JPS61273248A - Vacuum casting and molding device - Google Patents

Abstract

PURPOSE:To permit the easier exchange of a casting mold and to simplify the formation of a metallic moldy by providing micro through-holes to a recess in the cavity of the casting mold to be disposed in a reduced pressure chamber and extending the runner of the casting mold to the outside of a cap member. CONSTITUTION:The casting mold 6 provided with the micro through-holes 5 in the recess 4 in the cavity 3 is disposed in the reduced pressure chamber 2 which permits the pressure reduction. The aperture 8 of the runner 7 is extended to the outside of the cap member 1. The inside of the chamber 2 is evacuated to the reduced pressure by an evacuation pump P. A melt spreads to all the corners of the recess 4 in the reduced pressure cavity 3 when the melt is poured into the cavity through the runner 7. The casting or molded article having the intricate shape is thus obtd. with good accuracy. The accurate formation of the intricate product is thus made possible with the simple constitution. The exchange of the casting mold is easy and the formation of the metallic mold is simple.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vacuum casting forming apparatus, and more specifically, a molten material such as molten metal or molten plastic is placed in a mold placed in a vacuum chamber evacuated to a reduced pressure. This invention relates to a vacuum casting molding apparatus that can manufacture vacuum castings or vacuum molded products with clear shapes by pouring and casting molds, and can also be equipped with molds of various sizes.

[Prior Art] Conventionally, there is a vacuum casting apparatus described in Japanese Patent Publication No. Sho 56-87256.

This vacuum casting device forms an air passage communicating with an air pump in either a fixed mold or a movable mold,
The air pump is configured to produce a cast product by reducing the pressure in the cavity within the mold via an air passage.

However, since this vacuum casting apparatus connects the pipe directly to the air passage provided in the mold, a means for connecting the pipe must be provided for each mold, making mold manufacturing extremely complicated. It is.

In addition, as a vacuum casting method, JP-A-55-120447
There is something described in the No.

This vacuum casting method requires a mold with a flange with a smooth sealing surface on the sprue surface, and in order to perform vacuum casting, the wax pattern is dipped into refractory slurry many times to create the mold. , mold production is extremely complicated.

Further, the mold cannot be easily changed using the vacuum casting apparatus or the vacuum casting method described in any of the above-mentioned publications.

This invention has been made based on the above circumstances.

That is, with this IN+, a mold having a simple configuration can be easily changed, and complex thin-walled products can be cast or molded with high dimensional accuracy. An object of the present invention is to provide a vacuum casting molding device with a simple configuration.

[Means for Solving the Problems] The outline of the present invention for solving the problems described above is as shown in FIG. This vacuum casting forming apparatus is characterized in that a mold 6 having a minute through hole 5 in a recess 4 in the mold 6 is arranged with a runner 7 of the mold 6 extending outside the lid member 1. .

More specifically, the decompression chamber 2 may have any size and shape as long as it can accommodate the mold 6, and the decompression chamber 2 has an opening large enough to accommodate the mold 6. It is sufficient if it has the following.

The lid member 1 attached to this opening can airtightly seal the inside of the decompression chamber 2, and the opening 8 of the runner 7 of the mold 6 placed inside the decompression chamber 2 can be placed outside of the lid member l. It may have any structure as long as it can protrude.

The decompression chamber 2 may be equipped with a suction pipe 9 to reduce the pressure inside, and the exhaust pump P may be used to exhaust the air directly through the suction pipe 9. The reason why it is preferable to interpose the buffer tank 10 in between is as follows.
When the inside of the decompression chamber 2 is evacuated by the exhaust pump P through the wIfi tank 10, the decompression chamber 2 is removed without the buffer tongue 10.
This is because damage to the exhaust pump P is alleviated compared to the case where the exhaust pump P is evacuated, and the inside of the decompression chamber 2 can be quickly brought to a predetermined degree of depressurization.

The mold 6 placed in the vacuum chamber 2 is placed in the vacuum chamber z under reduced pressure.
In the cavity 3 of this mold 6 placed inside, there is a vacuum chamber z
For example, a runner opening 8 of the mold 6 may be provided with a IO# that allows injection of the melt from the outside and has a recess 4 in the cavity 3 and a micro through hole 5 penetrating the outside of the mold 6. It is also possible to have a structure in which the mold 6 is extended to protrude outside the lid member 1. Also, when the mold 6 is placed in the decompression chamber 2 and the runner opening 8 of the mold 6 is lower than the lid member 1, An auxiliary runner pipe is attached to the runner opening 8 of the mold 6 so that the auxiliary runner pipe projects outside the lid member l, so that the runner opening 8 of the mold 6 is connected to the lid member l. There is no particular limitation on the number of the minute through-holes 5, which may have a structure that protrudes outside of the structure, and it is preferable that the minute through-holes 5 have an inner diameter that does not allow molten material to penetrate.

The number of runner openings 8 of the mold 6 that protrudes outside of the two members 1 may be one, but it is preferable to have two runner openings 8 because the melt can be removed from one runner opening 8. This is because it is convenient for injecting gas, releasing the gas from the other runner opening 8, and checking the amount of injection.

Examples of the mold 6 include gun metal, iron molds, stone molds, etc.
Examples include ceramic molds and rubber molds.

What is injected into the cavity 3 of the mold 6 may be molten metal or molten plastic.

[Action of the invention] The above configuration of the present invention has the following effects.

That is, first, the mold 6 is placed in the decompression chamber 2, the lid member l is airtightly attached to the decompression chamber 2 so that the runner opening 8 extends outside the lid member l, and then the exhaust pump is installed. P evacuates the inside of the decompression chamber 2 to a reduced pressure. Then, a molten material such as molten metal or molten plastic is injected through the runner opening 8 that projects outside the lid member 1. At this time, since the mold 6 has a minute through hole 5 passing through the recess 4 of the cavity 3, the pressure inside the cavity 3 is reduced and an airflow is generated from the runner opening 8 toward the inside of the cavity 3. Therefore, the injection of the melt from the runner opening 8 becomes extremely easy and smooth, and the melt flows into every corner of the recess 4 of the cavity 3, making it possible to accurately copy the inner contour of the cavity. Cast or molded products with complex shapes can be formed with high dimensional accuracy. Further, even when changing the mold 6, it is sufficient to simply insert the runner opening 8 of the mold 6 into the runner insertion hole 11 provided in the lid member 1, for example.

[Example] Next, examples of the present invention will be shown to further specifically illustrate the present invention.

FIG. 2 is a longitudinal cross-sectional view showing the first embodiment of the invention,
FIG. 3 is a front view of this first embodiment.

As shown in FIG. 2, the decompression chamber 2 according to this embodiment has an opening at the top and a leak valve 1 at one side.
2 and an exhaust valve 13.

The lid member l is airtightly attached to the opening 11 via the first part and the king 14. As shown in FIG. 3, this lid member 1 has a circular first runner insertion hole 15a and a second runner insertion hole 15b.
A second backing 16 for maintaining airtightness is attached to each edge of the second runner insertion hole 15b. Third
As shown in the figure, a buffer tank IO is connected to the exhaust valve 13 via a suction pipe 9, and this buffer tank 10 is further connected to a pressure reducing pump P via the suction pipe 9.

The mold 6 is formed from a first mold 6a and a second mold 6b, and when the first mold 6a and the second mold 6b are clamped together, a cavity 3 is formed inside. . A large number of minute through-holes 5 with minute diameters communicating between the inside of the cavity 3 and the outside of the mold 6 are provided in the recess 4 of the cavity 3.

Further, the mold 6 has a first runner 7a and a second runner 7b communicating with the cavity 3 and extending upward. Then, this mold 6 inserts the first runner pipe 7a and the second WII pipe 7b into the first runner pipe insertion hole 15a.
and the second runner pipe insertion hole 15b respectively.
The runner opening 8a and the second runner opening 8b are arranged in the reduced pressure chamber 2 so as to open to the outside of the lid member 1.

