JPS6056924B2 - hydraulic circuit - Google Patents
hydraulic circuitInfo
- Publication number
- JPS6056924B2 JPS6056924B2 JP56071370A JP7137081A JPS6056924B2 JP S6056924 B2 JPS6056924 B2 JP S6056924B2 JP 56071370 A JP56071370 A JP 56071370A JP 7137081 A JP7137081 A JP 7137081A JP S6056924 B2 JPS6056924 B2 JP S6056924B2
- Authority
- JP
- Japan
- Prior art keywords
- hydraulic
- valve
- pump
- valves
- pilot pressure
- 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
Links
Landscapes
- Operation Control Of Excavators (AREA)
- Fluid-Pressure Circuits (AREA)
Description
【発明の詳細な説明】
本発明は油圧回路に係り、特にパラレル油圧回路に各方
向切換弁を制御する油圧操作回路を付加した、たとえば
油圧ショベル、ブルドーザ等に好適な油圧回路に関する
。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic circuit, and more particularly to a hydraulic circuit suitable for, for example, hydraulic excavators, bulldozers, etc., in which a hydraulic operating circuit for controlling each directional control valve is added to a parallel hydraulic circuit.
油圧機器作動用ポンプに各方向切換弁を同時に平行して
接続した、いわゆるパラレル油圧回路においては、ポン
プからの圧油が各方向切換弁にパラレルに入り、複数個
の油圧機器を同時に操作した場合、軽負荷の方が先に作
動するので、各油圧機器にかかる負荷の軽量が絶えす変
化する油圧ショベル等に適した場合には、どちらの油圧
機器が動くか判然とせす作業動作が不安定になる。In a so-called parallel hydraulic circuit, in which directional control valves are connected simultaneously and parallel to a pump for operating hydraulic equipment, pressure oil from the pump enters each directional control valve in parallel, and multiple hydraulic equipment are operated simultaneously. , the light load operates first, so if it is suitable for hydraulic excavators where the load on each hydraulic device is constantly changing, it is difficult to tell which hydraulic device is moving, resulting in unstable work operation. become.
たとえば、パラレル油圧回路に接続された２つの油圧機
器のうち、一方の油圧機器をパケットシリンダ、他方の
油圧機器をアームシリンダとし、アームシリンダを伸長
して（アームをクラウドさせて）土砂掘削を行い、次い
でパケットシリンダを伸長して（パケットをクラウドさ
せて）土砂をすくい込み、さらにアームシリンダを動作
させる連続作業について考察する。このような連続作業
を行うには、まずアーム用操作レバーを操作しアームを
クラウドして土砂掘削を行い、アーム用操作レバーを完
全に中立に戻し、次いでパケット用操作レバーを操作し
てパケットをクラウドさせ土砂をすくい込む。For example, among two hydraulic devices connected to a parallel hydraulic circuit, one hydraulic device is a packet cylinder and the other hydraulic device is an arm cylinder, and the arm cylinder is extended (the arm is clouded) to excavate earth and sand. Next, consider the continuous work of extending the packet cylinder (clouding the packets) to scoop up the earth and sand, and then operating the arm cylinder. To carry out continuous work like this, first operate the arm control lever to cloud the arm and excavate soil, return the arm control lever completely to neutral, and then operate the packet control lever to remove the packet. Scoop up the soil and sand.
ここでアーム用操作レバーを完全に戻さないでパケット
用操作レバーを入れると、パケットは動作しないことが
起こる。次いでパケット用操作レバーを完全に中立に戻
してアーム用操作レバーを操作しアームを動作する。し
たがつて作業サイクルタイムが長くなるばかりでなく、
作業動作が非常に不安定となる。そこで油圧ショベル等
にパラレル油圧回路を適用する場合には、複数個のポン
プを使用し、複合操作をひんぱんに行う油圧機器を別ポ
ンプにより作動するように配置する等の手段を講じてい
るが、複合操作を行う油圧機器の数に対応したポンプ数
を設けなければ複合操作による作業動作の不安定化を完
全に解消することができない欠点があつた。If the packet control lever is turned on without fully returning the arm control lever, the packet may not operate. Next, the packet control lever is completely returned to neutral and the arm control lever is operated to operate the arm. This not only increases the work cycle time, but also
Work movement becomes extremely unstable. Therefore, when applying parallel hydraulic circuits to hydraulic excavators, etc., measures are taken such as using multiple pumps and arranging hydraulic equipment that frequently performs complex operations so that it is operated by a separate pump. There is a drawback that unless the number of pumps corresponding to the number of hydraulic equipment that performs multiple operations is provided, it is not possible to completely eliminate the instability of work operations caused by multiple operations.
