JPH0232484B2 - - Google Patents
Info
- Publication number
- JPH0232484B2 JPH0232484B2 JP57118882A JP11888282A JPH0232484B2 JP H0232484 B2 JPH0232484 B2 JP H0232484B2 JP 57118882 A JP57118882 A JP 57118882A JP 11888282 A JP11888282 A JP 11888282A JP H0232484 B2 JPH0232484 B2 JP H0232484B2
- Authority
- JP
- Japan
- Prior art keywords
- throttle
- valve
- pressure
- switching valve
- variable
- 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
- 230000007246 mechanism Effects 0.000 claims description 10
- 238000011144 upstream manufacturing Methods 0.000 claims description 9
- 238000000926 separation method Methods 0.000 claims description 6
- 230000007423 decrease Effects 0.000 description 5
- 230000007935 neutral effect Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
Landscapes
- Fluid-Pressure Circuits (AREA)
- Control Of Fluid Gearings (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、油圧ポンプとアクチユエータとの間
に介設した絞り切換弁の絞り前後の差圧を圧力補
償弁により一定圧に保持して、アクチユエータへ
の最大流量を一定量に保持するようにした油圧回
路の改良に関するものである。Detailed Description of the Invention (Industrial Application Field) The present invention maintains the differential pressure before and after the throttle of a throttle switching valve interposed between a hydraulic pump and an actuator at a constant pressure by a pressure compensation valve. This invention relates to an improvement in a hydraulic circuit that maintains the maximum flow rate to an actuator at a constant level.
（従来の技術）
一般に、この種の油圧回路においては、アクチ
ユエータへの最大流量を一定量に保持する機能に
加えて、アクチユエータの最大速度を操作者の熟
練度や場所、使用状態に応じて複数段に変速でき
るよう、最大流量を可変にすることが望まれる。(Prior art) In general, in this type of hydraulic circuit, in addition to the function of maintaining the maximum flow rate to the actuator at a constant level, the maximum speed of the actuator can be controlled at multiple speeds depending on the operator's skill level, location, and usage conditions. It is desirable to make the maximum flow rate variable so that the speed can be changed in stages.
このため、従来、絞り切換弁のスプールを加工
してスプールストロークを機械的に複数段階に制
限することにより、絞り部の最大開口面積を変化
させて最大流量を複数段階に調整するようにした
ものが知られている。 For this reason, in the past, the spool of the throttle switching valve was machined to mechanically limit the spool stroke to multiple stages, thereby changing the maximum opening area of the throttle section and adjusting the maximum flow rate to multiple stages. It has been known.
（発明が解決しようとする課題）
しかしながら、上記従来のものでは、絞り切換
弁のスプールの形状によつては所定の加工が困難
なものもあり、特定の絞り切換弁に限定されると
いう欠点があつた。(Problems to be Solved by the Invention) However, the above-mentioned conventional device has the disadvantage that it may be difficult to process the spool in a specified manner depending on the shape of the spool of the throttle switching valve, and it is limited to specific throttle switching valves. It was hot.
そこで、圧力補償弁のバネ圧を可変にすること
が考えられるが、この考えのものでは、複数個の
絞り切換弁を並列に接続した油圧回路において、
各絞り切換弁毎に独自の最大流量を設定すること
ができないという欠点がある。 Therefore, it is possible to make the spring pressure of the pressure compensation valve variable, but in this idea, in a hydraulic circuit in which multiple throttle switching valves are connected in parallel,
A drawback is that it is not possible to set a unique maximum flow rate for each throttle valve.
