JPH032722Y2 - - Google Patents
Info
- Publication number
- JPH032722Y2 JPH032722Y2 JP1985135597U JP13559785U JPH032722Y2 JP H032722 Y2 JPH032722 Y2 JP H032722Y2 JP 1985135597 U JP1985135597 U JP 1985135597U JP 13559785 U JP13559785 U JP 13559785U JP H032722 Y2 JPH032722 Y2 JP H032722Y2
- Authority
- JP
- Japan
- Prior art keywords
- pilot
- control valve
- valve
- pressure
- port
- 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
Links
- 239000003921 oil Substances 0.000 description 53
- 230000007935 neutral effect Effects 0.000 description 15
- 239000010720 hydraulic oil Substances 0.000 description 11
- 238000006073 displacement reaction Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000035939 shock Effects 0.000 description 4
- 230000007547 defect Effects 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B9/00—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member
- F15B9/02—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type
- F15B9/08—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by valves affecting the fluid feed or the fluid outlet of the servomotor
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Operation Control Of Excavators (AREA)
- Safety Valves (AREA)
- Fluid-Pressure Circuits (AREA)
- Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
Description
【考案の詳細な説明】
（産業上の利用分野）
本考案は油圧シヨベル等の油圧機械のアクチユ
エータを駆動制御する方向切換弁をパイロツト圧
で駆動するための方向切換弁駆動油圧回路係り、
特に当該アクチユエータの負荷がが慣性体である
場合に好適な方向切換弁駆動油圧回路に関する。[Detailed description of the invention] (Field of industrial application) The present invention relates to a directional valve drive hydraulic circuit for driving a directional valve using pilot pressure to drive and control an actuator of a hydraulic machine such as a hydraulic excavator.
In particular, the present invention relates to a directional control valve drive hydraulic circuit suitable when the load on the actuator is an inertial body.
各種油圧機械には所要の油圧アクチユエータが
備えられ、これらの油圧アクチユエータを適宜駆
動することにより当該油圧機械の所期の動作を達
成せしめる。ところで、上記油圧アクチユエータ
の駆動は、それぞれの油圧アクチユエータの方向
切換弁により制御され、これら方向切換弁は操作
レバーの操作により駆動される。近年、方向切換
弁をパイロツト圧を用いて駆動するパイロツト式
操作装置が一般に使用されている。このようにパ
イロツト圧を用いた方向切換弁駆動油圧回路を、
油圧シヨベルにおける使用例を例示して説明す
る。
Various hydraulic machines are equipped with required hydraulic actuators, and by appropriately driving these hydraulic actuators, the desired operation of the hydraulic machine is achieved. Incidentally, the driving of the hydraulic actuators is controlled by the directional switching valves of the respective hydraulic actuators, and these directional switching valves are driven by operating a control lever. In recent years, pilot operating devices that drive directional switching valves using pilot pressure have generally been used. In this way, the directional valve drive hydraulic circuit using pilot pressure is
An example of use in a hydraulic excavator will be explained.
第５図および第６図は油圧シヨベルの概略構成
の側面図および平面図である。図で、１は上部旋
回体、２は下部走行体、３は上部旋回体１を旋回
させる旋回モータ（油圧モータ）、４，６はそれ
ぞれ下部走行体２の左右の履帯、５，７はそれぞ
れ下部走行体２を走行させる左右の走行モータ
（油圧モータ）である。８は上部旋回体１に回動
自在に支持されたブーム、９はブーム８に回動自
在に支持されたアーム、１０はアーム９に回動自
在に支持されたバケツトである。１１はブームシ
リンダ、１２はアームシリンダ、１３はバケツト
シリンダであり、それぞれブーム８、アーム９、
バケツト１０を駆動する。 FIGS. 5 and 6 are a side view and a plan view of the schematic structure of the hydraulic excavator. In the figure, 1 is an upper rotating body, 2 is a lower traveling body, 3 is a swing motor (hydraulic motor) that turns the upper rotating body 1, 4 and 6 are left and right tracks of the lower traveling body 2, respectively, and 5 and 7 are respectively These are left and right travel motors (hydraulic motors) that make the lower traveling body 2 travel. 8 is a boom rotatably supported by the upper revolving structure 1; 9 is an arm rotatably supported by the boom 8; and 10 is a bucket rotatably supported by the arm 9. 11 is a boom cylinder, 12 is an arm cylinder, and 13 is a bucket cylinder, each of which has a boom 8, an arm 9, and a bucket cylinder.
The bucket cart 10 is driven.
第７図は第５図に示す走行モータの方向切換弁
の駆動油圧回路の回路図である。図で、１５は油
圧シヨベルに搭載された油圧ポンプ、１６は油圧
ポンプ１５から走行モータ５への圧油の供給を制
御する方向切換弁、１６ａ，１６ｂは方向切換弁
１６の左右両側に設けられたパイロツト室、１７
は作動油タンク１８ａ，１８ｂは方向切換弁１６
と走行モータ５を接続する左右の主管路、１９は
主管路１８ａ，１８ｂに接続されたクロスオーバ
リリーフ弁である。 FIG. 7 is a circuit diagram of a drive hydraulic circuit for the directional control valve of the travel motor shown in FIG. 5. In the figure, 15 is a hydraulic pump mounted on a hydraulic excavator, 16 is a directional switching valve that controls the supply of pressure oil from the hydraulic pump 15 to the travel motor 5, and 16a and 16b are provided on both left and right sides of the directional switching valve 16. Pilot cabin, 17
The hydraulic oil tanks 18a and 18b are the directional control valve 16.
19 is a crossover relief valve connected to the main pipes 18a and 18b.
２１はパイロツト油圧ポンプ、２２はパイロツ
ト油圧ポンプ２１の最高吐出圧力を規定するリリ
ーフ弁、２３は走行モータ５の駆動を操作する操
作レバー、２４は操作レバー２３により切換えら
れるパイロツト弁、２５ａ，２５ｂはパイロツト
弁２４の２つの室、２６ａ，２６ｂは各室２５
ａ，２５ｂに挿入されたスプール、２７ａ，２７
ｂは各スプール２６ａ，２６ｂに連結されたロツ
ドである。２８はパイロツト油圧ポンプ２１と各
室２５ａ，２５ｂとを連結するための通路、２９
は作動油タンク１７と各室２５ａ，２５ｂとを連
結するための通路、３０ａ，３０ｂは方向切換弁
１６と各室２５ａ，２５ｂとを連結するための通
路である。３１ａ，３１ｂはそれぞれ通路３０
ａ，３０ｂと方向切換弁１６のパイロツト室１６
ａ，１６ｂとを連結するパイロツト管路である。 21 is a pilot hydraulic pump, 22 is a relief valve that regulates the maximum discharge pressure of the pilot hydraulic pump 21, 23 is an operating lever that operates the drive of the travel motor 5, 24 is a pilot valve that is switched by the operating lever 23, and 25a and 25b are The two chambers 26a and 26b of the pilot valve 24 correspond to each chamber 25.
