JPH0410536B2 - - Google Patents
Info
- Publication number
- JPH0410536B2 JPH0410536B2 JP59264599A JP26459984A JPH0410536B2 JP H0410536 B2 JPH0410536 B2 JP H0410536B2 JP 59264599 A JP59264599 A JP 59264599A JP 26459984 A JP26459984 A JP 26459984A JP H0410536 B2 JPH0410536 B2 JP H0410536B2
- Authority
- JP
- Japan
- Prior art keywords
- directional
- valve
- switching valve
- group
- valves
- 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 39
- 238000011144 upstream manufacturing Methods 0.000 claims description 12
- 238000010276 construction Methods 0.000 claims description 6
- 238000010586 diagram Methods 0.000 description 10
- 230000002265 prevention Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 1
- 238000010291 electrical method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010297 mechanical methods and process Methods 0.000 description 1
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)
- 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）
本発明は油圧シヨベル等の建設機械の油圧回路
に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulic circuit for construction machinery such as a hydraulic excavator.
（従来技術）
建設機械の走行中に他のアクチエータを作動さ
せた場合、従来の油圧シヨベルの油圧回路はすべ
ての方向切換弁がパラレル接続されているため、
直進走行中に負荷の軽いアクチエータを作動させ
た方の走行モータ側に供給される油量が、他の一
方の走行モータ側に供給される油量より少なくな
り蛇行する。又直進走行中に負荷圧が高い他のア
クチエータを走行中に作動させると、そのアクチ
エータが作動しないという欠点があつた。(Prior art) When other actuators are activated while the construction machine is running, the hydraulic circuit of a conventional hydraulic excavator has all directional control valves connected in parallel.
While the vehicle is traveling straight, the amount of oil supplied to the side of the travel motor in which the actuator with the lighter load is activated is less than the amount of oil supplied to the other travel motor side, causing meandering. Another drawback is that if another actuator with a high load pressure is operated while the vehicle is traveling straight, that actuator will not operate.
即ち、例えば第４図に示す如き従来のシヨベル
油圧回路図は、概略次の様に構成されている。 That is, a conventional shovel hydraulic circuit diagram as shown in FIG. 4, for example, is roughly constructed as follows.
１は第１の油圧ポンプ、２は第２の油圧ポン
プ、３は第１、第２の油圧ポンプ１，２を駆動す
る原動機である。４は第１の方向切換弁のグルー
プであつて、メインリリーフバルブ４ａ、左走行
モータ用方向切換弁４ｂ、旋回モータ用方向切換
弁４ｃ、アームシリンダ用方向切換弁４ｄ、第２
のブーム用方向切換弁４ｅよりなつていて、これ
ら方向切換弁４ｂ〜４ｅはパラレル接続となつて
いる。４ｆは中立通路、４ｇはパラレル通路、４
ｈは戻り通路である。 1 is a first hydraulic pump, 2 is a second hydraulic pump, and 3 is a prime mover that drives the first and second hydraulic pumps 1 and 2. Reference numeral 4 denotes a first group of directional switching valves, which includes a main relief valve 4a, a directional switching valve 4b for the left traveling motor, a directional switching valve 4c for the swing motor, a directional switching valve 4d for the arm cylinder, and a second directional switching valve 4d for the arm cylinder.
The boom has a directional switching valve 4e, and these directional switching valves 4b to 4e are connected in parallel. 4f is neutral passage, 4g is parallel passage, 4
h is the return path.
５は第２の方向切換弁のグループで、メインリ
リーフバルブ５ａ、右走行モータ用方向切換弁５
ｂ、第１のブームシリンダ用方向切換弁５ｃ、バ
ケツトシリンダ用方向切換弁５ｄよりなり、各方
向切換弁５ｂ〜５ｄはパラレル接続となつてい
る。５ｆは中立通路、５ｇはパラレル通路、５ｈ
は戻り通路である。６は第１の油圧ポンプ１と第
１の方向切換弁のグループ４の主入口ポートP1
を結ぶ管路、７は第２の油圧ポンプ２と第２の方
向切換弁のグループ５の主入口ポートP1を結ぶ
管路である。 Reference numeral 5 designates a second group of directional control valves, including a main relief valve 5a and a directional control valve 5 for the right travel motor.
b, a first boom cylinder directional switching valve 5c, and a bucket cylinder directional switching valve 5d, and each of the directional switching valves 5b to 5d are connected in parallel. 5f is neutral passage, 5g is parallel passage, 5h
is the return passage. 6 is the main inlet port P 1 of the group 4 of the first hydraulic pump 1 and the first directional valve
A pipe line 7 connects the second hydraulic pump 2 and the main inlet port P1 of the second directional valve group 5.
このような従来の油圧シヨベルの油圧回路では
以下の如き不具合がある。すなわち、
(1) 左走行モータ用方向切換弁４ｂと右走行モー
タ用方向切換弁５ｂを操作中（同方向に操作す
ると直進走行となり、又互に逆に操作するとス
ピンターンとなる）にアーム操作をすると、ア
ームシリンダ用方向切換弁４ｄと左走行モータ
用方向切換弁４ｂとはパラレル接続のため、ア
ーム駆動圧＜左走行モータ駆動圧の関係である
と、左走行用方向切換弁４ｂ側に比較して負荷
の軽いアームシリンダ用方向切換弁４ｄ側に第
１の油圧ポンプ１の圧油が流れる傾向となる。
その結果左走行モータの速度が右走行モータの
速度より遅くなり、アームは動くが直進走行或
いはスピンターンができないこととなる。 The hydraulic circuit of such a conventional hydraulic excavator has the following problems. That is, (1) The arm is operated while operating the left travel motor directional selector valve 4b and the right travel motor directional selector valve 5b (operating them in the same direction will result in straight travel, and operating them in the opposite direction will result in a spin turn). Then, since the arm cylinder directional switching valve 4d and the left running motor directional switching valve 4b are connected in parallel, if the arm drive pressure is less than the left running motor driving pressure, the left running directional switching valve 4b side The pressure oil of the first hydraulic pump 1 tends to flow to the side of the arm cylinder directional control valve 4d, which has a relatively light load.
As a result, the speed of the left travel motor becomes slower than the speed of the right travel motor, and although the arm moves, it is not possible to travel straight or spin turn.
又アームシリンダ駆動圧＞左走行モータ駆動
圧であると、アームシリンダに与える圧力が不
足するので、直進走行又はスピンターンはでき
てもアームは動かない。 If the arm cylinder drive pressure is greater than the left travel motor drive pressure, the pressure applied to the arm cylinder will be insufficient, so the arm will not move even if it can travel straight or spin turn.
(2) 左走行モータ用方向切換弁４ｂと右走行モー
タ用方向切換弁５ｂを操作中（直進走行あるい
はスピンターン中）に旋回操作をする場合、右
走行モータ用方向切換弁４ｂと旋回用方向切換
弁４ｃはパラレル接続となつているため、旋回
モータ駆動圧＜走行モータ駆動圧であると、左
走行モータ用方向切換弁４ｂ側に比較して負荷
の軽い旋回モータ用方向切換弁４ｃ側に第１の
油圧ポンプ１の圧油が流れる傾向となる。その
結果左走行モータの速度が右走行モータの速度
より遅くなり旋回動作はするが直進走行あるい
はスピンターンができない。(2) When performing a turning operation while operating the left-hand motor directional control valve 4b and the right-hand motor directional control valve 5b (while traveling straight or during a spin turn), the right-hand motor directional control valve 4b and the turning direction Since the switching valves 4c are connected in parallel, if the swing motor drive pressure is less than the travel motor drive pressure, the directional control valve 4c for the swing motor, which has a lighter load compared to the directional control valve 4b for the left travel motor, will be connected. The pressure oil of the first hydraulic pump 1 tends to flow. As a result, the speed of the left travel motor becomes slower than the speed of the right travel motor, and although the vehicle can turn, it is unable to travel straight or spin turn.
