JP2001334516A - Molding method and molding device for molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding method wherein a molded article having unevenness on the surface can be easily manufactured by a simple constitution using a uniaxial molding press. SOLUTION: One section of the surface of a lower punch 12 of this molding device is projected upward under a separated state. At the same time, the projected member (movable block 12c) is made movable accompanying the deformation of an elastic material 12d arranged under the movable black 12c. First, a MnZn based powder 15 is filled in the upper space (recess 11a) of the lower punch, and then, an upper punch 13 is arranged above the powder. At the same time, the powder is pressurized by a specified molding pressure through the upper punch by using the uniaxial molding press. The powder is compressed, and a recess is formed at the section corresponding with the movable block. At the time of pressurization, the elastic material is elastically deformed, and moves the movable block downward. Thus, one section of the pressure applied to the recess is absorbed by the elastic material, and the pressure is suppressed from being concentrated to the recess. Therefore, the pressure is uniformly applied to the whole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for molding a molded article.

[0002]

BACKGROUND OF THE INVENTION In order to produce a ferrite core, a dry-granulated powder is filled in a mold having a predetermined shape and pressed to produce a ferrite molded body having a predetermined shape.
Next, the ferrite molded body is fired and then subjected to processing and finishing such as surface grinding.

[0003] A ferrite molded body is formed to have a certain size larger than a final ferrite core in consideration of a shrinkage rate during firing and a polishing allowance in processing and finishing treatments. It is formed. Therefore,
The surface of the ferrite molded body for a ferrite core having a concave portion on the surface also has a concave portion, and the shape of the mold of the molding device also has a structure in which a convex portion corresponding to the concave portion is formed on the surface of the lower punch.

[0004] When a ferrite molded body is molded by using a uniaxial molding press, stress is concentrated on a thin portion due to a difference in wall thickness due to surface irregularities, and the density is increased. The density distribution of each part varies. This variation in density causes variation in dimensional accuracy of the sintered body due to variation in sintering density and distortion during sintering, and eventually variation in magnetic properties in the final ferrite core. The degree of this variation becomes more pronounced as the size and shape of the final product are larger.

[0005] Therefore, in order to improve the characteristics of the ferrite core of the final product, it is necessary to make the density of each part of the ferrite molded body uniform. For that purpose, a high-performance multi-axis press, a mold set having a complicated structure of a mold set, and a molding device equipped with a mechanism for moving the mold at a predetermined timing are required, and the device is large, complicated, and expensive. Becomes

In the case where the ferrite core has a relatively small size and shape, even if it is formed using a uniaxial pressing machine, the difference in thickness is small, and the variation in characteristics occurring in each part is also small. According to the above, it is possible to manufacture easily and inexpensively by using a molding apparatus using a uniaxial molding press, but a ferrite molded body having a large size and shape exceeding 10 cm has a large difference in density, and a uniaxial molding press is required. It is difficult to manufacture with the used molding equipment.

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and an object of the present invention is to solve the above-mentioned problems, to have a simple configuration using a uniaxial molding press, and to have irregularities on the surface. It is an object of the present invention to provide a molding method and a molding apparatus for a molded body that can easily produce a molded body.

[0008]

Means for Solving the Problems In order to achieve the above-mentioned object, a method for molding a molded article according to the present invention is a method for molding a molded article having a concave portion on the surface. Then, a part of the surface of the lower punch of the forming device is protruded upward in a separated state, and the protruded member is made movable along with the deformation of the elastic material disposed therebelow. First, a powder is filled in the space above the lower punch, and then an upper punch is disposed above the powder, and a predetermined pressure is applied to the powder via the upper punch using a uniaxial molding press. Pressing is performed at a molding pressure, and at the time of the pressing, the elastic material is elastically deformed to move the protruding member downward.
In the embodiment, the molded body is a ferrite molded body, but the present invention can be applied to other molded bodies as long as the powder used as the molding material is other than the ferrite material. Of course, when the magnetic properties are taken into consideration, a ferrite molded article is obtained.

A molding apparatus suitable for carrying out such a method is a molding apparatus for forming a molded body having a concave portion on the surface, wherein a lower punch constituting the molding device has a concave portion on the surface. And a moving member (corresponding to a “moving block” in the embodiment) disposed on the elastic material in the concave portion. Further, the upper punch disposed above the lower punch was formed so as to be able to press the powder filled between the lower punch and the upper punch by a uniaxial press.

In this manner, the powder pressed by the upper punch is compressed and formed. At this time, the powder portion facing the protruding member (moving member) is pushed by the member. As a result, a concave portion is formed on the surface of the molded body. At this time, stress tends to concentrate on the concave portion, but the force is absorbed by the elastic deformation of the elastic material. Therefore, the density distribution of the molded article becomes uniform as a whole, and the sintered density and the magnetic properties of the sintered body obtained by the subsequent firing treatment become uniform. Such a uniform and high-performance formed body and sintered body can be realized by a simple-shaped lower punch and a uniaxial forming press.

The elastic material only needs to be capable of elastic deformation.
Various materials can be used. In particular, it is preferable to use a rubber-based material, because when the molding pressure is removed, the shape returns to the original shape by the elastic restoring force, so that the material can be repeatedly used. Various materials such as natural rubber, general-purpose synthetic rubber, and special synthetic rubber can be used as the rubber-based material. Further, various shapes such as solid and powder can be applied.

According to the experimental results, when the elastic material has a Young's modulus of 1 × 10 ⁹ Pa or less, the variation in the molding density and the sintering density at each position in one solid is small, and the final sintered body is small. It was also found that the magnetic properties of the samples were uniform. Further, various kinds of powders can be used as the powder, for example, a ferrite powder can be used, and further, a MnZn-based ferrite powder can be used.

On the other hand, as a specific shape of the molded body, for example, the planar shape is a sector shape, and the concave portion is a concave groove formed along an arc (in the first embodiment). Realization), the planar shape is a disk shape, and the concave portion may be a ring-shaped concave groove formed along the circumference (realized in the second embodiment), or the planar shape. Is a disk shape, and the concave portion is a concave portion formed at the center (realized in the third embodiment). Of course, other shapes may be used.

[0014]

FIG. 1 shows an example of a ferrite core manufactured according to a first embodiment of the present invention. As shown in the figure, eight disc-shaped ferrite cores 1 are prepared by preparing eight fan-shaped ferrite cores 2 having a central angle of 45 degrees and arranging them so that their centers coincide with each other.
Is formed. The fan-shaped ferrite core 2
On the outer peripheral side of the upper surface, a concave groove 2a is formed along the peripheral side. Therefore, when the eight fan-shaped ferrite cores 2 are arranged, the concave grooves 2a are connected to form a ring shape. By arranging a coil in the ring-shaped concave groove 2a, a transformer or the like can be configured.

The ferrite core 1 has a large diameter of, for example, 370 mm. In other words, the radius of the fan-shaped ferrite core 2 is 185 mm.
Is formed using a uniaxial molding press.
Specifically, as shown in FIG. 2, a mold die 11 having a plane fan shape is placed on a base 10. Mold die 11
Is a frame along the contour of the sector, and the inside is a recess 11
a. Then, the out-of-plane shape of the recess 11a is substantially equal to the dimension and shape of the outer shape of the ferrite molded body (strictly, slightly smaller in consideration of the amount of expansion when the ferrite molded body is extracted from the mold). Has formed.

The lower punch 12 is inserted and arranged in the recess 11a of the mold die 11. The planar shape of the lower punch 12 substantially matches the inner shape of the recess 11a.
On the upper surface of the lower punch 12, a convex portion is formed at a position where the concave groove 2a of the fan-shaped ferrite core 2 is formed. The convex portion is one of the features of the present invention, and a detailed description of the structure will be described later.

