JP2760702B2 - Work vehicle hydraulic circuit structure - Google Patents
Work vehicle hydraulic circuit structureInfo
- Publication number
- JP2760702B2 JP2760702B2 JP4159889A JP15988992A JP2760702B2 JP 2760702 B2 JP2760702 B2 JP 2760702B2 JP 4159889 A JP4159889 A JP 4159889A JP 15988992 A JP15988992 A JP 15988992A JP 2760702 B2 JP2760702 B2 JP 2760702B2
- Authority
- JP
- Japan
- Prior art keywords
- control valve
- oil
- pump
- hydraulic
- traveling
- 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
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- Operation Control Of Excavators (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は油圧式走行装置を左右一
対備えた作業車の油圧回路構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic circuit structure of a working vehicle having a pair of left and right hydraulic traveling devices.
【０００２】[0002]
【従来の技術】油圧式走行装置の一例であるクローラ式
の走行装置（クローラを油圧モータで駆動する型式) を
左右一対備えた作業車において、例えば特開平４‐１１
８４２８号公報に開示されているような油圧回路構造を
備えているものがある。この構造においては、第１ポン
プ（前記公報の第１図中の１０）及び第２ポンプ（前記
公報の第１図中の１６）からの作動油を先ず、走行装置
用の制御弁（前記公報の第１図中の１３ａ，１３ｂ）に
供給し、この制御弁の下手側に作業装置駆動用のセンタ
ーバイパス型式の制御弁（前記公報の第１図中の１５，
１９，２１）を並列的に接続している。2. Description of the Related Art A working vehicle equipped with a pair of right and left crawler-type traveling devices (a type in which a crawler is driven by a hydraulic motor), which is an example of a hydraulic traveling device, is disclosed in, for example, Japanese Patent Laid-Open No. 4-11.
Some have a hydraulic circuit structure as disclosed in Japanese Patent No. 8428. In this structure, hydraulic oil from a first pump (10 in FIG. 1 of the above publication) and a second pump (16 in FIG. 1 of the above publication) is first supplied to a control valve for a traveling device (the above publication). 1a, 13b in FIG. 1 and a control valve of a center bypass type (15, FIG. 1 in FIG.
19, 21) are connected in parallel.
【０００３】この構造では、走行装置用の制御弁の下手
側に作業装置用の制御弁が位置しているので、左右の走
行装置を駆動して直進しながら作業装置を駆動したい場
合、作業装置駆動用の作動油が不足気味になり作業装置
を十分に駆動できない場合がある。逆に、この状態で作
業装置側に作動油が奪われるような状態となれば、片側
の走行装置用の油圧モータの回転が低下して機体が斜め
に向いてしまうような場合がある。In this structure, since the control valve for the working device is located on the lower side of the control valve for the traveling device, if it is desired to drive the working device while driving the left and right traveling devices to move straight, In some cases, the operating oil for driving tends to be insufficient and the working device cannot be driven sufficiently. Conversely, in this state, if hydraulic oil is deprived to the working device side, the rotation of the hydraulic motor for the traveling device on one side may decrease, and the machine body may be inclined.
【０００４】そこで、前記公報の構造においては、左右
の走行装置を駆動しての直進中に作業装置を駆動しよう
とした場合、別の第３ポンプ（前記公報の第１図中の２
７）からの作動油を、切換弁（前記公報の第１図中の３
１）から走行装置用の制御弁の下手側に適時補給して、
作業装置側での作動油の不足を補うように構成してい
る。Therefore, in the structure of the above-mentioned publication, when the working device is driven during straight traveling by driving the left and right traveling devices, another third pump (2 in FIG. 1 of the above-mentioned publication) is required.
7) is supplied to the switching valve (3 in FIG.
From 1), replenish the lower side of the control valve for the traveling device as needed.
It is configured to compensate for the lack of hydraulic oil on the working device side.
