JPH01258860A - Venting device for die - Google Patents

Abstract

PURPOSE:To eliminate the need for a moving member and to allow easy mounting of the venting device to the existing die with a simple construction by boring a circular conical hole communicating with a discharge port to the die parting face and forming a spiral vent passage to the moving die to separate a molten metal and gas. CONSTITUTION:The circular conical hole 27 is bored perpendicularly to the die parting face 23 communicating with an overflow trap 26 and the discharge port 28 is communicated and opened to the peak part of the circular conical hole 27. The spiral groove 30 is provided to the outside circumference of the moving die 22 opposite to the circular conical hole 27 of the fixed die to form the spiral vent passage 31 of a small spacing. An ejector rod 40 integral with a solidified casting product is provided. The molten metal packed in a cavity 25 by pressure casting passes the overflow trap 26. The gas is separated from the molten metal and the molten metal is solidified to close the passage 31 when said metal passes the spiral vent passage 31. The gas in the cavity 25 passes the overflow trap 26 from an overflow gate 24 and is discharged from the discharge port 28.

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention) [Industrial Field of Application 1] The present invention relates to a degassing device for a mold such as a die casting machine or a plastic molding machine.

[Prior Art] Conventional technologies include a degassing device as typified by Japanese Patent Application No. 123167/1982, and a degassing vent called a pine sieve vent.

Japanese Patent Application No. 54-123167 discloses that a movable valve is provided in a gas vent groove consisting of a curved flow path and a straight flow path provided on a mold mating surface, and the movement of the valve communicates the gas vent groove with the atmosphere. The inertia of the molten metal operates the valve to shut off the gas vent groove and the atmosphere, and when the molten metal does not act on the valve, the gas vent groove and the atmosphere are communicated.

The latter pine sieve vent is located above the cavity 13 provided on the mating surface of the movable mold 11 and the fixed mold 12, as shown in Fig. 8 and Fig. 9.
and an overflow tundish 15, above which pine sieve vents 16, 17 attached to both molds 11 and 12 are provided. There is a gap C3 between the pine sheave vents 16 and 17, and the gap C3
communicates with the atmosphere from the exhaust lower. In Figures 8 and 9, the gas in both dies 11 and 12 passes through the gap C3 and is discharged to the atmosphere from the exhaust port 17, and when the molten metal reaches the gap C3, the molten metal solidifies in the gap C3. and block it.

On the other hand, in a die-casting machine, the amount of molten metal filled into the mold is 2
It is injected at a high speed of 0 to 50 m/s, becomes a mist, and is cast into the cavity.

Therefore, in the aforementioned Japanese Patent Application No. 54-123167,
The gas in the mold is vented to the atmosphere with the gas vent groove communicating with the atmosphere, but as mentioned above, the molten metal is cast into the cavity in the form of a mist, so only the gas is released through the gas vent groove. It is impossible to discharge the gas from the valve, and particulate molten metal may pass through the valve during gas discharge. At this time, the particulate molten metal passing through the valve adheres to the valve and makes the sliding movement for opening and closing the valve unsmooth. Therefore, when casting operations are performed continuously, it is necessary to clean the valves repeatedly during each casting operation.

The latter pine sieve vent has no moving parts, but requires a pine sieve vent with a large projected area on the mold separation surface.
The entire mold was large, requiring a large die-casting machine.

[Problems to be Solved by the Invention] Therefore, in the former technique of the prior art, it is necessary to clean the valve, which is a movable member, in every casting cycle, which inevitably lowers productivity, so it is necessary to increase the size of the mold. It is a specialized product and cannot be installed on existing molds.

Furthermore, the former gas venting S device has problems such as high equipment costs, frequent failures, and high maintenance costs.

