JPH0322876A - Ultrasonic motor - Google Patents
Ultrasonic motorInfo
- Publication number
- JPH0322876A JPH0322876A JP1152112A JP15211289A JPH0322876A JP H0322876 A JPH0322876 A JP H0322876A JP 1152112 A JP1152112 A JP 1152112A JP 15211289 A JP15211289 A JP 15211289A JP H0322876 A JPH0322876 A JP H0322876A
- Authority
- JP
- Japan
- Prior art keywords
- piezoelectric
- vibrator
- torsional
- electrodes
- longitudinal
- 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
- 239000000919 ceramic Substances 0.000 claims abstract description 53
- 239000002131 composite material Substances 0.000 claims abstract description 43
- 230000002093 peripheral effect Effects 0.000 claims abstract description 8
- 238000000034 method Methods 0.000 abstract description 8
- 230000010355 oscillation Effects 0.000 abstract 6
- 230000010287 polarization Effects 0.000 description 18
- 239000002184 metal Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 230000008602 contraction Effects 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
Landscapes
- General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
Abstract
Description
【発明の詳細な説明】
[産業上の利用分野]
本発明はOA機器等に用いられる圧電振動子の超音波振
動を用いたいわゆる超音波モータに関し、特に構造が簡
単な縦一捩り振動子型超音波モータに関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a so-called ultrasonic motor that uses ultrasonic vibration of a piezoelectric vibrator used in OA equipment, etc., and particularly relates to a so-called ultrasonic motor that uses ultrasonic vibration of a piezoelectric vibrator used in OA equipment, etc. Regarding ultrasonic motors.
[従来の技術]
17図は従来の縦一捩り振動子型超音波モータに用いら
れている縦一捩り複合振動子101の構造例の斜視図で
あり、圧電捩り振動子102および圧電縦振動子103
が金属円柱104を介して接合され、さらにこれらの両
側に金属円柱105及び106が接合されている。この
場合、金属円柱105の代りに金属円筒を用いることが
できる。[Prior Art] FIG. 17 is a perspective view of a structural example of a vertical single-torsion composite vibrator 101 used in a conventional vertical single-torsion vibrator type ultrasonic motor, and includes a piezoelectric torsional vibrator 102 and a piezoelectric longitudinal vibrator. 103
are joined via a metal cylinder 104, and metal cylinders 105 and 106 are further joined to both sides thereof. In this case, a metal cylinder can be used instead of the metal cylinder 105.
第8図は第7図に示した縦一捩り複合振動子101を用
いて構或した超音波モータの構造例を示す斜視図であり
、縦一捩り複合振動子101の一方の端部の中心に軸1
07が立てられ、軸受け8により回転自在に支持された
ローター109がコイルバネ110及びナット111に
より前記縦一捩り複合振動子101の端面に圧接される
。FIG. 8 is a perspective view showing a structural example of an ultrasonic motor constructed using the vertical single-torsion composite vibrator 101 shown in FIG. axis 1
07 is erected, and a rotor 109 rotatably supported by a bearing 8 is pressed against the end surface of the longitudinal single-twist composite vibrator 101 by a coil spring 110 and a nut 111.
第9図は第7図に示した圧電捩り振動子の構造例であり
、円筒状の圧電捩り振動子102は4個の4分割された
扇形圧電セラミックス板112が接合されて構成されて
いる。各々の扇形の圧電セラミックス板112は、11
0図に示すようにそれぞれ扇の弦の方向112aに分極
処理が施されており、扇形の圧電セラミックス板112
の上下面に電極を施し、上下電極間に直流電圧を印加す
ると扇形の圧電セラミックス板には板厚,と平行なすべ
り歪みが発生する。FIG. 9 shows an example of the structure of the piezoelectric torsional vibrator shown in FIG. 7, and the cylindrical piezoelectric torsional vibrator 102 is constructed by joining four sector-shaped piezoelectric ceramic plates 112 divided into quarters. Each fan-shaped piezoelectric ceramic plate 112 has 11
As shown in FIG.
When electrodes are applied to the upper and lower surfaces of the piezoelectric ceramic plate and a DC voltage is applied between the upper and lower electrodes, a sliding strain parallel to the thickness of the piezoelectric ceramic plate is generated in the fan-shaped piezoelectric ceramic plate.
第9図に示すように、4個の扇形の圧電セラミックス板
112が円板状に接合されている場合、各々の扇形の圧
電セラミックス板112に発生したすべり歪みは合成さ
れて、円板の上下面が捩じれるような捩り歪みとなる。As shown in FIG. 9, when four fan-shaped piezoelectric ceramic plates 112 are joined in a disk shape, the sliding strain generated in each sector-shaped piezoelectric ceramic plate 112 is combined and This results in torsional distortion such that the lower surface is twisted.
交流電圧を印加した場合には、このような、捩じり歪み
を生ずる振動(捩り振動と呼ぶ)が励起される。When an alternating current voltage is applied, such vibrations that cause torsional distortion (referred to as torsional vibrations) are excited.
