JPH0624209Y2 - Wire dot print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a wire dot print head.

<Prior Art> An example of a conventional wire dot print head will be described below with reference to FIGS. 5 to 9.

That is, the wire dot print head 1 has a plurality of printing wires 3, 3 ... Arranged so that the pitch on the side fixed to the armature 2 is wider than the pitch on the front side of printing.
Are guided by the wire guide holes 5, 5 ... Provided in the three wire guide plates 4a, 4b, 4c arranged in order from the armature fixed side to the print front side, and are directed toward the print front side. As shown in FIG. 6, the wire guide hole 5 has its entire wall 6 upright with respect to the surface of the wire guide plate 4. That is, the wire guide hole 5 has a true cylindrical shape that is perpendicular to the surface of the wire guide plate 4. The reason why the wire guide hole 5 is formed in a true cylindrical shape at a right angle to the surface of the wire guide plate 4 is that die-cutting at the time of molding is easy and workability is good. These wire guide holes 5 are shown in FIG.
As shown in FIG. 9, each wire guide plate 4a, 4b, 4c is arranged in a predetermined shape according to the convergence of the wire 3. In the figure, 7 is a magnet, 8 is an ink ribbon, 9 is paper, and 10 is a platen.

<Problems to be Solved by the Invention> However, with such a wire guide hole 5, the converging wire 3 is guided in an inclined state with respect to the wire guide hole 5 as shown in FIG. Become. This is not preferable in the following points.

The contact of the wire 3 with the wire guide hole 5 is 0 m and O.
As a result of only two points of n, the contact area is small, and the contact area, especially O on the side receiving the contact force P due to the convergence of the wire 3.
The wear amount at n increases. This problem becomes more important as the printing speed increases.

Since the wire 3 is inclined with respect to the wire guide hole 5, the diameter of the wire guide hole 5 increases. Specifically, the wire guide hole diameter R is R = r with respect to the wire diameter r.
/ Cos Θ + t tan Θ, for example, r = 0.2 mm, Θ =
If 10 ° and t = 1 mm, R is required to be 0.38 or more. As a result, when the number of wire guide holes 5 increases as the number of wires 3 mounted increases, the surplus thickness S between the wire guide holes decreases, which increases the difficulty of machining and also reduces the margin for the aforementioned wear. The durability will deteriorate.

<Means for Solving the Problems> The present invention has been made in order to solve these points, and the side of the hole wall of the wire guide hole that receives the contact force due to the convergence of the wire is the wire. The gist is that the wire guide plate is tilted with respect to the convergent / inclined state and the other side is made upright with respect to the surface of the wire guide plate.

<Operation> With this configuration, the contact of the wire with the wire guide hole is point-shaped on the side not receiving the contact force due to the convergence, but linear on the side receiving the contact force due to the convergence, and The amount of wear can be significantly reduced compared to the conventional one, and since the wire guide hole is, so to speak, an eccentric elliptical cone, the diameter of one end of the wire guide hole can be approximately the same as the diameter of the wire. The extra thickness between the guide holes can be made larger than that of the conventional one, and at the same time, the molding process becomes easy.

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS. The same parts as those of the conventional example described above are designated by the same reference numerals, and the duplicated description will be omitted.

The wire guide plate 20 of this wire dot print head
The wire guide hole 21 in is a part of the hole wall 22,
That is, the side 22p that receives the contact force due to the convergence of the wire 3
Is inclined with respect to the surface of the wire guide plate 21 corresponding to the convergence / inclination state of the wire 3, and the other side 2
2q is erected on the surface of the wire guide plate 21. As a result, the diameter Rm of the armature fixed side of the wire guide hole 21 is substantially equal to the diameter r of the wire 3, and the diameter Rn of the printing tip side is the value given by the above-mentioned R = r / cos Θ + t tan Θ. The wire 3 has a conical shape, and the contact of the wire 3 with the wire guide hole 21 is point-like on the side that does not receive the contact force due to the convergence, but linear on the side that receives the contact force due to the convergence. Compared with the conventional one, the thickness can be remarkably reduced, and the surplus thickness S between the wire guide holes on the armature fixed side can be increased by t / tan Θ compared with the conventional one, and at the same time, the molding process is facilitated. .

Here, the increase of the extra thickness S will be further described with reference to FIG. 10 as follows. That is, in the case of the wire guide hole 21 according to the present invention, a surplus thickness S is obtained between the adjacent wire guide holes 21, 21 on the side facing the armature fixing side. The extra thickness S is thicker by S'corresponding to the portion clearly indicated by different hatching as compared with the case where the wire guide hole is formed as in the conventional case.

The wire guide plate 30 shown in FIGS. 3 and 4 has a pair of wire guide holes 21, 21 ... Corresponding to each wire 3 in the above-described embodiment. All the wires 3, 3 ... Are guided by the wire guide holes 31, 31. The hole wall 32 of the wire guide hole 31 has a corrugated side 32p for receiving the contact force due to the convergence of the wire 3 and a flat side 32q, as shown in FIG. 32p is tilted and 32q is made upright. And each wire 3 will be guided in the state fitted in the recessed part of each wave.

<Effect of the Invention> As described above, in the wire dot print head according to the present invention, the side of the hole wall of the wire guide hole of the wire guide plate that receives the contact force due to the convergence of the wire is in the convergent inclination state of the wire. Correspondingly, since the other side is upright with respect to the surface of the wire guide plate while inclining to the surface of the wire guide plate, the side of the wire that does not receive the contact force due to the convergence is dotted. Although there is some, the side that receives the contact force due to the convergence becomes linear, the wear amount of the contact part is significantly reduced compared to the conventional one, and the wire guide hole becomes so-called eccentric elliptical cone, so the one end side of the wire guide hole Since the diameter will be approximately the same as the diameter of the wire, the extra thickness between the wire guide holes will be larger than that of the conventional one, and at the same time the molding process will be easier,
It has a great effect on its miniaturization, high speed, and easy manufacturing.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing the shape of a wire guide hole in one embodiment of the present invention, FIG. 2 is a schematic sectional view of the wire guide hole in one embodiment of the present invention, and FIG. 4 is a schematic side view of a wire guide plate in another embodiment of the present invention, FIG. 4 is a schematic sectional view taken along the line IV-IV in FIG. 3, and FIG. 5 is a schematic side view of a conventional wire dot print head. FIG. 6 is a schematic sectional view of wire guide holes in a conventional wire dot print head, and FIGS. 7 to 9 are schematic side views showing the arrangement of the wire guide holes in each wire guide plate, and FIG. FIG. 10: is explanatory drawing about the increase state of surplus. 1 ... Wire dot print head 2 ... Armature 3 ... Wire 4, 20, 30 ... Wire guide plate 5, 21, 31 ... Wire guide hole 6, 22, 32 ... Hole wall

Claims (1)

[Scope of utility model registration request] 1. A plurality of printing wires, which are arranged with a pitch on the armature fixed side wider than the pitch on the printing tip side, are respectively guided by wire guide holes provided in a wire guide plate toward the printing tip side. In the wire dot print head that is converged by the wire guide hole, the wire guide hole has a surface of the wire guide plate whose side that receives the contact force due to the convergence of the wire corresponds to the convergence and inclination of the wire. A wire dot print head, which is inclined with respect to the other side and is upright on the other side with respect to the surface of the wire guide plate.