JPH0326554A - Printing hammer mechanism - Google Patents

Abstract

PURPOSE:To obtain a printer small in size, light in weight, enhanced in speed, and provided with profitability and good efficiency by newly using an electromechanical energy conversion mechanism made of a piezoelectric element for a printing hammer in place of a conventional electromagnetic printing hammer mechanism. CONSTITUTION:A printing hammer 1 consists of a printing wire 2 fixed on the upper end (free end) thereof and a buckling spring 4, which is formed with an approximately U-shaped groove extending from the upper end to the lower end at the center part of the printing hammer 1 and engaged with a frame 3 at the lower end thereof so as to be curved oppositely to the printing wire 2. One end of a piezoelectric element 5 is fixed to the printing hammer 1 through a plate 6, and the other end thereof is fixed to the frame 3 having such a sufficient rigidity that the frame 3 can be assumed to be a rigid body. With the application of a voltage to the piezoelectric element 5, the piezoelectric element 5 rapidly expands to move the lower end of the printing hammer 1 in the direction of an arrow A. After it is moved by some distance, a snap action is generated by the action of the buckling spring 4, and the printing hammer 1 rapidly flings in the direction of an arrow B to conduct printing with a printing wire 2.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a printing hammer 8 of a dot impact printer that prints characters or figures in a dot matrix.
Regarding 1 ellipse.

[Conventional technology]

Many electromagnets and permanent magnets have been used in the stamp hammer mechanism of conventional dot impact printers. This type of electromagnetic type is extremely inefficient due to Joule heat generated in the coil, eddy currents in the yoke and armature, hysteresis loss, etc., and most of the input energy is dissipated as heat.

[Problem to be solved by the invention]

Therefore, the drive circuit becomes unnecessarily large-scale and the power supply becomes large, leading to an increase in the price of the entire device. Furthermore, since the electromagnetic type is mainly composed of iron and copper wire, the printing hammer machine is heavy, which hinders printers from becoming faster, smaller, lighter, and cheaper.

[Means to solve the problem]

The present invention provides a small, lightweight, high-speed, economical, and efficient printer by newly adopting an electromechanical energy conversion mechanism using a piezo element in the printing hammer instead of the conventional electromagnetic printing hammer. do. The present invention utilizes the deformation of the piezo element due to electrostatic polarization, expands the amount of minute deformation of the piezo element by a displacement magnification mechanism using a snap action mechanism, and integrates the piezo element with the displacement output of the expanded snap action mechanism. This is a printing hammer machine that operates the printing hammer to obtain the displacement necessary for printing. Therefore, it is possible to provide an extremely efficient high-speed printing hammer mechanism that generates less heat than an electromagnetic printing hammer mechanism. In addition, since it uses a displacement magnification mechanism using a snap action mechanism, a large magnification ratio can be easily obtained. [Example] Next, the present invention will be described with reference to drawings showing examples of the present invention.

In FIG. 1 showing a first embodiment of the present invention, a printing hammer 1 has a printing wire 2 fixed at its upper end (free end) and a groove formed in a substantially U shape from the upper end to the lower end at the center of the printing hammer 1. The piezo element 5 is formed by a buckling spring 4 whose lower end is engaged with the frame 3 so as to curve in the opposite direction to the printing wire 2.The piezo element 5 has one end connected to the printing hammer 11 through a plate 6. In addition, the other end is fixed to a frame 3 having sufficient rigidity to be considered as a rigid body.

Now, when a voltage is applied to the piezo element 5, the piezo element 5 expands rapidly and begins to move the lower end of the printing hammer 1 in the direction of arrow A in the figure, and when it moves to a certain extent, a snap action occurs due to the action of the buckling spring 4. The printing hammer 1 suddenly pops out in the direction of arrow B, and printing is performed by the printing wire 2.

Referring now to FIG. 2, a second embodiment of the present invention shows a print hammer mechanism that operates using the contraction of a piezo element.

A piezo element has high responsiveness, an extremely simple structure that does not require a coil, a yoke, or an armature, and has highly efficient electromechanical performance. However, on the other hand, it has a major drawback in that the displacement output obtained is small, and it requires some kind of expansion mechanism. With conventional means, the mechanism is not only extremely complicated and expensive, but also significantly reduces the advantages of the piezo element. In the present invention, by utilizing a snap action as an enlarging mechanism, a very simple, horizontal, reliable, and high-speed printing hammer mechanism can be realized.

〔Effect of the invention〕

As explained above, the present invention achieves high efficiency by snap action of the printing hammer by the expansion and contraction of the piezo element. This provides a high-speed, low-cost printing hammer mechanism. The printing hammer mechanism according to the present invention can be applied to serial printers, line printers, and X-Y blotters.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention, and FIG. 2 is a perspective view showing a second embodiment. 1, 7... Printing hammer, 2.8... Printing wire, 3
, 9... Frame, 4, 10... Buckling spring, 5.1
1... Piezo element, 6, 12... Plate. No.
7 mouths

Claims (1)

[Claims] A frame which is a structure of a printing hammer mechanism, a piezo element having both ends fixed to the frame and a printing hammer having a snap action mechanism, and a printing mark attached to the frame so as to perform a snap action when the piezo element expands or contracts. A printing hammer mechanism characterized by having a hammer.