Next, the operation of the embodiment apparatus having the above structure will be explained.

First, after closing the exhaust valve 13, the lid member l is opened, and the mold 6 formed by clamping the first mold 6a and the second mold 6b is placed in the decompression chamber 2. The first runner pipe 7a and the second runner pipe 7b are inserted into the first NI pipe insertion hole 15, respectively.
a and the lid member l is attached to the opening of the decompression chamber 2 by inserting it into the second runner pipe insertion hole 15b.Next, the leak valve 12 is closed, while the exhaust valve 13 is opened. At this time, the pressure reduction pump P has already been driven to reduce the pressure in the buffer tank 10, so when the exhaust valve 13 is opened, the pressure in the pressure reduction chamber 2 immediately becomes reduced.

The decompression chamber 2 and the lid member l are connected by a first puffing 14, and the first runner pipe insertion hole 15a and the second runner pipe insertion hole 1 of the lid member l are connected to each other.
5b, the first runner pipe 7a, and the second runner pipe 7b are sealed by the double sealing 16, so that the inside of the decompression chamber 2 is airtightly reduced in pressure. As a result, inside the cavity 3, the first
Since air currents are generated from the runner openings 8a and the second runner openings 8b toward the minute through holes 5, for example, if molten metal is injected from the first runner openings 8a.

Molten metal will flow in smoothly. Moreover, mold 6
Since a minute through-hole 5 is formed in the recess 4 in the cavity 3, molten metal can reliably flow into the recess fi4, which has been difficult to flow into in the past. That is, the cavity is filled with molten metal so that the molten metal faithfully contacts the inner contour of the cavity 3. As a result, it becomes possible to manufacture cast products and molded products with clear outlines.

After filling the cavity 3 with molten metal, the exhaust valve 13 is closed and the leak valve 12 is opened to open the decompression chamber z.
By returning the inside to normal pressure and removing the lid member l, the mold 6 can be taken out from the inside of the decompression chamber 2, and a cast product can be obtained.

Next, a second embodiment will be explained with reference to FIG. 4.

FIG. 4 is a longitudinal sectional view showing the second embodiment.

The difference between this second embodiment and the first embodiment is as follows.
It is as follows. That is, as shown in FIG. 4, the mold 6 has a height smaller than the height of the decompression chamber 2, and the mold 6 has a 1s runner entrance B& and a 2nd runner opening. Each of 8b has an inverted circular metal-shaped tapered surface, and this tapered surface has a truncated cone-shaped joint surface that closely contacts the tapered surface, and a hollow hole having an opening on the opposite side of the joint surface. A cylindrical auxiliary runner pipe 17 is attached. The length of this auxiliary runner pipe 17 is adjusted so that the opening protrudes outside the lid member l when it is attached to the tapered surface.

In this way, when the auxiliary runner pipe 17 is attached to the runner opening 8 of the mold 6, the size of the mold 6 is adjusted so that the mold 6 is
! Even if the upper surface of the mold 6 is located below the lid member l when the mold 6 is placed, the opening of the auxiliary runner pipe 17 may be located outside the lid member 1. Therefore, it is possible to achieve the same effects as in the embodiment described above.

Next, a third embodiment will be described with reference to FIGS. 5 and 6.

FIG. 5 is a longitudinal sectional view showing this third embodiment, and FIG. 6 is a front view showing this third embodiment.

The difference between this third embodiment and the first embodiment is as follows:
It is as follows. That is, the mold 6 is held in the vicinity of the runner opening 8 with the lid member l, and the mold 6 is placed in the decompression chamber 2 in a suspended state. More specifically, as shown in FIG. 5, the lid member l has a first lid part 1a and a second lid part 1.
As shown in FIG. 6, the first lid 1111a has two substantially U-shaped notches 18 at one end edge, and a backing is provided in the arc-shaped part of the notches 18. 1
Attach 9. Further, the second M portion lb includes the first lid portion 1
Similarly to a, two arcuate notches 18 having backings 19 are provided at one edge thereof. The notch 18 of the first lid part 1a and the second M part lb is the t-th
When the M portion 1a and the second lid portion ib are opposed to each other, the respective notches 18 are in a positional relationship facing each other.

