JP2556999B2 - Hydraulic circuit - Google Patents

Hydraulic circuit

Info

Publication number
JP2556999B2
JP2556999B2 JP2122956A JP12295690A JP2556999B2 JP 2556999 B2 JP2556999 B2 JP 2556999B2 JP 2122956 A JP2122956 A JP 2122956A JP 12295690 A JP12295690 A JP 12295690A JP 2556999 B2 JP2556999 B2 JP 2556999B2
Authority
JP
Japan
Prior art keywords
pressure
valve
load
hydraulic
inlet side
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
Application number
JP2122956A
Other languages
Japanese (ja)
Other versions
JPH0419410A (en
Inventor
照夫 秋山
清 白井
直樹 石崎
光治 山下
晋一 篠崎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Komatsu Ltd
Original Assignee
Komatsu Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority to JP2122956A priority Critical patent/JP2556999B2/en
Application filed by Komatsu Ltd filed Critical Komatsu Ltd
Priority to EP95103115A priority patent/EP0657656B1/en
Priority to DE69120818T priority patent/DE69120818T2/en
Priority to PCT/JP1991/000641 priority patent/WO1991018212A1/en
Priority to KR1019910701937A priority patent/KR920702755A/en
Priority to US07/793,395 priority patent/US5271227A/en
Priority to EP91909094A priority patent/EP0536398B1/en
Priority to DE69132071T priority patent/DE69132071T2/en
Publication of JPH0419410A publication Critical patent/JPH0419410A/en
Application granted granted Critical
Publication of JP2556999B2 publication Critical patent/JP2556999B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2221Control of flow rate; Load sensing arrangements
    • E02F9/2225Control of flow rate; Load sensing arrangements using pressure-compensating valves

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、1つの油圧ポンプあるいは複数であるが、
操作弁の上流側にポンプの吐出回路が接続されていて実
質的に1つと見なせる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油圧回路に関する。
DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention may be one hydraulic pump or a plurality of hydraulic pumps.
The present invention relates to a hydraulic circuit in which a discharge circuit of a pump is connected to an upstream side of an operation valve to supply discharge hydraulic fluid of a hydraulic pump, which can be regarded as substantially one, to a plurality of hydraulic actuators.

〔従来の技術〕[Conventional technology]

1つの油圧ポンプあるいは複数であるが、操作弁の上
流側にポンプの吐出回路が接続されていて実質的に1つ
と見なせる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。
One hydraulic pump or a plurality of hydraulic pumps has a discharge circuit connected to the upstream side of the operating valve and can be regarded as substantially one. It is sufficient to supply multiple pressure valves to each hydraulic actuator by providing multiple operation valves on the discharge passage of the switch and switching the operation valves. The pressure oil is supplied only to the hydraulic actuator having a small load, and the pressure oil is not supplied to the hydraulic actuator having a large load.

そこで複数の油圧アクチュエータを有する油圧ショベ
ルの油圧回路においては、前述のような場合、オペレー
タが負荷の小さな油圧アクチュエータ側の操作弁の操作
量を減少させて開口面積を小さくし、圧油を流れにくく
することによって、負荷の大きな油圧アクチュエータに
も圧油を供給できるようにして負荷の異なる複数の油圧
アクチュエータを同時に駆動できるようにしていた。つ
まりオペレータがいつも負荷のバランスをとりながら、
複数の操作弁の操作量を異ならせて複数の油圧アクチュ
エータを同時に駆動するという繁雑なことを行ってい
た。
Therefore, in the hydraulic circuit of a hydraulic excavator having a plurality of hydraulic actuators, in the above-mentioned case, the operator reduces the operation amount of the operation valve on the side of the hydraulic actuator with a small load to reduce the opening area, making it difficult for pressure oil to flow. By doing so, it is possible to supply pressure oil to a hydraulic actuator having a large load, and to simultaneously drive a plurality of hydraulic actuators having different loads. In other words, the operator always balances the load,
The complicated operation of driving a plurality of hydraulic actuators at the same time by changing the operation amount of a plurality of operating valves has been performed.

このことを解消する油圧回路としては、例えば特開昭
59−197603号公報に示すものが提案されている。
A hydraulic circuit that solves this problem is disclosed in
The one shown in Japanese Patent Laid-Open No. 59-197603 has been proposed.

かかる油圧回路を模式的に示すと第2図に示すように
なる。
A schematic view of such a hydraulic circuit is shown in FIG.

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と各油圧アクチュエータ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シャト
ル弁6で検出し、その検出した負荷圧を各圧力補償弁5
の第1の受圧部5aに作用し、操作弁2の出口側圧力を圧
力補償弁5の第2の受圧部5bに作用してその負荷圧に見
合う圧力にセットしている。ここでセットするとは、複
数の油圧アクチュエータの中の最も高い負荷圧で、他の
油圧アクチュエータに接続されている圧力補償弁の開口
面積を小さくし、その上流圧(つまり操作弁2の出口
圧)を最も高い負荷圧と同一の圧力にすることである。
That is, a plurality of operating valves 2 are provided in the discharge passage 1a of the hydraulic pump 1, a pressure compensating valve 5 is provided in each circuit 4 that connects each operating valve 2 and each hydraulic actuator 3, and the pressure of each circuit 4, that is, the load. The highest pressure among the pressures is detected by the shuttle valve 6, and the detected load pressure is detected by each pressure compensation valve 5.
Of the operating valve 2 and the second pressure-receiving portion 5b of the pressure compensating valve 5 to set the pressure corresponding to the load pressure. Here, the setting means that the opening area of the pressure compensating valve connected to another hydraulic actuator is made smaller with the highest load pressure among the plurality of hydraulic actuators, and its upstream pressure (that is, the outlet pressure of the operating valve 2). Is to be the same as the highest load pressure.

