JPS634962A - Wire guide - Google Patents

Abstract

PURPOSE:To alleviate the load on a wire drive source, reduce abrasion of wires and a wire guide and contrive a longer useful life, by forming in a curved surface shape a lamellar body formed of a ceramio and provided with a plurality of guide holes. CONSTITUTION:A wire guide 1 is a lamellar body formed of a ceramic, is curved as a whole in the longitudinal direction, and is provided With guide holes 1a perpendicularly to the curved surface, so that the guide holes 1a are inclined relative to each other. When the wire guide 1 is fitted to a printing head H' with the recessed side of the curve on the side of tips of wires, the wires 2 slantingly enter the guide holes 1a, so tht the directions of the wires 2 substantially coincide with the directions of the corresponding guide holes 1a, resulting in favorable sliding characteristics of the wires 2 and the guide holes 1a and less abrasion thereof. In addition, since the shape of the wire guide 1 is close to the shape of a platen 5, differences in impact force between the wires 2 and deviations of timing are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wire guide for guiding a wire in a dot printer.

[Conventional technology]

The structure of the printing part of a dot printer consists of a wire guide 1 provided at the tip of the print head H, as shown in FIG. 4(a).
An ink ribbon 3 is sandwiched between the ink ribbon 3 and the paper 4 is supported by a platen 5, and the wire 2 is caused to protrude toward the ink ribbon 3 by a drive source (not shown). Pass the tip of the wire 2 through the ink ribbon 3 to the paper 4.
When you hit it, dots were printed. In addition, about two intermediate guides 6 are provided in the print head 11, and the wires 2 are converged by passing the wires 2 through the intermediate guides 6. In the vicinity of the wire guide 11 at the tip, each wire 2 is They were almost parallel.

As shown in FIGS. 3(a) and 3(b), this wire guide 11 was a substantially rectangular flat plate made of ceramic and had mutually parallel guide holes 11a.

[Problems with conventional technology]

The printed dot ■ shown in FIG. 4(a) above has a length of 45 mm.
It used to be about v++ for a long time, but in recent years printer devices have become smaller,
Due to weight reduction, the length is 251 mm as shown in Figure 4(b).
Print heads as short as III11 began to be used.

However, since the print head I' has a short length to the tip, the wire 2 cannot be completely converged, and the wire guide 11
The wire 2 was inserted diagonally. That is, as shown in FIG. 4(c), which is an enlarged cross-sectional view of the vicinity of the guide hole 11a, since the wire 2 enters the horizontally formed guide hole 11a obliquely, when the wire 2 protrudes, the guide lla
The end of the wire 2 rubs against each other, causing severe wear on each other.
The sliding properties were also poor. Severe wear on the wire 2 and wire guide 11 shortens the lifespan of each other, and poor sliding characteristics weaken the impact force of the wire 2, resulting in thinner prints and excessive wear on the drive source of the wire 2. There were problems such as heavy load.

Furthermore, as shown in FIGS. 4(a) and 4(b), the conventional wire guide 11 is a flat plate-like body, and the tip of each wire 2 is also arranged in a flat shape. Therefore, it has a cylindrical shape, and the paper 4 is also arranged along the platen 5 in the shape of a cylindrical side surface. Therefore, the peripheral wire 2
The distance to the paper 4 is larger than the wire 2 in the center,
Since the impact force is different, the density of the dots is different, and there is a lag in the timing of striking the dots, there are disadvantages such as the position of the dots being shifted when printing at higher speeds.

[Means for solving problems]

In view of the above, the present invention provides a wire guide in which a ceramic plate having a plurality of guide holes is curved.

〔Example〕

Hereinafter, the wire guide according to the present invention will be explained with reference to the drawings.

As shown in FIGS. 1(a) and 1(b), the wire guide 1 is a plate-shaped body made of ceramic, and is curved in the vertical direction as a whole, with a guide hole 1a formed perpendicular to the curved surface. Therefore, the guide holes 1a are at an angle to each other. This wire guide 1 is connected to the print head H shown in FIG. 4(b) with the curved concave side as the wire tip side.
'', the wire 2 enters obliquely, so it almost matches the direction of the guide hole 1a, and the sliding characteristics between the wire 2 and the guide hole 1a are good, reducing mutual wear. Since the shape of the wire guide 1 is close to the shape of the platen 5, differences in impact force between the wires 2 and timing shifts are reduced.