本発明は斯かる点に鑑みてなされたもので、絞
り切換弁のポンプ通路に可変絞りを介設するとと
もに、該可変絞りの上流側と前記絞り切換弁の絞
り下流側との差圧を圧力補償弁により一定圧に保
持し、この状態で前記可変絞りの開度を変化させ
ると、該可変絞り前後の差圧が変化し、この差圧
の変化に応じて絞り切換弁の絞り前後の差圧が変
化して、アクチユエータへの最大流量を変化させ
ることができることに着目し、その目的は、絞り
切換弁が最大開口面積をとる際の最大流量を容易
に調整し得るようにすることにある。 The present invention has been made in view of the above, and includes a variable throttle interposed in the pump passage of the throttle switching valve, and a pressure difference between the upstream side of the variable throttle and the downstream side of the throttle of the throttle switching valve. When the pressure is maintained at a constant level by the compensation valve and the opening degree of the variable throttle is changed in this state, the differential pressure before and after the variable throttle changes, and according to the change in pressure, the difference before and after the throttle of the throttle switching valve changes. Focusing on the fact that the maximum flow rate to the actuator can be changed by changing the pressure, the purpose is to easily adjust the maximum flow rate when the restrictor switching valve takes the maximum opening area. .
（課題を解決するための手段）
その目的を達成するため、本発明では、第１図
ないし第３図に示すように、油圧ポンプ１と、該
油圧ポンプ１からアクチユエータ２への圧油供給
方向を切換える絞り切換弁３と、該絞り切換弁３
のポンプ通路４に介設され上記絞り切換弁３の絞
り前後の差圧を変化させる可変絞り９とを設け
る。そして、該可変絞り９の構成につき、弁座８
ａと、該弁座８ａに対して上記ポンプ通路４に供
給される圧油の供給方向に対抗する方向から着座
する弁体８ｂとを設けると共に、該弁座８ａと弁
体８ｂとの間に弁体８ｂの離座量に応じた開度の
可変絞り部９ａを形成するように構成する。さら
に上記可変絞り９上流側と上記絞り切換弁３下流
側との差圧を一定値に保持する圧力補償弁１１
と、上記可変絞り９の弁体８ｂの離座量を調整し
て上記絞り切換弁３が最大開口面積をとる際の最
大流量を規制する調整機構１０とを設ける構成と
している。(Means for Solving the Problems) In order to achieve the object, the present invention provides a hydraulic pump 1 and a pressure oil supply direction from the hydraulic pump 1 to the actuator 2, as shown in FIGS. a throttle switching valve 3 that switches the throttle switching valve 3;
A variable throttle 9 is provided which is interposed in the pump passage 4 and changes the differential pressure before and after the throttle of the throttle switching valve 3. Regarding the configuration of the variable throttle 9, the valve seat 8
a, and a valve body 8b that is seated on the valve seat 8a from a direction opposite to the supply direction of the pressure oil supplied to the pump passage 4, and between the valve seat 8a and the valve body 8b. It is configured to form a variable throttle portion 9a whose opening degree corresponds to the amount of separation of the valve body 8b. Further, a pressure compensation valve 11 maintains the differential pressure between the upstream side of the variable throttle 9 and the downstream side of the throttle switching valve 3 at a constant value.
and an adjustment mechanism 10 that regulates the maximum flow rate when the throttle switching valve 3 takes the maximum opening area by adjusting the amount of separation of the valve body 8b of the variable throttle 9.
（作用）
以上の構成により、本発明では、絞り切換弁３
の下流側と可変絞り９上流側との差圧、つまりこ
の２つの絞りの合計差圧が圧力補償弁１１により
一定圧に圧力補償される。(Function) With the above configuration, in the present invention, the throttle switching valve 3
The differential pressure between the downstream side of the variable throttle 9 and the upstream side of the variable throttle 9, that is, the total differential pressure of these two throttles, is compensated to a constant pressure by the pressure compensating valve 11.
今、可変絞り９の弁体８ｂの離座量が調整手段
１０により例えば少なく調整されて、その絞り開
度が小さくなつた場合には、この可変絞り９の前
後の差圧が大きくなり、これに伴い、その差圧が
大きくなつた圧力分だけ絞り切換弁３前後の差圧
は小さくなる。その結果、該絞り切換弁３が最大
開口面積をとつている場合には、その最大流量は
この最大開口面積と該絞り切換弁３前後の差圧と
により決定されるものの、この差圧が上記のよう
に小さくなる分、最大流量は少なく規制されるこ
とになる。 Now, if the amount of separation of the valve body 8b of the variable throttle 9 is adjusted to a small value by the adjusting means 10, and the throttle opening becomes small, the differential pressure before and after the variable throttle 9 becomes large. As a result, the differential pressure across the throttle switching valve 3 decreases by the increased pressure. As a result, when the throttle switching valve 3 has the maximum opening area, the maximum flow rate is determined by this maximum opening area and the differential pressure before and after the throttle switching valve 3. As the flow rate becomes smaller, the maximum flow rate is regulated to be smaller.