このようにすることで、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2の出口
側圧力(下流圧)は、最も高い負荷圧と同じ圧力とな
り、また操作弁2の入口側圧力は、共通の油圧ポンプ1
のポンプ圧であるから各操作弁2の開口面積の前後差圧
は、等しくなるので、各操作弁の開口面積に比例した分
流比で各油圧アクチュエータ3に圧油を供給できる。
By doing so, the outlet side pressure (downstream pressure) of each operating valve 2 becomes the same pressure as the highest load pressure when the operating valve 2 is operated at the same time by making the outlet side pressures of the operating valves 2 equal, The pressure on the inlet side of the operating valve 2 is the same as that of the common hydraulic pump 1.
Since the pump pressure is equal to each other, the differential pressure across the opening area of each operation valve 2 becomes equal, so that the pressure oil can be supplied to each hydraulic actuator 3 at a diversion ratio proportional to the opening area of each operation valve.

〔発明が解決しようとする課題〕[Problems to be Solved by the Invention]

第2図に示した従来技術は、複数の油圧アクチュエー
タ3を有する油圧回路において、油圧アクチュエータ3
に作用する負荷の大きさによらず、操作弁2の操作量に
比例した圧油を、複数の油圧アクチュエータ3に供給し
ようとすることを目的とするものであるが、第2図の構
成では、以下の問題点がある。
The conventional technique shown in FIG. 2 is a hydraulic circuit having a plurality of hydraulic actuators 3.
The purpose of the present invention is to supply pressure oil proportional to the operation amount of the operation valve 2 to a plurality of hydraulic actuators 3, regardless of the magnitude of the load acting on the. However, there are the following problems.

第2図において、右に油圧アクチュエータ(シリン
ダ)3を高負荷側、左の油圧アクチュエータ(モータ)
3を低負荷側であるとすると、右の油圧アクチュエータ
3の負荷圧がシャトル弁6で選択されて油圧ポンプ1の
制御装置に導入されるとともに、自らの圧力補償弁(右
側)5と低負荷側の圧力補償弁(左側)5に作用する。
In FIG. 2, the hydraulic actuator (cylinder) 3 is shown on the right side on the high load side, and the hydraulic actuator (motor) on the left side is shown.
Assuming that 3 is on the low load side, the load pressure of the right hydraulic actuator 3 is selected by the shuttle valve 6 and introduced into the control device of the hydraulic pump 1, and at the same time, the pressure compensation valve (right side) 5 and low load It acts on the side pressure compensation valve (left side) 5.

自らの圧力補償弁(右側)5には、圧力補償弁5の開
口を絞る側に、自らの負荷圧P3と弱いバネ力(番号を指
示せず)が作用し、開口を開く側に圧力補償弁5の入口
側圧力P2が作用する。圧力補償弁5には若干の通路抵抗
が存在するため入口側圧力P2と出口側圧力(負荷圧)P3
の関係はP2>P3であるから自らの圧力補償弁5は、 (P2による開き方向の力)=(P3による閉じ開き方向の
力)+(弱いバネ力)+(フローフォース) というバランス状態となり、ほぼ全開に近い状態で流量
Q1の圧油を右の油圧アクチュエータ3(シリンダ)に供
給する。
The pressure compensating valve 5 (right side) of the pressure compensating valve 5 has its own load pressure P 3 and a weak spring force (without indicating the number) acting on the side where the opening of the pressure compensating valve 5 is narrowed, and pressure is applied to the side where the opening is opened. The inlet side pressure P 2 of the compensating valve 5 acts. Since there is some passage resistance in the pressure compensation valve 5, the inlet side pressure P 2 and the outlet side pressure (load pressure) P 3
Since the relation of P 2 > P 3 , the pressure compensating valve 5 of its own is (force in the opening direction by P 2 ) = (force in the closing / opening direction by P 3 ) + (weak spring force) + (flow force) It becomes a balanced state, and the flow rate is almost full
Supply Q1 pressure oil to the right hydraulic actuator 3 (cylinder).

一方、低負荷側の圧力補償弁5には、開口を絞る側に
高負荷側の負荷圧P3が作用するため、圧力補償弁5の開
口は絞られて、その入口側圧P2は結果としてP3の圧力ま
で昇圧する。(より正確には、弱いバネのバネ力分もプ
ラスされる) つまり高負荷側の圧油の流量Q1(Cは常数、a1は操作弁2の開口面積、P1は油圧ポンプ
1の吐出圧力) 低負荷側の圧油の流量Q2は、 (Cは常数、a2は操作弁2の開口面積、P1は油圧ポンプ
1の吐出圧力) となり開口面積a1=a2としても、それぞれの油圧アクチ
ュエータ3への供給流量は、Q1=Q2とならない。
On the other hand, in the pressure compensation valve 5 on the low load side, the load pressure P 3 on the high load side acts on the side that throttles the opening, so the opening of the pressure compensation valve 5 is throttled, and the inlet side pressure P 2 is consequently It boosted to a pressure of P 3. (More accurately, the spring force of the weak spring is also added.) In other words, the flow rate Q 1 of the pressure oil on the high load side is (C is a constant, a 1 is the opening area of the operation valve 2, P 1 is the discharge pressure of the hydraulic pump 1) The flow rate Q 2 of the pressure oil on the low load side is (C is a constant, a 2 is the opening area of the operation valve 2, P 1 is the discharge pressure of the hydraulic pump 1), and even if the opening area is a 1 = a 2 , the supply flow rate to each hydraulic actuator 3 is Q 1 = It doesn't become Q 2 .

