JP2766365B2 - Hydraulic circuit of excavator - Google Patents
Hydraulic circuit of excavatorInfo
- Publication number
- JP2766365B2 JP2766365B2 JP2041140A JP4114090A JP2766365B2 JP 2766365 B2 JP2766365 B2 JP 2766365B2 JP 2041140 A JP2041140 A JP 2041140A JP 4114090 A JP4114090 A JP 4114090A JP 2766365 B2 JP2766365 B2 JP 2766365B2
- Authority
- JP
- Japan
- Prior art keywords
- traveling
- pump
- switching valve
- valve
- switching
- 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
Landscapes
- Fluid-Pressure Circuits (AREA)
- Operation Control Of Excavators (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は油圧ショベルの油圧回路に関するものであ
る。Description: TECHNICAL FIELD The present invention relates to a hydraulic circuit of a hydraulic shovel.
（従来技術） 一般に油圧ショベルは旋回体及び走行体の外に、ブー
ム、アーム及びバケットなどから成るアタッチメントを
備えており、これらはそれぞれ旋回モータ、左右走行モ
ータ、ブームシリンダ、アームシリンダ、バケットシリ
ンダなどの油圧アクチュエータによって駆動される。そ
してこれらの油圧アクチュエータは方向切換弁によりそ
れぞれ単独にあるいは複合して制御される。(Prior Art) In general, a hydraulic shovel is provided with attachments including a boom, an arm, a bucket, and the like, in addition to a revolving unit and a traveling unit, and these respectively include a swing motor, a left and right traveling motor, a boom cylinder, an arm cylinder, a bucket cylinder, and the like. Driven by a hydraulic actuator. These hydraulic actuators are controlled individually or in combination by a direction switching valve.
従来最も一般的な油圧駆動方式はこれらの方向切換弁
を２つのグループに分け、各グループを別個の油圧ポン
プに接続すると共に、各グループ内では方向切換弁を油
圧ポンプに対して並列に接続していた。この従来型の油
圧回路の一例を第２図に示す。Conventionally, the most common hydraulic drive system divides these directional control valves into two groups, and connects each group to a separate hydraulic pump, and in each group, connects the directional control valve in parallel to the hydraulic pump. I was FIG. 2 shows an example of this conventional hydraulic circuit.
第２図において1,2は油圧ポンプである。油圧ポンプ
１に対して左走行モータ３、旋回モータ５、アームシリ
ンダ６が第１のグループを形成している。又油圧ポンプ
２に対して右走行モータ４、ブームシリンダ７、バケッ
トシリンダ８が第２のグループを形成している。各アク
チュエータの作動を制御する方向制御弁として、ポンプ
１に対して左走行切換弁11、ブーム２速切換弁13、旋回
切換弁14、アーム切換弁15がそれぞれ並列に接続され、
又ポンプ２に対して右走行切換弁12、ブーム切換弁18、
バケット切換弁17、予備切換弁16がそれぞれ並列に接続
されている。In FIG. 2, reference numerals 1 and 2 denote hydraulic pumps. The left traveling motor 3, the turning motor 5, and the arm cylinder 6 form a first group with respect to the hydraulic pump 1. The right traveling motor 4, the boom cylinder 7, and the bucket cylinder 8 form a second group with respect to the hydraulic pump 2. As a directional control valve for controlling the operation of each actuator, a left travel switching valve 11, a boom second speed switching valve 13, a swing switching valve 14, and an arm switching valve 15 are connected in parallel to the pump 1, respectively.
Also, for the pump 2, the right travel switching valve 12, the boom switching valve 18,
The bucket switching valve 17 and the spare switching valve 16 are respectively connected in parallel.
19は前記切換弁11の上流に設置した走行直進弁であ
り、ポンプ１の吐出油ラインの中立流路34上及びポンプ
２の吐出油ラインの並列流路37上最上流に設けている。
方向切換弁11乃至18はそれぞれ主切換弁の切換に連動し
て信号用油圧ラインを遮断する補助切換弁21乃至28を有
している。Numeral 19 is a straight traveling valve installed upstream of the switching valve 11, and is provided on the neutral flow path 34 of the discharge oil line of the pump 1 and the uppermost stream on the parallel flow path 37 of the discharge oil line of the pump 2.
The direction switching valves 11 to 18 have auxiliary switching valves 21 to 28 for shutting off the signal hydraulic line in conjunction with the switching of the main switching valve, respectively.
