路図、第３図は同圧力流量特性図、第４図は
他の実施例を示す要部断面図、第５図及び第６図は従来
例の断面図である。 （１）……可変制御要素 （２）……操作プランジャ （３）……圧力補償弁 （４）……流量制御弁 （６）……制御圧室 （７）……第１漏らし通路 （８）……第２漏らし通路 （30）……スプール1 is a cross-sectional view of a variable displacement hydraulic device according to the present invention, FIG. 2 is a circuit diagram thereof, FIG. 3 is a pressure flow characteristic diagram thereof, and FIG. 5 and 6 are cross-sectional views of a conventional example. (1) Variable control element (2) Operating plunger (3) Pressure compensating valve (4) Flow control valve (6) Control pressure chamber (7) First leak passage (8) )… Second leak passage (30)… Spool
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) F04B 1/26 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 6 , DB name) F04B 1/26
Claims (2)
位量を調節する操作プランジャ（２）と、圧力補償弁
（３）及び流量制御弁（４）を備え、前記圧力補償弁
（３）の二次側を前記プランジャ（２）の制御圧室
（６）に接続すると共に、前記流量制御弁（４）の二次
側を前記圧力補償弁（３）の二次側を介して前記制御圧
室（６）に接続し、吐出圧力を設定値に保持する圧力補
償制御と吐出流量を設定値に制限制御する流量制御とを
可能にした可変容量形液圧装置において、前記制御圧室
（６）に、圧力補償制御時の制御流体をドレンに漏らす
第１漏らし通路（７）を開口すると共に、流量制御時に
前記制御圧室（６）に連通され且つ圧力補償制御時に前
記制御圧室（６）に対し遮断される流路に、流量制御時
の制御流体をドレンに漏らす第２漏らし通路（８）を開
口したことを特徴とする可変容量形液圧装置。A pressure control valve (3), a flow control valve (4), a variable control element (1), an operation plunger (2) for adjusting an amount of displacement of the element (1); The secondary side of the valve (3) is connected to the control pressure chamber (6) of the plunger (2), and the secondary side of the flow control valve (4) is connected to the secondary side of the pressure compensating valve (3). A variable displacement hydraulic pressure device connected to the control pressure chamber (6) via the pressure control device and capable of performing pressure compensation control for maintaining a discharge pressure at a set value and flow control for limiting and controlling a discharge flow rate to a set value. In the control pressure chamber (6), a first leak passage (7) for leaking a control fluid at the time of pressure compensation control to the drain is opened, and the control pressure chamber (6) is communicated with the control pressure chamber (6) at the time of flow rate control and the pressure leakage control is performed at the time of pressure compensation control. The control fluid during the flow rate control leaks into the drain in the flow path cut off from the control pressure chamber (6). Variable capacitance form hydraulic device, characterized in that the second leak opening a passage (8).
（３）のスプール（30）に設けている請求項１記載の可
変容量形液圧装置。2. The variable displacement hydraulic device according to claim 1, wherein the second leakage passage (8) is provided in a spool (30) of the pressure compensating valve (3).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2210948A JP2874303B2 (en) | 1990-08-08 | 1990-08-08 | Variable displacement hydraulic device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2210948A JP2874303B2 (en) | 1990-08-08 | 1990-08-08 | Variable displacement hydraulic device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0494467A JPH0494467A (en) | 1992-03-26 |
| JP2874303B2 true JP2874303B2 (en) | 1999-03-24 |
Family
ID=16597752
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2210948A Expired - Fee Related JP2874303B2 (en) | 1990-08-08 | 1990-08-08 | Variable displacement hydraulic device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2874303B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3360056B2 (en) | 1999-12-06 | 2002-12-24 | 米沢日本電気株式会社 | Lighting device for electronic device and lighting method for electronic device |
| GB2366542B (en) * | 2000-09-09 | 2004-02-18 | Ibm | Keyboard illumination for computing devices having backlit displays |
-
1990
- 1990-08-08 JP JP2210948A patent/JP2874303B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0494467A (en) | 1992-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101688628B (en) | Force feedback poppet valve having an integrated pressure compensator | |
| JP2001055968A (en) | Displacement control valve for variable displacement hydraulic rotating machine | |
| JP2547734B2 (en) | Control device for at least one hydraulically operated actuator | |
| JPS6249471B2 (en) | ||
| JP2874303B2 (en) | Variable displacement hydraulic device | |
| JP2003519348A (en) | Pressure regulating valve | |
| JPS593770B2 (en) | genatsuben | |
| JP3584642B2 (en) | Pressure reducing valve for water supply device | |
| JPS6022201B2 (en) | fluid equipment | |
| KR960016819B1 (en) | Flow control hydraulic circuit for a pump | |
| JPS62460Y2 (en) | ||
| JPS6113762Y2 (en) | ||
| JP2899108B2 (en) | Valve device with air release plug | |
| JPH0828506A (en) | Pressure compensation valve | |
| JPH07332246A (en) | Load sensing device for variable displacement pump | |
| US20260002551A1 (en) | Fluid system damping adjusting valves | |
| JPH0359307B2 (en) | ||
| JPH081345Y2 (en) | Electromagnetic flow control valve | |
| JPH0425521Y2 (en) | ||
| JPS5843537B2 (en) | Hydraulic excavator hydraulic control device | |
| SU1483116A1 (en) | Hydraulic drive | |
| JPH0386684A (en) | Hydraulic system for industrial vehicle | |
| JP2550198Y2 (en) | Displacement control device for variable displacement hydraulic pump | |
| SU1616529A1 (en) | Agricultural tractor | |
| JP3494470B2 (en) | Standby flow controller for load sensing circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |