JPH04237882A - Piston pump - Google Patents
Piston pumpInfo
- Publication number
- JPH04237882A JPH04237882A JP3072229A JP7222991A JPH04237882A JP H04237882 A JPH04237882 A JP H04237882A JP 3072229 A JP3072229 A JP 3072229A JP 7222991 A JP7222991 A JP 7222991A JP H04237882 A JPH04237882 A JP H04237882A
- Authority
- JP
- Japan
- Prior art keywords
- valve
- cylinder
- valve body
- valve seat
- piston
- 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.)
- Granted
Links
- 239000012530 fluid Substances 0.000 claims description 13
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- 238000013459 approach Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 235000012489 doughnuts Nutrition 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Reciprocating Pumps (AREA)
- Details Of Reciprocating Pumps (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明はピストンポンプの改良に
関する。FIELD OF THE INVENTION This invention relates to improvements in piston pumps.
【０００２】0002
【従来の技術】従来のピストンポンプ、例えば図１０に
示す、回転斜板式アキシャルピストンポンプでは、シリ
ンダブロック２０に摺動自由に収装したピストン２１が
、斜板２２の回転により往復動し、シリンダの拡大する
行程で吸込弁２３を介してシリンダ内に吸込んだ作動液
を、シリンダの縮小する行程で吐出弁２４を介して圧送
する。2. Description of the Related Art In a conventional piston pump, for example, a rotating swash plate type axial piston pump shown in FIG. The hydraulic fluid sucked into the cylinder through the suction valve 23 during the expansion stroke is pumped through the discharge valve 24 during the cylinder contraction stroke.
【０００３】また、特願昭６３−１６４３５５号にもあ
るようなラジアルピストンポンプでは、シリンダ室２５
と連通する吐出通路２６に吐出弁２７が備えられ、吸込
行程では閉じているが、ピストン２８の上昇によりシリ
ンダ内圧がこの吐出圧を越えると開いて、作動液を吐出
する（図１１参照）。Furthermore, in a radial piston pump as disclosed in Japanese Patent Application No. 63-164355, the cylinder chamber 25
A discharge valve 27 is provided in a discharge passage 26 that communicates with the cylinder, and is closed during the suction stroke, but opens when the cylinder internal pressure exceeds this discharge pressure due to the rise of the piston 28, and discharges the hydraulic fluid (see FIG. 11).
【０００４】上記いずれの吐出弁２４，２７としても用
いられるチェック弁は、吸込行程などシリンダ内圧が低
いときは流れを遮断するが、このとき高い背圧を受ける
ため、十分な強度を持たせる必要があることから、一般
には頑強で重量もあるポペット弁や円板弁が用いられて
いる。[0004] The check valves used as both of the above discharge valves 24 and 27 shut off the flow when the cylinder internal pressure is low, such as during the suction stroke, but they are subject to high back pressure at this time, so they must have sufficient strength. Because of this, poppet valves and disc valves, which are strong and heavy, are generally used.
【０００５】[0005]
【発明が解決しようとする課題】ところで、ポンプ吐出
行程で、シリンダ内圧が吐出通路の圧力よりも上昇する
とチェック弁が開くが、実際にはチェック弁の慣性質量
などに依存して応答遅れがある。このため、チェック弁
が開くまでの間にシリンダ内圧が上昇し、これがピーク
圧となり、振動や騒音を発生させる原因となっている。[Problems to be Solved by the Invention] By the way, during the pump discharge stroke, the check valve opens when the cylinder internal pressure rises above the pressure in the discharge passage, but in reality there is a response delay depending on the inertial mass of the check valve. . For this reason, the cylinder internal pressure increases until the check valve opens, and this becomes a peak pressure, causing vibration and noise.
【０００６】ポンプ回転数が増加すると、ピストン速度
もこれに比例して上昇するため、吐出行程でチェック弁
が開くまでの応答遅れの間に変位するピストン変位量は
大きく、とくにチェック弁の慣性質量による応答遅れが
大きい場合には、シリンダ内に発生するピーク圧力も非
常に高くなり、ポンプの振動、騒音が大きな問題となっ
てくると共に、耐久性にも大きな影響を及ぼす。As the pump rotational speed increases, the piston speed also increases in proportion to this, so the amount of piston displacement during the response delay until the check valve opens during the discharge stroke is large, especially the inertial mass of the check valve. If the response delay is large, the peak pressure generated within the cylinder will also become very high, causing serious problems with pump vibration and noise, and also having a large impact on durability.
