JPS5846609A - Core of dot printer head and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve the fragility of a core by using a high Si content ferrosilicon for its internal part while using a low Si content ferrosilicon for its circumference part. CONSTITUTION:A metal mold 5 for extrusion molding has at its lower end an extruding opening 8 with a triangular section. A core circumference material layer 6, made from a mixture of a low Si content (1-2wt% after sintering) ferrosilicon powder, a binder, a thermoplastic plasticizer and an organic solvent, is provided to the inner surface of the metal mold 5 which is then filled with a mixture 7 of a high Si content (6.5wt% after sintering) ferrosilicon powder and the minimum of a low evaporation temperature organic solvent. Then, using a press 4, the material layer 6 and the mixture 7 are extruded from the extruding opening 8 while heating the mold 5 by means of a heating coil placed around the mold. An extruded ferrosilicon rod 9 is cut and sintered to obtain a dot printer head core 2 with its circumference part made from a low Si content ferrosilicon 6' and with the internal parts made from a high Si content ferrosilicon 7'.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a core for a dot printer head. It has been improved to improve the magnetic properties of the 9-dot fv printer head and to make it easier to install it.

The dot fv printer head has an electromagnetic element that drives the print bin! Dunnetts are provided for each of the plurality of bins. For example, as shown in FIG. 1, a plurality of electrodes 2 are arranged in a ring shape on one base 1 to form this electromagnetic network. One method of attaching the core 2 to the page 1 is by press-fitting it into the recess 3 provided in the pace l as shown in Figure 2; It is used. Usually l~ as core material
Silicon iron containing 2wtX silicon (81) is used. For example, 81@6.5wt%Ot with a high 81 content
It is well known that silicon iron exhibits excellent magnetic properties as a core material.However, silicon iron, which is abundant in FK81, is very brittle, so it is difficult to make the core by the press-fitting method described above. If you try to lock in pace, your core will break.

The purpose of the present invention is to obtain a 6.5wtX Sl content with excellent magnetic properties.
An object of the present invention is to provide a core for a dot printer head that uses silicon iron and can be easily press-fitted and fixed to a pace, and a method for manufacturing the same. For this reason, the core for a dot printer head according to the present invention has an interior made of silicon iron with a high silicon content, and an outer peripheral part made of silicon iron with a low silicon content. The core for such a dot printer head is made of an extruded material made of silicon iron powder and an organic component, filled in an extrusion mold, heated and extruded through an extrusion port of a predetermined shape to form a silicon iron rod. It is manufactured by forming a bar material and cutting (sintering) the bar material. A peripheral material layer is provided on the inner surface of the extrusion mold, and silicon iron powder with a high silicon content is filled inside the core peripheral material layer, and this is extruded together with the core peripheral material layer. The above-mentioned silicon iron bar is formed.

Hereinafter, the present invention will be explained in more detail based on the drawings. Figure 3 shows nine states of 0Wf after filling the extrusion mold with extrusion material.
In FIG. riI, the extrusion mold S has an extrusion port 8Yt having a triangular cross section, for example, at its lower end.

Low Si with a silicon content of 1 to 2 vtX after sintering
On the inner surface of the extrusion mold 5, a layer of external material 6 made of a mixture of a certain amount of silicon iron powder, a binder, a thermoplastic lubricant and an organic solvent is provided. Inside this core outer peripheral material layer 6, after sintering, there is a high Si content such that the i content is a5wtX.
An organic solvent with a low evaporation temperature is added to a quantity of silicon iron powder to fill it with 7 tons of mixture. This mixture 7t-core outer peripheral material layer 6 and % KIE 4 are extruded through an extrusion port 8 using a press 4 as shown in Figure 4. At this time, a heating coil (@ (No) Fri 11! 100-200CI! The silicon iron shrine is extruded from the extrusion port 8 by JIK heating, cut and sintered as shown in Fig. 11, and the outer periphery becomes low Si content silicon iron 6 as shown in Fig. 11. ′, high Si content silicon iron inside 7′
A core 2 for a dot printer head is obtained.