又旋回モータ駆動圧＞走行モータ駆動圧の場
合では、旋回モータに与える圧力が不足して、
直進走行あるいはスピンターンはできても旋回
動作ができない。 In addition, if swing motor drive pressure > travel motor drive pressure, the pressure applied to the swing motor is insufficient,
Although it can run straight or spin turns, it cannot turn.
(3) 左走行モータ用方向切換弁４ｂと右走行モー
タ用方向切換弁５ｂを操作中、（直進走行中あ
るいはスピンターン中）にバケツト操作をする
場合、右走行モータ用方向切換弁５ｂとバケツ
トシリンダ用方向切換弁５ｃとはパラレル接続
となつているため、バケツトシリンダ駆動圧＜
右走行モータ用駆動圧であると、右走行モータ
用方向切換弁５ｂ側に比較して負荷の軽いバケ
ツト用方向切換弁５ｄ側に第２の油圧ポンプ２
の圧油が流れる傾向となる。その結果右走行モ
ータ速度が左走行モータ速度より遅くなりバケ
ツトは動くが直進走行あるいはスピンターンが
できない。(3) When operating the left travel motor directional selector valve 4b and the right travel motor directional selector valve 5b, when performing a bucket operation (while traveling straight or during a spin turn), the right travel motor directional selector valve 5b and the bucket Since it is connected in parallel with the bucket cylinder directional switching valve 5c, the bucket cylinder driving pressure <
When the drive pressure is for the right travel motor, the second hydraulic pump 2 is placed on the side of the bucket directional changeover valve 5d, which has a lighter load than the side of the right travel motor directional changeover valve 5b.
Pressure oil tends to flow. As a result, the right travel motor speed is slower than the left travel motor speed, and although the bucket moves, it is unable to travel straight or spin turns.
さらにバケツトシリンダ駆動圧＞右走行モー
タ駆動圧であると、バケツトシリンダに与える
圧力が不足し、直進走行はできてもバケツトは
動かない。 Furthermore, if the bucket cylinder drive pressure is greater than the right travel motor drive pressure, the pressure applied to the bucket cylinder will be insufficient, and even if the vehicle can travel straight, the bucket will not move.
(4) 左走行モータ用方向切換弁４ｂと右走行モー
タ用方向切換弁５ｂを操作中（直進走行中又は
スピンターン）ブーム操作をする場合、左走行
モータ用方向切換弁４ｂと第２のブームシリン
ダ用方向切換弁４ｅとが、又右走行モータ用方
向切換弁５ｂと第１のブームシリンダ用方向切
換弁５ｃとが各々パラレル接続となつているた
め、ブームシリンダ駆動圧＜走行モータ駆動圧
であると負荷の軽い第１、第２ブームシリンダ
用方向切換弁４ｅ，５ｃの方に第１、２の油圧
ポンプ１，２の圧油が夫々流れ、ブームは動く
が走行あるいはスピンターンができないことと
なる。(4) When operating the boom while operating the left travel motor directional selector valve 4b and the right travel motor directional selector valve 5b (while traveling straight or in a spin turn), the left travel motor directional selector valve 4b and the second boom Since the cylinder directional switching valve 4e, the right traveling motor directional switching valve 5b, and the first boom cylinder directional switching valve 5c are connected in parallel, boom cylinder driving pressure < traveling motor driving pressure. If so, the pressure oil from the first and second hydraulic pumps 1 and 2 will flow to the light-loaded first and second boom cylinder directional control valves 4e and 5c, respectively, and the boom will move, but it will not be able to travel or spin turn. becomes.
又ブームシリンダ駆動圧＞走行モータ駆動圧
であると、ブームシリンダに与える圧力が不足
し、直進走行あるいはスピンターンはできても
ブームは動かない。 If boom cylinder drive pressure>travel motor drive pressure, the pressure applied to the boom cylinder will be insufficient and the boom will not move even if it can run straight or spin turns.
（発明が解決しようとする問題点）
本発明は上記公知技術の問題点を解決しようと
するもので走行中に他のアクチエータを作動させ
た場合でも、直進走行あるいはスピンターンが可
能で、しかも他のアクチエータも確実に作動でき
るようにした油圧回路を提供しようとするもので
ある。(Problems to be Solved by the Invention) The present invention attempts to solve the above-mentioned problems of the known technology, and even if other actuators are activated during driving, it is possible to drive straight or spin turn, and furthermore, it is possible to The present invention aims to provide a hydraulic circuit that can reliably operate the actuator.
（問題点を解決する手段）
本発明は以上のような従来の油圧シヨベルの油
圧回路の不具合を解決するためなされたもので、
その解決手段は次の通りである。即ち、アクチエ
ータの油圧を制御する２つの方向制御弁のグルー
プの内第１の方向切換弁のグループには左右の走
行の内、定められた一方の走行モータ用方向切換
弁（以下左走行モータ用とする）を上流側に、走
行との複合操作の対象とするアクチエータ用の方
向切換弁たとえば旋回モータ用、アームシリンダ
用、及び第２のブームシリンダ用の方向切換弁を
逆流防止用チエツク弁を介して走行モータ用方向
切換弁に対して直列に接続する。なおこれら旋回
モータ用、アームシリンダ用及び第２のブームシ
リンダ用の各方向切換弁は互にパラレル接続し、
第２の方向切換弁のグループには左右の走行の
内、定められた他方の走行モータ用方向切換弁
（以下右走行モータ用とする）を上流に、走行と
の複合操作の対象となるアクチエータ用の方向切
換弁たとえば第１のブームシリンダ用及びバケツ
トシリンダ用の方向切換弁を逆流防止用チエツク
弁を介して走行モータ用方向切換弁に対して直列
に接続する。なお、これら第１のブームシリンダ
用及びバケツトシリンダ用の各方向切換弁は互に
パラレル接続している。(Means for Solving the Problems) The present invention has been made to solve the problems of the hydraulic circuit of the conventional hydraulic excavator as described above.
The solution is as follows. That is, of the two directional control valve groups that control the hydraulic pressure of the actuator, the first directional control valve group has a directional control valve for one of the left and right travel motors (hereinafter, a directional control valve for the left travel motor). ) on the upstream side, directional switching valves for actuators that are subject to combined operation with travel, such as directional switching valves for the swing motor, arm cylinder, and second boom cylinder, and check valves for preventing backflow. Connected in series to the directional control valve for the travel motor via the directional control valve for the travel motor. Note that these directional control valves for the swing motor, arm cylinder, and second boom cylinder are connected in parallel to each other.
The second group of directional control valves includes an actuator that is the target of a combined operation with the drive, upstream of the directional control valve for the other travel motor (hereinafter referred to as the right travel motor) of the left and right travel. For example, the directional control valves for the first boom cylinder and the bucket cylinder are connected in series to the directional control valve for the travel motor via a check valve for preventing backflow. Note that these directional switching valves for the first boom cylinder and the bucket cylinder are connected in parallel to each other.
さらに前記第１あるいは第２の方向切換弁のグ
ループのいずれか一方の走行モータ用方向切換弁
の上流に切換弁を設け、この切換弁によつて第
１、第２の油圧ポンプの圧油の流れを以下の如く
切換えるように構成している。なお、説明上、上
記切換弁は第２の方向切換弁のグループに設けた
場合とする。つまり、切換弁が
(イ) Ａ位置にある場合は、第１の油圧ポンプは第
１の方向切換弁のグループの第１の入口ポート
に入つて中立通路に供給され、又第２の油圧ポ
ンプは第２の方向切換弁のグループの第１の入
口ポートに入り、前記切換弁を介して中立通路
に供給されている。 Furthermore, a switching valve is provided upstream of the travel motor directional switching valve of either the first or second directional switching valve group, and this switching valve controls the pressure oil of the first and second hydraulic pumps. The flow is configured to be switched as follows. For purposes of explanation, it is assumed that the switching valve described above is provided in a group of second directional switching valves. That is, when the switching valve is in position A, the first hydraulic pump enters the first inlet port of the first group of directional valves and is supplied to the neutral passage, and the second hydraulic pump enters the first inlet port of the second group of directional valves and is fed through said directional valves to the neutral passage.
(ロ) 前記切換弁がＢ位置に切換つた場合は、第１
の油圧ポンプは第１の方向切換弁の第１の入口
ポートに入り、中立通路に供給されるととも
に、第２の方向切換弁のグループの第２の入口
ポートに入り、前記切換弁を介して中立通路に
供給される。又、第２の油圧ポンプは第２の方
向切換弁の第１の入口ポートに入り前記切換弁
を介して、第１の方向切換弁のグループの左走
行モータ用方向切換弁以外の方向切換弁のパラ
レル通路と、第２の方向切換弁のグループの右
走行モータ用方向切換弁以外の方向切換弁のパ
ラレル通路に供給されている。(b) When the switching valve is switched to the B position, the first
The hydraulic pump enters the first inlet port of the first directional valve and is supplied to the neutral passage, and the hydraulic pump enters the second inlet port of the second group of directional valves and is supplied to the neutral passage through said directional valve. It is fed to the neutral passage. Also, the second hydraulic pump enters the first inlet port of the second directional valve and passes through the directional valve to the directional valves other than the left travel motor directional valve of the first directional valve group. and the parallel passages of the directional control valves other than the right travel motor directional control valve of the second directional control valve group.
（発明の実施例）
以下本発明の油圧シヨベル等建設機械の油圧回
路の実施例について説明する。第１図は本発明の
第１の実施例の油圧回路図、第２図は本発明の第
２の実施例の油圧回路図で、第３図は本発明の第
３実施例の油圧回路図である。これらの図におい
て第４図の従来例と同一構成要素については同一
符号で示すものとする。(Embodiments of the Invention) Hereinafter, embodiments of a hydraulic circuit for a construction machine such as a hydraulic excavator according to the present invention will be described. Fig. 1 is a hydraulic circuit diagram of a first embodiment of the present invention, Fig. 2 is a hydraulic circuit diagram of a second embodiment of the invention, and Fig. 3 is a hydraulic circuit diagram of a third embodiment of the invention. It is. In these figures, the same components as in the conventional example shown in FIG. 4 are designated by the same reference numerals.
（第１実施例）
第１図の第１の実施例に於て、１は第１の油圧
ポンプ、２は第２の油圧ポンプ、３は第１、第２
の油圧ポンプ１，２及びパイロツト用油圧ポンプ
１０を駆動する原動機、４は第１の方向切換弁の
グループであつて、メインリリーフバルブ４ａ、
上流より左走行モータ用方向切換弁４ｂ、旋回モ
ータ用方向切換弁４ｃ、アームシリンダ用方向切
換弁４ｄ、第２のブームシリンダ用方向切換弁４
ｅ、の順に設けており、これら方向切換弁で走行
との複合操作の対象となる旋回モータ用、アーム
シリンダ用及び第２のブームシリンダ用の各方向
切換弁４ｃ〜４ｅを左走行モータ用方向切換弁４
ｂに対して直列に接続している。なお、旋回モー
タ用、アームシリンダ用及び第２のブームシリン
ダ用の各方向切換弁４ｃ〜４ｅはパラレル接続と
している為、順序がかわつてもよい。４ｆは中立
通路、４ｇはパラレル通路で第２の入口ポート
P0と接続されている。４ｈは戻り通路、４ｉは
左走行モータ用方向切換弁４ｂの下流に直列に設
けた他の方向切換弁４ｃ〜４ｅの中立通路４ｆと
パラレル通路４ｇを接続する通路に設けた逆流防
止用チエツク弁で中立通路４ｆからパラレル通路
４ｇに自由に流れ、その逆には流れない様に組込
まれている。４b′，４c′，４d′は左走行モータ用、
旋回モータ用及びアームシリンダ用の各方向切換
弁４ｂ〜４ｄに連動する補助弁である。(First embodiment) In the first embodiment shown in FIG. 1, 1 is a first hydraulic pump, 2 is a second hydraulic pump, and 3 is a first and a second hydraulic pump.
4 is a group of first directional valves, which include main relief valves 4a,
From the upstream, the left running motor directional switching valve 4b, the swing motor directional switching valve 4c, the arm cylinder directional switching valve 4d, and the second boom cylinder directional switching valve 4
The directional switching valves 4c to 4e for the swing motor, arm cylinder, and second boom cylinder, which are subject to combined operation with traveling, are installed in the order of directional switching valves 4c to 4e for the left travel motor. Switching valve 4
It is connected in series to b. Note that since the directional switching valves 4c to 4e for the swing motor, arm cylinder, and second boom cylinder are connected in parallel, the order may be changed. 4f is the neutral passage, 4g is the parallel passage and the second inlet port
Connected to P 0 . 4h is a return passage, and 4i is a check valve for preventing backflow provided in a passage connecting the parallel passage 4g with the neutral passage 4f of other directional switching valves 4c to 4e provided in series downstream of the left-hand drive motor directional switching valve 4b. It is built in such a way that it flows freely from the neutral passage 4f to the parallel passage 4g, and does not flow in the opposite direction. 4b', 4c', 4d' are for left travel motor,
This is an auxiliary valve that is interlocked with the directional switching valves 4b to 4d for the swing motor and arm cylinder.
５は第２の方向切換弁のグループで、メインリ
リーフバルブ５ａと、上流より右走行モータ用方
向切換弁５ｂ、第１のブームシリンダ用方向切換
弁５ｃ、バケツトシリンダ用方向切換弁５ｄの順
に設けられており、これらの方向切換弁で走行と
の複合操作の対象となる第１のブームシリンダ用
及びバケツトシリンダ用の各方向切換弁５ｃ，５
ｄを右走行モータ用方向切換弁５ｂに対して直列
に接続している。なお、第１のブームシリンダ用
及びバケツトシリンダ用の各方向切換弁はパラレ
ルに接続されている為に、順序がかわつてもよ
い。５ｅは右走行モータ用方向切換弁５ｂの上流
に設けられた切換弁で、これにより第１、第２の
油圧ポンプ１，２の圧油の供給状態を切り換えう
る。５ｆは中立通路、５ｇはパラレル通路、５ｈ
は戻り通路、５ｉは右走行モータ用方向切換弁５
ｂの下流に直列に設けられ、他の方向切換弁５
ｃ，５ｄの中立通路5fとパラレル通路５ｇを接続
する通路に設けた逆流防止用チエツク弁で、中立
通路５ｆからパラレル通路５ｇに自由に流れ、そ
の逆には流れない様に組まれている。５b′，５
c′，５d′は右走行モータ用、第１のブームシリン
ダ用及びバケツトシリンダ用の各方向切換弁５ｂ
〜５ｄに連動する補助弁である。 Reference numeral 5 designates a second group of directional control valves, which in order from the upstream are a main relief valve 5a, a directional control valve 5b for the right traveling motor, a directional control valve 5c for the first boom cylinder, and a directional control valve 5d for the bucket cylinder. Directional switching valves 5c, 5 for the first boom cylinder and for the bucket cylinder are provided, and these directional switching valves are used for combined operation with traveling.
d is connected in series to the right travel motor directional switching valve 5b. Note that since the directional switching valves for the first boom cylinder and the bucket cylinder are connected in parallel, the order may be changed. Reference numeral 5e denotes a switching valve provided upstream of the right travel motor directional switching valve 5b, which can switch the supply state of pressure oil to the first and second hydraulic pumps 1 and 2. 5f is neutral passage, 5g is parallel passage, 5h
is the return passage, and 5i is the directional control valve 5 for the right travel motor.