【０００５】前記公報の構造のように直進中に作業装置
側に作動油を補給する場合、先ず左右の走行装置が駆動
された直進中であることを検出する構造が必要である。
この場合、左右の走行装置用の制御弁が走行位置に切換
操作されたことを検出する一対のリミットスイッチ（前
記公報の第１図中の３５ａ，３５ｂ）を備えて、このリ
ミットスイッチからの検出信号に基づいて、切換弁（前
記公報の第１図中の３１）を作動油の補給側に切換操作
するように構成している。[0005] When supplying working oil to the working device while the vehicle is traveling straight as in the structure of the above-mentioned publication, it is necessary to first have a structure for detecting that the left and right traveling devices are being driven and traveling straight.
In this case, a pair of limit switches (35a, 35b in FIG. 1 of the above-mentioned publication) for detecting that the control valves for the left and right traveling devices are switched to the traveling position are provided. The switching valve (31 in FIG. 1 of the above-mentioned publication) is switched to the supply side of the hydraulic oil based on the signal.
【０００６】[0006]
【発明が解決しようとする課題】例えば土木掘削用のバ
ックホウ等の作業車においては一般に、走行装置を停止
させて一定位置で作業を行う定地作業の場合が多く、直
進しながら作業装置を作動させる場合はあまり多くな
い。又、直進しながら作業装置を作動させる場合、作業
装置用の複数の油圧アクチュエータを同時に作動させる
ことは少なく、走行中に１個又は２個程度の油圧アクチ
ュエータを作動させる場合が多い。For example, in the case of a working vehicle such as a backhoe for excavating civil engineering, in general, there are many cases of stationary work in which a traveling device is stopped and work is performed at a fixed position. Not so much if you let it. When operating the working device while traveling straight, it is rare that a plurality of hydraulic actuators for the working device are operated at the same time, and often one or two hydraulic actuators are operated during traveling.
【０００７】従って前記公報のように、直進中に走行系
の第１及び第２ポンプとは全く別の第３ポンプから、第
１及び第２ポンプ系の作業装置用の制御弁に作動油を供
給すると、作業装置用の制御弁等にとって作動油の供給
過多となり、作動油の温度上昇や圧力損失を伴う場合が
ある。又、前記公報の構造においては、左右の走行装置
が駆動されていることを検出する検出系（電気的なリミ
ットスイッチ系）が必要になっている。従って、この検
出系を備えている点において構造的な面で改良の余地が
ある。Therefore, as described in the above-mentioned publication, the hydraulic oil is supplied from the third pump completely different from the first and second pumps of the traveling system to the control valves for the working devices of the first and second pump systems during straight traveling. If the supply is performed, the supply of the hydraulic oil becomes excessive for the control valve for the working device or the like, which may cause a rise in the temperature of the hydraulic oil or a pressure loss. Further, the structure disclosed in the above publication requires a detection system (electric limit switch system) for detecting that the left and right traveling devices are being driven. Therefore, there is room for improvement in terms of structure in terms of having this detection system.
【０００８】本発明は、直進中において作業装置用の油
圧アクチュエータ側に作動油を補給する場合、作動油の
供給過多にならないように、又、左右の走行装置が駆動
されている状態を検出する検出系の構造の簡素化を図る
ことを目的としている。According to the present invention, when hydraulic oil is supplied to the hydraulic actuator for a working device while traveling straight, the supply of hydraulic oil is prevented from being excessive, and a state in which the left and right traveling devices are driven is detected. It is intended to simplify the structure of the detection system.
