JPH045328Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an impact printing unit, and more particularly to the structure of a head of a printing unit using piezoelectric or electrostrictive ceramics.

Conventionally, the structure of this type of printing unit is as shown in FIG. The coupling member 3 is fixed. The expansion due to strain of the piezoelectric body 2 displaces the first coupling member 3 in the direction of arrow F in the figure. The displacement of the first coupling member 3 is transmitted to one end of the first arm 10 via the second coupling member 4 and to the second arm 1 via the third coupling member 5.
1. Since one end of the first arm 10 is fixed to the upper end portion of the fixing member 1 by the fourth coupling member 6, when it is displaced in the direction of arrow F from the second coupling member 4, the above-mentioned Fourth
It rotates counterclockwise about the coupling member 6 of FIG. On the other hand, the second arm 11 is supported and fixed to the fixing member 1 by the fifth coupling member 7, and rotates clockwise about the support point as a fulcrum.
A pair of connecting members 8 and 9 are fixed adjacent to each other near one end of the printing arm 12, and the other ends of the pair of connecting members are fixed to the upper ends of the first and second arms in the figure, respectively. ing. Therefore, when the connecting member 8 is displaced in the direction of arrow G in the figure and the connecting member 9 is displaced in the direction of arrow H in the figure due to the expansion of the piezoelectric body 2, the printing arm 12 is displaced in the two opposite directions. It rotates clockwise under the force of the couple, and the printing pin 13 implanted at the other end moves in the direction of arrow K in the figure to perform a printing operation. 1st to 5th above
coupling members 3 to 7 and first and second arms 1
0, 11, etc. are enlarging means for enlarging the displacement of the coupling member 3 and transmitting it to the printing arm 12, and there are various modifications in addition to the above-mentioned structure. In the above-described conventional structure, since the pair of connecting members 8 and 9 have a shape having a constant width and a constant thickness, the distribution of stress generated when a printing operation is performed due to deflection displacement is not uniform. The stress distribution between the joint A between the connecting member 9 and the second arm 11 and the joint B between the printing arm 12 is as shown by the dotted line in FIG.
That is, stress is concentrated at the joint A, and rupture occurs from the stress-concentrated location, resulting in a decrease in lifetime reliability, which has a drawback.

The purpose of the present invention is to solve the above-mentioned conventional drawbacks,
The objective is to provide an impact printing unit with high reliability over a long life.

The printing unit of the present invention includes a piezoelectric body whose one end is fixed to a fixing member, an enlarging means for amplifying the displacement of the piezoelectric body and transmitting it to the printing arm, and a means for transmitting the displacement of the enlarging means to one end of the printing arm. a pair of connecting members that generate a couple on the printing arm by transmitting power to two points close to each other; In an impact printing unit equipped with an arm,
The pair of connecting members may have a tapered thickness.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 3 is a perspective view showing an embodiment of the present invention. That is, the pair of connecting members 8 and 9 are tapered in thickness, and are connected from joint part A to joint part B.
Its thickness gradually becomes thinner as it approaches.
Therefore, as shown by the solid line in FIG. 2, the stress on the connecting members 8 and 9 is uniform in the length direction, making it difficult for them to break. The rest is the same as the conventional example described above, and the same reference numerals indicate the same elements.

As described above, in the present invention, the thickness of the connecting member that connects the printing arm and the expansion means that magnifies the displacement of the piezoelectric body and transmits it to the printing arm is tapered so that it becomes thinner at the tip. Because it was formed into
The stress of the connecting member becomes uniform over the length direction, which has the effect of making it difficult to break. In addition, since there is no change in width, the printing arm and the connecting member can be used as they are in the past, with the same width, without using a special printing arm, and there is no need to change the manufacturing process. effective.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a conventional impact printing unit, FIG. 2 is a view showing stress distribution of a connecting member, and FIG. 3 is a perspective view showing an embodiment of the present invention. In the figure, 1... fixed member, 2... piezoelectric body,
3...first coupling member, 4...second coupling member,
5... Third coupling member, 6... Fourth coupling member,
7...Fifth connecting member, 8...Connecting member, 9...
Connection member, 10...first arm, 11...second
arm, 12...arm for printing, 13...pin for printing.

Claims (1)

[Scope of Claim for Utility Model Registration] A piezoelectric body whose one end is fixed to a fixing member, an enlarging means for amplifying the displacement of the piezoelectric body and transmitting it to the printing arm, and a displacement of the enlarging means for transmitting the displacement of the piezoelectric body to the printing arm. a pair of connecting members that transmit power to two adjacent points on one end to generate a couple on the printing arm; and printing in which the pair of connecting members are connected to one end and a printing pin is implanted in the other end. 1. An impact printing unit comprising: an arm; and an impact printing unit, characterized in that the pair of connecting members has a tapered thickness.