JPH0250323B2 - - Google Patents
Info
- Publication number
- JPH0250323B2 JPH0250323B2 JP56186950A JP18695081A JPH0250323B2 JP H0250323 B2 JPH0250323 B2 JP H0250323B2 JP 56186950 A JP56186950 A JP 56186950A JP 18695081 A JP18695081 A JP 18695081A JP H0250323 B2 JPH0250323 B2 JP H0250323B2
- Authority
- JP
- Japan
- Prior art keywords
- port
- valve
- ports
- pressure
- actuator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000004891 communication Methods 0.000 claims description 10
- 230000007935 neutral effect Effects 0.000 description 6
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000002689 soil 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
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
-
- 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
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/20576—Systems with pumps with multiple pumps
-
- 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
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/305—Directional control characterised by the type of valves
- F15B2211/30505—Non-return valves, i.e. check valves
-
- 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
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/31—Directional control characterised by the positions of the valve element
- F15B2211/3105—Neutral or centre positions
- F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
-
- 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
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
- F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
- F15B2211/31582—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having multiple pressure sources and a single output member
-
- 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
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/505—Pressure control characterised by the type of pressure control means
- F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
- F15B2211/50536—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using unloading valves controlling the supply pressure by diverting fluid to the return line
-
- 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
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
- F15B2211/5157—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and a return line
-
- 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
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/55—Pressure control for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve
-
- 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
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/605—Load sensing circuits
- F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
- F15B2211/6054—Load sensing circuits having valve means between output member and the load sensing circuit using shuttle valves
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、ブルドーザなどの土木機械を制御す
る油圧装置内に用いる圧力補償付比例制御弁に関
するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a proportional control valve with pressure compensation used in a hydraulic system for controlling civil engineering machines such as bulldozers.
ブルドーザなどの土木機械を制御するための油
圧装置には、油圧ポンプを１個用いるものと２個
用いるものとがあるが、従来の上記油圧装置にお
いて、１個の油圧ポンプを用いた場合、チルトド
ーザの場合ブレードチルトシリンダの速度はブレ
ードリフトの速度に比較して小さくする必要があ
るため、ポンプからチルトシリンダへ行く部分に
ブリードオフ形式の流量制御弁を設け、少流量を
チルトシリンダへ送つている。
Hydraulic systems for controlling civil engineering machinery such as bulldozers include those that use one hydraulic pump and those that use two. In this case, the speed of the blade tilt cylinder must be smaller than the speed of the blade lift, so a bleed-off type flow control valve is installed in the section going from the pump to the tilt cylinder to send a small flow rate to the tilt cylinder. .
一方２ポンプシステムの場合、ブレードチルト
用小ポンプを別にもち、ブレードチルトを使用し
ないとき、その流量を２ポンプシステムの他方の
大ポンプと合流させてブレードリフトシリンダに
供給するようになつている。 On the other hand, in the case of a two-pump system, there is a separate small pump for blade tilt, and when the blade tilt is not used, the flow rate is combined with the other large pump of the two-pump system and supplied to the blade lift cylinder.
上記従来の技術のうち、前者の１個の油圧ポン
プを用いた場合は、ブレードをチルト操作した時
にも油圧ポンプは大流量を吐出しており、エネル
ギの損失が非常に大きいという問題がある。
Among the conventional techniques described above, in the case of using one hydraulic pump in the former case, there is a problem in that the hydraulic pump discharges a large flow rate even when the blade is tilted, resulting in a very large loss of energy.
また後者の２ポンプシステムの場合は、ブレー
ドチルトシリンダを操作したときは小ポンプ側し
か圧力が上昇せず、大ポンプはアンロードしてい
るので、１ポンプシステムに比較してエネルギの
損失が少ないが、ブレードリフトシリンダにて押
土、整地作業を行なうときのようにリフトシリン
ダを微操作を行なう場合、リフトシリンダへ行く
流量は大小ポンプが合流した全流量は必要ない。
このためこの２ポンプシステムの場合、ブレード
リフト弁にて合流した全流量を比例制御弁にて流
量制御しており、上記微操作範囲では２ポンプと
も圧力が上昇し、やはりエネルギの損失が大きい
という問題がある。 In addition, in the case of the latter two-pump system, when the blade tilt cylinder is operated, the pressure increases only on the small pump side, and the large pump is unloaded, so there is less energy loss compared to the one-pump system. However, when the blade lift cylinder is used to perform fine operations such as when performing soil dozing and land leveling work, the flow rate going to the lift cylinder does not need to be the entire flow rate that is the sum of the large and small pumps.
For this reason, in the case of this two-pump system, the total flow rate that merges at the blade lift valve is controlled by a proportional control valve, and in the above-mentioned fine operation range, the pressure of both pumps increases, resulting in a large energy loss. There's a problem.
