JPH07151552A - Vibrator for piezoelectric vibration gyro - Google Patents

Abstract

PURPOSE:To utilize the piezoelectric longitudinal effect by making the crossing fingers of electrodes for driving, detecting, and earthing, parallel to the circumferential direction of a cylindrical piezoelectric ceramics. CONSTITUTION:On the peripheral surface of a cylindrical piezoelectric ceramics 1, belt form electrodes 8 to 12 are formed in the longitudinal direction, belt form electrodes in the circumferential direction are formed between the electrodes 8 and 9, 9 and 10, 10 and 11, and 11 and 12, and they are connected alternatively with the electrodes 8 to 12 each other. After polarizing by connecting the electrodes 8, 10, and 12, and 9 and 11 respectively, the electrodes 9 and 11 are made as common earthing electrodes, the electrode 10 as a driving electrode, and the electrodes 8 and 12 as detecting electrodes. When an AC current is applied between the electrode 10 and the electrodes 9 and 11, plural electrodes between the electrodes 10 and 9, and the electrodes 10 and 11, in the circumferential direction are displaced, and the ceramics 1 is bending vibrated by a piezoelectric longitudinal effect. When a vibrator is rotated parallel to the central axis, it is bending vibrated in the direction square to the bending vibration by Coriolis force. By this rotation, the potential difference is generated between the electrodes 8 and 9, and 12 and 11, and the rotary angular velocity can be found by measuring the potential differences.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、カメラ一体型ＶＴＲの
手振れ防止装置や自動車のナビゲーションシステム等に
用いられるジャイロスコープの内、特に棒状屈曲振動子
を用いた圧電振動ジャイロ用振動子に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrator for a piezoelectric vibrating gyroscope using a rod-shaped bending vibrator, among gyroscopes used for a camera shake preventive device of a camera-integrated VTR, a car navigation system and the like.

【０００２】[0002]

【従来の技術】圧電振動ジャイロは、振動している物体
に回転角速度が与えられると、その振動と直角な方向に
コリオリ力を生ずるという力学現象を利用したジャイロ
スコープである。互いに直交する二つの方向の励振と検
出が可能であるように構成した振動系において、一方の
振動を励振した状態で、振動子自身を二つの振動面が交
わる線と平行な軸を中心として回転させると、前述のコ
リオリ力の作用により、この振動と直角な方向に力が働
き、他方の振動が励振される。この励振された振動の大
きさは、入力側の振動の大きさ及び回転角速度に比例す
るため、入力電圧が一定の場合、出力電圧の大きさから
回転角速度の大きさを求めることができる。2. Description of the Related Art A piezoelectric vibrating gyro is a gyroscope utilizing a mechanical phenomenon in which a Coriolis force is generated in a direction perpendicular to a vibration when a rotating angular velocity is applied to a vibrating object. In an oscillating system configured to be able to excite and detect in two directions orthogonal to each other, the oscillator itself is rotated about an axis parallel to the line where the two oscillating surfaces intersect, with one oscillation being excited. Then, due to the action of the Coriolis force described above, a force acts in a direction perpendicular to this vibration, and the other vibration is excited. Since the magnitude of this excited vibration is proportional to the magnitude of the vibration on the input side and the rotation angular velocity, the magnitude of the rotation angular velocity can be obtained from the magnitude of the output voltage when the input voltage is constant.

【０００３】図３（ａ）は従来の圧電振動ジャイロに用
いられている圧電振動子の外観斜視図、図３（ｂ）は従
来の圧電振動ジャイロに用いられている圧電振動子の電
極構造の概略を平面に展開して示した図であり、図４は
従来の圧電振動ジャイロ用振動子を支持固定した状態の
外観を斜視図で示したものである。円柱状圧電セラミッ
クス１の外周側面上の円周を六等分する位置に、長さ方
向と平行な六本の帯状電極２，３，４，５，６，７が形
成されている。この帯状電極を互いに一つおきに接続し
て２端子として分極処理を施し、分極処理後、一つおき
の帯状電極２，４，６を接続して共通アース電極とし、
残りの帯状電極の内、帯状電極３を駆動電極、帯状電極
５及び７を検出電極として圧電振動ジャイロ用振動子を
構成している。FIG. 3A is an external perspective view of a piezoelectric vibrator used in a conventional piezoelectric vibrating gyro, and FIG. 3B shows an electrode structure of the piezoelectric vibrator used in a conventional piezoelectric vibrating gyro. FIG. 4 is a diagram showing a schematic plan view, and FIG. 4 is a perspective view showing an appearance of a conventional piezoelectric vibrating gyroscope supported and fixed. Six strip electrodes 2, 3, 4, 5, 6, 7 parallel to the length direction are formed on the outer peripheral side surface of the cylindrical piezoelectric ceramic 1 at positions that divide the circumference into six equal parts. Every other strip-shaped electrode is connected to each other for polarization treatment as two terminals, and after polarization treatment, every other strip-shaped electrode 2, 4, 6 is connected as a common ground electrode,
Of the remaining strip electrodes, the strip electrode 3 is used as a drive electrode, and the strip electrodes 5 and 7 are used as detection electrodes to form a piezoelectric vibrating gyro oscillator.

【０００４】この構造においては、円柱状圧電セラミッ
クスに屈曲振動を励振するために帯状電極３と帯状電極
２及び帯状電極４との間隔の変位を利用した圧電横効果
を利用している。又、検出側においても、帯状電極５と
帯状電極４及び帯状電極６、帯状電極７と帯状電極６及
び帯状電極２に関する圧電横効果を利用している。前述
のコリオリ力による振動の大きさは、入力側の振動の大
きさに比例するが、圧電横効果は圧電縦効果に比べ、電
気エネルギーを機械エネルギーに変換する効率が劣るた
め、同等の入力側の振動の大きさを得るためには、より
大きな電気エネルギーが必要であるという欠点があっ
た。In this structure, in order to excite bending vibration in the cylindrical piezoelectric ceramics, the piezoelectric lateral effect utilizing the displacement of the interval between the strip electrodes 3 and the strip electrodes 2 and 4 is utilized. Also on the detection side, the piezoelectric lateral effect of the strip electrode 5, the strip electrode 4, the strip electrode 6, the strip electrode 7, the strip electrode 6, and the strip electrode 2 is used. The magnitude of vibration due to the Coriolis force described above is proportional to the magnitude of vibration on the input side, but the piezoelectric lateral effect is less efficient in converting electrical energy into mechanical energy than the piezoelectric longitudinal effect, so the equivalent input side In order to obtain the magnitude of the vibration of, there was a drawback that larger electric energy was required.

【０００５】[0005]

【発明が解決しようとする課題】本発明の課題は、従来
用いられている圧電横効果によらず、圧電縦効果を利用
することにより、駆動及び検出の電気エネルギーと機械
エネルギーとの変換効率を向上させて、駆動電圧を低下
できる圧電振動ジャイロ用振動子を提供することであ
る。SUMMARY OF THE INVENTION An object of the present invention is to improve the conversion efficiency between electrical energy for driving and detection and mechanical energy by utilizing the piezoelectric longitudinal effect instead of using the piezoelectric lateral effect which has been conventionally used. It is an object of the present invention to provide a vibrator for a piezoelectric vibrating gyro that can be improved to reduce the driving voltage.

【０００６】[0006]

【課題を解決するための手段】円柱状圧電セラミックス
の外周側面に、その長さ方向と平行に複数個の帯状電極
を形成した圧電振動ジャイロ用振動子であって、駆動、
検出及びアース用の電極の交差指が円柱状圧電セラミッ
クスの円周方向と平行に向いた交差指電極なので、圧電
縦効果を利用することが可能な圧電振動ジャイロ用振動
子となる。A vibrator for a piezoelectric vibrating gyroscope in which a plurality of strip electrodes are formed on the outer peripheral side surface of a cylindrical piezoelectric ceramic in parallel with the length direction of the cylindrical piezoelectric ceramic.
Since the cross fingers of the detection and ground electrodes are parallel to the circumferential direction of the cylindrical piezoelectric ceramics, the piezoelectric vibrating gyroscope can utilize the piezoelectric longitudinal effect.

【０００７】[0007]

【作用】本発明による電極パターンを円柱状圧電セラミ
ックスの外周側面に形成すると、圧電縦効果により円柱
状圧電セラミックスに屈曲振動を励振することが可能と
なり、この振動子をその中心軸に平行な軸を中心に回転
させた場合、コリオリ力により駆動の屈曲振動と直角方
向の屈曲振動が励振されて、この振動が本発明の検出用
電極に電位差を与えて回転角速度を測定することが可能
となる。このようにして、圧電縦効果を利用できるの
で、従来の圧電横効果を利用するよりも電気・機械変換
効率に優れた圧電振動ジャイロ用振動子となる。When the electrode pattern according to the present invention is formed on the outer peripheral side surface of the cylindrical piezoelectric ceramic, it becomes possible to excite the bending vibration in the cylindrical piezoelectric ceramic by the piezoelectric longitudinal effect. When it is rotated around, the driving bending vibration and the bending vibration in the perpendicular direction are excited by the Coriolis force, and this vibration gives a potential difference to the detection electrode of the present invention, and the rotational angular velocity can be measured. . Since the piezoelectric longitudinal effect can be utilized in this way, the piezoelectric vibrating gyroscope has a better electromechanical conversion efficiency than the conventional piezoelectric transverse effect.

【０００８】[0008]

【実施例】本発明の実施例について、図面を用いて説明
する。図１（ａ）は、本発明による圧電振動ジャイロ用
振動子の外観斜視図である。図１（ｂ）は、本発明によ
る圧電振動ジャイロ用振動子の電極パターンを平面に展
開して示した図である。図２は、本発明の振動子を支持
固定した状態を斜視図で示したものである。円柱状圧電
セラミックス１の外周面上に長さ方向と平行な５本の帯
状電極８，９，１０，１１，１２が形成され、更に帯状
電極８と９、９と１０、１０と１１、１１と１２の間に
円周方向に沿った帯状電極を複数個形成し、それぞれが
一つおきに８と９、９と１０、１０と１１、１１と１２
の長さ方向と平行に走っている帯状電極と交互に接続す
る。Embodiments of the present invention will be described with reference to the drawings. FIG. 1A is an external perspective view of a vibrator for a piezoelectric vibrating gyroscope according to the present invention. FIG. 1B is a diagram showing an electrode pattern of a piezoelectric vibrating gyroscope vibrator according to the present invention developed on a plane. FIG. 2 is a perspective view showing a state in which the vibrator of the present invention is supported and fixed. Five strip-shaped electrodes 8, 9, 10, 11, 12 parallel to the length direction are formed on the outer peripheral surface of the cylindrical piezoelectric ceramic 1, and further strip-shaped electrodes 8 and 9, 9, 10 and 10, 11 and 11. A plurality of strip-shaped electrodes are formed along the circumferential direction between No. 12 and No. 12, and every other one is 8 and 9, 9 and 10, 10 and 11, 11 and 12, respectively.
, Alternating with strip electrodes running parallel to the length direction.

【０００９】この帯状電極８，１０および１２を接続
し、又９および１１を接続することにより、２端子とし
て分極処理を施し、分極処理後、帯状電極９，１１を接
続して共通アース電極とし、残りの帯状電極のうち、帯
状電極１０を駆動電極、帯状電極８及び１２を検出用電
極とする。By connecting the strip electrodes 8, 10 and 12 and by connecting 9 and 11, polarization treatment is performed as two terminals, and after the polarization treatment, the strip electrodes 9 and 11 are connected to form a common ground electrode. Of the remaining strip electrodes, the strip electrode 10 is used as a drive electrode, and the strip electrodes 8 and 12 are used as detection electrodes.

【００１０】この状態で、帯状電極１０（駆動電極）と
帯状電極９及び１１（共通アース電極）との間に交流電
圧を印加することにより、帯状電極１０と９、１０と１
１との間の円周方向に沿った複数個の帯状電極の間隔に
変位を生じ、圧電縦効果により円柱状圧電セラミックス
１に屈曲振動を励振させる。この振動子を円柱状圧電セ
ラミックス１の中心軸に平行な軸を中心に回転させる
と、コリオリ力により駆動の屈曲振動と直角方向の屈曲
振動が励振される。この振動は、帯状電極８（検出用電
極）と９（アース電極）、帯状電極１２（検出用電極）
と１１（アース電極）との間の円周方向に沿った複数個
の帯状電極の間隔を変化させ、帯状電極８と９、１２と
１１との間に電位差を生じる。この二つの検出電位に発
生する二つの電位差を測定することにより、回転角速度
を測定することができる。In this state, by applying an AC voltage between the strip electrodes 10 (driving electrode) and the strip electrodes 9 and 11 (common ground electrode), strip electrodes 10, 9, 10 and 1 are formed.
A displacement is generated in the space between a plurality of strip electrodes along the circumferential direction between the columnar piezoelectric ceramics 1 and the cylindrical piezoelectric ceramics 1 to excite bending vibration. When this vibrator is rotated around an axis parallel to the central axis of the cylindrical piezoelectric ceramics 1, Coriolis force excites the bending vibration of the drive and the bending vibration in the perpendicular direction. This vibration is caused by the strip electrodes 8 (detection electrode) and 9 (ground electrode), the strip electrode 12 (detection electrode).
And 11 (ground electrode), the distance between the plurality of strip electrodes along the circumferential direction is changed to generate a potential difference between the strip electrodes 8 and 9, 12 and 11. The rotational angular velocity can be measured by measuring the two potential differences generated between the two detected potentials.