第9図に示した従来の圧電捩り振動子を作製する場合は
、まず、第11図に示すように、幅方向に分極処理され
た圧電セラミックス板11、.3から超音波加工により
扇形の圧電セラミックス板を打ち抜いて第10図に示す
ような扇の弦の方向に分極された扇形の圧電セラミック
ス板112を作り、これを4個接着して円板状に構成す
るか、第12図(a)に示すように、厚さ方向に分極さ
れた圧電セラミックスのブロック114から、第12図
(b)に示すように分極方向が対角線の方向となるよう
な正四角柱115を切り出し、第12図(c)に示すよ
うに、4本の正四角柱115を分極方向が閉じたループ
となるように重ねて接着し、第12図(d)に示すよう
に外周をバイブ状に研磨した後、第12図(e)に示す
ように円板状に切断することにより形成している。When manufacturing the conventional piezoelectric torsional vibrator shown in FIG. 9, first, as shown in FIG. 11, piezoelectric ceramic plates 11, . A fan-shaped piezoelectric ceramic plate 112 polarized in the direction of the chord of the fan as shown in FIG. 10 is made by punching out a fan-shaped piezoelectric ceramic plate 112 using ultrasonic processing from step 3, and four of these are glued together to form a disc-shaped piezoelectric ceramic plate 112. Alternatively, as shown in FIG. 12(a), from a piezoelectric ceramic block 114 polarized in the thickness direction, a regular square is formed such that the polarization direction is diagonal as shown in FIG. 12(b). A square prism 115 is cut out, and as shown in FIG. 12(c), four regular square prisms 115 are stacked and glued together so that the polarization direction forms a closed loop, and the outer periphery is shaped as shown in FIG. 12(d). After polishing into a vibrator shape, it is formed by cutting into a disk shape as shown in FIG. 12(e).
M13図は従来の圧電縦振動子103の一橋造例であり
、両面に電極が施され、厚さ方向に分極された圧電セラ
ミックスリング116に電圧を印加し厚さ方向の振動(
縦振動と呼ぶ)を得るものである。Figure M13 is an example of a conventional piezoelectric longitudinal vibrator 103 made of Hitotsubashi construction, in which a voltage is applied to a piezoelectric ceramic ring 116 that has electrodes on both sides and is polarized in the thickness direction to generate vibrations in the thickness direction (
(called longitudinal vibration).
低い印加電圧で大きな振動振幅を得るために、第14図
のように薄い圧電セラミックスリング116−を複数個
積層して、圧電縦振動子103′を構成する場合もある
。In order to obtain a large vibration amplitude with a low applied voltage, a piezoelectric longitudinal vibrator 103' may be constructed by laminating a plurality of thin piezoelectric ceramic rings 116- as shown in FIG.
[発明が解決しようとする課題]
第9図に示した従来の圧電捩り振動子102においては
、複数個の圧電セラミックスが接着されて構成されてい
るため、接着による特性のばらつきが大きい。また、第
10図、第11図および第12図に示したように圧電捩
り振動子102を得るための加工が複雑で、コスト的に
も非常に費用がかかるものであった。さらに捩り振動ど
懺振動を同時に得ようとした場合は第9図に示した圧電
捩り振動子102と第13図又は第14図に示した圧電
縦振動子103を接着するため、やはり接着による特性
のばらつきと接着コストがかかるという問題があった。[Problems to be Solved by the Invention] Since the conventional piezoelectric torsional vibrator 102 shown in FIG. 9 is configured by bonding a plurality of piezoelectric ceramics, there are large variations in characteristics due to bonding. Furthermore, as shown in FIGS. 10, 11, and 12, the processing to obtain the piezoelectric torsional vibrator 102 is complicated and extremely expensive. Furthermore, when trying to obtain torsional and longitudinal vibrations at the same time, the piezoelectric torsional vibrator 102 shown in FIG. 9 and the piezoelectric longitudinal vibrator 103 shown in FIG. There was a problem with the variation in the amount of adhesive and the high cost of adhesion.
そこで、本発明の技術的課題は、以上に示した従来の圧
電捩り振動子および縦一捩り複合振動子の欠点を除去し
、加工が簡単で、接着工程のない、ばらつきの少ない圧
電捩り振動子を提供し、さらに同一の圧電素子に縦振動
子を形成した圧電縦一捩り複合振動子を用いた超音波モ
ータを提供することにある。Therefore, the technical problem of the present invention is to eliminate the drawbacks of the conventional piezoelectric torsional vibrator and vertical single-torsion composite vibrator as described above, and to create a piezoelectric torsional vibrator that is easy to process, does not require a bonding process, and has little variation. Furthermore, it is an object of the present invention to provide an ultrasonic motor using a piezoelectric vertical single-torsion composite vibrator in which a longitudinal vibrator is formed in the same piezoelectric element.
また、本発明の別の技術的課題は、中空状の圧電縦一捩
り複合振動子を用いることにより、中空部を貫通する軸
により二つのロータを前記圧電縦−捩り複合振動子の両
端部に圧接した2ロータ型の超音波モータを提供するこ
とにある。Another technical problem of the present invention is to use a hollow piezoelectric vertical-torsional composite vibrator, and to connect two rotors to both ends of the piezoelectric vertical-torsional composite vibrator by means of a shaft penetrating the hollow part. An object of the present invention is to provide a two-rotor type ultrasonic motor that is pressed into contact with each other.