本発明は上記のことにかんがみなされたもの
で、２ポンプシステムの油圧装置を改良して、方
向制御弁の微操作範囲において不必要側の油圧ポ
ンプからの圧油をアンロードしてエネルギロスを
少なくすることができるようにした圧力補償付比
例制御弁を提供することを目的とするものであ
る。 The present invention was conceived in consideration of the above-mentioned problems, and improves the hydraulic system of the two-pump system to unload pressure oil from the unnecessary hydraulic pump in the fine operation range of the directional control valve, thereby reducing energy loss. It is an object of the present invention to provide a proportional control valve with pressure compensation that can reduce the amount of pressure.
上記目的を達成するために、本発明に係る圧力
補償付比例制御弁は、入力ポート７と、チルトシ
リンダ等のアクチユエータに連通するアクチユエ
ータポート８，９とドレンポート１２，１３とパ
イロツトポート１０，１１を有する弁穴に、移動
することにより上記アクチユエータポート８，９
が入力ポート７あるいはドレンポート１２，１３
に選択的に連通し、またこのとき入力ポート７に
連通するアクチユエータポートに上記パイロツト
ポートを連通するスプール３ａを嵌挿した方向制
御弁３と、第１、第２ポート２２，２３と、ドレ
ンポート２４，２５と、ばね２７が内装され、か
つパイロツトポート２６を有して一側部に設けた
ばね室２８と、他側部に設けた圧力室２９とを有
する弁穴に、ばね室２８に発生する押し力にて移
動したときに第１ポート２２、第２ポート２３と
ドレンポート２４，２５との連通を順次遮断する
ランド３０，３１と、第１ポート２２と圧力室２
９とを連通する導通孔３２を有するスプール２ａ
を嵌挿した圧力補償弁２とからなり、上記方向制
御弁３と圧力補償弁２の両パイロツトポート１
０，１１，２６を接続すると共に、リリーフ弁３
３を介してドレンポートに接続し、また方向制御
弁３の入力ポート７と圧力補償弁の第１ポート２
２に第１のロードチエツク弁４を介して連通する
第１ポンプポート２０と、上記入力ポート７と第
２ポート２３に上記第１のロツトチエツク弁４の
ほかに第２のロードチエツク弁５を介して連通す
る第２ポンプポート２１とを設けた構成となつて
いる。
In order to achieve the above object, the proportional control valve with pressure compensation according to the present invention has an input port 7, actuator ports 8, 9 communicating with an actuator such as a tilt cylinder, drain ports 12, 13, and a pilot port 10. , 11 by moving said actuator ports 8, 9 into valve holes having
is input port 7 or drain port 12, 13
a directional control valve 3 in which a spool 3a is inserted into an actuator port that communicates with the input port 7, and a spool 3a that communicates with the pilot port, and first and second ports 22 and 23; A spring chamber 28 is installed in the valve hole, which has drain ports 24, 25 and a spring 27 inside, and has a pilot port 26 and a spring chamber 28 provided on one side, and a pressure chamber 29 provided on the other side. Lands 30 and 31 that sequentially block communication between the first port 22, the second port 23, and the drain ports 24 and 25 when moved by the pushing force generated in the first port 22 and the pressure chamber 2.
The spool 2a has a conduction hole 32 that communicates with the spool 2a.
The pilot port 1 of the directional control valve 3 and the pressure compensation valve 2 is
0, 11, 26, and the relief valve 3
3 to the drain port, and also to the input port 7 of the directional control valve 3 and the first port 2 of the pressure compensation valve.
A first pump port 20 communicates with the rotary pump 2 via a first load check valve 4, and a second load check valve 5 is connected to the input port 7 and the second port 23 in addition to the first rot check valve 4. The configuration includes a second pump port 21 that communicates with the pump.
方向制御弁３が中立の状態では、２個のポンプ
P1、P2から第１、第２ポート２０，２１に圧油
が流入すると、第１ポート２２からの圧力が導通
孔３２を通つて圧力補償弁２の圧力室２９に作用
し、圧力補償弁２のスプール２ａは、圧力室２９
の押圧力とばね２７の押し力とが釣り合つた位置
で静止し、この状態で両ポート２２，２３がドレ
ンポート２４，２５に連通し、両ポンプP1、P2
からの圧油はドレンされる。
When the directional control valve 3 is in the neutral state, the two pumps
When pressure oil flows into the first and second ports 20 and 21 from P 1 and P 2 , the pressure from the first port 22 acts on the pressure chamber 29 of the pressure compensation valve 2 through the communication hole 32 , and the pressure is compensated. The spool 2a of the valve 2 is connected to the pressure chamber 29
It stands still at a position where the pushing force of the spring 27 and the pushing force of the spring 27 are balanced, and in this state, both ports 22 and 23 communicate with the drain ports 24 and 25, and both pumps P 1 and P 2
The pressure oil from is drained.