本発明は上記に鑑みてなされたもので、その目的は、パ
ラレル油圧回路に接続された各油圧機器を油圧操作弁に
より複合操作したときの作業動作を安定化することのて
きる油圧回路を提供するにある。The present invention has been made in view of the above, and an object of the present invention is to provide a hydraulic circuit that can stabilize work operations when hydraulic equipment connected to a parallel hydraulic circuit is operated in a combined manner by hydraulic operation valves. There is something to do.
第１および第２ポンプと、第１ポンプにパラレルに接続
された第１および第２方向切換弁と、第１および第２方
向切換弁を介して第１ポンプの圧一油により作動される
第１および第２油圧機器と、第２ポンプに接続された第
３方向切換弁と、第３方向の切換弁を介して第２ポンプ
の圧油により作動される第３油圧機器と、パイロット圧
操作信号により第１、第２および第３方向切換え制御す
る！第１、第２および第３油圧操作弁と、これらの油圧
操作弁にパイロット圧を発生するための補助ポンプと、
第２ポンプに第３方向切換弁とパラレルに接続され、且
つ第１油圧操作弁のパイロット圧操作信号により切換え
制御される第４方向切換弁！と、第４方向切換弁を介し
て第２ポンプを第１油圧機器に接続する回路と、第２お
よび第３油圧操作弁の少なくともいずれか一方からのパ
イロット圧操作信号により作動し、第１油圧操作弁から
のパイロット圧操作信号が発生しており且つ第２おダよ
び第３の油圧操作弁の少なくともいずれか一方からのパ
イロット圧操作信号が発生している複合操作時に、第１
油圧操作弁のパイロット圧操作信号による前記第４方向
切換弁の切換え制御を有効とする操作信号制御弁とを備
えたことを特徴とする。first and second pumps, first and second directional valves connected in parallel to the first pump, and a first pump operated by pressure oil of the first pump via the first and second directional valves. 1 and 2 hydraulic equipment, a 3rd directional switching valve connected to the 2nd pump, a 3rd hydraulic equipment operated by pressure oil of the 2nd pump via the 3rd directional switching valve, and pilot pressure operation. The first, second, and third directions are controlled by signals! first, second and third hydraulically operated valves; an auxiliary pump for generating pilot pressure to these hydraulically operated valves;
A fourth directional switching valve that is connected to the second pump in parallel with the third directional switching valve and is switched and controlled by the pilot pressure operating signal of the first hydraulic operating valve! and a circuit connecting the second pump to the first hydraulic device via the fourth directional valve, and a pilot pressure operation signal from at least one of the second and third hydraulic operation valves, and the first hydraulic During a combined operation in which a pilot pressure operation signal is generated from the operation valve and a pilot pressure operation signal is generated from at least one of the second and third hydraulic operation valves, the first pressure operation signal is generated.
The present invention is characterized by comprising an operation signal control valve that enables switching control of the fourth directional switching valve based on a pilot pressure operation signal of the hydraulic operation valve.
以下、本発明を図示の実施例に基づいて詳細に説明する
。Hereinafter, the present invention will be explained in detail based on illustrated embodiments.
図において、ポンプ１は油圧方向切換弁２，３を介して
油圧シリンダ４，油圧モータ５に接続され、ポンプ６は
油圧方向切換弁７，８を介して油圧モータ９、油圧シリ
ンダ４に接続されている。In the figure, a pump 1 is connected to a hydraulic cylinder 4 and a hydraulic motor 5 via hydraulic directional switching valves 2 and 3, and a pump 6 is connected to a hydraulic motor 9 and a hydraulic cylinder 4 via hydraulic directional switching valves 7 and 8. ing.
方向切換弁２，３はポンプ１に対して、方向切換ｌ弁７
，８はポンプ６に対してそれぞれパラレルに接続されて
いる。油圧操作弁１０はパイロット圧操作信号Ａ，ｂに
より方向切換弁３を各Ａ，Ｂ位置に切換え油圧モータ５
を駆動する。油圧操作弁１１はパイロット圧操作信号Ｃ
，ｄにより方向切換弁８を各Ｃ，Ｄ位置に切換え油圧シ
リンダを伸縮する。また油圧操作弁１２はパイロット圧
操作信号Ｅ，ｆにより方向切換弁７を各Ｅ，Ｆ位置に切
換え、油圧モータ９を駆動する。１３は油圧操作弁１１
の操作信号ｃを制御する油圧切換弁からなる操作信号制
御弁で、通常Ｇ位置に設定され油圧操作弁１０の操作信
号Ａ，ｂおよび油圧操作弁１２の操作信号Ｅ，ｆによつ
てＨ位置に切換えられる。The directional valves 2 and 3 are the directional valve 7 for the pump 1.
, 8 are each connected in parallel to the pump 6. The hydraulic operation valve 10 switches the directional control valve 3 to the A and B positions by the pilot pressure operation signals A and B, and the hydraulic motor 5
to drive. The hydraulic operation valve 11 receives a pilot pressure operation signal C.
, d, the directional control valve 8 is switched to the C and D positions to extend and retract the hydraulic cylinder. Further, the hydraulic operation valve 12 switches the directional control valve 7 to the E and F positions by the pilot pressure operation signals E and f, and drives the hydraulic motor 9. 13 is a hydraulically operated valve 11
This is an operation signal control valve consisting of a hydraulic switching valve that controls the operation signal c of the hydraulic operation valve.It is normally set to the G position and is changed to the H position by the operation signals A and b of the hydraulic operation valve 10 and the operation signals E and f of the hydraulic operation valve 12. can be switched to
１４は油圧操作弁１１の操作信号ｄを制御する油圧方向
切換弁からなる操作信号制御弁１で、通常１位置に設定
され油圧操作弁１０の操作信号Ａ，ｂおよび油圧操作弁
１２の操作信号Ｅ，ｆによつてＪ位置に切換えられる。Reference numeral 14 denotes an operation signal control valve 1 consisting of a hydraulic directional switching valve that controls the operation signal d of the hydraulic operation valve 11, which is normally set to 1 position and receives the operation signals A and b of the hydraulic operation valve 10 and the operation signal of the hydraulic operation valve 12. It is switched to the J position by E and f.
シャトル弁１５は各操作信号Ａ，ｂ，ｅ，ｆを操作信号
制御弁１３，１４に伝達する中継所の役割を果たす。切
換弁２は油圧操作弁１１の操作信号Ｃ．ｄを受けるど各
Ｃ，Ｄ゛位置に切換わり、ポンプ１の圧油を油圧シリン
ダ４に送る。１６は上記パイロット圧発生用補助ポンプ
てある。The shuttle valve 15 serves as a relay station for transmitting each operation signal A, b, e, f to the operation signal control valves 13 and 14. The switching valve 2 receives the operation signal C. of the hydraulically operated valve 11. When it receives d, it switches to the C and D positions, and the pressure oil from the pump 1 is sent to the hydraulic cylinder 4. 16 is the auxiliary pump for generating the pilot pressure.
次に、この油圧回路の動作について説明する。Next, the operation of this hydraulic circuit will be explained.