次にパイロットポンプ31により発生したパイロット圧
油はオペレータのレバー操作により操作用パイロットバ
ルブ29,30等（図では走行のみを示す）を介して適宜前
記方向切換弁11乃至18の両端に導かれ、方向切換弁を切
換え、各アクチュエータを作動させる。Next, the pilot pressure oil generated by the pilot pump 31 is appropriately guided to both ends of the direction switching valves 11 to 18 through operating pilot valves 29, 30 and the like (only traveling is shown in the figure) by lever operation of an operator, The direction switching valve is switched, and each actuator is operated.
さらにこのパイロット圧油は信号用として用いられ
る。すなわち信号用油圧ライン32aは補助切換弁21を、
信号用油圧ライン32bは補助切換弁22を、信号用油圧ラ
イン32cは補助切換弁23,24,25,26,27及び28をこの順に
介してタンクへ連通している。信号用油圧ライン32dは
油圧ライン32cから分岐して前述走行直進弁のポートへ
導かれる。尚ここでパイロットポンプ31で発生する圧油
は、信号用油圧ライン32a,32b,32cがタンクへ連通して
いるにもかかわらず、絞り33により確保され前述パイロ
ットバルブ29,30等へ導かれ、操作を可能としている。Further, the pilot pressure oil is used for a signal. That is, the signal hydraulic line 32a connects the auxiliary switching valve 21,
The signal hydraulic line 32b communicates with the auxiliary switching valve 22, and the signal hydraulic line 32c communicates with the tank via the auxiliary switching valves 23, 24, 25, 26, 27 and 28 in this order. The signal hydraulic line 32d branches off from the hydraulic line 32c and is led to the port of the above-mentioned straight traveling valve. The pressure oil generated by the pilot pump 31 is secured by the throttle 33 and guided to the pilot valves 29, 30, etc., despite the signal hydraulic lines 32a, 32b, 32c being connected to the tank, Operation is possible.
左走行切換弁11の入口ポートは、入口ポート38側への
み圧油を供給する逆止弁付絞り弁39を介して油圧ポンプ
１の並列流路35に接続されている。ブーム２速切換弁13
とブーム切換弁18の入口ポートは管路40で接続され、ブ
ーム上げ操作時の２ポンプ合流を可能にしている。The inlet port of the left travel switching valve 11 is connected to the parallel flow path 35 of the hydraulic pump 1 via a throttle valve 39 with a check valve that supplies pressure oil only to the inlet port 38 side. Boom second speed switching valve 13
The boom switching valve 18 is connected to the inlet port of the boom switching valve 18 by a line 40, so that the two pumps can be joined at the time of the boom raising operation.
更に本回路はアーム切換弁15と旋回切換弁14を同時に
操作した場合の旋回加速力低下を防止する為の絞り41を
有している。油圧ポンプ１及び２はその中立流路34及び
36の最下流にポンプコントロール弁42及び43を介してタ
ンク44に連通し、また上流の各方向切換弁が中立状態す
なわち何も仕事をしていない時にはポンプ1,2の吐出量
を最少の位置に保持するレギュレータ45,46を有してい
る。ポンプ1,2,3はそれぞれその吐出圧力を設定するリ
リーフ弁47,48,49を回路中に有している。Further, this circuit has a throttle 41 for preventing a decrease in the turning acceleration force when the arm switching valve 15 and the turning switching valve 14 are simultaneously operated. Hydraulic pumps 1 and 2 have neutral paths 34 and
The pump is connected to the tank 44 via the pump control valves 42 and 43 at the most downstream position of the pump 36, and when the upstream directional control valves are in a neutral state, that is, when no work is performed, the discharge amount of the pumps 1 and 2 is set to the minimum position. , And regulators 45 and 46 to be held. Each of the pumps 1, 2, 3 has a relief valve 47, 48, 49 for setting its discharge pressure in the circuit.
上記の如き構成である油圧回路の特徴は走行と他のア
クチュエータを同時操作した場合の走行の直進性を確保
するものであり、その作動を説明すると次の通りであ
る。The feature of the hydraulic circuit having the above configuration is to secure the straightness of traveling when traveling and other actuators are simultaneously operated. The operation of the hydraulic circuit will be described below.
（１）走行のみを操作した場合； 左走行切換弁11のみ、または右走行切換弁12のみ、あ
るいは左右切換弁を同時に操作した場合、信号用油圧ラ
イン32a及び32bは補助切換弁21及び22が断位置となるた
め遮断されるが、他のアクチュエータを操作していない
ため信号用油圧ライン32cはタンクに連通したままであ
る。従って信号用油圧ライン32dに圧油は発生せず走行
直進弁19は切換らない。これにより左走行モータ３はポ
ンプ１の流量を、右走行モータ４はポンプ２の流量をそ
れぞれ吸収し、独立に駆動される。(1) When only traveling is operated; When only the left traveling switching valve 11 or only the right traveling switching valve 12 is operated, or the left and right switching valves are simultaneously operated, the signal switching hydraulic lines 32a and 32b are connected to the auxiliary switching valves 21 and 22. Although it is cut off because of the disconnection position, the signal hydraulic line 32c remains in communication with the tank because no other actuator is operated. Therefore, no pressure oil is generated in the signal hydraulic line 32d, and the straight traveling valve 19 is not switched. As a result, the left traveling motor 3 absorbs the flow rate of the pump 1 and the right traveling motor 4 absorbs the flow rate of the pump 2, and are driven independently.
