JPH058135Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a printing element, and particularly to a printing element that performs dot printing using a piezoelectric element as a driving source.

[Conventional technology]

Conventionally, in order to reduce the size and power consumption of dot printing heads, a pair of levers was used to magnify the dimensional distortion caused by the electrostrictive longitudinal effect of the piezoelectric element, and the couple force generated in this pair of levers was applied to the dot printing head. A printing element has been proposed in which a signal is transmitted to another lever to which a wire is attached, causing the wire to print dots. In this printing element, one end of the printing wire is attached and welded to a mounting hole or groove provided in the lever, and the other end is guided to the printing position via a wire guide.

[Problem that the invention attempts to solve]

In the conventional printing element described above, during printing, the lever to which the wire is attached rotates, but the wire itself moves linearly at the location where it is restrained by the hole in the wire guide. As a result, there is a problem in that the base of the wire attached to the lever is bent and deformed, and a fairly large bending stress is concentrated and acts on the wire, making it easy for the wire to break.

An object of the present invention is to provide a printing element that solves the above-mentioned problems and prevents wire breakage.

[Means for solving problems]

The printing element of the present invention magnifies the dimensional distortion generated in the piezoelectric element during printing driving by a pair of first and second levers, transmits the force as a couple, and transmits the couple to the third lever to which a printing wire is attached. In the printing element that performs dot printing by transmitting the information to the third lever, the wire is attached to the third lever, and the dot is placed over the wire and one end is inserted into the recess provided in the third lever. A reinforcing portion is provided, which is made of a coil spring inserted and fixed in parallel to the direction of printing, and a resin material that covers and holds the coil spring over substantially its entire length.

〔Example〕

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

FIGS. 1a and 1b are a front view and a partially enlarged front view, respectively, showing an embodiment of the present invention. One end of the piezoelectric element 2, which is a drive source, is fixed to the inner bottom of the U-shaped base 1 (a part of the piezoelectric element 2 is omitted from the illustration), and the piezoelectric element 2 is moved by an electrostrictive longitudinal effect in response to a printing drive signal. Dimensional strain generated at the other end in the direction indicated by arrow A is transmitted to a pair of levers 3 and 4, which are connected to base 1 and piezoelectric body 2, respectively. The levers 3 and 4 are displaced at their respective tips in opposite directions as shown by arrows B and C, magnifying the dimensional strain given by the piezoelectric body 2. This displacement is transmitted to the lever 7 through a plate-shaped hinge that has one end fixed to the levers 3 and 4 and the other end fixed to the lever 7, and provides a couple. In response to this, the lever 7 performs a rotational movement in the direction shown by arrow D, and applies an impact force to the wire 8, one end of which is attached to the lever 7, to print dots. The wire 8 is passed through guide holes of wire guides 13 and 14 and guided to the printing position. The root part of the wire 8 is attached to the hole or groove for attachment provided in the lever 7 while penetrating the hollow part of the coil spring 12 as shown in FIG.
After welding and fixing with welding material 11, welding material 10
is applied and hardened to hold the coil spring 12 on the surface of the lever 7.

During printing, as in the conventional case, the lever 7 rotates as shown by arrow D, and the portion of the wire 8 restrained by the wire guides 13 and 14 moves linearly, so that the distance between the wire guide 13 and the base is In some parts, the wire 8 is bent and deformed. However, in this embodiment, a reinforcing part made of a coil spring 12 and a resin material 10 is provided near the base of the wire 8, and the bending stress generated due to deflection deformation is dispersed to the reinforcing part. This prevents bending stress from concentrating at the base of the lever 7. As a result, the incidence of breakage of the wire 8 during printing can be reduced. An overload test was conducted in which wire breakage occurred in 90% of the samples using a conventional printing element in which the wire 8 was simply attached and welded to the lever 7, and was conducted on samples in which the base of the wire 8 was simply reinforced with a coil spring. In the ivy example, the number of samples is 70.
In the case of a sample in which only the base of the wire 8 was reinforced with a resin material, wire breakage occurred in 20% of the cases. In an example in which an overload test under the same conditions was performed on the samples of this example, wire breakage occurred in less than 1% of the samples, and the synergistic effect of reinforcement by the coil spring 12 and the resin material 10 is remarkable.

FIG. 2 is a partially enlarged front view showing another embodiment of the present invention. In this embodiment, the tip of the lever 7 is provided with a protruding wire attachment point, and the base of the wire 8 is attached to the hollow part of the coil spring 12, as in the embodiment shown in FIG. 1b. In the penetrating state, it is welded with a welding material 11 and fixed in a mounting hole or groove, and then a resin material 10 is applied and hardened.

In this embodiment as well, the bending stress that is applied due to the bending of the wire 8 during printing is caused by the coil spring 12.
This is dispersed and absorbed by the reinforcing portion made of the resin material 10, thereby preventing bending stress from concentrating on the root of the wire 8 and causing breakage.

[Effect of idea]

As explained above, the present invention has the effect of realizing a printing element that prevents wire breakage during printing.

[Brief explanation of the drawing]

1A and 1B are a front view and a partially enlarged front view showing an embodiment of the present invention, respectively, and FIG. 2 is a partially enlarged front view showing an embodiment of the present invention. 1... Base, 2... Piezoelectric element, 3, 4, 7...
...Lever, 5, 6...Hinge, 8...Wire, 1
0... Resin material, 11... Welded part, 12... Coil spring, 13, 14... Wire guide.

Claims (1)

[Claims for Utility Model Registration] The first category is the dimensional distortion generated by the piezoelectric element during printing drive.
The second pair of levers magnifies the force and transmits it as a couple, and the couple is transmitted to the third lever to which the printing wire is attached.
In the printing element that performs dot printing by transmitting the information to the third lever, the wire is attached to the third lever, and the dot is placed over the wire and one end is inserted into the recess provided in the third lever. A printing element characterized in that it is provided with a reinforcing part consisting of a coil spring inserted and fixed in parallel to the direction of printing and a resin material covering and holding the coil spring over almost its entire length.