方向制御弁３のスプール３ａを例えば左方へ少
し移動した状態では、第２ポート２３とドレンポ
ート２５とが徐々に開き始め、第２ポンプP2か
らの圧油の一部がドレンされ、方向制御弁３の入
力ポート７からアクチユエータポート８へ流出す
る流量は減少し、圧力補償弁２により、アクチユ
エータポート８と第１ポンプポート２０との圧力
差が一定に保たれ、このことから、入力ポート７
からアクチユエータポート８への流量はポンプ吐
出量、アクチユエータの負荷圧に関係なく入力ポ
ート７からアクチユエータポート８への流路断面
積のみで定められる。 When the spool 3a of the direction control valve 3 is moved a little to the left, for example, the second port 23 and the drain port 25 begin to gradually open, and a part of the pressure oil from the second pump P2 is drained, and the direction control valve 3 is moved slightly to the left. The flow rate flowing out from the input port 7 of the control valve 3 to the actuator port 8 is reduced, and the pressure difference between the actuator port 8 and the first pump port 20 is kept constant by the pressure compensation valve 2, and this From, input port 7
The flow rate from the input port 7 to the actuator port 8 is determined only by the cross-sectional area of the flow path from the input port 7 to the actuator port 8, regardless of the pump discharge amount or the load pressure of the actuator.
以下本発明の実施例を図面に基づいて説明す
る。 Embodiments of the present invention will be described below based on the drawings.
図中１は弁体であり、この弁体１内に圧力補償
弁２と方向制御弁３と２個のロードチエツク弁
４，５とシヤトル弁６とが組込まれている。 In the figure, 1 is a valve body, and a pressure compensation valve 2, a directional control valve 3, two load check valves 4 and 5, and a shuttle valve 6 are incorporated into the valve body 1.
上記方向制御弁３のスプール３ａが嵌挿される
弁穴には、軸方向中央に位置する入力ポート７
と、これの両側に位置するアクチユエータポート
８，９と、さらにその外側に順次位置するパイロ
ツトポート１０，１１およびドレンポート１２，
１３とが設けてある。一方スプール３には入力ポ
ート７とこれの両側のアクチユエータポート８，
９との連通を遮断（中立時）、あるいはどちらか
一方を選択的に連通（操作時）する入力ランド１
４，１５と、この入力ランド１４，１５の軸方向
外側に位置し、スプール３が中立位置にあるとき
にはパイロツトポート１０，１１をドレンポート
１２，１３に連通し、操作位置のときに、操作側
のアクチユエータポートとパイロツトポートとを
連通、他側のアクチユエータポートとパイロツト
ポートとをドレンポートに連通させるドレン切換
ランド１６，１７とが設けてある。上記２個のパ
イロツトポート１０，１１はシヤトル弁６を介し
てパイロツト回路１８に接続してある。また２個
のアクチユエータポート８，９はブレードのチル
トシリンダ１９の両側に接続してある。 The valve hole into which the spool 3a of the directional control valve 3 is inserted has an input port 7 located at the center in the axial direction.
, actuator ports 8 and 9 located on both sides of this, and pilot ports 10 and 11 and drain port 12 located sequentially outside of the actuator ports 8 and 9.
13 are provided. On the other hand, the spool 3 has an input port 7 and actuator ports 8 on both sides of it.
Input land 1 that cuts off communication with 9 (when in neutral) or selectively communicates with either one (when operated)
4, 15, and are located axially outside of these input lands 14, 15, and when the spool 3 is in the neutral position, the pilot ports 10, 11 are connected to the drain ports 12, 13, and when the spool 3 is in the operating position, the pilot ports 10, 11 are connected to the drain ports 12, 13. Drain switching lands 16 and 17 are provided for communicating the actuator port on the other side with the pilot port and communicating the actuator port on the other side and the pilot port with the drain port. The two pilot ports 10 and 11 are connected to a pilot circuit 18 via a shuttle valve 6. Two actuator ports 8, 9 are also connected to either side of the blade tilt cylinder 19.