Spools inserted into a, 25b, 27a, 27
b is a rod connected to each spool 26a, 26b. 28 is a passage for connecting the pilot hydraulic pump 21 and each chamber 25a, 25b; 29;
30a, 30b are passages for connecting the hydraulic oil tank 17 and each chamber 25a, 25b, and 30a, 30b are passages for connecting the directional control valve 16 and each chamber 25a, 25b. 31a and 31b are passages 30, respectively.
a, 30b and the pilot chamber 16 of the directional control valve 16
16b.
ここで、第７図に示す油圧回路の動作を第８図
ａ〜ｃに示すタイムチヤートを参照しながら説明
する。今、油圧シヨベルのオペレータが時刻t1に
おいて操作レバー２３を図の左側に倒すと、スプ
ール２６ａが移動し、パイロツト油圧ポンプ２１
からの圧油は通路２８、室２５ａ、通路３０ａ、
管路３１ａを経て方向切換弁１６のパイロツト室
１６ａに供給される。これにより、方向切換弁１
６は第８図ｂに示すように時刻t3において作動を
開始し、時刻t4において最大変位量となる。操作
レバー２３が操作されてから方向切換弁１６が駆
動開始するまでの応答遅れはパイロツト管路３１
ａ等の中の作動油の圧縮性により生じ、その時間
（t3−t1）は、パイロツト油圧ポンプ２１の吐出
油が方向切換弁１６のパイロツト室１６ａに供給
されるときの圧損、作動油ホース等の圧縮性によ
り定まる。第８図ｂに示すように、方向切換弁１
６が中立位置から左側位置に駆動されると、油圧
ポンプ１５の圧油は方向切換弁１６、主管路１８
ｂを介して走行モータ５へ供給され、走行モータ
５の両側主管路間には第８図ｃに示すように有効
圧力が生じ、走行モータ５は回転を開始し、以後
通常回転を継続して油圧シヨベルを走行させる。 Here, the operation of the hydraulic circuit shown in FIG. 7 will be explained with reference to the time charts shown in FIGS. 8a to 8c. Now, when the operator of the hydraulic excavator tilts the operating lever 23 to the left side in the figure at time t1 , the spool 26a moves and the pilot hydraulic pump 21
Pressure oil from the passage 28, chamber 25a, passage 30a,
It is supplied to the pilot chamber 16a of the directional control valve 16 via the conduit 31a. As a result, the directional control valve 1
6 starts operating at time t3 , as shown in FIG. 8b, and reaches its maximum displacement at time t4 . The response delay from when the operating lever 23 is operated until the directional control valve 16 starts driving is due to the pilot conduit 31.
The time (t 3 - t 1 ) is the pressure drop when the discharge oil of the pilot hydraulic pump 21 is supplied to the pilot chamber 16a of the directional control valve 16, the hydraulic oil Determined by the compressibility of the hose, etc. As shown in FIG. 8b, the directional control valve 1
6 is driven from the neutral position to the left position, the pressure oil of the hydraulic pump 15 flows through the directional control valve 16 and the main pipe 18.
b, and effective pressure is generated between the main pipes on both sides of the travel motor 5 as shown in FIG. Run the hydraulic excavator.
時刻t5に至り、油圧シヨベルを停止すべくオペ
レータが操作レバー２３を中立位置に戻すと、パ
イロツト弁２４の室２５ａは通路２８と遮断状
態、通路２９と導通状態となり、パイロツト室１
６ａはパイロツト管路３１ａおよび弁２４を介し
て作動油タンク１７と導通する。したがつて、方
向切換弁１６は第８図ｂに示すように、時刻t5か
ら僅かに遅れた時刻t6で戻り作動を開始し、時刻
t7で中立位置となる。この場合の方向切換弁１６
の戻り速度は、方向切換弁１６の両端に設けられ
ているばねのばね力、およびパイロツト管路３１
ａとパイロツト弁２４に生じる戻り圧損により定
まる。 At time t5 , when the operator returns the operating lever 23 to the neutral position to stop the hydraulic excavator, the chamber 25a of the pilot valve 24 is cut off from the passage 28 and communicated with the passage 29, so that the pilot chamber 1
6a communicates with the hydraulic oil tank 17 via the pilot line 31a and the valve 24. Therefore, as shown in FIG. 8b, the directional control valve 16 starts its return operation at time t6 , which is slightly delayed from time t5 .
Neutral position at t 7 . Directional switching valve 16 in this case
The return speed is determined by the spring force of the springs provided at both ends of the directional control valve 16 and the pilot line
a and the return pressure loss occurring in the pilot valve 24.
方向切換弁１６の戻り動作が開始されると、第
８図ｃに示すように走行モータ５の両端の圧力の
差は急速に減少する。そして、走行モータ５の慣
性は大きいので、その両端の圧力差が０になつて
も走行モータ５は停止せずに回転を続け、主管路
１８ｂの油を吸い込んで主管路１８ａへ吐出す
る。このとき、方向切換弁１６はほぼ遮断状態に
あるので、主管路１８ａの油圧（主管路１８ｂ側
からみて負の油圧）は第８図ｃに示すように急速
に上昇し、これがブレーキ圧となつて走行モータ
５は停止する。主管路１８ａの圧力の上昇により
クロスオーバリリーフ弁１９が作動し、主管路１
８ａの油は主管路１８ｂに戻され、時刻t8におい
て走行モータ５の両端の圧力はほぼ０となる。 When the return operation of the directional control valve 16 is started, the difference in pressure between both ends of the travel motor 5 rapidly decreases as shown in FIG. 8c. Since the inertia of the travel motor 5 is large, the travel motor 5 continues to rotate without stopping even when the pressure difference between both ends becomes zero, sucking oil from the main pipe 18b and discharging it to the main pipe 18a. At this time, since the directional control valve 16 is almost in a closed state, the oil pressure in the main pipe 18a (negative oil pressure when viewed from the main pipe 18b side) rapidly rises as shown in Fig. 8c, and this becomes the brake pressure. Then, the traveling motor 5 stops. The crossover relief valve 19 operates due to the increase in pressure in the main pipe 18a, and the main pipe 1
8a is returned to the main pipe 18b, and at time t8 the pressure at both ends of the travel motor 5 becomes approximately zero.
