200819631 (1) 九、發明說明 【發明所屬之技術領域】 本發明是關於使用壓電振動子之壓電泵及壓電振動器 【先前技術】 令薄片狀的壓電振動子振動就會獲得泵作用之壓電泵 ，係藉由壓電振動子及殻體來形成泵室，在與該泵室相連 結的一對流路，設置與流動方向不同的一對逆止閥（允許 流體流往泵室之逆止閥及允許來自泵室的流體流之逆止閥 )。令壓電振動子振動，泵室的容積就會變化，隨著該容 積變化，一對逆止閥的其中一方閉合而另一方開啓的動作 反覆進行，因而會獲得泵作用。這種壓電泵由於薄型，作 爲例如水冷筆記型電腦的冷卻循環泵來使用。 壓電振動子，係將壓電體層積在墊片（導電性金屬薄 片）的正反面的至少其中一方而形成。壓電體具有對該正 反方向施加分極特性，當對正反之間施加與該分極方向同 方向或是反方向的正負極性的話，其中一方的表面積會擴 大而另一方的表面積則會縮小的性質。因而，令施加至壓 電體的正反面之正負極性交互地反轉，則正反面的其中一 方延伸而另一方收縮的循環反覆進行，墊片就會振動。 專利文獻1 :日本實用新案登錄2510590號公報 專利文獻2 :日本專利實開平3 一 8 679號公報 專利文獻3:日本專利特開2004— 257337號公報 200819631 (2) 這種用於壓電泵的壓電振動子，過去是形成爲平板狀 (圓板狀），該周緣部所抵接的〇形環（液密密封構件） 在與殼體之間受到壓縮而形成液密構造。被壓縮的0形環 會對壓電振動子與殼體之間施加分開方向的力。該力雖在 短期內不會對液密構造造成影響，但長期受力下，恐會有 對液密構造造成不良影響之虞。上述的水冷筆記型電腦的 冷卻循環泵，在用途上最好是有萬全的液密構造。 【發明內容】 本發明基於以上的問題點，其目的是要提供圍繞壓電 振動子的液密構造上有很高的可靠度之壓電泵。 另外的目的是要提供容易獲得可靠度很高的液密構造 之壓電振動子。 習知的平板狀（圓板狀）的壓電振動子，不得不朝向 與該振動子的平面方向成垂直的方向壓縮液密密封構件， 本發則是基於對該構造受到長期壓縮之液密構造會成爲不 穩定的原因有所認識，並基於壓縮方向若爲該振動子的徑 方向的話，針對提高可靠度而形成。 即是本發明的壓電泵是一種具有在由導電性金屬薄片 所組成之墊片的正反面的至少其中一方層積壓電體所形成 的壓電振動子、及將該壓電振動子的周緣予以液密來形成 泵室之殻體，將交變電流施加至該壓電振動子的墊片與壓 電體之間來讓該壓電振動子振動以使泵產生作用，在壓電 振動子之墊片的周緣部，形成圓筒狀彎折部，在該圓筒狀 -5- 200819631 (3) 彎折部與殻體之間，中間隔著液密密構件之壓電泵。 泵室可以是形成在壓電振動子的正反面其中一方的形 式、及形成在正反面的雙方的形式。形成在正反面其中一 方的形式則液密密封構件位於該壓電振動子的墊片之圓筒 狀曲折部的內周面或是外周面的其中一方即可。 一方面，形成在正反面的雙方的形式則最好是分別令 液密密封構件位於該壓電振動子的墊片之圓筒狀曲折部的 內周面及外周面。 另外，最好是在墊片之該圓筒狀曲折部的端部，形成 向外方曲折之外方凸緣部。 本發明中，在由導電性金屬薄片所組成之墊片的正反 面的至少其中一方層積壓電體所形成之壓電振動子的形態 ，係在墊片的周緣部形成圓筒狀曲折部。 【實施方式】 第7圖爲以模式來表示2個閥型壓電泵的槪念構成例 子。壓電振動子10係被夾持支撐在構成殼體20之上部殻 體20U與底部殼體20L之間，在與上部殼體20U之間構 成泵室A。 在殼體20 (上部殼體20U )具有冷卻水（液体）的入 口埠2 1及出口埠2 2的開口，在入口埠21與泵室A之間 、及泵室A與出口埠22之間，分別設置逆止閥1 1、1 2。 逆止閥1 1爲允許流體從入口埠2 1流往泵室A但不允許該 反向的流體流動之吸入側逆止閥，逆止閥1 2則爲允許流 -6 - (4) (4)200819631 體從泵室A流往出口埠22但不允許該反向的流體流動之 流出側逆止閥。 以上的壓電泵，當壓電振動子1 〇向正反彈性變形的 話，則泵室A的容積擴大之行程中，吸入側逆止閥n張 開而流出側逆止閥1 2閉合，故流體會從入口埠2 1流入泵 室A內（第7(B)圖）。一方面，縮小泵室A的容積之 行程中，流出側逆止閥1 2張開而吸入側逆止閥1 1閉合， 故流體會從泵室A流出至出口埠22(第7(A)圖）。因 此，令壓電振動子1 〇向正反連續彈性變形（進行振動） ，就會獲得泵作用。 第1〜3圖爲表示將本發明用於例如具有以上的基本 構成之壓電泵之第1實施形態。至於壓電振動子1 0，本實 施形態則是圖示中具有中心部的墊片1 0 1、及層積形成在 墊片101的正反面的其中一面（圖的下面）之壓電體102 之單層壓電樑型（unimorph type )。墊片101係用導電性 的金屬薄片材料，例如厚度0.2 mm程度的不銹鋼薄片， 經由壓模成型等眾所皆知的方法一體地構成，在中心圓形 部1 0 1 a的周緣，具有向圖的上方彎折形成之圓筒狀彎折 部1 〇 1 b，在該圓筒狀彎折部1 0 1 b的上端部，還形成有向 外方彎折形成之凸緣部1 0 1 c。壓電體1 02係由例如厚度 0.3 mm程度的PZT ( Pb ( Zr、Ti ) 03 )所構成，並朝向該 正反方向施予分極處理。壓電體102形成爲與墊片101的 中心圓形部1 〇 1 a相對應的圓形，藉由導電性黏著劑黏著 在該中心圓形部l〇la的背面，壓電體102的上下面則用 01 ) 200819631 (5) 電極來覆蓋。 在上部殼體20U形成有將壓電振動子10 (墊片1 的圓筒狀曲折部1 0 1 b及凸緣1 0 1 c及Ο形環（液密密 件）24予以插入之環狀溝25，在底部殼體20L形成 墊片1 0 1的凸緣部1 〇 1 C予以插入之段形凹部26，利 段形凹部2 6來決定壓電振動子1 〇之軸方向的位置。 環24會在圓筒狀曲折部l〇lc的內周面與環狀溝25 ，朝向與壓電振動子10的平面方向成平行的方向壓 以保持液密。第2圖、第3圖中，圖示中逆止閥1 1 均爲傘形，不過基本構成則是與第1圖同樣。墊片11 凸緣部1 〇 1 c能夠省略，但存在的話，可以提高壓電 子1 〇的位置精度。另外，墊片1 〇 1包括中心圓形部 、圓筒狀曲折部l〇lb以及凸緣部l〇lc，由不銹鋼薄 一體構成，故可以確保很高的液密性。進而，〇形写 的壓縮方向爲平面方向，故上部殼體20U和底部殼體 即使很薄仍可以確保剛性，因而對於薄型的壓電泵也 易對應。 上述構成的本壓電泵係對墊片101與壓電體1〇2 施加交變電流，壓電振動子1 〇因而振動’獲得與用 圖說明過同樣的泵作用。然後，0形環2 4不會朝向 電振動子1 〇的平面方向成平行的方向壓縮且不會承 平面方向成垂直的力。也就是0形環24不會對上部 20U和底部殼體20L施加使兩者分開方向的力’故可 期間保證液密性。 封構 有將 用該 0形 之間 縮， 、12 "的 振動 101a 片來 1 24 20L 很容 之間 第7 與壓 受與 殼體 以長 -8- (6) (6)200819631 第4圖爲表示〇形環位於墊片101之圓筒狀曲折部 1 0 1 b的外周側之本發明的另外實施形態。本實施形態中， 僅以上部殻體20U的環狀溝25來支撐薄片101 (壓電振 動子10)，只呈現上部殼體20U，底部殼體20L則省略圖 示。 以上的實施形態之單層壓電樑型（unimorph type)的 壓電振動子1〇，係在與泵室A相反的面層積壓電體102, 不過理論上也可以在泵室A側層積壓電體102。但是在與 泵室A相反的面層積壓電體1 02，則會有液體接觸到壓電 體1 02之虞，故最好是用於例如腐蝕性液體或水溶液等的 液體輸送用。另外，在泵室A側層積壓電體1 02的情況， 可以用保護薄膜等來覆蓋壓電體102，以防止液體與壓電 體1 02直接接觸，但會有長期間使用下液體濕透保護薄膜 的情況，基於這個觀點，最好是在與泵室A相反側層積壓 電體102。 