（２）走行以外のアクチュエータのみを操作した場合； 走行以外の切換弁13乃至18のいずれか１個以上の切換
弁を操作した場合、上記と同様に信号用油圧ライン32c
はいずれかの補助切換弁により遮断されるが、信用用油
圧ライン32a及び32bがタンクに連通しており、信号用油
圧ライン32dに圧油が発生せず、走行直進弁19は切換ら
ない。これにより走行以外のアクチュエータもポンプ１
及び２の流量をそのまま吸収する。(2) When only the actuator other than traveling is operated; When one or more of the switching valves 13 to 18 other than traveling is operated, the signal hydraulic line 32c is operated in the same manner as described above.
Is shut off by any of the auxiliary switching valves, but the hydraulic lines for credit 32a and 32b are in communication with the tank, no hydraulic oil is generated in the hydraulic line for signal 32d, and the traveling straight valve 19 is not switched. As a result, the actuator other than the traveling can
And 2 are absorbed as they are.
（３）走行を左右同時に操作中に他のアクチュエータを
操作した場合； 信号用油圧ライン32a,32bがそれぞれ左右走行切換弁1
1,12に連動した補助切換弁21,22により遮断され、かつ
信号用油圧ライン32cが他のアクチュエータの切換弁に
連動した補助切換弁により遮断されるので、信号用油圧
ライン32dに圧油が発生し走行直進弁19が位置19bに切換
る。これによりポンプ２の圧油が走行切換弁11,12を介
して左右の走行モータ3,4を並列に駆動し、ポンプ１が
他のアクチュエータを並列に駆動する。このことはすな
わち左右走行による直進中にブーム上げ、旋回などの他
の作動を行なっても、ポンプ１の圧油が左右走行モータ
に優先的に供給され、且つ並列供給による走行の直進性
を保証するものである。尚この場合ポンプ２にて２個の
モータを同時に駆動する為、走行のみを操作した場合の
走行速度の半分すなわち0.5速となる。(3) When other actuators are operated while running the left and right simultaneously; the signal hydraulic lines 32a and 32b
Since the auxiliary switching valves 21 and 22 interlocked with the switching valves 1 and 12 and the signal hydraulic line 32c are interrupted by the auxiliary switching valve interlocked with the switching valves of the other actuators, hydraulic oil is supplied to the signal hydraulic line 32d. Then, the straight travel valve 19 is switched to the position 19b. As a result, the pressure oil of the pump 2 drives the left and right traveling motors 3 and 4 in parallel via the traveling switching valves 11 and 12, and the pump 1 drives the other actuators in parallel. That is, even if other operations such as boom raising and turning are performed during the straight traveling by the left and right traveling, the pressure oil of the pump 1 is preferentially supplied to the left and right traveling motors, and the straight traveling of the traveling by the parallel supply is guaranteed. Is what you do. In this case, since two motors are simultaneously driven by the pump 2, the traveling speed becomes half of the traveling speed when only traveling is operated, that is, 0.5 speed.
次に逆止弁付絞り弁39について説明すると、走行直進
中にひんぱんに他のアクチュエータをON−OFF的に操作
した場合、走行直進弁19の断続的切換えに伴って走行速
度が１速−0.5速とひんぱんに切換り本体動作にショッ
クを伴うこととなる。そこでこのチェック弁付絞り弁39
の開度を適当に設定することにより、例えばブーム上
げ、アーム上げなどの走行回路より駆動圧力が高い部分
を一部走行回路へ供給して走行速度の急変を防止し、ま
た走行中に旋回操作をした場合は、一般に旋回起動圧は
回転のリリーフ圧力まで上昇し、旋回加速中はそのほと
んどがリリーフ弁よりタンクへ捨てられることになる
が、この絞り弁39により一部を走行回路へ供給できるの
で走行速度の向上を図ることができる。Next, the throttle valve 39 with a check valve will be described. If the other actuator is frequently operated in an ON-OFF manner during the straight traveling of the vehicle, the traveling speed becomes 1-0.5 with the intermittent switching of the straight traveling valve 19. Switching between speed and frequent will cause a shock to the body operation. Therefore, this throttle valve with check valve 39
By setting the degree of opening appropriately, parts with higher driving pressure than the traveling circuit, such as raising the boom and arm, are supplied to some traveling circuits to prevent sudden changes in traveling speed, and also to perform turning operations during traveling. In general, the turning start pressure rises to the relief pressure of rotation, and during turning acceleration, most of the turning start pressure is discarded from the relief valve to the tank, but a part of the throttle valve 39 can be supplied to the traveling circuit. Therefore, the traveling speed can be improved.
尚第１図では逆止弁付絞り弁39から左走行切換弁11に
のみ余剰油を供給しているが、ポンプ２が並列に走行モ
ータ3,4を駆動しているので、走行モータの同期性から
直進性は保たれる。In FIG. 1, the excess oil is supplied only from the throttle valve 39 with a check valve to the left traveling switching valve 11, but since the pump 2 drives the traveling motors 3 and 4 in parallel, the synchronous operation of the traveling motors is performed. Straightness is maintained from sex.
以上の様に第２図に示した従来回路は走行直進中に他
のアクチュエータを操作してもポンプ２からの圧油を優
先的に吸収するので走行直進性は保たれ、更に他のアク
チュエータを同時作動してもその余剰油の一部を走行回
路へ供給し、速度アップを向上させる効率的な油圧回路
を提供しているが、次の様な欠点を有している。As described above, the conventional circuit shown in FIG. 2 preferentially absorbs the pressure oil from the pump 2 even if another actuator is operated during the straight traveling, so that the straight traveling property is maintained. Although an efficient hydraulic circuit that supplies a part of the surplus oil to the traveling circuit even at the same time and improves the speed-up is provided, it has the following disadvantages.
即ち、１）直進走行中にブーム下げ、アーム下げなど
の負荷の小さい操作を同時に行なった場合、走行直進弁
が切換り、ポンプ１はブーム下げ、アーム下げなどを駆
動するが、走行回路より低圧のため、絞り弁39より走行
側へ圧油を供給できない。この結果それまでポンプ1,2
と２個のポンプで走行していた本体が急にポンプ２のみ
で走行することになり急減速を起こしてしまう。これを
ひんぱんにくり返す作業では荷揺れ荷こぼれを起こし非
常に操縦しにくいものとなる。That is, 1) When operations with a small load, such as lowering the boom and lowering the arm, are simultaneously performed during straight running, the straight running valve is switched, and the pump 1 drives the lowering of the boom and the lowering of the arm. Therefore, pressure oil cannot be supplied from the throttle valve 39 to the traveling side. As a result of this, pumps 1,2
Then, the main body running with the two pumps suddenly runs only with the pump 2 and sudden deceleration occurs. If this operation is repeated frequently, the cargo will sway and spill, making it very difficult to control.
２）また本回路では走行のみを操作した場合はいわゆる
１速となり、精密な作業を行なう為の微速走行を実現す
るには、別に設けたスロットルレバーによりエンジン回
転数を下げる必要があり操作が面倒である。2) Also, in this circuit, when only traveling is operated, so-called 1st speed is achieved, and in order to realize very low speed traveling for precise work, it is necessary to lower the engine speed by a separately provided throttle lever, which is troublesome operation. It is.
（発明が解決しようとする課題） 油圧ショベルはその汎用性によりあらゆる建設現場で
使用されているが、とりわけ走行については近年高速走
行による機動性改善が進み、現場移動、資材運搬等に威
力を発揮している。ところが資材運搬や生コン打ちなど
の走行しながらの作業には時として微速走行が要求さ
れ、また走行を含む複合操作時において他のアクチュエ
ータの作動の開始や停止時に走行スピードが変化するこ
とは荷揺れ、荷こぼれを誘発し、精密作業をする場合に
好ましくない。(Problems to be solved by the invention) Hydraulic excavators are used at all construction sites due to their versatility, but especially in traveling, the mobility has been improved by high-speed traveling in recent years, and it is effective in moving on site, transporting materials, etc. doing. However, work while traveling, such as transporting materials or mixing ready-mixed concrete, is sometimes required to run at a very low speed.During complex operations including traveling, the running speed changes when starting or stopping the operation of other actuators. However, this is not preferable for inducing spills and performing precision work.
本発明は油圧ショベルの走行作業において、通常速度
より低い微速走行を実現し、更に微速走行時に他のアク
チュエータを作動しても走行スピードが変化しない走行
独立の油圧回路を提供することを目的とするものであ
る。SUMMARY OF THE INVENTION It is an object of the present invention to provide a traveling independent hydraulic circuit that realizes a low-speed traveling at a speed lower than a normal speed in a traveling operation of a hydraulic shovel, and that does not change the traveling speed even when another actuator is operated at the low-speed traveling. Things.
