JPS6112355A - Dot printer head - Google Patents

Abstract

PURPOSE:To conserve power consumption for driving a coil by enhancing the magnetic flux density of a side magnetic path by reducing the clearance between the guide groove of an armature guide and an armature to enhance the attraction force of the coil, by forming the side magnetic path by forming the armature guide from a magnetic material. CONSTITUTION:Because an armature 20 is attracted to a core 18 when a coil 17 is excited, the armature 20 is revolved around a fulcrum 26 and a needle 25 is collided with a platen to perform printing. At this time, a magnetic path of core 18 armature 20 Yoke 16 core 18 is formed while a side magnetic path of (peripheral edge of armature 20) (opening edge of guide groove 30) armature guide 27 yoke 16 is formed. As mentioned above, because the side magnetic path is formed by an armature guide 27 formed of a magnetic material, the clearance between the armature 20 and the guide groove 30 can be reduced. Further, because the enlarged open edge 23 of the armature 20 is contacted with the partial edge 35 of the opening edge of the guide groove 30 by the elasticity of the needle 25, the permeability between the armature 20 and the armature guide 27 is high and magnetic flux density can be enhanced.

Description

[Detailed description of the invention] Technical field of invention The present 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 core as well as the opposing area between the armature and the yoke, but if this opposing area is expanded on the same plane, from the fulcrum of the armature to the center of the core The distance becomes longer and the equivalent mass of the armature becomes larger, making it impossible to perform high-speed printing. For this reason, a method is adopted in which a side magnetic path is formed from the side surface of the armature to the yoke via a magnetic material. A conventional example is shown below.

First, FIG. 3 shows the invention described in Japanese Unexamined Patent Publication No. 53-141717. This is the core 3 screwed onto the yoke 1.
A coil 2 is attached to the core 3 and an individual armature 5 to which a plunger 4 facing the core 3 is fixed is connected to a petal-shaped leaf spring 6 by a pin 7 to form a ring-shaped magnetic member into which each plunger 4 is fitted. A body 8 is screwed to the yoke 1 so as to face the end faces of the yoke 1 and the core 3, and a film 10 is interposed between the magnetic body 8 and the armature 5.

Therefore, a magnetic path is formed that connects the core 3, the armature 5, the magnetic body 8, the yoke 1, and the core 3.
Magnetic material 8. A side magnetic path leading to the yoke 1 is formed. However, since it is difficult to accurately position the armature 5 held by the leaf spring 6, in order to slidably fit the plunger 4 of the armature 5 into the hole 9 of the magnetic body 8, it is necessary to
The clearance between the fitting portion of the plunger 4 and the hole 9 must be increased, and therefore the magnetic permeability between the plunger 4 and the hole 9 deteriorates, and the meaning of forming the side magnetic path is lost.

Next, FIG. 4 shows the invention described in Japanese Unexamined Patent Publication No. 53-141720. Note that the same parts as those explained in FIG. 3 will be explained using the same reference numerals. In this conventional example, a bobbin 1 holds a coil 2 and is fitted into a core 3.
1 is formed with a protrusion 13 that fits into a notch 12 formed on the outer periphery of the magnetic body 8 and a protrusion 15 that fits into a hole 14 formed on the outside of the armature 5. 4 is fitted into the hole 9 of the magnetic body 8.

Therefore, a side magnetic path is formed from the outer circumference of the plunger 4 to the magnetic body 8 via the outer circumference of the hole 9 of the magnetic body 8. However, although it is possible to position the magnetic body 8 by the protrusion 13 and to position the armature 5 outside by the protrusion 15,
It is not possible to prevent the inner end of the armature 5 from swinging out. Even if an armature guide is separately provided to prevent the inner end of the armature 5 from swinging out, the relative position between the armature 5 and the magnetic body 8 will change due to the accumulation of manufacturing errors, and the clearance between the hole 9 of the magnetic body 8 and the plunger 4 will change. If it is not made large, the operation of the plunger 4 will become unsmooth, resulting in a problem similar to that shown in FIG.

Purpose of the Invention The present invention was made in view of the above points, and it is possible to increase the magnetic flux density in the side magnetic path and reduce the opposing area between the yoke and the armature on the attraction surface of the core.
The purpose of this invention is to provide a hanging dot printer head that reduces the equivalent mass of the armature and enables high-speed printing and power saving.

Summary of the Invention This invention provides an armature that has a suction surface that faces the core and an elongated extension extending from a widened edge of one end of the suction surface, and that the armature is fitted into the armature. An armature guide made of a magnetic material having a guide groove to be aligned is provided in contact with the yoke, thus forming a magnetic path leading to the core, armature, yoke, and core, and also forming a magnetic path between the periphery of the armature, the opening edge of the guide groove, the armature guide, and the yoke. By forming a side magnetic path leading to the side magnetic path and forming the side magnetic path with an armature guide, it is possible to reduce the clearance between the armature and the guard C groove, and it is possible to increase the magnetic flux density of the side magnetic path. By biasing the armature in the radial direction and keeping its expanded edge in constant contact with a part of the opening edge of the guide groove, the armature is prevented from rubbing against the opening edge of the guide groove during the armature's up-and-down movement. This prevents wear on both, further increases the magnetic permeability of both, and therefore reduces the opposing area of the armature and yoke on the attraction surface of the core, reducing the equivalent mass of the armature, resulting in high-speed printing and power saving. It has been designed to be easy to understand.