【００１１】[0011]

【発明の効果】以上説明したように、本発明によれば、
圧電縦効果を利用することにより、圧電横効果を利用し
たものよりも、電気・機械変換効率に優れた圧電振動ジ
ャイロ用振動子が得られた。As described above, according to the present invention,
By utilizing the piezoelectric longitudinal effect, a vibrator for a piezoelectric vibrating gyroscope, which is superior in electro-mechanical conversion efficiency to the one using the piezoelectric transverse effect, was obtained.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の圧電振動ジャイロ用振動子の電極パタ
ーンを示す説明図で、図１（ａ）は振動子の外観斜視
図、図１（ｂ）は本発明の電極パターンを示す展開図。FIG. 1 is an explanatory view showing an electrode pattern of a vibrator for a piezoelectric vibration gyroscope of the present invention, FIG. 1 (a) is an external perspective view of the vibrator, and FIG. 1 (b) is a development view showing the electrode pattern of the present invention. .

【図２】本発明の圧電振動ジャイロ用振動子を支持固定
した状態の外観斜視図。FIG. 2 is an external perspective view of the piezoelectric vibrating gyroscope of the present invention in a supported and fixed state.

【図３】従来例の圧電振動ジャイロ用振動子の電極パタ
ーンを示す説明図で、図３（ａ）は振動子の外観斜視
図、図３（ｂ）は従来例の電極パターンを示す展開図。3A and 3B are explanatory views showing an electrode pattern of a vibrator for a piezoelectric vibration gyroscope of a conventional example, FIG. 3A is an external perspective view of the vibrator, and FIG. 3B is a developed view showing an electrode pattern of the conventional example. .

【図４】従来例の圧電振動ジャイロ用振動子を支持固定
した状態の外観斜視図。FIG. 4 is an external perspective view showing a state in which a conventional piezoelectric vibrating gyroscope vibrator is supported and fixed.

【符号の説明】[Explanation of symbols]

１ 円柱状圧電セラミックス ２，４，６，９，１１ 帯状電極（共通アース用電
極） ３，１０ 帯状電極（駆動用電極） ５，７，８，１２ 帯状電極（検出用電極） １３ 駆動・検出及び共通アース用リード線 １４ 駆動・検出及び共通アース用リード線取り出し
用の半田点1 Cylindrical Piezoelectric Ceramics 2, 4, 6, 9, 11 Strip Electrode (Common Earth Electrode) 3,10 Strip Electrode (Drive Electrode) 5, 7, 8, 12 Strip Electrode (Detection Electrode) 13 Drive / Detect And lead wire for common ground 14 Soldering point for driving / detection and lead wire for common ground

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 円柱状圧電セラミックスの外周側面に、
該円柱状圧電セラミックスの長さ方向と平行に複数個の
帯状電極を形成した圧電振動ジャイロ用振動子におい
て、駆動、検出及びアース用の電極は、交差指方向が前
記円柱状圧電セラミックスの円周方向と平行な交差指電
極であることを特徴とする圧電振動ジャイロ用振動子。1. The outer peripheral side surface of the cylindrical piezoelectric ceramic,
In a vibrator for a piezoelectric vibrating gyroscope in which a plurality of strip-shaped electrodes are formed in parallel with the length direction of the cylindrical piezoelectric ceramic, electrodes for driving, detecting and grounding have a cross finger direction which is the circumference of the cylindrical piezoelectric ceramic. A vibrator for a piezoelectric vibration gyro, which is an interdigital electrode parallel to the direction.