JPH01141004A - Molding of sintering prototype body - Google Patents

Abstract

PURPOSE:To mold a sintering prototype body being capable of mold release without getting out of shape even if the prototype body has a complicate shape, by molding a mold for the sintering prototype body by solidifying ferromagnetic particles. CONSTITUTION:A molding frame 1 and a prototype member 4 are monolithically vibrated by means of a vibrator and filled with a filling material 18 tightly. A magnetic plate 2 of the molding frame 1 is charged with electricity to magnetize the filling material 18 and to prevent each particle of the filling material 18 from moving relatively. A mold face 19 having the same shape as that of the mold face 5 of the prototype member 4 is thereby formed of the filling material 18, a mold coating material 17 and an insulating film 16. Molds 22 thus obtained are set face to face on the upper and lower sides while the magnetized condition and the condition of reduced pressure are being kept to form a cavity 21 having the same shape as that of a molded item to be molded and a slurry path 23 one end of which is open to the cavity 21 and another end of which is open to the outer walls of the molds 22 and 22. When a ceramic slurry is poured into the cavity 21, contained water is brought into contact with the insulating film 16, dissolved and furthermore vaporized and a ceramic prototype body made of the slurry aggregate is formed in the cavity 21.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for forming a sintering prototype having a complex shape from ceramic powder or metal/non-metal powder.

(Prior art and problems to be solved by the invention) Conventionally, one of the methods used to form a prototype body for sintering from ceramic powder is the mud casting method, in which ceramics are placed in a plaster mold. There is a method of injecting a slurry and allowing the slurry solvent to be absorbed by plaster to obtain a prototype. By the way, the original shape inside the plaster mold has low strength, and when it dries, it may shrink and cling to the mold, so it is difficult to release the original mold with a complicated shape from the plaster mold. It tends to lose its shape when

The present invention has been made in view of the above-mentioned circumstances, and aims to provide a method for molding a sintering prototype that can be releasable, without losing its shape even if the shape is complex. It is something.

(Means for Solving the Problems) In order to achieve the above object, the gist of the present invention is to mold a mold for a sintering original body by solidifying ferromagnetic particles by magnetic force. That is, in the present invention, a non-porous shielding film that can be dissolved in a slurry solvent or a porous shielding film that can be penetrated by a slurry solvent is suction-adhered to the molding surface of an original member, and a ferromagnetic film is applied to the surface of the shielding film. A molding material is applied, a molding frame is placed on the opposite side of the shielding film to the original member, a filler made of ferromagnetic particles is filled in the molding frame, and the filler is applied with a magnetic force. After solidifying and adsorbing the shielding film to the filler side, the original member is released from the shielding film to form a mold having a molding surface, and another mold is molded in the same manner. A cavity is formed by aligning the mold with the mold, and the pressure inside the mold is reduced, and a slurry containing sintering raw material as aggregate is injected into the cavity, and after a predetermined period of time, the inside of the mold is reduced. The depressurized state of the mold is released, and after a predetermined period of time has elapsed, the magnetized state within the mold is released.

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

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional view showing the state of the molding surface during molding, and FIG. 2 is a longitudinal sectional view showing the state of the molding die during cavity molding and depressurization.

In the figure, (1) is a molding frame with a rectangular plane formed by communicating openings on the upper and lower surfaces, and the molding frame K (1)
A magnet plate (2) is attached to the inner peripheral surface of the magnet plate (2), and the magnet plate (2) is connected to a power source (not shown) via a conductive wire (3).

Next, (4) is an original member made of wood or the like, and the original member (
4) A molding surface (5) is formed on the upper surface, and
A protrusion (6) for a slurry flow path is provided on the negative side of the molding surface (5).
is formed. Furthermore, a hollow chamber (7) is formed in one part of the original member (4), and the molding surface (5)
A plurality of ventilation holes (8) communicating with the hollow chamber (7) are bored in the hollow chamber (7). A communication hole (9) communicating with the outside is provided at one end of the hollow chamber (7), and the communication hole (9) is connected to a suction device (not shown) via a hose (11).

Further, (12) is a suction plate that can close the opening on the upper surface of the molding frame (1), and a porous member (13) is attached to the recessed portion on the lower surface of the suction plate (12). A communication hole (14) leading to the outside is provided in the center of the recess,
The communication hole (14) is connected to a suction device (not shown) via a hose (15).

(Operation) The process of forming a sintering original body using the apparatus configured as described above will be explained. First, the molding surface of the original member (4) (
5), a shielding film (16) made of water-soluble polyvinyl alcohol and having a thickness of about 30 μm is added while being moisturized to give flexibility. Second, a suction device (not shown) on the original member (4) side is activated to pass the forming surface of the original member (4) from the communication hole (9) through the hollow chamber (7) and each ventilation hole (8). (5)
The shielding film (
16) is suctioned and adhered along the molding surface (5), and the shielding film (16) is provided on the molding surface (5) and the molding surface (5), which is the same as the T-nisrary channel protrusion (6). Form into shape. Third, a coating material (17) made of ferromagnetic soft ferrite powder, phenol powder, polyvinyl butyral, and ethanol is applied to the surface of the shielding film (16).

Fourth, the molding frame (1) is placed on the molding surface (5) having the shielding film (16) of the prototype member (4), and the molding frame (1) is placed on the molding surface (5) having the shielding film (16).
) is filled from above with a filler (18) consisting of metal particles (PC Permalloy, manufactured by Width Metal Foil & Powder Industry Co., Ltd.), and the forming frame (18) is filled with a vibrator (not shown).
) and the original member (4) are vibrated together, and the filling material (
18) Firmly (fill).

Fifth, the magnet plate (2) of the molding frame (1) is energized to magnetize the filler (18) so that the particles of the filler (18) cannot move relative to each other. As a result, a molding surface (19) having the same shape as the molding surface (5) of the original member (4) is formed using the filler (18), mold coating material (17), and shielding film (16).

Sixthly, the back opening of the molding frame body (1) is connected to a suction plate (12).
The suction device (not shown) on the suction plate (12) side is operated to reduce the pressure inside the molding frame (1) through the communication hole (14) and the porous member (13). Stop the operation of the suction device on the original member (4) side, and
) When the original member (4) is removed from the molding frame (1) with the molding surface (5) side of the molding surface (5) in communication with the atmosphere, the molding surface (19) is held on the molding frame (1) side. The original member (4) is released from the molding surface (5) in the T2 state.

Seventh, the molds (22) molded in this way are placed vertically opposite each other as shown in FIG. 2 while maintaining their internal magnetization state and depressurized state. 2
1) and a slurry flow path (23) which opens at one end into the cavity (21) and at the other end into the outer wall of the mold (22) (22).

Eighth, from a storage tank (not shown), a ceramic slurry made by adding an acrylic resin wax emulsion and distilled water to alumina powder (manufactured by Showa Denko, AL-170'J, mixing and degassing) is poured into the slurry flow path (23 ) into the cavity (21).

At this time, the moisture in the ceramic slurry is removed from the molding surface (19
) is in contact with the shielding film (16) to melt it, which is further sucked into the filling material (18) toward the suction plate (12) and vaporized, resulting in a slurry in the cavity (21). A ceramic prototype body made of aggregate is formed.

At this time, the pressure and flow rate of the ceramic slurry are controlled by a high-pressure pump (not shown) and the ceramic slurry is pumped into the cavity (21).
Because it is injected into the interior, the original form is densely packed and has fewer and smaller internal voids.

Ninth, when the original shape has solidified to some extent after a predetermined period of time has elapsed, the operation of the suction device on the suction plate (12) (12) is stopped and the suction plate (12) (12) is removed. Tenthly, the original shape body is molded into a mold (22) (22
) is left in the mold (22) for a predetermined period of time to dry and solidify it, and then the electromagnet (2) is turned off to release the magnetized state inside the mold (22). , each particle of the filler (18) can move freely, and the molding surface (1
9) collapses, the original mold body can be easily taken out from within the mold (22) (22).

In the examples, alumina powder was used as the aggregate of the ceramic slurry, but other ceramic powders may be used. The method of the second embodiment can be applied not only to ceramics but also to powder metallurgy using metals and non-metals.

Furthermore, in the examples, an alloy of iron and nickel (trade name, PC Permalloy) was used as the ferromagnetic particles, but pure iron,
Metal grains made of an alloy of iron and silicon, an alloy of aluminum and silicon, etc. may also be used. In this case,
The smaller the particle size (and the smaller the residual magnetism, the better).