The latter pine sieve vent has no moving parts and is inexpensive, but the gas venting channel has a gap of 0.2 mm, so in order to increase the cross-sectional area of the channel, it needs to be widened and a relatively large projection on the mold separation surface. This requires a pine sieve vent with a large area, which forces the mold to be larger and makes it difficult to install the device on existing molds.The present invention can be installed on existing molds without increasing the size of the mold. obtain. Another object of the present invention is to provide an inexpensive degassing device that does not have any movable members.

(Structure of the Invention) [Means for Solving the Problems] The present invention provides a degassing device for a mold having an overflow pool following a cavity provided at a mold separation surface between a movable mold and a fixed mold. a conical hole bored perpendicularly to the mold separation surface that communicates with the pool; an exhaust port that communicates with the top of the conical hole; and a fixed mold that releases the exhaust port to atmospheric pressure or connects it to a vacuum evacuation device; A movable type is equipped with a conical member that has a spiral groove on the outer periphery of the conical hole to form a spiral gas vent flow path with a small gap, and a cooling means for the conical member and a spiral gas vent attached to the movable type. The flow path is equipped with an extrusion rod device that extrudes the solidified cast product and the solidified end material, and the molten metal filled into the cavity by pressure casting passes through the overflow pool and creates a spiral degassing flow. The gas and the molten metal are separated from each other when passing through the channel, and the molten metal is solidified to close the spiral gas vent channel.

In the present invention, the spiral groove on the outer periphery of the conical member has a draft angle (
It is preferable to form a spiral groove with θ2<θ1.

[Function] When the molten metal filled into the cavity by pressure casting passes through the molten metal pool and reaches the spiral gas venting channel, the molten metal becomes mist and is cooled in the spiral gas venting channel, and is affected by inertial force (centrifugal force). The gas and molten metal are separated by force), the gas flows along the spiral groove on the outer periphery of the conical member, and the molten metal particles collide with the inner surface of the conical hole drilled in the fixed mold, adhere and solidify, and finally By closing the spiral gas vent flow path, the high casting pressure of pressure casting can be maintained within the cavity.

[Example] Hereinafter, the present invention will be described based on drawings of examples. 1st
In the figure, 21 is a fixed mold, 22 is a movable mold, and 23 is a mold separation surface. 24 is a cavity 25 (partially illustrated).
(see Figure 7).
26 is an overflow pool. 27 is a conical hole bored perpendicularly to the mold separation surface 23, and 28 is an exhaust port communicating with the conical hole 27. The exhaust port 28 may be connected to a vacuum evacuation device (not shown) in addition to the case shown in the figure where it is open to atmospheric pressure. 29 is a conical member inserted into the conical hole 27, and a spiral groove 30 is provided on the outer periphery. Reference numeral 31 denotes a spiral gas vent passage in the gap between the conical hole 27 and the spiral groove 30, in which the gas in the cavity 25 flows from the overflow gate 24 through the overflow pool 26 in the direction of the arrow. It flows in a spiral shape as shown in FIG. 3 and is discharged from the exhaust port 28.

As shown in FIG. 4, the cross-sectional shape of the spiral gas vent passage 31 is such that the spiral groove 30
is a spiral groove of the lead P, which has a relief slope θ2. Here, CI and C2 are gaps between the conical hole 27 and the spiral groove 30.

C, , < C, and the gap is small.

FIG. 2 is a view taken from arrow A in FIG. 1, and the tundish basin 26 and the spiral groove 30 are connected as shown. Returning to FIG. 1 and continuing the explanation, reference numeral 32 denotes a holding member that attaches the conical member 29 to the movable mold 22.

33 is a spacer made of a heat insulating material. Reference numeral 34 denotes a cooling water hole bored in the conical member 29, into which a cooling water supply member 36 is screwed through a threaded groove 35.

37 is a cooling water supply pipe screwed onto the cooling water supply member 36;
8 is a cooling water discharge pipe screwed into the cooling water hole. 40
An extrusion rod is slidably supported by the movable mold 22, and is constructed integrally with an extrusion rod device for extruding a cast product 39 (see FIG. 5) from the mold, and operates simultaneously with the extrusion line device.

