JPS59155057A - Dot printer head - Google Patents

Abstract

PURPOSE:To raise magnetic permeability of a dot printer head by making the gap between both sides of armature and a magnetic body smaller by a method in which an armature guide is integrally formed in a guide holder and the magnetic body is fixedly provided while positioning to the armature guide. CONSTITUTION:In a plastic guide holder 23, an armature guide 25 of a rib to guide both sides of the tip of an armature 24 and an armature guide 26 of a recession to guide both sides of the rear end are integrally formed. An annular magnetic body 27 to make face-contact with the end face of the projection 19 of a yoke 18 is inserted when molding the guide holder 23. In the magnetic body 27, a slight aperture is formed with both sides of the armature 24, and the recession 27a to house each armature 24 is radially shaped. By eliminating the accumulating factor of tolerance, the positions and dimensions of the armature guide and the magnetic body can be controlled within small tolerance to both sides of the armature.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION This invention relates to a dot printer head.

Technical background of the invention and its problems Conventionally, there has been a dot printer head in which an armature is opposed to a core and a yoke to which a coil is attached, and the armature is operated together with a needle by the excitation action of the coil to perform printing. In order to obtain sufficient magnetic flux, it is necessary to increase the opposing area between the armature and the yoke, but if this opposing area is expanded on the same plane, the fulcrum will be If the distance to the tip of the needle is long, or if the image quality is too high for amateurs, high-speed printing will not be possible. To solve this problem, we not only formed a closed magnetic path between the attracting surface of the core and the facing surfaces of the armature and yoke on the same plane, but also created a closed magnetic path from both sides of the armature to the yoke via the magnetic material. A means of forming a path is employed.

A conventional example is shown below.

First, a first conventional example is shown in FIGS. 1 and 2. A core (3) to which a coil (2) is attached is screwed into the yoke (1). Plunger (4) facing core (3)
The individual armatures (5) and plate springs (6) are swaged to the bottle (7). And yoke (1
) is screwed to a disc-shaped magnetic body (8). This magnetic material (8) is the plunger (4) of the amateur (5)
It has a plurality of holes (9) for full holding, and a film αυ is interposed between the magnetic body (8) and the armature (5).

Therefore, the core (3), the armature (5), the magnetic material (
8), a magnetic path from the yoke (1) to the core (3) is formed, and the surroundings of the plunger (4) of the armature (5), the inner peripheral surface of the hole (9) of the magnetic body (8), and the magnetic body (8),
A side magnetic path is formed leading to the yoke (1).

However, it is difficult to align the plunger (4) of the armature (5) with the hole (9) of the magnetic body (8), so it is necessary to provide sufficient clearance between the plunger (4) and the hole (9). . Due to this, magnetic permeability is poor.

Next, a second conventional example is shown in FIGS. 3 and 4. Yoke (1), coil (2), core (3), plunger (
4), the armature (5), the magnetic body (8), and the hole (9) will be designated by the same reference numerals as those described above, and their explanation will be omitted. A plurality of notches α corresponding to the holes (9) are formed on the outer periphery of the magnetic body (8).
A small hole (6) is formed in the armature (5). The bobbin α9 that holds the entire coil (2) has a protrusion (B) that fits into the notch α℃, and this protrusion α
A protrusion α9 that stands upright from → and fits into the small hole α2 is integrally formed.

Therefore, by fitting the protrusion α41 of the bobbin ← sword into the notch α sword, the magnetic body (8) is fully positioned, and by fitting the protrusion αυ into the small hole (b), the armature (5) is fitted. The position of the fulcrum can be determined. However, amateur (
5) The guide for guiding the tip must be formed on a member other than the bobbin αj. As a result, the armature (5) swings out due to the accumulation of tolerances, and it is necessary to provide sufficient clearance between the hole (9) of the magnetic body (8) and the plunger (4) of the armature (5). is the same as the first conventional example described above.

Purpose of the Invention The present invention was made in view of the above-mentioned points, and an object thereof is to provide a dot printer head that can improve magnetic permeability by reducing the gap between both sides of the armature and the magnetic material. .

SUMMARY OF THE INVENTION This invention integrally forms an armature guide in a guide holder, and provides a magnetic body in a fixed manner while positioning it relative to the armature guide, thereby eliminating the cause of accumulation of tolerances and allowing both side surfaces of the armature to be fixed. The position and dimensions of the armature guide and the magnetic body can be kept within small tolerances, thus reducing the gap between both sides of the armature and the magnetic body, improving magnetic permeability and reducing power consumption. It is configured as follows.

Embodiment of the Invention An embodiment of the invention will be described with reference to FIGS. 5 to 7. Yoke α is applied to case α where fin αG is formed.
G is retained. This yoke (lEi) has an annular protrusion α9) and a coil (
A) A plurality of cores Q1) holding the cores Q1) are integrally formed. Furthermore, an armature stopper (A) located on the same plane as the protrusion α9) and the end face of the core Qρ is fixed to the center of the yoke α9.