The other directional control valve 5 is provided in series downstream of b.
A check valve for preventing backflow is provided in the passage connecting the neutral passage 5f and the parallel passage 5g of c and 5d, and is constructed so that the flow can freely flow from the neutral passage 5f to the parallel passage 5g, but not in the opposite direction. 5b', 5
c', 5d' are directional switching valves 5b for the right travel motor, the first boom cylinder, and the bucket cylinder.
This is an auxiliary valve linked to ~5d.
６は第１の油圧ポンプ１と第１の方向切換弁の
グループ４の第１入口ポートP1とを接続する管
路。７は第２の油圧ポンプ２と第２の方向切換弁
のグループ５の第１入口ポートP1とを接続する
管路、８は第１の油圧ポンプ１と第２の方向切換
弁のグループ５の第２の入口ポートP2とを接続
する管路、９は切換弁５ｅの出口ポートP0と第
１の方向切換弁のグループ４の第２入口ポート
P0とを接続する管路、１０はパイロツト用ポン
プ、１１は前記パイロツト用ポンプ１０の最高圧
を制限するリリーフバルブ、１２はパイロツト用
ポンプ１０の圧油を切換弁５ｅに導びく管路、１
３は前記管路１２から分岐して補助弁５b′と接続
する管路、１４は前記管路１２から分岐して補助
弁４b′を接続する管路、１５は補助弁５b′からタ
ンクに接続する管路、１６は補助弁５b′の出口と
補助弁５c′を接続する管路、１７は補助弁５c′の
出口と補助弁５d′を接続する管路、１８は補助弁
５d′の出口と補助弁４d′を接続する管路、１９は
補助弁４d′の出口と補助弁４c′を接続する管路で
ある。２０は補助弁４b′，４c′の各出口と接続す
る管路で管路２１でもつてタンクと接続されてい
る。ここで左右の走行モータ用方向切換弁４ｂ，
５ｂと同時に左右の走行モータ用方向切換弁４
ｂ，５ｂ以外の他の方向切換弁４ｃ，４ｄ，５
ｃ，５ｄのいずれかを切換ると管路１２の圧力が
上昇し、切換弁５ｅがＡ位置よりＢ位置に切換
る。 6 is a conduit connecting the first hydraulic pump 1 and the first inlet port P1 of the first directional valve group 4; 7 is a pipe connecting the second hydraulic pump 2 and the first inlet port P 1 of the second directional valve group 5; 8 is the first hydraulic pump 1 and the second directional valve group 5; A pipe line 9 connects the second inlet port P2 of the switching valve 5e with the outlet port P0 of the switching valve 5e and the second inlet port of group 4 of the first directional switching valve.
10 is a pilot pump, 11 is a relief valve that limits the maximum pressure of the pilot pump 10, 12 is a pipeline that leads pressure oil from the pilot pump 10 to the switching valve 5e, 1
3 is a pipe branching from the pipe 12 and connecting to the auxiliary valve 5b', 14 is a pipe branching from the pipe 12 and connecting the auxiliary valve 4b', and 15 is a pipe connecting the auxiliary valve 5b' to the tank. 16 is a pipe connecting the outlet of the auxiliary valve 5b' and the auxiliary valve 5c', 17 is a pipe connecting the outlet of the auxiliary valve 5c' and the auxiliary valve 5d', and 18 is the outlet of the auxiliary valve 5d'. A pipe line 19 connects the outlet of the auxiliary valve 4d' and the auxiliary valve 4c'. Numeral 20 is a pipe connected to each outlet of the auxiliary valves 4b' and 4c', and is also connected to the tank by a pipe 21. Here, the left and right travel motor directional control valves 4b,
At the same time as 5b, the left and right travel motor directional control valves 4
Directional switching valves 4c, 4d, 5 other than b, 5b
When either of c and 5d is switched, the pressure in the pipe line 12 increases, and the switching valve 5e is switched from the A position to the B position.
この構成で切換弁５ｅによる第１、第２の油圧
ポンプ１，２の圧油の流れは以下のようになる。 With this configuration, the flow of pressure oil in the first and second hydraulic pumps 1 and 2 by the switching valve 5e is as follows.
(イ) 切換弁５ｅがＡ位置（第１図の状態）にある
場合；
第１の油圧ポンプ１の圧油は管路６を通つて
第１の方向切換弁のグループ４の第１入口ポー
トP1に供給され、中立通路４ｆを通り、タン
ク通路４ｈに流れる。又旋回モータ用方向切換
弁４ｃの上流で逆流防止チエツク弁４ｉを介し
てパラレル通路４ｇにもつながる。(a) When the switching valve 5e is in the A position (the state shown in Fig. 1); the pressure oil of the first hydraulic pump 1 passes through the pipe 6 to the first inlet port of group 4 of the first directional switching valve. P1 , passes through the neutral passage 4f, and flows into the tank passage 4h. It is also connected to the parallel passage 4g via a backflow prevention check valve 4i upstream of the swing motor directional switching valve 4c.
又、第１の油圧ポンプ１の圧油は管路８を通
つて第２の方向切換弁のグループ５の第２入口
ポートP2に供給されるが、切換弁５ｅによつ
て遮断されている。第２の油圧ポンプ２の圧油
は７を通つて第２の方向切換弁のグループ５の
第１入口ポートP1に供給され、切換弁５ｅ、
中立通路５ｆを通り、タンク通路５ｈに流れ
る。又第１のブームシリンダ用方向切換弁５ｃ
の上流で逆流防止チエツク弁５ｉを介してパラ
レル通路５ｇにもつながる。 Further, the pressure oil of the first hydraulic pump 1 is supplied to the second inlet port P2 of the second directional valve group 5 through the pipe line 8, but is blocked by the switching valve 5e. . The pressure oil of the second hydraulic pump 2 is supplied through 7 to the first inlet port P 1 of the group 5 of the second directional valves, the directional valves 5e,
It passes through the neutral passage 5f and flows into the tank passage 5h. Also, the first boom cylinder directional control valve 5c
It also connects to the parallel passage 5g via the backflow prevention check valve 5i upstream of the .
(ロ) 切換弁５ｅがＢ位置に切換つた場合；
第１の油圧ポンプ１の圧油は管路６を通り、
第１の方向切換弁のグループ４の第１入口ポー
トP1に供給され、中立通路４ｆに流れる。又
管路８を通つた第１の油圧ポンプ１の圧油は、
第２の方向切換弁グループ５の第２入口ポート
P2に供給され切換弁５ｅを介して中立通路５
ｆに流れる。つまり第１の油圧ポンプ１の圧油
は左右走行モータ用方向切換弁４ｂ，５ｂに専
用として供給される。(b) When the switching valve 5e is switched to the B position; the pressure oil of the first hydraulic pump 1 passes through the pipe 6,
It is supplied to the first inlet port P1 of the first group 4 of directional valves and flows into the neutral passage 4f. Moreover, the pressure oil of the first hydraulic pump 1 passing through the pipe line 8 is
Second inlet port of second directional valve group 5
P2 is supplied to the neutral passage 5 via the switching valve 5e.
flows to f. That is, the pressure oil of the first hydraulic pump 1 is exclusively supplied to the left and right travel motor directional switching valves 4b and 5b.