[課題を解決するための手段]
本発明によれば、中心軸と該中心軸の周りに外周面を有
する棒状圧電セラミックスの該中心軸方向の中央部に形
成された圧電捩り振動子部と該圧電捩り振動子部の両側
に形成された一対の縦振動子部とをもち、該棒状圧電セ
ラミックスの両端に縦一捩り複合振動を励起する圧電縦
一捩り複合振動子と、該圧電縦一捩り複合振動子の少な
くとも一端に圧接され、前記縦一捩り複合振動を回転運
動に変換するロータとを備え、前記圧電捩り振動子部は
、該外周面に該中心軸に交差し、互いに平行に形成され
た複数の斜め電極をもち、該複数の斜め電極を用いて該
中央部を分極し、第1の周波数をもつ第1の交流駆動電
圧を印加して該棒状圧電セラミックスの両端に捩り振動
を励起するとともに、前記縦振動子部の夫々は、該外周
面に該中心軸に直交して平行に形成された複数の周電極
を夫々もち、該複数の周電極を用いて該圧電捩り振動子
部の両側を分極し、前記第1のの周波数と等しい周波数
をもつ第2の交流駆動電圧を印加して該棒状圧電セラミ
ックスの両端に伸縮振動を励起することを特徴とする超
音波モータが得られる。[Means for Solving the Problems] According to the present invention, a piezoelectric torsional vibrator portion formed at the center in the direction of the central axis of a rod-shaped piezoelectric ceramic having a central axis and an outer circumferential surface around the central axis; A piezoelectric vertical single-torsion composite vibrator that has a pair of vertical vibrator parts formed on both sides of a piezoelectric torsional vibrator part and excites longitudinal single-torsion composite vibrations at both ends of the rod-shaped piezoelectric ceramic; a rotor that is press-contacted to at least one end of the composite vibrator and converts the vertical torsional composite vibration into rotational motion; The central part is polarized using the plurality of diagonal electrodes, and a first AC driving voltage having a first frequency is applied to generate torsional vibration at both ends of the rod-shaped piezoelectric ceramic. Each of the vertical vibrator parts has a plurality of circumferential electrodes formed on the outer circumferential surface in parallel with orthogonal to the central axis, and the piezoelectric torsion vibrator is excited by using the plurality of circumferential electrodes. There is provided an ultrasonic motor characterized in that both sides of the rod-shaped piezoelectric ceramic are polarized and a second AC driving voltage having a frequency equal to the first frequency is applied to excite stretching vibrations at both ends of the rod-shaped piezoelectric ceramic. It will be done.
1作 用]
本発明の超音波モータは、圧電縦一捩り複合振動子とロ
ータとを備えている。1 Effect] The ultrasonic motor of the present invention includes a piezoelectric vertical single-torsion composite vibrator and a rotor.
圧電縦一捩り複合振動子は、中心軸とこの中心軸の周り
に外周面を有する棒状圧電セラミックスの中心軸方向の
中央部に形成された圧電捩り振動子部とこの圧電捩り振
動子部の両側に形成された一対の縦振動子部とをもち、
この棒状圧電セラミックスの両端に縦一捩り複合振動を
励起する。A piezoelectric longitudinal single-torsion composite vibrator includes a piezoelectric torsional vibrator section formed at the center in the direction of the central axis of a bar-shaped piezoelectric ceramic having a central axis and an outer peripheral surface around the central axis, and a piezoelectric torsional vibrator section on both sides of this piezoelectric torsional vibrator section. It has a pair of vertical vibrator parts formed in
A vertical torsional complex vibration is excited at both ends of this rod-shaped piezoelectric ceramic.
一方、ロータは圧電縦一捩り複合振動子の少なくとも一
端に圧接され、縦一捩り複合振動を回転運動に変換する
。On the other hand, the rotor is pressed against at least one end of the piezoelectric longitudinal single-torsion compound vibrator, and converts the longitudinal single-torsion compound vibration into rotational motion.
この圧電捩り振動子部は、この外周面にこの中心軸に交
差し、互いに平行に形成された複数の斜め電極をもち、
この複数の斜め電極を用いてこの棒状圧電セラミックス
の中央部を分極が施されている。This piezoelectric torsional vibrator section has a plurality of diagonal electrodes formed parallel to each other and intersecting the central axis on the outer circumferential surface,
The central portion of this rod-shaped piezoelectric ceramic is polarized using the plurality of oblique electrodes.
また、この圧電縦振動子部の夫々は、棒状圧電セラミッ
クスの外周面に中心軸に直交して平行に形成された複数
の周電極を夫々もち、この複数の周電極を用いてこの圧
電捩り振動子部の両側を夫々分極が施されている。Furthermore, each of the piezoelectric vertical vibrator sections has a plurality of circumferential electrodes formed on the outer peripheral surface of the rod-shaped piezoelectric ceramic in parallel and orthogonal to the central axis, and uses the plurality of circumferential electrodes to generate the piezoelectric torsional vibration. Both sides of the child part are polarized respectively.
このような、斜め電極に、第1の周波数をもつ第1の交
流駆動電圧を印加するとこの棒状圧電セラミックスの両
端には縦振動が励起される。When a first AC driving voltage having a first frequency is applied to such an oblique electrode, longitudinal vibration is excited at both ends of the rod-shaped piezoelectric ceramic.
また、周電極に前記第1のの周波数と等しい周波数をも
つ第2の゛交流駆動電圧を印加すると、この棒状圧電セ
ラミックスの両端には、伸縮振動が励起される。Furthermore, when a second AC drive voltage having a frequency equal to the first frequency is applied to the circumferential electrode, stretching vibrations are excited at both ends of the rod-shaped piezoelectric ceramic.
従って、第1の交流駆動電圧と第2の交流駆動電圧を夫
々、対応する電極に印加すると、棒状圧電セラミックス
の両端に捩り振動と伸縮振動が複合された縦一捩り振動
が励起される。この縦一捩り振動は、ロータによりこの
ロータの軸の回り回転運動に変換される。Therefore, when the first AC drive voltage and the second AC drive voltage are respectively applied to the corresponding electrodes, longitudinal torsional vibration, which is a combination of torsional vibration and stretching vibration, is excited at both ends of the rod-shaped piezoelectric ceramic. This longitudinal torsional vibration is converted by the rotor into rotational motion around the axis of the rotor.
[実施例]
以下本発明の実施例について図面を用いて詳1,く説明
する。[Examples] Examples of the present invention will be described in detail below with reference to the drawings.
第1図は本発明の実施例に係る超音波モータの構造を示
す斜視図である。後述する圧電縦一捩り抜合振動子28
の中空部に軸7を貫通させ、この圧電縦一捩り複合振動
子28の内側で共振の節の部分で固定してある。軸7の
両端部に軸受8,8′により回転自在に支持されたロー
ター9.9″をスプリング10.10−を介してナット
11.11=により圧電縦一捩り振動子28の端面に夫
々圧接することにより構或されている。FIG. 1 is a perspective view showing the structure of an ultrasonic motor according to an embodiment of the present invention. Piezoelectric vertical single-torsion extraction vibrator 28 to be described later
The shaft 7 is passed through the hollow part of the piezoelectric vertical single-torsion composite vibrator 28, and is fixed at the resonance node inside the piezoelectric vertical single-torsion composite vibrator 28. A rotor 9.9'' rotatably supported by bearings 8 and 8' at both ends of the shaft 7 is pressed onto the end face of the piezoelectric vertical single-torsion vibrator 28 by nuts 11 and 11 through springs 10 and 10, respectively. It is constructed by
圧電縦一捩り振動子28は、捩り振動の共振の節の付置
となる中央部をリング状の支持枠30で支持することが
可能で、この場合には、安定な支持ができる。The piezoelectric vertical torsional vibrator 28 can be supported by a ring-shaped support frame 30 at the center portion where the resonance node of torsional vibration is placed, and in this case, stable support can be achieved.
第2図(a) . (b) . (c)及び(d)は本
発明の実施例に係る超音波モータに用いる圧電縦一捩り
複合振動子の動作原理の説明図である。Figure 2(a). (b). (c) and (d) are explanatory diagrams of the operating principle of a piezoelectric vertical single-torsion composite vibrator used in an ultrasonic motor according to an embodiment of the present invention.
第2図(a)において、圧電セラミックス板1、7の一
方の面には互いに交差する複数個の第1及び第2の交差
電極18.19が形成され、それぞれ一つおきに第1及
び第2の共通電極18′19′に接続され、交差指電極
を形成している。In FIG. 2(a), a plurality of first and second intersecting electrodes 18 and 19 are formed on one surface of the piezoelectric ceramic plates 1 and 7, and the first and second intersecting electrodes 18 and 19 intersect with each other. It is connected to two common electrodes 18'19' to form interdigital electrodes.
m2図(b)において破線の矢印はこのような交差指電
極を用いて分極処理を施したときの分極の向きを示して
おり、第2図(c) ,(d)は第2図(b)のように
分極処理された圧電セラミックス板17に直流電圧を印
加した場合に発生する歪みの状態を示しており、実線の
矢印は電界の向きを示している。第2図(C)に示すよ
うに、電圧の極性が分極時の電圧の極性と同じ場合は分
極の方向に伸び歪みが発生し、一方、第2図(d)に示
すように電圧の極性が分極時の電圧の極性と逆の場合は
分極の方向に縮み歪みが発生する。In Fig. m2 (b), the dashed arrow indicates the direction of polarization when polarization processing is performed using such interdigital electrodes, and Fig. 2 (c) and (d) show the direction of polarization in Fig. 2 (b). ) shows the state of distortion that occurs when a DC voltage is applied to the polarized piezoelectric ceramic plate 17, and solid arrows indicate the direction of the electric field. As shown in Figure 2 (C), when the polarity of the voltage is the same as the polarity of the voltage during polarization, an elongation strain occurs in the direction of polarization, while as shown in Figure 2 (d), the polarity of the voltage If the polarity is opposite to the polarity of the voltage during polarization, shrinkage distortion occurs in the direction of polarization.
第3図は圧電セラミックス中空円柱20の両端面が図の
実線の矢印のように捩じれている場合に、圧電セラミッ
クス中空円柱20の外周面に発生する歪みの状態を示し
ており、圧電セラミックス中空円柱20の軸方向に対し
て45″の角度の方向で、しかも捩じれの破線で示す矢
印の向きに伸び縮みが発生し、これと一点鎖線の矢印で
示す直角な方向に縮み歪みが発生している。FIG. 3 shows the state of distortion that occurs on the outer peripheral surface of the piezoelectric ceramic hollow cylinder 20 when both end surfaces of the piezoelectric ceramic hollow cylinder 20 are twisted as shown by the solid arrows in the figure. Expansion and contraction occurs in the direction of an angle of 45'' with respect to the axial direction of 20, and in the direction of the arrow indicated by the broken torsional line, and shrinkage distortion occurs in the direction perpendicular to this indicated by the dashed-dotted arrow. .
