JPS63193847A - 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 making it possible to adjust the position of a coil in an electromagnetic actuator with respect to the longitudinal direction of a yoke so as to adjust the dynamic characteristics of the actuator. CONSTITUTION:A coil spool 14a around which a coil is wound is provided with a male thread concentrical with the coil at a lower outer peripheral part thereof, and is positioned relative to a yoke column part having a circular cross section by fastening the male thread part to a female thread part provided, substantially concentrically with the yoke column part, on a base member 14b fixed on an inner bottom surface of a yoke. By rotating the coil spool 14a, 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 part, namely, closer to a gap part 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 printing for dot matrix printers that print by selectively impacting a recording medium with a print wire;
Regarding de.

[Conventional technology]

Conventionally, in this printing, the yokes and coils forming an electromagnet were fixed and mounted at a fixed position relative to the two yokes.

[Problem that the invention seeks to solve]

The conventional print head described above suffers from fluctuations in dynamic characteristics (printing force, response speed) after assembly due to fluctuation factors such as fluctuations in the dimensional accuracy of individual component parts and fluctuations in the material. Because of the large K, it is difficult to obtain the desired characteristics and the yield is inevitably poor. On the other hand, in order to reduce the variation in wJ%, it is necessary to suppress the variation in precision of each individual component to a small level, which has the disadvantage of increasing manufacturing costs.

[Means for solving problems]

The print head of the present invention has a mechanism that allows the position of the coil within the actuator to be adjusted in the longitudinal direction of the yoke in order to adjust the dynamic characteristics of the electromagnetic actuator that is a component of the print head.

〔Example〕

Referring to FIGS. 1 and 2, in one embodiment of the invention, an armature 1 holds a print wire 2 at one end and a jaw 5 at the other end by a support rubber 4 integrally molded with a stopper plate 3. It is supported on the outer peripheral side end face of and forms a fulcrum. A coil 6 wound around a coil spool 14H is located in the columnar part 5C corresponding to each armature located inside the yoke, and the bottom part 5 of the yoke outer peripheral part 5a1 is
b.

A magnetic circuit is formed by forming a U-shape with the inner pillar portion 5C and placing the armature on top of the U-shape.

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 is a pace member 14 which has a male thread concentric with the coil molded on its lower outer periphery and is fixed to the inside of the yoke and the bottom surface.
Since it is formed approximately concentrically with the yoke column having a circular cross section at b, it is fitted onto the joke column by being fastened to the threaded portion.

By rotating the coil spool 14a, its position can be arbitrarily adjusted along the longitudinal direction of the yoke column.

Coil position f? If t is brought closer to the end face of the yoke column, that is, the gap in the magnetic circuit, the magnetic flux that flows through the gap t'' when the coil is driven increases, and the attractive force acting on the armature can be increased, which in turn speeds up the corresponding speed of the armature. In addition, the impression force of the printed wire can be increased. Conversely, if the coil is moved away from the yoke end face, the response speed of the armature can be slowed and the impression force can be weakened.

〔Effect of the invention〕

As explained above, the present invention is based on '@stone acti'.

Arbitrary position of the coil in the longitudinal direction of the yoke of the motor
By adding a mechanism that can adjust the magnetic flux flowing through the gap in the magnetic circuit of the electromagnet and adjusting the attractive force f acting on the armature, the print head can be used as a print head after assembly due to variations in the constituent parts. It is possible to provide a print head with good 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 sectional view of the actuator.

Claims (2)

[Claims] (1) In a print head having multiple electromagnetic actuators formed by a yoke, an armature, and a coil,
A print head characterized by having a positioning adjustment mechanism for each coil in the longitudinal direction of the yoke. (2) A yoke in which the portion on which the coil is placed has a cylindrical shape, a coil spool in which the coil is wound and has a cylindrical shape and a thread is formed concentrically with the coil on the lower outer periphery, and the bottom surface of the yoke. A base member is fixed to the yoke column and has a base member formed with a female screw corresponding to the male screw, and the coil is installed around the yoke column by fastening the male screw and the female screw. Print head described in section 1).