Next, the guide holder made of plastic is integrally formed with an amateur guide (C) having a lip that guides both sides of the distal end of the armature (C) and an amateur guide (C) having a concave portion that guides both sides of the rear end. [Furthermore, an annular magnetic material (material) that makes surface contact with the end surface of the protrusion (to) of the yoke α dipper is inserted into the guide holder during molding. This magnetic material (c) is an amateur.

Furthermore, the guide holder (to) holds a needle fixed to the armature (c), a needle guide holder (g) for holding the armature (c), and a plurality of coil springs Op. The armature (goods) is plate-shaped, and its - side is formed in two stages so as to leave a space between it and the armature stopper (c) when printing. An edge-shaped fulcrum 02 is formed which makes contact with the two ends.

Incidentally, a PC board 03 is attached to the case α to connect each coil (A) to an external circuit.

In such a configuration, the end face of the core (C), the armature (C), the end face of the protrusion α9 of the yoke (17), and the core G2
]), but the magnetic body (b) comes into contact with the protrusion α□□□ of the yoke α→ over a wide area, leading to the recess (
27cL) 'ii surrounds the amateur (goods), so both sides of the amateur (c), magnetic material (goods),
A side magnetic path is formed that reaches the protrusion α (to) of the yoke αθ.

Therefore, the armature (c) is attracted to the core 01) by the excitation operation of the coil wire, the needle (c) is made to impact the platen, and printing is performed, and the armature is returned to the position by the zero force of the coil spring. However, since a side magnetic path is formed by the magnetic material, sufficient magnetic flux can flow through it. Moreover, the amateur (c) is guided by the amateur guides (c) and (c) to restrict lateral movement, and the guide holder (c) integrally has these amateur guides (c) and (b). By inserting a magnetic material into the
The gap between both sides of the recess (27cL) of the magnetic material (27 cL) and both sides of the armature (C) can be kept within a small tolerance, and the gap between both sides of the armature (C) and the armature guide (C) (H) can be kept within a small tolerance. ) can be kept within a small tolerance to allow the armature (c) to operate smoothly, which improves the magnetic permeability between both sides of the armature (c) and the magnetic material (a). be able to.

Therefore, while obtaining sufficient magnetic flux, the opposing area between the armature (c) and the protrusion α marked with yoke α can be reduced, and the fulcrum 0■ is brought closer to the core Qη, and the needle (ha) is moved from the fulcrum 02 to the core Qη. ) to distance 12, fulcrum 0 ■
to the core Q]) The distance to the center can be reduced by 1hk. That is, the lever ratio is 12/1. By increasing the armature (c), the equivalent mass of the armature (c) can be reduced, allowing high-speed printing to be performed, and by reducing the air gap, a large suction force can be obtained.

Furthermore, since the coil wire is located on the outer periphery of the yoke α$, wiring to the PC board 0'3 is easy, and the needle (c)
Also, there is no need to pass through the center of the annularly arranged coil (c), making assembly easier. Since the shape of the armature (c) is also plate-like, it can be easily formed including its fulcrum structure. By forming the magnetic body (b) also from sintered metal, dimensional accuracy can be further improved.

Effects of the Invention Since the present invention is constructed as described above, it is possible to eliminate the factor of tolerance accumulation and keep the opposing distance between the armature guide and the magnetic body on both sides of the armature within a small tolerance. It is possible to improve magnetic permeability by reducing the gap between both sides of the armature and the magnetic material while satisfying smooth operation, and this has the effect of reducing power consumption. be.

[Brief explanation of the drawing]

Figure 1 is a partial longitudinal side view showing the first conventional example;
The figure is an exploded perspective view showing a part of it in a reduced size, FIG. FIG. 5 is a longitudinal sectional side view showing one embodiment of the present invention, FIG. 6 is a partial horizontal sectional view showing an enlarged main part thereof, and FIG. 7 is a line taken along A-A in FIG.
FIG. 18...Yoke, 20...Coil, 21...Core, 23...Guide holder, 24...Amateur, 2
5, 26...Amateur guide, 27...Magnetic material - Figure 8'' 4 is also U figure

Claims (1)

[Claims] A guide in which a plurality of armatures are provided facing a plurality of cores and a yoke to which coils are attached, and a plurality of armature guides are integrally formed to face both sides of the armatures and hold the individual armatures in a freely undulating manner. A holder is provided, and a magnetic body facing both sides of the armature and forming a side magnetic path extending from both sides of the armature to the yoke is positioned relative to the position of the armature guide and fixed to the guide holder. A dot printer head characterized by: