JPH10175334A - Hammer mechanism part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize an initial bend of a dot-printing hammer and obtain good printing quality at all times without extending a drive cycle, by forming a yoke in the vicinity of a leaf spring among yokes constituting a magnetic circuit so that the yoke can be divided to apply a predetermined amount of bend to the leaf spring. SOLUTION: A printing hammer has a yoke 1 constituting a magnetic circuit, a yoke base 3, front yokes 41, 42, a magnet 2 and a leaf spring 5 with a printing pin 6 set at a leading end part. Magnetism of the magnet 2 is negated when a freeing electromagnetic coil 7 is magnetized, thereby popping the leaf spring 5 and printing via the printing pin 6. At this time, the front yoke 41 is made separable, and an initial bend is adjusted before the front yoke 41 is fitted. The leaf spring 5 can thus be bent large and deformed to a specific amount of initial bend. After the initial bend is adjusted, the front yoke 41 is fitted and a required magnetic circuit is consequently formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reciprocates a hammer bank holding a plurality of spring-charge type dot printing hammers provided side by side in a row direction or a circumferential direction. The present invention relates to a dot printer that prints dot rows in a moving process.

[0002]

2. Description of the Related Art The prior art will be described with reference to FIGS.

A dot printing hammer in the form of a leaf spring is moved to a non-printing position (yoke 1
Side), and a release current of a predetermined pulse width is supplied to the release electromagnetic coil 7 to release the print hammer and perform printing. (Referred to as deflection δ1), a special adjustment jig 8 was attached for adjustment.

[0004] The reason is that, with the front yoke 43 attached, the leaf spring 5 cannot be bent to the deflection required to give the initial deflection δ1 (referred to as the deflection δ2 during adjustment).

[0005] or as an alternative, larger than the conventional gap L ₁ (air gap L ₂ between the front yoke and the plate spring 5) space between the plate spring 5 to the front yoke 44 as shown in FIG. 5, There is a method in which an adjustment allowance that can secure the required deflection amount δ2 at the time of adjustment is provided in advance.

[0006]

However, the above-mentioned conventional hammer has the following problems.

In the case where a dedicated adjusting jig 8 is attached and adjusted to give the initial deflection δ to the leaf spring 5, it is necessary to remove the adjusting jig 8 when the adjustment is completed. further,
Since the original front yoke 43 is attached after the adjustment jig 8 is removed, the state of adjustment of the fulcrum and the base changes when the adjustment is made, so the initial deflection δ1 of the adjusted leaf spring and the length of the leaf spring 5 vary. As a result, the deflection energy of the leaf spring 5 of the printing hammer also changes, and there is a disadvantage that the printing density varies.

Next, as shown in FIG.
In the method in which the deflection adjustment allowance is provided in 4, it is necessary to previously install an adjustment space on the leaf spring 5 side of the front yoke 44. For this reason, the front yoke 44 forming the magnetic circuit has a space (increment = increment) to secure a predetermined magnetic path cross-sectional area (front yoke thickness t).
L ₂ -L ₁₎ only need to increase the thickness on the opposite side of the yoke 1.

Accordingly, in a normal dot line printer, it is necessary to project the tip of the print pin 61 from the front yoke 44 by about 0.2 mm. (Increment = L ₂
−L ₁ ) It is necessary to lengthen. For this reason, the weight of the print head increases, and as a result, there is a drawback that the drive cycle of the print hammer becomes longer, and the longer, the greater the moment applied to the mounting portion of the print pin 61.

An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art, stabilize the initial deflection δ1 of the dot print hammer without lengthening the drive cycle, and always ensure good print quality.

