JPH06104361B2 - Print head and printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a print head of a dot impact printer that prints Chinese characters, alphabets and numbers, and a printer including the print head.

[Conventional technology]

Conventionally, as noise sources of a printer, sound from a platen or a hitting sound due to printing, a driving noise 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 concrete conventional example thereof, Japanese Patent Application Laid-Open No. 60-151065 can be mentioned. In the print head described in this, damping material is attached to the inner surface of the lower body,
As a result, the noise of the print head is reduced. Another conventional example is JP-A-59-19169.
In the print head described therein, a back stopper plate is composed of two plates, and a layer of viscoelastic material is bonded between the two plates, and the viscoelastic material reduces the noise of the print head. Is being promoted. Further, as a similar conventional example, there is JP-A-60-46262, but the description thereof is omitted. Yet another conventional example is JP-A-60-178078. The print head described in this publication has a cover joined to the nose plate by metal, and has a double structure in which the inside is hermetically sealed, thereby reducing the noise of the print head.

[Problems to be Solved by the Invention]

None of the above-mentioned conventional examples considers the nose plate in order to reduce the noise of the print head. Therefore, the noise reduction of the print head has not been sufficient yet.

This point will be described with reference to FIGS. 11 to 16. 11th
The figure shows a cross-sectional view of a print head. In the figure, 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 the end surface of the core 1 on which 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 by spot welding to the tip of this leaf spring. The armature 9 is magnetically attachable to and detachable from the end surface of the core 1 on the coil winding side. That is, 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, the armature 9 magnetically adheres to the core 1 against the spring of the leaf spring 8 by the magnetic force of the magnet 4 when the coil 2 is not energized, and when the coil is energized, the magnetic force of the magnet 4 is canceled out. 9 is configured to separate from the core 1. A nose plate 11 is provided on the leaf spring 8 via a spacer 10 by screws 12. A nose 13 is provided at the center of the nose plate 11. The nose 13 holds a bearing 14 at its tip, and a printing wire 15 is inserted in the bearing 14. This printing wire 15
The base end is connected to the lever 16, which is the armature 9
And brazed together. 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. 11 will be described. When the coil 2 is energized, the magnetic force of the magnet 4 is canceled, whereby the armature 9 is detached from the core 1 by the spring force of the leaf spring 8. Due to this detachment, the printing wire 15 is moved forward via the lever 16 and predetermined printing is performed. still,
FIG. 12 is a plan view of the print head shown in FIG. 11, FIG. 13 is an exploded perspective view of a main part of the print head, and FIG. 14 is an exploded perspective view of a main part of another conventional print head. The one in FIG. 13 is generally called an armature assembly, and the one in FIG. 14 is called a magnet assembly.

However, when the armature 9 and the core 1 collide, not only the collision sound but also the core 1, the magnet 4, the yoke
5, there is a problem that the vibration reaches the nose plate 11 through the spacers 6 and 10, and the nose plate 11 becomes a noise source. When the nose plate 11 vibrates in this manner, it vibrates when actually printed and becomes a noise source. 15 and 16 are diagrams showing the reason why the nose plate is a noise source, and FIG. 15 shows the frequency analysis result of noise of the wire dot printer. It can be seen that the noise is highest at 5 to 7 kHz. FIG. 16 shows a frequency analysis result of vibration of the nose plate when hitting the nose plate, and again, there is a peak acceleration at 5 to 7 kHz. From both, it can be said that the main cause of noise in the wire dot printer shown in FIG. 15 is the nose plate.

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

[Means for Solving the Problems]

In order to achieve the above object, the print head according to the present invention,
The nose plate is provided with a damping mass that makes frictional contact with the nose plate with little vibration. Here, the damping mass is preferably attached to the nose plate by a spring member. The damping mass is preferably formed on a ring-shaped plate made of a rigid body.

Further, it is preferable to provide a corrugated plate or a ring-shaped member formed of a metal wire between the damping mass and the nose plate.

