JPS60183166A - Wire dot head - Google Patents

Abstract

PURPOSE:To arrange so that the heat radiation effect may be increased and the noise level be minimized by forming in an aluminium-zinc alloy a heat release member which constitutes a radiation fin for releasing heat generated through application of pulses to a magnet. CONSTITUTION:The pulses generated by a flexible cable 3 is applied to a coil 7 of a bobbin 8 to drive an armature 14. At that time, the heat generated by the coil 7 is transferred to a back holder 21 which is a heat release member through a core 6, a yoke 5 and a spacer 4 for radiation. This back holder 21, provided with a radiation fin, has almost an equal thermal conductivity to that of aluminium and high vibroisolating property. In addition, it is formed with aluminium- zinc alloy of high molding property which allows the forming of thin fins. Consequently, the heat release property can be enhanced. Further said alloy can be used as a material for the back holder 21, an intermediate guide 2 and a damper 18, thus reducing the head temperature by 8 deg.C and the noise level by approx. 10dB.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a wire dot head, and more particularly to a wire dot head with increased heat dissipation effect and vibration damping effect.
It concerns ζ.

[Prior art]

A wire tod printer is known in which a plurality of wires are driven by applying a pulse current to their corresponding electromagnets, the wires are advanced in a predetermined order, and printing is performed by the impact force G of the wires.

The wire tod head used in such printers contains the same number of electromagnets as the number of wires, and when a pulse current is applied to these electromagnets, heat is generated from the coils of the electromagnets, and this If you use a wire tod printer continuously for a long time due to heat, the coil resistance will increase. Otherwise, printing defects may occur: resulting in poor printing quality.

For this reason, conventional wire tops were equipped with heat dissipation fins to dissipate the heat of the electromagnetic coil.

Conventionally, these heat dissipating fins have been formed from aluminum die castings or machined die castings from the viewpoints of overlay and thermal conductivity.

However, when using the die-casting method, thin heat dissipating fins cannot be formed due to the problem of molding 1-.

The heat dissipation effect is poor, and the print head as a whole has to be large in order to achieve the necessary heat dissipation effect.

In addition, when the heat dissipation fins are formed by mechanical loading, the cost increases and it is difficult to produce them repeatedly.

By the way, the printing principle of the wire tod head is that it prints by impact force, so is it possible to print? Sometimes there is noise.

The first source of this noise is noise generated from sources other than the head main body, such as paper vibrations and impact sounds generated in the printing section when the wire prints the M1c two dots via the ink ribbon.

Another type of noise is generated from within the head body.When the armature, which is integrated with the wire, is attracted by the pulse current applied to the coil, and when it comes into contact with the stopper on the printing direction side, and when printing ends. This is caused by the impact sound when hitting the stopper to return to the initial state after R and O.

The first type of noise can be significantly reduced by reducing the pressure of the paper in the printer body and by minimizing the openings to the outside.

In addition, attempts have been made to solve the second noise by making the stopper part an elastic material, or by molding the drive part of the head body completely from synthetic resin and sealing it with metal such as aluminum, but the noise There was a limit to the decrease.

[Objective 1] The present invention has been made to eliminate the following disadvantages of the conventional technology.It has excellent heat dissipation effect, low printing noise, small size and inexpensive wire drive head. is intended to provide.

〔Example〕

Hereinafter, the present invention will be described in detail based on the embodiment shown in FIG. Lii.

Figures 1 to 1F illustrate one embodiment of the present invention.
Details of the wire tod head are shown in the figures and in FIG.

In Figs. 1 and 2, the reference numeral 1 indicates wire 2.
This is a tip guide for guiding the tip of the wire 2 and facilitating the work of assembling the wire into the head main body 100.

The distal end guide 1 is fixed to the distal end G of the intermediate guide 2.

The intermediate guide 2 is fixed to a bag holder, which will be described later, with a screw 23 or the like via a positioning fitting part (not shown).

Further, the intermediate guide 2 is provided with a screw groove 2a for accessing the head body 100 to a key T-ridge (not shown), and a groove 2c here is provided to facilitate attachment and detachment of the head body. It is U-shaped.