第8圖爲表示使用本發明之4個閥型壓電泵的動作原 理。該4個閥型壓電泵係在壓電振動子10與上部殼體 20U之間、以及壓電振動子1〇與底部殼體20L之間，分 別形成泵室A和B，一方面還在殼體20設置單一的入口 埠21及單一的出口璋22，在一對的的泵室A和B與入口 埠2 1之間，分別設置允許流體從該入口埠2 1流往該一對 的泵室A和B但不允許該相反方向的流體流動之第1、第 2吸入側逆止閥HU、UL，在一對的泵室A和B與出口 埠22之間，分別設置允許流體從該一對的泵室A和B流 -9- (7) (7)200819631 往出口埠2 2但不允許該相反方向的流體流動之第1、第2 流出側逆止閥1 2 U、1 2 L。 該4個閥型壓電泵，當壓電振動子1〇向正反彈性變 形（振動）的話，則泵室A和B的任何一方容積增大但另 一方的容積減少的行程反覆進行。泵室A的容積增大（泵 室B的容積減少）的行程中，逆止閥1 1 U張開，流體從入 口埠2 1流入泵室A內，泵室B內的流體則是經由逆止閥 1 2U的張開而流出至出口埠22 (第8 ( B )圖）。相反地 泵室A的容積減少（泵室B的容積增大）的行程中，吸入 側逆止閥1 1 L張開而流體從入口埠2 1流入泵室B內，泵 室A內的流體則是經由流出逆止閥1 2U的張開而流出至 出口埠22 (第8 ( A)圖）。因此，可以縮短出口埠22的 脈動循環（比只在壓電振動子1〇的上下其中一方形成泵 室的情況還要縮短一半）。 第5圖、第6圖爲表示將本發明用於以上的動作原理 之4個閥型壓電泵之實施形態。該實施形態中，壓電振動 子1〇係由在中心圓形部l〇la的兩面層積壓電體1〇2之單 層壓電樑型（unimorph type)所構成，在上部殻體20U與 底部殻體20L之間，形成將墊片1〇1的圓筒狀曲折部 101b及0形環24予以插入之環狀溝27。即是藉由上部殼 體20U的圓柱狀凸部27a、及底部殼體20L的圓筒狀凹部 27b來形成環狀溝27。圓筒狀曲折部l〇lb及分別位於該 內周側和外周側之〇形環24，插入該環狀溝27 ’朝向與 壓電振動子1 〇的平面方向成平行的方向壓縮來保持液密 -10- 200819631 (8) 。第 5圖、第 6圖中，圖示中逆止閥11U、11L、12U、 12L均爲傘形，不過基本構成則是與第8圖同樣。 該4個閥型的實施形態也可以對相同電位之正反的壓 電體1 02與墊片1 0 1之間施加交變電流，令壓電振動子1 0 振動，獲得泵作用。依據雙層壓電樑型（bimorph type ) ’ 的壓電振動子10，可以比單層壓電樑型（unimorph type )還要更增大振動的振幅，又可以提高泵效率。然後，分 別位於墊片1 〇 1之圓筒狀曲折部1 0 1 b的內周面及外周面 之Ο形環24，朝向與壓電振動子10的平面方向成平行的 方向壓縮，不會朝向與平面方向成垂直的方向壓縮。於是 ，不會對上部殼體20U及底部殼體20L，施加分開方向的 力，可以長期保證液密構造。 【圖式簡單說明】 第1圖爲表示本發明之壓電振動子的實施形態之模式 分解圖。 第2圖爲表示使用第1圖中的壓電振動子之壓電泵的 實施形態之重要部位的半剖面立體圖。 第3圖同上之剖面圖。 第4圖爲表示使用第1圖中的壓電振動子之壓電泵的 另外實施形態之剖面圖。 第5圖爲表示本發明之壓電振動子的其他實施形態之 模式分解圖。 第6圖爲表示使用第5圖中的壓電振動子之壓電泵的 -11 - (9) (9)200819631 實施形態之剖面圖。 第7(A) 、7(B)圖爲表示本發明之作爲適用對象 之2個閥型壓電泵的槪念構成例子之模式圖。 第8(A) 、8(B)圖爲表示本發明之作爲適用對象 之4個閥型壓電栗的槪念構成例子之模式圖。 【主要元件符號說明】 1 〇 :壓電振動子 I 1 :逆止閥 II u :第1吸入側逆止閥 1 1 L :第2吸入側逆止閥 1 2 :逆止閥 12U :第1流出側逆止閥 12L :第2流出側逆止閥 20 :殻體 20U :上部殼體 20L :底部殼體 21 :入口埠 22 :出口埠 24 : Ο形環 25 :環狀溝 27 :環狀溝 27a :圓柱狀凸部 101 :墊片 -12- 200819631 (10) 1 0 1 a ·中心圓形部 1 0 1 b :圓筒狀彎折部 1 0 1 C :凸緣部 1 02 :壓電體 A ·栗室 ' B :泵室200819631 (1) Inventive description [Technical Field] The present invention relates to a piezoelectric pump using a piezoelectric vibrator and a piezoelectric vibrator. [Prior Art] A sheet-shaped piezoelectric vibrator is vibrated to obtain a pump. The piezoelectric pump is configured to form a pump chamber by a piezoelectric vibrator and a casing, and a pair of flow passages connected to the pump chamber are provided with a pair of check valves different in flow direction (allowing fluid to flow to the pump) The check valve of the chamber and the check valve that allows fluid flow from the pump chamber). When the piezoelectric vibrator vibrates, the volume of the pump chamber changes, and as the volume changes, one of the pair of check valves closes and the other opens, and the pump action is obtained. Such a piezoelectric pump is used as a cooling circulation pump such as a water-cooled notebook computer because of its thin shape. The piezoelectric vibrator is formed by laminating a piezoelectric body on at least one of the front and back surfaces of a spacer (conductive metal foil). The piezoelectric body has a polarization characteristic applied to the forward and reverse directions. When positive and negative polarities are applied between the positive and negative directions in the same direction or in the opposite direction to the polarization direction, one surface area is enlarged and the other surface area is reduced. nature. Therefore, the positive and negative polarities applied to the front and back surfaces of the piezoelectric body are alternately reversed, and the cycle in which one of the front and back surfaces is extended and the other contracted is repeated, and the spacer vibrates. [Patent Document 1] Japanese Utility Model Registration No. 2510590 Patent Document 2: Japanese Patent Application Laid-Open No. Hei No. Hei No. Hei No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. In the past, the piezoelectric vibrator was formed into a flat plate shape (a disk shape), and a ring-shaped ring (liquid-tight sealing member) that the peripheral edge portion abuts was compressed between the casing and the liquid-tight structure. The compressed O-ring applies a force in the direction of separation between the piezoelectric vibrator and the housing. Although this force does not affect the liquid-tight structure in the short term, it may cause adverse effects on the liquid-tight structure under long-term stress. The above-mentioned cooling circulating pump of the water-cooled notebook computer preferably has a liquid-tight structure in its application. SUMMARY OF THE INVENTION The present invention is based on the above problems, and an object thereof is to provide a piezoelectric pump having high reliability in a liquid-tight structure around a piezoelectric vibrator. Another object is to provide a piezoelectric vibrator that is easy to obtain a highly reliable liquid-tight structure. A conventional flat (disk-shaped) piezoelectric vibrator has to compress a liquid-tight sealing member in a direction perpendicular to the plane direction of the vibrator, and the present invention is based on a liquid-tight structure in which the structure is subjected to long-term compression. The reason why the structure is unstable is known, and if the direction of compression is the radial direction of the vibrator, it is formed to improve the reliability. That is, the piezoelectric pump of the present invention is a piezoelectric vibrator formed by laminating at least one of the front and back surfaces of a spacer composed of a conductive metal foil, and a peripheral edge of the piezoelectric vibrator Liquid-tightly forming a housing of the pump chamber, applying an alternating current between the spacer of the piezoelectric vibrator and the piezoelectric body to vibrate the piezoelectric vibrator to cause the pump to act, in the piezoelectric vibrator The peripheral portion of the gasket forms a cylindrical bent portion, and a piezoelectric pump having a liquid-tight member interposed therebetween is disposed between the bent portion and the casing. The pump chamber may be in the form of one of the front and back surfaces of the piezoelectric vibrator and one of the front and back surfaces. In the form of one of the front and back surfaces, the liquid-tight sealing member may be located on one of the inner circumferential surface or the outer circumferential surface of the cylindrical bent portion of the spacer of the piezoelectric vibrator. On the other hand, it is preferable that the form of both of the front and back surfaces is such that the liquid-tight sealing member is located on the inner circumferential surface and the