The upper space of the lower punch 12 (recess 1)
1a) is filled with a predetermined powder 15 and the recess 1
A flat upper punch 13 is inserted into 1a, and the powder 15 is pressed through the upper punch 13 with a predetermined pressure by a hydraulic press or the like.

As a result, the powder 15 is compacted into a space formed by the lower surface (flat surface) of the upper punch 13, the upper surface of the lower punch 12, and the inner peripheral surface of the mold die 11.
A ferrite molded body having a predetermined shape (a concave groove 2a is formed at a portion facing the convex portion) is formed.

Here, in the present embodiment, the configuration of the convex portion of the lower punch 12 where the stress is concentrated when pressing by the upper punch 13 is as follows. That is, the concave groove 12b is formed at the position where the convex portion is formed on the upper surface of the fan-shaped substrate 12a. Then, an elastic material 12d is loaded into the concave groove 12b, and the elastic material 1
On the 2d, a moving block 12c having an outer shape corresponding to the concave groove 12b was mounted. In other words, the position where the convex portion is formed is divided, and the substrate 12a and the moving block 12 are divided.
c, and an elastic material 12d is formed between the moving block 12c and the concave groove 12b formed in the divided portion of the substrate 12a.
Is configured to intervene.

At the time of no pressure application, the upper surface is located lower than the upper surface of the substrate 12a as shown in the figure, and the space formed by the upper surface of the elastic material 12d and the concave groove 12b formed in the substrate 12a has: The lower part of the moving block 12c is inserted and positioned.

The elastic material 12d has a certain volume when no pressure is applied, and has a function of being elastically deformed and compressed when pressurized. Specifically, the elastic material 12d is formed using a rubber-based material. You. At this time, the Young's modulus is more preferably 1 × 10 ⁹ Pa or less. The elastic material 12d is preferably a rubber-based material as in the present embodiment, because when the pressure is released by the elastic restoring force, the elastic material returns to its original shape and can be reused. However, focusing only on processing, various materials such as urethane and sand can be used, since elastic deformation is sufficient. However, in the case of urethane or sand, once the elastic material is elastically deformed and its volume (volume) shrinks, it does not return to its original state even if the pressing force is released, so it is necessary to replace the elastic material 12d each time. is there. Therefore, it is preferable to use a rubber-based material that does not need to be replaced.

With this configuration, FIGS. 2A and 3
As shown in (a), after filling the granulated powder into the concave portion of the die 11, the upper punch 13 is placed on the powder 15 and pressed at a predetermined pressure. Then, the powder 15 is compressed and formed into a predetermined mold shape. At this time, the molding pressure applied to the powder located above the moving block 12c is higher than the molding pressure applied to the surrounding powder.

Therefore, stress tends to concentrate on the concave groove 2a of the fan-shaped ferrite core 2 formed corresponding to the moving block 12c, but the molding pressure applied above the moving block 12c is elastically deformed via the moving block 12c. Material 12d
The elastic material 12d is compressed and deformed (see FIG. 3).
(B)). Due to this elastic deformation, a part of the excessive molding pressure is absorbed, the concentration of stress on a part of the powder 15 can be suppressed, and a ferrite molded body having a uniform density distribution as a whole is formed. Therefore, the magnetic properties of the sintered body (fan-shaped ferrite core 2) obtained by firing the ferrite molded body are also uniform no matter where the measurement is made.

Next, the following experiment was conducted in order to verify the effect of the present invention. Using the molding apparatus of the above-described embodiment, a predetermined amount of MnZn-based powder (6H40 material: manufactured by Fuji Electric Chemical Co., Ltd.) granulated by the spray drying method is filled in the fan-shaped mold die 11. Next, a fan-shaped ferrite molded body was molded at a molding pressure of 0.75 ton / cm ² using a hydraulic press with the upper punch 13 inserted into the mold die 11. At this time, the holding time at the time of maximum pressurization was 10 seconds, and the shape of the upper punch was always constant. Next, the ferrite compact was taken out and fired according to the temperature pattern shown in FIG.

