KR970009410B1 - Ferrite core processing method - Google Patents

Abstract

A method for manufacturing a ferrite magnetic core for a digital displacement apparatus capable of improving precision of a size of an inserting hole which is formed therein by dividing a ferrite magnetic core is disclosed. In the method for manufacturing a ferrite magnetic core for a digital displacement apparatus, an inserting hole(2) is formed at a center of a body(1). Body(1) is symmetrically divided along a horizontal direction of inserting hole(2). A slot(3a) of a dielectric(3) is combined with inserting hole(2). After a switch wire(4) is put in the slot(3a), the dielectric(3) is fixed to the inserting hole(2). Another body(1a) is assembled on the body(1).

Description

Manufacturing method of ferrite magnetic core for digital displacement machine

1 is a schematic view showing the structure of a general digital displacement device.

2 is a longitudinal cross-sectional view for explaining the magnetization direction of the ferrite magnetic core.

3 is the magnetic history curve of magnetic materials.

4 is a magnetic history curve of a magnetic material having excellent angle formation.

5 is a longitudinal cross-sectional view of a mold for explaining an embodiment of a conventional powder molding method.

6 is a longitudinal sectional view of a mold for explaining another embodiment of the conventional powder molding method.

7 is a longitudinal sectional view showing a defective product of ferrite cores produced by a conventional manufacturing method.

8 is a longitudinal sectional view of a mold for explaining the manufacturing method of the present invention.

9 is an exploded perspective view showing a ferrite magnetic core obtained by the present invention.

10 is a perspective view showing a state of polishing the insertion hole of the ferrite magnetic core obtained by the present invention.

11 is an exploded perspective view showing a ferrite magnetic core obtained by another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1,1a, 1b: main body 2: insertion hole

2a: insertion defect 3: dielectric

3a: Indentation 4: Switching wire

9: polishing wheel

The present invention relates to a method for manufacturing a ferrite magnetic core for a digital displacement machine used in a phased array radar, which is a fixed radar. More specifically, the ferrite magnetic core is divided into two to improve the dimensional accuracy of the insertion hole formed therein and at the same time the manufacturing method. This is to make it easier.

1 is a schematic view showing a structure of a general digital displacement device, in which a rod-shaped dielectric 3 is inserted into an insertion hole 2 formed in the center of a main body 1 of a ferrite magnetic core, and then the main body 1 and the dielectric ( 3) The switching wires 4 are inserted in between.

Such a digital displacement device uses a magnetization force induced by the current applied to the switching wire 4, and the ferrite magnetic core moves in the direction of the arrow of FIG. 2 according to the direction in which the pulsed magnetization current passes through the switching wire 4. Magnetized.

That is, the direction of magnetization is determined according to the direction of the magnetization current applied to the switching wire 4 as shown in (a) and (b) of FIG. 2.

The magnetized ferrite magnetic core has a magnetic hysteresis curve showing the inherent performance of the magnetic material as shown in FIG.

As such, inherent performance of the ferrite material varies in shape of the curve depending on the performance of the material.

The ferrite permeability (μ) of the ferrite is degraded by the relaxed shape of the magnetic moment when the frequency is high, and thus loses its function as a magnetic material before the microwave band.

However, if a suitable external magnetic field is applied to the ferrite material and a microwave magnetic field is applied in a direction perpendicular to the direction of the magnetic field, the magnetic moment inside the material causes precession.

The precession is the source of the permeability of the microwave band of the material, expressed as the amount of tensor.

If there is a material having a good ratio (magnet ratio) of the magnetization value and the maximum magnetization value of the magnetic hysteresis curve as shown in Fig. 4, a phase shifter having excellent performance can be manufactured using such a material.

That is, if the magnetic field is removed after applying the magnetic field to the maximum magnetic flux density through the coil wound on the ferrite material, the magnetic flux of the magnetic core remains as much as the residual magnetic flux by the magnetic hysteresis characteristic curve.

The residual magnetic flux acts on the magnetic core equivalently to the external magnetic field, and when the microwave passes in a direction perpendicular to the direction of the external magnetic field, the magnetic moment inside the iron core has a tensor permeability due to a new motion.

The amount of the tensor permeability, the dielectric properties of the ferrite and the dielectric constant of the dielectric are synthesized to cause phase shift with respect to the microwave.

The amount of variation of the weft is changed by the performance and phenomenon of the material, the amount of current.

The method of manufacturing a magnetic core using the ferrite material is roughly classified into an extrusion molding and a powder molding method.

5 is a method of forming a ferrite core after charging a raw material such that the center rod 5 is positioned between the lower mold 6 and the upper mold 7 to which the center rod 5 is fixed (hereinafter, referred to as one-time molding method). In the attached drawing, the raw material is inserted between the lower mold (6) and the upper mold (7), followed by primary molding, then the mold is separated, and a mandrel (8) is placed on the upper part of the primary molded semi-finished product. The remaining raw material is charged to the upper portion and the upper and lower molds are pressed to be molded (hereinafter, referred to as a two-time molding method).

In the two molding methods, the mandrel is removed after removing the molded body from the mold.

On the other hand, in the extrusion method, since a lot of pores, etc. are generated in the molded body during the molding operation, the defective rate is increased.

Therefore, in order to prevent this, an additional facility must be provided, which increases the cost of purchasing the facility and complicates the process, thereby decreasing productivity.

In addition, a large amount of pores generated during molding is the root cause of increasing the loss of microwave when applied to the actual product.

On the other hand, the one-time forming method has the advantage of being the most easy to work among the above-described methods, the productivity is excellent, while causing a long density and a severe density gradient penetrating the center.

Such a density gradient causes product breakage in subsequent processes or warpage in a subsequent firing process, making it difficult to insert a dielectric into the insertion hole. In addition, when the precision of the molded insertion hole is lower than the reference value (outer diameter of the dielectric material), a gap is formed between the dielectric to be inserted, so that the conductive paste is applied by inserting a conductive paste on the outside of the dielectric to eliminate the gap. Flows to the outside, which causes a problem that the switching wire cannot be inserted.

In the powder forming method, the two-time forming method is a dry forming method, so that the incidence of pores can be minimized, and the density gradient can be overcome by selecting the molding stroke length in the smallest direction, but this method is known from FIG. As it is, the molding process is very complicated and after completion of the molding operation is necessary to take out the mandrel from the molded body, there is a problem that the productivity is lowered.

In addition, the microwave material cannot achieve the desired performance even if all the other characteristics are satisfied unless the precision of the dimension is very high. In the above method, the shaping of the microwave material is shown in FIG. The same defective product may be mass-produced, and it becomes difficult to secure the precision of insertion hole of the final product, resulting in deterioration of performance.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem in the related art, and is intended to facilitate the manufacture of ferrite cores and to improve the processing precision.

According to a form of the present invention for achieving the above object, the main body is formed by inserting the main body is formed in the center of the insertion hole symmetrically in the horizontal direction from the center line of the insertion hole, and the indentation defect of the dielectric coupled to the insertion groove A method of manufacturing a ferrite magnetic core for a digital displacement machine is provided, which comprises a step of placing a switching wire and then dividing a dielectric body in a direction perpendicular to the center line of the insertion hole and inserting the switching wire into the recess of the dielectric.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 8 to 11 of the accompanying drawings.

8 is a longitudinal cross-sectional view of a mold for explaining the manufacturing method of the present invention, FIG. 9 is an exploded perspective view showing a ferrite core obtained by the present invention, and FIG. 10 is a view for polishing the insertion hole of the ferrite core obtained by the present invention. As a perspective view showing the state, the present invention is the upper and lower dies as shown in Figure 8 to form the main body 1, the insertion hole (2) is formed in the center of the insertion hole symmetrically divided in the horizontal direction One side of (6) (7) is formed in the same manner as the one outer surface of the main body 1, and the other side forms a protrusion 10 which is 1/2 of the height of the insertion hole.

Therefore, the raw material is charged between the upper and lower molds 6 and 7, and the molding is completed to obtain the main body la as shown in Fig. 9 having a good density gradient.

If the dimensional accuracy of the insertion flaw 2a formed on one side of the main body la is good, the post process may be performed. However, if the dimensional precision is lowered, the microwave passes through the inside of the coating pipe 11 of FIG. This results in a loss of, thereby increasing the precision of the dimensions by post-processing using the polishing wheel 10 as shown in FIG. 10. By this process, the body la is obtained and the recesses of the dielectric 3 are a After inserting the switching wire 4 into the inside, the dielectric 3 is fixed in the insertion flaw 2a of the main body 1a as shown in FIG.

Thereafter, the assembly work is completed by assembling the main bodies so as to overlap each other as shown in FIG. 9 with the insertion flaws 2a formed in the other main body 1a facing the dielectric 3 side.

Figure 11 is an exploded perspective view showing a ferrite magnetic core obtained by the embodiment according to the present invention, the manufacturing method is as follows.

In order to form the main body 1b on which the insertion hole 2 is formed by dividing and forming the body 1b at right angles from the center line G of the insertion hole, a one-time molding method of the powder molding method is used.

Accordingly, the stroke length of the upper and lower Geumhyeon is very short during the molding operation, thereby minimizing the pressure gradient of the molded body (main body), thereby minimizing the density gradient of the molded body.

After the main body 1b is obtained by such a process, a plurality of main bodies are arranged and fixed to each other as shown in FIG. 11, and the dielectric 3 is inserted into the insertion holes 2 formed in the main body.

Thereafter, the assembly process is completed by inserting the switching wire 4 into the recessed groove 3a formed in the dielectric 3.

As described above, the present invention divides the main body so that the stroke length of the mold is minimized during the molding operation, thereby minimizing the density gradient, and thus reducing the incidence of defective products, as well as inserting the post-processing process. The effect is to minimize losses.

Claims (4)

The main body 1 having the insertion hole 2 formed at the center thereof is symmetrically divided in the horizontal direction of the insertion hole, and is switched to the recesses 3A of the dielectric agent 3 joined by the insertion holes of the main body. A method of manufacturing a ferrite magnetic core for a digital displacement machine comprising a step of mounting a wire (4) and then fixing a dielectric to an insertion defect of a main body, and assembling another main body (1a) with an upper surface of the main body. The method of manufacturing a ferrite magnetic core for a digital displacement machine according to claim 1, further comprising a step of post-processing the insertion groove (2a) of the molded body. The method of manufacturing a ferrite magnetic core for a digital displacement machine according to claim 2, wherein the insertion flaw (2a) is post-processed by a polishing wheel (9). Splitting and molding the main body 1 in which the insertion hole 2 is formed at right angles from the center line G of the insertion height, assembling the molded main body 1b, and the insertion hole of the assembled main body And (2) inserting and fixing the dielectric (3) and inserting the switching wire (4) into the recesses (3a) of the dielectric.