JPH0723721B2 - Hydraulic circuit of hydraulic actuator - Google Patents
Hydraulic circuit of hydraulic actuatorInfo
- Publication number
- JPH0723721B2 JPH0723721B2 JP62072390A JP7239087A JPH0723721B2 JP H0723721 B2 JPH0723721 B2 JP H0723721B2 JP 62072390 A JP62072390 A JP 62072390A JP 7239087 A JP7239087 A JP 7239087A JP H0723721 B2 JPH0723721 B2 JP H0723721B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- hydraulic pump
- oil chamber
- pressure
- auxiliary circuit
- 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
- 239000003921 oil Substances 0.000 claims description 25
- 239000002199 base oil Substances 0.000 claims description 20
- 230000007423 decrease Effects 0.000 description 3
- 239000010720 hydraulic oil Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
Landscapes
- Fluid-Pressure Circuits (AREA)
- Control Of Positive-Displacement Pumps (AREA)
Description
【発明の詳細な説明】 （ａ）産業上の利用分野 本発明は油圧アクチュエータに急激な負荷の増大等によ
る通常の作動圧力以上の衝撃圧力がかかった場合、可変
油圧ポンプからの吐出量を自動的に減少させて通常の作
動圧力に戻す油圧アクチュエータの油圧回路に関する。DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention automatically adjusts the discharge amount from a variable hydraulic pump when an impact pressure exceeding a normal working pressure is applied to a hydraulic actuator due to a sudden increase in load. Hydraulic circuit of a hydraulic actuator that is reduced to a normal operating pressure.
（ｂ）従来の技術 第２図は従来の油圧アクチュエータの油圧回路を示すも
ので、可変油圧ポンプ（01）には、可変油圧ポンプ（0
1）に内蔵され、可変油圧ポンプ（01）の吐出量を制御
する回路の一部である制御回路（08）が設けられてい
る。(B) Conventional Technology FIG. 2 shows a hydraulic circuit of a conventional hydraulic actuator. The variable hydraulic pump (01) includes a variable hydraulic pump (0
A control circuit (08), which is a part of a circuit for controlling the discharge amount of the variable hydraulic pump (01), is provided in the 1).
前記制御回路（08）は、可変油圧ポンプ（01）と油圧ア
クチュエータ（02）間の主回路（03）より分岐した補助
回路（04）に可変油圧ポンプ（01）の斜板（05）を作動
させて、可変油圧ポンプ（01）の吐出量を制御する制御
シリンダ（06）と、可変油圧ポンプ（01）の吐出圧力が
設定圧力以上になると切換わり、制御シリンダ（06）を
作動させて可変油圧ポンプ（01）の吐出量を自動的に減
少させる制御弁（07）とを設けていた。The control circuit (08) operates the swash plate (05) of the variable hydraulic pump (01) to the auxiliary circuit (04) branched from the main circuit (03) between the variable hydraulic pump (01) and the hydraulic actuator (02). The control cylinder (06) for controlling the discharge amount of the variable hydraulic pump (01) and the control cylinder (06) are switched when the discharge pressure of the variable hydraulic pump (01) exceeds the set pressure, and the control cylinder (06) is operated to change the value. A control valve (07) for automatically reducing the discharge amount of the hydraulic pump (01) was provided.
（ｃ）発明が解決しようとする問題点 ところが、油圧アクチュエータに急激な負荷の増大等に
よる通常の作動圧力以上の衝撃圧力がかかっても制御弁
は設定圧力になるまでは作動せず、油圧アクチュエータ
は通常の作動圧力より制御弁の設定圧力になるまではそ
のまま作動を続ける。このため油圧アクチュエータや配
管等に無理がかかるばかりか大きな騒音や振動が発生す
るという問題があった。(C) Problems to be Solved by the Invention However, the control valve does not operate until the set pressure is reached even if an impact pressure higher than the normal operating pressure is applied to the hydraulic actuator due to a sudden increase in load, etc. Will continue to operate until the set pressure of the control valve is reached from the normal operating pressure. For this reason, there has been a problem that not only the hydraulic actuator and the piping are forced, but also large noise and vibration are generated.