【０００９】[0009]
【課題を解決するための手段】本発明の特徴は以上のよ
うな作業車の油圧回路構造において、次のように構成し
ていることにある。つまり、第１ポンプに対して、左右
一対の油圧式走行装置の一方用でセンターバイパス型式
の制御弁と、作業装置用でセンターバイパス型式の制御
弁とを並列的に接続し、第２ポンプに対して、左右一対
の油圧式走行装置の他方用でセンターバイパス型式の制
御弁と、作業装置用でセンターバイパス型式の制御弁と
を並列的に接続すると共に、第１及び第２ポンプ系の各
々のセンター排油路において、油圧式走行装置用の制御
弁を圧油供給方向の最下手側位置に配置し、そのセンタ
ー排油路における走行装置用制御弁に対する圧油供給方
向上手側であり、かつ、他の制御弁の圧油供給方向下手
側となる部位から油路を各々分岐させ、これら一対の油
路のうち第１ポンプ側の油路を第２ポンプ側の作業装置
用の制御弁に接続し、第２ポンプ側の油路を第１ポンプ
側の作業装置用の制御弁に接続して、油圧式走行装置用
の一対の制御弁の走行位置にセンター排油路を遮断する
遮断部を備えてある。The feature of the present invention resides in that the hydraulic circuit structure of the working vehicle as described above is configured as follows. That is, a center bypass type control valve for one of the pair of left and right hydraulic traveling devices and a center bypass type control valve for a working device are connected in parallel to the first pump, and the second pump is connected to the second pump. On the other hand, a center bypass type control valve for the other of the pair of left and right hydraulic traveling devices and a center bypass type control valve for the working device are connected in parallel and each of the first and second pump systems is connected. In the center drainage passage, the control valve for the hydraulic traveling device is disposed at the lowermost position in the pressure oil supply direction, and the control valve for the traveling device in the center drainage passage is on the upper side in the pressure oil supply direction relative to the control valve for the traveling device, An oil passage is branched from a portion of the other control valve that is on the lower side in the pressure oil supply direction, and the oil passage on the first pump side of the pair of oil passages is a control valve for a working device on the second pump side. To the second pump The road connected to the first control valve for the pump side of the working device, are provided with a blocking portion for blocking the center discharge oil passage to the travel position of the pair of control valves for hydraulic traveling apparatus.
【００１０】[0010]
【作用】本発明のように構成すると例えば図１に示すよ
うに、油圧式走行装置用の制御弁１９，２７を中立位置
１９Ｎ，２７Ｎに操作して機体を停止させている状態で
は、センター排油路２８，３０を通る作動油は、制御弁
１９，２７の中立位置１９Ｎ，２７Ｎを通り排出され
る。そして、油圧式走行装置用の制御弁１９，２７を走
行位置１９Ｆ，２７Ｆ又は１９Ｒ，２７Ｒに操作して機
体を直進させると、第１及び第２ポンプ１１，２０のセ
ンター排油路２８，３０が、制御弁１９，２７で遮断さ
れる。According to the structure of the present invention, as shown in FIG. 1, for example, when the control valves 19 and 27 for the hydraulic traveling device are operated to the neutral positions 19N and 27N to stop the body, the center discharge is performed. The hydraulic oil passing through the oil passages 28 and 30 is discharged through the neutral positions 19N and 27N of the control valves 19 and 27. Then, when the control valve 19, 27 for the hydraulic traveling device is operated to the traveling position 19F, 27F or 19R, 27R to make the body go straight, the center oil passages 28, 30 of the first and second pumps 11, 20 are moved. Is shut off by the control valves 19 and 27.
【００１１】これにより、第１ポンプ１１側のセンター
排油路２８を通る作動油が排出されずに、油路２９，２
９ａ，２９ｂを通り作業装置用の制御弁２４，２５に供
給される。又、第２ポンプ２０側のセンター排油路３０
を通る作動油が排出されずに、油路３１，３１ａを通り
作業装置用の制御弁１５に供給される。As a result, the hydraulic oil passing through the center oil passage 28 on the first pump 11 side is not discharged, and the oil passages 29 and 2 are not discharged.
It is supplied to control valves 24 and 25 for working equipment through 9a and 29b. Also, the center oil discharge passage 30 on the second pump 20 side
Is supplied to the control valve 15 for the working device through the oil passages 31 and 31a without being discharged.
【００１２】この直進状態において、例えば第１ポンプ
１１側の作業装置用の制御弁１５を操作したとすると、
この制御弁１５には第１ポンプ１１からの作動油と第２
ポンプ２０のセンター排油路３０からの作動油が供給さ
れることになるので、この制御弁１５において作動油不
足になるようなことはない。In this straight traveling state, for example, if the control valve 15 for the working device on the first pump 11 side is operated,
The control valve 15 is provided with the hydraulic oil from the first pump 11 and the second
Since hydraulic oil is supplied from the center oil discharge passage 30 of the pump 20, the control valve 15 does not run out of hydraulic oil.
【００１３】このように制御弁１５を操作した場合、第
１ポンプ１１側の油圧式走行装置用の制御弁１９におい
て作動油の流量が落ちるが、第２ポンプ２０側において
もセンター排油路３０からの作動油が抜かれて、この作
動油が制御弁１５に供給されるので、第２ポンプ２０側
の油圧式走行装置用の制御弁２７においても同様に作動
油の流量が落ちる。これにより、左右の油圧式走行装置
の駆動速度に差が生じるようなことはなく、機体は斜め
に向くことなく正常に直進する。When the control valve 15 is operated in this manner, the flow rate of the hydraulic oil drops at the control valve 19 for the hydraulic traveling device on the first pump 11 side, but also on the second pump 20 side. , The hydraulic oil is drained and supplied to the control valve 15, so that the flow rate of the hydraulic oil also drops at the control valve 27 for the hydraulic traveling device on the second pump 20 side. As a result, there is no difference between the driving speeds of the left and right hydraulic traveling devices, and the aircraft normally travels straight without turning diagonally.
【００１４】従来の構造では直進中に作業装置を作動さ
せた場合、第１及び第２ポンプとは全く別の第３ポンプ
からの作動油を作業装置用の制御弁に補給しているの
で、全体として作動油の供給過多になる場合がある。In the conventional structure, when the working device is operated while traveling straight, hydraulic oil from a third pump completely different from the first and second pumps is supplied to the control valve for the working device. As a whole, the supply of hydraulic oil may be excessive.
【００１５】これに対して、本発明では直進中に作業装
置を作動させた場合、別の第３ポンプからの作動油を入
れると言うようなことは行わず、第１及び第２ポンプ系
内において油圧式走行装置用と作業装置用の作動油の分
配比を変更しているだけで、全体の作動油の総量（第１
及び第２ポンプの和）はそのままである。従って、全体
として作動油の供給過多となるようなことはなく、作動
油の温度上昇や圧力損失を伴うことはない。On the other hand, according to the present invention, when the working device is operated while traveling straight, it is not necessary to supply the hydraulic oil from another third pump, and the first and second pump systems are not operated. In the above, only by changing the distribution ratio of the hydraulic oil for the hydraulic traveling device and the working device, the total amount of the entire hydraulic oil (first
And the sum of the second pump). Therefore, the supply of the hydraulic oil does not become excessive as a whole, and there is no accompanying increase in the temperature of the hydraulic oil or pressure loss.
【００１６】又、従来の構造のように、左右の油圧式走
行装置が駆動されている状態を検出する専用の検出系
（リミットスイッチ等）を装備せずに、本発明では油圧
式走行装置用の制御弁を走行位置に操作すると、作業装
置用の制御弁に作動油が補給されるように構成してい
る。このように、油圧式走行装置用の制御弁自身を検出
系に構成してしまうことにより、リミットスイッチ等の
専用の検出系を装備する必要がなくなる。Further, unlike the conventional structure, a dedicated detection system (a limit switch or the like) for detecting a state in which the left and right hydraulic traveling devices are driven is not provided. When the control valve is operated to the traveling position, the working oil is supplied to the control valve for the working device. In this way, by configuring the control valve for the hydraulic traveling device itself as a detection system, it is not necessary to provide a dedicated detection system such as a limit switch.
【００１７】加えて、走行用制御弁をセンター排油路に
おける最下手側に配置し、かつ、その弁の直ぐ上手側箇
所から作業用制御弁に接続する油路を取出してあるの
で、走行用制御弁に備えた遮断部のみによってセンタ−
排油路から作業制御弁に圧油供給できる単純な構造が実
現できている。In addition, since the traveling control valve is disposed at the lowermost side of the center oil discharge passage and the oil passage connected to the working control valve is taken out from a position immediately above the valve, the traveling control valve is provided. The center is controlled only by the shut-off part of the control valve.
A simple structure capable of supplying pressurized oil from the oil drain to the work control valve has been realized.
【００１８】例えば、特開平６０‐７８０２２号公報に
示された油圧回路では、アームシリンダとブームシリン
ダへの供給圧によって操作される計２個の切換弁と、左
右の走行用制御弁の圧油供給方向で直ぐ上手側位置どう
しを接続可能な油路に設けた開閉弁とを備え、作動油不
足や斜行が解消される上述の作用を得るには、走行装置
のみ駆動させるときには開閉弁を閉じ、走行装置と作業
装置とを同時駆動させるときには開閉弁を開くという操
作が必要であり、回路及び操作共に複雑化するが、本願
のものでは切換弁や開閉弁及びその弁操作が不要であ
り、構造及び操作共にシンプルなもので済む。For example, in a hydraulic circuit disclosed in Japanese Patent Application Laid-Open No. 60-78022, a total of two switching valves operated by supply pressures to an arm cylinder and a boom cylinder, and hydraulic oil for left and right traveling control valves are provided. An on-off valve provided in an oil path that can connect the positions immediately upstream to each other in the supply direction, and in order to obtain the above-mentioned effect of eliminating hydraulic oil shortage and skewing, the on-off valve is used when only the traveling device is driven. When closing and simultaneously driving the traveling device and the working device, it is necessary to open the on-off valve, which complicates both the circuit and the operation.However, the switching valve, the on-off valve and the valve operation thereof are unnecessary in the present invention. The structure and operation are simple.
【００１９】[0019]
【発明の効果】以上のように、直進中において作業装置
に作動油を補給する場合、作動油の供給過多を抑えて作
動油の温度上昇や圧力損失を未然に防止することができ
るようになり、作業車の油圧回路系の耐久性を向上させ
ることができた。そして、左右の油圧式走行装置が駆動
されている状態を検出する専用の検出系を不要にするこ
とができるようになって、構造の簡素化を図ることがで
きるとともに、油圧回路並びに走行装置や作業装置の操
作のシンプル化も図れ、生産コスト面や操作面でも有利
な構造が得られた。As described above, when replenishing the working equipment with the working oil while traveling straight, it is possible to suppress the excessive supply of the working oil and prevent the temperature rise and the pressure loss of the working oil from occurring. Thus, the durability of the hydraulic circuit system of the working vehicle could be improved. In addition, a dedicated detection system for detecting a state in which the left and right hydraulic traveling devices are driven can be eliminated, so that the structure can be simplified, and the hydraulic circuit, the traveling device, The simplification of the operation of the work equipment was achieved, and an advantageous structure was obtained in terms of production cost and operation.
【００２０】[0020]
【実施例】以下、本発明の実施例を図面に基づいて説明
する。図２に示すように、左右一対のクローラ式の走行
装置１（油圧式走行装置に相当）の上部に旋回台２が支
持され、旋回台２の前部にバックホウ装置３（作業装置
に相当）を備えて作業車の一例であるバックホウを構成
している。Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 2, a swivel 2 is supported on the upper part of a pair of left and right crawler traveling devices 1 (corresponding to a hydraulic traveling device), and a backhoe device 3 (corresponding to a working device) is provided in front of the swivel 2. To constitute a backhoe which is an example of a work vehicle.
【００２１】このバックホウ装置３は、第１油圧シリン
ダ７により上下に揺動駆動されるブーム４、第２油圧シ
リンダ８により前後に揺動駆動されるアーム５、及び第
３油圧シリンダ９により掻き込み揺動駆動されるバケッ
ト６等で構成されている。そして、旋回台２の前部の縦
軸芯Ｐ１周りにバックホウ装置３全体が、第４油圧シリ
ンダ１０により揺動操作される。The backhoe device 3 is driven by a first hydraulic cylinder 7 to swing up and down, a boom 4 is driven by a second hydraulic cylinder 8 to move back and forth, and a third hydraulic cylinder 9 is used to scrape the backhoe. It is composed of a swing-driven bucket 6 and the like. Then, the entire backhoe device 3 is swung by the fourth hydraulic cylinder 10 around the longitudinal axis P1 at the front part of the swivel 2.
【００２２】次に、第１，２，３油圧シリンダ７，８，
９に対する油圧回路構造について説明する。図１に示す
ように、第１ポンプ１１からの油路１２，１３，１４
に、アーム５の第２油圧シリンダ８用の制御弁１５、サ
ービスポート１６用の制御弁１７、及び右の走行装置１
の油圧モータ１８用の制御弁１９が並列的に接続されて
いる。Next, the first, second, third hydraulic cylinders 7, 8,
9 will be described. As shown in FIG. 1, the oil passages 12, 13, 14 from the first pump 11
The control valve 15 for the second hydraulic cylinder 8 of the arm 5, the control valve 17 for the service port 16, and the right traveling device 1
The control valves 19 for the hydraulic motors 18 are connected in parallel.
【００２３】第２ポンプ２０からの油路２１，２２，２
３に、ブーム４の第１油圧シリンダ７用の制御弁２４、
バケット６の第３油圧シリンダ９用の制御弁２５、及び
左の走行装置１の油圧モータ２６用の制御弁２７が並列
的に接続されている。そして、左右の走行装置１用の制
御弁１９，２７、サービスポート１６用の制御弁１７、
及びバックホウ装置３用の制御弁１５，２４，２５がセ
ンターバイパス型式に構成されている。The oil passages 21, 22, 2 from the second pump 20
3, a control valve 24 for the first hydraulic cylinder 7 of the boom 4;
A control valve 25 for the third hydraulic cylinder 9 of the bucket 6 and a control valve 27 for the hydraulic motor 26 of the left traveling device 1 are connected in parallel. Then, the control valves 19 and 27 for the left and right traveling devices 1, the control valve 17 for the service port 16,
The control valves 15, 24, 25 for the backhoe device 3 are of a center bypass type.
【００２４】図１に示すように、第１ポンプ１１のセン
ター排油路２８において、圧油供給方向の最下手側に配
置された走行装置１用の制御弁１９と、サービスポート
１６用の制御弁１７との間の部分２８ａ（他の制御弁１
５の下手側部位に相当）から、油路２９が分岐延出さ
れ、この油路２９が一対の油路２９ａ，２９ｂに分岐し
て、油路２１，２２に接続されている。又、第２ポンプ
２０のセンター排油路３０において、圧油供給方向の最
下手側に配置された走行装置１用の制御弁２７と、バケ
ット６用の制御弁２５との間の部分３０ａ（他の制御弁
２４，２５の下手側部位に相当）から、油路３１が分岐
延出され、この油路３１が一対の油路３１ａ，３１ｂに
分岐して、油路１２，１３に接続されている。As shown in FIG. 1, in the center drain passage 28 of the first pump 11, a control valve 19 for the traveling device 1 and a control valve for the service port 16 are arranged at the lowermost side in the pressure oil supply direction. Portion 28a between the valve 17 and the other control valve 1
5), the oil passage 29 is branched and extended, and the oil passage 29 is branched into a pair of oil passages 29a and 29b and connected to the oil passages 21 and 22. In the center oil discharge passage 30 of the second pump 20, a portion 30a between the control valve 27 for the traveling device 1 and the control valve 25 for the bucket 6, which is disposed on the lowermost side in the pressure oil supply direction ( An oil passage 31 is branched and extended from the other control valves 24 and 25), and the oil passage 31 is branched into a pair of oil passages 31a and 31b and connected to the oil passages 12 and 13. ing.
【００２５】図１に示すように、左右の走行装置１用の
制御弁１９，２７を中立位置１９Ｎ，２７Ｎに操作して
いると、センター排油路２８，３０は連通状態となる。
そして、制御弁１９，２７を前進位置１９Ｆ，２７Ｆ
（走行位置に相当）、及び後進位置１９Ｒ，２７Ｒ（走
行位置に相当）に操作すると、センター排油路２８，３
０が、制御弁１９，２７で遮断されるように構成してい
る（遮断部に相当）。As shown in FIG. 1, when the control valves 19, 27 for the left and right traveling devices 1 are operated to the neutral positions 19N, 27N, the center drain passages 28, 30 are in a communicating state.
Then, the control valves 19 and 27 are moved to the forward positions 19F and 27F.
(Corresponding to the traveling position) and the reverse positions 19R, 27R (corresponding to the traveling position), the center oil passages 28, 3
0 is shut off by the control valves 19 and 27 (corresponding to an interrupting section).
【００２６】以上の構造により、左右の走行装置１用の
制御弁１９，２７を中立位置１９Ｎ，２７Ｎに操作して
機体を停止させている状態において、センター排油路２
８，３０を通る作動油は、制御弁１９，２７の中立位置
１９Ｎ，２７Ｎを通りタンク３２に戻る。With the above-described structure, the center oil discharge passage 2 is provided in a state where the control valves 19, 27 for the left and right traveling devices 1 are operated to the neutral positions 19N, 27N to stop the machine body.
The hydraulic oil passing through 8, 30 returns to the tank 32 through the neutral positions 19N, 27N of the control valves 19, 27.
【００２７】そして、左右の走行装置１用の制御弁１
９，２７を前進位置１９Ｆ，２７Ｆ、又は後進位置１９
Ｒ，２７Ｒに操作して、機体を前進又は後進させると、
第１及び第２ポンプ１１，２０のセンター排油路２８，
３０が遮断される。これによって、第１ポンプ１１側の
センター排油路２８を通る作動油が、油路２９，２９
ａ，２９ｂを通り、ブーム４用の制御弁２４及びバケッ
ト６用の制御弁２５に補給される。又、第２ポンプ２０
側のセンター排油路３０を通る作動油が、油路３１，３
１ａ，３１ｂを通り、アーム５用の制御弁１５及びサー
ビスポート１６用の制御弁１７に補給される。Then, the control valve 1 for the left and right traveling devices 1
9, 27 are set to the forward positions 19F, 27F or the reverse positions 19
By operating the R and 27R to move the aircraft forward or backward,
The center drain passage 28 of the first and second pumps 11, 20
30 is shut off. As a result, the hydraulic oil passing through the center oil discharge passage 28 on the first pump 11 side is turned into oil passages 29, 29.
The control valve 24 for the boom 4 and the control valve 25 for the bucket 6 are supplied through a and 29b. Also, the second pump 20
The hydraulic oil passing through the side center drain passage 30 is
The control valve 15 for the arm 5 and the control valve 17 for the service port 16 are supplied through 1a and 31b.
【００２８】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
付図面の構成に限定されるものではない。In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.
【図１】第１及び第２ポンプ系の油圧回路図FIG. 1 is a hydraulic circuit diagram of first and second pump systems.
【図２】バックホウの全体側面図FIG. 2 is an overall side view of the backhoe.
１ 油圧式走行装置 ３ 作業装置 １１ 第１ポンプ １９，２７ 油圧式走行装置
用の制御弁 １９Ｆ，１９Ｒ，２７Ｆ，２７Ｒ 制御弁の走行位
置 １５，２４，２５ 作業装置用の制
御弁 ２０ 第２ポンプ ２８，３０ センター排油路 ２８ａ，３０ａ センター排油路
の上手側部位 ２９，２９ａ，２９ｂ，３１，３１ａ 油路Reference Signs List 1 hydraulic traveling device 3 working device 11 first pump 19, 27 control valve for hydraulic traveling device 19F, 19R, 27F, 27R traveling position of control valve 15, 24, 25 control valve for working device 20 second pump 28, 30 Center oil drain 28a, 30a Upper part of center oil drain 29, 29a, 29b, 31, 31a Oil
Claims (1)
の油圧式走行装置（１）の一方用でセンターバイパス型
式の制御弁（１９）と、作業装置（３）用でセンターバ
イパス型式の制御弁（１５）とを並列的に接続し、第２
ポンプ（２０）に対して、左右一対の油圧式走行装置
（１）の他方用でセンターバイパス型式の制御弁（２
７）と、作業装置（３）用でセンターバイパス型式の制
御弁（２４），（２５）とを並列的に接続すると共に、 前記第１及び第２ポンプ（１１），（２０）系の各々の
センター排油路（２８），（３０）において、前記油圧
式走行装置（１）用の制御弁（１９），（２７）を圧油
供給方向の最下手側位置に配置し、該センター排油路
（２８），（３０）における前記走行装置用制御弁（１
９），（２７）に対する圧油供給方向上手側であり、か
つ、他の制御弁（１５），（２４），（２５）の圧油供
給方向下手側となる部位（２８ａ），（３０ａ）から油
路（２９），（２９ａ），（２９ｂ），（３１），（３
１ａ）を各々分岐させ、 前記 一対の油路（２９），（２９ａ），（２９ｂ），
（３１），（３１ａ）のうち第１ポンプ（１１）側の油
路（２９），（２９ａ），（２９ｂ）を第２ポンプ（２
０）側の作業装置（３）用の制御弁（２４），（２５）
に接続し、第２ポンプ（２０）側の油路（３１），（３
１ａ）を第１ポンプ（１１）側の作業装置（３）用の制