すなわち、低負荷側の操作弁2の出口圧力(圧力補償
弁5の入口側圧力)P2は、高負荷側の操作弁2の出口圧
力(圧力補償弁5の入口側圧力)P2とならず、それより
低い高負荷側の圧力補償弁5の出口側圧力(負荷圧)P3
となるため、操作弁2の開口面積が同じでも低負荷側の
油圧アクチュエータ3への供給流量の方が多くなってし
まう。
That is, if the outlet pressure of the operation valve 2 on the low load side (the inlet side pressure of the pressure compensation valve 5) P 2 is the same as the outlet pressure of the operation valve 2 on the high load side (the inlet side pressure of the pressure compensation valve 5) P 2. No pressure, lower than that, the outlet side pressure (load pressure) P 3 of the pressure compensating valve 5 on the high load side.
Therefore, even if the opening area of the operation valve 2 is the same, the flow rate supplied to the hydraulic actuator 3 on the low load side becomes larger.

この問題を解決するため、負荷圧を圧力補償弁5の出
口側の回路4ではなく、圧力補償弁5の入口側(P2部)
で検出するという案もあるが、こうすると自ら(高圧
側)の圧力補償弁5には、開口を開く方向に入口側圧力
P2が、また閉じる方向に入口側圧力P2が作用するため、
自らの圧力補償弁5は開弁できなくなってしまう。
In order to solve this problem, load pressure is applied not to the circuit 4 on the outlet side of the pressure compensation valve 5 but to the inlet side of the pressure compensation valve 5 (P 2 part).
There is also a plan to detect it with this method, but if this is done, the pressure compensating valve 5 on its own (high pressure side) will have pressure on the inlet side in the direction of opening the opening.
Since P 2 acts on the inlet side pressure P 2 in the closing direction again,
The pressure compensation valve 5 of its own cannot be opened.

あるいは、負荷圧として検出する圧力を操作弁2と圧
力補償弁5の間で入口側圧力P2を検出する位置より、圧
力補償弁5に近い側で検出(すなわち負荷圧P3を入口側
圧力P2よりわずかに低い圧力P′として検出)し、自
らの圧力補償弁5が開弁するようにしたとしても、圧力
補償弁5には圧油の通過によるフローフォースが作用す
るため、自らの圧力補償弁5はより開口が絞られる位置
に動いてしまい、その結果P2,P′はより上昇してしま
う。
Alternatively, the pressure detected as the load pressure is detected closer to the pressure compensating valve 5 than the position where the inlet pressure P 2 is detected between the operation valve 2 and the pressure compensating valve 5 (that is, the load pressure P 3 is the inlet pressure P 2). detected) as a slightly lower pressure P '2 from P 2, even 5 themselves of the pressure compensating valves so as to open, to act the flow force due to the passage of the pressure oil in the pressure compensating valve 5, itself The pressure compensating valve 5 is moved to a position where the opening is further narrowed, and as a result, P 2 and P ′ 2 are further raised.

するとP2,P′と負荷圧P3の圧力差は大きくなり、フ
ローフォースは圧力差に応じて大きくなるので圧力補償
弁5はさらに絞られてP2,P′はさらに上昇してしまう
結果となり、高圧側の圧力補償弁5は、本来若干の通過
抵抗で全開に近い状態でいるべきものが絞られて、大き
な圧力差を発生してしまい、アパワーロスを生じてしま
うためこの方式も採用できない。
Then, the pressure difference between P 2 and P ′ 2 and the load pressure P 3 increases, and the flow force increases in accordance with the pressure difference, so the pressure compensating valve 5 is further throttled and P 2 and P ′ 2 further rise. As a result, the pressure compensating valve 5 on the high pressure side, which should have been in a state close to full open by a slight passage resistance, is throttled, causing a large pressure difference and causing a power loss. Cannot be adopted.

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 capable of solving the above-mentioned problems.

〔課題を解決するための手段及び作用〕[Means and Actions for Solving the Problems]