（ｄ）問題点を解決するための手段 本発明は前記問題点を解決するためになされたもので、
可変油圧ポンプと油圧アクチュエータとを主回路で連結
し、前記可変油圧ポンプには可変油圧ポンプの斜板を作
動させて可変油圧ポンプの吐出量を制御する制御シリン
ダを設け、前記制御シリンダは斜板に連結されたスプー
ルと、このスプールの前後に形成した基部油室と先部油
室とよりなり、前記基部油室には主回路より分岐した第
１補助回路を連結し、前記先部油室には主回路より分岐
した第２補助回路を連結し、前記第１補助回路には基部
油室をオイルタンクに導き、スプールを基部油室側に移
動させて可変油圧ポンプの吐出量を減少させるように切
換え可能な切換弁を設け、更に主回路より分岐させた第
３補助回路を前記切換弁側に接続し、前記第３補助回路
には、油圧アクチュエータの通常の作動圧力以上の衝撃
圧力により、第３補助回路を解放させ、主回路の作動油
をパイロット油圧として切換弁に導き、基部油室とオイ
ルタンクとが連通するように切換弁を切換制御する弁を
介装したことを特徴としている。(D) Means for Solving the Problems The present invention has been made to solve the above problems.
A variable hydraulic pump and a hydraulic actuator are connected by a main circuit, and the variable hydraulic pump is provided with a control cylinder that operates a swash plate of the variable hydraulic pump to control the discharge amount of the variable hydraulic pump. And a base oil chamber and a front oil chamber formed in front of and behind the spool. A first auxiliary circuit branched from a main circuit is connected to the base oil chamber, and the front oil chamber is connected to the front oil chamber. Is connected to a second auxiliary circuit branched from the main circuit, the base oil chamber is guided to the oil tank in the first auxiliary circuit, and the spool is moved to the base oil chamber side to reduce the discharge amount of the variable hydraulic pump. A switching valve that can be switched is provided, and a third auxiliary circuit branched from the main circuit is connected to the switching valve side. The third auxiliary circuit receives an impact pressure higher than the normal working pressure of the hydraulic actuator. , Third To release the auxiliary circuit, leads to the hydraulic fluid of the main circuit switching valve as a pilot pressure, is characterized in that a base oil chamber and the oil tank is interposed a valve for switching and controlling the switching valve so as to communicate.
（ｅ）作用 油圧アクチュエータの作動中に通常の負荷より大きい負
荷が急激にかかると、油圧アクチュエータには通常の作
動圧力以上の衝撃圧力がかかる。(E) Action When a load larger than the normal load is suddenly applied during the operation of the hydraulic actuator, the hydraulic actuator receives an impact pressure higher than the normal operating pressure.
すると、その衝撃圧力で第３補助回路に介装した弁が開
き、主回路の作動油のパイロット油圧で切換弁が左位置
に切換わり、制御シリンダの基部油室がオイルタンクに
連通し、制御シリンダのスプールは左に移動する。Then, the impact pressure opens the valve interposed in the third auxiliary circuit, the pilot pressure of the hydraulic oil in the main circuit switches the switching valve to the left position, and the base oil chamber of the control cylinder communicates with the oil tank for control. The cylinder spool moves to the left.
すると、可変油圧ポンプの斜板は閉じられる方向に移動
し、可変油圧ポンプの吐出量は減少して、油圧アクチュ
エータの作動圧力は通常の作動圧力に戻る。Then, the swash plate of the variable hydraulic pump moves in the closing direction, the discharge amount of the variable hydraulic pump decreases, and the working pressure of the hydraulic actuator returns to the normal working pressure.
（ｆ）実施例 以下、本発明の実施例を図面に基づいて説明する。(F) Example An example of the present invention will be described below with reference to the drawings.
（１）は可変油圧ポンプ（２）と油圧アクチュエータ
（３）とを連結した主回路である。（４）は可変油圧ポ
ンプ（２）の斜板（５）を作動させて油圧ポンプ（２）
の吐出量を制御する制御シリンダで、この制御シリンダ
（４）は、斜板（５）に連結されたスプール（25）と、
このスプール（25）の前後に形成した基部油室（６）と
先部油室（７）とより構成されている。(1) is a main circuit that connects the variable hydraulic pump (2) and the hydraulic actuator (3). (4) operates the swash plate (5) of the variable hydraulic pump (2) to operate the hydraulic pump (2).
A control cylinder (4) for controlling the discharge amount of the spool (25) connected to the swash plate (5),
It is composed of a base oil chamber (6) and a front oil chamber (7) formed in front of and behind the spool (25).
前記基部油室（６）は主回路（１）より分岐した第１補
助回路（８）に連結されている。The base oil chamber (6) is connected to a first auxiliary circuit (8) branched from the main circuit (1).
また先部油室（７）は主回路（１）より分岐した第２補
助回路（９）に連結されている。The front oil chamber (7) is connected to a second auxiliary circuit (9) branched from the main circuit (1).
