JPH02108733A - Hydraulic circuit for back hoe - Google Patents

Hydraulic circuit for back hoe

Info

Publication number
JPH02108733A
JPH02108733A JP63261159A JP26115988A JPH02108733A JP H02108733 A JPH02108733 A JP H02108733A JP 63261159 A JP63261159 A JP 63261159A JP 26115988 A JP26115988 A JP 26115988A JP H02108733 A JPH02108733 A JP H02108733A
Authority
JP
Japan
Prior art keywords
control valve
arm
hydraulic pump
bucket
boom
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.)
Pending
Application number
JP63261159A
Other languages
Japanese (ja)
Inventor
Kazuyoshi Arii
一善 有井
Shizuo Shimoie
下家　静夫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kubota Corp
Original Assignee
Kubota Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kubota Corp filed Critical Kubota Corp
Priority to JP63261159A priority Critical patent/JPH02108733A/en
Publication of JPH02108733A publication Critical patent/JPH02108733A/en
Pending legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2292—Systems with two or more pumps

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

PURPOSE:To restrain the occurrence of a difference in rotational speed between a running device and a running motor during an arm being cooperated, by connecting one end of a hydraulic feed passage having the other end connected to at a predetermined position a center bypass passage in a right side running device, to an arm control valve. CONSTITUTION:A second running control valve V6 is disposed downstream of a boom control valve V4 and a bucket control valve V5. Then, the intermediate position 7a of a center bypass passage 7 between the valves V4, V6 and the valve V5 is connected to an arm control valve V2 by means of a hydraulic feed passage 9 through the intermediary of a first hydraulic pump P1 and a connection passage 10. During both arm and a running device being simultaneously operated, the valves V4, V5 are manipulated to their neutral positions so as to communicate the connected position 7a of the passage 7 with a second hydraulic pump P2, and accordingly, hydraulic oil flowing into the flow passage 7 from the pump P2 by way of the feed passage 9 is allowed to merge with hydraulic oil from the pump P1, and then is fed into the valve V2 to control the oblique movement of the vehicle. Further, the valves V4, V5 are simultaneously driven.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、左走行用モータと右走行用モータの一方のた
めの第１走行用制御弁及びアーム用制御弁を第１油圧ポ
ンプに並列接続し、前記左走行用モータと前記右走行用
モータの他方のための第２走行用制御弁、ブーム用制御
弁及びバケット用制御弁をセンターバイパス弁に形成す
ると共に第２油圧ポンプに並列接続したバックホウの油
圧回路に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a first travel control valve and an arm control valve for one of a left travel motor and a right travel motor in parallel with a first hydraulic pump. A second travel control valve, a boom control valve, and a bucket control valve for the other of the left travel motor and the right travel motor are formed as a center bypass valve, and are connected in parallel to a second hydraulic pump. Regarding the hydraulic circuit of a backhoe.

〔従来の技術〕[Conventional technology]

上記バックホウは、機体移送時の如く走行装置のみを駆
動する際、左走行用モータと右走行用モータに第１油圧
ポンプと第２油圧ポンプから各別に圧油供給されること
により、モータ間に回転数差が生じて機体が斜行するト
ラブルが発生しにくいように配慮されたものである。When the above-mentioned backhoe drives only the traveling device, such as when transferring an aircraft, pressure oil is supplied to the left traveling motor and right traveling motor separately from the first hydraulic pump and the second hydraulic pump, so that there is a gap between the motors. This was designed to prevent problems such as rotational speed differences resulting in the aircraft tilting.

この種バックホウにおいて、従来、例えば実開昭６１−
１０２６６０号公報に示されるように、湿地脱出時等、
走行装置駆動とアーム駆動とを併せてする場合、第１油
圧ポンプからの油が一方の走行用モータとアームシリン
ダとに分流供給され、第２油圧ポンプからの油が他方の
走行用モータのみに供給されるようになっていた。In this type of backhoe, conventionally, for example,
As shown in Publication No. 102660, when escaping from a wetland, etc.
When driving the traveling device and driving the arm at the same time, the oil from the first hydraulic pump is dividedly supplied to one traveling motor and the arm cylinder, and the oil from the second hydraulic pump is supplied only to the other traveling motor. It was being supplied.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

従来、走行装置とアームの併行駆動時に、前記給油形態
のために走行用モータ間に回転数差が生じ、機体が斜行
し易くなっていた。Conventionally, when the traveling device and the arm are driven in parallel, a rotational speed difference occurs between the traveling motors due to the refueling type, making it easy for the aircraft to travel diagonally.