In addition, in the examples, a polyvinyl alcohol composition was used as a water-bathable shielding film to be applied to the molding surface of the original member, but in addition to this, polyvinyl alcohol compositions were used, such as polyethylene glycol, polyethylene oxide, methyl cellulose, carboxymethyl cellulose, polysodium acrylate, polyvinyl alcohol composition, vinyl pyrrolidone,
A proboscis made of polyvinyl bumolana or the like may also be used.

Further, in the examples, a water-bathable shielding membrane was used, but a porous shielding membrane (for example, a polypropylene polymer separation membrane) that is permeable to the solvent in the slurry may also be used.

Further, in the examples, when applying the shielding film to the molding surface of the original member, humidification treatment was performed to increase flexibility, but it may be heated and softened.

Further, in the embodiment, a previously formed shielding film was applied to the molding surface of the original member, but a shielding film raw material may be applied to the molding surface and solidified to form a film.

Furthermore, in the examples, the pressure inside the molding frame is reduced when the original member is released from the molding frame, but this is not an essential requirement.
The inside of the mold may be depressurized when the ceramic slurry is injected into the cavity formed by fitting the molds together.

(Effects of the Invention) According to the present invention as described above, the solvent (moisture) in the ceramic slurry injected into the mold dissolves the shielding film or permeates through the shielding film and is quickly absorbed into the mold. Since it is absorbed by the filler, the slurry is rapidly dehydrated and solidified.

Furthermore, when the original mold body in the mold cavity dries to some extent and solidifies, the metal particles forming the mold are released from the solidified state due to the magnetic force, so the molding surface also collapses and the original mold shrinks due to drying. It does not cling to the mold, and even if the original shape is weak, it will not lose its shape (it can be removed from the mold).

Therefore, the present invention is suitable for molding a sintering original body having a complicated shape.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional view showing the state of the molding surface during molding, and FIG. 2 is a longitudinal sectional view showing the state of the molding die during cavity molding and depressurization. (1): Molding frame (4): Original member (5): Molding surface (16): Shielding film (17): Coating material (18): Filling material (21): Cavity (22): Molding mold procedure City Sho Show $1163318 August 1986 Special 6'1 condyles No. 301141 2, Invention? - Formation method of the prototype body for sintering 3, relationship with the amended table case Patent applicant address (residence) 4-7-23 Meieki, Nakamura-ku, Nagoya, Aichi Prefecture Shin 1-Ukogi, Toyota Building 311 Name: Shinto Kogyo Co., Ltd. February 3, 1988 (Shipping date: February 23, 1988)
6. Details of the amendment The following has been added between page 2, line 3, tr and line 4. [3. Detailed Description of the Invention] The above procedures are as follows: April 1, 1988, Case Description, 1988, Patent Application No. 301141, 2, Name of the Invention: Molding of a master body for sintering I'j payment 3. Relationship with the Akane case to be amended Patent applicant address (residence) 4-7W Meieki, Nakamura-ku, Nagoya, Aichi Prefecture
No. 123 Inside the Toyota Building 1-U Name Shinto Kogyo Co., Ltd. Company details Page 9, lines 13 to 14 "Polyvinyl butyral" is referred to as "Polyvinyl butyral" and correct it. that's all

Claims (1)

[Claims] A non-breathable shielding film (16) that can be dissolved in a slurry solvent or a porous shielding film (16) that can be penetrated by a slurry solvent is adhered to the molding surface (5) of the original member (4) by suction. Applying a ferromagnetic mold coating material (17) to the surface of the shielding film (16), placing a molding frame (1) on the opposite side of the shielding film (16) to the original member (4), The molding frame (1
) is filled with a filler (18) made of ferromagnetic particles,
The filler (18) is solidified by magnetic force to form the shielding plate (1).
6) to the filler (18) side, and then the original member (4) is released from the shielding film (16) and the molding surface (1
9) is molded, and the mold (22) is
) is molded in the same manner as another mold (22) to form a cavity (21), and the mold (22)
) (22) and reduce the pressure inside the cavity (21).
A slurry containing sintering raw materials as aggregate is injected into the mold (22), and after a predetermined period of time, the reduced pressure inside the mold (22) is released, and after a further predetermined period of time, the mold (22) is (22
) A method for forming an original body for sintering, characterized by canceling the magnetized state within ).