outer circumferential surface of the cylindrical bent portion of the spacer of the piezoelectric vibrator. Further, it is preferable that the outer flange portion is formed to be outwardly bent at the end portion of the cylindrical bent portion of the spacer. In the present invention, a piezoelectric vibrator formed by laminating at least one of the front and back surfaces of a spacer composed of a conductive metal foil forms a cylindrical bent portion at a peripheral portion of the spacer. [Embodiment] Fig. 7 is a view showing an example of a structure of a two-valve piezoelectric pump in a mode. The piezoelectric vibrator 10 is sandwiched and supported between the upper casing 20U and the bottom casing 20L constituting the casing 20, and a pump chamber A is formed between the upper casing 20U and the upper casing 20U. The housing 20 (upper housing 20U) has an opening for the inlet (21) and the outlet port 22 of cooling water (liquid) between the inlet port 21 and the pump chamber A, and between the pump chamber A and the outlet port 22 , the check valves 1 1 and 1 2 are respectively provided. The check valve 1 1 is a suction side check valve that allows fluid to flow from the inlet 埠 2 1 to the pump chamber A but does not allow the reverse flow of the fluid, and the check valve 1 2 allows the flow -6 - (4) ( 4) 200819631 The flow side from the pump chamber A to the outlet port 22 but does not allow the reverse flow of the outflow side check valve. In the piezoelectric pump described above, when the piezoelectric vibrator 1 is deformed in a positive reversing manner, the suction side check valve n is opened and the outflow side check valve 12 is closed during the stroke in which the volume of the pump chamber A is expanded. Fluid will flow from the inlet 埠2 1 into the pump chamber A (Fig. 7(B)). On the other hand, in the stroke of reducing the volume of the pump chamber A, the outflow side check valve 12 is opened and the suction side check valve 11 is closed, so that the fluid flows out from the pump chamber A to the outlet port 22 (Section 7(A) Figure). Therefore, the piezoelectric vibrator 1 is continuously elastically deformed (vibrated) in the forward and reverse directions, and a pump action is obtained. Figs. 1 to 3 show a first embodiment in which the present invention is applied to, for example, a piezoelectric pump having the above basic configuration. As for the piezoelectric vibrator 10, the present embodiment is a spacer 10 having a center portion in the drawing, and a piezoelectric body 102 laminated on one of the front and back surfaces of the spacer 101 (below the figure). Single layer piezoelectric beam type (unimorph type). The spacer 101 is integrally formed of a conductive metal foil material, for example, a stainless steel sheet having a thickness of about 0.2 mm, by a well-known method such as press molding, and has a circumferential edge at the center circular portion 10 1 a. A cylindrical bent portion 1 〇 1 b formed by bending the upper side of the figure, and a flange portion 1 0 1 formed by bending outward is formed at an upper end portion of the cylindrical bent portion 10 1 b c. The piezoelectric body 102 is composed of, for example, PZT (Pb (Zr, Ti) 03 ) having a thickness of about 0.3 mm, and is subjected to