本発明は、油圧ポンプ10の吐出路10aに複数の操作弁1
5を設け、各操作弁15と各油圧アクチュエータ16の接続
回路に圧力補償弁18をそれぞれ設け各圧力補償弁18を第
1受圧部19の圧油で開口面積大方向に押され、第2受圧
部20の圧油で開口面積小方向に押されるものとし、 前記各圧力補償弁18の入口側と出口側を第1負荷圧導
入路29でそれぞれ接続し、この各第1負荷圧導入路29に
おける前記入口側寄りに入口側から出口側への圧油流れ
を阻止するチェック弁28をそれぞれ設け、前記第1負荷
圧導入路29におけるチェック弁28よりも入口側寄りに第
1絞り26の第2絞り27をそれぞれ設け、前記各第1負荷
圧導入路29における第1絞り26と第2絞り27との間を第
2シャトル弁22の入口側に接続し、その第2シャフト弁
22の出口側に回路32を接続し、前記各圧力補償弁18の出
口側にアクチュエータ保持導入路33をそれぞれ接続し、
その各アクチュエータ保持導入路33と前記回路32を各第
1シャトル弁21の入口側にそれぞれ接続すると共に、そ
の各第1シャトル弁21の出口側を各圧力補償弁18の第2
受圧部20にそれぞれ接続し、各圧力補償弁18の第1受圧
部19を各操作弁15の出力側にそれぞれ接続したことを特
徴とする油圧回路である。
The present invention provides a plurality of operation valves 1 in the discharge passage 10a of the hydraulic pump 10.
5, the pressure compensating valve 18 is provided in the connection circuit of each operation valve 15 and each hydraulic actuator 16, and each pressure compensating valve 18 is pushed by the pressure oil of the first pressure receiving portion 19 in the large opening area direction, and the second pressure receiving It is assumed that the pressure oil of the portion 20 pushes the opening area in a small direction, and the inlet side and the outlet side of each of the pressure compensating valves 18 are connected by a first load pressure introducing passage 29, and each of the first load pressure introducing passages 29 is connected. Check valves 28 for blocking the flow of pressure oil from the inlet side to the outlet side are respectively provided near the inlet side of the first throttle valve 26 of the first throttle valve 26 in the first load pressure introduction path 29 closer to the inlet side than the check valve 28. Two throttles 27 are provided respectively, and the first load pressure introducing path 29 is connected between the first throttle 26 and the second throttle 27 on the inlet side of the second shuttle valve 22, and the second shaft valve thereof is connected.
The circuit 32 is connected to the outlet side of 22, and the actuator holding introduction path 33 is connected to the outlet side of each of the pressure compensation valves 18,
The respective actuator holding and introducing passages 33 and the circuit 32 are respectively connected to the inlet sides of the respective first shuttle valves 21, and the outlet sides of the respective first shuttle valves 21 are connected to the second side of the respective pressure compensation valves 18.
The hydraulic circuit is characterized in that it is connected to the pressure receiving portion 20 and the first pressure receiving portion 19 of each pressure compensation valve 18 is connected to the output side of each operation valve 15.

本発明の油圧回路においては、圧力補償弁18の入口側
圧力と出口側圧力との中間圧力を負荷圧として検出して
いることにより、低負荷側の圧力補償弁18の第1受圧部
19の圧力と第2受圧部20の圧力との差圧は小さくなって
低負荷側の油圧アクチュエータ16の流量と高負荷側の油
圧アクチュエータ16の流量との差が小さくなり、高負荷
側の圧力補償弁18の第1受圧部19の圧力は第2受圧部の
圧力よりも必ず高くなり、その圧力補償弁18がほぼ全開
に近い状態に開弁する。
In the hydraulic circuit of the present invention, since the intermediate pressure between the inlet side pressure and the outlet side pressure of the pressure compensation valve 18 is detected as the load pressure, the first pressure receiving portion of the low load side pressure compensation valve 18 is detected.
The pressure difference between the pressure of 19 and the pressure of the second pressure receiving portion 20 becomes small, and the difference between the flow rate of the hydraulic actuator 16 on the low load side and the flow rate of the hydraulic actuator 16 on the high load side becomes small, and the pressure on the high load side becomes small. The pressure of the first pressure receiving portion 19 of the compensating valve 18 is always higher than the pressure of the second pressure receiving portion, and the pressure compensating valve 18 opens in a state of being almost fully opened.

また、油圧アクチュエータ16のアクチュエータ保持圧
と負荷圧が第1シャトル弁21で比較されて高い方の圧力
が圧力補償弁18の第2受圧部20に供給することから、操
作弁15を中立位置とした圧力補償弁18の第2受圧部20に
はそのアクチュエータ保持圧が供給されるので、その操
作弁15を操作して油圧アクチュエータ16に圧油を供給す
る時に圧力補償弁18の開口面積が小さく、油圧ポンプ10
の圧力が速く昇圧する。
Further, the actuator holding pressure of the hydraulic actuator 16 and the load pressure are compared by the first shuttle valve 21, and the higher pressure is supplied to the second pressure receiving portion 20 of the pressure compensating valve 18, so that the operation valve 15 is set to the neutral position. Since the actuator holding pressure is supplied to the second pressure receiving portion 20 of the pressure compensating valve 18, the opening area of the pressure compensating valve 18 is small when the operating valve 15 is operated to supply pressure oil to the hydraulic actuator 16. Hydraulic pumps 10
The pressure rises quickly.

〔実 施 例〕〔Example〕

第1図に示すように、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。
As shown in FIG. 1, the hydraulic pump 10 is a variable displacement type 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. The swash plate 11 has a large-diameter piston 12 Tilts in the capacity decreasing direction, and tilts in the capacity increasing direction with the small diameter piston 13.

前記大径ピストン12の受圧室12a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に接続している。
The pressure receiving chamber 12a of the large-diameter piston 12 is connected to and cut off from the discharge passage 10a of the hydraulic pump 10 by the switching valve 14, and the small-diameter piston 13
The pressure receiving chamber 13a is connected to the discharge passage 10a.