一方第２の油圧ポンプ２の圧油は、管路７を
通つて第２の方向切換弁のグループ５の第１入
口ポートP1に供給され、切換弁５ｅを介して
パラレル通路５ｇと、第２の方向切換弁のグル
ープ５の出口ポートP0に供給される。この出
口ポートP0を出た圧油は配管９を通り、第１
の方向切換弁のグループ４の第２入口ポート
P0に供給され、パラレル通路４ｇに流れる。
つまり第２の油圧ポンプ２の圧油は左右の走行
モータ用切換弁４ｂ，５ｂ以外の他のアクチエ
ータ用方向切換弁４ｃ〜４ｅ及び５ｃ，５ｄに
専用に供給されることとなる。 On the other hand, the pressure oil of the second hydraulic pump 2 is supplied through the line 7 to the first inlet port P1 of the group 5 of the second directional control valve, and is connected to the parallel passage 5g and the 2 to the outlet port P 0 of group 5 of the directional valves. The pressure oil that exited this outlet port P0 passes through the pipe 9 and the first
The second inlet port of group 4 of the directional valve
It is supplied to P 0 and flows to parallel path 4g.
In other words, the pressure oil of the second hydraulic pump 2 is exclusively supplied to the actuator directional switching valves 4c to 4e, 5c, and 5d other than the left and right travel motor switching valves 4b and 5b.
（第２実施例）
第２図は本発明の第２実施例を示すものであ
る。これは第１図に示す実施例と基本的には同一
構成であるが、異なる点は切換弁５ｅの構造が異
なることである。これについて説明すると切換弁
５ｅがＢ位置に切り換つた時、第２の油圧ポンプ
２の圧油すなわち左右の走行モータ用の方向切換
弁４ｂ，５ｂ以外の他のアクチエータ用の各方向
切換弁４ｃ〜４ｅ及５ｃ，５ｄに供給される圧油
の余剰分を、切換弁５ｅの内部に直列に設けられ
た絞り及びチエツク弁を介して左右の走行モータ
用の方向切換弁４ｂ，５ｂ側に供給することで、
第２の油圧ポンプ２の圧油を有効に利用すること
ができるようにしたことにある。(Second Embodiment) FIG. 2 shows a second embodiment of the present invention. This is basically the same configuration as the embodiment shown in FIG. 1, but the difference is that the structure of the switching valve 5e is different. To explain this, when the switching valve 5e switches to the B position, the pressure oil of the second hydraulic pump 2, that is, the directional switching valves 4c for actuators other than the directional switching valves 4b and 5b for the left and right travel motors. The surplus of the pressure oil supplied to ~4e, 5c, and 5d is supplied to the directional switching valves 4b and 5b for the left and right travel motors via the throttle and check valve provided in series inside the switching valve 5e. by doing,
The purpose is to enable effective use of the pressure oil of the second hydraulic pump 2.
（第３実施例）
第３図は本発明の第３の実施例を示すものであ
る。これも第１図に示す実施例と基本的には同一
構成であるが、異なる点は第１、第２の方向切換
弁のグループ４，５の各々のパラレル通路４ｇ，
５ｇと、中立通路４ｆ，５ｆを接続する通路４
ｊ，５ｊを夫々設け、それらの通路４ｊ，５ｊに
絞り４ｌ，５ｌ及びチエツク弁４ｋ，５ｋを直列
に設けたことである。なお各チエツク弁４ｋ，５
ｋはパラレル通路４ｇ，５ｇから中立通路４ｆ，
５ｆには自由に圧油は流れうるが、その逆には流
れないようにしている。(Third Embodiment) FIG. 3 shows a third embodiment of the present invention. This also has basically the same configuration as the embodiment shown in FIG. 1, but the difference is that each of the parallel passages 4g and
Passage 4 connecting 5g and neutral passages 4f and 5f
5j, respectively, and throttles 4l, 5l and check valves 4k, 5k are provided in series in the passages 4j, 5j. In addition, each check valve 4k, 5
k is parallel passage 4g, 5g to neutral passage 4f,
Although pressure oil can freely flow through 5f, it is prevented from flowing in the opposite direction.
以上の構成で切換弁５ｅがＢ位置に切り換つた
時、第２の油圧ポンプ２の圧油すなわち左右の走
行モータ用の方向切換弁４ｂ，５ｂ以外の他のア
クチエータ用の各方向切換弁４ｃ〜４ｅ及び５
ｃ，５ｄに供給される圧油の余剰分を、通路４
ｊ，５ｊに設けられた絞り４ｌ，５ｌ及びチエツ
ク弁４ｋ，５ｋを介して左右の走行モータ用の方
向切換弁４ｂ，５ｂ側に供給することで、第２の
油圧ポンプ２の圧油を有効に利用することができ
る。 With the above configuration, when the switching valve 5e is switched to the B position, the pressure oil of the second hydraulic pump 2, that is, the directional switching valves 4c for actuators other than the directional switching valves 4b and 5b for the left and right travel motors. ~4e and 5
The surplus of pressure oil supplied to channels c and 5d is transferred to passage 4.
The pressure oil of the second hydraulic pump 2 is made effective by supplying it to the directional control valves 4b and 5b for the left and right travel motors through the throttles 4l and 5l and check valves 4k and 5k provided at the left and right travel motors. It can be used for.
又、上記第１図〜第３図に示された各実施例の
回路図で、切換弁５ｅを作動させるのに、各補助
弁４b′〜４d′及び５b′〜５d′の動きの組合せでパ
イロツト用ポンプ１０の圧油を上昇させて行なう
ようにした構成を説明したが、これらの回路図に
示す回路組合せに限定するものではなく、他の回
路の組合せでも良く又、他の方法例えば手動式あ
るいは電気式で行なつても勿論よい。 In addition, in the circuit diagrams of the respective embodiments shown in FIGS. 1 to 3 above, in order to operate the switching valve 5e, the combination of movements of the auxiliary valves 4b' to 4d' and 5b' to 5d' is required. Although a configuration has been described in which the pressure oil of the pilot pump 10 is increased, the circuit combinations are not limited to those shown in these circuit diagrams, and other circuit combinations may be used. Of course, it may be performed using a mechanical or electrical method.
（発明の作用）
本発明は以上の通りの構成であつて、その作用
を以下説明する。(Operations of the Invention) The present invention has the above configuration, and its operation will be explained below.
(A) 左右の走行モータ用の方向切換弁４ｂ，５ｂ
を切換え、他のアクチエータ用方向切換弁４ｃ
〜４ｅ，５ｃ，５ｄを切換えない場合（つまり
走行単独操作の場合）；
パイロツト用ポンプ１０の圧油は補助弁５
b′，５c′，５d′，４d′，４c′は開き状態である
ためタンクに戻り、管路１２には油圧力の発生
はなく、切換弁５ｅは図の状態のままであり、
第１の油圧ポンプ１の圧油は管路６、第１の方
向切換弁のグループ４の第１入口ポートP1、
中立通路４ｆを経て左走行モータ用方向切換弁
４ｂに供給される。又第２の油圧ポンプ２の圧
油は管路７、第２の方向切換弁のグループ５の
第１入口ポートP1、切換弁５ｅ、中立通路５
ｆを経て右走行モータ用方向切換弁５ｂに供給
される。よつて従来の油圧回路と同様の作動が
可能である。(A) Directional switching valves 4b and 5b for left and right travel motors
directional control valve 4c for other actuators.
~ If 4e, 5c, and 5d are not switched (that is, in the case of traveling only operation); Pressure oil for the pilot pump 10 is supplied to the auxiliary valve 5.
Since b', 5c', 5d', 4d', and 4c' are in the open state, they return to the tank, no hydraulic pressure is generated in the pipe line 12, and the switching valve 5e remains in the state shown in the figure.