弁体１には第１および第２ポンプポート２０，
２１が設けてあり、これの第１ポンプポート２０
に大容量の油圧ポンプP1、第２ポンプポート２
１に小容量の油圧ポンプP2が接続してある。そ
して第１ポンプポート２０は第１のロードチエツ
ク弁４を介して方向制御弁３の入力ポート７に連
通し、また第２ポンプポート２１は上記第１のロ
ードチエツク弁４のほかに第２のロードチエツク
弁５を介して上記入力ポート７に連通するように
なつている。 The valve body 1 has first and second pump ports 20,
21 is provided, the first pump port 20 of this
Large capacity hydraulic pump P 1 , second pump port 2
1 is connected to a small-capacity hydraulic pump P2 . The first pump port 20 communicates with the input port 7 of the directional control valve 3 via the first load check valve 4, and the second pump port 21 communicates with the input port 7 of the directional control valve 3 in addition to the first load check valve 4. It communicates with the input port 7 via the load check valve 5.
圧力補償弁２のスプール２ａが嵌挿される弁穴
には第１ポンプポート２０に連通する第１ポート
２２と、第２ポンプポート２１と連通する第２ポ
ート２３と、ドレンポート２４，２５とパイロツ
トポート２６とが設けてある。またこの弁穴の一
側にはスプール２ａを一方へ付勢するばね２７が
内装してあり、このばね２７が収納されるばね室
２８に上記パイロツトポート２６が連通してあ
る。また弁穴の他側には上記ばね２７に対応する
圧力を発生させる圧力室２９がスプール２ａの端
面に対向させて構成してある。スプール２ａに
は、これがばね２７にて付勢されたときに第１ポ
ート２２とドレンポート２４を遮断し、圧力室２
９の圧力にて逆方向に移動したときにこれを連通
する第１ランド３０と、上記ばね２７の付勢力に
てスプール２ａが移動したときに第２ポート２３
とドレンポート２５との連通を遮断する第２ラン
ド３１とが設けてある。またこのスプール２ａに
は第１ポート２２と圧力室２９とを常時連通する
導通孔３２が設けてある。上記ばね室２８に連通
するパイロツトポート２６は上記シヤトル弁６に
パイロツト回路１８を介して接続されている。そ
してこのパイロツト回路１８にはリリーフ弁３３
が接続してある。 The valve hole into which the spool 2a of the pressure compensation valve 2 is inserted has a first port 22 communicating with the first pump port 20, a second port 23 communicating with the second pump port 21, drain ports 24, 25, and a pilot port. A port 26 is provided. A spring 27 for biasing the spool 2a in one direction is installed on one side of the valve hole, and the pilot port 26 communicates with a spring chamber 28 in which the spring 27 is accommodated. Further, on the other side of the valve hole, a pressure chamber 29 for generating a pressure corresponding to the spring 27 is configured to face the end surface of the spool 2a. The spool 2a has a pressure chamber 2 which blocks the first port 22 and the drain port 24 when it is biased by a spring 27.
When the spool 2a moves under the biasing force of the spring 27, the second port 23
and a second land 31 that blocks communication with the drain port 25. Further, this spool 2a is provided with a communication hole 32 that constantly communicates the first port 22 and the pressure chamber 29. A pilot port 26 communicating with the spring chamber 28 is connected to the shuttle valve 6 via a pilot circuit 18. This pilot circuit 18 is equipped with a relief valve 33.
is connected.
上記構成における作用を以下に説明する。 The operation of the above configuration will be explained below.
(1) 中立時（第１図）
方向制御弁３を中立とした状態で２個のポン
プP1、P2からそれぞれ圧油が弁体１の第１、
第２ポンプポート２０，２１に流入すると、こ
のとき方向制御弁３の入力ポート７が閉じられ
ているから、圧力補償弁２の第１、第２ポート
２２，２３の圧力が上昇する。かくすると上記
第１ポート２２の圧力スプール２ａの導通孔３
２を通つて圧力室２９に作用する。そしてこの
圧力室２９の押圧力とばね２７による押し力と
が釣り合つた位置でスプール２ａが静止し、こ
の状態で両ポート２２，２３がドレンポート２
４，２５に連通し、上記両ポンプP1、P2から
の圧油はドレンされる。なおこのとき、ばね室
２８もパイロツトポート２６、パイロツト回路
１８、シヤトル弁６、方向制御弁３を介してド
レンされている。(1) Neutral state (Fig. 1) With the directional control valve 3 in the neutral state, pressure oil is supplied from the two pumps P 1 and P 2 to the first and second valve bodies of the valve body 1, respectively.
When it flows into the second pump ports 20, 21, the input port 7 of the directional control valve 3 is closed at this time, so the pressure in the first and second ports 22, 23 of the pressure compensating valve 2 increases. Thus, the through hole 3 of the pressure spool 2a of the first port 22
2 and acts on the pressure chamber 29. The spool 2a comes to rest at a position where the pressing force of the pressure chamber 29 and the pressing force of the spring 27 are balanced, and in this state both ports 22 and 23 are connected to the drain port 2.
4 and 25, and the pressure oil from both pumps P 1 and P 2 is drained. At this time, the spring chamber 28 is also drained via the pilot port 26, the pilot circuit 18, the shuttle valve 6, and the directional control valve 3.
(2) 微操作時（第２図）
方向制御弁３のスプール３ａを例えば左方へ
移動すると、まず左側のパイロツトポート１０
とドレンポート１２との連通が遮断され、その
後左側のアクチユエータポート８とパイロツト
ポート１０とが連通される。従つてアクチユエ
ータであるチルトシリンダ１９の負荷圧が圧力
補償弁２のばね室２８に導かれる。なおこのと
き右側のパイロツトポート１１はドレンポート
１３に連通しているが、シヤトル弁６によりこ
こから上記パイロツト圧が逃げることがない。
ばね室２８に上記パイロツト圧が入ると、この
ばね室２８の圧力が上昇し、圧力補償弁２のス
プール２ａは圧力室２９の圧力に抗して右方へ
移動する。かくとすると、圧力補償弁２の第
１、第２ポート２２，２３とドレンポート２
４，２５との連通が遮断され第１、第２ポート
２２，２３の圧力が上昇する。(2) During fine operation (Fig. 2) When the spool 3a of the directional control valve 3 is moved, for example, to the left, the pilot port 10 on the left side first
The communication between the actuator port 8 and the drain port 12 is cut off, and then the left actuator port 8 and the pilot port 10 are communicated with each other. Therefore, the load pressure of the tilt cylinder 19, which is an actuator, is guided to the spring chamber 28 of the pressure compensation valve 2. At this time, the right pilot port 11 is in communication with the drain port 13, but the shuttle valve 6 prevents the pilot pressure from escaping from there.
When the pilot pressure enters the spring chamber 28, the pressure in the spring chamber 28 increases, and the spool 2a of the pressure compensation valve 2 moves to the right against the pressure in the pressure chamber 29. In this case, the first and second ports 22 and 23 of the pressure compensation valve 2 and the drain port 2
4, 25 is cut off, and the pressures in the first and second ports 22, 23 increase.
方向制御弁３のスプール３ａをさらに左方へ
移動すると、左側の入力ランド１４の切欠１４
ａが左側のアクチユエータポート８に連通し、
入力ポート７の圧油はこの切欠１４ａを通つて
アクチユエータポート８へ流れ込め。ところが
この連通開度は小さいため第１、第２ポート２
０，２１の圧力はさらに上昇し、第１ポート２
０の圧力は圧力補償弁２の圧力室２９に作用さ
れ、この圧力室２９の圧力が上昇する。従つて
圧力補償弁２のスプール２ａは上記ばね２７と
ばね室２８の圧力による押圧力に打勝つて圧力
室２９の圧力による押圧力により左方へ移動さ
れる。すると第２ポート２３とドレンポート２
５とが徐々に開き始め、第２ポンプP2からの
圧油の一部はドレンされる。これにより方向制
御弁３の入力ポート７からアクチユエータポー
ト８へ流出する流量は減少し、これの流路断面
積に合つた流量となる。結局圧力補償弁２はア
クチユエータポート８と第１ポート２０との圧
力差を一定に保つことになる。 When the spool 3a of the directional control valve 3 is further moved to the left, the notch 14 of the input land 14 on the left side
a communicates with the left actuator port 8,
Pressure oil in the input port 7 can flow into the actuator port 8 through this notch 14a. However, since this communication opening is small, the first and second ports 2
The pressure at 0,21 further increases, and the pressure at the first port 2
The zero pressure is applied to the pressure chamber 29 of the pressure compensation valve 2, and the pressure in this pressure chamber 29 increases. Therefore, the spool 2a of the pressure compensating valve 2 is moved to the left by the pressing force due to the pressure of the pressure chamber 29, overcoming the pressing force due to the pressure of the spring 27 and the spring chamber 28. Then, the second port 23 and drain port 2
5 begins to gradually open, and a portion of the pressure oil from the second pump P2 is drained. As a result, the flow rate flowing out from the input port 7 of the directional control valve 3 to the actuator port 8 is reduced, and becomes a flow rate that matches the cross-sectional area of the flow path. As a result, the pressure compensating valve 2 maintains a constant pressure difference between the actuator port 8 and the first port 20.
このことから入力ポート７からアクチユエー
タポート８への流量はポンプ吐出量、アクチユ
エータの負荷圧に関係なく入力ポート７からア
クチユエータポート８への流路断面積のみで定
められる。 Therefore, the flow rate from the input port 7 to the actuator port 8 is determined only by the cross-sectional area of the flow path from the input port 7 to the actuator port 8, regardless of the pump discharge amount or the load pressure of the actuator.