前記油圧ポンプ10の吐出路10aには複数の操作弁15が
設けてあり、各操作弁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受圧弁19の圧油で開口面積が大きくな
る方向に押され第2受圧部20の圧油で開口面積が小さく
なる方向に押される構成としてあり、第1受圧部19は圧
力補償弁18の入口側に接続されて入口側圧力が供給さ
れ、第2受圧部20は第1・第2シャトル弁21,22を経て
各負荷圧導入路23に接続されて最も高い負荷圧又は後述
するアクチュエータ保持圧導入路33によりアクチュエー
タ保持圧が供給される。
A plurality of operating valves 15 are provided in the discharge passage 10a of the hydraulic pump 10, and a pressure compensating valve 18 is provided in a circuit 17 connecting each operating valve 15 and the hydraulic actuator 16, and the pressure compensating valve 18 is The pressure oil of the first pressure receiving valve 19 pushes the opening area in a larger direction and the pressure oil of the second pressure receiving portion 20 pushes the opening area in a smaller direction. The inlet pressure is supplied to the second pressure receiving portion 20, and the second pressure receiving portion 20 is connected to the respective load pressure introducing passages 23 via the first and second shuttle valves 21 and 22 and has the highest load pressure or the actuator described later. The holding pressure introduction passage 33 supplies the actuator holding pressure.

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24と前記負荷圧でドレーン方向に押されて、吐
出圧力P1と負荷圧力PLSの差圧(P1−PLS)がバネ22で設
定したバネ力よりも大きくなると、切換弁14は連通位置
に切換わり大径ピストン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と負荷圧
PLSの差圧(P1−PLS)がバネ22で設定したバネ力よりも
小さくなると、切換弁14はドレーン位置に切換わり大径
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。
The switching valve 14 is pushed in the communicating direction by the pressure in the discharge passage 10a, and is pushed in the drain direction by the spring 24 and the load pressure, and the differential pressure between the discharge pressure P 1 and the load pressure PLS (P 1 -P LS ). Becomes larger than the spring force set by the spring 22, the switching valve 14 switches to the communicating position, supplies the discharge pressure to the pressure receiving chamber 12a of the large-diameter piston 12, tilts the swash plate 11 in the capacity decreasing direction, and P 1 and load pressure
When the differential pressure of PLS (P 1 -P LS ) becomes smaller than the spring force set by the spring 22, the switching valve 14 switches to the drain position and flows out from the pressure receiving chamber 12a of the large diameter piston 12 to the tank side and the swash plate. Tilt 11 in the capacity increasing direction.

前記操作弁15はパイロット制御弁25よりのパイロット
圧油に比例して開口面積が増大する方向に操作され、そ
のパイロット圧油はレバー25aの操作ストロークに比例
する。
The operation valve 15 is operated in a direction in which the opening area increases in proportion to the pilot pressure oil from the pilot control valve 25, and the pilot pressure oil is proportional to the operation stroke of the lever 25a.

前記負荷圧導入路23は圧力補償弁18の入口側と出口側
を接続し、かつ第1・第2絞り26,27とチェック弁28を
有する第1負荷圧導入路29と、この第1負荷圧導入路29
における第1絞り26と第2絞り27との間を操作弁15の負
荷圧ポート15aに連通する第2負荷圧導入路30と、操作
弁15の負荷圧ポート15aと前記第2シャトル弁22を接続
する第3負荷圧導入路31より成り、第2シャトル弁22の
出口側が回路32で第1シャトル弁21の一方の入口側に接
続し、かつ他方の入口側がアクチュエータ保持圧導入路
33で圧力補償弁18の出口側に接続していると共に、その
第1シャトル弁21の出口側が第2受圧部20に接続してい
る。
The load pressure introducing passage 23 connects the inlet side and the outlet side of the pressure compensating valve 18, and has a first load pressure introducing passage 29 having first and second throttles 26, 27 and a check valve 28, and the first load. Pressure introduction path 29
The second load pressure introducing passage 30 communicating between the first throttle 26 and the second throttle 27 in the load pressure port 15a of the operation valve 15, the load pressure port 15a of the operation valve 15 and the second shuttle valve 22. The third load pressure introducing passage 31 is connected, the outlet side of the second shuttle valve 22 is connected to one inlet side of the first shuttle valve 21 in the circuit 32, and the other inlet side is an actuator holding pressure introducing passage.
33 is connected to the outlet side of the pressure compensating valve 18, and the outlet side of the first shuttle valve 21 is connected to the second pressure receiving portion 20.

前記操作弁15の負荷圧ポート15aは中立位置Nの時に
タンクに連通し、第1・第2圧油供給位置I,IIの時にタ
ンクと遮断して第2負荷圧導入路30と第3負荷圧導入路
31を連通する。
The load pressure port 15a of the operation valve 15 communicates with the tank at the neutral position N, and is disconnected from the tank at the first and second pressure oil supply positions I and II, and the second load pressure introducing passage 30 and the third load Pressure introduction path
Connect 31.

次に作動を説明する。 Next, the operation will be described.

複数の操作弁15を第1圧油供給位置Iに切換えて複数
の油圧アクチュエータ16に圧油を供給する時を例として
説明する。
An example will be described in which the plurality of operation valves 15 are switched to the first pressure oil supply position I to supply the pressure oil to the plurality of hydraulic actuators 16.