しかも、油圧ポンプ１の吐出量が減少して圧力
降下したポンプダウン等の場合には、アクチユエ
ータ２内の油の圧力により可変絞り９の弁体８ｂ
が押圧されて、弁座８ａに着座するので、ポンプ
通路４が閉じられて、アクチユエータ２の油が油
圧ポンプ１に逆流することが確実に防止されるこ
とになる。 Moreover, in the case of pump down, etc. in which the discharge amount of the hydraulic pump 1 decreases and the pressure drops, the valve body 8b of the variable throttle 9 is affected by the oil pressure in the actuator 2.
is pressed and seats on the valve seat 8a, so the pump passage 4 is closed and the oil in the actuator 2 is reliably prevented from flowing back into the hydraulic pump 1.
（実施例）
以下、本発明の実施例を図面に基いて詳細に説
明する。(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.
第１図は本発明に係る油圧回路を示し、１は定
容量型の油圧ポンプ、２はアクチユエータ、３は
中立位置、順位置および逆位置の３位置を有する
絞り切換弁であつて、該絞り切換弁３のポンプポ
ートＰはポンプ通路４を介して上記油圧ポンプ１
に、また負荷ポートＡ，Ｂは圧油供給通路５，５
を介して上記アクチユエータ２に、さらにタンク
ポートＴはタンク通路６を介してタンク７にそれ
ぞれ接続されており、該絞り切換弁３の順位置お
よび逆位置への切換えにより油圧ポンプ１の圧油
供給方向を切換えて、アクチユエータ２を順作動
および逆作動するようになされている。尚、該絞
り切換弁３には負荷圧検出ポートR1，R2が設け
られている。 FIG. 1 shows a hydraulic circuit according to the present invention, in which 1 is a constant displacement hydraulic pump, 2 is an actuator, and 3 is a throttle switching valve having three positions: a neutral position, a normal position, and a reverse position. The pump port P of the switching valve 3 is connected to the hydraulic pump 1 via the pump passage 4.
In addition, load ports A and B are connected to pressure oil supply passages 5 and 5.
The tank port T is connected to the actuator 2 through the tank 7, and the tank port T is connected to the tank 7 through the tank passage 6. Pressure oil supply to the hydraulic pump 1 is controlled by switching the throttle switching valve 3 to the forward and reverse positions. By switching the direction, the actuator 2 is operated in forward and reverse directions. Note that the throttle switching valve 3 is provided with load pressure detection ports R 1 and R 2 .
また、８は上記絞り切換弁３のポンプ通路４に
介設された可変絞り９を有するチエツク弁であつ
て、該可変絞り９は絞り開度を調整する調整機構
１０を備えている。 Reference numeral 8 denotes a check valve having a variable throttle 9 interposed in the pump passage 4 of the throttle switching valve 3, and the variable throttle 9 is equipped with an adjustment mechanism 10 for adjusting the opening degree of the throttle.
さらに、１１は上記ポンプ通路４の可変絞り９
上流側とタンク通路６とを接続するバイパス通路
１２に介設されたバイパス型のパイロツト操作形
圧力補償弁であつて、該圧力補償弁１１における
バネ１１ａを有するバネ室１１ｂは、パイロツト
通路１３を介して上記絞り切換弁３の負荷圧検出
ポートR1に接続されている。また、該絞り切換
弁３の負荷圧検出ポートR2はパイロツト通路１
４およびタンク通路６の一部を介してタンク７に
接続されており、上記絞り切換弁３が中立位置に
あるときには、該圧力補償弁１１のバネ室１１ｂ
をパイロツト通路１３，１４およびタンク通路６
の一部を介してタンク７に開放することにより、
圧力補償弁１１をアンロード弁として機能させ
て、油圧ポンプ１からの圧油をバネ室１１ｂのバ
ネ１１ａのスプリング圧でもつてタンク７にリリ
ーフさせる一方、絞り切換弁３が順位置又は逆位
置にあるときには、圧力補償弁１１のバネ室１１
ｂをパイロツト通路１３および油圧供給通路５を
介してアクチユエータ２に連通せしめてアクチユ
エータ２の負荷圧を作用させることにより、該圧
力補償弁１１を本体の圧力補償弁として機能させ
て、可変絞り９上流側と絞り切換弁３の絞り下流
側との差圧をバネ室１１ｂのバネ１１ａのスプリ
ング圧に保持するようにしている。尚、１５は上
記圧力補償弁１１のバネ室１１ｂに作用する圧力
の最大値を規制するパイロツト弁である。 Furthermore, 11 is a variable throttle 9 of the pump passage 4.
