| 摘要 |
PURPOSE:To enable continuous printing at high speed through restriction of heat generation of an electromagnetic coil, by separating a hammer attracted to a core by the effect of demagnetization of the electromagnetic coil and the extending action of an extensible operating stand having a piezoelectric element. CONSTITUTION:When an electromagnetic coil 3 is supplied power to demagnetize the magnetic field by a permanent magnet, and at the same time a piezoelectric element 7 is energized, the piezoelectric element 7 is elongated to press up a hammer spring 1b. Accordingly, the neutral point (c) of the hammer spring 1b is changed from S0 to S1 and also the spring constant thereof is changed. The spring characteristic of the leaf spring 1b is resulted in H'. The hammer pin 1a is thus made to fly at high speeds by the printing energy of A part, thereby carrying out printing. When the excitation of the electromagnetic coil 3 and the electric field of the piezoelectric element 7 are cut, the spring neutral point (c) of the leaf spring is returned to S0, with the spring constant being returned to the original, namely, to the condition shown by H, so that the hammer 1 is attracted to the core by the suction energy in B part and returned to be in the waiting condition. Thus, in comparison with prior arts, the current of the electromagnetic coil can be lowered while the printing energy is increased, and therefore it becomes possible to continuously print with less generation of heat. |