操作弁15の負荷圧ポート15aがタンクと遮断して第2
負荷圧導入路30と第3負荷圧導入路31を連通するので、
圧力補償弁18の入口側圧力と出口側圧力との中間圧が負
荷圧PLSとして第2シャトル弁22の入口側に流入し、複
数の油圧アクチュエータ16の各負荷圧を比較して最高負
荷圧を回路32に出力し、その最高負荷圧が第1シャトル
弁21より各圧力補償弁18の第2受圧部20に供給される。
The load pressure port 15a of the operating valve 15 shuts off from the tank
Since the load pressure introducing passage 30 and the third load pressure introducing passage 31 are communicated with each other,
The intermediate pressure between the inlet side pressure and the outlet side pressure of the pressure compensating valve 18 flows into the inlet side of the second shuttle valve 22 as the load pressure P LS , and the load pressures of the plurality of hydraulic actuators 16 are compared to determine the maximum load pressure. Is output to the circuit 32, and the maximum load pressure is supplied from the first shuttle valve 21 to the second pressure receiving portion 20 of each pressure compensation valve 18.

このようであるから、右の油圧アクチュエータ(シリ
ンダ)16を高負荷側、左の油圧アクチュエータ(モー
タ)16を低負荷側であるとすると、右の圧力補償弁18の
入口側圧力P2と出口側圧力P3の中間の圧力P4が負荷圧と
して検出され、この中間の圧力P4は左右の圧力補償弁18
の第2受圧部20にそれぞれ作用する。
Therefore, assuming that the right hydraulic actuator (cylinder) 16 is on the high load side and the left hydraulic actuator (motor) 16 is on the low load side, the inlet pressure P 2 and the outlet of the right pressure compensating valve 18 are An intermediate pressure P 4 of the side pressure P 3 is detected as a load pressure, and this intermediate pressure P 4 is applied to the left and right pressure compensation valves 18
To the second pressure receiving portion 20 of each.

このために、高負荷側(右側)の圧油の流量Q1は、 (Cは常数、a1は操作弁2の開口面積、P1は油圧ポンプ
1の吐出圧力) 低負荷側(左側)の圧油の流量Q2は、 (Cは常数、a2は操作弁2の開口面積、P1は油圧ポンプ
1の吐出圧力) となる。
For this reason, the flow rate Q 1 of the pressure oil on the high load side (right side) is (C is a constant number, a 1 is the opening area of the operation valve 2, P 1 is the discharge pressure of the hydraulic pump 1) The flow rate Q 2 of the pressure oil on the low load side (left side) is (C is a constant, a 2 is an opening area of the operation valve 2, and P 1 is a discharge pressure of the hydraulic pump 1).

ここで、前記の中間の圧力P4は入口側圧力P2より低く
出口側圧力P3より高いので(P1−P4)は(P1−P3)より
も小さくなり、低負荷側の流量Q2は従来よりも少ないか
ら、左右の操作弁2の開口面積が同じ場合に高負荷側の
流量Q1と低負荷側の流量Q2との差が従来よりも小さくな
る。
Here, since the intermediate pressure P 4 is lower than the inlet pressure P 2 and higher than the outlet pressure P 3 , (P 1 −P 4 ) becomes smaller than (P 1 −P 3 ), and the low load side Since the flow rate Q 2 is smaller than before, the difference between the flow rate Q 1 on the high load side and the flow rate Q 2 on the low load side becomes smaller than before when the opening areas of the left and right operation valves 2 are the same.

また、高負荷側の圧力補償弁18の第1受圧部19には入
口側圧力P2が作用し、第2受圧部20には中間の圧力P4
作用し、P2>P4であるから圧力補償弁5は開弁できる。
In addition, the inlet pressure P 2 acts on the first pressure receiving portion 19 of the pressure compensation valve 18 on the high load side, and the intermediate pressure P 4 acts on the second pressure receiving portion 20, so that P 2 > P 4 . Therefore, the pressure compensation valve 5 can be opened.

また、高負荷側の圧力補償弁5がフローフォースによ
り開口を絞られる位置に動くと、入口側圧力P2は若干高
くなるが、出口側圧力P3は一定であるために、中間の圧
力P4が若干高くなる程度であり、結局高負荷側の圧力補
償弁5はほぼ全開に近い状態なり、パワーロスが発生し
ない。
Further, when the pressure compensation valve 5 on the high load side moves to a position where the opening is throttled by the flow force, the inlet side pressure P 2 becomes slightly higher, but the outlet side pressure P 3 is constant, so the intermediate pressure P 2 4 is slightly higher, and the pressure compensating valve 5 on the high load side is in a state of being almost fully opened, so that power loss does not occur.

各操作弁15が中立位置Nで油圧アクチュエータ16に保
持圧がある時。
When each operating valve 15 is in the neutral position N and the hydraulic actuator 16 has a holding pressure.

操作弁15の負荷ポート15aがタンクに連通するが、第
1負荷圧導入路29におけるチェック弁28より上流側には
油圧アクチュエータ16の保持圧が発生し、その油圧アク
チュエータ16の保持圧はアクチュエータ保持圧導入路33
より第1シャトル弁21に流入し、この時の負荷圧導入路
23の負荷圧はゼロであるからアクチュエータ保持圧が圧
力補償弁18の第2受圧部20に供給され、圧力補償弁18の
開口面積は小さくなっている。
Although the load port 15a of the operation valve 15 communicates with the tank, the holding pressure of the hydraulic actuator 16 is generated on the upstream side of the check valve 28 in the first load pressure introducing path 29, and the holding pressure of the hydraulic actuator 16 is held by the actuator. Pressure introduction path 33
From the first shuttle valve 21, and the load pressure introduction path at this time
Since the load pressure of 23 is zero, the actuator holding pressure is supplied to the second pressure receiving portion 20 of the pressure compensating valve 18, and the opening area of the pressure compensating valve 18 is small.

