JPH0438153B2 - - Google Patents
Info
- Publication number
- JPH0438153B2 JPH0438153B2 JP58208963A JP20896383A JPH0438153B2 JP H0438153 B2 JPH0438153 B2 JP H0438153B2 JP 58208963 A JP58208963 A JP 58208963A JP 20896383 A JP20896383 A JP 20896383A JP H0438153 B2 JPH0438153 B2 JP H0438153B2
- Authority
- JP
- Japan
- Prior art keywords
- piezoelectric
- ring
- electrode
- displacement
- piezoelectric element
- 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
- 238000006073 displacement reaction Methods 0.000 claims description 22
- 230000010287 polarization Effects 0.000 claims description 5
- 239000000853 adhesive Substances 0.000 claims 1
- 230000001070 adhesive effect Effects 0.000 claims 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000008602 contraction Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/20—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators
- H10N30/204—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
- H10N30/2047—Membrane type
Landscapes
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明の圧電変位素子は、ビデオテープレコー
ダのビデオヘツドの位置制御を行うものである。
すなわち、圧電変位素子の先端にビデオヘツドを
取付け、記録テープのスピードが変化した場合で
も、記録テープの記録部を忠実にビデオヘツドが
トレースするように、圧電変位素子に印加する電
圧を変えることによりヘツドの位置を制御するこ
とができるものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The piezoelectric displacement element of the present invention controls the position of a video head of a video tape recorder.
In other words, by attaching a video head to the tip of the piezoelectric displacement element, and changing the voltage applied to the piezoelectric displacement element, the video head faithfully traces the recorded portion of the recording tape even when the speed of the recording tape changes. The position of the head can be controlled.
（従来例の構成とその問題点）
実用化されている圧電変位素子の中で、２枚の
各々全面電極を有するリング状の圧電素子をその
分極方向が同一になるように接着するとともに、
リング状圧電素子を二分割する線上の二つの支持
部で支持して二つの片持梁部を設け、そして電圧
を印加することにより支持部の両側の片持梁部で
たわみ変位を生じさせる圧電変位素子がある。但
し、中間の電極とリード線を接続するため、下段
のリング状の圧電素子の内径を上段のリング状の
圧電素子の内径よりも小さくしている。又、リン
グ状圧電素子の二つの片持梁部の先端に取付けた
ヘツドを独立して制御するため、リング状圧電素
子の中間の電極は支持部で分割されている。上記
従来の圧電変位素子に電圧を印加すると、リング
状のためヘツドを取付ける先端に応力集中が起こ
り、クラツクや破断が生じたりあいは変位特性を
妨げるという問題があつた。(Structure of conventional example and its problems) Among piezoelectric displacement elements that have been put into practical use, two ring-shaped piezoelectric elements each having a full-surface electrode are bonded together so that their polarization directions are the same, and
A piezoelectric device in which a ring-shaped piezoelectric element is supported by two supporting parts on a line that divides it into two, two cantilever parts are provided, and a deflection is caused in the cantilever parts on both sides of the support part by applying a voltage. There is a displacement element. However, in order to connect the middle electrode and the lead wire, the inner diameter of the lower ring-shaped piezoelectric element is made smaller than the inner diameter of the upper ring-shaped piezoelectric element. Further, in order to independently control the heads attached to the tips of the two cantilever parts of the ring-shaped piezoelectric element, the middle electrode of the ring-shaped piezoelectric element is divided by the support part. When a voltage is applied to the conventional piezoelectric displacement element described above, stress concentration occurs at the tip where the head is attached due to its ring shape, causing problems such as cracking or breakage or impeding displacement characteristics.
（発明の目的）
本発明は、かかる事情に鑑みてなされたもの
で、片持梁の場合の先端に発生する応力集中に起
因するクラツクや破断、あるいは変位特性を妨げ
るという欠点を解消することを目的とする。(Objective of the Invention) The present invention has been made in view of the above circumstances, and aims to eliminate the drawbacks of a cantilever beam, such as cracks and fractures caused by stress concentration occurring at the tip, and hindering displacement characteristics. purpose.
