JPH02147348A - Dot impact printing head - Google Patents

Abstract

PURPOSE:To enable execution of high-speed printing with the intrinsic frequency of a lever increased and also to facilitate an assembling operation of a printing unit by disposing the main body of the printing unit at a position near to an outer periphery being apart sufficiently from the central part of a printing head, and by shortening the lever of the printing unit. CONSTITUTION:A printing head is constructed of a head frame 13 having a central opening 12 and an outer peripheral stepped part 13a, a disk-shaped bottom plate 14, a tubular retaining member 16 connecting the outer peripheral parts of these members and having a plurality of slots 15 formed at unequal intervals in the inner periphery thereof, and a plurality of printing units 1. Each of the printing unit 1 has a lever connected to a drive element of a frame 2 and extending inward radially from a base part, a wire 10 projecting from the fore end of the lever 9 outward at a right angle substantially, and a laminate-type piezoelectric element 11 deviating the lever 9. The wire 10 projects outside of the central opening 12 of the head frame 13, while the base part of the frame 2 is fitted and fixed in the slot 15 formed in the inner periphery of the tubular retaining member 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dot impact print head, and particularly to a dot impact print head capable of high-speed printing.

[Conventional technology]

For example, the conventional dot impact print head was developed in 1983.
The one shown in Japanese Patent No. 72042 is known.

In such a dot impact print head, the first
As shown in Figure 0, both sides of the frame 2 of each printing unit 1 are provided on the outer periphery of the cylindrical spider step 5 of the head spider 4 at equal or unequal intervals, and the bottom surface thereof is centered on the shaft. Slots 6 having an annular or elliptical contour, and slots 6 having an annular or elliptical contour, and slots 6 provided at equal or irregular intervals on the outer periphery of the spider plate 7 connected to the above-mentioned Radospider 4 through the holding member 3, the bottom surface of which is annular with the shaft portion as the center. Alternatively, they are fitted into the slots 8 having an elliptical outline, and in this state they are fixed to each other, and at this time, the levers 9 are inserted outwardly at a substantially right angle to the tip of the lever 9 extending from the driving part of the frame 2 of the printing unit 1 toward the base of the frame. A wire 10 attached to extend extends outwardly through the slot 6 of the cylindrical spider step 5, and when an electrical signal is applied to the laminated piezoelectric element 11, the wire 10 of the printing unit l having this piezoelectric element becomes a lever. The wire 10 moves forward and backward through the wire 9, and the printing operation is performed by the tip of the wire 10.

[Problem to be solved by the invention]

In order to increase the printing speed with the dot impact print head as described above, it is necessary to reduce the mass of the lever 9 of the printing unit 1 and increase its natural frequency. It is better to shorten the length of the lever 9 to the extent that this does not occur.

However, if the length of the lever 9 is shortened as described above while the wire 10 is located near the center of the print head, each print unit 1 in the print head will inevitably be
The arrangement position of the frame 2 approaches the center of the print head. Therefore, in a print head in which, for example, 24 printing units are arranged spaced apart from each other in the circumferential direction, the lower ends of the frame 2 of each printing unit are arranged closer to each other. Otherwise, the slots 6 and 8 for fitting and holding them may not be able to be formed technically in the hemlock spider plate 4 and the spider plate 7, making it impossible to achieve high-speed printing. There were drawbacks.

The dot impact print head of the present invention is designed to eliminate these drawbacks.

[Means to solve the problem]

To the dot impact printing of the present invention - The gutter includes a frame, a lever connected to the drive part of the frame and extending in a direction away from the base of the frame, a wire extending outwardly from the tip of this lever, and a wire that extends outward from the tip of the lever. It has a plurality of printing units comprising piezoelectric elements for deflection, the wire is arranged at the center of the printing head, and the base of the frame is fixed to the outer periphery of the printing head. .

[For production]

In the dot impact print head of the present invention, the length of the lever of the print unit is sufficiently small to achieve high speed printing.

〔Example〕

The present invention will be explained in detail below with reference to the drawings.

In the present invention, an example will be described in which the bottom of the slot has an elliptical profile centered on the shaft.

1 and 2 show a first embodiment of the present invention.

In this embodiment, a head frame 13 having a central opening 12 and an outer peripheral stepped portion 13a, and a disc-shaped bottom plate 14 are shown.
A cylindrical holding member 16 that connects the outer peripheral portions of the head frame 13 and the bottom plate 14 and has a plurality of slots 15 formed at unequal intervals on its inner periphery, and a hanging wall 17 provided on the cylindrical holding member 16. and a plurality of printing units 1 constitute a dot impact printing head, and the printing unit 1 is connected to a frame 2 and a drive section of this frame 2 and extends radially inward away from the base of the frame 2. It consists of a lever 9, a wire 10 extending outward at a substantially right angle from the tip of the lever 9, and a laminated piezoelectric element 11 that deflects the lever 9. The base of the frame 2 protrudes outward and is fitted into a slot 15 formed on the inner periphery of the cylindrical holding member 16, and the adhesive or protrusion 18 and the screw hole 1
6a (not shown).

