JPH0310849A - Impact dot head - Google Patents

Abstract

PURPOSE:To enable a great amount of printing to be quickly performed by removing deterioration of printing quality due to heating by a method wherein a coil is formed by winding a conductive wire on a core, and the core is fixed to a core block. CONSTITUTION:A conductive wire 2 forms a coil 3 by being wound close fast onto a columnar core 1. The core 1 is fixed to a groove to which a core block fits, and a radiator 5 abuts against an outer periphery of the core block 4. Through the coil 3 is heated by Joule's loss in electrification, since the coil 3 is close to the core 1, heat is soon transmitted to the core 1, and temperature of the coil 3 is prevented from ascending. Since the heat transmitted to the core 1 is transmitted to the core block 4 and is radiated into the air from the radiator 5, temperature of the whole of an impact head can be also prevented from ascending. Since the conductive wire is directly on the core 1 when the coil 3 is formed, a special technique for keeping a shape is not required like a bobbinless coil, and the title impact dot head can be manufactured at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an impact dot head for an impact printer.

[Conventional technology]

Impact dot heads perform printing by selectively protruding printing wires by energizing or demagnetizing them with a coil. Conventionally, a coil bobbin with conductive wire wound around the required number of cores arranged circularly in a core block was inserted into each. has been done. Because this coil bobbin was molded from plastic, the heat generated by the coil could not be effectively transferred to the core and core block, resulting in low cooling efficiency.

In addition, bobbinless coils have been used in the past, but in order to prevent damage when inserted into the core, a clearance is required between the coil and the core, and the coil does not necessarily fit tightly to the core, so even bobbinless coils have low cooling efficiency. There was a limit.

In this way, with the conventional structure, heat transfer from the coil to the core is poor, and the temperature of the coil tends to rise.One reason is that the increase in coil resistance causes the current to decrease, resulting in a decrease in printing force, resulting in poor print quality. There is a problem of decreasing
One problem is that the amount of printing is limited to prevent coil burnout, making it impossible to quickly print a large number of letters.

Furthermore, bobbinless coils require special technology to form, and to maintain a certain shape, it is necessary to use special wire materials such as heat-sealable wire materials. The problem was that soldering was difficult and expensive.

[Problem to be solved by the invention]

Therefore, the present invention was developed to solve these problems.The purpose of the present invention is to use a coil and core structure with extremely high cooling efficiency to print a large amount of characters without deteriorating print quality due to heat generation. To provide an inexpensive impact dot head that can be produced quickly.

[Means to solve the problem]

Therefore, the impact dot head of the present invention has (1) an impact dot head that performs printing by selectively protruding a plurality of printing wires by energizing and attracting or demagnetizing and releasing them with a coil, in which the coil is formed by winding a conducting wire around a core. (2) Further, the core is provided with a terminal guide made of an insulating member having a coil terminal, and the end of the conductive wire wound around the core is fixed to the coil. It is characterized by being fixed to the terminal.

(3) Furthermore, the core is molded by a sintering method using powder injection molding.

〔Example〕

Hereinafter, the present invention will be described in detail based on examples.

FIG. 1 is a sectional view showing one embodiment of claim 1.

A conductive wire 2 is tightly wound around a columnar core 1 to form a coil 3. The core 1 is fixed in a groove into which a core block 4 fits, and a radiator 5 is in contact with the outer periphery of the core block 4. Further, a yoke plate 6 is laminated on the core block 4,
Holding amateur 7. When the armature 7 is on standby, it is pressed by the return spring 8 and positioned by the damper 9.
It faces the core 1 with a predetermined air gap and is arranged rotatably about one end on the core block 4 as a fulcrum by a fulcrum holder 16 made of an elastic material, and a wire 10 is fixed to the narrow end. The end of the coil wire 2 passes through a tapered hole in the leg extending close to the coil 3 of an insulating plate 17 made of insulating resin, and is soldered to a copper foil on the board 11, and is connected to a wire drive (not shown). connected to the circuit. core 1
, the core block 4, the yoke plate 6, and the armature 7 are made of high magnetic permeability material and form one magnetic circuit. By making the core 1 a material with extremely high magnetic permeability such as permendur and molding the core block 4 from an inexpensive material such as pure iron or silicon steel, an impact dot head with good magnetic efficiency and low cost is provided. It is also possible to do so. Further, the method of fixing the core 1 to the core block 4 is not limited to fitting, adhesion, welding, and brazing, and is not limited to the same timing.

The coil 3 is energized in response to a printing instruction, the armature 7 is attracted, and the wire 10 fixed to the tip of the armature 7 collides with the printing medium 13 via the ink ribbon 12, thereby printing a dot. After printing, the wire 10 returns to its standby position due to the reaction force at the time of the collision and the spring force of the return spring 8.