従って、第3図に示す圧電セラミックス中空円柱20の
外周面に、第2図で示したような第1及び第2の交差指
電極を、第3図に示すように交差指の方向が圧電セラミ
ックス中空円柱20の長さ方向に対して45″の角度と
なるように形成し、この第1及び第2の交差指電極を用
いて分極処理を行い、同じ交差指電極に直流電圧を印加
すると、電圧の極性が分極時の電圧の極性と同じ場合に
は、圧電セラミック中空円柱20は一方向に捩じれ、電
圧の極性が分極時の電圧の極性と逆の場合は逆方向に捩
じれる。Therefore, first and second interdigital electrodes as shown in FIG. 2 are placed on the outer peripheral surface of the piezoelectric ceramic hollow cylinder 20 shown in FIG. The hollow cylinder 20 is formed at an angle of 45'' with respect to the length direction, polarization is performed using the first and second interdigital electrodes, and a DC voltage is applied to the same interdigital electrodes. When the polarity of the voltage is the same as the polarity of the voltage during polarization, the piezoelectric ceramic hollow cylinder 20 is twisted in one direction, and when the polarity of the voltage is opposite to the polarity of the voltage during polarization, it is twisted in the opposite direction.
さらに、圧電セラミックス中空円柱20の外周面に、第
2図に示したような第1及び第2の交差指電極を交差指
の方向が圧電セラミックス中空円柱20の円周方向と平
行に形或し、この第1及び第2の交差指電極を用いて分
極処理を行い、同じ交差指電極に直流電圧を印加すると
、電圧の極性が分極時の電圧の極性と同じ場合に圧電セ
ラミックス中空円柱20は長さ方向に伸び、電圧の極性
が分極時の電圧の極性と逆の場合は逆に長さ方向に縮む
。Furthermore, first and second interdigital electrodes as shown in FIG. When a polarization process is performed using the first and second interdigital electrodes and a DC voltage is applied to the same interdigital electrodes, when the polarity of the voltage is the same as the polarity of the voltage during polarization, the piezoelectric ceramic hollow cylinder 20 It extends in the length direction, and conversely contracts in the length direction when the polarity of the voltage is opposite to the polarity of the voltage during polarization.
第4図は本発明の実施例に係る超音波モータに用いられ
る圧電縦一捩り複合振動子部の一例を7T\す斜視図で
ある。この図において、圧電縦一捩り?立合振動子部2
1は、圧電セラミックス中空円柱20″の中央部分の外
周面に長さ方向に対して45″の角度となるように、互
いに交差する複数の第1及び第2の斜め電極22および
23が形成され、それぞれ第1及び第2の共通電極22
′および23′に接続されて、捩り振動子部21aを形
成している。FIG. 4 is a 7T perspective view of an example of the piezoelectric longitudinal single-torsion composite vibrator section used in the ultrasonic motor according to the embodiment of the present invention. In this figure, piezoelectric vertical twist? Standing vibrator section 2
1, a plurality of first and second oblique electrodes 22 and 23 are formed on the outer circumferential surface of the central portion of a piezoelectric ceramic hollow cylinder 20'' at an angle of 45'' with respect to the length direction, and intersect with each other. , first and second common electrodes 22, respectively.
' and 23' to form a torsional vibrator section 21a.
さらに、この45°の交差指電極の両側の部分の外周面
に円周方向と平行に複数の第1及び第2の周電極24.
25及び26.27が形成され、夫々同じ番号の電極が
電気的に接続され、一対の縦振動子部21b,21cを
形成している。Furthermore, a plurality of first and second circumferential electrodes 24 are arranged parallel to the circumferential direction on the outer circumferential surface of the portions on both sides of this 45° interdigital electrode.
25, 26, and 27 are formed, and electrodes having the same number are electrically connected to form a pair of vertical vibrator parts 21b and 21c.
第4図において、第1及び第2の共通電極22′および
23′間に直流高電圧を印加して分極処理を施した後、
この複合振動子の共振周波数に等しい周波数の交流電圧
を印加すれば圧電セラミックス中空円柱20′は両端部
が捩じれるように共振する。In FIG. 4, after polarization treatment is performed by applying a DC high voltage between the first and second common electrodes 22' and 23',
When an alternating current voltage having a frequency equal to the resonant frequency of this composite vibrator is applied, the piezoelectric ceramic hollow cylinder 20' resonates so that both ends thereof are twisted.
同様にして第1及び第2の周電極24及び25間1及び
第3及び第4の周電極26及び27間の夫々に直流高電
圧を印加して分極処理を施した後、上記捩りの共振周波
数に等しい交流電圧を印加すれば圧電セラミックス中空
円柱20゛は捩りの共振周波数でこの圧電セラミックス
中空円柱20゛の長さ方向に伸縮振動(縦振動)する。Similarly, after polarization treatment is performed by applying a DC high voltage between the first and second circumferential electrodes 24 and 25 and between the first and third and fourth circumferential electrodes 26 and 27, the torsional resonance When an alternating current voltage equal to the frequency is applied, the piezoelectric ceramic hollow cylinder 20' undergoes stretching vibration (longitudinal vibration) in the length direction of the piezoelectric ceramic hollow cylinder 20' at the torsional resonance frequency.