たとえば図示の油圧回路を油圧ショベルに採用して、油
圧モータ５を右走行用モータ、油圧モータ９を左走行用
モータ、油圧シリンダ４をアームシリンダとしたとき、
直線前進走行をする場合には油圧操作弁１０により操作
信号ａを発し、油圧操作弁１２により操作信号ｅを同時
に発すれば、方向切換弁３，７はそれぞれＡ位置、Ｅ位
置に切換わり、ポンプ１およびポンプ６の圧油がそれぞ
れ油圧モータ５および油圧モータ９に送られて、油圧モ
ータ５および油圧モータ９はそれぞれーポンプ分の油量
により同方向に駆動され油圧ショベルは直進走行する。
また油圧操作弁１１を単独に操作して操作信号ｃまたは
ｄを発すれば、アームシリンタ４は伸縮動作をして掘削
作業を行う。今直線前進走行しながらアームを伸ばそう
とする場合、単に油圧操作弁１０，１１，１２を同時操
作して操作信号Ａ，ｂ，ｃを発すると、操作信号制御弁
１３は操作信号ａおよびｅによりシャトル弁１５を介し
てＨ位置に切換わるので、アームシリンダ４はポンプ１
およびポンプ６の両ポンプより送油される。したがつて
、油圧モータ５および油圧モータ９はそれぞれポンプ１
およびポンプ６よりはぼ均等量の油量を受けるので、蛇
行することなく直線前進掘削作業が行われる。その結果
、作業動作が安定すると共に作業サイクルタイムを短縮
して効率よく作業を行うことができる。なお、操作信号
制御弁１３を作動するパイロット圧操作信号として油圧
操作弁１２の操作信号ｅを用いて、油圧操作弁１１のパ
イロット圧操作信号ｃまたはｄを制御する場合について
述べたが、操作信号制御弁１３を作動するパイロット圧
操作信号としては、操作信号ｅのほかに、１つの操作信
号Ｆ，ａ，ｂまたは２つの操作信号ｅとＡ，ｆとｂを用
いてもよいことは図から見て明らかである。For example, when the illustrated hydraulic circuit is adopted in a hydraulic excavator, the hydraulic motor 5 is used as a right-hand travel motor, the hydraulic motor 9 is used as a left-hand travel motor, and the hydraulic cylinder 4 is used as an arm cylinder.
When traveling in a straight line, if the hydraulically operated valve 10 issues the operating signal a and the hydraulically operated valve 12 simultaneously issues the operating signal e, the directional control valves 3 and 7 are switched to the A position and the E position, respectively. The pressure oil of the pump 1 and the pump 6 is sent to the hydraulic motor 5 and the hydraulic motor 9, respectively, and the hydraulic motor 5 and the hydraulic motor 9 are each driven in the same direction by the amount of oil corresponding to the pump, so that the hydraulic excavator moves straight.
Furthermore, when the hydraulic operation valve 11 is operated independently and the operation signal c or d is issued, the arm cylinder 4 is extended and retracted to perform excavation work. If you are trying to extend the arm while moving forward in a straight line, simply operate the hydraulic control valves 10, 11, and 12 simultaneously to issue the control signals A, b, and c, and the control valve 13 will respond to the control signals a and e. The arm cylinder 4 is switched to the H position via the shuttle valve 15, so the arm cylinder 4 is switched to the H position via the shuttle valve 15.
Oil is supplied from both pumps 6 and 6. Therefore, the hydraulic motor 5 and the hydraulic motor 9 are respectively connected to the pump 1.
Since the pump 6 receives an approximately equal amount of oil, the excavation work can be carried out in a straight line without meandering. As a result, work operations are stabilized, work cycle time is shortened, and work can be performed efficiently. In addition, although the case has been described in which the pilot pressure operation signal c or d of the hydraulic operation valve 11 is controlled using the operation signal e of the hydraulic operation valve 12 as the pilot pressure operation signal that operates the operation signal control valve 13, the operation signal As can be seen from the figure, in addition to the operation signal e, one operation signal F, a, b or two operation signals e, A, f and b may be used as the pilot pressure operation signal for operating the control valve 13. It's obvious.
上記複合操作時における可能な作動状況一覧表を以下に
示す。A list of possible operating conditions during the above combined operation is shown below.
ただし、Ｐ１はポンプ１，Ｐ６はポンプ６の圧油が流れ
るか、またはその圧油によつて作動されることを意味す
るものである。However, P1 means pump 1, and P6 means that the pressure oil of pump 6 flows or is operated by the pressure oil.
