JPS63193848A - Printing head - Google Patents

Abstract

PURPOSE:To correct scatter of dimensions or characteristics of assembled printing heads due to scatter of dimensions or characteristics of component parts, by providing a coil spool cylindrically shaped at a part for disposing a coil and provided with a female thread concentrical with the coil at the inner periphery thereof, and disposing the coil around a yoke column by fastening a male thread and the female thread to each other. CONSTITUTION:A coil spool 14a around which a coil is wound is provided with a female thread concentrical with the coil at the inner periphery thereof, whereas a cylindrical yoke column part is provided with a male thread at the outer periphery thereof, and the coil spool is positioned relative to the yoke column by fastening the threads to each other. By rotating the coil spool, the position of the spool can be arbitrarily adjusted along the longitudinal direction of the yoke column part. When the position of the coil is brought closer to an end face of the yoke column, namely, closer to a gap of a magnetic circuit, the magnetic flux developed in the gap part when the coil is driven is increased, whereby an attracting force exerted on an armature can be increased, leading to a higher response speed of the armature and a greater impact force of a printing wire.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head for a dot matrix printer that prints by selectively impacting a recording medium with a print wire.

[Conventional technology]

Conventionally, this print head has a yoke and a coil that form an electromagnet, and the coil is fixedly mounted at a fixed position with respect to the yoke.

[Problem that the invention seeks to solve]

In the conventional print head mentioned above, the dynamic characteristics (printing force, response speed) of the head after assembly have large variations due to fluctuation factors such as variations in dimensional accuracy of component parts and variations in materials. It is difficult to obtain the required predetermined characteristics, and the yield rate is inevitably poor. On the other hand, in order to reduce the variation in dynamic characteristics, it is necessary to suppress the variation in precision of individual parts to a small level, which has the disadvantage of increasing manufacturing costs.

[Means for solving problems]

The uninvented print head has a yoke in which the part where the coil is arranged has a cylindrical shape and a thread is formed on the outer periphery, and a cylindrical shape in which the coil is wound and a female thread concentric with the coil on the inner periphery. Has a molded coil spool.

〔Example〕

Referring to FIGS. 1 and 2, in one embodiment of the present invention, an armature 1 holds a printed wire 2 at one end and a yoke 5 at the other end by a support rubber 4 integrally molded with a stopper plate 3. It is supported by the outer peripheral end surface and forms a fulcrum. A coil 6 wound around a coil spool 14a is located in a columnar part 5c corresponding to each armature located inside the yoke, and a yoke outer peripheral part 5a, a bottom part 5b
.

The inner pillar portion 5c forms a U-shape, and the armature is placed on top of the U-shape, thereby forming a magnetic circuit.

When a current is applied to the coil, magnetic flux flows in the magnetic circuit, and an attractive force acts on the gap formed between the armature and the yoke, and the armature is attracted toward the end face of the yoke.

The printed wire moves between intermediate guides 8°9 and main guides 10 held on the head frame 7 as the armature moves.
The ink ribbon is guided by the ink ribbon 11 and the paper 12 and collides with the platen 13 to perform printing.

Coil spool 14 with a coil wound thereon as shown in FIG.
A has a female thread formed on its inner circumference concentrically with the coil, while a thread is formed on its outer circumference on the cylindrical yoke column, and when they are fastened together by the screw, the coil spool is attached to the yoke column. It takes a structure arranged in .

By rotating the coil spool, its position can be arbitrarily adjusted along the longitudinal direction of the yoke column.

By positioning the coil close to the end face of the yoke column, that is, the gap in the magnetic circuit, the magnetic flux flowing through the gap increases when the coil is driven, increasing the attractive force acting on the armature. It is possible to increase the printing power of Conversely, if the coil is moved away from the yoke end face, the response speed of the armature can be slowed down and the striking force can be weakened.

〔Effect of the invention〕

As explained above, the present invention adds a mechanism that can arbitrarily adjust the coil position with respect to the longitudinal direction of the yoke of the electromagnetic actuator, thereby controlling the magnetic flux flowing in the magnetic circuit gap of the electromagnet and adjusting the attractive force acting on the armature. By doing so, it is possible to correct variations in the print head after assembly due to variations in the constituent parts, and it is possible to provide a print head with high yield and low manufacturing cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the print head of the present invention, and FIG.
The figure is an enlarged view of the actuator. 1... Armature, 2... Print wire, 3... Stroller plate, 4...
...Support rubber, 5...Yoke, 6...
...Coil, 7...Head frame, 8,9.
...Intermediate guide, 10 ...Main guide, 1
1... Ink ribbon, 12... Paper, 1
3...Platen, 14a...Spool winding section, 15a.../4b

Claims (1)

[Claims] The print head has a plurality of electromagnetic actuators formed by a yoke, an armature, and a coil, and the part where the coil is arranged has a cylindrical shape, and has a coil spool with a female thread concentric with the coil formed on the inner periphery. , a print head characterized in that the coil is installed around the yoke pillar by fastening the male screw and the female screw.