JPS5835475B2 - Structure of wire dot printer head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire-type dot printer that uses electromagnets as driving means for a plurality of print wires, and particularly relates to an electromagnetic coil of a dot head having a magnetic circuit forming a common magnetic path for the plurality of electromagnets. It concerns the array of .

An object of the present invention is to realize a very compact and lightweight dot head by efficiently arranging electromagnetic coils of a dot head having a plurality of electromagnets configured to form a common magnetic path.

In an electromagnetic device that is composed of a plurality of electromagnets and is configured such that the plurality of electromagnets have a common magnetic path, the direction of the magnetic flux generated from each electromagnet is determined as follows when passing through the aforementioned common magnetic path. They were usually arranged in the same direction.

However, in this structure, it is necessary to provide a cross-sectional area of the common magnetic path described above with a sufficient size so that the magnetic flux density passing through the plurality of electromagnets is not saturated when all of the plurality of electromagnets are excited, and it is necessary to design the device compactly. This is a difficult problem if this is the case.

The present invention was made in an attempt to improve these drawbacks and realize a compact dot printer head.
Hereinafter, a specific example of the present invention will be explained in detail with reference to the cross-sectional view of FIG. 1.

Reference numeral 1 denotes a frame made of a magnetic material in which a plurality (seven) of wire drive coils 3 are arranged on the circumference, and the center portion 1a is a central column that forms a common magnetic path for the magnetic flux generated from the plurality of wire drive coils 3. , 4 is a coil core, 5 is a plunger fixed to the actuating plate 6 and attracted to the end face of the coil core 4, and the actuating plate 6
One end is held down by the outer periphery of the actuating plate holder 7 and rotates about the fulcrum A when the plunger 5 is attracted.

The other end of the actuating plate 6 engages with a wire pin 11 fixed to the non-printing end of the print wire 10, and in the non-printing state, it is returned to the non-printing direction by a print wire return spring 12 and is positioned at a perforation of 8. .

Reference numeral 9 denotes a yoke plate made of a magnetic material and attached to the center column 1a.

20 is a printed wire unit nose.

Further, FIG. 2 is an exploded view of FIG. 1, and explanations of parts not directly related to the present invention are omitted.

1. To briefly explain the printing operation shown in FIG. 1, when the wire drive coil 3 is energized according to the printing command, the plunger 5 is attracted to the end surface of the coil core 4, and the actuating plate 6 is moved to the fulcrum A.
The wire pin 11 that rotates around the center of rotation and engages with the other end of the actuating plate 6 is driven, and the printing end surface of the print wire 10 impacts the print wire 10 to print on a recording paper (not shown) via an ink ribbon. .

After printing, the printing wire 10 is pulled back in the non-printing direction by the repulsion from the recording medium and the wire return spring 12, and the tip of the actuating plate 6 stops at the position determined by the perforation 8, thus completing the -printing process.

Assuming that the direction of the magnetic flux generated from the coil 3 shown in Fig. 1 flows as shown by the arrow, if all seven coils are arranged so that it flows in the direction of arrow A, the center forming the common magnetic path The cross-sectional area of the pillar etc. is the cross-sectional area of the coil core 4 7
A cross-sectional area is required, which is the product of the individual parts and the leakage coefficient, and a considerably large cross-sectional area is required.

This can be solved, as in the present invention, by making the coils marked with an "X" in the coil arrangement diagram of FIG. 2 in the opposite direction to the direction of the coils without a "x" mark.

In other words, in Figure 1, if the direction of the magnetic flux of the coil without the cross mark in Figure 2 is arrow A, then the direction of the magnetic flux of the coil with the cross mark is in the direction of the arrow, and they cancel each other out in the common magnetic path section. Magnetic flux flows in the common magnetic path part corresponding to the difference in the number of coils that are excited together, and magnetic flux flows in the other magnetic path through the coil core part of the coils that are excited in opposite directions, and magnetic flux flows in the common magnetic path part. Therefore, the cross-sectional area of the common magnetic path portion can be designed to be the minimum, and a compact dot head can be realized.

Therefore, in the worst case scenario, the cross-sectional area of the common magnetic path should be sufficient as long as it has enough cross-sectional area to obtain sufficient performance when four coils arranged in the same direction are excited at the same time. will be understood.

This can be explained by actually measuring the operation of the printed wire.

As shown in FIG. 1, one of the seven print wires 10 has a printed end face lengthened for motion analysis, and its motion is measured using an optical displacement measuring device (trade name: Optron).

First, FIG. 3 shows the measurement results when all wire drive coils not according to the present invention are arranged in the same direction.

t is the time axis, and X is the moving distance of the printing end surface of the print wire.

Si is the movement of the print wire printed end surface when one coil is excited, S4 is the measurement result when four coils are excited, and S7 is the measurement result when seven coils are excited at the same time.

As we will see, if the cross-sectional area of the common magnetic path section is not sufficient, normal operation of the wire can be expected with 4 wires, but when there are 7 wires, the common magnetic path will become saturated and will not be sufficient. This shows that it is not possible to obtain a printed wire with good printing energy and frequency response characteristics.

FIG. 4 is a measurement diagram of the operation of the printing end face of the print wire when the above-mentioned coil arrangement according to the present invention is used, and shows R□(
The operating state of the printed wire for measurement is when only one coil (same as SL) and 4 coils arranged in the same direction is excited for R4 (same as S4). It can be seen that there is almost no difference in the operation of the two.

Therefore, even if the cross-sectional area of the common magnetic path section is smaller than the cross-sectional area required when seven coils are arranged in the same direction, the operation of the printed end surface of the printed wire is such that even if the cross-sectional area of the common magnetic path section is smaller than the cross-sectional area required when seven coils are arranged in the same direction, By reversing the arrangement, a compact wire-type dot printer head can be realized.

As described above, the present invention provides a printed wire dot head having a plurality of wire drive coils and configured to form a conventional common magnetic path generated from the plurality of wire drive coils. By arranging some of the drive coils in the opposite direction, the amount of magnetic flux flowing through the common magnetic path is reduced, and the cross-sectional area is reduced to realize a more compact dot head. As shown in the above experimental results, the operation of the printed wire is as follows.
It gives good results and the results are truly doggy.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a cross-sectional view of a specific example of the present invention, 1...
...Frame, 1a...Central pillar, 3...
・Wire drive coil, 4... Coil core, 5.
... Plunger, 6... Actuation plate, 7...
...Operating plate presser, 8...Degree, 9...
... Yoke plate, 10 ... Printed wire, 1
1... Wire pin, 12... Printed wire return spring. FIG. 2 is a partially exploded view of FIG. 1, and FIG. 3 is a diagram of the printed wire operation not according to the present invention. FIG. 4 is a diagram showing the operation of the printed wire according to the present invention.

Claims (1)

[Claims] 1. In a wire-type dot printer having a plurality of electromagnets configured to form a common magnetic path, the direction of magnetic flux generated from less than half of the plurality of electromagnets passing through the common magnetic path is determined. A structure of a wire type dot printer head, characterized in that the direction of magnetic flux is opposite to that generated from the remaining electromagnets.