（考案が解決しようとする課題）
ところで、上記従来の油圧路路では、操作レバ
ー２３が中立位置から操作位置へ操作されたと
き、方向切換弁１６が急速に移動し、このため、
第８図ｃからも明らかなように、走行モータ５が
急に駆動されることとなり、車体に衝撃が発生す
るる。さらに、操作レバー２３が操作位置から中
立位置へ戻されたとき、方向切換弁１６が中立位
置へ戻る速度は極めて速く、このため、主管路１
８ａに生じるブレーキ圧の立上がりも第８図ｃに
示すように極めて急峻となり、停止時の油圧シヨ
ベルの車体全体に加わる衝撃も又極めて大きなも
のとなる。このように、起動時および停止時に生
じる衝撃のため、油圧シヨベルの操作性は低下
し、オペレータの疲労感は増大し、加えて機械の
耐久性は損なわれるという欠点を生じていた。こ
のような欠点は、上記油圧シヨベルの走行モータ
に限らず、その他の作業機械の油圧アクチユエー
タにおいても発生し、特に当該油圧アクチユエー
タの負荷の慣性が大きい程その欠点が著るしく現
れる。(Problems to be Solved by the Invention) By the way, in the conventional hydraulic path described above, when the operating lever 23 is operated from the neutral position to the operating position, the directional control valve 16 moves rapidly.
As is clear from FIG. 8c, the traveling motor 5 is suddenly driven, and a shock is generated on the vehicle body. Furthermore, when the operating lever 23 is returned from the operating position to the neutral position, the speed at which the directional control valve 16 returns to the neutral position is extremely fast.
The rise of the brake pressure generated at point 8a also becomes extremely steep as shown in FIG. 8c, and the impact applied to the entire body of the hydraulic excavator when stopped also becomes extremely large. As described above, the shocks generated when starting and stopping the hydraulic excavator reduce the operability of the hydraulic excavator, increase operator fatigue, and impair the durability of the machine. Such defects occur not only in the travel motor of the hydraulic excavator but also in the hydraulic actuators of other working machines, and in particular, the defects become more pronounced as the inertia of the load of the hydraulic actuator increases.
本考案の目的は、上記従来の欠点を除き、油圧
アクチユエータ起動時および停止時の衝撃を緩和
することができ、ひいては操作性の向上、操作者
の疲労感の軽減、耐久性の向上を達成することが
できる方向切換弁駆動油圧回路を提供するにあ
る。 The purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional technology and to reduce the shock when starting and stopping a hydraulic actuator, thereby improving operability, reducing operator fatigue, and improving durability. The purpose of the present invention is to provide a hydraulic circuit capable of driving a directional valve.
上記の目的を達成するため、本考案は、慣性の
大きい油圧アクチユエータの駆動を制御する方向
切換弁と、この方向切換弁を操作するパイロツト
弁とを備えた方向切換弁駆動油圧回路において、
前記パイロツト弁と前記方向切換弁の間に、前記
パイロツト弁と連通する第１のポート、前記方向
切換弁と連通する第２のポート、前記第１のポー
トと前記第２のポート間の開閉を行うスプール、
このスプールと一体構成され前記第１のポートと
前記第２のポート間の流路内に介在しその両側差
圧により当該スプールを移動させる絞り、および
前記スプールの移動により面積が制御される開口
で構成される圧力補償付流量制御弁を介在せしめ
たことを特徴とする。
In order to achieve the above object, the present invention provides a directional valve drive hydraulic circuit that includes a directional valve that controls the drive of a hydraulic actuator with large inertia, and a pilot valve that operates the directional valve.
A first port communicating with the pilot valve, a second port communicating with the directional control valve, and an opening/closing control between the first port and the second port are provided between the pilot valve and the directional control valve. spool to do,
A throttle that is integrally formed with the spool and is interposed in the flow path between the first port and the second port and moves the spool by a pressure difference on both sides thereof, and an opening whose area is controlled by the movement of the spool. The present invention is characterized in that a flow rate control valve with pressure compensation is interposed therebetween.
（作用）
油圧アクチユエータ起動時、圧油は第１のポー
トから絞りを通つて第２のポートへ流れる。これ
によりスプールが移動し、開口が開いてゆき、圧
油が第１のポートから第２のポートへ供給され
る。また、油圧アクチユエータ停止時、圧油は第
２のポートから絞りおよび開口を通つて流れる。
これによりスプールが移動し、開口が小さくな
り、圧油の急激な戻りを阻止する。(Function) When the hydraulic actuator is activated, pressure oil flows from the first port to the second port through the throttle. This moves the spool and opens the opening, supplying pressurized oil from the first port to the second port. Further, when the hydraulic actuator is stopped, pressure oil flows from the second port through the throttle and the opening.
This moves the spool, making the opening smaller and preventing the pressure oil from returning suddenly.
以下、本考案を図示の実施例に基づいて説明す
る。
Hereinafter, the present invention will be explained based on the illustrated embodiments.
第１図は本考案の実施例に係る走行モータの方
向切換弁駆動油圧回路の回路図である。図で、第
７図に示す部分と同一部分には同一符号が付して
てある。３５ａ，３５ｂは方向切換弁１６とパイ
ロツト弁２４との間に介在せしめられた圧力補償
付流量制御弁である。３６a1，３６b1は各圧力補
償付流量制御弁３５ａ，３５ｂとパイロツト弁２
４とを接続するパイロツト管路、３６a2，３６b2
は各圧力補償付流量制御弁３５ａ，３５ｂと方向
切換弁１６のパイロツト室１６ａ，１６ｂとを接
続するパイロツト管路である。圧力補償付流量制
御弁３５ａ，３５ｂの詳細構造は第２図により説
明する。 FIG. 1 is a circuit diagram of a hydraulic circuit for driving a directional control valve of a travel motor according to an embodiment of the present invention. In the figure, the same parts as those shown in FIG. 7 are given the same reference numerals. 35a and 35b are pressure-compensated flow control valves interposed between the directional control valve 16 and the pilot valve 24. 36a 1 and 36b 1 are the respective pressure compensated flow control valves 35a and 35b and the pilot valve 2.
Pilot pipe connecting 4, 36a 2 , 36b 2
are pilot pipes connecting each of the pressure compensated flow control valves 35a, 35b and the pilot chambers 16a, 16b of the directional control valve 16. The detailed structure of the pressure compensated flow rate control valves 35a, 35b will be explained with reference to FIG.
第２図は第１図に示す圧力補償付流量制御弁の
断面図である。図には一方の圧力補償付流量制御
弁３５ａのみが示されているが、他方の圧力補償
付流量制御弁３５ｂの構造も同じであるので、そ
の図示と説明は省略する。図で、３７ａはパイロ
ツト管路３６a1が接続されるポート、３８ａはパ
イロツト管路３６a2が接続されるポート、３９ａ
はスプール、４０ａはスプール３９ａに設けられ
た絞である。４１ａ，４２ａはそれぞれ絞り４０
ａの両側に形成される油室、４３ａ，４４ａはス
プール３９ａの両側に装架されたばね、４５ａは
スプール３９ａに設けられた穴である。穴４５ａ
は油室４１ａに面して貫通形成されている。４６
ａはポート３７ａに連続して形成された環状溝、
４７ａはポート３８ａに連続して形成された環状
溝である。４８ａ，４９ａはスプール３９ａと摺
動するランドである。 FIG. 2 is a sectional view of the pressure compensated flow control valve shown in FIG. 1. Although only one pressure-compensated flow control valve 35a is shown in the figure, the other pressure-compensated flow control valve 35b has the same structure, so illustration and description thereof will be omitted. In the figure, 37a is a port to which the pilot pipe 36a 1 is connected, 38a is a port to which the pilot pipe 36a 2 is connected, and 39a is a port to which the pilot pipe 36a 2 is connected.
is a spool, and 40a is a diaphragm provided on the spool 39a. 41a and 42a are each aperture 40
Oil chambers 43a and 44a are springs mounted on both sides of the spool 39a, and 45a is a hole provided in the spool 39a. Hole 45a
is formed to penetrate and face the oil chamber 41a. 46
a is an annular groove formed continuously in the port 37a;
47a is an annular groove formed continuously with the port 38a. 48a and 49a are lands that slide on the spool 39a.
次に、本実施例の動作を第３図ａ〜ｃに示すタ
イムチヤートを参照しながら説明する。なお、第
３図ａ〜ｃに示す時刻において、第８図ａ〜ｃに
示す時刻と同一時刻には同一符号が付してある。
この符号から判るように、以下の説明における操
作レバー２３の変位は、第８図ａに示す変位と同
一である。 Next, the operation of this embodiment will be explained with reference to the time charts shown in FIGS. 3a to 3c. Incidentally, in the times shown in FIGS. 3a to 3c, the same times as those shown in FIGS. 8a to 8c are given the same reference numerals.
As can be seen from this reference numeral, the displacement of the operating lever 23 in the following explanation is the same as the displacement shown in FIG. 8a.
今、油圧シヨベルのオペレータが時刻t1におい
て操作レバー２３を図の左側に倒すと、スプール
２６ａが移動し、パイロツト油圧ポンプ２１から
の圧油は通路２８、室２５ａ、通路３０ａ、管路
３６a1を経て圧力補償付流量制御弁３５ａのポー
ト３７ａに供給される。この油は環状溝４６ａ、
穴４５ａ、油室４１ａを経て絞り４０ａを通り油
室４２ａに抜ける。このとき、絞り４０ａを通る
油量が多くなると、絞り４０ａの両側に差圧を生
じ、この差圧がばね４４ａのばね力より大きくな
ると、図示の中立位置にあつたスプール３９ａは
図の左方へ移動する。このため、油は環状溝４６
ａ，４７ａを通りポート３８ａ、パイロツト管路
３６a2を経て方向切換弁１６のパイロツト室１６
ａに供給される。これにより、方向切換弁１６は
第３図ｂに示すように前述の応答遅れをもつて時
刻t3において作動を開始し、時刻t4′において最大
変位量となる。時刻t4′は第８図ｂにおける時刻t4
よりある程度遅れた時刻であり、この遅れにより
衝撃が緩和されるが、この遅れについては、さら
に後述する。 Now, when the operator of the hydraulic excavator tilts the operating lever 23 to the left side in the figure at time t1 , the spool 26a moves and the pressure oil from the pilot hydraulic pump 21 flows through the passage 28, the chamber 25a, the passage 30a, and the pipe line 36a 1 It is supplied to the port 37a of the pressure compensated flow rate control valve 35a. This oil is in the annular groove 46a,
It exits through the hole 45a, the oil chamber 41a, the throttle 40a, and the oil chamber 42a. At this time, when the amount of oil passing through the throttle 40a increases, a pressure difference is generated on both sides of the throttle 40a, and when this pressure difference becomes larger than the spring force of the spring 44a, the spool 39a, which was in the neutral position shown in the figure, moves to the left in the figure. Move to. For this reason, the oil flows into the annular groove 46.
a, 47a to the pilot chamber 16 of the directional control valve 16 via the port 38a and the pilot pipe 36a2 .
supplied to a. As a result, the directional control valve 16 starts operating at time t3 with the aforementioned response delay, as shown in FIG. 3b, and reaches its maximum displacement at time t4 '. Time t 4 ' is time t 4 in FIG. 8b.
This time is delayed to some extent, and the impact is alleviated by this delay, which will be described further below.
方向切換弁１６が中立位置から左側位置に駆動
されると、油圧ポンプ１５の圧油は方向切換弁１
６、主管路１８ｂを経て走行モータ５へ供給さ
れ、走行モータ５の有効圧力は第３図ｃに示すよ
うに上昇し、走行モータ５は回転を開始する。そ
して、時刻t4′以後通常回転を継続し油圧シヨベ
ルを走行させる。時刻t3から時刻t4′間における上
記有効圧力の上昇の態様は第８図ｃに示す態様と
異なるが、これについても後述する。 When the directional control valve 16 is driven from the neutral position to the left position, the pressure oil of the hydraulic pump 15 is transferred to the directional control valve 1.
6. The pressure is supplied to the traveling motor 5 through the main pipe 18b, and the effective pressure of the traveling motor 5 increases as shown in FIG. 3c, and the traveling motor 5 starts rotating. After time t4 ', the hydraulic excavator continues to rotate normally and travels. The manner in which the effective pressure increases between time t3 and time t4 ' is different from the manner shown in FIG. 8c, but this will also be described later.
時刻t5に至り、操作レバー２３が中立位置に戻
されると、パイロツト弁２４の室２５ａは作動油
タンク１７と導通する。したがつて、ポート３７
ａ、環状溝４６ａ、穴４５ａ、油室４１ａは作動
油タンク１７に導通し、油室４２ａ側の圧力が油
室４１ａ側の圧力より高くなる。これにより、方
向切換弁１６のパイロツト室１６ａに供給されて
いた油はポート３８ａから圧力補償付流量制御弁
３５ａに流入する。この油は油室４２ａから絞り
４０ａを通り、油室４１ａ、穴４５ａ、環状溝４
６ａ、ポート３７ａ、パイロツト管路３６a1、パ
イロツト弁２４を経て作動油タンク１７に流れ
る。このとき、絞り４０ａを通過する油量が多く
なり、絞り４０ａの両側の差圧がばね４３ａのば
ね力より大きくなると、スプール３９ａは右方へ
移動する。このため、穴４５ａとランド４８ａの
ラツプ量は大きくなり、ここを通る油の量は制限
される。そして、さらに油が流れると、スプール
３９ｃはさらに右方へ移動し、穴４５ａは塞がれ
て油の流れを停止する。そうすると、絞り４０ａ
を通る油の量は０となるので、絞り４０ａの両側
の差圧も０となり、ばね４３ａのばね力によりス
プール３９ａは左方へ移動して再び油を通過せし
める。短時間内におけるこのような動作の繰返し
により、遂には絞り４０ａに発生する上記差圧と
ばね４３ａのばね力とが釣り合うような流量が生
じる個所でスプール３９ａが停止する。即ち、パ
イロツト室１６ａ、パイロツト管路３６a2を経て
圧力補償付流量制御弁３５ａからパイロツト管路
３６a1、パイロツト弁２４、作動油タンク１７に
流出する流の流量は一定流量となる。したがつ
て、第３図ｂに示すように、方向切換弁１６は操
作レバー２３が急速に中立位置に戻されてもその
戻り速度は遅く、時刻t8よりも可成り遅い時刻
t8′に至つてようやく中立位置に戻る。 At time t5 , when the operating lever 23 is returned to the neutral position, the chamber 25a of the pilot valve 24 is brought into communication with the hydraulic oil tank 17. Therefore, port 37
a, the annular groove 46a, the hole 45a, and the oil chamber 41a communicate with the hydraulic oil tank 17, and the pressure on the oil chamber 42a side becomes higher than the pressure on the oil chamber 41a side. As a result, the oil that has been supplied to the pilot chamber 16a of the directional control valve 16 flows into the pressure compensated flow rate control valve 35a from the port 38a. This oil passes from the oil chamber 42a through the throttle 40a, to the oil chamber 41a, through the hole 45a, and into the annular groove 4.
6a, the port 37a, the pilot pipe 36a 1 and the pilot valve 24 to the hydraulic oil tank 17. At this time, when the amount of oil passing through the throttle 40a increases and the differential pressure on both sides of the throttle 40a becomes greater than the spring force of the spring 43a, the spool 39a moves to the right. Therefore, the amount of overlap between the hole 45a and the land 48a becomes large, and the amount of oil passing therethrough is limited. Then, as oil flows further, the spool 39c moves further to the right, and the hole 45a is closed, stopping the flow of oil. Then, the aperture 40a
Since the amount of oil passing through becomes 0, the differential pressure on both sides of the throttle 40a also becomes 0, and the spring force of the spring 43a moves the spool 39a to the left to allow the oil to pass through again. By repeating this operation within a short period of time, the spool 39a finally stops at a point where a flow rate is generated such that the differential pressure generated at the throttle 40a and the spring force of the spring 43a are balanced. That is, the flow rate of the flow flowing out from the pressure-compensated flow control valve 35a to the pilot pipe 36a 1 , the pilot valve 24, and the hydraulic oil tank 17 through the pilot chamber 16a and the pilot pipe 36a 2 becomes a constant flow rate. Therefore, as shown in FIG. 3b, even if the operating lever 23 is rapidly returned to the neutral position, the return speed of the directional control valve 16 is slow, and the return speed is considerably slower than the time t8 .
It finally returns to the neutral position at t 8 ′.
方向切換弁１６の中立位置への戻り速度が上記
のように制限されると、主管路１８ａ，１８ｂの
遮断も急速には行なわれず、したがつて、第３図
ｃに示すように、主管路１８ａに生じるブレーキ
圧力の上昇もゆるやかとなる。このため、停止時
に油圧シヨベルの車体全体に加わる衝撃も大幅に
緩和され、操作性や機械の耐久性は向上し、オペ
レータの疲労感も低減せしめられる。 If the return speed of the directional control valve 16 to the neutral position is limited as described above, the main pipes 18a and 18b will not be shut off quickly, and therefore, as shown in FIG. The increase in brake pressure generated at 18a also becomes gradual. As a result, the shock applied to the entire hydraulic excavator body when the machine is stopped is significantly reduced, improving operability and machine durability, and reducing operator fatigue.
ここで、操作レバー２３の中立位置から操作時
における方向切換弁１６の動作の遅れ時刻t4およ
び走行モータ５の有効圧力の上昇の態様について
説明する。前述のように、操作レバー２３が左側
に倒されると、時刻t3において方向切換弁１６が
切換動作を開始する。この場合、圧力補償付流量
制御弁３５ａにおいては圧損はほとんど生じな
い。方向切換弁１６が切換動作を開始すると、方
向切換弁１６のパイロツト室１６ｂおよびパイロ
ツト管路３６b2に存在していた油は、圧力補償付
流量制御弁３５ｂ、パイロツト管路３６b1、パイ
ロツト弁２４を経て作動油タンク１７へ排出され
る。このとき、圧力補償付流量制御弁３５ｂのポ
ート３８ｂ（圧力補償付流量制御弁３５ａのポー
ト３８ａに相当する）からポート３７ｂ（圧力補
償付流量制御弁３５ａのポート３７ａに相当す
る）へ流れる油は前述のように制限される。この
ため、方向切換弁１６が最大変位量に達する時刻
t4′は圧力補償付流量制御弁３５ｂが存在しない
場合の時刻t4よりも遅れる。しかし、この場合、
方向切換弁１６の動作開始時刻t3においては、パ
イロツト室１６ｂはすでに作動油タンク１７に連
通した状態にあり、この状態から方向切換弁１６
の移動によりそのパイロツト室１６から油が押し
出されても、その油は管路を形成するホースの圧
縮性および油自身の圧縮性により吸収され、圧力
補償付流量制御弁３５ｂの絞り４０ｂ（圧力補償
付流量制御弁３５ａの絞り４０ａに相当する）を
通る流量は少なく、絞り４０ｂの両側の差圧も小
さく、したがつて、油の流れが制限される程度は
少ない。ところで、このように制限される程度が
少ないとはいえ、制限自体は存在するのであるか
ら、それだけ方向切換弁１６の切換速度が遅くな
り、このため、主管路１８ｂを経て走行モータ５
に供給される圧油の圧力の立上がりも第３図ｃに
示すようにゆるやかとなり、走行モータ５の起動
時における衝撃は緩和される。 Here, the manner in which the delay time t4 of the operation of the directional control valve 16 and the increase in the effective pressure of the travel motor 5 when the operating lever 23 is operated from the neutral position will be explained. As described above, when the operating lever 23 is pushed to the left, the directional switching valve 16 starts the switching operation at time t3 . In this case, almost no pressure loss occurs in the pressure compensated flow control valve 35a. When the directional control valve 16 starts the switching operation, the oil present in the pilot chamber 16b and the pilot line 36b2 of the directional control valve 16 is transferred to the pressure compensated flow control valve 35b, the pilot line 36b1 , and the pilot valve 24. The oil is discharged to the hydraulic oil tank 17 through . At this time, the oil flowing from the port 38b (corresponding to the port 38a of the pressure-compensated flow control valve 35a) of the pressure-compensated flow control valve 35b to the port 37b (corresponding to the port 37a of the pressure-compensated flow control valve 35a) is Limited as above. Therefore, the time when the directional control valve 16 reaches the maximum displacement amount
The time t 4 ' is later than the time t 4 when the pressure compensated flow control valve 35b is not present. But in this case,
At time t3 when the directional control valve 16 starts operating, the pilot chamber 16b is already in communication with the hydraulic oil tank 17, and from this state the directional control valve 16
Even if oil is pushed out of the pilot chamber 16 due to the movement of The flow rate passing through the throttle 40a (corresponding to the throttle 40a of the attached flow rate control valve 35a) is small, and the differential pressure on both sides of the throttle 40b is also small, so the extent to which the oil flow is restricted is small. By the way, although the extent of the restriction is small, the restriction itself does exist, so the switching speed of the directional control valve 16 becomes slower, and as a result, the switching speed of the directional control valve 16 becomes slower, and therefore, the speed of the directional control valve 16 is reduced.
As shown in FIG. 3c, the rise in the pressure of the pressure oil supplied to the drive motor 5 also becomes gradual, and the impact upon starting the travel motor 5 is alleviated.
このように、本実施例では、パイロツト弁と方
向切換弁とを接続する両パイロツト管路に圧力補
償付流量制御弁を介在せしめたので、走行モータ
停止時および起動時の衝撃を緩和することがで
き、ひいては、操作性、耐久性を向上させ、か
つ、オペレータの疲労感を低減せしめることがで
きる。 In this way, in this embodiment, since the flow control valve with pressure compensation is interposed in both pilot pipes connecting the pilot valve and the directional control valve, it is possible to reduce the impact when the traveling motor is stopped and started. As a result, operability and durability can be improved, and operator fatigue can be reduced.
さらに、本実施例では次のよう効果も有する。
即ち、操作レバー２３が操作位置から中立位置に
戻されたときの圧力補償付流量制御弁３５ａ，３
５ｂにおける圧油の制御流量は、ランド４８ａと
穴４５ａとのラツプ量で定まら、このラツプ量は
絞り４０ａを通過する流量による圧力損失とばね
４３ａのセツト荷重との釣り合いにより定まる。
したがつて、ばね４３ａのセツト荷重を適切に設
計すれば同一制御流量に対して絞り４０ａのオリ
フイス径を比較的大きく設定することができる。
この結果、パイロツト系の圧油内に存在する微小
な切粉（金属粉末）等の塵埃で絞り４０ａが閉塞
されるような事故を防止することができる。 Furthermore, this embodiment also has the following effects.
That is, when the operating lever 23 is returned from the operating position to the neutral position, the pressure compensated flow control valves 35a, 3
The controlled flow rate of the pressure oil at 5b is determined by the amount of overlap between land 48a and hole 45a, and this amount of overlap is determined by the balance between the pressure loss due to the flow rate passing through throttle 40a and the set load of spring 43a.
Therefore, if the set load of the spring 43a is appropriately designed, the orifice diameter of the throttle 40a can be set relatively large for the same control flow rate.
As a result, it is possible to prevent an accident in which the orifice 40a is blocked by dust such as minute chips (metal powder) existing in the pressure oil of the pilot system.
又、絞りであるオリフイスの厚さは温度変化に
よる影響をできる限り少くするために薄い方がよ
いが、オリフイスを通る流量、圧力に対応する強
度が必要なため必然的に限定される。したがつ
て、同じ厚さであるならば、オリフイス径が大径
の方が小径の方より温度変化による絞りの影響が
小さいのは明らかである。そして、本実施例では
上記のようにオリフイス径を比較的大きく設定で
きるので、温度変化による悪影響を抑制すること
ができる。 Further, the thickness of the orifice, which is a restriction, is preferably thin in order to minimize the influence of temperature changes, but it is necessarily limited because it must have strength corresponding to the flow rate and pressure passing through the orifice. Therefore, if the thickness is the same, it is clear that the influence of temperature change on the restriction is smaller when the orifice diameter is larger than when the orifice diameter is smaller. In this embodiment, the orifice diameter can be set relatively large as described above, so that the adverse effects of temperature changes can be suppressed.
さらに又、本実施例では流量制御弁が圧力補償
付であるので、パイロツト圧力の如何にかかわら
ず方向切換弁１６の戻り速度は一定である。とこ
ろで、方向切換弁のスプールストロークに対する
流量特性は滑らかに設定されているのが通常であ
り、本実施例では上記のように戻り速度が一定で
あるので、操作性が良好となる。 Furthermore, in this embodiment, since the flow control valve is pressure compensated, the return speed of the directional control valve 16 is constant regardless of the pilot pressure. Incidentally, the flow rate characteristics of the directional control valve with respect to the spool stroke are normally set smoothly, and in this embodiment, the return speed is constant as described above, so that operability is improved.
また、以上の全ての機能を一個の弁構造で達成
することができ、従来の油圧回路への取付が極め
て容易となる。 Furthermore, all of the above functions can be achieved with a single valve structure, making installation into a conventional hydraulic circuit extremely easy.
