JPS602148B2 - Mold equipment for molten metal forging - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold device for forging molten metal that solidifies a falling sun under pressure within a product cavity.

For example, as shown in FIG.
While sealing the upper surface closure c of the product cavity b formed by the sealing part e of the upper mold d inserted therein, the pressurizing punch f inserts the molten metal in the product cavity b from below the lower mold a. In this case, the molten metal is generally poured into the product cavity b by pulling up the upper mold d and opening the top surface □c. Air is drawn into the molten metal and oxides are formed inside the molten metal, causing defects in the product. In addition, in order to prevent such oxidation, the air in the product cavity b is replaced with an inert gas with a relatively large specific gravity before pouring western hot water, but as mentioned above, when pouring hot water from the top opening, Inert gas gets caught up in the molten metal and takes time to vent, and some of the inert gas is trapped in the upper space of product cavity b due to the seal on the top opening c, and this occurs when pressurized at high pressure. The disadvantage is that the gas is likely to diffuse into the flaw, resulting in product defects.

In addition, according to Tokukan Sho 52-13 Bulletin No. 24, molten metal is pumped by electromagnetic force or pressure from a separate layer of a sunbath tank installed at a lower level at the bottom of the product cavity through a lotus-like supply pipe. A device in which a pushing force is applied by gas or the like to cause the flow to flow is also known, but this method requires a pushing force generating device and has the disadvantage of being more expensive than the above-mentioned gravity-cracking method. .

An object of the present invention is to provide an apparatus which adopts a gravity bathing method which is advantageous in terms of cost, and which can eliminate the above-mentioned disadvantages of such a method. In a type in which the upper surface of the product cavity is sealed with the seal part of the upper mold inserted into the seal, the molten metal in the product cavity is pressurized with a pressurizing punch inserted from below the bottom mold. The mold is formed with a pouring port separate from the top opening, and the pouring port is conveyed to the bottom of the product cavity through a runner that diverts from the mold, and the degree of sealing by the sealing part of the top opening is completely ensured. It is characterized in that it can be variably adjusted from a sealed state to a state that allows ventilation, and that the runner is formed in a slit shape that gradually becomes narrower toward the communication hole with the product cavity. Next, one example of implementing the present invention will be explained with reference to FIGS. 2 to 7. The illustrated mold device is used to obtain a piston for an engine, and includes a lower mold 1, an upper mold 3 that is inserted into a product cavity 2 formed therein from its upper surface entrance 2a, and a bottom surface that extends into the product cavity 2. It consists of a pressure punch 5 inserted into the hole 4.

The lower mold 1 includes a pair of split molds la, la, as shown in FIG.
The product cavity 2 is located at the center of the joint surface of the split molds la, la, and the product cavity 2 is located at the outside of the product cavity 2 and is located on the side of the upper surface opening 2a. A runner 7 is formed to convey the formed pouring spout 6 to the bottom of the product cavity 2, and a pool 8 is formed on the outside opposite to the flaw 7 and extends to the bottom of the product cavity 2. was formed. As shown in FIGS. 4 to 6, the wound channel 7 is formed in a slit shape and narrows in order toward the passage hole 9 with the product cavity 2, and the flow rate of the Rakuyo poured from the pouring port 6 is The molten metal gradually decreases in the runner channel 7, and the molten metal flows through the channel 9.
The static pressure on the upstream side of the product is used to cause the product to flow quietly into the cavity 7, and the oxides mixed in the moat are successively removed from the inner wall surface of the moat channel 7 formed narrowly. The upper mold 3 is lifted and lowered by a press device (not shown), and includes a sealing portion 3a that engages with the upper surface closing 2a of the product cavity 2, and a core portion 3b protruding below the sealing portion 3a. Furthermore, the upper surface exit 2a and the seal portion 3
The inner peripheral surface and the outer peripheral surface of the upper surface opening 2a are sequentially tapered downward to have a diameter of 4 mm, and the degree of sealing by the seal portion 3a of the upper surface closure 2a is determined according to the insertion depth of the seal portion 3a. There are two states: a ventilation state (the state shown in FIG. 7a) that allows ventilation, and a sealed state (the state shown in FIG. 7a) that completely seals the upper barrier gate 2a by cutting off ventilation.
It can be variably adjusted to (state b) in Fig. 7).

The drawing shows a lid that is rotatably provided on the upper surface of the lower mold 1 with the upper mold 3 as an axis, and the lid 10 is in an open position where a through hole 11 formed therein is aligned with the pouring port 6. The handle 12 can be rotated to a closed position where the connection between the spout 6 and the through hole 11 is cut off. In the drawing, 3c indicates a golden part formed on the upper mold 3 to be brought into contact with the upper surface of the lid body 10, and the flange part 3c
When inserting the seal portion 3a into the ventilation state, the lid body 10
Somewhat in between. A clearance exists to allow rotation of the lid 10, but when inserted into a sealed state, the lid 10
This prevents the molten metal from spouting out from the sprue port 6 when pressurized. Next, to explain its operation,
First, the upper mold 3 is lowered, the seal part 3a is inserted into the upper surface closing opening 2a in a ventilated state, and the lid body 10 is rotated to the open position to open the pouring spout 6.
Inject inert gas from As the inert gas, a gas with a higher specific gravity than air, such as nitrogen, carbon dioxide, argon, or sulfur hexafluoride gas, is used. When this is done, the inert gas flows into the product cavity 2 through the wound channel 7. However, the air inside the cavity 2 is replaced with an inert gas.

Next, molten metal is poured from the face opening 6 as shown in FIG. Entrainment of inert gas into the product cavity 3 is also prevented, and as the amount of molten metal in the product cavity 3 increases, the inert gas is pushed out from the upper entrance 2a, and the product cavity 3 is completely filled with molten metal. Thereafter, no inert gas will be trapped inside the product cavity 2 even by the sealing of the upper surface barrier port 2a.

Incidentally, if the hot water reservoir 8 is not present, the split mold la that formed the scar 7
, one side of the joint surface of la will be distorted by the heat of the hot water, and the split molds la will warp, resulting in poor mold clamping.
If there is, the same distortion as that on the other side will occur on the joint surface on the pond side that forms this, so such inconvenience will not occur.

Next, the lid body 10 is rotated to the closed position, and the seal portion 3a is moved to the seventh position.
The product is inserted in a sealed state as shown in FIG.

In addition, when the runner 7 is formed into a narrow slit shape in sequence toward the lotus hole 9 as described above, the molten metal in the wound channel 7 solidifies relatively quickly in the vicinity of the lotus hole 9. Since the lotus passage hole 9 is closed, if the pressurization of the rising sun by the pressurizing punch 5 is delayed a little, it is possible to prevent the molten metal from spewing out even without providing the lid 10.

Further, in the above embodiment, the inner circumferential surface of the upper surface checkpoint 2a and the outer circumferential surface of the seal portion 3a are formed into tapered surfaces, and the seal portion 3a is formed into a tapered surface.
By finely adjusting the insertion depth of the sealing part 3a, it is possible to change between the aeration state and the sealing state.
It is also possible to change between the ventilation state and the sealing state by rotating the valve. As described above, according to the present invention, the molten metal can be quietly filled into the product cavity from the bottom side through the narrow slit-like wound channels formed sequentially toward the product cavity, thereby preventing oxidation of the molten metal. Even if the inside of the product cavity is replaced with an inert gas in advance to prevent this, the entrainment of inert gas into the sun is prevented as much as possible, and the seal part is ventilated to the upper surface of the product cavity. By inserting the molten metal into the product cavity, the product cavity is completely filled with molten metal while pushing out the inert gas from the upper entrance to the outside due to the western hot springs, so the product cavity is filled with inert gas. It has the effect of producing high-quality products with a relatively simple device that uses the Gravity Souyu method.

[Brief explanation of the drawing]

Fig. 1 is a cut side view showing a conventional example, Fig. 2 is a cut side view of an example of the device of the present invention, Fig. 3 is a plan view cut along mm line in Fig. 2, and Figs. 4 to 6. 7 is an enlarged cross-sectional view taken along line WW to Choichi line in FIG. 2, and FIG. DESCRIPTION OF SYMBOLS 1... Lower mold, 2... Product cavity, 2a... Upper surface Sekiguchi, 3... Upper mold, 3a... Seal part, 5...
Pressure punch, 6... pouring spout, 7... runner. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. Pressurization to insert the molten metal in the product capi- ty from below the lower mold while sealing the upper surface opening of the product capi- ty formed in the lower mold with the sealing part of the upper mold inserted into the upper mold. In the pressurizing type with a punch, a pouring port separate from the top opening is formed in the lower mold, and the pouring port is communicated with the bottom of the product capitivity via a runner connected thereto, and the top opening The degree of sealing by the seal portion can be variably adjusted from a completely sealed state to a state that allows ventilation, and the runner is formed in a slit shape that gradually narrows in width toward the communication hole with the product capsule. Features a mold device for hot water molding. The molten metal forging according to claim 1, wherein the inner circumferential surface of the upper surface opening and the outer circumferential surface of the seal portion that fits therein are formed into downwardly tapered surfaces with smaller diameters. Mold equipment.