（課題を解決するための手段） 第１のポンプに対して一方の走行切換弁及び走行以外
のアクチュエータを並列に接続し、又第２のポンプに対
して他方の走行切換弁及び走行以外のアクチュエータを
並列に接続し、前記一方の走行切換弁の直前の中立流路
上に、通常時は第１ポンプの中立流路と第２ポンプの並
列流路を構成する第１の位置と、切換時は第１のポンプ
の圧油を第２ポンプの走行以外のアクチュエータ切換弁
に並列に供給し、第２ポンプの圧油を一方の走行切換弁
に供給する流路を構成する第２の位置を有する走行直進
弁を配置した油圧回路において、前記第１ポンプの並列
流路と一方の走行方向切換弁の入口ポート間を通常時は
逆止弁付絞り弁で連通し、切換時には通路を閉塞する位
置を有する切換弁を設置し、また前記第１ポンプの並列
流路と中立流路の最下流部とを通常時は閉塞し、切換時
には連通する位置を有する切換弁を設置し、かつ左右の
走行を同時操作した場合に、前記２つの切換弁が同時に
切換わる様な信号用油圧ラインを構成した。(Means for Solving the Problems) One traveling switching valve and an actuator other than traveling are connected in parallel to a first pump, and the other traveling switching valve and an actuator other than traveling are connected to a second pump. Are connected in parallel, on a neutral flow path immediately before the one travel switching valve, a first position that normally forms a parallel flow path of the first pump neutral flow path and the second pump flow path, It has a second position that constitutes a flow path that supplies the pressure oil of the first pump in parallel to an actuator switching valve other than the traveling of the second pump and supplies the pressure oil of the second pump to one traveling switching valve. In a hydraulic circuit in which a straight traveling valve is disposed, a position between a parallel flow path of the first pump and an inlet port of one of the traveling direction switching valves is normally communicated with a throttle valve with a check valve, and the passage is closed at the time of switching. A switching valve having a In the case where the parallel flow path of the pump and the most downstream part of the neutral flow path are normally closed, a switching valve having a position communicating with each other at the time of switching is installed, and the left and right traveling are simultaneously operated, the two switching valves are used. The hydraulic line for signals is configured so that the pressure changes simultaneously.
（実施例） 第１図に基いて説明する。ただし従来技術と同一構成
要素については第２図の公知回路と同一符号を付してそ
の説明は省く。(Example) A description will be given based on FIG. However, the same components as those in the prior art are denoted by the same reference numerals as those in the known circuit in FIG. 2, and description thereof is omitted.
左走行切換弁11の入口ポート38とポンプ１の並列流路
35を、通常時は逆止弁付絞り弁50aで連通し、信号圧力
を受けた時は閉塞する位置50bを有する２位置切換弁50
を介して接続する。Parallel flow path of inlet port 38 of left travel switching valve 11 and pump 1
The valve 35 communicates normally with a throttle valve 50a with a check valve, and has a position 50b which closes when a signal pressure is applied.
Connect through.
ポンプ１の並列流路35の最下流と中立流路34の最下流
を通常時は閉塞し、信号圧力を受けた時は連通する２位
置切換弁51を介して接続する。The lowermost stream of the parallel flow path 35 of the pump 1 and the lowermost stream of the neutral flow path 34 are normally closed, and are connected via a two-position switching valve 51 which communicates when receiving a signal pressure.
パイロット信号用油圧ライン32c中、ブーム２速補助
切換弁23の直前に電磁切換弁52を設置する。An electromagnetic switching valve 52 is installed in the pilot signal hydraulic line 32c immediately before the boom second speed auxiliary switching valve 23.
切換弁50,51,52の各ポートを52cと51cを信号用油圧ラ
イン53で、52dと51dを信号用油圧ライン54で、更に52d
と50cを信号用油圧ライン55でそれぞれ連通する。Each port of the switching valves 50, 51, 52 is connected to a signal hydraulic line 53 for 52c and 51c, and a signal hydraulic line 54 for 52d and 51d.
And 50c are communicated with each other by a signal hydraulic line 55.
（作用） 第１図において電磁切換弁52が通常位置52aにあると
きは、パイロットポンプ31の吐出油は信号用油圧ライン
32cから32e、補助切換弁23乃至28を経てタンク44へ連通
しているため、信号用油圧ライン53,54,55に圧油は発生
せず、従って切換弁50,51は切換らず、従来回路と何ら
機能的に変らない。(Operation) When the electromagnetic switching valve 52 is at the normal position 52a in FIG. 1, the oil discharged from the pilot pump 31 is supplied to the signal hydraulic line.