When energized, coil 3 generates heat due to Joule loss, but core 1
Because it is in close contact with core 1, heat is quickly transferred to core 1,
It is possible to prevent the temperature of the coil 3 from rising. The heat transferred to the core 1 is transferred to the core block 4, and is radiated into the air from the radiator 5, so that an upper limit on the temperature of the entire impact head can be prevented.

In forming the coil 3, the coil 3 is wound directly onto the core 1, so special techniques to maintain the shape unlike bobbinless coils are not required, and the coil 3 can be manufactured at low cost.

FIG. 2 is a sectional view showing one embodiment of claim 2.

The operation of the impact dot head is the same as that of the embodiment shown in FIG. 1, so a description thereof will be omitted. Further, FIG. 3 shows a partially sectional perspective view of the core 1, coil 3, coil terminal 14, and terminal guide 15 shown in the embodiment of FIG. 2.

The core 1 is columnar and has a stepped portion 1a, and has a terminal guide 15.
is positioned and inserted into the stepped portion 1a. Also,
The terminal guide 15 of the stepped portion 1a is positioned in the height direction with respect to the core block 4 by the surface of the stepped portion 1a opposite to the surface on which the terminal guide 15 is positioned.

The terminal guide 15 is injection molded from an organic material with good heat resistance and high insulation properties, and the two coil terminals 14 are press-fitted therein. The coil terminal 14 is made of a rod-shaped conductive material. The coil 3 is made by winding the conducting wire 2 around the side surface of the pillar of the core 1 in the above state, and tying the end of the conducting wire 2 to the coil terminal 14.
Molded by soldering.

In the impact dot head constructed in this manner, the coil 3 is in close contact with the core 1 as in the embodiment shown in FIG. is possible. Furthermore, since it is soldered to the coil terminal 14 like a coil with a coil bobbin, it is easy to insert into the board 11 and solder, and unlike a bobbinless coil, special technology is not required, so the cost is low. It can be manufactured by

In addition, by molding with a sintering method using powder injection molding, it is possible to obtain the core 1 at low cost and with good precision. Since materials not suitable for forging can be used, an impact dot head with good magnetic efficiency can be provided at low cost. Furthermore, it is also possible to obtain a more complex core shape.

In each example, in order to ensure electrical insulation, it is preferable to provide an insulating synthetic resin coating on the side surface of the core around which the coil is wound.The thickness of this coating is several tens of microns to 0.1 microns.
Approx. mm is suitable. The film is formed by powder coating.

Although this embodiment uses an excitation-attraction type impact dot head as an example, it goes without saying that the same effect can be obtained in a spring-charge type impact dot head that drives a wire by demagnetization and release.

〔Effect of the invention〕

In the impact dot head constructed as in claim 1, the conductor is wound closely around the core, so the heat generated in the coil is quickly transferred to the core, and the cooling efficiency of the coil is extremely high. Therefore, there is no deterioration in printing quality due to heat generation, and there is a small restriction on the amount of printing to prevent coil burnout, so it is possible to quickly print a large amount of printing. Furthermore, unlike a bobbinless coil, special techniques are not required for winding, so an inexpensive impact dot head can be provided.

In the impact dot head configured as claimed in claim 2, the ends of the conductive wires are soldered to the coil terminals, so insertion into the board and soldering is easy, and assembly can be performed at low cost. Therefore, in addition to the effect of claim 1, it is possible to obtain an impact dot head that is cheaper.

In the impact dot head constructed as in claim 3, the height is 3! A highly accurate core made of Il property can be obtained at a low cost, and therefore the effect of claim 1 can be obtained at a lower cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the invention, FIG. 2 is a sectional view showing another embodiment of the invention, and FIG. 3 is a partially sectional perspective view of the embodiment of FIG. 1...Core 1a...Core step portion 2...Conducting wire 3...Coil 4...Core block 5...Radiator 6...Yoke plate 7...Amateur 11...Substrate 12... Ink ribbon 13... Print medium 14... Coil terminal 15... Terminal guide 16... Support holder 17... Insulating plate or above 7 fa

Claims (3)

[Claims] (1) In an impact dot head that performs printing by selectively protruding a plurality of printing wires by energizing or demagnetizing them with a coil, the coil is formed by winding a conducting wire around the core, and the core is formed into a core block. An impact dot head characterized by being fixed to. (2) The impact dot head according to claim 1, wherein the core is provided with a terminal guide made of an insulating member having a coil terminal, and an end portion of the conductor wire wound around the core is fixed to the coil terminal. . (3) The impact dot head according to claim 1, wherein the core is formed by a sintering method using powder injection molding.