JPH08192521A - Dot line printer - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a dot line printer that always performs high-quality printing even in high-speed printing. [Composition] By providing a buffer section fixed via a spring or the like at or near the fastening section between the hammer bank and the shuttle mechanism section, even if the temperature of the hammer bank rises and the yoke base thermally expands, the buffer section The structure is such that the expansion can be absorbed by the part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reciprocates a hammer bank, which holds a plurality of spring-charged dot printing hammers arranged side by side in the row direction, in the row direction. The present invention relates to a dot line printer that prints lines.

[0002]

2. Description of the Related Art As shown in FIG. 1, a hammer bank of a spring charge type printing hammer holds a leaf spring type printing hammer at a non-printing position by a magnetic attraction force of a magnet 2, for example, and a release electromagnetic coil 7 (hereinafter simply referred to as a release electromagnetic coil 7). By supplying a release current having a predetermined pulse width to a coil, the print hammer is released and printed. In this hammer bank, for example, as shown in FIG.
Both ends were fixed by a shuttle mechanism 11 and bolts 12 that control the reciprocating movement of the hammer bank.

[0003]

However, the above-mentioned conventional dot line printer has the following problems.

As the printing speed increases, the printing hammer driving cycle increases, and the number of hits per unit time increases,
The excitation time of the coil 7 also increases. When the excitation time of the coil 7 increases, the heat generated from the coil 7 also increases, and as a result, the temperature of the entire hammer bank rises. On the other hand, the temperature of the member of the shuttle mechanism unit 11 to which the hammer bank is fixed hardly rises. Therefore, a thermal stress is generated between the two members due to a temperature difference, and the member behaves like a bimetal, and is deformed as shown in FIG.

In FIG. 6, when the hammer bank is deformed in the direction of the arrow, the gap between the print pin 6 and the platen 10 becomes smaller, the running resistance of the ink ribbon 8 increases, and the movement of the ink ribbon 8 becomes worse. Ink ribbon 8
However, there is a problem in that the printing quality is deteriorated due to a problem that ink does not remain on the printing paper because the same place is hit.

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to always secure the gap between the printing pin 6 and the platen 10 even if the driving cycle of the printing hammer rises and the temperature of the hammer bank rises, thereby ensuring the printing quality. Is to prevent the decrease.

[0007]

SUMMARY OF THE INVENTION The present invention comprises a leaf spring and a printing pin, a plurality of dot printing hammers arranged side by side at a predetermined pitch along a printing line and a non-printing position of the printing hammer. Magnet means for generating a magnetic attraction force to be held on the magnetic head, and a release electromagnetic coil provided corresponding to each print hammer for driving the print hammer and canceling the magnetic field of the magnet means by supplying a pulse current of a predetermined width. And a hammer bank that holds the printing hammer and reciprocates along the row direction, and a shuttle mechanism for reciprocating the hammer bank. Each of the printing hammers is moved in the course of the reciprocating movement of the hammer bank. In a dot line printer that drives and prints, a buffer section fixed via a spring or the like is provided at or near the fastening section between the hammer bank and the shuttle mechanism section. It is achieved by the.

[0008]

According to the above construction, even if the driving cycle of the printing hammer is increased by increasing the printing speed and the temperature of the hammer bank is increased, the buffer portion is provided to release the thermal stress,
Since the gap between the print pin and the platen can be always secured, it is possible to prevent deterioration of print quality.

[0009]

The present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of a printing hammer according to the present invention. The printing hammer comprises a yoke 1 constituting a magnetic circuit, a yoke base 3, a front yoke 4, a magnet 2 for generating magnetism, and a printing pin for controlling printing. 6, a leaf spring 5 for storing printing energy as a spring deflection, a coil 7 for canceling the magnetism of the magnet 2 and causing the leaf spring 5 to fly to form dots by the printing pin 6, an ink ribbon 8 for printing, an ink ribbon It is composed of a platen 10 for transferring the ink of No. 8 to the printing paper 14 and a shuttle mechanism 11 for moving the hammer bank in the digit direction.

In the hammer bank constructed as above, FIG.
One end of the yoke base 3 is fixed via a spring 13 as shown in FIG. Here, it goes without saying that the force F of the spring is equal to or greater than the force with which the hammer bank overcomes the print reaction force (the force that does not move at the maximum DUTY printing), and is a force capable of eliminating thermal expansion.

As a result, the driving cycle of the printing pin 6 becomes faster, and even if the hammer bank becomes hot and expands, the expansion can be released by the spring 13 in the direction of the arrow.

In the present invention, it is not preferable to provide the buffer portions at both ends of the yoke base 3 because the hammer bank itself is displaced and the printing position accuracy is lowered.

FIG. 4 shows another embodiment of the present invention.

In FIG. 4, both ends of the yoke base 3 are fixed by bolts 22. However, in the shuttle mechanism portion 11, by fixing one of the base portions for fixing the yoke base 3 via the spring 13, it is possible to obtain the same effect as that of the above embodiment.

[0016]

As described in detail above, according to the present invention,
Even if the hammer bank gets hot, the spring part between the shuttle mechanism part and the hammer bank can escape the thermal expansion, so it will not deform in the gap direction, and a dot line printer with stable and high print quality will always be provided. Will be able to provide.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a printing hammer used in a dot line printer of the present invention.

FIG. 2 is a front view of the main part of FIG.

FIG. 3 is a top view during printing of FIG.

FIG. 4 is a front view showing another embodiment of the present invention.

FIG. 5 is a front view showing a conventional example.

FIG. 6 is a top view during printing of FIG.

[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 print pin, 7 is a coil, 8 is an ink ribbon, 9 is a ribbon separator, 10 is a platen, 11 is a shuttle mechanism. Parts, 12, 22 are bolts, 13 is a spring, 14 is a printing paper, and 15 is a shaft.

Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location B41J 9/50 B41J 7/92 Z 9/38 Z (72) Inventor Yoshikane Matsumoto 1060 Takeda Hitachi-city, Ibaraki Hitachi Koki Co., Ltd. (72) Inventor Yasuki Motoki 1060 Takeda, Hitachinaka City, Ibaraki Prefecture Hitachi Koki Co., Ltd. (72) Inventor Hironori Kobayashi 1060 Takeda, Hitachinaka City, Ibaraki Hitachi Koki Co., Ltd. (72 ) Inventor Satoru Tobita 1060 Takeda, Hitachinaka City, Ibaraki Prefecture Inside Hitachi Koki Co., Ltd.

Claims (1)

[Claims] 1. A plurality of dot printing hammers, which are composed of leaf springs and printing pins and are arranged side by side at a predetermined pitch along a printing line, and a magnetic attraction force for holding the printing hammers in a non-printing position. Magnet means for driving, a release electromagnetic coil provided corresponding to each print hammer for driving the print hammer, for canceling the magnetic field of the magnet means by supplying a pulse current of a predetermined width, and holding the print hammer. A dot line printer that includes a hammer bank that reciprocates along a row direction and a shuttle mechanism that reciprocates the hammer bank, and drives each of the printing hammers to perform printing in the course of the reciprocating movement of the hammer bank. The dot line is characterized in that a buffer portion fixed via a spring or the like is provided at or near the fastening portion between the hammer bank and the shuttle mechanism portion. Printer.