JPH0211491Y2 - - Google Patents
Info
- Publication number
- JPH0211491Y2 JPH0211491Y2 JP1981071981U JP7198181U JPH0211491Y2 JP H0211491 Y2 JPH0211491 Y2 JP H0211491Y2 JP 1981071981 U JP1981071981 U JP 1981071981U JP 7198181 U JP7198181 U JP 7198181U JP H0211491 Y2 JPH0211491 Y2 JP H0211491Y2
- Authority
- JP
- Japan
- Prior art keywords
- switching valve
- valve
- pressure
- swing
- 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
Links
- 230000000694 effects Effects 0.000 description 4
- 230000033001 locomotion Effects 0.000 description 4
- 230000001133 acceleration Effects 0.000 description 3
- 230000000903 blocking effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000009977 dual effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 238000009412 basement excavation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
Landscapes
- Operation Control Of Excavators (AREA)
- Fluid-Pressure Circuits (AREA)
Description
【考案の詳細な説明】
（産業上の利用分野）
この考案は油圧シヨベルの作業性を向上させる
ための油圧回路に関するものである。[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a hydraulic circuit for improving the workability of a hydraulic excavator.
（従来技術とその問題点）
従来、油圧シヨベルの複合動作をする場合、そ
の動作を二つ、或いは三つの動作群に分け、それ
ぞれの動作群毎に別個の油圧源（油圧ポンプ）を
設けて操作している。(Prior art and its problems) Conventionally, when a hydraulic excavator performs multiple motions, the motion is divided into two or three motion groups, and a separate hydraulic power source (hydraulic pump) is provided for each motion group. operating.
即ち、第１図に示す如く旋回操作群６と右走
行・アーム及びブーム増速の操作群４と左走行・
バケツト及びブームの操作群５の３群に分け、そ
れぞれ油圧システムを構成しているが、この場
合、旋回操作のサイクル確保のために所望の旋回
速度を得るためには旋回操作群６も略他の２群
４，５と同量の油量（吐出量）を必要とする。 That is, as shown in FIG.
The hydraulic system is divided into three groups: the bucket and boom operation group 5, and each of them constitutes a hydraulic system. It requires the same amount of oil (discharge amount) as the second group 4 and 5.
従つて、全体の動力（エンジン能力）が一定な
らば旋回操作に消費される動力分だけ２群４，５
の使用可能動力は少くなり所望動力を得るために
は大容量の動力（エンジン）を必要とする不具合
がある。 Therefore, if the overall power (engine capacity) is constant, the 2nd group 4, 5
There is a problem in that the usable power of the engine decreases and a large capacity power (engine) is required to obtain the desired power.
このため、すでに実開昭55−93706号公報に記
載されている如く、旋回回路に圧力制御弁を設
け、殊に旋回モータは起動時の負荷が大きいため
リリーフする旋回ポンプからの吐出油を作業回路
に導びき有効に利用することによつて、全体とし
てパワロスを低減するようにしたものが提案され
ている。 For this reason, as already described in Japanese Utility Model Application Publication No. 55-93706, a pressure control valve is installed in the swing circuit, and since the load on the swing motor is particularly large at startup, the oil discharged from the swing pump to be relieved is controlled. It has been proposed to reduce power loss as a whole by guiding the power to the circuit and making effective use of it.
この提案は、旋回加速時のリリーフ損失を低減
するために、旋回用回路と作業機用回路との間に
圧力制御弁装置を挿入し、通常はシーケンス弁と
して作用させ旋回用回路のリリーフ流量を作業機
回路に導いて作業機回路の速度向上を図り、作業
機回路の負荷状態によつてはリリーフ弁として作
動して旋回回路の異常圧を防止するようにしたも
のであるが、旋回用回路が独立しているため、旋
回用アクチユエータの駆動は常に旋回用ポンプの
圧油のみに頼ることとなり、高圧小流量で足りる
旋回加速時のみならず、比較的低圧大流量を必要
とする定常運転状態においても必要とされる圧油
流量をすべて旋回用ポンプから供給しなければな
らないので、大容量の旋回用ポンプを必要とし、
その駆動のため必然的に大容量エンジンを搭載す
る必要が生じ、エンジン容量の小さい小型油圧シ
ヨベルには適用できず、また、小容量の旋回用ポ
ンプを用いた場合には所望の定常旋回速度が得ら
れず低速旋回を余儀なくされるという問題点があ
る。 This proposal involves inserting a pressure control valve device between the swing circuit and the work equipment circuit in order to reduce relief loss during swing acceleration, and normally acts as a sequence valve to reduce the relief flow rate of the swing circuit. It is designed to improve the speed of the work equipment circuit by guiding it to the work equipment circuit, and to operate as a relief valve depending on the load condition of the work equipment circuit to prevent abnormal pressure in the swing circuit. Because the swing actuator is independent, the drive of the swing actuator always relies only on the pressure oil of the swing pump, and is used not only during swing acceleration when a high pressure and small flow rate is sufficient, but also during steady operation conditions that require a relatively low pressure and large flow rate. Since all the required pressure oil flow must be supplied from the swing pump, a large-capacity swing pump is required.
In order to drive it, it is necessary to install a large-capacity engine, which cannot be applied to small hydraulic excavators with small engine capacity, and if a small-capacity swing pump is used, the desired steady swing speed cannot be achieved. There is a problem in that you are forced to turn at low speed without being able to achieve this.
（この考案が解決しようとする課題）
この考案は、上記した従来技術の問題点を解決
し小容量エンジンの採用を可能ならしめた油圧シ
ステムを提供することを目的とし、旋回用ポンプ
としては、起動に必要な圧力と流量を確保できる
程度の小容量のポンプを用い、比較的大流量を必
要とする定常旋回時には、作業機用回路から圧油
を合流させ所望の旋回速度を得られるように考案
を施したものである。(Problems to be solved by this invention) The purpose of this invention is to provide a hydraulic system that solves the above-mentioned problems of the conventional technology and makes it possible to use a small-capacity engine. A small-capacity pump is used to ensure the pressure and flow rate necessary for startup, and during steady swings that require a relatively large flow rate, pressure oil is merged from the work equipment circuit to obtain the desired swing speed. It was devised.
すなわち、旋回用アクチユエータを駆動するた
め高圧を必要とするが小流量で足りる旋回起動時
や旋回による壁面の押し付け掘削時には、旋回用
ポンプの独立性を保ち、作動機用アクチユエータ
の圧力に影響されることなく旋回力を確保し、一
方、比較的低圧で足りるが所要の旋回速度を得る
ために大流量を必要とする定常旋回時には、旋回
単独操作時でも作動機用アクチユエータとの複合
操作時でも、作業機用回路から圧油を合流させ、
旋回用ポンプ＋作動機用ポンプの吐出量に見合つ
た定常旋回速度が得られるようにすることによつ
て、旋回用ポンプの小型化を達成し、小容量エン
ジンを搭載した小型油圧シヨベルにおいても所要
の旋回トルク、旋回スピードを確保することがで
きる油圧回路を提供することを課題とするもので
ある。 In other words, when starting a swing, which requires high pressure to drive the swing actuator, but requires a small flow rate, or when pressing a wall while excavating, the swing pump maintains its independence and is not affected by the pressure of the operating actuator. On the other hand, during steady swings where a relatively low pressure is sufficient, but a large flow rate is required to obtain the required swing speed, the system can be used for both single swing operation and combined operation with the actuator for the actuator. Combine the pressure oil from the work equipment circuit,
By making it possible to obtain a steady swing speed commensurate with the discharge volume of the swing pump + actuator pump, the swing pump can be made smaller, which is also required for small hydraulic excavators equipped with small-capacity engines. It is an object of the present invention to provide a hydraulic circuit that can secure the turning torque and turning speed of the vehicle.
（課題を解決するための手段）
この考案は上記に鑑みなされたものであつて、
作動機用アクチユエータに接続されたセンターバ
イパス形Ｍ連切換弁５と旋回用アクチユエータに
接続されたセンターバイパス形Ｎ連切換弁６のセ
ンターバイパス５ｄ，６ｄ同志をＭ連切換弁５側
からＮ連切換弁６側への流通のみを許容する逆止
弁８を介して接続し、かつ、前記各切換弁５，６
にはそれぞれ別個の油圧源２，３からの圧油を供
給し、Ｍ連切換弁５の圧油供給管路１０とＮ連切
換弁６の圧油供給管路１１とを互いに管路９によ
り連結すると共に、該管路９に、ノルマルクロー
ズでＮ連切換弁６の定常作動圧より低い設定圧で
開路されるシーケンス弁１２と、ノルマルオープ
ンでＮ連切換弁の定常作動圧より高い設定圧で閉
路される切換弁１３及びこれらの両弁１２，１３
よりもＮ連切換弁６側にＭ連切換弁５への流通を
阻止する逆止弁１５を設け、かつ該シーケンス弁
１２と切換弁１３のパイロツトポートにＮ連切換
弁６の圧油供給管路１１から分岐したパイロツト
管路１６を接続したことにより、複数群の油圧シ
ステムの使用動力を合理的に配分し、上記課題を
解決したものである。(Means for solving the problem) This invention was made in view of the above, and
The center bypass type M-contact switching valve 5 connected to the actuator for the actuator and the center bypass type N-contact switching valve 6 connected to the swing actuator 5d and 6d are N-contacted from the M-contact switching valve 5 side. Connected via a check valve 8 that allows flow only to the valve 6 side, and each of the switching valves 5 and 6
are supplied with pressure oil from separate hydraulic sources 2 and 3, respectively, and the pressure oil supply pipe 10 of the M-switch valve 5 and the pressure oil supply pipe 11 of the N-switch valve 6 are connected to each other by a pipe 9. At the same time, a sequence valve 12 is connected to the pipe line 9, and a sequence valve 12 is normally closed and opened at a set pressure lower than the steady operating pressure of the N-switching valve 6, and a sequence valve 12 is opened at a set pressure higher than the steady operating pressure of the N-switching valve when normally open. The switching valve 13 and both these valves 12, 13 are closed.
A check valve 15 for blocking the flow to the M-series switching valve 5 is provided on the N-series switching valve 6 side, and a pressure oil supply pipe of the N-series switching valve 6 is connected to the pilot ports of the sequence valve 12 and the switching valve 13. By connecting the pilot pipe 16 branched from the line 11, the power used by the hydraulic systems of the plurality of groups can be rationally distributed, and the above-mentioned problem can be solved.
（実施例）
以下、この考案を図面に示した実施例について
説明する。(Example) Hereinafter, an example of this invention shown in the drawings will be described.
１，２，３は油圧ポンプで図示しない動力源
（エンジン）により駆動されている。 Hydraulic pumps 1, 2, and 3 are driven by a power source (engine) not shown.
４はパラレル通路を備えたセンターバイパス形
M1連切換弁で本実施例では３個の切換弁４ａ，
４ｂ，４ｃを有し、これらの切換弁は互にセンタ
ーバイパス４ｄとパラレル管路４ｆとにより連通
されており、前記油圧ポンプ１からの圧油を図示
しないアクチユエータに供給する。 4 is a center bypass type with parallel passage.
In this embodiment , there are three switching valves 4a,
4b and 4c, these switching valves are communicated with each other by a center bypass 4d and a parallel pipe line 4f, and supply pressure oil from the hydraulic pump 1 to an actuator (not shown).
５はパラレル通路を備えたセンターバイパス形
M2連切換弁で本実施例では３個の切換弁５ａ，
５ｂ，５ｃを有し、これらの切換弁は互にセンタ
ーバイパス５ｄとパラレル管路５ｆとにより連通
されており、前記油圧ポンプ２からの圧油を図示
しないアクチユエータに供給する。 5 is a center bypass type with parallel passage.
M Two switching valves, in this embodiment three switching valves 5a,
5b and 5c, these switching valves are communicated with each other by a center bypass 5d and a parallel pipe 5f, and supply pressure oil from the hydraulic pump 2 to an actuator (not shown).
６はセンターバイパス形Ｎ連切換弁で本実施例
では、センターバイパス６ｄを有する１個の切換
弁を有し、前記油圧ポンプ３からの圧油を図示し
ない旋回用アクチユエータに供給する。 Reference numeral 6 denotes a center bypass type N-switching valve, which in this embodiment has one switching valve having a center bypass 6d, and supplies pressure oil from the hydraulic pump 3 to a swing actuator (not shown).