本発明の目的は、走行装置とアームの併行駆動時におけ
る走行用モータの回転数差発生を、ブーム及びバケット
の駆動力低下を防止しながら抑制できるようにすること
にある。SUMMARY OF THE INVENTION An object of the present invention is to suppress the occurrence of a difference in rotational speed of a traveling motor when a traveling device and an arm are driven in parallel while preventing a reduction in the driving force of the boom and bucket.

〔課題を解決するための手段〕[Means to solve the problem]

本発明の特徴構成は冒記したバックホウの油圧回路にお
いて、前記第２走行用制御弁を前記ブーム用制御弁及び
前記バケット用制御弁より下流側に配置し、前記ブーム
用制御弁、前記バケット用制御弁及び前記第２走行用制
御弁を通るセンターバイパス流路の前記ブーム用制御弁
及び前記バケット用制御弁より下流側で前記第２走行用
制御弁より上流側に位置する箇所と、前記アーム用制御
弁とを接続して、前記センターバイパス流路からの圧油
を前記アーム用制御弁に前記第１油圧ポンプからの圧油
に合流させて供給する給油路を設けてあることにある。The characteristic configuration of the present invention is that in the hydraulic circuit of the backhoe described above, the second traveling control valve is arranged downstream of the boom control valve and the bucket control valve, and the boom control valve and the bucket control valve are arranged downstream of the boom control valve and the bucket control valve. A portion of a center bypass flow path passing through the control valve and the second traveling control valve that is located downstream of the boom control valve and the bucket control valve and upstream of the second traveling control valve, and the arm. An oil supply path is provided which connects the arm control valve to the arm control valve and supplies the pressure oil from the center bypass flow path to the arm control valve by merging it with the pressure oil from the first hydraulic pump.

そして、その作用及び効果は次のとおりである。The functions and effects thereof are as follows.

〔作　用〕[For production]

走行装置とアームを併行駆動する場合には、ブーム用制
御弁及びバケット用制御弁が中立位置にあってセンター
バイパス流路の給油路接続箇所を第２油圧ポンプに連通
させることにより、給油路が第２油圧ポンプに連通ずる
状態になる。When driving the traveling device and the arm in parallel, the boom control valve and the bucket control valve are in the neutral position, and the oil supply passage is connected to the second hydraulic pump by communicating the oil supply passage connection point of the center bypass passage. It becomes in communication with the second hydraulic pump.

そして、第２走行用制御弁はブーム用制御弁及びバケッ
ト用制御弁と並列状態で第２油圧ポンプに接続している
ことにより、第２油圧ポンプからの油が第２走行用制御
弁を通り、この制御弁に接続の走行用モータに供給され
る他に、センタバイパス流路及び給油路を通ってアーム
用制御弁に供給され、第１油圧ポンプからの油と合流し
てアームシリンダにも供給される。つまり、第１油圧ポ
ンプからの油が一方の走行用モータとアームシリンダと
に分流供給されると共に、第２油圧ポンプからの油も他
方の走行用モータとアームシリンダとに分流供給され、
第１油圧ポンプによる一方の走行用モータへの給油と第
２油圧ポンプによる他方の走行用モータへの給油とに量
差が生じに（くなってモータ間の回転数差が生じにくく
なる。The second traveling control valve is connected to the second hydraulic pump in parallel with the boom control valve and the bucket control valve, so that oil from the second hydraulic pump passes through the second traveling control valve. In addition to being supplied to the traveling motor connected to this control valve, the oil is also supplied to the arm control valve through the center bypass passage and the oil supply passage, where it joins the oil from the first hydraulic pump and is also supplied to the arm cylinder. Supplied. That is, the oil from the first hydraulic pump is supplied in a branched manner to one of the traveling motors and the arm cylinder, and the oil from the second hydraulic pump is also supplied in a divided manner to the other traveling motor and arm cylinder.
As a result, a difference in the amount of oil supplied to one traveling motor by the first hydraulic pump and that supplied to the other traveling motor by the second hydraulic pump becomes less likely to occur.

