JP3964942B2 - Hammer mechanism - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a dot line printer that reciprocates a hammer bank holding a plurality of spring-charged dot printing hammers arranged side by side in the row direction and prints the dot rows in the process of this reciprocation. This relates to the hammer mechanism.
[0002]
[Prior art]
As shown in FIGS. 3 and 4, the leaf spring 5 of the printing hammer is held at a non-printing position by, for example, the magnetic attraction force of the magnet 2, and a release current having a predetermined pulse width is supplied to the release electromagnetic coil 7 (hereinafter simply referred to as a coil). In the spring charge type printing hammer that performs printing by releasing the printing hammer by supplying the leaf spring 5, the leaf spring 5 is fixed to the yoke base via the rear plate.
[0003]
[Problems to be solved by the invention]
However, the conventional hammer mechanism described above has the following problems.
[0004]
When the number of strikes per unit time increases as the printing speed increases, it is generally necessary to increase the spring constant of the leaf spring in order to increase the printing hammer drive cycle.
[0005]
As the spring constant increases, the change in natural frequency due to the change in spring length also increases. If the change in the natural frequency becomes large, the hammer driving cycle also varies, and as a result, there is a problem in that the timing at which the hammer is struck differs, and the print quality is ultimately lowered.
[0006]
The object of the present invention is to eliminate the drawbacks of the prior art described above, and to stabilize the printing hammer's spring constant even if the printing hammer's spring constant increases as the speed increases. It is to prevent the decrease of.
[0007]
In order to achieve the above-described object, the present invention is characterized in that a groove is provided in the vicinity of a leaf spring fulcrum of the rear plate provided on the rear fixed end side of the printing hammer and on the tip side of the fastening member. is there.
[0008]
[Action]
According to the above configuration, the fulcrum of the printing hammer spring is always kept constant even if the printing hammer spring constant increases as the printing speed is increased. Can be prevented.
[0009]
【Example】
Hereinafter, the present invention will be described with reference to the accompanying drawings.
[0010]
FIG. 1 shows a side view of the hammer mechanism of the present invention. The hammer mechanism unit stores the yoke 1, the yoke base 3, the front yoke 4, and the rear plate 9 constituting the magnetic circuit, the magnet 2 that generates magnetism, the printing pin 6 that controls printing, and the printing energy as deflection of the spring. Plate spring 5, adjustment plate 11 and adjustment screw 12 for adjusting the amount of deflection, and coil 7 for canceling the magnetism of magnet 2 and flying plate spring 5 to form dots by printing pins 6. ing.
[0011]
Further, an ink ribbon 8 that controls printing, a platen 10 for transferring the ink of the ink ribbon 8 to the printing paper 14, and a ribbon separator 13 for preventing the ink of the ink ribbon 8 from sticking to the printing paper 14 are provided.
[0012]
In the hammer mechanism portion as described above, the rear plate 9 provided with the groove A in the upper portion is fixed as shown in FIG.
[0013]
Here, the side where the groove A is provided is the contact surface side of the leaf spring 5 and is fixed.
[0014]
As a result, the leaf spring 5 does not hit the entire rear plate 9, and the contact area between the two can be reduced. As a result, the amount of warpage of the leaf spring 5 is reduced, and the leaf spring 5 can be suppressed only at a portion close to the fulcrum. Therefore, even if the spring constant of the printing hammer increases, the fulcrum of the printing hammer spring can be kept constant.
[0015]
That is, the fulcrum of the leaf spring 5 of the printing hammer can stabilize the spring length by making the contact portion with the rear plate 9 near the upper fulcrum, and the spring constant can be stabilized.
[0016]
【The invention's effect】
As described above, according to the present invention, even if the spring constant of the printing hammer increases, the fixed end of the printing hammer is always stabilized at the upper end surface, and as a result, the spring length of the printing hammer is always stabilized. As a result, variations in the spring constant of the printing hammer can be suppressed, and deterioration in printing quality can be prevented.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of a hammer mechanism used in a dot line printer of the present invention.
FIG. 2 is a side view of the main part of FIG.
FIG. 3 is a side view showing a conventional example.
4 is a side view of the main part of FIG. 3;
[Explanation of symbols]
1 is a yoke, 2 is a magnet, 3 is a yoke base, 4 is a front yoke, 5 is a leaf spring, 6 is a printing pin, 7 is a coil, 8 is an ink ribbon, 9/91 is a rear plate, 10 is a platen, 11 is An adjustment plate, 12 is an adjustment screw, 13 is a ribbon separator, 14 is printing paper, and A is a groove.

Claims (1)

A plurality of dot printing hammers configured by a leaf spring and a printing pin and arranged at a predetermined pitch along a printing line; and magnet means for generating a magnetic attractive force to hold the printing hammer in a non-printing position; The rear plate provided on the rear fixed end side of the printing hammer for fixing the printing hammer, the adjustment plate and adjustment screw for adjusting the spring constant of the plate spring, and the plate spring, rear plate and adjustment plate are fastened. A fastening member, a release electromagnetic coil that is provided corresponding to each printing hammer to drive the printing hammer, is supplied with a pulse current of a predetermined width and cancels the magnetic field of the magnet means, and holds the printing hammer. A hammer bank that reciprocates along the row direction, and a shuttle mechanism for reciprocating the hammer bank, the hammer bank Grooves of the in the course of reciprocating a dot line printer for printing by driving the print hammer, a leaf spring supporting point near the leaf spring contact surface side of the rear plate and the front end side of the fastening member A dot line printer characterized by comprising:

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