JPH0238065B2 - DEISUKUHOIRUJOSEIKEIYOKANAGATA - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a disc foil-shaped mold for a vertical injection molding apparatus.

[Prior Art] For example, vertical die casting machines are often used to cast aluminum automobile disc foils because there is little gas entrainment during injection of molten metal. FIG. 4 is a schematic vertical cross-sectional view showing the left half of the mold and injection device of a conventional die casting machine of this kind with the phase shifted by 45 degrees with respect to the right half, and this will be explained based on the same figure. Fixed platen 1 fixed on the machine base includes
A fixed mold 2 having a cylindrical convex portion at the center is mounted, and a movable platen 3 that is supported by a mold clamping cylinder (not shown) and moves up and down has a low convex portion at the center. A movable mold 4 is attached. Reference numeral 5 indicates a plurality of cores inserted into the molds 2 and 4 so as to be movable in the horizontal direction from positions dividing the circumferential direction into a plurality of equal parts, and a piston rod of a cylinder 6 supported on the movable platen 3 side. 7, and is configured to move horizontally as the piston rod 7 moves forward and backward using hydraulic pressure. A cavity 8 is formed by both the molds 2 and 4 and the closed core 5. An injection sleeve 9 is inserted into the sleeve hole formed in the fixed platen 1 and the fixed mold 2 so as to be freely inserted and removed from below, and the injection sleeve 9 is moved forward and backward by an injection cylinder (not shown). A plunger tip 10 is fitted so that it can move forward and backward. The molten metal 11 is injected into the injection sleeve 9 after it has been removed from the sleeve hole.

The cavity 8 has an annular plate-shaped disk portion 8a as a corresponding portion of a disk foil as a molded product.
and a cylindrical rim portion 8b extending downward from its outer periphery.
It is formed of. The inventors of the present invention have also discovered that a gas venting device 12 is provided at one location at the lower end of the rim portion 8b.
I tried molding by connecting the two through the gas vent groove 13. This degassing device 12 is, for example,
Those known in Japanese Patent Publication No. 48-46386, Japanese Patent Publication No. 59-309, and Japanese Patent Publication No. 59-310, etc.,
It is equipped with an exhaust valve that opens and closes a valve chamber connected to the gas vent groove 13, and this exhaust valve is configured to
During the injection of the molten metal 1, it is open and allows gas in the cavity 8 to pass through so as to be discharged to the outside of the machine, and when the molten metal 11 reaches the exhaust valve, it is closed by the inertia of the molten metal 11.

With the above structure, when the injection sleeve 9 supplied with the molten metal 11 is inserted into the sleeve hole of the fixed mold 2, and the exhaust valve of the gas venting device 12 is opened, the plunger tip 10 is advanced. The molten metal 11 is pushed up inside the injection sleeve 9 and reaches the disk portion 8a, and after flowing radially through the disk portion 8a, the molten metal 11 hangs down the rim portion 8b by its own weight. The gas in the cavity 8 is exhausted to the atmosphere through the open exhaust valve of the gas venting device 12. When the molten metal 11 reaches the exhaust valve, the molten metal 1
The exhaust valve is closed by the inertia force of 1, and the outflow of the molten metal 11 is blocked. After filling the molten metal 11 in this manner, the mold is opened after the molten metal 11 has solidified and cooled, and the core 5 is opened to take out the molded product.

[Problems to be Solved by the Invention] However, in such a disk foil molding die, as shown in a perspective view of the flow of molten metal in the cavity, the molten metal flows radially through the disk portion 8a. Afterwards, the molten metal 11 hanging down the rim part 8b will accumulate in sequence from the lower end of the rim part 8b downward, so the molten metal 11 will be accumulated in the rim part 8b.
The inlet 15 of the gas vent groove 13 extending directly from the end of the cavity 8 is closed by the molten metal 11 while the space 14 where the gas does not reach is left, and the gas in the space 14 is not exhausted. may be contained. As a result, there was a problem in that the molten metal 11 solidified while still containing gas, creating cavities in the molded product and deteriorating the quality of the molded product.

[Means for Solving the Problems] In order to solve these problems, in the present invention, a mold cavity is provided on the outer periphery of at least one end in the vertical direction of the mold cavity at a predetermined distance from the outer peripheral surface of the cavity. An annular groove is provided, a gas venting groove is provided in a part of the annular groove in the radial direction, a gas venting device is connected to the end of the gas venting groove, and a gas venting device is connected to the end of the gas venting groove, and between the outer circumference of the cavity and the annular groove. Exhaust passages that communicate the cavity and the annular groove are provided at a plurality of locations in the circumferential direction except on the extension line of the axis of the gas vent groove extending in the gas venting device section.

[Function] When the molten material inside the injection sleeve is pushed up by the plunger tip, the molten metal flows radially through the disc section of the cavity and then ascends the rim section.At this time, the gas within the cavity flows through the exhaust passage, the annular groove, It is discharged from the gas venting device to the outside through the gas venting groove. However, in this case, since the exhaust passage that communicates the cavity and the annular groove is not provided on the extension of the axis of the gas vent groove, the molten metal flowing inside the cavity does not suddenly proceed to the gas vent groove.
Therefore, the gas is not enveloped by the molten metal, the gas can be discharged well, and a high-quality product without voids can be obtained.

[Example] FIGS. 1 and 2 show an example in which a disc foil molding mold according to the present invention is applied to a vertical die-casting machine. FIG. 1 is a partially expanded schematic sectional view of a mold and an injection device, and FIG. 2 is a sectional view taken along the line -- in FIG. Note that FIG. 1 shows the left half broken with a phase shift of 45° in the circumferential direction with respect to the right half. Further, members having the same configuration as those of the conventional device shown in FIG. 4 are given the same reference numerals, and detailed explanation thereof will be omitted, and will be briefly explained below.

A low convex portion of a fixed mold 2 mounted on a fixed platen 1 and a movable mold 4 mounted on a movable platen 3
A cavity 8 is formed by a high convex part and four cores 5 arranged at 90 degrees out of phase with each other and moved forward and backward by the cylinder 6. It is formed of a disk portion 8a and a substantially cylindrical rim portion 8b. In addition, the first
The one in the figure is different from the one in FIG.
The long and short parts of are turned upside down.

At one location between adjacent cylinders 6, a degassing device 12 equipped with an exhaust valve and a vacuum device is located at the junction of both molds 2 and 4, 45° out of phase with the cylinder 6, and for example, a fixed metal It is supported and provided on the mold 2 side.

Annular grooves 16 and 17 are formed on the outside of the upper end outer periphery 8c of the rim portion 8b of the cavity 8 and the lower end outer periphery 8d of the rim portion 8b, keeping a predetermined distance from the outer circumferential surface of the cavity 8 and concentric with these. Movable mold 4
These annular grooves 16, 17 and the outer periphery 8 of the upper and lower ends of the rim portion 8b
c and 8d are connected to each other by a plurality of exhaust passages 18 and 19 provided at positions that substantially equally divide the circumferential direction. However, the cavity 8 is provided only in a portion other than the extension line of the axis of the gas vent groove 13 extending to the gas venting device 12 section, which will be described next.
an exhaust passage 18 that communicates with the annular grooves 16 and 17;
19 was established. This was done to prevent part of the molten metal that has progressed through the cavity 8 from directly entering the gas vent groove 13, and to prevent the molten metal from enveloping gas that has not yet been exhausted. be. A gas venting groove 13 connected to the valve chamber of the gas venting device 12 is opened in a part of the upper annular groove 14 in the radial direction. Further, this gas vent groove 13 and the lower annular groove 17 are communicated with each other through a communication hole 20 provided in the fixed mold 2. Note that, for convenience of processing, the fixed mold 2 has a penetrating portion of the communication hole 20 formed separately. Reference numeral 21 denotes a detour-like bypass provided to communicate the gas venting groove 13 and the valve chamber of the gas venting device 12 installation part.