縦振動に対しては共振周波数と異なった周波数となるた
め、縦方向の振動振幅は共振時の振幅よりかなり小さく
なるが実用的には充分な振幅が得られる。For longitudinal vibration, the frequency is different from the resonance frequency, so the vibration amplitude in the longitudinal direction is considerably smaller than the amplitude at resonance, but a sufficient amplitude can be obtained for practical use.
第5図は本発明の実施例に係る超音波モータに用いられ
る圧電縦一捩り複合振動子の一橋造例を示す斜視図であ
る。この図において、圧電縦一捩り複合振動子は、第4
図に示した圧電縦一捩り複合振動子部21をほぼ中央部
に有する棒状圧電セラミックスからなる圧電縦一捩り複
合振動子28の両側に耐磨耗性の部材29.29−を接
合して構成される。この場合、圧電縦一捩り複合振動子
28の振動状態は、第6図(a)に示すようになる。即
ち、捩り振動に対しては、圧電縦一捩り複合振動子28
の中央部が振動の節になる。FIG. 5 is a perspective view showing an example of a hitotsubashi structure of a piezoelectric vertical single-torsion composite vibrator used in an ultrasonic motor according to an embodiment of the present invention. In this figure, the piezoelectric longitudinal single-torsion composite vibrator has the fourth
It is constructed by bonding wear-resistant members 29 and 29- to both sides of a piezoelectric vertical single-torsion composite vibrator 28 made of rod-shaped piezoelectric ceramics having a piezoelectric vertical single-torsion composite vibrator portion 21 shown in the figure approximately in the center. be done. In this case, the vibration state of the piezoelectric vertical single-torsion composite vibrator 28 is as shown in FIG. 6(a). That is, for torsional vibration, the piezoelectric longitudinal single-torsion composite vibrator 28
The center part becomes the node of vibration.
第6図(a)から分かるように、圧電縦一捩り複合振動
子28の両端部は、逆向きに捩じれる。As can be seen from FIG. 6(a), both ends of the piezoelectric vertical single-torsion composite vibrator 28 are twisted in opposite directions.
また、縦振動に対しては、印加電圧の周波数を捩りの共
振周波数と同じ周波数とすると、圧電縦一捩り複合振動
子28の両端部は逆向きに捩じれる。Regarding longitudinal vibration, if the frequency of the applied voltage is the same as the torsion resonance frequency, both ends of the piezoelectric longitudinal single-torsion composite vibrator 28 are twisted in opposite directions.
また、縦振動に対しては、印加電圧の周波数を捩りの共
振周波数と同じ周波数とすると、圧電縦一捩り複合振動
子28の両端部は、捩りの共振と同期して長さ方向の伸
縮振動をする。このとき、圧電縦一捩り複合振動子21
の両側に形成された縦捩振動子部それぞれに印加する電
圧の極性を逆向きにすると、伸縮歪みの方向は、第6図
(b)に示すようになる。したがって、圧電縦一捩り複
合振動子28の端部が振動の節の位置から両側に伸びる
ときの捩り振動の変位の向きが同じになり、圧電縦一捩
り複合振動子28の端部に同じ向きの楕円運動振動が発
生する。この場合に捩り振動の印加電圧または縦振動印
加電圧の位相を180”変化させると楕円振動の向きが
逆転する。Regarding longitudinal vibration, if the frequency of the applied voltage is set to the same frequency as the torsional resonance frequency, both ends of the piezoelectric longitudinal single-torsion composite vibrator 28 will undergo stretching vibration in the longitudinal direction in synchronization with the torsional resonance. do. At this time, the piezoelectric vertical single-torsion composite vibrator 21
When the polarities of the voltages applied to the longitudinal helical vibrator portions formed on both sides of the oscillator are reversed, the direction of expansion/contraction strain becomes as shown in FIG. 6(b). Therefore, when the end of the piezoelectric vertical single-torsion composite vibrator 28 extends from the vibration node position to both sides, the direction of displacement of torsional vibration is the same, and the end of the piezoelectric vertical single-torsion composite vibrator 28 is directed in the same direction. An elliptical motion vibration occurs. In this case, if the phase of the voltage applied to the torsional vibration or the voltage applied to the longitudinal vibration is changed by 180'', the direction of the elliptic vibration is reversed.
[発明の効果]
以上示したように、本発明によれば、超音波モータ用圧
電縦振動子及び捩り振動子として、通常一般的に適用さ
れているプレス成型技術により容易に製造することが可
能な棒状圧電セラミックスを用いて、これらの外周面に
これも一般的な技術である電極印刷を施すことにより圧
電捩り振動子及び圧電縦振動子が一体形状として得られ
るため、製造が容易で、接着工程や複雑な加工工程によ
る特性のばらつきの少ない圧電縦一捩り複合振動子が得
られる。[Effects of the Invention] As shown above, according to the present invention, piezoelectric longitudinal vibrators and torsional vibrators for ultrasonic motors can be easily manufactured using commonly used press molding techniques. By using rod-shaped piezoelectric ceramics and printing electrodes on their outer peripheral surfaces, which is also a common technique, a piezoelectric torsional vibrator and a piezoelectric longitudinal vibrator can be obtained as an integrated structure, which is easy to manufacture and requires no adhesives. A piezoelectric longitudinal single-torsion composite vibrator with little variation in characteristics due to process or complicated processing steps can be obtained.
