JPS6376749A - Reducing pressure and pressurizing casting method - Google Patents

Abstract

PURPOSE:To obtain a casting having solid good quality by a forming die having pressure proof and high durability by opening an inside of alpha-'Sialon(R)' quality ceramic forming die, made by a hot-pressing or sintering under ordinary pressure, by shifting a stopper pin at the same time of reducing pressure by sucking, to feed the molten metal under pressurizing. CONSTITUTION:The forming die A composing of an upper and a lower both dies is a solid solution having alpha-Si3N4 structure and it is constituted by alpha-'Sialon(R)' quality ceramic composing of closed complex structure phase, called to 'partial stabilizing' alpha-'Sialon(R)' region, in which 60 vol.% of alpha-'Sialon(R)' granular crystal shown by Mx(Si, N)12(O, N)16 (in this molecular formula, M is used for Mg, Ca, Y, etc.) and 40 vol.% of columnar crystal of beta-Si3, N4 co-exist. At the same time of reducing pressure 2 by sucking from a cavity (a) by drawing the stopper pin 6, the molten metal is introduced from a runner 7a and by pressing the pin 6, the molten metal is poured under pressurizing. By the forming die having pressure proof and high durability, the casting is cast under good venting, and the casting having solid good quality is obtd. and the forming die A can be repeatedly used.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to vacuum and pressure casting methods, and relates to 1)
Using high-temperature molten metal with a pouring temperature of up to about 650°C, the inside of the mold is depressurized by suction before filling the molten metal into the mold, and after filling the molten metal, the inside of the mold is pressurized to solidify the molten metal. This invention relates to a casting method for casting and molding products.

<Traditional Limb Techniques> Traditionally, this type of decompression and pressurization method has not been performed since it is dangerous due to the material of the pair of female molds. .

In other words, conventional molds are made of heat-resistant metal such as high chromium molybdenum steel for both the male and I molds.
For this reason, metal fatigue caused by heat rain from high-temperature molten metal up to 600-1650'C (M) is severe, and if pressure is applied to it, there is a risk of mold cracking, and if mold cracking occurs, etc. There is a risk that a part of the molten metal filled in the mold will enter the cracked part of the mold and solidify (solidify) with the product part, causing major problems such as making it impossible to remove the product part. There is.

<Problems to be solved by the invention> The problems to be solved by the invention are 600 to 1650
Up to ℃? By providing a reduced pressure, H0 pressure casting method that enables pressure casting using 5-temperature melting, it is possible to cast products with high density, high quality, and high precision made of ultra-fine structures. be.

<Means for Solving the Problems> The technical means taken by the present invention to solve the above problems is to suck the inside of a pair of molds made of sintered ceramics after closing the molds. At the same time as reducing the pressure, the hot water supply stopper bottle that opens and closes the g port is moved backward to close the hot water supply port, the mold is filled with molten metal, and the hot water supply stopper bottle is moved forward to close the hot water supply port and molded. The feature is that the inside of the mold is pressurized to solidify the molten metal while tightening.

<Example> An example of the present invention will be described based on the drawings. The drawings show a vertical die casting machine, and the mold (Δ) is a movable platen (
b+) is installed on the male type (at) and the fixed platen (
The installation in b2) consists of a set with an IL mold (al) to be installed, and after closing the similar molds (at) and (al), the pressure inside the mold (hereinafter referred to as the cavity) (a) is reduced. At the same time, the melt 313 (M) of the product/material is filled, and the melt C (M) is solidified while pressurizing the interior of the kitobity (a).

The male and 1111 molds (at) and (al) are made of sintered ceramics, and the molds (at) and (aZ) are connected to the outside of the mold at appropriate locations on the dividing surface within the kitobity (a). A wide gas vent path (1) is formed, and a suction device (2) is installed and removed at the end of the gas vent path (1).

The suction device (2) has the function of suctioning and reducing the pressure inside the opening/bite (a) after the male and female molds (al) are closed. At the terminal opening, there is a female type (a
A suction pipe (2a) is connected to the suction pipe (2a) in a fixed state on the side (l), and connected to the suction pipe (2a) via a connecting means such as a connecting hose.

Then, the suction device (2) is connected to the drive source (shown in the figure) of the mold closing cylinder (3) to complete the operation of the layer V'' source.
At the same time as the end of the mold closing operation, the operation is started to suction and depressurize the inside of the cavity (a).