【０００７】そこで本発明は、シリンダ内に発生するピ
ーク圧を効果的に下げ、ポンプ振動、騒音の低減や耐久
性の向上を図ることを目的とする。SUMMARY OF THE INVENTION Therefore, an object of the present invention is to effectively lower the peak pressure generated within the cylinder, reduce pump vibration and noise, and improve durability.
【０００８】[0008]
【課題を解決するための手段】本発明は、シリンダに収
装したピストンの往復動に伴い作動液を吸入、吐出する
ピストンポンプにおいて、シリンダ室に接続する吐出通
路に介装するチェック弁を、弁口として多数の小孔をも
つ弁座と、この弁座と接離して小孔を開閉する可撓性の
ある薄板状の弁体と、この弁体を弁座に向けて付勢する
バネとで構成した。[Means for Solving the Problems] The present invention provides a piston pump that sucks in and discharges working fluid as a piston housed in a cylinder reciprocates, and includes a check valve interposed in a discharge passage connected to a cylinder chamber. A valve seat with many small holes as a valve opening, a flexible thin plate-shaped valve body that moves into and out of contact with the valve seat to open and close the small holes, and a spring that biases the valve body toward the valve seat. It was composed of
【０００９】[0009]
【作用】したがって、ポンプ吐出行程でのシリンダ内圧
の上昇に応じて、薄い弁体の一部がたわみ始め、一部の
作動液を排出する。さらにピストンの上昇に伴い、弁体
のたわみ量が増し、シリンダ内圧がチェック弁の吐出圧
に達したときは全体的にリフトして全開する。[Operation] Therefore, as the cylinder internal pressure increases during the pump discharge stroke, a portion of the thin valve body begins to bend, discharging a portion of the working fluid. Furthermore, as the piston rises, the amount of deflection of the valve body increases, and when the cylinder internal pressure reaches the discharge pressure of the check valve, the entire valve is lifted and fully opened.
【００１０】吐出行程で弁体がたわみ、作動液の排出が
開始されると、シリンダ内圧の上昇は抑制され、ピーク
圧が下がり、ピーク圧に依存しての振動、騒音の低減が
図れる。[0010] When the valve body is bent during the discharge stroke and discharge of the hydraulic fluid is started, the increase in cylinder internal pressure is suppressed, the peak pressure is reduced, and vibrations and noise depending on the peak pressure can be reduced.
【００１１】[0011]
【実施例】図１〜図３は本発明の第１の実施例を示すも
ので、図中１はシリンダ、２はピストンで、ピストン２
は図示しないカムにより押されてシリンダ内で摺動する
。ピストン２には図示しないが吸込口が形成され、吸込
行程でピストン２が一定以上に下降すると開いて、シリ
ンダ１の内部のシリンダ室３に作動液を吸い込む。なお
、この吸込口は、例えばピストン２の側面に形成されて
いて、ピストン２の一部がシリンダ１から抜け出すこと
により開通して、カム側（吸込側）に充満している作動
液を吸い込むようになっている。[Embodiment] Figures 1 to 3 show a first embodiment of the present invention, in which 1 is a cylinder, 2 is a piston, and the piston 2 is a cylinder.
is pushed by a cam (not shown) and slides within the cylinder. Although not shown, the piston 2 is formed with a suction port, which opens when the piston 2 descends beyond a certain level during the suction stroke, and sucks the working fluid into the cylinder chamber 3 inside the cylinder 1. Note that this suction port is formed, for example, on the side surface of the piston 2, and opens when a part of the piston 2 comes out of the cylinder 1, so that it sucks in the hydraulic fluid that is filling the cam side (suction side). It has become.
【００１２】シリンダ室３と接続する吐出通路４にはチ
ェック弁５が介装され、ピストン２の上昇する吐出行程
で開き、シリンダ内の作動液を吐出通路４に圧送する。A check valve 5 is interposed in a discharge passage 4 connected to the cylinder chamber 3, and is opened during the upward discharge stroke of the piston 2 to forcefully feed the working fluid in the cylinder to the discharge passage 4.
【００１３】チェック弁５は、弁口として多数の小孔６
をもつ弁座７と、この弁座７に接離して小孔６を開閉す
る可撓性のある薄板状の弁体８と、この弁体８を弁座７
に向けて付勢するバネ９とで構成される。The check valve 5 has a large number of small holes 6 as valve ports.
a flexible thin plate-shaped valve element 8 that approaches and separates from the valve seat 7 to open and close the small hole 6;
It is composed of a spring 9 that urges toward.
