JP2700300B2 - Print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head of a dot impact printer for printing kanji, alphabets, numerals, and the like, and a printer including the print head.

[0002]

2. Description of the Related Art Conventionally, as a noise source of a printer, a striking sound due to a sound or printing from a platen, a driving sound of a stepping motor of a carrier, and the like have been considered, and from this viewpoint, the noise of a print head has been reduced. As a specific conventional example, Japanese Patent Application Laid-Open No. Sho 60-15065 is first mentioned. In the print head described therein, a vibration damping material is attached to the inner surface of the lower body, thereby reducing the noise of the print head. Another conventional example is disclosed in
No. 9169. In the print head described therein, a back stopper plate is composed of two plates, and a layer of a viscoelastic material is bonded between the two plates. Is being planned. A similar prior art example is disclosed in Japanese Patent Application Laid-Open No. 60-4626.
No. 2 is cited, but the description is omitted. Still another conventional example is disclosed in JP-A-60-178078. The print head described therein has a cover joined to a nose plate by metal, and has a double structure in which the inside is sealed by the cover, thereby reducing the noise of the print head.

[0003]

In each of the above conventional examples, no nose plate is considered at all in order to reduce the noise of the print head. Therefore, the noise reduction of the print head has not been sufficient yet.

[0004] This point will be described with reference to FIGS. 10 to 15. FIG. 10 shows a cross-sectional view of the print head. In FIG. 10, reference numeral 1 denotes a core, and a coil 2 is wound around the core 1. A casing 3 is further provided on the core 1. A magnet 4 is provided on an end face of the core 1 where the coil 2 is not wound, a yoke 5 is provided on the magnet 4, and a side yoke 7 is provided via a spacer 6. A leaf spring 8 is fixed to the side yoke 7, and an armature 9 is fixed to the tip of the leaf spring by spot welding. The armature 9 is formed so as to be magnetically detachable from the end face of the core 1 on the coil winding side. That is, the core 1, the magnet 4, the yoke 5, and the armature 9 are arranged so as to form a magnetic circuit. In this magnetic circuit, when the coil 2 is not energized, the armature 9 magnetically attaches to the core 1 against the spring force of the leaf spring 8 due to the magnetic force of the magnet 4, and when the coil is energized, the magnetic force of the magnet 4 is canceled and the armature is 9 is configured to separate from the core 1. The leaf spring 8 is provided with a nose plate 11 with a screw 12 via a spacer 10. A nose 13 protrudes from the center of the nose plate 11. The nose 13 holds a bearing 14 at its tip, and a printing wire 15 is inserted into the bearing 14. The printing wire 15 has a base end connected to a lever 16, and the lever 16 is connected to the armature 9 by brazing. That is, the magnetic circuit forms a wire driving unit that reciprocates the printing wire 15.

Next, the operation of the print head shown in FIG. 10 will be described. When the coil 2 is energized, the magnetic force of the magnet 4 is negated, whereby the armature 9 is separated from the core 1 by the spring force of the leaf spring 8. Due to this detachment, the printing wire 15 moves forward via the lever 16 and predetermined printing is performed. 11 is a plan view of the print head shown in FIG. 10, FIG. 12 is an exploded perspective view of a main part of the print head, and FIG.
FIG. 3 is an exploded perspective view of a main part of another conventional print head.
12 is generally called an armature assembly, and FIG. 13 is called a magnet assembly.

However, when the armature 9 and the core 1 collide, not only the collision noise, but also vibration passes through the core 1, magnet 4, yoke 5, spacers 6, and 10 to the nose plate 11, and this nose There is a problem that the plate 11 becomes a noise source. Nose plate 1
When 1 is vibrated, it vibrates when printing is actually performed, and becomes a noise source. FIG. 14 and FIG. 15 are diagrams showing the grounds that the nose plate is a noise source.
Indicates the frequency analysis result of the noise of the wire dot printer. It can be seen that the noise is highest at 5 to 7 kHz. FIG. 15 shows the frequency analysis result of the vibration of the nose plate when hitting the nose plate.
There is a peak acceleration at 5-7 kHz. From both, it can be said that the main cause of the noise of the wire dot printer shown in FIG. 14 is the nose plate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a print head and a printer which can prevent a nose plate from vibrating due to a collision between an armature and a core and becoming a noise source.