In addition, as shown in the figure, a heat-resistant porous material such as porous ceramics (4) is fitted at the entrance of the suction pipe (2a) connected to the gas vent passage (1).
Prevent impurities such as cast burrs in the bit (a) from entering the suction device (2).

In addition, (
) A hot water supply communication passage (5) communicating with the cavity (a) is formed on the mold dividing surface facing the gas vent passage (1), and a hot water supply stopper bin (5) is formed in the communication passage (5). 6) is inserted so that it can slide forward and backward.

This hot water supply stopper bin (6) is connected to the hot water supply connection path (5).
) to move the hjl through (al) to the movable platen (bl) by moving it forward and backward as if opening and opening the hot water supply port (8) of the hot water supply path (7), which is perforated vertically on all four sides. Metal (including sintered metal), in this embodiment, sintered ceramic, is formed into a square or round rod shape, and its tip side is slidably connected to the hot water supply communication path (5) 1'. While freely inserting the JJ, the rear end side is connected to a drive source (Size shown in the figure), and the drive source moves it backwards and forwards to open the hot water supply port (8) when filling with (M). , the hot water supply port (8) is closed at the same time as filling is completed.

Note that the hot water supply path (7) is connected to the hot water supply connection path (5) as shown in the figure.
), the male mold (al) is provided with one hole, and the lower opening protrudes from the first step 513 (bl) that connects to the hot water supply port. The second sleeve body (7b) consists of:

In the figure (9), Molten iQ (M) is filled into the cavity (a) and the hot water supply stopper bottle (6) is inserted into the hot water supply port (
The movable bob (9) is made of sintered ceramics and has a male mold. (a
The pressurizing cylinder (b+) is fitted into the center of the upper and lower passages so as to be movable, and the pressurizing cylinder (
io), the pressurized cylinder (10) is operated to slow down the vertical movement. In addition, pressurized cylinder <10)
The drive source (shown in the figure) is connected to the drive 1FII source of the hot water supply stopper bin (6) and the drive source of the mold closing cylinder (3), and the forward movement of the hot water supply stopper pin (6) is completed, that is, the hot water supply port ( 8) starts to operate almost at the same time as it is closed, moves the movable hob (9) forward and downward, and starts to operate almost simultaneously when the mold closing cylinder (3) starts or ends the mold tapping operation. The movable hob (9) is moved backward and raised.

Next, the above-mentioned composition type (at) (a2).

The compositional structure of the sintered ceramics used to make the hot water supply stopper pin (6) and movable hob (9) will be briefly explained.

The ceramics we refuse are solid solutions with α-Si3N4 structure, MX (Si, #) +2 (O,N) +6
(In the above formula, M is t%, Ca, Y, etc.)
Sialon granules (α phase) 60vol% βSi
3N4 columnar crystal (β phase) 40vo! Hot-pressed α-sialon ceramics or pressureless sintered α-sialon ceramics are composed of a dense composite (solid solution) structure phase that is fired and intercalated into a solid solution between α-sia[1].
1% of granular crystals and 40 VO of β-3L3N4 columnar crystals
In the composition range called the "partially stabilized" α-sialon region, which coexists with 1%, it has excellent mechanical properties such as strength, hardness, and fracture toughness, and - [1 thermal shock resistance, n (
It has excellent chemical resistance.

In addition, (11) in the figure indicates product extrusion cylinder 1 (12) (1
3) has both movable and fixed boards (b+ > (b2) and male, ti
A cold part installed in both types (at > (a2)),
IJJa3 is a heating mechanism, and is also a heating mechanism in this embodiment.
A support shaft (14) that movably supports (b + )
The so-called tie bar has a double cylinder structure consisting of a ceramic inner cylinder and a metal outer cylinder such as heat-resistant 44, and is a male.

Heat such as radiant heat emitted from the two types (a3) and (a2) m
? Care has been taken to avoid distortion etc.