従つて方向制御弁３のスプール３ａのストロ
ークと流路断面積の関係と、圧力補償弁２のス
プール２ａのストロークと流路断面積を適切に
定めてブルドーザ等の土工機に使用した場合、
微操作時においては小容量の第２ポンプP2は
アンロードされ、省エネを図れる。 Therefore, when the relationship between the stroke of the spool 3a of the directional control valve 3 and the cross-sectional area of the flow path and the stroke of the spool 2a of the pressure compensation valve 2 and the cross-sectional area of the flow path are appropriately determined and used in an earth-moving machine such as a bulldozer,
During fine operation, the small capacity second pump P2 is unloaded to save energy.
(3) フルストローク時（第３図）
方向制御弁３のスプール３ａを左方へストロ
ークエンドまで移動すと、入力ポート７とアク
チユエータポート８との流路断面積が大きくな
り、この部分を通過すときの流体圧力損失が下
がるため、第１ポート２２の圧力が低下し、圧
力補償弁２のスプール２ａはばね２７により右
方へ押され、圧力補償弁２の両ドレンポート２
４，２５が閉じられ第１、第２ポンプP1、P2
双方の全流量がアクチユエータへ流れる。(3) At full stroke (Fig. 3) When the spool 3a of the directional control valve 3 is moved to the left to the stroke end, the cross-sectional area of the flow path between the input port 7 and the actuator port 8 increases, and this part Since the fluid pressure loss when passing through decreases, the pressure in the first port 22 decreases, the spool 2a of the pressure compensation valve 2 is pushed to the right by the spring 27, and both drain ports 2 of the pressure compensation valve 2 are pushed to the right.
4 and 25 are closed and the first and second pumps P 1 and P 2
The entire flow of both flows to the actuator.
(4) リリーフ時
方向制御弁３の操作時において、アクチユエ
ータ１９がストロークエンドになつたとき、ま
たは大きな外力を受けた場合は、リリーフ弁３
３の設定まで回路圧が上昇するが、それ以上に
なるとリリーフ弁３３がリリーフし始める。す
ると、圧力補償弁２のばね室２７の圧力と圧力
室２９の圧力のバランスがくずれ、ばね室２７
内の圧力が低くなるから、スプール２ａは圧力
室２９の圧力により左方へ移動され、第１、第
２ポート２２，２３がドレンポート２４，２５
に連通し、油圧回路の過剰圧力発生が防止され
る。(4) At the time of relief When the actuator 19 reaches the stroke end or receives a large external force when operating the directional control valve 3, the relief valve 3
The circuit pressure increases up to the setting of 3, but when it rises above that, the relief valve 33 starts to relieve. Then, the balance between the pressure in the spring chamber 27 and the pressure in the pressure chamber 29 of the pressure compensation valve 2 is lost, and the pressure in the spring chamber 27
Since the internal pressure becomes low, the spool 2a is moved to the left by the pressure in the pressure chamber 29, and the first and second ports 22 and 23 are connected to the drain ports 24 and 25.
This prevents excessive pressure from occurring in the hydraulic circuit.
なお上記実施例において、第２ポンプP2と第
２ポンプポート２１との間の回路に他の操作弁３
４を介装する。 In the above embodiment, another operating valve 3 is provided in the circuit between the second pump P 2 and the second pump port 21.
Interpose 4.
また方向制御弁３のスプール３ａに設けたドレ
ン切換ランド１６，１７には、スプール３ａを微
操作したときにおいて、アクチユエータポート
８，９とパイロツトポート１０，１１とが徐々に
連通するよう切欠１６ａ，１７ａが設けてある。 In addition, the drain switching lands 16 and 17 provided on the spool 3a of the directional control valve 3 have notches so that the actuator ports 8 and 9 and the pilot ports 10 and 11 gradually communicate with each other when the spool 3a is slightly operated. 16a and 17a are provided.