As a comparative example, the shape of the lower punch is shown in FIG.
A flat type flat plate as shown in (a) (hereinafter referred to as type (a)) and an integral type with convex portion as shown in FIG. A ferrite core sintered body was manufactured under the experimental conditions. The lower punch in the molding apparatus of the present invention is a separation type (hereinafter, type (c)) in which an elastic material 12d is interposed below a moving block 12c as shown in FIG.

Then, the fan-shaped ferrite cores manufactured using the type (a) and the type (c) of the present invention have cracks,
Although chipping did not occur, the fan-shaped ferrite core manufactured using type (b) had poor moldability and a high incidence of cracking and chipping. Also, when the warpage of the sintered body was confirmed, there was almost no warpage in types (a) and (c),
In the type (b), warpage was confirmed.

Further, the ferrite molded body (before firing) in nine points No. 1 to No. 9 shown in FIG. 6 (type (a) is a flat fan-shaped plate having no grooves in the portions No. 4 to No. 6). ) And the sintered density (see FIG. 8) of the ferrite compacts and the sintered compacts manufactured using the lower punches of each type. As is clear from FIGS. 7 and 8, the molding density distribution of each part of the ferrite molded body manufactured by using the present invention (type (c)) and the sintered density distribution of the sintered body have no irregularities. As in the case of the flat plate, uniform characteristics without variation were obtained in each part. On the other hand, those manufactured using the integrated lower punch of the type (b) are No. 4 to No.
It was confirmed that the portion of No. 6 was significantly different from the other portions.

The temperature characteristics of the magnetic characteristics (core loss value [100 kHz, 200 mT]) at each point were measured. FIG. 9 shows the temperature characteristics of the core loss value of the sintered body manufactured using the type (a), FIG. 10 shows the temperature characteristics of the core loss value of the sintered body manufactured using the type (b), FIG. 11 shows a temperature characteristic of a core loss value of a sintered body manufactured using the type (c).

As is clear from these figures, the magnetic properties produced by the method of the present invention (FIG. 11) are the same as those of the type (a) producing a flat sintered body (FIG. 9). Similarly, it becomes uniform over the entire sintered body, but the type (b)
It can be seen that the core loss is significantly different between the parts manufactured by using No. (FIG. 10) and the concave groove part where the stress concentration occurs (No. 4 to No. 6) and the other parts.

As described above, the ferrite molded body and the sintered body manufactured by the apparatus (method) of the present invention have uniform characteristics and the like even if the surface has irregularities. It can be confirmed that a flat ferrite molded body or a sintered body having the same size as that of the sintered body can be obtained. In addition, a die, an upper punch, and a lower punch can be realized with a simple configuration using a uniaxial press.

Further, when each product was manufactured using the molding pressure applied when manufacturing a ferrite molded body using the type (c) and the sintering temperature during firing as parameters, the magnetic characteristics (core loss value) were , As shown in FIG. As is apparent from the figure, it is possible to further reduce the loss by optimizing the molding pressure and the firing temperature.

Further, specific illustration is omitted, the pressure distribution of the ferrite green body formed by changing the Young's modulus of the elastic material was confirmed by a simulation by the finite element method, a Young's modulus of 5 × 10 ⁶ of The deviation (variation) of the pressure applied to each part at that time was 1.9%. Also,
Young's modulus is 1 × 10 ⁹ , 2.50 × 10 ¹⁰ , 1.97
The deviation of the pressure applied to each part at the time of × 10 ¹¹ was 10%, 44%, and 45%, respectively. When it was 1 × 10 ⁹ or less, it was confirmed that the molding density was suppressed within ± 5% and the firing density was suppressed within ± 1% with respect to the average value.