[0011]

In order to achieve the above object, the present invention comprises a leaf spring and a printing pin provided with a predetermined amount of deflection, and a predetermined pitch along a printing line. A plurality of dot printing hammers arranged side by side, magnet (magnet) means for generating a magnetic attraction force for holding the printing hammers at a non-printing position, and a magnetic circuit for flowing magnetic flux through the dot printing hammers. A hammer mechanism having a yoke to be formed, a release electromagnetic coil provided to correspond to each dot print hammer for driving the dot print hammer, and for canceling the magnetic field of the magnet means by supplying a pulse current of a predetermined width. In the part, the yoke in the vicinity of the leaf spring among the yokes forming the magnetic circuit is divided into a front yoke so that a predetermined amount of deflection can be given to the leaf spring. It was a possible structure.

According to the above arrangement, a stable initial deflection can be obtained without reducing the hammer driving cycle.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a printing hammer of the present invention. The printing hammer includes a yoke 1, a yoke base 3, a front yoke A41, a front yoke B42, a magnet 2 for generating magnetism, and a magnetic circuit. It comprises a printing pin 6 for controlling printing, a leaf spring 5 for storing printing energy as deflection of a spring, and a release electromagnetic coil 7 for canceling the magnetism of the magnet 2 and causing the leaf spring 5 to fly to form a dot with the printing pin 6. I'm done.

In the dot printing hammer configured as described above,
The initial deflection adjustment is performed before the front yoke A41 is attached as shown in FIG.

Normally, in order to obtain a specified amount of initial deflection δ1,
It is necessary to bend the leaf spring 5 to the permanent deformation region. Therefore, the amount of deformation for adjustment is a value larger than the initial deflection δ1. This amount is defined as the amount of deflection δ2 during adjustment. In the present invention, since there is no front yoke A41, the leaf spring 5
Can be greatly deformed and deformed so as to have a specified amount of initial deflection δ1.

After the adjustment, a magnetic circuit can be formed by attaching the front yoke A41.

As a result, since it is not necessary to remove the adjusting jig 8 unlike the conventional example, the fluctuation of the initial deflection δ1 is eliminated, so that the printing quality can be stabilized.

In this embodiment, the leaf spring 5 is attached to the yoke base 3.
Has been described, but even if the leaf spring 5 is attached as a module structure sandwiched between the front yoke B422 and the rear plate 45 as shown in FIG. It is clear that a similar effect can be produced if the structure is possible.

[0020]

As described in detail above, according to the present invention,
Since it is possible to adjust the initial deflection of the leaf spring without using an adjustment jig, it is possible to obtain a hammer characteristic without variation, so that stable print quality can always be obtained.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a hammer mechanism according to the present invention.

FIG. 2 is a structural explanatory view of a front yoke part of FIG. 1;

FIG. 3 is a side view of a conventional hammer mechanism.

FIG. 4 is a structural explanatory view of a front yoke part in FIG. 3;

FIG. 5 is a structural explanatory view of a conventional front yoke portion.

FIG. 6 is a side view showing another example of the hammer mechanism of the present invention.

[Explanation of symbols]

1 is a yoke, 2 is a magnet, 3 is a yoke base, 4
1, 411 are front yokes A, 42 and 422 are front yokes B, 43 and 44 are front yokes, 45 is a rear plate, 5 is a leaf spring, 6 and 61 are printing pins, 7 is a release electromagnetic coil, and 8 is an adjustment. Jigs, L ₁ and L ₂ are the air gap between the front yoke and the leaf spring, δ 1 is the initial deflection, δ 2
Indicates the amount of deflection at the time of adjustment.

Claims (1)

[Claims] A plurality of dot print hammers, each of which is composed of a leaf spring and a print pin provided with a predetermined amount of deflection, and arranged at a predetermined pitch along a print line; It has a magnet (magnet) means for generating a magnetic attraction force for holding at a printing position, and a yoke for forming a magnetic circuit for flowing a magnetic flux through the dot printing hammer. A hammer mechanism provided corresponding to the dot printing hammer and having a release electromagnetic coil for canceling a magnetic field of the magnet means by supplying a pulse current of a predetermined width, wherein a leaf spring is formed of a yoke forming the magnetic circuit. A yoke in the vicinity of the hammer mechanism having a split structure so that a predetermined amount of deflection can be given to the leaf spring.