The operation of molding a disk foil using the mold and injection device configured as above will be explained. Molten metal 1
1 is supplied into the sleeve hole of the fixed mold 2, and after opening the exhaust valve of the degassing device 12, the plunger tip 10 is advanced.
The molten metal 11 is pushed up inside the injection sleeve 9, reaches the disk portion 8a, flows through the disk portion 8a in a radial direction, reaches the cylindrical rim portion 8b, and begins to be filled into the rim portion 8b. At this time, some of the gas in the disk portion 8a and the rim portion 8b is exhausted through the exhaust passage 18, the annular groove 16,
The gas is discharged from the gas venting device 12 to the outside through the gas venting groove 13 and the bypass 18 . In addition, the gas in the lower part is passed through the exhaust passage 19, the annular groove 17, and the communication hole 2.
0, is discharged to the outside from the gas venting device 12 via the gas venting groove 13 and the bypass 18. In this case, the gas is discharged simultaneously from both the upper and lower ends of the rim portion 8b, so that even if the molten metal 11 accumulates sequentially from the lower end of the rim portion 8b, the gas is not trapped in the molten metal 11. In this embodiment, by providing the annular grooves 16 and 17, the gas spreads within the annular grooves 16 and 17, so that the exhaust passages 18 and 19
Even if a part of the molten metal 11 is blocked, the exhaust is not obstructed. In addition, in this embodiment, the cavity 8 and the annular groove 1 are provided only in the portion other than the extension line of the axis of the gas vent groove 13 extending to the gas vent device 12.
Since the exhaust passages 18 and 19 are provided to communicate the molten metal 6 and 17, the molten metal does not directly enter the gas vent groove 13 from the cavity 8 before the gas in the cavity 8 is sufficiently exhausted. The entrance of the gas vent groove 13 is not blocked by molten metal. Therefore, the occurrence of gas being surrounded by the molten metal within the cavity 8 is extremely reduced, the gas is sufficiently discharged, and a molded product of good quality without voids can be easily obtained.

In this way, when the molten metal 11 is filled and reaches the exhaust valve of the degassing device 12, the exhaust valve is closed by the inertia of the molten metal 11, and the outflow of the molten metal 11 is blocked. After filling the molten metal 11 in this manner, the mold is opened after waiting for the molten metal 11 to solidify and cool, and the core 5 is opened to take out the molded product.

In such an injection operation, the gas vent groove 1
Molten metal 11 from 3 side and molten metal 1 from communication hole 20 side
1 and 1 do not reach the gas venting device 12 at almost the same time, gas may not be sufficiently vented on the side that reaches the slower side. It is desirable to make it larger than the diameter.

FIG. 3 is a partially exploded schematic vertical sectional view of a mold and an injection device showing another embodiment of the present invention, and in this embodiment, a vacuum device is attached to the gas venting device 12. Since the rest has the same configuration as that shown in FIG. 1, the same reference numerals are given and the explanation thereof will be omitted. That is, an electromagnetic switching valve 22 is installed in the exhaust hole of the gas venting device 12, which was open to the atmosphere in the above embodiment.
A pipe 23 equipped with is connected, and this pipe 2
3 is connected to a vacuum tank 24. Further, a vacuum pump 25 is connected to the vacuum tank 24 . The pipe 23 is provided with a discharge hole that closes when the switching valve 22 is opened and opens when the switching valve 22 closes and opens to the atmosphere. By doing this, when the switching valve 22 is opened during injection to communicate the exhaust hole of the degassing device 12 with the vacuum tank 24, the pressure inside the cavity 8 is reduced, so that the molten metal 11
This reduces gas entrainment and further improves the quality of the molded product.

