JPS59114088A - Wire dot head - Google Patents

Abstract

PURPOSE:To obtain a wire dot head accompanied by low noise and a small temperature rise, by a method wherein the periphery of a wire-driving part in a wire dot head is hermetically sealed by members high in heat-radiating property. CONSTITUTION:An intermediate guide 30 for guiding a wire 15 is fixed to a back holder 28 through a plate 29 by small screws 32, and the wire-driving part comprised of a yoke 10, a coil 17, a plunger 17, an armature 13 or the like is hermetically sealed by the back holder 28 and an intermediate guide 31. Therefore, after printing is completed, impact vibration generated when the armature 13 collides against a stopper 21 is transferred through the stopper 21, a holder 23, a leaf spring 24 and a damper 25, and is then attenuated in the back holder 28. The heat generated from the coil 17 is released to the back holder 28 through the plate 29, and since the back holder 28 is formed of a material having high thermal conductivity and is provided with heat-radiating fins, heat is radiated to the exterior.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a wire tod head for a wire tod printer, and more particularly to a wire tod head equipped with a plurality of wires driven by an electromagnet.

(Prior Art) In general, a wire tod printer prints one character using an mxn dot matrix by moving a wire tod head, which has a plurality of wires arranged in a vertical line, in a certain direction at a predetermined pitch. .

FIG. 1 shows a conventional example, in which reference numeral 1 denotes a solenoid that sucks an armature 3 to which a wire 2 is fixed to perform printing. After printing is completed, armature 6 with wire 2 fixed
returns due to the restoring force of the spring 4, comes into contact with the stopper 5, and stops. The shock vibration caused by the stoppage of armature B is
Opening 8 formed between back holder 6 and yoke 7
The other part is transmitted to the bag holder B via the stopper 5 and the spring 4, and from there, it is emitted as a sound wave to the outside. For this reason, conventional wire tod heads have extremely high noise levels. Also, although a large amount of heat is generated from the solenoid 1, the heat dissipation area for this is small, which has the disadvantage of causing the head to become hot.
High heat of the head in this manner has negative effects in many ways.

(Objective) An object of the present invention is to eliminate the above-mentioned drawbacks and provide a wire tod head that produces low noise and does not generate high heat.

(Embodiment) FIG. 2 is an assembled sectional view of an embodiment of the present invention, and FIG. 6 is a perspective view showing an exploded state.

In the figure, a core 11 is coupled to a yoke 10, and a bobbin 12 having a coil 17 wound therein is inserted into the core 11. On the other hand, the armature 13 has a plunger 14
A wire 15 is fixed to the tip of one armature 13 by brazing. The other end of the armature 16 is provided with a hole into which the protrusion 12A of the bobbin 12 is inserted, and the armature 13 rotates around this protrusion.

An auxiliary yoke 16 is installed on the yoke 10, and a coil 17
When energized, yoke 10. Auxiliary yoke 16° plunger 14. A closed magnetic path is formed by the core 11, and the core 1
1, the plunger 14 is attracted.

As a result, wire 1 coupled to armature 13
5 is extruded and forms a dot on the printing paper via the ink ribbon. A restoring spring 20 is fixed to the rear guide 19 of the wire, and the armature 13 is attracted, and after printing dots with the wire 15, the armature is pulled back to the initial position, hits a stopper 21, and is stopped at the initial position. The restoring spring 20 and the stopper 21 are aligned so that the armature 13 can move smoothly. That is, the strength of the restoring spring 200 and the stopper 21
The hardness of the ring is determined to enable stable movement of the armature 13, and in this embodiment, a stopper made of polyurethane rubber is used. By the way, the armature 13 generally rotates through line contact with the auxiliary yoke 16, but the contact between the two tends to wear out, making the movement of the armature 16 unstable. In addition, a υ magnetic path is formed by the yoke 10, the auxiliary yoke 16, the plunger 14, and the core 11, but due to the residual magnetism of the auxiliary yoke 16, the armature 1
6 movement tends to become unstable.

In this embodiment, a spacer 22 is interposed between the auxiliary yoke 16 and the armature 16 in order to prevent the movement of the armature 13 from becoming unstable as described above. In this embodiment, a polyester film is used for the spacer. When the armature 16 rotates, the pivot portion is in pressure contact with the armature holder 26, thereby stabilizing the rotation of the armature 16. The stopper 21 and the armature holder 23 are fitted together. A plate spring 24 is in contact with the armature holder 23, and this plate spring 2
4 presses the armature holder 23 uniformly. Damper 2 on the opposite side of the armature holder of the leaf spring 24
5 holes, damper 25 has washer 26, spring washer 2
7 and is pressed by the back holder 2B. This damper 25 is for vibration isolation, and is made of a material with high specific gravity.
In this embodiment, lead is used. This damper 25 is suspended in the air by the plate spring 24 and spring washer 27, further enhancing the vibration-proofing effect.

Also, in order to prevent the damper 25 VC spring washer 27 from digging in, a washer 26 is used to prevent the spring washer 27 from digging into the damper 25.

By the way, when the coil/I/17 is energized, it generates heat 1r' due to the resistance of the coil 17 itself and the generation of eddy current in the core 11. This may lead to deterioration in character quality and is also dangerous for the operator. Therefore, in this embodiment, the heat generated by the coil 17 is transferred to the plate 29 via the plate 29.
Heat is radiated to the back holder 28 which is in surface contact with the back holder 28. This plate 29 and back holder 28 have heat dissipation properties, that is,
It must have good thermal conductivity, and in this example,
Both use aluminum. The back holder 28 also has heat radiation fins to enhance the heat radiation effect. The bobbin 12 has two terminals,
The winding start and winding end of the coil 17 are soldered. These two terminals are also soldered to the flexible cable 30, and the flexible cable 60 supplies driving current to the coil 17.

The intermediate guide 6 is attached to the back holder 28 via the freight 29.
1 is fixed with screws 62. In this way, the wire driving section consisting of the coil 17, plunger 14, armature 13, etc. is sealed by the back holder 28 and the i-space guide 31.

The ring-shaped protrusion M31A of the intermediate guide 31 fits into the circular groove 28A of the if back holder 28, and the back holder 28
is being positioned. The intermediate guide 31 has a notch 31B for a screw for attaching it to the carriage, but it has a U-groove for ease of attaching and detaching the head. A tip guide 63 is fitted into the intermediate guide '51 in order to facilitate the insertion of the wire 15. The wire 15 is supported by a distal guide 3'5, an intermediate guide 61, and a rear guide 19, and the curvature of the wire 150 is made as small as possible. This reduces the drag force from the guide, reduces the sliding resistance of the wire 15, and increases the conversion efficiency of electrical energy into printing energy.

Further, the outer shape of the yoke 10 is elliptical as shown in FIG. 4, and the sliding resistance of each wire 15 is made uniform to prevent density unevenness between each dot.

Next, the operation of this embodiment will be explained.

First, when the coil 17 is energized, the armature 13 is attracted, and the armature 13 is connected to the protrusion 12A of the bobbin 12.
The dots are printed using the wire 15.

After printing is completed, the armature 13 is stopped by the stopper 21. The impact r (vibration) caused by the armature 13 is transmitted to the armature holder 23 via the stopper 21, and from the armature holder 23 to the leaf spring 24 and the damper 25.The impact vibration transmitted to the damper 25 is transmitted to the washer 26, Back holder 2 via spring washer 27
8 and attempts to diffuse to the outside by transmitting the space, but since there are no openings nearby, it is transmitted to the front, but since there is a plate 29 on the front, it does not go to the outside at all. The impact sound cannot be dissipated and is attenuated within two days of the back holder.Therefore, the impact vibration and impact noise that occur when the armature 13 is stopped by the stopper 21 are mostly attenuated within the back holder 28, resulting in significant soundproofing. effect can be achieved.

Further, the heat generated from the coil 17 is transferred to the back holder 28.
is emitted to the outside by the fins, reducing the temperature of the entire head.

In addition, compared to our conventional female wire head, this female wire head has a noise reduction of 10 dB and a head temperature reduction of 10 dB.
It was possible to reduce the temperature by ℃.

(Effects) As described above, according to the present invention, a wire tod head with low noise and low temperature rise can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional wire tod head, FIG. 2 is a sectional view of an embodiment of the present invention, FIG. 6 is an exploded perspective view of this embodiment, and FIG. 4 is a line A-A' in FIG. 2. 5 shows the B-B/arrow view of FIG. 2. 11--Core 13-11-Armature 14
-...Plunger 15..."Wire 16@...Auxiliary yoke 17...Coil 21-...Stopper 28...
・11/(Tsukuholder 61・■Intermediate Guide Applicant Canon Co., Ltd. Canon Electronics Co., Ltd.

Claims (1)

[Claims] A wire tod head characterized in that the periphery of a driving part that drives the wire is sealed with a material having high heat dissipation.