This is a bypass type pilot-operated pressure compensating valve installed in a bypass passage 12 connecting the upstream side and the tank passage 6, and a spring chamber 11b having a spring 11a in the pressure compensating valve 11 connects the pilot passage 13. It is connected to the load pressure detection port R1 of the throttle switching valve 3 through the throttle valve 3. In addition, the load pressure detection port R2 of the throttle switching valve 3 is connected to the pilot passage 1.
4 and a tank 7 through a part of the tank passage 6, and when the throttle switching valve 3 is in the neutral position, the spring chamber 11b of the pressure compensation valve 11
pilot passages 13, 14 and tank passage 6
By opening to tank 7 through a part of
The pressure compensating valve 11 functions as an unloading valve to relieve the pressure oil from the hydraulic pump 1 into the tank 7 using the spring pressure of the spring 11a of the spring chamber 11b, while the throttle switching valve 3 is placed in the normal position or the reverse position. In some cases, the spring chamber 11 of the pressure compensation valve 11
b is communicated with the actuator 2 via the pilot passage 13 and the hydraulic pressure supply passage 5, and the load pressure of the actuator 2 is applied, so that the pressure compensation valve 11 functions as a pressure compensation valve of the main body, and the variable throttle 9 upstream The differential pressure between the throttle side and the throttle downstream side of the throttle switching valve 3 is maintained at the spring pressure of the spring 11a of the spring chamber 11b. Note that 15 is a pilot valve that regulates the maximum value of the pressure acting on the spring chamber 11b of the pressure compensating valve 11.
次に、上記可変絞り９および調整機構１０の具
体的構造を第２図および第３図に示す。 Next, the specific structures of the variable diaphragm 9 and the adjustment mechanism 10 are shown in FIGS. 2 and 3.
このものは、上記絞り切換弁３に一体的に組込
まれたもので、Ｐは上記絞り切換弁３の断面Ｕ字
状のポンプポート、ＡおよびＢはそれぞれ負荷ポ
ート、T1およびT2はそれぞれタンクポート、ま
た３ａは上記各ポート間の連通状態を中立位置、
順位置および逆位置の３位置に切換えるスプール
である。 This is integrated into the throttle switching valve 3, where P is a pump port with a U-shaped cross section of the throttle switching valve 3, A and B are load ports, respectively, and T1 and T2 are respectively The tank port and 3a are in the neutral position when the communication state between the above ports is set.
This is a spool that can be switched to three positions: forward position and reverse position.