また、本発明によれば、圧電縦一捩り複合振動子の形状
がパイプ状である場合には、中空部に軸を貫通させ、2
つのローターを同時に回転させる方式の超音波モータが
できる。Further, according to the present invention, when the shape of the piezoelectric longitudinal single-torsion composite vibrator is pipe-like, the shaft is penetrated through the hollow part, and two
An ultrasonic motor that rotates two rotors simultaneously can be created.
このように、圧電縦一捩り複合振動子を用いて超音波モ
ータを構成すれば構造が簡単で、特性のばらつきの少な
い超音波モータが得られ、実用的な効果が大きい。In this way, if an ultrasonic motor is constructed using a piezoelectric vertical single-torsion composite vibrator, an ultrasonic motor with a simple structure and less variation in characteristics can be obtained, which has great practical effects.
第1図は本発明の実施例に係る超音波モータの構造例を
示す斜視図、第2図(a).(b).(c),(d)は
交差指電極を用いて分極および電圧印加を行った場合の
歪みの発生状態の説明図、第3図は圧電セラミックス中
空円柱を捩ったときの歪みの発生状態の説明図、第4図
は本発明の実施例に係る圧電縦一捩り複合振動子の構造
を示す斜視図、第5図は本発明の超音波モータに用いら
れるバイブ状ランジュバン振動子の構造例を示す斜視図
、第6図(a)は第5図の圧電縦一捩り複合振動子の捩
り変位の相対的な大きさを示す図、第6図Cb)は第5
図の圧電縦一捩り複合振動子の伸び変位の相対的な大き
さを示す図、第7図は従来の縦一捩リランジュバン型振
動子の構造を示す斜視図、第8図は従来の縦一捩り型朧
音波モータの構造を示す斜視図、第9図は従来の捩り振
動子の構造を示す斜視図、第10図および第11図は従
来の捩り振動子の製造工程の説明図、第12図(a).
(b).(c)、(d).(e)は従来の捩り振動子の
製造工程の説明図、第13図は従来の縦振動子の構造を
示す斜視図、第14図は従来の縦振動子の他の構造を示
す斜視図である。
図中、1・・・圧電縦一捩り複合振動子、2・・・圧電
捩り振動子、3・・・圧電縦一振動子、4,5.6・・
・金属中空円柱、7・・・軸、8.8″・・・軸受、9
,9・・・ローター 10.10−・・・スプリング、
11.11′・・・ナット、17・・・圧電セラミック
ス薄板、18.19・・・交差指電極、18−,19−
・・・共通電極、20・・・中空円柱状弾性体、20′
・・・圧電セラミックス中空円柱、21・・・縦一捩り
複合振動子部、21a・・・捩り振動子部、21b,2
1c・・・縦振動子部、22.23・・・捩り振動子用
交差指電極、22″.23゛・・・共通電極、24,2
5.26.27・・・縦振動子用交差指電極、28・・
・圧電縦一捩り複合振動子、29.29=・・・耐磨耗
材、30・・・支持枠、101・・・圧電縦一捩り複合
振動子、〕02・・・圧電捩り振動子、103,103
’・・・圧電縦一振動子、104,105,106・・
・金属中空円柱、107・・・軸、108・・・軸受、
109・・・ローター 110・・・スプリング、11
1・・・ナット、112・・・扇型圧電セラミックス板
、113,114・・・圧電セラミックス板、115・
・・圧電セラミックス板角柱、116.116−・・・
圧電セラミックスリング。
}六町
第3図
第4図
第5図
第9図
第10図
第11図
〔縮み〕
第8図FIG. 1 is a perspective view showing a structural example of an ultrasonic motor according to an embodiment of the present invention, and FIG. 2(a). (b). (c) and (d) are illustrations of how distortion occurs when polarization and voltage are applied using interdigital electrodes, and Figure 3 shows how distortion occurs when a piezoelectric ceramic hollow cylinder is twisted. An explanatory diagram, FIG. 4 is a perspective view showing the structure of a piezoelectric vertical single-torsion composite vibrator according to an embodiment of the present invention, and FIG. FIG. 6(a) is a diagram showing the relative magnitude of torsional displacement of the piezoelectric vertical single-torsion composite vibrator of FIG. 5, and FIG.
Figure 7 is a perspective view showing the structure of a conventional vertical single-torsion Lilangevin type vibrator, and Figure 8 is a conventional vertical single-torsion composite vibrator. FIG. 9 is a perspective view showing the structure of a conventional torsional oscillator; FIGS. 10 and 11 are explanatory diagrams of the manufacturing process of a conventional torsional oscillator; Figure 12(a).