In this embodiment, only one gas venting device 12 is provided, and the exhaust passage from the upper end of the rim portion 8b and the exhaust passage from the lower end of the rim portion 8b are merged into this, but the gas venting device 12 Two gas venting devices 12 may be provided and the upper and lower ends of the rim portion 8b may be connected to each other through separate exhaust passages. Further, although this embodiment shows an example in which the present invention is applied to a vertical die-casting machine, it can be similarly applied to an injection molding machine for plastics.

In addition, in the embodiment shown in FIG.
A plurality of exhaust passages 19 are provided at positions other than the extension line of a part of the axis of the communication hole 20 that is parallel to the axis of the gas vent groove 13 extending toward the side.
In the embodiment shown in the figure, the above-mentioned communication hole 2
An exhaust passage 19 was also provided on the extension line of a part of the axis of 0.

Furthermore, if a molded product obtained by die casting is heat-treated at high temperature for several hours, even if there are very small bubbles that cannot be seen on the surface of the molded product, they will swell and appear as blisters, indicating that the product is defective. However, depending on the molded product, if gas was vented only from above cavity 8, the failure rate due to blisters would be about 40%, but if gas was vented from both the top and bottom of cavity 8. In some cases, the defect rate due to blisters was reduced to approximately 5%.
It can be seen that better results can be obtained by venting gas from both the upper and lower sides of the cavity at the same time.

[Effects of the Invention] As is clear from the above description, according to the present invention, in the disk foil mold, a predetermined portion is formed on the outer periphery of at least one end of the mold cavity in the vertical direction from the outer peripheral surface of the cavity. An annular groove is provided at a distance, a gas venting groove is provided in a part of the annular groove in the radial direction, a gas venting device is connected to the end of the gas venting groove, and the outer periphery of the cavity and the annular groove are connected to each other. Exhaust passages that communicate the cavity and the annular groove are provided at multiple locations in the circumferential direction, excluding the extension of the axis of the gas vent groove extending to the gas venting device, so that the gas inside the cavity can be removed. The molten metal does not directly enter the gas venting groove from the cavity before it has completely escaped, and the entrance of the gas venting groove is not blocked by molten metal. Therefore, the occurrence of gas being surrounded by the molten metal within the cavity is extremely reduced, the gas is sufficiently discharged, and a molded product of good quality without voids can be easily obtained. Further, in the present invention, by providing the annular groove, gas spreads within the annular groove, so even if a part of the exhaust passage is blocked by molten metal, the exhaust is not obstructed.

[Brief explanation of drawings]

FIG. 1 is a partially exploded schematic vertical cross-sectional view of a mold and an injection device showing one embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line -- in FIG. 1, and FIG. A partially expanded schematic longitudinal sectional view of a mold and an injection device showing an example,
Fig. 4 is a partially exploded schematic longitudinal cross-sectional view of a mold and injection device showing a conventional example, and Fig. 5 is a fixed mold convex shown for explaining the flow of molten metal in the cavity in the one shown in Fig. 4. FIG. 2... Fixed mold, 4... Movable mold, 5... Core, 8... Cavity, 8a... Disk part, 8
b...Rim part, 8c...Rim part upper end outer periphery, 8d...
... Rim lower end outer circumference, 12 ... Gas venting device, 13
... Gas vent groove, 16, 17 ... Annular groove, 18,
19...Exhaust passage, 20...Communication hole, 25...Vacuum pump.

Claims (1)

[Claims] 1. In a disc foil molding mold having a cavity in which the mold axis direction corresponding to the rotational axis of the disc foil molded product is perpendicular and the melt is injected from below in the mold axis direction, the upper and lower sides of the cavity An annular groove is provided on the outer periphery of at least one end of the cavity at a predetermined distance from the outer peripheral surface of the cavity, a gas vent groove is provided in a part of the annular groove in the radial direction, and an end of the gas vent groove is provided. A gas venting device is connected to the gas venting device, and the cavity is connected at multiple locations in the circumferential direction between the outer periphery of the cavity and the annular groove, excluding the extension line of the axis of the gas venting groove extending to the gas venting device portion. A mold for forming a disc foil shape with an exhaust passage that communicates with the annular groove.