第４図は本考案の他の実施例に係る走行モータ
の方向切換弁駆動油圧回路に使用される流量制御
弁の断面図である。図で、５０は流量制御弁を示
し、この流量制御弁５０はさきの実施例における
圧力補償付流量制御弁３５ａ，３５ｂの代りにパ
イロツト管路３６a1，３６a2の間および３６b1，
３６b2の間に接続される。５１はパイロツト管路
３６a1，３６b1に接続されるポート、５２はパイ
ロツト管路３６a2，３６b2に接続されるポートで
ある。５３はスプール、５４はスプール５３を押
圧するばね、５５ａ，５５ｂは油室、５６はスプ
ール５３の先端に設けられた絞り、５７は油室５
５ａ，５５ｂ間を導通するスプール５３に設けら
れた穴、５８は弁座である。 FIG. 4 is a sectional view of a flow control valve used in a directional valve drive hydraulic circuit for a travel motor according to another embodiment of the present invention. In the figure, numeral 50 indicates a flow control valve, and this flow control valve 50 is located between the pilot pipes 36a 1 and 36a 2 and between the pilot pipes 36a 1 and 36b 1 , instead of the pressure-compensated flow control valves 35a and 35b in the previous embodiment.
36b2 . 51 is a port connected to the pilot pipes 36a 1 and 36b 1 , and 52 is a port connected to the pilot pipes 36a 2 and 36b 2 . 53 is a spool, 54 is a spring that presses the spool 53, 55a and 55b are oil chambers, 56 is a throttle provided at the tip of the spool 53, and 57 is an oil chamber 5.
A hole 58 provided in the spool 53 that provides electrical continuity between the valves 5a and 55b is a valve seat.
このような流量制御弁５０を第１図に示す油圧
回路において圧力補償付流量御弁３５ａ，３５ｂ
の代りに設け、操作レバー２３を左方に倒すと、
パイロツト油圧ポンプ２１からの吐出油はパイロ
ツト弁２４，パイロツト管路３６a1を経て流量制
御弁５０のポート５１に供給される。このため、
スプール５３はばね５４のばね力に抗して下方へ
押下げられ、油はポート５１、油室５５ｂ、穴５
７、油室５５ａ、ポート５２を通り、パイロツト
管路３６a2を経て方向切換弁１６のパイロツト室
１６ｂに供給される。この場合、流量制御弁５０
においてはほとんど圧損を生じない。方向切換弁
１６が動作を開始すると、パイロツト室１６ｂの
油はパイロツト管路３６b2、流量制御弁５０、パ
イロツト管路３６b1、パイロツト弁２４を経てタ
ンクに排出される。このとき、流量制御弁５０に
おいて、油は絞り５６を通過するので方向切換弁
１６の切換速度は若干遅くなり、走行モータ５の
起動時の衝撃を緩和する。 Such a flow control valve 50 is used as pressure compensated flow control valves 35a and 35b in the hydraulic circuit shown in FIG.
If you install it instead of and tilt the operating lever 23 to the left,
The oil discharged from the pilot hydraulic pump 21 is supplied to the port 51 of the flow rate control valve 50 via the pilot valve 24 and the pilot line 36a1 . For this reason,
The spool 53 is pushed down against the spring force of the spring 54, and the oil flows through the port 51, the oil chamber 55b, and the hole 5.
7, the oil passes through the oil chamber 55a, the port 52, and is supplied to the pilot chamber 16b of the directional control valve 16 via the pilot pipe line 36a2 . In this case, the flow control valve 50
Almost no pressure loss occurs. When the directional control valve 16 starts operating, the oil in the pilot chamber 16b is discharged into the tank via the pilot line 36b 2 , the flow control valve 50, the pilot line 36b 1 and the pilot valve 24. At this time, in the flow rate control valve 50, the oil passes through the throttle 56, so that the switching speed of the directional switching valve 16 is slightly slowed, and the impact when the travel motor 5 is started is alleviated.
走行モータ５の停止時、操作レバー２３が中立
位置に戻されると、パイロツト室１６ａ、パイロ
ツト管路３６a2の油は流量制御弁５０のポート５
２に流入し、スプール５３の先端部は弁座５８に
押付けられる。したがつて、油は絞り５６のみを
通つてポート５１に流れ、パイロツト管路３６
a1、パイロツト弁２４を経て作動油タンク１７に
排出される。このように、油の戻りは絞り５６に
より制限され、方向切換弁１６の戻り速度は遅く
なる。このため、主管路１８ａのブレーキ圧の上
昇はゆるやかとなり、走行モータ５の停止時にお
ける衝撃は大巾に緩和される。 When the operating lever 23 is returned to the neutral position when the travel motor 5 is stopped, the oil in the pilot chamber 16a and the pilot pipe 36a2 flows to the port 5 of the flow control valve 50.
2, and the tip of the spool 53 is pressed against the valve seat 58. Therefore, oil flows only through the throttle 56 to the port 51 and into the pilot line 36.
a 1 and is discharged into the hydraulic oil tank 17 via the pilot valve 24. In this way, the return of the oil is limited by the throttle 56, and the return speed of the directional valve 16 is slowed down. Therefore, the brake pressure in the main conduit 18a increases gradually, and the impact when the travel motor 5 is stopped is greatly alleviated.
このように、本実施例では、パイロツト弁と方
向切換弁とを接続する両パイロツト管路に流量制
御弁を設けたので、さきの実施例と同じ効果を奏
するばかりでなく、より簡単な構造の流量制御弁
を用いるのでコストを低下させることができる。 In this way, in this embodiment, since flow control valves are provided in both pilot pipes connecting the pilot valve and the directional control valve, it not only provides the same effect as the previous embodiment, but also has a simpler structure. Since a flow control valve is used, costs can be reduced.
なお、上記各実施例の説明では、油圧シヨベル
の走行モータの方向切換弁を例示して説明した
が、これに限ることはなく、種々の作業機械にお
ける種々のアクチユエータの方向切換弁にも適用
可能であることは明らかである。又、２つのパイ
ロツト管路のいずれにも流量制御弁を設ける例に
ついて説明したが、アクチユエータ又は負荷の作
動条件により、これをいずれか一方のパイロツト
管路のみに設けるようにしてもよい。 In addition, in the description of each of the above embodiments, the directional switching valve of the travel motor of a hydraulic excavator was explained as an example, but the invention is not limited to this, and can also be applied to directional switching valves of various actuators in various working machines. It is clear that Further, although an example has been described in which a flow control valve is provided in both of the two pilot pipes, it may be provided in only one of the pilot pipes depending on the operating conditions of the actuator or the load.
以上述べたように、本考案では、パイロツト弁
と方向切換弁とを接続するパイロツト管路に圧力
補償付流量制御弁を介在せしめたので、油圧アク
チユエータ起動時および停止時の衝撃を緩和する
ことができ、ひいては、操作性および機械の耐久
性を向上させ、操作者の疲労感を低減することが
できる。また、上記の機能を一個の弁構造で達成
することができ、従来の機構への取付が極めて容
易となる。
As described above, in the present invention, a flow control valve with pressure compensation is interposed in the pilot pipe connecting the pilot valve and the directional control valve, so that it is possible to reduce the impact when starting and stopping the hydraulic actuator. As a result, operability and durability of the machine can be improved, and operator fatigue can be reduced. Furthermore, the above functions can be achieved with a single valve structure, making it extremely easy to attach to conventional mechanisms.