(b). (c), (d). (e) is an explanatory diagram of the manufacturing process of a conventional torsional oscillator, FIG. 13 is a perspective view showing the structure of a conventional longitudinal oscillator, and FIG. 14 is a perspective view showing another structure of the conventional longitudinal oscillator. be. In the figure, 1... Piezoelectric vertical single torsion composite vibrator, 2... Piezoelectric torsional vibrator, 3... Piezoelectric vertical single vibrator, 4, 5, 6...
・Metal hollow cylinder, 7...shaft, 8.8"...bearing, 9
,9...Rotor 10.10-...Spring,
11.11'... Nut, 17... Piezoelectric ceramic thin plate, 18.19... Interdigital electrode, 18-, 19-
... Common electrode, 20 ... Hollow cylindrical elastic body, 20'
. . . Piezoelectric ceramic hollow cylinder, 21 . . . Vertical one-torsion composite oscillator portion, 21a . . . Torsional oscillator portion, 21b, 2
1c...Longitudinal vibrator part, 22.23...Interdigital electrode for torsional vibrator, 22''.23゛...Common electrode, 24,2
5.26.27... Interdigital electrode for vertical vibrator, 28...
・Piezoelectric vertical single-twist composite vibrator, 29.29=... Wear-resistant material, 30... Support frame, 101... Piezoelectric vertical single-twist composite vibrator, 〕02... Piezoelectric torsional vibrator, 103 ,103
'...Piezoelectric vertical single vibrator, 104, 105, 106...
・Metal hollow cylinder, 107...shaft, 108...bearing,
109...Rotor 110...Spring, 11
DESCRIPTION OF SYMBOLS 1... Nut, 112... Fan-shaped piezoelectric ceramic plate, 113, 114... Piezoelectric ceramic plate, 115.
・Piezoelectric ceramic plate prismatic column, 116.116-...
Piezoelectric ceramic sling. }Rokumachi Figure 3 Figure 4 Figure 5 Figure 9 Figure 10 Figure 11 [Shrinkage] Figure 8
Claims (1)
セラミックスの該中心軸方向の中央部に形成された圧電
捩り振動子部と該圧電捩り振動子部の両側に形成された
一対の縦振動子部とをもち、該棒状圧電セラミックスの
両端に縦−捩り複合振動を励起する圧電縦−捩り複合振
動子と、該圧電縦−捩り複合振動子の少なくとも一端に
圧接され、前記縦−捩り複合振動を回転運動に変換する
ロータとを備え、 前記圧電捩り振動子部は、該外周面に該中心軸に交差し
、互いに平行に形成された複数の斜め電極をもち、該複
数の斜め電極を用いて該中央部を分極し、第1の周波数
をもつ第1の交流駆動電圧を印加して該棒状圧電セラミ
ックスの両端に捩り振動を励起するとともに、 前記縦振動子部の夫々は、該外周面に該中心軸に直交し
て平行に形成された複数の周電極を夫々もち、該複数の
周電極を用いて該圧電捩り振動子部の両側を分極し、前
記第1のの周波数と等しい周波数をもつ第2の交流駆動
電圧を印加して該棒状圧電セラミックスの両端に伸縮振
動を励起することを特徴とする超音波モータ。1. A piezoelectric torsional vibrator portion formed at the center in the direction of the central axis of a rod-shaped piezoelectric ceramic having a central axis and an outer peripheral surface around the central axis, and a pair of longitudinal vibrations formed on both sides of the piezoelectric torsional vibrator portion. a piezoelectric longitudinal-torsional composite vibrator which excites longitudinal-torsional composite vibration at both ends of the rod-shaped piezoelectric ceramic; a rotor that converts vibration into rotational motion; the piezoelectric torsional vibrator section has a plurality of diagonal electrodes on the outer circumferential surface that intersect with the central axis and are formed parallel to each other; and applying a first alternating current driving voltage having a first frequency to excite torsional vibration at both ends of the rod-shaped piezoelectric ceramic, and each of the longitudinal vibrator parts The plane has a plurality of circumferential electrodes formed perpendicularly and parallel to the central axis, and the plurality of circumferential electrodes are used to polarize both sides of the piezoelectric torsional vibrator section, and the frequency is equal to the first frequency. An ultrasonic motor characterized in that a second AC driving voltage having a certain frequency is applied to excite stretching vibrations at both ends of the rod-shaped piezoelectric ceramic.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1152112A JP2832614B2 (en) | 1989-06-16 | 1989-06-16 | Ultrasonic motor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1152112A JP2832614B2 (en) | 1989-06-16 | 1989-06-16 | Ultrasonic motor |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH0322876A true JPH0322876A (en) | 1991-01-31 |
JP2832614B2 JP2832614B2 (en) | 1998-12-09 |
Family
ID=15533322
Family Applications (1)
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JP1152112A Expired - Fee Related JP2832614B2 (en) | 1989-06-16 | 1989-06-16 | Ultrasonic motor |
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JP (1) | JP2832614B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6108567A (en) * | 1997-05-30 | 2000-08-22 | Nec Corporation | Radio communication apparatus having a hands-free communication mode |
-
1989
- 1989-06-16 JP JP1152112A patent/JP2832614B2/en not_active Expired - Fee Related
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6108567A (en) * | 1997-05-30 | 2000-08-22 | Nec Corporation | Radio communication apparatus having a hands-free communication mode |
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Publication number | Publication date |
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JP2832614B2 (en) | 1998-12-09 |
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