Since it communicates with the tank 44 through 32c to 32e and the auxiliary switching valves 23 to 28, no pressure oil is generated in the signal hydraulic lines 53, 54, 55, and therefore, the switching valves 50, 51 do not switch. It is not functionally different from the circuit.
次に電磁切換弁52を52b位置に切換えると、信号用油
圧ライン54,55はパイロットポンプに連通し、また信号
用油圧ライン32e,53は電磁切換弁52b内の絞り56を介し
てパイロットポンプに連通する。一方信号用油圧ライン
32a,32bは従来通り補助切換弁21,22を経てタンクへ通じ
ている。Next, when the electromagnetic switching valve 52 is switched to the position 52b, the signal hydraulic lines 54 and 55 communicate with the pilot pump, and the signal hydraulic lines 32e and 53 communicate with the pilot pump via the throttle 56 in the electromagnetic switching valve 52b. Communicate. On the other hand, hydraulic line for signal
32a and 32b communicate with the tank via auxiliary switching valves 21 and 22 as before.
さて電磁切換弁52を52bに切換えた状態で、オペレー
タが左右の走行切換弁11及び12を同時に切換えると、連
動した補助切換弁21,22が信号用油圧ライン32a及び32b
を閉塞し、電磁切換弁52b中の絞り56により信号用油圧
ライン32dに圧力が発生する。同時に走行直進弁19は19b
に切換り、更に電磁切換弁52bを介して信号通路54,55に
同じ圧力が発生し、切換弁50,51をそれぞれ50b,51bに切
換える。When the operator switches the left and right traveling switching valves 11 and 12 simultaneously with the electromagnetic switching valve 52 switched to 52b, the linked auxiliary switching valves 21 and 22 are connected to the signal hydraulic lines 32a and 32b.
And the throttle 56 in the electromagnetic switching valve 52b generates pressure in the signal hydraulic line 32d. At the same time, the straight travel valve 19 is 19b
Then, the same pressure is generated in the signal passages 54 and 55 via the electromagnetic switching valve 52b, and the switching valves 50 and 51 are switched to 50b and 51b, respectively.
これによりポンプ１は切換弁50が閉塞され切換弁51が
開くので、走行切換弁11への応援を断たれ、並列流路の
最下流からタンクへ戻ることとなり、ポンプ２で左右走
行切換弁11,12を並列に駆動するため、通常走行速度の
半分つまり0.5速走行を実現できる。As a result, the switching valve 50 is closed and the switching valve 51 is opened, the support of the traveling switching valve 11 is cut off, and the pump 1 returns to the tank from the lowermost stream of the parallel flow path. , 12 are driven in parallel, so that half the normal traveling speed, that is, 0.5 speed traveling can be realized.
次に走行0.5速で直進中に走行以外のアクチュエータ
を操作した場合は、補助切換弁23乃至28の少なくとも１
個以上が信号用油圧ライン32eを遮断するため、信号用
油圧ライン53にも圧力が発生し、これは切換弁51の他方
のポート51cに作用する。切換弁51は両端ポートに同じ
圧力を受けるためつりあうが、バネ力により中立流路を
閉塞する位置51aに保持される。Next, when an actuator other than traveling is operated while traveling straight at the traveling 0.5 speed, at least one of the auxiliary switching valves 23 to 28 is operated.
Since more than one unit shuts off the signal hydraulic line 32e, pressure is also generated in the signal hydraulic line 53, which acts on the other port 51c of the switching valve 51. The switching valve 51 receives the same pressure at the ports at both ends and balances, but is held at the position 51a where the neutral flow path is closed by the spring force.
つまり走行0.5速直進中に走行以外のアクチュエータ
を同時操作した場合、ポンプ２の圧油は左右走行モータ
3,4に並列に供給され、微速走行を実現すると共に、ポ
ンプ１の圧油は切換弁50,51がいずれも閉位置50b,51aに
保持されることにより、操作された走行以外のアクチュ
エータにのみ供給される。これにより走行と他のアクチ
ュエータの独立性が保証される。In other words, when the actuators other than the traveling are operated simultaneously during traveling 0.5 speed straight ahead, the pressure oil of the pump 2
3 and 4 are supplied in parallel to achieve a very low speed traveling, and the pressure oil of the pump 1 is supplied to the actuators other than the operated traveling by holding the switching valves 50 and 51 at the closed positions 50b and 51a. Only supplied. This ensures independence of travel and other actuators.