御弁（１５）に接続して、前記油圧式走行装置（１）用
の一対の制御弁（１９），（２７）の走行位置（１９
Ｆ），（１９Ｒ），（２７Ｆ），（２７Ｒ）に、前記セ
ンター排油路（２８），（３０）を遮断する遮断部を備
えてある作業車の油圧回路構造。1. A control valve (19) of a center bypass type for one of a pair of left and right hydraulic traveling devices (1) and a center bypass type for a working device (3) with respect to a first pump (11). And the control valve (15) of the second
For the pump (20), a center bypass type control valve (2) is used for the other of the pair of left and right hydraulic traveling devices (1).
7) and a center bypass type control valve (24), (25) for the working device (3) are connected in parallel, and each of the first and second pump (11), (20) systems Center oil discharge passage (28) and (30), the hydraulic
Control valves (19) and (27) for hydraulic traveling device (1)
It is located at the lowermost position in the supply direction, and
(28), (30) the traveling device control valve (1
9) and (27) are on the upstream side in the pressure oil supply direction.
And other control valves (15), (24), (25)
Oil from the parts (28a) and (30a) on the lower side in the supply direction
Roads (29), (29a), (29b), (31), (3
1a) each are branched, said pair of oil passages (29), (29a), (29b),
Of the (31) and (31a), the oil passages (29), (29a) and (29b) on the first pump (11) side are connected to the second pump (2).
Control valves (24), (25) for the working device (3) on the 0) side
To the oil passages (31), (3) on the second pump (20) side.
1a) is connected to a control valve (15) for a working device (3) on the first pump (11) side, and a pair of control valves (19) and (27) for the hydraulic traveling device (1) is connected. Travel position (19
F), (19R), (27F), and (27R), a hydraulic circuit structure of a working vehicle including a cut-off portion for cutting off the center oil discharge passages (28) and (30).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4159889A JP2760702B2 (en) | 1992-06-19 | 1992-06-19 | Work vehicle hydraulic circuit structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4159889A JP2760702B2 (en) | 1992-06-19 | 1992-06-19 | Work vehicle hydraulic circuit structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH062342A JPH062342A (en) | 1994-01-11 |
| JP2760702B2 true JP2760702B2 (en) | 1998-06-04 |
Family
ID=15703396
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4159889A Expired - Lifetime JP2760702B2 (en) | 1992-06-19 | 1992-06-19 | Work vehicle hydraulic circuit structure |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2760702B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6915600B2 (en) | 2000-09-12 | 2005-07-12 | Yanmar Co., Ltd. | Hydraulic circuit of excavating and slewing working vehicle |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6078022A (en) * | 1983-10-05 | 1985-05-02 | Yutani Juko Kk | Oil-pressure circuit of oil-pressure shovel |
-
1992
- 1992-06-19 JP JP4159889A patent/JP2760702B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6915600B2 (en) | 2000-09-12 | 2005-07-12 | Yanmar Co., Ltd. | Hydraulic circuit of excavating and slewing working vehicle |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH062342A (en) | 1994-01-11 |
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