以上述べたように、本発明は、第１および第２ポンプ（
たとえば６，１）と、第１ポンプ（たとえば６）にパラ
レルに接続された第１および第２方向切換弁（たとえば
８，７）と、第１および第２方向切換弁（たとえば８，
７）を介して第１ポンプ（たとえば６）の圧油により作
動される第１および第２油圧機器（たとえ４，９）と、
第２ポンプ（たとえば１）に接続された第３方向切換弁
（たとえば３）と、第３方向切換弁（たとえば３）を介
して第２ポンプ（たとえば１）の圧油により作動される
第３油圧機器（たとえば５）と、パイロット圧操作信号
（たとえばＣ，ｄ；Ｅ，ｆ：Ａ，ｄ）により第１、第２
および第３方向切換弁（たとえば８，７，３）を切換え
制御する第１、第２および第３油圧操作弁（たとえば１
１，１２，１０）と、これらの油圧操作弁（たとえば１
１，１２，１０）にパイロット圧を発生するための補助
ポンプ（たとえば１６）と、第２ポンプ（たとえば１）
に第３方向切換弁（たとえば３）とパラレルに接続され
、且つ第１油圧操作弁（たノとえば１１）のパイロット
圧操作信号（たとえばＣ，ｄ）により切換え制御される
第４方向切換弁（たとえば２）と、第４方向切換弁（た
とえば２）を介して第２ポンプ（たとえば１）を第１油
圧機器（たとえば４）に接続する回路と、第２お７よび
第３油圧操作弁（たとえは１２，１０）の少なくともい
ずれか一方からのパイロット圧操作信号（Ｅ，ｆ；Ａ，
ｂ）により作動し、第１油圧操作弁（たとえば１１）か
らのパイロット圧操作信号（たとえばＣ，ｄ）が発生し
ており且第２およフび第３油圧操作弁（たとえば１２，
１０）の少なくともいずれか一方からのパイロット圧操
作信号（たとえばＥ，ｆおよび／またはＡ，ｂ）が発生
している複合操作時に、第１油圧操作弁（たとえば１１
）のパイロット圧操作信号（たとえばＣ，ｄ）による前
記第４方向切換弁（たとえば２）の切換え制御を有効と
する操作信号制御弁（たとえは１３，１４）とを備え、
第１油圧機器（たとえば４）を、単独（たとえば４）操
作時には第１ポンプ（たとえば６）の圧油により作動し
、複合（たとえば４，９．操作時には第１および第２ポ
ンプ（たとえば６，１）の圧油により作動するように構
成したので、パラレル回路に接続された各油圧機器を油
圧操作弁により複合操作する場合の作業動作を安定化て
きるとともに、その作業サイクルタイムを短縮して効率
よく作業を行うことができる等の効果を奏する。As described above, the present invention provides the first and second pumps (
For example, 6,1), first and second directional valves (for example, 8,7) connected in parallel to the first pump (for example, 6), and first and second directional valves (for example, 8,7) connected in parallel to the first pump (for example, 6);
7) first and second hydraulic equipment (for example 4, 9) operated by the pressure oil of the first pump (for example 6);
a third directional valve (e.g. 3) connected to the second pump (e.g. 1); and a third directional valve (e.g. 3) which is operated by pressure oil of the second pump (e.g. 1) via the third directional valve (e.g. 3). Hydraulic equipment (e.g. 5) and pilot pressure operation signals (e.g. C, d; E, f: A, d)
and the first, second, and third hydraulically operated valves (for example, 1
1, 12, 10) and these hydraulically operated valves (e.g. 1
1, 12, 10) for generating pilot pressure (for example, 16), and a second pump (for example, 1)
a fourth directional control valve that is connected in parallel with the third directional control valve (for example, 3), and that is switched and controlled by the pilot pressure operation signal (for example, C, d) of the first hydraulically operated valve (for example, 11); (e.g. 2), a circuit connecting the second pump (e.g. 1) to the first hydraulic device (e.g. 4) via a fourth directional valve (e.g. 2), and second, seventh and third hydraulically operated valves. (for example, 12, 10) pilot pressure operation signal (E, f; A,
b), a pilot pressure operation signal (for example, C, d) is generated from the first hydraulically operated valve (for example, 11), and the second and third hydraulically operated valves (for example, 12,
10) during a combined operation in which a pilot pressure operation signal (e.g. E, f and/or A, b) is generated from at least one of the first hydraulically operated valves (e.g. 11).
) operation signal control valves (for example, 13, 14) that enable switching control of the fourth directional switching valve (for example, 2) by pilot pressure operation signals (for example, C, d);
The first hydraulic device (for example, 4) is operated by the pressure oil of the first pump (for example, 6) when operating alone (for example, 4), and by the pressure oil of the first pump (for example, 6) when operating in combination (for example, 4, 9. 1) Since it is configured to operate using pressure oil, it not only stabilizes the work operation when multiple hydraulic equipment connected to the parallel circuit is operated by the hydraulic operation valve, but also shortens the work cycle time. This has effects such as being able to work efficiently.