本発明は以上のようになり、入力ポート７と、
チルトシリンダ等のアクチユエータに連通するア
クチユエータポート８，９と、ドレンポート１
２，１３とパイロツトポート１０，１１を有する
弁穴に、移動することにより上記アクチユエータ
ポート８，９が入力ポート７あるいはドレンポー
ト１２，１３に選択的に連通し、またこのとき入
力ポート７に連通するアクチユエータポートに上
記パイロツトポートを連通するスプール３ａを嵌
挿した方向制御弁３と、第１、第２ポート２２，
２３と、ドレンポート２４，２５と、ばね２７が
内装され、かつパイロツトポート２６を有して一
側部に設けたばね室２８と、他側部に設けた圧力
室２９とを有する弁穴に、ばね室２８に発生する
押し力にて移動したときに第１ポート２２、第２
ポート２３とドレンポート２４，２５との連通を
順次遮断するランド３０，３１と、第１ポート２
２と圧力室２９とを連通する導通孔３２を有する
スプール２ａを嵌挿した圧力補償弁２とからな
り、上記方向制御弁３と圧力補償弁２の両パイロ
ツトポート１０，１１，２６を接続すると共に、
リリーフ弁３３を介してドレンポートに接続し、
また方向制御弁３の入力ポート７と圧力補償弁の
第１ポート２２に第１のロードチエツク弁４を介
して連通する第１ポンプポート２０と、上記入力
ポート７と第２ポート２３に上記第１のロードチ
エツク弁４のほかに第２のロードチエツク５を介
して連通する第２ポンプポート２１とを設けて圧
力補償付比例制御弁を構成したから、第１ポンプ
ポート２０と第２ポンプポート２１にそれぞれ油
圧ポンプP1、P2を接続した２ポンプシステムに
おいて、方向制御弁３の微操作範囲において、１
個のポンプ吐出量でたりる場合には他方の油圧ポ
ンプからの圧油は圧力補償弁２よりアンロードさ
れ、このアンロードされた方の油圧ポンプの駆動
力が小さくなり、エネルギロスを少なくすること
ができる。また本発明の構成によれば、圧力補償
弁２にはこれの１つのスプール２ａに２個の圧力
補償機能が内蔵されていることになり、圧力補償
のための構成の簡素化を図ることができる。また
上記圧力補償弁２の各圧力補償機能は方向制御弁
３のスプール３ａの動きに従つて自動的順次作動
するため、この圧力補償弁を作動するための補助
的な方向制御弁は必要なく、圧力補償用の油圧回
路の簡素化をも図ることができる。
The present invention is as described above, and the input port 7 and
Actuator ports 8 and 9 that communicate with actuators such as tilt cylinders, and drain port 1
2, 13 and the pilot ports 10, 11, the actuator ports 8, 9 selectively communicate with the input port 7 or the drain ports 12, 13, and at this time the input port 7 a directional control valve 3 in which a spool 3a communicating with the pilot port is inserted into an actuator port communicating with the actuator port, and a first port 22, a second port 22,
23, drain ports 24, 25, and a spring 27 are installed in the valve hole, which has a pilot port 26, a spring chamber 28 provided on one side, and a pressure chamber 29 provided on the other side. When moved by the pushing force generated in the spring chamber 28, the first port 22 and the second port
Lands 30 and 31 that sequentially block communication between the port 23 and the drain ports 24 and 25, and the first port 2
The directional control valve 3 and the pilot ports 10, 11, 26 of the pressure compensation valve 2 are connected to each other. With,
Connected to the drain port via the relief valve 33,
Further, a first pump port 20 communicates with the input port 7 of the directional control valve 3 and the first port 22 of the pressure compensation valve via the first load check valve 4, and the first pump port 20 communicates with the input port 7 of the directional control valve 3 and the first port 22 of the pressure compensation valve via the first load check valve 4, and the In addition to the first load check valve 4, the second pump port 21 communicating through the second load check 5 is provided to constitute the proportional control valve with pressure compensation. In a two-pump system in which hydraulic pumps P 1 and P 2 are respectively connected to 21, in the fine operation range of the directional control valve 3, 1
When the pump discharge amount is equal to 1, the pressure oil from the other hydraulic pump is unloaded from the pressure compensation valve 2, and the driving force of the unloaded hydraulic pump becomes smaller, reducing energy loss. be able to. Furthermore, according to the configuration of the present invention, one spool 2a of the pressure compensation valve 2 has two pressure compensation functions built-in, so that the configuration for pressure compensation can be simplified. can. Furthermore, since each pressure compensation function of the pressure compensation valve 2 is automatically operated sequentially according to the movement of the spool 3a of the directional control valve 3, there is no need for an auxiliary directional control valve to operate this pressure compensation valve. It is also possible to simplify the hydraulic circuit for pressure compensation.
図面は本発明の実施例を示すもので、第１図は
中立時、第２図は微操作時、第３図はフルストロ
ーク時のそれぞれの操作状態を示す断面図であ
る。
２は圧力補償弁、３は方向制御弁、２ａ，３ａ
はスプール、７は入力ポート、８，９はアクチエ
ータポート、１０，１１，２６はパイロツトポー
ト、１２，１３，２４，２５はドレンポート、２
０，２１はポンプポート、２２，２３は第１、第
２ポート、２７はばね、２８はばね室、２９は圧
力室、３０，３１はランド、３２は導通孔。
The drawings show an embodiment of the present invention, and FIG. 1 is a cross-sectional view showing the operation state in neutral, FIG. 2 in fine operation, and FIG. 3 in full stroke. 2 is a pressure compensation valve, 3 is a direction control valve, 2a, 3a
is a spool, 7 is an input port, 8, 9 are actuator ports, 10, 11, 26 are pilot ports, 12, 13, 24, 25 are drain ports, 2
0 and 21 are pump ports, 22 and 23 are first and second ports, 27 is a spring, 28 is a spring chamber, 29 is a pressure chamber, 30 and 31 are lands, and 32 is a conduction hole.