The pressure oil of the first hydraulic pump 1 is supplied to the line 6, the first inlet port P 1 of the group 4 of the first directional valve,
It is supplied to the left travel motor directional switching valve 4b via the neutral passage 4f. The pressure oil of the second hydraulic pump 2 is supplied to the pipe line 7, the first inlet port P 1 of the second directional valve group 5, the switching valve 5e, and the neutral passage 5.
It is supplied to the right travel motor directional switching valve 5b via f. Therefore, the same operation as a conventional hydraulic circuit is possible.
(B) 左右の走行モータ用方向切換弁４ｂ，５ｂは
切換えず（図の状態）にしておき、他のアクチ
エータ用の方向切換弁４ｃ〜４ｅ，５ｃ，５ｄ
を切換えた場合；
パイロツト用ポンプ１０の圧油は補助弁４
b′，５b′は開き状態であるため、タンクに戻
り、管路１２には油圧力の発生はなく、切換弁
５ｅは図示の状態のままであり、第１、第２の
方向切換弁のグループ４，５の中立通路４ｆ，
５ｆは前記走行モータ用方向切換弁４ｂ，５ｂ
以外の他のアクチエータ用の方向切換弁４ｃ〜
４ｅ，５ｃ，５ｄのいずれかで遮断されている
ので、第１の油圧ポンプ１の圧油は管路６、第
１の方向切換弁のグループ４の第１入口ポート
中立通路４ｆ、左走行モータ用方向切換弁４
ｂ、中立通路４ｆとパラレル通路４ｇを接続す
る通路に設けられた逆流防止チエツク弁４ｉを
経て、旋回モータ用、アームシリンダ用及び第
２のブームシリンダ用の各方向切換弁４ｃ〜４
ｅにパラレルに供給される。又第２の油圧ポン
プ２の圧油は管路７、第２の方向切換弁のグル
ープ５の第１入口ポートP1、切換弁５ｅ、中
立通路５ｆ、右走行モータ用方向切換弁５ｂ、
中立通路５ｆとパラレル通路５ｇを接続する通
路に設けられた逆流防止チエツク弁５ｉを経て
第１のブームシリンダ用及びバケツトシリンダ
用の各方向切換弁５ｃ，５ｄにパラレルに供給
される。よつて従来の油圧回路と同様の作動が
可能となる。(B) Left and right directional control valves 4b and 5b for the left and right travel motors are left unswitched (as shown in the figure), and directional control valves 4c to 4e, 5c, and 5d for other actuators are connected.
When the pressure oil of the pilot pump 10 is switched to the auxiliary valve 4
Since b' and 5b' are in the open state, they return to the tank, no hydraulic pressure is generated in the pipe line 12, the switching valve 5e remains in the state shown, and the first and second directional switching valves Groups 4 and 5 neutral passage 4f,
5f is the travel motor directional control valve 4b, 5b.
Directional switching valve 4c for actuators other than
4e, 5c, and 5d, the pressure oil of the first hydraulic pump 1 is supplied to the pipe 6, the first inlet port neutral passage 4f of the first directional valve group 4, and the left traveling motor. Directional switching valve 4
b. Directional switching valves 4c to 4 for the swing motor, arm cylinder, and second boom cylinder are passed through the check valve 4i provided in the passage connecting the neutral passage 4f and the parallel passage 4g.
e in parallel. Further, the pressure oil of the second hydraulic pump 2 is supplied to the pipe line 7, the first inlet port P 1 of the second directional switching valve group 5, the switching valve 5e, the neutral passage 5f, the directional switching valve 5b for the right travel motor,
It is supplied in parallel to the first boom cylinder and bucket cylinder directional switching valves 5c and 5d through a check valve 5i provided in a passage connecting the neutral passage 5f and the parallel passage 5g. Therefore, the same operation as a conventional hydraulic circuit is possible.
(C) 左右の走行モータ用方向切換弁４ｂ，５ｂを
同方向あるいは逆方向に同時に操作して、他の
アクチエータ用の方向切換弁４ｃ〜４ｅ，５
ｃ，５ｄを同時に切換えた場合、説明上旋回モ
ータ用方向切換弁４ｃを切換えた場合について
説明する；
パイロツトポンプ１０の圧油は補助弁４b′，
４c′により遮断されるので、管路１２の油圧力
はリリーフバルブ１１の設定圧まで上昇し切換
弁５ｅは切換つてＢ位置となるので、第１の油
圧ポンプ１の圧油は管路６、第１の方向切換弁
のグループ４の第１入口ポートP1、中立通路
４ｆを経て左走行モータ用方向切換弁４ｂに供
給される。なお、左走行モータ用方向切換弁４
ｂにより中立通路４ｆは遮断されるので、それ
以降の方向切換弁４ｃ〜４ｅには第１の油圧ポ
ンプ１の圧油は供給されない。(C) Directional switching valves 4c to 4e, 5 for other actuators are operated by simultaneously operating the left and right travel motor directional switching valves 4b, 5b in the same direction or in opposite directions.
For the sake of explanation, we will explain the case where the directional control valve 4c for the swing motor is switched at the same time; the pressure oil of the pilot pump 10 is supplied to the auxiliary valves 4b' and 5d.
4c', the hydraulic pressure in the pipe line 12 rises to the set pressure of the relief valve 11, and the switching valve 5e is switched to the B position, so that the pressure oil in the first hydraulic pump 1 is transferred to the pipe line 6, It is supplied to the left travel motor directional control valve 4b via the first inlet port P 1 of the first directional control valve group 4 and the neutral passage 4f. In addition, the direction switching valve 4 for the left travel motor
Since the neutral passage 4f is blocked by b, the pressure oil of the first hydraulic pump 1 is not supplied to the subsequent directional control valves 4c to 4e.
一方管路８にも供給された第１の油圧ポンプ
１の圧油は、第２の方向切換弁のグループ５の
第２入口ポートP2、切換弁５ｅを経て中立通
路５ｆを通じ、右走行モータ用方向切換弁５ｂ
に供給される。なお右走行モータ用方向切換弁
５ｂにより中立通路５ｆは遮断されるので、そ
れ以降の方向切換弁５ｃ，５ｄには第１の油圧
ポンプ１の圧油は供給されない。 On the other hand, the pressure oil of the first hydraulic pump 1, which is also supplied to the pipe line 8, passes through the second inlet port P 2 of the second directional switching valve group 5, the switching valve 5e, and the neutral passage 5f to the right traveling motor. Directional switching valve 5b
supplied to Note that since the neutral passage 5f is blocked by the right travel motor directional switching valve 5b, the pressure oil of the first hydraulic pump 1 is not supplied to the subsequent directional switching valves 5c and 5d.
一方、第２の油圧ポンプ２の圧油は管路７を
通じ、第２の方向切換弁のグループ５の第１入
口ポートP1に供給され、切換弁５ｅによつて
第２の方向切換弁のグループ５のパラレル通路
５ｇと出口ポートP0に供給される。この内、
パラレル通路５ｇにに供給された第２の油圧ポ
ンプ２の圧油は、第１のブームシリンダ用及び
バケツトシリンダ用の各方向切換弁５ｃ，５ｄ
にパラレルに供給される。又、第２の方向切換
弁のグループ５の出口ポートP0に供給された
第２の油圧ポンプ２の圧油は管路９を介して第
１の方向切換弁のグループ４の第２入口ポート
P0を経て、パラレル通路４ｇを通じ、旋回モ
ータ用、アームシリンダ用及び第２のブームシ
リンダ用の各方向切換弁４ｃ，４ｄ，４ｅにパ
ラレルに供給される。 On the other hand, the pressure oil of the second hydraulic pump 2 is supplied to the first inlet port P1 of the group 5 of the second directional valves through the line 7, and is transferred to the first inlet port P1 of the group 5 of the second directional valves by the switching valve 5e. It is supplied to the parallel passage 5g of group 5 and the outlet port P0 . Of these,
The pressure oil of the second hydraulic pump 2 supplied to the parallel passage 5g is supplied to each direction switching valve 5c, 5d for the first boom cylinder and bucket cylinder.
are supplied in parallel. Further, the pressure oil of the second hydraulic pump 2 supplied to the outlet port P 0 of the group 5 of the second directional control valve is supplied to the second inlet port of the group 4 of the first directional control valve via the pipe line 9.