前記第１補助回路（８）とオイルタンク（13）とは接続
回路（23）で連結されている。The first auxiliary circuit (8) and the oil tank (13) are connected by a connection circuit (23).
前記第１補助回路（８）と接続回路（23）との分岐点に
は３ポート２位置の切換弁（10）が介装され、この切換
弁（10）は通常はスプリング（12）により右位置であ
り、主回路（１）の作動油のパイロット油圧により左位
置に切換わると、制御シリンダ（４）の基部油室（６）
を第１補助回路（８）と接続回路（23）とを介してオイ
ルタンク（13）に連通させる。At the branch point between the first auxiliary circuit (8) and the connection circuit (23), a 3-port / 2-position switching valve (10) is provided, and the switching valve (10) is normally connected to the right by a spring (12). Position, and when switched to the left position by the pilot hydraulic pressure of the hydraulic oil of the main circuit (1), the base oil chamber (6) of the control cylinder (4)
Is communicated with the oil tank (13) through the first auxiliary circuit (8) and the connection circuit (23).
（11）は主回路（１）より分岐し、前記切換弁（10）に
接続した第３補助回路である。(11) is a third auxiliary circuit branched from the main circuit (1) and connected to the switching valve (10).
（14）は前記第３補助回路（11）の途中に介装したロジ
ック弁で油圧アクチュエータ（３）の通常の作動圧力で
は閉じており、通常の作動圧力以上の衝撃圧力がかかる
とバネ室（15）のスプリング（16）力に抗して段付弁体
（24）が押し上げられて開放作動し、切換弁（10）に主
回路（１）の作動油のパイロット油圧を送り、切換弁
（10）を切換える。Reference numeral (14) is a logic valve interposed in the middle of the third auxiliary circuit (11), which is closed at the normal working pressure of the hydraulic actuator (3), and when an impact pressure higher than the normal working pressure is applied, the spring chamber ( The stepped valve body (24) is pushed up against the force of the spring (16) of 15) to open, and the pilot oil pressure of the hydraulic fluid of the main circuit (1) is sent to the switching valve (10) to switch the switching valve ( 10) Switch.
（17）は可変油圧ポンプ（２）の吐出圧力が設定圧力以
下や油圧アクチュエータ（３）にかかる前記衝撃圧力で
はスプリング（18）により左位置で第１補助回路（８）
を制御シリンダ（４）の基部油室（６）に連通させ、設
定圧力以上になると第２補助回路（９）に連結したプー
ル（19）に押されて右位置に切換わり、制御シリンダ
（４）の基部油室（６）をオイルタンク（13）に連通さ
せる制御弁である。(17) is the first auxiliary circuit (8) at the left position due to the spring (18) when the discharge pressure of the variable hydraulic pump (2) is less than or equal to the set pressure or at the impact pressure applied to the hydraulic actuator (3).
Is communicated with the base oil chamber (6) of the control cylinder (4), and when the pressure exceeds a set pressure, it is pushed by the pool (19) connected to the second auxiliary circuit (9) and switched to the right position, and the control cylinder (4 2) is a control valve for communicating the base oil chamber (6) of (1) with the oil tank (13).
なお（20）は第３補助回路とロジック弁（14）のバネ室
（15）間に介装した絞り弁である。Reference numeral (20) is a throttle valve provided between the third auxiliary circuit and the spring chamber (15) of the logic valve (14).
本発明は前記の如き構成で、次に作用について説明す
る。The present invention has the above-mentioned configuration, and the operation will be described below.
まず、油圧アクチュエータ（３）が通常の作動圧力で作
動中には、制御弁（17）は設定圧力以下なのでスプリン
グ（18）により左位置であり、制御シリンダ（４）も移
動せず、ロジック弁（14）も閉であり、切換弁（10）は
スプリング（12）により右位置である。First, when the hydraulic actuator (3) is operating at normal operating pressure, the control valve (17) is at or below the set pressure, so the spring (18) is in the left position, the control cylinder (4) does not move, and the logic valve (14) is also closed, and the switching valve (10) is in the right position due to the spring (12).
次に油圧アクチュエータ（３）の作動中に通常の負荷よ
り大きい負荷が急激にかかると、油圧アクチュエータ
（３）には通常圧力以上の衝撃圧力がかかる。Next, when a load larger than the normal load is suddenly applied during the operation of the hydraulic actuator (3), the hydraulic actuator (3) receives an impact pressure higher than the normal pressure.