そして、Poは上記ポンプ通路４に連通する入
口ポートであつて、該入口ポートPoと上記ポン
プポートＰとの間には弁座８ａが形成され、該弁
座８ａはポンプポートＰに向かうに従つて段差状
に開く形状に構成されている。また、該弁座８ａ
には、弁体８ｂがポンプポートＰから入口ポート
Poに向かう方向、つまり油圧ポンプ１からポン
プ通路４に供給される圧油の供給方向に対抗する
方向から着座し、かつ該弁体８ｂと切換弁本体３
ｂに固着された円筒部材１６のスプリング受け部
１７との間に縮装されたスプリング８ｃにより第
３図上方に付勢されて設けられている。上記の構
成により、該弁体８ｂの離座時には該弁体８ｂと
弁座８ａとの間に、該弁体８ｂの離座量に応じた
絞り開度の可変絞り部９ａが形成されている。以
上により、弁体８ｂの離座時には、入口ポート
PoからポンプポートＰに流入する圧油を可変絞
り９で絞るようにした可変絞り９付のチエツク弁
８を構成している。また、上記円筒部材１６内に
は、先端部が上記チエツク弁８の弁体８ｂに対向
し該弁体８ｂの最大開弁ストローク位置を規制す
るストツパ１０ａが摺動自在に設けられ、該スト
ツパ１０ａの後端部には円筒部材１６に螺動可能
に装着された調整ネジ１０ｂの先端部が当接係合
し、該調整ネジ１０ｂの後端部は円筒部材１６よ
り外方に突出している。よつて、該調整ネジ１０
ｂの回動操作によりストツパ１０ａの先端高さ位
置を調整することにより、弁体８ｂの最大開弁ス
トローク位置、つまり離座量を調整し、可変絞り
９の絞り開度を所定開度に変化調整するようにし
た調整機構１０を構成している。 Po is an inlet port communicating with the pump passage 4, and a valve seat 8a is formed between the inlet port Po and the pump port P. It is structured in a shape that opens out in a step-like shape. In addition, the valve seat 8a
In this case, the valve body 8b is connected from the pump port P to the inlet port.
It is seated from the direction toward Po, that is, from the direction opposite to the supply direction of pressure oil supplied from the hydraulic pump 1 to the pump passage 4, and the valve body 8b and the switching valve body 3
The spring 8c is compressed between the spring receiving part 17 of the cylindrical member 16 and the spring 8c fixed to the cylinder member b, and is biased upward in FIG. With the above configuration, when the valve body 8b is unseated, a variable throttle portion 9a is formed between the valve body 8b and the valve seat 8a, the throttle opening degree of which is variable according to the amount of unseating of the valve body 8b. . As described above, when the valve body 8b is unseated, the inlet port
A check valve 8 with a variable throttle 9 is configured to throttle the pressure oil flowing into the pump port P from Po. Further, a stopper 10a is slidably provided in the cylindrical member 16, the tip of which faces the valve body 8b of the check valve 8, and which restricts the maximum opening stroke position of the valve body 8b. The tip of an adjustment screw 10b that is screwably attached to the cylindrical member 16 is engaged with the rear end, and the rear end of the adjustment screw 10b projects outward from the cylindrical member 16. Therefore, the adjustment screw 10
By adjusting the height position of the tip of the stopper 10a by rotating b, the maximum opening stroke position of the valve body 8b, that is, the amount of unseating is adjusted, and the throttle opening of the variable throttle 9 is changed to a predetermined opening. This constitutes an adjustment mechanism 10 adapted to perform adjustment.
次に、上記実施例の作動について説明するに、
絞り切換弁３が中立位置から順位置又は逆位置に
切換えられると、油圧ポンプ１からの圧油は該絞
り切換弁３から所定の圧油供給通路５を介してア
クチユエータ２に供給される。この時、圧力補償
弁１１のバネ室１１ｂはパイロツト通路１３およ
び上記圧油供給通路５を介してアクチユエータ２
に連通されているため、該圧力補償弁１１は本来
の圧力補償弁として機能しており、可変絞り９の
上流側と絞り切換弁３の下流側との差圧は、該圧
力補償弁１１によりバネ室１１ｂのバネ１１ａの
スプリング圧に保持されている。その結果、絞り
切換弁３が最大開口面積をとる際における該絞り
切換弁３からアクチユエータ２への最大流量Ｑ
は、絞り切換弁３の絞り前後の差圧、すなわち圧
力補償弁１１のバネ１１ａのスプリング圧Psよ
り可変絞り９前後の差圧（ΔP）を減じた圧力
（Ps−ΔP）と、絞り切換弁３の絞り開度（つま
り最大開口面積）とに応じた流量となつている。 Next, to explain the operation of the above embodiment,
When the throttle switching valve 3 is switched from the neutral position to the forward position or the reverse position, pressure oil from the hydraulic pump 1 is supplied from the throttle switching valve 3 to the actuator 2 via a predetermined pressure oil supply passage 5. At this time, the spring chamber 11b of the pressure compensation valve 11 is connected to the actuator 2 via the pilot passage 13 and the pressure oil supply passage 5.