[0008]

In order to achieve the above object, a print head according to the present invention comprises a print wire, a bearing for the print wire, a nose plate having a nose for holding the bearing, and a nose plate. And a wire drive unit for reciprocating the print wire, the wire drive unit comprising a core wound with a coil, a magnet and a yoke arranged to form a magnetic circuit with the core. And an armature, wherein the armature is supported by a spring member, is magnetically detachable from the core, is magnetically detachable, and is connected to the print wire, and the damping pin is in frictional contact with the core.
Guma is attached via a corrugated sheet .

Another aspect of the present invention is directed to a printing wire, a bearing for the printing wire, a nose plate having a nose for holding the bearing, and a wire driving unit for holding the nose plate and reciprocating the printing wire. The wire driving unit includes a core around which a coil is wound, a magnet, a yoke, and an armature arranged to form a magnetic circuit with the core, and the armature is supported by a spring member. in Rutotomoni said core and magnetically detachably formed and the printing wires and the print head are connected, da Npin <br/> Gumasu formed from the ring-shaped plate, and entangle a plurality of metal lines formed Characterized in that it is attached to the core via a ring-shaped member.

Further, a printer according to the present invention includes any one of the print heads described above.

[0011]

The damping mass or the like provided on the core attenuates the vibration of the core itself as soon as the vibration caused by the collision between the armature and the core propagates through the core, and prevents the vibration from being transmitted to the nose plate.

The printer according to the present invention can reduce the noise of the entire printer.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 is a sectional view of a print head according to the present invention, and FIG. 2 is a perspective view of a print head before a damping mass and a spring member are attached. A damping mass 17 formed of a rigid ring-shaped plate is screwed and fixed to the core 1 by several spring members 18. The damping mass 17 is formed of a mass that does not itself vibrate even when the core 1 vibrates, and attenuates the vibration of the core 1 by frictional contact with the core 1. As a result, no vibration is transmitted to the nose plate 11. In FIG. 1, other configurations are the same as those in FIG. 10, and the same portions are denoted by the same reference numerals and description thereof will be omitted.

FIG. 3 is a sectional view of another embodiment of the present invention.
The corrugated plate 19 of the ring plate as shown in FIG.
7 and the core 1. Dumping mass 1
The contact surface between the core 7 and the core 1 must be flat, and if it is distorted, it is difficult to obtain a sufficient frictional contact. However, even if the damping mass 17 is slightly distorted by providing the corrugated sheet 19, the distortion is caused by the distortion. The reduction in frictional contact can be prevented by the corrugated sheet.

FIG. 5 is an exploded perspective view of a main part of another embodiment of the present invention. In place of the corrugated plate 19 of FIG. 4, a ring-shaped member 20 formed by wrapping a metal wire is provided. This member 2
In addition to the same operational effects as the corrugated sheet 19, frictional attenuation occurs between the metal wires during vibration and further noise reduction can be achieved.

FIG. 6 shows another embodiment of the present invention, in which a rigid member 23 is provided on a ring-shaped elastic member 22 such as rubber to form a sandwich structure. The vibration of the core 1 is absorbed by the elastic member 22 and the nose plate 11
Vibration is not transmitted until.

FIG. 7 is a perspective view of a printer according to the present invention. Two support rails 31 and 32 are installed on the support 30 in parallel. The sliding bearing 33, the rolling member 34,
A carrier 36 with 35 is provided. A print head 37 is mounted on the carrier 36. The ribbon cassette 39 containing the ink ribbon 38 is detachably attached to the carrier 36. The ink ribbon 38 is hung on the head end 37 a of the print head 37. A print wire (not shown) emerges from the print head tip 37a and strikes the sheet via the ink ribbon 38.

FIG. 8 is a sectional view taken along line XVI-XVI of FIG. The platen 40 is provided below the print head 37,
1 is transported on the platen 40. An ink ribbon 38 exists between the print head 37 and the paper 41.

FIG. 9 is a plan view of FIG. 7 showing the driving means of the carrier 36. The drive belt 42 is fixedly attached to the carrier 36 using screws or the like, and is looped around the drive pulley 43 and the driven pulley 44. The drive pulley 43 is attached to a shaft of a drive motor 45. The power from the drive motor 45 is
It is transmitted to the carrier 36 via the drive belt, and is movable in the longitudinal direction with the support rails 31 and 32.

In the printer having the above-described configuration, the print head 37 is formed by any of the print heads described above. By providing this print head, the core 1
The vibration of itself can be attenuated, and the vibration can be prevented from reaching the nose plate 11. Therefore, the vibration of the nose plate, which is the main noise source, can be reduced, and the noise of the entire printer can be reduced.