７は前記M2連切換弁５のセンターバイパス５
ｄとＮ連切換弁６のセンターバイパスとを連通す
る管路で、該管路７にはＮ連切換弁６側からM2
連切換弁５側への圧油の流通を阻止する逆止弁８
が介装されている。 7 is the center bypass 5 of the M dual switching valve 5.
d and the center bypass of the N-switch valve 6, and the pipe 7 has an M 2
A check valve 8 that prevents the flow of pressure oil to the continuous switching valve 5 side
is interposed.
９は前記油圧ポンプ２とM2連切換弁５とを連
通する圧油供給管路１０と油圧ポンプ３とＮ連切
換弁６とを連通する圧油供給管路１１とを連通す
る管路で、該管路９には、管路１０側から順次シ
ーケンス弁１２、切換弁１３、リリーフ弁１４及
び管路１１側から管路１０側への圧油の流通を阻
止する逆止弁１５が介装されている。 Reference numeral 9 denotes a pipe that communicates a pressure oil supply pipe 10 that communicates the hydraulic pump 2 and the M double switching valve 5 with a pressure oil supply pipe 11 that communicates the hydraulic pump 3 and the N switching valve 6. A sequence valve 12, a switching valve 13, a relief valve 14, and a check valve 15 for blocking the flow of pressure oil from the pipe line 11 side to the pipe line 10 side are interposed in the pipe line 9 in order from the pipe line 10 side. equipped.
１６はパイロツト管路で、油圧ポンプ３の圧油
供給管路１１から分岐し、前記シーケンス弁１２
及び切換弁１３のパイロツトポートにそれぞれ連
通している。なお、前記シーケンス弁１２と切換
弁１３の介装位置は前後しても差支えない。 Reference numeral 16 denotes a pilot line, which branches from the pressure oil supply line 11 of the hydraulic pump 3 and connects to the sequence valve 12.
and a pilot port of the switching valve 13, respectively. Note that the sequence valve 12 and the switching valve 13 may be installed at different positions.
また、切換弁１３はＮ連切換弁６により作動さ
れる旋回用アクチユエータの定常作動圧より高
く、後述するリリーフ弁１７ｃの設定圧より低く
設定されていて、前記旋回用アクチユエータに定
常作動圧以上の圧力が発生した時に切換わる（管
路９が連通する）ようになつており、かつシーケ
ンス弁１２はＮ連切換弁６が作動位置にあり、圧
油供給管路１１に油圧が発生している時に切換わ
る（管路９が連通する）ようになつている。１７
ａ，１７ｂ，１７ｃはリリーフ弁、１８はタンク
である。 In addition, the switching valve 13 is set higher than the steady operating pressure of the swing actuator operated by the N-switching valve 6, and lower than the set pressure of a relief valve 17c, which will be described later, so that the swing actuator has a pressure higher than the steady operating pressure. The sequence valve 12 is designed to switch when pressure is generated (pipe line 9 communicates), and the N-sequence switching valve 6 of the sequence valve 12 is in the operating position, and hydraulic pressure is generated in the pressure oil supply line 11. It is designed such that the pipe line 9 is switched (the pipe line 9 is brought into communication) from time to time. 17
a, 17b, and 17c are relief valves, and 18 is a tank.
この考案は以上の如き構成である。 This idea has the structure described above.
次にその作用を説明する。 Next, its effect will be explained.
１ Ｎ連切換弁の単独操作時
Ｎ連切換弁６により作動される旋回用アクチユ
エータの起動時において、起動圧力はリリーフ弁
１７ｃの設定圧まで上昇し、徐々に旋回用アクチ
ユエータを加速する。1 When the N-switching valve is operated alone When the swing actuator operated by the N-switching valve 6 is activated, the starting pressure rises to the set pressure of the relief valve 17c, gradually accelerating the swing actuator.
この時、油圧ポンプ３からの吐出圧がパイロツ
ト管路１６を介してシーケンス弁１２及び切換弁
１３に作用しており、かつ、シーケンス弁１２が
切換えられ、管路９を連通するが、この起動圧は
通常切換弁１３の作動圧より高いため切換弁１３
はパイロツト圧により切換えられ、管路９は遮断
される。 At this time, the discharge pressure from the hydraulic pump 3 is acting on the sequence valve 12 and the switching valve 13 via the pilot line 16, and the sequence valve 12 is switched and communicates with the line 9. Since the pressure is normally higher than the operating pressure of the switching valve 13, the switching valve 13
is switched by pilot pressure, and line 9 is shut off.