The first lid part 1a and the second lid part tb are placed in opposition to each other and partially overlapped so that a circular hole is formed by the arc-shaped part of the notch 18, so that the upper part of the decompression chamber 2 is The φ mold 6 is configured to form a lid member l that covers the opening, and when the mold 6 is suspended in the air with the lid member l, the first mold 6a and the second mold 6b are connected. To prevent it from opening at the bottom, an engaging recess @ 2 is provided at the bottom of the first mold 6a.
0, and an engaging claw 2 is provided at the bottom of the second mold 6b.
1 is formed, and the engaging claw 21 is engaged with the engaging recess 20.

This casting! ! ! 6 is a slightly longer cylindrical crane neck part 22 from the runner opening 8 to the cavity 3 body,
The middle part of this crane neck part 22 is connected to the first m part la and the second m part la.
By tightening the arcuate portion of the U-shaped notch 18 in the M portion lb, it is held by the lid member l in a suspended state within the decompression chamber 2.

In this case, in order to eliminate the instability caused by hanging the mold 6 in the lid member 1, a stand, a spring, etc. (not shown) is installed between the bottom of the mold 6 and the bottom of the decompression chamber 2. Interventions may be used.

The effects of this third embodiment are similar to those of the first embodiment.

[Effects of the Invention] According to the present invention, a mold having a cavity having a minute through-hole penetrating the mouth of the cavity and the outside is placed in a vacuum chamber such that the runner opening is located outside the lid member. Since the molten material is injected into this cavity while the vacuum chamber is in a reduced pressure state, the flow of the molten material is improved, and a cast or molded product that accurately copies the inner contour of the cavity can be produced. It is possible to provide a vacuum casting molding device with a simple configuration that can perform the following steps.

Furthermore, the vacuum casting molding apparatus according to the present invention employs a method of evacuating the vacuum chamber in which the mold is housed.
By replacing the mold with another mold, production can be easily changed to other cast or molded products while using the same equipment.

Furthermore, this vacuum casting IItN is suitable for manufacturing casting products using molten metal and molding products using molten plastic.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view showing the structure of the present invention, FIG. 2 is a vertical cross-sectional view showing a first embodiment of the invention, FIG. 3 is a front view showing the first embodiment, and FIG. FIG. 5 is a longitudinal sectional view showing a second embodiment of the invention, FIG. 5 is a longitudinal sectional view showing the gS3 embodiment of the invention, and FIG. 6 is a front view showing the third embodiment. 111--Lid member, 2--Hand pressure chamber, 3--Cavity, 411-ψ four parts, 5--Vent hole, 6--Mold,
lo---@shock tank, 17-...auxiliary runner pipe. Patent applicant: Noguchi Vacuum Deposition Plating Co., Ltd. Figure 1 Figure 3 +4 80 15° ellipse 2 Figure 4 Figure 5

Claims (6)

[Claims] (1) Inside the decompression chamber, which is sealed with a lid member and can be decompressed,
1. A vacuum casting forming apparatus comprising a mold having a minute through hole in a recess in a cavity, with a runner of the mold extending outside the lid member. (2) The vacuum casting forming apparatus according to claim 1, wherein the decompression chamber is evacuated via a buffer tank. (3) The mold is a metal mold.
The vacuum casting molding apparatus according to any one of Items 1 and 2. (4) The vacuum casting forming apparatus according to any one of claims 1 to 3, wherein the mold is a rubber mold. (5) The runner according to any one of claims 1 to 4, wherein the runner extends outside the lid member via an auxiliary runner pipe connected to a runner port of the mold. Vacuum casting molding equipment. (6) The vacuum casting forming apparatus according to claims 1 to 5, wherein the two runners extend outside the lid member.