polarization treatment in the forward and reverse directions. The piezoelectric body 102 is formed in a circular shape corresponding to the central circular portion 1 〇 1 a of the spacer 101, and is adhered to the back surface of the central circular portion 10a by the conductive adhesive, on the piezoelectric body 102 The following is covered with 01) 200819631 (5) electrodes. An annular groove in which the piezoelectric vibrator 10 (the cylindrical bent portion 1 0 1 b of the spacer 1 and the flange 1 0 1 c and the Ο ring (liquid tight member) 24 are inserted is formed in the upper casing 20U. 25, a segment-shaped recess 26 into which the flange portion 1 〇1 C of the spacer 110 is inserted is formed in the bottom case 20L, and the segment-shaped recess portion 26 determines the position of the piezoelectric vibrator 1 in the axial direction. 24, the inner circumferential surface of the cylindrical bent portion l〇lc and the annular groove 25 are pressed in a direction parallel to the plane direction of the piezoelectric vibrator 10 to maintain liquid-tightness. In Figs. 2 and 3, In the figure, the check valve 1 1 is of an umbrella shape, but the basic configuration is the same as that of Fig. 1. The gasket 11 flange portion 1 〇 1 c can be omitted, but the positional accuracy of the electron press 1 可以 can be improved. Further, the spacer 1 〇1 includes a central circular portion, a cylindrical bent portion l lb and a flange portion l lc, and is integrally formed of stainless steel, so that high liquid tightness can be ensured. The written compression direction is the planar direction, so that the upper casing 20U and the bottom casing can ensure rigidity even if it is thin, and thus it is easy for a thin piezoelectric pump. In the piezoelectric pump of the above configuration, an alternating current is applied to the spacer 101 and the piezoelectric body 1〇2, and the piezoelectric vibrator is vibrated to obtain the same pumping action as described with reference to the drawing. The ring 24 does not compress in a direction parallel to the plane direction of the electric vibrator 1 且 and does not exert a vertical force in the plane direction. That is, the O-ring 24 does not apply to the upper portion 20U and the bottom case 20L so that both The force in the direction of separation can be ensured during the period of liquid tightness. The seal has a vibration 101a piece that will be contracted between the 0-shapes, 12 " 1 24 20L, between the 7th and the pressure and the housing Length -8- (6) (6) 200819631 Fig. 4 is a view showing another embodiment of the present invention in which the 〇-shaped ring is located on the outer peripheral side of the cylindrical bent portion 1 0 1 b of the spacer 101. In the present embodiment, only The annular groove 25 of the upper casing 20U supports the sheet 101 (piezoelectric vibrator 10), and only the upper casing 20U is present, and the bottom casing 20L is omitted. The single-layer piezoelectric beam type of the above embodiment ( The piezoelectric vibrator of the unimorph type is laminated on the surface opposite to the pump chamber A, but the theory The piezoelectric body 102 may be laminated on the pump chamber A side. However, when the piezoelectric body 102 is laminated on the surface opposite to the