On the other hand, what is indicated by reference numeral 3 is a flexible goople for supplying current to a coil for an electromagnet, which will be described later, and is fixed to the side surface of the heat dissipation plate 4.

This heat dissipation plate 4 is the yoke and back halter of the electromagnet]
In addition to being in contact with each other, it also serves as a spacer between the flexible cable 3 and the yoke.

In this embodiment, the thickness of the heat dissipation plate 4 is approximately 2 mm to enable the heat of the yoke to be sufficiently transferred to the back holder side, and the material is made of heat conductive material. Aluminum and magnesium with good properties are preferable.

On the other hand, the one indicated by code 5 is the yoke of the electromagnet.

As shown in Fig. 3, it is formed into an elliptical cylindrical shape and has a structure that equalizes the sliding resistance of the wire 22 and prevents density unevenness between each dot formed on the paper. .

Cores 6 corresponding to the number of wires 22 are fixed to this yoke 5, and these cores, , j3. A bobbin 8 with a coil 7 wound thereon is fitted into the G section. This bobbin 8 is provided with two ends i'-8a, the winding start and winding end portions of the coil 7 are soldered, and each terminal 8a is formed as shown in the cross-sectional view of FIG. Then, a solder pad 1 is applied to the flexible cable 3 side through the yoke 5 and the heat dissipation plate 4, and the coil 7 is energized.

On the other hand, the reference numeral 9 is a rear guide located at the center of the head body and accommodated in the yoke 5.

One end of a return spring 10 for returning the armature to the initial position after driving the armature is fixed to this rear guide 90, and after the armature 14 is attracted and dot printing is performed by the wire 22, the return spring IO restores the position. , the stopper 15 placed at the rear contacts the stopper 15 and returns to the initial state.

The restoring spring lO and the stopper 15 are aligned so that the movement of the armature 14 is stabilized.

That is, the strength of the restoring spring lO and the hardness of the stopper 15 are determined to enable stable movement of the armature I4, and in this embodiment, polyurethane or the like is used as the material of the stopper 15. There is.

On the other hand, the reference numeral 11 is an auxiliary yoke that is installed in parallel with the yoke 5, and the reference numeral 12 is an auxiliary yoke that causes problems such as wear that occurs when the armature 14 rotates due to line contact with the auxiliary yoke 11, and problems when forming a closed magnetic circuit. A spacer such as a polyester film is inserted between the auxiliary yoke 11 and the armature 14 in order to prevent the movement of the armature 14 from becoming unstable due to residual magnetism of the auxiliary yoke 11.

Further, reference numeral 13 indicates a plunger fixed to the armature 14, and a wire 22 is fixed to the tip of the armature 14 by brazing.

The other end of the armature 14 is provided with a through hole (not shown) into which the fitting portion of the bobbin 8 is fitted.
Armature I4 rotates using this fitting portion as a fulcrum.

Reference numeral 16 denotes an armature holder, which stabilizes the rotation of the armature 14 by pressing and holding the pivot portion from behind when the armature 14 rotates.

The armature boulder 16 is fitted with the stopper 15 . A leaf spring 17 is provided in contact with the armature holder 16.

The armature holder 16 is evenly pressed against the armature holder 16 by elastic displacement of the temporary spring 17.

The arrangement of the auxiliary yoke 11, armature 14, armature holder 16, and leaf spring 17 is shown in FIG. 4G.

On the other hand, what is indicated by the reference numeral 18 is a damper, which is provided on the leaf spring 171-. This damper 18 is made of an aluminum-zinc alloy with excellent vibration damping properties.

This damper 18 has a washer 19. It is held in pressure contact via a spring washer 20 by an external heat radiating part 4j and a back holder 21 made of aluminum Uno-zinc alloy which functions as a vibration isolating member.

Note that the shape of the back holder 21 has a large effect on heat radiation of the wire tod head, so it is desirable that the surface area be as large as possible.

The electromagnet section and the stopper 15 mentioned above are completely sealed by this back holder 21.

By providing the damper 18 so that it can swing freely using the leaf spring 17 and the spring washer 20, the damper 18 has the effect of further enhancing the vibration-proofing effect.