ブーム及びバケットを駆動する場合には、ブーム用制御
弁やバケット用制御弁がシリンダ駆動位置に切換えられ
ることによって、センタバイパス流路を給油路接続箇所
より上流側で遮断することになり、給油路が第２油圧ポ
ンプに対する非連通状態になる。すなわち、第２油圧ポ
ンプからの油がアーム用制御弁の方には供給されないで
ブームシリンダやバケットシリンダにのみ供給される。When driving the boom and bucket, the boom control valve and the bucket control valve are switched to the cylinder drive position, thereby blocking the center bypass flow path upstream from the oil supply path connection point, thereby blocking the oil supply path. is out of communication with the second hydraulic pump. That is, the oil from the second hydraulic pump is not supplied to the arm control valve, but only to the boom cylinder and bucket cylinder.

つまり、第２走行用制御弁をブーム用制御弁やバケット
用制御弁より上流側に配置し、第２油圧ポンプからの油
をアーム用制御弁に分流供給する給油路を、センターバ
イパス流路の第２走行用制御弁より上流側に位置する箇
所に接続することによっても、アームと走行装置の併行
駆動時に第２油圧ポンプからの油も走行用モータとアー
ムシリンダとに分流供給されるようになる。この分流構
成にあってはブームやバケットの駆動時に、この時にも
分流供給されてブームシリンダやバケットへの給油量が
低下するのに対し、本発明による構成にあっては給油量
低下が生じない。In other words, the second travel control valve is placed upstream of the boom control valve and the bucket control valve, and the oil supply path that supplies oil from the second hydraulic pump to the arm control valve is connected to the center bypass flow path. By connecting it to a location located upstream of the second travel control valve, oil from the second hydraulic pump can also be supplied in a branched manner to the travel motor and arm cylinder when the arm and travel device are driven in parallel. Become. In this branch configuration, when the boom or bucket is driven, the branch flow is supplied at this time as well, reducing the amount of oil supplied to the boom cylinder or bucket, whereas with the configuration according to the present invention, no decrease in the amount of oil supplied occurs. .

〔発明の効果〕〔Effect of the invention〕

アームと走行装置を併行駆動する際に左走行用モータと
右走行用モータの間に回転数差が発生することを給油路
の作用によって抑制したり防止でき、アームを使用して
の湿地脱出を機体斜行が伴わないとか極力少ない状態で
できる等、安全度の高いものになった。When the arm and the traveling device are driven in parallel, the difference in rotational speed between the left traveling motor and the right traveling motor can be suppressed or prevented by the action of the oil supply path, making it easier to escape from the wetland using the arm. This has resulted in a high level of safety, with no skewing of the aircraft and the ability to do so with as little as possible.

しかも、ブーム及びバケットの駆動時には、制御弁配置
、給油路とセンターバイパス流路の接続構成のために、
第２油圧ポンプからの油をブームシリンダやバケットシ
リンダにのみ供給してブーム駆動やアーム駆動を強力に
でき、掘削が能率よくできるようになった。Moreover, when driving the boom and bucket, due to the control valve arrangement and the connection configuration of the oil supply path and center bypass flow path,
By supplying oil from the second hydraulic pump only to the boom cylinder and bucket cylinder, the boom drive and arm drive can be made more powerful, allowing more efficient excavation.

〔実施例〕〔Example〕

次に実施例を示す。 Next, examples will be shown.

第２図に示すように、ドーザ（１）が備えられたクロー
ラ式走行機台に、原動部（２）及び運転部（３）が備え
られた旋回台（４）を付設すると共に、この旋回台（４
）にスウィングブラケット（５）を介して向き変更自在
にバックホウ装置（６）を取付けて、ドーザ付きバック
ホウを構成しである。As shown in Fig. 2, a swivel base (4) equipped with a driving unit (2) and a driving unit (3) is attached to a crawler-type traveling machine base equipped with a dozer (1), and this stand (4
), a backhoe device (6) is attached to the backhoe device (6) via a swing bracket (5) so that the direction can be changed freely, thereby forming a backhoe with a dozer.

ドーザ（１）、旋回台（４）及びバックホウ装置（６）
の操作を可能にするに、原動部（２）に第１ないし第３
油圧ポンプ（ＰＩ）、　（Ｐ２）、　（Ｐ３）を同一の
エンジン（Ｅ）　によって駆動されるように設けると共
に、油圧回路を第１図に示す如く構成しである。Dozer (1), swivel table (4) and backhoe device (6)
In order to enable the operation of the
Hydraulic pumps (PI), (P2), and (P3) are provided to be driven by the same engine (E), and the hydraulic circuit is constructed as shown in FIG.