In FIG. 1, the extrusion rod 40 is installed in a position to extrude the overflow tundish 6, but it is not in a position to effectively extrude the solidified scraps integrated with the cast product 39 solidified in the spiral gas vent channel 31. Just set it up.

FIG. 5 shows parts that are integrally cast with the cast product 39, and 41 is an overflow gate part, 42 is an overflow pool part, and 43 is a spiral gas venting passage part. 44 is the leading edge of the molten metal, and the molten metal is discontinued in the middle of the spiral gas venting channel.
I and C2 are properly designed. It is designed so that the molten metal does not flow out from the exhaust port 28.

[Effects of the Invention] As explained above, the present invention has no movable members on the mold dividing surface, has a simple structure, and has no causes of failure. Furthermore, it is easy to attach to an existing mold, and a spiral gas venting passage may be provided so as to be connected to an overflow pool of the existing mold.

Moreover, the projected area is an annular ring with a gap CI, which is extremely small compared to the conventional pine sieve vent.

Furthermore, when increasing the cross-sectional area of the gas venting channel, the gas venting device of the present invention may be installed in a plurality of overflow pools, and the gas venting effect can be easily doubled.

[Brief explanation of the drawing]

Figure 1 is a sectional view of an embodiment of the present invention, and Figure 2 is A of Figure 1.
The arrow view and FIG. 3 are gas flow explanatory diagrams. 4 is a cross-sectional view of the spiral gas venting channel, FIG. 5 is a perspective view of the cast member, FIG. 6 is a perspective view in the A direction of FIG. 1, FIG. 7 is a perspective view in the B direction of FIG. 1, and FIG. FIG. 8 is a cross-sectional view of a conventional pine sieve vent, and FIG. 9 is a view taken along arrow D in FIG. 11...Movable type, 12...Fixed type, 13...Cavity, 14...Overflow gate, l5...Overflow pool, 16.17...Mer7 sieve vent, 18...Exhaust Mouth, 21...fixed type, 22...movable type, 23...
Mold dividing surface, 24... Overflow gate, 25... Cavity, 26... Overflow pool, 27... Conical hole, 28... Exhaust port, 29... Conical member, 30...
Spiral groove, 31... Spiral gas vent passage, 32...
Holding member, 33... Spacer, 34... Hole, 35...
...Thread groove, 36... Cooling water supply member, 37... Cooling water supply pipe, 38... Cooling water discharge pipe, 39... Cast product, 40... Extruded rod, 41... Overflow gate part, 42... Overflow pool part, 43... Spiral gas venting channel part, 44... Most extreme part of molten metal.

Claims (2)

[Claims] (1) In a degassing device for a mold having an overflow pool following a cavity provided on a mold separation surface between a movable mold and a fixed mold, a conical hole is bored perpendicularly to the mold separation surface communicating with the mold pool. a hole, an exhaust port communicating with the top of the conical hole, a fixed mold that releases the exhaust port to atmospheric pressure or connects it to a vacuum evacuation device, and a spiral groove provided on the outer periphery of the conical hole, A movable mold equipped with a conical member forming a spiral gas venting passage with a small gap, a cooling means for the conical member, and a solidified casting in the spiral gas venting passage attached to the movable mold. It is equipped with an extrusion rod device that extrudes solidified scraps integrated with the product, and when the molten metal filled into the cavity by pressure casting passes through the overflow pool and passes through the spiral gas venting channel, gas is generated. A degassing device for a mold, characterized in that the molten metal is separated from the molten metal, the molten metal is solidified, and the spiral gas degassing channel is closed. (2) The spiral groove on the outer periphery of the conical member has a draft angle (θ_1) of the conical hole bored in the fixed mold.
The mold degassing device according to claim 1, characterized in that θ_2) is a spiral groove in which θ_2<θ_1.