（効果） 本発明の回路によれば、あらかじめ別途設けたスイッ
チ等により電磁切換弁52を52b位置に切換えることによ
り、左右走行のみを同時操作した場合に、ポンプ２の圧
油を走行モータ3,4で等分する為、従来回路の半分の走
行速度（0.5速）を実現できる。また該微速走行中に他
のアクチュエータを操作してもポンプ１は走行回路へ圧
油を供給し得ないので走行の独立性が保証される。(Effect) According to the circuit of the present invention, when the electromagnetic switching valve 52 is switched to the position 52b by a switch or the like separately provided in advance, when only the left and right traveling is simultaneously operated, the hydraulic oil of the pump 2 is supplied to the traveling motor 3, Since it is equally divided by four, half the traveling speed (0.5 speed) of the conventional circuit can be realized. In addition, even if another actuator is operated during the low-speed traveling, the pump 1 cannot supply the pressure oil to the traveling circuit, so that the traveling independence is guaranteed.
すなわち油圧ショベルで走行しながらアタッチメント
を操作して、例えばバケット内土砂の排土や生コン打ち
などを行なう時も走行速度に変化なく、なめらかな精密
作業が可能となる。もちろん電磁切換弁52を通常位置52
aに戻すと従来通り走行速度アップが可能となる。In other words, when the attachment is operated while traveling with the hydraulic excavator, for example, when soil is removed from the bucket or when the raw concrete is cast, smooth running can be performed without any change in traveling speed. Of course, the electromagnetic switching valve 52 is moved to the normal position 52.
Returning to a allows the running speed to be increased as before.
第１図は本発明に係る油圧回路。 第２図は公知油圧回路を示す。 図において； 1,2……油圧ポンプ、３……左走行モータ ４……右走行モータ、５……旋回モータ ６……アームシリンダ、７……ブームシリンダ ８……バケットシリンダ、11……左走行切換弁 12……右走行切換弁、13……ブーム２速切換弁 14……旋回切換弁、15……アーム切換弁 16……予備切換弁、17……バケット切換弁 18……ブーム切換弁、19……走行直進弁 21,22,23,24,25,26,27,28……補助切換弁 29,30……パイロットバルブ 31……パイロットポンプ 32a,32b,32c,32d,32e……信号用油圧ライン 33……絞り、34……中立流路 35……並列流路、36……中立流路 37……並列流路、38……入口ポート 39……絞り弁、40……管路 41……絞り 42,43……ポンプコントロール弁 44……タンク、45,46……レギュレータ 47,48,49……リリーフ弁、50……２位置切換弁 50a……絞り弁、50b……（閉塞する）位置 51……２位置切換弁、52……電磁切換弁 53,54,55……信号用油圧ライン 56……絞り FIG. 1 shows a hydraulic circuit according to the present invention. FIG. 2 shows a known hydraulic circuit. In the figure: 1,2 ... hydraulic pump, 3 ... left traveling motor 4 ... right traveling motor, 5 ... slewing motor 6 ... arm cylinder, 7 ... boom cylinder 8 ... bucket cylinder, 11 ... left Travel switching valve 12 ... Right traveling switching valve, 13 ... Boom 2-speed switching valve 14 ... Swirl switching valve, 15 ... Arm switching valve 16 ... Preliminary switching valve, 17 ... Bucket switching valve 18 ... Boom switching Valve, 19: Traveling straight valve 21, 22, 23, 24, 25, 26, 27, 28 Auxiliary switching valve 29, 30 Pilot valve 31 Pilot pump 32a, 32b, 32c, 32d, 32e ... Signal hydraulic line 33 ... Throttle, 34 ... Neutral flow path 35 ... Parallel flow path, 36 ... Neutral flow path 37 ... Parallel flow path, 38 ... Inlet port 39 ... Throttle valve, 40 ... Pipe line 41… Throttle 42,43… Pump control valve 44 …… Tank, 45,46 …… Regulator 47,48,49 …… Relief valve, 50 …… Two-position switching valve 50a …… Throttle valve, 50b ... (closing) position 51 ...... 2-position switching valve, hydraulic line 56 ...... diaphragm 52 ...... electromagnetic switching valve 53, 54, 55 ...... signals
Claims (1)
び走行以外のアクチュエータを並列に接続し、又第２の
ポンプに対して他方の走行切換弁及び走行以外のアクチ
ュエータを並列に接続し、前記一方の走行切換弁の直前
の中立流路上に、通常時は第１ポンプの中立流路と第２
ポンプの並列流路を構成する第１の位置と、切換時には
第１のポンプの圧油を第２ポンプの走行以外のアクチュ
エータ切換弁に並列に供給し、第２ポンプの圧油を一方
の走行切換弁に供給する流路を構成する第２の位置を有
する走行直進弁を配置した油圧回路において、前記第１
ポンプの並列流路と一方の走行方向切換弁の入口ポート
間を通常時は逆止弁付絞り弁で連通し、切換時には通路
を閉塞する位置を有する切換弁を設置し、また前記第１
ポンプの並列流路と中立流路の最下流部とを通常時は閉
塞し、切換時には連通する位置を有する切換弁を設置
し、かつ左右の走行を同時操作した場合に、前記２つの
切換弁が同時に切換わる様な信号用油圧ラインを構成し
たことを特徴とする油圧ショベルの油圧回路。1. A travel switching valve and a non-traveling actuator are connected in parallel to a first pump, and the other travel switching valve and a non-traveling actuator are connected in parallel to a second pump. Normally, the neutral flow path of the first pump is placed on the neutral flow path immediately before the one travel switching valve.
At the first position forming the parallel flow path of the pump, and at the time of switching, the pressure oil of the first pump is supplied in parallel to the actuator switching valve other than the travel of the second pump, and the pressure oil of the second pump is supplied to one of the travels. In a hydraulic circuit in which a traveling straight valve having a second position forming a flow path to be supplied to the switching valve is disposed,
A switching valve having a position for closing the passage at the time of switching is installed, and a switching valve having a check valve provided at the time of switching is provided between the parallel flow path of the pump and the inlet port of the one traveling direction switching valve during normal operation.
In the case where the parallel flow path of the pump and the most downstream part of the neutral flow path are normally closed, a switching valve having a position communicating with each other at the time of switching is installed, and the left and right traveling are simultaneously operated, the two switching valves are used. A hydraulic circuit for a hydraulic excavator, comprising a signal hydraulic line that switches simultaneously.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2041140A JP2766365B2 (en) | 1990-02-23 | 1990-02-23 | Hydraulic circuit of excavator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2041140A JP2766365B2 (en) | 1990-02-23 | 1990-02-23 | Hydraulic circuit of excavator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03244721A JPH03244721A (en) | 1991-10-31 |
| JP2766365B2 true JP2766365B2 (en) | 1998-06-18 |
Family
ID=12600127
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2041140A Expired - Lifetime JP2766365B2 (en) | 1990-02-23 | 1990-02-23 | Hydraulic circuit of excavator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2766365B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011075025A (en) * | 2009-09-30 | 2011-04-14 | Kyb Co Ltd | Traveling linear advancement control device |
| CN104265702B (en) * | 2014-09-10 | 2016-12-07 | 徐工集团工程机械股份有限公司 | A kind of startup system of natural gas loader |
| CN105889158B (en) * | 2016-06-04 | 2018-03-27 | 淄博大力矿山机械有限公司 | A kind of dirt loader air pressure transmission control system |
-
1990
- 1990-02-23 JP JP2041140A patent/JP2766365B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03244721A (en) | 1991-10-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0927794B1 (en) | Turning excavator comprising a hydraulic circuit | |
| US4875337A (en) | Construction machine dual-dump hydraulic circuit with piloted arm-boom cylinder supply priority switching valves | |
| JP4380643B2 (en) | Hydraulic control device for work machine | |
| JPH08184078A (en) | Heavily equipped straightly running apparatus | |
| KR870000506B1 (en) | Hydraulic circuit system for civil engineering and architectural machinery | |
| JP2766365B2 (en) | Hydraulic circuit of excavator | |
| JPH0232167B2 (en) | ||
| JP2766371B2 (en) | Hydraulic circuit of excavator | |
| JPH0352275Y2 (en) | ||
| JPH0374292B2 (en) | ||
| JPH0694679B2 (en) | Hydraulic equipment for construction vehicles | |
| JP3511504B2 (en) | Hydraulic circuit of construction machinery | |
| JPH04285303A (en) | Hydraulic circuit for improving operability in load sensing system | |
| JP2520653B2 (en) | Running control device for construction machinery | |
| KR970011612B1 (en) | Travel driving system for heavy equipment | |
| JPH0258412B2 (en) | ||
| JPH09165791A (en) | Hydraulic circuit for working machine | |
| JPH0324680Y2 (en) | ||
| JP2594686Y2 (en) | Traveling hydraulic circuit | |
| JPH0411690B2 (en) | ||
| JPH09165796A (en) | Hydraulic circuit for working machine | |
| JPH1018357A (en) | Oil pressure regeneration circuit of hydraulic machine | |
| JPH0429813B2 (en) | ||
| JP2624268B2 (en) | Hydraulic drive for construction machinery | |
| JPH06241203A (en) | Oil pressure circuit for traveling |