（発明の構成）
本発明は、２枚のリング状の圧電素子をその分
極方向が同一になるように接着するとともに、リ
ング状の圧電素子を二分割する線上の二つの支持
部で支持して二つの片持梁部を設け、前記片持梁
部が印加電圧によりたわみ変位を生じる圧電変位
素子において、前記リング状圧電素子の二つの片
持梁部において変位が最大となる先端付近の電極
を欠除させ、全面電極としないように構成したも
ので、駆動部のリング状の圧電素子の内径をｄと
した時、電極長さｌをｌ＝（1/3）ｄ〜ｄとするも
のである。このようにすると、先端は電極がなく
電圧を印加しても歪がなく、応力集中が起こら
ず、そのため従来のように先端にクラツクや破断
がなく、又変位特性が妨げられることもない。(Structure of the Invention) The present invention includes bonding two ring-shaped piezoelectric elements so that their polarization directions are the same, and supporting the ring-shaped piezoelectric elements with two supporting parts on a line that divides them into two. In a piezoelectric displacement element in which two cantilever parts are provided, and the cantilever parts undergo deflection displacement due to an applied voltage, electrodes are arranged near the tips of the two cantilever parts of the ring-shaped piezoelectric element where the displacement is maximum. When the inner diameter of the ring-shaped piezoelectric element of the drive part is d, the electrode length l is l = (1/3) d~d. be. In this way, there is no electrode at the tip, so there is no distortion even when a voltage is applied, stress concentration does not occur, and therefore there is no crack or breakage at the tip unlike in the conventional case, and the displacement characteristics are not disturbed.
（実施例の説明）
第１図で圧電変位素子の原理を説明する。圧電
素子１と２を分極方向（矢印a1，a2）が同一にな
るように接着し、並列型バイモルフ３を作る。第
１図では圧電素子１の上面が＋極、下面が−極、
圧電素子２の上面が＋極、下面が−極の構成であ
る。この並列型バイモルフ３を支持体４，５で支
持し片持梁とする。同図イで示すように、中間電
極に＋、支持体４，５に−の電圧を印加すると、
圧電効果により圧電素子１は矢印で示すように伸
びる方向に変形し、圧電素子２は縮む方向に変形
する。この結果、並列型バイモルフ３の片持梁の
先端は下方（矢印ｂ）に変位する。同図ロで示す
ように、印加電圧の極性を逆にすると、並列型バ
イモルフ３の片持梁の先端は上方（矢印ｃ）に変
位する。変位の大きさは印加電圧に応じて増減す
る。(Description of Examples) The principle of a piezoelectric displacement element will be explained with reference to FIG. Piezoelectric elements 1 and 2 are glued together so that their polarization directions (arrows a 1 , a 2 ) are the same, and a parallel bimorph 3 is created. In Figure 1, the top surface of the piezoelectric element 1 is the + pole, the bottom surface is the - pole,
The top surface of the piezoelectric element 2 has a positive pole and the bottom surface has a negative pole. This parallel bimorph 3 is supported by supports 4 and 5 to form a cantilever beam. As shown in Figure A, when + voltage is applied to the intermediate electrode and - voltage is applied to the supports 4 and 5,
Due to the piezoelectric effect, the piezoelectric element 1 is deformed in the direction of extension as shown by the arrow, and the piezoelectric element 2 is deformed in the direction of contraction. As a result, the tip of the cantilever beam of the parallel bimorph 3 is displaced downward (arrow b). As shown in FIG. 7B, when the polarity of the applied voltage is reversed, the tip of the cantilever of the parallel bimorph 3 is displaced upward (arrow c). The magnitude of the displacement increases or decreases depending on the applied voltage.