Also, the spring washer 19 is attached to the damper 18 with the spring washer 20
prevents it from digging in.

The wire 22 is attached to each guide 1, 2 for ease of assembly.
's 9 to reduce the resistance from each guide and reduce the sliding resistance of the wire 22.

It has a configuration that improves the efficiency of converting electrical energy into printing energy.

Note that the reference numeral 23 is a screw for attaching the intermediate guy 1-2 to the back holder 2I via the heat radiation plate 4.

Next, the wire 1 of the present invention configured as above
-Explain the operation of the throat head.

Now, when the coil 7 is energized via the flexible/pull cable 3, the yoke 5, i! Ili assistant yoke 11, planon-
v13. Since a closed magnetic path is formed by the core 6, the core 6G coplanon A 13 is attracted, and as a result, the wire 22 coupled to the armature 14 is pushed out, and a 1- A cut is formed.

Now, the function of the heat radiating member that radiates heat generated from the electromagnet during pulse application will be explained.

The pulses supplied from the dot printer main body through the flexible cable 3 are sent from the end r of the bobbin 8 to the fill 7.
The magnetic force Q generated by the armadure 14
is driven. At this time, the heat generated by the coil 7 is transmitted to the yoke 5 via the core 6, and further transmitted to the yoke 5 via the spacer 4 to the back holder 21, which is a heat radiating member.

The heat transferred to the back holder 20 is transferred to the back holder 21.
Heat is radiated from the outside air surface to the outside air.

In this case, the heat radiation effect depends on the original thermal conductivity, surface area size, thermal conductivity, and shape O of the holder 21 having radiation fins.

That is, as shown in FIG. 5, the compatible thermal conductivity of the back holder 21 is λ, the surface area is S, and the thickness is d.

When the degree of blackness of the inner wall of the back bolt 21 is tl, and the temperature of the contact area with the outside air is L2, the thermal fusion Q1 conducted through the back holder 21 is expressed by the following equation (1).

1-t2 Ql-λS ・・・・・・・・・・・・(1) On the other hand, the heat loss Q2 transferred from the surface of the back holder 21 to the outside air is as follows, assuming that the heat transfer coefficient is α and the outside air temperature is 13. It is shown by equation (2).

Yu-α5 (t2-coffin)・・・・・・・・・・・・・・・
(2) Since Q1=Q2 in the steady state, the following equation (3) holds true.

According to Equations (1) to (3) in Part 2, lunar materials with large thermal conductivity λ, that is, aluminum, magosium, or an alloy of aluminum and zinc can be considered as practical metals, but in terms of thermal conductivity, rain The sounds are almost the same.

However, when using aluminum, red sea bream, or silver, instead of the aluminum and zinc alloy that was used for vibration-proofing properties, the wire l-button head can also produce low noise and silent printing. Becomes a genius.

In addition, an alloy of aluminum and zinc has better formability than aluminum or magnesium, so it can be made into a thin layer.

Therefore, since the surface area S in equation (3) can be increased (and the thickness d can be decreased), the heat dissipation effect is extremely low.

Furthermore, aluminum and zinc alloy has a high ability to reduce corrosion, so when molded into a frame or case, it can cause vibrations and noise.
．． Prevention or soundproofing effect is extremely effective for people >< , 4J of wire tod head kborda related to this QltlJ
X') is optimal.

By using an alloy of aluminum and zinc as the back holder 21 which is the heat dissipation part 4, the intermediate guide 2 and the damper 18. It was experimentally confirmed that the head temperature was reduced by 8°C and the noise level decreased by 8°C compared to the conventional head.

In the embodiments described above, the material of the back boulder is an alloy of aluminum and zinc, but the present invention can further adopt the following structure.

That is, the heat dissipation fins formed on the back holder are molded, and the molded F body contains a fine powder with high thermal conductivity and excellent vibration isolation Q, such as an alloy of aluminum and zinc, to improve the heat conductivity of the heat dissipation fins. It is possible to improve the heat dissipation effect and the vibration damping effect.

When such a molding method is employed, the surface area of the heat dissipation fins can be increased due to good moldability, and heat dissipation effects and vibration isolation effects that are approximately the same as those of metal heat dissipation fins can be obtained.