The pressure compensation valve 11 functions as an original pressure compensation valve, and the pressure difference between the upstream side of the variable throttle 9 and the downstream side of the throttle switching valve 3 is controlled by the pressure compensation valve 11. It is held by the spring pressure of the spring 11a in the spring chamber 11b. As a result, the maximum flow rate Q from the throttle switching valve 3 to the actuator 2 when the throttle switching valve 3 takes the maximum opening area.
is the differential pressure before and after the throttle of the throttle switching valve 3, that is, the pressure (Ps - ΔP) obtained by subtracting the differential pressure (ΔP) before and after the variable throttle 9 from the spring pressure Ps of the spring 11a of the pressure compensating valve 11, and the pressure of the throttle switching valve 3. The flow rate corresponds to the aperture opening degree (that is, the maximum opening area) of No. 3.
今、可変絞り９の弁体８ｂの離座量を調整機構
１０により変化させて、該可変絞り９の絞り開度
を増減変化させると、それに応じて該可変絞り９
前後の差圧が大小変化し、これに伴い絞り切換弁
３の絞り前後の差圧（Ps−ΔP）はそれとは逆に
可変絞り９前後の差圧の変化分だけ小大変化す
る。その結果、アクチユエータ２への最大流量
Q′は上記絞り切換弁３の絞り前後の差圧の大小
変化に応じて増減変化することになる。 Now, when the amount of separation of the valve body 8b of the variable throttle 9 is changed by the adjustment mechanism 10 to increase or decrease the throttle opening of the variable throttle 9, the variable throttle 9
The differential pressure before and after the throttle changes in magnitude, and accordingly, the differential pressure (Ps - ΔP) before and after the throttle of the throttle switching valve 3 changes by the amount of the change in the pressure difference before and after the variable throttle 9. As a result, the maximum flow rate to actuator 2
Q' increases or decreases in accordance with changes in the differential pressure before and after the throttle of the throttle switching valve 3.
よつて、複数個の絞り切換弁３…を並列接続し
た油圧回路においても、各絞り切換弁３…に対応
する可変絞り９…を各々の調整機構１０…により
絞り開度調整することにより、各絞り切換弁３…
毎にその絞り前後の差圧を変化せしめて、各アク
チユエータ２…毎に独自の最大流量を設定するこ
とができる。また、可変絞り９の絞り開度の変化
により、絞り切換弁３が最大開口面積をとる際の
アクチユエータ２への最大流量を調整することが
できるので、絞り切換弁３のスプール３ａの加工
が不要となり、絞り切換弁３として如何なる種類
のものをも使用することができる。 Therefore, even in a hydraulic circuit in which a plurality of throttle switching valves 3 are connected in parallel, each throttle opening can be adjusted by adjusting the throttle opening of the variable throttle 9 corresponding to each throttle switching valve 3 using each adjustment mechanism 10. Throttle switching valve 3...
By changing the differential pressure before and after the throttle each time, a unique maximum flow rate can be set for each actuator 2. In addition, by changing the throttle opening degree of the variable throttle 9, the maximum flow rate to the actuator 2 when the throttle switching valve 3 takes the maximum opening area can be adjusted, so there is no need to process the spool 3a of the throttle switching valve 3. Therefore, any type of throttle switching valve 3 can be used.
しかも、油圧ポンプ１の吐出量が減少し圧力降
下した際、例えばポンプダウンした際には、アク
チユエータ２の油の圧力が絞り切換弁３のポンプ
ポートＰに作用して可変絞り９の弁体８ｂを入口
ポートPo側に押圧し、このため該弁体８ｂは弁
座８ａに着座して入口ポートPoを閉じるので、
アクチユエータ２の油が油圧ポンプ１に逆流する
ことが確実に防止される。 Moreover, when the discharge amount of the hydraulic pump 1 decreases and the pressure drops, for example when the pump is down, the pressure of the oil in the actuator 2 acts on the pump port P of the throttle switching valve 3, causing the valve element 8b of the variable throttle 9 to act on the pump port P of the throttle switching valve 3. is pressed toward the inlet port Po side, and thus the valve body 8b seats on the valve seat 8a and closes the inlet port Po.