According to this embodiment, a large-diameter disk-shaped ferrite core can be formed. Therefore, for example, one of the non-contact type transformers, which is one of the charging methods for electric vehicles,
Next, it becomes practically usable as a ferrite core for coils on the secondary and secondary sides. That is, the ferrite core is required to have a low-loss material to suppress heat generation during charging and a material having a high saturation magnetic flux density to cope with a large current at the time of input. Yes, inevitably,
The diameter also increases. According to the present invention, since a large-diameter disk-shaped ferrite core can be formed with uniform characteristics as a whole and without deformation, it is used as a core for a non-contact transformer for quick charging. it can.

FIG. 13 et seq. Show a second embodiment of the present invention. In the present embodiment, as shown in FIG. 13, a disk-shaped ferrite core 3 having a ring-shaped concave groove 3a on its upper surface is manufactured. That is, the disk-shaped ferrite core 3 is integrally formed.

A cylindrical die 11 ′ (center is a flat circular recess 11 ′ a) is placed on the base 10 in accordance with the outer diameter of the disk-shaped ferrite core 3. Also,
The lower punch 12 'has a ring-shaped concave groove 12'b formed at a predetermined position on the upper surface of a substantially disk-shaped substrate 12'a. A rubber-based or other elastic material 12'd is mounted in the groove 12'b, and a cylindrical moving block 12'c corresponding to the inner shape of the groove 12'b is set thereon. . At this time, the lower part of the moving block 12'c is mounted in the concave groove 12'b.

Further, the upper punch 13 'is used for the die 1
It has a disk shape having an outer diameter that matches the inner diameter of the recess 11'a of 1 ', has a pressurizing portion having a flat lower surface, and moves downward by receiving pressure from a hydraulic pump.

With this configuration, similarly to the first embodiment, the die 15 'is filled with the predetermined powder 15 and the powder 15 is pressed by the upper punch 13' at the predetermined molding pressure. (Hydraulic press). As a result, a disk-shaped ferrite molded body in which a ring-shaped groove is formed in a portion corresponding to the operation block 12'c. At this time,
Due to the elastic deformation of the elastic material 12'd, stress is suppressed from being concentrated on the concave groove portion of the ferrite molded body, the molding pressure becomes uniform as a whole, and the sintering density and magnetic properties are uniform after firing. A body is formed.

Also in this embodiment, FIGS. 15 (a) to 15 (c)
3 lower punches (types (a) to (c))
, A MnZn-based powder (6H40 material: manufactured by Fuji Electric Chemical Co., Ltd.) was pressed at 0.75 ton / cm ² to produce a ferrite molded body, and the sintered body was formed according to the firing pattern shown in FIG. Was manufactured. Each of the lower punches is basically formed in a disk shape. FIG. 1 (a) has a flat upper surface, and FIG. 1 (b) has a ring-shaped projection formed integrally on the upper surface. FIG. 9C shows a moving block 12'c according to the present invention, which is separated from a substrate 12'a.

As a result, the disk-shaped ferrite core manufactured using the type (a) and the type (c) of the present invention did not have any cracks or chips, but the disk-shaped ferrite core manufactured using the type (b). The ferrite core had poor moldability and a high incidence of cracking and chipping. In addition, when the warpage of the sintered body was confirmed, there was almost no warpage in types (a) and (c), but warpage was confirmed in type (b).

Further, a ferrite molded body and a sintered body having a planar shape as shown in FIG. 16 are formed. Then, for the nine points No. 1 to No. 9 shown in the figure, the molding density (see FIG. 17) and the sintering density (see FIG. 18) of the ferrite molded body (before firing) were determined using a lower punch of each type. The measurements were performed on the ferrite compacts and sintered compacts manufactured by the method described above.

The temperature characteristics of the magnetic characteristics (core loss value [100 kHz, 200 mT]) at each point were measured. FIG. 19 shows the temperature characteristics of the core loss value of the sintered body manufactured using the type (a), FIG. 20 shows the temperature characteristics of the core loss value of the sintered body manufactured using the type (b), FIG. 21 shows a temperature characteristic of a core loss value of a sintered body manufactured using the type (c).