A molding 1 which also serves as a heat dissipating fin containing a fine powder of Zunawara aluminum and an alloy of Ni, i′r; It was experimentally confirmed that the head temperature was 6°C lower than that of the previous model.

In this case, as is clear from equation (3), the back holder 2
If the thermal conductivity α from the surface of 1 is directed, the heat dissipation effect will be further increased.

When heat dissipation fins are also molded from metal, the surface of the molded product is smooth, so the heat dissipation rate, which is an element of the heat transfer coefficient α, is low, and the heat dissipation effect is small. When treated, the emissivity increases several tens of times, so a remarkable heat dissipation effect can be obtained.

Therefore, in the present invention, the heat dissipation effect can be improved by further applying surface treatment such as painting or chemical treatment to the surface of the back holder 21 which also serves as a heat dissipation fin.

For example, in the case of black paint or aluminum, black alumite treatment can be considered.

Next, the alloy O of aluminum and zinc will be explained.

Figure 6 shows a phase diagram of aluminum and zinc.

The cost of mixing aluminum and zinc, which have excellent anti-vibration properties, is 22% by weight for aluminum and 78% for zinc.

In this state, the alloy is in the form of fine crystals of C1, 5 to 5 μm, and the interfacial friction of these crystals causes vibrations to occur.
Vibration damping properties occur due to the so-called self-respect effect, in which energy is converted into thermal energy and absorbed.

On the other hand, Fig. 7 shows an aluminum multi-canute ADC-12.
Figure 8 shows the vibration damping state when an alloy containing 22% aluminum and 78% zinc by weight is used.

As is clear from a comparison of FIGS. 7 and 8, the aluminum and zinc alloy has better vibration damping properties than the solid aluminum casing.

〔effect〕

As is clear from the following explanation, according to the present invention, an alloy of aluminum and zinc is used for the back holder, which is a heat dissipating member that also serves as a heat dissipating fin, and the support member for the carriage of the print head, and an alloy of aluminum and zinc is used inside the head body. Since a structure using an alloy of aluminum and zinc is adopted as a certain vibration-proofing member, a soil dot printer with excellent heat dissipation and low noise can be obtained.

43. Aluminum and zinc alloys can also be used in parts other than the head that generate vibration J (4. For example, core metal of carriages and platens, bearings, gears, etc.).

4 The simplified tilt explanatory diagrams of the drawings are for explaining one embodiment of the present invention, and FIG. 1 is a sectional view taken along the line A--A of the wire tod head 1 diagram, and FIG. -B cross-sectional view, Fig. 5 is an explanatory diagram explaining heat conduction, Fig. 6 is an aluminum laminar l, and sub-j? Figure 7 is a diagram showing the vibration damping state of aluminum and 14 alloys, and Figure 8 is the vibration damping state of an alloy containing 22% aluminum and 78% zinc in terms of ton-to-gross ratio. FIG.

1... Tip guide 2... Intermediate guide 6... Core 7... Coil 14... Armature ■5... Nutopper 18...
・Damper 2■...Back holder 22...Wire patent applicant Canon Co., Ltd. θ.

Agent: Patent attorney Yumi Kafuji (

Claims (4)

[Claims] (1) In the wire dot heel 1-, which is equipped with an armature which is suction operated by an electromagnet housed in the head body, and a plurality of wires, etc., which are fixed at one end of this armature and driven into pressure contact with the paper side, A wire tod head characterized in that a heat dissipating member forming heat dissipating fins for dissipating heat generated by pulse application G to an electromagnet is molded from an alloy of aluminum and zinc. (2) The wire A-- according to claim 1, characterized in that the supporting member of the carriage on which the wire tod head is mounted is molded from an alloy of aluminum and zinc.
Dot head. (3) The wire dot head according to claim 1 or 2, characterized in that the material of the tambour that absorbs vibrations in the dot head is made of an alloy of aluminum and zinc. . (4) The wire tod head according to any one of claims 1 to 3, wherein the alloy of aluminum and zinc has a weight ratio of 22% aluminum and 78% zinc. .