【００１４】チェック弁５は、シリンダ１の側面に取付
けられた箱型の弁ケース１０に構成され、この弁ケース
１０の一部にシリンダ室３と連通して弁座７が一体に形
成され、弁ケース１０の内部において、円形の弁体８が
、その周囲に配置したガイド１１を介して、半径方向に
ずれることなく摺動自由に案内されると共に、弁体８の
背面に近接してストッパ１２が配設され、このストッパ
１２の周囲に巻かれたバネ９により弁体８が弁座７に圧
接している。弁ケース１０の上下には、吐出通路４と接
続するための通口１３Ａ、１３Ｂが設けられる。The check valve 5 is constructed of a box-shaped valve case 10 attached to the side surface of the cylinder 1, and a valve seat 7 is integrally formed in a part of the valve case 10 in communication with the cylinder chamber 3. Inside the valve case 10, a circular valve body 8 is guided so as to be able to slide freely in the radial direction via a guide 11 disposed around the valve body 8, and a stopper is provided close to the back surface of the valve body 8. 12 is disposed, and the valve element 8 is pressed against the valve seat 7 by a spring 9 wound around the stopper 12. At the top and bottom of the valve case 10, ports 13A and 13B are provided for connection to the discharge passage 4.
【００１５】なお、弁体８を摺動自由に案内するガイド
１１は、図５のように、弁体８の外周に等間隔で配設し
、弁ケース１０の内周面に摺接させてもよい。Note that guides 11 for freely slidingly guiding the valve body 8 are arranged at equal intervals around the outer circumference of the valve body 8 and are brought into sliding contact with the inner circumferential surface of the valve case 10, as shown in FIG. Good too.
【００１６】以上のように構成され、次に作用について
説明する。The system is constructed as described above, and its operation will be explained next.
【００１７】ピストン２の下降する吸込行程では、図示
しない吸込口を介して作動液がシリンダ室３に吸い込ま
れ、この後、ピストン２が上昇する吐出行程で、吸込口
が閉じると、シリンダ内の圧力が上昇を始める。During the suction stroke in which the piston 2 descends, hydraulic fluid is sucked into the cylinder chamber 3 through the suction port (not shown), and then, in the discharge stroke in which the piston 2 ascends, when the suction port closes, the inside of the cylinder Pressure begins to rise.
【００１８】図４の（Ａ）〜（Ｃ）にも示すように、シ
リンダ内圧が低いときは、バネ９により弁体８が弁座７
に密着して小孔６を閉じているが、シリンダ内圧の上昇
に伴い、薄板状の弁体８が周囲からたわみ始め、シリン
ダ室３の作動液の一部が吐出通路４に流れ出す。それ以
後、シリンダ内圧の上昇に応じて弁体８をたわませつつ
、やがてバネ９を圧縮しながら全体的にリフトして全開
する。As shown in FIGS. 4(A) to 4(C), when the cylinder internal pressure is low, the valve body 8 is pushed against the valve seat 7 by the spring 9.
However, as the cylinder internal pressure increases, the thin plate-like valve body 8 begins to flex from its surroundings, and a portion of the working fluid in the cylinder chamber 3 flows out into the discharge passage 4. After that, the valve body 8 is bent in accordance with the increase in the cylinder internal pressure, and eventually the spring 9 is compressed and the entire valve body is lifted to be fully opened.
【００１９】このようにして、チェック弁５はシリンダ
内圧が吐出圧に達する付近から、徐々に開き出し、ある
時間遅れ後に全開するが、この間に弁体８のたわみによ
る圧力解放と、たわみ部分の容積拡大によるアキュムレ
ータ効果もあって、シリンダ内圧の上昇を緩和するため
、ピーク圧が過度に高まることがなく、振動、騒音の発
生を効果的に低減することができる。また、ピーク圧の
低下により、ポンプ内部に伝達される衝撃力が減少し、
耐久性の向上にもつながる。In this way, the check valve 5 gradually opens from the vicinity where the cylinder internal pressure reaches the discharge pressure, and fully opens after a certain time delay. During this time, the pressure is released due to the deflection of the valve body 8, and the There is also an accumulator effect due to the increased volume, which alleviates the increase in cylinder internal pressure, so the peak pressure does not increase excessively, making it possible to effectively reduce the generation of vibrations and noise. In addition, the reduction in peak pressure reduces the impact force transmitted inside the pump,
This also leads to improved durability.
【００２０】弁体８は最大リフト位置でストッパ１２に
阻止され、必要以上のリフトをしないことにより、次の
吸込行程での閉弁応答性をよくしている。The valve body 8 is stopped by the stopper 12 at the maximum lift position, and by not lifting more than necessary, the valve closing response in the next suction stroke is improved.