図は本発明の一実施例に係る油圧回路の系統図てある。 The figure is a system diagram of a hydraulic circuit according to an embodiment of the present invention.
Claims (1)
切換弁と、第１および第２方向切換弁を介して第１ポン
プの圧油により作動される第１および第２油圧機器と、
第２ポンプに接続された第３方向切換弁と、第３方向の
切換弁を介して第２ポンプの圧油により作動される第３
油圧機器と、パイロット圧操作信号により第１、第２お
よび第３方向切換弁を切換え制御する第１、第２および
第３油圧操作弁と、これらの油圧操作弁にパイロット圧
を発生するための補助ポンプと、第２ポンプに第３方向
切換弁とパラレルに接続され、且つ第１油圧操作弁のパ
イロット圧操作信号により切換え制御される第４方向切
換弁と、第４方向切換弁を介して第２ポンプを第１油圧
機器に接続する回路と、第２および第３油圧操作弁の少
なくともいずれか一方からのパイロット圧操作信号によ
り作動し、第１油圧操作弁からのパイロット圧操作信号
が発生しており且つ第２および第３の油圧操作弁の少な
くともいずれか一方からのパイロット圧操作信号が発生
している複合操作時に、第１油圧操作弁のパイロット圧
操作信号による前記第４方向切換弁の切換え制御を有効
とする操作信号制御弁と、を備えたことを特徴とする油
圧回路。[Claims] 1. First and second pumps, first and second directional control valves connected in parallel to the first pump, and pressure of the first pump via the first and second directional control valves. first and second hydraulic equipment operated by oil;
a third direction switching valve connected to the second pump; and a third direction switching valve that is operated by pressure oil of the second pump via the third direction switching valve.
Hydraulic equipment, first, second, and third hydraulically operated valves that switch and control the first, second, and third directional switching valves based on a pilot pressure operating signal, and a hydraulically operated valve that generates pilot pressure in these hydraulically operated valves. an auxiliary pump, a fourth directional control valve that is connected to the second pump in parallel with the third directional control valve and is switched and controlled by a pilot pressure operation signal of the first hydraulically operated valve; The second pump is operated by a pilot pressure operation signal from at least one of the second and third hydraulically operated valves and a circuit that connects the second pump to the first hydraulic equipment, and a pilot pressure operation signal is generated from the first hydraulically operated valve. and the fourth directional switching valve is operated by the pilot pressure operation signal of the first hydraulic operation valve during a combined operation in which the pilot pressure operation signal from at least one of the second and third hydraulic operation valves is generated. A hydraulic circuit comprising: an operation signal control valve that enables switching control;
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56071370A JPS6056924B2 (en) | 1981-05-14 | 1981-05-14 | hydraulic circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56071370A JPS6056924B2 (en) | 1981-05-14 | 1981-05-14 | hydraulic circuit |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2709974A Division JPS539346B2 (en) | 1974-03-11 | 1974-03-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5779307A JPS5779307A (en) | 1982-05-18 |
| JPS6056924B2 true JPS6056924B2 (en) | 1985-12-12 |
Family
ID=13458540
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56071370A Expired JPS6056924B2 (en) | 1981-05-14 | 1981-05-14 | hydraulic circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6056924B2 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3720059A (en) * | 1969-10-15 | 1973-03-13 | Linde Ag | Hydraulic system and valve therefor |
| JPS4919281A (en) * | 1972-04-17 | 1974-02-20 | ||
| JPS5417114A (en) * | 1977-07-06 | 1979-02-08 | Drythanol Ltd | Dislanol composition for treating favus disease |
-
1981
- 1981-05-14 JP JP56071370A patent/JPS6056924B2/en not_active Expired
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3720059A (en) * | 1969-10-15 | 1973-03-13 | Linde Ag | Hydraulic system and valve therefor |
| JPS4919281A (en) * | 1972-04-17 | 1974-02-20 | ||
| JPS5417114A (en) * | 1977-07-06 | 1979-02-08 | Drythanol Ltd | Dislanol composition for treating favus disease |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5779307A (en) | 1982-05-18 |
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