次に、本発明による一実施例を第２図に示す。
同図イは平面図、ロは正面図、ハは底面図、ニは
側面図である。リング状の２枚の圧電素子６，７
を分極方向が同一になるように貼り合わせ並列型
バイモルフ８を構成する。圧電素子６，７に、圧
電素子６の内径ｄ（駆動部の内径と考えてよい）
としたとき、電極長さｌ＝１／３ｄ〜ｄの電極９が
それぞれ形成されている。中間の電極よりリード
線１０，１１を接続するため、圧電素子７の内径
は圧電素子６の内径より若干小さくしてある。
又、二つのヘツド（図示せず）は、圧電素子６の
先端部１２，１３付近に取付けられ、それぞれ独
立して駆動するため、中間の電極は、圧電素子
６，７を二分割する線上の二つの支持部におい
て、中間１４で示すように分割されている。この
ような構成の並列型バイモルフ８は、中間電極を
分割した中間１４の位置、すなわち圧電素子６，
７を二分割する線上の二つの支持部で２対の支持
体１５により支持され、これにより二つの片持梁
部が形成される。（第２図イ，ハでは支持体を記
載していない。）上下の支持体１５を電気的に接
続し支持体１５とリード線１０の間、支持体１５
とリード線１１の間に電圧を印加すると、それぞ
れ片持梁部の先端は電圧の大きさに応じて変位す
ることになる。さらに、片持梁部の先端付近は電
極がなく、電圧を印加しても圧電効果は働かず、
全面電極と比べて殆ど応力集中は起こらない。 Next, an embodiment according to the present invention is shown in FIG.
In the figure, A is a plan view, B is a front view, C is a bottom view, and D is a side view. Two ring-shaped piezoelectric elements 6, 7
are bonded together so that the polarization directions are the same to form a parallel bimorph 8. The piezoelectric elements 6 and 7 have an inner diameter d of the piezoelectric element 6 (which can be considered as the inner diameter of the drive part).
In this case, the electrodes 9 each having an electrode length l=1/3d to d are formed. In order to connect the lead wires 10 and 11 from the intermediate electrode, the inner diameter of the piezoelectric element 7 is made slightly smaller than the inner diameter of the piezoelectric element 6.
Furthermore, since the two heads (not shown) are attached near the tips 12 and 13 of the piezoelectric element 6 and are driven independently, the middle electrode is located on the line dividing the piezoelectric elements 6 and 7 into two. The two supports are divided as indicated by the middle 14. The parallel bimorph 8 having such a configuration is located at the intermediate position 14 where the intermediate electrode is divided, that is, the piezoelectric element 6,
It is supported by two pairs of supports 15 at two support parts on a line that divides 7 into two, thereby forming two cantilever parts. (Supports are not shown in Fig. 2 A and C.) The upper and lower supports 15 are electrically connected, and between the supports 15 and the lead wires 10, the supports 15
When a voltage is applied between the lead wire 11 and the lead wire 11, the tips of the cantilever portions will be displaced depending on the magnitude of the voltage. Furthermore, there is no electrode near the tip of the cantilever, so the piezoelectric effect does not work even if voltage is applied.
There is almost no stress concentration compared to a full surface electrode.
第３図は、本発明による圧電素子の完成斜視図
である（支持体は図示せず）。 FIG. 3 is a completed perspective view of a piezoelectric element according to the present invention (the support is not shown).
（発明の効果）
以上のように本発明による圧電変位素子は、リ
ング状圧電素子からなる並列型バイモルフにおい
て、二つの片持梁部の先端付近の電極を欠除した
ため、応力集中、クラツク、破断等が発生せず、
変位特性が妨げられるということもない等、非常
に実用価値の高いものである。(Effects of the Invention) As described above, the piezoelectric displacement element according to the present invention is a parallel bimorph consisting of a ring-shaped piezoelectric element, and the electrodes near the tips of the two cantilever parts are omitted, which causes stress concentration, cracks, and breakage. etc. do not occur,
It has a very high practical value as it does not interfere with the displacement characteristics.