Oil in the actuator 2 is reliably prevented from flowing back into the hydraulic pump 1.
尚、上記実施例では、バイパス形の圧力補償弁
１１により可変絞り９上流側と絞り切換弁３の絞
り下流側との差圧をバネ１１ａのスプリング圧に
保持するようにしたが、該圧力補償弁１１に代
え、減圧形の圧力補償弁を用いて上記差圧を一定
に保持するようにしてもよいのは勿論のこと、上
記差圧に応動するロードセンシングを用いて、上
記固定ポンプ１に代わる可変ポンプの吐出量を制
限するようにしてもよいのはいうまでもない。 In the above embodiment, the differential pressure between the upstream side of the variable throttle 9 and the downstream side of the throttle of the throttle switching valve 3 is maintained at the spring pressure of the spring 11a by the bypass type pressure compensation valve 11. Of course, instead of the valve 11, a pressure reducing type pressure compensating valve may be used to maintain the differential pressure at a constant level. Needless to say, the discharge amount of the variable pump may be limited instead.
（発明の効果）
以上説明したように、本発明によれば、アクチ
ユエータへの圧油供給方向を切換える絞り切換弁
のポンプ通路に可変絞りを介設し、該可変絞りの
上流側と絞り切換弁の絞り下流側との差圧を圧力
補償弁により一定圧に保持し、この状態で上記可
変絞りの絞り開度を調整機構により調整すること
により、絞り切換弁の絞り前後の差圧を変化せし
めて、該絞り切換弁が最大開口面積をとる際のア
クチユエータへの最大流量を規制するようにした
ので、絞り切換弁の種類とは無関係に絞り切換弁
の加工を要さずに、このアクチユエータへの最大
流量の調整を容易にかつ無段階に行うことができ
ると共に、複数個の絞り切換弁を並列接続した油
圧回路においては各絞り切換弁毎に最大流量を個
別に設定することができ、しかも上記可変絞りを
逆流防止機能を有するように構成したので、ポン
プダウン時などの際の油の逆流を確実に防止でき
るなど、実用上著効を発揮することができる。(Effects of the Invention) As explained above, according to the present invention, a variable throttle is interposed in the pump passage of the throttle switching valve that switches the direction of pressure oil supply to the actuator, and the upstream side of the variable throttle and the throttle switching valve are connected to each other. The differential pressure between the throttle and the downstream side of the throttle is maintained at a constant pressure by the pressure compensation valve, and in this state, the throttle opening of the variable throttle is adjusted by the adjustment mechanism, thereby changing the differential pressure before and after the throttle of the throttle switching valve. Therefore, the maximum flow rate to the actuator when the throttle switching valve takes the maximum opening area is regulated, so the actuator can be easily flown to the actuator regardless of the type of throttle switching valve without the need for processing the throttle switching valve. The maximum flow rate can be easily and steplessly adjusted, and in a hydraulic circuit in which multiple throttle switching valves are connected in parallel, the maximum flow rate can be set individually for each throttle switching valve. Since the variable throttle is configured to have a backflow prevention function, it is possible to reliably prevent backflow of oil when the pump is down, etc., and it is possible to exhibit remarkable practical effects.
図面は本発明の実施例を示し、第１図は油圧回
路図、第２図は可変絞り付チエツク弁および調整
機構を絞り切換弁に一体的に組込んだ場合の具体
的構造を示す断面図、第３図は第２図の要部拡大
図である。
１……油圧ポンプ、２……アクチユエータ、３
……絞り切換弁、Ｐ……ポンプポート、４……ポ
ンプ通路、８ａ……弁座、８ｂ……弁体、９……
可変絞り、９ａ……可変絞り部、１０……調整機
構、１０ａ……ストツパ、１０ｂ……調整ネジ、
１１……圧力補償弁、１１ａ……スプリング。
The drawings show an embodiment of the present invention, and FIG. 1 is a hydraulic circuit diagram, and FIG. 2 is a sectional view showing a specific structure when a check valve with a variable throttle and an adjustment mechanism are integrated into a throttle switching valve. , FIG. 3 is an enlarged view of the main part of FIG. 2. 1... Hydraulic pump, 2... Actuator, 3
... Throttle switching valve, P... Pump port, 4... Pump passage, 8a... Valve seat, 8b... Valve body, 9...
Variable aperture, 9a... Variable aperture section, 10... Adjustment mechanism, 10a... Stopper, 10b... Adjustment screw,
11...Pressure compensation valve, 11a...Spring.
Claims (1)
ユエータ２への圧油供給方向を切換える絞り切換
弁３と、該絞り切換弁３のポンプ通路４に介設さ
れ上記絞り切換弁３の絞り前後の差圧を変化させ
る可変絞り９とを備え、該可変絞り９は弁座８ａ
と、該弁座８ａに対して上記ポンプ通路４に供給
される圧油の供給方向に対抗する方向から着座す
る弁体８ｂとを備え、該弁座８ａと弁体８ｂとの
間に弁体８ｂの離座量に応じた開度の可変絞り部
９ａを形成するよう構成され、さらに上記可変絞
り９上流側と上記絞り切換弁３下流側との差圧を
一定値に保持する圧力補償弁１１と、上記可変絞
り９の弁体８ｂの離座量を調整して上記絞り切換
弁３が最大開口面積をとる際の最大流量を規制す
る調整機構１０とを備えたことを特徴とする油圧
回路。1 A hydraulic pump 1, a throttle switching valve 3 that switches the direction of pressure oil supply from the hydraulic pump 1 to the actuator 2, and a throttle valve 3 that is interposed in the pump passage 4 of the throttle switching valve 3 and that controls the difference between before and after the throttle of the throttle switching valve 3. The variable throttle 9 is provided with a variable throttle 9 that changes the pressure, and the variable throttle 9 is connected to the valve seat 8a.
and a valve body 8b that is seated on the valve seat 8a from a direction opposite to the supply direction of the pressure oil supplied to the pump passage 4, and a valve body 8b is provided between the valve seat 8a and the valve body 8b. a pressure compensation valve configured to form a variable throttle part 9a with an opening degree according to the amount of separation of the valve 8b, and further to maintain a differential pressure between the upstream side of the variable throttle 9 and the downstream side of the throttle switching valve 3 at a constant value; 11, and an adjustment mechanism 10 that adjusts the amount of separation of the valve body 8b of the variable throttle 9 and regulates the maximum flow rate when the throttle switching valve 3 takes the maximum opening area. circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11888282A JPS599355A (en) | 1982-07-07 | 1982-07-07 | Hydraulic circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11888282A JPS599355A (en) | 1982-07-07 | 1982-07-07 | Hydraulic circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS599355A JPS599355A (en) | 1984-01-18 |
| JPH0232484B2 true JPH0232484B2 (en) | 1990-07-20 |
Family
ID=14747463
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11888282A Granted JPS599355A (en) | 1982-07-07 | 1982-07-07 | Hydraulic circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS599355A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01116302A (en) * | 1987-10-30 | 1989-05-09 | Mitsubishi Heavy Ind Ltd | Direction change-over valve with variable flow rate compensating valve |
| JP2549377Y2 (en) * | 1991-06-03 | 1997-09-30 | 株式会社小松製作所 | Pressure oil supply device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4820087U (en) * | 1971-07-15 | 1973-03-07 | ||
| JPS5022178A (en) * | 1973-06-29 | 1975-03-10 | ||
| JPS5311754U (en) * | 1976-07-14 | 1978-01-31 | ||
| JPS5524575B2 (en) * | 1975-05-21 | 1980-06-30 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5524575U (en) * | 1978-08-04 | 1980-02-16 |
-
1982
- 1982-07-07 JP JP11888282A patent/JPS599355A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4820087U (en) * | 1971-07-15 | 1973-03-07 | ||
| JPS5022178A (en) * | 1973-06-29 | 1975-03-10 | ||
| JPS5524575B2 (en) * | 1975-05-21 | 1980-06-30 | ||
| JPS5311754U (en) * | 1976-07-14 | 1978-01-31 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS599355A (en) | 1984-01-18 |
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