このため、油圧ポンプ２からの圧油はセンター
バイパス形M2連切換弁５のセンターバイパス５
ｄを通り管路７に介装した逆止弁８までは送られ
るが、通常Ｎ連切換弁６側の方がM2連切換弁５
側より高く設定されているためリリーフ弁１７ｂ
を介してタンク１８に戻される。 Therefore, the pressure oil from the hydraulic pump 2 is transferred to the center bypass type M of the center bypass type M dual switching valve 5.
d to the check valve 8 installed in the conduit 7, but normally the N-switching valve 6 side is the M 2 -switching valve 5.
Since the relief valve 17b is set higher than the
is returned to tank 18 via.
そして、油圧ポンプ３により作動される旋回用
アクチユエータの起動（加速）が完了し定常作動
状態になると旋回用アクチユエータの圧力は起動
圧力から定常圧力に近ずくように低下する。 Then, when the activation (acceleration) of the swing actuator operated by the hydraulic pump 3 is completed and a steady operating state is reached, the pressure of the swing actuator decreases from the starting pressure to approach the steady pressure.
従つて、前述した通り、切換弁１３の作動圧は
Ｎ連切換弁６の旋回用アクチユエータの定常作動
圧より高く設定されているため切換弁１３はパイ
ロツト圧に打勝ち元に戻される（再び切換られ管
路９は連通する）ので、油圧ポンプ２側の圧油の
うち、センターバイパス５ｄを通り管路７に導び
かれた圧油は逆止弁８を介して、また、管路９に
導びかれた圧油は切換弁１３、シーケンス弁１
２、逆止弁１５を介して夫々、油圧ポンプ３側に
合流し、油圧ポンプ３側の圧油量が増加し、旋回
用アクチユエータは大きな（所定の）速度が得ら
れる（第３図）。 Therefore, as described above, since the operating pressure of the switching valve 13 is set higher than the steady operating pressure of the swing actuator of the N-series switching valve 6, the switching valve 13 overcomes the pilot pressure and returns to its original state (switching again). Therefore, among the pressure oil on the hydraulic pump 2 side, the pressure oil led to the pipe line 7 through the center bypass 5d passes through the check valve 8 and into the pipe line 9. The guided pressure oil passes through the switching valve 13 and the sequence valve 1.
2. The oil flows into the hydraulic pump 3 side through the check valve 15, and the amount of pressure oil on the hydraulic pump 3 side increases, allowing the swing actuator to obtain a large (predetermined) speed (FIG. 3).
２ Ｎ連切換弁とM2連切換弁との同時操作時Ｎ
連切換弁６により作動される旋回用アクチユエ
ータは起動時には、前記１で説明した通り油圧
ポンプ３により起動される。2 N when the N switching valve and the M dual switching valve are operated simultaneously
At startup, the swing actuator operated by the connection switching valve 6 is activated by the hydraulic pump 3 as explained in 1 above.
この時、Ｎ連切換弁６側の圧油が切換弁１３の
作動（切換）圧以上となれば切換弁１３は切換わ
り管路９は遮断されると共に、M2連切換弁５の
センターバイパス５ｄは切換弁５ａ，５ｂ，５ｃ
の少くとも一つにより遮断される。 At this time, if the pressure oil on the N-switching valve 6 side becomes higher than the operating (switching) pressure of the switching valve 13, the switching valve 13 is switched and the pipe line 9 is cut off, and the center bypass of the M - switching valve 5 is switched off. 5d is the switching valve 5a, 5b, 5c
is blocked by at least one of the following.
従つて、油圧ポンプ２側の圧油はM2連切換弁
５により作動されるアクチユエータによつて消費
される。 Therefore, the pressure oil on the hydraulic pump 2 side is consumed by the actuator operated by the M double switching valve 5.