3 and 4 show a second embodiment of the present invention, in which the slot 15 is not provided on the inner periphery of the cylindrical holding member 16, and the hanging wall 17 provided on the cylindrical holding member 16 is Projecting pieces 19. are provided on the inner side of the stepped portion 13a of the head frame 13, respectively.
20, and a slot 21 is formed in this part, so that the base of the frame 2 of the printing unit 1 is fitted into the slot 1-21 and fixed with adhesive or a screw screwed into the protrusion 18 and the screw hole 16a. It was designed so that

Reference numeral 18a designates an engagement hole formed in the stepped outer circumferential portion 13a of the head frame 13 so as to engage with a protrusion 18 provided at the base of the frame body 2. FIGS. 5(a) and 5(bl) are perspective views of the outer peripheral stepped portion 13a of the head frame 13 and the inner surface of the hanging wall 17, respectively.

FIG. 6 shows a third embodiment of the present invention, and in this embodiment, a protrusion piece 20 and an engaging part are attached to the stepped portion 13a of the head frame 13 in the second embodiment shown in FIGS. 3 and 4. Hole 1
8a, instead, a hanging wall 22 is provided on the inner periphery of the cylindrical holding member 16 at a position adjacent to the outer peripheral stepped portion 13a of the head frame 13, and the protruding piece 20 and the engagement hole 18a are provided on this hanging wall 22. establish.

FIG. 7 shows a fourth embodiment of the present invention. In this embodiment, instead of providing a hanging wall 17 on the inner periphery of the cylindrical holding member 16 in the second embodiment, a similar hanging wall 17 is provided on the bottom plate 14. A wall 23 is provided.

FIG. 8 shows a fifth embodiment of the present invention, in which a bottom plate 14 is provided instead of providing a hanging wall 17 on the inner periphery of the cylindrical holding member 16 in the third embodiment shown in FIG.
A similar hanging wall 23 is provided.

FIG. 9 shows a sixth embodiment of the present invention, in which the slit 1 is different from the first embodiment shown in FIGS. 1 and 2.
5 is provided through the cylindrical holding member 16, and instead of forming an engagement hole 18a that engages with a protrusion 18 provided at the base of the frame body 2 in the outer circumferential stepped portion 13a of the head frame 13, this outer circumferential stepped portion is provided. It is formed on a hanging wall 22 formed on the cylindrical holding member 16 adjacent to the portion 13a.

Since the dot impact print head of the present invention has the above-described configuration, the print unit main body is located at a position close to the outer periphery sufficiently far from the center of the print head. The length of the printing unit lever can be shortened by moving the printing unit closer to the printer.

〔Effect of the invention〕

According to the dot impact print head of the present invention, it is possible to increase the natural vibration of the lever of the print unit to enable high-speed printing, and the print unit can be placed within a large space within the print head, so that printing on the print head is possible. There is a significant benefit in that the assembly process of the unit becomes easier.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of the dot impact print head of the present invention, FIG. 2 is a left side view thereof excluding the head frame,
3 and 4 are a longitudinal sectional front view and a left side view showing the second embodiment of the present invention, and FIGS. 6 to 9 are longitudinal sectional front views showing third to sixth embodiments of the present invention, and FIG. 10 is an exploded perspective view of a conventional dot impact print head.1... Printing unit, 2... Frame, 3. 16...
・Holding member, 4...Hentspigoo 5...Cylindrical spider step, 6,8.15°21...Slot,
7... Spigoo plate, 9... Lever 10
...Wire 11...Laminated piezoelectric element, 12...
・Center opening, 13...Head frame, 13a...
Outer peripheral stepped portion, 14... bottom plate, 16a...
Screw hole, 17.22.23... Hanging wall, 18... Protrusion, 18a... Engagement hole, 19.20... Projection piece.稟子 缟子 高图 い已Criminal order (a) order (b) genealogy 稟 dent for concave milk bird 10 diagrams

Claims (1)

[Claims] 1. A frame, a lever connected to a drive part of the frame and extending in a direction away from the base of the frame, a wire extending outwardly from the tip of the lever, and a wire for deflecting the lever. The dot impact has a plurality of printing units each including a piezoelectric element for printing, the wire is arranged at the center of the print head, and the base of the frame is fixed to the outer periphery of the print head. print head. 2. The dot impact print head according to claim 1, wherein the base of the frame is fitted and fixed into a slot formed in a cylindrical holding portion of the print head. 3. The dot impact print head according to claim 1, wherein the base of the frame is fitted and fixed into a slot formed in a head frame and a bottom plate of the print head. 4. The dot impact print head according to claim 1, wherein the base of the frame is fitted and fixed into a slot formed in either the cylindrical holding part of the print head, the head frame, or the bottom plate of the print head.