すなわち、サービスポートバルブ（Ｖυ、アームシリン
ダ（Ｃ１）の制御のためのアーム用制御弁（Ｖ２）、及
び左側走行装置を駆動する左走行用モータ（Ｍ１）の制
御のための左走行用制御弁（Ｖ１）を、センターバイパ
ス型の多連弁に形成すると共に第１油圧ポンプ（Ｐ１）
に並列接続しである。そして、ブームシリンダ（Ｃ３）
の制御のためのブーム用制御弁（Ｖ４）、バケットシリ
ンダ（Ｃ２）の制御のためのバケット用制御弁（Ｖ１）
、及び、右側走行装置を駆動する右走行用モータ（Ｍ２
）の制御のための右走行用制御弁（Ｖ６）を、センター
バイパス型で、かつ、右走行用制御弁（Ｖ６）がブーム
用制御弁（Ｖ１）及びバケット用制御弁（Ｖ１）より下
流側に位置する多連弁に形成すると共に第２油圧ポンプ
（Ｐ２）に並列接続しである。そして、旋回モータ（Ｍ
１）の制御のための旋回用制御弁（Ｖ？）、スウィング
シリンダ（Ｃ４）の制御のためのスウィング用制御弁（
Ｖ１）、及びドーザシリンダ（Ｃ６）の制御のためのド
ーザ用制御弁（Ｖ１）をセンタバイパス型に形成すると
共に第３油圧ポンプ（Ｐ３）に接続しである。That is, a service port valve (Vυ), an arm control valve (V2) for controlling the arm cylinder (C1), and a left travel control valve for controlling the left travel motor (M1) that drives the left travel device. (V1) is formed into a center bypass type multiple valve, and the first hydraulic pump (P1)
are connected in parallel. And boom cylinder (C3)
boom control valve (V4) for controlling the bucket cylinder (C2), bucket control valve (V1) for controlling the bucket cylinder (C2)
, and a right travel motor (M2) that drives the right travel device.
) is a center bypass type, and the right travel control valve (V6) is located downstream of the boom control valve (V1) and the bucket control valve (V1). It is formed into a multiple valve located at , and is connected in parallel to the second hydraulic pump (P2). And the swing motor (M
1) A swing control valve (V?) for controlling the swing cylinder (C4), a swing control valve (V?) for controlling the swing cylinder (C4)
V1) and a dozer control valve (V1) for controlling the dozer cylinder (C6) are formed in a center bypass type and are connected to a third hydraulic pump (P3).

ブーム用制御弁（Ｖ４）、バケット用制御弁（Ｖ５）及
び右走行用制御弁（Ｖ６）を通るセンターバイパス流路
（７）のブーム用制御弁（Ｖ４）及びバケット用制御弁
（Ｖ５）より下流側で右走行用制御弁（Ｖ６）より上流
側に位置する箇所（７ａ）に一端側を接続すると共に逆
止弁（８）を有した給油路（９）の他端側を、第１油圧
ポンプ（ｐ＋）とアーム用制御弁（Ｖ２）の接続路（１
０）を介してアーム用制御弁（Ｖ１）に接続して、第１
油圧ポンプ（Ｐ１）からの圧油によるアームシリンダ（
２）の駆動を可能にしながら、かつ、ブーム（１１）及
びバケツ）　（１２）の駆動時には第２油圧ポンプ（Ｐ
２）からの圧油がアーム用制御弁（Ｖ２）の方に分流し
ないようにしながら、アーム（１３）と走行装置の併行
駆動時には第２油圧ポンプ（Ｐ２）からの圧油が右走行
用モータ（Ｍ２）とアームシリンダ（Ｃυとに分流する
ことを可能にしである。From the boom control valve (V4) and bucket control valve (V5) of the center bypass flow path (7) passing through the boom control valve (V4), bucket control valve (V5), and right travel control valve (V6) One end side is connected to a point (7a) located upstream of the right travel control valve (V6) on the downstream side, and the other end side of the oil supply path (9) having a check valve (8) is connected to the first side. Connection path (1) between hydraulic pump (p+) and arm control valve (V2)
0) to the arm control valve (V1).
The arm cylinder (
2), and when driving the boom (11) and bucket) (12), the second hydraulic pump (P
2), while preventing the pressure oil from flowing toward the arm control valve (V2), when the arm (13) and the traveling device are driven in parallel, the pressure oil from the second hydraulic pump (P2) is transferred to the right traveling motor. (M2) and the arm cylinder (Cυ).