Embodiment of the Invention An embodiment of the invention will be described with reference to FIG. 1 and FIG. 2. A plurality of cores 18 holding coils 17 are continuously formed on the outer periphery of an annular yoke 16, and fins 19 are formed on the back surface of the yoke 16. The armature 20 facing the yoke 16 and the core 18 has a wide suction surface 22 facing the suction surface 21 of the core 18, and a wide suction surface 22 facing the suction surface 21 of the core 18.
An extension portion 24 extending inward from the widening edge 23 at the inner end of 2
The rear end of the needle 25 is connected to the inner end of the extending portion 24. Further, the extending portion 24 is thinner than the suction surface 22 so as to leave a gap on the yoke 16 side, and therefore, the portion where the expanded edge 23 and the suction surface 22 intersect has an edge shape supported by the yoke 16. A fulcrum 26 is formed.

Then, the amateur guide 27 and the guide frame 28 are sequentially stacked on the yoke 16 and fixed with screws 29. The armature guide 27 is formed in an annular shape from a magnetic material, and is attached to the attracted surface 22 of the armature 20.
A guide groove 30 is formed radially into which the peripheral edge of the extension part 24 and a part of the peripheral edge of the extension part 24 are fitted with a small clearance.

The guide holder 28 includes needle guides 31 and 32 that align the needles 25 while curving them, and an armature 20.
A spring 33 for returning the arm and a ring-shaped armature stopper 34 made of rubber are held. The needle 25 exhibits an action of returning to a straight line due to its own elasticity, and thereby the armature 20 is urged inward in the radial direction of the armature guide 27. In addition, coil 17
When Amateur 20 is not powered, Core 1
8 with a gap therebetween, and the expanded edge 23 is substantially inclined with respect to a straight line perpendicular to the end surface of the yoke 16. The edge 35 of the part of the guide groove 30 that the expansion #23 contacts is substantially inclined with respect to a straight line orthogonal to the plane of the amateur guide 27. That is, when the coil 17 is not energized, it comes into surface contact with the entire edge 35 of the expanded ′a 23 of the armature 20 .

In this configuration, when the coil 17 is energized, the armature 20 is attracted to the core 18 and rotates about the fulcrum 26, causing the needle 25 to collide with the platen and printing is performed. At this time, core 18, amateur 20,
A magnetic path leading to the yoke 16 and the core 18 is formed, and a side magnetic path leading to the peripheral edge of the armature 20, the opening edge of the guide groove 30, the armature guide 27, and the yoke 16 is formed. In this way, since the side magnetic path is formed by the armature guide 27 formed of a magnetic material, the armature 20
The clearance between the armature 20 and the guide groove 30 can be reduced, and the elasticity of the needle 25 allows the armature 20
The expanded edge 23 is a part of the opening edge of the guide groove 30! 135
Because it comes into contact with.

The magnetic permeability between the armature 20 and the armature guide 27 is high, and the magnetic flux density can be increased.

Thereby, the attraction force of the core 18 can be increased, and the capacity of the coil 17 can be reduced to save power.

In addition, the opposing area between the suction surface 22 of the armature 20 and the yoke 16 can be reduced, and the fulcrum 26 can be brought closer to the core 18 to reduce the equivalent mass of the armature 20, thus enabling high-speed printing. I can do it.

Further, in the armature 20, the edge portion of the expanding edge 23 on the fulcrum 26 side is always elastically in contact with the opening edge of the guide groove 30 of the armature guide 27.

The fulcrum 26 does not move on the yoke 1G, and the expanded edge 23 does not rub against the guide groove 30, so that wear can be prevented.

Effects of the Invention Since the present invention is constructed as described above, by forming the armature guide from a magnetic material to form the side magnetic path, the clearance between the guide groove of the armature guide and the armature is reduced, and the side magnetic path is reduced. The magnetic flux density can be increased, which increases the attraction force of the core and reduces the power consumption to drive the coil.The fulcrum is moved closer to the core, reducing the equivalent mass of the armature and enabling high-speed printing. Furthermore, by urging the armature in the radial direction of the armature guide and bringing the expanded edge into contact with the opening edge of the guide groove of the armature guide, the fulcrum moves during the armature's up-and-down motion, and the armature's This prevents the expanded edge from rubbing against the guide groove of the amateur guide, and therefore has the effect of preventing wear on the amateur and the amateur guide.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view showing one embodiment of the present invention. FIG. 2 is a plan view of the amateur and the amateur guide, and FIGS. 3 and 4 are longitudinal sectional side views of a part of a conventional example. 16... Yoke, 17... Coil, 1 8-... Core, 20... Armature, 22... Attracted surface, 23
... widened margin. 24... Extension portion, 25... Needle, 26... Fulcrum, 27... Amateur guide, 30... Guide leakage Applicant Tokyo Electric Co., Ltd. Figure 33

Claims (1)

[Claims] A yoke is provided along the arrangement direction of a plurality of cores arranged in an annular shape while holding the coils, and a yoke is provided along the arrangement direction of a plurality of cores arranged in an annular shape, and a yoke is provided along the arrangement direction of a plurality of cores arranged in an annular shape, and a wide suction surface facing the core and a direction from the widened edge of the inner end of this suction surface to the needle. A plurality of armatures each having an elongated extension part are provided to be able to rise and fall freely using the contact part with the yoke as a fulcrum, and an annular armature guide that contacts the yoke is formed of a magnetic material. A plurality of guide grooves are formed in which the armatures are fitted with a small clearance, and a side magnetic path is formed between the opening edges of these guide grooves and the peripheral edge of the armature, and the armature is inserted into the armature in the radial direction of the armature guide. The dot printer head is characterized in that the expanding edge of the armature is always brought into contact with a part of the opening edge of the guide groove.