As can be seen from the above figures, the molding density distribution of each part of the ferrite molded body manufactured by using the present invention (type (c)), the sintered density distribution of the sintered body, and the magnetic properties (core loss value) In the case of ()), uniform characteristics without variation were obtained in each part as in the case of a flat plate having no irregularities. On the other hand, in the case of using the integrated lower punch of the type (b), it was confirmed that the portions of No. 4 to No. 6 which become the concave portions and the other portions were significantly different.

Further, the molding pressure applied when manufacturing a ferrite molded body using the type (c) according to the second embodiment of the present invention and the sintering temperature during firing are used as parameters for each product. When manufactured, the magnetic properties (core loss values) were as shown in FIG. As is apparent from the figure, it is possible to further reduce the loss by optimizing the molding pressure and the firing temperature.

FIG. 23 et seq. Show a third embodiment of the present invention. In the present embodiment, as shown in FIG. 23, a disk-shaped ferrite core 4 having a flat circular recess 4a at the center of the upper surface is manufactured. A cylindrical mold die 11 ″ (central recess 11 ″ a at the center) is placed on the base 10 in accordance with the outer diameter of the ferrite core 4. In the lower punch 12 ", a circular recess 12" b is formed at the center of the upper surface of the substantially disk-shaped substrate 12 "a. In the recess 12" b, a rubber-based or other elastic material 12 is formed. ″ D, and from above, the recess 1
2 "disk-shaped moving block 12" corresponding to the inner shape of "b"
Set c. At this time, the lower part of the moving block 12 "c is mounted in the recess 12" b.

The upper punch 13 'is used for the die 1
It has a disk shape having an outer diameter matching the inner diameter of the 1 "recess 11", has a pressurizing portion having a flat lower surface, and moves downward by receiving pressure from a hydraulic pump.

With this configuration, similarly to the first and second embodiments, the mold die 11 "is filled with the predetermined powder 15 and the upper punch 13" separates the powder 15 into the predetermined powder. Pressure at the molding pressure (hydraulic press). As a result, a disk-shaped ferrite molded body in which a circular recess is formed in a portion corresponding to the operating block 12 "c. At this time, the concave of the ferrite molded body is formed by the elastic deformation of the elastic material 12" d. Concentration of stress on the groove portion is suppressed, the molding pressure becomes uniform as a whole, and a sintered body having uniform sintering density and magnetic properties is formed after firing.

[0047]

As described above, in the method and apparatus for molding a molded article according to the present invention, a part of the surface of the lower punch of the forming apparatus is separated, and the lower part of the lower punch is moved under the separated member (moving member). Since the elastic material is arranged and the member is lowered by elastic deformation of the elastic material at the time of pressure molding,
The stress is not concentrated on the concave portion of the powder pressed by the member, and the molding pressure can be applied uniformly as a whole. Therefore, it is possible to easily produce a molded body having a simple structure using a uniaxial molding press and having irregularities on the surface.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a ferrite core manufactured according to a first embodiment of the present invention.

FIG. 2 (a) is a cross-sectional view showing a first embodiment of a molding apparatus according to the present invention. (B) is a top view showing a die.

FIG. 3 is a diagram illustrating an operation.

FIG. 4 is a diagram showing firing conditions.

FIG. 5 is a diagram showing an example of a lower punch used to demonstrate the effect of the present invention.

FIG. 6 is a diagram showing measurement points in a manufactured molded body and a ferrite core.

FIG. 7 is a view showing an experimental result (molding density).

FIG. 8 is a view showing an experimental result (sintering density).

FIG. 9 is a diagram showing experimental results (temperature characteristics of Type-a core loss).

FIG. 10 is a diagram showing experimental results (temperature characteristics of Type-b core loss).

FIG. 11 is a diagram showing experimental results (temperature characteristics of core loss of Type-c).

FIG. 12 is a diagram showing experimental results (pressure characteristics of core loss).

FIG. 13 is a diagram illustrating an example of a ferrite core manufactured according to the second embodiment of the present invention.