このようであるから、操作弁2を操作して油圧アクチ
ュエータ16に圧油を供給する際には、その圧力補償弁18
の開口面積が小さく、油圧ポンプ10の圧力が速く昇圧す
るから応答性が優れたものとなる。
Because of this, when the operating valve 2 is operated to supply pressure oil to the hydraulic actuator 16, the pressure compensating valve 18
Has a small opening area, and the pressure of the hydraulic pump 10 rises quickly, resulting in excellent responsiveness.

〔発明の効果〕〔The invention's effect〕

圧力補償弁18の入口側圧力と出口側圧力の中間の圧力
を油圧アクチュエータ16の負荷圧として検出し、各油圧
アクチュエータの最も高い負荷圧を各圧力補償弁18の第
2受圧部20に供給するので、複数の油圧アクチュエータ
16を同時に操作した時に低負荷側の圧力補償弁18の入口
側圧力と油圧ポンプの吐出圧力との差圧は小さくなる
し、高負荷側の圧力補償弁18の第1受圧部19の圧力は第
2受圧部20の圧力よりも必ず高くなる。
An intermediate pressure between the inlet side pressure and the outlet side pressure of the pressure compensating valve 18 is detected as the load pressure of the hydraulic actuator 16, and the highest load pressure of each hydraulic actuator is supplied to the second pressure receiving portion 20 of each pressure compensating valve 18. So multiple hydraulic actuators
When 16 are operated simultaneously, the differential pressure between the inlet side pressure of the low load side pressure compensating valve 18 and the discharge pressure of the hydraulic pump becomes small, and the pressure of the first pressure receiving portion 19 of the high load side pressure compensating valve 18 becomes It is always higher than the pressure of the second pressure receiving portion 20.

したがって、複数の油圧アクチュエータを同時に操作
した時に高負荷側の油圧アクチュエータの流量と低負荷
側の油圧アクチュエータの流量の差が小さくなるし、高
負荷圧側の圧力補償弁18がほぼ全開に近い状態に開弁し
てパワーロスが生じることもない。
Therefore, when a plurality of hydraulic actuators are operated simultaneously, the difference between the flow rate of the hydraulic actuator on the high load side and the flow rate of the hydraulic actuator on the low load side becomes small, and the pressure compensation valve 18 on the high load pressure side becomes almost full open. There is no power loss due to valve opening.

また、油圧アクチュエータ16のアクチュエータ保持圧
と負荷圧が第1シャトル弁21で比較されて高い方の圧力
が圧力補償弁18の第2受圧部20に供給されるから、操作
弁15を中立位置とした時に圧力補償弁18の第2受圧部20
にはそのアクチュエータ保持圧が供給されるので、その
操作弁15を操作して油圧アクチュエータ16に圧油を供給
する時に圧力補償弁18の開口面積が小さく、油圧ポンプ
10の圧力が速く昇圧し、応答性が向上する。
Further, the actuator holding pressure of the hydraulic actuator 16 and the load pressure are compared by the first shuttle valve 21, and the higher pressure is supplied to the second pressure receiving portion 20 of the pressure compensating valve 18, so that the operation valve 15 is set to the neutral position. The second pressure receiving portion 20 of the pressure compensating valve 18
Since the actuator holding pressure is supplied to the hydraulic pump, the opening area of the pressure compensating valve 18 is small when the operating valve 15 is operated to supply pressure oil to the hydraulic actuator 16.
The pressure of 10 rises quickly and the responsiveness is improved.

【図面の簡単な説明】[Brief description of drawings]

第1図は本発明の実施例を示す油圧回路図、第2図は従
来例の油圧回路図である。 10は油圧ポンプ、10aは吐出路、15は操作弁、16は油圧
アクチュエータ、17は回路、18は圧力補償弁、19,20は
第1・第2受圧部、21,23は第1・第2シャトル弁、23
は負荷圧導入路、26,27は第1・第2絞り、28はチェッ
ク弁、29は第1負荷圧導入路、30は第2負荷圧導入路、
31は第3負荷圧導入路、32は回路、33はアクチュエータ
保持圧導入路。
FIG. 1 is a hydraulic circuit diagram showing an embodiment of the present invention, and FIG. 2 is a hydraulic circuit diagram of a conventional example. Reference numeral 10 is a hydraulic pump, 10a is a discharge passage, 15 is an operation valve, 16 is a hydraulic actuator, 17 is a circuit, 18 is a pressure compensating valve, 19 and 20 are first and second pressure receiving portions, and 21 and 23 are first and second. 2 shuttle valves, 23
Is a load pressure introducing path, 26 and 27 are first and second throttles, 28 is a check valve, 29 is a first load pressure introducing path, 30 is a second load pressure introducing path,
Reference numeral 31 is a third load pressure introducing passage, 32 is a circuit, and 33 is an actuator holding pressure introducing passage.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 山下 光治 神奈川県川崎市川崎区中瀬3―20―1 株式会社小松製作所川崎工場内 (72)発明者 篠崎 晋一 神奈川県川崎市川崎区中瀬3―20―1 株式会社小松製作所川崎工場内 (56)参考文献 特開 昭59−197603(JP,A) 特開 昭63−9703(JP,A) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Yamashita 3-20-1 Nakase, Kawasaki-ku, Kawasaki-shi, Kanagawa Komatsu Ltd. Kawasaki Plant (72) Inventor Shinichi Shinozaki Nakase-ku, Kawasaki-ku, Kanagawa 3-20 ―1 Komatsu Ltd. Kawasaki Plant (56) References JP 59-197603 (JP, A) JP 63-9703 (JP, A)

