| 摘要 |
<p>A piezoelectric actuator(6) is disclosed, wherein a superposing pulse is generated just after a command pulse falls to thereby reduce oscillations of displacement in piezoelectric elements(7). In the piezoelectric actuator(6), an exciting pulse having a preselected pulse width is applied across terminals of the piezoelectric elements(7) to cause strains in dimension for the piezoelectric elements(7). A pulse is superposed such that it is superposed at a timing a at which the exciting pulse is turned on, and then the exciting pulse is once turned off for a minute length of time, or an interval between b and b', and turned on again at c. The pulse to be superposed is supplied with a timing less than one-fourth a period of an oscillation of the piezoelectric elements(7). The piezoelectric actuator(6) is effective to prevent the resonance phenomenon and preferably employed for the fuel-injection apparatus. <IMAGE></p> |
