JPH04232603A - Manufacture of ceramic fixing frame for magnetic head - Google Patents

Abstract

PURPOSE:To provide a manufacturing method of a ceramic fixing frame for magnetic heads which is excellent in dimensional accuracy and can be worked easily by a powder molding method. CONSTITUTION:When this ceramic fixing frame for magnetic head is press- molded by using a concave punch 4 for forming the projecting section of the molded body on the bottom side, a top punch 1 is inserted into a die 2 0.1 second earlier than the starting of pressurization and the die 2 is pressed when the punch 1 reaches the 1/4-1/2 of the filling amount of the die 2.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method of manufacturing a ceramic fixing frame for a magnetic head, which has high dimensional accuracy and excellent workability using a powder molding method. The present invention relates to a method of manufacturing a required ceramic fixing frame for a magnetic head.

0002

[Prior art] Ceramic fixing frames for magnetic heads generally use titania-based ceramic materials.
It is obtained by performing predetermined processing on blocks manufactured through the steps of calcination, crushing, granulation, molding, and firing. However, the magnetic head fixing frame is rarely used in a simple shape such as a flat plate, and requires some kind of unevenness.For this reason, if you try to provide a stepped part during molding, the shape will be small and the molding of the stepped part will be difficult. It was difficult, and defects such as pinholes and cracks were likely to occur. Furthermore, since high dimensional accuracy is required, conventionally it has been customary to first form a plate into a plate shape, sinter it, and then form it into a stepped shape using a grinding process. Therefore, the yield of the material is poor and the grinding process requires a large number of steps.

0003

[Problems to be Solved by the Invention] The present invention eliminates the drawbacks of the conventional method and achieves high dimensional accuracy and high homogeneity of the sintered body by integrally molding it into a stepped convex shape during molding. ,
The purpose of the present invention is to provide a manufacturing method for producing a ceramic fixing frame for a magnetic head by only cutting, without microscopic internal defects such as pinholes and cracks, and with excellent workability.

0004

[Means for Solving the Problems] That is, in the present invention, when pressure molding is performed by using a concave punch on the lower side to form a convex portion of a molded article, the upper punch is moved 0.1 seconds or less earlier than the start of pressing. When the die is inserted into the die and reaches 1/4 to 1/2 of the die filling amount, pressure is forcibly applied from below by pressing the die to increase the density of the compression molded product to 2.0 g/cm3 or more. Provided is a method for manufacturing a ceramic fixing frame for a magnetic head, which prevents the occurrence of cracks in the stepped part of the molded body by keeping the upper punch in contact with the molded body for 0.1 to 0.3 seconds after the product has finished rising. do.

[0005] Furthermore, according to the present invention, if the contact of the upper punch is made shorter than 0.1 seconds after the product has been lifted, cracks will occur at the boundary line.
If the time exceeds 0.3 seconds, the product may adhere to the upper punch.

[0006]

[Function] With the above-described structure, the present invention makes it possible to manufacture a ceramic fixing frame by only cutting, by preventing cracks from occurring at the boundary line of the rising part of the convex fixing frame bar in the shape of the convex fixing frame bar. It can be manufactured at 1/4 of the conventional processing cost.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1A and 1B are perspective views of the molded body. (C) is a perspective view of the ceramic fixing frame after cutting.

FIGS. 2 and 3(A) to 3(E) are explanatory diagrams of a press apparatus showing the manufacturing method of the present invention.

An upper punch 1 is provided above the granulated powder 3 of calcium titanate having a specific particle size filled in the space of the die 2, and a lower punch 4 is provided below.

