JPS6374648A - Print head - Google Patents

Abstract

PURPOSE:To obtain a highly reliable print head, by forming an armature assembly and determining the dimension of a gap at a attraction section during assembling stage. CONSTITUTION:A core 4 is coupled to one ends of two board type upper and lower springs 5, 7 facing each other the tips of which coupled each other together with a print wire 8. An armature 6 is arranged through an air gap G to a position nearer to the central side than said core 4. Said armature 6 is coupled only with the under spring 7. Consequently, an armature assembly integrated with the core 4, the upper spring 5, the armature 6, the udder spring 7 and the print wire 8 is constructed. When power is fed to a coil 2, attracting force is produced in the air gap to displace the armature 6 to the left so as to pull the under spring 7 in the direction of an arrow A, thereby the upper spring 5 is flexed to operate the print wire 8 in the direction of an arrow B thus making a printing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head for use in a dot matrix printer.

[Prior Art] In dot matrix printers that print characters, figures, etc. using print wires, recent PC/O
Due to the A-boom, many compact multi-core print heads capable of printing in Mincho typeface have been developed. In response to market demands, higher density, smaller size, higher speed, and lower cost are required. Most of the print heads used in this type of dot matrix printer have an electromagnet as a basic configuration for driving the print wire, and in particular, an armature that directly drives the print wire, and a magnetic attraction force applied to the armature. Most of them had yokes facing each other to give the same effect. In this case, the armature and yoke are manufactured separately, and when assembled, an air gap created by the dimensional relationship between the two generates an electric attraction force.

[Problems to be solved] In the conventional print head mentioned above, the armature and yoke are manufactured separately, and when assembled, the magnetic attraction force is applied by the air gap created by the dimensional relationship between the two, so it is stable. In order to achieve this performance, it was necessary to make the dimensions of each individual component highly accurate. Alternatively, there is a drawback that sufficient dimensional accuracy cannot be obtained, which hinders improvements in speed, quality, and reliability. Alternatively, since the ratio of the printing stroke to the air gap at the magnetic attraction point cannot be made sufficiently large, it is necessary to increase the air gap at the magnetic attraction point, which has the drawback of requiring a large amount of electric power for driving.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned conventional problems, and as a means for solving the problems, it is possible to solve the problems by using two plate-shaped springs facing each other in the print head of a dot matrix printer. In addition to joining one end to the other and making it possible to connect a printed wire to the joint, a core is attached to the other end of one spring, and a core for magnetic attraction is installed at a position closer to the center than the core of the other spring. The armature is installed with a gap and is equipped with a Tomoe armature assembly.

[Example] Next, an example of the present invention will be described with reference to the drawings.

1 to 4 are diagrams showing one embodiment of the present invention. FIG. 1 is a perspective view of one hammer showing the configuration of a print head according to the present invention, FIG. 2 is a sectional view at the center Bs of FIG. 1, and FIG. 3 is a front view of FIG. 1. . In the figure, 1 is an inner yoke, and this inner yoke 1 is integrally molded with an outer yoke 3, and a coil 2 is wound around the outer yoke 3. Further, 4 is a core, and the tip of this core 4 is connected to the other ends of two opposing plate-shaped springs, that is, an upper spring 5 and an underspring 7, which are connected to each other together with a printed wire 8. An armature 6 is disposed at a position closer to the center than the core 4 with an air gap G serving as a gap for magnetic attraction relative to the core 4. This armature 6 is coupled only to the underspring 7 disposed inside the V-shape formed by the opposing combination of the upper spring 5 and the underspring 7. As shown in FIG. 4, the core 4, upper spring 5, armature 6, underspring 7, and printed wire 8 form an integrated armature assembly 10.

Further, as shown in FIG. 3, the armature assembly 10 is inserted into the groove 1a formed at the upper end of the inner yoke 1 without touching it, and as shown in FIG.
The side is fixed to the outer yoke 3 with screws 9. Further, the underspring 7 is connected to the armature 6 and the core 4.
As shown in FIG. 4, there is a U-shaped spring portion 7a between the two.

The upper spring 5 and the lower spring 7 constitute a displacement magnifying mechanism.

With the above configuration, when the coil 2 is energized, the magnetic flux flows through the outer yoke 3, core 4, air gap G, and armature 6.
, the groove 1a, the inner yoke 1, and the magnetic path that returns to the outer yoke 3, and an attractive force is generated in the air gap G. Due to this suction force, the armature 6 is displaced to the left in FIG.
moves in the direction of arrow B to perform printing. In this case, the amount of displacement of the printed wire 8 can be increased relative to the displacement of the magnetic attraction portion.

FIG. 5 is a partial cross-sectional view of the side surface of a print head in which a plurality of armature assemblies 10 shown in FIG. 1 are mounted, and FIG. 6 is a partial cross-sectional view of the back surface of the print head shown in FIG. 5. As shown in FIG. 6, a plurality of armature assemblies 10 are arranged in a circle, and by sharing an inner yoke 1, they are integrally molded with an outer yoke 3, and a coil 2 is wound around the outer yoke 3. . Note that 11 is a cover and 12 is a frame.

Furthermore, since the coil 2 is wound around the outer periphery of the head, the number of turns of the coil 2 can be increased, and the heat dissipation of the coil 2 is good, so a highly reliable print head that generates little heat can be provided.

The other configurations and operations are the same as those in the previous embodiment, so their explanations will be omitted.

[Effects of the Invention] As explained above, in the present invention, since the armature assembly is formed, the gap size of the attraction part can be determined at the assembly stage, so a stable magnetic attraction force can be obtained, and reliability can be improved. This has the effect of providing a high quality print head.

Furthermore, since the dimensional accuracy of individual parts is relaxed, it is possible to provide an inexpensive print head that is easy to assemble.

On the other hand, since the printed wire is arranged at the tips of two opposing plate-shaped springs, the ratio of the displacement of the printed wire to the displacement of the magnetically attracting part can be increased several times compared to the conventional method. It has the effect of being small and providing high-speed printing with high efficiency and low power consumption.

Furthermore, since the wire stroke can be increased, it is possible to provide a highly versatile print head that can print on sheets of different thicknesses.

Furthermore, the mass of the movable part can be reduced, making high-speed printing possible.

Furthermore, since the armature assembly can be replaced freely, it is possible to provide a print head that is easy to maintain.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of the print head of the present invention, and FIG.
3 is a front view of FIG. 1, FIG. 4 is a perspective view of the core assembly, and FIG. 5 is a print head showing another embodiment of the present invention. FIG. 6 is a partial cross-sectional view of the back side of the print head of FIG. 4: Core 5 Near spring 6: Armature 7: Under spring 8 Niblint wire 10: 7-mature assembly

Claims (1)

[Claims] In the print head of a dot matrix printer, one end of two opposing plate-shaped springs is joined to each other, and a print wire can be connected to the joint, and
A print head characterized by comprising an armature assembly in which a core is attached to the other end of one spring, and an armature is attached to a position closer to the center than the core of the other spring with a gap for magnetic attraction relative to the core. .