pump chamber A, liquid contacts the piezoelectric body 102, so it is preferably used for For example, when a piezoelectric body 102 is laminated on the pump chamber A side, the piezoelectric body 102 may be covered with a protective film or the like to prevent the liquid from directly contacting the piezoelectric body 102. In the case of contact, there is a case where the liquid-permeable protective film is used for a long period of time. From this point of view, it is preferable to laminate the piezoelectric body 102 on the side opposite to the pump chamber A. Fig. 8 is a view showing the principle of operation of the four valve type piezoelectric pumps of the present invention. The four valve type piezoelectric pumps are disposed between the piezoelectric vibrator 10 and the upper casing 20U, and between the piezoelectric vibrator 1〇 and the bottom casing 20L to form pump chambers A and B, respectively. The housing 20 is provided with a single inlet port 21 and a single outlet port 22, between which a pair of pump chambers A and B and an inlet port 21 are respectively provided to allow fluid to flow from the inlet port 21 to the pair. The pump chambers A and B, but not allowing the first and second suction side check valves HU, UL of the fluid flow in the opposite direction, are respectively provided between the pair of pump chambers A and B and the outlet port 22 to allow fluid to be supplied from The pair of pump chambers A and B flow -9-(7) (7) 200819631 to the outlet 埠2 2 but do not allow the first and second outflow side check valves 1 2 U, 1 of the fluid flow in the opposite direction 2 L. In the four-valve piezoelectric pump, when the piezoelectric vibrator 1 is deformed in a positive reversal manner (vibration), the stroke of the pump chambers A and B is increased, but the other volume is decreased. In the stroke in which the volume of the pump chamber A is increased (the volume of the pump chamber B is decreased), the check valve 1 1 U is opened, the fluid flows into the pump chamber A from the inlet 埠 2 1 , and the fluid in the pump chamber B is reversed. The valve 1 2U is opened and flows out to the outlet port 22 (Fig. 8 (B)). Conversely, in the stroke in which the volume of the pump chamber A is reduced (the volume of the pump chamber B is increased), the suction side check valve 1 1 L is opened and the fluid flows from the inlet port 2 1 into the pump chamber B, and the fluid in the pump chamber A Then, it flows out to the outlet port 22 via the opening of the outflow check valve 1 2U (Fig. 8 (A)). Therefore, the pulsation cycle of the outlet port 22 can be shortened (half the case where the pump chamber is formed only on one of the upper and lower sides of the piezoelectric vibrator 1). Fig. 5 and Fig. 6 show an embodiment of a four-valve piezoelectric pump in which the present invention is applied to the above operational principle. In this embodiment, the piezoelectric vibrator 1 is composed of a single-layer piezoelectric beam type (unimorph type) in which the piezoelectric bodies 1〇2 are laminated on both sides of the central circular portion 10a, and is in the upper casing 20U and Between the bottom case 20L, an annular groove 27 into which the cylindrical bent portion 101b and the O-ring 24 of the spacer 1〇1 are inserted