次にＮ連切換弁６のアクチユエータが定常運転
状態になると、前述した通りＮ連切換弁６側の油
圧が切換弁１３の作動（復帰）圧以下に低下し、
切換弁１３は元に戻る（管路９は連通する）。こ
のため、油圧ポンプ２と油圧ポンプ３の圧油供給
管路１０と１１は管路９を介して連通される油圧
ポンプ２側の圧油の一部が管路９を介して油圧ポ
ンプ３側に供給される。 Next, when the actuator of the N-series switching valve 6 enters a steady operating state, the oil pressure on the N-switching valve 6 side drops below the operating (return) pressure of the switching valve 13, as described above.
The switching valve 13 returns to its original state (the pipe line 9 is in communication). For this reason, the pressure oil supply lines 10 and 11 of the hydraulic pump 2 and the hydraulic pump 3 are communicated via the line 9, and a part of the pressure oil on the side of the hydraulic pump 2 is transferred via the line 9 to the side of the hydraulic pump 3. supplied to
なお、管路９からの圧油の合流の際、旋回用ア
クチユエータの駆動圧の安定化をはかるためリリ
ーフ弁１４を設けており、この設定圧をリリーフ
弁１７ｃの設定圧より低い値にしている。即ち、
切換弁１３のフルストローク作動圧よりも低く選
ばれている。 In addition, in order to stabilize the driving pressure of the swing actuator when the pressure oil from the pipe 9 joins, a relief valve 14 is provided, and this set pressure is set to a value lower than the set pressure of the relief valve 17c. . That is,
The pressure is selected to be lower than the full stroke operating pressure of the switching valve 13.
３ M2連切換弁の単独操作時
Ｎ連切換弁６は中立位置にありかつ逆止弁８，
１５によりＮ連切換弁６側からM2連切換弁５側
への圧油の流通は阻止されているので、油圧ポン
プ３からの圧油はセンターバイパス６ｄを通りタ
ンク１８に戻される。3 M When the two- way switching valve is operated independently, the N-switching valve 6 is in the neutral position and the check valve 8,
15 prevents the flow of pressure oil from the N-series switching valve 6 side to the M - series switching valve 5 side, so the pressure oil from the hydraulic pump 3 is returned to the tank 18 through the center bypass 6d.
一方、M2連切換弁５とＮ連切換弁６の圧油供
給管路１０，１１とを連通する管路９に設けたシ
ーケンス弁１２と切換弁１３はＮ連切換弁６の圧
油供給管路１１に油圧が発生しないので、夫々の
パイロツトポートにもパイロツト圧は作用せず、
シーケンス弁１２と切換弁１３は共に作動しない
（第２図に示した状態）から、管路９はシーケン
ス弁１２によつて遮断されているので、油圧ポン
プ２からの圧油が管路９を介してＮ連切換弁６側
に供給されることもないので、油圧ポンプ２から
の圧油は全量M2連切換弁５側のアクチユエータ
によつて消費される。 On the other hand, a sequence valve 12 and a switching valve 13 provided in a pipe line 9 that communicates the pressure oil supply lines 10 and 11 of the M double switching valve 5 and the N switching valve 6 supply pressure oil to the N switching valve 6. Since no hydraulic pressure is generated in the pipe line 11, no pilot pressure acts on each pilot port.
Since both the sequence valve 12 and the switching valve 13 do not operate (the state shown in FIG. 2), the pipeline 9 is blocked by the sequence valve 12, so that the pressure oil from the hydraulic pump 2 does not flow through the pipeline 9. Since the pressure oil from the hydraulic pump 2 is not supplied to the N-switching valve 6 side via the M-switching valve 6, the entire amount of pressure oil from the hydraulic pump 2 is consumed by the actuator on the M 2 -switching valve 5 side.
（考案の効果）
以上の通り本考案によれば、M2連切換弁５を
単独操作する場合、シーケンス弁１２により管路
９を遮断して油圧ポンプ２側の独立性を保つと共
に、Ｎ連切換弁６の単独操作或いは、Ｎ連切換弁
６とM2連切換弁５との同時操作時には、Ｎ連切
換弁６側の油圧に応じてシーケンス弁１２と切換
弁１３とを操作して、管路９を選択的に連通又は
遮断することにより、油圧ポンプ３側の旋回用ア
クチユエータの起動時には油圧ポンプ３側は独立
状態に保たれ起動に必要な高い油圧を得ることを
可能とし、かつ起動後定常運転時には油圧ポンプ
２側からの圧油が油圧ポンプ３側に合流し所望の
定常旋回速度を得るに必要な圧油量が得られる。(Effects of the invention) As described above, according to the present invention, when the M two -way switching valve 5 is operated independently, the sequence valve 12 shuts off the pipe line 9 to maintain the independence of the hydraulic pump 2 side, and the N-way switching valve 5 is operated independently. When operating the switching valve 6 alone or operating the N switching valve 6 and the M double switching valve 5 simultaneously, the sequence valve 12 and the switching valve 13 are operated according to the oil pressure on the N switching valve 6 side. By selectively communicating or blocking the pipe line 9, when the turning actuator on the hydraulic pump 3 side is started, the hydraulic pump 3 side is kept in an independent state, making it possible to obtain the high oil pressure necessary for starting, and During the post-steady operation, the pressure oil from the hydraulic pump 2 side joins the hydraulic pump 3 side, and the amount of pressure oil necessary to obtain the desired steady rotation speed is obtained.
即ち、油圧ポンプ２と３の油圧の関係で油圧ポ
ンプ３側が低圧となつた時（定常運転時）には油
圧ポンプ３側が油圧ポンプ２側からの圧油で増速
されて所望の旋回速度が得られ、逆に油圧ポンプ
３側が高圧時（起動時）には油圧ポンプ３側の独
立性が保たれる。 That is, when the pressure on the hydraulic pump 3 side becomes low due to the relationship between the oil pressures of the hydraulic pumps 2 and 3 (during steady operation), the speed of the hydraulic pump 3 side is increased by the pressure oil from the hydraulic pump 2 side, and the desired rotation speed is achieved. On the other hand, when the pressure on the hydraulic pump 3 side is high (at startup), the independence of the hydraulic pump 3 side is maintained.
従つて、従来の３油圧ポンプの場合に比較し、
第３ポンプ（油圧ポンプ３）を小容量ポンプと
し、該ポンプで無駄に消費する馬力が少なくな
り、その分第１、第２の油圧ポンプ（油圧ポンプ
１，２）に大きな動力（馬力）を配分することが
可能となる等の効果を有する。 Therefore, compared to the conventional three-hydraulic pump,
The third pump (hydraulic pump 3) is a small-capacity pump, which reduces the amount of horsepower wasted by the pump, and increases power (horsepower) to the first and second hydraulic pumps (hydraulic pumps 1 and 2) accordingly. This has the effect of making it possible to allocate funds.
このように本考案によれば、実用新案登録請求
の範囲記載の構成を備えることにより、旋回用ア
クチユエータを駆動するため高圧を必要とするが
小流量で足りる旋回起動時や旋回による壁面の押
し付け掘削時（高トルクを必要とするが低速旋回
で足りる場合）には、旋回用ポンプの独立性を保
ち、作動機用アクチユエータの圧力に影響される
ことなく所要の旋回力を確保し、一方、比較的低
圧で足りるが所要の旋回速度を得るために大流量
を必要とする定常旋回時（低トルクで足りるが旋
回速度を必要とする場合）には、旋回単独操作時
でも作動機用アクチユエータとの複合操作時であ
つても、作業機用回路から圧油を合流させ、旋回
用ポンプ＋作動機用ポンプの吐出量に見合つた定
常旋回速度が得られるような油圧回路を提供する
ことができるので、旋回用ポンプを小型化するこ
とが可能となり小容量エンジンを搭載した小型油
圧シヨベルにおいても所要の旋回トルク、旋回ス
ピードを確保することができる等実用上顕著な効
果がある。 As described above, according to the present invention, by having the configuration described in the claimed scope of utility model registration, high pressure is required to drive the swing actuator, but a small flow rate is sufficient during swing start-up and wall pressing excavation due to swing. (when high torque is required but low-speed swing is sufficient), the independence of the swing pump is maintained and the required swing force is secured without being affected by the pressure of the actuator for the actuator. During steady swinging, where low pressure is sufficient but high flow rate is required to obtain the required swinging speed (when low torque is sufficient but high swinging speed is required), it is necessary to connect the actuator for the actuator even when swinging alone Even during combined operations, it is possible to provide a hydraulic circuit that merges pressure oil from the work equipment circuit and provides a steady swing speed commensurate with the discharge amount of the swing pump + actuator pump. , it is possible to downsize the swing pump, and the required swing torque and speed can be ensured even in a small hydraulic excavator equipped with a small-capacity engine, which has significant practical effects.
