【特許請求の範囲】
【請求項１】 圧電体に分極方向の電圧を印加する第１の駆動回路と、上記圧電体に分極方向と逆方向に電圧を印加する第２の駆動回路と、上記第１の駆動回路と上記第２の駆動回路とを交互に駆動して上記圧電体の伸張速度と縮小速度とに差を生じさせ伸縮運動させる駆動制御回路とからなるインパクト形圧電アクチュエータの駆動装置において、上記第１，第２の駆動回路の少なくとも一方の駆動回路を抵抗体のみからなる電流制限回路で構成したことを特徴とするインパクト形圧電アクチュエータの駆動装置。
【請求項２】 請求項１記載のインパクト形圧電アクチュエータの駆動装置において、上記第１の駆動回路は上記圧電体の分極方向と逆方向に蓄積された電荷を放電し、分極方向に充電する第１の充放電回路からなり、上記第２の駆動回路は上記圧電体の分極方向に蓄積された電荷を放電し、分極方向と逆の方向に充電する第２の充放電回路からなることを特徴とするインパクト形圧電アクチュエータの駆動装置。
【請求項３】 スイッチ回路からなる第１〜第４回路を直列接続するとともに、スイッチ回路と抵抗体との直列回路からなる第５回路と第６回路とをそれぞれ第１回路と第４回路とに並列接続し、上記第２回路と第３回路との接続点と上記第１回路と第４回路との接続点との間に電源が接続され、かつ、上記第１回路と第２回路との接続点と上記第３回路と第４回路との接続点との間に圧電体が接続されてなるブリッジ回路からなり、上記第１の駆動回路は上記電源、上記第２回路及び上記第４回路又は上記電源、上記第２回路及び上記第６回路により構成され、上記第２の駆動回路は上記電源、上記第３回路及び上記第５回路又は上記電源、上記第３回路及び上記第１回路により構成されていることを特徴とする請求項２記載のインパクト形圧電アクチュエータの駆動装置。
【請求項４】 上記スイッチ回路は電界効果型トランジスタで構成されていることを特徴とする請求項３記載のインパクト形圧電アクチュエータの駆動装置。
[Claims]
1. A first drive circuit for applying a voltage in a polarization direction to a piezoelectric body, a second drive circuit for applying a voltage to the piezoelectric body in a direction opposite to the polarization direction, and the first drive circuit. In the drive device of the impact type piezoelectric actuator including the drive control circuit that alternately drives the second drive circuit to cause a difference between the expansion speed and the reduction speed of the piezoelectric body to cause expansion and contraction movements, the first A drive device for an impact type piezoelectric actuator, characterized in that at least one drive circuit of the second drive circuit is composed of a current limiting circuit composed of only a resistor.
2. In the drive device for the impact type piezoelectric actuator according to claim 1, the first drive circuit discharges the electric charge accumulated in the direction opposite to the polarization direction of the piezoelectric body and charges it in the polarization direction. The second drive circuit comprises one charge / discharge circuit, and the second drive circuit comprises a second charge / discharge circuit that discharges the electric charge accumulated in the polarization direction of the piezoelectric body and charges the charge in the direction opposite to the polarization direction. Impact type piezoelectric actuator drive device.
3. The first to fourth circuits composed of a switch circuit are connected in series, and the fifth circuit and the sixth circuit composed of a series circuit of a switch circuit and a resistor are connected to the first circuit and the fourth circuit, respectively. A power supply is connected between the connection point between the second circuit and the third circuit and the connection point between the first circuit and the fourth circuit, and the first circuit and the second circuit are connected to each other. It is composed of a bridge circuit in which a piezoelectric body is connected between the connection point of the above and the connection point of the third circuit and the fourth circuit, and the first drive circuit is the power supply, the second circuit and the fourth circuit. It is composed of a circuit or the power supply, the second circuit and the sixth circuit, and the second drive circuit is the power supply, the third circuit and the fifth circuit or the power supply, the third circuit and the first circuit. The drive device for an impact type piezoelectric actuator according to claim 2, wherein the drive device is configured by the above.
4. The drive device for an impact type piezoelectric actuator according to claim 3, wherein the switch circuit is composed of a field effect transistor.
【００１６】
【課題を解決するための手段】本発明は、圧電体に分極方向の電圧を印加する第１の駆動回路と、上記圧電体に分極方向と逆方向に電圧を印加する第２の駆動回路と、上記第１の駆動回路と上記第２の駆動回路とを交互に駆動して上記圧電体の伸張速度と縮小速度とに差を生じさせ伸縮運動させる駆動制御回路とからなるインパクト形圧電アクチュエータの駆動装置において、上記第１，第２の駆動回路の少なくとも一方の駆動回路を抵抗体のみからなる電流制限回路で構成したものである（請求項１）。
0016.
According to the present invention, a first drive circuit for applying a voltage in a polarization direction to a piezoelectric body and a second drive circuit for applying a voltage to the piezoelectric body in a direction opposite to the polarization direction. An impact type piezoelectric actuator including a drive control circuit that alternately drives the first drive circuit and the second drive circuit to cause a difference between the expansion speed and the reduction speed of the piezoelectric body to cause expansion and contraction movements. In the drive device, at least one of the first and second drive circuits is composed of a current limiting circuit composed of only a resistor (claim 1).
インパクト形圧電アクチュエータは、圧電体と、この圧電体の一方端に固着された棒状の駆動部材と、この駆動部材に所定の摩擦力で軸方向に移動可能な被駆動部材と、圧電体の駆動装置とからなり、圧電体に分極方向の電圧と分極方向と逆方向の電圧とを交互に印加して当該圧電体を振動させ、これにより駆動部材を軸方向に往復動させて被駆動部材を当該駆動部材に対して相対的に一方向に移動させるようになっている。この場合、圧電体を分極方向に充電する速度と分極方向と逆方向に充電する速度とを異ならせることで当該圧電体の伸長速度と縮小速度と（すなわち、駆動部材の往動速度と復動速度と）に差を生じさせ、これにより往動時の摩擦力と復動時の摩擦力とが相違して被駆動部材は駆動部材に対して相対的に一方向に移動する。
The impact type piezoelectric actuator is a drive of a piezoelectric body, a rod-shaped drive member fixed to one end of the piezoelectric body, a driven member that can move in the axial direction with a predetermined frictional force on the drive member, and a piezoelectric body. It consists of a device, and a voltage in the polarization direction and a voltage in the direction opposite to the polarization direction are alternately applied to the piezoelectric body to vibrate the piezoelectric body, whereby the driving member is reciprocated in the axial direction to move the driven member. It is designed to move in one direction relative to the driving member. In this case, by making the speed at which the piezoelectric body is charged in the polarization direction different from the speed at which the piezoelectric body is charged in the direction opposite to the polarization direction, the extension speed and the reduction speed of the piezoelectric body (that is, the forward speed and the return speed of the driving member) There is a difference in speed), which causes the frictional force during forward movement and the frictional force during recovery to be different, and the driven member moves in one direction relative to the driving member.