Further, a damping material may be provided on the nose plate instead of the damping mass, or an elastic member may be provided on the nose plate and a rigid member may be provided thereon.

A printer according to the present invention includes any one of the print heads described above.

[Action]

Damping mass installed on the nose plate, damping material,
The elastic member and the rigid member (sandwich structure of elastic material) provided as a pair on the elastic member immediately after the vibration due to the collision between the armature and the core is transmitted to the nose plate through the core, magnet, yoke, etc. Vibration damping.

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

〔Example〕

Hereinafter, the present invention will be described in detail based on the illustrated embodiments.
FIG. 1 is an exploded perspective view of a main part of a print head according to the present invention, and FIG. 2 is a sectional view of the print head. A damping mass 17 formed by a ring-shaped plate made of a rigid body is screwed and fixed onto the nose plate 11 by several spring members 18. The damping mass 17 is formed of a mass that does not itself vibrate even if the nose plate 11 vibrates, and damps the vibration of the nose plate 11 by frictional contact with the nose plate 11. In FIG. 2, other configurations are the same as those in FIG. 11, so the same reference numerals are given to the same portions and the description thereof will be omitted.

FIG. 3 is an exploded perspective view of a main part of another embodiment of the present invention, in which the corrugated plate 19 of the ring plate is the damping mass 17 and the nose plate 11.
It is provided between and. The contact surface between the damping mass 17 and the nose plate 11 must be flat, and if it is distorted, it is difficult to obtain sufficient frictional contact, but by providing the corrugated plate 19, even if the damping mass 17 or the like is distorted to some extent. The corrugated plate can prevent reduction in frictional contact due to the distortion.

FIG. 4 is also an exploded perspective view of the essential parts of another embodiment of the present invention, in which a corrugated plate 19 of FIG. 3 is replaced by a ring-shaped member 20 formed by entwining metal wires. This member 20 is the corrugated plate 19
In addition to the same function and effect, the friction damping also occurs between each metal wire at the time of vibration, and the noise can be further reduced. Fifth
The drawing is a sectional view of the print head corresponding to FIG. 3 or FIG.

FIG. 6 is a sectional view showing another embodiment of the present invention. In this embodiment, a damping material 21 is provided on the nose plate 11 instead of the damping mass 17. The material of the damping material 21 is preferably silicon rubber or the like. The print head is 100-150 ℃ when used, so it is recommended to use a heat-resistant material.

FIG. 7 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 elastic member 22 absorbs the vibration of the nose plate 11.

FIG. 8 is a perspective view of the printer according to the present invention. Support
Two support rails 31 and 32 are installed in parallel on the 30.
A carrier 36 having a slide bearing 33 and rolling members 34, 35 is provided so as to be movable in the longitudinal direction of the rails 31, 32. A print head 37 is attached to the carrier 36. Ribbon cassette containing the ink ribbon 38
39 is detachably attached to the carrier 36. The ink ribbon 38 is hooked on the head tip portion 37a of the print head 37. A print wire (not shown) emerges from the print head tip portion 37a and strikes the paper through the ink ribbon 38.

FIG. 9 is a sectional view taken along line XVI-XVI in FIG. Platen 40
Is provided below the print head 37, and the paper 41 is
Is transported over. An ink ribbon 38 exists between the print head 37 and the paper 41.

FIG. 10 is a plan view of FIG. 8 showing the driving means of the carrier 36. The drive belt 42 is fixedly attached to the carrier 36 with screws or the like, and is looped around the drive pulley 43 and the driven pulley 44. The drive pulley 43 is attached to the shaft of the drive motor 45. Power from the drive motor 45 is supplied to the carrier via the drive pulley and drive belt.
It is transmitted to the support rails 31 and 32 and is movable in the longitudinal direction.