すなわち、第１油圧ポンプ（Ｐυからアーム用制御弁（
Ｖ２）に供給される圧油が給油路（９）を通ってセンタ
ーバイパス流路（７）に流入することが逆止弁（８）　
の作用によって阻止されるようにしである。そして、ブ
ーム（１１）及びバケット（１２）の駆動時には、ブー
ム用制御弁（Ｖ４）及びバケット用制御弁（Ｖ５）がシ
リンダ駆動位置に切換え操作されてセンターバイパス流
路（７）を給油路接続箇所（７ａ）より上流側で遮断す
ることによって、給油路（９）が第２油圧ポンプ（Ｐ２
）に対する非連通状態になり、第２油圧ポンプ（Ｐ２）
からの圧油が給油路（９）を通ってアーム用制御弁（Ｖ
２）に流入することが不能になるようにしである。そし
て、アーム（１３）と走行装置の併行駆動時には、ブー
ム用制御弁（Ｖ１）及びバケット用制御弁（Ｖ１）を中
立位置に操作することにより、センターバイパス流路（
７）の給油路接続箇所（７ａ）が第２油圧ポンプ（Ｐ２
）に対する連通状態になり、給油路（９）が第２油圧ポ
ンプ（Ｐ２）からセンターバイパス流路（７）　に流入
した圧油を第１油圧ポンプ（Ｐ１）からの圧油に合流さ
せてアーム用制御弁（Ｖ２）に供給することが可能にな
るようにしである。That is, from the first hydraulic pump (Pυ) to the arm control valve (
Check valve (8) allows the pressure oil supplied to V2) to flow into the center bypass flow path (7) through the oil supply path (9).
This is to be prevented by the action of When the boom (11) and bucket (12) are driven, the boom control valve (V4) and bucket control valve (V5) are switched to the cylinder drive position to connect the center bypass flow path (7) to the oil supply path. By shutting off the point (7a) upstream, the oil supply path (9) is connected to the second hydraulic pump (P2).
), and the second hydraulic pump (P2)
Pressure oil from the arm passes through the oil supply path (9) to the arm control valve (V
2) so that it is impossible to flow into. When the arm (13) and the traveling device are driven in parallel, the center bypass flow path (
The oil supply path connection point (7a) of 7) is connected to the second hydraulic pump (P2
), the oil supply path (9) merges the pressure oil flowing from the second hydraulic pump (P2) into the center bypass flow path (7) with the pressure oil from the first hydraulic pump (P1), and connects the arm. This makes it possible to supply the control valve (V2) to the control valve (V2).

〔別実施例〕[Another example]

右走行用制御弁（Ｖ６）を第１油圧ポンプ（Ｐυの方に
接続し、左走行用制御弁（Ｖ１）を第２油圧ポンプ（Ｐ
１）の方に接続して実施する場合にも本発明は適用でき
る。したがって、左走行用制御弁（Ｖ３）を左走行用モ
ータ（Ｍ１）と右走行用モータ（Ｍ１）の一方のための
第１走行用制御弁（Ｖ１）と称し、右走行用制御弁（Ｖ
６）を左走行用モータ（Ｍ１）と右走行用モータ（Ｍ２
）の他方のための第２走行用制御弁（Ｖ６）と称する。The control valve for right travel (V6) is connected to the first hydraulic pump (Pυ), and the control valve for left travel (V1) is connected to the second hydraulic pump (Pυ).
The present invention can also be applied when connected to method 1). Therefore, the left travel control valve (V3) is referred to as the first travel control valve (V1) for one of the left travel motor (M1) and the right travel motor (M1), and the right travel control valve (V
6) to the left travel motor (M1) and the right travel motor (M2).
) is called the second travel control valve (V6) for the other one.

尚、特許請求の範囲の項に図面との対照を便利にする為
に符号を記すが、該記入により本発明は添付図面の構造
に限定されるものではない。Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

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

図面は本発明に係るバックホウの油圧回路の実施例を示
し、第１図は油圧回路図、第２図はドーザ付きバックホ
ウ全体の側面図である。 （７）・・・・・・センターバイパス流Ｌ　（７ａ）・
・・・・・箇所、（９）・・・・・・給油路、（Ｍ１）
・・・・・・左走行用モータ、（Ｍ２）・・・・・・右
走行用モータ、（Ｖ２）・・・・・・アーム用制御弁、
（Ｖ１）・・・・・・第１走行用制御弁、（Ｖ４）・・
・・・・ブーム用制御弁、（Ｖ１）・・・・・・バケッ
ト用制御弁、（Ｖ６）・・・・・・第２走行用制御弁、
（Ｐ１）・・・・・・第１油圧ポンプ、（Ｐ２）・・・
・・・第２油圧ポンプ。The drawings show an embodiment of a hydraulic circuit for a backhoe according to the present invention, and FIG. 1 is a hydraulic circuit diagram, and FIG. 2 is a side view of the entire backhoe with a dozer. (7)...Center bypass flow L (7a)・
... Location, (9) ... Oil supply path, (M1)
...Left travel motor, (M2)...Right travel motor, (V2)...Arm control valve,
(V1)...First travel control valve, (V4)...
... Boom control valve, (V1) ... Bucket control valve, (V6) ... Second traveling control valve,
(P1)...First hydraulic pump, (P2)...
...Second hydraulic pump.

Claims (1)

【特許請求の範囲】[Claims] 左走行用モータ（Ｍ＿１）と右走行用モータ（Ｍ＿２）
の一方のための第１走行用制御弁（Ｖ＿３）及びアーム
用制御弁（Ｖ＿２）を第１油圧ポンプ（Ｐ＿１）に並列
接続し、前記左走行用モータ（Ｍ＿１）と前記右走行用
モータ（Ｍ＿２）の他方のための第２走行用制御弁（Ｖ
＿６）、ブーム用制御弁（Ｖ＿４）及びバケット用制御
弁（Ｖ＿５）をセンターバイパス弁に形成すると共に第
２油圧ポンプ（Ｐ＿２）に並列接続したバックホウの油
圧回路であって、前記第２走行用制御弁（Ｖ＿６）を前
記ブーム用制御弁（Ｖ＿４）及び前記バケット用制御弁
（Ｖ＿５）より下流側に配置し、前記ブーム用制御弁（
Ｖ＿４）、前記バケット用制御弁（Ｖ＿５）及び前記第
２走行用制御弁（Ｖ＿６）を通るセンターバイパス流路
（７）の前記ブーム用制御弁（Ｖ＿４）及び前記バケッ
ト用制御弁（Ｖ＿５）より下流側で前記第２走行用制御
弁（Ｖ＿６）より上流側に位置する箇所（７ａ）と、前
記アーム用制御弁（Ｖ＿２）とを接続して、前記センタ
ーバイパス流路（７）からの圧油を前記アーム用制御弁
（Ｖ＿２）に前記第１油圧ポンプ（Ｐ＿１）からの圧油
に合流させて供給する給油路（９）を設けてあるバック
ホウの油圧回路。Left running motor (M_1) and right running motor (M_2)
A first travel control valve (V_3) and an arm control valve (V_2) for one of the two are connected in parallel to the first hydraulic pump (P_1), and the left travel motor (M_1) and the right travel motor ( the second travel control valve (V
_6), a hydraulic circuit for a backhoe in which a boom control valve (V_4) and a bucket control valve (V_5) are formed as a center bypass valve and are connected in parallel to a second hydraulic pump (P_2), A control valve (V_6) is arranged downstream of the boom control valve (V_4) and the bucket control valve (V_5), and
V_4), from the boom control valve (V_4) and the bucket control valve (V_5) of the center bypass flow path (7) passing through the bucket control valve (V_5) and the second traveling control valve (V_6). A point (7a) located upstream of the second travel control valve (V_6) on the downstream side is connected to the arm control valve (V_2), and the pressure from the center bypass flow path (7) is connected to the arm control valve (V_2). A hydraulic circuit for a backhoe, which is provided with an oil supply path (9) that supplies oil to the arm control valve (V_2) by merging it with pressure oil from the first hydraulic pump (P_1).
JP63261159A 1988-10-17 1988-10-17 Hydraulic circuit for back hoe Pending JPH02108733A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP63261159A JPH02108733A (en) 1988-10-17 1988-10-17 Hydraulic circuit for back hoe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63261159A JPH02108733A (en) 1988-10-17 1988-10-17 Hydraulic circuit for back hoe

Publications (1)

Publication Number Publication Date
JPH02108733A true JPH02108733A (en) 1990-04-20

Family

ID=17357933

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63261159A Pending JPH02108733A (en) 1988-10-17 1988-10-17 Hydraulic circuit for back hoe

Country Status (1)

Country Link
JP (1) JPH02108733A (en)

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US8893490B2 (en) 2011-10-21 2014-11-25 Caterpillar Inc. Hydraulic system
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US8919114B2 (en) 2011-10-21 2014-12-30 Caterpillar Inc. Closed-loop hydraulic system having priority-based sharing
US8944103B2 (en) 2011-08-31 2015-02-03 Caterpillar Inc. Meterless hydraulic system having displacement control valve
US8943819B2 (en) 2011-10-21 2015-02-03 Caterpillar Inc. Hydraulic system
US8966892B2 (en) 2011-08-31 2015-03-03 Caterpillar Inc. Meterless hydraulic system having restricted primary makeup
US8966891B2 (en) 2011-09-30 2015-03-03 Caterpillar Inc. Meterless hydraulic system having pump protection
US8973358B2 (en) 2011-10-21 2015-03-10 Caterpillar Inc. Closed-loop hydraulic system having force modulation
US8978374B2 (en) 2011-10-21 2015-03-17 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
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US8984873B2 (en) 2011-10-21 2015-03-24 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US9051714B2 (en) 2011-09-30 2015-06-09 Caterpillar Inc. Meterless hydraulic system having multi-actuator circuit
US9057389B2 (en) 2011-09-30 2015-06-16 Caterpillar Inc. Meterless hydraulic system having multi-actuator circuit
US9068578B2 (en) 2011-10-21 2015-06-30 Caterpillar Inc. Hydraulic system having flow combining capabilities
US9080310B2 (en) 2011-10-21 2015-07-14 Caterpillar Inc. Closed-loop hydraulic system having regeneration configuration
US9151018B2 (en) 2011-09-30 2015-10-06 Caterpillar Inc. Closed-loop hydraulic system having energy recovery
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US8944103B2 (en) 2011-08-31 2015-02-03 Caterpillar Inc. Meterless hydraulic system having displacement control valve
US8863509B2 (en) 2011-08-31 2014-10-21 Caterpillar Inc. Meterless hydraulic system having load-holding bypass
US8966892B2 (en) 2011-08-31 2015-03-03 Caterpillar Inc. Meterless hydraulic system having restricted primary makeup
US9051714B2 (en) 2011-09-30 2015-06-09 Caterpillar Inc. Meterless hydraulic system having multi-actuator circuit
US9057389B2 (en) 2011-09-30 2015-06-16 Caterpillar Inc. Meterless hydraulic system having multi-actuator circuit
US9151018B2 (en) 2011-09-30 2015-10-06 Caterpillar Inc. Closed-loop hydraulic system having energy recovery
US8966891B2 (en) 2011-09-30 2015-03-03 Caterpillar Inc. Meterless hydraulic system having pump protection
US8910474B2 (en) 2011-10-21 2014-12-16 Caterpillar Inc. Hydraulic system
US8973358B2 (en) 2011-10-21 2015-03-10 Caterpillar Inc. Closed-loop hydraulic system having force modulation
US8978374B2 (en) 2011-10-21 2015-03-17 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US8978373B2 (en) 2011-10-21 2015-03-17 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US8984873B2 (en) 2011-10-21 2015-03-24 Caterpillar Inc. Meterless hydraulic system having flow sharing and combining functionality
US8893490B2 (en) 2011-10-21 2014-11-25 Caterpillar Inc. Hydraulic system
US8919114B2 (en) 2011-10-21 2014-12-30 Caterpillar Inc. Closed-loop hydraulic system having priority-based sharing
US9068578B2 (en) 2011-10-21 2015-06-30 Caterpillar Inc. Hydraulic system having flow combining capabilities
US9080310B2 (en) 2011-10-21 2015-07-14 Caterpillar Inc. Closed-loop hydraulic system having regeneration configuration
US8943819B2 (en) 2011-10-21 2015-02-03 Caterpillar Inc. Hydraulic system
US9279236B2 (en) 2012-06-04 2016-03-08 Caterpillar Inc. Electro-hydraulic system for recovering and reusing potential energy
US9290911B2 (en) 2013-02-19 2016-03-22 Caterpillar Inc. Energy recovery system for hydraulic machine

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