第１図は従来の３ポンプ形油圧回路図、第２図
は本考案の油圧回路図、第３図は本考案のＮ連切
換弁側の圧力線図である。
図において；１，２，３……油圧ポンプ、４，
５……Ｍ連切換弁、６……Ｎ連切換弁、１０，１
１……圧油供給管路、１２……シーケンス弁、１
３……切換弁、１５……逆止弁、１６……パイロ
ツト管路。
FIG. 1 is a conventional three-pump type hydraulic circuit diagram, FIG. 2 is a hydraulic circuit diagram of the present invention, and FIG. 3 is a pressure diagram on the N-switching valve side of the present invention. In the figure; 1, 2, 3...hydraulic pump, 4,
5...M switching valve, 6...N switching valve, 10,1
1...Pressure oil supply pipe, 12...Sequence valve, 1
3...Switching valve, 15...Check valve, 16...Pilot conduit.
Claims (1)
バイパス形Ｍ連切換弁と旋回用アクチユエータに
接続されたセンターバイパス形Ｎ連切換弁のセン
ターバイパス同志をＭ連切換弁側からＮ連切換弁
側への流通のみを許容する逆止弁を介して接続
し、かつ、前記各切換弁にはそれぞれ別個の油圧
源からの圧油を供給し、Ｍ連切換弁の圧油供給管
路とＮ連切換弁の圧油供給管路とを互いに管路に
より連結すると共に、該管路に、ノルマルクロー
ズでＮ連切換弁の定常作動圧より低い設定圧で開
路されるシーケンス弁と、ノルマルオープンでＮ
連切換弁の定常作動圧より高い設定圧で閉路され
る切換弁及びこれらの両弁よりもＮ連切換弁側に
Ｍ連切換弁への流通を阻止する逆止弁を設け、か
つ、該シーケンス弁と切換弁のパイロツトポート
にＮ連切換弁の圧油供給管路から分岐したパイロ
ツト管路を接続したことを特徴とする油圧シヨベ
ルの油圧回路。 The center bypass type M-switching valve connected to the actuator for the actuator and the center bypass type N-switching valve connected to the swing actuator are only allowed to flow from the M-switching valve side to the N-switching valve side. The switching valves are connected via check valves that allow for The oil supply pipes are connected to each other by a pipe, and the pipe is equipped with a sequence valve that is normally closed and opened at a set pressure lower than the steady operating pressure of the N-switch valve, and a sequence valve that is normally open and opens at a set pressure lower than the steady operating pressure of the N-switch valve.
A switching valve that closes at a set pressure higher than the steady operating pressure of the continuous switching valve, and a check valve that prevents flow to the M switching valve on the side of the N switching valve from both of these valves, and the sequence A hydraulic circuit for a hydraulic excavator, characterized in that a pilot pipe branched from a pressure oil supply pipe of an N-switching valve is connected to a pilot port of a valve and a switching valve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1981071981U JPH0211491Y2 (en) | 1981-05-20 | 1981-05-20 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1981071981U JPH0211491Y2 (en) | 1981-05-20 | 1981-05-20 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57184169U JPS57184169U (en) | 1982-11-22 |
| JPH0211491Y2 true JPH0211491Y2 (en) | 1990-03-23 |
Family
ID=29867769
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1981071981U Expired JPH0211491Y2 (en) | 1981-05-20 | 1981-05-20 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0211491Y2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10332024A (en) * | 1997-05-27 | 1998-12-15 | Fuji Koki Corp | Motor operated valve |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS597409Y2 (en) * | 1978-06-15 | 1984-03-07 | 日立建機株式会社 | Hydraulic circuit of hydraulic excavator loader |
| JPS594164Y2 (en) * | 1978-12-25 | 1984-02-06 | 株式会社小松製作所 | pressure control valve device |
-
1981
- 1981-05-20 JP JP1981071981U patent/JPH0211491Y2/ja not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10332024A (en) * | 1997-05-27 | 1998-12-15 | Fuji Koki Corp | Motor operated valve |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57184169U (en) | 1982-11-22 |
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