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】油圧ポンプ10の吐出路10aに複数の操作弁1
5を設け、各操作弁15と各油圧アクチュエータ16の接続
回路に圧力補償弁18をそれぞれ設け、各圧力補償弁18を
第1受圧部19の圧油で開口面積大方向に押され、第2受
圧部20の圧油で開口面積小方向に押されるものとし、 前記各圧力補償弁18の入口側と出口側を第1負荷圧導入
路29でそれぞれ接続し、この各第1負荷圧導入路29にお
ける前記入口側寄りに入口側から出口側への圧油流れを
阻止するチェック弁28をそれぞれ設け、前記各第1負荷
圧導入路29におけるチェック弁28よりも入口側寄りに第
1絞り26と第2絞り27をそれぞれ設け、前記各第1負荷
圧導入路29における第1絞り26と第2絞り27との間を第
2シャトル弁22の入口側に接続し、その第2シャトル弁
22の出口側に回路32を接続し、前記各圧力補償弁18の出
口側にアクチュエータ保持圧導入路33をそれぞれ接続
し、その各アクチュエータ保持圧導入路33と前記回路32
を各第1シャトル弁21の入口側にそれぞれ接続すると共
に、その各第1シャトル弁21の出口側を各圧力補償弁18
の第2受圧部20にそれぞれ接続し、各圧力補償弁18の第
1受圧部19を各操作弁15の出力側にそれぞれ接続したこ
とを特徴とする油圧回路。
1. A plurality of operating valves 1 in a discharge passage 10a of a hydraulic pump 10.
5, the pressure compensating valve 18 is provided in the connection circuit of each operation valve 15 and each hydraulic actuator 16, and each pressure compensating valve 18 is pushed in the large opening area direction by the pressure oil of the first pressure receiving portion 19, It is assumed that the pressure oil of the pressure receiving portion 20 is pushed in the direction of the small opening area, and the inlet side and the outlet side of each of the pressure compensating valves 18 are connected by the first load pressure introducing passages 29, respectively. Check valves 28 for blocking the flow of pressure oil from the inlet side to the outlet side are provided near the inlet side at 29, and the first throttle 26 is provided closer to the inlet side than the check valve 28 at each of the first load pressure introducing paths 29. And a second throttle 27 are respectively provided, and the first load pressure introducing passage 29 is connected between the first throttle 26 and the second throttle 27 on the inlet side of the second shuttle valve 22.
A circuit 32 is connected to the outlet side of 22 and an actuator holding pressure introducing passage 33 is connected to the outlet side of each pressure compensating valve 18, and each actuator holding pressure introducing passage 33 and the circuit 32 are connected.
Are connected to the inlet side of each first shuttle valve 21, and the outlet side of each first shuttle valve 21 is connected to each pressure compensation valve 18
And a first pressure receiving portion 19 of each pressure compensating valve 18 is connected to an output side of each operation valve 15, respectively.
JP2122956A 1990-05-15 1990-05-15 Hydraulic circuit Expired - Fee Related JP2556999B2 (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
JP2122956A JP2556999B2 (en) 1990-05-15 1990-05-15 Hydraulic circuit
DE69120818T DE69120818T2 (en) 1990-05-15 1991-05-15 HYDRAULIC SYSTEM
PCT/JP1991/000641 WO1991018212A1 (en) 1990-05-15 1991-05-15 Hydraulic system
KR1019910701937A KR920702755A (en) 1990-05-15 1991-05-15 Hydraulic system
EP95103115A EP0657656B1 (en) 1990-05-15 1991-05-15 Hydraulic apparatus
US07/793,395 US5271227A (en) 1990-05-15 1991-05-15 Hydraulic apparatus with pressure compensating valves
EP91909094A EP0536398B1 (en) 1990-05-15 1991-05-15 Hydraulic system
DE69132071T DE69132071T2 (en) 1990-05-15 1991-05-15 Hydraulic system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2122956A JP2556999B2 (en) 1990-05-15 1990-05-15 Hydraulic circuit

Publications (2)

Publication Number Publication Date
JPH0419410A JPH0419410A (en) 1992-01-23
JP2556999B2 true JP2556999B2 (en) 1996-11-27

Family

ID=14848790

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2122956A Expired - Fee Related JP2556999B2 (en) 1990-05-15 1990-05-15 Hydraulic circuit

Country Status (1)

Country Link
JP (1) JP2556999B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2579202Y2 (en) * 1992-04-10 1998-08-20 株式会社小松製作所 Operating valve with pressure compensation valve

Also Published As

Publication number Publication date
JPH0419410A (en) 1992-01-23

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