FIG. 14A is a cross-sectional view showing a second embodiment of the molding apparatus according to the present invention. (B) is a top view showing a die.

FIG. 15 is a diagram showing an example of a lower punch used to demonstrate the effect of the present invention.

FIG. 16 is a diagram showing measurement points in a manufactured molded product and a ferrite core.

FIG. 17 is a diagram showing an experimental result (molding density).

FIG. 18 is a view showing an experimental result (sintering density).

FIG. 19 is a diagram showing experimental results (temperature characteristics of type-a core loss).

FIG. 20 is a diagram showing experimental results (temperature characteristics of core loss of Type-b).

FIG. 21 is a diagram showing experimental results (temperature characteristics of Type-c core loss).

FIG. 22 is a diagram showing experimental results (pressure characteristics of core loss).

FIG. 23 is a diagram showing an example of a ferrite core manufactured according to the third embodiment of the present invention.

FIG. 24 (a) is a sectional view showing a second embodiment of the molding apparatus according to the present invention. (B) is a top view showing a die.

[Explanation of symbols]

 Reference Signs List 1 ferrite core 2 fan-shaped ferrite core 2a groove 3 disk-shaped ferrite core 3a groove 4 disk-shaped ferrite core 4a recess 10 base 11, 11 ', 11 "mold die 11a, 11'a, 11" a recess 12 , 12 ', 12 "Lower punch 12a, 12'a, 12" a Substrate 12b, 12'b, Groove 12 "b Recess 12c, 12'c, 12" c Moving block 12d, 12'd, 12 " d Elastic material 13, 13 ', 13 "Upper punch 15 Powder

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B30B 11/02 B30B 11/02 F H01F 41/02 H01F 41/02 D (72) Inventor Kiyoto Ono Tokyo 5-36-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. (72) Inventor Fumiaki Nakao 5-36-11 Shimbashi, Minato-ku, Tokyo F-term in Fuji Electric Chemical Co., Ltd. 4G053 AA11 CA03 DA03 EA01 EA27 EB17 4G054 AA07 AB03 AC00 BA45

Claims (10)

[Claims] 1. A method of molding a molded body having a concave portion on a surface, wherein a part of the surface of a lower punch of a molding device is protruded upward in a separated state, and the protruded member is moved to a lower side thereof. The upper punch is placed above the powder, and the upper punch is placed above the powder by using a uniaxial press. And pressurizing the powder with a predetermined molding pressure through the elastic member. At the time of the pressing, the elastic material is elastically deformed and the protruding member is moved downward. Molding method. 2. The method according to claim 1, wherein the elastic material is made of a rubber material. 3. The elastic material has a Young's modulus of 1 × 10 ⁹ P
The molding method according to claim 1 or 2, wherein a is equal to or less than a. 4. The method according to claim 1, wherein the powder is a MnZn-based ferrite powder. 5. The molding according to claim 1, wherein the molded body has a fan shape in plan view, and the concave portion is a concave groove formed along an arc. A method for forming a molded body. 6. The molded product according to claim 1, wherein the planar shape is a disk shape, and the concave portion is a ring-shaped concave groove formed along a circumference. A method for molding a molded article according to claim 1. 7. The molding according to claim 1, wherein the molding has a disk shape in plan view, and the recess is a recess formed in the center. Body molding method. 8. A molding apparatus for forming a molded body having a concave portion on a surface, wherein a lower punch constituting the molding device comprises: a substrate having a concave portion on the surface; and an elastic material mounted in the concave portion. A moving member disposed on the elastic material in the concave portion, wherein the upper punch disposed above the lower punch is filled between the lower punch and the upper punch by a uniaxial press. A molding apparatus characterized in that powder can be pressurized. 9. The molding apparatus according to claim 8, wherein the elastic material is made of a rubber material. 10. The elastic material has a Young's modulus of 1 × 10 ^9.
The molding apparatus according to claim 8, wherein the pressure is Pa or less.