Therefore, the example that is refused is a pair of separated molds (A).
600 to 165 by forming it into sintered ceramics.
The mold structure has the necessary and sufficient durability and pressure resistance to withstand high-temperature thermal shock and high pressure against high-temperature molten metal (M) up to about 0°C, and the mold I'll has both male and female molds <8+) (a2). Me N (
, the suction device (2) is operated to suction and depressurize the inside of the cavity (a), and the hot water supply stopper pin (6) is moved backward to open the hot water supply port (8), and the ladle ( The melt i4 (M) supplied in step 15) is filled into the cavity (a). And molten metal (M)
When the filling is completed, the stopper pin (6) for hot water supply is moved forward to close the hot water supply port (8), and the movable hob (9) is moved forward and downward to close the cavity (a).
) is applied to the molten metal (M) filled in the cavity (a) while applying a processing line to the molten metal (M); Super fine! This is a high-density, high-quality product made of a single weave, which is molded into a VJ shape.

In the above embodiment, the filling of the molten metal (M) into the cavity (a) is communicated with the hot water supply connection path (5) into which the tip side of the hot water supply stopper pin (6) is inserted. It has been described in detail that molten W (M) is supplied to the hot water supply path (7) provided in the hot water supply path (7), and is filled from the hot water supply port (8) through the hole 110 by moving the hot water supply stopper pin (6) backward. As shown in the figure, the female type (a2
) and place the molten metal storage container (16) on top of the container (16).
Connect the lifting pipe (18) from a relative such as a melting furnace to the lid (17) that closes the opening of the relative. 8 gata (M)
The molten metal is supplied periodically; it is easily refilled, and the molten metal is filled through the opening of the hot water supply port (8) at the bottom of the molten metal storage container (16) by the backward movement of the hot water supply stopper pin (6). As shown in the figure, it is optional to adopt an injection mechanism (20) that injects (pressurizes) the molten metal by fitting the hot water supply stopper bottle (6) into the Q4 outlet sleeve (19) so as to be able to move forward and backward. .

It goes without saying that the molten metal storage container (16) has a moisturizing function to keep the stored molten metal (M) at a constant temperature, such as a heating wire or heating element as a heat source.

<Effects of the Invention> As described above, the present invention includes a pair of molds that are separated from each other to form a set.
□Since it is made of ceramics, the temperature is 600 to 1650℃.
High temperature thermal shock for high temperature molten metal up to ? : Withstands 5 pressure (
7.The mold structure has sufficient durability and pressure resistance.
It becomes a mold for high temperature and high pressure with great durability.

Therefore, after closing the mold, when the inside of the mold is suctioned and depressurized, the hot water supply stub bin that opens and closes the hot water supply port is moved backward, the hot water supply port is closed, and the inside of the mold is heated to about 600 to 1650℃. At the same time, the hot water supply stopper pin is moved forward to close the hot water supply port, and the molten metal can be solidified while pressurizing the inside of the mold.
= High-density, high-quality, high-precision products made of ultra-fine structures using high-temperature molten metal with a pouring humidity of up to 1650℃! We can provide vacuum and pressurized vJ manufacturing methods that enable 7i molding.

Therefore, the intended purpose can be achieved.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show an embodiment of the reduced pressure and pressure casting method of the present invention. Fig. 1 is a front view with a partially cutaway cross section showing the mold in the open state, and Fig. 2 shows the state after the mold is closed. FIG. 3 and FIG. 4 are front views showing other embodiments with a partially cutaway section. In addition, in the figure (A): Molding mold (a+): Male mold (a2): Female mold (6): Hot water supply stopper pin (8): Hot water supply port (a): Cavity (inside the mold) Applicant Nakano
Akio Figure 1 Figure 2 @ Figure 3

Claims (2)

[Claims] (1) After closing a pair of male and female molds made of sintered ceramics, the inside of the mold is suctioned and depressurized, and the hot water supply stopper pin that opens and closes the hot water supply port is moved backward to open the hot water supply port; Filling the mold with molten metal and moving the hot water supply stopper pin forward to close the hot water supply port,
A vacuum and pressure casting method characterized by solidifying molten metal while pressurizing the inside of the mold. (2) The above sintered ceramic is a solid solution with α-Si_3N_4 structure, and Mx(Si,Al)_1_2(O,N
)_1_6 (in the above formula, M is Mg, Ca, Y, etc.) α-sialon granular crystals 60 vol% and β-Si_
The patent claim is hot-pressed α-sialon ceramics or pressureless sintered α-sialon ceramics consisting of a dense composite structure phase called a “partially stabilized” α-sialon region in which 40 vol% of 3N_4 columnar crystals coexist. The vacuum and pressure casting method described in Scope 1.