[0021]

According to the print head of the present invention, the damping mass which makes frictional contact with the core is attached to the core via a corrugated plate, or is formed from a ring-shaped plate.
The da Npingumasu is, because attached to the core via the ring-shaped member formed by entangled a plurality of metal wires, can damp the vibration of the core itself, it is possible to prevent vibration of the nose plate with.

According to the printer of the present invention, the noise reduction level can be improved as a whole.

[Brief description of the drawings]

FIG. 1 is a sectional view of a print head according to the present invention.

FIG. 2 is a perspective view before a damping mass and a spring member are attached.

FIG. 3 is a sectional view of another embodiment of the present invention.

FIG. 4 is an exploded perspective view of a main part of the embodiment in FIG. 3;

FIG. 5 is an exploded perspective view of a main part of another embodiment corresponding to FIG. 4;

FIG. 6 is a sectional view of still another embodiment of the present invention.

FIG. 7 is a perspective view of the printer according to the invention.

8 is a sectional view taken along line XVI-XVI in FIG. 7;

FIG. 9 is a plan view of FIG. 7;

FIG. 10 is a sectional view of a conventional example.

FIG. 11 is a plan view of a conventional example.

FIG. 12 is an exploded perspective view of a main part of a different conventional example.

FIG. 13 is an exploded perspective view of a main part of a different conventional example.

FIG. 14 is a frequency characteristic diagram of noise of a print head.

FIG. 15 is a characteristic diagram of the nose plate.

[Explanation of symbols]

 Reference Signs List 1 core 2 coil 4 magnet 5 yoke 7 side yoke 8 leaf spring 9 armature 11 nose plate 13 nose 14 bearing 15 printing wire 17 damping mass 19 corrugated plate 20 ring-shaped member 21 damping material 22 elastic member 23 rigid member 36 carrier 39 ribbon cassette

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shunichi Ohara 502 Kandachicho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Katsumi Aoki 1070 Ichimo, Katsuta-shi, Ibaraki Pref.Hitachi, Ltd.Mito Plant, Hitachi, Ltd. (72) Inventor Masayuki Ariga 1070 Ma, Katsuta-shi, Ibaraki Pref.Hitachi, Ltd., Mito Plant (72) Inventor Ryo Asano Hitachi, Ltd. 1070, Mo, Katsuta-shi, Ibaraki Pref.Hitachi, Ltd., Mito Plant (72) Inventor Toshiyuki Tamatsu 1070 Ma, Katsuta-shi, Ibaraki Pref.Hitachi, Ltd., Mito Plant (72) Inventor Toshiro Ikemura 1070, Mo, Katsuta-shi, Ibaraki Pref.Hitachi, Ltd., Mito Plant (56) References JP 57-103169 (JP, A) JP-A-61-204873 (JP, A) JP-A-61-61865 (JP, A) JP-A-62-54878 (J , A) JP-A-59-71169 (JP, A) JP-A-57-9496 (JP, A) JP-A-2-81638 (JP, A) JP-A-60-46262 (JP, A) JP-A-5-220986 (JP, A) JP-A-61-15153 (JP, U) JP-A-61-105152 (JP, U) JP-A-60-184650 (JP, A) U)

Claims (2)

(57) [Claims] A print wire, a bearing for the print wire, a nose plate having a nose for holding the bearing, and a wire driving unit for holding the nose plate and reciprocating the print wire. The wire driving unit includes a core around which a coil is wound,
The core includes a magnet, a yoke, and an armature arranged to form a magnetic circuit. The armature is supported by a spring member, is magnetically detachable from the core, and is connected to the print wire. The print head according to claim 1, wherein a damping mass that comes into frictional contact with the core is attached to the core via a corrugated plate. 2. A printing wire comprising: a printing wire; a bearing for the printing wire; a nose plate having a nose for holding the bearing; and a wire driving unit for holding the nose plate and reciprocating the printing wire. The wire driving unit includes a core around which a coil is wound,
The core includes a magnet, a yoke, and an armature arranged to form a magnetic circuit. The armature is supported by a spring member, is magnetically detachable from the core, and is connected to the print wire. in the print head, the print head da Npingumasu formed from the ring-shaped plate, characterized in that attached to the core via the ring-shaped member formed by entangled a plurality of metal wires.