It is supplied in parallel to the directional control valves 4c, 4d, and 4e for the swing motor, arm cylinder , and second boom cylinder through the parallel passage 4g.
以上を要約すると、第１の油圧ポンプ１の圧油
は、左右の走行モータ用方向切換弁４ｂ，５ｂに
専用に供給され、これらの方向切換弁４ｂ，５ｂ
が同方向に切換つていれば直進走行は維持され
る。逆方向に切換つていればスピンターンが維持
される。又第２の油圧ポンプ２の圧油は左右の走
行モータ用方向切換弁４ｂ，５ｃ以外の他のアク
チエータ用の方向切換弁４ｃ〜４ｅ，５ｃ，５ｄ
に専用に供給される。今回の場合は他のアクチエ
ータ用方向切換弁４ｄ，４ｅ，５ｃ，５ｅは操作
していないので旋回モータ用方向切換弁４ｃに全
量供給される。このことは走行と他のアクチエー
タが完全に独立していることを意味している。 To summarize the above, the pressure oil of the first hydraulic pump 1 is exclusively supplied to the left and right travel motor directional control valves 4b, 5b, and these directional control valves 4b, 5b
If both are switched in the same direction, straight-line driving will be maintained. If the switch is in the opposite direction, the spin turn is maintained. Moreover, the pressure oil of the second hydraulic pump 2 is supplied to directional switching valves 4c to 4e, 5c, and 5d for actuators other than the left and right travel motor directional switching valves 4b and 5c.
Supplied exclusively to In this case, since the other actuator directional control valves 4d, 4e, 5c, and 5e are not operated, the entire amount is supplied to the swing motor directional control valve 4c. This means that travel and other actuators are completely independent.
（発明の効果）
本発明は以上のような構成であるので、左右の
走行を操作中に走行以外の他のアクチエータを操
作する場合、切換弁５ｅが切り換るので、第１、
第２の油圧ポンプのうち、一方の油圧ポンプから
の圧油を他のアクチエータと独立して走行専用
に、他の油圧ポンプからの圧油を走行以外の他の
アクチエータの専用に供給することができるよう
にしたので、直進走行中あるいはスピンターン操
作中に他のアクチエータを作動させた場合でも直
進走行、スピンターンの動作が確実で、しかも走
行以外の他のアクチエータの作動も確実にでき、
能率の良い作業を保障できる。(Effects of the Invention) Since the present invention has the above-described configuration, when an actuator other than travel is operated while left and right travel is being operated, the switching valve 5e is switched.
Among the second hydraulic pumps, it is possible to supply pressure oil from one hydraulic pump exclusively for traveling independently from the other actuators, and to supply pressure oil from the other hydraulic pump exclusively for other actuators other than traveling. Therefore, even if other actuators are activated during straight travel or spin turn operation, straight travel and spin turn operations can be ensured, and other actuators other than travel can also be operated reliably.
Efficient work can be guaranteed.
第１図は本発明の第１実施例油圧回路図。第２
図は同じく第２実施例油圧回路図。第３図は同じ
く第３実施例油圧回路図。第４図は従来公知の油
圧回路図。図において；
１……第１の油圧ポンプ、２……第２の油圧ポ
ンプ、３……原動機、４……第１の方向切換弁グ
ループ、４ａ，５ａ……メインリリーフバルブ、
４ｂ……左走行モータ用方向切換弁、４ｃ……旋
回モータ用方向切換弁、４ｄ……アームシリンダ
用方向切換弁、４ｅ……第２のブームシリンダ用
方向切換弁、４ｆ……中立通路、４ｇ……パラレ
ル通路、４ｈ……戻り通路、４ｉ……逆流防止用
チエツク弁、４ｊ……通路、４ｋ……チエツク
弁、４ｌ……絞り、５……第２の方向切換弁グル
ープ、５ｂ……右走行モータ用方向切換弁、５ｃ
……第１のブームシリンダ用方向切換弁、５ｄ…
…バケツトシリンダ用方向切換弁、５ｅ……切換
弁、５ｆ……中立通路、５ｇ……パラレル通路、
５ｈ……戻り通路、５ｉ……逆流防止用チエツク
弁、５ｊ……通路、５ｋ……チエツク弁、５ｌ…
…絞り、１０……パイロツトポンプ、１１……リ
リーフ弁、６，７，８，９，１２，１３，１４，
１５，１６，１７，１８，１９，２０，２１……
管路。
FIG. 1 is a hydraulic circuit diagram of a first embodiment of the present invention. Second
The figure is also a hydraulic circuit diagram of the second embodiment. FIG. 3 is a hydraulic circuit diagram of the third embodiment. FIG. 4 is a conventionally known hydraulic circuit diagram. In the figure: 1...first hydraulic pump, 2...second hydraulic pump, 3...prime mover, 4...first directional valve group, 4a, 5a...main relief valve,
4b... Directional switching valve for left traveling motor, 4c... Directional switching valve for swing motor, 4d... Directional switching valve for arm cylinder, 4e... Directional switching valve for second boom cylinder, 4f... Neutral passage, 4g...parallel passage, 4h...return passage, 4i...check valve for backflow prevention, 4j...passage, 4k...check valve, 4l...throttle, 5...second directional valve group, 5b... ...Directional switching valve for right travel motor, 5c
...First boom cylinder directional control valve, 5d...
...Direction switching valve for bucket cylinder, 5e...Switching valve, 5f...Neutral passage, 5g...Parallel passage,
5h... Return passage, 5i... Check valve for backflow prevention, 5j... Passage, 5k... Check valve, 5l...
... Throttle, 10... Pilot pump, 11... Relief valve, 6, 7, 8, 9, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21...
conduit.