The wire guide 10 shown in FIGS. 2(a) and 2(b) is a plate-shaped body made of -3=ceramic, is curved in the vertical direction and the horizontal direction, and has a spherical shape as a whole, and the guide hole 10a is curved. It is formed in a direction perpendicular to the plane. Further, a fixing portion 10b for connecting to the print head is formed at the end portion, and since this fixing portion 10b has a planar shape, it can be firmly bonded to the print head.

The wire guide 1.10 described above is made of ceramic such as alumina, zirconia, silicon carbide, silicon nitride, etc., and the manufacturing method for forming it into such a curved shape is as follows. First, the guide hole of the wire guide is molded so as to be perpendicular to the flat surface, and then the wire guide is pressed against a mold having a certain radius of curvature while being refired. Moreover, in addition to this, the guide hole may be formed perpendicularly to the curved shape after being molded into a curved shape in advance.

Next, the wire guide 1 according to the present invention shown in FIG.
Curved in the vertical direction with a radius of curvature R of 4311I11,
It was formed of alumina and attached to the print head 1 (=5- shown in FIG. 4(b)) together with the conventional flat wire guide 11 made of alumina. When we investigated the relationship between the number of printed dots and the diameter of the wire 2, we found that when the conventional wire guide 11 was used, as shown in Fig. 5, the wire 2 suffered a lot of wear, with an initial diameter of 250 μm. However, after printing 500 million dots, the sliding part was greatly worn and the printing was slightly irregular.On the other hand, when the wire guide 1 according to the present invention was used, even after printing 500 million dots, The amount of wear on the wire 2 was approximately several μm, and no disturbance occurred in the printed state.

Further, since the wire guide 1 according to the present invention is curved to have an angle in the direction of the guide hole 1a, if the radius of curvature R of the wire guide 1 is changed, the angle of the guide hole 1a is also changed. . -Generally, in the case of the print head ■° shown in FIG. It will be optimal if 1a is also tilted at the same angle.

The guide hole 1a at the end of the wire guide l is located 1 from the center.
Generally, the radius of curvature R of the wire guide 1 is 14 to 571111 when calculated from these values, since the wire guide 1 is generally located at a position of about 14 to 571111.

We actually produced prototype wire guides l with various curvature radii P, and conducted printing tests similar to those described above to examine the amount of wear on the wire 2. As a result, we found that wire guides l with curvature radius R larger than 65ml11 and smaller than 14III11 The amount of wear of wire 2 was large. That is, the radius of curvature R including the range of the above calculation was 14 to b.

In addition, since the platen 5 generally has a diameter of about 30n+m, if the radius of curvature R of the wire guide l is within the range of 14 to 65vn, it will be close to the radius of curvature of the platen 5.
The difference in distance from the tip of each wire 2 to the girdle 4 is reduced, and differences in impact force of each wire 2 and timing deviation can be prevented.

In the above embodiments, the wire guide 1 shown in FIGS. 1(a) and (b) is curved only in the vertical direction, but the wire guide 1 shown in FIGS. The same applies to the shaped wire guide 10, and the same applies even if the material used to form the wire guide is zirconia, silicon carbide, silicon nitride, etc. other than alumina.

〔Effect of the invention〕

As described above, according to the present invention, the wire guide is formed by forming a curved plate-like ceramic plate having a plurality of guide holes, so that the sliding characteristics between the wire and the guide holes are improved. This not only increases the impact force and reduces the load on the wire drive source, but also
Wires and wire guides experience less wear and can have a longer lifespan. In addition, since the shape of the wire guide is similar to that of the platen, the distance from the tip of each wire to the paper is almost the same, which prevents differences in the impact force of each wire and timing discrepancies, among other features. It is possible to provide a wire guide having:

[Brief explanation of drawings]

FIG. 1(a) is a perspective view showing a wire guide according to the present invention, and FIG. 1(b) is a sectional view taken along the line X--X in FIG. 1(a). FIG. 2(a) is a perspective view showing another embodiment of the present invention, and FIG. 2(b) is a sectional view taken along the line Y--Y in FIG. 2(a). Figure 3(a) is a perspective view showing a conventional wire guide;
Figure (b) is a sectional view taken along the Z-Z line in figure (a). Figures 4(a) and 4(b) are cross-sectional views showing the printing part of a dot printer using a conventional wire guide, respectively.
Figure (c) is an enlarged sectional view of portion A in figure (b). FIG. 5 is a graph showing the relationship between the number of printed dots and the wire diameter in a dot printer. 1.10.11 ... Wire guide 2 ... Wire 4 ... Paper 5 ... Platen

Claims (1)

[Claims] A wire guide characterized by having a curved plate-like ceramic plate having a plurality of guide holes.