is formed. That is, the annular groove 27 is formed by the cylindrical convex portion 27a of the upper casing 20U and the cylindrical concave portion 27b of the bottom casing 20L. The cylindrical bent portion l〇1b and the ring-shaped ring 24 located on the inner peripheral side and the outer peripheral side, respectively, are inserted into the annular groove 27' to be compressed in a direction parallel to the plane direction of the piezoelectric vibrator 1 来 to retain the liquid. Secret-10-200819631 (8). In Figs. 5 and 6, the check valves 11U, 11L, 12U, and 12L are all of an umbrella shape, but the basic configuration is the same as that of Fig. 8. In the embodiment of the four valve type, an alternating current is applied between the piezoelectric body 102 and the spacer 1 0 1 of the same potential, and the piezoelectric vibrator 10 is vibrated to obtain a pumping action. According to the piezoelectric vibrator 10 of the bimorph type, the vibration amplitude can be increased more than the single-layer piezoelectric unimorph type, and the pump efficiency can be improved. Then, the ring-shaped rings 24 on the inner circumferential surface and the outer circumferential surface of the cylindrical bent portion 1 0 1 b of the spacer 1 〇1 are compressed in a direction parallel to the plane direction of the piezoelectric vibrator 10, and will not be compressed. Compressed in a direction perpendicular to the plane direction. Therefore, the force in the separating direction is not applied to the upper casing 20U and the bottom casing 20L, and the liquid-tight structure can be secured for a long period of time. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic exploded view showing an embodiment of a piezoelectric vibrator of the present invention. Fig. 2 is a half cross-sectional perspective view showing an important part of an embodiment of a piezoelectric pump using the piezoelectric vibrator of Fig. 1. Figure 3 is a cross-sectional view of the same as above. Fig. 4 is a cross-sectional view showing another embodiment of the piezoelectric pump using the piezoelectric vibrator of Fig. 1. Fig. 5 is a schematic exploded view showing another embodiment of the piezoelectric vibrator of the present invention. Fig. 6 is a cross-sectional view showing the embodiment of -11 - (9) (9) 200819631 using a piezoelectric vibrator of the piezoelectric vibrator of Fig. 5. 7(A) and 7(B) are schematic diagrams showing an example of a structure of a two-valve piezoelectric pump to which the present invention is applied. 8(A) and 8(B) are schematic diagrams showing an example of a structure of a four-valve type piezoelectric pump to which the present invention is applied. [Explanation of main component symbols] 1 〇: Piezoelectric vibrator I 1 : Check valve II u : 1st suction side check valve 1 1 L : 2nd suction side check valve 1 2 : Check valve 12U : 1st Outflow side check valve 12L: 2nd outflow side check valve 20: Housing 20U: Upper case 20L: Bottom case 21: Inlet port 22: Outlet port 24: Cylinder ring 25: Annular groove 27: Ring shape Groove 27a: cylindrical projection 101: spacer -12- 200819631 (10) 1 0 1 a · center circular portion 1 0 1 b : cylindrical bent portion 1 0 1 C : flange portion 1 02 : pressure Electric body A · chestnut room ' B : pump room