JPH0410534B2 - - Google Patents
Info
- Publication number
- JPH0410534B2 JPH0410534B2 JP58137583A JP13758383A JPH0410534B2 JP H0410534 B2 JPH0410534 B2 JP H0410534B2 JP 58137583 A JP58137583 A JP 58137583A JP 13758383 A JP13758383 A JP 13758383A JP H0410534 B2 JPH0410534 B2 JP H0410534B2
- Authority
- JP
- Japan
- Prior art keywords
- valve
- valves
- switching
- switching valve
- logic
- 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
- 230000007935 neutral effect Effects 0.000 claims description 9
- 238000000034 method Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
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
- E02F9/2278—Hydraulic circuits
- E02F9/2292—Systems with two or more pumps
-
- 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
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)
Description
【発明の詳細な説明】
この発明は油圧シヨベルの油圧回路に関するも
のである。その目的とするところは、
(1) １本のレバーあるいはペダルの操作だけで蛇
行なく直進走行を可能にすること。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic circuit for a hydraulic excavator. The objectives are: (1) To enable the vehicle to travel straight without meandering by simply operating a single lever or pedal.
(2) 前記直進走行の操作注に他の操作、例えば旋
回、アーム、ブームあるいはバケツト操作を同
時にしても走行の直進性能を維持し続けること
ができること、そしてこれにより油圧シヨベル
の機能が高まり、多用途への使用が可能とな
り、さらに運転者の疲労低減が計れると共に、
作業能率が向上する油圧シヨベルの油圧回路を
提供しようとするものである。(2) It is possible to maintain the straight running performance even when other operations such as turning, arm, boom, or bucket operation are performed at the same time as the above-mentioned straight running operation Note, and this improves the functionality of the hydraulic excavator. It can be used for multiple purposes, and it also reduces driver fatigue.
The present invention aims to provide a hydraulic circuit for a hydraulic excavator that improves work efficiency.
第１図は従来型の油圧回路を示し、１は第１油
圧ポンプ、２は第２油圧ポンプで、それぞれ図示
していないエンジンにて駆動される。 FIG. 1 shows a conventional hydraulic circuit, where 1 is a first hydraulic pump and 2 is a second hydraulic pump, each of which is driven by an engine (not shown).
３は第１油圧ポンプ１より圧油が供給される第
１コントロールバルブで左走行用バルブ３ａ、旋
回用バルブ３ｂ、アーム用バルブ３ｃ、ブーム２
速用バルブ３ｄ、メインリリーフバルブ３ｅを有
している。 3 is a first control valve to which pressure oil is supplied from the first hydraulic pump 1, and includes a left travel valve 3a, a swing valve 3b, an arm valve 3c, and a boom 2.
It has a speed valve 3d and a main relief valve 3e.
４は第２油圧ポンプ２より圧油が供給される第
２コントロールバルブで右走行用バルブ４ａ、ブ
ーム１速用バルブ４ｂ、バケツト用バルブ４ｃ、
メインリリーフバルブ４ｄを有している。 Reference numeral 4 denotes second control valves to which pressure oil is supplied from the second hydraulic pump 2, including a right travel valve 4a, a boom 1st speed valve 4b, a bucket valve 4c,
It has a main relief valve 4d.
さて、この従来型油圧回路では、
(1) 直進走行をする場合たえず左右の走行用バル
ブ３ａと４ａを同時に同方向に入れて保持して
おかねばならず、運転者の疲労が多くなる欠点
があつた。 Now, with this conventional hydraulic circuit, (1) When driving straight, the left and right travel valves 3a and 4a must be constantly turned on and held in the same direction at the same time, which increases driver fatigue. It was hot.
(2) 又直進走行中に他の操作をした場合、その操
作側の油圧ポンプの吐出量が他の操作用にも分
流することになるので、その操作側の走行モー
タの速度が低下し蛇行する欠点があつた。(2) If other operations are performed while traveling straight, the discharge amount of the hydraulic pump on the operation side will be diverted to other operations, so the speed of the travel motor on the operation side will decrease and the meandering will occur. There was a drawback.
本発明はこのような従来型油圧回路を改良した
もので、その構成を要約すると次の如くである。 The present invention is an improvement on such a conventional hydraulic circuit, and its structure can be summarized as follows.
即ち、
２ポンプ・２コントロールバルブを有する油圧
シヨベルの油圧回路において、第１・第２コント
ロールバルブと左右走行バルブと左右の走行モー
タとを連結する管路に左右の走行モータへの圧油
の給排を独立と並列に切換える切換弁を設け、か
つ第１・第２コントロールバルブの中立通路の最
下流にロジツクバルブを設けると共に、該ロジツ
クバルブの前段から分岐した管路を前記切換弁に
接続し、かつロジツクバルブのパイロツト管路を
前記切換弁の独立・並列切換操作時に連動して切
換えられる切換弁に接続し、開閉するようにした
ことを特徴としている。 That is, in the hydraulic circuit of a hydraulic excavator having two pumps and two control valves, pressure oil is supplied to the left and right travel motors through a pipe connecting the first and second control valves, the left and right travel valves, and the left and right travel motors. A switching valve is provided to switch the exhaust independently and in parallel, and a logic valve is provided at the lowest downstream of the neutral passage of the first and second control valves, and a pipe line branched from the stage before the logic valve is connected to the switching valve, and The pilot pipe of the logic valve is connected to a switching valve that is switched in conjunction with the independent/parallel switching operation of the switching valve, and is opened and closed.
以下本発明を採用した油圧シヨベルの油圧回路
を実施例に沿い説明する。 DESCRIPTION OF THE PREFERRED EMBODIMENTS The hydraulic circuit of a hydraulic excavator employing the present invention will be described below with reference to embodiments.
第２図において、１は第１油圧ポンプ、２は第
２油圧ポンプで、それぞれ図示していないエンジ
ンにて駆動される。３は第１油圧ポンプ１より圧
油が供給される第１コントロールバルブで左走行
用バルブ３ａ、旋回用バルブ３ｂ、アーム用バル
ブ３ｃ、ブーム２速用バルブ３ｄ、メインリリー
フバルブ３ｅを有し、かつロジツクバルブ３ｆを
中立通路の最下流に配している。 In FIG. 2, 1 is a first hydraulic pump, and 2 is a second hydraulic pump, each of which is driven by an engine (not shown). 3 is a first control valve to which pressure oil is supplied from the first hydraulic pump 1, and includes a left travel valve 3a, a swing valve 3b, an arm valve 3c, a boom 2nd speed valve 3d, and a main relief valve 3e. In addition, the logic valve 3f is disposed at the most downstream position of the neutral passage.
４は第２油圧ポンプ２より圧油が供給される第
２コントロールバルブで右走行用バルブ４ａ、ブ
ーム１速用バルブ４ｂ、バケツト用バルブ４ｃ、
メインリリーフバルブ４ｄを有し、かつロジツク
バルブ４ｅを中立通路の最下流に配している。
５，６はロジツクバルブ３ｆ，４ｅの上流側中立
通路より圧油を導びく管路で口述する切換弁１８
に接続する管路７に合流している。８と９，１０
と１１は左走行用給排管路、１２と１３及び１４
と１５は右走行用給排管路である。 Reference numeral 4 denotes second control valves to which pressure oil is supplied from the second hydraulic pump 2, including a right travel valve 4a, a boom 1st speed valve 4b, a bucket valve 4c,
It has a main relief valve 4d, and a logic valve 4e is arranged at the most downstream of the neutral passage.
5 and 6 are switching valves 18 that are controlled by pipes that lead pressure oil from the neutral passages on the upstream side of the logic valves 3f and 4e.
It joins the pipe line 7 which connects to the pipe line 7. 8 and 9, 10
and 11 are supply and exhaust pipes for left running, 12, 13 and 14
and 15 are supply and discharge pipes for right travel.
１６はロジツクバルブ３ｆ，４ｅのパイロツト
ポートと切換弁１７を結ぶパイロツト管路、１７
はロジツクバルブ３ｆ，４ｅのパイロツト圧を制
御する切換弁である。この切換弁は中立位置では
パイロツト管路１６はタンクと接続され該管路１
６にパイロツト圧は発生しないため、ロジツクバ
ルブ３ｆ，４ｅは開かれた状態にある。このため
第１と第２油圧ポンプ１，２の油圧は管路５，
６，７側には流れない。又切換弁１７を「イ」あ
るいは「ロ」位置に切換えるとパイロツト管路１
６はブロツクとなりパイロツト管路１６にパイロ
ツト圧が発生しロジツク３ｆ，４ｅは閉じられた
状態になるため、第１、第２油圧ポンプ１，２の
圧油は管路５，６，７に流れることとなる。 16 is a pilot pipe connecting the pilot ports of the logic valves 3f and 4e and the switching valve 17; 17;
is a switching valve that controls the pilot pressure of logic valves 3f and 4e. In the neutral position of this switching valve, the pilot line 16 is connected to the tank and the pilot line 16 is connected to the tank.
Since no pilot pressure is generated at 6, logic valves 3f and 4e are in an open state. Therefore, the oil pressure of the first and second hydraulic pumps 1 and 2 is
It does not flow to the 6th and 7th sides. Also, when the switching valve 17 is switched to the "A" or "B" position, the pilot pipe 1
6 becomes a block and pilot pressure is generated in the pilot line 16, and the logics 3f and 4e are closed, so the pressure oil of the first and second hydraulic pumps 1 and 2 flows into the lines 5, 6, and 7. That will happen.
１８は前記切換弁１７と連動して切換えられる
並列・独立切換弁で中立位置では左走行用給排管
路８は管路９と、管路１０は管路１１と、管路１
２は管路１３と管路１４は管路１５と又管路７は
タンク通路に各々接続している。そして切換弁１
８を「イ」位置に切換えた場合は、管路７は管路
９及び管路１５とに接続され、管路１０は管路１
１と、管路１２は管路１３と接続され、他の管路
１８及び管路１４の通路はブロツクされる。逆に
「ロ」位置に切換えた場合は、管路７は管路１１
及び管路１３とに接続され、管路８は管路９と、
管路１４は管路１５と夫々接続され、他の管路１
０及び管路１２はブロツクされる構造となつてい
る。このようにして、並列回路の場合、モータへ
の圧油の供給方向を切換え前・後進走行を可能に
している。 Reference numeral 18 denotes a parallel/independent switching valve that is switched in conjunction with the switching valve 17, and in the neutral position, the left running supply/discharge pipe 8 is connected to the pipe 9, the pipe 10 is connected to the pipe 11, and the pipe 1
2 is connected to a pipe 13, pipe 14 is connected to a pipe 15, and pipe 7 is connected to a tank passage. and switching valve 1
8 is switched to the "A" position, the pipe line 7 is connected to the pipe line 9 and the pipe line 15, and the pipe line 10 is connected to the pipe line 1.
1 and conduit 12 are connected to conduit 13, and passages of other conduit 18 and conduit 14 are blocked. Conversely, when switched to the "ro" position, pipe line 7 is switched to pipe line 11.
and conduit 13, conduit 8 is connected to conduit 9,
The pipe lines 14 are connected to the pipe lines 15, respectively, and are connected to the other pipe lines 1.
0 and conduit 12 are structured to be blocked. In this way, in the case of a parallel circuit, the direction of supply of pressure oil to the motor is switched to enable forward and reverse running.
第３図は切換弁１８の内部接続の他の実施例を
示すもので、切換弁１８を「イ」及び「ロ」位置
に切り換えた場合、圧油供給側の管路７と接続す
る管路以外はすべてタンクと接続するような構造
にしたものである。 FIG. 3 shows another embodiment of the internal connection of the switching valve 18, and when the switching valve 18 is switched to the "A" and "B" positions, the pipe line connecting to the pressure oil supply side pipe line 7 is shown. All other parts are designed to be connected to the tank.
また第４図は切換弁１７と切換弁１８の連動方
法の他の実施例を示すもので、切換弁１７を切換
弁１８の補助弁として直接切換が可能になつてい
る。 FIG. 4 shows another embodiment of the interlocking method of the switching valve 17 and the switching valve 18, in which the switching valve 17 is used as an auxiliary valve for the switching valve 18 to enable direct switching.
なお、前記した実施例では、ロジツクバルブ３
ｆ，４ｅと切換弁１７とを連結するパイロツト管
路を合流させた後、切換弁１７に導いた実施例に
ついて説明したが、ロジツクバルブのパイロツト
管路を合流させずに切換弁１８に連動する２個の
切換弁によつて切換えるようにする等、本発明の
要旨を逸脱しない範囲の変更が可能なことはいう
までもない。 In addition, in the embodiment described above, the logic valve 3
An example has been described in which the pilot pipes connecting the logic valves f and 4e and the switching valve 17 are merged and then led to the switching valve 17. It goes without saying that changes can be made without departing from the gist of the present invention, such as switching by separate switching valves.
本発明は以上のような構成であつて以下作動に
ついて説明する。 The present invention has the above structure, and its operation will be explained below.
１ 直進走行を単独にする場合：
(A) 切換弁１８を「イ」位置に切換えた場合、
管路７は管路９及び管路１５とに接続され、
管路１０は管路１１に、管路１２は管路１３
に各々接続され、管路８及び管路１４はブロ
ツクとなる。又切換弁１８に連動した切換弁
１７も「イ」位置に切換わるので、パイロツ
ト管路１６は切換弁１７によりタンクと遮断
されるので、ロジツクバルブ３ｆ，４ｅは閉
状態となる。1. When traveling straight ahead independently: (A) When switching the switching valve 18 to the "A" position,
The conduit 7 is connected to the conduit 9 and the conduit 15,
Conduit 10 is connected to conduit 11, and conduit 12 is connected to conduit 13.
The conduit 8 and the conduit 14 form a block. Furthermore, since the switching valve 17 linked to the switching valve 18 is also switched to the "A" position, the pilot pipe line 16 is isolated from the tank by the switching valve 17, so that the logic valves 3f and 4e are closed.
このことにより第１油圧ポンプ１及び第２
油圧ポンプ２の圧油は各々管路５及び管路６
を経て管路７に合流して流入し、切換弁１８
を介して管路９と管路１５に等量に分流し、
左右の走行モータに流入する。又左右の走行
モータからの戻り油は各々管路１１及び管路
１３、切換弁１８を介して管路１０及び管路
１２、左走行用バルブ３ａ及び右走行用バル
ブ４ａを通つてタンクに戻る。 As a result, the first hydraulic pump 1 and the second hydraulic pump
The pressure oil of the hydraulic pump 2 is supplied to pipes 5 and 6, respectively.
It flows into the pipe 7 through the switching valve 18.
The flow is divided into equal amounts into pipe line 9 and pipe line 15 via
Flows into the left and right travel motors. Also, return oil from the left and right running motors returns to the tank through pipes 11 and 13, switching valves 18, pipes 10 and 12, left-hand travel valve 3a, and right-hand travel valve 4a, respectively. .
従つて左右の走行モータに同圧、同量の圧
油が供給され同速で前進方向に直進すること
となる。 Therefore, the same pressure and the same amount of pressure oil are supplied to the left and right travel motors, and the vehicle moves straight in the forward direction at the same speed.
(B) 切換弁１８を「ロ」位置に切換えた場合、
(A)項の説明とは、走行モータへの圧油の供給
方向が逆になるが同様にして左右走行モータ
は同速で後進方向に直進することとなる。 (B) When switching the switching valve 18 to the "ro" position,
Although the direction of supply of pressure oil to the travel motors is reversed from the explanation in item (A), the left and right travel motors similarly move straight in the reverse direction at the same speed.
２ 直進走行中に他の操作を同時にした場合：
(A) 直進走行中の旋回同時操作の場合、
切換弁１８を「イ」（前進）あるいは「ロ」
（後進）位置に切換えて、なおかつ旋回用バ
ルブ３ｂを切換えた時、切換弁１７、ロジツ
クバルブ３ｆ，４ｅは前記１−(A)及び１−(B)
で説明したと同様になるが、旋回用バルブ３
ｂとロジツクバルブ３ｆはタンデム回路とな
り、ロジツクバルブ３ｆ側には第１油圧ポン
プ１の圧油は流れず、全量旋回モータ側に流
入する。2 If other operations are performed at the same time while traveling straight: (A) If turning is performed simultaneously while traveling straight, set the switching valve 18 to "A" (forward) or "B".
(reverse) position and when the turning valve 3b is switched, the switching valve 17 and the logic valves 3f and 4e are switched to the above-mentioned 1-(A) and 1-(B).
It will be the same as explained in , but the turning valve 3
b and the logic valve 3f form a tandem circuit, and the pressure oil of the first hydraulic pump 1 does not flow to the logic valve 3f side, but flows entirely to the swing motor side.
又第２油圧ポンプ２の圧油は全量左右走行
モータに分流される。従つて、旋回と走行は
各々独立した油圧ポンプの圧油を使用するこ
とになるので旋回操作をしても直進走行が可
能となる。 Further, the entire pressure oil of the second hydraulic pump 2 is diverted to the left and right travel motors. Therefore, since pressure oil from independent hydraulic pumps is used for turning and traveling, straight-line traveling is possible even when turning is performed.
(B) 直進走行中のアーム同時操作の場合：
上記２−(A)と全く同様となる直進走行しな
がらアーム操作が可能である。 (B) In the case of simultaneous arm operation while traveling straight: It is possible to operate the arm while traveling straight, which is exactly the same as in 2-(A) above.
(C) 直進走行中のブーム１速同時操作の場合：
前記２−(A)、２−(B)と圧油の供給側油圧ポ
ンプが入れ替るだけであとは同様であるの
で、直進しながらブーム１速操作は可能であ
る。 (C) When simultaneously operating the boom in 1st gear while traveling straight: Since the rest is the same except that the hydraulic pump on the pressure oil supply side is replaced with 2-(A) and 2-(B) above, Boom 1st speed operation is possible.
(D) 直進走行中のバケツト同時操作の場合：
前記２−(C)と同様であり直進走行を維持し
ながらバケツト操作が可能である。 (D) In the case of simultaneous bucket and tot operation while traveling straight: This is the same as 2-(C) above, and it is possible to perform bucket and tot operations while maintaining straight travel.
以上の様に本発明に於ては切換弁１８と切換弁
１７とを１本のレバーあるいはペダルの操作のみ
で、第１・第２ポンプからの合流と走行方向の切
換が可能となり操作が非常に楽である。 As described above, in the present invention, it is possible to merge the first and second pumps and switch the running direction by operating the switching valves 18 and 17 with only one lever or pedal, which makes the operation extremely easy. It's easy.
又上記操作中に他の操作を行つても走行の直進
性を維持でき、油圧シヨベルを多目的に使用する
ことができる。なお、従来と同じ走行操作をする
場合、切換弁１８を操作せずに、従来と同様の左
右走行用バルブ３ａ及び４ａを操作すれば可能で
ある。 Further, even if other operations are performed during the above operation, the straightness of travel can be maintained, and the hydraulic excavator can be used for multiple purposes. In addition, when performing the same traveling operation as in the conventional case, it is possible to do so by operating the left and right traveling valves 3a and 4a, which are the same as in the conventional case, without operating the switching valve 18.