Claims (1)
ユエータに連通するアクチユエータポート８，９
と、ドレンポート１２，１３とパイロツトポート
１０，１１を有する弁穴に、移動することにより
上記アクチユエータポート８，９が入力ポート７
あるいはドレンポート１２，１３に選択的に連通
し、またこのとき入力ポート７に連通するアクチ
ユエータポートに上記パイロツトポートを連通す
るスプール３ａを嵌挿した方向制御弁３と、第
１、第２ポート２２，２３と、ドレンポート２
４，２５と、ばね２７が内装され、かつパイロツ
トポート２６を有して一側部に設けたばね室２８
と、他側部に設けた圧力室２９とを有する弁穴
に、ばね室２８に発生する押し力にて移動したと
きに第１ポート２２、第２ポート２３とドレンポ
ート２４，２５との連通を順次遮断するランド３
０，３１と、第１ポート２２と圧力室２９とを連
通する導通孔３２を有するスプール２ａを嵌挿し
た圧力補償弁２とからなり、上記方向制御弁３と
圧力補償弁２の両パイロツトポート１０，１１，
２６を接続すると共に、リリーフ弁３３を介して
ドレンポートに接続し、また方向制御弁３の入力
ポート７と圧力補償弁の第１ポート２２に第１の
ロードチエツク弁４を介して連通する第１ポンプ
ポート２０と、上記入力ポート７と第２ポート２
３に上記第１のロツトチエツク弁４のほかに第２
のロードチエツク弁５を介して連通する第２ポン
プポート２１とを設けたことを特徴とする圧力補
償付比例制御弁。1 Input port 7 and actuator ports 8 and 9 that communicate with actuators such as tilt cylinders
By moving the actuator ports 8 and 9 to the valve holes having the drain ports 12 and 13 and the pilot ports 10 and 11, the actuator ports 8 and 9 become the input port 7.
Alternatively, a directional control valve 3 which selectively communicates with the drain ports 12 and 13, and in which a spool 3a that communicates with the pilot port is inserted into an actuator port that communicates with the input port 7; Ports 22, 23 and drain port 2
4, 25, and a spring chamber 28 in which a spring 27 is housed and has a pilot port 26 and is provided on one side.
and a pressure chamber 29 provided on the other side, when the valve hole is moved by the pushing force generated in the spring chamber 28, the first port 22, the second port 23, and the drain ports 24, 25 communicate with each other. Land 3 which sequentially shuts off
0, 31, and a pressure compensating valve 2 into which a spool 2a having a communication hole 32 communicating between the first port 22 and the pressure chamber 29 is inserted, and both pilot ports of the directional control valve 3 and the pressure compensating valve 2 are connected to each other. 10, 11,
26 and is connected to the drain port via the relief valve 33, and also communicates with the input port 7 of the directional control valve 3 and the first port 22 of the pressure compensation valve via the first load check valve 4. 1 pump port 20, the input port 7 and the second port 2
3, in addition to the first rotary check valve 4, a second rotary check valve 4 is installed.
A proportional control valve with pressure compensation, characterized in that it is provided with a second pump port 21 that communicates with the load check valve 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18695081A JPS5891903A (en) | 1981-11-24 | 1981-11-24 | Proportional control valve with pressure compensation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18695081A JPS5891903A (en) | 1981-11-24 | 1981-11-24 | Proportional control valve with pressure compensation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5891903A JPS5891903A (en) | 1983-06-01 |
| JPH0250323B2 true JPH0250323B2 (en) | 1990-11-02 |
Family
ID=16197556
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18695081A Granted JPS5891903A (en) | 1981-11-24 | 1981-11-24 | Proportional control valve with pressure compensation |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5891903A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60129501U (en) * | 1984-02-10 | 1985-08-30 | 株式会社小松製作所 | Proportional control valve with pressure compensation |
| JP6096002B2 (en) * | 2013-02-21 | 2017-03-15 | ナブテスコ株式会社 | Hydraulic control device and construction machine equipped with the hydraulic control device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5824007Y2 (en) * | 1978-03-15 | 1983-05-23 | ダイキン工業株式会社 | hydraulic circuit |
-
1981
- 1981-11-24 JP JP18695081A patent/JPS5891903A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5891903A (en) | 1983-06-01 |
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