Next, a description will be given based on FIG. 3. Granulated powder 7
During pressure molding, when the upper punch 5 descends (after the start of the pressurization process), the upper punch 5 lowers 0.1 seconds or less earlier than before the main pressurization.
is inserted into the die with an air pressure of 3.0 kg/cm2 (the moment the upper punch is lowered and inserted into the die, the upper punch holder part 10 is moved from the upper punch fixing part 9 to the upper punch holder part 10 at a pressure of 3.0 kg/cm2).
It is lowered independently at a pressure of cm2. ) After moving the granules, start the main pressurization and reduce the amount to 1/4 to 1/4 of the required die filling amount.
When the upper punch is inserted to 1/2, pressure is generated from below by pressing the die, and the molding pressure is 1.0.
By applying pressure from above and below at T/cm2, the molding density is 2.
It was possible to achieve a uniformity of 0 g/cm3 or more. Also, after the end of the pressurization, the die descends and the molded object rises, and after the end of the rise, the upper punch is kept in contact with the molded object for 0.1 to 0.3 seconds, and the air pressure is 1.5 k.
By raising the upper punch holder part 10 at a rate of g/cm2, it was possible to prevent the generation of cracks in the stepped part of the molded body. In addition, the relationship between upper punch insertion, contact time, insertion pressure, and contact OFF pressure against cracks is shown in Figures 4 (A) and (B).
Shown below.

Subsequently, the obtained molded body was fired in a firing furnace, and as a result, the dimensional accuracy of the ceramic fixing frame bar was ±1 in width dimension.
%, and there were no cracks or pinholes.

[0012] Compared to the conventional method of grinding a plate-shaped fired body into a ceramic fixing frame, the method of the present invention makes it possible to reduce the processing cost by 60%.

[0013] In this invention, the particle size of the granulation raw material (
The reason for limiting the size of particles constituting the powder is 20
If fine powder of less than 150 μm is mixed in, bridges will be formed in the granulated raw material powder filled in the die, causing variations in the unit weight height of the molded product, which is undesirable. This is because if it is mixed, it will cause variations in molding density, which is not preferable.

[0014] Furthermore, if the upper punch is inserted into the die more than 0.1 seconds after the start of pressurization, cracks will occur at the boundary line between the stepped part, the stepped bottom part, and the stepped convex part of the molded product. I don't like it. Also, 1/4 to 1/2 of the required die filling amount.
If pressure is applied from below at points other than point 2, it will be difficult to make the density of the compression molded product uniform to 2.0 g/cm3 or more. Further, if the density of the compression molded body is less than 2.0 g/cm 3 , it is difficult to reduce the dimensional accuracy after firing to ±1% or less, and excellent workability cannot be obtained.

[0015] Although this embodiment has been explained using the method of molding a convex molded body as a representative example, it is of course possible to mold other molded bodies requiring complicated unevenness under similar conditions. .

[0016]

[Effects of the Invention] As explained above, according to the present invention, a fixing frame for a magnetic head having a complex shape with a convex portion can be manufactured easily and with high precision, and the processing cost is also significantly reduced, which is extremely useful industrially. It is.

[Brief explanation of the drawing]

[Fig. 1] (A) is a perspective view of a ceramic fixing frame according to an embodiment of the present invention; (B) is a perspective view of the same ceramic fixing frame; (C) is a perspective view of the ceramic fixing frame after cutting;

[Fig. 2] A cross-sectional view of a press device used in an embodiment of the present invention.

FIG. 3: (A) is a cross-sectional view of the press process of the present invention; (B) is a cross-sectional view of the press process of the present invention; (C) is a cross-sectional view of the press process of the present invention; (D) is a cross-sectional view of the press process of the present invention; Cross-sectional view (E)
is a sectional view of the pressing process of the present invention

[Figure 4] (A) is a characteristic diagram of time and air pressure for crack generation (B) is a characteristic diagram of time and air pressure for crack generation

[Explanation of symbols]

1 Upper punch 2 Dice 4 Lower punch 5 Upper punch 6 Dice 8 Lower punch 9 Upper punch fixing part

Claims (2)

[Claims] 1. Ceramic fixing for a magnetic head, characterized in that a concave mold forming a convex part of a molded body using Ca-based titania granules having a particle size of 20 to 150 μm during powder molding uses a punch on the lower side. How to manufacture the frame. [Claim 2] When performing pressure molding, insert the upper punch into the die 0.1 seconds or less before the start of pressurization, and force it when the required die filling amount reaches 1/4 to 1/2. Apply pressure from below to reduce the density of the compression molded product to 2.0g/c.
2. The method for manufacturing a ceramic fixing frame for a magnetic head according to claim 1, wherein the upper punch is kept in contact with the molded body for 0.1 to 0.3 seconds after the lifting of the product is finished.