第１図は圧電変位素子の原理を示す図、第２図
は本発明の一実施例を示す図で、イは平面図、ロ
は正面図、ハは底面図、ニは側面図、第３図は本
発明による完成圧電素子の斜視図である。
１，２，６，７……圧電素子、３，８……並列
型バイモルフ、９……電極、４，５，１５……支
持体、１０，１１……リード線。
FIG. 1 is a diagram showing the principle of a piezoelectric displacement element, and FIG. 2 is a diagram showing an embodiment of the present invention, in which A is a plan view, B is a front view, C is a bottom view, D is a side view, and FIG. The figure is a perspective view of a completed piezoelectric element according to the present invention. 1, 2, 6, 7... Piezoelectric element, 3, 8... Parallel bimorph, 9... Electrode, 4, 5, 15... Support body, 10, 11... Lead wire.
Claims (1)
同一になるように重ねて接着するとともに、上下
面及び接着面に電極を設け、かつ前記リング状の
圧電素子を二分割する線上の二つの支持部で支持
して二つの片持梁部を設け、前記片持梁部が電圧
印加によりたわみ変位を生じる圧電変位素子にお
いて、前記リング状圧電素子の二つの片持梁部に
おいて変位が最大となる先端付近の電極部分を欠
除させたことを特徴とする圧電変位素子。 ２ 駆動部のリング状の圧電素子の内径をｄとし
た時、電極長さｌをｌ＝１／３ｄ〜ｄとしたことを 特徴とする特許請求の範囲第１項記載の圧電変位
素子。 ３ 接着面の電極は、中央支持部で分割されてい
る特許請請求の範囲第１項記載の圧電変位素子。[Claims] 1. Two ring-shaped piezoelectric elements are stacked and bonded together so that their polarization directions are the same, and electrodes are provided on the upper and lower surfaces and the bonded surface, and the ring-shaped piezoelectric elements are bonded together. In a piezoelectric displacement element in which two cantilever parts are provided by being supported by two support parts on a dividing line, and the cantilever parts are deflected and displaced by voltage application, the two cantilever parts of the ring-shaped piezoelectric element 1. A piezoelectric displacement element characterized in that an electrode portion near the tip where the displacement is maximum is removed. 2. The piezoelectric displacement element according to claim 1, wherein the electrode length l is 1/3d to d, where d is the inner diameter of the ring-shaped piezoelectric element of the drive section. 3. The piezoelectric displacement element according to claim 1, wherein the electrode on the adhesive surface is divided by the central support portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58208963A JPS60102777A (en) | 1983-11-09 | 1983-11-09 | piezoelectric displacement element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58208963A JPS60102777A (en) | 1983-11-09 | 1983-11-09 | piezoelectric displacement element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60102777A JPS60102777A (en) | 1985-06-06 |
| JPH0438153B2 true JPH0438153B2 (en) | 1992-06-23 |
Family
ID=16565050
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58208963A Granted JPS60102777A (en) | 1983-11-09 | 1983-11-09 | piezoelectric displacement element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60102777A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6386488A (en) * | 1986-09-30 | 1988-04-16 | Matsushita Electric Ind Co Ltd | Piezoelectric actuator |
| US6017313A (en) | 1998-03-20 | 2000-01-25 | Hypertension Diagnostics, Inc. | Apparatus and method for blood pressure pulse waveform contour analysis |
| US6331161B1 (en) * | 1999-09-10 | 2001-12-18 | Hypertension Diagnostics, Inc | Method and apparatus for fabricating a pressure-wave sensor with a leveling support element |
-
1983
- 1983-11-09 JP JP58208963A patent/JPS60102777A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60102777A (en) | 1985-06-06 |
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