又第２図では第１、第２の油圧ポンプ１，２は
固定容量ポンプで表示したが可変容量ポンプでも
よく、又切換弁１７及び切換弁１８は手動操作で
表示したが、パイロツト操作弁あるいは電磁弁で
もよい。さらにロジツクバルブ３ｆ，４ｅは第
１、第２コントロールバルブ３，４と各々１体と
しているが別置でもよい。 Although the first and second hydraulic pumps 1 and 2 are shown as fixed capacity pumps in FIG. 2, they may also be variable capacity pumps, and the switching valves 17 and 18 are shown as being manually operated, but they may be pilot operated valves or A solenoid valve may also be used. Further, although the logic valves 3f and 4e are integrated with the first and second control valves 3 and 4, they may be placed separately.
以上の実施例では油圧シヨベルについて説明し
たが、走行が油圧モータで駆動され、しかも他の
操作が油圧モータあるいは油圧シリンダで駆動さ
れる機械、例えば油圧クローラクレーン等にも適
用できることはいうまでもない。 In the above embodiments, a hydraulic excavator has been described, but it goes without saying that the application can also be applied to machines whose travel is driven by a hydraulic motor and whose other operations are driven by a hydraulic motor or hydraulic cylinder, such as a hydraulic crawler crane. .
第１図は従来公知の油圧シヨベルの油圧回路。
第２図は本発明に係る油圧シヨベルの油圧回路。
第３図は切換弁１８の別の実施例。第４図は２つ
の切換弁の連動方法の他の実施例。
図において；１……第１油圧ポンプ、２……第
２油圧ポンプ、３……第１コントロールバルブ、
３ａ……左走行用バルブ、３ｂ……旋回用バル
ブ、３ｃ……アーム用バルブ、３ｄ……ブーム２
速用バルブ、３ｅ……メインリリーフバルブ、３
ｆ……ロジツクバルブ、４……第２コントロール
バルブ、４ａ……右走行用バルブ、４ｂ……ブー
ム１速用バルブ、４ｃ……バケツト用バルブ、４
ｄ……メインリリーフバルブ、４ｅ……ロジツク
バルブ、５……（第１ポンプグループのロジツク
バルブの中立流路より圧油を導く）管路、６……
（第２ポンプグループのロジツクバルブの上流の
中立流路より圧油を導く）管路、７……（管路５
と管路６の）合流管路、８，９，１０，１１……
左走行用給排管路、１２，１３，１４，１５……
右走行用給排管路、１６……（ロジツクバルブ３
ｆ，４ｅと切換弁１７を結ぶ）パイロツト管路、
１７……（ロジツクバルブ３ｆ，４ｅを制御する
ための）切換弁、１８……切換弁。
Figure 1 shows the hydraulic circuit of a conventionally known hydraulic excavator.
FIG. 2 is a hydraulic circuit of a hydraulic excavator according to the present invention.
FIG. 3 shows another embodiment of the switching valve 18. FIG. 4 shows another embodiment of the method of interlocking two switching valves. In the figure: 1...first hydraulic pump, 2...second hydraulic pump, 3...first control valve,
3a... Valve for left running, 3b... Valve for turning, 3c... Valve for arm, 3d... Boom 2
Speed valve, 3e...Main relief valve, 3
f...Logic valve, 4...Second control valve, 4a...Valve for right travel, 4b...Valve for boom 1st speed, 4c...Valve for bucket, 4
d...Main relief valve, 4e...Logic valve, 5...Pipe line (leading pressure oil from the neutral flow path of the logic valve of the first pump group), 6...
(Guiding pressure oil from the neutral flow path upstream of the logic valve of the second pump group) Pipe, 7... (Pipe 5
and pipe line 6) confluence pipe line, 8, 9, 10, 11...
Supply and exhaust pipes for left travel, 12, 13, 14, 15...
Right running supply/discharge pipe, 16... (Logic valve 3
a pilot pipe connecting f, 4e and the switching valve 17;
17...Switching valve (for controlling logic valves 3f, 4e), 18...Switching valve.
Claims (1)
圧シヨベルの油圧回路において、第１及び第２コ
ントロールバルブ３，４の左右走行用バルブ３
ａ，４ａと左右の走行モータとを連結する管路に
左右の走行モータへの圧油の給排を独立と並列に
切換える切換弁１８を設け、かつ第１及び第２コ
ントロールバルブ３，４の中立通路の最下流にロ
ジツクバルブ３ｆ，４ｅを設けると共に、これら
ロジツクバルブ３ｆ，４ｅの前段から夫々分岐し
た管路５，６を前記切換弁１８に接続し、かつ前
記ロジツクバルブ３ｆ，４ｅのパイロツト管路１
６を前記独立と並列に切換える切換弁１８の独
立・並列切換操作に連動して切換えられる切換弁
１７に接続して前記切換弁１８の切換えに応じて
交互に開・閉するようにし、前記切換弁１８の切
換により第１コントロールバルブ３側と第２コン
トロールバルブ４側の両ロジツクバルブ３ｆ，４
ｅを閉にし、並列の場合には、両ロジツクバルブ
３ｆ，４ｅを遮断しその前段から合流して走行モ
ータへ圧油が供給され、左右走行用バルブ３ａ，
４ａからは圧油は供給されないようにしたことを
特徴とする油圧シヨベルの油圧回路。1 In the hydraulic circuit of a hydraulic excavator having two pumps and two control valves, the left and right travel valves 3 of the first and second control valves 3 and 4
A switching valve 18 for switching the supply and discharge of pressure oil to the left and right travel motors independently and in parallel is provided in the pipe connecting the left and right travel motors to the left and right travel motors, and the first and second control valves 3 and 4 are connected to each other. Logic valves 3f and 4e are provided at the most downstream of the neutral passage, and pipes 5 and 6 branched from the front stages of these logic valves 3f and 4e are connected to the switching valve 18, and a pilot pipe 1 of the logic valves 3f and 4e is connected.
6 is connected to the switching valve 17 which is switched in conjunction with the independent/parallel switching operation of the switching valve 18 which switches the independent and parallel switching valves so that the switching valve 17 is opened and closed alternately in response to switching of the switching valve 18, By switching the valve 18, both the logic valves 3f and 4 on the first control valve 3 side and the second control valve 4 side are activated.
e is closed, and in the case of parallel operation, both logic valves 3f and 4e are shut off, and pressure oil is merged from the previous stage and supplied to the travel motor, and the left and right travel valves 3a,
A hydraulic circuit for a hydraulic excavator, characterized in that no pressure oil is supplied from 4a.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58137583A JPS6030734A (en) | 1983-07-29 | 1983-07-29 | Oil-pressure circuit for oil-pressure shovel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58137583A JPS6030734A (en) | 1983-07-29 | 1983-07-29 | Oil-pressure circuit for oil-pressure shovel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6030734A JPS6030734A (en) | 1985-02-16 |
| JPH0410534B2 true JPH0410534B2 (en) | 1992-02-25 |
Family
ID=15202104
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58137583A Granted JPS6030734A (en) | 1983-07-29 | 1983-07-29 | Oil-pressure circuit for oil-pressure shovel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6030734A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4541209B2 (en) * | 2005-03-31 | 2010-09-08 | ナブテスコ株式会社 | Hydraulic circuit |
| JP5572827B2 (en) * | 2011-01-17 | 2014-08-20 | 日立建機株式会社 | Hydraulic circuit system for work machines |
-
1983
- 1983-07-29 JP JP58137583A patent/JPS6030734A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6030734A (en) | 1985-02-16 |
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