As explained above, the original F! The core for dot printer heads related to AK has good magnetic properties because the inside is made of high-81 silicon iron, and the outer periphery is made of low-Si silicon iron, which improves brittleness and allows the core to be press-fitted. Even if it is fixed to a pace according to the law, it will not break and can be easily installed. In the present invention, when the core is extruded, the organic material containing the pineapple plasticizer and solvent-based carbon is brought into contact with the mold in order to tightly bond the outer periphery of the core and improve the bond between the core and the mold. The minimum amount of organic solvent may be added to the internal high-St silicon iron powder, which is mixed in large amounts in the outer peripheral material layer of the core. Therefore, carbon, which causes deterioration of magnetic properties, does not remain inside the core, and since the part with a large amount of carbon is the outer periphery containing binder and plasticizer, carbon is easily removed during the high-temperature sintering process. A core with a small amount of residual carbon can be obtained as a whole. Also, during extrusion molding;
5.Nine extrusion rotor with excellent wearability - There is no need to use special pressure-resistant materials to create it.

Examples are shown below based on specific numerical values of the present invention.

The amount of Sl in the outer peripheral portion was set to gvrt%. The amount of Sl after Kerr sintered Niru iron powder and 17wtX81 silicon iron alloy powder!
Mix it so that it becomes vtX, and this mixed powder 190115
On the other hand, as a binder? sls libinyl putte tool
, 14 parts methyl ethyl ketone as a solvent, methyl alcohol t 7
1 part, butyl alcohol t-2 parts, stainless steel -
A slurry was prepared by boiling for 72 hours in 4 bottles of 49 ethylene with the molten metal. Using this slurry tube, a thickness of 0.
A green sheet of No. 8 was molded. This green sheet was pasted on the inner surface of an extrusion mold.

The amount of S1 in the center is (L 5 v t X. Car?
8 after sintering the 17vtX81 silicon iron alloy powder and the 17vtX81 silicon iron alloy powder.
1 amount is 6. S v t A 0-order mold filled with the powder obtained by K in this way is placed inside the raw sheet.
These powders were extruded while heating at 00CK. By performing K in this manner, a molded body having a low S1 in the outer peripheral portion and a high St in the central portion is obtained. This molded body was sintered at 1350° C. for 1 hour in a hydrogen atmosphere. When the sintered body thus obtained was pushed into the recess of the base material, it was able to be fixed without breaking.

In addition, when molding the outer periphery of the core, a paste may be made and the yeast may be applied to the inner surface of the mold instead of producing the green sheet.

[Brief explanation of the drawing]

FIG. 1 is an external view of a dot printer head according to the present invention;
FIG. 2 is a cross-sectional view showing the core fixed state of the dot printer head according to the present invention, FIGS. 3 and 4 are cross-sectional views of a mold sequentially showing the steps of the method of the present invention, and FIGS. FIG. 2 is a perspective view of the core for a dot printer head. 1...Pace, 2...Core, 3...Concavity, 5...
・Length for extrusion molding: 6" ・Low 81% silicon iron, 7'
...High 81% silicon iron. Patent originator Fujitsu Ltd. Patent application agent Akira Saneki Patent attorney Kazuyuki Nishidate Patent attorney Yukio Uchida Akira Yamaguchi Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. A core for a dot printer head, in which the interior is made of silicon iron with a high silicon content, and the outer peripheral part is made of silicon iron with a low silicon content. 2 Fill an extrusion molding material consisting of silicon iron powder and an organic component into an extrusion molding hanger, extrude it through an extrusion port of a predetermined shape while heating it, and form a silicon iron bar. A silicon iron powder and a binder with a low silicon content in a method of manufacturing a core for a dot printer head by cutting and sintering. A core peripheral material layer made of a mixture with a thermoplastic plasticizer is provided on the inner surface of the extrusion mold, and silicon iron powder with a high silicon content is filled inside this core peripheral material layer. A method for manufacturing a core for a dot printer head, characterized in that the core outer peripheral material layer is extruded to form the silicon iron O bar material.