すると、この衝撃圧力による圧油によりロジック弁（1
4）のバネ室（15）のスプリング（16）力に抗して段付
弁体（24）が押し上げられてロジック弁（14）が開き、
主回路（１）の作動油のパイロット油圧は切換弁（10）
に達して、切換弁（10）を左位置に切換え、制御シリン
ダ（４）の基部油室（６）とオイルタンク（13）とが第
１補助回路（８）と接続回路（23）とを介して連通し、
このため制御シリンダ（４）のスプール（25）は左に移
動する。Then, the logic valve (1
The stepped valve body (24) is pushed up against the spring (16) force of the spring chamber (15) of 4) to open the logic valve (14),
The pilot oil pressure of the hydraulic oil in the main circuit (1) is the switching valve (10)
And the switching valve (10) is switched to the left position, and the base oil chamber (6) of the control cylinder (4) and the oil tank (13) connect the first auxiliary circuit (8) and the connection circuit (23). Communication through
Therefore, the spool (25) of the control cylinder (4) moves to the left.
すると、可変油圧ポンプ（２）の斜板（５）は閉じられ
る方向に移動し、可変油圧ポンプ（２）の吐出量は減少
して、油圧アクチュエータ（３）の作動圧力は通常の作
動圧力に戻る。Then, the swash plate (5) of the variable hydraulic pump (2) moves in the closing direction, the discharge amount of the variable hydraulic pump (2) decreases, and the working pressure of the hydraulic actuator (3) becomes the normal working pressure. Return.
するとロジック弁（14）が閉じ、切換弁（10）は右位置
となって、制御シリンダ（４）の基部油室（６）とオイ
ルタンク（13）との連通を遮断する。Then, the logic valve (14) is closed and the switching valve (10) is moved to the right position to shut off the communication between the base oil chamber (6) of the control cylinder (4) and the oil tank (13).
すると制御シリンダ（４）のスプール（25）は右に移動
して可変油圧ポンプ（２）の斜板（５）を開く方向に移
動させ、可変油圧ポンプ（２）の吐出量が多くなり、通
常の吐出量となる。Then, the spool (25) of the control cylinder (4) moves to the right to move the swash plate (5) of the variable hydraulic pump (2) in the opening direction, and the discharge amount of the variable hydraulic pump (2) increases, Discharge amount.
ところで、急激な衝撃圧力ではなくゆっくりした状態で
圧力が上昇していく場合には、その圧油はロジック弁
（14）のバネ室（15）にも絞り弁（20）を通過して入る
ので、ロジック弁（14）は開かず、ついには制御弁（1
7）の設定圧力に達する。By the way, when the pressure rises slowly rather than suddenly, the pressure oil enters the spring chamber (15) of the logic valve (14) through the throttle valve (20). , The logic valve (14) did not open, and finally the control valve (1
7) Set pressure is reached.
すると、制御弁（17）はスプール（19）に押されて右位
置となり、制御シリンダ（４）の基部油室（６）とオイ
ルタンク（13）とが連通し、制御シリンダ（４）のスプ
ール（25）は左に移動し、可変油圧ポンプ（２）の斜板
（５）は閉じられる方向に移動し、可変油圧ポンプ
（２）の吐出量は減少して、油圧アクチュエータ（３）
の作動圧力は通常の作動圧力に戻る。Then, the control valve (17) is pushed to the right position by being pushed by the spool (19), the base oil chamber (6) of the control cylinder (4) and the oil tank (13) communicate with each other, and the spool of the control cylinder (4). (25) moves to the left, the swash plate (5) of the variable hydraulic pump (2) moves in the closing direction, the discharge amount of the variable hydraulic pump (2) decreases, and the hydraulic actuator (3)
The working pressure of returns to the normal working pressure.
（ｇ）発明の効果 以上の如く本発明は、可変油圧ポンプと油圧アクチュエ
ータ間の主回路より分岐した第１及び第２補助回路に制
御シリンダを介装し、油圧アクチュエータに急激な負荷
の増大等により通常の作動圧力以上の衝撃圧力がかかる
と第３補助回路に介装した弁が開き、切換弁を切換えて
制御シリンダを作動させ、可変油圧ポンプの吐出量を減
少させて油圧アクチュエータの作動圧力を通常の作動圧
力に戻すので、従来のように油圧アクチュエータの作動
圧力が設定圧力まで上昇し、油圧アクチュエータや配管
等に無理がかかったり、大きな騒音や振動が発生するこ
とはない。(G) Effects of the Invention As described above, according to the present invention, the control cylinder is provided in the first and second auxiliary circuits branched from the main circuit between the variable hydraulic pump and the hydraulic actuator, and the hydraulic actuator is suddenly increased in load. When a shock pressure higher than the normal working pressure is applied, the valve installed in the third auxiliary circuit opens, the switching valve is switched to operate the control cylinder, and the discharge amount of the variable hydraulic pump is reduced to reduce the operating pressure of the hydraulic actuator. Is restored to the normal operating pressure, the operating pressure of the hydraulic actuator does not rise to the set pressure as in the conventional case, and the hydraulic actuator and piping are not overpowered and no large noise or vibration is generated.
第１図は本発明の油圧回路図、第２図は従来の油圧回路
図である． （１）は主回路、（２）は可変油圧ポンプ、（３）は油
圧アクチュエータ、（４）は制御シリンダ、（５）は斜
板、（６）は基部油室、（７）は先部油室、（８）は第
１補助回路、（９）は第２補助回路、（10）は切換弁、
（11）は第３補助回路、（13）はオイルタンク、（14）
はロジック弁、（15）はバネ室、（16）はスプリング、
（24）は段付弁体、（25）はスプールである。FIG. 1 is a hydraulic circuit diagram of the present invention, and FIG. 2 is a conventional hydraulic circuit diagram. (1) is a main circuit, (2) is a variable hydraulic pump, (3) is a hydraulic actuator, (4) is a control cylinder, (5) is a swash plate, (6) is a base oil chamber, and (7) is a front part. Oil chamber, (8) first auxiliary circuit, (9) second auxiliary circuit, (10) switching valve,
(11) is the third auxiliary circuit, (13) is the oil tank, (14)
Is a logic valve, (15) is a spring chamber, (16) is a spring,
(24) is a stepped valve body, and (25) is a spool.
Claims (1)
主回路で連結し、前記可変油圧ポンプには可変油圧ポン
プの斜板を作動させて可変油圧ポンプの吐出量を制御す
る制御シリンダを設け、前記制御シリンダは斜板に連結
されたスプールと、このスプールの前後に形成した基部
油室と先部油室とよりなり、前記基部油室には主回路よ
り分岐した第１補助回路を連結し、前記先部油室には主
回路より分岐した第２補助回路を連結し、前記第１補助
回路には基部油室をオイルタンクに導き、スプールを基
部油室側に移動させて可変油圧ポンプの吐出量を減少さ
せるように切換え可能な切換弁を設け、更に主回路より
分岐させた第３補助回路を前記切換弁側に接続し、前記
第３補助回路には、油圧アクチュエータの通常の作動圧
力以上の衝撃圧力により、第３補助回路を解放させ、主
回路の作動油をパイロット油圧として切換弁に導き、基
部油室とオイルタンクとが連通するように切換弁を切換
制御する弁を介装してなる油圧アクチュエータの油圧回
路。1. A variable hydraulic pump and a hydraulic actuator are connected by a main circuit, and the variable hydraulic pump is provided with a control cylinder for controlling a discharge amount of the variable hydraulic pump by operating a swash plate of the variable hydraulic pump. The control cylinder includes a spool connected to the swash plate, a base oil chamber and a front oil chamber formed in front of and behind the spool, and the base oil chamber is connected to a first auxiliary circuit branched from the main circuit, A second auxiliary circuit branched from the main circuit is connected to the front oil chamber, a base oil chamber is guided to an oil tank in the first auxiliary circuit, and a spool is moved to the base oil chamber side to control the variable hydraulic pump. A switching valve that can be switched to reduce the discharge amount is provided, and a third auxiliary circuit branched from the main circuit is connected to the switching valve side. The third auxiliary circuit has a normal operating pressure of the hydraulic actuator. Impact pressure above Thus, the third auxiliary circuit is released, the operating oil of the main circuit is used as a pilot oil pressure to guide the switching valve, and a valve for controlling the switching of the switching valve so that the base oil chamber communicates with the oil tank is interposed. Hydraulic circuit of the actuator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62072390A JPH0723721B2 (en) | 1987-03-25 | 1987-03-25 | Hydraulic circuit of hydraulic actuator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62072390A JPH0723721B2 (en) | 1987-03-25 | 1987-03-25 | Hydraulic circuit of hydraulic actuator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63235704A JPS63235704A (en) | 1988-09-30 |
| JPH0723721B2 true JPH0723721B2 (en) | 1995-03-15 |
Family
ID=13487905
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62072390A Expired - Lifetime JPH0723721B2 (en) | 1987-03-25 | 1987-03-25 | Hydraulic circuit of hydraulic actuator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0723721B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4127342C2 (en) * | 1991-08-19 | 1995-02-16 | Danfoss As | Hydraulic system with a pump |
-
1987
- 1987-03-25 JP JP62072390A patent/JPH0723721B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63235704A (en) | 1988-09-30 |
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