Claims (1)
る第１の油圧ポンプと第２の油圧ポンプの２個の
油圧ポンプ及びこれらの油圧ポンプによつて駆動
される複数のアクチエータに供給される圧油の方
向を制御する第１の方向切換弁グループ４と第２
の方向切換弁グループ５を備えた油圧シヨベル等
の建設機械の油圧回路。 (1) 第１の方向切換弁のグループ４には左右の走
行の内、定められた１方の走行モータ用方向切
換弁４ｂを上流に、走行との複合操作の対象と
なるアクチエータ用の方向切換弁たとえば旋回
モータ用方向切換弁４ｃ、アームシリンダ用方
向切換弁４ｄ、第２のブームシリンダ用方向切
換弁４ｅ等を下流に直列に接続し、第２の方向
切換弁のグループ５には左右の走行の内、定め
られた他方の走行モータ用方向切換弁５ｂを上
流に、走行との複合操作の対象となるアクチエ
ータ用の方向切換弁、たとえば第１のブームシ
リンダ用方向切換弁５ｃ、バケツトシリンダ用
方向切換弁５ｄ等を下流に直列に接続する。 (2) これら直列に接続した通路に、中立通路４
ｆ，５ｆから自由に圧油が流れる方向に逆流防
止用チエツク弁４ｉ，５ｉを各々設ける。 (3) 第２の方向切換弁のグループ５あるいは第１
の方向切換弁のグループ４のいずれか一方の上
流に切換弁５ｅを設け、この切換弁５ｅによ
り、 (a) 通常は一方の油圧ポンプ１又は２の圧油は
一方の方向切換弁のグループ４又は５の中立
通路４ｆ又は５ｆのみに供給し、他方の油圧
ポンプ２又は１の圧油は他方の方向切換弁の
グループ５又は４の切換弁５ｅを介して中立
通路５ｆ又は４ｆのみに供給する。 (b) この切換弁５ｅが切換つた状態では、一方
の油圧ポンプ１又は２の圧油は一方の方向切
換弁のグループ４又は５の中立通路４ｆ又は
５ｆと他方の方向切換弁のグループ５又は４
の切換弁５ｅを介して中立通路５ｆ又は４ｆ
に供給し、他方の油圧ポンプ２又は１の圧油
は他方の方向切換弁のグループ５又は４の切
換弁５ｅを介して他方の方向切換弁のグルー
プ５又は４のパラレル通路５ｇ又は４ｇと、
一方の方向切換弁のグループ４又は５のパラ
レル通路４ｇ又は５ｇとに供給可能とした。 ２ 第２の方向切換弁のグループ５あるいは第１
の方向切換弁のグループ４のいずれか一方の上流
に設けられた切換弁５ｅが切換わつた時、切換弁
５ｅの内部に、他方の油圧ポンプ５又は４の圧油
の一部が一方の油圧ポンプ４又は５の圧油の方に
流れうるような通路を構成し、この通路に絞り及
びチエツク弁を直列に設けたことを特徴とする特
許請求の範囲１記載の油圧シヨベル等の建設機械
の油圧回路。 ３ 第１と第２の方向切換弁のグループ４，５の
それぞれに、パラレル通路４ｇ，５ｇと中立通路
４ｆ，５ｆを接続する通路４ｊ，５ｊを設け、こ
れら通路４ｊ，５ｊにパラレル通路４ｇ，５ｇか
ら中立通路４ｆ，５ｆのみに流れうる方向に各々
チエツク弁４ｋ，５ｋを設け、かつそれらチエツ
ク弁４ｋ，５ｋと直列に各々絞り４ｌ，５ｌを設
けたことを特徴とする特許請求の範囲１記載の油
圧シヨベル等の建設機械の油圧回路。[Claims] 1. Two hydraulic pumps, a first hydraulic pump and a second hydraulic pump, and these hydraulic pumps, which are characterized by the following structural requirements (1) to (3): A first directional control valve group 4 and a second directional control valve group control the direction of pressure oil supplied to a plurality of driven actuators.
A hydraulic circuit for a construction machine such as a hydraulic excavator, which is equipped with a directional control valve group 5. (1) The first directional control valve group 4 has one of the left and right running motor directional control valves 4b upstream, and a direction for the actuator that is subject to combined operation with running. Switching valves such as a swing motor directional switching valve 4c, an arm cylinder directional switching valve 4d, a second boom cylinder directional switching valve 4e, etc. are connected in series downstream, and the second directional switching valve group 5 has left and right directional switching valves. While traveling, the other travel motor directional control valve 5b is placed upstream, and the actuator directional control valve that is subject to combined operation with travel, for example, the first boom cylinder directional control valve 5c, the bucket. The cylinder directional switching valve 5d and the like are connected in series downstream. (2) A neutral passage 4 is added to these series-connected passages.
Check valves 4i and 5i for preventing backflow are provided in the direction in which pressure oil freely flows from f and 5f, respectively. (3) Group 5 or first of the second directional valves
A switching valve 5e is provided upstream of either group 4 of directional switching valves, and by this switching valve 5e, (a) Normally, the pressure oil of one hydraulic pump 1 or 2 is transferred to the group 4 of one directional switching valve. Or, the pressure oil of the other hydraulic pump 2 or 1 is supplied only to the neutral passage 5f or 4f through the switching valve 5e of the other directional switching valve group 5 or 4. . (b) When the switching valve 5e is switched, the pressure oil of one hydraulic pump 1 or 2 is transferred between the neutral passage 4f or 5f of the group 4 or 5 of one directional valve and the neutral passage 4f or 5f of the group 5 or 5 of the other directional valve. 4
Neutral passage 5f or 4f via switching valve 5e
The pressure oil of the other hydraulic pump 2 or 1 is supplied to the parallel passage 5g or 4g of the other directional valve group 5 or 4 via the switching valve 5e of the other directional valve group 5 or 4,
It was possible to supply the parallel passage 4g or 5g of group 4 or 5 of one directional control valve. 2 Group 5 of the second directional valve or the first
When the switching valve 5e provided upstream of one of the directional switching valve groups 4 is switched, a part of the pressure oil of the other hydraulic pump 5 or 4 is transferred to one hydraulic pressure inside the switching valve 5e. A construction machine such as a hydraulic excavator according to claim 1, characterized in that a passage is formed so that the pressure oil of the pump 4 or 5 can flow, and a throttle and a check valve are provided in series in this passage. Hydraulic circuit. 3 Each of the first and second directional valve groups 4 and 5 is provided with passages 4j and 5j connecting the parallel passages 4g and 5g and the neutral passages 4f and 5f, and the parallel passages 4g and 5j are connected to these passages 4j and 5j. Claim 1 characterized in that check valves 4k and 5k are provided in a direction that allows flow from 5g to only neutral passages 4f and 5f, and throttles 4l and 5l are provided in series with these check valves 4k and 5k, respectively. Hydraulic circuit of construction machinery such as hydraulic excavator described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59264599A JPS61142235A (en) | 1984-12-17 | 1984-12-17 | Oil-pressure circuit for construction machine such as oil-pressure shovel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59264599A JPS61142235A (en) | 1984-12-17 | 1984-12-17 | Oil-pressure circuit for construction machine such as oil-pressure shovel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61142235A JPS61142235A (en) | 1986-06-30 |
| JPH0410536B2 true JPH0410536B2 (en) | 1992-02-25 |
Family
ID=17405546
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59264599A Granted JPS61142235A (en) | 1984-12-17 | 1984-12-17 | Oil-pressure circuit for construction machine such as oil-pressure shovel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61142235A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6389403U (en) * | 1986-12-02 | 1988-06-10 | ||
| JPH0643259Y2 (en) * | 1988-01-30 | 1994-11-09 | 川崎重工業株式会社 | Hydraulic equipment for construction machinery |
| JPH0649644Y2 (en) * | 1988-02-18 | 1994-12-14 | 油谷重工株式会社 | Hydraulic circuit of crawler type hydraulic excavator |
| JPH0643260Y2 (en) * | 1988-02-29 | 1994-11-09 | 川崎重工業株式会社 | Hydraulic equipment for construction machinery |
| JP2504571Y2 (en) * | 1988-03-24 | 1996-07-10 | 油谷重工株式会社 | Hydraulic circuit of hydraulic excavator |
| JP2504572Y2 (en) * | 1988-04-11 | 1996-07-10 | 油谷重工株式会社 | Hydraulic circuit of hydraulic excavator |
| JPH0649633Y2 (en) * | 1988-06-07 | 1994-12-14 | 油谷重工株式会社 | Hydraulic circuit of hydraulic excavator |
| US5115835A (en) * | 1990-01-26 | 1992-05-26 | Zexel Corporation | Stacked type hydraulic control valve system |
| JP3614121B2 (en) * | 2001-08-22 | 2005-01-26 | コベルコ建機株式会社 | Hydraulic equipment for construction machinery |
| JP2006329248A (en) * | 2005-05-24 | 2006-12-07 | Kobelco Contstruction Machinery Ltd | Hydraulic pressure supply device for working machine |
-
1984
- 1984-12-17 JP JP59264599A patent/JPS61142235A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61142235A (en) | 1986-06-30 |
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