第１図は本考案の実施例に係る走行モータの方
向切換弁駆動油圧回路の回路図、第２図は第１図
に示す圧力補償付流量制御弁の断面図、第３図
ａ，ｂ，ｃは第１図に示す回路の動作を説明する
タイムチヤート、第４図は本考案の他の実施例に
係る走行モータの方向切換弁駆動回路に使用され
る流量制御弁の断面図、第５図および第６図はそ
れぞれ油圧シヨベルの概略構成の側面図および平
面図、第７図は従来の走行モータの方向切換弁駆
動回路の回路図、第８図ａ，ｂ，ｃは第７図に示
す回路の動作を説明するタイムチヤートである。
５……走行モータ、１５……油圧モータ、１６
……方向切換弁、１６ａ，１６ｂ……パイロツト
室、２３……操作レバー、２４……パイロツト
弁、３５ａ，３５ｂ……圧力補償付流量制御弁、
３６a1，３６a2，３６b1，３６b2……パイロツト
管路、５０……流量制御弁。
FIG. 1 is a circuit diagram of a hydraulic circuit for driving a directional valve of a travel motor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the flow control valve with pressure compensation shown in FIG. 1, and FIGS. 3 a, b, c is a time chart explaining the operation of the circuit shown in Fig. 1; Fig. 4 is a sectional view of a flow control valve used in a directional control valve drive circuit for a travel motor according to another embodiment of the present invention; 6 and 6 are respectively a side view and a plan view of the schematic configuration of a hydraulic excavator, FIG. 7 is a circuit diagram of a conventional directional control valve drive circuit for a travel motor, and FIGS. 2 is a time chart illustrating the operation of the circuit shown in FIG. 5...Travel motor, 15...Hydraulic motor, 16
...Directional switching valve, 16a, 16b...Pilot chamber, 23...Operation lever, 24...Pilot valve, 35a, 35b...Flow control valve with pressure compensation,
36a 1 , 36a 2 , 36b 1 , 36b 2 ... Pilot pipe line, 50 ... Flow rate control valve.
Claims (1)
する方向切換弁と、この方向切換弁を操作するパ
イロツト弁とを備えた方向切換弁駆動油圧回路に
おいて、前記パイロツト弁と前記方向切換弁の間
に、前記パイロツト弁と連通する第１のポート、
前記方向切換弁と連通する第２のポート、前記第
１のポートと前記第２のポート間の開閉を行うス
プール、このスプールと一体構成され前記第１の
ポートと前記第２のポート間の流路内に介在しそ
の両側に生じる差圧により当該スプールを移動さ
せる絞り、および前記スプールの移動により面積
が制御される開口で構成される圧力補償付流量制
御弁を介在せしめたことを特徴とする方向切換弁
駆動油圧回路。 In a directional valve drive hydraulic circuit comprising a directional valve that controls the drive of a hydraulic actuator with large inertia and a pilot valve that operates this directional valve, the pilot valve is connected between the pilot valve and the directional valve. a first port communicating with the valve;
a second port that communicates with the directional control valve; a spool that opens and closes between the first port and the second port; and a spool that is integrated with the spool and that controls the flow between the first port and the second port A flow control valve with pressure compensation is interposed, which is comprised of a throttle that is interposed in the passage and moves the spool based on the differential pressure generated on both sides thereof, and an opening whose area is controlled by the movement of the spool. Directional valve drive hydraulic circuit.
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1985135597U JPH032722Y2 (en) | 1985-09-06 | 1985-09-06 | |
| KR1019860007275A KR920001908B1 (en) | 1985-09-06 | 1986-08-30 | Slant detecting head pilot hydraulic system for operating directional control valve |
| EP86112328A EP0218901B1 (en) | 1985-09-06 | 1986-09-05 | Pilot hydraulic system for operating directional control valve |
| DE8686112328T DE3678090D1 (en) | 1985-09-06 | 1986-09-05 | HYDRAULIC PILOT CONTROL SYSTEM FOR THE USE OF DIRECTION VALVES. |
| US06/904,119 US4753158A (en) | 1985-09-06 | 1986-09-05 | Pilot hydraulic system for operating directional control valve |
| CN 89105618 CN1011733B (en) | 1985-09-06 | 1986-09-06 | Flow controlling valve with pressure compensation |
| CN86106036.9A CN1007447B (en) | 1985-09-06 | 1986-09-06 | Handle the hydraulic control circuit device that selector valve is used |
| IN669/CAL/86A IN165707B (en) | 1985-09-06 | 1986-09-08 | |
| KR1019860011369A KR900001755B1 (en) | 1985-09-06 | 1986-12-27 | Pilot hydraulic system for operating derectional control valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1985135597U JPH032722Y2 (en) | 1985-09-06 | 1985-09-06 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6244105U JPS6244105U (en) | 1987-03-17 |
| JPH032722Y2 true JPH032722Y2 (en) | 1991-01-24 |
Family
ID=15155538
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1985135597U Expired JPH032722Y2 (en) | 1985-09-06 | 1985-09-06 |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH032722Y2 (en) |
| KR (1) | KR900001755B1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH076521B2 (en) * | 1987-06-30 | 1995-01-30 | 日立建機株式会社 | Load sensing hydraulic drive circuit controller |
| JPH0747602Y2 (en) * | 1988-05-09 | 1995-11-01 | 日立建機株式会社 | Directional switching valve drive hydraulic circuit |
| CN102616687B (en) * | 2012-03-28 | 2013-07-24 | 中联重科股份有限公司 | Rotatable engineering machinery rotation constant power control method, system and engineering machinery |
| JP5848721B2 (en) * | 2013-03-21 | 2016-01-27 | 川崎重工業株式会社 | Buffer valve |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5634161U (en) * | 1979-08-24 | 1981-04-03 |
-
1985
- 1985-09-06 JP JP1985135597U patent/JPH032722Y2/ja not_active Expired
-
1986
- 1986-12-27 KR KR1019860011369A patent/KR900001755B1/en not_active IP Right Cessation
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5634161U (en) * | 1979-08-24 | 1981-04-03 |
Also Published As
| Publication number | Publication date |
|---|---|
| KR870006320A (en) | 1987-07-10 |
| JPS6244105U (en) | 1987-03-17 |
| KR900001755B1 (en) | 1990-03-19 |
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