【００２１】また、チェック弁５が閉弁するときは、弁
体８は弁座７に全面的に密着して支持されるので、非常
に薄くしても破損する心配はなく、シリンダ室３と吐出
通路４との間に働く大きな差圧に対して、高い耐久性を
発揮する。Furthermore, when the check valve 5 is closed, the valve body 8 is fully supported in close contact with the valve seat 7, so there is no risk of damage even if it is made very thin, and the cylinder chamber 3 and It exhibits high durability against the large differential pressure that acts between it and the discharge passage 4.
【００２２】図６は他の実施例を示し、これは、弁体８
の中心に穴１５を設け、弁ケース１０の中心軸１６に摺
動自由に挿入し、これによって弁体８の半径方向のずれ
を防ぐガイドを構成するようにしたものである。なお、
弁座７に形成される多数の小孔６は、弁体８に対応して
ドーナツ状に形成される。FIG. 6 shows another embodiment, in which the valve body 8
A hole 15 is provided in the center of the valve case 10, and the valve body 8 is slidably inserted into the central shaft 16 of the valve case 10, thereby forming a guide that prevents the valve body 8 from shifting in the radial direction. In addition,
A large number of small holes 6 formed in the valve seat 7 are formed in a donut shape corresponding to the valve body 8.
【００２３】図７の実施例は、中空円盤状の弁体８を備
え、弁体８の外周部位に対応した巻線径のバネ９により
外側を保持し、シリンダ内圧の上昇時に中心からたわま
せ、アキュムレータ効果を高めるようにしたものである
。The embodiment shown in FIG. 7 has a hollow disk-shaped valve body 8, and the outer side is held by a spring 9 with a winding diameter corresponding to the outer circumferential portion of the valve body 8, so that when the cylinder internal pressure increases, the valve body 8 is deflected from the center. This is to increase the accumulator effect.
【００２４】なお、チェック弁５の開弁時に、作動液は
弁体８の中央に設けた穴１５から流出する。Note that when the check valve 5 is opened, the hydraulic fluid flows out from the hole 15 provided in the center of the valve body 8.
【００２５】図８、図９の実施例は、弁座７に対する弁
体８の着座面に中央が深い凹面１７を形成したもので、
その他の構成は、図１の実施例と変わりない。In the embodiments shown in FIGS. 8 and 9, a concave surface 17 with a deep center is formed on the seating surface of the valve body 8 relative to the valve seat 7.
Other configurations are the same as the embodiment shown in FIG.
【００２６】この場合、図９の（Ａ）のように、シリン
ダ内圧が低いときは弁体８が凹面１７に沿って弁座７に
密着しているが、シリンダ内圧がある程度上昇すると、
（Ｂ）のように弁体８の弾性により中央が膨らみ、シリ
ンダ室３から流出する作動液の一部を蓄えるアキュムレ
ータ効果を発揮する。In this case, as shown in FIG. 9A, when the cylinder internal pressure is low, the valve body 8 is in close contact with the valve seat 7 along the concave surface 17, but when the cylinder internal pressure increases to a certain extent,
As shown in (B), the center swells due to the elasticity of the valve body 8, creating an accumulator effect that stores a portion of the hydraulic fluid flowing out from the cylinder chamber 3.
【００２７】これによって圧力の上昇特性の傾きが緩ま
り、ピーク圧も低減する。[0027] As a result, the slope of the pressure increase characteristic becomes gentler, and the peak pressure is also reduced.
【００２８】この後は、上記実施例と同様に、弁体８が
バネ９に抗して全体的にリフトして全開する。After this, the valve body 8 is entirely lifted against the spring 9 to be fully opened, as in the above embodiment.
【００２９】なお、本発明はラジアルピストンポンプに
限らず、回転斜板型のアキシャルピストンポンプ等にも
適用できる。Note that the present invention is applicable not only to radial piston pumps but also to rotary swash plate type axial piston pumps and the like.
【００３０】[0030]
【発明の効果】以上のように本発明によれば、シリンダ
室に接続する吐出通路に介装するチェック弁を、弁口と
して多数の小孔をもつ弁座と、この弁座と接離して小孔
を開閉する可撓性のある薄板状の弁体と、この弁体を弁
座に向けて付勢するバネとで構成したため、ポンプ吐出
行程でのシリンダ内圧の上昇により弁体がたわみ、これ
に応じて徐々にシリンダ内圧を解放するので、チェック
弁が全開するまでの圧力上昇を緩和することができ、シ
リンダ内のピーク圧が抑制され、ポンプの振動、騒音の
低減が図れると共に、耐久性や信頼性も向上する。As described above, according to the present invention, a check valve installed in a discharge passage connected to a cylinder chamber is provided with a valve seat having a large number of small holes as a valve opening, and a valve seat that is connected to and separated from the valve seat. It consists of a flexible thin plate-shaped valve body that opens and closes a small hole, and a spring that biases this valve body toward the valve seat, so the valve body flexes as the cylinder internal pressure increases during the pump discharge stroke. Since the cylinder internal pressure is gradually released in response to this, the pressure rise until the check valve is fully opened can be alleviated, suppressing the peak pressure inside the cylinder, reducing pump vibration and noise, and increasing durability. performance and reliability are also improved.