In the printer configured as described above, the print head 37 is formed by any of the above print heads. By providing this print head, the vibration of the nose plate, which is the main noise source, can be reduced, so that the noise of the entire printer can be reduced.

〔The invention's effect〕

According to the print head of the present invention, the nose plate is provided with the damping mass or the like for damping the vibration, so that the vibration of the nose plate can be prevented.

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

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a main part of a print head according to the present invention, FIG. 2 is a sectional view of the same print head, and FIGS. 3 and 4 are exploded perspective views of a main part of a different embodiment of the present invention. 5 is a sectional view of the print head of FIG. 3 or 4, FIG. 6 and FIG. 7 are sectional views of different embodiments of the present invention, and FIG. 8 is a perspective view of a printer according to the present invention. FIG. 9 is a sectional view taken along the line XVI-XVI in FIG. 8, FIG. 10 is a plan view of FIG. 8, FIG. 11 is a sectional view of a conventional example, FIG. 12 is the same plan view, and FIGS. Fig. 15 is an exploded perspective view of a main part of a different conventional example, Fig. 15 is a frequency characteristic diagram of noise of the print head, and Fig. 16 is a characteristic diagram of the nose plate. 1 ... Core, 2 ... Coil, 4 ... Magnet, 5 ...
Yoke, 7 ... Side yoke, 8 ... Leaf spring, 9 ... Armature, 11 ... Nose plate, 13 ... Nose, 14
...... Bearing, 15 ...... Print wire, 17 ...... Damping mass,
19 ... Corrugated sheet, 20 ... Ring-shaped member, 21 ... Damping material, 22 ...
… Elastic member, 23 …… Rigid member, 36 …… Carrier, 39 ……
Ribbon cassette.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shunichi Ohara 502 Jinritsucho, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Manufacturing Co., Ltd. (72) Katsumi Aoki 1070, Ige, Katsuta-shi, Ibaraki Hitachi, Ltd. Mito In-house (72) Inventor Masaaki Ariga 1070 Imo, Katsuta-shi, Ibaraki Prefecture Mito Factory, Hitachi, Ltd. (72) Inventor Ryo Asano 1070 I-mo, Katsuta City, Ibaraki Hitachi, Ltd. In Mito Factory, Hitachi (72) Invention Toshiyuki Tamazu 1070, Moe, Katsuta-shi, Ibaraki Prefecture Mito Plant, Hitachi, Ltd. (72) Inventor Toshiro Ikemura 1070, Moe, Katsuta City, Ibaraki Hitachi, Ltd., Mito Plant, Hitachi

Claims (8)

[Claims] 1. A print wire and a bearing for the print wire,
A nose plate having a nose for holding this bearing,
A wire driving unit that holds the nose plate and reciprocates the printing wire, and the wire driving unit includes a core around which a coil is wound;
This core and a magnet arranged to form a magnetic circuit, a yoke, and an armature are provided. 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, a damping mass is attached to the nose plate so as to make frictional contact with the nose plate when the nose plate vibrates. 2. The print head according to claim 1, wherein the damping mass is attached to the nose plate by a spring member. 3. The print head according to claim 1, wherein the damping mass is a ring-shaped plate made of a rigid body. 4. The print head according to claim 1, wherein a corrugated plate is provided between the damping mass and the nose plate. 5. The print head according to claim 3, wherein a ring-shaped member made of a metal wire is provided between the damping mass and the nose plate. 6. The print head according to claim 1, wherein a damping material is provided on the nose plate instead of the damping mass. 7. The print head according to claim 1, wherein an elastic member is provided on the nose plate in place of the damping mass, and a rigid member is provided on the elastic member. 8. A carrier movably provided in a longitudinal direction of a support rail, a print head attached to the carrier, and an ink ribbon attached to the carrier and passing through a bearing surface of a print wire of the print head. A dot impact printer comprising a cassette and a platen provided at a position facing the bearing surface of the print head, wherein the print head comprises the print head according to any one of claims 1 to 7. Printer.