【図１】本発明の実施例を示す断面図である。FIG. 1 is a sectional view showing an embodiment of the present invention.
【図２】図１のＡ−Ａ線矢示図である。FIG. 2 is an arrow diagram taken along line A-A in FIG. 1;
【図３】図１のＢ−Ｂ線矢示図である。FIG. 3 is a BB-line arrow diagram in FIG. 1;
【図４】チェック弁の作動状態を示す説明図で、（Ａ）
はシリンダ内圧の低いとき、（Ｂ）はシリンダ内圧があ
る程度上昇したとき、（Ｃ）はシリンダ内圧が高いとき
の状態を示す。FIG. 4 is an explanatory diagram showing the operating state of the check valve, (A)
(B) shows the state when the cylinder internal pressure has increased to some extent, and (C) shows the state when the cylinder internal pressure is high.
【図５】他の実施例を示す図１のＡ−Ａ線矢示相当図で
ある。FIG. 5 is a diagram corresponding to the arrow AA line in FIG. 1 showing another embodiment.
【図６】さらに他の実施例の断面図である。FIG. 6 is a sectional view of still another embodiment.
【図７】同じく他の実施例の断面図である。FIG. 7 is a sectional view of another embodiment.
【図８】同じく他の実施例の断面図である。FIG. 8 is a sectional view of another embodiment.
【図９】チェック弁の作動状態を示す説明図で、（Ａ）
はシリンダ内圧の低いとき、（Ｂ）はシリンダ内圧があ
る程度上昇したときの状態を示す。FIG. 9 is an explanatory diagram showing the operating state of the check valve, (A)
(B) shows the state when the cylinder internal pressure is low, and (B) shows the state when the cylinder internal pressure has increased to some extent.
【図１０】従来例の断面図である。FIG. 10 is a sectional view of a conventional example.
【図１１】さらに別の従来例の断面図である。FIG. 11 is a sectional view of yet another conventional example.
１ シリンダ ２ ピストン ３ シリンダ室 ４ 吐出通路 ５ チェック弁 ６ 小孔 ７ 弁座 ８ 弁体 ９ バネ 1 Cylinder 2 Piston 3 Cylinder chamber 4 Discharge passage 5 Check valve 6 Small hole 7 Valve seat 8 Valve body 9 Spring
Claims (1)
に伴い作動液を吸入、吐出するピストンポンプにおいて
、シリンダ室に接続する吐出通路に介装するチェック弁
を、弁口として多数の小孔をもつ弁座と、この弁座と接
離して小孔を開閉する可撓性のある薄板状の弁体と、こ
の弁体を弁座に向けて付勢するバネとで構成したことを
特徴とするピストンポンプ。Claim 1: In a piston pump that sucks in and discharges hydraulic fluid as a piston housed in a cylinder reciprocates, a check valve installed in a discharge passage connected to a cylinder chamber has a large number of small holes as valve ports. The valve seat is characterized by being composed of a valve seat, a flexible thin plate-shaped valve body that moves into and out of contact with the valve seat to open and close a small hole, and a spring that biases the valve body toward the valve seat. piston pump.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3072229A JP2984079B2 (en) | 1991-01-18 | 1991-01-18 | Piston pump |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3072229A JP2984079B2 (en) | 1991-01-18 | 1991-01-18 | Piston pump |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04237882A true JPH04237882A (en) | 1992-08-26 |
| JP2984079B2 JP2984079B2 (en) | 1999-11-29 |
Family
ID=13483233
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3072229A Expired - Fee Related JP2984079B2 (en) | 1991-01-18 | 1991-01-18 | Piston pump |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2984079B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006097637A (en) * | 2004-09-30 | 2006-04-13 | Hitachi Ltd | Fluid machine |
-
1991
- 1991-01-18 JP JP3072229A patent/JP2984079B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006097637A (en) * | 2004-09-30 | 2006-04-13 | Hitachi Ltd | Fluid machine |
| JP4566676B2 (en) * | 2004-09-30 | 2010-10-20 | 日立オートモティブシステムズ株式会社 | air compressor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2984079B2 (en) | 1999-11-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |